Relationship of Anterior and Posterior Subcutaneous Abdominal Fat to Insulin Sensitivity in Nondiabetic Men

Recent studies from our group reveal that adipose tissue (AT) in the subcutaneous abdominal region is the most important determinant of peripheral and hepatic insulin sensitivity. Because of different anatomic and physiologic characteristics of anterior and posterior subcutaneous abdominal AT, we investigated the relationship of the masses of each compartment, as determined by magnetic resonance imaging, to insulin sensitivity (using euglycemic hyperinsulinemic glucose clamp technique), and other anthropometric variables. Thirty-four healthy men with varying ranges of obesity were recruited for the study. The mass of posterior subcutaneous abdominal AT was ～1.6 times more than that of the anterior compartment, and these masses accounted for 12.9% and 8.2% of the total body fat mass, respectively. All anthropometric variables, including body mass index (BMI), waist-to-hip circumference ratio (WHR), skinfold thicknesses, and intraperitoneal AT mass were more significantly related to the posterior than the anterior subcutaneous abdominal AT mass. Compared to the anterior compartment mass, the posterior compartment mass displayed stronger relationship with insulin-mediated glucose disposal (Rd) (r=-0.44, p=0.009, and r=-0.76, p=0.0001, respectively) as well as with residual hepatic glucose output during the 40 mU.^?2.min-¹ insulin infusion (r=0.39, p=0.02, and r=0.53, p=0.001, respectively). After adjusting for total body fat, the Rd values showed a significant partial correlation with the posterior subcutaneous abdominal AT mass (r=-0.52, p=0.002). To conclude, posterior subcutaneous abdominal AT mass is a more important determinant of peripheral and hepatic insulin sensitivity than the anterior subcutaneous abdominal AT.     

Establishment of Elevated Serum Levels of IL-10, IL-8 and TNF-β as Potential Peripheral Blood Biomarkers in Tubercular Lymphadenitis: A Prospective Observational Cohort Study

Background

Tubercular lymphadenitis (TL) is the most common form of extra-pulmonary tuberculosis (TB) consisting about 15–20% of all TB cases. The currently available diagnostic modalities for (TL), are invasive and involve a high index of suspicion, having limited accuracy. We hypothesized that TL would have a distinct cytokine signature that would distinguish it from pulmonary TB (PTB), peripheral tubercular lymphadenopathy (LNTB), healthy controls (HC), other lymphadenopathies (LAP) and cancerous LAP. To assess this twelve cytokines (Tumor Necrosis Factor (TNF)—α, Interferon (IFN) -γ, Interleukin (IL)-2, IL-12, IL-18, IL-1β, IL-10, IL-6, IL-4, IL-1Receptor antagonist (IL-1Ra), IL-8 and TNF-β, which have a role in pathogenesis of tuberculosis, were tested as potential peripheral blood biomarkers to aid the diagnosis of TL when routine investigations prove to be of limited value.

Methods and Findings

A prospective observational cohort study carried out during 2010–2013. This was a multi-center study with three participating hospitals in Delhi, India where through random sampling cohorts were established. The subjects were above 15 years of age, HIV-negative with no predisposing ailments to TB (n = 338). The discovery cohort (n = 218) had LNTB (n = 50), PTB (n = 84) and HC (n = 84). The independent validation cohort (n = 120) composed of patients with cancerous LAP (n = 35), other LAP (n = 20) as well as with independent PTB (n = 30), LNTB (n = 15) and HC (n = 20). Eight out of twelve cytokines achieved statistical relevance upon evaluation by pairwise and ROC analysis. Further, variable selection using random forest backward elimination revealed six serum biosignatures including IL-12, IL-4, IL-6, IL-10, IL-8 and TNF-β as optimal for classifying the LNTB status of an individual. For the sake of clinical applicability we further selected a three analyte panel (IL-8, IL-10 and TNF-β) which was subjected to multinomial modeling in the independent validation cohort which was randomised into training and test cohorts, achieving an overwhelming 95.9% overall classifying accuracy for correctly classifying LNTB cases with a minimal (7%) misclassification error rate in the test cohort.

Conclusions

In our study, a three analyte serum biosignatures and probability equations were established which can guide the physician in their clinical decision making and step wise management of LNTB patients. This set of biomarkers has the potential to be a valuable adjunct to the diagnosis of TL in cases where AFB positivity and granulomatous findings elude the clinician.     

Ethylene oligomerization using nickel dithiolene complexes Ni(S2C2R2)2 (R=Ph, CF3) and the crystal structure of Ni[S2C2(CF3)2]2

Nickel bis(dithiolene) complexes have been known for over four decades, yet little is known regarding the chemistry of this important subclass of inorganic coordination complexes in olefin oligomerization or polymerization. We report here that Ni(S(2)C(2)R(2))(2) (R=Ph, CF(3)) are converted to active catalysts for ethylene oligomerization when activated with methylaluminoxane (MAO). The catalyst activity is comparable to some nickel coordination complexes with N-donor ligands under similar conditions. The products are mainly butenes and hexenes, with small amounts of higher oligomers. The product distribution pattern is consistent with a nickel hydride species being the active center, where fast beta-hydride elimination limits the products to mostly butenes and hexenes. The exact nature of the active center and the reaction mechanism remain to be investigated. In addition, we determined the crystal structure for Ni[S(2)C(2)(CF(3))(2)](2). The molecule crystallizes in the P2(1)/n space group and adopts a planar geometry with expected bond lengths and angles. Comparing this structure with that for the donor-acceptor complex with perylene reveals elongation of both the Ni-S and the S-C bonds in the latter, suggesting reduction of Ni[S(2)C(2)(CF(3))(2)](2) may have occurred in the latter.     

TILLING by Sequencing (TbyS) for targeted genome mutagenesis in crops

TILLING (Targeting Induced Local Lesions in Genomes) by Sequencing (TbyS) refers to the application of high-throughput sequencing technologies to mutagenised TILLING populations as a tool for functional genomics. TbyS can be used to identify and characterise induced variation in genes (controlling traits of interest) within large mutant populations, and is a powerful approach for the study and harnessing of genetic variation in crop breeding programmes. The extension of existing TILLING platforms by TbyS will accelerate crop functional genomics studies, in concert with the rapid increase in genome editing capabilities and the number and quality of sequenced crop plant genomes. In this mini-review, we provide an overview of the growth of TbyS and its potential applications to crop molecular breeding.     

Lipodystrophy: lessons in lipid and energy metabolism

PURPOSE OF REVIEW: Lipodystrophies are rare inherited and acquired disorders characterized by the selective loss of adipose tissue. Despite marked phenotypic and genotypic heterogeneity, most lipodystrophic syndromes predispose to similar metabolic complications seen in patients with obesity, such as insulin resistance, diabetes mellitus, hepatic steatosis and dyslipidemia. The purpose of this review is to highlight the current understanding of the mechanisms underlying dyslipidemia in patients with lipodystrophies. RECENT FINDINGS: Marked hypertriglyceridemia and reduced levels of high-density lipoprotein cholesterol are commonly seen, and the severity of these metabolic abnormalities seems to be related to the extent of fat loss. The precise mechanisms by which the lack of adipose tissue causes hypertriglyceridemia remain unknown. Anecdotal kinetic studies in hyperglycemic patients with lipodystrophies have revealed accelerated lipolysis and increased free fatty acid turnover, which drives hepatic triglyceride and very low-density lipoprotein synthesis. Other mechanisms may also be involved in causing dyslipidemia and ectopic triglyceride accumulation in the liver and skeletal muscles that remain to be identified. SUMMARY: Understanding the pathophysiology of dyslipidemia in these rare disorders of lipodystrophies may offer insights into the normal role of adipocytes in maintaining metabolic homeostasis, and its disturbances in common forms of obesity.     

Computational modeling for osteogenic potential assessment of physical exercises based on loading-induced mechanobiological environments in cortical bone remodeling

Biomechanics and Modeling in Mechanobiology - Osteoporosis and disuse can cause bone loss which reduces the weight-bearing strength of long bones. Physical exercise or mechanical loading prevents...     

Investigation of efficient photoconduction and enhanced luminescence characteristics of Ce-doped ZnO nanophosphors for UV sensors

This study involves the single-step, mass-scale productive synthesis, photoconduction, and luminescence characteristics of pure and cerium rare-earth-ion-doped ZnO (CZO) nanophosphors with different Ce concentrations (Ce: 0, 2, 4, 6, and 8 wt.%) synthesized using the solid-state reaction method. The synthesized nanophosphors were characterized for their structural, morphological, optical, and photoconductivity (PC) properties using X-ray diffraction (XRD), field-effect scanning electron microscopy (FE-SEM), energy dispersive spectroscopy, Fourier-transform infrared (FT-IR), photoluminescence (PL), and PC measurements. The sharp diffraction peaks of XRD results exhibit the formation of crystalline hexagonal wurtzite ZnO nanostructures. The decrease in diffraction peak intensities of CZO with an increase in Ce concentrations signifies the deterioration of the ZnO crystal. FE-SEM images exhibit the good crystalline quality of nanophosphors composed of spherical- and elongated-shaped nanoparticles that are distributed consistently on the surface. The energy dispersive X-ray pattern of the 4 wt.% Ce-doped ZnO (CZO₄) sample confirms the doping of Ce in ZnO. The presence of chemical bonds and functional groups corresponds to transmittance peaks established using FT-IR spectroscopy. Deconvoluted PL spectra show two major emission peaks, one in the UV region, which is near-band-edge, and the other in the visible region ranging from ~456 to 561 nm. In PC studies, current–voltage (I–V) and current–time (I–T) characteristics, that is, rise/decayin current under dark as well as UV light conditions, are also investigated. Efficient photoconduction is observed in CZO samples. The obtained results indicate the suitability to luminescent and photosensor applications.