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Biomedical subjects

P Bennett

Publications and source records attributed to P Bennett.

At least 199 records · Page 11Linked to original sources
PubMed1983

Hypothalamic-pituitary-gonadal function in relation to liver function in men with alcoholic cirrhosis.

Serum concentrations of oestrone, oestradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and sex hormone-binding globulin (SHBG) were significantly (P less than 0.01) raised in men with alcoholic liver cirrhosis (no. = 42) compared with age-matched controls (no. = 20). No significant difference was observed when comparing serum testosterone concentrations. Patients were divided into three groups in accordance with the severity of liver cirrhosis, using biochemical and clinical criteria. Patients with the best-preserved liver function (no. = 11) and patients with moderately affected liver function (no. = 18) had significantly (P less than 0.05) raised serum concentrations of testosterone, FSH, and LH when compared with both controls and patients with severely affected liver function (no. = 13). Serum concentrations of testosterone, FSH, and LH in the latter group showed no significant differences from the controls. Serum concentrations of oestrone and oestradiol were significantly (P less than 0.05) increased in all patient groups, and serum oestrone increased with decreasing liver function. No significant differences were observed concerning SHBG concentrations in the three groups of patients. Dexamethasone suppression did not change the concentration of testosterone significantly, but oestrone and oestradiol concentrations decreased significantly (P less than 0.01) in controls and patients. In patients, but not in controls, a significant (P less than 0.01) increase in FSH and LH concentrations was observed after dexamethasone suppression. The mean percentage increase of FSH and LH was higher the greater the severity of liver cirrhosis.

Adult↗
PubMed1982

The prevalence of diabetes mellitus and impaired glucose tolerance in Melanesians and part-Polynesians in rural New Caledonia and Ouvea (Loyalty Islands).

The study of different ethnic groups living in the same physical environment provides the opportunity to examine interaction of genetic and environmental factors in the aetiology of diabetes mellitus. In rural New Caledonia, the prevalence of diabetes was higher in part-Polynesians than in Melanesians: males - 6.6 versus 0.5%; females - 6.3 versus 3.5% respectively. The prevalence of abnormal glucose tolerance (impaired glucose tolerance and diabetes) was 11.5 and 15.7% in part-Polynesian males and females, respectively, and 4.7 and 9.2% in Melanesian males and females. Mean age and degree of obesity in these ethnic groups were sufficiently similar to suggest that these factors played no significant role in the difference in diabetes prevalence. Furthermore, adjustment of relative risk of impaired glucose tolerance and diabetes for age and obesity indicated that the modest differences between groups were not responsible for the observed variation in diabetes prevalence. The differences in prevalence of impaired glucose tolerance and diabetes between Melanesians and part-Polynesians may be genetically determined, although the role of certain environmental factors other than obesity, e.g. differences in physical activity or qualitative aspects of diet, cannot be excluded.

Adult↗
PubMed1982

Plasma testosterone and androstenedione in insulin dependent patients at time of diagnosis and during the first year of insulin treatment.

Ten male patients and 6 female patients with newly diagnosed insulin dependent diabetes mellitus and significant ketosis were studied before and during the first year of insulin treatment. At onset plasma concentrations of testosterone and androstenedione were significantly (P less than 0.02) decreased in female patients when compared to healthy sex- and age-matched controls. Plasma concentrations of testosterone and androstenedione increased significantly (P less than 0.001 and P less than 0.05) in both sexes during insulin therapy. Plasma concentrations of testosterone were not significantly different from controls in both sexes after 4 days of insulin treatment and remained so during the first year of insulin treatment. Plasma concentrations of androstendeione were not significantly different from controls in both sexes after 4 days of insulin treatment, but increased to levels significantly raised in both males (P less than 0.001) and females (P less than 0.05) after 7 days and during the first year of insulin treatment.

Adolescent↗
PubMed1981

Pituitary-testicular function in patients with alcoholic cirrhosis of the liver.

In forty-two patients with alcoholic liver cirrhosis and without recent alcohol ingestion the pituitary-testicular function was studied in an effort to relate the endocrine abnormalities with the degree of liver cell dysfunction, evaluated on a quantitative basis. Compared with values in twenty-one healthy controls, we found significantly elevated serum oestrone, oestradiol, follicle-stimulating hormone, luteinizing hormone and prolactin (P less than 0.01). Serum dehydro-epiandrosterone and dehydroepiandrosterone sulphate were significantly reduced in the cirrhotics (P less than 0.01), whereas serum testosterone was not significantly different from that in the controls. Raised levels of sex-hormone binding globulin were found in 71% (22/31) of the patients (median 8 x 10(-18) mol/l, range 3-17 x 10(-8) mol/l). The incidence of gynaecomastia (38%), cutaneous spiders (67%), testicular atrophy (24%) and reduced axillary hair (71%) was without significant relation to raised levels of sex-hormone binding globulin or progressively reduced liver function. In the presence of clinical or hormonal hypo-gonadism we found evidence of a state of primary hypogonadism together with an inadequate secretion of gonadotropins. The state of hyperoestrogenaemia and the concentration of gonadotropins were significantly correlated to the hepatic synthesis of coagulation factors.

Adult↗
PubMed1981

Molecular nature of a plasmid specifying beta-lactamase production in Haemophilus ducreyi.

We characterized pJB1, the plasmid previously reported to mediate beta-lactamase production in Haemophilus ducreyi. We studied its relationship to pMR0360 and RSF0885, the plasmids responsible for beta-lactamase production in Neisseria gonorrhoeae and Haemophilus parainfluenzae, respectively. Although pJB1 was maintained as a multicopy pool in Escherichia coli, it was not stably maintained in the absence of antibiotic selection. Electron microscope heteroduplex studies showed that it carried 100% of the transposable ampicillin resistance sequence TnA. This sequence was transposed to plasmid pUB307 at a low rate. Heteroduplexes between pMR0360 and pJB1 showed that they contained 3.3 megadaltons of homologous sequences. Two sets of nonhomologous sequences, one a TnA sequence and the other a non-TnA sequence, took the form of insertion loops. For plasmids pMR0360 and RSF0885, previously shown to be highly related, the nonhomologous sequences took the form of a substitution loop. We concluded that all three plasmids shared major portions of their sequences but differed in discrete segments. pJB1 was the first such plasmid to have a physically and functionally intact TnA sequence.

Ampicillin↗
PubMed1981

Monocyte function in Crohn's disease and ulcerative colitis.

Monocyte function as reflected by phagocytosis of Candida albicans and chemotaxis towards zymosan-activated serum has been assessed in Crohn's disease and ulcerative colitis. Phagocytosis and random movement were significantly increased to a similar degree in both diseases when compared with controls (p less than 0.001). There was no significant difference in chemotaxis between the disease and control groups, although there was a trend towards its being increased in ulcerative colitis. There was no correlation between the results obtained and disease activity or medication.

Adult↗
PubMed1981

Short-term parenteral and peroral testosterone administration in men with alcoholic cirrhosis.

Serum concentrations of testosterone were measured in 24 male patients with alcoholic cirrhosis during testosterone administration. The purpose was to compare serum concentrations of testosterone during peroral with those during parenteral testosterone administration in these patients. Patients who were injected intramuscularly with a combination of short- and long-acting testosterone (Triolandren, 348 mg testosterone) had median peak values of serum testosterone of about 40 ng/ml, which fell to basal levels after a fortnight. During testosterone propionate injections (84 mg testosterone) every other day, rather constant serum concentrations with median values of about 30 ng/ml were reached after 4 days. Peroral testosterone administration (800 mg micronized free testosterone) each day also resulted in fairly constant serum concentrations after 4 days, and the median values were about 50 ng/ml. No side effects were observed.

Administration, Oral↗
PubMed1981

Gastric function in Crohn's disease.

Gastric acid secretion before and after stimulation with pentagastrin assessed in 11 patients with Crohn's disease. Age and sex-matched patients with ulcerative colitis and healthy controls were used for comparison. Basal acid output was found to be significantly elevated in patients with Crohn's disease who had had surgery (P less than 0.01). This elevation was related to ileal resection rather than ileal disease. There was no difference in the maximal or peak acid outputs between any of the groups.

Adult↗
PubMed1980

Persistence and spread of a chloramphenicol resistance-mediating plasmid in antigenic types of Escherichia coli, pathogenic for piglets.

All chloramphenicol-resistant Escherichia coli strains isolated from piglets in the State veterinary Serum Laboratory, Copenhagen, in 1974-1975 harbored plasmids of IncFII group with largely the same resistance markers. Two strains from 1978 carried plasmids with similar characters. Restriction enzyme analysis of DNA from these plasmids with restriction endonucleases EcoRI, BglII, and PstI shows that the Cm plasmids are extremely closely related; but the patterns obtained (particularly from PstI digests) enable the classification of the plasmids into groups. These bear a strong relation to time and place of isolation so that plasmids isolated on the same farm belong to the same group even when their host strains are of different antigenic types. It is concluded that these plasmids have evolved from a single plasmid.

Animals↗
PubMed1980

Properties and structural role of the subunits of human spectrin.

The subunits of spectrin from human erythrocytes were separated by ion-exchange chromatography on hydroxyapatite in the presence of urea. When renatured from the urea solution they are found to be monomeric, although the smaller subunit (band 2) is prone to aggregation. In shape, solubility and secondary structure the subunits resemble the native spectrin dimer, indicating that subunit interaction is not essential for maintaining the native conformation. When the subunits are recombined, a dimer with the sedimentation coefficient of the native species is formed. This constitutes direct evidence that native spectrin is a heterodimer, rather than a mixture containing homologous and heterologous species. The interaction of the separated subunits with the chymotryptic fragment of the spectrin-binding protein (protein 2.1, or ankyrin) of the erythrocyte membrane was studied. Only the smaller subunit has the ability to bind, and thus presumably contains the site by which the cytoskeleton is attached to the plasma membrane. On the other hand, the formation of a complex with F-actin and protein 4.1 requires the presence of both subunits. A complex of these proteins with band 2 is formed, however, when traces of an additional, as yet unidentified, protein are present.

Adult↗
PubMed1979

The effect of repeated intramuscular gonadotrophin-releasing hormone injections on luteinizing hormone, follicle-stimulating hormone, testosterone, oestrogens, dehydroepiandrosterone and dehydroepiandrosterone sulfate in normal men.

The endocrine response to three daily intramuscular injections of 500 microgram LH-RH was measured in 9 normal men during a period of 3 days. A marked but declining response in LH was seen in addition to a significant increase in the serum concentration of FSH, testosterone, oestradiol and the urinary excretion of oestrogenic substances. No change could be demonstrated in the DHA, DHAS or cortisol secretion which confirms our previous results of a direct effect of clomiphene on adrenal steroidogenesis.

Adrenal Cortex↗