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Biomedical subjects

M Aronson

Publications and source records attributed to M Aronson.

At least 109 records · Page 6Linked to original sources
PubMed1981

Impaired monocyte function in liver cirrhosis.

Monocyte function in patients with cirrhosis of the liver was measured by phagocytosis and killing of Candida pseudotropicalis and C albicans. Both variables were significantly decreased in the patients compared with controls. Control monocytes exposed for two hours to patients' serum showed a significant decrease in intracellular killing compared with control monocytes incubated in autologous serum. This suggests the presence of an inhibiting factor in the patients' serum. This inhibitory factor passed through a dialysis membrane that permitted the passage of molecules of less than 12 000 daltons. Treating monocytes from patients with trypsin significantly increased phagocytosis, indicating that the possible inhibitory factor was attached to the monocyte surface. Metabolism of monocytes during phagocytosis as determined by chemoluminescence was significantly lower in monocytes from patients compared with controls, indicating metabolic impairment. Monocytes are a component of the monocyte-macrophage system, which includes Kupffer's cells. Impairment of the function of these cells, which have a pivotal role in clearing portal blood, might well be extremely important in the development of chronic liver disease.

Adult↗
PubMed1981

Immunological studies in senile dementia of the Alzheimer type: evidence for enhanced suppressor cell activity.

To examine immunological variables in senile dementia of the Alzheimer type (SDAT), we compared SDAT patients with elderly and young controls with regard to concanavalin A (Con A)-induced suppression, lymphocyte proliferation, interferon production, and serum immunoglobulin levels. The results showed exaggerated Con A suppression and reduced lymphocyte proliferation in SDAT patients compared to elderly control subjects. Interferon production after stimulation by Con A and immunoglobulin levels did not differ between SDAT and elderly control subjects. The results suggest impaired immunoregulatory mechanisms in patients with SDAT that may be related to the cause or course of SDAT. Alternatively, these immunological changes may be secondary to pathological changes in the central nervous system.

Adult↗
PubMed1980

Spontaneous bacterial clearance in experimental urinary tract infections in mice: cellular aspects of the process.

The morphological aspects of Proteus mirabilis clearance from the urinary tract of experimentally infected mice were investigated. For this purpose, two groups of mice were compared: a group infected with the bacterium and a group that had just recovered from the infection. Differences between the two groups were found in extent of bladder and kidney inflammation, depth of infiltration into the bladder wall, and in the increment of bladder volume. There was no clear-cut difference between the two groups in number of lymphocytes and monocytes, but the number of granulocytes was significantly lower in the bladder and kidneys of the recently healed animals. Likewise, the plasma cells were fewer in healed animals than in infected ones, the difference being statistically significant for bladders and on the verge of significance for kidneys.

Animals↗
PubMed1979

Differential effect of polycations on uptake and desulphation of heparin.

Previous work has established that macrophages in culture release sulphate from heparin. We now report that increased uptake and desulphation of heparin occurred in the presence of polycations (poly-L-ornithine and poly-DL-lysine) and that the increase in heparin uptake was by about 30-fold. The desulphation was less related to uptake than to the nature of the bound polycation. Serum was found to have an inhibitory effect on heparin uptake while polycations inhibited heparin desulphation by macrophage extracts.

Albumins↗
PubMed1979

Prevention of colonization of the urinary tract of mice with Escherichia coli by blocking of bacterial adherence with methyl alpha-D-mannopyranoside.

Methyl alpha-D-mannopyranoside (alpha MM), a competitor inhibitor of the binding of mannose by Escherichia coli, was tested for its ability to prevent infection of the urinary tract of mice with infective strains of the organisms. Injection of the bacteria in the presence of the drug resulted in a considerable reduction in the number of bacteriuric mice. In this system alpha MM was inactive against Proteus mirabilis in accordance with its inability to inhibit the adherence of this organism to epithelial cells in vitro, and methyl alpha-D-glucopyranoside proved inactive against both E. coli and P. mirabilis.

Adhesiveness↗
PubMed1979

Differential evaluation of students' performance in histology. All questions are equal but some are more equal than others.

Construction of multiple choice questions in histology is often hampered by the difficulty in finding alternatives to the correct answer which will be neither trivial nor ludicrous. An additional problem appears when the student performance on the morphological and the functional aspects needs to be assessed. A method of test construction is presented which includes 'multi-dimensional' questions. The questions reflect the objectives of the course and performance is evaluated differentially according to the importance attributed to their content. 'Essential knowledge' is more highly rewarded than knowledge deemed secondary by the course's planners.

Education, Medical, Undergraduate↗
PubMed1978

Increased uptake and desulphation of heparin by mouse macrophages in the presence of polycations.

Heparin uptake and desulphation by cultured macrophages were investigated. Histones, polyamino-acids, protamine and eosinophil-basic protein stimulated both heparin uptake and desulphation, processes found to be non-related. Poly-L-ornithine and poly-DL-lysine increased the heparin uptake by about 33-fold, and histone produced up to 7.5-fold increase in the desulphation. The same polycations inhibited heparin desulphation by macrophage extracts.

Animals↗
PubMed1978

Thiethylperazine; clinical antipsychotic efficacy and correlation with potency in predictive systems.

A one-to-one relationship between clinical antipsychotic potency and pharmacologic dopaminergic antagonism is implicit in the dopamine hypothesis of neuroleptic action. Thiethylperazine maleate, a classical antiemetic phenothiazine, displays dopaminergic antagonism in behavioral, neurochemical, and neuroendocrine systems, but is paradoxical insofar as it is thought not to possess clinical neuroleptic activity. In three tests of dopaminergic antagonism--elevation of levels of CSF homovanillic acid in monkeys, striatal dihydroxyphenylacetic acid in rats, and prolactin in man--as well as in a clinical trial of neuroleptic efficacy in schizophrenics, thiethylperazine was fully active and approximately three times as potent as chlorpromazine. Differences in efficacy between this and earlier clinical studies can be accounted for on the basis of dosage.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1978

An ultrastructural examination of the interaction between macrophages and Cryptococcus neoformans.

The interaction of mononuclear phagocytes with Cryptococcus neoformans was examined in vitro and in vivo using ultrastructural techniques. Immune serum roughens the surface of the yeast and in the first 2 hr, increases the number of organisms attaching to the macrophage surface, as well as the number of contacts between individual yeasts and the phagocyte. Contact is established by means of thin filopodia and cytoplasmic flaps. During the next few days the macrophages increase in size, and, by intimate apposition of their contiguous cell surfaces, a cellular barrier surrounds the now enclosed yeast. These events are accompanied by thinning of fungal capsule, degradation of the enclosed cryptococcus, and the formation of macrophage polykaryons. Electron cytochemical techniques for peroxidase reveal that these multinucleated cells are formed predominantly by the fusion of stimulated macrophages. Destruction of the enclosed yeast probably results from the secretion of various agents by the surrounding cells.

Animals↗
PubMed1977

Differential susceptibility of Escherichia coli and Proteus mirabilis to mouse urine and to urea.

The purpose of this investigation was to compare the antimicrobial properties of mouse urine and of urea against Escherichia coli and Proteus mirabilis. Nornal urine was found to inhibit the growth of E. coli and P. mirabilis, whereas urine from diuresing animals permitted multiplication of these bacteria. Addition of urea to urine from diuresing animals restored its bactericidal effect on P. mirabilis but not on E. coli. This bactericidal effect on P. mirabilis was dependent on the additive action of high content of urea and high pH and was prevented by the addition of urease inhibitor.

Animals↗
PubMed1977

Immediate and long-term effects of developmental training in children with Down's syndrome.

The aim of the present experiment was to determine whether the rate of develoment of a group of mentally retarded children could be improved by early, systematic mental training. Eight children with Down's syndrome, aged from 21 to 69 months, were trained systematically, following the pattern of normal development, over a period of 1 1/2 years. The mental age of the trained children was compared with that of eight matched controls before, during and after the training period. Both groups were living in a small institution, offering a homogeneous environment. Results showed that training had a significant effect on the mental age of the trained children. However, in a follow-up study one year after the completion of training, the good effect was reduced in the trained group, although still higher over-all than the control group. This finding indicates that while early training is effective for mentally retarded children, it must be a continuous process to achieve long-term benefit.

Child Development↗
PubMed1977

Osler node, Janeway lesions, and splinter hemorrhages.

This report documents the occurrence of an Osler node, subungual hemorrhages, and Janeway lesions peripheral to an infected arterial catheter. A brief review of these dermatological manifestations of infection is given and the importance of surgical removal of the involved artery after poor response to medical therapy is stressed.

Aged↗
PubMed1976

Elemental analysis of biological specimens in air with a proton microprobe.

The unique capabilities of the proton microprobe in an atmospheric environment as a biological tool are illustrated in studies of arsenic and mercury distributions in siingle strands of hair from poisoning victims and of the distributions of several abundant elements in frozen hydrated eye and kidney specimens from rats.

Animals↗