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Biomedical subjects

R C Noble

Publications and source records attributed to R C Noble.

At least 127 records · Page 7Linked to original sources
PubMed1980

Ovulation and reproductive hormones following steroid pretreatment, calf removal and GnRH in postpartum suckled beef cows.

Two experiments were conducted to determine the effect of calf removal, steroid pretreatment and treatment with gonadotropin releasing hormone (GnRH) on subsequent reproductive hormone secretion and ovulation. In the first experiment, GnRH was administered to postpartum beef cows at two levels (100 and 250 microgram) and in two carrier vehicles (saline and carboxymethylcellulose [CMC]). Although peak luteinizing hormone (LH) concentrations were similar for all cows, the interval from treatment to peak LH release and the duration of the LH release was prolonged (P < .05) in the cows that were given GnRH in CMC. In the second experiment, 30 postpartum suckled beef cows were assigned to a 2 X 3 factorial experiment, with calf removal (none or short-term) and steroid pretreatment (none, norgestomet implant or Synchro-Mate B) as main effects. Short-term calf removal consisted of a 36-hr nonsuckling period beginning at the time of implant removal. GnRH (250 microgram in CMC) was injected subcutaneously 24 hr after implant and calf removal. An increased GnRH-induced LH release due to short-term calf removal (P < .05) and steroid pretreatment (P < .10) was detected. The interaction was not significant, however, (P < .25). Therefore, the suckling-induced suppression of pituitary LH release to exogenous GnRH can be at least partially eliminated within 24 hr of calf separation of norgestomet implant removal. The GnRH-induced LH release was correlated with pretreatment concentrations of estradiol-17 beta for cows that were not separated from their calves (r = .61; P < .05) but not for cows that were subjected to short-term calf removal (r = .28; P > .10). Ovulation occurred in all cows (100%) that were separated from their calves and given GnRH, whereas only 67% of cows not subjected to calf removal ovulated following GnRH treatment. Although the ovulation responses differed (P < .025) between cows that were and were not separated from their calves, ovulation response was not affected by steroid pretreatment (P > .10).

Animals↗
PubMed1979

Pharyngeal colonisation by Neisseria gonorrhoeae and Neisseria meningitidis in black and white patients attending a venereal disease clinic.

Pharyngeal colonisation by Neisseria gonorrhoeae and Neisseria meningitidis was studies in 2000 patients attending a venereal disease clinic. Of these patients, 64% were white and 36% were black. The incidence of gonococcal infections was highest in the period from June to August. The incidence of genital or rectal infections or both was higher in the black patients. Pharyngeal colonisation by gonococci was present in 1.3% of the patients. There was no significant associations between pharyngeal colonisation and the pharyngeal symptoms, race, sex, or marital state of the patients. Pharyngeal colonisation was more frequent in patients with gonococcal infections at other sites. However, in 40.7% of the patients with pharyngeal colonisation, the pharynx was the only culture-positive site. There was no significant difference in the auxotypes or in the antibiotic susceptibility of the pharyngeal and the rectal-genital isolates except in the susceptibility to spectinomycin. Our findings do not indicate that gonococci isolated from the pharynx differ significantly from gonococci isolated from rectal or genital sites. It was notable that meningococcal colonisation of the pharynx was significantly more frequent in the white patients. This may be a genetically determined phenomenon.

Adult↗
PubMed1979

Meningococcal colonisation misdiagnosed as gonococcal pharyngeal infection.

Three cases of pharyngeal gonorrhoea were misdiagnosed in patients harbouring meningococci which failed to utilise maltose in CTA medium. The microbiological identity of the isolates was established by other means. Although meningococci giving atypical reactions to carbohydrate utilisation tests occur only rarely, the possibility of a misdiagnosis of gonorrhea, and its social and legal repercussions, should be considered.

Adult↗
PubMed1979

Fetal to maternal transfer of palmitic and linoleic acids across the sheep placenta.

Maternal and fetal blood samples were obtained at 2.5, 10 and 20 min after the injection of 3H-palmitic acid and 14C-linoleic acid into the fetal circulation of pregnant ewes. 3H-palmitic acid was easily detected in the maternal circulation within 2.5 min after its injection into the fetus resulting in an appreciable accumulation in the maternal plasma by the 20th min after injection. In contrast the presence of 14C-linoleic acid in the maternal circulation was barely detectable over the 20-min sampling period. The concentrations of total lipid and unesterified fatty acids within the fetal plasma were considerably lower than in the maternal plasma thereby providing an adverse concentration gradient for the passage of fatty acids between fetus and mother. The differential permeability of the placenta to the passage of the 3H-palmitic acid and 14C-linoleic acid is discussed in relation to their passage from fetus to mother in non-ruminant species and the adverse essential fatty acid status known to exist in the developing ruminant fetus.

Animals↗
PubMed1979

Delta 9- and delta 6-desaturase activities of the ovine placenta and their role in the supply of fatty acids to the fetus.

Although the fatty acid compositions of the total lipids of the sheep placenta and fetal plasma were shown to be broadly similar, they differed significantly from the fatty acid composition of the maternal plasma unesterified fatty acids, the plasma lipid component from which the fetus derives almost all of its requirements for pre-formed fatty acids. In particular, the placental and fetal plasma lipids displayed a 3-fold higher oleic acid/stearic acid ratio and contained a significantly higher proportion of arachidonic acid than the maternal unesterified fatty acids. These differences correlated well with the high delta 9- and delta 6-desaturase activities, respectively, shown to be present in sheep placental tissue in vitro. The levels of these enzymes in placental tissue contrasted with the relatively low desaturase activities found to be present in adult and neonatal sheep liver and in the placentas of other, non-ruminant, species. The possible role of such high levels of desaturase activity in the sheep placenta is discussed in relation to the particularly poor essential fatty acid status imposed upon the fetal ruminant.

Animals↗
PubMed1979

The role of maternal triglycerides in the supply of lipids to the ovine fetus.

Maternal and fetal blood samples were obtained for up to 20 min after the injection of an emulsion of 14C-labelled glycerol tripalmitate into the circulation of pregnant ewes. No evidence was obtained for the direct transfer of intact triglycerides across the placenta. Results obtained suggest that there was a very rapid uptake of the triglyceride from the maternal circulation followed by hydrolysis and release of free fatty acids back into the maternal circulation.

Animals↗
PubMed1978

"Protected" polyunsaturated fatty acid in the diet of the ewe and the essential fatty acid status of the neonatal lamb.

A polyunsaturated fatty acid supplement, protected from biohydrogenation in the rumen by a formaldehyde-treated protein coat, was fed to ewes during the last 8 weeks of pregnancy as a possible method of improving the poor essential fatty acid status of the newborn lambs. Significant increases were observed in the concentrations of 18:2 (n-6) in both the cholesteryl ester and phospholipid fractions of the plasma and in the phospholipid fraction of the liver of the lamb at birth. Concomitantly, there were significant increases in 20:4 (n-6) concentrations and reductions in the concentrations of 20:3 (n-9). In addition, the concentration of 18:2 (n-6) in the colostrum of the ewes was increased some eightfold thereby providing a secondary source of this essential fatty acid to the lamb. A marked decrease in erythrocyte fragility was observed in lambs whose ewes had received the "protected" polyunsaturated fatty acid diet. These findings are discussed in relation to the known metabolic roles of essential fatty acids in the animal body, with particular reference to the essential fatty acid status of the lamb at birth.

Animals↗
PubMed1978

Acrylamide gel electrophoresis of proteins of Neisseria gonorrhoeae as an epidemiological tool.

The electrophoresis patterns of gonococcal cell proteins were assessed as an aid to gonococcal epidemiology. Lyophilized gonococci were extracted in heated lauryl sulfate with 2-mercaptoethanol. The solubilized gonococcal cell proteins were subjected to alkaline sodium dodecyl sulfate gel electrophoresis, and the resulting patterns were scanned with a spectrophotometer. The electrophoresis patterns were judged to be alike by superimposition of the gel scans. Gonococci thus compared were also auxotyped and tested for sensitivity to penicillin, ampicillin, tetracycline, and spectinomycin. The electrophoresis patterns were reproducible and not affected by serial subculture of the isolates. Patterns from nongonococcal Neisseria species did not resemble those of gonococci. To test the utility of the electrophoresis patterns, duplicate isolates were made from 12 cultures of Neisseria gonorrhoeae. After randomization and blind coding of the 24 isolates, all were successfully matched by their electrophoresis patterns. Cervical-rectal paired isolates from 45 patients were studied by means of their electrophoresis patterns, auxotypes, and results of antibiotic sensitivity tests. Results indicated that the electrophoresis patterns are useful in characterizing paired isolates of gonococci.

Anti-Bacterial Agents↗
PubMed1978

Dietary influences on fatty acid metabolism in the liver of the neonatal lamb.

A "protected" polyunsaturated fatty acid supplement was fed to ewes during the last 8 weeks of pregnancy. The effect of this dietary supplement on the essential fatty acid composition of the liver phospholipids and associated changes in the liver delta9- and delta6-desaturase activities were investigated and compared with the effects of directly dosing the newborn lambs for 8 days with an unprotected polyunsaturated oil, maize oil. The maternal dietary supplement produced significant changes in the essential fatty acid composition of the neonatal lamb liver phospholipids. Although the liver delta6-desaturase activity in these animals was also significantly higher than in the lambs from control ewes, the delta9-desaturase was unaffected by maternal dietary supplementation. Direct dosing of the newborn lambs with maize oil failed to produce any signficant changes either in the liver phospholipid fatty acid composition or in the delta9- and delta6-desaturase activities. These results are discussed in terms of the dietary control of liver desaturase enzyme systems.

Animals↗
PubMed1978

In vivo changes in the composition of cattle skin surface lipid with time.

The skin surface lipid composition was examined in cattle over a period of 13 days after cleaning the skin at 15 degrees C and 35 degrees C. Little change was observed in the concentrations and fatty acid compositions of all the major sebum fractions other than the unesterified fatty acids. Changes which occurred in the proportions of fatty acids present in the unesterified fatty acid fraction were similar at both environments. At 15 degrees C the total amounts per unit area of unesterified fatty acids on the skin did not alter significantly with time. However, at 35 degrees C there was a significant increase in the total amounts of unesterified fatty acids per unit area and concomitant increases in the amounts of individual fatty acids, in particular linoleic acid.

Animals↗
PubMed1977

Ocular involvement in Yersinia enterocolitica infection presenting as Parinaud's oculoglandular syndrome.

Ocular involvement in Yersinia enterocolitica infection presenting as a Parinaud's oculoglandular syndrome occurred in a 77-year-old woman with diabetes. Yersinia enterocolitica was recovered from cultures of the conjunctiva, cornea, fistula tract, and blood. The patient responded to parenteral and topical administration of gentamicin and a corneal transplant. While hospitalized, she developed peritonsillar inflammation and enlarged, tender lymph nodes in the preauricular, submaxillary, and submandibular areas. The combination of the unilateral granulomatous conjunctivitis and enlarged regional lymph nodes was consistent with the diagnosis of Parinaud's oculoglandular syndrome. Yersinia enterocolitica may be another cause of Parinaud's oculoglandular syndrome.

Aged↗
PubMed1977

Lecithin--cholesterol--acyltransferase activity in the plasma of immature, oestrogenised and laying fowl (Gallus domesticus).

A study was made of the role of the lecithin-cholesterol-acyltransferase (LCAT) enzyme in the changes in the concentrations and fatty acid composition of the plasma cholesteryl esters of the fowl associated with oestrogen treatment and sexual maturity. Although there was a considerable increase in the concentration of free cholesterol in the plasma of oestrogen treated and laying birds, only in the oestrogen treated birds was it associated with an increased rate of cholesterol esterification. In both laying and oestrogen treated birds, changes in the fatty acid composition of the plasma cholesterol esters could be attributed to related changes in the fatty acid specificity of the LCAT enzyme. Evidence is provided to indicate that the cholesterol esters in the plasma of the fowl are synthesised mainly by the plasma LCAT system. The changes in the rates and fatty acid specificity of the LCAT system in the plasma of the fowl associated with sexual maturity or oestrogen treatment are discussed in relation to the extensive alterations shown to occur in the lipoprotein pattern of the plasma.

Acyltransferases↗
PubMed1976

A simple method for the differential measurement of 125I and 3H by liquid-scintillatin spectrometry.

1. A method is described for the differential radioactivity counting of 125I and 3H in a liquid-scintillation spectrometer without a separate gamma counter. 2. The sample was contained in a polyethylene miniature vial placed centrally in a standard 20 ml glass scintillation vial containing a tin-loaded scintillant. 3. A direct measure of the 125I radioactivity at an efficiency of 30% was then obtained by radioactivity counting in the pre-set 3H window of a scintillation spectrometer. No counts for 3H radioactivity were registered at this stage because of the barrier to the passage of the low-energy beta-particles provided by the wall of the polyethylene vial. 4. After mixing the sample and scintillant both 125I and 3H were detected at efficiencies of 73% and 29% respectively. Subtraction of the 125I contribution from the combined radioactivity count rate then gave the net 3H count.

Humans↗