Inhibition by salbutamol of GHRH-induced GH release in type 1 diabetes mellitus.

Patients with type 1 diabetes mellitus (IDDM) show augmented GH secretion, which is implicated in the pathogenesis of microvascular complications. On the other hand, it is well known that beta-adrenergic receptors have inhibitory influence on GH secretion, likely via stimulation of hypothalamic somatostatin. Since the possibility of pharmacological suppression of GH secretion would be of value in IDDM, we investigated the effect of salbutamol (SAL, 4 mg orally at -60 min) on the GH response to GHRH (1 micrograms/kg iv at 0 min) in 6 well-controlled (mean HbA1c +/- SEM: 7.3 +/- 0.5%) patients with IDDM. Salbutamol was able to inhibit basal GH levels (p < 0.05) as well as to abolish the GHRH-induced GH rise. After SAL administration, a significant (p < 0.05) reduction of glucagon levels was also found. Our data show that the enhancement of beta 2 adrenergic activity by oral therapeutical doses of SAL inhibits basal and GHRH-stimulated GH secretion in patients with IDDM.     

Antibodies to influenza A virus in wild birds across Mongolia, 2006-2009

Wild waterbirds sampled July 2006-September 2009 in Mongolia were tested for antibodies to avian influenza (AI) virus with the use of a commercially available blocking enzyme-linked immunosorbent assay. Antibodies were detected in 25% (572/2,282) of tested birds representing 26 species, and all antibody-positive samples were from 12 species in the orders Anseriformes and Charadriiformes. The highest antibody prevalence was in Ruddy Shelducks (Tadorna ferruginea; 61.7%; n=261; 95% confidence interval [CI] 55.8-67.6%), Whooper Swans (Cygnus cygnus; 38.4%; n=242; 95% CI 32.3-44.5%), Swan Geese (Anser cygnoides; 15%; n=127; 95% CI 8.6-21.4%), Bar-headed Geese (Anser indicus; 13%; n=738; 95% CI 10.3-15.1%), and Mongolian Gulls (Larus mongolicus; 3.9%; n=255; 95% CI 1.3-6.5%). There was no significant temporal or spatial variation in the presence of antibodies in the sampled species. However, Bar-headed Geese and Mongolian Gulls showed spatial variation in antibody prevalence in 2007 and 2008, respectively. Our study provides insights into the hatch year waterbirds' exposure to AI virus at their natal and molting sites in Mongolia.     

The impact of mating and sugar feeding on blood-feeding physiology and behavior in the arbovirus vector mosquito Aedes aegypti

BackgroundAedes aegypti mosquitoes are globally distributed vectors of viruses that impact the health of hundreds of millions of people annually. Mating and blood feeding represent fundamental aspects of mosquito life history that carry important implications for vectorial capacity and for control strategies. Females transmit pathogens to vertebrate hosts and obtain essential nutrients for eggs during blood feeding. Further, because host-seeking Ae. aegypti females mate with males swarming near hosts, biological crosstalk between these behaviors could be important. Although mating influences nutritional intake in other insects, prior studies examining mating effects on mosquito blood feeding have yielded conflicting results.Methodology/Principal findingsTo resolve these discrepancies, we examined blood-feeding physiology and behavior in virgin and mated females and in virgins injected with male accessory gland extracts (MAG), which induce post-mating changes in female behavior. We controlled adult nutritional status prior to blood feeding by using water- and sugar-fed controls. Our data show that neither mating nor injection with MAG affect Ae. aegypti blood intake, digestion, or feeding avidity for an initial blood meal. However, sugar feeding, a common supplement in laboratory settings but relatively rare in nature, significantly affected all aspects of feeding and may have contributed to conflicting results among previous studies. Further, mating, MAG injection, and sugar intake induced declines in subsequent feedings after an initial blood meal, correlating with egg production and laying. Taking our evaluation to the field, virgin and mated mosquitoes collected in Colombia were equally likely to contain blood at the time of collection.Conclusions/SignificanceMating, MAG, and sugar feeding impact a mosquito’s estimated ability to transmit pathogens through both direct and indirect effects on multiple aspects of mosquito biology. Our results highlight the need to consider natural mosquito ecology, including diet, when assessing their physiology and behavior in the laboratory.     

Detection of resistance genes and susceptibility patterns in Bacteroides and Parabacteroides strains

Susceptibility to five antimicrobials was determined for Bacteroides spp. (n = 52) and Parabacteroides distasonis (n = 8). All isolates were susceptible to metronidazole. The resistance rates to ampicillin, cefoxitin, tetracycline and clindamycin were 98%, 9.6%, 65.3% and 19.2% of the Bacteroides strains, respectively. The genes cepA, cfiA, cfxA, tetQ, ermF and nim were found in 69.2%, 17.3% 9.6%, 50%, 7.7% and 3.8% for these strains respectively. All P. distasonis strains were resistant to ampicilin. Cefoxitin, tetracycline and clindamycin resistance rates were 75%, 87.5% and 50%, respectively. The ermF and nim genes were absent and 37.5%, 12.5%, 12.5% and 87.5% of this strains possessed cepA, cfiA, cfxA and tetQ genes, respectively. Ten cfiA gene positive strains of Bacteroides and Parabacteroides were submitted to E-test with imipenem and amoxicillin–clavulanate. The resistance rate to imipenem was 4.1% and 8.3% to amoxicillin–clavulanate. This feature is for the first time described in Brazil.     

Differential rates of evolution for the ZFY-related zinc finger genes,Zfy, Zfx,and Zfa in the mouse genus Mus

A comparative study of the last exon of the zinc finger genes Zfx, Zfy, and Zfa from species of mice in the genus Mus was conducted to assess the extent of gene-specific and chromosome-specific effects on the evolutionary patterns among related X-, Y-, and autosomal-linked genes. Phylogenetic analyses of 29 sequences from Zfx, Zfa, and Zfy from 10 taxa were performed to infer relatedness among the zinc finger loci, and codon-based maximum likelihood analyses were conducted to assess evolutionary pattern among genes. Five models of nucleotide sequence evolution were applied and compared using a likelihood ratio test. Estimates of nonsynonymous to synonymous changes (dN/dS) for these genes suggest that amino acid substitutions are occurring at a more rapid rate across the autosomal- and Y-specific lineages compared to the X-specific lineage, with the Y-specific lineage showing the highest rate under certain models. The data suggest the action of gene-specific effects on evolutionary pattern. In particular, Zfa and Zfy genes, both with presumed restricted expression, appear less functionally constrained relative to ubiquitously expressed Zfx. Slightly elevated dN/dS for Zfy genes in comparison to Zfa also suggest Y-specific effects.     

Curly bare (cub), a new mouse mutation on chromosome 11 causing skin and hair abnormalities,and a modifier gene (mcub) on chromosome 5

In the outcrossing of a new recessive mouse mutation causing hair loss, a new wavy-coated phenotype appeared. The two distinct phenotypes were shown to be alternative manifestations of the same gene mutation and attributable to a single modifier locus. The new mutation, curly bare (cub), was mapped to distal Chr 11 and the modifier (mcub) was mapped to Chr 5. When homozygous for the recessive mcub allele, cub/cub mice appear hairless. A single copy of the dominant Mcub allele confers a full, curly coat in cub/cub mice. Reciprocal transfer of full-thickness skin grafts between mutant and control animals showed that the skin phenotype was tissue autonomous. The hairless cub/cub mcub/mcub mice show normal contact sensitivity responses to oxazolone. The similarity of the wavy coat phenotype to those of Tgfa and Egfr mutations and the map positions of cub and mcub suggest candidate genes that interact in the EGF receptor signal transduction pathway.