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Biomedical subjects

C Sims

Publications and source records attributed to C Sims.

32 records · Page 2Linked to original sources
PubMed1985

In vivo and in vitro resistance to maximal insulin-stimulated glucose disposal in insulin deficiency.

The effect of streptozotocin-induced diabetes mellitus on maximal insulin-stimulated glucose uptake in the rat was studied in isolated adipocyte, perfused hindlimb, and the intact organism. Basal glucose transport per fat cell was reduced by approximately two-thirds (P less than 0.001), being associated with a similar decrease in glucose oxidation per fat cell (P less than 0.001). There was also a significant decrease (P less than 0.001) in basal glucose uptake by perfused hindlimb of diabetic rats of approximately 40%. Furthermore, maximal insulin-stimulated glucose transport and oxidation were approximately 50% lower (P less than 0.001) in fat cells of diabetic as compared with control rats. In contrast, maximal insulin-stimulated glucose disposal by perfused hindlimbs from diabetic and control rats was similar, and this was also true of the ability of insulin to maximally stimulate glucose uptake in the intact normal and diabetic rat. These findings indicate that variation exists in the manner in which insulin-sensitive tissues respond to experimentally induced insulin deficiency and support the view that total body glucose disposal is primarily related to insulin action on muscle.

Adipose Tissue↗
PubMed1985

Spontaneous running activity in male rats: effect of age.

Alterations in the intensity and pattern of spontaneous running activity as rats increase in age from 7 wk to 1 yr was studied in male rats placed in exercise wheel cages. Daily running records were obtained on 27 rats for periods up to 12 mo, and 24-h activity recordings were made of selected runners to study the variation in activity during the day. The data indicate that for rats running over 2,940 revolutions (or 2 miles/day), the maximum intensity of running attained can be divided into a group of high achievers (approximately 8 miles/day) and moderate achievers (averaging 4.5 miles/day). For both groups, spontaneous running activity reached maximal rates after 4-5 wk. This maximal rate was sustained for 7-8 wk, then fell to levels approximately 60% of maximum for 4-5 mo, and then fell again to levels approximately 25% of maximum from 8 to 12 mo of age. The hourly pattern of running activity during the day was defined in rats of increasing age, who averaged 13,280, 6,662, 3,874, and 1,755 rev/day, corresponding to 9.0, 4.5, 2.6, and 1.2 miles/day, respectively. The overall patterns at each level indicated that the major running period occurred between 6:00 P.M. and 6:00 A.M., the greater activity of younger rats was paralleled by faster speeds and longer duration at each hour of the day, and the peak running activity for each group generally occurred between 7:00 and 9:00 P.M. In summary, there is a progressive loss in speed and duration of spontaneous running activity as male rats increase in age, with intensity of exercise falling below 2 miles/day after 7-8 mo of age.

Aging↗
PubMed1978

Effects of sodium azide on the quantitation of the chemical constituents of serum. Inhibition of bilirubin and cholesterol.

Azide salts frequently are added as a preservative to biologic fluids and reagents, or are introduced into serum through accidental exposure, intoxication, or pharmaceuticals. Sodium azide can interfere with the quantitation of biochemical constituents in serum. Serum pools containing 0.2-9.0 mg/dl (3.42-153.9 mumol/l) total bilirubin, 0.2-5.0 mg/dl (3.42-94.1 mumol/l) direct bilirubin, and 175-313 mg/dl (4.55-8.14 mmol/l) cholesterol were analyzed using the SMA 12/60. Sodium azide was added in concentrations of 0.1-1.0% (13.6-136 mmol/l). Sodium azide in concentrations of 0.1% (13.6 mmol/l) or more reduced total and direct bilirubin values 60-100%. At concentrations above 0.5% (68 mmol/l), no bilirubin, or only a very small quantity, was measured. Sodium azide at concentrations above 0.05% (6.8 mmol/l) exerted a significant decreasing effect on serum cholesterol values. At 0.1% (13.6 mmol/l) or more, reductions in cholesterol values ranging from 30 to 85% were observed. These studies showed that sodium azide (0.1%, 13.6 mmol/l, or more) in the serum can result in falsely low bilirubin or cholesterol values.

Alkaline Phosphatase↗
PubMed1977

Determination of serum creatinine by reaction with methyl-3,5-dinitrobenzoate in Methyl Sulfoxide.

Creatinine in serum is determined with a new reagent system consisting of methyl-3,5-dinitrobenzoate and tetramethyl ammonium hydroxide in 50% methyl sulfoxide. The method shows excellent correlation with manual and automated alkaline picrate procedures and has comparable sensitivity. The proposed method has advantages over the dinitrobenzoyl chloride assay system in terms of sensitivity, reagent stability and precision. The day-to-day coefficient of variation is 2.9-3.8%, while within day is 1.5-2.1%. The standard curve is linear beyond 20 mg/dl creatinine. Compared to the picrate method, the proposed assay is less than one half as susceptible to a combination of known interfering agents. Based on the present studies, it is recommended as an excellent alternative to the commonly used picrate procedures.

Acetoacetates↗
PubMed1977

Serum creatinine assay by use of 3,5-dinitrobenzoates: a critique.

Methyl-3,5-dinitrobenzoate and 3,5-dinitrobenzoyl chloride are demonstrated to react with creatinine through their conversion to 3,5-dinitrobenzoate. Analytical recovery of creatinine added to serum is improved by an "acid-supernate" modification, which is also much less susceptible to a combination of known interfering agents than is the picrate procedure. The "neutral-supernate" procedure shows negligible interference by cephalothin as compared to commonly used picrate procedures. Replacement of tetramethylammonium hydroxide by sodium hydroxide was also tested. The interrelationships between dimethyl sulfoxide concentration, recoveries of creatinine, and slopes of correlations (r greater than .992) of various dinitrobenzoate and picrate methods are critically assessed. Because of its precision, greater specificity, and other criteria, we recommend the methyl-3,5-dinitrobenzoate (or 3,5-dinitrobenzoic acid) neutral-supernate method for routine applications.

Cephalothin↗
PubMed1976

A new method for the determination of serum creatinine based on reaction with 3.5-dinitrobenzoyl chloride in an organic medium.

A new method for the determination of serum creatine, based on its reaction with 3,5-dinitrobenzoyl chloride in an organic medium is described. Various analytical parameters are studied and comparisons are made with the routine picrate procedures, as well as the dinitrobenzoic acid methods reported in the literature. On the basis of the data submitted, the proposed method is recommended for routine clinical use.

Colorimetry↗
PubMed1976

Extra-amniotic prostaglandin E2 and the unfavourable cervix.

A small dose of prostaglandin E2 suspended in a viscous medium was instilled as a single application into the extra-amniotic space of patients with unfavourable induction features the day before planned induction in an attempt to improve the condition of the cervix. Two groups of 15 patients were studied, one receiving prostaglandin E2 250 mug suspended in methyl ethyl cellulose ('Tylose') 6% solution, and the other tylose alone. Cervical status did not change in those receiving tylose alone, whereas a significant improvement occurred in 14 out of 15 patients receiving the prostaglandin. Labour began before formal induction in 1 patient receiving tylose and in 8 receiving prostaglandin.

Adolescent↗
PubMed1976

Interference of sodium azide with the quantitation of serum cholesterol: a comparative study.

Interference of sodium azide (employed widely as a preservative for serum) with six different cholesterol methods and two modified procedures is analyzed and compared. Sodium azide is shown to lower the serum cholesterol values of the iron-cholesterol methods from 5 to 50% at 0.1 g% azide, and from 60 to 95% at 1.0 g% azide concentration, depending on the method employed. This inhibition is independent of serum cholesterol concentration. Increased serum to reagent (v/v) ratio, i.e., increased azide concentration, caused increased depression of serum cholesterol values. Appropriate choice of low serum-to-reagent (v/v) ratio thus decreases the magnitude of the azide interference in the iron-cholesterol reaction to 3-10% for the precipitation procedures, and to 25% for the non-precipitation procedure at 0.1 g% azide concentration in serum.

Azides↗
PubMed1975

Steroid interference in iron-cholesterol reactions: a comparative study.

Interference from various physiological and non-physiological steroids in the spectrophotometric determination of cholesterol by the Zak method (ferric chloride) and the method of Parekh and Jung (ferric acetate) was quantitatively measured. Contribution of the steroids at the specific absorption maxima of the cholesterol assays was determined by employing the steroids (40 mg/dl) alone, or added to a serum pool of known cholesterol content. The results show that the method of Parekh and Jung is less influenced by the presence of steroids than the Zak method. Observations on the structural specificity of the iron-cholesterol reaction are discussed.

Binding Sites↗
PubMedDate not supplied

MR imaging using a rampable system.

A series of cranial images obtained at three magnetic field strengths in a volunteer on a fast ramp magnetic resonance system is presented. This study was undertaken in the space of 5 h.

Brain↗
PubMedDate not supplied

Masseter spasm after suxamethonium in children.

This review examines the nature of masseter spasm, its controversial relation to malignant hyperpyrexia, and the management of the child who develops it during induction of anaesthesia.

Child↗