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Biomedical subjects

S Hopwood

Publications and source records attributed to S Hopwood.

4 recordsLinked to original sources

Plasma sialyltransferase levels in psychiatric disorders as a possible indicator of HPA axis function.

A dysfunction in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis, possibly attributed to a change in glucocorticoid receptor (GR) functionality, has been implicated in depression. We have measured both lymphocyte GR receptor binding parameters and plasma sialyltransferase activity, as a biochemical marker of GR function, in two groups of patients suffering from depression or schizophrenia and in a group of age- and sex-matched controls. While there was a significant increase in plasma cortisol levels in the depressed group, there were no changes in the lymphocyte GR binding parameters (K(m) and Bmax). There was, however, a significant decrease in the plasma sialyltransferase: cortisol ratio in the depressed group suggesting an inability of the raised cortisol levels to induce enzyme expression and this ratio may provide a useful biochemical marker of cortisol receptor function. Although there was an increase in the plasma activity of the alpha 2,6 sialyltransferase isozyme in the schizophrenic group, no other changes were determined. Therefore, while the total plasma sialyltransferase:cortisol ratio reflects HPA axis function, alterations in specific isozyme activity may also be associated with other CNS disease states.

Binding Sites↗

The influence of age on lithium efficacy and side-effects in out-patients.

One hundred and sixty-six unipolar and bipolar out-patients (21-78 years) on long-term lithium treatment were studied on a prospective basis. Although there was a possible tendency for manic attacks to increase in prevalence and severity with age, it was difficult to demonstrate a general age-related decline in lithium efficacy. There was a tendency for the prevalence and severity of fine hand tremor to increase with age. This was not seen with polydipsia/polyuria, the other typical lithium side-effect.

Adult↗

Physical growth and development of urban native Americans: a study in urbanization and its implications for nutritional status.

Anthropometric measurements and hematocrits are reported on a mixed longitudinal sample of 1309 urban native Americans from Minneapolis from 22 days through 19 years of age (the sample size for each measurement varied from 276 to 1309). The results are compared to the United States national probability samples from the National Center for Health Statistics (HANES and HES), as well as, from 6 through 12 years, to a sample of related American Indians from a reservation in northern Minnesota. Compared to the United States standards, the urban sample is slightly shorter and, in general, consistently heavier. The skinfold thicknesses (triceps and subcapular) varied by site, sex, and age, relative to the standard. In general, the native Americans had thicker skinfolds except for males below 6 years of age, and for the subcapsular in female at all ages. Relative to the sample from the reservation, the urban natives are taller, heavier, with thicker skinfolds and greater weights-for-height. The potentially greater risk for obesity associated with urbanization is discussed. While the mean hematocrits were very close to accepted standards, 35% of infants and children less then 6 years of age had values less than 34.

Adolescent↗

Age as a factor affecting lithium therapy.

1 We examined the case notes of 82 psychiatric out-patients (aged 21-84 years) receiving lithium prophylaxis and with steady-state plasma lithium levels. 2 The mean weight-related daily dose of lithium prescribed decreased by about 50% between the third and eight decades. 3 The corresponding steady-state plasma lithium levels showed a less marked tendency to decrease, this only being seen in the seventh and eighth decades. 4 In patients aged 50 years or over the daily lithium dose required to give a plasma level of 1 mmol l-1 (0.50 mmol kg-1) was significantly lower than that (0.65 mmol kg-1) in patients aged under 50 years (P less than 0¿5, Student's t-test). In patients aged 70-79 years this dose was 31% lower than in patients under 50 years. However, interindividual variation was great and it was estimated that age only contributed about 14% to the total interpatient variation. 5 Of the 36 patients under 50 years of age, 42% had minor lithium side-effects and 17% were not optimally controlled with lithium. The corresponding figures for the 46 'older' patients were 46% and 28%. 6 Generally the 50% dosage reduction seemed necessary to compensate for an age-related decrease in lithium excretion and to reduce lithium side effects to a level comparable to that acceptable in younger patients.

Adult↗