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Biomedical subjects

M Levitt

Publications and source records attributed to M Levitt.

At least 181 records · Page 10Linked to original sources
PubMed1982

Sequential methotrexate and 5-FU in the treatment of colorectal cancer.

Administration of methotrexate (MTX), 5-FU, and leucovorin rescue in 29 patients with metastatic colorectal cancer produced an objective response rate of 41.7%, with two complete remissions. Two patients developed fatal toxic effects and three others had severe toxic effects. This trial, however, supports the evidence for the synergistic effect of this drug combination.

Colonic Neoplasms↗
PubMed1981

Platelet monoamine oxidase values and genetic heterogeneity in schizophrenia research.

Platelet monoamine oxidase (MAO) activity is significantly reduced in chronic schizophrenics with family history of schizophrenia. The degree of reduction is related to the extent of genetic load. Schizophrenics with no affected relatives do not differ from control subjects. These findings are consistent with the hypothesis of genetic heterogeneity in schizophrenia. Discrepancies among previously reported data sets can thus be explained by overrepresentation of nongenetic phenocopies with normal MAO levels. The implications for biologic and genetic research in schizophrenia are discussed.

Blood Platelets↗
PubMed1981

The deafferentation syndrome in genetically blind rats: a model of the painful phantom limb.

The hypothesis was tested which states that the somatic deafferentation syndrome is a visually prompted response to sensorimotor loss. The dorsal roots, C5-T2, were bilaterally cut in a strain of rats known to be genetically blind. These complete dorsal rhizotomies left the forelimbs totally anesthetic, analgesic and paretic. Contact and visual placing reactions were absent, and responses to pinprick or pinch were absent. Self-mutilation limited to the distal digits appeared on the first or second postoperative days and then progressed proximally. The forelimbs were symmetrically affected, and no other body parts were mutilated. The spatial precision of this syndrome, in the absence of visual as well as peripheral somatosensory information from the affected limb, indicates that controlled guidance of the behavior arises from an existing central representation of the limb and its relationship with the total body; a phantom limb. Consideration of other reports regarding the deafferentation syndrome leads to the view that it is motivated by disturbing abnormal sensations (pain) of central neural origin.

Afferent Pathways↗
PubMed1981

The deafferentation syndrome in monkeys: dysesthesias of spinal origin.

Chronic thoracic spinal lesions were surgically placed in 35 monkeys of 6 different species. In a very large percent of the cases, a bizarre behavioral pattern was released, which persisted for many months of observation. This syndrome was one in which the monkey severely attacked an hypoalgesic area of the body, namely, the leg. The syndrome resulted from contralateral anterolateral cordotomy or hemisection. It was very similar to the deafferentation syndrome which results from extensive dorsal rhizotomies. Bilateral spinal lesions indicated that the release of the syndrome was dependent upon the integrity of a widespread bilateral spinal pathway for peripheral nociception, but was independent of the integrity of specific sensory tracts. The deafferentation syndrome is considered to be a behavioral response to abnormal subjective sensations of central neural origin, and appears not to be relieved by morphine therapy. The incidence of this syndrome in the primate was subject to genetic variation.

Afferent Pathways↗
PubMed1980

Colony morphology, cell growth and viral radiosensitivity as parameters for detecting strain differences in Epstein-Barr virus (EBV).

Several parameters of two lymphocyte-transforming Epstein-Barr viruses (EBVs), B95-8 and Olare, derived from infectious mononucleosis (IM) and African Burkitt's lymphoma (BL), respectively, were compared to determine if there were biological differences between Epstein-Barr viral strains. Morphology of transformed colonies, growth of transformed cell lines, sensitivity to UV light and X-irradiation, as well as EBV-related, antigens were investigated in autochthonous cell lines. The morphology of transformed colonies was found to differ consistently both in new transformants and in lines which had been continuously growing in culture for almost 1 year. The BL transformants grew to greater density than did the IM transformants, and BL-derived virus was more sensitive to both UV light and X-irradiation. No immunologic differences were noted in the strains in assays performed for EBV-related antigens.

Cell Line↗
PubMed1980

Combination v. sequential therapy with melphalan, 5-fluorouracil and methotrexate for advanced ovarian cancer.

The results of a national clinical trial to compare combination and sequential chemotherapy for stage III or IV ovarian cancer are reported. Of the 253 patients from 16 centres across Canada who were admitted to the trial 13 were excluded from the analysis. All the patients were observed for 2 to 5 years from entry into the trial. There were no differences in response to therapy or in survival between the patients treated with melphalan followed by 5-fluorouracil and then by methotrexate in high dosage and the patients treated with the same agents in combination. Patients with minimal residual disease after resection of stage III ovarian cancer had a good prognosis. Other favourable prognostic factors were age (less than 55 years), performance status (90% or 100% on the Karnofsky scale) and histologic grade of the tumour.

Adult↗
PubMed1980

Platelet monoamine oxidase activity: relation to genetic load of schizophrenia.

Platelet monoamine oxidase (MAO) activity is significantly lower in chronic schizophrenic patients with a family history of schizophrenia compared to schizophrenics with no affected relatives and normal controls. These results are consistent with the concept of genetic and biologic heterogeneity in schizophrenia and suggest that the lack of uniformity across previous MAO studies of schizophrenia may be explained in part by the presence of biochemically normal phenocopies.

Blood Platelets↗