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A G Mallinger

Publications and source records attributed to A G Mallinger.

63 records · Page 4Linked to original sources
PubMed1977

The relationship between extra- and intracellular lithium concentration in human red blood cells: an in vitro study.

Red blood cells (RBC's) from normal volunteers were incubated in vitro at four different extracellular lithium concentrations. Extracellular lithium concentration affected RBC lithium accumulation in several ways. As extracellular lithium concentration increased, the inter-individual variability of RBC lithium accumulation increased. Furthermore, the ratio of RBC lithium concentration to extracellular lithium concentration (lithium ratio) increased in relation to increasing extracellular lithium concentration. A lack of agreement among the authors of recent reports dealing with the significance of the lithium ratio as a psychobiological measure has been noted. It is suggested that this lack of agreement may be due, in part, to the study of patients with differing levels of extracellular lithium.

Cell Membrane Permeability↗
PubMed1976

Pharmacokinetics of lithium in human plasma and erythrocytes.

The time course of lithium concentration in plasma and RBCs was measured in normal adult males following administration of single and multiple doses of lithium carbonate. From the single dose profiles, it was determined that lithium distribution between plasma and RBCs is not a simple partitioning phenomenon. The single dose time course measurements in both blood components were fit to a two compartment pharmacokinetic model in which the plasma was representative of the central compartment and the RBCs were representative of the tissue compartment. The importance of correction for trapped plasma volume in studies measuring lithium RBC kinetics was emphasized. In this study it was also demonstrated that one can accurately predict plasma and RBC lithium concentrations which are observed following multiple dosing, on the basis of single dose parameters obtained in the same subject.

Adult↗
PubMed1976

Effect of chlorothiazide on the pharmacokinetics of lithium in plasma and erythrocytes.

The effect of chlorothiazide on the pharmacokinetics of lithium in both plasma and RBCs was studied in normal adult males. This was accomplished by administering single, 300 mg. doses of lithium carbonate alone and concurrently with chlorothiazide (0.5 grams/day for one week). Thiazide administration resulted in increases in plasma and RBC concentrations of 26.2 and 25.4%, respectively, as well as a 26.5% decrease in renal lithium clearance. The data were analyzed in terms of a two compartment pharmacokinetic model as previously reported (8). The results of this analysis showed that the change in renal lithium clearance could be accounted for by a 24.1% reduction in the value of ke, the excretion rate constant. It was also shown that changes in plasma lithium concentration during chronic lithium therapy would be expected to increase by 25-30% when chlorothiazide therapy is employed. The model also predicts that changes in RBC concentrations would parallel those occurring in plasma and thus no change in the RBC/plasma lithium ratio would be expected.

Adult↗
PubMed1975

In vitro and in vivo transport of lithium by human erythrocytes.

An in vitro system that can be used to measure both uptake and efflux of lithium by erythrocytes (RBCs) is described. Using this system, RBC lithium accumulation in vitro was compared with in vivo RBC lithium concentrations observed in 6 normal volunteers. A significant correlation was demonstrated between in vitro RBC lithium accumulation after 48-hr incubation and in vivo RBC lithium concentration at 24, 48, 72, and 96 hr following the beginning of lithium ingestion. In addition, when efflux of lithium from RBCs in vitro was studied, a significant correlation was observed between residual lithium in RBCs and in vitro RBC lithium accumulation. Finally, it has been demonstrated that storage of blood in ice for 5 hr prior to incubation with lithium results in increased RBC lithium accumulation. A potential role for this in vitro incubation system as a model for in vivo RBC lithium accumulation is suggested.

Adult↗
PubMedDate not supplied

MRI study of posterior fossa structures and brain ventricles in bipolar patients.

Previous brain imaging studies have suggested anatomical abnormalities in posterior fossa structures and brain ventricles in bipolar patients. Such abnormalities could possibly be implicated in the pathophysiology of bipolar disorder. Twenty-two DSM-IV bipolar outpatients (mean age+/-S.D.=36+/-10 years) and 22 healthy controls (mean age+/-S.D.=38+/-10 years) underwent an 1.5T MRI (3D-gradient echo-imaging SPGR), performed in the coronal plane (TR=25 ms, TE=5 ms, slice thickness=1.5 mm). The brain structures of interest were traced blindly with a semi-automated software. No significant differences were found between bipolar patients and healthy controls for any posterior fossa measures, or for measures of third or lateral ventricles (MANOVA, age covariate, P>0.05). Age was directly correlated with 3rd ventricle volumes in bipolar patients (Pearson correlation coefficient=0.458, P=0.032), but not in healthy controls (Pearson correlation coefficient=0.313, P=0.155). There was a significant direct correlation between the number of prior illness episodes and right lateral ventricle volumes (Partial correlation coefficient=0.658, P=0.011). Familial patients had smaller left and right cerebellar hemispheres and total vermis volumes, and larger left lateral ventricle volumes compared with non-familial ones (MANOVA, age covariate, P<0.05). In this preliminary study, we were not able to replicate previous findings of abnormalities in cerebellum or brain ventricles in bipolar individuals. However, there were suggestions that abnormalities in cerebellum, vermis, and lateral ventricle sizes may be present in familial cases of the disorder, which should be further examined in future studies with larger patient samples.

Adult↗