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Biomedical subjects

H P Cohen

Publications and source records attributed to H P Cohen.

5 recordsLinked to original sources
PubMed1975

Patterns of clinical response and plasma dopa levels in Parkinson's disease.

Serial determinations of plasma dihydroxyphenylalanine (dopa) in 16 Parkinson's disease patients receiving levodopa showed a negative correlation between plasma dopa levels and disability scores among patients who exhibited daily fluctuations of signs and symptoms. This suggests that the amount of levodopa delivered to the brain from the periphery is of major importance in the production of the "on-off" phenomenon. A close relationship between plasma dopa levels and abnormal involuntary movements was present in six patients. In three a striking dissociation between control of Parkinson's disease and abnormal involuntary movements was present, suggesting that in some patients these two effects are mediated through different underlying mechanisms. Administration of levodopa in such a way as to prevent both high and low levels of dopa in plasma minimizes disability in Parkinson's disease and may lessen abnormal involuntary movements in patients with the "on-off" effect.

Adult↗
PubMed1975

Catecholamine content of cerebral tissue after occlusion or manipulation of middle cerebral artery in cats.

The authors determined by fluorimetry the norepinephrine-epinephrine content (NE-E) of cerebral tissue from 38 cats, to ascertain whether constriction of hypersensitive arterial vessels by vasoactive agents in ischemic cerebral tissue could cause extension of cerebral infarcts and worsening of neurological deficits. Twenty-three cats had the left middle cerebral artery (MCA) occluded transorbitally, and 10 cats had sham operations. Five cats had only the surgical procedures necessary for obtaining tissue; mean NE-E content was 0.30 mug/gm (SD=0.041). For the other 33 cats, including those with sham operations, values were variable, ranging from 0.07 to 0.60 mug/gm. Low values usually were obtained for ischemic hemispheres 24 hours and 7 days after MCA occlusion, but at other times values could be high or low on either side. Many factors unrelated to tissue damage, including arterial manipulation, influence the catecholamine content of cerebral tissue.

Animals↗