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S Watters

Publications and source records attributed to S Watters.

4 recordsLinked to original sources
PubMed1997

Longitudinal study of plasma cortisol and 17-hydroxyprogesterone in very-low-birth-weight infants during the first 16 weeks of life.

There are few published data on plasma cortisol and 17-hydroxyprogesterone (17-OHP) in very-low-birth-weight (VLBW) infants beyond the 1st week of life. We therefore measured plasma cortisol and 17-OHP longitudinally in 26 infants (median birth weight 930 g, median gestational age 28 weeks) from 1 to 16 postnatal weeks to document normative values. We also examined the effect of clinical state on plasma cortisol and 17-OHP levels. Median plasma cortisol decreased with postnatal age from 1 to 8 weeks (110 vs. 60 nmol/l; p = 0.0007) and with postconceptional age from 25 to 36 weeks (104 vs. 47 nmol/l; p = 0.002). Median plasma 17-OHP decreased with postnatal age from 1 to 16 weeks (17.0 vs. 7.1 nmol/l; p < 0.0005) and also with postconceptional age from 25 to 42 weeks (21.1 vs. 7.1 nmol/l; p < 0.0005). Plasma cortisol was not influenced by the clinical state. Median plasma 17-OHP was significantly higher for 'unwell' versus 'well' infants at 5-8 weeks postnatal age (23.0 vs. 12.5 nmol/l; p = 0.012) but not at other postnatal age intervals. These data provide information on adrenocortical function in VLBW infants during the first 4 months of life.

17-alpha-Hydroxyprogesterone↗
PubMed1991

Computerized method for validating laboratory reference ranges for triiodothyronine and thyroxin immunoassays.

We used a computer-based method to help validate the reference ranges of assays for triiodothyronine (T3) and thyroxin (T4). A retrospective search of a database of laboratory results for the previous six months identified all patients with apparent euthyroid status, as defined by methods independent of the immunoassay under review. A computer-generated reference group (CGR Group) of 2001 records had a gaussian distribution of T4 values and a reference range (mean +/- 2 SD) of 56-161 nmol/L, compared with the supplier's suggested range for euthyroid subjects (58-148 nmol/L) and an in-house range of 60-144 nmol/L for a group of 97 normal subjects. A similar CGR Group of 1902 records gave a reference range for T3 of 0.7-2.1 nmol/L (manufacturer's range 0.8-2.8; normal subjects 0.8-2.2). An attempt to devise a reference range for thyrotropin failed when we found that its concentration in the population of patients with normal values for thyroid hormones was distributed differently from that in the normal population. The method is intended to be used in addition to conventionally derived ranges based on results for healthy subjects. It allows the laboratory to conveniently verify the reference ranges for T3 and T4 assays at regular intervals by using very large samples with appropriate age, sex, and weight distribution, drawn from the population of patients' samples submitted for analysis.

Computers↗
PubMed1990

Concentric and eccentric quadriceps torque in pre-adolescent males.

The purpose of this study was to evaluate the applicability of using the Kin Com (Chattecx Corp., Chattanooga, TN) isokinetic machine to measure concentric and eccentric quadriceps torque in a group of 12 healthy male volunteers aged 10-12 years. Each individual was tested by an experienced physiotherapist using a 60 degree per second velocity mode according to our standardized protocol. Average and peak torque values for concentric and eccentric contractions of the quadriceps were recorded; based upon the best of three maximum effort trials on each lower extremity. Retesting was performed on a randomly selected sub-group in an identical manner two weeks later. Our results showed no statistically significant difference between the original and retest values using the method error of repeated measurements and paired t-test analyses. Eccentric peak torque was greater on average than concentric. This was significant with p-values of 0.01 for the non-dominant quadriceps and 0.002 for the dominant side (paired t-test). There was no significant difference between the dominant and non-dominant sides. In conclusion, eccentric muscle testing has been reliably quantitated for the first time in children. This study has shown a practical and reproducible method of quantitative muscle strength assessment.

Child↗