PubMed HealthSearch

Biomedical subjects

P H Anderson

Publications and source records attributed to P H Anderson.

17 recordsLinked to original sources

In vitro inactivation of aminoglycosides by sulbactam, other beta-lactams, and sulbactam-beta-lactam combinations.

At clinically achievable levels (e.g., 25 micrograms/ml), sulbactam exerted no effect on aminoglycoside concentrations when incubated together in pooled serum at 37 degrees C for up to 24 h. Sulbactam alone and in combination with ampicillin or cefoperazone inactivated tobramycin, gentamicin, netilmicin, and amikacin in vitro when the sulbactam concentration was 200 to 225 micrograms/ml. At 75 micrograms/ml, sulbactam inactivated only tobramycin. Inactivation of tobramycin by high concentrations of sulbactam occurred even at -20 degrees C, but not at -70 degrees C, and was influenced by the serum matrix.

Amikacin

Community cholesterol screening: medical follow-up in subjects identified with high plasma cholesterol levels.

Population screening or plasma cholesterol is an effective method of detecting hypercholesterolemia; however, follow-up and treatment are essential components of such a program. After a city-wide screening in 1987 of more than 19,872 persons, using a mailed survey with a response rate of 48%, we evaluated subsequent actions of 3,078 individuals with high plasma cholesterol levels. Slightly more than half the population was aware of high blood cholesterol levels prior to the time of screening and apparently used the program for follow-up. Overall, after the screening, 65% consulted a physician within 5 months of screening and blood cholesterol levels were remeasured in 80% of the sample. Procrastination and expense were cited as the primary reasons for failing to consult a physician. If screening is to be effectively utilized as a means of reducing the prevalence of high plasma cholesterol levels, diligent follow-up must be made of all individuals identified to be at increased risk on the basis of their initial values.

Adult

Identification of factor XI deficiency in Holstein-Friesian cattle in Britain.

Blood coagulation tests were performed on dairy cattle in a herd with haemorrhagic problems on a farm in Gloucestershire. The characteristic pattern of prolonged partial thromboplastin time with normal prothrombin time and thrombin time was shown to be associated with a partial factor XI deficiency, a congenital defect previously identified in cattle in North America.

Animals

The biological selenium status of livestock in Britain as indicated by sheep erythrocyte glutathione peroxidase activity.

The reliability of erythrocyte glutathione peroxidase activity as an indicator of selenium status in livestock is discussed. Based on this measurement, a survey is described of the biological selenium status of sheep on each of 329 farms in Britain. Results showed that 47 per cent of these farms were probably unable to provide grazing livestock with sufficient selenium to maintain blood levels greater than 0.075 microgram per ml. Increased selenium deficiency from the increasing use of home grown feeds as a major constituent of livestock rations may be causally related to the increase of white muscle disease and other selenium responsive diseases in Britain.

Animals

Biochemical indicators of liver injury in calves with experimental fascioliasis.

Twenty calves were infected with 1000 metacercariae of Fasciola hepatica, the activities of 10 enzymes in plasma or serum were assayed and concentrations in serum of proteins, urea and bilirubin were determined. These values were compared with control data obtained from 14 uninfected calves. Aspartate aminotransferase, lactate dehydrogenase, sorbitol dehydrogenase, glutamate dehydrogenase, ornithine carbamoyl transferase and gamma-glutamyl transpeptidase activities increased in infected calves. Total serum protein increased, albumin decreased, globulin increased and the albumin/globulin ratio was decreased in infected calves. Plasma alanine aminotransferase, leucine aminopeptidase, alkaline phosphatase and cholinesterase activities and serum concentration of urea and bilirubin were unaffected. It was concluded that glutamate dehydrogenase and gamma-glutamyl transpeptidase were the most sensitive indicators of liver cell damage in fascioliasis.

Animals

Some observations on "paralytic myoglobinuria" of cattle in Britain.

Characteristics of 44 outbreaks of "paralytic myoglobinuria" in yearling cattle reported to veterinary investigation centres during 1974 and 1975 are described. The clinical syndrome and associated nutrition and management of cattle are discussed in the light of present knowledge of this disease with particular reference to the diagnostic and epidemiological value of plasma creatine phosphokinase and blood glutathione peroxidase activities.

Animals

Radioimmunoassay of plasma testosterone, with use of polyethylene glycol to separate antibody-bound and free hormone.

We have developed a reliable radioimmunoassay for testosterone in plasma, polyethylene glycol ("Carbowax 6000") being used to separate antibody-bound and free hormone. Testosteron is separated from interfering steroids, notably dihydrotestosterone, by liquid-liquid partition chromatography on infusorial earth (Celite). The assay is sensitive (9 pg for standards), precise, and accurate. The lowest measurable concentration fo testosterone is 350 ng/liter for plasma from men and 70 ng/liter for plasma from women. Intra- and inter-assay coefficients of variation were 6.9% and 9.7%, respectively, for plasma from men, and 9.6% and 11.8%, respectively, for plasma from women. Our method for separating antibody-bound and free hormone is practical and convenient and may be generally applicable to all radioimmunoassays of steroid hormones in plasma.

Antibodies

Mechanism for the interaction between triazolam and cimetidine.

Four normal volunteers each received three intraduodenal infusions of 0.5 mg triazolam solutions. Three treatments were: a pH 2.3 solution in which 47 per cent of the dose had hydrolysed to form a triazolo-benzophenone (TB); a pH 6.0 solution containing negligible TB; the pH 6.0 solution administered during cimetidine treatment (1200 mg day-1). TB was stable in serum and only very low TB serum concentrations were observed from the pH 2.3 treatment. No difference was observed in any triazolam pharmacokinetic parameter between the pH 6.0 and the pH 2.3 treatments. Cimetidine increased the triazolam AUC infinity and Cmax by 54 and 35 per cent, respectively. These results indicate that TB undergoes extensive presystemic conversion to triazolam and the triazolam-cimetidine interaction occurs primarily through a reduction in triazolam clearance.

Adult