Insulin stimulates somatostatin and inhibits glucagon secretion from the perfused chicken pancreas-duodenum.

The isolated perfused chicken pancreas-duodenum was used to study the secretion of somatostatin and glucagon. With perfusate glucose at 50 mg/dl, bovine insulin was infused at a concentration of 20, 000 μU/ml, resulting in a rapid increase of somatostatin secretion, with peak concentrations seen at 5 minutes. This was accompanied by suppression of glucagon secretion. These data suggest that there may be a paracrine negative feedback loop between B and D cells.     

Carbohydrates as recognition molecules in infection and immunity

Consideration of host-parasite interactions encompasses a wide range of phenomena from adhesion to epithelial surfaces to interactions with cells of the immune system. This review focuses on the role of carbohydrates as recognition molecules in these complex interactions. The abundant glycoproteins and glycolipids of cell surfaces of both prokaryotic and eukaryotic cells have the ability to exist in a variety of spatial configurations through alpha- and beta-linkages and the formation of branched structures. This ability carries with it the opportunity of acting as informational molecules greater than that possible for proteins or nucleic acids. The blood group substances are probably the best characterized of these carbohydrate containing molecules. Whilst at present a detailed understanding of the importance of these molecules in host-parasite interaction is lacking, the material covered in this discussion emphasizes the way in which carbohydrate based recognition has been shown to be involved and may provide the basis for further understanding.     

Percutaneous Vaccination as an Effective Method of Delivery of MVA and MVA-Vectored Vaccines

The robustness of immune responses to an antigen could be dictated by the route of vaccine inoculation. Traditional smallpox vaccines, essentially vaccinia virus strains, that were used in the eradication of smallpox were administered by percutaneous inoculation (skin scarification). The modified vaccinia virus Ankara is licensed as a smallpox vaccine in Europe and Canada and currently undergoing clinical development in the United States. MVA is also being investigated as a vector for the delivery of heterologous genes for prophylactic or therapeutic immunization. Since MVA is replication-deficient, MVA and MVA-vectored vaccines are often inoculated through the intramuscular, intradermal or subcutaneous routes. Vaccine inoculation via the intramuscular, intradermal or subcutaneous routes requires the use of injection needles, and an estimated 10 to 20% of the population of the United States has needle phobia. Following an observation in our laboratory that a replication-deficient recombinant vaccinia virus derived from the New York City Board of Health strain elicited protective immune responses in a mouse model upon inoculation by tail scarification, we investigated whether MVA and MVA recombinants can elicit protective responses following percutaneous administration in mouse models. Our data suggest that MVA administered by percutaneous inoculation, elicited vaccinia-specific antibody responses, and protected mice from lethal vaccinia virus challenge, at levels comparable to or better than subcutaneous or intramuscular inoculation. High titers of specific neutralizing antibodies were elicited in mice inoculated with a recombinant MVA expressing the herpes simplex type 2 glycoprotein D after scarification. Similarly, a recombinant MVA expressing the hemagglutinin of attenuated influenza virus rgA/Viet Nam/1203/2004 (H5N1) elicited protective immune responses when administered at low doses by scarification. Taken together, our data suggest that MVA and MVA-vectored vaccines inoculated by scarification can elicit protective immune responses that are comparable to subcutaneous vaccination, and may allow for antigen sparing when vaccine supply is limited.     

Non-secretion of ABO blood group antigens: a host factor predisposing to recurrent urinary tract infections and renal scarring

Abstract In a study of 718 women referred for specialist investigation for recurrent urinary tract infections, 250 (34.8%, P <0.01) were non-secretors. The proportion of non-secretors among the women with renal scars (42.6%) was higher than that found for women with no evidence of renal scars (36.6%). Among 29 patients in whom symptoms began in childhood or adolescence, 51.7% were non-secretors. The proportion of non-secretors among individuals with renal scars in this study (42.6%) and that reported in the accompanying paper for Swedish children (40%) suggests that non-secretion might influence the pathogenic sequelae of these infections. Possible host-parasite interactions underlaying the increased proportion of non-secretors among women with recurrent urinary tract infections and those leading to development of renal scars are discussed.     

Prostaglandin synthesis does not mediate the pulmonary vasodilatory effect of acetylcholine

We wondered if inhibition of hypoxic pulmonary vasoconstriction by acetylcholine was mediated by prostaglandin synthesis. In 5 calves at a simulated altitude of 4,570 m, acetylcholine (10 μg/kg/min) decreased mean pulmonary arterial pressure and total pulmonary resistance by 24 ± 2 and 35 ± 3% before and by 21 ± 2 and 27 ± 4% after the administration of meclofenamate (2 mg/kg). Since there was no difference in the effect of acetylcholine before and after meclofenamate, it was concluded that pulmonary vasodilation by activation of muscarinic receptors was not dependant on prostaglandin synthesis.