Search PubMed⌕ Search

Biomedical subjects

G Slater

Publications and source records attributed to G Slater.

At least 37 records · Page 2Linked to original sources
PubMed1993

Management of chondrosarcoma including modular ceramic and alumina prosthetic replacement.

Forty-one cases of chondrosarcoma from varying sites throughout the body, and treated exclusively by one of the authors (R.L.H.) from 1972 to 1990 were reviewed. The symptoms, signs, location of tumours, treatment and progress are presented. Particular attention was paid to modular bone replacement techniques. Excision and reconstruction of the bone or joint were carried out in 17 femora, five tibia and six humeri. Comparison between this method of management and other techniques is discussed. Titanium and alumina prostheses for the hip, femur, tibia, shoulder and humerus have been designed by the senior author. These are both inert and modular, and have been found to be superior to other methods of treatment in both function and cosmesis. They do not possess the same potential donor infection risks and other disadvantages of allograft replacement. Immediate postoperative weight bearing and mobilization are possible with these systems. The Huckstep prostheses allow for bony ingrowth into their porous coated alumina sleeves, spacers and stems. In addition, the titanium alloy locking component for the femoral stems has an elasticity half that of other metal alloys and this was found to minimize stress shielding.

Adult↗
PubMed1991

Small bowel length in Crohn's disease.

The length of the small intestine in patients with Crohn's disease who are referred for surgery has not been well studied. In this report, 25 patients with Crohn's disease who were being operated on for the first time had their small intestine measured at the time of surgery. The mean length of small intestine in this group was 501 cm, which was not different from a group of patients without Crohn's disease who were being operated on for other problems. In the group of patients with Crohn's disease, as well as the entire group, there was a correlation between increasing height and longer small bowel length. No other parameters investigated, including weight, surface area, age, sex, and duration of disease, correlated with bowel length. The results of this study are somewhat encouraging to patients with Crohn's disease, since these patients do not start off with a shortened bowel prior to surgery.

Adolescent↗
PubMed1990

Synchronous carcinoma of the colon and rectum.

Reports on the incidence of synchronous carcinoma of the colon and rectum have varied from 2 to 11 per cent. The variability is a result of a lack of uniformity in criteria of diagnosis, differences in the population studied and differences in time period used. In this study, we evaluated the incidence and distribution of synchronous lesions during a recent time period before the use of colonoscopy became widespread. We reviewed the records of all patients with newly diagnosed adenocarcinoma of the colon and rectum who were operated upon at our institution between 1976 and 1981. In a total group of 1,000 patients of which 52 per cent were men, there were 54 patients or 5.4 per cent who had synchronous carcinomas. The group of patients with synchronous carcinomas were older than the group with nonsynchronous carcinomas (72.4 versus 68.8 years). There was also a higher incidence of associated benign polyps in the group with synchronous carcinomas (70 versus 30 per cent for a nonsynchronous carcinomas). The anatomic distribution of carcinomas of the colon and rectum in the group with synchronous lesions (111 in total) revealed a higher percentage of carcinomas located on the right side (29.7 versus 22.5 per cent), although the difference did not reach statistical significance. Synchronous carcinomas were located in nonadjacent segments of the colon in 37 per cent. There was no difference in stage between the groups with and without synchronous carcinomas. The preoperative identification of synchronous lesions by either colonoscopy or barium enema is important for the proper treatment of patients with carcinoma of the colon and rectum. Failure to locate these tumors may lead to the demise of the patient.

Adenocarcinoma↗
PubMed1989

Age and sex distribution of patients with colorectal cancer.

A retrospective review of 922 colorectal cancer patients was undertaken to determine whether the nonuniform anatomic distribution of colorectal cancer was influenced by age and/or sex. The mean age of patients with right colon lesions (71.2 years) was significantly higher than for either patients with left colon lesions (68.2 years) or rectal lesions (65.6 years). Further analysis disclosed that patients with proximal tumors were older than patients with distal tumors primarily because of the later presentation of females with cecal or ascending colon cancers. Comparison of the anatomic distribution of tumors in patient groups above and below the age of 70 revealed that right colon cancers accounted for a greater percentage of colorectal tumors in the older patient group than in the younger patient group. These findings support the roles played by both age and sex in influencing colorectal cancer location. Furthermore, these data provide a plausible explanation for the increasing incidence of proximal colonic lesions.

Adenocarcinoma↗
PubMed1989

Gastric fistulas in Crohn's disease. Report of cases.

Nine cases of gastric fistula occurring in patients with Crohn's disease were treated at The Mount Sinai Hospital over the past three decades. Six cases were found in a review of 1480 patients with Crohn's disease admitted between 1960 and 1983. Three others seen at this institution outside the time frame of the author's study have also been included. Among six new cases, five with cologastric fistula occurred among 907 patients with Crohn's disease involving the colon (0.6 percent), while only one with ileogastric fistula was encountered among 1211 patients with ileal disease (0.08 percent). Fistulas between the stomach and colon always originated in an area of colitis, usually passing from distal transverse colon to greater curvature, but occasionally from midtransverse colon to antrum. The only pathognomonic clinical features were feculent vomiting, eructations, or odor. Diagnosis usually was made by barium enema or, less frequently, by upper gastrointestinal series; rarely, the gastric fistula was found unexpectedly at surgery. The conventional and recommended therapy is colectomy with wedge excision of the stomach. Medical treatment with 6-mercaptopurine has been completely successful in one patient and intermittently successful in a second patient.

Adult↗
PubMed1989

In vivo formation of hydroxyl radicals following intragastric administration of ferrous salt in rats.

Accidental poisoning by oral iron preparations is a serious problem in young children. We investigated the formation of hydroxyl radicals (.OH) in rats after intragastric instillation of ferrous sulfate. .OH was detected via its reaction with intragastrically administered 2-keto-4-methylthiobutyrate to generate ethylene gas. Ascorbic acid is typically present in oral iron preparations in order to facilitate absorption by maintaining iron in the reduced state. However, ascorbate possesses two properties that can affect .OH, recycling of oxidized iron to the ferrous state augments .OH production, while ascorbate in high concentration scavenges .OH. In experiments conducted in vitro, both actions were evident, depending upon the concentration of ascorbate. In parallel experiments conducted in vivo, the scavenging action of ascorbate was more prominent. Experiments in vitro with .OH-scavengers (dimethylsulfoxide, ethanol) and with the enzyme, catalase, confirmed both the presence of .OH and its dependence upon generated hydrogen peroxide during the oxidation of ferrous salt by molecular oxygen. Hydroxyl radicals (and/or reactive higher oxidation states of iron) may play a role in tissue damage after accidental overdose of oral iron.

Administration, Oral↗
PubMed1989

Ultrasonic mucosal proctectomy in patients with ulcerative colitis.

A technique for performing mucosal proctectomy in patients with ulcerative colitis using ultrasonic fragmentation is described. Twenty-eight patients undergoing colectomy and ileoanal anastomosis were studied. Removal of the mucosal layer of the distal rectum was performed using a titanium probe vibrating at 23 kHZ with an amplitude of 300 microns. This method produces complete mucosal destruction and the resulting debris and irrigating fluid is removed through the hollow central portion of the probe. Healing of the ileoanal anastomosis does not appear to be adversely affected by the use of this technique. Because ultrasonic fragmentation is not dependent on the integrity of the submucosal plane, it may be advantageous in those cases in which severe inflammation and submucosal scarring make manual dissection of the rectal mucosa difficult to perform.

Adolescent↗
PubMed1988

Production of ethane by rats treated with the colon carcinogen, 1,2-dimethylhydrazine.

Ethane was exhaled by rats treated with the colon carcinogen, 1,2-dimethylhydrazine (DMH). At 1 hr, ethane production (mean +/- SD) was 0.2 +/- 0.2 nmol/kg (controls) and 5.2 +/- 1.3, 13.7 +/- 3.4, and 27.7 +/- 9.6, respectively, for DMH injections of 0.15 mmol/kg (20 mg/kg of the dihydrochloride salt), 0.45 mmol/kg, and 1.35 mmol/kg. Rates of ethane evolution tapered off after 2 hr, but persisted for up to 3 hr at the lower dose, and up to 5-6 hr at the higher dose. Although ethane is produced in vivo during lipid peroxidation, experiments with vitamin E, a potent lipid antioxidant, indicated that lipid peroxidation was unlikely to be the source of ethane in DMH-treated rats: pretreatment with vitamin E had no effect on ethane formation from DMH but did suppress ethane production from rats treated with carbon tetrachloride, an inducer of hepatic lipid peroxidation. When rats were injected with 1,2-diethylhydrazine in place of DMH, large amounts of ethane and ethylene were produced (9800 and 5600 nmol/kg/hr). The hydrocarbon gases exhaled by rats may arise from dimerization of methyl radicals (.CH3) generated during the metabolism of DMH, and from ethyl radicals (.CH2CH3) generated during the metabolism of 1,2-diethylhydrazine. Previously, it was shown that methane and ethane are formed from methyl radicals in vitro. Other investigators have observed formation of hydrocarbon gases during the in vitro metabolism of monoalkylhydrazines by microsomes, and ethyl radicals, derived from monoethylhydrazine, have been detected by electron spin-resonance spectroscopy. The results presented here suggest that in vivo metabolism of DMH may produce methyl radicals. Methyl radicals are capable of interacting with biomolecules. Their indiscriminate reaction with tissue constituents may be a contributory factor in DMH-induced carcinogenesis.

1,2-Dimethylhydrazine↗
PubMed1988

Colorectal cancer location and synchronous adenomas.

In this study, the relationship between the location of colorectal cancer and synchronous benign adenomas was assessed in 591 patients. Adenomas were found in 29.7% of all patients. Patients with cancer of the cecum, ascending colon, and hepatic flexure had the highest percentage of benign adenomas. Patients with right-sided cancer had adenomas in 47% of resected specimens, which percentage was significantly higher than that in the group of patients with left-sided cancer, who had adenomas in 22% of their specimens (p less than 0.001). Patients with cancer and synchronous adenomas were also older (70.2 vs 67.8, p less than 0.02) and more likely to be male (p less than 0.002) than patients with cancer and no adenomas. It is suggested that efforts be made to identify adenomas preoperatively in patients with colorectal cancer. In addition, since patients with cancer and associated adenomas are at increased risk of developing metachronous cancer, the group with right-sided cancer should be part of a particularly active surveillance program.

Adenoma↗
PubMed1987

In vivo ethane production in vitamin E-deficient rats with DMH-induced colon cancer.

The effect of both a vitamin E-deficient and a high polyunsaturated fat (PUFA) diet was tested on rats injected with the colon carcinogen 1,2-dimethylhydrazine (DMH). In vivo lipid peroxidation was monitored by measuring exhaled ethane from the animals. Higher mean weights were found in animals fed high PUFA and vitamin E-sufficient diets. There was no difference in ethane exhalation between DMH-treated and control animals regardless of diet. Mean ethane exhalation was highest in animals fed either vitamin E-deficient or high PUFA diets. There was no difference in tumor formation between the vitamin E-deficient and the vitamin E-sufficient groups. The high PUFA groups had more tumors than the low PUFA groups. Diet was shown to be the major factor affecting ethane exhalation. There was no evidence that vitamin E-deficiency promoted DMH-induced tumors or that DMH caused increased lipid peroxidation.

1,2-Dimethylhydrazine↗
PubMed1987

Colorectal cancer in regional ileitis.

Six patients, with overt Crohn's disease of the small bowel developed colorectal cancer. Three distinct clinical patterns were observed. Three patients had advanced rectal adenocarcinoma and a relatively long duration of Crohn's disease, two patients had an early adenocarcinoma and a short antecedent history, and a sixth patient had advanced cloacogenic cancer of the anorectum. The prognosis for a patient with carcinoma in association with regional enteritis was poor when there was advanced disease at the time of diagnosis. The late diagnosis of the cancer may have been the result of three erroneous assumptions. First, scepticism as to the association of Crohn's disease and cancer despite the evidence to the contrary; second, misinterpretation of the intestinal symptoms of the carcinoma as those of the underlying inflammatory bowel disease; and third, confusing the clinical picture of colorectal cancer with that of benign perianal disease with stricture formation. Increased awareness of the association of cancer and Crohn's disease, particularly the development of cancer in apparently normal bowel, and careful evaluation of all new symptoms should improve the prognosis of this potentially lethal complication of inflammatory bowel disease.

Adenocarcinoma↗
PubMed1986

A comparison of multiple synchronous colorectal cancer in ulcerative colitis, familial polyposis coli, and de novo cancer.

Multiple synchronous colorectal cancer (MSCC) among 1537 patients (69 with familial polyposis coli (FPC), 780 with ulcerative colitis (UC), and 685 with de novo colorectal (DNC) cancers) admitted to The Mount Sinai Hospital between 1945 and 1981 was tabulated. MSCC occurred in five of 24 cancer patients with FPC (21%), in 12 of 65 cancer patients with UC (18%), but in only 17 of 685 DNC patients (2.5%). The proportions of MSCC cases with more than two synchronous tumors were also much greater in the former two groups (UC 6/12 = 50%, FPC 3/5 = 60%) than in DNC (0/17 = 0%). Multiplicity of cancers is thus a distinguishing feature of UC and FPC. MSCC differed from solitary cancers by association with older age and more advanced stage at diagnosis in patients with FPC and by a rightward shift in anatomic distribution in all patients, especially those with FPC and UC.

Adult↗
PubMed1985

Left ear suppression on verbal dichotic tests in patients with multiple sclerosis.

Verbal dichotic listening tests employing nonsense consonant-vowel stimulus pairs were administered to 11 right-handed patients with chronic multiple sclerosis and to 10 right-handed normal controls. A highly significant reduction of left-ear scores was found in the multiple sclerosis group. We propose that the basis for this finding is a disconnection of the auditory callosal pathway and that dichotic listening tests may be of value in detecting the presence of lesions of the deep white matter of the cerebral hemispheres in multiple sclerosis.

Adult↗
PubMed1985

Distribution of colorectal cancer in patients with and without ulcerative colitis.

A comparison of the anatomic distribution of colorectal cancer in patients with and without CUC is difficult because of the unequal number of patients in each group and the changing epidemiologic parameters of colorectal cancer in general. In the present study, the distribution of colorectal tumors in patients with and without CUC was compared over two different time periods at a single hospital. In the early time period (1960 to 1975), there was a significantly higher percentage of proximal tumors in the group with cancer and CUC compared to the group with cancer alone. In the most recent time period (1975 to 1981), there was no difference in distribution of colorectal cancer regardless of whether the patient had CUC or not. We believe that the increased percentage of proximal tumors in patients with colorectal cancers and no CUC that has occurred in recent years has led to the present findings of a similar distribution of tumors in patients with and without CUC.

Adenocarcinoma↗
PubMed1985

Laboratory evaluation of enoxacin: comparison with norfloxacin and nalidixic acid.

Enoxacin displayed activity similar to that of norfloxacin against enterobacteria, Pseudomonas aeruginosa, staphylococci, streptococci and Bacteroides spp. The activity of enoxacin against many strains was reduced in acid conditions, but the pH effect was not so marked as that seen with norfloxacin. Nalidixic acid was found to be more active in acid conditions, particularly against staphylococci, Streptococcus faecalis and Ps. aeruginosa. In conditions simulating the treatment of bacterial cystitis, a single dose of enoxacin, achieving a peak concentration of 50 mg/l, suppressed growth of nalidixic acid-sensitive and -resistant Gram-negative bacilli for periods of between 18 and 25 X 5 h. Reduced susceptibility of bacteria surviving exposure to enoxacin was observed in one nalidixic acid-resistant strain of Escherichia coli and in nalidixic acid-sensitive strains exposed to low doses (peak concentration = 5 mg/l) of enoxacin. These results are similar to those obtained with norfloxacin and substantially better than those obtained with nalidixic acid.

Anti-Bacterial Agents↗
PubMed1984

Cholesterol, weight, height, Quetelet's index, and colon cancer recurrence.

The association of low serum cholesterol with colon cancer mortality suggests that low serum cholesterol promotes colon cancer recurrence. We compared cumulative 5-year recurrence-free rates of 279 colon cancer patients in relation to serum cholesterol, weight, height, and Quetelet's index. The median value for each variable was used to divide patients into those above the median, or at the median and below. Patients with median and lower serum cholesterol exhibited an 11% lower disease-free rate at 5 years. Patients above median weight were at significantly increased risk of recurrence in both sexes (76 vs 54%, z = 3.0026, p = 0.003). Progressively decreasing weight was noted with advancing stage in males but not in females. Women above median Quetelet's index were also at significantly greater risk of recurrence (74 vs 52%, z = 2.6109, p = 0.009). Patients above median height were at insignificantly increased risk of recurrence. This study indicates that body weight is a significant prognostic factor for patients with colon cancer.

Body Height↗
PubMed1984

Anal carcinoma in patients with Crohn's disease.

Three patients with Crohn's disease and carcinoma of the anus are reported and compared to a group of patients with anal cancer and no inflammatory bowel disease. The three patients with Crohn's disease were relatively young women with significant perianal disease. There were two squamous cell lesions and one cloacogenic tumor in this group. The relative incidence of anal cancer as a proportion of all colorectal cancer, in patients with Crohn's disease (14%) was found to be significantly higher than the incidence of anal cancer in patients without inflammatory bowel disease (1.4%). Possible reasons for the increased incidence of anal cancer in Crohn's disease mentioned were: an overall increase in malignancies in inflammatory bowel disease, the high incidence of perianal disease, and the chronic long-standing perianal inflammation present. All patients with Crohn's disease, especially if they have active perianal disease, should be observed for the occurrence of anal cancer.

Adult↗