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Biomedical subjects

M H Sohn

Publications and source records attributed to M H Sohn.

42 records · Page 3Linked to original sources
PubMed1993

Fluid absorption and circulating endotoxins during transurethral resection of the prostate.

Recent publications report increased cardiovascular morbidity and mortality after transurethral prostatic resection (TURP). Repeated breath-ethanol monitoring with a new infrared device permits a highly sensitive peroperative registration of fluid absorption. A prospective study in 52 patients revealed surprisingly high rates of intravascular fluid loads without clinical manifestations. Only 4 patients developed clinical signs of the TUR syndrome. Immunological work-up in 41 patients demonstrated circulating endotoxins and significant rise of endogenous tumour necrosis factor (TNF) in 3 of these patients. In 11 patients transient endotoxins could be detected during resection under prophylactic parenteral antibiosis. In the face of less invasive approaches to benign prostatic hyperplasia, close intraoperative monitoring and antibiotic coverage should be demanded as a routine procedure during TURP. Elective surgery should be delayed until appropriate antibiotic therapy has been given.

Absorption↗
PubMed1993

Enrichment for metallothionein does not confer resistance to cisplatin in transfected NIH/3T3 cells.

Evidence has been presented both that metallothionein does and does not produce resistance to cisplatin. The metallothionein-enriched cells described in most previous studies have been selected for resistance to heavy metals, such as cadmium, or have been maintained in a medium enriched for the metals. Exposure to toxic metals could alter the cells in many ways. This report addresses the effect of metallothionein content alone, independent of exposure to metals, on cellular resistance to cisplatin. The toxicity of cisplatin was compared in NIH/3T3 cells that vary in their content of metallothionein as a consequence of transfection with a plasmid that results in the constitutive expression of metallothionein. The plasmid contains the bovine papillomavirus genome and the mouse metallothionein-I gene; it is driven by a glucose-regulated protein of 78 kD. Control cells were transfected with a similar plasmid in which the coding sequences for metallothionein were inverted and separated from the promoter, thereby abolishing expression. Expression of metallothionein required neither selection nor maintenance of cells in the presence of heavy metals. Despite large differences between the two types of cells in their cellular content of metallothionein and in their resistance to the toxicity of cadmium, no differences in resistance to cisplatin were observed.

3T3 Cells↗
PubMed1993

Distribution of gallium-67 in normal and hypotransferrinemic tumor-bearing mice.

The mechanism by which 67Ga accumulates in tumors is controversial. The most popular theory is that 67Ga binds to transferrin and gains access to cells by the transferrin receptor. However, substantial evidence suggests that uptake of 67Ga may not be universally mediated by transferrin in tumors. To determine whether transferrin is required for uptake of 67Ga in vivo, we compared the uptake of 67Ga by two types of implanted tumors and by normal tissues in normal and severely hypotransferrinemic strains of Balb/C mice. One type of tumor was strongly gallium-avid in normal mice; the other was not. Uptake of 67Ga by normal soft tissues was markedly less in hypotransferrinemic than in normal mice. Uptake of 67Ga by bone was equivalent in the two types of mice. For the more gallium-avid tumor, uptake of 67Ga was similar and the ratio of tumor-to-background activity was substantially higher in the hypotransferrinemic than in the normal mice. For the less gallium-avid tumor, uptake was significantly less in hypotransferrinemic than in normal mice. These data suggest that uptake of 67Ga by bone and by some tumors may be a transferrin-independent process.

Animals↗
PubMed1993

Criteria for examiner-independent nocturnal penile tumescence and rigidity monitoring (NPTR): correlations to invasive diagnostic methods.

78 patients (pts.) with erectile dysfunction (ED) underwent conventional diagnostic evaluation including NPTR monitoring with the Rigiscan, intracavernous drug testing, dynamic cavernosometry, doppler evaluation, pharmaco-angiography and neurologic tests. Only erections of the best rigidity recorded over three nights served for classification into three classes of rigidity. Patients with neurogenic impotence showed significantly poorer and fewer erectile events per hour than vasculogenic impotent men. Patients with arteriogenic ED had better erections than patients with venogenic or mixed arterio-venogenic ED. Severity of organic ED during conventional diagnostic work-up correlated to loss of rigidity during NPTR recordings, but no differential diagnosis between arteriogenic, venogenic or neurogenic impotence could be made with NPTR data alone. The presented criteria for NPTR evaluation permit a time-saving, examiner-independent analysis.

Adult↗
PubMed1992

Uptake of cadmium is diminished in transfected mouse NIH/3T3 cells enriched for metallothionein.

To determine the relationship between cellular uptake of cadmium and content of metallothionein, we measured uptake of 109Cd in cells that differed in content of metallothionein (MT). MT cells were derived from NIH/3T3 cells by transfection with a plasmid containing the genome of bovine papilloma virus and the mouse metallothionein-I gene, driven by the promotor for the glucose-regulated protein of 78 kDa. Control cells were similarly transfected with bovine papilloma virus-based plasmids with the gene for metallothionein inverted and thus separated from the promoter (TM), or deleted, along with the promoter (BPA). The number of copies of bovine papilloma virus-based plasmids was similar in MT, TM, and BPA cells, approximately 100 per cell. MT cells were more than 10 times more resistant to the lethal effect of cadmium than were the control cells. Synthesis of metallothionein was 15-fold greater in the MT cells than in the TM or BPA cells. The uptake of 109Cd by the cells enriched in metallothionein was 4-fold less than by the control cells. These data suggest that an increased content of metallothionein may protect some cells from the toxic effects of cadmium, in part, by diminishing uptake of the metal.

3T3 Cells↗