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K Willey

Publications and source records attributed to K Willey.

5 recordsLinked to original sources

Epitope mapping of the human TSH receptor; structure function studies.

With the aid of recombinant DNA technology (PCR/site directed mutagenesis, sequencing) the full length coding region of the human TSH receptor was manipulated to place a specific epitope peptide tag (FLAG epitope sequence) at the carboxyl end of the protein. The resulting construct was cloned into a eukaryotic expression vector and stably transfected into HeLa cells. The expression/translation of the tagged TSH receptor molecule was monitored by immune-precipitation and western blotting of protein lysates, and was found to be expressed at considerable levels using the commercially available antibodies directed towards the FLAG epitope. This analysis revealed two discrete specific bands 90-120 KDa representing, presumably, differently glycosylated forms of the receptor. TSH radio receptor assays demonstrated that the FLAG tagged TSH receptor bound TSH comparable with the wild type receptor. Furthermore TSH stimulated cAMP response in these transfected cells were comparable to the wild type receptor, thus demonstrating that the tagged receptor was functionally identical to the transfected wild type receptor. These cell lines will be of great value when analysing TSH/receptor or receptor/autoantibody interactions considering the availability of well characterized experimental anti-TSH receptor sera.

Blotting, Western↗

Regression of microalbuminuria: results of a controlled study, indapamide versus captopril.

Our aim was to assess the effect of blood pressure treatment on albumin excretion rate (AER) in diabetic patients using two antihypertensive agents with different modes of action: indapamide and captopril. Patients with persistent microalbuminuria on two occasions (AER 20-200 micrograms/min) entered a randomized crossover study of 12 weeks of therapy with a constant dose of either indapamide 2.5 mg daily or captopril 12.5 mg three times daily, with a 4-week washout between therapy periods. Blood pressure was measured using a random-zero sphygmomanometer and AER by radioimmunoassay on a timed urine collection. Results (mean +/- standard deviation) were analyzed by repeated measures of analysis of variance after log transformation of AER data. Twelve patients [nine men; mean age 58 +/- 7.5 years (range 49-73 years), all with non-insulin-dependent diabetes mellitus (NIDDM)] were studied. Both blood pressure [initial mean systolic 144 +/- 14 mm Hg (range 124-166)/initial mean diastolic 85 +/- 6 mm Hg (range 75-96)] and AER [initial 92 +/- 36 micrograms/min (range 36-161)] were significantly reduced below basal levels (at the 0.05 level) at all study intervals by both antihypertensive agents. The results show the importance of blood pressure and its treatment on AER in patients with NIDDM. In this study, indapamide was as effective as an angiotensin-converting enzyme inhibitor in reducing both blood pressure and microalbuminuria.

Aged↗

Increased oxidizability of plasma lipoproteins in diabetic patients can be decreased by probucol therapy and is not due to glycation.

Atherosclerosis is considered to be the major complication of diabetes mellitus. Since diabetic patients have increased blood levels of lipid peroxidation products we investigated whether the susceptibility of blood components to oxidation is altered in this disease. We analysed the parameters characterizing the extent of oxidative change and the antioxidant status of low density lipoprotein (LDL) and high density lipoprotein (HDL) in a group of diabetic patients and in a control population. LDL oxidizability was significantly higher for patients (P = 0.001) than for individuals in the control group. There were no significant differences in the alpha-tocopherol content or levels of performed peroxides in LDL samples isolated from diabetic patients and control individuals which could account for this effect. Similarly, LDL glycation, common in diabetes mellitus, was not responsible, since LDL glycated in vitro was more rather than less resistant to oxidation. Even the presence of unbound glucose at normal or elevated physiological concentrations had a delaying effect on the oxidation of LDL. The increased oxidizability of LDL isolated from diabetic patients could be reduced to control levels by a 6-week standard treatment with Probucol, originally applied to reduce their blood cholesterol.

Adult↗