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Biomedical subjects

W Glinsmann

Publications and source records attributed to W Glinsmann.

15 recordsLinked to original sources
PubMed2001

Inulin and oligofructose as dietary fiber: a review of the evidence.

This critical review article examines the composition and source of inulin and oligofructose, the physiological effects of their consumption, and how these materials relate to the concept of dietary fiber. Inulin and oligofructose are fructans extracted on a commercial basis from the chicory root. Inulin has been defined as a polydisperse carbohydrate material consisting mainly, if not exclusively, of beta (2-1) fructosyl-fructose links ranging from 2 to 60 units long. Native chicory inulin has an average degree of polymerization (DP) of 10 to 20, whereas oligofructose contains chains of DP 2 to 10, with an average DP of 4. While a universally accepted definition for dietary fiber does not exist, it is generally agreed that this term includes saccharides (+ lignin) that are not hydrolyzed or absorbed in the upper part of the gastrointestinal tract. These materials reach the colon, where they may be totally fermented, partially fermented, or remain unfermented. In addition, fibers contribute to fecal bulking. Inulin and oligofructose are not digested in the upper part of the gastrointestinal tract or are they absorbed and metabolized in the glycolytic pathway, or directly stored as glycogen like 'sugars' or starches. None of the molecules of fructose and glucose that form inulin and oligofructose appear in the portal blood. These materials are quantitatively fermented by the microflora of the colon; further, it has been demonstrated that this fermentation leads to the selective stimulation of the growth of the bifidobacteria population. After reviewing their chemistry, origin, and physiological effects, it is the opinion of the authors that inulin and oligofructose are dietary fiber. They share the basic common characteristics of dietary fibers, that is, saccharides of plant origin, resistance to digestion and absorption in the small intestine, and fermentation in the colon to produce short-chain fatty acids that are absorbed and metabolized in various parts of the body. Moreover, this fermentation induces a bulking effect.

Animals↗
PubMed1983

Chromium supplementation of human subjects: effects on glucose, insulin, and lipid variables.

Seventy-six normal, free-living subjects were given supplements of 200 micrograms chromium (Cr) in the form of chromic chloride or a placebo in a double-blind crossover study with 3-month experimental periods. Twenty of the 76 subjects had serum glucose concentrations greater than or equal to 100 mg/dL 90 minutes after a glucose challenge (1 g glucose per kilogram of body weight). Chromium supplementation significantly decreased (P less than 0.05) the 90-minute glucose concentration of these subjects from 135 +/- 9 to 116 +/- 11 mg/dL; fasting glucose concentrations also decreased significantly. The 90-minute serum glucose levels of the 35 subjects with glucose concentrations less than the fasting serum glucose level were increased significantly by Cr supplementation, from 71 +/- 1 to 81 +/- 4 mg/dL. Fasting and 90-minute serum glucose concentrations of the remaining subjects who displayed 90-minute glucose concentrations greater than fasting levels but less than 100 mg/dL were not affected by Cr supplementation. In this study, immunoreactive serum insulin concentration, body weight, lipids, and other selected clinical variables did not change significantly during Cr supplementation. These data demonstrate that Cr supplementation decreases the serum glucose levels of subjects with 90-minute glucose concentrations greater than or equal to 100 mg/dL following a glucose challenge, increases serum glucose levels of subjects with 90-minute glucose concentrations less than fasting levels, and has no effect on the serum glucose levels of subjects with 90-minute glucose values similar to but greater than fasting levels.

Adult↗
PubMed1982

Urinary chromium excretion of human subjects: effects of chromium supplementation and glucose loading.

The utilization of inorganic chromium by free-living human subjects was studied in 76 volunteers (male, 48; female, 28) who were supplemented with 200 micrograms of inorganic chromium as chromic chloride or a placebo tablet for 3 months in a double-blind, cross-over experiment. For all subjects, initial mean +/- SEM urinary chromium (Cr) level was 0.20 +/- 0.01 (range, 0.05 to 0.58) ng/ml and did not differ by sex. Initial chromium/creatinine ratio (Cr/Ct) was 0.15 +/- 0.01 (range 0.03 to 0.36) ng Cr/mg creatinine for females and was significantly lower, 0.10 +/- 0.01 (range 0.03 to 0.36) for males. Mean urinary Cr level increased to 1.0 +/- 0.12 after 2 and to 1.13 +/- 0.08 ng/ml after 3 months' supplementation. The Cr/Ct ratio increased to 0.69 +/- 0.10 for females and to 0.50 +/- 0.04 for males after 2 months' supplementation; values were similar after 3 months. An increase in urinary Cr excretion in response to a glucose load was demonstrated for nonsupplemented normal free-living subjects but not for subjects supplemented daily with trivalent chromium. Urinary Cr excretion after a glucose challenge was not predictable and did not depend on Cr status.

Adult↗
PubMed1977

Protein inhibitors of phosphorylase phosphatase and cyclic AMP-dependent protein kinase from rabbit skeleta muscle.

A heat-and acid-stable protein inhibitor of phosphorylase phosphatase is present in a highly purified preparation of protein inhibitor of cyclic AMP-dependent protein kinase from rabbit skeletal muscle. Although these two inhibitors have strikingly similar properties to each other, such as sensitivity to trypsin and behavior on gel permeation chromatography, they can be separated by polyacrylamide disc gel electrophoresis. This indicates that the phosphatase-inhibitory and kinase-inhibitory activities reside with different protein species. The inhibition of both the enzymes is not altered by incubating the inhibitor preparation with a general phosphoprotein phosphatase, with phosvitin kinase, or with cyclic AMP-dependent protein kinase. Inhibition of phosphorylase phosphatase is of a non-competitive type supporting the idea that the phosphatase inhibitor is not an alternative substrate for the enzyme. Inhibition of phosphatase activity is selective in that it does no occur when phosphorylated histone or phosphorylated protamine are used as substrates.

Animals↗
PubMed1977

Inhibition of rabbit skeletal muscle phosphorylase phosphatase by spermine.

The effect of three naturally occurring polyamines (putrescine, spermidine, and spermine) on the activity of rabbit skeletal muscle phosphorylase phosphatase was investigated. Only spermine significantly inhibited the enzyme. The mode of inhibition (ki value of 0.3 mM) of the phosphatase by spermine appears to be different from that caused by divalent metal ions or by other organic cations, such as arginine and lysine esters, since it is noncompetitive with respect to the substrate, phosphorylase a.

Animals↗
PubMed1970

Pineal gland: dibutyryl cyclic adenosine monophosphate stimulation of labeled melatonin production.

In organ cultures of intact rat pineal glands, N(6)O(2')-dibutyryl adenosine 3', 5'-monophosphate stimulates the conversion of tritiated trytophan to tritiated melatonin, as does L-norepinephrine. Potential sites of stimulation of melatonin production by dibutyryl cyclic adenosine monophosphate are discussed, based on observations that the dibutyryl analog also stimulates the conversion of serotonin labeled with carbon-14 to carbon-14-labeled melatonin without altering hydroxyin-dole-O-methyl transferase activity or intracellular accumulation of serotonin labeled with carbon-14.

Adenine Nucleotides↗