In chickens, colibacillosis is caused by avian pathogenic Escherichia coli (APEC) via respiratory tract infection. Many virulence factors, including type 1 (F1A) and P (F11) fimbriae, curli, aerobactin, K1 capsule, and temperature-sensitive hemagglutinin (Tsh) and plasmid DNA regions have been associated with APEC. A strong correlation between serum resistance and virulence has been demonstrate...

Intra-abdominal infections (IAI) continue to be a serious clinical problem. Bacterial synergism is an important factor that influences the shift from contamination to IAI, leading to the development of lesions and abscess formation. Escherichia coli and Bacteroides fragilis are particularly abundant in IAI. The underlying molecular mechanisms of this pathogenic synergy are still unclear. The ro...

The presence of antimicrobial resistance and virulence factors of 174 Escherichia coli strains isolated from healthy Portuguese Gallus gallus was evaluated. Resistance profiles were determined against 33 antimicrobials by microbroth dilution. Resistance was prevalent for tetracycline (70%) and ampicillin (63%). Extended-spectrum beta-lactamase (ESBL) phenotype was observed in 18% of the isolate...

The present study reports on layer chickens with colibacillosis in 2 commercial egg-producing farms (referred to as farm A and farm B, which were managed by the same owner and were about 1 km apart) in the middle region of the Korean peninsula. The 2 flocks were infected at the initiation of egg laying. They were characterized by no previous clinical signs but sudden mortality (2.7-4.0%), with ...

Highly purified bovine TSH (thyroid-stimulating hormone) was labelled with 125I by using very low concentrations of chloramine-T. Human thyroid membranes prepared by discontinuous sucrose-density-gradient centrifugation were homogeneous on examination by electron microscopy. Incubation of radioiodinated TSH with the membranes showed that radioactivity could be bound to the membranes. Under the ...

The temperature-sensitive swoH1 mutant of Aspergillus nidulans was previously identified in a screen for mutants with defects in polar growth. In the present work, we found that the swoH1 mutant swelled, lysed, and did not produce conidia during extended incubation at the restrictive temperature. When shifted from the permissive to the restrictive temperature, swoH1 showed the temperature-sensi...

In two patients with congenital isolated thyrotropin (TSH) deficiency, serum TSH determined by a sensitive immunoradiometric assay (IRMA) was consistently undetectable. The basal levels of serum free TSH-alpha subunit (TSH-alpha) determined by a specific radioimmunoassay (RIA) were elevated in the hypothyroid state, and decreased to the undectable level during displacement therapy with thyroid ...

Radioimmunoassay of thyrotropin (TSH) is well-established, and highly sensitive radioimmunometric assay is often used clinically (1). Some recent results indicate that TSH immunoreactivity and bioactivity are not always synonymous (2). The detection limit of present bioassays for bovine TSH is about 0.5-1 milli-int. unit/L (3-6). More-sensitive bioassay is necessary for evaluating human TSH. Th...

In seasonal animals, photoperiod exerts profound effects on physiology, such as growth, energy balance and reproduction, via changes in the neuroendocrine axes. A key element of the photoperiodic response is the thyroid hormone level in the hypothalamus, which is controlled via retrograde transport of thyroid-stimulating hormone (TSH) from the pars tuberalis of the pituitary. TSH regulates type...

Mutant V.24.1, a member of the End4 complementation group of temperature-sensitive CHO cells, is defective in secretion at the restrictive temperature (Wang, R.-H., P. A. Colbaugh, C.-Y. Kao, E. A. Rutledge, and R. K. Draper. 1990. J. Biol. Chem. 265:20179-20187; Presley, J. F., R. K. Draper, and D. T. Brown. 1991. J. Virol. 65:1332-1339). We have further investigated the secretory lesion and r...