T-Cell Protein Tyrosine Phosphatase Attenuates STAT3 and Insulin Signaling in the Liver to Regulate Gluconeogenesis

OBJECTIVE: Insulin-induced phosphatidylinositol 3-kinase (PI3K)/Akt signaling and interleukin-6 (IL-6)-instigated JAK/STAT3-signaling pathways in the liver inhibit the expression of gluconeogenic genes to decrease hepatic glucose output. The insulin receptor (IR) and JAK1 tyrosine kinases and STAT3 can serve as direct substrates for the T-cell protein tyrosine phosphatase (TCPTP). Homozygous TCPTP-deficiency results in perinatal lethality prohibiting any informative assessment of TCPTP's role in glucose homeostasis. Here we have used Ptpn2+/- mice to investigate TCPTP's function in glucose homeostasis. RESEARCH DESIGN AND METHODS: We analyzed insulin sensitivity and gluconeogenesis in chow versus high-fat-fed (HFF) Ptpn2+/- and Ptpn2+/+ mice and insulin and IL-6 signaling and gluconeogenic gene expression in Ptpn2+/- and Ptpn2+/+ hepatocytes. RESULTS: HFF Ptpn2+/- mice exhibited lower fasted blood glucose and decreased hepatic glucose output as determined in hyperinsulinemic euglycemic clamps and by the decreased blood glucose levels in pyruvate tolerance tests. The reduced hepatic glucose output coincided with decreased expression of the gluconeogenic genes G6pc and Pck1 and enhanced hepatic STAT3 phosphorylation and PI3K/Akt signaling in the fasted state. Insulin-induced IR-beta-subunit Y1162/Y1163 phosphorylation and PI3K/Akt signaling and IL-6-induced STAT3 phosphorylation were also enhanced in isolated Ptpn2+/- hepatocytes. The increased insulin and IL-6 signaling resulted in enhanced suppression of G6pc and Pck1 mRNA. CONCLUSIONS: Liver TCPTP antagonises both insulin and STAT3 signaling pathways to regulate gluconeogenic gene expression and hepatic glucose output

Estudo anatomico do ligamento popliteo obliquo

OBJECTIVE:To study the anatomy of the oblique popliteal ligament, as regards its dimensions, expansion and anatomical relationships.METHODS:Eleven cadaver knees were dissected in order to study the anatomy and take mea-surements of anatomical structures and relationships of the oblique popliteal ligament. The dissection was for posterior access to the proper exposure of the oblique popliteal ligament, the semimembranosus muscle and its expansions. For measurement of dimensions, 40 × 12 needles were used for marking the specific points and a caliper. The angles were calculated using the software ImagePro Plus(r) .RESULTS:The distance from the origin of the oblique popliteal ligament to the tibial plateau was 7.4 mm, the thickness at its origin was 7.3 mm, length was 33.6 mm and the tibial plateau angle 34.8°. The length of the expansion of the proximal oblique popliteal ligament was 39.2 mm, thickness 7.8 mm and angle of the oblique popliteal ligament with its expansion 32.2°.CONCLUSION:The oblique popliteal ligament is thick, rises in the semimembranosus and protrudes proximally forming an acute angle with the joint interline, crossing the popliteal fossa. In some cases it has a proximal expansion.OBJETIVO:Estudar a anatomia do ligamento poplíteo oblíquo no que se refere às suas dimensões, expansões e relações anatômicas.MÉTODOS:Onze joelhos de cadáveres foram dissecados com o intuito de se estudar a anatomia e fazer medições das estruturas e das relações anatômicas do ligamento poplíteo oblíquo. A dissecção foi por acesso posterior até a exposição adequada do ligamento poplíteo oblíquo, do músculo semimembranoso e de suas expansões. Para aferição das medidas, foram usados agulhas 40x12 na marcação dos pontos específicos e um paquímetro. Os ângulos foram calculados com o auxílio do software ImagePro Plus(r).RESULTADOS:A distância da origem do ligamento poplíteo oblíquo ao platô tibial foi de 7,4 mm, a espessura na sua origem foi de 7,3 mm, o comprimento foi de 33,6 mm e o ângulo com o platô tibial foi de 34,8°. O comprimento da expansão proximal do ligamento poplíteo oblíquo foi de 39,2 mm, a espessura foi de 7,8 mm e o ângulo do ligamento poplíteo oblíquo com sua expansão foi de 32,2°.CONCLUSÃO:O ligamento poplíteo oblíquo é espesso, nasce no músculo semimembranoso, projeta-se proximalmente, forma um ângulo agudo com a interlinha articular e cruza a fossa poplítea. Em alguns casos apresenta uma expansão proximal.Universidade Federal do ParanaUniversidade Federal de São Paulo (UNIFESP)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaPontificia Universidade Catolica do ParanaUNIFESP, EPMSciEL

Restriction of essential amino acids dictates the systemic metabolic response to dietary protein dilution

Dietary protein dilution, where protein is reduced and replaced by other nutrient sources without caloric restriction, promotes metabolic health via the hepatokine Fgf21. Here, the authors show that essential amino acids threonine and tryptophan are necessary and sufficient to induce these effects

Restriction of essential amino acids dictates the systemic metabolic response to dietary protein dilution

Dietary protein dilution (DPD) promotes metabolic-remodelling and -health but the precise nutritional components driving this response remain elusive. Here, by mimicking amino acid (AA) supply from a casein-based diet, we demonstrate that restriction of dietary essential AA (EAA), but not non-EAA, drives the systemic metabolic response to total AA deprivation; independent from dietary carbohydrate supply. Furthermore, systemic deprivation of threonine and tryptophan, independent of total AA supply, are both adequate and necessary to confer the systemic metabolic response to both diet, and genetic AA-transport loss, driven AA restriction. Dietary threonine restriction (DTR) retards the development of obesity-associated metabolic dysfunction. Liver-derived fibroblast growth factor 21 is required for the metabolic remodelling with DTR. Strikingly, hepatocyte-selective establishment of threonine biosynthetic capacity reverses the systemic metabolic response to DTR. Taken together, our studies of mice demonstrate that the restriction of EAA are sufficient and necessary to confer the systemic metabolic effects of DPD.These studies were supported by Monash Biomedicine Discovery Institute laboratory start-up funds to A.J.R. as well as a Monash Joint Science-Medicine Interdisciplinary Research Seed Funding to A.J.R. and M.D.W.P

ATRX dysfunction Induces replication defects in primary mouse cells

The chromatin remodeling protein ATRX, which targets tandem repetitive DNA, has been shown to be required for expression of the alpha globin genes, for proliferation of a variety of cellular progenitors, for chromosome congression and for the maintenance of telomeres. Mutations in ATRX have recently been identified in tumours which maintain their telomeres by a telomerase independent pathway involving homologous recombination thought to be triggered by DNA damage. It is as yet unknown whether there is a central underlying mechanism associated with ATRX dysfunction which can explain the numerous cellular phenomena observed. There is, however, growing evidence for its role in the replication of various repetitive DNA templates which are thought to have a propensity to form secondary structures. Using a mouse knockout model we demonstrate that ATRX plays a direct role in facilitating DNA replication. Ablation of ATRX alone, although leading to a DNA damage response at telomeres, is not sufficient to trigger the alternative lengthening of telomere pathway in mouse embryonic stem cells

Oestrogen blocks the nuclear entry of SOX9 in the developing gonad of a marsupial mammal

<p>Abstract</p> <p>Background</p> <p>Hormones are critical for early gonadal development in nonmammalian vertebrates, and oestrogen is required for normal ovarian development. In contrast, mammals determine sex by the presence or absence of the <it>SRY </it>gene, and hormones are not thought to play a role in early gonadal development. Despite an XY sex-determining system in marsupial mammals, exposure to oestrogen can override <it>SRY </it>and induce ovarian development of XY gonads if administered early enough. Here we assess the effect of exogenous oestrogen on the molecular pathways of mammalian gonadal development.</p> <p>Results</p> <p>We examined the expression of key testicular (<it>SRY</it>, <it>SOX9</it>, <it>AMH </it>and <it>FGF9</it>) and ovarian (<it>WNT4</it>, <it>RSPO1</it>, <it>FOXL2 </it>and <it>FST</it>) markers during gonadal development in the marsupial tammar wallaby (<it>Macropus eugenii</it>) and used these data to determine the effect of oestrogen exposure on gonadal fate. During normal development, we observed male specific upregulation of <it>AMH </it>and <it>SOX9 </it>as in the mouse and human testis, but this upregulation was initiated before the peak in <it>SRY </it>expression and 4 days before testicular cord formation. Similarly, key genes for ovarian development in mouse and human were also upregulated during ovarian differentiation in the tammar. In particular, there was early sexually dimorphic expression of <it>FOXL2 </it>and <it>WNT4</it>, suggesting that these genes are key regulators of ovarian development in all therian mammals. We next examined the effect of exogenous oestrogen on the development of the mammalian XY gonad. Despite the presence of <it>SRY</it>, exogenous oestrogen blocked the key male transcription factor SOX9 from entering the nuclei of male somatic cells, preventing activation of the testicular pathway and permitting upregulation of key female genes, resulting in ovarian development of the XY gonad.</p> <p>Conclusions</p> <p>We have uncovered a mechanism by which oestrogen can regulate gonadal development through the nucleocytoplasmic shuttling of SOX9. This may represent an underlying ancestral mechanism by which oestrogen promotes ovarian development in the gonads of nonmammalian vertebrates. Furthermore, oestrogen may retain this function in adult female mammals to maintain granulosa cell fate in the differentiated ovary by suppressing nuclear translocation of the SOX9 protein.</p> <p>See commentary: http://www.biomedcentral.com/1741-7007/8/110</p

The management and outcome for patients with chronic subdural hematoma: a prospective, multicenter, observational cohort study in the United Kingdom

Symptomatic chronic subdural hematoma (CSDH) will become an increasingly common presentation in neurosurgical practice as the population ages, but quality evidence is still lacking to guide the optimal management for these patients. The British Neurosurgical Trainee Research Collaborative (BNTRC) was established by neurosurgical trainees in 2012 to improve research by combining the efforts of trainees in each of the United Kingdom (UK) and Ireland's neurosurgical units (NSUs). The authors present the first study by the BNTRC that describes current management and outcomes for patients with CSDH throughout the UK and Ireland. This provides a resource both for current clinical practice and future clinical research on CSDH

Mammalian sex determination—insights from humans and mice

Disorders of sex development (DSD) are congenital conditions in which the development of chromosomal, gonadal, or anatomical sex is atypical. Many of the genes required for gonad development have been identified by analysis of DSD patients. However, the use of knockout and transgenic mouse strains have contributed enormously to the study of gonad gene function and interactions within the development network. Although the genetic basis of mammalian sex determination and differentiation has advanced considerably in recent years, a majority of 46,XY gonadal dysgenesis patients still cannot be provided with an accurate diagnosis. Some of these unexplained DSD cases may be due to mutations in novel DSD genes or genomic rearrangements affecting regulatory regions that lead to atypical gene expression. Here, we review our current knowledge of mammalian sex determination drawing on insights from human DSD patients and mouse models

Relatório de estágio em farmácia comunitária

Relatório de estágio realizado no âmbito do Mestrado Integrado em Ciências Farmacêuticas, apresentado à Faculdade de Farmácia da Universidade de Coimbr

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)