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H Kashtan

Publications and source records attributed to H Kashtan.

At least 19 recordsLinked to original sources
PubMed1992

The effect of lowering faecal pH on the rate of proliferation of the normal colonic mucosa.

Epidemiological and animal studies suggest that faecal pH may be a risk factor for colorectal cancer with low faecal pH associated with a lower incidence of the disease. The aim of this study was to determine whether faecal pH (or dietary fibre) affects the short-term risk factors for colon cancer. Sixty-nine normal volunteers were randomized into three equal groups (A-C). They provided food records, faecal specimens and submitted to rectal biopsy for thymidine labelling studies before and after a 2-week intervention. Group A received a placebo of fruit juice. Group B, approximately 3.0 g d-1 sodium sulphate in juice. Group C, 30 g d-1 supplementary dietary fibre as wheat bran in bread. Age, sex, weight, height and intake of macronutrients and minerals were similar in the groups prior to intervention. Faecal pH was similar for the three groups before and was reduced in Group B after intervention (P = 0.001) with a relative reduction of 0.5 pH units. The labelling index for the three groups was similar prior to intervention; after, it was lowest in Group B with a relative reduction of 0.5% points, although this difference was not statistically significant. The results thus do not support the hypothesis that an acidification of faecal pH leads to a reduction in risk markers for colon cancer.

Adult↗
PubMed1992

Intra-rectal injection of tumour cells: a novel animal model of rectal cancer.

The purpose of this study was to develop an animal model of rectal cancer. Three murine-derived cell lines, B16 melanoma, CT26 and MCA38 colon carcinoma, as well as the human colon cancer cell line LS174T were injected into the submucosa of the mouse rectum. Subcutaneous CT26 anbd B16 tumours and intra-caecal CT26 tumours served as controls for tumourigenicity of the cell lines. B16 melanoma produced a locally aggressive rectal tumour as well as skin and para-aortic lymph node metastases. CT26 produced local tumour when injected intra-rectally and colon tumours and liver metastases when injected into the caecum. MCA38 and LS174T intra-rectal injections resulted in large rectal carcinomas without metastases. We believe that growth of a colon cancer cell line in the rectum approximates the human disease more closely than other models of colorectal cancer. We would expect that the model could similarly be utilized to assess the effects of novel adjuvant treatments for rectal cancer as well as in the study of the tumour biology of rectal cancer.

Adenocarcinoma↗
PubMed1992

Colonic fermentation and markers of colorectal-cancer risk.

The aim of this study was to determine the effect of soluble fiber on indexes of colon-cancer risk in postpolypectomy and nonpolyp patients. Forty-five postpolypectomy and 49 nonpolyp volunteers completed 2-wk metabolic studies where half of the group received oat-bran supplements and the other half took wheat-brain supplements. Colonic biopsies taken before and after the intervention showed no difference in the index of thymidine colonic-crypt-cell labeling, thymidine-labeling pattern, or nuclear aberrations. Nevertheless, fecal pH was significantly reduced by 0.23 +/- 0.07 pH units (P less than 0.002) as an index of increased colonic fermentation on oat bran. This was not associated with increased basal breath hydrogen concentrations; fecal butyrate concentrations were higher on wheat bran. We conclude that soluble fiber as oat brain appears to have no advantage over wheat bran in modifying putative risk factors for colonic cancer.

Butyrates↗
PubMed1992

Wheat-bran and oat-bran supplements' effects on blood lipids and lipoproteins.

To compare the effects of oat-bran fiber on blood lipids, we studied 84 healthy middle-aged men and women who were placed on metabolic diets, for 2 wk, that were supplemented with either wheat bran (n = 42) or oat bran (n = 42). Fiber supplementation was 1.6 micrograms dietary fiber/J (6.8 g dietary fiber/1000 kcal) to a maximum of 16.4 g fiber/d. Significantly greater decrease with oat than with wheat were seen in total cholesterol (0.56 +/- 0.08 mmol/L and 0.29 +/- 0.08 mmol/L, P = 0.022) and low-density-lipoprotein cholesterol (0.39 +/- 0.07 mmol/L and 0.15 +/- 0.07 mmol/L, P = 0.024). No significant differences were seen in high-density lipoprotein, apolipoproteins A-1 and B, or triglyceride. We conclude that oat bran has an advantage over wheat bran in lowering serum lipids when tested in metabolic diets on large numbers of individuals with an initial mean serum cholesterol concentration above the desirable range, at 5.61 +/- 0.16 mmol/L.

Adult↗
PubMed1992

Colorectal cancer in patients over 70 years old. A prospective study of operative results.

All patients (284, mean age 70.8 years) admitted with a diagnosis of primary colorectal cancer to our surgical department during the years 1984-87 were evaluated prospectively. We compare 170 (59.9%) patients > 70 years old and 114 (40.1%) patients < or = 70 years. The overall operability rate was 97.3% and the resectability rate 92.8%. The overall operative mortality rate was 2.1%, four patients in the older group and two patients in the younger group (NS). Among patients who underwent emergency surgery, the operative mortality was 6.1% (4 patients). The overall morbidity rate was 26.7% without significant differences between the two age-groups. A separate subset analysis was done to compare the very old patients (age > or = 80) to the old patients (age 70-79). There were no significant differences between these groups in tumor location, presentation and staging, as well as in operability rate and operative morbidity and mortality. The operative mortality in those over the age of 80 was 3.5%. We concluded that age should not be a determinant in consideration of operation for primary colorectal cancer, since operative mortality and morbidity are similar in both the elderly and their younger counterparts.

Academic Medical Centers↗
PubMed1992

Colonic proliferation and colon cancer risk. A review of clinical studies.

The purpose of this review is to discuss some of the recent hypotheses regarding the dietary etiology of colorectal cancer. We will review some of the epidemiological background and animal studies that were performed to test these hypotheses. The use of the rectal mucosal proliferation rate as measured by thymidine labelling index as an intermediate endpoint for clinical studies is discussed, including the results of testing these hypotheses using this marker. We believe that all hypotheses must eventually be tested in the human model and that carefully controlled, sequential analyses of each acceptable hypothesis is the most prudent road to understanding the environmental causes of colorectal cancer.

Biomarkers, Tumor↗
PubMed1991

Use of photodynamic therapy in the palliation of massive advanced rectal cancer. Phase I/II study.

Photodynamic therapy (PDT) is a relatively new form of cancer therapy utilizing a photosensitizer such as hematoporphyrin derivative. We conducted a pilot study to determine the efficacy of its use in palliating advanced rectal cancer, to determine toxicity, and to establish objective outcome criteria. Six patients with very advanced, usually recurrent rectal cancer were treated with PDT after being photosensitized with Photofrin II. A protocol was established to measure clinical and radiologic response to therapy. A new intraluminal delivery system was incorporated. Five patients had both clinical and radiologic responses to therapy. In two patients we observed such significant responses that they cannot be accounted for on a photobiologic basis alone. One patient developed a significant sunburn after discharge. There was no major toxicity of bleeding or sepsis even at maximum doses (200 J/cm2). We are confident that PDT has a role to play in rectal cancer and speculate as to future applications.

Adenocarcinoma↗
PubMed1991

Effect of high-fat and low-fiber meals on the cell proliferation activity of colorectal mucosa.

Normal healthy volunteers (n = 43) were divided into four groups that received diets providing low or high levels of dietary fat (33 or 96 g/day) and low or high levels of dietary fiber (6 and 41 g/day) for a period of five days. Proliferation was assessed with tritiated thymidine labeling of three rectal biopsies. After five days on the prescribed diets, the average thymidine labeling index (LI) of the group on the high fat-low fiber diet was only 25% higher than the average LI of the group on the low fat-high fiber diet, a difference that is not statistically significant. We conclude that a short-term increase in dietary fat and decrease in dietary fiber does not result in a large increase in cell proliferation rate.

Adult↗
PubMed1991

Is age an independent variable in the morbidity and mortality of patients with colorectal cancer? A prospective study.

The authors examine prospectively the results of a single surgeon (H.S.S.), using a computerized database to determine the effect of age on morbidity and mortality in the management of colorectal cancer. Computer input was performed by a nurse data manager (20 minutes per patient), and data retrieval required approximately 30 minutes of computer time. Between 1984 and 1989, 241 patients with primary colorectal cancer underwent operation. The average age was 67.9 years (range from 31 to 94 years). The authors compared 108 (44.8%) patients who were older than 70 years with 133 (55.2%) patients who were 70 years of age or younger. Rectal carcinoma was more common in the younger age group (41.3% v. 20.4%), but right-sided carcinoma was more common in the older age group (36.1% v. 19.6%, p less than 0.001). Bleeding was more frequent in the younger patients than in the older ones (51.9% v. 35.2%, p less than 0.01). There was no difference between the two groups in tumour staging, using the modified Dukes' classification. The overall mortality was 2.5% and morbidity was 39.4%, with no significant differences between the groups. The authors conclude that age should not be a determinant in consideration of operation for colorectal cancer and that a personal computerized database facilitates simple prospective studies.

Adult↗
PubMed1990

Effects of sodium sulfate on fecal pH and proliferation of colonic mucosa in patients at high risk for colon cancer.

High fecal pH level has been suggested as a risk factor for colorectal cancer. We previously demonstrated that, although sodium sulfate did not affect the proliferation rate of colonic mucosa, as indicated by thymidine-labeling index, it did lower fecal pH in subjects at average risk for colon cancer. In the current study, we evaluated the effects of sodium sulfate on fecal pH and proliferation of colonic mucosa in subjects at high risk for colon cancer. Fifty-seven patients who had had colonic polyps removed were randomly assigned to two groups to receive either sodium sulfate (27 patients) or a placebo (25 patients) at a mean dose of 4 g/day for 14 days. Age, sex, height, and weight were comparable in both groups. Before intervention, levels of fecal pH were similar in the two groups, but after intervention, fecal pH was reduced only in the sodium sulfate group (mean decrease, 0.3 U; P less than .01). Thymidine-labeling index (number of labeled cells per number of cells counted) was similar in the two groups prior to intervention and did not change significantly after intervention (mean increase, 0.9%; P = .35). Regression analysis revealed no correlation between the change in labeling index and the change in fecal pH. We conclude that high fecal pH level is only indirectly associated with the development of colon cancer and, therefore, may be a secondary, rather than a primary, measure of cancer risk.

Adult↗
PubMed1990

Comparative evaluation of propofol and thiopentone for total intravenous anaesthesia.

Sixty unpremedicated ASA physical status I or II patients scheduled for surgical procedures of intermediate duration (15 to 60 min) were studied to evaluate the safety and efficacy of propofol, to measure recovery times and to compare the return of psychomotor and cognitive function with thiopentone. Patients were randomly allocated into two groups. Anaesthesia was induced and maintained by either propofol (2.0-2.5 mg.kg-1 followed by a continuous infusion 0.1-0.2 mg.kg-1.min-1) or thiopentone (4.0-5.0 mg.kg-1, and infusion rate 0.16-0.32 mg.kg-1.min-1), titrated to patient response. Succinylcholine was administered to facilitate tracheal intubation and maintain neuromuscular blockade. Induction of anaesthesia was slightly longer with propofol than thiopentone (42.2 vs 29.8 sec) and was smooth with both drugs. Post-intubation increases in heart rate, and systolic and diastolic blood pressures were attenuated by propofol when compared with thiopentone. After the administration of propofol, times to eye opening (6.4 +/- 4.3 vs 13.9 +/- 15.9 min), response to verbal command (7.6 +/- 6.3 vs 15.4 +/- 16.6 min) and orientation (22.7 +/- 12.8 vs 36.2 +/- 23.1 min), were significantly shorter. Psychomotor and cognitive function returned earlier with propofol and fewer side effects were noted. At 24 hr there was no distinguishable difference between groups. Propofol is a safe anaesthetic agent with the potential for early patient discharge and street fitness after outpatient procedures.

Adult↗
PubMed1990

Manipulation of fecal pH by dietary means.

Epidemiological and animal studies suggest that colonic fermentation and fecal pH may be risk factors for colorectal cancer. To modify these factors, we sought to develop a simple instrument for use in intervention studies. Three 14-day studies with 32, 40, and 30 healthy volunteers maintained on their regular diet were carried out to evaluate the effect of various food supplements on fecal pH. The interventions tested included supplementary lactulose, Metamucil, oat bran, wheat bran, or no supplement. The results showed that it is possible to provide a simple intervention to reduce fecal pH by 0.4 unit with oat bran administered at 75-100 g/day over a 14-day period, using a wheat combination, equivalent in macronutrients and fiber, as a control.

Adult↗
PubMed1990

Long-term effects of dietary calcium on risk markers for colon cancer in patients with familial polyposis.

There is conflicting evidence regarding the benefit of calcium in prevention of colon cancer. Patients who have undergone ileorectal operations for familial polyposis can be useful to study hypotheses on prevention of colon cancer. In this study we evaluated the effect of long-term calcium supplementation on risk markers of colon cancer. Thirty-one patients with familial polyposis, after subtotal colectomy, were randomized to group A, which received placebo, and group B, which received 1200 mg of calcium daily. Intervention lasted 9 months, in which they underwent four 3-monthly evaluations that included food records, fecal pH, calcium and bile acids, and rectal biopsy for thymidine labeling. Age, height, weight, macronutrients, and dietary fiber were comparable in both groups. More women were in the group that received placebo. Fecal pH, weight, and bile acid levels were similar before intervention and remained unchanged. Fecal calcium levels were similar before intervention and increased in the calcium group throughout the study (p less than 0.05). Labeling index of placebo and calcium groups was similar before intervention (4.8 and 6.1, respectively). After 3 months it was reduced in both groups (3.1 and 4.4, respectively; p less than 0.05). After 6 months it was reduced only in the calcium group (3.4; p less than 0.05). After 9 months it did not differ from the starting point (3.4 and 4.0, respectively). In a long-term intervention study with a homogenous group of patients with familial polyposis, supplemental dietary calcium did not affect mucosal risk factors for colon cancer.

Adenomatous Polyposis Coli↗
PubMed1990

Perforated duodenal ulcer in the elderly patient.

Acute perforation of a duodenal ulcer in a patient over of 70 years of age is associated with a high death rate. During a 10-year period, 35 such patients were operated on; in all omentopexy was performed. Two courses of the disease were observed: the first (19 patients) was defined by acute disease of less than 24 hours' duration preceding surgery; the second (16 patients) was of longer duration, starting with various abdominal complaints and presenting more severely only after the first 24 hours. Postoperative death rates were 0% in the first group and 50% in the second. Other factors that were studied, including diabetes mellitus, presence of concomitant malignant diseases and intake of ulcerogenic drugs, had no significant effect on the outcome in these patients.

Aged↗
PubMed1989

[Referrals to the surgical emergency room].

A review of 871 consecutive patients referred to our surgical emergency room is presented. 54% were self-referred, 18% were soldiers referred by army physicians and only 8% were referred by family physicians. Only 60% lived in the hospital admission area. The average stay in the emergency room was 4.1 hours, and only 6.5% needed to be hospitalized. We suggest setting up first aid stations in hospitals to serve as pre-emergency rooms, and that only cases that really require its services be referred to the emergency room.

Emergency Service, Hospital↗
PubMed1989

The area moment of inertia of the tibia: a risk factor for stress fractures.

In a prospective study of stress fractures among Israeli infantry recruits, the area moment of inertia of the tibia was found to have a statistically significant correlation with the incidence of tibial, femoral and total stress fractures. Recruits with "low" area moments of inertia of the tibia were found to have higher stress fracture morbidity than those with "high" area moments of inertia. The best correlation was obtained when the area moment of inertia was calculated about the AP axis of bending at a cross-sectional level corresponding to the narrowest tibial width on lateral X-rays, a point which is at the distal quarter of the tibia. This finding indicates that bending forces about the approximate AP axis are an important causal factor for tibial and many other stress fractures. The bone's bending strength, or ability to resist bending moments, as measured by the area moment of inertia, helps determine risk to stress fracture.

Biomechanical Phenomena↗