PubMed Health⌕ Search

Biomedical subjects

C Small

Publications and source records attributed to C Small.

30 records · Page 2Linked to original sources
PubMed1991

The guinea-pig ileum preparation as a model for 5-HT1A receptors: anomalous effects with RS-30199-193.

1. Agents that have high and selective affinity for the 5-HT1A site such as 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) and N,N-dipropyl-5-carboxamidotryptamine (DP5CT) inhibited the responses to field stimulation in guinea-pig ileum preparations; the inhibitory effects were antagonized by methiothepin and spiperone, consistent with effects at the 5-HT1A site. 2. The inhibitory effects of DP5CT were pronounced in Tyrode solution containing low Ca2+ (0.9 mM), but were much less apparent in Tyrode solution containing 1.8 or 5.4 mM Ca2+. 3. Responses to DP5CT were abolished by pretreatment with phorbol dibutyrate (3 microM), whereas the responses to UK14304 were only slightly inhibited. 4. Buspirone and ipsapirone (1 microM) inhibited the responses to field stimulation, and the effects were resistant to idazoxan, but inhibited by 8-OH-DPAT or spiperone. 5. RS-30199-193 (5-chloro-2-methyl-1,2,3,4,8,9,10,10a-octahydronaphth-[1,8-cd]- aze pine hydrochloride) an azepine with high affinity for the 5-HT1A site in rat cerebral cortex in binding experiments, augmented contractions, but did not antagonize the responses to DP5CT or to 8-OH-DPAT. 6. The hybrid compound of RS-30199-193 with buspirone, RS-64459-193 (5-chloro-2-[4-(8-azaspiro[4,5]decane-7,9-dione)-but-1-yl]- 1,2,3,4,8,9,10,10a-octahydronaphth[1,8-cd]-3-azepine hydrochloride) maintained high affinity for the 5-HT1A binding site in rat brain and both inhibited the response to field stimulation and antagonized the responses to 8-OH-DPAT and DP5CT. Thus the buspirone side chain when added to RS-30199-193 appears either to induce affinity for a distinct subset of receptors in the guinea-pig ileum or is required for functional effectiveness at the 5-HTlA receptor.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1990

Trends in cardiovascular risk factors in Auckland, 1982 to 1987.

This paper examines trends in Auckland over a five year period (1982-87) in the major cardiovascular risk factors: serum total cholesterol, blood pressure and cigarette smoking; trends in body mass index are also presented. The data came from two independent random samples of European people aged 40-64 years chosen from the central Auckland electoral rolls in 1982 (915 men and 476 women) and 1986-88 (503 men and 359 women); response rates were over 80% in both surveys. In the five year period self reported smoking declined by 22% in men and 10% in women; the decline was particularly marked in upper socioeconomic men and women aged 55-64 years. There were no consistent changes in either blood pressure or body mass index levels. Serum cholesterol levels, after adjustment for the change in laboratory methods, declined by approximately 1% in both men and women. Cardiovascular risk factor levels remain high in Auckland; comprehensive population based prevention programmes, such as Heartbeat (New Zealand), are urgently required in New Zealand.

Adult↗
PubMed1989

Effect of diet on growth of M. leprae in mouse footpads.

Semipurified diets, with equal amounts of vitamins, minerals and fibre, but varied in protein and fat content from pork, barbel fish or soya beans were tested for their possible effect on the growth of M. leprae in mouse footpads. 105 BALB/c male weanling mice were randomly divided into five diet groups of 21 mice each and fed for six months. Differences between bacterial counts of diet groups were found. The mouse foot pad model is suitable for dietary study in leprosy.

Animals↗
PubMed1988

Nutrition in leprosy: a review.

The literature relating diet to leprosy is abundant between 1900 and 1960, peaking around 1940. Dietary factors that appear to influence the etiopathogenesis of Hansen's disease include: vitamin A, vitamin B group, vitamin C, vitamin D, vitamin E, calcium, and zinc. We noted a frequent lack of detailed dietary data in much of the literature cited. This is particularly true when the thrust of the investigation is not dietary. The literature strongly suggests the beneficial influence of adequate diet on the outcome of Hansen's disease and the deleterious effect of a deficient diet. In contrast with the paucity of reported hard data in the previous reviews concerned with the effect of nutrition and diet on leprosy, is the increasing volume of literature reviews and experimental studies showing the profound impact of nutrition and diet on the immune system of man and laboratory animals. That diet has a global, if poorly understood, effect on the immune system is being increasingly recognized. The difficult question that remains is how to use this information in the control and prevention of disease. Therefore, we believe that more emphasis should be given to diet in the study of this important worldwide disease in light of the current understanding of biochemistry and immunology.

Diet↗
PubMed1987

A specific radiochemical assay for pyrroline-5-carboxylate dehydrogenase.

Previous studies of pyrroline-5-carboxylate dehydrogenase have been conducted using a spectrophotometric method to monitor substrate-dependent NAD(P)H production. For the assay of the mammalian enzyme, the spectrophotometric assay was found to be unacceptable for kinetic studies as the production of NAD(P)H was nonlinear with time and protein concentration. An assay which measures radiolabeled glutamate production by this enzyme in the presence of NAD+ from radiolabeled pyrroline-5-carboxylate has been developed. Separation of substrate from product is achieved by column chromatography using Dowex 50 cation-exchange resin. The product isolated by this procedure was identified as glutamate. This new assay is linear with time and protein concentration and gives reproducible results. The assay is not influenced by competing enzyme activities, such as glutamate dehydrogenase, in a liver homogenate so that quantitative conversion of pyrroline-5-carboxylate to glutamate is observed.

1-Pyrroline-5-Carboxylate Dehydrogenase↗
PubMed1983

Factors influencing pyrroline 5-carboxylate synthesis from glutamate by rat intestinal mucosa mitochondria.

Factors influencing pyrroline 5-carboxylate (P5C) synthesis from glutamate by a subcellular fraction enriched in mitochondria of rat small intestinal mucosa have been studied. P5C synthesis decreased rapidly if this subcellular fraction was preincubated at 20 degrees C in the absence of substrates; this effect suggests that the enzyme(s) catalyzing P5C synthesis from glutamate (P5C synthase) is unstable in the absence of substrates. In the presence of substrates P5C synthesis increased linearly for the first 30 min of incubation, suggesting that the substrates promote enzyme stability. Pyridoxal 5'-phosphate is an effective inhibitor of P5C synthase whereas pyridoxamine 5'-phosphate and pyridoxal are not inhibitory. Potassium phosphate, KCl, and KBr each inhibited P5C synthase but potassium-Hepes (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) did not. Potassium phosphate was the most potent inhibitor followed by KBr, and then KCl. These results suggest P5C synthase is sensitive to anion inhibition. Both L-ornithine and D-ornithine inhibited P5C synthase; L-proline did not inhibit. Several analogs of ornithine and proline were also tested and none was found to inhibit P5C synthase; the inhibition by ornithine is, therefore, rather specific and it may prove to contribute to the regulation of metabolism of these amino acids.

Animals↗
PubMed1975

Sutures and bladder wound healing in the experimental animal.

An incision was made in the bladder of each of 81 female rats, then closed with various types and sizes of sutures and by different methods in order to determine the optimum suture and method to facilitate watertight closure and wound healing. Chromic catgut, collagen, and polyglycolic acid sutures, of different sizes, were used. Pressure studies and microscopic examinations of the wound were done at different intervals. All sutures lasted long enough to allow healing of the wound and none broke during pressure studies. A two-layer continuous closure with fine suture was the most watertight. Tissue reaction was almost absent when polyglycolic acid suture was used and was minimal with fine chromic catgut.

Absorption↗
PubMedDate not supplied

Stability of Revex, nalmefene hydrochloride injection.

The stability of Revex, nalmefene hydrochloride injection, has been studied at several temperatures for periods up to 36 months. The data were obtained using a HPLC method for the potency determination, and for the level of the sole degradation product (2,2'-bisnalmefene). These methods were found to be characterized by excellent precision, linearity, and accuracy over the analyte concentration ranges established. The stability data were found to be interpretable using first-order kinetics, and essentially comparable rate constants were calculated for both the potency loss and the formation of 2,2'-bisnalmefene. Applying the Arrhenius equation to these data, a rate constant of 0.00441 month-1 was deduced for the reactions taking place at 25 degrees C. This low value is consistent with the excellent stability exhibited by the product, and amply justifies its shelf life.

Chromatography, High Pressure Liquid↗