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Biomedical subjects

E M Mahoney

Publications and source records attributed to E M Mahoney.

50 records · Page 3Linked to original sources

Post-diversion pre-cystectomy irradiation for carcinoma of the bladder.

In 47 patients treated sequentially with urinary diversion and laparotomy staging, irradiation therapy and total cystectomy for invasive carcinoma of the bladder, the mortality rate was 2 per cent and the complication rate was 20 per cent. The survival rate was most favorable in patients in whom the pathologic specimen revealed no tumor after irradiation. The lower mortality and morbidity rates are attributed to staging of surgical procedures and the challenge remains to increase the number of patients in whom carcinoma of the bladder is converted by irradiation therapy to a lower stage or no tumor.

Carcinoma↗

Declining immune function in children and adolescents with hemophilia and HIV infection: effects on neuropsychological performance. Hemophilia Growth and Development Study.

OBJECTIVE: To determine whether declines in immune functioning are associated with changes in neuropsychological performance in children and adolescents with hemophilia who are infected with the human immunodeficiency virus (HIV). METHODS: Participants were 333 males with hemophilia, ages 6-19 years at entry. A baseline and four annual neuropsychological evaluations were given. A longitudinal growth curves analysis of data was performed to detect changes associated with declining immune function. The cohort was stratified into four groups: (1) HIV- (n = 126); (2) HIV+, average of first two and last two CD4 counts > or = 200, (n = 106; High CD4 group); (3) HIV+, average first two counts > or = 200, average last two counts < 200 (n = 41; CD4 Drop group); and (4) HIV+, average first two and last two counts < 200 (n = 60; Low CD4 group). RESULTS: There were significant differences among the four groups over time in nonverbal intelligence, perceptual/performance skills, nonverbal memory, academic achievement, and language. The Low CD4 group consistently showed the greatest decrement in performance. On measures showing a practice effect for repeated measurements, the Low CD4 group participants' scores remained stable over time, suggesting opposing effects of practice and HIV-related declines. Lowered academic performance relative to IQ was found in all groups. CONCLUSIONS: Declines in neuropsychological functioning are directly related to declines in immune functioning in HIV+ children, adolescents, and young adults with hemophilia. Hemophilia itself may be a risk factor for academic underachievement.

Adolescent↗

Enhanced macrophage degradation of biologically modified low density lipoprotein.

Low density lipoprotein (LDL) conditioned by incubation in the presence of rabbit aortic or human umbilical vein endothelial cells (endothelial cell-modified LDL) was degraded by macrophages three to five times more rapidly than LDL incubated in the absence of cells (control LDL). This enhanced degradation occurred mostly via a high affinity, saturable pathway related to the pathway for macrophage uptake of acetylated LDL. Conditioning LDL with cultured aortic smooth muscle cells had a qualitatively similar but smaller effect; conditioning with fibroblasts had no effect. Conditioning very low density lipoproteins or high density lipoproteins with endothelial cells did not affect subsequent metabolism of these lipoproteins by macrophages. Endothelial cell-modified LDL, while degraded more rapidly than control LDL by macrophages, was degraded more slowly by cultured smooth muscle cells and by human skin fibroblasts. Degradation of endothelial cell-modified LDL by macrophages was accompanied by stimulation of cholesterol esterification, inhibition of cholesterol synthesis, and a net increment in total cellular cholesterol content. Thus, a biologically generated modification of LDL is described that markedly alters cholesterol metabolism of macrophages and, consequently, may play a role in foam cell formation during atherogenesis.

Acetylation↗

Neutral triglyceride lipase in macrophages.

High levels of neutral triglyceride lipase activity have been demonstrated in several types of macrophages (J774 cells, human monocyte/macrophages, rabbit alveolar macrophages, and resident mouse peritoneal macrophages). The pH optima ranged from 6.5 to 7.4 depending upon the buffer and the conditions of incubation. The addition of bovine serum albumin stimulated activity at low concentrations, as expected for a fatty acid-releasing reaction, but strongly inhibited at higher concentrations; maximal activity was observed in the presence of 0.625 mg/ml of bovine serum albumin. The enzyme was remarkably thermostable, showing no apparent loss of activity at 50 degrees C for as long as 6 hours. The lipase was inhibited 80% by 0.1 M NaCl. Assayed under optimal conditions, the specific activity of the neutral triglyceride lipase from J774 cells was more than 100-fold greater than the activity of lipoprotein lipase or neutral cholesterol esterase from those cells; this activity was 10-fold greater than the levels of hormone-sensitive lipase from 3T3-L1 adipocytes. This neutral triglyceride lipase may play an important role in the degradation and mobilization of cytosolic triglyceride in macrophage-derived foam cells.

Animals↗