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Biomedical subjects

S Chalkley

Publications and source records attributed to S Chalkley.

6 recordsLinked to original sources
PubMed1998

Blood lead in U.K. children--time for a lower action level?

1. Blood lead measurements in samples collected from 660 London schoolchildren during 1991 to 1992 suggest that the blood lead values in children in the U.K. are decreasing. 2. Geometric mean values for blood lead were 0.18 (range 0.05-0.71) micromol/l [3.7 (1. 0-15.0) microgram/dl]. Analysis of variance showed differences between ethnic groups, sex and schools. An age-matched subset of 148 children was compared with 136 children from an earlier study in 1986 and 1987. Trend analysis of the geometric mean lead values showed a negative slope (b=-0.484, P<0.0001), with maximum values of 0.81, 1.00, 0.71 and 0.43 micromol/l (17, 21, 15 and 9 microgram/dl) for the years 1986, 1987, 1991 and 1992 respectively. 3. It is recommended that children in the U.K. being investigated for anaemia, pica, recurrent abdominal pain or a high-risk environment should have blood lead values measured and that the action level for blood lead in children should be decreased from 1.19 micromol/l to 0.48 micromol/l (from 25 microgram/dl to 10 microgram/dl). 4. Guidance is offered to clinicians and other health professionals investigating excessive lead exposure.

Adolescent↗
PubMed1997

Rat amylin-(8-37) enhances insulin action and alters lipid metabolism in normal and insulin-resistant rats.

To clarify roles of amylin, we investigated metabolic responses to rat amylin-(8-37), a specific amylin antagonist, in normal and insulin-resistant, human growth hormone (hGH)-infused rats. Fasting conscious rats were infused with saline or hGH, each with and without amylin-(8-37) (0.125 mumol/h), over 5.75 h. At 3.75 h, a hyperinsulinemic (100 mU/l) clamp with bolus 2-deoxy-D-[3H]glucose and [14C]glucose was started. hGH infusion led to prompt (2- to 3-fold) basal hyperamylinemia (P < 0.02) and hyperinsulinemia. Amylin-(8-37) reduced plasma insulin (P < 0.001) and enhanced several measures of whole body and muscle insulin sensitivity (P < 0.05) in both saline- and hGH-infused rats. Amylin-(8-37) corrected hGH-induced liver insulin resistance, increased basal plasma triglycerides and lowered plasma nonesterified fatty acids in both groups, and reduced muscle triglyceride and total long-chain acyl-CoA content in saline-treated rats (P < 0.05). In isolated soleus muscle, amylin-(8-37) blocked amylin-induced inhibition of glycogen synthesis but had no effect in the absence of amylin. Thus 1) hyperamylinemia accompanies insulin resistance induced by hGH infusion; 2) amylin-(8-37) increases whole body and muscle insulin sensitivity and consistently reduces basal insulin levels in normal and hGH-induced insulin resistant rats; and 3) amylin-(8-37) elicits a significant alteration of in vivo lipid metabolism. These findings support a role of amylin in modulating insulin action and suggest that this could be mediated by effects on lipid metabolism.

Acyl Coenzyme A↗
PubMed1975

Hormonal pattern of relapse in hyperthyroidism.

22 patients with Grave's disease were followed up for up to a year after antithyroid drug therapy was discontinued. Clinical assessment and serum T3, T4, and thyroid-stimulating-hormone (T.S.H.) estimations were done serially and simultaneously. Serum T3 or T4 concentrations may be elevated briefly in the first few weeks after antithyroid drugs are stopped, as a rebound effect not necessarily indicative of subsequent relapsf. Clinical relapse of hyperthyroidism with subsequent improvement on antithyroid drugs occurred in 13 patients. Of these 13, serum T3 concentrations became elevated before serum T4 concentrations in 5, thus predicting the subsequent development of clinical hyperthyroidism. In the remaining 8 patients who relapsed, serum T4 was elevated a month before the serum T3. Hyperthyroidism was diagnosed clinically after elevated serum T3 concentrations in 11 patients and at the same time in 2 patients. The mean period of "biochemical hyperthyroidism" in these 11 patients was 12 weeks, with a range of 1 to 56 weeks. During this period 9 of the 11 had minor clinical changes attributable to hyperthyroidism. It is concluded that serial estimations of serum T3 provide the most reliable method of monitoring relapse in hyperthyroidism.

Carbimazole↗