Differential pathways to adult metabolic dysfunction following poor nutrition at two critical developmental periods in sheep

Epidemiological and experimental studies suggest early nutrition has long-term effects on susceptibility to obesity, cardiovascular and metabolic diseases. Small and large animal models confirm the influence of different windows of sensitivity, from fetal to early postnatal life, on offspring phenotype. We showed previously that undernutrition in sheep either during the first month of gestation or immediately after weaning induces differential, sex-specific changes in adult metabolic and cardiovascular systems. The current study aims to determine metabolic and molecular changes that underlie differences in lipid and glucose metabolism induced by undernutrition during specific developmental periods in male and female sheep. Ewes received 100% (C) or 50% nutritional requirements (U) from 1–31 days gestation, and 100% thereafter. From weaning (12 weeks) to 25 weeks, offspring were then fed either ad libitum (CC, UC) or were undernourished (CU, UU) to reduce body weight to 85% of their individual target. From 25 weeks, all offspring were fed ad libitum. A cohort of late gestation fetuses were studied after receiving either 40% nutritional requirements (1–31 days gestation) or 50% nutritional requirements (104–127 days gestation). Post-weaning undernutrition increased in vivo insulin sensitivity, insulin receptor and glucose transporter 4 expression in muscle, and lowered hepatic methylation at the delta-like homolog 1/maternally expressed gene 3 imprinted cluster in adult females, but not males. Early gestational undernutrition induced lower hepatic expression of gluconeogenic factors in fetuses and reduced in vivo adipose tissue insulin sensitivity in adulthood. In males, undernutrition in early gestation increased adipose tissue lipid handling mechanisms (lipoprotein lipase, glucocorticoid receptor expression) and hepatic methylation within the imprinted control region of insulin-like growth factor 2 receptor in adulthood. Therefore, undernutrition during development induces changes in mechanisms of lipid and glucose metabolism which differ between tissues and sexes dependent on the period of nutritional restriction. Such changes may increase later life obesity and dyslipidaemia risk

Bidirectional relationship between acute pancreatitis and pancreatic cancer

Purpose of reviewThe burdens of pancreatic ductal adenocarcinoma (PDAC) and acute pancreatitis are increasing globally. We reviewed current literature on whether acute pancreatitis is a causal factor for PDAC and examined clinical manifestations of PDAC-associated acute pancreatitis.Recent findingsRecent findings detail the timing of acute pancreatitis before and after PDAC occurrence, further solidifying the evidence for PDAC-associated acute pancreatitis and for acute pancreatitis as a causal risk factor for PDAC. The risk of PDAC remains elevated above the general population in patients with distant history of acute pancreatitis. PDAC risk also increases with recurrent acute pancreatitis episodes, independent of smoking and alcohol. Mechanisms linking acute pancreatitis to PDAC include inflammation and neutrophil infiltration, which can be attenuated by suppressing inflammation and/or epigenetic modulation, thus slowing the progression of acinar-to-ductal metaplasia. Clinical presentation and management of acute pancreatitis in the context of PDAC are discussed, including challenges acute pancreatitis poses in the diagnosis and treatment of PDAC, and novel interventions for PDAC-associated acute pancreatitis.SummaryPDAC risk may be reduced with improved acute pancreatitis prevention and treatment, such as antiinflammatories or epigenetic modulators. Increased acute pancreatitis and PDAC burden warrant more research on better diagnosis and management of PDAC-associated acute pancreatitis

Evolutionary game theory in growing populations

Existing theoretical models of evolution focus on the relative fitness advantages of different mutants in a population while the dynamic behavior of the population size is mostly left unconsidered. We here present a generic stochastic model which combines the growth dynamics of the population and its internal evolution. Our model thereby accounts for the fact that both evolutionary and growth dynamics are based on individual reproduction events and hence are highly coupled and stochastic in nature. We exemplify our approach by studying the dilemma of cooperation in growing populations and show that genuinely stochastic events can ease the dilemma by leading to a transient but robust increase in cooperationComment: 4 pages, 2 figures and 2 pages supplementary informatio

Vascular Endothelial Growth Factor-A Gene Electrotransfer Promotes Angiogenesis in a Porcine Model of Cardiac Ischemia

This study aimed to assess safety and therapeutic potential of gene electrotransfer (GET) as a method for delivery of plasmid encoding vascular endothelial growth factor A (VEGF-A) to ischemic myocardium in a porcine model. Myocardial ischemia was induced by surgically occluding the left anterior descending coronary artery in swine. GET following plasmid encoding VEGF-A injection was performed at four sites in the ischemic region. Control groups either received injections of the plasmid without electrotransfer or injections of the saline vehicle. Animals were monitored for 7 weeks and the hearts were evaluated for angiogenesis, myocardial infarct size and left ventricular contractility. Arteriograms suggest growth of new arteries as early as 2 weeks after treatment in electrotransfer animals. There is a significant reduction of infarct area and left ventricular contractility is improved in GET-treated group compared with controls. There was no significant difference in mortality of animals treated with GET of plasmid encoding VEGF-A from the control groups. Gene delivery of plasmid encoding VEGF-A to ischemic myocardium in a porcine model can be accomplished safely with potential for myocardial repair and regeneration

Mechanisms and immunogenicity of nsPEF-induced cell death in B16F10 melanoma tumors

Accumulating data indicates that some cancer treatments can restore anticancer immunosurveillance through the induction of tumor immunogenic cell death (ICD). Nanosecond pulsed electric fields (nsPEF) have been shown to efficiently ablate melanoma tumors. In this study we investigated the mechanisms and immunogenicity of nsPEF-induced cell death in B16F10 melanoma tumors. Our data show that in vitro nsPEF (20-200, 200-ns pulses, 7 kV/cm, 2 Hz) caused a rapid dose-dependent cell death which was not accompanied by caspase activation or PARP cleavage. The lack of nsPEF-induced apoptosis was confirmed in vivo in B16F10 tumors. NsPEF also failed to trigger ICD-linked responses such as necroptosis and autophagy. Our results point at necrosis as the primary mechanism of cell death induced by nsPEF in B16F10 cells. We finally compared the antitumor immunity in animals treated with nsPEF (750, 200-ns, 25 kV/cm, 2 Hz) with animals were tumors were surgically removed. Compared to the naïve group where all animals developed tumors, nsPEF and surgery protected 33% (6/18) and 28.6% (4/14) of the animals, respectively. Our data suggest that, under our experimental conditions, the local ablation by nsPEF restored but did not boost the natural antitumor immunity which stays dormant in the tumor-bearing host

Daily monthly and seasonal variation in PSA levels and the association with weather parameters

International audienceProstate-specific antigen (PSA) levels have shown daily and seasonal variation, although data are conflicting regarding the season with higher PSA levels and the clinical relevance of this. We assessed the correlation of total PSA levels with meteorological data on a daily, weekly, monthly and seasonal basis. Data from 53 224 men aged 45-74 years, with an initial PSA <10.0ng/ml were correlated with temperature (oC), duration of bright sunshine (hours) and rainfall (mm). There was seasonal variation in PSA levels, with median PSA being higher in spring compared to other seasons (1.18 vs. 1.10ng/ml, p=0.004). Seasonal variation was not apparent when PSA levels were age-adjusted (p=0.112). Total PSA was not correlated with daily, weekly or monthly hours of sunshine, rainfall nor mean temperature. In contrast, age-adjusted PSA varied with weekday, with higher PSA levels on Thursday and Friday compared to other days (1.16 vs. 1.10ng/ml respectively). On multivariate analysis, only age predicted for PSA levels >3.0ng/ml. In conclusion, PSA levels did show seasonal variation although there was no direct correlation between PSA and any meteorological parameter. The degree of seasonal variation is small and the decision to proceed to prostate biopsy should be independent of season or weather parameters

Mechanisms and Immunogenicity of nsPEF-Induced Cell Death in B16F10 Melanoma Tumors

Accumulating data indicates that some cancer treatments can restore anticancer immunosurveillance through the induction of tumor immunogenic cell death (ICD). Nanosecond pulsed electric fields (nsPEF) have been shown to efficiently ablate melanoma tumors. In this study we investigated the mechanisms and immunogenicity of nsPEF-induced cell death in B16F10 melanoma tumors. Our data show that in vitro nsPEF (20-200, 200-ns pulses, 7 kV/cm, 2 Hz) caused a rapid dose-dependent cell death which was not accompanied by caspase activation or PARP cleavage. The lack of nsPEF-induced apoptosis was confirmed in vivo in B16F10 tumors. NsPEF also failed to trigger ICD-linked responses such as necroptosis and autophagy. Our results point at necrosis as the primary mechanism of cell death induced by nsPEF in B16F10 cells. We finally compared the antitumor immunity in animals treated with nsPEF (750, 200-ns, 25 kV/cm, 2 Hz) with animals were tumors were surgically removed. Compared to the naive group where all animals developed tumors, nsPEF and surgery protected 33% (6/18) and 28.6% (4/14) of the animals, respectively. Our data suggest that, under our experimental conditions, the local ablation by nsPEF restored but did not boost the natural antitumor immunity which stays dormant in the tumor-bearing host

Use of serial qualitative interviews to understand patients’ evolving experiences and needs

Interviewing patients over the course of their illness can give a much better picture of their experience than single interviews, but the approach is rarely used. Scott Murray and colleagues explain how to get the most from it