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Biomedical subjects

N Williams

Publications and source records attributed to N Williams.

At least 397 records · Page 22Linked to original sources
PubMed1977

Psychopathology and mental retardation: a statistical study of 100 mentally retarded children treated at a psychiatric clinic: II. hyperactivity.

The authors studied 100 mentally retarded children referred to a psychiatric clinic and found that 39 were hyperactive. However, there was no significant relationship between hyperactivity and mental retardation (with or without psychosis) or brain damage. Comparison with a group of nonretarded children revealed no significant difference regarding hyperactivity, thus suggesting that the disorder is not an inevitable concomitant of mental retardation.

Brain Damage, Chronic↗
PubMed1977

Analysis of populations of macrophage-granulocyte progenitor cells stimulated by activities in mouse lung-conditioned medium.

Granulocyte and macrophage progenitor cells which clone in semi-solid agar cultures were characerized by separating murine bone marrow cells by equilibrium density centrifugation. These in vitro colony forming cells (CFU-c), when induced by stimuli in mouse lung-conditioned medium, were found to be heterogeneous in their density properties. Differences were found in the dose responsiveness of two major subpopulations of these progenitor cells. One population (modal density 1.074 gcm-3) responded in an identical manner to stimuli present in mouse lung-conditioned medium and pregnant mouse uterus extract. A second population (modal density 1.070 gcm-3) was found to be markedly different in its dose responsiveness to mouse lung-conditioned medium, from the other subset (1.074 gcm-3). The cloning of the low density progenitor cells and the observed dose responsiveness was found to correlate with an activity present in a stimulus in mouse lung-conditioned medium but was not identical to the stimulus in pregnant mouse uterus extract. No subpopulation, however, gave exclusively granulocyte or macrophage colonies.

Animals↗
PubMed1975

Separation of subpopulations of in vitro colony forming cells from mouse marrow by equilibrium density centrifugation.

Equilibrium density centrifugation was used to characterise and separate subpopulations of mouse haemopoietic progenitor cells capable of producing colonies of granulocytes and macrophages in vitro. The material used to induce colony formation (CSF) was prepared from an extract of pregnant mouse uteri. This CSF preparation was found to be free of factors modifying the response. Under these culture conditions, in vitro colony forming cells (CFU-c) were found to be relatively homogeneous in their buoyant density. This homogeneity was independent of CSF concentration. A heterogeneous density profile of CFU-c was obtained when various cell fractions were cultured in the presence of CSF and rat blood lysate. The majority of the additional cells which responded to erythrocyte lysate were dense (modal density 1.080 g/cm3) compared to CFU-c which responded to CSF alone (modal density 1.074 g/cm3). It is concluded that in vitro colonies induced by CSF and in vitro colonies grown in the presence of CSF and erythrocyte lysate reflect two different populations of CFU-c.

Animals↗
PubMed1975

Mechanism of release of endogenous cholecystokinin by jejunal amino acid perfusion in man.

Ertan et al have shown that the perfusion of the proximal jejunum with a mixture of amino acids (MAA) in physiological concentration releases endogenous cholecystokinin (CCK) in man. In the present experiment, we investigate the mechanism by which jejunal MAA perfusion mediates an increase in exocrine pancreatic and biliary secretions. The effects of a bolus of topical anesthetic (oxethazaine, 0.5 mg/kg of 0.4% solution) or the simultaneous jejunal perfusion of a topical anticholinergic agent (atropine, 1 mg/liter) were studied in the same five normal patients on different days. Suppression of the response to jejunal MAA perfusion but not to intravenous infusion of CCK or jejunal saline perfusion, was noted in these normal subjects following jejunal application of oxethazaine and atropine. These results suggest a local involvement of the cholinergic mechanism for the endogenous release of CCK, while exogenous CCK acts directly on the pancreatic cells.

Amino Acids↗
PubMed1975

Psychopathology and mental retardation: A study of 100 mentally retarded children: I. Psychopathology.

The authors studied 100 mentally retarded children referred to a psychiatric clinic in regard to the severity of their retardation, their ages at the time of referral, their social class, their presenting symptoms and diagnoses, and the effects of organicity on their clinical pictures. They found that 38 of these children were psychotically disturbed, 13 had no evidence of psychiatric disorder, and 49 showed symptoms of characterologic, neurotic, behavioral, or situational disorders. Although the incidence of emotional disorder was high among these children, their symptoms did not differ in kind from those found in a group of nonretarded children referred to the clinic.

Adolescent↗