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Biomedical subjects

S L Gorbach

Publications and source records attributed to S L Gorbach.

At least 19 recordsLinked to original sources
PubMed1992

Survival of Lactobacillus species (strain GG) in human gastrointestinal tract.

A newly isolated strain of a species of Lactobacillus of human origin, designated GG (Lactobacillus GG), has been studied to determine its ability to survive in the human gastrointestinal tract. When fed to 76 volunteers as a frozen concentrate or as a fermented preparation in milk or whey, Lactobacillus GG was recovered in the feces of all subjects receiving the fermented milk or whey and in 86% receiving the frozen concentrate when a single fecal specimen was cultured. The organism was also present in the feces of subjects concurrently receiving ampicillin. After terminating feeding of the organism, Lactobacillus GG persisted in the feces of 87% of volunteers four days later and in 33% of subjects seven days later. Lactobacillus GG lowered fecal bacterial beta-glucuronidase activity by approximately 80% in volunteers given the organism for four weeks. These studies demonstrate that Lactobacillus GG can survive and temporarily colonize the human gastrointestinal tract and can affect the metabolic activity of the resident microflora.

Digestive System↗
PubMed1992

Enhancing the level of nutrition education at Tufts University's Medical and Dental Schools.

The current medical and dental curricula at Tufts were evaluated to ascertain the breadth and depth of their nutrition programs. The program, which both schools plan to initiate, to enhance the level of nutrition education involves (1) development of nutrition units for the first and second year, (2) expansion of required nutrition courses in the second year, (3) diet lunches in the third year introducing the role of nutrition in the clinical setting, and (4) nutrition rounds in the fourth year. A combined medical-dental seminar will be presented each year. At the end of the five-year funding period, it is anticipated that a manual will be available to all medical and dental schools that includes (1) nutrition units, (2) methods of dietary assessment in medical-dental practices, (3) nutrition interaction for the prevention of chronic disease in medical-dental practices, and (4) nutrition support for chronic disease and cancer, and case studies on nutrition and disease. The success of this program will be evaluated on the basis of goals and a national nutritional literacy exam.

Boston↗
PubMed1992

Evaluation of new anti-infective drugs for surgical prophylaxis. Infectious Diseases Society of America and the Food and Drug Administration.

It has been established by substantial research that antimicrobial prophylaxis for various surgical procedures can reduce the risk of postoperative morbidity and mortality. When the incidence of infectious complications is high, the reduction with prophylaxis is most dramatic. However, even for many "clean" procedures (vascular procedures, total joint replacement), the small reduction in potentially calamitous complications justifies the use of prophylaxis. Many issues of detail remain unanswered: timing and duration of administration of antimicrobial drug; type of drug; use of topical anti-infective agents as ancillary measures; and choices for high-risk individuals and others ordinarily excluded from clinical trials. An approach to the conduct of clinical trials of anti-infective drugs for surgical prophylaxis is provided. Both general guidelines and specific recommendations for total hip replacement, colorectal operations, appendectomy, and transurethral resection of the prostate are included.

Anti-Infective Agents↗
PubMed1991

Food use and health effects of soybean and sunflower oils.

This review provides a scientific assessment of current knowledge of health effects of soybean oil (SBO) and sunflower oil (SFO). SBO and SFO both contain high levels of polyunsaturated fatty acids (PUFA) (60.8 and 69%, respectively), with a PUFA:saturated fat ratio of 4.0 for SBO and 6.4 for SFO. SFO contains 69% C18:2n-6 and less than 0.1% C18:3n-3, while SBO contains 54% C18:2n-6 and 7.2% C18:3n-3. Thus, SFO and SBO each provide adequate amounts of C18:2n-6, but of the two, SBO provides C18:3n-3 with a C18:2n-6:C18:3n-3 ratio of 7.1. Epidemiological evidence has suggested an inverse relationship between the consumption of diets high in vegetable fat and blood pressure, although clinical findings have been inconclusive. Recent dietary guidelines suggest the desirability of decreasing consumption of total and saturated fat and cholesterol, an objective that can be achieved by substituting such oils as SFO and SBO for animal fats. Such changes have consistently resulted in decreased total and low-density-lipoprotein cholesterol, which is thought to be favorable with respect to decreasing risk of cardiovascular disease. Also, decreases in high-density-lipoprotein cholesterol have raised some concern. Use of vegetable oils such as SFO and SBO increases C18:2n-6, decreases C20:4n-6, and slightly elevated C20:5n-3 and C22:6n-3 in platelets, changes that slightly inhibit platelet generation of thromboxane and ex vivo aggregation. Whether chronic use of these oils will effectively block thrombosis at sites of vascular injury, inhibit pathologic platelet vascular interactions associated with atherosclerosis, or reduce the incidence of acute vascular occlusion in the coronary or cerebral circulation is uncertain. Linoleic acid is needed for normal immune response, and essential fatty acid (EFA) deficiency impairs B and T cell-mediated responses. SBO and SFO can provide adequate linoleic acid for maintenance of the immune response. Excess linoleic acid has supported tumor growth in animals, an effect not verified by data from diverse human studies of risk, incidence, or progression of cancers of the breast and colon. Areas yet to be investigated include the differential effects of n-6- and n-3-containing oil on tumor development in humans and whether shorter-chain n-3 PUFA of plant origin such as found in SBO will modulate these actions of linoleic acid, as has been shown for the longer-chain n-3 PUFA of marine oils.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Effect of long-term fish oil supplementation on vitamin E status and lipid peroxidation in women.

Fifteen young (22-35 y) and 10 older (51-71 y) women received six capsules of fish oil (Pro-Mega)/d, providing a total of 1,680 mg eicosapentaenoic (EPA), 720 mg docosahexaenoic (DHA), 600 mg other fatty acids, and 6 IU vitamin E. Blood was collected before and after 1, 2 and 3 mo of supplementation. Compliance was confirmed by the significant increase in plasma EPA and DHA in all women. Older women had a significantly higher increase in EPA and DHA than did young women (10-fold increases in EPA and 2.5-fold increases in DHA vs. 8-fold in EPA and 2-fold in DHA for older and young women, respectively). The decrease in the arachidonic acid:EPA ratio was more dramatic in the older women. Plasma total triglycerides (TG) decreased significantly, and the ratio of polyunsaturated fatty acids to saturated fatty acids was significantly (P less than 0.01) increased. Plasma vitamin E levels did not change significantly after supplementation; however, after 3 mo of supplementation by young women, plasma vitamin E was significantly lower than after 1 mo. The vitamin E: TG ratio was significantly increased and vitamin E:(EPA + DHA) significantly decreased. All women showed a significant increase in plasma lipid peroxide through mo 2 of supplementation. After 2 mo, older women had significantly higher lipid peroxide levels than young women. The lipid peroxide:TG ratio, which declined by mo 3, was still significantly higher than baseline. These data indicate that although long-term fish oil supplementation may be beneficial in reducing plasma total TG, susceptibility of plasma lipids to free radical attack is potentiated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Oral (n-3) fatty acid supplementation suppresses cytokine production and lymphocyte proliferation: comparison between young and older women.

The effect of (n-3) fatty acid supplementation on cytokine production and lymphocyte proliferation was investigated in young (23-33 y) and older (51-68 y) women. Subjects supplemented their diets with 2.4 g of (n-3) fatty acid/d for 3 mo. Blood was collected before and after 1, 2 and 3 mo of supplementation. The (n-3) fatty acid supplementation reduced total interleukin (IL)-1 beta synthesis by 48% in young women but by 90% in older women; tumor necrosis factor was reduced by 58% in young and 70% in older women. Interleukin-6 was reduced in young women by 30% but by 60% in older women. Older women produced less IL-2 and had lower mitogenic responses to phytohemagglutinin (PHA) than young women prior to (n-3) fatty acid supplementation. The (n-3) fatty acid supplementation reduced IL-2 production in both groups; however, this reduction was significant only in older women. The PHA-stimulated mitogenic response was significantly reduced by (n-3) fatty acid in older women (36%). Thus, long-term (n-3) fatty acid supplementation reduced cytokine production in young women and cytokine production and T cell mitogenesis in older women. The reduction was more dramatic in older women than in young women. Although (n-3) fatty acid-induced reduction in cytokine production may have beneficial anti-inflammatory effects, its suppression of IL-2 production and lymphocyte proliferation in older women may not be desirable.

Adult↗
PubMed1990

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↗
PubMed1990

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↗
PubMed1990

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↗
PubMed1990

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↗
PubMed1990

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↗
PubMed1990

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↗