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S Wilkins

Publications and source records attributed to S Wilkins.

33 records · Page 2Linked to original sources
PubMed1989

Immunoreactive beta-endorphin and met- and leu-enkephalin contents in pancreas and pituitary of corpulent (cp/cp) rats.

Previous reports have provided suggestive evidence for a role of endogenous opiates in modulating feeding behavior as well as insulin secretion from the pancreas. This evidence includes pharmacologic studies as well as studies of endogenous opioid peptides in tissues of genetically obese rodent models. In the present study, content of three opioid peptide immunoreactivities (beta-endorphin, met-enkephalin and leu-enkephalin) were measured in pituitary and pancreas of two recently described, genetically obese rats, the LA/N-cp and the SHR/N-cp. Although both of these inbred strains carry the same cp allele, the SHR-cp rat is obese and diabetic by 8 weeks of age, while the LA/N-cp is obese but remains euglycemic. There were no significant differences in content of immunoreactive beta-endorphin, met-enkephalin or leu-enkephalin in whole pituitary, posterior or anterior lobes of the pituitary, or pancreas which could be ascribed to the effect of the obese phenotype. These data are in contrast to previously reported studies in which significant alterations in opioid peptide immunoreactivities were found in genetically obese Zucker fa/fa rats, C57BL/6 ob/ob mice and C57BL/Ks db/db mice. The present work provides no support for pathological involvement of opioid peptides in the genetically obese cp/cp rat.

Animals↗
PubMed1988

The late J.A. Bogan.

Explore the source record for details and available documents.

History, 20th Century↗
PubMed1988

Is 5% dextrose in water a proper choice for initial postoperative feeding in infants?

Forty infants undergoing inguinal hernia repair were divided equally into two groups. After adequate recovery from anesthesia, one group was given an initial feeding of 5% dextrose in water while the other received 15% milk formula (5 mL/kg in each case). Samples of gastric content were taken 15, 30, and 60 minutes after feeding and measurements of gastric residual volume, pH, and osmolality were obtained. A statistically significant difference in the pH and osmolality of the gastric samples was present without any difference in the gastric residual volumes or rates of gastric clearance between these two groups. Initial feedings of milk appear to offer no substantial disadvantages when compared with dextrose in water feedings in the prevention of the acid aspiration syndrome.

Gastric Emptying↗
PubMed1987

Occupational asthma and rhinitis related to laboratory rats: serum IgG and IgE antibodies to the rat urinary allergen.

Allergic reactions to rat urinary proteins are an important cause of occupational asthma and rhinitis among laboratory workers. We have measured IgG and IgE antibodies to a purified rat urinary allergen in sera from 179 laboratory workers of whom 30 reported symptoms on exposure to rats. There was a very good correlation between IgE antibodies and positive skin tests. In addition, there was a close correlation between reported asthmatic reactions and serum IgE antibody to rat allergen: IgE ab was present in 12/18 of workers with asthmatic reactions but in only 2/135 of workers without symptoms (p less than 0.001). Serum IgG antibodies to rat allergen were present in all sera with IgE antibody but were also present in 30% of asymptomatic individuals. The incidence and quantity of IgG antibody correlated with the degree of exposure to animals (i.e., hours per day) but not with the length of exposure in years. Our results on rat allergy confirm that there is an increased incidence of asthma among individuals who were atopic as judged by positive skin tests to other allergens. However, this relationship did not apply to individuals with rhinitis alone, and excluding atopic individuals from employment would have been a very inefficient method of reducing asthma or rhinitis in this group. Our results confirm that IgE antibody responses to rat urinary allergen are an important cause of occupational disease. The results for IgG antibody suggest that their prevalence represents a marker for the degree of exposure to rat proteins.

Animals↗
PubMed1986

Altered beta-endorphin, Met- and Leu-enkephalins, and enkephalin-containing peptides in pancreas and pituitary of genetically obese diabetic (db/db) mice during development of diabetic syndrome.

We have recently shown that in addition to beta-endorphin the opioid peptides Met- and Leu-enkephalin and their apparent precursors are localized in islet endocrine cells of the rat pancreas. To begin evaluating a possible role for these pancreatic opiates in the pathophysiology of genetic diabetes in rodents, immunoreactive beta-endorphin and Met- and Leu-enkephalins were measured in acetic acid extracts of pancreas and pituitary of C57BL/KsJ db/db mice and their lean littermates. Groups of animals were studied during three phases of development of the diabetic syndrome in the mutant mice: at 4 (hyperinsulinemic and prediabetic); 6, 9, and 12 (frankly obese and diabetic); and 30 (hypoinsulinemic) wk of age. Elevations or decreases (P less than .05) were found in db/db mice (vs. lean littermates) as follows: pituitary content of Met-enkephalin was twofold higher at all ages studied; pituitary free Leu-enkephalin was lower at 4 wk and reversed to higher at 6-30 wk; pancreatic beta-endorphin was 30% lower at 4 wk and reversed to threefold higher at 6-12 wk; Met- and Leu-enkephalin-containing larger peptides were elevated at one or more points between 6 and 12 wk in both the pancreas and the pituitary. Thus, the onset of overt obesity between 4 and 6 wk of age was accompanied by a marked rise in both pancreatic beta-endorphin and pituitary Leu-enkephalin; similar elevations in these parameters have been reported previously in C57BL/6J ob/ob mice at approximately 12 wk of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1985

Reduction of house dust mite allergen levels in the home: use of the acaricide, pirimiphos methyl.

House dust mite sensitivity is very common in patients with bronchial asthma, yet dust mite avoidance frequently receives little attention in clinical management. It is likely that any reduction in allergen levels associated with routine cleaning is insufficient to allow clinical improvement. In the present study the acaricide pirimiphos methyl is shown to reduce the levels of Dermatophagoides pteronyssinus, antigen P1 in homes. Following a single application the level of antigen P1 in dust from carpets was reduced by up to 73% and by more than 50% in soft furnishings. Serial sampling showed a reduction for 6 weeks under conditions where carpets and chairs treated with solvent showed a progressive rise in allergen level. Furthermore the survival of mites in cultures or infested carpet segments was markedly inhibited, with antigen P1 accumulation reduced by greater than 90%. These results suggest major reductions in house dust mite allergen levels in the home can be achieved.

Allergens↗
PubMed1984

Mitomycin C-induced deoxyribose degradation inhibited by superoxide dismutase. A reaction involving iron, hydroxyl and semiquinone radicals.

Mitomycin C stimulates deoxyribose degradation with the release of thiobarbituric acid-reactive material under conditions of low oxygen concentration. This damage is inhibited by scavengers of the hydroxyl radical, iron chelators and the specific proteins catalase and superoxide dismutase. The reactive radical species appears to arise from a Fenton-type sequence in which iron is reduced by the mitomycin C semiquinone radical.

Animals↗
PubMed1984

Non-protein-bound iron within bacterial cells and the action of bleomycin.

Damage to DNA by bleomycin in vitro is entirely dependent on the presence of an iron salt and molecular oxygen. This same reaction has been used to measure non-protein-bound iron in different bacterial species. Although several of the species examined were insensitive to the toxic effects of bleomycin, they all contained a concentration of non-protein-bound iron which should have been sufficient to allow iron-dependent damage to DNA. Other factors such as permeability or inactivation of the drug must explain their apparent insensitivity.

Bacillus subtilis↗
PubMed1983

Copper salt-dependent hydroxyl radical formation. Damage to proteins acting as antioxidants.

Cupric ions (Cu2+) and ferric ions (Fe3+) added to hydrogen peroxide generate hydroxyl radicals (OH) capable of degrading deoxyribose with the formation of thiobarbituric acid-reactive products. This damage can be inhibited by catalase, OH radical scavengers and specific metal ion chelators. All proteins tested nonspecifically inhibited copper-dependent damage but have little effect on the iron-dependent reaction. Copper ions appear to bind to the proteins which prevents formation of OH radicals in free solution. However, OH radicals are still generated at a site-specific location on the protein molecule. Protein damage is detected as fluorescent changes in amino acid residues.

Albumins↗
PubMed1983

Doxorubicin degradation: changes in activity compared by bacterial growth inhibition and free radical-dependent damage to deoxyribose.

Doxorubicin (DX) under partially anaerobic conditions can degrade deoxyribose with the release of thiobarbituric acid-reactive products. This activity is lost, together with the ability to inhibit bacterial growth, when DX is damaged by exposure to intense white light. Deoxyribose degradation may provide useful information about the anticancer properties of the drug.

Bacteria↗
PubMed1982

The immune response to bee venom. Comparison of the antibody response to phospholipase A2 with the response to inhalant antigens.

The antibody response to phospholipase A2 (PLA2) was studied by using radiolabelled antigen-binding techniques for both IgG and IgE antibodies. The results are compared with results for antigen P1 from Dermatophagoides pteronyssinus and for rye I from rye grass pollen. The response to PLA2 differs from the response to the inhalant allergens in several ways: almost all exposed bee keepers produce IgG antibodies to PLA2; among the allergic bee keepers there was no quantitative correlation between IgG and IgE antibodies; and the antibodies to PLA2 are not produced locally in the nose. Bee keepers with hay fever did not appear to have an increased incidence of allergic reactions to bee venom. In addition, the bee keepers with hay fever and the same levels of IgG and IgE antibodies to rye I as other individuals with hay fever. However, the bee keepers who had no history of hay fever were found to have high levels of IgG antibodies to rye I. These antibodies did not cross-react with PLA2 or bee venom, and the results suggest that bee stings may act as an adjuvant for IgG antibodies to pollen antigens.

Allergens↗