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Biomedical subjects

H Menge

Publications and source records attributed to H Menge.

At least 109 records · Page 6Linked to original sources
PubMed1976

Dietary restrictions during adolescence and subsequent reproductive performance of turkey breeder males.

A study was conducted to investigate the effect of early dietary restriction of protein and/or energy on the subsequent reproductive ability of the tom. One hundred 8-week old Large White turkey toms (April hatch) were placed at random into four floor pens of 25 each and fed the following diets: group 1, 20.6% protein with 2,4 Mcal. M.E./kg. diet 8-12 weeks, 15.3% protein with 2.68 Mcal. 12-16 weeks, 10.4% protein with 2.85 Mcal. 16-24 weeks; group 2, 20.3% protein with 2.9 Mcal. 8-12 weeks, 14.8% protein with 2.98 Mcal. 12-16 weeks, 9.8% protein with 3.27 Mcal. 16-24 weeks; group 3, 22% protein with 2.4 Mcal. 8-12 weeks, 18.9% protein with 2.57 Mcal. 12-16 weeks, 16.3% protein with 2.81 Mcal. 16-24 weeks; group 4 (control), 22% protein with 2.91 Mcal. 8-12 weeks, 19% protein with 3.03 Mcal. 12-16 weeks, 15.9% protein with 3.17 Mcal. 16-24 weeks. Beginning with the 25th weeks all toms received a 14.3% protein diet with 2.8 Mcal. The restriction of energy significantly reduced the percentage of males producing semen, and the restriction of energy significantly reduced the percentage of males producing semen, and the restriction of energy and both protein and energy significantly depressed semen volume per male in comparison with the average produced by the control males. Other reproductive traits were not affected by early dietary controls.

Animals↗
PubMed1976

[Adaptive changes in intestinal mucosa of the small intestine as a result of intraluminal stress].

Under physiological conditions, the intestinal mucosa is the site of a delicate balance between cell proliferation in the crypt region and cell desquamation at the villus tips. This balance can be deranged by a number of endogenous or exogenous factors, oneof which is the intraluminal contents. This review discusses the effects of different modifications of the luminal milieu on the structure and function of the mucosa. Following intestinal resection or loop transposition, the contents reaching the remnant or the transposed loop differ markedly from those with which they come into contact under normal conditions. Hyperplasia without zonal transformation then develops in the experimental loop. The villi do not become wider, and changes in the strucutre of the epithelium are not observed. There are conflicting resutls in the literature concerning the enzyme activities in the individual enterocytes resulting from this hyperplasia. However, the epithelium its functionally immature, since transport capacities measured in vitro are reduced. On the other hand, the hyperplasia of the mucosa is such that absorptive capacities in vivo, when expressed in terms of intestinal length, are larger than normal. When the intestine is subjected to prolonged infusion of lactic acid, the enterocytes are damaged and increased exfoliation results. A similar result is obtained in the blind-loop syndrome, where the accumulation of bile acids and bacteria provides the stress responsible for the destruction of the enterocytes, and in non-tropical spure, where the epithelium is attacked by noxious peptides in the diet. The first consequence of the accelerated desquamation is epithelial hyperplasia without zonal transformation, though the enterocytes are damaged - in contrast to those of the resected intestine - and apparently possess reduced enzyme activities. If the application of the stress is continued, a stage is reached in which the cell proliferation does not suffice to counteract the cell loss at the villus tips. Then a zonal transformation occurs whereby, despite the lengthened crypts, the villi become shorter and wider until, in extreme cases, the mucosa is completely devoid of villi. The transport capacity in vitro and in vivo - even when expressed in terms of unit-length is reduced, and good correlations exist between the reduction in function and the diminution in surface area of the intestine. In a self-emptying blind loop, the intestine is devoid of all contact with nutritional material. Under these circumstances, hypoplasia of the mucosa develops in which the enterocytes appear unchanged, though in extreme cases they may possess reduced enzyme levels, and the absorption capacity in vivo is consequently reduced.

Adaptation, Physiological↗
PubMed1975

Protection of the intestinal mucosa during ischaemia by intraluminal perfusion.

The function of the intestinal mucosa immediately after one hour's ischaemia was examined by means of tests in vivo and in vitro. During the ischaemia, the intestinal loop was perfused with media of different compositions, in an attempt to assess which provided the best protection of the epithelium from the deleterious effects of the ischaemia. The absorption of water, ions and glucose was then monitored in vivo, and the uptake of phenylalanine and beta methyl-glucoside by slices of mucosa was determined in vitro. The unprotected mucosa loses all active transport capacity in vitro following one hour's ischaemia, and is the site of a pronounced loss of water and ions into the lumen in vivo. Glucose absorption in vivo is also abolished. If the loop is perfused during the ischaemia with glucose-containing Krebs bicarbonate buffer, much of the transport capacity in vitro is retained; the loss of ions and water is prevented, and glucose absorption in vivo occurs. Perfusion during the ischaemia with other media, such as isotonic mannitol, Krebs bicarbonate buffer, or Ringer-lactate solution, results in a marked protection of the mucosa, in comparison with the unperfused loop, but the effects are not as pronounced as those of the glucose-containing buffer. It is concluded that the act of perfusing the intestine is the most beneficial factor, but that the presence of glucose in the perfusate does afford added protection.

Animals↗
PubMed1975

Functional, biochemical and morphological alterations in the intestines of rats with an experimental blind-loop syndrome.

In rat self-filling blind loops and in the contiguous regions of the intestinal tract, considerable functional impairment, accompanied by pronounced morphological transformations of the mucosa, has been observed. The histological alterations consist of mucosal hypertrophy and a reduction in the villus height: crypt length ratio, which is indicative of a hyper-regenerative change. Various enzyme activities of the epithelial cells are reduced and the absorption otinal juices is greatly altered in favour of the free acids. Two mec,anisms have 0een dicids, or meta0olites from bacterial degradation, on the absorptive epithelium; 2. Reduced cellular maturity in response to the effect of bile acids and/or bacteria on the lifespan of the cells.

Animals↗
PubMed1975

The response of the dog colon mucosa one hour's ischaemia.

Segments of dog colon were subjected to one hour's ischaemia, and their morphology and function were studied either immediately after the ischaemia or 24 hours later. As functional tests, net sodium transport across the mucosa in vitro, the transport capacity in vitro for sugars and amino-acids, tissue respiration, lactate production, and the liberation of acid phosphatase were applied. Immediately after the ischaemia, all parameters differed significantly from the control mucosa: net sodium transport was abolished; amino-acid and sugar uptake, oxygen consumption and lactate production were reduced; and lysosomal enzyme release was increased. All parameters, except sugar uptake, had normalised 24 hours after the trauma. Histological examinations revealed much variation in the lesions occurring after the ischaemia, varying from slight epithelial desquamation to considerable mucosal destruction. In most cases, the mucosa had almost normalised 24 hours later. Morphometric analysis revealed decreased mean mucosal thickness immediately after the trauma, though 24 hours later, there was again no significant difference with the control group.

Acid Phosphatase↗
PubMed1975

Active amino-acid and sugar uptake by gall bladder epithelium in dog, guinea-pig and man.

Slices of dog gall bladder are capable of accumulating amino-acids and sugars against considerable concentration gradients across the luminal membrane of the cell. The epithelium of the common bile duct also absorbs these substrates. The transport systems are sodium-dependent, saturable and inhibited by ouabain and metabolic poisons. The specificity of the mechanisms is more reminiscent of kidney than of intestinal transport. Glycine is preferentially transported across dog gall bladder from the mucosa to the serosa, but the net flux is small. It is concluded that the contraluminal membrane of the epithelial cell might be relatively impermeable to the amino-acid. concentrative uptake also occurs in guinea-pig gall bladder; however it appears to be practically non-existent in rabbit tissue. Human gall bladders, obtained at random from the operating room, also displayed active accumulation. The gall bladder epithelium is remarkably resistant to anoxia. Furthermore, following obstruction of the common bile duct for 2 weeks in dogs, the gall bladder is still able to concentrate amino-acids and sugars, but the extent of the uptake is significantly reduced.

Amino Acids↗
PubMed1975

Function and structure of the mucosa of continent ileostomy reservoirs in dogs.

Continent ileostomy reservoirs were constructed in dogs. Nine to 29 days after formation of the pouches, they were excised together with a loop of adjacent ileum for biochemical and morphological assessment. The villous and epithelial cell heights were reduced, whereas villous width and mitotic index were increased. The mucosa of the pouch was able to absorb phenylalanine and Beta-methyl-glucoside against a concentration gradient, although this absorptive capaciti was lower than that of normal ileum. Similar considerations applied to oxygen consumption. The results indicate that the mucosa of the pouch undergoes transformation, but the intergrity of the epithelial layer is maintained.

Acid Phosphatase↗
PubMed1975

The nutritive effect of glucose on the structure and function of jejunal self-emptying blind loops in the rat.

In an attempt to obtain further information on the influence of the intestinal contents on the development of mucosal structure and function, self-emptying blind loops of rat jejunum were constructed, and the oral end was exteriorized with a stoma to permit infusion of different solutions into the loop. Ringer solution or media containing glucose or galactose was instilled into the loops three times daily for 27 days before functional and structural examination of the loops. The body weight and food intake of the animals did not differ significantly from one group to another. Treatment with glucose, but not with galactose or Ringer solution alone, induced a significant increase in the villus height. Disaccharidase but not dipeptidase activity was concomitantly increased. Infusion of glucose or galactose both led to an increase in the transport capacity of the loop, as determined by glucose absorption in vivo. These results indicate that glucose has a nutritive effect, probably due to its intracellular metabolism, which is responsible for the structural alterations observed. On the other hand, the increase in transport capacity may be attributed to substrate-induced stimulation of the specific monosaccharide transport system in the epithelial cell.

Animals↗
PubMed1975

The influence of food intake on the development of structural and functional adaptation following ileal resection in the rat.

The present study was undertaken to determine the influence of hyperphagia on the adaptive changes occurring in the rat jejunal mucosa as a result of intestinal resection. One group of resected rats was subjected to pair feeding with a sham-operated population, whilst another group was nourished ad libitum. The animals which ate ad libitum developed hypertrophy of the mucosa which was accompanied by increased glucose absorption in vivo without changes in enzyme levels. These alterations were much less pronounced in the pair-fed group of resected animals, a finding that indicates that the adaptive changes are at least partially influenced by increased luminal nutrition.

Adaptation, Physiological↗