Screening for congenital hypothyroidism in Hong Kong

A pilot cord blood TSH screening program for congenital hypothyroidism was commenced in Hong Kong in April 1982. By April 1984, 14 411 neonates born in two hospitals were screened for this disorder. Five cases of primary hypothyroidism and two cases of transient hypothyroidism were detected. The detection of cases of congenital hypothyroidism with only moderately elevated cord blood TSH values means that the recall rate will remain high.

Single-dose pharmacokinetics of leuprolide in humans following intravenous and subcutaneous administration

A group of six normal adult male volunteers was divided into two groups (I and II) who received bolus intravenous and subcutaneous 1-mg doses of leuprolide. The study was of a randomized, complete-crossover design. Blood was collected from 0 to 48 h postdosing, and plasma was analyzed for leuprolide using a radioimmunoassay procedure. The data from the intravenous doses were fitted to a two-compartment open model with elimination from the central compartment, assuming a bolus (instantaneous) injection. The data from the subcutaneous doses were fitted to a two-compartment open model with elimination from the central compartment and first-order (monoexponential) absorption from the injection site. Statistical moments were also calculated for both sets of data. The mean beta half-life after the intravenous dosings was 2.9 h and after the subcutaneous dosings was 3.6 h. The difference between these two values, as well as those for plasma clearance, variance in residence time, and volume of distribution at steady state was not statistically significant; however, the differences between the mean values of k21, k12, kel, apparent volume of distribution of the central compartment, mean residence time, and area under the moment curve for the routes of administration were significant (p less than 0.05). The mean residence time following the intravenous dosings averaged 3.1 h and following the subcutaneous dosings averaged 4.3 h, indicating an average mean residence time at the subcutaneous injection site of 1.2 h. The mean volume of distribution at steady state from the intravenous and subcutaneous doses were 26.5 and 37.1 L, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Depression of serum cholinesterase activity as an indicator for insecticide exposure--consideration of the analytical and biological variations

Interest has recently been shown in the use of serum cholinesterase levels as a marker for chronic organophosphate insecticide exposure. Interpretation of the results must, however, take into account both long-term biological and analytical variations. The intraindividual variation of serum cholinesterase activity for 12 laboratory workers was 4.3%. The variation was much smaller than the interindividual variation of the whole population (20%). Based on the homogeneity of the intraindividual variance, it is possible to show the level of minimal decrease in enzyme activity which constitutes a departure from "normal".

The use of BMC Chemstrip 9 in the macroscopic urine screening procedure

The usefulness of a stick test for detection of leukocyte esterase activity in urine as part of a "macroscopic screen" was examined, as well as the efficiency of our existing broad screening criteria for detecting abnormalities in urine without microscopic examination. In a study of 923 unselected urine samples submitted to the laboratory, a false-negative rate of 0.6% was observed as judged by microscopic examination. The results of our present studies tend to confirm the usefulness of our "screen" program. The new leukocyte esterase test has been demonstrated to be an important adjunct to the macroscopic screening program.

A comparison of frequency and quantitative dietary methods for epidemiologic studies of diet and disease

Agreement between frequency and quantitative dietary methods was assessed for the ability of frequency intake data to substitute for quantitative intake data in diet-disease investigations. Frequency and quantitative intakes of 342 male subjects participating in an ongoing case-control study in Hawaii during 1981-1982 were obtained using a recall interview method designed to assess usual dietary habits. The extent of agreement between frequency and quantitative intakes of various dietary components (44 food items, 20 food groups, 8 nutrients) was determined at the group and individual subject levels, and with regard to specific study objectives. The results showed that for studies based on aggregate data, frequency and quantitative dietary methods will give reasonably comparable results in analyses involving food items. However, for similar studies involving food groups and nutrients, and for all studies based on individual data, frequency dietary methods cannot be relied on to yield the same diet-disease associations as would corresponding quantitative methods.

Assessment of a solid-phase reagent for urinary specific gravity determination

We have compared the specific gravity (S.G.) determined by the N-Multistix method with that obtained from the Total Solids (TS) meter. Overall, 88.7% of the specific gravity results obtained with the reagent strip method were within 0.005 of those obtained with the TS meter. There was a good correlation between the methods and there was no bias for the group means obtained by either method. A good correlation was also found between the S.G. on the strip and osmolality (correlation coefficient of 0.955). The results obtained with the reagent strip for urinary specific gravity therefore appear acceptable for routine laboratory purposes.

Differences in reaction characteristics between human and bovine-based control materials for iron determination

Reaction rate studies were carried out on various quality control specimens using a ferrozine iron determination kit. The time required for complete color formation differed among the various materials tested. Quality control materials of bovine origin required a much longer incubation time for full color formation. Using a fixed incubation procedure, the bovine controls would give a falsely low result. The present study suggests that caution is indicated when quality control data using bovine materials are interpreted.

A "one-minute" direct bilirubin determination using the Abbott ABA-100 Bichromatic Analyser

We describe a "one-minute" direct bilirubin procedure using the ABA-100. The procedure correlates well with the manual Jendrassik-Grof method and gives good precision at a relatively low direct bilirubin level. In comparison with certain other Abbott ABA-100 direct bilirubin methods, the proposed procedure appears to be the least affected by the presence of high unconjugated bilirubin levels.

Radioimmunoassay of carteolol in human plasma

A radioimmunoassay for the direct measurement of carteolol, a new beta-adrenoreceptor blocker, in human plasma was developed. Carteolol was acylated to form O-glutarylcarteolol, which was conjugated to bovine serum albumin to provide the immunogen. Antibody to carteolol was raised in New Zealand albino rabbits. The tracer was the radioiodinated derivative of O-glutarylcarteolol-tyrosine methyl ester conjugate. The method is highly sensitive, with a lower quantifiable concentration of approximately 0.4 ng of carteolol/ml using 0.1 ml of plasma, and has good specificity, with the major metabolite (8-hydroxycarteolol) showing only 0.2% cross-reactivity. It is reproducible, with relative standard deviations from triplicate standard curves being mostly within +/- 8%. The method is currently being used to monitor carteolol levels in clinical samples.

Nutrient intakes in relation to cancer incidence in Hawaii

A representative sample of 4657 adults greater than or equal to 45 years of age from the 5 main ethnic groups in Hawaii (Caucasians, Japanese, Chinese, Filipinos and Hawaiians) were interviewed during 1977-1979 regarding their diets. Quantitative food-consumption histories were obtained, from which average daily intakes of fat (saturated, unsaturated, cholesterol, meat, dairy, fish, animal, vegetable and total), protein (animal, meat, fish, dairy and total), carbohydrate, and vitamins A and C (including supplements) were calculated using food-consumption data from standard sources. Multiple regression analysis, with sex as a controlled variable, was used to assess the statistical relationship between these ethnic-sex-specific intakes and corresponding population-based cancer incidence rates of 15 selected sites for which nutrient components are suspected to be either causal or protective. Based on pre-set criteria for establishing important relationships, significant positive associations were found for 6 of the cancer sites: breast cancer with fat (saturated, unsaturated, animal, total) and protein (animal), corpus-uteri cancer with the same components as breast cancer, prostate cancer with fat (saturated, animal) and protein (animal, total), stomach cancer with fat (fish only) and protein (fish only), lung cancer with cholesterol, and laryngeal cancer with cholesterol. Breast and corpus-uteri cancers also showed significant negative associations with carbohydrate intake. The implications of these findings for future research are discussed.