Triglyceride pools, flight and activity variation at the Gpdh locus in Drosophila melanogaster

We have created a set of P-element excision-derived Gpdh alleles that generate a range of GPDH activity phenotypes ranging from zero to full activity. By placing these synthetic alleles in isogenic backgrounds, we characterize the effects of minor and major activity variation on two different aspects of Gpdh function: the standing triglyceride pool and glycerol-3-phosphate shuttle-assisted flight. We observe small but statistically significant reductions in triglyceride content for adult Gpdh genotypes possessing 33-80% reductions from normal activity. These small differences scale to a notable proportion of the observed genetic variation in triglyceride content in natural populations. Using a tethered fly assay to assess flight metabolism, we observed that genotypes with 100 and 66% activity exhibited no significant difference in wing-beat frequency (WBF), while activity reductions from 60 to 10% showed statistically significant reductions of approximately 7% in WBF. These studies show that the molecular polymorphism associated with GPDH activity could be maintained in natural populations by selection in the triglyceride pool.     

Modulation of hydrogen sulfide gasotransmitter limits the proven benefits of garlic

Phytochemistry Reviews - Garlic has been used as a medicinal food for centuries. The biological activity of garlic relies on the presence of highly reactive sulfur compounds. Widespread in vitro...     

Optimization of culture conditions for in vitro fertilization and reproduction of Microphallus turgidus (Trematoda: Microphallidae)

Most attempts to culture adult digeneans in vitro are unsuccessful. Even progenetic digeneans typically fail to produce infective eggs in axenic culture. However, metacercariae of Microphallus turgidus grown in vitro mature into adults and release eggs infective to the hydrobiid snail Spurwinkia salsa. The objectives of the present study were to verify the reproducibility of the M. turgidus culture protocol, to define optimal culture conditions for M. turgidus further, and to investigate why the parasite can be grown successfully in the absence of the definitive host. In the original cultivation protocol, excysted M. turgidus metacercariae from grass shrimp (Palaemonetes pugio) were incubated overnight in a conical-bottom centrifuge tube containing Hank's balanced salt solution and then cultivated in flat-bottom culture plate wells containing RPMI-1640 plus 20% horse serum. The gas phase was air. Worms cultured under this protocol consistently deposited eggs infective to snails. Worms grown in anaerobic conditions deposited few eggs, and those cultured in a gas phase of 5% CO(2) survived longer and produced more eggs than those cultured in air. However, snails were less likely to become infected when fed eggs deposited by worms cultured in 5% CO(2). Additionally, worms incubated with conspecifics in conical-bottom tubes prior to cultivation were more likely to be inseminated than worms incubated in flat-bottom culture wells; the highest percentages of inseminated worms occurred when metacercariae were incubated 24 hr in conical-bottom tubes at a density of 50 worms/tube and at a temperature of 37 C. Worms incubated in the absence of conspecifics were not fertilized and failed to produce infective eggs.     

Genetic diversity and structure of Populus nigra populations in two highly fragmented river ecosystems from Turkey

Tree Genetics & Genomes - This study aimed to further clarify the mechanisms of salt-alkali tolerance in Fraxinus velutina Torr. Shoots obtained from Fraxinus velutina Torr (also known as...     

A novel method for constructing an acellular 3D biomatrix from bovine spinal cord for neural tissue engineering applications

In this study, we aimed at generating 3-dimensional (3D) decellularized bovine spinal cord extracellular matrix-based scaffolds (3D-dCBS) for neural tissue engineering applications. Within this scope, bovine spinal cord tissue pieces were homogenized in 0.1 M NaOH and this viscous mixture was molded to attain 3D bioscaffolds. After resultant bioscaffolds were chemically crosslinked, the decellularization process was conducted with detergent, buffer, and enzyme solutions. Nuclear remnants in the native tissue and 3D-dCBS were determined with DNA content analysis and agarose gel electrophoresis. Afterward, 3D-dCBS were biochemically characterized in depth via glycosaminoglycan (GAG) content, hydroxyproline (HYP) assay, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Cellular survival of human adipose-derived mesenchymal stem cells (hAMSCs) on the 3D-dCBS for 3rd, 7th, and 10th days was assessed via MTT assay. Scaffold and cell/scaffold constructs were also evaluated with scanning electron microscopy and histochemical studies. DNA contents for native and 3D-dCBS were respectively found to be 520.76 ± 18.11 and 28.80 ± 0.20 ng/mg dry weight (n = 3), indicating a successful decellularization process. GAG content, HYP assay, and SDS-PAGE results proved that the extracellular matrix was substantially preserved during the decellularization process. In conclusion, it is believed that the novel decellularization method may allow fabricating 3D bioscaffolds with desired geometry from soft nervous system tissues.     

The Principal Genetic Determinants for Nasopharyngeal Carcinoma in China Involve the HLA Class I Antigen Recognition Groove

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy facilitated by Epstein-Barr Virus infection. Here we resolve the major genetic influences for NPC incidence using a genome-wide association study (GWAS), independent cohort replication, and high-resolution molecular HLA class I gene typing including 4,055 study participants from the Guangxi Zhuang Autonomous Region and Guangdong province of southern China. We detect and replicate strong association signals involving SNPs, HLA alleles, and amino acid (aa) variants across the major histocompatibility complex-HLA-A, HLA –B, and HLA -C class I genes (P_{HLA-A-aa-site-62} = 7.4×10⁻²⁹; P _{HLA-B-aa-site-116} = 6.5×10⁻¹⁹; P _{HLA-C-aa-site-156} = 6.8×10⁻⁸ respectively). Over 250 NPC-HLA associated variants within HLA were analyzed in concert to resolve separate and largely independent HLA-A, -B, and -C gene influences. Multivariate logistical regression analysis collapsed significant associations in adjacent genes spanning 500 kb (OR2H1, GABBR1, HLA-F, and HCG9) as proxies for peptide binding motifs carried by HLA- A*11:01. A similar analysis resolved an independent association signal driven by HLA-B*13:01, B*38:02, and B*55:02 alleles together. NPC resistance alleles carrying the strongly associated amino acid variants implicate specific class I peptide recognition motifs in HLA-A and -B peptide binding groove as conferring strong genetic influence on the development of NPC in China.     

Influence of Intraventricular Application of Baclofen on Arterial Blood Pressure and Neurotransmitter Concentrations in the Hypothalamic Paraventricular Nucleus of Rats

The hypothalamic paraventricular nucleus (PVN) is a key site for regulating neuroendocrine functions in the magnocellular part and autonomic activities in the parvocellular part. Its anatomical proximity to the third ventricle could be a good target for intrathecal injection of baclofen. We investigated the correlation of intrathecal application of baclofen (a specific GABAB receptor agonist) and the release of epinephrine, norepinephrine, dopac, homovanillinic acid (HVA), glutamate and aspartate from the PVN. The decomposition products HVA, dopa and dopac of norepinephrine, epinephrine and dopamine, respectively, were used as parameters for the secretion of dopamine. We implanted a microdialysis probe in the PVN of 25 Wistar rats. In 13 rats, 1.5 μg baclofen was injected in the lateral ventricle and the equivalent quantity of Ringer’s lactate solution injected in the remaining 12 rats as a control group. Neurotransmitters and amino acids were quantified by high-performance liquid chromatography. There was a conspicuous but not significant effect of baclofen concerning the secretion of epinephrine, norepinephrine, dopac, glutamate and aspartate from the PVN. A significant increase in HVA concentration was observed only in rats treated with baclofen compared with the control group. These findings suggest that baclofen influences the secretion of neurotransmitters and amino acids involved in autonomic activities mediated by GABAB receptors.     

Influence of nanofibers on growth and gene expression of human tendon derived fibroblast

Background  

Rotator cuff tears are a common and frequent lesion especially in older patients. The mechanisms of tendon repair are not fully understood. Common therapy options for tendon repair include mini-open or arthroscopic surgery. The use of growth factors in experimental studies is mentioned in the literature. Nanofiber scaffolds, which provide several criteria for the healing process, might be a suitable therapy option for operative treatment. The aim of this study was to explore the effects of nanofiber scaffolds on human tendon derived fibroblasts (TDF's), as well as the gene expression and matrix deposition of these fibroblasts.     

Genetic Variants in Nuclear-Encoded Mitochondrial Genes Influence AIDS Progression

Background

The human mitochondrial genome includes only 13 coding genes while nuclear-encoded genes account for 99% of proteins responsible for mitochondrial morphology, redox regulation, and energetics. Mitochondrial pathogenesis occurs in HIV patients and genetically, mitochondrial DNA haplogroups with presumed functional differences have been associated with differential AIDS progression.

Methodology/Principal Findings

Here we explore whether single nucleotide polymorphisms (SNPs) within 904 of the estimated 1,500 genes that specify nuclear-encoded mitochondrial proteins (NEMPs) influence AIDS progression among HIV-1 infected patients. We examined NEMPs for association with the rate of AIDS progression using genotypes generated by an Affymetrix 6.0 genotyping array of 1,455 European American patients from five US AIDS cohorts. Successfully genotyped SNPs gave 50% or better haplotype coverage for 679 of known NEMP genes. With a Bonferroni adjustment for the number of genes and tests examined, multiple SNPs within two NEMP genes showed significant association with AIDS progression: acyl-CoA synthetase medium-chain family member 4 (ACSM4) on chromosome 12 and peroxisomal D3,D2-enoyl-CoA isomerase (PECI) on chromosome 6.

Conclusions

Our previous studies on mitochondrial DNA showed that European haplogroups with presumed functional differences were associated with AIDS progression and HAART mediated adverse events. The modest influences of nuclear-encoded mitochondrial genes found in the current study add support to the idea that mitochondrial function plays a role in AIDS pathogenesis.