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Biomedical subjects

L Levin

Publications and source records attributed to L Levin.

At least 73 records · Page 4Linked to original sources
PubMed1981

Metabolic alterations in cancer. Part II. Protein and fat metabolism.

Intracellular changes in protein metabolism within cancer cells may facilitate cell reduplication, and this may be supported by changes in enzymes responsible for protein synthesis and degradation. Synthesis of ectopic hormones probably reflects genetic de-repression. Increased muscle proteolysis has been reported by some workers in cancer patients, and this may be associated with muscle cells, increased glucocorticoid secretion by the adrenal cortex, increased gluconeogenesis or impaired muscle glycolysis. Decreased proteogenesis has also been reported to occur in the muscles of cancer patients. Although tumour tissue may inhibit muscle proteogenesis, there are as yet no data to suggest a direct tumour-derived ectopic substance which affects muscle proteolysis or proteogenesis. Data regarding serum levels of free fatty acids (FFA) in weight-losing cancer patients are conflicting, although it is likely that abnormally high values are due to liver dysfunction rather than enhanced peripheral lipolysis. Nevertheless, since serum levels may be normal if FFA consumption is increased to the same extent as release, these levels need not indicate overall FFA turnover. If enhanced FFA release from fat stores does occur, this may provide the liver with an energy source required for its increased commitment to gluconeogenesis.

Animals↗
PubMed1981

Metabolic alterations in cancer. Part I. Carbohydrate metabolism.

Glucose intolerance seen in weight-losing patients may not result from qualitative or quantitative alterations in insulin secretion or binding. It may, however, be the result of increased gluconeogenic flux which occurs in these patients. This may be due to increased substrate availability resulting from lactate production as the unoxidized-end-product of tumour glycolysis (Warburg effect). In addition, increased levels of glucogenic amino acid may be associated with preferential amino acid sequestration by the tumour, causing decreased muscle proteogenesis and therefore atrophy. Enhanced glucose demand by tumour cells may also lead to an increased hepatic gluconeogenesis, as will the production of ectopic ACTH.

Acetyl Coenzyme A↗
PubMed1980

Enterovesical fistulas in Crohn disease.

Fistulous communication between the intestinal tract and the bladder is uncommon in Crohn disease. Only 2% of patients afflicted with this disease present with bladder symptoms. Five patients with a mean age of thirty years presented with a prolonged history of bowel disease but a short history of urinary symptoms. Only three patients presented with pneumaturia and fecaluria. None of the fistulas could be demonstrated radiographically. Cystoscopy disclosed the fistulous site as well as acute and chronic inflammation of the bladder. Small-bowel resection with excision of the fistula, partial bladder resection, and diverting ileostomy were performed as a first stage. Ileostomy closure was done two to four weeks later.

Adult↗
PubMed1976

Active specific immunotherapy for ovarian cancer.

Ten patients with advanced or recurrent ovarian cancer were treated with a combination of chemotherapy and active specific immunotherapy after tumour stasis had been induced. They were inoculated with irradiated allogeneic cryopreserved tumour cells and B.C.G. once monthly in addition to receiving conventional chemotherapy. The overall duration of "remission", median survival, and projected 24-month actuarial survival in the patients receiving immunotherapy were apparently better than in a retrospectively matched control group treated by chemotherapy alone.

Adult↗
PubMed1976

Tumour-associated immune responses and isolated carcinoembryonic antigen and alpha feto-protein levels related to survival in ovarian cancer patients.

The presence of a tumour-associated immune response in 37 patients with ovarian cancer as assessed by blastogenesis (lymphocyte transformation) evoked by ovarian cancer cell extracts, has been correlated with survival following the test. The difference in these responses is unlikely to be accounted for on the basis of general impairment of cell-mediated immuno-competence. Serum carcinoembryonic antigen (CEA) was also determined in 27 ovarian cancer patients to assess its prognostic significance. Raised CEA levels and absence of blastogenic response to tumour cell extract during relapse are associated with a worse prognosis but neither of these parameters are significant in remission. Possible applications of these findings to the clinical management of ovarian cancer patients are discussed. Serum alpha feto-protein levels measured by radioimmunoassay were not found to be raised in any of the 32 ovarian cancer patients in whom it was measured.

Aged↗
PubMed1976

The surgical management of toxic dilatation of the colon: a report of 28 cases and review of the literature.

Experience with 28 patients with toxic dilatation of the colon is reviewed. The operative mortality in this series was 32% (9/28). Eight of the 9 patients who died were found to have colonic perforations at operation; in contrast, the group of patients with no perforations had a mortality rate of only 6%. Colonic perforation and sepsis were the most significant factors contributing to mortality and morbidity in this series. A review of the literature showed an overall operative mortality rate of 19.5% for patients with toxic megacolon; the mortality rate was 41% for patients with perforations and 8.8% for patients without perforations. It appears that the keystone to successful management is the avoidance of colonic perforation and sepsis; protracted medical management of toxic megacolon seems to have been at least partly responsible for these complications. Sixteen of the 18 survivors following subtotal colectomy required removal of the rectum within 9 months because of continued symptoms and disease in the rectal stump.

Adolescent↗
PubMed1976

Tumour associated immunity and immunocompetence in ovarian cancer.

Cell-free extracts of autologous ovarian cancer cells evoked a delayed hypersensitivity response (DHR) in skin in four out of six patients in remission from disease and none of seven patients in relapse. These initial results appear to be consistent with in vitro blastogenic assay using the same autologous extracts. To assess whether diminished tumour-associated immunity was due to impaired cell-mediated immunocompetence, blastogenic responses to purified protein derivative of tuberculin (PPD), a secondary recall antigen, and phytohaemagglutinin (PHA) were assessed. Impaired responses to PHA were seen in the relapse group of patients, but responses to PPD did not appear to be impaired in this group.

Female↗