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Biomedical subjects

J W Anderson

Publications and source records attributed to J W Anderson.

At least 163 records · Page 9Linked to original sources
PubMed1990

Oat-bran cereal lowers serum total and LDL cholesterol in hypercholesterolemic men.

Oat bran lowers serum lipid concentrations in healthy and hyperlipidemic subjects. To determine the effects of a ready-to-eat oat-bran cereal on lipid concentrations, we fed control (corn flakes) and oat-bran cereal diets for 2 wk to 12 men with undesirably high serum total-cholesterol concentrations. Subjects were randomly assigned to one of the two diets upon admission to the metabolic ward. After completing the first diet, subjects completed 2 wk on the alternate diet. Intakes of carbohydrate, protein, fat, and cholesterol were virtually identical on the two diets. The oat-bran cereal provided 25 g oat bran/d. The oat-bran cereal diet compared with the corn flakes diet lowered serum total-cholesterol and serum LDL-cholesterol concentrations significantly by 5.4% (p less than 0.05) and 8.5% (p less than 0.025), respectively. Final body weights on each of the diets were similar. Ready-to-eat oat-bran cereal provides a practical means to incorporate soluble fiber into the diet to lower serum cholesterol.

Aged↗
PubMed1990

High-carbohydrate, high-fiber diets increase peripheral insulin sensitivity in healthy young and old adults.

To examine extra-alimentary effects of high-carbohydrate, high-fiber (HCF) diets, insulin-mediated glucose disposal employing the euglycemic clamp and hepatic glucose output (HGO) employing [6,6-2H2]glucose were measured in 12 healthy young and old individuals before and after 21-28 d of an HCF diet. Diet lowered fasting concentrations of glucose from 5.3 +/- 0.2 to 5.1 +/- 0.1 mmol/L (p less than 0.01) and insulin from 66.0 +/- 7.9 to 49.5 +/- 5.7 pmol/L (p less than 0.01). Fasting serum cholesterol decreased from 5.17 +/- 0.18 to 3.80 +/- 0.20 mmol/L (p less than 0.01) in young individuals and from 6.15 +/- 0.52 to 4.99 +/- 0.49 mmol/L (p less than 0.01) in elderly individuals. Fasting serum triglyceride concentrations, basal HGO, and insulin suppression of HGO were unchanged by the diet. Glucose disposal rates increased from 18.87 +/- 1.66 before 23.87 +/- 2.78 mumol.kg-1.min-1 after the diet (p less than 0.02). Therefore, HCF diets may improve carbohydrate economy by enhanced peripheral sensitivity to insulin.

Adult↗
PubMed1990

Propionate inhibits hepatocyte lipid synthesis.

Oat bran lowers serum cholesterol in animals and humans. Propionate, a short-chain fatty acid produced by colonic bacterial fermentation of soluble fiber, is a potential mediator of this action. We tested the effect of propionate on hepatocyte lipid synthesis in rats using [1-14C]acetate, 3H2O, and [2-14C]mevalonate as precursors. Propionate produced a statistically significant inhibition of cholesterol biosynthesis from [1-14C]acetate at a concentration of 1.0 mM and from 3H2O and [2-14C]mevalonate at concentrations of 2.5 mM. Propionate also produced a significant inhibition of fatty acid biosynthesis at concentrations of 2.5 mM using [1-14C]acetate as a precursor. The demonstration of propionate-mediated inhibition of cholesterol and fatty acid biosynthesis at these concentrations suggests that propionate may inhibit cholesterol and fatty acid biosynthesis in vivo and may mediate in part the hypolipidemic effects of soluble dietary fiber. Further studies are needed to clarify this action of propionate and to establish the exact mechanisms by which the inhibition occurs.

Animals↗
PubMed1989

Combinations of recombinant colony-stimulating factors are required for optimal hematopoietic differentiation in serum-deprived culture.

Previous in vitro investigations on enriched human hematopoietic progenitors have led to the conclusion that the purified recombinant multipoietins, interleukin 3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) can alone induce the formation of colonies from a variety of multipotent and lineage committed progenitors. Since fetal calf serum was included in these cultures and itself might contain growth factors or other cofactors, we re-examined the actions of the CSFs in serum-deprived conditions. Results show that both the multipoietins are inadequate stimuli of colony formation. At maximal concentrations IL-3 alone induces only 25% of the granulocyte and macrophage colony-forming units (CFU-G and CFU-M) produced by a T-cell conditioned medium that contains a mixture of CSFs. When IL-3 was added at the initiation of the cultures and erythropoietin (ep), G-CSF, or M-CSF added on day 3, almost full recovery of erythroid, granulocytic, and monocytic colonies, respectively, was obtained. Similar results were obtained with GM-CSF except that fewer erythroid colonies were recovered at high concentrations, and almost maximal CFU-M proliferation could be induced. These results show that in serum-deprived conditions, the multipoietins must be combined with lineage specific CSFs for full progenitor expression.

Colony-Forming Units Assay↗
PubMed1989

Recent advances in carbohydrate nutrition and metabolism in diabetes mellitus.

The last decade has brought a tremendous turnaround in nutritional recommendations for diabetes management, moving from low-carbohydrate, high-fat diets to high-carbohydrate, high-fiber, low-fat diets. Clinical studies which furthered understanding of carbohydrate metabolism greatly contributed to the change. This paper reviews recent advances in selected aspects of carbohydrate nutrition and metabolism in diabetes mellitus.

Carbohydrate Metabolism↗
PubMed1989

Dietary fiber content of a simulated American diet and selected research diets.

Few studies accurately report total-dietary-fiber (TDF) content of current and alternative diets. In this study we analyzed and calculated TDF content of a simulated American diet with household Nationwide Food Consumption Survey data. We also analyzed the fiber content of four research diets: control; bean; high fiber, maintenance (HFM); and high carbohydrate, high fiber (HCF). Analyzed and calculated fiber values for the simulated diet were similar. The simulated, control, bean, HFM, and HCF diets provided 5.6, 8.1, 12.2, 17.4, and 22.8 g TDF/1000 kcal, respectively. Soluble-fiber content ranged from 1.7 g/1000 kcal for the simulated diet to 6.1 g/1000 kcal for the HCF diet. Cereal products contributed the most to total fiber content of the simulated diet, followed in order by vegetables, legumes, fruits, and miscellaneous foods. Fiber content of the simulated diet was below recommended levels. The HFM diet is suggested for individuals desiring to increase their dietary fiber intake.

Dietary Fiber↗
PubMed1989

Metabolic effects of fructose supplementation in diabetic individuals.

With new diabetes diet guidelines recommending high carbohydrate intake, questions arise regarding acceptable intake of simple sugars. Whereas several short-term studies report flattened glycemic and insulin response to fructose consumption, some also report increased serum triglyceride levels. Few studies examine the effects of long-term fructose consumption. We evaluated the long-term safety of fructose consumption in 14 middle-aged men with diabetes. Subjects followed an ambulatory high-fiber high-carbohydrate control diet at home for 8 wk, entered the hospital for 5 days on this diet, and spent the next 7 days on a similar diet supplemented with 50-60 g fructose. They continued the fructose diet at home for 23 wk, then resumed a postcontrol diet for an additional 16 wk. In the hospital, glycemic control improved significantly on the fructose-supplemented diet compared with the hospital control diet. In the ambulatory setting, no significant differences in plasma glucose, glycohemoglobin, serum cholesterol, triglycerides, lactate, or urate occurred between precontrol, fructose, or postcontrol periods. Fasting serum lactate was higher by 0.5 meq/L during the ambulatory fructose period than during the precontrol period. Body weight also increased during the ambulatory fructose period due to higher calorie intake. Adherence to fructose consumption was excellent and improved adherence to carbohydrate and fat recommendations. If total calorie intake is controlled to promote desirable body weight, crystalline fructose used with a high-carbohydrate high-fiber low-fat diet appears to be safe and acceptable for diabetic individuals.

Blood Glucose↗
PubMed1988

New perspectives in nutrition management of diabetes mellitus.

Diet remains the cornerstone in the management of diabetes mellitus. A prudent nutrition plan reduces the exaggerated risk for atherosclerotic heart disease and metabolic complications of diabetes by improving lipid and glycemic control. The current consensus diabetes diet recommends 55 to 60 percent of energy as carbohydrate, 12 to 20 percent as protein, and less than 30 percent fat. Total cholesterol intake should be less than 300 mg per day. Fiber appears to have distinct benefits in improving glucose and lipid levels; therefore, an intake of up to 40 g per day or 15 to 25 g/1,000 kcal of food is recommended. Other considerations in meal planning for diabetes include alternative sweeteners, salt intake, alcohol consumption, and vitamin and mineral needs. Individualized and flexible nutrition plans, designed within established guidelines, promote adherence. Persons with diabetes can change their eating patterns and closely adhere to a diet plan if the entire health care team is enthusiastic, supportive, and instructive.

Diabetes Mellitus↗
PubMed1988

Dietary fiber content of selected foods.

Dietary fiber measurements are essential to assessment of the potential therapeutic and preventive effects of fiber intake. Ideally, dietary fiber analyses should measure all components--soluble polysaccharides, noncellulosic polysaccharides, cellulose, and lignin--and the constituent sugars of the soluble and noncellulosic polysaccharides. We modified existing techniques to measure reproducibly the total dietary fiber, polysaccharide, and lignin components and the sugar constituents of selected foods. Soluble-fiber content as percentage of total dietary fiber for groups of foods averaged 32% for cereal products, 32% for vegetables, 25% for dried beans, and 38% for fruits. Lignin content, estimated gravimetrically, was approximately 1.4 g/100 g dry wt for 24 foods. Detailed fiber measurements are critical for evaluating the potential health benefits of dietary fiber intake.

Bread↗
PubMed1988

Hypocholesterolemic effects of oat and bean products.

Oat and bean products, which contain large amounts of water-soluble fiber, are particularly effective hypocholesterolemic agents. Recent experiments with human subjects using these products as supplements to the diet are reviewed. High-carbohydrate, high-fiber diets offer a nutritious, economical, and readily accepted means to reduce serum cholesterol.

Adult↗
PubMed1988

Osmolality, NaCl dietary intake, and regulation of ventilation by CO2.

The ventilatory response to CO2 (VR) was examined in six awake dogs during the 2nd week of sequential dietary periods of low NaCl (less than 5 meq NaCl/day), high NaCl (approximately 120 meq NaCl/day), and then repeated low NaCl. Water intake was maintained constant at 77 ml.kg-1.day-1. PCO2 of arterial blood (PaCO2) and the PaCO2 threshold of the VR increased between the high-NaCl and the second low-NaCl period; the PaCO2 threshold did not change between the first low-NaCl and the high-NaCl period. In contrast, arterial [H+] ([H+]a) threshold of the VR increased between the first low-NaCl period and the high-NaCl period, but did not change further in the second low-NaCl period. Variations in [H+]a threshold of the VR between dogs on high- and low-NaCl diets were correlated with plasma osmolality, and this accounted for a positive linear relation between [H+]a and plasma osmolality. During the high-NaCl period, the arterial strong ion difference [[SID]a = ([Na+] + [K+]) - ([lactate-] + [Cl-])] decreased, forcing [H+]a to increase. However, during high-NaCl diet, PaCO2 decreased relative to plasma osmolality, counterbalancing the decrease in [SID]a and maintaining the relation between [H+]a and plasma osmolality. The compensatory mechanism for the decrease in PaCO2 during high NaCl was a shift in the relation between PaCO2 threshold of the VR and plasma osmolality to a lower PaCO2 threshold. Chemoreceptor, osmoreceptor, and/or humoral mechanisms are potentially involved in these respiratory adaptations to alterations in electrolyte and water balance.

Animals↗
PubMed1988

H+ homeostasis, osmolality, and body temperature during controlled NaCl and H2O intake.

Arterial PCO2, arterial [H+] ([H+]a), electrolytes, and osmolality, as well as rectal temperature (Tre), were monitored in six awake dogs over sequential 12- or 13-day periods in which their NaCl intake was first less than 5 meq/day, then approximately 120 meq/day, and finally less than 5 meq/day. Water intake was maintained constant at 77 ml.kg-1.day-1 throughout. During low-NaCl periods, decreases in body and plasma water, indicated by weight loss did not prevent lower arterial [Na+] ([Na+]a), arterial [Cl-] ([Cl-]a), and osmolality relative to the high-NaCl period. During high dietary NaCl, the arterial strong ion difference [[SID]a = ([Na+]a + [K+]a) - (arterial [lactate-] + [Cl-]a)] was lower. From physicochemistry, this lowered [SID]a results in a higher [H+]a. However, independent of NaCl intake, [H+]a was positively correlated with plasma osmolality; moreover, [H+]a, relative to plasma osmolality, was higher at lower Tre than at higher Tre. We speculate that this spectrum of plasma osmolality and body temperature may contribute to the creation of an appropriate protein pK to match plasma [H+]a. We also found that the difference between plasma [protein] (measured by the biuret test) and [ATOT]a (an estimation of plasma protein as total weak acid from physicochemistry) was related to plasma osmolality, [SID]a, and [Na+]a. These latter relations may reflect the effect of plasma water concentration (osmolality) and strong ions on the pK of plasma proteins.

Animals↗
PubMed1988

A comparison of the lipid-lowering and intestinal morphological effects of cholestyramine, chitosan, and oat gum in rats.

Cholestyramine, chitosan, and oat gum are lipid-lowering compounds. Cholestyramine use in humans may contribute to colonic adenocarcinoma; chitosan and oat gum are being studied in the rat to determine their potential for human use. To compare these compounds, we fed three groups of 10 male Sprague-Dawley rats one of the substances at 5% of diet with 1% cholesterol and 0.2% cholic acid; two other groups were fed cellulose with and without 1% cholesterol and 0.2% cholic acid. All groups had similar food intake and weight gains. Cholesterol feeding increased total liver lipids almost 3-fold and liver cholesterol concentration almost 10-fold. Cholestyramine, oat gum, and chitosan all significantly lowered liver cholesterol with cholestyramine feeding yielding levels identical to the noncholesterol-fed basal group. Chitosan and oat gum lowered liver cholesterol moderately. Cholestyramine and chitosan both significantly lowered serum cholesterol compared to the cellulose group. Oat gum was less effective. Hemoglobin and serum iron were similar in all groups except the oat gum group, which had decreased serum iron. Histological examination of small and large bowel with morphometry revealed statistically significant increases in both proximal and distal small bowel and distal large bowel mucosal thickness in the cholestyramine-fed group. No changes were noted in the proximal large bowel. Neither chitosan nor oat gum produced mucosal change other than an increase in the distal small bowel with the oat gum diet. Chitosan may have lipid-lowering effects similar to those of cholestyramine without the deleterious changes in intestinal mucosa.

Animals↗
PubMed1988

Cholesterol-lowering effects of psyllium hydrophilic mucilloid for hypercholesterolemic men.

The effect of psyllium hydrophilic mucilloid on serum cholesterol levels was investigated in 26 men with mild to moderate hypercholesterolemia (range of cholesterol level, 4.86 to 8.12 mmol/L [188 to 314 mg/dL]) in a double-blind, placebo-controlled parallel study. Following a two-week baseline period, subjects were treated for eight weeks with 3.4 g of psyllium or cellulose placebo at mealtimes (three doses per day). All subjects maintained their usual diets, which provided less than 300 mg of cholesterol per day and approximately 20% of energy from protein, 40% from carbohydrate, and 40% from fat. Eight weeks of treatment with psyllium reduced serum total cholesterol levels by 14.8%, low-density lipoprotein (LDL) cholesterol by 20.2%, and the ratio of LDL cholesterol to high-density lipoprotein cholesterol by 14.8% relative to baseline values. The reductions in total cholesterol and LDL cholesterol became progressively larger with time, and this trend appeared to be continuing at the eighth week. Psyllium treatment did not affect body weight, blood pressure, or serum levels of high-density lipoprotein cholesterol, triglycerides, glucose, iron, or zinc. No significant changes in serum lipid levels, body weight, blood pressure, or other serum parameters were observed with placebo treatment. Subject adherence to psyllium treatment was excellent, and no adverse effects were observed. Results of this study show that psyllium is an effective and well-tolerated therapy for mild to moderate hypercholesterolemia.

Adult↗
PubMed1988

Chemotherapeutic strategies in the multidisciplinary treatment of head and neck cancer.

A role for chemotherapy in the multidisciplinary treatment of patients with advanced squamous cell carcinoma of the head and neck (SCCHN) is yet to be defined. Results of uncontrolled studies indicate high response rates to induction chemotherapy and an association between a response to chemotherapy and either local-regional control or survival. Unfortunately, results of randomized, controlled trials have not confirmed an overall survival advantage with such treatment. From 1979 to the present, the Dana-Farber Cancer Institute has registered more than 224 patients on two trials of induction and adjuvant chemotherapy for patients with stage III to IV SCCHN. Protocol 80-016 (1979 to 1983) evaluated two cycles of induction cisplatin, bleomycin, and methotrexate/leucovorin (PBM) before local regional treatment in 114 patients. Eighty-nine (78%) patients responded to PBM, with 30 (28%) patients achieving a complete response (CR). After surgery and/or radiotherapy (RT), 46 responders to induction PBM entered a trial of the randomly assigned additional adjuvant PBM. Protocol 83-084 (1983 to present) randomly assigned patients to receive up to four cycles of either induction PBM or cisplatin and infusion 5-fluorouracil before local treatment. Adjuvant chemotherapy was not used in the latter study. Updated results from both trials will be presented, with their implications for future phase II and III multidisciplinary studies. Optimal approaches to the treatment of patients with advanced SCCHN can include planned reductions in the extent of surgery or RT offered to selected patients with a good response to induction chemotherapy but may require adjuvant chemotherapy for patients at high risk for recurrent disease. Until the rate of CR to induction chemotherapy is reproducibly over 50%, documentation of an improved overall survival with multidisciplinary treatment may be difficult.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Dietary fiber, lipids and atherosclerosis.

Dietary fiber has important hypocholesterolemic effects and may reduce risk for coronary artery disease. Careful clinical studies indicate that foods such as oat bran or beans, rich in water-soluble fiber, can decrease serum total cholesterol by 19% while decreasing serum low density lipoprotein cholesterol by 22%. Food supplements rich in soluble fiber such as psyllium mucilloid are well tolerated and may lower serum cholesterol by 15%. Thus, high fiber foods or soluble fiber food supplements may decrease serum cholesterol by 15% to 19% and decrease estimated risk for coronary heart disease by greater than 30%.

Adult↗
PubMed1987

High-carbohydrate, high-fiber diet. Is it practical and effective in treating hyperlipidemia?

More than one half of middle-aged Americans have undesirably high serum lipid levels. Diets high in fiber and carbohydrate and low in fat reduce serum lipid levels two to four times more than the widely recognized American Heart Association diet. High intake of soluble fiber is especially effective for lowering serum cholesterol levels; alcohol restriction and weight reduction help lower serum triglycerides. High-carbohydrate, high-fiber diets combined with regular exercise and healthy life-style hold great potential to reduce hyperlipidemia and the incidence of coronary artery disease in the United States.

Coronary Disease↗