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Biomedical subjects

D Scott

Publications and source records attributed to D Scott.

At least 379 records · Page 21Linked to original sources
PubMed1980

Stomal ulcers after gastric bypass.

Introduction of gastric bypass as treatment for morbid obesity in 1966 caused over its ulcerogenic potential as an antral exclusion procedure. However, in only 20 of our 653 patients has marginal ulceration developed. Predominant symptoms were epigastric pain, occult gastrointestinal bleeding, and vomiting. Barium contrast roentgenography was as diagnostically accurate as endoscopy in these lesions. Objective measurement ensuring creation of a gastric reservoir of 50 mL maximum size reduced the incidence of marginal ulcer from 3.8% to 0.98%. Upper pouch size determined the mode of therapy. Nonoperative therapy was successful in patients with small pouches, but did not relieve symptoms of patients with large reservoirs. Truncal vagotomy and resection of redundant upper pouch was the preferred operative approach in these patients.

Adult↗
PubMed1980

Unusual presentations of pleural sarcoidosis.

Three patients with unusual patterns of pleural involvement by sarcoidosis are described. Two patients presented with massive recurrent pleural effusions and the third had extensive bilateral pleural thickening. Because of the uncommon presentations, the possibility of sarcoidosis in these patients was initially overlooked. The diagnoses were made only after extensive investigations including multiple biopsies.

Adult↗
PubMed1980

Malignant myelomonocytic cells after in vitro infection of marrow cells with Friend leukaemia virus.

Infection of long-term BDF1 marrow cultures with Friend leukaemia virus complex (FLV) induced transformed cells with myelomonocytic characteristics, which were isolated only 14 days after the viral infection. Criteria for transformation were growth in suspension cultures and high plating efficiency in agar. The lymphatic leukaemia virus (LLV) replicates in these suspension cultures, but the spleen focus-forming virus (SFFV) component of the FLV complex has not been detected. Injection of the transformed cells into syngeneic neonatal or adult mice leads to the development of leukaemia which can be demonstrated to be of donor origin by the presence of two metacentric marker chromosomes which are also seen in the cultured cells.

Agar↗
PubMed1980

The relationship between cell killing, chromosome aberrations, spindle defects and mitotic delay in mouse lymphoma cells of differential sensitivity to X-rays.

The ultrasensitivity of a subline of L5178Y mouse lymphoma cells to X-rays was thought to result from chromosome structural aberrations which are much more frequent in these cells than in radiation-resistant cells derived from them (Scott, Fox and Fox 1974). However, Ehmann, Nagasawa, Peterson and Lett (1974) in time-lapse photography studies of the sensitive line, concluded that the induction of multipolar mitoses by X-rays might be a more important mechanism of cell killing than chromosome aberrations. We have now shown that at survival levels above about 20 per cent, chromosome structural aberrations which lead to bridges and fragments at anaphase are about four times more frequent than spindle defects. We have confirmed the higher frequency of structural aberrations and spindle defects, and the greater mitotic delay in the X-ray-sensitive than in the X-ray-resistant cell line and have proposed a model which causally relates these end-points to cell killing and DNA repair.

Anaphase↗
PubMed1980

Evaluation of citrate flushing solution using the isolated perfused rat kidney.

The isolated rat kidney perfused at 37 C with dialyzed bovine serum albumin (6.5 g/100 ml) in Krebs-Henseleit buffer was used to examine why a hypertonic citrate flush permits rapid recovery of renal function after storage. The composition of the original hyperosmolar citrate solution was varied so that the roles of osmolality, magnesium, and citrate could be evaluated. All kidneys were flushed with the test solutions and stored for 24 hr in the test solutions at 0 C. The citrate flushing solution requires both the citrate anion and magnesium for efficacy. Hyperosmolality does not enhance its action, an isosmolar solution is more effective. Citrate can be replaced by a nonmetabolizable analogue, tricarballylate, if the solution is suitably buffered. The mechanism of action of citrate is still uncertain, it does not seem primarily to act as a metabolic fuel or inhibitor.

Animals↗
PubMed1980

The erythrocyte sodium and potassium in patients treated with digoxin.

1 Four healthy persons and ten patients with heart failure were studied for 5 to 20 days after they started taking digoxin. The sodium content of their erythrocytes increased and there was an equimolar decrease in potassium content. 2 The increase in erythrocyte sodium for a given increase in plasma digoxin during this acute digitalization was less on average and varied more in the patients than in the healthy persons, that is the patients' erythrocytes were less responsive to digoxin. 3 The average erythrocyte sodium was greater in 183 patients who had been taking digoxin for at least 2 months than in 100 healthy persons not taking digoxin but there was no significant correlation between the plasma digoxin concentrations and erythrocyte sodium concentration in the patients. Indeed, there was no apparent change in the erythrocyte sodium in many of the patients taking digoxin. 4 If the erythrocyte sodium concentration is a reliable guide to the tissue effects of digoxin then the results suggest that there is a wide variation in the response to digoxin between patients both during acute digitalization and during chronic treatment with digoxin.

Digoxin↗
PubMed1980

Automated differential leucocyte counters: an evaluation of the Hemalog D and A comparison with the Hematrak. I. Principles of operation; reproducibility and accuracy on normal blood samples.

The precision and accuracy of the Hemalog D, which uses cytochemical identification of cells in suspension, and of the Hematrak, which uses image recognition of cells on a stained blood film, have been compared counting normal blood samples. The Hemalog D showed superior precision for all cell types, as would be expected since 10,000 cells are counted per sample; however, the precision for monocytes was worse than expected for the number of cells counted. The precision of the Hematrak was equivalent or superior to that of a manual count of the same number of cells but showed the poor precision inevitable when only 100 cells are counted. With respect to accuracy, both automated counters showed statistically significant differences from manual counts and from each other in counting neutrophils, lymphocytes and eosinophils, bu the differences were not sufficiently great to be of practical importance. The Hematrak counted monocytes accurately (though imprecisely) whereas the Hemalog D overestimated monocytes on average by 2.3%, or 40% of the mean monocyte percentage. This was consequent on the counting of esterase positive neutrophils as monocytes, and the difference from the manual count was sufficient to be of some practical importance. The Hemalog D counted basophils both accurately and precisely. The precision of manual and Hematrak basophil counts was poor; the accuracy of the Hematrak basophil count was dependent on the quality of the stain and that of the manual basophil count was dependent on the quality of the stain and the attentiveness of the technologist. For other cell types in blood samples from normal volunteers, the Hematrak was versatile and accuracy was not greatly affected by the use of May-Grünwald-Giemsa rather than Wright's stain, nor by the use of hand spread rather than machine spread films.

Automation↗
PubMed1980

Automated differential leucocyte counters: an evaluation of the Hemalog D and A comparison with the Hematrak. II. Evaluation of performance on routine blood samples from hospital patients.

The performance of the Hemalog D on routine blood samples from patients was assessed over a 6 wk period, 500 samples being studied in detail. The performance of the Hematrak was assessed on 85 routine blood samples. It was found that in our hospital population at least 58% of blood samples counted by the Hemalog D would require a blood film to be examined. Occasional patients with haematological diseases had abnormalities on the blood film but had normal Hemalog 8 and Hemalog D printouts. The Hemalog D was unable to perform an accurate differential count on the blood from a large proportion of patients with uraemia, including dialysis patients. The Hematrak was imprecise because of the small number of cells counted; it was also found to be inaccurate if blood films were not made rapidly after the blood was taken.

Automation↗
PubMed1979

Heatstroke in well-wrapped infants.

In a 3-year period in Newcastle upon Tyne a sudden illness, of which the main features were fever, shock, convulsions, hepatic disturbance, and a bleeding tendency, affected 5 infants, 4 of whom died. No aetiological agent could be demonstrated, and in the absence of a satisfactory alternative diagnosis it is suggested that a principal component of the illness was heatstroke, brought about by excessive wrapping or warming during a mild infection.

Blood Cell Count↗
PubMed1979

Joint laxity leading to osteoarthrosis.

Joint laxity was compared in 50 females with symptomatic osteoarthrosis and an age-matched control group without osteoarthrosis. Generalized joint laxity measured by the scoring system of Cater and Wilkinson (1964) modified by Beighton (1973) was significantly higher in the osteoarthritic group (X2 = 10.00, P less than 0.05). In osteoarthritics the pattern of clinical joint involvement varied with the degree of generalized joint laxity.

Humans↗
PubMed1978

The effects of intravenous phosphate loading on salivary phosphate secretion and plasma parathyroid hormone levels in the sheep.

Adult sheep were given intravenous infusions of a solution of Na2HPO4 and the effects on parotid salivary composition and on plasma parathyroid hormone levels were studied. Infusion of the phosphate solution resulted in increases in the concentration of inorganic phosphate in the plasma and to proportional increases in the concentration and amount of phosphate secreted in the saliva. There was, however, no evidence that the salivary response was dependent upon a change in endogenous parathyroid hormone release. In other studies infusion of bovine parathyroid hormone or stimulation of endogenous hormone release through infusion of EDTA both led to a fall in the concentration of inorganic phosphate in the plasma and to a fall in the concentration and amount of phosphate secreted in the saliva. Taken together these results suggest that the major factor affecting salivary phosphate secretion in these studies was the concentration of inorganic phosphate in the plasma. Parathyroid hormone does not appear to have any direct effect on salivary phosphate secretion in the sheep though it may indirectly influence phosphate secretion through its effects on plasma inorganic phosphate level.

Animals↗