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Biomedical subjects

S E Fleming

Publications and source records attributed to S E Fleming.

35 records · Page 2Linked to original sources
PubMed1988

Repeated consumption of high-fiber breakfasts: effects on postprandial glucose and insulin responses after breakfast and lunch.

The objective of this study was to evaluate the effects of repeated consumption of two high-fiber diets on postprandial glucose and insulin responses. Two mixed-food breakfast meals composed predominantly of either red kidney beans or bran cereal were fed to six healthy young men. The meals provided equivalent levels of digestible carbohydrate, protein, fat, and fiber. Insulin responses measured after breakfast were lower with the bean diet than with the bran cereal diet but higher when measured after a standard lunch. No significant interactions were found between the diets and the length of the time the subjects were on the diets (days 1 vs 7). In comparison to the postprandial responses on day 1 of the diet periods, postprandial responses on day 7 showed reduced glucose and insulin responses to breakfast and reduced insulin responses to lunch. Responses to an oral glucose tolerance test were not affected by repeated consumption of these diets.

Adaptation, Physiological↗
PubMed1987

Analysis of volatile fatty acids in biological specimens by capillary column gas chromatography.

A method was developed to analyze and quantify volatile fatty acids (VFA) such as acetic, propionic, butyric, isobutyric, valeric and isovaleric acids in biological specimens. To obtain good sample transfer into the chromatographic system an organic solvent had to be used together with an aqueous milieu, thus improving wetting properties of the liquid sample plug introduced into the column. Sample preparation was carried out under alkaline conditions in order to exclude or minimize sample losses due to sample transfer during the extraction and work-up procedure. A cold on-column injection was applied to avoid irregular discrimination of the various acids due to sample splitting and an automatic injection technique was used to accommodate the large number of samples generated from biological origin. Connection of a pre-column of wide internal diameter (0.53 mm) to the analytical column (0.32 m) was optimized and adapted to the nature of the injection solvent mixture consisting of acetonitrile, water and hydrochloric acid. To obtain well-separated and correctly quantifiable gas chromatographic peaks, it was essential to perform the chromatography under acidic aqueous conditions. Standard resolution conditions and response factors were evaluated. The chromatographic results of applying this method to biological specimens from both rats and humans are provided.

Animals↗
PubMed1987

Effects of cigarette smoking on phobic anxiety.

Smokers report that smoking reduces anxiety. However, experimental research on the anxiety-reducing effects of smoking is limited to two self-report studies, both of which have methodological problems. We tested the effects of smoking on self-reported anxiety and avoidance behavior in a behavioral avoidance test (BAT) using a large white rat. In a counterbalanced within subjects design, 20 rat phobic female smokers smoked or were smoking deprived in two separate administrations of the BAT. A second group of 20 rat phobic nonsmokers also received two BATs. Subjects manifested substantial anxiety during BATs. However, neither smoking condition nor smoker versus nonsmoker status affected self-reported or motoric anxiety. Although smoking did not reduce anxiety in this study, smoking may affect anxiety in other situations, such as social settings, where the stimulus is more diffuse or less intense. It may also affect anxiety in individuals who are heavier smokers than our subjects, who smoked only 10-20 cigarettes per day.

Anxiety↗
PubMed1987

High-fiber foods at breakfast: influence on plasma glucose and insulin responses to lunch.

This study evaluates acute effects of red kidney bean consumption on postprandial glucose and insulin responses in six healthy young men. Comparisons were made among three mixed-food breakfast meals comprised predominantly of either red kidney beans, bran cereal, or white bread. These meals provided equivalent levels of digestible carbohydrate, protein, and fat. The bean and bran meals contained equivalent levels of fiber while the white-bread meal contained a lower level. The postprandial glucose and insulin responses to the three meals were similar and responses also were similar after a standard whole-wheat-bread meal 4 h later. There appeared to be a reciprocal relationship between glucose and insulin responses after the lunch meal. This would influence interpretation of data regarding second-meal response.

Adult↗
PubMed1986

Imperforate anus in females: frequency of genital tract involvement, incidence of associated anomalies, and functional outcome.

Of 162 female patients with imperforate anus, 21% had a noncommunicating and 79% a communicating anomaly of the rectum or anus. Associated anatomical abnormalities were found in the lower urinary tract (15%), upper urinary tract (25%), lower genital tract (27%), upper genital tract (35%), and additional organ systems (51%). Death occurred in 26 patients and in 19, this was attributed to the associated abnormalities. Functional outcome was assessed in those patients 13 years of age or older. Bowel function was normal or near normal in 85%, as was urinary and renal function. In 44% of patients evaluated, there was persistent vaginal abnormality or scarring and in 25%, this was severe enough to require future surgery.

Abnormalities, Multiple↗
PubMed1986

Volatile fatty acids: their production, absorption, utilization, and roles in human health.

The evidence shows that microbial fermentation of carbohydrates and endogenous substrates occurs in the large intestine of humans and that VFA represent a major endproduct. The large number of bacterial species, the complex nature of their interactions, and the endproducts of their fermentation processes are all likely to have significance in human health. Fermentation in the human intestine resembles rumen fermentation with respect to the metabolic pathways involved in anaerobic degradation of organic matter and in the concentrations of VFA endproducts. Thus, rumen bacteria are useful for understanding the dynamics and potential interactions of human intestinal bacteria. Current research is directed towards examining fermentation processes in animals, such as the pig and some species of monkey, since these animals most closely resemble the human. From such animal studies the metabolic activities of VFA and the processes by which they are produced and absorbed can be more clearly investigated and understood. The effects of diet on the microflora and on the metabolic pathways leading to the generation of VFA are under investigation. Modification of diet seems the most likely way of modifying the extent to which VFA are produced and absorbed by the human. As methodologies and protocols for evaluating human intestinal fermentation in vivo are revised and made more sensitive, the significance of fermentation will become more clearly understood. However, it appears that VFA make a physiologically significant contribution to the health of the colonic mucosa, and to the energy supply of the host. The magnitude of these effects is probably influenced by diet.

Animals↗
PubMed1985

Influence of frequent and long-term bean consumption on colonic function and fermentation.

The objective of this study was to determine the influence of frequent and long-term consumption of legume seeds on colonic function. Two groups of subjects were studied--one group habitually consumed legume seeds as part of their normal diet, a second group only infrequently consumed legumes. No differences between these groups could be detected for fecal output and frequency, intestinal transit time, VFA excretion or fecal pH during 23-day study periods in which subjects consumed either their usual diet or 100 g red kidney beans, daily. However, the addition of beans to the diets of both groups provided significantly more dietary fiber, and produced greater fecal output and a higher concentration of VFA in feces. Fecal output appeared to be determined by two independent parameters--dietary fiber intake and VFA excretion. Beans provided a physiologically useful source of dietary fiber and favorably influenced colonic function.

Adult↗
PubMed1984

Influence of frequent and long-term consumption of legume seeds on excretion of intestinal gases.

The objective of this study was to determine the influence of long-term and frequent consumption of legume seeds on the excretion of fermentation gases. This was done by comparing gas excretion for one group (B) of individuals that habitually consumed legumes to that of another group (NB) of individuals that only infrequently consumed legumes. Gas excretion was measured during one diet period (control) when they consumed their normal diets and during one diet period (bean) when they consumed 100 g (dry weight), daily, of red kidney beans. Twelve men participated in this study on an outpatient basis and received each diet for 23 days. We found that there was neither short-term (no difference throughout the 23 days) nor long-term (NB and B groups were equivalent) adaptation in the quantity of gas that was excreted. However, both groups subjectively expressed greater tolerance and less physical discomfort as the bean-consuming period continued.

Adult↗
PubMed1983

Colonic function and fermentation in men consuming high fiber diets.

The relationships between fermentation in the gut and colonic function were studied by using data derived from a human metabolic study. Five healthy men were fed diets that were fiber-free or contained cellulose, xylan, pectin or corn bran. Fermentation was assessed by measuring the excretion of flatus gas, volatile fatty acids (VFA) in feces and fecal pH. Colonic function was assessed by measuring transit time, fecal frequency, fecal output and fecal composition. Fibers that were only marginally fermented included cellulose and corn bran, and these fibers caused large fecal output, frequent defecations and prolonged the residence time of digesta in the gut; feces contained high levels of neutral detergent fiber (NDF); neither diet influenced fecal pH nor flatus gas excretion; and only corn bran increased VFA excretion in feces. Fibers that were mostly fermented in the gut included xylan and pectin, and these fibers did not influence fecal frequency or fecal output, but they did decrease transit time; both diets caused high levels of flatus gas to be excreted; pectin caused higher VFA excretion in feces and lower fecal pH. The excretion of VFA in feces was highly correlated with total fecal output, and high levels of VFA were associated with low flatus gas excretion. Mutagenic activity in feces was negligible for all subjects on all diets as measured by the fluctuation test.

Adult↗
PubMed1983

Growth performance and intestinal transit time of rats fed purified and natural dietary fibers.

The effects of some selected purified fibers were compared to those derived from cereals or legume seeds. Rats were fed for at least 9 weeks and measurements were taken to determine feed consumption, weight gain, feed efficiency ratios (FER), protein efficiency ratios (PER), apparent protein digestibility, and rate of transit through the gastrointestinal tract. Most diets were designed to contain approximately 10% dietary fiber and 10% protein. Compared to the fiber-free diet, pectin reduced weight gain, FER, PER and apparent protein digestibility values. Cellulose, xylan and raffinose had no influence on feed intake, weight gains or FERs. However, cellulose and xylan increased PER values and the rates of food passage but decreased the apparent protein digestibility values. Feed utilization, protein digestibility and growth were similar for the wheat bran, corn bran and fiber-free diets. These cereal fibers caused the rates of transit to be significantly increased relative to the fiber-free control diet. The hull and cell-wall-fiber fractions of beans, when compared to the fiber-free diet, had little effect on feed consumption, growth, FER or PER. The cell-wall-fiber fraction reduced apparent protein digestibility and the hull fraction accelerated food passage relative to the fiber-free diet.

Animals↗
PubMed1983

Influence of dietary fiber on fecal excretion of volatile fatty acids by human adults.

The ability of dietary fibers to influence the excretion of volatile fatty acids (VFA) in feces was evaluated in five healthy men. Throughout the 63-day study subjects were confined to a metabolic unit and fed semipurified diets. Each diet was consumed for 9 days. Feces were homogenized, and aliquots were analyzed for VFA by a steam distillation procedure followed by gas-liquid chromatography. Individuals showed wide variability in the extent to which they excreted VFA, and there is evidence of some subject-diet interaction. Acetate, propionate and butyrate were generally present in the ratios of 35:25:20, but the proportion of acetate was increased when xylan and corn bran were consumed. The excretion of VFA during the last 3 days of each metabolic period increased with diet as follows: xylan, fiber free, cellulose, pectin and corn bran. Corn bran caused a significant increase in total VFA excretion over the fiber-free diet. Concentration of VFA in excreted feces (or expressed as percentage of fecal solids) increased by diet in the following order: cellulose, xylan, corn bran, pectin and fiber free. Thus, the concentration of VFA in feces showed no relationship to the total quantity of VFA excreted.

Adult↗
PubMed1983

Errors in the measurement of blood pressure.

The effect of posture on blood pressure measurement in pregnant and non-pregnant subjects was studied. In non-pregnant patients undergoing cardiac catheterization, central blood pressure remained unaltered with a change from the supine to the lateral position. However in all subjects studied, an apparent decrease in both systolic and diastolic blood pressure occurred when measured in the upper arm in the lateral position. This fall is artifactual and does not represent a change in blood pressure. It is concluded that blood pressure measurements in the lateral position are inaccurate.

Blood Pressure Determination↗
PubMed1982

Excretion of breath and flatus gases by humans consuming high-fiber diets.

The abilities of dietary fibers to promote the excretion of intestinal fermentation gases were evaluated in five healty men. Flatus and breath gases were collected and analyzed during 3 days of each 9-day metabolic period. Responses to feeding xylan, pectin, cellulose and corn bran were compared to a fiber-free formula diet. Generally, hydrogen production increased throughout the day, whereas methane production remained more constant. Methane excretion was greater while consuming the xylan and pectin diets than while consuming the other diets. These two purified fibers also caused higher flatus volume, hydrogen and carbon dioxide excretion. Cellulose and corn bran generally resulted in breath and flatus gas excretion at levels equivalent to fiber-free diets. Considerable variation was noted in the response of subjects to an individual diet. However, in most cases 2-5 days of frequent and daily consumption of the diets was necessary to establish a relatively constant level of gas excretion. This time may represent the period of microbial and enzymatic adaptation to the new dietary constituents.

Adult↗
PubMed1979

Preparation of high-fructose syrup from the tubers of the Jerusalem artichoke (Helianthus tuberosus L.

Fructose has recently received much attention due to renewed interest in natural sweeteners. In addition, fructose has some advantages to sucrose in sweetness, solubility, viscosity, and dental health characteristics. Fructose is deposited as storage fructans of the inulin (beta-1,2) type in tubers and rhizomes of the Compositae family. The utilization of the Jerusalem artichoke (Helianthus tuberosus) tuber as a source of fructose syrup is discussed. This plant has the potential to produce more sugar per acre than corn or sugar beets. In addition, the artichoke has higher frost resistance and lower heat unit requirements than corn and is somewhat more tolerant to low moisture conditions than sugar beets. A high quality fructose syrup can be produced from artichoke tubers. The extraction step was found to be particularly important since development of adverse colors and flavors must be prevented. The fructans may be acid or enzyme hydrolyzed but the latter method gave a higher quality syrup. Ion-exchange resins and activated charcoal were effective in removing coloring and flavoring materials, and also reduced other noncarbohydrate constituents. Since the enzymatic hydrolysis of the fructans is an attractive alternative to acid hydrolysis, a process was developed for producing and purifying a special beta-fructofuranosidase (inulase) from Saccharomyces fragilis. Inulase has a much higher specificity for fructans than commerically available beta-fructofuranosidase (invertase).

Carbohydrates↗
PubMed1979

Digestibility of raw and cooked starches from legume seeds using the laboratory rat.

The in vivo digestibility and growth responses to diets containing raw and cooked legume starches were determined using male Wistar rats. These starches were obtained from seven legumes including smooth- and wrinkled-seeded field peas, navy beans, kidney beans, garbanzo beans, mung beans and lentils. Wheat and potato starch diets were fed for comparative purposes. With the exception of potato and the field pea starches, rats fed uncooked starch diets had higher weight gains than those fed cooked starch diets. The starches from wheat and all legumes, excluding the high-amylose wrinkled pea, were nearly 100% digestible but the legume starches reduced the digestibility of casein protein by 3 to 4%. Raw potato starch was shown to be only 57% digestible. The starches from potato and wrinkled pea reduced the digestibility of casein protein to 87% and gave high cecum weights. These characteristics were not altered by cooking the starch of wrinkled pea. The starches of smooth-seeded peas, lentils and all beans were highly digestible, showed no adverse effects on growth and were comparable to wheat starch in this evaluation.

Animals↗