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Biomedical subjects

S L Gorbach

Publications and source records attributed to S L Gorbach.

At least 73 records · Page 4Linked to original sources

Bismuth therapy in gastrointestinal diseases.

Bismuth therapy has shown efficacy against two major gastrointestinal disorders: peptic ulcer disease and diarrhea. In peptic ulcer disease it is as effective as the H2-receptor antagonists, costs considerably less, and offers a lower rate of relapse. When Helicobacter pylori is implicated, bismuth acts as an antimicrobial agent, suppressing the organism but not eliminating it. In recent studies, bismuth compounds have been used with conventional antibiotics, producing elimination of the organism, histological improvement, and amelioration of symptoms for periods longer than one year. Bismuth subsalicylate has shown modest efficacy in treating traveler's diarrhea and acute and chronic diarrhea in children, and it is effective prophylactically for traveler's diarrhea. An epidemic of neurological toxicity was reported in France in the 1970's with prolonged bismuth treatment, usually bismuth subgallate and subnitrate. Such toxicity has been rare with bismuth subsalicylate and colloidal bismuth subcitrate. However, recent studies have demonstrated intestinal absorption of bismuth (about 0.2% of the ingested dose) and sequestration of this heavy metal in multiple tissue sites, even occurring with conventional dosing over a 6-week period. These findings have inspired recommendations that treatment periods with any bismuth-containing compound should last no longer than 6-8 weeks, followed by 8-week bismuth-free intervals.

Bismuth↗

Feasibility of a randomized trial of a low-fat diet for the prevention of breast cancer: dietary compliance in the Women's Health Trial Vanguard Study.

The Women's Health Trial Vanguard Study was conducted to examine the feasibility of a nationwide, randomized multicenter intervention trial to test the hypothesis that a low-fat diet followed for a period of 10 years will reduce breast cancer risk. Women ages 45-69 years at increased risk of breast cancer were randomized into intervention (low-fat diet, n = 184) and control (usual diet, n = 119) groups. On the basis of 4-day food records, baseline fat intakes were comparable in the two groups, averaging 1,718 kcal with 39% of energy as fat. Intervention women reported substantially lower fat intake at 6 (20.9% kcal), 12 (21.6%), and 24 months (22.6% kcal). In contrast, control women reported only slight reductions in fat intake (37.3% kcal at 12 months and 36.8% kcal at 24 months). Evidence that these women were indeed complying with the low-fat dietary intervention comes from (a) the reasonable nature of reported nutrient changes within food groups in the intervention women and (b) agreement between observed and expected differences in plasma total cholesterol between the control and the intervention groups. At 12 months, the observed control - intervention plasma cholesterol difference was 13.1 +/- 4.6 mg/dl while the expected difference based on the Keys equation was 15.1 +/- 1.1 mg/dl; at 24 months, the observed difference was 15.5 +/- 4.3 mg/dl and the expected difference was 12.0 +/- 1.2 mg/dl. These analyses indicate that the intervention women made substantial dietary changes and have successfully maintained these changes over a 2-year period. This study thus demonstrates the feasibility of a randomized trial with an intensive low-fat dietary intervention.

Aged↗

Analysis of the costs of a large prevention trial.

Total direct costs of the Women's Health Trial (WHT), a large multicenter prevention trial, were reduced by more than 50% by means of research cost analysis conducted during the trial design phase. The unit costs of specific trial activities were estimated so that total direct costs of the trial could be predicted from design parameters. The relative costs of screening, treatment, and follow-up, and the fixed costs associated with each clinical center in a multicenter prevention trial were taken into account. Direct costs of the WHT were reduced from +195 million to +95 million by refinement of the trial protocol, selection of an efficient design, and consideration of trial logistics. The analyses suggest several ways to reduce costs in a prevention trial. Use of the case-cohort approach can reduce costs substantially when the protocol includes collection of specimens or data that are costly to process. When establishing and maintaining a clinical center represents a significant proportion of a clinical center's costs, use of a smaller number of larger clinical centers offers important cost savings. Because restrictive eligibility requirements reduce the recruitment potential of each clinical center, use of high-risk participants may not improve the efficiency of a prevention trial; its favorable impact on sample size may fail to compensate for its cost in terms of additional clinical centers and higher recruitment costs.

Aged↗

Food uses and health effects of corn oil.

This review of corn oil provides a scientific assessment of the current knowledge of its contribution to the American diet. Refined corn oil is composed of 99% triacylglycerols with polyunsaturated fatty acid (PUFA) 59%, monounsaturated fatty acid 24%, and saturated fatty acid (SFA) 13%. The PUFA is linoleic acid (C18:2n-6) primarily, with a small amount of linolenic acid (C18:3n-3) giving a n-6/n-3 ratio of 83. Corn oil contains a significant amount of ubiquinone and high amounts of alpha- and gamma-tocopherols (vitamin E) that protect it from oxidative rancidity. It has good sensory qualities for use as a salad and cooking oil. Corn oil is highly digestible and provides energy and essential fatty acids (EFA). Linoleic acid is a dietary essential that is necessary for integrity of the skin, cell membranes, the immune system, and for synthesis of icosanoids. Icosanoids are necessary for reproductive, cardiovascular, renal, and gastrointestinal functions and resistance to disease. Corn oil is a highly effective food oil for lowering serum cholesterol. Because of its low content of SFAs which raises cholesterol and its high content of PUFAs which lowers cholesterol, consumption of corn oil can replace SFAs with PUFAs, and the combination is more effective in lowering cholesterol than simple reduction of SFA. PUFA primarily lowers low-density-lipoprotein cholesterol (LDL-C) which is atherogenic. Research shows that PUFA has little effect on high-density-lipoprotein cholesterol (HDL-C) which is protective against atherosclerosis. PUFA generally improves the ratio of LDL-C to HDL-C. Studies in animals show that PUFA is required for the growth of cancers; the amount required is considered to be greater than that which satisfies the EFA requirement of the host. At this time there is no indication from epidemiological studies that PUFA intake is associated with increased risk of breast or colon cancer, which have been suggested to be promoted by high-fat diets in humans. Recommendations for minimum PUFA intake to prevent gross EFA deficiency are about 3% of energy (en%). Recommendations for prevention of heart disease are 8-10 en%. Consumption of PUFA in the United States is 5-7 en%. The use of corn oil to contribute to a PUFA intake of 10 en% in the diet would be beneficial to heart health. No single source of salad or cooking oil provides an optimum fatty acid (FA) composition. Many questions remain to be answered about the relation of FA composition of the diet to various physiological functions and disease processes.

Animals↗

Lactic acid bacteria and human health.

Although claims for health and nutritional benefits have been made for lactic acid bacteria in fermented dairy products for nearly a century, the nutritional and therapeutic value of these organisms is still controversial. This article will review the scientific basis of these claims. There are numerous studies showing fermentation of food with lactobacilli increase the quantity, availability, digestibility, and assimilability of nutrients. The basis for this conclusion comes from direct measurements of vitamin synthesis and from increased feed efficiency when fermented products are fed to animals. There have been a number of studies showing that various fermented dairy products lower serum cholesterol levels in humans and animals. These studies are reviewed and the validity of these findings are assessed. A summary of the evidence indicating that lactase deficient individuals can eat yogurt and the mechanisms involved in this toleration is reviewed. The role of fermented dairy products in inhibiting tumor growth and chemically induced tumors in animals is discussed and the possible mechanisms involved in this protective effect are reviewed. Fermented dairy products and lypholized lactobacilli preparations have been shown to be useful in treating and preventing various intestinal infections including; salmonellosis, shigellosis and antibiotic induced diarrhea. In this context a specific lactobacillus designated GG has been shown to be useful in treating recurring diarrhea caused by a toxin produced by Clostridium difficile.

Carcinogens↗

Changes in food patterns during a low-fat dietary intervention in women.

The Women's Health Trial was initiated by the National Cancer Institute to study the effects of a low-fat diet on the incidence of breast cancer in women at elevated risk for the disease. The purpose of this article is to examine the specific dietary changes that 173 women made while participating in a feasibility intervention program to reduce their fat intake to approximately 20% of total calories over a 12-month period. The intervention program used group sessions to teach nutrition information and behavioral skills necessary to make a life-style dietary change. Four-day food records were collected from participants at the beginning of the study and again at 12 months. Women in the intervention group reduced their total fat intake from a mean of 76 gm (39% of total energy) to 31 gm (22% of total energy), mainly by decreasing their fat intake from milk products, red meats, and fats/oils. These women used cheddar cheese, American cheese, whole milk, butter, mayonnaise, salad dressing, bacon, and hamburgers less frequently, and used diet American cheese, low-fat cottage cheese, and skim milk more frequently. They consumed less fat in their vegetable dishes, and their total caloric intake from fruit increased slightly. In addition, the overall quality of the diets improved, since there was a 20% to 50% increase in the energy-adjusted intake of vitamins and minerals from food sources.

Aged↗

Plasma lipoprotein cholesterol and endogenous sex hormones in healthy young women.

Relationships between plasma levels of lipoproteins and sex hormones were studied in 24 healthy premenopausal women with no risk factors for coronary heart disease. The women were carefully selected to remove the effects of other environmental factors, such as smoking, drugs, alcohol, and exercise, which are known to influence lipid metabolism. They all ate precisely the same Western-style diet for 1 to 2 weeks before blood samples were obtained in the follicular phase of their menstrual cycle. After adjusting for other hormones by multiple regression, significant positive partial correlations were seen between high density lipoprotein cholesterol (HDL-C) and protein bound estradiol (r = .57, P = .02), as well as between very low density lipoprotein cholesterol (VLDL-C) and protein bound estradiol (r = .63, p = .01). A significant negative partial correlation was seen between VLDL-C and free estradiol (r = -.65 P = .01). Conversely, low density lipoprotein cholesterol (LDL-C) levels were negatively correlated with protein bound estradiol (r = -.77, P less than .001) and positively correlated with free estradiol (r = .71, P less than .001). No associations between plasma lipoproteins and testosterone were seen; however, androstenedione was positively correlated with VLDL-C (r = .59, P = .01). These findings show a close link between plasma lipoproteins and sex hormones, and may help to explain the lower risk of coronary heart disease in women.

Adult↗

Diet and plasma androgens in postmenopausal vegetarian and omnivorous women and postmenopausal women with breast cancer.

We studied 27 postmenopausal women, 9 vegetarians, 10 omnivores, and 8 apparently healthy women with breast cancer (BC), four times during 1 y. Dietary intakes were recorded and plasma androgens and sex-hormone-binding globulin (SHBG) binding capacity were determined. Androstenedione (A), testosterone (T), free T (FT), and SHBG were higher in omnivores than in vegetarians. In multiple correlation analysis, intakes of protein and fat were positively correlated with A, T, and FT, whereas the intakes of carbohydrate, grain, total fiber, and grain fiber showed the opposite correlations. Protein intake was positively correlated with percentage FT (%FT) and negatively with SHBG. BC patients had a similar pattern to omnivores with even higher levels of A and T (significant compared with vegetarians) and they showed significantly higher FT and lower SHBG than both control groups. We conclude that a Western-type diet in postmenopausal women is associated with high A, T, %FT, FT, and low SHBG and this pattern was apparent in the BC patients.

Androgens↗

Low-fat, high-fiber diet and serum estrone sulfate in premenopausal women.

The effect of diet on serum estrogen levels was investigated in 17 healthy premenopausal women consuming defined diets prepared in a metabolic unit. During an initial 4-wk control period all women consumed a typical Western diet (40% of total calories from fat, 400 mg cholesterol/d, 12 g dietary fiber/d, and a ratio of polyunsaturated to saturated fatty acids [P:S] of 0.5). After this control period they were switched to a low-fat, high-fiber diet for 8-10 wk, which consisted of 25% of calories from fat, P:S of 1.0, cholesterol of 200 mg cholesterol/d, and 40 g dietary fiber/d. Compared with the control period 16 of 17 women had lower serum estrone sulfate levels on the low-fat, high-fiber diet. There was an average decrease of 36% with mean levels decreasing from 2.11 +/- 0.25 nmol/L (means +/- SEM) on the control diet to 1.29 +/- 0.19 nmol/L on the experimental diet (p less than 0.001). We conclude that a low-fat, high-fiber diet can significantly reduce serum estrone sulfate levels.

Adult↗

The role of cephalosporins in surgical prophylaxis.

Worldwide, cephalosporins are the most widely used antibiotics for surgical prophylaxis. These drugs are recommended for prophylaxis because of their good safety profile, excellent antimicrobial activity against most of the bacteria causing postoperative wound infection, satisfactory penetration into critical tissues and, most importantly, a strong track record of efficacy in clinical trials. There are still unresolved questions about the choice of cephalosporin and the timing and duration of administration. In vaginal hysterectomy, Caesarian section, and biliary tract surgery a single preoperative dose of any one of several cephalosporins has been used effectively. There are no apparent benefits in using a longer course for prophylaxis, nor for choosing a third-generation cephalosporin rather than a first- or second-generation cephalosporin. Several cephalosporins have been employed successfully in cardiac surgery, mostly in trials using a 24-48 h regimen. A recent study with a single preoperative dose of ceftriaxone has produced favourable results. In elective colorectal surgery definitive conclusions are difficult because of limited controlled studies. The best results have been achieved with an oral bowel preparation such as neomycin-erythromycin. Metronidazole, combined with another agent to suppress facultative bacteria, has also produced excellent reduction in wound infections. While it is not firmly established that a systemic cephalosporin contributes to the proven good effects of an oral bowel preparation, there is evidence that the choice of the cephalosporin should be based, in part, on its activity against anaerobic bacteria.

Cephalosporins↗

Suppression of colonic microflora by cefoperazone and evaluation of the drug as potential prophylaxis in bowel surgery.

We evaluated the activity of cefoperazone (CPZ) on the intestinal flora in terms of its use as a single prophylactic drug in colon surgery. Twenty-four healthy male volunteers between the ages of 20 and 40 were assigned to receive either CPZ, oral neomycin-erythromycin, or no antibiotics. A mechanical bowel preparation, Golytely, was also given to each of the subjects. With intravenous CPZ, antibiotic levels in the stool ranged from less than 2 to 649 micrograms/ml and the total fecal bacterial counts dropped 3 to 4 log10 CFU/g. Higher levels of CPZ were detected in the stools when an oral dose was added, 1,446 to 5,445 micrograms/ml, and the bacterial counts were reduced maximally 4 to 6 log10 CFU/g. The combination of the oral and intravenous doses produced suppression of the microflora and high levels in blood, all with a single antibiotic.

Administration, Oral↗

Elimination of vaginal colonization with Escherichia coli by administration of indigenous flora.

A persistent vaginal colonization with a pyelonephritogenic strain of Escherichia coli, induced by administration of amoxicillin, was established in four adult cynomolgus monkeys. This colonization mimicked the one seen in urinary tract infection-prone human females. Attempts to eliminate the E. coli colonization and restore normal conditions were made. Either suspensions of lactobacilli or vaginal fluid from a healthy unmanipulated monkey was administered as repeated vaginal flushes for 5 to 9 days. A total elimination of vaginal E. coli was observed in two of six experiments with lactobacilli, and a decrease was observed in the other four. A better result was obtained with flushes of vaginal fluid, which eliminated the E. coli colonization in eight of eight experiments. In two of these, a single flush was sufficient to obtain a decolonization. The ability of fresh vaginal fluid to eliminate E. coli from the vagina could be transferred from one monkey to another. This study demonstrates the role of the normal flora in the defense against genital colonization with potentially pathogenic adhering E. coli. The possible clinical relevance of these findings must be further examined.

Amoxicillin↗

Prospective study comparing imipenem-cilastatin with clindamycin and gentamicin for the treatment of serious surgical infections.

Surgical infection remains a leading cause of hospital morbidity and mortality. We compared the efficacy and toxicity of imipenem-cilastatin sodium in 32 patients with that of clindamycin phosphate and gentamicin sulfate in 25 patients. In the imipenem-cilastatin group, 87.5% had a favorable outcome, with a 12.5% failure rate and 13 adverse reactions. In the clindamycin-gentamicin group, 80% had a favorable outcome, with a 20% failure rate and ten adverse reactions. Two significant superinfections with Pseudomonas and Candida were noted in patients treated with impenem-cilastatin. Each group had one case of Clostridium difficile-associated colitis. Cost analysis showed no differences between treatment arms, except in the appendicitis subgroup. For serious surgical infections, single-agent therapy with imipenem-cilastatin appears to be as efficacious as combination therapy with clindamycin and gentamicin.

Adolescent↗