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Biomedical subjects

R Watts

Publications and source records attributed to R Watts.

At least 91 records · Page 5Linked to original sources
PubMed1988

Metabolism of benz[j]aceanthrylene (cholanthrylene) and benz[l]aceanthrylene by induced rat liver S9.

The metabolites of benz[j]aceanthrylene (B[j]A) produced by incubation with liver S9 proteins from rats induced with Aroclor-1254 and phenobarbital have been identified as: trans-B[j]A-1,2-dihydrodiol, B[j]A-9,10-dihydrodiol, B[j]A-11,12-dihydrodiol, and 10-hydroxy-B[j]A. The major metabolite formed (58-60%) by both induced S9 preparations was trans-B[j]A-1,2-dihydrodiol, the cyclopenta-ring dihydrodiol while oxidation at the k-region or the proximal-bay region was minor. There were no statistical differences in individual or total B[j]A metabolite rates between the 2 induced S9 preparations. B[l]A was metabolized by Aroclor-1254 and phenobarbital induced rat liver S9 preparations to trans-B[l]A-1,2-dihydrodiol, B[l]A-7,8-dihydrodiol, and B[l]A-4,5-dihydrodiol. The major B[l]A metabolite formed (28-40%) by both induced S9 preparations was B[l]A-7,8-dihydrodiol, the k-region dihydrodiol. Cyclopenta-ring oxidation to trans-B[l]A-1,2-dihydrodiol was approximately 50% of that observed for k-region oxidation. Both induced S9s produced similar rates of B[l]A metabolites except for B[l]A-7,8-dihydrodiol formation which was higher for Aroclor-1254-induced S9.

Animals↗
PubMed1988

A non-flow cytometric system for detecting antibodies and cellular antigens in blood.

The system described here can distinguish between single and agglutinated erythrocytes by use of a non-flow fiber optic fluorometer. The method is capable of detecting cell-surface antigens and antibodies to cell-surface antigens present in blood. Significant features include high-efficiency fluorescent dyes that intercalate into cell membranes, a stretching membrane for transport and mixing of samples, charged colloidal magnetite for magnetic separation of erythrocytes, and an immersible fiber optic probe for measuring fluorescence associated with cells in a 1-nL volume of a bulk solution. We describe the application of the system to automation of ABO/Rh grouping and antibody screening.

ABO Blood-Group System↗
PubMed1987

Serum C-peptide after 6 months on glibenclamide remains higher than during insulin treatment.

Serum C-peptide was measured fasting and 6 minutes after glucagon (1 mg given intravenously) in 49 patients with non-insulin-dependent diabetes mellitus, after 4 and 6 months of successive periods of treatment with insulin and oral hypoglycaemics (glibenclamide and metformin), given in random order. Glycaemic control was not significantly different on the two treatments, but C-peptide was much higher while the patients were on glibenclamide. We conclude that glibenclamide stimulates pancreatic insulin production even after 6 months treatment.

Adult↗
PubMed1984

Mutagenicity of cyclopenta-fused isomers of benz(a)anthracene in bacterial and rodent cells and identification of the major rat liver microsomal metabolites.

The microsomal metabolites and mutagenic activity of four cyclopenta-fused benz(a)anthracenes, benz(j)aceanthrylene [B(j)A], benz(e)aceanthrylene [B(e)A], benz(l)aceanthrylene [B(l)A], and benz(k)acephenanthrylene [B(k)A], have been studied. Aroclor 1254-induced rat liver microsomes metabolized B(j)A to B(j)A-1,2-dihydrodiol, B(j)A-9,10-dihydrodiol, B(j)A-11,12-dihydrodiol, and 10-hydroxy-B(j)A; B(e)A-1,2-dihydrodiol, B(e)A-3,4-dihydrodiol, and B(e)A-5,6-dihydrodiol; B(l)A to B(l)A-1,2-dihydrodiol, B(l)A-4,5-dihydrodiol, and B(l)A-7,8-dihydrodiol; and B(k)A to B(k)A-4,5-dihydrodiol and B(k)A-8,9-dihydrodiol. With each polycyclic aromatic hydrocarbon, metabolism occurred on the cyclopenta ring. All four isomers were active as gene mutagens in Salmonella typhimurium and in Chinese hamster V79 cells. In the S. typhimurium mutation studies, using Aroclor 1254-induced rat liver S9, B(j)A, B(e)A, and B(l)A required significantly less microsomal protein for maximal mutation response than B(k)A and B(a)P, suggesting a one-step activation mechanism, presumably on the cyclopenta-fused ring. B(j)A, B(e)A, and B(l)A were significantly more mutagenic than B(k)A and B(a)P in S. typhimurium. In the Aroclor 1254-induced rat liver S9-mediated V79 mutagenesis system, all four isomers were active, with B(l)A the most active. When Syrian hamster embryo cells were used as the metabolic activation component for V79 cells, only B(l)A produced a significant response and was equivalent in activity to B(a)P. A helical configuration for B(l)A is inferred from the identification of two trans-B(l)A-1,2-dihydrodiols, syn and anti, which have been synthesized, separated, and characterized. The metabolically formed dihydrodiol is anti-trans-B(l)A-1,2-dihydrodiol, and experimental evidence suggests that the metabolically formed B(l)A-1,2-oxide is the anti-isomer. Synthetic B(l)A-1,2-oxide was found to be a direct-acting mutagen in S. typhimurium and Chinese hamster V79 cells and is estimated to account for up to 40% of the mutagenic activity of the parent hydrocarbon. Therefore, certain cyclopenta-ring fusions on benz(a)anthracene appear to markedly increase its genotoxic and carcinogenic activities.

Animals↗
PubMed1983

Intraventricular hemorrhage from ruptured aneurysm. Retrospective analysis of 91 cases.

Intraventricular hemorrhage (IVH) from aneurysm rupture is generally considered to be of grave prognostic significance. Ninety-one cases have been studied retrospectively from seven medical centers. The overall mortality rate was 64%. The dramatically poor condition of these patients leads to their rapid admission to the hospital. Eighty-seven percent were admitted on Day 0 or 1, and more than half were classified neurologically as Grade 4 or 5. A multiple regression analysis explained 56% of the variance in survival, using the variables of ventriculocranial ratio (VCR), day of admission, diastolic blood pressure, location of aneurysm, associated intracerebral hematoma, age, grade on admission, sex, and systolic blood pressure. No patient with a VCR of more than 0.25, as calculated from the initial computerized tomography (CT) scan, survived. No patient whose smallest VCR was 0.23 or more survived. This ratio can be simply measured with a millimeter ruler from the CT scan. Patients with IVH usually had enlarged ventricles, even initially. The overall results suggest that early management of intracranial hypertension should be more generally considered, although even when this was done the prognosis was still guarded. The timing of surgery was not an important determinant of outcome, although a significant number of patients died awaiting surgery.

Adolescent↗
PubMed1978

Essential fatty acid deficiency in infants receiving parenteral nutrition.

The clinical and biochemical features of essential fatty acid deficiency are described in an infant with gastroschisis who required long-term (6 mo) parenteral nutrition. The deficiency responded to therapy with Intralipid, topical sunflower oil, and breast milk. In a prospective study of three infants with gastroschisis, biochemical essential fatty acid deficiency developed in each during the first week of lipid-free parenteral nutrition; clinical signs of the deficiency were absent. The biochemical features were progressive in the one patient followed for 19 days, and were associated with a decrease in weight gain. Both the deficiency and weight gain were corrected by Intralipid. Biochemical essential fatty acid deficiency did not develop in three other gastroschisis infants who were given prophylactic Intralipid (two patients) or topical sunflower oil (one patient). We conclude that all infants on parenteral nutrition should receive a source of linoleic acid to prevent essential fatty acid deficiency.

Abdominal Muscles↗
PubMed1976

Production of 1,2-diacylglycerol and phosphatidate in human erythrocytes treated with calcium ions and ionophore A23187.

1. When the ionophore A23187 and Ca2+ were added to normal human erythrocytes, the incorporation of 32P into phosphatidate was enhanced within 1 min, but there was only slight labelling of other phospholipids. 2. Labelling of phosphatidate in these cells did not continue to increase after about 20min at 37 degrees C; by this time, radioactivity in phosphatidate was about ten times higher inionophore A23187-treated cells than in controls. A net synthesis of phosphatidate was measured in response to the increase in intracellular Ca2+ concentration; the content of this phospholipid in the cell was increased by approximately 50%. 3. In the presence of 2.5 mM-Ca2+ a maximum effect was seen with about 0.5 mug of ionophore/ml. 4. The concentration of Ca2+ giving half-maximal labelling of phosphatidate in the presence of 10 mug of ionophore A23187/ml was about 10 muM. 5. A rapid decrease of ATP content in the cell occurred in ionophore-treated cells. 6. Labelling of phosphatidate appeared to be secondary to the production of 1,2-diacylglycerol in the cells; accumulation of 1,2-diacylglycerol was only seen after about 15 min. After 60 min, the 1,2-diacylglycerol content of the cells was five to seven times that of untreated control cells. 7. The change in the shape of erythrocytes treated with Ca2+ and ionophore appeared to be related to accumulation of 1,2-diacylglycerol. 8. The source of 1,2-diacylglycerol has not been definitely identified, but its fatty acid compositon was similar to that of phosphatidylcholine. However, it has an unusually high content of hexadecenoic acid, a fatty acid not common in the major erythrocyte phospholipids. 9. Accumulation of 1,2-diacyglycerol also occurred in energy-starved cells, even in the absence of calcium; in this case it appeared to be produced by phosphatidate breakdown.

Adenosine Triphosphate↗
PubMed1976

Structure of some intact lipids of petrel stomach oils.

The stomach or proventricular oils from 16 species of petrel have been analyzed and the carbon number distributions of the wax esters, triglycerides, and diacylglyceryl ethers are reported. The wax esters have been fractionated further into less and more polar species. To determine whether any intermolecular specificity existed, carbon number distributions for each lipid class were calculated, assuming random esterifications. The tirglyceride and diacylglyceryl ether compositions observed were all found to aggree closely with those calculated. The wax esters from three petrel species were found to have greater proportions of the middle range species with carbon numbers 34-38 than calculated. However, most of the lipids examined had random structures which have been found to be characteristic of marine sources. The results in general support the belief that the oils are derived directly from dietary sources rather than synthesis by the proventricular glands.

Alcohols↗
PubMed1976

Results for serum cholesterol and triglycerides by gas-liquid chromatography, as compared with a continuous-flow technique.

We assessed the usefulness of gas-liquid chromatography forthe routine and reference measurement of cholesterol and triglycerides (triacylglycerols). Compared with results obtained by an AutoAnalyzer II method, correlation was good with both serum specimens (triglycerides, r = 0.88; cholesterol, r = 0.90) and lipoprotein fractions isolated by ultracentrifugation (triglycerides, r = 0.98; cholesterol, r = 0.98). However, none of the comparisons was completely free of analytical bias, and in general the AutoAnalyzer method underestimated the cholesterol value and overestimated triglycerides. The obvious advantage of the AutoAnalyzer is its greater analytical speed, but the chromatographic method appeared to be more accurate and precise and to suffer less from interfering substances, and in addition gave information about the cholesterol ester and triglyceride composition. We expect gas-liquid chromatography to be of major importance in the calibration of other analytical methods.

Autoanalysis↗