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Biomedical subjects

J Mendels

Publications and source records attributed to J Mendels.

At least 91 records · Page 5Linked to original sources

Red blood cell Li+ to plasma Li+ ratios. Are they related to plasma Li+ concentrations?

The relationship between the lithium ratio (ratio of lithium in blood cells to that in plasma) and plasma lithium concentration was examined in a group of male inpatients taking lithium carbonate for affective disorders. The lithium ratio was found to increase in the majority of these patients as plasma lithium concentration increased. However, the magnitude of variation of the lithium ratio with plasma lithium concentration observed in these patients is not sufficient to seriously affect the value of determining the lithium ratio in the clinical situation.

Erythrocytes↗

Erythrocyte concentrations of the lithium ion: clinical correlates and mechanisms of action.

When lithium carbonate is administered to individuals, there is considerable intersubject variation in the extent of accumulation of Li+ by erythrocytes. The primary reason for this is differences in the activity of a Li+-Na+ counterflow system, which, under clinical conditions, removes Li+ from the cell. It appears that some bipolar patients accumulate more Li+ in their red cells than either unipolar depressives or normal controls. The precise clinical characteristics of the bipolar patients who accumulate relatively large amounts of erythrocyte Li+ need to be clarified in future research. Finally, the measurement of red cell concentrations of Li+, in addition to the usual plasma measurement, can be used as an indicator of patient compliance.

Biological Transport, Active↗

Prediction of the lithium ratio in man by means of an in vitro test.

The movement of the lithium ion (Li+) across the membrane of intact erythrocytes incubated in vitro was assessed under two different experimental conditions in which such transfer occurred primarily due to the activity of a lithium-sodium countertransport system. The 13 subjects on whom the in vitro procedures were done subsequently received lithium carbonate for 14 to 56 days, and the extent of accumulation of Li+ by erythrocytes in vivo was measured. While both in vitro procedures yielded data that correlated with the extent of accumulation of Li+ by erythrocytes in vivo, a system measuring the efflux of Li+ from Li+-loaded cells produced a much higher correlation (0.976). The magnitude of this correlation suggests that this in vitro system can be used for further investigations into the relevance of the erythrocyte accumulation of Li+ to the pathogenesis and treatment of affective disorders.

Adult↗

The role of stress as a precipitating factor of psychiatric illness.

Fifty-six psychiatric patients were interviewed to obtain a record of life events preceding admission to hospital, using a modified version of the Schedule of Recent Experiences. Two control groups were studied for comparison: medical and surgical in-patients and a "normal" population studied independently by Myers. Psychiatric patients reported a significantly larger number of events than the medical-surgical patients, who, in turn, reported significantly more events than the "normal" population. There were no significant differences in the specific life event histories between groups.

Family↗

Life events and illness: a three year prospective study.

In an investigation of the relation between life events (stressors) and illness, 87 medical students reported on a prospective basis their health and life events history over a three year period. There were a few positive findings, e.g. that subjects who reported more life events during the period also reported more illnesses during that period. Overall, however, the study showed a lack of statistically significant association between life events and illness.

Adult↗