Effect of carboxyl-reduced heparin on the growth inhibition of bovine pulmonary artery smooth muscle cells

Heparin (HP) inhibits the proliferation of bovine pulmonary artery smooth muscle cells (BPASMC’s), among other cell types in vitro. In order to develop a potential therapeutic agent to reverse vascular remodeling, we are involved in deciphering the relationship between the native HP structure and its antiproliferative potency. We have previously reported the influence of the molecular size and the effects of various O-sulfo and N-acetyl groups of HP on growth-inhibitory activity. In this study, to understand the influence of carboxyl groups in the HP structure required for endogenous activity, a chemically modified derivative of native HP was prepared by converting the carboxyl groups of hexuronic acid residues in HP to primary hydroxyl groups. This modification procedure involves the treatment of HP with N-(3-dimethylaminopropyl)-N-ethylcarbodiimide followed by reduction with NaBH₄ to yield carboxyl-reduced heparin (CR-HP). When compared to the antiproliferative potency of native HP on cultured BPASMC’s at three dose levels (1, 10, and 100 μg/mL), the CR-HP showed significantly less potency at all the doses. These results suggest that hexuronic acid residues in both major and variable sequences in HP are essential for the antiproliferative properties of native HP.     

Species confirmation of fungal isolates by molecular analysis

Traditional taxonomy of hyphomycetes has been based on conidial morphology and development. In order to confirm species level for the detection and identification of the entomopathogenic fungus, we analysed the species-specific fingerprints to investigate molecular characteristics within isolates of six species and to resolve morphologically atypical isolates. The extent of fingerprint profile observed by RAPD was sufficient to confirm the species level of all the isolates. The genetic similarity among morphologically identified isolates of each species was considerably higher, allowing us to conclude that all the isolates are of same species. These results establish a molecular framework for further taxonomic, phylogenetic and comparative biological investigations.     

Reduction of heteroduplex formation in PCR amplification

Heteroduplex formation is known to occur during mixed-template polymerase chain reaction (PCR) using universal primers, and may represent a serious problem in several PCR-based analyses. A common way to eliminate heteroduplex formation is to use reconditioning PCR. Because we detected that reconditioning PCR was not always sufficient to prevent heteroduplex formation, we focused on developing methods for the elimination of heteroduplexes during PCR. We detected that the heteroduplex to homoduplex ratio can be decreased by the addition of Taq polymerase and by a decrease in the number of PCR cycles. An appropriate combination of both of these approaches can be a method generally applicable to decrease the formation of heteroduplexes.     

Detection of microRNAs in dried serum blots

We observed the preservation of microRNAs in unrefrigerated dried serum blots. Preservation was not adversely affected by drying or storing at 37, 45, or 60 °C instead of room temperature, but it was harmed when blots were dried incompletely before storage. Preservation of microRNAs in serum was not diminished if, instead of being kept frozen at −80 °C, it was stored as dried blots at room temperature for 5 months or at 37 °C for 4 weeks. Thus, dried blots can be a convenient and safer way to save, transport, and store serum for microRNA assays.     

Eph and ephrins in epithelial stem cell niches and cancer

The family of Eph tyrosine kinase receptors is an important part of signaling pathways involved in development, tissue homeostasis and tumorigenesis. Binding and activation of the receptors by their ligands, the ephrins, result in bidirectional signaling into both receptor and ligand expressing cells. Adult stem cell niches and tumors frequently express receptors and ligands, although their function is only beginning to be understood. Thus, Eph receptors and ephrins have become important molecules for understanding basic biological processes as well as tumorigenesis, and are promising targets for potential therapeutic intervention in human disease.     

PKC phosphorylates GluA1-Ser831 to enhance AMPA receptor conductance

AMPA receptors mediate fast excitatory synaptic transmission in the brain, and are dynamically regulated by phosphorylation of multiple residues within the C-terminal domain. CaMKII phosphorylates Ser831 within the AMPA receptor GluA1 subunit to increase single channel conductance, and biochemical studies show that PKC can also phosphorylate this residue. In light of the discovery of additional PKC phosphorylation sites within the GluA1 C-terminus, it remains unclear whether PKC phosphorylation of Ser831 increases GluA1 conductance in intact receptors. Here, we report that the purified, catalytic subunit of PKC significantly increases the conductance of wild-type GluA1 AMPA receptors expressed in the presence of stargazin in HEK293T cells. Furthermore, the mutation GluA1-S831A blocks the functional effect of PKC. These findings suggest that GluA1 AMPA receptor conductance can be increased by activated CaMKII or PKC, and that phosphorylation at this site provides a mechanism for channel modulation via a variety of protein signaling cascades.     

Extensive introgressive hybridization within the northern oriole group (Genus Icterus) revealed by three‐species isolation with migration analysis

Until recently, studies of divergence and gene flow among closely‐related taxa were generally limited to pairs of sister taxa. However, organisms frequently exchange genes with other non‐sister taxa. The “northern oriole” group within genus Icterus exemplifies this problem. This group involves the extensively studied hybrid zone between Baltimore oriole (Icterus galbula) and Bullock's oriole (I. bullockii), an alleged hybrid zone between I. bullockii and black‐backed oriole (I. abeillei), and likely mtDNA introgression between I. galbula and I. abeillei. Here, we examine the divergence population genetics of the entire northern oriole group using a multipopulation Isolation‐with‐Migration (IM) model. In accordance with Haldane's rule, nuclear loci introgress extensively beyond the I. galbula–I. bullockii hybrid zone, while mtDNA does not. We found no evidence of introgression between I. bullockii and I. abeillei or between I. galbula and I. abeillei when all three species were analyzed together in a three‐population model. However, traditional pairwise analysis suggested some nuclear introgression from I. abeillei into I. galbula, probably reflecting genetic contributions from I. bullockii unaccounted for in a two‐population model. Thus, only by including all members of this group in the analysis was it possible to rigorously estimate the level of gene flow among these three closely related species.     

Superior Appetite Hormone Profile After Equivalent Weight Loss by Gastric Bypass Compared to Gastric Banding

The goal of this study was to understand the mechanisms of greater weight loss by gastric bypass (GBP) compared to gastric banding (GB) surgery. Obese weight‐ and age‐matched subjects were studied before (T0), after a 12 kg weight loss (T1) by GBP (n = 11) or GB (n = 9), and at 1 year after surgery (T2). peptide YY_3–36 (PYY_3–36), ghrelin, glucagon‐like peptide‐1 (GLP‐1), leptin, and amylin were measured after an oral glucose challenge. At T1, glucose‐stimulated GLP‐1 and PYY levels increased significantly after GBP but not GB. Ghrelin levels did not change significantly after either surgery. In spite of equivalent weight loss, leptin and amylin decreased after GBP, but not after GB. At T2, weight loss was greater after GBP than GB (P = 0.003). GLP‐1, PYY, and amylin levels did not significantly change from T1 to T2; leptin levels continued to decrease after GBP, but not after GB at T2. Surprisingly, ghrelin area under the curve (AUC) increased 1 year after GBP (P = 0.03). These data show that, at equivalent weight loss, favorable GLP‐1 and PYY changes occur after GBP, but not GB, and could explain the difference in weight loss at 1 year. Mechanisms other than weight loss may explain changes of leptin and amylin after GBP.     

High Rates of Obesity and Chronic Disease Among United Methodist Clergy

We used self‐reported data from United Methodist clergy to assess the prevalence of obesity and having ever been told certain chronic disease diagnoses. Of all actively serving United Methodist clergy in North Carolina (NC) 95% (n = 1726) completed self‐report height and weight items and diagnosis questions from the Behavioral Risk Factor Surveillance Survey (BRFSS). We calculated BMI categories and diagnosis prevalence rates for the clergy and compared them to the NC population using BRFSS data. The obesity rate among clergy aged 35–64 years was 39.7%, 10.3% (95% CI = 8.5%, 12.1%) higher than their NC counterparts. Clergy also reported significantly higher rates of having ever been given diagnoses of diabetes, arthritis, high blood pressure, angina, and asthma compared to their NC peers. Health interventions that address obesity and chronic disease among clergy are urgently needed.