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Biomedical subjects

S Rogers

Publications and source records attributed to S Rogers.

At least 253 records · Page 14Linked to original sources
PubMed1987

Some long term effects of smoking on the haemostatic system: a report from the Caerphilly and Speedwell Collaborative Surveys.

Data from two community studies on men from South Wales and the west of England suggest that the effects of smoking on the haemostatic system remain for many years after giving up. Long term correlations between several variables, including plasma fibrinogen and white cell count, and the length of time after giving up were seen in ex-smokers. Dose response relations were apparent in current smokers in terms of the white cell count and two haematological variables, the packed and mean cell volumes. These long term correlations probably reflect the toxicity of other agents in tobacco smoke besides nicotine and carbon monoxide, which act only in the short term. Identification of these agents may further our understanding of the mechanism by which cigarette smoking is associated with atherosclerotic disease.

Blood Viscosity↗
PubMed1987

Distribution of IGF receptors in the plasma membrane of proximal tubular cells.

To characterize the distribution of receptors for insulin-like growth factors I and II (IGF I and II) in the plasma membrane of the renal proximal tubular cell, we measured binding of 125I-labeled IGF I and 125I-labeled IGF II to proximal tubular basolateral and brush-border membranes and characterized IGF I-stimulated phosphorylation of detergent-solubilized membranes. 125I-IGF I bound primarily to a 135,000 relative molecular weight (Mr) protein and IGF II to a 260,000 Mr protein in isolated membranes. Binding of 125I-IGF I was severalfold greater in basolateral than in brush-border membranes. IGF I-stimulated phosphorylation of the 92,000 Mr beta-subunit of its receptor could be demonstrated only in basolateral membranes. These findings are consistent with an asymmetrical distribution of receptors for IGF I in the plasma membrane of the renal proximal tubular cell, localization being primarily on the basolateral side. In contrast, binding of 125I-IGF II to isolated basolateral and brush-border membranes was equivalent, suggesting that receptors for this peptide are distributed more symmetrically in the plasma membrane. Our findings suggest that the actions of IGF I in proximal tubule are mediated via interaction of circulating peptide with specific receptors in the basolateral membrane. However, our findings establish the potential for actions of IGF II to be exerted in proximal tubule via interaction with both basolateral and/or brush-border membrane receptors.

Animals↗
PubMed1987

Adrenal suppression following low-dose topical clobetasol propionate.

The use of topical steroids is associated with adverse systemic effects such as suppression of the hypothalamic-pituitary-adrenal (HPA) axis, and application of more than 50 g per week of clobetasol propionate cream has been shown to cause secondary adrenal failure. We describe 4 patients who used clobetasol propionate cream over a prolonged period; 3 patients used less than 50 g per week (7.5, 25 and 30 g per week) and yet all developed secondary adrenal failure for up to 4 months after cessation of therapy. Adrenal insufficiency following prolonged use of clobetasol propionate in moderate dosages may therefore be more common than previously recognized. It is suggested that the metyrapone test, which conveniently examines the entire HPA axis, should be employed in patients receiving long-term topical clobetasol propionate cream and that glucocorticoid supplementation should be given during episodes of stress, such as infections and surgery, for up to 4 months after cessation of therapy.

Administration, Topical↗
PubMed1986

Amino acid sequences common to rapidly degraded proteins: the PEST hypothesis.

The amino acid sequences of ten proteins with intracellular half-lives less than 2 hours contain one or more regions rich in proline (P), glutamic acid (E), serine (S), and threonine (T). These PEST regions are generally, but not always, flanked by clusters containing several positively charged amino acids. Similar inspection of 35 proteins with intracellular half-lives between 20 and 220 hours revealed that only three contain a PEST region. On the basis of this information, it was anticipated that caseins, which contain several PEST sequences, would be rapidly degraded within eukaryotic cells. This expectation was confirmed by red blood cell-mediated microinjection of 125I-labeled caseins into HeLa cells where they exhibited half-lives of less than 2 hours. The rapid degradation of injected alpha- and beta-casein as well as the inverse correlation of PEST regions with intracellular stability indicate that the presence of these regions can result in the rapid intracellular degradation of the proteins containing them.

Amino Acid Sequence↗
PubMed1986

Plasma levels of fibrin fragments in men with myocardial infarction.

Degradation products of cross-linked fibrin were measured in the plasma of 30 men who had been discharged from hospital following a myocardial infarct and in 30 age-matched controls selected from a general practice list. Levels were significantly higher in cases than controls, and the direction of the differences was highly consistent in case control pairs. These findings may represent increased thrombogenesis, increased fibrinolysis, or both, in persons who have suffered myocardial infarction.

Adult↗
PubMed1986

First morning urinary albumin concentration is a good predictor of 24-hour urinary albumin excretion in children with type 1 (insulin-dependent) diabetes.

Twenty-four hour urinary albumin excretion was measured in 97 children with Type 1 (insulin-dependent) diabetes and found to have a geometric mean of 6 mg/day (range 1-38 mg/d). The same geometric mean of 6 mg/day (range 1-45 mg/d) was found in 120 normal children. The relationship of 24-h urinary albumin excretion to the albumin concentration (mg/l) and to the ratio of albumin: creatinine (mg:mmol) on first morning urine samples in 64 patients was highly significant (r = 0.93 and r = 0.62 respectively, p less than 0.001). In 41 patients, the relationship between 24-h urinary albumin excretion and albumin concentration upon urine samples at various times was assessed. The correlation was highest on the first morning sample (r = 0.86); 09.00 h to 13.00 h, 0.51; 13.00 h to 18.00 h, 0.68; 18.00 h to 23.00 h, 0.32. High sensitivity and moderate specificity was obtained using a first morning albumin concentration of greater than 20 mg/l to detect increased albumin excretion. These results show that the measurement of albumin concentration on the first morning urine sample can be used for a screening test for microalbuminuria in children.

Adolescent↗
PubMed1986

Treatment of nickel dermatitis with Trientine.

23 nickel-sensitive patients with hand eczema were treated with Trientine 300 mg daily and a placebo in a double-blind, crossover trial. No significant improvement occurred in the hand eczema. A surprising finding was that there was no detectable increase in urinary nickel excretion, in contrast to animal studies.

Adult↗
PubMed1986

Phorbol ester-stimulated phosphorylation of basolateral membranes from canine kidney.

To determine whether protein kinase C is present in the basolateral membrane of the renal proximal tubular cell, we performed experiments to ascertain whether specific binding of [3H]phorbol 12,13-dibutyrate could be demonstrated in basolateral membranes isolated from canine kidney. Specific binding was demonstrable that was half maximal at between 10(-7) and 10(-8) M phorbol 12,13-dibutyrate. Binding was inhibited by 12-O-tetradecanoylphorbol-13-acetate (TPA) and other tumor-promoting phorbol esters, but not by inactive phorbol esters, including 4 alpha-phorbol. Incubation of basolateral membranes with TPA and phorbol 12,13-dibutyrate, but not with 4 alpha-phorbol, in the presence of submicromolar concentrations of free calcium, enhanced phosphorylation of several proteins demonstrable in autoradiograms of sodium dodecyl sulfate-polyacrylamide gels originating from membranes subsequently exposed to [gamma-32P]ATP for 30 s. Dephosphorylation of [32P]phosphoproteins was observed in gels from membranes incubated with [gamma-32P]ATP over time. TPA-stimulated phosphorylation of one protein band with Mr 135,000 was quantitated and was found to increase as a function of [TPA]. Half-maximal TPA-stimulated phosphorylation of this protein band occurred at slightly less than 10(-9) M TPA. Our findings are consistent with a role for protein kinase C-effected phosphorylation of basolateral membrane proteins in the mediation or modulation of hormonal actions in the proximal tubular cell.

Adenosine Triphosphate↗