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Biomedical subjects

N Gordon

Publications and source records attributed to N Gordon.

At least 109 records · Page 6Linked to original sources
PubMed1990

Endoscopic and radiographic evaluation of the murine colon.

Endoscopic and radiographic techniques have not been widely applicable in the evaluation of chemically induced murine colon cancer. The authors investigated methods of cleansing the rat colon and refined endoscopic and radiographic techniques. They compared total colonoscopy (TC) and air-contrast (ACBE) and single-contrast barium enema (SCBE) findings with those obtained at necropsy in rats with 1,2-dimethylhydrazine (DMH)-induced colon cancer. Gastrograffin enemas with bisacodyl suppositiories showed complete evacuation of solid feces. Sprague-Dawley rats treated with DMH had their colons cleansed and then underwent TC (5.0-mm Olympus bronchoscope) and either SCBE or ACBE. Colonoscopy and ACBE were equally sensitive (81.5% and 76.3%, respectively), although SCBE was significantly insensitive in identifying lesions (P less than 0.001). This study demonstrates that: (1) mechanical cleansing of the rat colon is feasible, (2) TC and barium radiology can be done routinely after mechanical cleansing, and (3) TC and double-contrast BE are sensitive in identifying colon lesions. These techniques will provide a means for manipulation of murine tumors and in vivo surveillance.

1,2-Dimethylhydrazine↗
PubMed1990

Antibiotics in elective colon surgery. A randomized trial of oral, systemic, and oral/systemic antibiotics for prophylaxis.

A prospective, randomized double-blind study was undertaken to compare the efficacy of three prophylactic regimens (oral neomycin and erythromycin, intravenous cefoxitin, and a combination of both oral and intravenous antibiotics) in patients undergoing elective colorectal surgery. One hundred sixty-nine patients were randomized and 146 patients were evaluable. Septic complications occurred in 11.4 per cent of patients receiving oral antibiotics only, in 11.7 per cent of patients receiving intravenous cefoxitin alone, and in 7.8 per cent of patients receiving both oral and intravenous antibiotics. These differences were not statistically different. The greatest number of septic complications occurred in those patients with anastomotic disruptions. Two patients died (1.3%), both of whom had major anastomotic failures. There was no advantage between any of the groups in the incidence of wound infection (3.9-6.8%). Thus, no advantage could be identified in this study in the combination of oral and intravenous antibiotics in elective colorectal surgery.

Administration, Oral↗
PubMed1989

An epidemiologic investigation of birth outcomes in relation to dibromochloropropane contamination in drinking water in Fresno County, California, USA.

This report describes an epidemiologic investigation of the relationship between dibromochloropropane (DBCP), contamination in drinking water and birth outcomes between 1978 and 1982 in Fresno County, California, USA. Census tracts in the county were categorized according to DBCP level in drinking water. A direct comparison between exposure categories was done by the use of the Mantel-Haenszel chi-square procedure to compute relative ratios or risks for low birth weight and birth defect, adjusting for age, race, percent Hispanic, and parity. No correlation between these birth outcomes and DBCP contamination was found. In addition, we did not find any difference in sex ratio in relation to DBCP contamination.

Adolescent↗
PubMed1989

Ecological analyses and case-control studies of gastric cancer and leukaemia in relation to DBCP in drinking water in Fresno County, California.

Through ecological analyses and case-control studies, the possible relation of gastric cancer and leukaemia to dibromochloropropane (DBCP) contamination of drinking water in Fresno County, California, has been examined. The ecological analyses examined the correlation between gastric cancer and leukaemia (including the lymphatic varieties), mortality rates, and DBCP concentrations in drinking water by census tract in Fresno County, 1960-83. No correlation was found between gastric cancer or leukaemia and DBCP. The gastric cancer case-control study consisted of 263 deaths from gastric cancer in the county, 1975 to mid-1984, and 1044 controls, using information on residential history and occupation of both cases and controls. Analyses were based on residence at death, as well as one and ten years before death. The case-control study did not find any relation between gastric cancer and DBCP in drinking water. Hispanics in the county were found to experience a relative risk of gastric cancer of 2.77, compared with non-Hispanics. A similar case-control study consisting of 259 cases of leukaemia and 1161 controls found no relation between all leukaemia or lymphatic leukaemia and DBCP in drinking water. Farm workers, however, do appear to have an increased risk of leukaemia.

Agricultural Workers' Diseases↗
PubMed1989

Metachromatic leukodystrophy (MLD) in hospitalized adult schizophrenic patients resistant to drug treatment.

Metachromatic leukodystrophy (MLD) is a rare inherited neurodegenerative disease associated with a defect in the catabolism of sulphatide (galactocerebroside-sulphate) which accumulates in the nervous system. MLD can be diagnosed biochemically by demonstrating deficiency in the activity of the enzyme arylsulphatase A (ASA) and an excess of sulphatide in urine and tissues. Clinically adult MLD may present as a schizophrenic-like psychosis, which typically develops years before the onset of neurologial signs which are not inevitable. Urinary ASA was investigated in 99 chronic hospitalized psychiatric patients (including 77 schizophrenics). Thirteen showed reduced ASA activity. Of the nine who were available for further study, only one evinced reduced ASA activity in other tissues (for example, leukocytes and cultured fibroblasts). However, there was no evidence of sulphatidurea with impaired sulphatide hydrolysis in his intact cultured fibroblasts. Therefore, he tested negative for MLD. This biochemical profile is known as pseudosulphatase deficiency. The possible relationship of pseudosulphatase deficiency to schizophrenic-like conditions is discussed.

Cerebroside-Sulfatase↗
PubMed1988

Splenectomy and the induction of murine colon cancer.

The influence of a functional spleen on induction and growth of cancer is unknown. Both beneficial and detrimental results have been observed in tumor-bearing hosts following splenectomy. We examined the effect of splenectomy, splenic autotransplantation, and splenic preservation on the induction and growth of 1,2-dimethylhydrazine (DMH)-induced murine colon cancer. Following splenectomy there was a significant increase in malignant tumors but no increase in benign tumors. To rule out the possibility that splenectomy increased the carcinogenicity of DMH by decreasing the capacity for DNA repair in colon cells, the units of 06-alkylguanine DNA alkyltransferase were measured in tumor-free and malignant colon tissue from both splenectomized and control rats. This repair protein was chosen because it is known to protect cells from the mutagenic effects of methylating agents. There was no significant difference in the alkyltransferase activity of tumor-free colon vs malignant tumor or between treatment regimens. Thus, the ability of the spleen to protect rats from the induction of malignant colon tumors induced by DMH is most likely due to preservation of immunologic surveillance in the host.

Adenocarcinoma↗
PubMed1988

Effects of muramyl dipeptide and core body temperature on peritoneal bacterial clearance.

To examine the interaction between muramyl dipeptide (MDP) and core body temperature in murine peritonitis, 120 Sprague-Dawley rats were randomized to receive either 0, 1, or 4 micrograms/g body weight of MDP. Twenty-four hours later a sublethal intraperitoneal inoculation of Escherichia coli was given after core body temperature regulation at 32 degrees C to 40 degrees C, which was maintained for 30 minutes. Killing of the rats at 1, 3, or 6 hours later allowed evaluation of peritoneal white blood cell and bacterial counts. Results demonstrated that MDP (independent of core body temperature) caused an increased peritoneal white blood cell response at one and six hours and an increased peritoneal bacterial clearance at three hours. Increasing core body temperature adversely affected peritoneal bacterial clearance. High-dose MDP was clearly significant in acceleration of peritoneal bacterial clearance. No interaction between MDP and core body temperature was seen.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1988

Moxalactam vs tobramycin-clindamycin. A randomized trial in secondary peritonitis.

One hundred five patients with peritonitis were randomized to receive either tobramycin sulfate plus clindamycin phosphate or moxalactam alone before surgical intervention. Fifty-nine patients were evaluable. A mean of 3.1 (moxalactam) and 3.5 (tobramycin-clindamycin) pathogens per patient were identified. Overall success rate was 85% (tobramycin-clindamycin, 24/30; moxalactam, 26/29). When patients with appendicitis were excluded, there was an observed but not statistically significant advantage of moxalactam over tobramycin-clindamycin (85% vs 67%). There were five deaths (tobramycin-clindamycin, four; moxalactam, one). Other complications included hypoprothrombinemia (tobramycin-clindamycin, five; moxalactam, five), renal dysfunction (tobramycin-clindamycin, three; moxalactam, one), and superinfection (tobramycin-clindamycin, nine; moxalactam, six). More wound infections were noted in the group given tobramycin-clindamycin. These data suggest that moxalactam is as safe and efficacious as tobramycin plus clindamycin. The observed benefits of this agent warrant study in a larger sample to verify advantages of moxalactam over combination therapy.

Abscess↗