Question: ATM and Rad3 related protein have no role in sensing DNA damage.

Deletion of the developmentally essential gene ATR in adult mice leads to age-related phenotypes and stem cell loss.
Developmental abnormalities, cancer, and premature aging each have been linked to defects in the DNA damage response (DDR). Mutations in the ATR checkpoint regulator cause developmental defects in mice (pregastrulation lethality) and humans (Seckel syndrome). Here we show that eliminating ATR in adult mice leads to defects in tissue homeostasis and the rapid appearance of age-related phenotypes, such as hair graying, alopecia, kyphosis, osteoporosis, thymic involution, fibrosis, and other abnormalities. Histological and genetic analyses indicate that ATR deletion causes acute cellular loss in tissues in which continuous cell proliferation is required for maintenance. Importantly, thymic involution, alopecia, and hair graying in ATR knockout mice were associated with dramatic reductions in tissue-specific stem and progenitor cells and exhaustion of tissue renewal and homeostatic capacity. In aggregate, these studies suggest that reduced regenerative capacity in adults via deletion of a developmentally essential DDR gene is sufficient to cause the premature appearance of age-related phenotypes.

The lncRNAs PCGEM1 and PRNCR1 are not implicated in castration resistant prostate cancer
Long noncoding RNAs (IncRNAs) are increasingly implicated in cancer biology, contributing to essential cancer cell functions such as proliferation, invasion, and metastasis. In prostate cancer, several lncRNAs have been nominated as critical actors in disease pathogenesis. Among these, expression of PCGEM1 and PRNCR1 has been identified as a possible component in disease progression through the coordination of androgen receptor (AR) signaling (Yang et al., Nature 2013, see ref. [1]). However, concerns regarding the robustness of these findings have been suggested. Here, we sought to evaluate whether PCGEM1 and PRNCR1 are associated with prostate cancer. Through a comprehensive analysis of RNA-sequencing data (RNA-seq), we find evidence that PCGEM1 but not PRNCR1 is associated with prostate cancer. We employ a large cohort of >230 high-risk prostate cancer patients with long-term outcomes data to show that, in contrast to prior reports, neither gene is associated with poor patient outcomes. We further observe no evidence that PCGEM1 nor PRNCR1 interact with AR, and neither gene is a component of AR signaling. Thus, we conclusively demonstrate that PCGEM1 and PRNCR1 are not prognostic lncRNAs in prostate cancer and we refute suggestions that these lncRNAs interact in AR signaling.

The prognostic impact of the platelet distribution width-to-platelet count ratio in patients with breast cancer
Activated platelets promote tumor cell growth, angiogenesis, and invasion. Platelet activity can be inferred by platelet volume indices (PVIs), which include platelet distribution width (PDW), mean platelet volume (MPV), platelet distribution width-to-platelet count ratio (PDW/P), and mean platelet volume-to-platelet count ratio. Platelets and platelet-related markers, such as the platelet-to-lymphocyte ratio, have been found to be significant prognostic factors in patients with breast cancer. However, the role of PVIs for predicting survival in breast cancer remains unknown; hence, we performed this retrospective analysis of 275 patients with breast cancer. PVIs were compared with clinicopathological variables, and were assessed to identify independent indicators associated with disease-free survival (DFS) using the Cox proportional hazards model. An elevated PDW/P significantly correlated with age and HER2 status. Univariate analysis revealed that elevated PDW, MPV, and PDW/P as well as tumor size, nuclear grade, and lymph node involvement were significantly associated with inferior DFS rates (tumor size: p<0.01; nuclear grade, lymph node involvement, PDW, MPV, and PDW/P: p<0.05). On multivariate analysis, a large tumor size and elevated PDW/P were significant prognostic factors for DFS, with hazard ratios of 3.24 (95% confidence interval [CI]: 1.24-8.47) and 2.99 (95% CI: 1.18-7.57), respectively (p<0.05). Our study is the first to reveal that an elevated PDW/P significantly reduces DFS in patients with breast carcinoma. Measuring the PDW/P is simple, relatively inexpensive, and almost universally available using routine blood counts; this makes it an attractive biomarker for improved risk assessment.

Nonproductive human immunodeficiency virus type 1 infection in nucleoside-treated G0 lymphocytes.
Productive infection by human immunodeficiency virus type 1 (HIV-1) requires the activation of target cells. Infection of quiescent peripheral CD4 lymphocytes by HIV-1 results in incomplete, labile, reverse transcripts. We have previously identified G1b as the cell cycle stage required for the optimal completion of the reverse transcription process in T lymphocytes. However, the mechanism(s) involved in the blockage of reverse transcription remains undefined. In this study we investigated whether nucleotide levels influence viral reverse transcription in G0 cells. For this purpose the role of the enzyme ribonucleotide reductase was bypassed, by adding exogenous deoxyribonucleosides to highly purified T cells in the G0 or the G1a phase of the cell cycle. Our data showed a significant increase in the efficiency of the reverse transcription process following the addition of the deoxyribonucleosides. To define the stability and functionality of these full reverse transcripts, we used an HIV-1 reporter virus that expresses the murine heat-stable antigen on the surfaces of infected cells. Following activation of infected quiescent cells treated with exogenous nucleosides, no increased rescue of productive infection was seen. Thus, in addition to failure to complete reverse transcription, there was an additional nonreversible blockage of productive infection in quiescent T cells. These experiments have important relevance in the gene therapy arena, in terms of improving the ability of lentivirus vectors to enter metabolically inactive cells, such as hematopoietic stem cells.

Proteogenomics to discover the full coding content of genomes: a computational perspective.
Proteogenomics has emerged as a field at the junction of genomics and proteomics. It is a loose collection of technologies that allow the search of tandem mass spectra against genomic databases to identify and characterize protein-coding genes. Proteogenomic peptides provide invaluable information for gene annotation, which is difficult or impossible to ascertain using standard annotation methods. Examples include confirmation of translation, reading-frame determination, identification of gene and exon boundaries, evidence for post-translational processing, identification of splice-forms including alternative splicing, and also, prediction of completely novel genes. For proteogenomics to deliver on its promise, however, it must overcome a number of technological hurdles, including speed and accuracy of peptide identification, construction and search of specialized databases, correction of sampling bias, and others. This article reviews the state of the art of the field, focusing on the current successes, and the role of computation in overcoming these challenges. We describe how technological and algorithmic advances have already enabled large-scale proteogenomic studies in many model organisms, including arabidopsis, yeast, fly, and human. We also provide a preview of the field going forward, describing early efforts in tackling the problems of complex gene structures, searching against genomes of related species, and immunoglobulin gene reconstruction.

Effects of aging on central and peripheral mammalian clocks.
Circadian organization changes with age, but we do not know the extent to which age-related changes are the result of alterations in the central pacemakers, the peripheral oscillators, or the coupling mechanisms that hold the system together. By using transgenic rats with a luciferase (luc) reporter, we assessed the effects of aging on the rhythm of expression of the Period 1 (Per1) gene in the suprachiasmatic nucleus (SCN) and in peripheral tissues. Young (2 months) and aged (24-26 months) Per1-luc transgenic rats, entrained to light-dark cycles, were killed, and tissues were removed and cultured. Per1-luc expression was measured from 10 tissues. In the SCN, the central mammalian pacemaker, Per1-luc expression was robustly rhythmic for more than 7 weeks in culture. The only difference between SCN rhythmicity in young and old rats was a small but significant age-related shortening of the free-running period. Circadian rhythmicity in some peripheral tissues was unaffected by aging, whereas rhythmicity in other tissues was either phase advanced relative to the light cycle or absent. Those tissues that were arrhythmic could be induced to oscillate by application of forskolin, suggesting that they retained the capacity to oscillate but were not being appropriately driven in vivo. Overall, the results provide new insights into the effects of aging on the mammalian circadian system. Aging seems to affect rhythms in some but not in all tissues and may act primarily on interactions among circadian oscillators, perhaps attenuating the ability of the SCN to drive damped oscillators in the periphery.

Treatment outcome of an unselected cohort of tuberculosis patients in relation to human immunodeficiency virus serostatus in Zomba Hospital, Malawi.
There is little information about treatment outcome in patients with smear-negative pulmonary tuberculosis (PTB) or extrapulmonary tuberculosis (EPTB) treated under routine programme conditions in subsaharan Africa. A prospective study was carried out to determine treatment outcome in an unselected cohort of TB patients admitted to Zomba General Hospital, Malawi. Eight hundred and twenty-seven adult TB patients (451 men and 376 women) were registered between 1 July and 31 December 1995. Standardized treatment outcomes of treatment completion, death, default, and transfer to another district were assessed in relation to type of TB, human immunodeficiency virus (HIV) serostatus, age and gender. Two hundred and fifty-four patients (31%) died by the end of treatment, half of the deaths occurring in the first month. Death rates were 19% among 386 patients with smear-positive PTB, 46% among 211 patients with smear-negative PTB, and 37% among 230 patients with EPTB; 77% of the patients were HIV seropositive. Among new patients, HIV-positive patients had higher death rates than HIV-negative patients (hazard ratio [HR] 2.5; 95% confidence interval [95% CI] 1.6-3.8). Smear-negative patients had the highest death rates (HR 3.9; 95% CI 2.7-5.5 compared to smear-positive patients), followed by EPTB patients (HR 2.6, 95% CI 1.8-3.7 compared to smear-positive patients). Death rates increased with age but were similar in men and women. Adult patients in Malawi with smear-negative PTB and EPTB have low treatment completion and high death rates, related to high levels of HIV infection. National TB control programmes in areas of high HIV prevalence should no longer ignore treatment outcomes in patients with smear-negative PTB or EPTB.

Multiple archaeal groups mediate methane oxidation in anoxic cold seep sediments.
No microorganism capable of anaerobic growth on methane as the sole carbon source has yet been cultivated. Consequently, information about these microbes has been inferred from geochemical and microbiological observations of field samples. Stable isotope analysis of lipid biomarkers and rRNA gene surveys have implicated specific microbes in the anaerobic oxidation of methane (AOM). Here we use combined fluorescent in situ hybridization and secondary ion mass spectrometry analyses, to identify anaerobic methanotrophs in marine methane-seep sediments. The results provide direct evidence for the involvement of at least two distinct archaeal groups (ANME-1 and ANME-2) in AOM at methane seeps. Although both archaeal groups often occurred in direct physical association with bacteria, they also were observed as monospecific aggregations and as single cells. The ANME-1 archaeal group more frequently existed in monospecific aggregations or as single filaments, apparently without a bacterial partner. Bacteria associated with both archaeal groups included, but were not limited to, close relatives of Desulfosarcina species. Isotopic analyses suggest that monospecific archaeal cells and cell aggregates were active in anaerobic methanotrophy, as were multispecies consortia. In total, the data indicate that the microbial species and biotic interactions mediating anaerobic methanotrophy are diverse and complex. The data also clearly show that highly structured ANME-2/Desulfosarcina consortia are not the sole entities responsible for AOM at marine methane seeps. Other microbial groups, including ANME-1 archaea, are capable of anaerobic methane consumption either as single cells, in monospecific aggregates, or in multispecies consortia.

Microbial engineering for the production of advanced biofuels
Advanced biofuels produced by microorganisms have similar properties to petroleum-based fuels, and can 'drop in' to the existing transportation infrastructure. However, producing these biofuels in yields high enough to be useful requires the engineering of the microorganism's metabolism. Such engineering is not based on just one specific feedstock or host organism. Data-driven and synthetic-biology approaches can be used to optimize both the host and pathways to maximize fuel production. Despite some success, challenges still need to be met to move advanced biofuels towards commercialization, and to compete with more conventional fuels.

Maternal alloantigens promote the development of tolerogenic fetal regulatory T cells in utero.
As the immune system develops, T cells are selected or regulated to become tolerant of self antigens and reactive against foreign antigens. In mice, the induction of such tolerance is thought to be attributable to the deletion of self-reactive cells. Here, we show that the human fetal immune system takes advantage of an additional mechanism: the generation of regulatory T cells (Tregs) that suppress fetal immune responses. We find that substantial numbers of maternal cells cross the placenta to reside in fetal lymph nodes, inducing the development of CD4+CD25highFoxP3+ Tregs that suppress fetal antimaternal immunity and persist at least until early adulthood. These findings reveal a form of antigen-specific tolerance in humans, induced in utero and probably active in regulating immune responses after birth.

Prevention of Rectal SHIV Transmission in Macaques by Daily or Intermittent Prophylaxis with Emtricitabine and Tenofovir
BACKGROUND In the absence of an effective vaccine, HIV continues to spread globally, emphasizing the need for novel strategies to limit its transmission. Pre-exposure prophylaxis (PrEP) with antiretroviral drugs could prove to be an effective intervention strategy if highly efficacious and cost-effective PrEP modalities are identified. We evaluated daily and intermittent PrEP regimens of increasing antiviral activity in a macaque model that closely resembles human transmission. METHODS AND FINDINGS We used a repeat-exposure macaque model with 14 weekly rectal virus challenges. Three drug treatments were given once daily, each to a different group of six rhesus macaques. Group 1 was treated subcutaneously with a human-equivalent dose of emtricitabine (FTC), group 2 received orally the human-equivalent dosing of both FTC and tenofovir-disoproxil fumarate (TDF), and group 3 received subcutaneously a similar dosing of FTC and a higher dose of tenofovir. A fourth group of six rhesus macaques (group 4) received intermittently a PrEP regimen similar to group 3 only 2 h before and 24 h after each weekly virus challenge. Results were compared to 18 control macaques that did not receive any drug treatment. The risk of infection in macaques treated in groups 1 and 2 was 3.8- and 7.8-fold lower than in untreated macaques (p = 0.02 and p = 0.008, respectively). All six macaques in group 3 were protected. Breakthrough infections had blunted acute viremias; drug resistance was seen in two of six animals. All six animals in group 4 that received intermittent PrEP were protected. CONCLUSIONS This model suggests that single drugs for daily PrEP can be protective but a combination of antiretroviral drugs may be required to increase the level of protection. Short but potent intermittent PrEP can provide protection comparable to that of daily PrEP in this SHIV/macaque model. These findings support PrEP trials for HIV prevention in humans and identify promising PrEP modalities.

Instruction: Given a scientific claim, retrieve documents that support or refute the claim


Question: AZT given with ribavirin increases anemia.

Hepatotoxicity associated with antiretroviral therapy in adults infected with human immunodeficiency virus and the role of hepatitis C or B virus infection.
CONTEXT Use of antiretroviral drugs, including protease inhibitors, for treatment of human immunodeficiency virus (HIV) infection has been anecdotally associated with hepatotoxicity, particularly in persons coinfected with hepatitis C or B virus. OBJECTIVES To ascertain if incidence of severe hepatotoxicity during antiretroviral therapy is similar for all antiretroviral drug combinations, and to define the role of chronic viral hepatitis in its development. DESIGN Prospective cohort study. SETTING University-based urban HIV clinic. PATIENTS A total of 298 patients who were prescribed new antiretroviral therapies between January 1996 and January 1998, 211 (71%) of whom received protease inhibitors as part of combination therapy (median follow-up, 182 days) and 87 (29%) of whom received dual nucleoside analog regimens (median follow-up, 167 days). Chronic hepatitis C and B virus infection was present in 154 (52%) and 8 (2.7%) patients, respectively. MAIN OUTCOME MEASURE Severe hepatotoxicity, defined as a grade 3 or 4 change in levels of serum alanine aminotransferase and aspartate aminotransferase, evaluated before and during therapy. RESULTS Severe hepatotoxicity was observed in 31 (10.4%) of 298 patients (95% confidence interval [CI], 7.2%-14.4%). Ritonavir use was associated with a higher incidence of toxicity (30%; 95% CI, 17.9% -44.6%). However, no significant difference was detected in hepatotoxicity incidence in other treatment groups, ie, nucleoside analogs (5.7%; 95% CI, 1.2%-12.9%), nelfinavir (5.9%; 95% CI, 1.2%-16.2%), saquinavir (5.9%; 95% CI, 0.15%-28.7%), and indinavir(6.8%; 95% CI, 3.0%-13.1 %). Although chronicviral hepatitis was associated with an increased risk of severe hepatotoxicity among patients prescribed nonritonavir regimens (relative risk, 3.7; 95% CI, 1.0-11.8), most patients with chronic hepatitis C or B virus infection (88%) did not experience significant toxic effects. Rate of severe toxicity with use of any protease inhibitor in patients with hepatitis C infection was 12.2% (13/107; 95% CI, 6.6%-19.9%). In multivariate logistic regression, only ritonavir (adjusted odds ratio [AOR], 8.6; 95% CI, 3.0-24.6) and a CD4 cell count increase of more than 0.05 x 10(9)/L (AOR, 3.6; 95% CI, 1.0-12.9) were associated with severe hepatotoxicity. No irreversible outcomes were seen in patients with severe hepatotoxicity. CONCLUSIONS Our data indicate that use of ritonavir may increase risk of severe hepatotoxicity. Although hepatotoxicity may be more common in persons with chronic viral hepatitis, these data do not support withholding protease inhibitor therapy from persons coinfected with hepatitis B or C virus.

Survival rates of tropical and temperate passerines: a Trinidadian perspective.
Mark-recapture data collected using mist nets over a 10-yr period in Trinidad were used to estimate adult survival rates for 17 species of forest passerines. Trinidadian survival rates (mean 65%, range 45%-85%) were significantly higher than published estimates for European (mean survival 52%, range 32%-71%) and North American (mean survival 53%, range 29%-63%) passerines of similar body size (equivalent to 45% higher mean life expectancy in Trinidad). These findings were confirmed after controlling for phylogeny using a method of independent contrasts. Transient and/or young birds were an important feature of the Trinidad data, and studies that fail to allow for the presence of such birds risk underestimating adult survival. This study lends support to the hypothesis that avian survival rates are higher in the humid tropics, although the magnitude of the difference may be smaller than previously suggested.

Decoupling activation and exhaustion of B cells in spontaneous controllers of HIV infection.
OBJECTIVE To define the impact of chronic viremia and associated immune activation on B-cell exhaustion in HIV infection. DESIGN Progressive HIV infection is marked by B-cell anergy and exhaustion coupled with dramatic hypergammaglobulinemia. Although both upregulation of CD95 and loss of CD21 have been used as markers of infection-associated B-cell dysfunction, little is known regarding the specific profiles of dysfunctional B cells and whether persistent viral replication and its associated immune activation play a central role in driving B-cell dysfunction. METHODS Multiparameter flow cytometry was used to define the profile of dysfunctional B cells. The changes in the expression of CD21 and CD95 were tracked on B-cell subpopulations in patients with differential control of viral replication. RESULTS : Although the emergence of exhausted, CD21 tissue-like memory B cells followed similar patterns in both progressors and controllers, the frequency of CD21 activated memory B cells was lower in spontaneous controllers. CONCLUSION Our results suggest that the loss of CD21 and the upregulation of CD95 occur as separate events during the development of B-cell dysfunction. The loss of CD21 is a marker of B-cell exhaustion induced in the absence of appreciable viral replication, whereas the upregulation of CD95 is tightly linked to persistent viral replication and its associated immune activation. Thus, these dysfunctional profiles potentially represent two functionally distinct states within the B-cell compartment.

Effects of GC Bias in Next-Generation-Sequencing Data on De Novo Genome Assembly
Next-generation-sequencing (NGS) has revolutionized the field of genome assembly because of its much higher data throughput and much lower cost compared with traditional Sanger sequencing. However, NGS poses new computational challenges to de novo genome assembly. Among the challenges, GC bias in NGS data is known to aggravate genome assembly. However, it is not clear to what extent GC bias affects genome assembly in general. In this work, we conduct a systematic analysis on the effects of GC bias on genome assembly. Our analyses reveal that GC bias only lowers assembly completeness when the degree of GC bias is above a threshold. At a strong GC bias, the assembly fragmentation due to GC bias can be explained by the low coverage of reads in the GC-poor or GC-rich regions of a genome. This effect is observed for all the assemblers under study. Increasing the total amount of NGS data thus rescues the assembly fragmentation because of GC bias. However, the amount of data needed for a full rescue depends on the distribution of GC contents. Both low and high coverage depths due to GC bias lower the accuracy of assembly. These pieces of information provide guidance toward a better de novo genome assembly in the presence of GC bias.

Time and Money: The True Costs of Health Care Utilization for Patients Receiving "Free" HIV/Tuberculosis Care and Treatment in Rural KwaZulu-Natal.
BACKGROUND HIV and tuberculosis (TB) services are provided free of charge in many sub-Saharan African countries, but patients still incur costs. METHODS Patient-exit interviews were conducted in primary health care clinics in rural South Africa with representative samples of 200 HIV-infected patients enrolled in a pre-antiretroviral treatment (pre-ART) program, 300 patients receiving antiretroviral treatment (ART), and 300 patients receiving TB treatment. For each group, we calculated health expenditures across different spending categories, time spent traveling to and using services, and how patients financed their spending. Associations between patient group and costs were assessed in multivariate regression models. RESULTS Total monthly health expenditures [1 USD = 7.3 South African Rand (ZAR)] were ZAR 171 [95% confidence interval (CI): 134 to 207] for pre-ART, ZAR 164 (95% CI: 141 to 187) for ART, and ZAR 122 (95% CI: 105 to 140) for TB patients (P = 0.01). Total monthly time costs (in hours) were 3.4 (95% CI: 3.3 to 3.5) for pre-ART, 5.0 (95% CI: 4.7 to 5.3) for ART, and 3.2 (95% CI: 2.9 to 3.4) for TB patients (P < 0.01). Although overall patient costs were similar across groups, pre-ART patients spent on average ZAR 29.2 more on traditional healers and ZAR 25.9 more on chemists and private doctors than ART patients, whereas ART patients spent ZAR 34.0 more than pre-ART patients on transport to clinics (P < 0.05 for all results). Thirty-one percent of pre-ART, 39% of ART, and 41% of TB patients borrowed money or sold assets to finance health care. CONCLUSIONS Patients receiving nominally free care for HIV/TB face large private costs, commonly leading to financial distress. Subsidized transport, fewer clinic visits, and drug pick-up points closer to home could reduce costs for ART patients, potentially improving retention and adherence. Large expenditure on alternative care among pre-ART patients suggests that transitioning patients to ART earlier, as under HIV treatment-as-prevention policies, may not substantially increase patients' financial burden.

Comparison of glioblastoma (GBM) molecular classification methods.
Glioblastoma (GBM) is the most aggressive and common form of brain cancer in adults. GBM is characterized by poor survival and remarkably high tumors heterogeneity (both intertumoral and intratumoral), and lack of effective therapies. Recent high-throughput data revealed heterogeneous genetic/genomic/epigenetic features and led to multiple methods aiming to classify tumors according to the key molecular events that drive the most aggressive cellular components so that targeted therapies can be developed for individual subtypes. However, GBM molecular subtypes have not led to improvement of patients outcomes. Targeted or tailored therapies for specific mutations or subtypes largely failed due to the complexities arising from intratumoral molecular heterogeneity. Most tumors develop resistance to treatment and soon recur. GBM stem cells (GSCs) have been identified. Recent single cell sequencing studies of GBM suggest that intratumoral cellular heterogeneity can be partially explained by tumor cell hierarchy arising from GBM stem cells. Therefore, the molecular subtypes based on patient derived GSCs may potentially lead to more effective subtype-specific treatments. In this paper, we review the molecular alterations of GBM and molecular subtyping methods as well as subtype plasticity in primary and recurrent tumors emphasizing the clinical relevance of potential targets for further drug development.

Cardiovascular risk factors and migraine: the GEM population-based study.
BACKGROUND Migraine, particularly with aura, is a risk factor for early-onset ischemic stroke. The underlying mechanisms are unknown, but may in part be due to migraineurs having an increased risk profile for cardiovascular disease. In this study, the authors compare the cardiovascular risk profile of adult migraineurs to that of nonmigraineurs. METHODS Participants (n = 5,755, 48% men, age 20 to 65 years) are from the Genetic Epidemiology of Migraine (GEM) study, a population-based study in the Netherlands. A total of 620 current migraineurs were identified: 31% with aura (MA), 64% without aura (MO), and 5% unclassified. Controls were 5,135 individuals without lifetime migraine. Measured cardiovascular risk factors included blood pressure (BP), serum total and high-density lipoprotein cholesterol (TC, HDL), smoking, oral contraceptive use, and the Framingham risk score for myocardial infarction or coronary heart disease (CHD) death. RESULTS Compared to controls, migraineurs were more likely to smoke (OR = 1.43 [1.1 to 1.8]), less likely to consume alcohol (OR = 0.58 [0.5 to 0.7]), and more likely to report a parental history of early myocardial infarction. Migraineurs with aura were more likely to have an unfavorable cholesterol profile (TC > or = 240 mg/dL [OR = 1.43 (0.97 to 2.1)], TC:HDL ratio > 5.0 [OR = 1.64 (1.1 to 2.4)]), have elevated BP (systolic BP > 140 mm Hg or diastolic BP > 90 mm Hg [OR = 1.76 (1.04 to 3.0)]), and report a history of early onset CHD or stroke (OR = 3.96 [1.1 to 14.3]); female migraineurs with aura were more likely to be using oral contraceptives (OR = 2.06 [1.05 to 4.0]). The odds of having an elevated Framingham risk score for CHD were approximately doubled for the migraineurs with aura. CONCLUSIONS Migraineurs, particularly with aura, have a higher cardiovascular risk profile than individuals without migraine.

Predictive value of bone resorption and formation markers in cancer patients with bone metastases receiving the bisphosphonate zoledronic acid.
PURPOSE Three large, randomized trials of patients with bone metastases recently demonstrated that zoledronic acid reduces the risk of skeletal-related events. These trials provide an opportunity for investigating the correlation between bone metabolism and clinical outcome during bisphosphonate therapy. PATIENTS AND METHODS Urinary measurements of N-telopeptide (Ntx) and serum bone alkaline phosphatase (BAP) were obtained in 1,824 bisphosphonate-treated patients-1,462 with zoledronic acid (breast, 490; prostate, 411; myeloma, 210; non-small-cell lung, 183; other, 168) and 362 with pamidronate (breast, 254; myeloma, 108). This exploratory cohort analysis grouped patients by baseline and most recent levels of Ntx as low (< 50 nmol/mmol creatinine), moderate (50 to 99 nmol/mmol creatinine), or high (> or = 100 nmol/mmol creatinine), and BAP as low (< 146 U/L) or high (> or = 146 U/L). The relative risks for negative clinical outcomes were estimated for each group using multiple-event and Cox regression models with time-varying covariates. RESULTS Patients with high and moderate Ntx levels had 2-fold increases in their risk of skeletal complications and disease progression compared with patients with low Ntx levels (P < .001 for all). High Ntx levels in each solid tumor category were associated with a 4- to 6-fold increased risk of death on study, and moderate Ntx levels a 2- to 4-fold increased risk compared with low Ntx levels (P < .001 for all). Bone alkaline phosphatase also showed some correlation with risk of negative clinical outcomes. CONCLUSION The bone resorption marker Ntx provides valuable prognostic information in patients with bone metastases receiving bisphosphonates.

Role of PACAP and VIP in astroglial functions.
Astrocytes represent at least 50% of the volume of the human brain. Besides their roles in various supportive functions, astrocytes are involved in the regulation of stem cell proliferation, synaptic plasticity and neuroprotection. Astrocytes also influence neuronal physiology by responding to neurotransmitters and neuropeptides and by releasing regulatory factors termed gliotransmitters. In particular, astrocytes express the PACAP-specific receptor PAC1-R and the PACAP/VIP mutual receptors VPAC1-R and VPAC2-R during development and/or in the adult. There is now clear evidence that PACAP and VIP modulate a number of astrocyte activities such as proliferation, plasticity, glycogen production, and biosynthesis of neurotrophic factors and gliotransmitters.

Withdrawal Symptoms after Selective Serotonin Reuptake Inhibitor Discontinuation: A Systematic Review
Background: Selective serotonin reuptake inhibitors (SSRI) are widely used in medical practice. They have been associated with a broad range of symptoms, whose clinical meaning has not been fully appreciated. Methods: The PRISMA guidelines were followed to conduct a systematic review of the literature. Titles, abstracts, and topics were searched using the following terms: ‘withdrawal symptoms' OR ‘withdrawal syndrome' OR ‘discontinuation syndrome' OR ‘discontinuation symptoms', AND ‘SSRI' OR ‘serotonin' OR ‘antidepressant' OR ‘paroxetine' OR ‘fluoxetine' OR ‘sertraline' OR ‘fluvoxamine' OR ‘citalopram' OR ‘escitalopram'. The electronic research literature databases included CINAHL, the Cochrane Library, PubMed and Web-of-Science from inception of each database to July 2014. Results: There were 15 randomized controlled studies, 4 open trials, 4 retrospective investigations, and 38 case reports. The prevalence of the syndrome was variable, and its estimation was hindered by a lack of case identification in many studies. Symptoms typically occur within a few days from drug discontinuation and last a few weeks, also with gradual tapering. However, many variations are possible, including late onset and/or longer persistence of disturbances. Symptoms may be easily misidentified as signs of impending relapse. Conclusions: Clinicians need to add SSRI to the list of drugs potentially inducing withdrawal symptoms upon discontinuation, together with benzodiazepines, barbiturates, and other psychotropic drugs. The term ‘discontinuation syndrome' that is currently used minimizes the potential vulnerabilities induced by SSRI and should be replaced by ‘withdrawal syndrome'.

Key questions about the checkpoint blockade-are microRNAs an answer?
The introduction of immune-checkpoint blockade in the cancer therapy led to a paradigm change of the management of late stage cancers. There are already multiple FDA approved checkpoint inhibitors and many other agents are undergoing phase 2 and early phase 3 clinical trials. The therapeutic indication of immune checkpoint inhibitors expanded in the last years, but still remains unclear who can benefit. MicroRNAs are small RNAs with no coding potential. By complementary pairing to the 3' untranslated region of messenger RNA, microRNAs exert posttranscriptional control of protein expression. A network of microRNAs directly and indirectly controls the expression of checkpoint receptors and several microRNAs can target multiple checkpoint molecules, mimicking the therapeutic effect of a combined immune checkpoint blockade. In this review, we will describe the microRNAs that control the expression of immune checkpoints and we will present four specific issues of the immune checkpoint therapy in cancer: (1) imprecise therapeutic indication, (2) difficult response evaluation, (3) numerous immunologic adverse-events, and (4) the absence of response to immune therapy. Finally, we propose microRNAs as possible solutions for these pitfalls. We consider that in the near future microRNAs could become important therapeutic partners of the immune checkpoint therapy.

Instruction: Given a scientific claim, retrieve documents that support or refute the claim


Question: Activated Cdk5 phosphorylates the ATM protein in response to DNA damage.

Phosphorylation of ATM by Cdk5 mediates DNA damage signaling and regulates neuronal death
The phosphatidylinositol-3-kinase-like kinase ATM (ataxia-telangiectasia mutated) has a central role in coordinating DNA damage responses, including cell-cycle checkpoint control, DNA repair and apoptosis. Mutations of ATM cause a spectrum of defects ranging from neurodegeneration to cancer predisposition. However, the mechanism by which DNA damage activates ATM is poorly understood. Here we show that Cdk5 (cyclin-dependent kinase 5), activated by DNA damage, directly phosphorylates ATM at Ser 794 in post-mitotic neurons. Phosphorylation at Ser 794 precedes, and is required for, ATM autophosphorylation at Ser 1981, and activates ATM kinase activity. The Cdk5-ATM signal regulates phosphorylation and function of the ATM targets p53 and H2AX. Interruption of the Cdk5-ATM pathway attenuates DNA-damage-induced neuronal cell cycle re-entry and expression of the p53 targets PUMA and Bax, protecting neurons from death. Thus, activation of Cdk5 by DNA damage serves as a critical signal to initiate the ATM response and regulate ATM-dependent cellular processes.

6-phosphogluconate dehydrogenase links oxidative PPP, lipogenesis and tumor growth by inhibiting LKB1-AMPK signaling
The oxidative pentose phosphate pathway (PPP) contributes to tumour growth, but the precise contribution of 6-phosphogluconate dehydrogenase (6PGD), the third enzyme in this pathway, to tumorigenesis remains unclear. We found that suppression of 6PGD decreased lipogenesis and RNA biosynthesis and elevated ROS levels in cancer cells, attenuating cell proliferation and tumour growth. 6PGD-mediated production of ribulose-5-phosphate (Ru-5-P) inhibits AMPK activation by disrupting the active LKB1 complex, thereby activating acetyl-CoA carboxylase 1 and lipogenesis. Ru-5-P and NADPH are thought to be precursors in RNA biosynthesis and lipogenesis, respectively; thus, our findings provide an additional link between the oxidative PPP and lipogenesis through Ru-5-P-dependent inhibition of LKB1-AMPK signalling. Moreover, we identified and developed 6PGD inhibitors, physcion and its derivative S3, that effectively inhibited 6PGD, cancer cell proliferation and tumour growth in nude mice xenografts without obvious toxicity, suggesting that 6PGD could be an anticancer target.

In vivo effect of chronic hypoxia on the neurochemical profile of the developing rat hippocampus.
The cognitive deficits observed in children with cyanotic congenital heart disease suggest involvement of the developing hippocampus. Chronic postnatal hypoxia present during infancy in these children may play a role in these impairments. To understand the biochemical mechanisms of hippocampal injury in chronic hypoxia, a neurochemical profile consisting of 15 metabolite concentrations and 2 metabolite ratios in the hippocampus was evaluated in a rat model of chronic postnatal hypoxia using in vivo 1H NMR spectroscopy at 9.4 T. Chronic hypoxia was induced by continuously exposing rats (n = 23) to 10% O2 from postnatal day (P) 3 to P28. Fifteen metabolites were quantified from a volume of 9-11 microl centered on the left hippocampus on P14, P21, and P28 and were compared with normoxic controls (n = 14). The developmental trajectory of neurochemicals in chronic hypoxia was similar to that seen in normoxia. However, chronic hypoxia had an effect on the concentrations of the following neurochemicals: aspartate, creatine, phosphocreatine, GABA, glutamate, glutamine, glutathione, myoinositol, N-acetylaspartate (NAA), phosphorylethanolamine, and phosphocreatine/creatine (PCr/Cr) and glutamate/glutamine (Glu/Gln) ratios (P < 0.001 each, except glutamate, P = 0.04). The increased PCr/Cr ratio is consistent with decreased brain energy consumption. Given the well-established link between excitatory neurotransmission and brain energy metabolism, we postulate that elevated glutamate, Glu/Gln ratio, and GABA indicate suppressed excitatory neurotransmission in an energy-limited environment. Decreased NAA and phosphorylethanolamine suggest reduced neuronal integrity and phospholipid metabolism. The altered hippocampal neurochemistry during its development may underlie some of the cognitive deficits present in human infants at risk of chronic hypoxia.

Headache, migraine, and structural brain lesions and function: population based Epidemiology of Vascular Ageing-MRI study
OBJECTIVE To evaluate the association of overall and specific headaches with volume of white matter hyperintensities, brain infarcts, and cognition. DESIGN Population based, cross sectional study. SETTING Epidemiology of Vascular Ageing study, Nantes, France. PARTICIPANTS 780 participants (mean age 69, 58.5% women) with detailed headache assessment. MAIN OUTCOME MEASURES Brain scans were evaluated for volume of white matter hyperintensities (by fully automated imaging processing) and for classification of infarcts (by visual reading with a standardised assessment grid). Cognitive function was assessed by a battery of tests including the mini-mental state examination. RESULTS 163 (20.9%) participants reported a history of severe headache and 116 had migraine, of whom 17 (14.7%) reported aura symptoms. An association was found between any history of severe headache and increasing volume of white matter hyperintensities. The adjusted odds ratio of being in the highest third for total volume of white matter hyperintensities was 2.0 (95% confidence interval 1.3 to 3.1, P for trend 0.002) for participants with any history of severe headache when compared with participants without severe headache being in the lowest third. The association pattern was similar for all headache types. Migraine with aura was the only headache type strongly associated with volume of deep white matter hyperintensities (highest third odds ratio 12.4, 1.6 to 99.4, P for trend 0.005) and with brain infarcts (3.4, 1.2 to 9.3). The location of infarcts was predominantly outside the cerebellum and brain stem. Evidence was lacking for cognitive impairment for any headache type with or without brain lesions. CONCLUSIONS In this population based study, any history of severe headache was associated with an increased volume of white matter hyperintensities. Migraine with aura was the only headache type associated with brain infarcts. Evidence that headache of any type by itself or in combination with brain lesions was associated with cognitive impairment was lacking.

Bcl2 Regulation by the Melanocyte Master Regulator Mitf Modulates Lineage Survival and Melanoma Cell Viability
Kit/SCF signaling and Mitf-dependent transcription are both essential for melanocyte development and pigmentation. To identify Mitf-dependent Kit transcriptional targets in primary melanocytes, microarray studies were undertaken. Among identified targets was BCL2, whose germline deletion produces melanocyte loss and which exhibited phenotypic synergy with Mitf in mice. BCL2's regulation by Mitf was verified in melanocytes and melanoma cells and by chromatin immunoprecipitation of the BCL2 promoter. Mitf also regulates BCL2 in osteoclasts, and both Mitf(mi/mi) and Bcl2(-/-) mice exhibit severe osteopetrosis. Disruption of Mitf in melanocytes or melanoma triggered profound apoptosis susceptible to rescue by BCL2 overexpression. Clinically, primary human melanoma expression microarrays revealed tight nearest neighbor linkage for MITF and BCL2. This linkage helps explain the vital roles of both Mitf and Bcl2 in the melanocyte lineage and the well-known treatment resistance of melanoma.

Doxycycline induces apoptosis in PANC-1 pancreatic cancer cells.
BACKGROUND Tetracyclines such as doxycycline are reported to possess cytotoxic activity against mammalian tumor cells, but the mechanism of their effects on cell proliferation remains unclear. MATERIALS AND METHODS The antitumor effect of doxycycline was investigated in human pancreatic cancer cell line, PANC-1. We also investigated the effect of doxycycline on expression of a potent proangiogenic factor, interleukin (IL)-8. RESULTS In excess of 20 microg/ml, cytotoxic effects of doxycycline were accompanied by G(1)-S cell cycle arrest and DNA fragmentation in PANC-1 cells. Doxycycline consistently activated transcription of p53, p21 and Fas/FasL-cascade-related genes, while reducing the expression of Bcl-xL and Mcl-1. Doxycycline (5 microg/ml) below the cytotoxic level suppressed endogenous and paclitaxel-induced IL-8 expression. In the mouse xenograft model, doxycycline treatment was shown to suppress tumor growth by 80%. CONCLUSION These data suggest that doxycycline exerts its antitumor effect by activating proapoptotic genes, inhibiting IL-8 expression, and suppressing antiapoptotic genes.

A systematic review of randomized controlled trials of acupuncture in the treatment of depression.
BACKGROUND Acupuncture has become a popular complementary and alternative treatment approach. This review examined the randomized controlled trials (RCTs) examining the effects of acupuncture treatment of depression. METHODS RCTs of the treatment of depression with acupuncture were located using MEDLINE, Allied and Complementary Medicine and the Cochrane Central Register of Controlled Trials. The methodology of RCTs was assessed using the Jadad criteria, and elements of research design, i.e., randomization, blinding, assessment of attrition rates, were quantified for systematic comparisons among studies. RESULTS Among the 9 RCTs examined, five were deemed to be of low quality based upon Jadad criteria. The odds ratios derived from comparing acupuncture with control conditions within the RCTs suggests some evidence for the utility of acupuncture in depression. General trends suggest that acupuncture modalities were as effective as antidepressants employed for treatment of depression in the limited studies available for comparison. However, placebo acupuncture treatment was often no different from intended verum acupuncture. LIMITATIONS The RCTs extracted were limited by small sample sizes, imprecise enrollment criteria, problems with randomization, blinding, brief duration of study and lack of longitudinal follow-up. CONCLUSIONS Despite the findings that the odds ratios of existing literature suggest a role for acupuncture in the treatment of depression, the evidence thus far is inconclusive. However, efforts are being made to standardize complementary approaches to treat depression, and further systematized research into their use is warranted.

Systemic arterial hypertension in children following renal transplantation: prevalence and risk factors.
BACKGROUND Control of blood pressure (BP) following renal transplantation may improve allograft and patient survival. Our aims were (i) to describe the distribution of BP and the prevalence of systolic and/or diastolic hypertension in children over the first 5 years following renal transplantation and (ii) to evaluate clinical risk factors and centre-specific factors associated with hypertension in this population. METHODS We conducted a retrospective case note review of all current paediatric kidney transplant patients in the UK, with data collected at 6 months, 1, 2 and 5 years following transplantation in subjects with hypertension (systolic and/or diastolic BP > 95th > ) and non-hypertensive subjects BP ≤ 95th > . RESULTS In total, 27.3% (117/428), 27.6% (118/428), 26.0% (95/365) and 25.6% (50/195) of the patients were hypertensive (systolic and/or diastolic BP > 95th > ) at 6 months, 1, 2 and 5 years following transplantation, respectively. A total of 58.4% of the patients at 6 months, 52.8% at 1 year, 48.2% at 2 years and 48.2% at 5 years were receiving anti-hypertensive therapy, of whom 31.6-36.6% remained hypertensive. When subjects were identified as being hypertensive, on anti-hypertensive medication or had untreated hypertension (systolic and/or diastolic BP > 95th > ), 66.4, 61.0, 56.4 and 55.9% of patients were hypertensive at 6 months, 1, 2 and 5 years, respectively. In a multivariate model, odds ratios for systolic hypertension were 4.16 (deceased versus living donor), 2.65 (lowest versus highest quartile of height z-score) and 2.07 (if on anti-hypertensive; yes versus no). There was significant variation in prevalent rates of hypertension between centres (P < 0.0001) that remained significant (P = 0.003) after adjustment for all the factors in the multivariate model. CONCLUSIONS Control of BP after kidney transplantation remains sub-optimal in paediatric centres in the UK. Just over 25% of patients remain hypertensive 5 years following transplantation. Significant differences between centres remain unexplained and may reflect differences in assessment and management of hypertension.

The epidemiology of major depressive disorder: results from the National Comorbidity Survey Replication (NCS-R).
CONTEXT Uncertainties exist about prevalence and correlates of major depressive disorder (MDD). OBJECTIVE To present nationally representative data on prevalence and correlates of MDD by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria, and on study patterns and correlates of treatment and treatment adequacy from the recently completed National Comorbidity Survey Replication (NCS-R). DESIGN Face-to-face household survey conducted from February 2001 to December 2002. SETTING The 48 contiguous United States. PARTICIPANTS Household residents ages 18 years or older (N = 9090) who responded to the NCS-R survey. MAIN OUTCOME MEASURES Prevalence and correlates of MDD using the World Health Organization's (WHO) Composite International Diagnostic Interview (CIDI), 12-month severity with the Quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR), the Sheehan Disability Scale (SDS), and the WHO disability assessment scale (WHO-DAS). Clinical reinterviews used the Structured Clinical Interview for DSM-IV. RESULTS The prevalence of CIDI MDD for lifetime was 16.2% (95% confidence interval [CI], 15.1-17.3) (32.6-35.1 million US adults) and for 12-month was 6.6% (95% CI, 5.9-7.3) (13.1-14.2 million US adults). Virtually all CIDI 12-month cases were independently classified as clinically significant using the QIDS-SR, with 10.4% mild, 38.6% moderate, 38.0% severe, and 12.9% very severe. Mean episode duration was 16 weeks (95% CI, 15.1-17.3). Role impairment as measured by SDS was substantial as indicated by 59.3% of 12-month cases with severe or very severe role impairment. Most lifetime (72.1%) and 12-month (78.5%) cases had comorbid CIDI/DSM-IV disorders, with MDD only rarely primary. Although 51.6% (95% CI, 46.1-57.2) of 12-month cases received health care treatment for MDD, treatment was adequate in only 41.9% (95% CI, 35.9-47.9) of these cases, resulting in 21.7% (95% CI, 18.1-25.2) of 12-month MDD being adequately treated. Sociodemographic correlates of treatment were far less numerous than those of prevalence. CONCLUSIONS Major depressive disorder is a common disorder, widely distributed in the population, and usually associated with substantial symptom severity and role impairment. While the recent increase in treatment is encouraging, inadequate treatment is a serious concern. Emphasis on screening and expansion of treatment needs to be accompanied by a parallel emphasis on treatment quality improvement.

Nonproductive human immunodeficiency virus type 1 infection in nucleoside-treated G0 lymphocytes.
Productive infection by human immunodeficiency virus type 1 (HIV-1) requires the activation of target cells. Infection of quiescent peripheral CD4 lymphocytes by HIV-1 results in incomplete, labile, reverse transcripts. We have previously identified G1b as the cell cycle stage required for the optimal completion of the reverse transcription process in T lymphocytes. However, the mechanism(s) involved in the blockage of reverse transcription remains undefined. In this study we investigated whether nucleotide levels influence viral reverse transcription in G0 cells. For this purpose the role of the enzyme ribonucleotide reductase was bypassed, by adding exogenous deoxyribonucleosides to highly purified T cells in the G0 or the G1a phase of the cell cycle. Our data showed a significant increase in the efficiency of the reverse transcription process following the addition of the deoxyribonucleosides. To define the stability and functionality of these full reverse transcripts, we used an HIV-1 reporter virus that expresses the murine heat-stable antigen on the surfaces of infected cells. Following activation of infected quiescent cells treated with exogenous nucleosides, no increased rescue of productive infection was seen. Thus, in addition to failure to complete reverse transcription, there was an additional nonreversible blockage of productive infection in quiescent T cells. These experiments have important relevance in the gene therapy arena, in terms of improving the ability of lentivirus vectors to enter metabolically inactive cells, such as hematopoietic stem cells.

Scaffold-based three-dimensional human fibroblast culture provides a structural matrix that supports angiogenesis in infarcted heart tissue.
BACKGROUND We have developed techniques to implant angiogenic patches onto the epicardium over regions of infarcted cardiac tissue to stimulate revascularization of the damaged tissue. These experiments used a scaffold-based 3D human dermal fibroblast culture (3DFC) as an epicardial patch. The 3DFC contains viable cells that secrete angiogenic growth factors and has previously been shown to stimulate angiogenic activity. The hypothesis tested was that a viable 3DFC cardiac patch would stimulate an angiogenic response within an area of infarcted cardiac tissue. METHODS AND RESULTS A coronary occlusion of a branch of the left anterior descending coronary artery was performed by thermal ligation in severe combined immunodeficient mice. 3DFCs with or without viable cells were sized to the damaged area, implanted in replicate mice onto the epicardium at the site of tissue injury, and compared with animals that received infarct surgery but no implant. Fourteen and 30 days after surgery, hearts were exposed and photographed, and tissue samples were prepared for histology and cytochemistry. Fourteen and 30 days after surgery, the damaged myocardium receiving viable 3DFC exhibited a significantly greater angiogenic response (including arterioles, venules, and capillaries) than nonviable and untreated control groups. CONCLUSIONS In this animal model, viable 3DFC stimulates angiogenesis within a region of cardiac infarction and can augment a repair response in damaged tissue. Therefore, a potential use for 3DFC is the repair of myocardial tissue damaged by infarction.

Instruction: Given a scientific claim, retrieve documents that support or refute the claim


Question: Activated Cdk5 regulates DNA damage-induced neuronal death.

Phosphorylation of ATM by Cdk5 mediates DNA damage signaling and regulates neuronal death
The phosphatidylinositol-3-kinase-like kinase ATM (ataxia-telangiectasia mutated) has a central role in coordinating DNA damage responses, including cell-cycle checkpoint control, DNA repair and apoptosis. Mutations of ATM cause a spectrum of defects ranging from neurodegeneration to cancer predisposition. However, the mechanism by which DNA damage activates ATM is poorly understood. Here we show that Cdk5 (cyclin-dependent kinase 5), activated by DNA damage, directly phosphorylates ATM at Ser 794 in post-mitotic neurons. Phosphorylation at Ser 794 precedes, and is required for, ATM autophosphorylation at Ser 1981, and activates ATM kinase activity. The Cdk5-ATM signal regulates phosphorylation and function of the ATM targets p53 and H2AX. Interruption of the Cdk5-ATM pathway attenuates DNA-damage-induced neuronal cell cycle re-entry and expression of the p53 targets PUMA and Bax, protecting neurons from death. Thus, activation of Cdk5 by DNA damage serves as a critical signal to initiate the ATM response and regulate ATM-dependent cellular processes.

Hypoxia of the renal medulla--its implications for disease.
In land mammals, a major task of the kidney is to reabsorb water to allow survival in a dry environment. Water conservation is enhanced by the renal medulla, which concentrates the urine to a level up to four times the osmolality of plasma. To produce this unique gradient of osmolality, the medulla has a countercurrent system of vessels and tubules that dictates active reabsorption of sodium in a milieu poor in oxygen (Figure 1).1 In this review, we describe how hypoxia of the medulla may relate to susceptibility to acute and chronic renal injury. The Renal Medullary Concentrating Mechanism as . . .

The regulation of N-methyl-D-aspartate receptors by Src kinase.
Src family kinases (SFKs) play critical roles in the regulation of many cellular functions by growth factors, G-protein-coupled receptors and ligand-gated ion channels. Recent data have shown that SFKs serve as a convergent point of multiple signaling pathways regulating N-methyl-d-aspartate (NMDA) receptors in the central nervous system. Multiple SFK molecules, such as Src and Fyn, closely associate with their substrate, NMDA receptors, via indirect and direct binding mechanisms. The NMDA receptor is associated with an SFK signaling complex consisting of SFKs; the SFK-activating phosphatase, protein tyrosine phosphatase α; and the SFK-inactivating kinase, C-terminal Src kinase. Early studies have demonstrated that intramolecular interactions with the SH2 or SH3 domain lock SFKs in a closed conformation. Disruption of the interdomain interactions can induce the activation of SFKs with multiple signaling pathways involved in regulation of this process. The enzyme activity of SFKs appears 'graded', exhibiting different levels coinciding with activation states. It has also been proposed that the SH2 and SH3 domains may stimulate catalytic activity of protein tyrosine kinases, such as Abl. Recently, it has been found that the enzyme activity of neuronal Src protein is associated with its stability, and that the SH2 and SH3 domain interactions may act not only to constrain the activation of neuronal Src, but also to regulate the enzyme activity of active neuronal Src. Collectively, these findings demonstrate novel mechanisms underlying the regulation of SFKs.

Chaperoning 5S RNA assembly.
In eukaryotes, three of the four ribosomal RNAs (rRNAs)—the 5.8S, 18S, and 25S/28S rRNAs—are processed from a single pre-rRNA transcript and assembled into ribosomes. The fourth rRNA, the 5S rRNA, is transcribed by RNA polymerase III and is assembled into the 5S ribonucleoprotein particle (RNP), containing ribosomal proteins Rpl5/uL18 and Rpl11/uL5, prior to its incorporation into preribosomes. In mammals, the 5S RNP is also a central regulator of the homeostasis of the tumor suppressor p53. The nucleolar localization of the 5S RNP and its assembly into preribosomes are performed by a specialized complex composed of Rpf2 and Rrs1 in yeast or Bxdc1 and hRrs1 in humans. Here we report the structural and functional characterization of the Rpf2-Rrs1 complex alone, in complex with the 5S RNA, and within pre-60S ribosomes. We show that the Rpf2-Rrs1 complex contains a specialized 5S RNA E-loop-binding module, contacts the Rpl5 protein, and also contacts the ribosome assembly factor Rsa4 and the 25S RNA. We propose that the Rpf2-Rrs1 complex establishes a network of interactions that guide the incorporation of the 5S RNP in preribosomes in the initial conformation prior to its rotation to form the central protuberance found in the mature large ribosomal subunit.

Role of tumor associated macrophages in tumor angiogenesis and lymphangiogenesis
Tumor angiogenesis is an essential process for supplying rapidly growing malignant tissues with essential nutrients and oxygen. An angiogenic switch allows tumor cells to survive and grow, and provides them access to vasculature resulting in metastatic disease. Monocyte-derived macrophages recruited and reprogrammed by tumor cells serve as a major source of angiogenic factors boosting the angiogenic switch. Tumor endothelium releases angiopoietin-2 and further facilitates recruitment of TIE2 receptor expressing monocytes (TEM) into tumor sites. Tumor-associated macrophages (TAM) sense hypoxia in avascular areas of tumors, and react by production of angiogenic factors such as VEGFA. VEGFA stimulates chemotaxis of endothelial cells (EC) and macrophages. In some tumors, TAM appeared to be a major source of MMP9. Elevated expression of MMP9 by TAM mediates extracellular matrix (ECM) degradation and the release of bioactive VEGFA. Other angiogenic factors released by TAM include basic fibroblast growth factor (bFGF), thymidine phosphorylase (TP), urokinase-type plasminogen activator (uPA), and adrenomedullin (ADM). The same factors used by macrophages for the induction of angiogenesis [like vascular endothelial growth factor A (VEGF-A) and MMP9] support lymphangiogenesis. TAM can express LYVE-1, one of the established markers of lymphatic endothelium. TAM support tumor lymphangiogenesis not only by secretion of pro-lymphangiogenic factors but also by trans-differentiation into lymphatic EC. New pro-angiogenic factor YKL-40 belongs to a family of mammalian chitinase-like proteins (CLP) that act as cytokines or growth factors. Human CLP family comprises YKL-40, YKL-39, and SI-CLP. Production of all three CLP in macrophages is antagonistically regulated by cytokines. It was recently established that YKL-40 induces angiogenesis in vitro and in animal tumor models. YKL-40-neutralizing monoclonal antibody blocks tumor angiogenesis and progression. The role of YKL-39 and SI-CLP in tumor angiogenesis and lymphangiogenesis remains to be investigated.

Suppression of intestinal neoplasia by deletion of Dnmt3b
Aberrant gene silencing accompanied by DNA methylation is associated with neoplastic progression in many tumors that also show global loss of DNA methylation. Using conditional inactivation of de novo methyltransferase Dnmt3b in Apc(Min/+) mice, we demonstrate that the loss of Dnmt3b has no impact on microadenoma formation, which is considered the earliest stage of intestinal tumor formation. Nevertheless, we observed a significant decrease in the formation of macroscopic colonic adenomas. Interestingly, many large adenomas showed regions with Dnmt3b inactivation, indicating that Dnmt3b is required for initial outgrowth of macroscopic adenomas but is not required for their maintenance. These results support a role for Dnmt3b in the transition stage between microadenoma formation and macroscopic colonic tumor growth and further suggest that Dnmt3b, and by extension de novo methylation, is not required for maintaining tumor growth after this transition stage has occurred.

Induction of galactokinase in Saccharomyces cerevisiae: kinetics of induction and glucose effects.
The induced synthesis of galactokinase and the repressing effects of glucose on this synthesis have been investigated in whole yeast cells rendered permeable by treatment with dimethyl sulfoxide. It was found that the induction response of uninduced cells to galactose is clearly dependent on the nature of the carbon source upon which the culture was grown prior to exposure to galactose. Glucose-grown cells exhibited a long lag before induction, whereas lactate-grown cells exhibited induced synthesis within 8 min. A concentration of 0.5% galactose was found to be optimal for induction. The addition of glucose to yeast cultures growing on galactose resulted in a severe transient repression of synthesis which was followed by a resumed rate of synthesis characteristic of a weaker permanent catabolite repression. Neither 2-deoxygalactose nor fucose acted as gratuitous inducers of the pathway, nor did they serve as a substrates for galactokinase.

Cytochemistry and C-values: the less-well-known world of nuclear DNA amounts.
BACKGROUND In the plant sciences there are two widely applied technologies for measuring nuclear DNA content: Feulgen absorbance cytophotometry and flow cytometry (FCM). While FCM is, with good reasons, increasingly popular among plant scientists, absorbance-cytophotometric techniques lose ground. This results in a narrowing of the methodological repertoire, which is neither desirable nor beneficial. Both approaches have their advantages, but static cytophotometry seems to pose more instrumental difficulties and material-based problems than FCM, so that Feulgen-based data in the literature are often less reliable than one would expect. SCOPE The purpose of this article is to present a selective overview of the field of nuclear DNA content measurement, and C-values in particular, with a focus on the technical difficulties imposed by the characteristics of the biological material and with some comments on the photometrical aspects of the work. For over 20 years it has been known that plant polyphenols cause problems in Feulgen DNA cytophotometry, since they act as major staining inhibitors leading to unreliable results. However, little information is available about the chemical classes of plant metabolites capable of DNA staining interference and the mechanisms of their inhibition. Plant slimes are another source of concern. CONCLUSIONS In FCM research to uncover the effects of secondary metabolites on measurement results has begun only recently. In particular, the analysis of intraspecific genome size variation demands a stringent methodology which accounts for inhibitors. FCM tests for inhibitory effects of endogenous metabolites should become obligatory. The use of dry seeds for harvesting embryo and endosperm nuclei for FCM and Feulgen densitometry may often provide a means of circumventing staining inhibitors. The importance of internal standardization is highlighted. Our goal is a better understanding of phytochemical/cytochemical interactions in plant DNA photometry for the benefit of an ever-growing list of plant genome sizes.

The effect of N-acetylcysteine in the nucleus accumbens on neurotransmission and relapse to cocaine.
BACKGROUND Relapse to cocaine seeking has been linked with low glutamate in the nucleus accumbens core (NAcore) causing potentiation of synaptic glutamate transmission from prefrontal cortex (PFC) afferents. Systemic N-acetylcysteine (NAC) has been shown to restore glutamate homeostasis, reduce relapse to cocaine seeking, and depotentiate PFC-NAcore synapses. Here, we examine the effects of NAC applied directly to the NAcore on relapse and neurotransmission in PFC-NAcore synapses, as well as the involvement of the metabotropic glutamate receptors 2/3 (mGluR2/3) and 5 (mGluR5). METHODS Rats were trained to self-administer cocaine for 2 weeks and following extinction received either intra-accumbens NAC or systemic NAC 30 or 120 minutes, respectively, before inducing reinstatement with a conditioned cue or a combined cue and cocaine injection. We also recorded postsynaptic currents using in vitro whole cell recordings in acute slices and measured cystine and glutamate uptake in primary glial cultures. RESULTS NAC microinjection into the NAcore inhibited the reinstatement of cocaine seeking. In slices, a low concentration of NAC reduced the amplitude of evoked glutamatergic synaptic currents in the NAcore in an mGluR2/3-dependent manner, while high doses of NAC increased amplitude in an mGluR5-dependent manner. Both effects depended on NAC uptake through cysteine transporters and activity of the cysteine/glutamate exchanger. Finally, we showed that by blocking mGluR5 the inhibition of cocaine seeking by NAC was potentiated. CONCLUSIONS The effect of NAC on relapse to cocaine seeking depends on the balance between stimulating mGluR2/3 and mGluR5 in the NAcore, and the efficacy of NAC can be improved by simultaneously inhibiting mGluR5.

Phenylpropanolamine and the risk of hemorrhagic stroke.
BACKGROUND Phenylpropanolamine is commonly found in appetite suppressants and cough or cold remedies. Case reports have linked the use of products containing phenylpropanolamine to hemorrhagic stroke, often after the first use of these products. To study the association, we designed a case-control study. METHODS Men and women 18 to 49 years of age were recruited from 43 U.S. hospitals. Eligibility criteria included the occurrence of a subarachnoid or intracerebral hemorrhage within 30 days before enrollment and the absence of a previously diagnosed brain lesion. Random-digit dialing identified two matched control subjects per patient. RESULTS There were 702 patients and 1376 control subjects. For women, the adjusted odds ratio was 16.58 (95 percent confidence interval, 1.51 to 182.21; P=0.02) for the association between the use of appetite suppressants containing phenylpropanolamine and the risk of a hemorrhagic stroke and 3.13 (95 percent confidence interval, 0.86 to 11.46; P=0.08) for the association with the first use of a product containing phenylpropanolamine. All first uses of phenylpropanolamine involved cough or cold remedies. For men and women combined, the adjusted odds ratio was 1.49 (95 percent confidence interval, 0.84 to 2.64; P=0.17) for the association between the use of a product containing phenylpropanolamine and the risk of a hemorrhagic stroke, 1.23 (95 percent confidence interval, 0.68 to 2.24; P=0.49) for the association with the use of cough or cold remedies that contained phenylpropanolamine, and 15.92 (95 percent confidence interval, 1.38 to 184.13; P=0.03) for the association with the use of appetite suppressants that contained phenylpropanolamine. An analysis in men showed no increased risk of a hemorrhagic stroke in association with the use of cough or cold remedies containing phenylpropanolamine. No men reported the use of appetite suppressants. CONCLUSIONS The results suggest that phenylpropanolamine in appetite suppressants, and possibly in cough and cold remedies, is an independent risk factor for hemorrhagic stroke in women.

Recent developments and complexities in neutrophil transmigration.
PURPOSE OF REVIEW As the migration of neutrophils from blood to inflamed tissues is an essential component of innate immunity and a key contributing factor to the pathogenesis of inflammatory disorders, this aspect of leukocyte biology continues to be a highly dynamic field of research. This review summarizes recent findings in this area, focusing on the mechanisms that mediate neutrophil transmigration, an area where significant progress has been made. RECENT FINDINGS The topics to be covered will include responses that are prerequisite to neutrophil migration through venular walls, such as leukocyte luminal crawling and cellular and molecular changes in leukocytes and endothelial cells (e.g. formation of protrusions) that collectively support leukocyte transendothelial cell migration. Advances in both paracellular and transcellular neutrophil migration through endothelial cells will be discussed, addressing the associated roles and regulation of expression of endothelial cell luminal and junctional adhesion molecules. Beyond the endothelium, migration through the vascular pericyte coverage and basement membrane will be reviewed. SUMMARY The unquestionable role of neutrophils in the development and progression of inflammatory conditions suggests that a better understanding of the tissue-specific and stimulus-specific mechanisms that mediate this response may identify novel pathways that could be exploited for the development of more specific anti-inflammatory interventions.

Instruction: Given a scientific claim, retrieve documents that support or refute the claim


Question: Activation of PPM1D enhances p53 function.

Exome sequencing identifies somatic gain-of-function PPM1D mutations in brainstem gliomas
Gliomas arising in the brainstem and thalamus are devastating tumors that are difficult to surgically resect. To determine the genetic and epigenetic landscape of these tumors, we performed exomic sequencing of 14 brainstem gliomas (BSGs) and 12 thalamic gliomas. We also performed targeted mutational analysis of an additional 24 such tumors and genome-wide methylation profiling of 45 gliomas. This study led to the discovery of tumor-specific mutations in PPM1D, encoding wild-type p53-induced protein phosphatase 1D (WIP1), in 37.5% of the BSGs that harbored hallmark H3F3A mutations encoding p. Lys27Met substitutions. PPM1D mutations were mutually exclusive with TP53 mutations in BSG and attenuated p53 activation in vitro. PPM1D mutations were truncating alterations in exon 6 that enhanced the ability of PPM1D to suppress the activation of the DNA damage response checkpoint protein CHK2. These results define PPM1D as a frequent target of somatic mutation and as a potential therapeutic target in brainstem gliomas.

SWI/SNF-Brg1 regulates self-renewal and occupies core pluripotency-related genes in embryonic stem cells.
The SWI/SNF-Brg1 chromatin remodeling protein plays critical roles in cell-cycle control and differentiation through regulation of gene expression. Loss of Brg1 in mice results in early embryonic lethality, and recent studies have implicated a role for Brg1 in somatic stem cell self-renewal and differentiation. However, little is known about Brg1 function in preimplantation embryos and embryonic stem (ES) cells. Here we report that Brg1 is required for ES cell self-renewal and pluripotency. RNA interference-mediated knockdown of Brg1 in blastocysts caused aberrant expression of Oct4 and Nanog. In ES cells, knockdown of Brg1 resulted in phenotypic changes indicative of differentiation, downregulation of self-renewal and pluripotency genes (e.g., Oct4, Sox2, Sall4, Rest), and upregulation of differentiation genes. Using genome-wide promoter analysis (chromatin immunoprecipitation) we found that Brg1 occupied the promoters of key pluripotency-related genes, including Oct4, Sox2, Nanog, Sall4, Rest, and Polycomb group (PcG) proteins. Moreover, Brg1 co-occupied a subset of Oct4, Sox2, Nanog, and PcG protein target genes. These results demonstrate an important role for Brg1 in regulating self-renewal and pluripotency in ES cells.

Folate affects apoptosis in human trophoblastic cells.
Effects of folate deficiency on the rate of apoptosis in human cytotrophoblastic cells has been investigated. Apoptosis was determined in cytotrophoblastic cells after culture in 1. control medium, 2. folate-free medium and 3. folate-free medium plus 10% fetal calf serum. Apoptosis rates in cells cultured in mediums 2 and 3 were significantly higher than those cultured in the control medium (P<0.02 and P<0.03, respectively). In conclusion, human cytotrophoblastic cells show a significantly increased rate of apoptosis in vitro after culture in a folate-free medium. Possible explanations for the association between folate deficiency and pregnancy complications are suggested.

GiardiaDB and TrichDB: integrated genomic resources for the eukaryotic protist pathogens Giardia lamblia and Trichomonas vaginalis
GiardiaDB (http://GiardiaDB.org) and TrichDB (http://TrichDB.org) house the genome databases for Giardia lamblia and Trichomonas vaginalis, respectively, and represent the latest additions to the EuPathDB (http://EuPathDB.org) family of functional genomic databases. GiardiaDB and TrichDB employ the same framework as other EuPathDB sites (CryptoDB, PlasmoDB and ToxoDB), supporting fully integrated and searchable databases. Genomic-scale data available via these resources may be queried based on BLAST searches, annotation keywords and gene ID searches, GO terms, sequence motifs and other protein characteristics. Functional queries may also be formulated, based on transcript and protein expression data from a variety of platforms. Phylogenetic relationships may also be interrogated. The ability to combine the results from independent queries, and to store queries and query results for future use facilitates complex, genome-wide mining of functional genomic data.

Alterations on peripheral B cell subsets following an acute uncomplicated clinical malaria infection in children
BACKGROUND The effects of Plasmodium falciparum on B-cell homeostasis have not been well characterized. This study investigated whether an episode of acute malaria in young children results in changes in the peripheral B cell phenotype. METHODS Using flow-cytofluorimetric analysis, the B cell phenotypes found in the peripheral blood of children aged 2-5 years were characterized during an episode of acute uncomplicated clinical malaria and four weeks post-recovery and in healthy age-matched controls. RESULTS There was a significant decrease in CD19+ B lymphocytes during acute malaria. Characterization of the CD19+ B cell subsets in the peripheral blood based on expression of IgD and CD38 revealed a significant decrease in the numbers of naive 1 CD38-IgD+ B cells while there was an increase in CD38+IgD- memory 3 B cells during acute malaria. Further analysis of the peripheral B cell phenotype also identified an expansion of transitional CD10+CD19+ B cells in children following an episode of acute malaria with up to 25% of total CD19+ B cell pool residing in this subset. CONCLUSION Children experiencing an episode of acute uncomplicated clinical malaria experienced profound disturbances in B cell homeostasis.

Localization and requirement for Myosin II at the dorsal-ventral compartment boundary of the Drosophila wing.
As organisms develop, their tissues can become separated into distinct cell populations through the establishment of compartment boundaries. Compartment boundaries have been discovered in a wide variety of tissues, but in many cases the molecular mechanisms that separate cells remain poorly understood. In the Drosophila wing, a stripe of Notch activation maintains the dorsal-ventral compartment boundary, through a process that depends on the actin cytoskeleton. Here, we show that the dorsal-ventral boundary exhibits a distinct accumulation of Myosin II, and that this accumulation is regulated downstream of Notch signaling. Conversely, the dorsal-ventral boundary is depleted for the Par-3 homologue Bazooka. We further show that mutations in the Myosin heavy chain subunit encoded by zipper can impair dorsal-ventral compartmentalization without affecting anterior-posterior compartmentalization. These observations identify a distinct accumulation and requirement for Myosin activity in dorsal-ventral compartmentalization, and suggest a novel mechanism in which contractile tension along an F-actin cable at the compartment boundary contributes to compartmentalization.

Comparison of agar dilution, microdilution, and disk elution methods for measuring the synergy of cefotaxime and its metabolite against anaerobes.
The activities of cefotaxime (CTX) and desacetyl cefotaxime (des-CTX) were tested both singly and in combination against 173 anaerobic clinical isolates. The MIC of CTX for 50% of 60 Bacteroides fragilis isolates was 22.4 micrograms/ml in broth, compared with 47.4 micrograms/ml in agar. This reduced efficacy in agar was seen with all species tested and is in apparent conflict with reported clinical efficacy of the drug. Synergy between CTX and des-CTX was observed with 70 to 100% of the isolates, including 60% of all Bacteroides spp. tested. The susceptibility results in a synergy system correlated well with those noted in a broth-disk elution method incorporating 32 micrograms of CTX and 8 micrograms of des-CTX per ml. The correlation was poorer when the broth-disk method contained 16 micrograms of CTX and 8 micrograms of des-CTX per ml.

CD28 and ITK signals regulate autoreactive T cell trafficking
Activation of self-reactive T cells and their trafficking to target tissues leads to autoimmune organ destruction. Mice lacking the co-inhibitory receptor cytotoxic T lymphocyte antigen-4 (CTLA-4) develop fatal autoimmunity characterized by lymphocytic infiltration into nonlymphoid tissues. Here, we demonstrate that the CD28 co-stimulatory pathway regulates the trafficking of self-reactive Ctla4(-/-) T cells to tissues. Concurrent ablation of the CD28-activated Tec family kinase ITK does not block spontaneous T cell activation but instead causes self-reactive Ctla4(-/-) T cells to accumulate in secondary lymphoid organs. Despite excessive spontaneous T cell activation and proliferation in lymphoid organs, Itk(-/-); Ctla4(-/-) mice are otherwise healthy, mount antiviral immune responses and exhibit a long lifespan. We propose that ITK specifically licenses autoreactive T cells to enter tissues to mount destructive immune responses. Notably, ITK inhibitors mimic the null mutant phenotype and also prevent pancreatic islet infiltration by diabetogenic T cells in mouse models of type 1 diabetes, highlighting their potential utility for the treatment of human autoimmune disorders.

The use of biosimilars in immune-mediated disease: A joint Italian Society of Rheumatology (SIR), Italian Society of Dermatology (SIDeMaST), and Italian Group of Inflammatory Bowel Disease (IG-IBD) position paper.
Biological agents are widely used in rheumatology, dermatology and inflammatory bowel disease. Evidence about their efficacy and safety has been strengthened for all those therapeutic indications over the last decade. Biosimilar agents are monoclonal antibodies similar to previously approved biologics. In the European Union, they have been approved for all the indications in the management of immune-mediated inflammatory diseases (IMIDs), although data only in rheumatoid arthritis and ankylosing spondylitis are currently available. Direct evidence on efficacy, safety, and immunogenicity of biosimilars is mandatory in psoriasis, psoriatic arthritis, and inflammatory bowel disease, as well as in children. Based on the current evidence in the literature, we present the joint official position of the Italian Societies of Rheumatology, Dermatology and Inflammatory Bowel Disease on the use of biosimilars in IMIDs.

A three-dimensional human neural cell culture model of Alzheimer’s disease
Alzheimer’s disease is the most common form of dementia, characterized by two pathological hallmarks: amyloid-β plaques and neurofibrillary tangles. The amyloid hypothesis of Alzheimer’s disease posits that the excessive accumulation of amyloid-β peptide leads to neurofibrillary tangles composed of aggregated hyperphosphorylated tau. However, to date, no single disease model has serially linked these two pathological events using human neuronal cells. Mouse models with familial Alzheimer’s disease (FAD) mutations exhibit amyloid-β-induced synaptic and memory deficits but they do not fully recapitulate other key pathological events of Alzheimer’s disease, including distinct neurofibrillary tangle pathology. Human neurons derived from Alzheimer’s disease patients have shown elevated levels of toxic amyloid-β species and phosphorylated tau but did not demonstrate amyloid-β plaques or neurofibrillary tangles. Here we report that FAD mutations in β-amyloid precursor protein and presenilin 1 are able to induce robust extracellular deposition of amyloid-β, including amyloid-β plaques, in a human neural stem-cell-derived three-dimensional (3D) culture system. More importantly, the 3D-differentiated neuronal cells expressing FAD mutations exhibited high levels of detergent-resistant, silver-positive aggregates of phosphorylated tau in the soma and neurites, as well as filamentous tau, as detected by immunoelectron microscopy. Inhibition of amyloid-β generation with β- or γ-secretase inhibitors not only decreased amyloid-β pathology, but also attenuated tauopathy. We also found that glycogen synthase kinase 3 (GSK3) regulated amyloid-β-mediated tau phosphorylation. We have successfully recapitulated amyloid-β and tau pathology in a single 3D human neural cell culture system. Our unique strategy for recapitulating Alzheimer’s disease pathology in a 3D neural cell culture model should also serve to facilitate the development of more precise human neural cell models of other neurodegenerative disorders.

Isolation of a gene encoding a functional zinc finger protein homologous to erythroid Krüppel-like factor: identification of a new multigene family.
We have identified and characterized the gene for a novel zinc finger transcription factor which we have termed lung Krüppel-like factor (LKLF). LKLF was isolated through the use of the zinc finger domain of erythroid Krüppel-like factor (ELKF) as a hybridization probe and is closely related to this erythroid cell-specific gene. LKLF is expressed in a limited number of tissues, with the predominant expression seen in the lungs and spleen. The gene is developmentally controlled, with expression noted in the 7-day embryo followed by a down-regulation at 11 days and subsequent reactivation. A high degree of similarity is noted in the zinc finger regions of LKLF and EKLF. Beyond this domain, the sequences diverge significantly, although the putative transactivation domains for both LKLF and EKLF are proline-rich regions. In the DNA-binding domain, the three zinc finger motifs are so closely conserved that the predicted DNA contact sites are identical, suggesting that both proteins may bind to the same core sequence. This was further suggested by transactivation assays in which mouse fibroblasts were transiently transfected with a human beta-globin reporter gene in the absence and presence of an LKLF cDNA construct. Expression of the LKLF gene activates this human beta-globin promoter containing the CACCC sequence previously shown to be a binding site for EKLF. Mutation of this potential binding site results in a significant reduction in the reporter gene expression. LKLF and EKLF can thus be grouped as members of a unique family of transcription factors which have discrete patterns of expression in different tissues and which appear to recognize the same DNA-binding site.

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