Effect of leucine on amino acid and glucose metabolism in humans.

Leucine has been reported to be an important regulator of protein metabolism. We investigated the effect of intravenous infusion of L-leucine versus saline on amino acid metabolism in eight healthy human subjects. Plasma concentrations of amino acids were measured and protein turnover was estimated using L-(1-13C)lysine and L-(3,3,3,-2H3)leucine as tracers. Glucose kinetics were measured using D-(6,6-2H2)glucose as a tracer. Leucine infusion increased the plasma leucine concentration from 103 +/- 8 to 377 +/- 35 mumol/L (P less than .01). Plasma concentrations of essential amino acids, including threonine, methionine, isoleucine, valine, tyrosine, and phenylalanine were significantly decreased by leucine infusion. Leucine infusion did not change lysine flux significantly (108 +/- 4 during saline v 101 +/- 4 mumol/kg/h-1 during leucine infusion), but decreased lysine oxidation (13.2 +/- 0.9 v 10.7 +/- 1 mumol/kg/h, P less than .05) and endogenous leucine flux (from 128 +/- 4 to 113 +/- 7 mumol/kg/h, P less than .05) when plasma (2H3) ketoisocaproate (KIC) was used for calculation. During leucine infusion, the (2H3) KIC to (2H3) leucine plasma enrichment ratio increased from 0.76 +/- 0.02 to 0.88 +/- 0.01 (P less than .001), while estimation of leucine flux using plasma (2H3) leucine showed no change in endogenous leucine flux. Leucine infusion decreased hepatic glucose production and metabolic clearance of glucose, but did not change plasma concentrations of glucose, insulin, C-peptide, glucagon, epinephrine, norepinephrine, or free fatty acids. We conclude that leucine spares glucose and lysine catabolism and decreases plasma concentrations of essential amino acids.(ABSTRACT TRUNCATED AT 250 WORDS)     

A subset of human monocyte-derived dendritic cells expresses high levels of interleukin-12 in response to combined CD40 ligand and interferon-gamma treatment

Dendritic cells (DCs) may arise from multiple lineages and progress through a series of intermediate stages until fully mature, at which time they are capable of optimal antigen presentation and T-cell activation. High cell surface expression of CD83 is presumed to correlate with full maturation of DCs, and a number of agents have been shown to increase CD83 expression on DCs. We hypothesized that interleukin 12 (IL-12) expression would be a more accurate marker of functionally mature DCs capable of activating antigen-specific T cells. We used combinations of signaling through CD40, using CD40 ligand trimer (CD40L), and interferon gamma to demonstrate that CD83 expression is necessary but not sufficient for optimal production of IL-12 by DCs. Phenotypically mature DCs could be induced to produce high levels of IL-12 p70 only when provided 2 simultaneous stimulatory signals. By intracellular cytokine detection, we determined that only a subset of cells that express high levels of CD80 and CD83 generate large amounts of IL-12. DCs matured with both signals are superior to DCs stimulated with the individual agents in activating antigen-specific T cell in vitro. These findings have important implications regarding the identification, characterization, and clinical application of functionally mature DCs.     

Ten-year experience with mitral valve replacement in the elderly.

Limited data are available on mitral valve replacement in the elderly patient. Therefore we report our 10-year experience including predictors of perioperative mortality and subsequent long-term cardiac mortality in elderly patients with mitral valve replacement compared to younger patients. Of the 126 consecutive patients with mitral valve replacement, 26 were older (77 +/- 4, group 1) and 100 were younger (62 +/- 9, group 2) than 70 years. Bioprostheses were used more frequently in patients in group 1 (65% vs 7%, p less than 0.0001). Of the 21 clinical, ECG, hemodynamic, and angiographic variables studied, patients in group 1 had higher pulmonary artery systolic pressure (57 +/- 15 vs 48 +/- 19, p less than 0.05), fascicular block on ECGs (70% vs 33%, p less than 0.005), and greater pump time on cardiopulmonary bypass (160 +/- 75 vs 120 +/- 50 minutes, p less than 0.025). A trend toward a higher perioperative mortality rate was also seen in group 1 (27% vs 12%, p = 0.058). Predictors of perioperative mortality by multivariate analysis were the presence of aortic calcification and prolonged pump time on cardiopulmonary bypass in group 1 and coronary artery disease, female sex, elevated mean pulmonary artery pressure, and postoperative complete atrioventricular block in group 2. During a mean 4-year follow-up period, cardiac mortality and total mortality rates were 42% and 54%, respectively, for group 1 compared to 24% and 35%, respectively, for group 2.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bioactive nano‐fibrous scaffold for vascularized craniofacial bone regeneration

There has been a growing demand for bone grafts for correction of bone defects in complicated fractures or tumours in the craniofacial region. Soft flexible membrane like material that could be inserted into defect by less invasive approaches; promote osteoconductivity and act as a barrier to soft tissue in growth while promoting bone formation is an attractive option for this region. Electrospinning has recently emerged as one of the most promising techniques for fabrication of extracellular matrix such as nano‐fibrous scaffolds that can serve as a template for bone formation. To overcome the limitation of cell penetration of electrospun scaffolds and improve on its osteoconductive nature, in this study, we fabricated a novel electrospun composite scaffold of polyvinyl alcohol (PVA)‐poly (ε) caprolactone (PCL)‐Hydroxyapatite based bioceramic (HAB), namely, PVA‐PCL‐HAB. The scaffold prepared by dual electrospinning of PVA and PCL with HAB overcomes reduced cell attachment associated with hydrophobic PCL by combination with a hydrophilic PVA and the HAB can contribute to enhance osteoconductivity. We characterized the physicochemical and biocompatibility properties of the new scaffold material. Our results indicate PVA‐PCL‐HAB scaffolds support attachment and growth of stromal stem cells; [human bone marrow skeletal (mesenchymal) stem cells and dental pulp stem cells]. In addition, the scaffold supported in vitro osteogenic differentiation and in vivo vascularized bone formation. Thus, PVA‐PCL‐HAB scaffold is a suitable potential material for therapeutic bone regeneration in dentistry and orthopaedics.     

Household Debt and Relation to Intimate Partner Violence and Husbands' Attitudes Toward Gender Norms: A Study Among Young Married Couples in Rural Maharashtra,India

Objective

Evidence has linked economic hardship with increased intimate partner violence (IPV) perpetration among males. However, less is known about how economic debt or gender norms related to men''s roles in relationships or the household, which often underlie IPV perpetration, intersect in or may explain these associations. We assessed the intersection of economic debt, attitudes toward gender norms, and IPV perpetration among married men in India.

Methods

Data were from the evaluation of a family planning intervention among young married couples (n=1,081) in rural Maharashtra, India. Crude and adjusted logistic regression models for dichotomous outcome variables and linear regression models for continuous outcomes were used to examine debt in relation to husbands'' attitudes toward gender-based norms (i.e., beliefs supporting IPV and beliefs regarding male dominance in relationships and the household), as well as sexual and physical IPV perpetration.

Results

Twenty percent of husbands reported debt. In adjusted linear regression models, debt was associated with husbands'' attitudes supportive of IPV (b=0.015, p=0.004) and norms supporting male dominance in relationships and the household (b=0.006, p=0.003). In logistic regression models adjusted for relevant demographics, debt was associated with perpetration of physical IPV (adjusted odds ratio [AOR] = 1.4, 95% confidence interval [CI] 1.1, 1.9) and sexual IPV (AOR=1.6, 95% CI 1.1, 2.1) from husbands. These findings related to debt and relation to IPV were slightly attenuated when further adjusted for men''s attitudes toward gender norms.

Conclusion

Findings suggest the need for combined gender equity and economic promotion interventions to address high levels of debt and related IPV reported among married couples in rural India.Intimate partner violence (IPV) perpetrated by male partners or husbands occurs in high proportions globally as well as in low- to middle-income countries such as India.^1,2 One recent multi-country household study found that 37% of men in India reported having ever perpetrated physical violence against a female intimate partner in their lifetime. The health burden of IPV has been well demonstrated, with significant effects on women''s sexual and reproductive health (e.g., increased sexually transmitted infections, unintended pregnancy, and poor pregnancy outcomes),^3–5 mental health (e.g., anxiety, depression, and substance use),^6,7 as well as a multitude of other poor health outcomes among women and their children (e.g., maternal and child malnutrition and infant death).^8,9Recent research among women has identified economic hardship (e.g., financial dependence on male partners and economic instability) as increasing women''s vulnerability to IPV.^10,11 Although studies have found an association between economic stressors and reports of male IPV perpetration,^12–16 no research has examined debt in relation to these outcomes.Debt and other economic decisions in the context of marriage, particularly in rural India, are largely under the control of husbands. Taking on debt may be associated with economic hardship, heightening stress levels among men, and, in turn, IPV. Also, previous work documenting the association between economic hardship and increased IPV perpetration by males^12–15 has largely been explained by perceptions related to men''s roles financially within the family (e.g., men who do not feel that they are providing financially for their families may perceive that they are not fulfilling their roles as husbands/males, and this perception related to lack of role fulfillment may escalate into violence). Given that a decision to take on debt appears to be largely controlled by men in this context and likely tied to their perceived role of providing financially for the family, a man''s decision to take out loans may be determined, in part, by their support of masculine gender norms (e.g., a man''s role in the family and male dominance and control in the household). In addition, given previous work highlighting the association between masculine gender norms and a number of risk behaviors among boys and men (e.g., substance and tobacco use and behaviors resulting in unintentional injury),^17–21 such gender norms may also be linked to taking on risks associated with debt, as well as debt-acquiring behaviors (e.g., spending money on nonessential goods such as alcohol).Gender norms pertaining to IPV, relationships, and the household are also important driving factors in terms of understanding men''s behaviors related to IPV. Cross-cultural research has shown that societies with greater gender inequities in social norms and policies have a higher prevalence of IPV.²¹ In the context of India and elsewhere, women''s low status in families and high levels of societal tolerance and acceptance of IPV promote IPV.²²More research is needed to understand economic hardship, and debt specifically, in relation to attitudes toward gender norms and IPV perpetration. Many studies have hypothesized that stress related to economic hardship and debts increases IPV perpetration;^12–15 however, less research has sought to understand the role of attitudes supportive of men''s more traditional gender norms in relationships or households in contributing to decisions to take on debt as well as in terms of explaining its association with increased IPV perpetration. Increased understanding of the mechanisms that explain associations between economic hardship/debt and IPV is needed to inform prevention approaches, particularly given the increasing number of economic promotion interventions being implemented globally and throughout India.Thus, the primary objective of the current study was to assess household debt in relation to husbands'' support of gender-inequitable norms and norms promoting IPV as well as husbands'' use of IPV against wives. The secondary objective of this study was to assess whether or not gender-based attitudes are important factors in debt and IPV, as well as in explaining an association between debt and increased risk for IPV perpetration among husbands.     

Impact of Physical Activities on Frailty in Community-Dwelling Older Women

Aims: The aim of the study was to determine whether increased physical activities (PA) affect frailty for old women, 75 years and older (OO), compared to 60–74 years old (YO). Methods: This cross-sectional study measured 19 frailty indicators (muscle strength and endurance, balance, gait characteristics, and function), using 46 community-dwelling women. PA were divided into three levels by caloric expenditure per week (<2,000 kcal/week, 2,000–3,999 kcal/week, >4,000 kcal/week). Results: As PA level increased, a gap (=difference) between OO and YO narrowed for step length and function, but for quadriceps strength and endurance, a gap widened. Conclusions: Frailty progresses with aging but older women who engage in a high level of physical activity (>4,000 kcal/week) can increase mobility and functional capacity, but not for muscle strength and endurance. Starting regular resistance training activities early in the aging process is critical to improve or maintain muscle quality to offset age-related frailty.