Prostaglandin E2 mediates sensory nerve regulation of bone homeostasis

Abstract: Whether sensory nerve can sense bone density or metabolic activity to control bone homeostasis is unknown. Here we found prostaglandin E2 (PGE2) secreted by osteoblastic cells activates PGE2 receptor 4 (EP4) in sensory nerves to regulate bone formation by inhibiting sympathetic activity through the central nervous system. PGE2 secreted by osteoblasts increases when bone density decreases as demonstrated in osteoporotic animal models. Ablation of sensory nerves erodes the skeletal integrity. Specifically, knockout of the EP4 gene in the sensory nerves or cyclooxygenase-2 (COX2) in the osteoblastic cells significantly reduces bone volume in adult mice. Sympathetic tone is increased in sensory denervation models, and propranolol, a β2-adrenergic antagonist, rescues bone loss. Furthermore, injection of SW033291, a small molecule to increase PGE2 level locally, significantly boostes bone formation, whereas the effect is obstructed in EP4 knockout mice. Thus, we show that PGE2 mediates sensory nerve to control bone homeostasis and promote regeneration.


Prevalence of late-life depression and gap in mental health service use across European regions.

Abstract: Background We aimed to determine the prevalence and gap in use of mental health services for late-life depression in four European regions (Western Europe, Scandinavia, Southern Europe and Central and Eastern Europe) and explore socio-demographic, social and health-related factors associated with it. Methods We conducted a cross-sectional study based on data from the Survey on Health, Ageing and Retirement in Europe. Participants were a population-based sample of 28 796 persons (53% women, mean age 74 years old) residing in Europe. Mental health service use was estimated using information about the diagnosis or treatment for depression. Results The prevalence of late-life depression was 29% in the whole sample and was highest in Southern Europe (35%), followed by Central and Eastern Europe (32%), Western Europe (26%) and lowest in Scandinavia (17%). Factors that had the strongest association with depression were total number of chronic diseases, pain, limitations in instrumental activities of daily living, grip strength and cognitive impairment. The gap in mental health service use was 79%. Conclusions We suggest that interventions to decrease the burden of late-life depression should be targeted at individuals that are affected by chronic somatic comorbidities and are limited in mental and physical functioning. Promotion of help-seeking of older adults, de-stigmatization of mental illness and education of general practitioners could help decrease the gap in mental health service utilization.


Inhibition of the dipeptidyl peptidase DPP4 (CD26) reveals IL-33-dependent eosinophil-mediated control of tumor growth

Abstract: Post-translational modification of chemokines mediated by the dipeptidyl peptidase DPP4 (CD26) has been shown to negatively regulate lymphocyte trafficking, and its inhibition enhances T cell migration and tumor immunity by preserving functional chemokine CXCL10. By extending those initial findings to pre-clinical models of hepatocellular carcinoma and breast cancer, we discovered a distinct mechanism by which inhibition of DPP4 improves anti-tumor responses. Administration of the DPP4 inhibitor sitagliptin resulted in higher concentrations of the chemokine CCL11 and increased migration of eosinophils into solid tumors. Enhanced tumor control was preserved in mice lacking lymphocytes and was ablated after depletion of eosinophils or treatment with degranulation inhibitors. We further demonstrated that tumor-cell expression of the alarmin IL-33 was necessary and sufficient for eosinophil-mediated anti-tumor responses and that this mechanism contributed to the efficacy of checkpoint-inhibitor therapy. These findings provide insight into IL-33- and eosinophil-mediated tumor control, revealed when endogenous mechanisms of DPP4 immunoregulation are inhibited. Eosinophils have been described mainly in allergy settings but are increasingly appreciated as being involved in other aspects of immunity. Albert and colleagues use a clinically approved inhibitor of the dipeptidyl peptidase DPP4 to facilitate the recruitment of eosinophils to mouse tumors, where they are essential in tumor destruction.


Cycling Quiescence in Temozolomide Resistant Glioblastoma Cells Is Partly Explained by microRNA-93 and -193-Mediated Decrease of Cyclin D

Abstract: Glioblastoma multiforme (GBM) is a fatal malignancy of the central nervous system, commonly associated with chemoresistance. The alkylating agent Temozolomide (TMZ) is the front-line chemotherapeutic agent and has undergone intense studies on resistance. These studies reported on mismatch repair gene upregulation, ABC-targeted drug efflux, and cell cycle alterations. The mechanism by which TMZ induces cell cycle arrest has not been well-established. TMZ-resistant GBM cells have been linked to microRNA (miRNA) and exosomes. A cell cycle miRNA array identified distinct miRNAs only in exosomes from TMZ-resistant GBM cell lines and primary spheres. We narrowed the miRs to miR-93 and -193 and showed in computational analyses that they could target Cyclin D1. Since Cyclin D1 is a major regulator of cell cycle progression, we performed cause-effect studies and showed a blunting effects of miR-93 and -193 in Cyclin D1 expression. These two miRs also decreased cell cycling quiescence and induced resistance to TMZ. Taken together, our data provide a mechanism by which GBM cells can exhibit TMZ-induced resistance through miRNA targeting of Cyclin D1. The data provide a number of therapeutic approaches to reverse chemoresistance at the miRNA, exosomal and cell cycle points.


Longitudinal changes in maternal corin and mid-regional proatrial natriuretic peptide in women at risk of pre-eclampsia

Abstract: Objectives Corin, an atrial natriuretic peptide-converting enzyme, has been found to promote trophoblast invasion and spiral artery remodeling. Reduced maternal plasma atrial natriuretic peptide (ANP) levels and elevated corin levels have been reported in pregnancies complicated by PE. The aim of this study was to investigate longitudinal changes in maternal plasma levels of corin and midregional proatrial natriuretic peptide (MR-PANP) in pregnancies that develop preeclampsia (PE) and gestational hypertension (GH). Methods Nested case control study drawn from a larger prospective longitudinal study in singleton pregnancies identified by screening at 11 + 0 − 13 + 6 weeks’ gestation as being at high risk for PE. Blood samples were taken every four weeks until delivery. Values were compared in pregnancies that developed preterm-PE (requiring delivery before 37 weeks), term-PE, GH, and those that remained normotensive. The distribution of maternal plasma corin and PANP were made Gaussian after log 10 transformation. Analysis of repeated measures with multilevel mixed-effects linear model (fixed effects and random effects) was performed. The multilevel model was compared to one-level model by the likelihood radio (LR) test. Results A total of 471 samples were analyzed from 122 women, including 85 that remained normotensive, 12 that developed GH, 13 term-PE and 12 preterm-PE. In the normotensive group, log10corin levels were associated with gestational age ( p p  = 0.001). In the GH and term-PE groups, corin did not differ significantly from the normotensive group ( p  = 0.64 and p  = 0.16, respectively). Compared to the normotensive group, MR-PANP levels were significantly higher in the pregnancies that developed preterm-PE and GH ( p  = 0.046 and p  = 0.019, respectively), but not term-PE ( p  = 0.47). Conclusions Maternal plasma corin and MR-PANP could potentially be useful biomarkers for the prediction of preterm-PE. Disclosures A. Khalil: Research Support Recipient; Commercial Interests: USCOM, Roche, Alere, NICOM, Q-fFN; Speaker: Roche.


Excess risk of lymphomas, leukemia and myeloma in patients with rheumatoid arthritis

Abstract: The incidence of malignant neoplasms among 11 483 male and 34 618 female individuals with rheumatoid arthritis was studied using two separate nationwide data registers covering the whole Finnish population: the Social Insurance Institution9s Population Data Register, which includes information on medication for certain chronic diseases, and the Finnish Cancer Registry, with data on all cancer patients diagnosed in Finland. The follow-up comprised a total of 213 911 person years. The total incidence of all malignant neoplasms was higher in males and on the level expected in females. The expected number of cases of leukemia, lymphomas, Hodgkin9s disease and myeloma in both sexes was 59·6 as compared with the 130 cases observed. This difference is statistically highly significant (p


Novel Risk Factors for Systemic Atherosclerosis: A Comparison of C-Reactive Protein, Fibrinogen, Homocysteine, Lipoprotein(a), and Standard Cholesterol Screening as Predictors of Peripheral Arterial Disease

Abstract: ContextSeveral novel risk factors for atherosclerosis have recently been proposed, but few comparative data exist to guide clinical use of these emerging biomarkers. ObjectiveTo compare the predictive value of 11 lipid and nonlipid biomarkers as risk factors for development of symptomatic peripheral arterial disease (PAD).Design, Setting, and ParticipantsNested case-control study using plasma samples collected at baseline from a prospective cohort of 14 916 initially healthy US male physicians aged 40 to 84 years, of whom 140 subsequently developed symptomatic PAD (cases); 140 age- and smoking status–matched men who remained free of vascular disease during an average 9-year follow-up period were randomly selected as controls. Main Outcome MeasureIncident PAD, as determined by baseline total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol–HDL-C ratio, triglycerides, homocysteine, C-reactive protein (CRP), lipoprotein(a), fibrinogen, and apolipoproteins (apo) A-I and B-100.ResultsIn univariate analyses, plasma levels of total cholesterol (P<.001), LDL-C (P = .001), triglycerides (P = .001), apo B-100 (P = .001), fibrinogen (P = .02), CRP (P = .006), and the total cholesterol–HDL-C ratio (P<.001) were all significantly higher at baseline among men who subsequently developed PAD compared with those who did not, while levels of HDL-C (P = .009) and apo A-I (P = .05) were lower. Nonsignificant baseline elevations of lipoprotein(a) (P = .40) and homocysteine (P = .90) were observed. In multivariable analyses, the total cholesterol–HDL-C ratio was the strongest lipid predictor of risk (relative risk [RR] for those in the highest vs lowest quartile, 3.9; 95% confidence interval [CI], 1.7-8.6), while CRP was the strongest nonlipid predictor (RR for the highest vs lowest quartile, 2.8; 95% CI, 1.3-5.9). In assessing joint effects, addition of CRP to standard lipid screening significantly improved risk prediction models based on lipid screening alone (P<.001).ConclusionsOf 11 atherothrombotic biomarkers assessed at baseline, the total cholesterol–HDL-C ratio and CRP were the strongest independent predictors of development of peripheral arterial disease. C-reactive protein provided additive prognostic information over standard lipid measures.


Preconception Care and the Risk of Congenital Anomalies in the Offspring of Women With Diabetes Mellitus: A Meta-Analysis

Abstract: Preconception care (PCC) and strict periconceptional glycemic control are both used to minimize the risk of congenital birth defects in offspring of women with type 1 or type 2 diabetes mellitus (DM). These malformations are ascribed in large measure to poor periconceptional control. This study evaluated PCC by a meta-analysis of published studies of PCC in women with DM, published from 1970 to 2000. Two reviewers independently abstracted the data, and the rate and relative risk (RR) of major and minor malformations were pooled from eligible studies using a random effects model. Early first-trimester values of glycosylated hemoglobin were recorded. Eight retrospective and eight prospective cohort studies were included; they were carried out in Europe, the United Kingdom, the United States, and Israel. Most participants had type 1 DM, but three studies included women with type 2 DM. Women given PCC tended to be about 2 years older on average than the others. Methods of PCC were quite variable, although most centers provided some maternal education about the pregnancy risks associated with poor glycemic control. In seven studies reporting early gestational glycosylated hemoglobin values, mean levels were consistently lower in PCC patients. Among 2104 offspring, the pooled rate for major and minor anomalies was 2.4% in the PCC group and 7.7% in non-PCC recipients, for a pooled RR of 0.32. Among 2651 offspring, major malformations were less prevalent in the PCC group (2.1 vs. 6.5%; pooled RR = 0.36). Comparable results were obtained when only prospective studies were analyzed and in studies where the infant examiners were unaware of the mothers' PCC status. The lowest risk of major anomalies was in a study that administered folic acid periconceptionally to its PCC recipients; the RR was 0.11. This meta-analysis, which included both retrospective and prospective studies, demonstrates an association of PCC with a significantly lower risk of congenital anomalies in the offspring of women with established DM. The lowered risk was accompanied by significantly lower glycosylated hemoglobin values in the first trimester in recipients of PCC.


Beta-band oscillations--signalling the status quo?

Abstract: In this review, we consider the potential functional role of beta-band oscillations, which at present is not yet well understood. We discuss evidence from recent studies on top-down mechanisms involved in cognitive processing, on the motor system and on the pathophysiology of movement disorders that suggest a unifying hypothesis: beta-band activity seems related to the maintenance of the current sensorimotor or cognitive state. We hypothesize that beta oscillations and/or coupling in the beta-band are expressed more strongly if the maintenance of the status quo is intended or predicted, than if a change is expected. Moreover, we suggest that pathological enhancement of beta-band activity is likely to result in an abnormal persistence of the status quo and a deterioration of flexible behavioural and cognitive control.


Training toddlers seated on mobile robots to drive indoors amidst obstacles

Abstract: The goal of this research is to train children seated on mobile robots to purposefully and safely drive indoors. Our previous studies show that in about six weeks of training, infants can learn to drive directly to a goal using conventional joysticks. However, they are unable to acquire the advanced skill to avoid obstacles while driving. This limits mobility impaired children from exploring their home environment safely, which in turn impacts their cognitive and social developments in the important early years. In this paper, we describe results where toddlers are trained to drive a robot within an obstacle course. Using algorithms based on artificial potential fields to avoid obstacles, we create force field on the joystick that trains them to navigate while avoiding obstacles. In this ‘assist-as-needed’ approach, if the child steers the mobile robot outside a force tunnel centered around the desired direction, the driver experiences a bias force on the hand. The results suggest that force-feedback joystick results in faster learning than with a conventional joystick.


Amplification of siRNA in Caenorhabditis elegans generates a transgenerational sequence-targeted histone H3 lysine 9 methylation footprint

Abstract: Exogenous double-stranded RNA (dsRNA) has been shown to exert homology-dependent effects at the level of both target mRNA stability and chromatin structure. Using C. elegans undergoing RNAi as an animal model, we have investigated the generality, scope and longevity of dsRNA-targeted chromatin effects and their dependence on components of the RNAi machinery. Using high-resolution genome-wide chromatin profiling, we found that a diverse set of genes can be induced to acquire locus-specific enrichment of histone H3 lysine 9 trimethylation (H3K9me3), with modification footprints extending several kilobases from the site of dsRNA homology and with locus specificity sufficient to distinguish the targeted locus from the other 20,000 genes in the C. elegans genome. Genetic analysis of the response indicated that factors responsible for secondary siRNA production during RNAi were required for effective targeting of chromatin. Temporal analysis revealed that H3K9me3, once triggered by dsRNA, can be maintained in the absence of dsRNA for at least two generations before being lost. These results implicate dsRNA-triggered chromatin modification in C. elegans as a programmable and locus-specific response defining a metastable state that can persist through generational boundaries.


Physicians' initial management of acute low back pain versus evidence-based guidelines. Influence of sciatica.

Abstract:
BACKGROUND Little information is available on physician characteristics and patient presentations that may influence compliance with evidence-based guidelines for acute low back pain.
 OBJECTIVE To assess whether physicians' management decisions are consistent with the Agency for Health Research Quality's guideline and whether responses varied with the presentation of sciatica or by physician characteristics.
 DESIGN Cross-sectional study using a mailed survey.
 PARTICIPANTS Participants were randomly selected from internal medicine, family practice, general practice, emergency medicine, and occupational medicine specialties.
 MEASUREMENTS A questionnaire asked for recommendations for 2 case scenarios, representing patients without and with sciatica, respectively.
 RESULTS Seven hundred and twenty surveys were completed (response rate=25%). In cases 1 (without sciatica) and 2 (with sciatica), 26.9% and 4.3% of physicians fully complied with the guideline, respectively. For each year in practice, the odds of guideline noncompliance increased 1.03 times (95% confidence interval [CI]=1.01 to 1.05) for case 1. With occupational medicine as the referent specialty, general practice had the greatest odds of noncompliance (3.60, 95% CI=1.75 to 7.40) in case 1, followed by internal medicine and emergency medicine. Results for case 2 reflected the influence of sciatica with internal medicine having substantially higher odds (vs case 1) and the greatest odds of noncompliance of any specialty (6.93, 95% CI=1.47 to 32.78), followed by family practice and emergency medicine.
 CONCLUSIONS A majority of primary care physicians continue to be noncompliant with evidence-based back pain guidelines. Sciatica dramatically influenced clinical decision-making, increasing the extent of noncompliance, particularly for internal medicine and family practice. Physicians' misunderstanding of sciatica's natural history and belief that more intensive initial management is indicated may be factors underlying the observed influence of sciatica.


Assessment of hemodynamic efficacy and safety of 6% hydroxyethylstarch 130/0.4 vs. 0.9% NaCl fluid replacement in patients with severe sepsis: The CRYSTMAS study

Abstract: Inadequate initial treatment and delayed hemodynamic stabilization (HDS) may be associated with increased risk of death in severe sepsis patients. In order to compare the hemodynamic efficacy and safety of 6% HES 130/0.4 and NaCl 0.9% for HDS in patients with severe sepsis, we designed a prospective, multicenter, active-controlled, double-blind, randomized study in intensive care units. 174 out of 196 patients reached HDS (88 and 86 patients for HES and NaCl, respectively). Significantly less HES was used to reach HDS vs. NaCl (1,379 ±886 ml in the HES group and 1,709 ±1,164 ml in the NaCl group (mean difference = -331± 1,033, 95% CI -640 to -21, P = 0.0185). Time to reach HDS was 11.8 10.1 hours vs. 14.3 ±11.1 hours for HES and NaCl, respectively. Total quantity of study drug infused over four consecutive days, ICU and hospital LOS, and area under the curve of SOFA score were comparable. Acute renal failure occurred in 24 (24.5%) and 19 (20%) patients for HES and NaCl, respectively (P = 0.454). There was no difference between AKIN and RIFLE criteria among groups and no difference in mortality, coagulation, or pruritus up to 90 days after treatment initiation. Significantly less volume was required to achieve HDS for HES vs. NaCl in the initial phase of fluid resuscitation in severe sepsis patients without any difference for adverse events in both groups. NCT00464204


Comparisons between different polychemotherapy regimens for early breast cancer: meta-analyses of long-term outcome among 100,000 women in 123 randomised trials.

Abstract:
BACKGROUND Moderate differences in efficacy between adjuvant chemotherapy regimens for breast cancer are plausible, and could affect treatment choices. We sought any such differences.
 METHODS We undertook individual-patient-data meta-analyses of the randomised trials comparing: any taxane-plus-anthracycline-based regimen versus the same, or more, non-taxane chemotherapy (n=44,000); one anthracycline-based regimen versus another (n=7000) or versus cyclophosphamide, methotrexate, and fluorouracil (CMF; n=18,000); and polychemotherapy versus no chemotherapy (n=32,000). The scheduled dosages of these three drugs and of the anthracyclines doxorubicin (A) and epirubicin (E) were used to define standard CMF, standard 4AC, and CAF and CEF. Log-rank breast cancer mortality rate ratios (RRs) are reported.
 FINDINGS In trials adding four separate cycles of a taxane to a fixed anthracycline-based control regimen, extending treatment duration, breast cancer mortality was reduced (RR 0·86, SE 0·04, two-sided significance [2p]=0·0005). In trials with four such extra cycles of a taxane counterbalanced in controls by extra cycles of other cytotoxic drugs, roughly doubling non-taxane dosage, there was no significant difference (RR 0·94, SE 0·06, 2p=0·33). Trials with CMF-treated controls showed that standard 4AC and standard CMF were equivalent (RR 0·98, SE 0·05, 2p=0·67), but that anthracycline-based regimens with substantially higher cumulative dosage than standard 4AC (eg, CAF or CEF) were superior to standard CMF (RR 0·78, SE 0·06, 2p=0·0004). Trials versus no chemotherapy also suggested greater mortality reductions with CAF (RR 0·64, SE 0·09, 2p<0·0001) than with standard 4AC (RR 0·78, SE 0·09, 2p=0·01) or standard CMF (RR 0·76, SE 0·05, 2p<0·0001). In all meta-analyses involving taxane-based or anthracycline-based regimens, proportional risk reductions were little affected by age, nodal status, tumour diameter or differentiation (moderate or poor; few were well differentiated), oestrogen receptor status, or tamoxifen use. Hence, largely independently of age (up to at least 70 years) or the tumour characteristics currently available to us for the patients selected to be in these trials, some taxane-plus-anthracycline-based or higher-cumulative-dosage anthracycline-based regimens (not requiring stem cells) reduced breast cancer mortality by, on average, about one-third. 10-year overall mortality differences paralleled breast cancer mortality differences, despite taxane, anthracycline, and other toxicities.
 INTERPRETATION 10-year gains from a one-third breast cancer mortality reduction depend on absolute risks without chemotherapy (which, for oestrogen-receptor-positive disease, are the risks remaining with appropriate endocrine therapy). Low absolute risk implies low absolute benefit, but information was lacking about tumour gene expression markers or quantitative immunohistochemistry that might help to predict risk, chemosensitivity, or both.
 FUNDING Cancer Research UK; British Heart Foundation; UK Medical Research Council.


Invariant NKT cells modulate the suppressive activity of IL-10-secreting neutrophils differentiated with serum amyloid A.

Abstract: Neutrophils are the main effector cells during inflammation, but they can also control excessive inflammatory responses by secreting anti-inflammatory cytokines. However, the mechanisms that modulate their plasticity remain unclear. We now show that systemic serum amyloid A 1 (SAA-1) controls the plasticity of neutrophil differentiation. SAA-1 not only induced anti-inflammatory interleukin 10 (IL-10)-secreting neutrophils but also promoted the interaction of invariant natural killer T cells (iNKT cells) with those neutrophils, a process that limited their suppressive activity by diminishing the production of IL-10 and enhancing the production of IL-12. Because SAA-1-producing melanomas promoted differentiation of IL-10-secreting neutrophils, harnessing iNKT cells could be useful therapeutically by decreasing the frequency of immunosuppressive neutrophils and restoring tumor-specific immune responses.


Body-mass index and cause-specific mortality in 900 000 adults: collaborative analyses of 57 prospective studies.

Abstract:
BACKGROUND The main associations of body-mass index (BMI) with overall and cause-specific mortality can best be assessed by long-term prospective follow-up of large numbers of people. The Prospective Studies Collaboration aimed to investigate these associations by sharing data from many studies.
 METHODS Collaborative analyses were undertaken of baseline BMI versus mortality in 57 prospective studies with 894 576 participants, mostly in western Europe and North America (61% [n=541 452] male, mean recruitment age 46 [SD 11] years, median recruitment year 1979 [IQR 1975-85], mean BMI 25 [SD 4] kg/m(2)). The analyses were adjusted for age, sex, smoking status, and study. To limit reverse causality, the first 5 years of follow-up were excluded, leaving 66 552 deaths of known cause during a mean of 8 (SD 6) further years of follow-up (mean age at death 67 [SD 10] years): 30 416 vascular; 2070 diabetic, renal or hepatic; 22 592 neoplastic; 3770 respiratory; 7704 other.
 FINDINGS In both sexes, mortality was lowest at about 22.5-25 kg/m(2). Above this range, positive associations were recorded for several specific causes and inverse associations for none, the absolute excess risks for higher BMI and smoking were roughly additive, and each 5 kg/m(2) higher BMI was on average associated with about 30% higher overall mortality (hazard ratio per 5 kg/m(2) [HR] 1.29 [95% CI 1.27-1.32]): 40% for vascular mortality (HR 1.41 [1.37-1.45]); 60-120% for diabetic, renal, and hepatic mortality (HRs 2.16 [1.89-2.46], 1.59 [1.27-1.99], and 1.82 [1.59-2.09], respectively); 10% for neoplastic mortality (HR 1.10 [1.06-1.15]); and 20% for respiratory and for all other mortality (HRs 1.20 [1.07-1.34] and 1.20 [1.16-1.25], respectively). Below the range 22.5-25 kg/m(2), BMI was associated inversely with overall mortality, mainly because of strong inverse associations with respiratory disease and lung cancer. These inverse associations were much stronger for smokers than for non-smokers, despite cigarette consumption per smoker varying little with BMI.
 INTERPRETATION Although other anthropometric measures (eg, waist circumference, waist-to-hip ratio) could well add extra information to BMI, and BMI to them, BMI is in itself a strong predictor of overall mortality both above and below the apparent optimum of about 22.5-25 kg/m(2). The progressive excess mortality above this range is due mainly to vascular disease and is probably largely causal. At 30-35 kg/m(2), median survival is reduced by 2-4 years; at 40-45 kg/m(2), it is reduced by 8-10 years (which is comparable with the effects of smoking). The definite excess mortality below 22.5 kg/m(2) is due mainly to smoking-related diseases, and is not fully explained.


Signaling architectures that transmit unidirectional information despite retroactivity

Abstract: A signaling pathway transmits information from an upstream system to downstream systems, ideally in a unidirectional fashion. A key obstacle to unidirectional transmission is retroactivity, the additional reaction flux that affects a system once its species interact with those of downstream systems. This raises the fundamental question of whether signaling pathways have developed specialized architectures that overcome retroactivity and transmit unidirectional signals. Here, we propose a general procedure based on mathematical analysis that provides an answer to this question. Using this procedure, we analyze the ability of a variety of signaling architectures to transmit one-way (from upstream to downstream) signals, as key biological parameters are tuned. We find that single stage phosphorylation and phosphotransfer systems that transmit signals from a kinase show a stringent design trade-off that hampers their ability to overcome retroactivity. Interestingly, cascades of these architectures, which are highly represented in nature, can overcome this trade-off and thus enable unidirectional transmission. By contrast, phosphotransfer systems, and single and double phosphorylation cycles that transmit signals from a substrate are unable to mitigate retroactivity effects, even when cascaded, and hence are not well suited for unidirectional information transmission. Our results identify signaling architectures that, allowing unidirectional transmission of signals, embody modular processes that conserve their input/output behavior across multiple contexts. These findings can be used to decompose natural signal transduction networks into modules, and, at the same time, they establish a library of devices that can be used in synthetic biology to facilitate modular circuit design.


Association between pre-diabetes, type 2 diabetes and trabecular bone score: The Vietnam Osteoporosis Study.

Abstract:
AIMS Trabecular bone score (TBS) is a surrogate indicator of bone microarchitecture. The presenent study sought to examine the association between type 2 diabetes (T2D) and trabecular bone score (TBS) in adult Vietnamese men and women.
 METHODS The study was part of the Vietnam Osteoporosis Study, in which 2702 women and 1398 men aged ≥30 yrs were recruited from the general community in Ho Chi Minh City. HbA1c levels were measured by the ADAMS™ A1c HA-8160 (Arkray, Kyoto, Japan), and classified into 3 groups: normal if HbA1c <5.7%; pre-diabetes (5.7 to 6.4%); and diabetes (>6.4%). TBS was evaluated by iNsight Software, version 2.1 (Medimaps, Merignac, France) on lumbar spine BMD scan (Hologic Horizon). Differences in TBS between diabetic status were analyzed by the multivariable regression model with adjustment for age and body mass index.
 RESULTS The prevalence of pre-diabetes and diabetes in men and women was 30.2% and 8.3%, respectively. In women, TBS was lower in pre-diabetes (-0.02; P<0.001) and diabetes (-0.02; P<0.001) compared with normal individuals. In men, there was no statistically significant difference in TBS between diabetic status. Moreover, TBS was significantly inversely correlated with HbA1c levels in women (P = 0.01), but not in men (P = 0.89).
 CONCLUSION Women, but not men, with type 2 diabetes and pre-diabetes have lower TBS than individuals without diabetes. These data suggest that diabetes and prediabetes are associated with deterioration of bone microarchitecture.


Simplifying likelihood ratios

Abstract: Likelihood ratios are one of the best measures of diagnostic accuracy, although they are seldom used, because interpreting them requires a calculator to convert back and forth between “probability” and “odds” of disease. This article describes a simpler method of interpreting likelihood ratios, one that avoids calculators, nomograms, and conversions to “odds” of disease. Several examples illustrate how the clinician can use this method to refine diagnostic decisions at the bedside.


Mechanisms linking obesity to insulin resistance and type 2 diabetes

Abstract: Obesity is associated with an increased risk of developing insulin resistance and type 2 diabetes. In obese individuals, adipose tissue releases increased amounts of non-esterified fatty acids, glycerol, hormones, pro-inflammatory cytokines and other factors that are involved in the development of insulin resistance. When insulin resistance is accompanied by dysfunction of pancreatic islet β-cells — the cells that release insulin — failure to control blood glucose levels results. Abnormalities in β-cell function are therefore critical in defining the risk and development of type 2 diabetes. This knowledge is fostering exploration of the molecular and genetic basis of the disease and new approaches to its treatment and prevention.


Tracking the fate of glomerular epithelial cells in vivo using serial multiphoton imaging in novel mouse models with fluorescent lineage tags

Abstract: Podocytes are critical in the maintenance of a healthy glomerular filter; however, they have been difficult to study in the intact kidney because of technical limitations. Here we report the development of serial multiphoton microscopy (MPM) of the same glomeruli over several days to visualize the motility of podocytes and parietal epithelial cells (PECs) in vivo. In podocin-GFP mice, podocytes formed sporadic multicellular clusters after unilateral ureteral ligation and migrated into the parietal Bowman's capsule. The tracking of single cells in podocin-confetti mice featuring cell-specific expression of CFP, GFP, YFP or RFP revealed the simultaneous migration of multiple podocytes. In phosphoenolpyruvate carboxykinase (PEPCK)-GFP mice, serial MPM found PEC-to-podocyte migration and nanotubule connections. Our data support a highly dynamic rather than a static nature of the glomerular environment and cellular composition. Future application of this new approach should advance our understanding of the mechanisms of glomerular injury and regeneration.


Down-regulation of a host microRNA by a Herpesvirus saimiri noncoding RNA.

Abstract: T cells transformed by Herpesvirus saimiri express seven viral U-rich noncoding RNAs of unknown function called HSURs. We noted that conserved sequences in HSURs 1 and 2 constitute potential binding sites for three host-cell microRNAs (miRNAs). Coimmunoprecipitation experiments confirmed that HSURs 1 and 2 interact with the predicted miRNAs in virally transformed T cells. The abundance of one of these miRNAs, miR-27, is dramatically lowered in transformed cells, with consequent effects on the expression of miR-27 target genes. Transient knockdown and ectopic expression of HSUR 1 demonstrate that it directs degradation of mature miR-27 in a sequence-specific and binding-dependent manner. This viral strategy illustrates use of a ncRNA to manipulate host-cell gene expression via the miRNA pathway.


Generation of large numbers of dendritic cells from mouse bone marrow cultures supplemented with granulocyte/macrophage colony-stimulating factor

Abstract: Antigen-presenting, major histocompatibility complex (MHC) class II-rich dendritic cells are known to arise from bone marrow. However, marrow lacks mature dendritic cells, and substantial numbers of proliferating less-mature cells have yet to be identified. The methodology for inducing dendritic cell growth that was recently described for mouse blood now has been modified to MHC class II-negative precursors in marrow. A key step is to remove the majority of nonadherent, newly formed granulocytes by gentle washes during the first 2-4 d of culture. This leaves behind proliferating clusters that are loosely attached to a more firmly adherent "stroma. " At days 4-6 the clusters can be dislodged, isolated by 1-g sedimentation, and upon reculture, large numbers of dendritic cells are released. The latter are readily identified on the basis of their distinct cell shape, ultrastructure, and repertoire of antigens, as detected with a panel of monoclonal antibodies. The dendritic cells express high levels of MHC class II products and act as powerful accessory cells for initiating the mixed leukocyte reaction. Neither the clusters nor mature dendritic cells are generated if macrophage colony-stimulating factor rather than granulocyte/macrophage colony-stimulating factor (GM-CSF) is applied. Therefore, GM-CSF generates all three lineages of myeloid cells (granulocytes, macrophages, and dendritic cells). Since > 5 x 10(6) dendritic cells develop in 1 wk from precursors within the large hind limb bones of a single animal, marrow progenitors can act as a major source of dendritic cells. This feature should prove useful for future molecular and clinical studies of this otherwise trace cell type.


Effect of lowering blood pressure on cardiovascular events and mortality in patients on dialysis: a systematic review and meta-analysis of randomised controlled trials

Abstract:
BACKGROUND Patients undergoing dialysis have a substantially increased risk of cardiovascular mortality and morbidity. Although several trials have shown the cardiovascular benefits of lowering blood pressure in the general population, there is uncertainty about the efficacy and tolerability of reducing blood pressure in patients on dialysis. We did a systematic review and meta-analysis to assess the effect of blood pressure lowering in patients on dialysis.
 METHODS We systematically searched Medline, Embase, and the Cochrane Library database for trials reported between 1950 and November, 2008, without language restriction. We extracted a standardised dataset from randomised controlled trials of blood pressure lowering in patients on dialysis that reported cardiovascular outcomes. Meta-analysis was done with a random effects model.
 FINDINGS We identified eight relevant trials, which provided data for 1679 patients and 495 cardiovascular events. Weighted mean systolic blood pressure was 4.5 mm Hg lower and diastolic blood pressure 2.3 mm Hg lower in actively treated patients than in controls. Blood pressure lowering treatment was associated with lower risks of cardiovascular events (RR 0.71, 95% CI 0.55-0.92; p=0.009), all-cause mortality (RR 0.80, 0.66-0.96; p=0.014), and cardiovascular mortality (RR 0.71, 0.50-0.99; p=0.044) than control regimens. The effects seem to be consistent across a range of patient groups included in the studies.
 INTERPRETATION Treatment with agents that lower blood pressure should routinely be considered for individuals undergoing dialysis to reduce the very high cardiovascular morbidity and mortality rate in this population.


Activin/Nodal signalling in stem cells.

Abstract: Activin/Nodal growth factors control a broad range of biological processes, including early cell fate decisions, organogenesis and adult tissue homeostasis. Here, we provide an overview of the mechanisms by which the Activin/Nodal signalling pathway governs stem cell function in these different stages of development. We describe recent findings that associate Activin/Nodal signalling to pathological conditions, focusing on cancer stem cells in tumorigenesis and its potential as a target for therapies. Moreover, we will discuss future directions and questions that currently remain unanswered on the role of Activin/Nodal signalling in stem cell self-renewal, differentiation and proliferation.


Environmental factors that influence the cutaneous production of vitamin D

Abstract: All vertebrates, including humans, obtain most of their daily vitamin D requirement from casual exposure to sunlight. During exposure to sunlight, the solar ultraviolet B photons (290-315 nm) penetrate into the skin where they cause the photolysis of 7-dehydrocholesterol to precholecalciferol. Once formed, precholecalciferol undergoes a thermally induced rearrangement of its double bonds to form cholecalciferol. An increase in skin pigmentation, aging, and the topical application of a sunscreen diminishes the cutaneous production of cholecalciferol. Latitude, season, and time of day as well as ozone pollution in the atmosphere influence the number of solar ultraviolet B photons that reach the earth's surface, and thereby, alter the cutaneous production of cholecalciferol. In Boston, exposure to sunlight during the months of November through February will not produce any significant amounts of cholecalciferol in the skin. Because windowpane glass absorbs ultraviolet B radiation, exposure of sunlight through glass windows will not result in any production of cholecalciferol. It is now recognized that vitamin D insufficiency and vitamin D deficiency are common in elderly people, especially in those who are infirm and not exposed to sunlight or who live at latitudes that do not provide them with sunlight-mediated cholecalciferol during the winter months. Vitamin D insufficiency and deficiency exacerbate osteoporosis, cause osteomalacia, and increase the risk of skeletal fractures. Vitamin D insufficiency and deficiency can be prevented by encouraging responsible exposure to sunlight and/or consumption of a multivitamin tablet that contains 10 micrograms (400 IU) vitamin D.


Rank Signaling Links the Development of Invariant γδ T Cell Progenitors and Aire+ Medullary Epithelium

Abstract: The thymic medulla provides a specialized microenvironment for the negative selection of T cells, with the presence of autoimmune regulator (Aire)-expressing medullary thymic epithelial cells (mTECs) during the embryonic-neonatal period being both necessary and sufficient to establish long-lasting tolerance. Here we showed that emergence of the first cohorts of Aire(+) mTECs at this key developmental stage, prior to αβ T cell repertoire selection, was jointly directed by Rankl(+) lymphoid tissue inducer cells and invariant Vγ5(+) dendritic epidermal T cell (DETC) progenitors that are the first thymocytes to express the products of gene rearrangement. In turn, generation of Aire(+) mTECs then fostered Skint-1-dependent, but Aire-independent, DETC progenitor maturation and the emergence of an invariant DETC repertoire. Hence, our data attributed a functional importance to the temporal development of Vγ5(+) γδ T cells during thymus medulla formation for αβ T cell tolerance induction and demonstrated a Rank-mediated reciprocal link between DETC and Aire(+) mTEC maturation.


Duration of androgen suppression in the treatment of prostate cancer.

Abstract:
BACKGROUND The combination of radiotherapy plus long-term medical suppression of androgens (> or = 2 years) improves overall survival in patients with locally advanced prostate cancer. We compared the use of radiotherapy plus short-term androgen suppression with the use of radiotherapy plus long-term androgen suppression in the treatment of locally advanced prostate cancer.
 METHODS We randomly assigned patients with locally advanced prostate cancer who had received external-beam radiotherapy plus 6 months of androgen suppression to two groups, one to receive no further treatment (short-term suppression) and the other to receive 2.5 years of further treatment with a luteinizing hormone-releasing hormone agonist (long-term suppression). An outcome of noninferiority of short-term androgen suppression as compared with long-term suppression required a hazard ratio of more than 1.35 for overall survival, with a one-sided alpha level of 0.05. An interim analysis showed futility, and the results are presented with an adjusted one-sided alpha level of 0.0429.
 RESULTS A total of 1113 men were registered, of whom 970 were randomly assigned, 483 to short-term suppression and 487 to long-term suppression. After a median follow-up of 6.4 years, 132 patients in the short-term group and 98 in the long-term group had died; the number of deaths due to prostate cancer was 47 in the short-term group and 29 in the long-term group. The 5-year overall mortality for short-term and long-term suppression was 19.0% and 15.2%, respectively; the observed hazard ratio was 1.42 (upper 95.71% confidence limit, 1.79; P=0.65 for noninferiority). Adverse events in both groups included fatigue, diminished sexual function, and hot flushes.
 CONCLUSIONS The combination of radiotherapy plus 6 months of androgen suppression provides inferior survival as compared with radiotherapy plus 3 years of androgen suppression in the treatment of locally advanced prostate cancer. (ClinicalTrials.gov number, NCT00003026.)


Long-term outcome of patients with asystole induced by head-up tilt test.

Abstract:
AIMS To analyse the long-term outcome of the largest reported cohort of patients presenting asystole during head-up tilt test.
 METHODS AND RESULTS Since 1990, 1322 patients with syncope of unknown origin have undergone tilt-table testing. Of those, 330 patients (24 X 9%) presented an abnormal response (syncope or pre-syncope). Furthermore, 58 of those patients (17 X 5%) suffered a period of asystole (> or = 3000 ms) during the test. Asystole (median (interquartile range)) lasted 10 (4, 19 X 2) s (range 3-90). Two different protocols (angles) of tilting (Westminster (60 degrees) n=1124; isoproterenol (80 degrees) n=198)) influenced the time to the syncopal episode (13 (6 X 5, 20 X 5) vs 2 (1, 6 X 5) min, P=0,0005) but not the duration of the asystole. During this period, therapy for asystole featured three different stages: first patients were treated with pacemakers; later drug therapy (metoprolol and/or etilefrine) was recommended; lastly (from 1995), no specific treatment was given. In a cohort age- and gender-matched study, those patients without were compared to those with asystole in a 2:1 basis. During 40 X 7 months of follow-up (17 X 7, 66 X 8), 12 patients (20 X 6%) with asystole had syncopal recurrences. Furthermore, 34 patients (28 X 8%) without asystole presented syncopal episodes during a follow-up of 51 X 6 months (29 X 3, 73 X 1) (P=ns). The Kaplan-Meier analysis in patients with and without asystole showed a mean time free of recurrence of 92 X 6 +/- 6 months vs 82 X 6 +/- 4 X 7 months (P=ns). The previous number of syncopes had a significant relationship with recurrences (P=0 X 002), but not therapy. There were no cardiac related deaths.
 CONCLUSIONS (1) Asystole during head-up tilt test does not imply a malignant outcome and syncope recurrence is low; (2) pacemaker or drug therapy do not significantly influence outcome which correlates to the previous number of syncopal episodes but not to gender, age, asystole occurrence, asystole duration and timing to asystole during head-up tilt test; (3) tilting protocol (angle) might influence time to and incidence of asystole during head-up tilt test.


Loss of IGF-IEa or IGF-IEb impairs myogenic differentiation.

Abstract: Actions of protein products resulting from alternative splicing of the Igf1 gene have received increasing attention in recent years. However, the significance and functional relevance of these observations remain poorly defined. To address functions of IGF-I splice variants, we examined the impact of loss of IGF-IEa and IGF-IEb on the proliferation and differentiation of cultured mouse myoblasts. RNA interference-mediated reductions in total IGF-I, IGF-IEa alone, or IGF-IEb alone had no effect on cell viability in growth medium. However, cells deficient in total IGF-I or IGF-IEa alone proliferated significantly slower than control cells or cells deficient in IGF-IEb in serum-free media. Simultaneous loss of both or specific loss of either splice variant significantly inhibited myosin heavy chain (MyHC) immunoreactivity by 70-80% (P < 0.01) under differentiation conditions (48 h in 2% horse serum) as determined by Western immunoblotting. This loss in protein was associated with reduced MyHC isoform mRNAs, because reductions in total IGF-I or IGF-IEa mRNA significantly reduced MyHC mRNAs by approximately 50-75% (P < 0.05). Loss of IGF-IEb also reduced MyHC isoform mRNA significantly, with the exception of Myh7, but to a lesser degree (∼20-40%, P < 0.05). Provision of mature IGF-I, but not synthetic E peptides, restored Myh3 expression to control levels in cells deficient in IGF-IEa or IGF-IEb. Collectively, these data suggest that IGF-I splice variants may regulate myoblast differentiation through the actions of mature IGF-I and not the E peptides.


Outcome of pregnancy in women with moderate or severe renal insufficiency.

Abstract:
BACKGROUND Pregnant women with mild preexisting renal disease have relatively few complications of pregnancy, but the risks of maternal and obstetrical complications in women with moderate or severe renal insufficiency remain uncertain.
 METHODS We determined the frequency and types of maternal and obstetrical complications and the outcomes of pregnancy in 67 women with primary renal disease (82 pregnancies). All the women had initial serum creatinine concentrations of at least 1.4 mg per deciliter (124 mumol per liter) and gestations that continued beyond the first trimester.
 RESULTS The mean (+/- SD) serum creatinine concentration increased from 1.9 +/- 0.8 mg per deciliter (168 +/- 71 mumol per liter) in early pregnancy to 2.5 +/- 1.3 mg per deciliter (221 +/- 115 mumol per liter) in the third trimester. The frequency of hypertension rose from 28 percent at base line to 48 percent in the third trimester, and that of high-grade proteinuria (urinary protein excretion, > 3000 mg per liter) from 23 percent to 41 percent. For the 70 pregnancies (57 women) for which data were available during pregnancy and immediately post partum, pregnancy-related loss of maternal renal function occurred in 43 percent. Eight of these pregnancies (10 percent of the total) were associated with rapid acceleration of maternal renal insufficiency. Obstetrical complications included a high rate of preterm delivery (59 percent) and growth retardation (37 percent). The infant survival rate was 93 percent.
 CONCLUSIONS Among pregnant women with moderate or severe renal insufficiency, the rates of complications due to worsening renal function, hypertension, and obstetrical complications are increased, but fetal survival is high.


High Km soluble 5'-nucleotidase from human placenta. Properties and allosteric regulation by IMP and ATP.

Abstract: A human placental soluble "high Km" 5'-nucleotidase has been separated from "low Km" 5'-nucleotidase and nonspecific phosphatase by AMP-Sepharose affinity chromatography. The enzyme was purified 8000-fold to a specific activity of 25.6 mumol/min/mg. The subunit molecular mass is 53 kDa, and the native molecular mass is 210 kDa, suggesting a tetrameric structure. Soluble high Km 5'-nucleotidase is most active with IMP and GMP and their deoxy derivatives. IMP is hydrolyzed 15 times faster than AMP. The enzyme has a virtually absolute requirement for magnesium ions and is regulated by them. Purine nucleoside 5'-triphosphates strongly activate the enzyme with the potency order dATP greater than ATP greater than GTP. 2,3-Diphosphoglycerate activates the enzyme as potently as ATP. Three millimolar ATP decreased the Km for IMP from 0.33 to 0.09 mM and increased the Vmax 12-fold. ATP activation was modified by the IMP concentration. At 20 microM IMP the ATP-dependent activation curve was sigmoidal, while at 2 mM IMP it was hyperbolic. The A0.5 values for ATP were 2.26 and 0.70 mM, and the relative maximal velocities were 32.9 and 126.0 nmol/min, respectively. Inorganic phosphate shifts the hyperbolic substrate velocity relationship for IMP to a sigmoidal one. With physiological concentrations of cofactors (3 mM ATP, 1-4 mM Pi, 150 mM KCl) at pH 7.4, the enzyme is 25-35 times more active toward 100 microM IMP than 100 microM AMP. These data show that: (a) soluble human placental high Km 5'-nucleotidase coexists in human placenta with the low Km enzyme; (b) under physiological conditions the enzyme favors the hydrolysis of IMP and is critically regulated by IMP, ATP, and Pi levels; and (c) kinetic properties of ATP and IMP are each modified by the other compound suggesting complex interaction of the associated binding sites.


National study of physician awareness and adherence to cardiovascular disease prevention guidelines.

Abstract:
BACKGROUND Few data have evaluated physician adherence to cardiovascular disease (CVD) prevention guidelines according to physician specialty or patient characteristics, particularly gender.
 METHODS AND RESULTS An online study of 500 randomly selected physicians (300 primary care physicians, 100 obstetricians/gynecologists, and 100 cardiologists) used a standardized questionnaire to assess awareness of, adoption of, and barriers to national CVD prevention guidelines by specialty. An experimental case study design tested physician accuracy and determinants of CVD risk level assignment and application of guidelines among high-, intermediate-, or low-risk patients. Intermediate-risk women, as assessed by the Framingham risk score, were significantly more likely to be assigned to a lower-risk category by primary care physicians than men with identical risk profiles (P<0.0001), and trends were similar for obstetricians/gynecologists and cardiologists. Assignment of risk level significantly predicted recommendations for lifestyle and preventive pharmacotherapy. After adjustment for risk assignment, the impact of patient gender on preventive care was not significant except for less aspirin (P<0.01) and more weight management recommended (P<0.04) for intermediate-risk women. Physicians did not rate themselves as very effective in their ability to help patients prevent CVD. Fewer than 1 in 5 physicians knew that more women than men die each year from CVD.
 CONCLUSIONS Perception of risk was the primary factor associated with CVD preventive recommendations. Gender disparities in recommendations for preventive therapy were explained largely by the lower perceived risk despite similar calculated risk for women versus men. Educational interventions for physicians are needed to improve the quality of CVD preventive care and lower morbidity and mortality from CVD for men and women.


Pathway connectivity and signaling coordination in the yeast stress-activated signaling network

Abstract: Stressed cells coordinate a multi-faceted response spanning many levels of physiology. Yet knowledge of the complete stress-activated regulatory network as well as design principles for signal integration remains incomplete. We developed an experimental and computational approach to integrate available protein interaction data with gene fitness contributions, mutant transcriptome profiles, and phospho-proteome changes in cells responding to salt stress, to infer the salt-responsive signaling network in yeast. The inferred subnetwork presented many novel predictions by implicating new regulators, uncovering unrecognized crosstalk between known pathways, and pointing to previously unknown 'hubs' of signal integration. We exploited these predictions to show that Cdc14 phosphatase is a central hub in the network and that modification of RNA polymerase II coordinates induction of stress-defense genes with reduction of growth-related transcripts. We find that the orthologous human network is enriched for cancer-causing genes, underscoring the importance of the subnetwork's predictions in understanding stress biology.


Premigratory and migratory neural crest cells are multipotent in vivo.

Abstract: The neural crest (NC) is an embryonic stem/progenitor cell population that generates a diverse array of cell lineages, including peripheral neurons, myelinating Schwann cells, and melanocytes, among others. However, there is a long-standing controversy as to whether this broad developmental perspective reflects in vivo multipotency of individual NC cells or whether the NC is comprised of a heterogeneous mixture of lineage-restricted progenitors. Here, we resolve this controversy by performing in vivo fate mapping of single trunk NC cells both at premigratory and migratory stages using the R26R-Confetti mouse model. By combining quantitative clonal analyses with definitive markers of differentiation, we demonstrate that the vast majority of individual NC cells are multipotent, with only few clones contributing to single derivatives. Intriguingly, multipotency is maintained in migratory NC cells. Thus, our findings provide definitive evidence for the in vivo multipotency of both premigratory and migrating NC cells in the mouse.


Multiplex genome engineering using CRISPR/Cas systems.

Abstract: Functional elucidation of causal genetic variants and elements requires precise genome editing technologies. The type II prokaryotic CRISPR (clustered regularly interspaced short palindromic repeats)/Cas adaptive immune system has been shown to facilitate RNA-guided site-specific DNA cleavage. We engineered two different type II CRISPR/Cas systems and demonstrate that Cas9 nucleases can be directed by short RNAs to induce precise cleavage at endogenous genomic loci in human and mouse cells. Cas9 can also be converted into a nicking enzyme to facilitate homology-directed repair with minimal mutagenic activity. Lastly, multiple guide sequences can be encoded into a single CRISPR array to enable simultaneous editing of several sites within the mammalian genome, demonstrating easy programmability and wide applicability of the RNA-guided nuclease technology.


Non-invasive ventilation in chronic obstructive pulmonary disease patients: helmet versus facial mask

Abstract: The helmet is a new interface with the potential of increasing the success rate of non-invasive ventilation by improving tolerance. To perform a physiological comparison between the helmet and the conventional facial mask in delivering non-invasive ventilation in hypercapnic patients with chronic obstructive pulmonary disease. Prospective, controlled, randomized study with cross-over design. In 10 patients we evaluated gas exchange, inspiratory effort, patient–ventilator synchrony and patient tolerance after 30 min of non-invasive ventilation delivered either by helmet or facial mask; both trials were preceded by periods of spontaneous unassisted breathing. Arterial blood gases, inspiratory effort, duration of diaphragm contraction and ventilator assistance, effort-to-support delays (at the beginning and at the end of inspiration), number of ineffective efforts, and patient comfort. Non-invasive ventilation improved gas exchange (p< 0.05) and inspiratory effort (p< 0.01) with both interfaces. The helmet, however, was less efficient than the mask in reducing inspiratory effort (p< 0.05) and worsened the patient–ventilator synchrony, as indicated by the longer delays to trigger on (p< 0.05) and cycle off (p< 0.05) the mechanical assistance and by the number of ineffective efforts (p< 0.005). Patient comfort was no different with the two interfaces. Helmet and facial mask were equally tolerated and both were effective in ameliorating gas exchange and decreasing inspiratory effort. The helmet, however, was less efficient in decreasing inspiratory effort and worsened the patient–ventilator interaction.


Case Management and Client Access to Health and Social Services in Outpatient Substance Abuse Treatment

Abstract: A primary goal of case management is to coordinate services across treatment settings and to integrate substance abuse services with other types of services offered in the community, including housing, mental health, medical, and social services. However, case management is a global construct that consists of several key dimensions, which include extent of case management coverage, the degree of management of the referral process, and the location of case management activity (on-site, off-site, or both). This study examines the relationship between specific dimensions of case management and the utilization of health and ancillary social services in outpatient substance abuse treatment. In general, results suggest that more active case management during the referral process and providing case management both on-site and off-site are most consistent with our predictions of greater use of health and ancillary social services by substance abuse clients. However, these effects are specific to general health care and mental health services. Case management appears to have little effect on use of social services or aftercare plans.


Chemical approaches to stem cell biology and therapeutics.

Abstract: Small molecules that modulate stem cell fate and function offer significant opportunities that will allow the full realization of the therapeutic potential of stem cells. Rational design and screening for small molecules have identified useful compounds to probe fundamental mechanisms of stem cell self-renewal, differentiation, and reprogramming and have facilitated the development of cell-based therapies and therapeutic drugs targeting endogenous stem and progenitor cells for repair and regeneration. Here, we will discuss recent scientific and therapeutic progress, as well as new perspectives and future challenges for using chemical approaches in stem cell biology and regenerative medicine.


Genome-wide maps of chromatin state in pluripotent and lineage-committed cells

Abstract: We report the application of single-molecule-based sequencing technology for high-throughput profiling of histone modifications in mammalian cells. By obtaining over four billion bases of sequence from chromatin immunoprecipitated DNA, we generated genome-wide chromatin-state maps of mouse embryonic stem cells, neural progenitor cells and embryonic fibroblasts. We find that lysine 4 and lysine 27 trimethylation effectively discriminates genes that are expressed, poised for expression, or stably repressed, and therefore reflect cell state and lineage potential. Lysine 36 trimethylation marks primary coding and non-coding transcripts, facilitating gene annotation. Trimethylation of lysine 9 and lysine 20 is detected at satellite, telomeric and active long-terminal repeats, and can spread into proximal unique sequences. Lysine 4 and lysine 9 trimethylation marks imprinting control regions. Finally, we show that chromatin state can be read in an allele-specific manner by using single nucleotide polymorphisms. This study provides a framework for the application of comprehensive chromatin profiling towards characterization of diverse mammalian cell populations.


ANKTM1, a TRP-like Channel Expressed in Nociceptive Neurons, Is Activated by Cold Temperatures

Abstract: Mammals detect temperature with specialized neurons in the peripheral nervous system. Four TRPV-class channels have been implicated in sensing heat, and one TRPM-class channel in sensing cold. The combined range of temperatures that activate these channels covers a majority of the relevant physiological spectrum sensed by most mammals, with a significant gap in the noxious cold range. Here, we describe the characterization of ANKTM1, a cold-activated channel with a lower activation temperature compared to the cold and menthol receptor, TRPM8. ANKTM1 is a distant family member of TRP channels with very little amino acid similarity to TRPM8. It is found in a subset of nociceptive sensory neurons where it is coexpressed with TRPV1/VR1 (the capsaicin/heat receptor) but not TRPM8. Consistent with the expression of ANKTM1, we identify noxious cold-sensitive sensory neurons that also respond to capsaicin but not to menthol.


Plasma vitamin D metabolites and risk of colorectal cancer in women.

Abstract:
OBJECTIVE Experimental evidence suggests that 1,25-dihydroxyvitamin D and its precursor, 25-hydroxyvitamin D [25(OH)D], may aid in the prevention of colorectal cancer. We therefore examined risk in relation to plasma concentrations of these vitamin D metabolites.
 METHODS In a nested case-control study among women in the Nurses' Health Study, we identified 193 colorectal cancer cases, ages 46 to 78 years, diagnosed up to 11 years after blood collection. Two controls were matched per case on year of birth and month of blood draw. Odds ratios (OR) for risk of colorectal cancer were calculated using conditional logistic regression adjusted for body mass index, physical activity, smoking, family history, use of hormone replacement therapy, aspirin use, and dietary intakes.
 RESULTS We found a significant inverse linear association between plasma 25(OH)D and risk of colorectal cancer (P = 0.02). Among women in the highest quintile, the OR (95% confidence interval) was 0.53 (0.27-1.04). This inverse association remained strong when limited to women > or =60 years at blood collection (P = 0.006) but was not apparent among the younger women (P = 0.70). Benefit from higher 25(OH)D concentrations was observed for cancers at the distal colon and rectum (P = 0.02) but was not evident for those at the proximal colon (P = 0.81). In contrast to 25(OH)D, we did not observe an association between 1,25-dihydroxyvitamin D and colorectal cancer, although risk was elevated among the women in the highest quintile if they were also in the lower half of the 25(OH)D distribution (OR, 2.52; 95% confidence interval, 1.04-6.11).
 CONCLUSION From these results and supporting evidence from previous studies, we conclude that higher plasma levels of 25(OH)D are associated with a lower risk of colorectal cancer in older women, particularly for cancers at the distal colon and rectum.


DNA Deamination Mediates Innate Immunity to Retroviral Infection

Abstract: CEM15/APOBEC3G is a cellular protein required for resistance to infection by virion infectivity factor (Vif)-deficient human immunodeficiency virus (HIV). Here, using a murine leukemia virus (MLV)-based system, we provide evidence that CEM15/APOBEC3G is a DNA deaminase that is incorporated into virions during viral production and subsequently triggers massive deamination of deoxycytidine to deoxyuridine within the retroviral minus (first)-strand cDNA, thus providing a probable trigger for viral destruction. Furthermore, HIV Vif can protect MLV from this CEM15/APOBEC3G-dependent restriction. These findings imply that targeted DNA deamination is a major strategy of innate immunity to retroviruses and likely also contributes to the sequence variation observed in many viruses (including HIV).


Global, regional, and national disability-adjusted life-years (DALYs) for 315 diseases and injuries and healthy life expectancy (HALE), 1990–2015: a systematic analysis for the Global Burden of Disease Study 2015

Abstract:
BACKGROUND Healthy life expectancy (HALE) and disability-adjusted life-years (DALYs) provide summary measures of health across geographies and time that can inform assessments of epidemiological patterns and health system performance, help to prioritise investments in research and development, and monitor progress toward the Sustainable Development Goals (SDGs). We aimed to provide updated HALE and DALYs for geographies worldwide and evaluate how disease burden changes with development.
 METHODS We used results from the Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015) for all-cause mortality, cause-specific mortality, and non-fatal disease burden to derive HALE and DALYs by sex for 195 countries and territories from 1990 to 2015. We calculated DALYs by summing years of life lost (YLLs) and years of life lived with disability (YLDs) for each geography, age group, sex, and year. We estimated HALE using the Sullivan method, which draws from age-specific death rates and YLDs per capita. We then assessed how observed levels of DALYs and HALE differed from expected trends calculated with the Socio-demographic Index (SDI), a composite indicator constructed from measures of income per capita, average years of schooling, and total fertility rate.
 FINDINGS Total global DALYs remained largely unchanged from 1990 to 2015, with decreases in communicable, neonatal, maternal, and nutritional (Group 1) disease DALYs offset by increased DALYs due to non-communicable diseases (NCDs). Much of this epidemiological transition was caused by changes in population growth and ageing, but it was accelerated by widespread improvements in SDI that also correlated strongly with the increasing importance of NCDs. Both total DALYs and age-standardised DALY rates due to most Group 1 causes significantly decreased by 2015, and although total burden climbed for the majority of NCDs, age-standardised DALY rates due to NCDs declined. Nonetheless, age-standardised DALY rates due to several high-burden NCDs (including osteoarthritis, drug use disorders, depression, diabetes, congenital birth defects, and skin, oral, and sense organ diseases) either increased or remained unchanged, leading to increases in their relative ranking in many geographies. From 2005 to 2015, HALE at birth increased by an average of 2·9 years (95% uncertainty interval 2·9-3·0) for men and 3·5 years (3·4-3·7) for women, while HALE at age 65 years improved by 0·85 years (0·78-0·92) and 1·2 years (1·1-1·3), respectively. Rising SDI was associated with consistently higher HALE and a somewhat smaller proportion of life spent with functional health loss; however, rising SDI was related to increases in total disability. Many countries and territories in central America and eastern sub-Saharan Africa had increasingly lower rates of disease burden than expected given their SDI. At the same time, a subset of geographies recorded a growing gap between observed and expected levels of DALYs, a trend driven mainly by rising burden due to war, interpersonal violence, and various NCDs.
 INTERPRETATION Health is improving globally, but this means more populations are spending more time with functional health loss, an absolute expansion of morbidity. The proportion of life spent in ill health decreases somewhat with increasing SDI, a relative compression of morbidity, which supports continued efforts to elevate personal income, improve education, and limit fertility. Our analysis of DALYs and HALE and their relationship to SDI represents a robust framework on which to benchmark geography-specific health performance and SDG progress. Country-specific drivers of disease burden, particularly for causes with higher-than-expected DALYs, should inform financial and research investments, prevention efforts, health policies, and health system improvement initiatives for all countries along the development continuum.
 FUNDING Bill & Melinda Gates Foundation.


Genetic Tests for Ecological and Allopatric Speciation in Anoles on an Island Archipelago

Abstract: From Darwin's study of the Galapagos and Wallace's study of Indonesia, islands have played an important role in evolutionary investigations, and radiations within archipelagos are readily interpreted as supporting the conventional view of allopatric speciation. Even during the ongoing paradigm shift towards other modes of speciation, island radiations, such as the Lesser Antillean anoles, are thought to exemplify this process. Geological and molecular phylogenetic evidence show that, in this archipelago, Martinique anoles provide several examples of secondary contact of island species. Four precursor island species, with up to 8 mybp divergence, met when their islands coalesced to form the current island of Martinique. Moreover, adjacent anole populations also show marked adaptation to distinct habitat zonation, allowing both allopatric and ecological speciation to be tested in this system. We take advantage of this opportunity of replicated island coalescence and independent ecological adaptation to carry out an extensive population genetic study of hypervariable neutral nuclear markers to show that even after these very substantial periods of spatial isolation these putative allospecies show less reproductive isolation than conspecific populations in adjacent habitats in all three cases of subsequent island coalescence. The degree of genetic interchange shows that while there is always a significant genetic signature of past allopatry, and this may be quite strong if the selection regime allows, there is no case of complete allopatric speciation, in spite of the strong primae facie case for it. Importantly there is greater genetic isolation across the xeric/rainforest ecotone than is associated with any secondary contact. This rejects the development of reproductive isolation in allopatric divergence, but supports the potential for ecological speciation, even though full speciation has not been achieved in this case. It also explains the paucity of anole species in the Lesser Antilles compared to the Greater Antilles.


Deficiency and pharmacological stabilization of mast cells reduce diet-induced obesity and diabetes in mice

Abstract: Although mast cell functions have classically been related to allergic responses, recent studies indicate that these cells contribute to other common diseases such as multiple sclerosis, rheumatoid arthritis, atherosclerosis, aortic aneurysm and cancer. This study presents evidence that mast cells also contribute to diet-induced obesity and diabetes. For example, white adipose tissue (WAT) from obese humans and mice contain more mast cells than WAT from their lean counterparts. Furthermore, in the context of mice on a Western diet, genetically induced deficiency of mast cells, or their pharmacological stabilization, reduces body weight gain and levels of inflammatory cytokines, chemokines and proteases in serum and WAT, in concert with improved glucose homeostasis and energy expenditure. Mechanistic studies reveal that mast cells contribute to WAT and muscle angiogenesis and associated cell apoptosis and cathepsin activity. Adoptive transfer experiments of cytokine-deficient mast cells show that these cells, by producing interleukin-6 (IL-6) and interferon-gamma (IFN-gamma), contribute to mouse adipose tissue cysteine protease cathepsin expression, apoptosis and angiogenesis, thereby promoting diet-induced obesity and glucose intolerance. Our results showing reduced obesity and diabetes in mice treated with clinically available mast cell-stabilizing agents suggest the potential of developing new therapies for these common human metabolic disorders.


Anaphase-Promoting Complex/Cyclosome–Dependent Proteolysis of Human Cyclin a Starts at the Beginning of Mitosis and Is Not Subject to the Spindle Assembly Checkpoint

Abstract: Cyclin A is a stable protein in S and G2 phases, but is destabilized when cells enter mitosis and is almost completely degraded before the metaphase to anaphase transition. Microinjection of antibodies against subunits of the anaphase-promoting complex/cyclosome (APC/C) or against human Cdc20 (fizzy) arrested cells at metaphase and stabilized both cyclins A and B1. Cyclin A was efficiently polyubiquitylated by Cdc20 or Cdh1-activated APC/C in vitro, but in contrast to cyclin B1, the proteolysis of cyclin A was not delayed by the spindle assembly checkpoint. The degradation of cyclin B1 was accelerated by inhibition of the spindle assembly checkpoint. These data suggest that the APC/C is activated as cells enter mitosis and immediately targets cyclin A for degradation, whereas the spindle assembly checkpoint delays the degradation of cyclin B1 until the metaphase to anaphase transition. The “destruction box” (D-box) of cyclin A is 10–20 residues longer than that of cyclin B. Overexpression of wild-type cyclin A delayed the metaphase to anaphase transition, whereas expression of cyclin A mutants lacking a D-box arrested cells in anaphase.


Asthma in United States Olympic athletes who participated in the 1996 Summer Games.

Abstract:
BACKGROUND Asthma prevalence appears to be increasing in the general population. We sought to determine whether asthma prevalence has also increased in highly competitive athletes.
 OBJECTIVE Our aim was to determine how many United States Olympic athletes who were chosen to participate in the 1996 Summer Olympic Games had a past history of asthma or symptoms that suggested asthma or took asthma medications.
 METHODS We analyzed responses to questions that asked about allergic and respiratory diseases on the United States Olympic Committee (USOC) Medical History Questionnaire that was completed by all athletes who were chosen to represent the US at the 1996 Summer Olympic Games in Atlanta.
 RESULTS Of the 699 athletes who completed the questionnaire, 107 (15.3%) had a previous diagnosis of asthma, and 97 (13.9%) recorded use of an asthma medication at some time in the past. One hundred seventeen (16.7%) reported use of an asthma medication, a diagnosis of asthma, or both (which was our basis for the diagnosis of asthma). Seventy-three (10. 4%) of the athletes were currently taking an asthma medication at the time that they were processed in Atlanta or noted that they took asthma medications on a permanent or semipermanent basis and were considered to have active asthma. Athletes who participated in cycling and mountain biking had the highest prevalence of having been told that they had asthma or had taken an asthma medication in the past (50%). Frequency of active asthma varied from 45% of cyclists and emountain bikers to none of the divers and weight lifters. Only about 11% of the athletes who participated in the 1984 Summer Olympic Games were reported to have had exercise-induced asthma on the basis of other criteria that may have been less restrictive. On the basis of these less restrictive criteria, more than 20% of the athletes who participated in the 1996 Olympic Games might have been considered to have had asthma.
 CONCLUSIONS Asthma appeared to have been more prevalent in athletes who participated in the 1996 Summer Games than in the general population or in those who participated in the 1984 Summer Games. This study also suggests that asthma may influence the sport that an athlete chooses.


Relapse specific mutations in NT5C2 in childhood acute lymphoblastic leukemia

Abstract: Relapsed childhood acute lymphoblastic leukemia (ALL) carries a poor prognosis, despite intensive retreatment, owing to intrinsic drug resistance. The biological pathways that mediate resistance are unknown. Here, we report the transcriptome profiles of matched diagnosis and relapse bone marrow specimens from ten individuals with pediatric B-lymphoblastic leukemia using RNA sequencing. Transcriptome sequencing identified 20 newly acquired, novel nonsynonymous mutations not present at initial diagnosis, with 2 individuals harboring relapse-specific mutations in the same gene, NT5C2, encoding a 5'-nucleotidase. Full-exon sequencing of NT5C2 was completed in 61 further relapse specimens, identifying additional mutations in 5 cases. Enzymatic analysis of mutant proteins showed that base substitutions conferred increased enzymatic activity and resistance to treatment with nucleoside analog therapies. Clinically, all individuals who harbored NT5C2 mutations relapsed early, within 36 months of initial diagnosis (P = 0.03). These results suggest that mutations in NT5C2 are associated with the outgrowth of drug-resistant clones in ALL.


Histone deacetylases (HDACs) in frontotemporal lobar degeneration.

Abstract:
AIMS Frontotemporal lobar degeneration (FTLD) is clinically and pathologically heterogeneous. Although associated with variations in MAPT, GRN and C9ORF72, the pathogenesis of these, and of other nongenetic, forms of FTLD, remains unknown. Epigenetic factors such as histone regulation by histone deacetylases (HDAC) may play a role in the dysregulation of transcriptional activity, thought to underpin the neurodegenerative process.
 METHODS The distribution and intensity of HDACs 4, 5 and 6 was assessed semi-quantitatively in immunostained sections of temporal cortex with hippocampus, and cerebellum, from 33 pathologically confirmed cases of FTLD and 27 controls.
 RESULTS We found a significantly greater intensity of cytoplasmic immunostaining for HDAC4 and HDAC6 in granule cells of the dentate gyrus in cases of FTLD overall compared with controls, and specifically in cases of FTLD tau-Picks compared with FTLD tau-MAPT and controls. No differences were noted between FTLD-TDP subtypes, or between the different genetic and nongenetic forms of FTLD. No changes were seen in HDAC5 in any FTLD or control cases.
 CONCLUSIONS Dysregulation of HDAC4 and/or HDAC6 could play a role in the pathogenesis of FTLD-tau associated with Pick bodies, although their lack of immunostaining implies that such changes do not contribute directly to the formation of Pick bodies.


Evolution and Impact of Subclonal Mutations in Chronic Lymphocytic Leukemia

Abstract: Clonal evolution is a key feature of cancer progression and relapse. We studied intratumoral heterogeneity in 149 chronic lymphocytic leukemia (CLL) cases by integrating whole-exome sequence and copy number to measure the fraction of cancer cells harboring each somatic mutation. We identified driver mutations as predominantly clonal (e.g., MYD88, trisomy 12, and del(13q)) or subclonal (e.g., SF3B1 and TP53), corresponding to earlier and later events in CLL evolution. We sampled leukemia cells from 18 patients at two time points. Ten of twelve CLL cases treated with chemotherapy (but only one of six without treatment) underwent clonal evolution, predominantly involving subclones with driver mutations (e.g., SF3B1 and TP53) that expanded over time. Furthermore, presence of a subclonal driver mutation was an independent risk factor for rapid disease progression. Our study thus uncovers patterns of clonal evolution in CLL, providing insights into its stepwise transformation, and links the presence of subclones with adverse clinical outcomes.


The transcriptional program of sporulation in budding yeast

Abstract: Diploid cells of budding yeast produce haploid cells through the developmental program of sporulation, which consists of meiosis and spore morphogenesis. DNA microarrays containing nearly every yeast gene were used to assay changes in gene expression during sporulation. At least seven distinct temporal patterns of induction were observed. The transcription factor Ndt80 appeared to be important for induction of a large group of genes at the end of meiotic prophase. Consensus sequences known or proposed to be responsible for temporal regulation could be identified solely from analysis of sequences of coordinately expressed genes. The temporal expression pattern provided clues to potential functions of hundreds of previously uncharacterized genes, some of which have vertebrate homologs that may function during gametogenesis.


Pharmacological correction of a defect in PPARγ signaling ameliorates disease severity in Cftr-deficient mice

Abstract: Cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane conductance regulator (encoded by Cftr) that impair its role as an apical chloride channel that supports bicarbonate transport. Individuals with cystic fibrosis show retained, thickened mucus that plugs airways and obstructs luminal organs as well as numerous other abnormalities that include inflammation of affected organs, alterations in lipid metabolism and insulin resistance. Here we show that colonic epithelial cells and whole lung tissue from Cftr-deficient mice show a defect in peroxisome proliferator-activated receptor-gamma (PPAR-gamma, encoded by Pparg) function that contributes to a pathological program of gene expression. Lipidomic analysis of colonic epithelial cells suggests that this defect results in part from reduced amounts of the endogenous PPAR-gamma ligand 15-keto-prostaglandin E(2) (15-keto-PGE(2)). Treatment of Cftr-deficient mice with the synthetic PPAR-gamma ligand rosiglitazone partially normalizes the altered gene expression pattern associated with Cftr deficiency and reduces disease severity. Rosiglitazone has no effect on chloride secretion in the colon, but it increases expression of the genes encoding carbonic anhydrases 4 and 2 (Car4 and Car2), increases bicarbonate secretion and reduces mucus retention. These studies reveal a reversible defect in PPAR-gamma signaling in Cftr-deficient cells that can be pharmacologically corrected to ameliorate the severity of the cystic fibrosis phenotype in mice.


Coding of Sweet, Bitter, and Umami Tastes Different Receptor Cells Sharing Similar Signaling Pathways

Abstract: Mammals can taste a wide repertoire of chemosensory stimuli. Two unrelated families of receptors (T1Rs and T2Rs) mediate responses to sweet, amino acids, and bitter compounds. Here, we demonstrate that knockouts of TRPM5, a taste TRP ion channel, or PLCbeta2, a phospholipase C selectively expressed in taste tissue, abolish sweet, amino acid, and bitter taste reception, but do not impact sour or salty tastes. Therefore, despite relying on different receptors, sweet, amino acid, and bitter transduction converge on common signaling molecules. Using PLCbeta2 taste-blind animals, we then examined a fundamental question in taste perception: how taste modalities are encoded at the cellular level. Mice engineered to rescue PLCbeta2 function exclusively in bitter-receptor expressing cells respond normally to bitter tastants but do not taste sweet or amino acid stimuli. Thus, bitter is encoded independently of sweet and amino acids, and taste receptor cells are not broadly tuned across these modalities.


Myosin Light Chain–activating Phosphorylation Sites Are Required for Oogenesis in Drosophila

Abstract: The Drosophila spaghetti squash ( sqh ) gene encodes the regulatory myosin light chain (RMLC) of nonmuscle myosin II. Biochemical analysis of vertebrate nonmuscle and smooth muscle myosin II has established that phosphorylation of certain amino acids of the RMLC greatly increases the actin-dependent myosin ATPase and motor activity of myosin in vitro. We have assessed the in vivo importance of these sites, which in Drosophila correspond to serine-21 and threonine-20, by creating a series of transgenes in which these specific amino acids were altered. The phenotypes of the transgenes were examined in an otherwise null mutant background during oocyte development in Drosophila females. Germ line cystoblasts entirely lacking a functional sqh gene show severe defects in proliferation and cytokinesis. The ring canals, cytoplasmic bridges linking the oocyte to the nurse cells in the egg chamber, are abnormal, suggesting a role of myosin II in their establishment or maintenance. In addition, numerous aggregates of myosin heavy chain accumulate in the sqh null cells. Mutant sqh transgene sqh -A20, A21 in which both serine-21 and threonine-20 have been replaced by alanines behaves in most respects identically to the null allele in this system, with the exception that no heavy chain aggregates are found. In contrast, expression of sqh -A21, in which only the primary phosphorylation target serine-21 site is altered, partially restores functionality to germ line myosin II, allowing cystoblast division and oocyte development, albeit with some cytokinesis failure, defects in the rapid cytoplasmic transport from nurse cells to cytoplasm characteristic of late stage oogenesis, and some damaged ring canals. Substituting a glutamate for the serine-21 (mutant sqh -E21) allows oogenesis to be completed with minimal defects, producing eggs that can develop normally to produce fertile adults. Flies expressing sqh -A20, in which only the secondary phosphorylation site is absent, appear to be entirely wild type. Taken together, this genetic evidence argues that phosphorylation at serine-21 is critical to RMLC function in activating myosin II in vivo, but that the function can be partially provided by phosphorylation at threonine-20.


A mitochondrially targeted compound delays aging in yeast through a mechanism linking mitochondrial membrane lipid metabolism to mitochondrial redox biology☆

Abstract: A recent study revealed a mechanism of delaying aging in yeast by a natural compound which specifically impacts mitochondrial redox processes. In this mechanism, exogenously added lithocholic bile acid enters yeast cells, accumulates mainly in the inner mitochondrial membrane, and elicits an age-related remodeling of phospholipid synthesis and movement within both mitochondrial membranes. Such remodeling of mitochondrial phospholipid dynamics progresses with the chronological age of a yeast cell and ultimately causes significant changes in mitochondrial membrane lipidome. These changes in the composition of membrane phospholipids alter mitochondrial abundance and morphology, thereby triggering changes in the age-related chronology of such longevity-defining redox processes as mitochondrial respiration, the maintenance of mitochondrial membrane potential, the preservation of cellular homeostasis of mitochondrially produced reactive oxygen species, and the coupling of electron transport to ATP synthesis.


Role of the Single-Stranded DNA–Binding Protein SsbB in Pneumococcal Transformation: Maintenance of a Reservoir for Genetic Plasticity

Abstract: Bacteria encode a single-stranded DNA (ssDNA) binding protein (SSB) crucial for genome maintenance. In Bacillus subtilis and Streptococcus pneumoniae, an alternative SSB, SsbB, is expressed uniquely during competence for genetic transformation, but its precise role has been disappointingly obscure. Here, we report our investigations involving comparison of a null mutant (ssbB(-)) and a C-ter truncation (ssbBΔ7) of SsbB of S. pneumoniae, the latter constructed because SSBs' acidic tail has emerged as a key site for interactions with partner proteins. We provide evidence that SsbB directly protects internalized ssDNA. We show that SsbB is highly abundant, potentially allowing the binding of ~1.15 Mb ssDNA (half a genome equivalent); that it participates in the processing of ssDNA into recombinants; and that, at high DNA concentration, it is of crucial importance for chromosomal transformation whilst antagonizing plasmid transformation. While the latter observation explains a long-standing observation that plasmid transformation is very inefficient in S. pneumoniae (compared to chromosomal transformation), the former supports our previous suggestion that SsbB creates a reservoir of ssDNA, allowing successive recombination cycles. SsbBΔ7 fulfils the reservoir function, suggesting that SsbB C-ter is not necessary for processing protein(s) to access stored ssDNA. We propose that the evolutionary raison d'être of SsbB and its abundance is maintenance of this reservoir, which contributes to the genetic plasticity of S. pneumoniae by increasing the likelihood of multiple transformation events in the same cell.


A cohort study of the risk of cervical intraepithelial neoplasia grade 2 or 3 in relation to papillomavirus infection.

Abstract:
BACKGROUND Human papillomavirus (HPV) has been associated with cervical intraepithelial neoplasia, but the temporal relation between the infection and the neoplasia remains unclear, as does the relative importance of the specific type of HPV, other sexually transmitted diseases, and other risk factors.
 METHODS We studied prospectively a cohort of 241 women who presented for evaluation of sexually transmitted disease and had negative cervical cytologic tests. The women were followed every four months with cytologic and colposcopic examinations of the uterine cervix and tests for HPV DNA and other sexually transmitted diseases.
 RESULTS Cervical intraepithelial neoplasia grade 2 or 3 was confirmed by biopsy in 28 women. On the basis of survival analysis, the cumulative incidence of cervical intraepithelial neoplasia at two years was 28 percent among women with a positive test for HPV and 3 percent among those without detectable HPV DNA: The risk was highest among those with HPV type 16 or 18 infection (adjusted relative risk as compared with that in women without HPV infection, 11; 95 percent confidence interval, 4.6 to 26; attributable risk, 52 percent). All 24 cases of cervical intraepithelial neoplasia grade 2 or 3 among HPV-positive women were detected within 24 months after the first positive test for HPV. After adjustment for the presence of HPV infection, the development of cervical intraepithelial neoplasia was also associated with younger age at first intercourse, the presence of serum antibodies to Chlamydia trachomatis, the presence of serum antibodies to cytomegalovirus, and cervical infection with Neisseria gonorrhoeae.
 CONCLUSIONS Cervical intraepithelial neoplasia is a common and apparently early manifestation of cervical infection by HPV, particularly types 16 and 18.


Transgenic Interleukin 10 Prevents Induction of Experimental Autoimmune Encephalomyelitis

Abstract: The effectiveness of interleukin 10 (IL-10) in the treatment of autoimmune-mediated central nervous system inflammation is controversial. Studies of the model system, experimental autoimmune encephalomyelitis (EAE), using various routes, regimens, and delivery methods of IL-10 suggest that these variables may affect its immunoregulatory function. To study the influence of these factors on IL-10 regulation of EAE pathogenesis, we have analyzed transgenic mice expressing human IL-10 (hIL-10) transgene under the control of a class II major histocompatibility complex (MHC) promoter. The hIL-10 transgenic mice are highly resistant to EAE induced by active immunization, and this resistance appears to be mediated by suppression of autoreactive T cell function. Myelin-reactive T helper 1 cells are induced but nonpathogenic in the IL-10 transgenic mice. Antibody depletion confirmed that EAE resistance is dependent on the presence of the transgenic IL-10. Mice expressing the hIL-10 transgene but not the endogenous murine IL-10 gene demonstrated that transgenic IL-10 from MHC class II–expressing cells is sufficient to block induction of EAE. This study demonstrates that IL-10 can prevent EAE completely if present at appropriate levels and times during disease induction.


Autosomal dominant immune dysregulation syndrome in humans with CTLA4 mutations

Abstract: The protein cytotoxic T lymphocyte antigen-4 (CTLA-4) is an essential negative regulator of immune responses, and its loss causes fatal autoimmunity in mice. We studied a large family in which five individuals presented with a complex, autosomal dominant immune dysregulation syndrome characterized by hypogammaglobulinemia, recurrent infections and multiple autoimmune clinical features. We identified a heterozygous nonsense mutation in exon 1 of CTLA4. Screening of 71 unrelated patients with comparable clinical phenotypes identified five additional families (nine individuals) with previously undescribed splice site and missense mutations in CTLA4. Clinical penetrance was incomplete (eight adults of a total of 19 genetically proven CTLA4 mutation carriers were considered unaffected). However, CTLA-4 protein expression was decreased in regulatory T cells (Treg cells) in both patients and carriers with CTLA4 mutations. Whereas Treg cells were generally present at elevated numbers in these individuals, their suppressive function, CTLA-4 ligand binding and transendocytosis of CD80 were impaired. Mutations in CTLA4 were also associated with decreased circulating B cell numbers. Taken together, mutations in CTLA4 resulting in CTLA-4 haploinsufficiency or impaired ligand binding result in disrupted T and B cell homeostasis and a complex immune dysregulation syndrome.


Specific inhibition of cyclin-dependent kinase 4/6 by PD 0332991 and associated antitumor activity in human tumor xenografts.

Abstract: PD 0332991 is a highly specific inhibitor of cyclin-dependent kinase 4 (Cdk4) (IC50, 0.011 micromol/L) and Cdk6 (IC50, 0.016 micromol/L), having no activity against a panel of 36 additional protein kinases. It is a potent antiproliferative agent against retinoblastoma (Rb)-positive tumor cells in vitro, inducing an exclusive G1 arrest, with a concomitant reduction of phospho-Ser780/Ser795 on the Rb protein. Oral administration of PD 0332991 to mice bearing the Colo-205 human colon carcinoma produces marked tumor regression. Therapeutic doses of PD 0332991 cause elimination of phospho-Rb and the proliferative marker Ki-67 in tumor tissue and down-regulation of genes under the transcriptional control of E2F. The results indicate that inhibition of Cdk4/6 alone is sufficient to cause tumor regression and a net reduction in tumor burden in some tumors.


The evolution of Fox genes and their role in development and disease

Abstract: The forkhead box (Fox) family of transcription factors, which originated in unicellular eukaryotes, has expanded over time through multiple duplication events, and sometimes through gene loss, to over 40 members in mammals. Fox genes have evolved to acquire a specialized function in many key biological processes. Mutations in Fox genes have a profound effect on human disease, causing phenotypes as varied as cancer, glaucoma and language disorders. We summarize the salient features of the evolution of the Fox gene family and highlight the diverse contribution of various Fox subfamilies to developmental processes, from organogenesis to speech acquisition.


Cancer associated fibroblasts (CAFs) in tumor microenvironment.

Abstract: Cancer associated fibroblasts (CAFs) is one of the most crucial components of the tumor microenvironment which promotes the growth and invasion of cancer cells by various mechanisms. CAFs demonstrate a high degree of heterogeneity due to their various origins; however, many distinct morphological features and physiological functions of CAFs have been identified. It is becoming clear that the crosstalk between the cancer cells and the CAFs plays a key role in the progression of cancer, and understanding this mutual relationship would eventually enable us to treat cancer patients by targeting CAFs. In this review, we will discuss the latest findings on the role of CAFs in tumorigenesis and metastasis as well as potential therapeutic implication of CAFs.