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Biomedical subjects

A M Scott

Publications and source records attributed to A M Scott.

18 recordsLinked to original sources
PubMed1992

Cigarette smoking and nicotine delay postprandial mouth-cecum transit time.

The acute effects of both cigarette smoking and nicotine on postprandial mouth-cecum transit were studied in 20 habitual smokers, 10 males and 10 females. Mouth-cecum transit time was measured by the breath hydrogen technique, following ingestion of a standard mixed liquid meal. Each subject was studied on four separate occasions, either (1) sham or actively smoking two standard cigarettes, commencing 20 min after the meal, or (2) chewing two placebo or nicotine tablets over a 60-min period, commencing immediately after the meal. The time of administration of these stimuli was designed to minimize the effects on mouth-cecum transit time of alterations in gastric emptying. Mouth-cecum transit time was prolonged in response to both smoking [median and interquartile range: 120 (95, 150) min vs 100 (75, 140) min, P = 0.01] and nicotine [120 (80, 170) min vs 100 (70, 140) min, P = 0.002]. No difference was observed between sexes with respect to nicotine; the effect of smoking on mouth-cecum transit time, however, was less pronounced in females compared to males [difference active-placebo: 10 (10, 20) min vs 35 (20, 60) min, P = 0.01]. We conclude that acute cigarette smoking delays mouth-cecum transit time, an effect most likely due to nicotine.

Adult↗
PubMed1992

Suppression of anger and gastric emptying in patients with functional dyspepsia.

Psychologic distress and gastric motor dysfunction have both been implicated in the pathogenesis of functional (non-ulcer) dyspepsia (FD). This study assesses the association between psychologic factors and gastric emptying in 28 FD patients. Subjects completed an extensive range of psychologic questionnaires and underwent dual-isotope scintigraphic assessment of solid and liquid gastric emptying. Attempts to resist, control, suppress, and hold in anger, to adopt a fighting spirit whilst dealing with chronic stressors, and manifest unhappiness were predictors of prolonged gastric emptying. These findings suggest that psychologic factors may be important in the aetiology of gastric stasis and subsequent upper gastrointestinal symptoms in patients with functional dyspepsia.

Adaptation, Psychological↗
PubMed1992

Effects of anabolic-androgenic steroids on the pilosebaceous unit.

Examination of skin biopsy specimens from persons using anabolic-androgenic steroids demonstrates dramatic hypertrophy of the sebaceous glands. High dosages of testosterone and anabolic-androgenic steroids, often self-administered by athletes, increase skin surface lipids, the cutaneous population of Propionibacteria acnes and the cholesterol and free fatty acids of the skin surface lipids. Acne, oily hair and skin, sebaceous cysts, hirsutism, androgenic alopecia, striae atrophicae, seborrheic dermatitis, and secondary infections including furunculosis may occur in persons using these drugs.

Acne Vulgaris↗
PubMed1992

Comparison of technetium-99m-MIBI and thallium-201-chloride uptake in primary thyroid lymphoma.

A case of primary thyroid lymphoma demonstrating uptake of 99mTc-hexakis-2-methoxy isobutyl isonitrile (MIBI) is presented. The 99mTc-MIBI image more clearly delineated the extent of tumor as demonstrated on CT compared to 201Tl-chloride and [99mTc]pertechnetate images. Following two courses of chemotherapy, repeat radionuclide studies and CT scan showed complete resolution of the thyroid tumor. Technetium-99m-MIBI may be useful in the assessment of disease activity and monitoring response to treatment in patients with lymphoma.

Female↗
PubMed1990

Pulmonary toxicity of thioureas in the rat.

Administration of alpha-naphthylthiourea (ANTU) to rats causes damage to pulmonary endothelial cells and possibly mesothelial lining cells that together may account for the massive pleural effusion characteristic of thiourea toxicity. Using 35S-thiourea as a model compound, the extent of binding of 35S to lung proteins correlated well with the extent of edema, suggesting that the extent of binding of thiourea metabolites is a measure of lung toxicity. ANTU and phenylthiourea (PTU) compete for 35S binding to lung slices, suggesting that these toxins may act in a similar way. Binding of 35S in lung slices from resistant rats is much less than in controls, and resistance cannot be explained by differences in either whole body metabolism or redistribution of thiourea in vivo. Lung glutathione levels (in vitro and in vivo) in normal and resistant rats following thiourea administration were essentially the same. However, at doses of thiourea that cause pleural effusion, there was an increase in total lung glutathione.

Animals↗
PubMed1990

Epilation.

An ancient manual technique of epilation still in common usage, and modern electrical epilating devices, are compared. Folliculitis may occasionally be produced by either type of procedure.

Female↗
PubMed1988

Novel alpha haemoglobin haplotypes in horses.

Four minor haplotypes that produce abnormal haemoglobin phenotypes in horses have been characterized. Two of them, AIIb and V, are copy number variants with, respectively, one and three alpha genes instead of the normal complement of two. The AIIa and C haplotypes, on the other hand, each have two alpha genes but, as a result of probable gene conversions, they now encode identical, though haplotype specific, globins. Two out of 60 unrelated and phenotypically normal horses studied had an unusual triplicated rearrangement in the embryonic zeta-gene locus. Each of these variants appears to have been produced by aberrant recombination events.

Animals↗
PubMed1986

Potassium and rubidium permeability and potassium conductance of the beta-cell membrane in mouse islets of Langerhans.

The efflux of 42K+ and 86Rb+ has been studied in collagenase-isolated normal mouse islets of Langerhans. In double-labelled experiments, the ratio of efflux rate constants of Rb+ and K+ (kRb/kK) was 0.80 in 5 mM-K+ and 0 glucose. The ratio was unaffected by glucose concentrations up to 22.2 mM. In the presence of 50 mM-K+, 0 glucose, the ratio increased to 0.91 and in 50 mM-Rb+, 0 glucose and 0 K+, the ratio was 1.06. With these limitations, the results indicate that 86Rb+ is an acceptable isotope for K+. Using the Goldman model, K+ and Rb+ permeability coefficients and K+ slope and chord conductances were computed. The permeabilities decreased in glucose and in high K+ or high Rb+. In the case of high external K+, the K+ conductances increased. Also there may be more than one type of K+ channel with differing selectivities to K+ and Rb+. The addition of glucose in the presence of 50 mM-K+ had no further effect on Rb+ permeability. It is suggested that there are about ten small K+ channels open in the resting beta-cell and that progressive closure of these channels is involved in the depolarization of the cell membrane that initiates spike activity.

Animals↗
PubMed1979

Synthesis of DNA and lecithin in tissue culture and oestrogen receptor activity in rat mammary tumours dependent on and independent of the ovary.

Dimethylbenz(alpha)anthracene (DMBA)-induced and transplanted rat mammary tumours (2 lines) were examined for oestrogen receptor activity, and for sensitivity to hormones in vivo (by ovariectomy) and in vitro (by tissue culture). In vivo, the growth of all tumours induced by the administration of DMBA in random-bred Sprague-Dawley rats was found to be dependent on the ovary, whilst in all transplanted tumours (12 TG-3 and six TG-5 lines), maintained in an inbred strain of Sprague-dawley rats, growth was found to be independent of the ovary. In vitro, the capacity for DNA synthesis in DMBA-induced tumours was better maintained after 24 h when insulin (10 microgram/ml) and corticosterone (5 microgram/ml) or insulin, corticosterone and prolactin (each 5 microgram/ml) were present in the medium (five out of 12 and eight out of 11 tumours respectively); no effect of hormones in the media was detected after 48 h. In the transplanted tumours, no effect of hormones on DNA synthesis was detected after either 24 or 48 h of culture. Synthesis of lecithin was not detectably influenced by the presence of hormones in either DMBA-induced or transplanted tumours. Oestrogen receptor concentrations were, on average, significantly higher in the DMBA-induced tumours than in either line of transplanted tumour. For 22 DMBA-induced tumours and 15 transplanted tumours, the effect of hormones in vitro ('response') was directly correlated with receptor concentration at time 0 (Spearman's rho = +0.59) and inversely correlated with the rate of DNA synthesis ('basal') at time 0 (Spearman's rho = -0.62). No single parameter or pair of parameters permitted accurate distinction between the tumour types.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1978

Haemolytic disease of the newborn foal.

Clinical features of haemolytic disease of the newborn foal (HDNF) are reviewed. The state of knowledge concerning the serological factors associated with isoimmunisation of mares and as assessment of the methods available for screening potential "haemolytic mares" are presented. The treatment of severely affected foals has principally involved exchange transfusion but more recently a simple transfusion of mare's packed erythrocytes has proved more successful.

Animals↗
PubMed1977

Breast screening and surgical problems.

The Edinburgh Breast Screening Clinic in its first year completed the initial screening examination of 3005 invited women, who were apparently in good health, aged between 40 and 60 years; 141 were referred for a surgical opinion; 70 women ultimately underwent biopsy and 9 proved to have carcinoma. The indications for biopsy are described together with methods of management of the various lesions.

Adult↗
PubMed1977

Serum concentrations of lithium after three proprietary preparations of lithium carbonate (Priadel, Phasal and Camcolit).

1 The serum lithium concentration was measured before dosing, and at 2, 4, 6, 8, 10, 20, 22, and 24 h after three proprietary preparations of lithium carbonate (Camcolit, Phasal or Priadel). 2 A total of twenty-eight studies were performed on eleven patients. In seven studies the patients received Camcolit, in ten studies patients received Priadel and in eleven the patients took Phasal. 3 The dose of each preparation was adjusted during a 10 week run-in period to maintain the serum lithium within the normal therapeutic range (0.6-1.2 mmol/1). Five patients received one lithium preparation, one patient received three lithium preparations and five patients received four lithium preparations consecutively. 4 After a single daily dose of Phasal and Priadel, the serum lithium remained within the therapeutic range for 24 h. 5 After a single daily dose of Camcolit, the serum lithium remained within the therapeutic range for only 12 h. 6 After three doses of Camcolit (given at 0.800 h, 12.00 h, and 18.00 h) each day, the serum lithium was maintained in the therapeutic range for 24 h.

Delayed-Action Preparations↗