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Biomedical subjects

K Loeschke

Publications and source records attributed to K Loeschke.

At least 91 records · Page 5Linked to original sources
PubMed1980

[Antibiotic-associated diarrhoea and enterocolitis (author's transl)].

Many antibiotics, particularly the lincomycins, may cause diarrhoea with or without enterocolitis. The pathogenesis of antibiotic-associated diarrhoea without colitis is uncertain; colloidosmotic water binding in the colon by endogenous glycoproteins undegraded by colonic bacteria is considered. Antibiotic-associated enterocolitis is now known to be due to toxin-producing clostridia, proven for Cl. difficile. Improved methods for the detection of toxin and clostridia are presently being studied. Endoscopically, pseudomembranes are characteristic but not antibiotic-specific, they may be absent or missed diagnostically. A possible role of asymptomatic clostridia-carriers in enterocolitis clustering remains to be determined. The potentially lethal course of the disease requires rapid diagnosis and therapy, with discontinuation of the antibiotic, intensive supportive measures and, at least in severe disease, oral vancomycin.

Adult↗
PubMed1980

Effect of diphenolic laxatives on Na+-K+-activated ATPase and cyclic nucleotide content of rat colon mucosa in vivo.

1. The effect of bisacodyl and oxyphenisation on the Na+-K+- and Mg2+-activated ATPase and on the mucosa levels of cAMP and cGMP was investigated in transporting ligated loops of the rat colon in acute studies and in chronic feeding experiments 2. The specific activity of the Na+-K+-ATPase was lowered in both types of experiments, concomitantly with a reduction in net sodium absorption. The specific activity of the Mg2+-activated ATPase was unaffected. 3. The cAMP content per mg protein was elevated and the cGMP content decreased in the acute experiments in which the effect on transport was most marked. The content of cyclic nucleotides returned to normal within 2 h whereas absorption, Na+-K+-ATPase specific activity and the mucosal potential difference were still significantly depressed at that time. In chronic experiments with bisacodyl, cAMP was not affected and cGMP was increased in colon loops exhibiting reduced absorption. 4. The results indicate that the inhibition of the Na+-K+-activated ATPase by diphenolic laxatives may play a role in the inhibition of intestinal fluid absorption caused by these compounds. The increase of cAMP in acute experiments could point to a cAMP-mediated stimulation of secretory processes under this condition.

Animals↗
PubMed1980

Bacterial overgrowth in ileal reservoirs (Koch pouch): extended functional studies.

An absorptive, hormonal, bacteriological and morphological study was performed in 9 proctocolectomized patients with continent ileal reservoirs established for 2-57 months. Vitamin B 12 malassimilation (as assessed by the Schilling test and serum vitamin B 12 concentration), bile salt deconjugation (modified 14C-glycocholate breath test), increased stool fat excretion and high intestinal sodium loss with secondary hyperreninism/hyperaldosteronism were encountered in a large percentage of patients; proximal small intestinal absorption (serum parameters, xylose test) appeared intact. In reservoir stool samples total and differential bacterial cell counts yielded values close to a normal rectum flora. Morphologically (endoscopy, quantitative histology) the reservoir mucosa showed moderate to severe inflammation; structural changes were essentially absent and inflammation in the adjoining ileum was minimal. These results indicate that reservoir bacteria frequently produce disturbances in small intestinal function and that these may be found without secondary structural transformation of the mucosa.

Adolescent↗
PubMed1977

Induction of Na-K-ATPase in plasma membranes to rat cecum mucosa by diet: time course and kinetics.

Dietary polyethylene glycol (PEG) induces an increase in the specific activity of Na+-K+-activated adenosine triphosphatase (Na-K-ATPase) in the cecum mucosa of rats. Using cecum mucosa homogenates and cellular subfractions obtained by differential centrifugation, the induction process was studied with respect to time course, subcellular distribution and properties of the enzyme. In comparison with controls, Na-K-ATPase specific activity was stimulated in PEG treated rats in the total homogenate and the microsomal (105000 X g) but not in the mitochondrial (9000 X g) or nuclear (1000 X g) sediment. The specific activity of Mg-ATPase did not change in any of the fractions. Na-K-ATPase induction was statistically significant after 2 days and complete after 1-2 weeks, in parallel with the previously described stimulation in net sodium absorption. Kinetic analysis showed Vmax for ATP to be doubled while Km for ATP, Na and K as well as the optimal Mg/ATP ratio and Ki for ouabain remained unchanged. It is proposed that Na-K-ATPase and active sodium transport are closely associated in rat cecum and that dietary Na-K-ATPase stimulation is due to the induction of more enzyme molecules per unit basolateral cell membrane.

Adenosine Triphosphatases↗
PubMed1977

Nucleic acid and protein content of rat cecum mucosa in dietary adaptation-growth by cellular hyperplasia.

The deoxyribonucleic acid (DNA), ribonucleic acid (RNA) and protein content of the isolated cecum mucosa was determined in control rats and rats with adaptive cecum growth induced by dietary polyethylene glycol. Feeding the polymer resulted in an increase in the total amount of mucosal nucleic acids and protein which was statistically significant after 2-4 days and reached twice the control value after 2 months. During growth, the protein/DNA, protein/RNA and RNA/DNA ratios remained unaltered, indicating hyperplasia and not hypertrophy of the epithelial cells. The water content of the mucosa increased from 75 to 81% during adaptation, possibly related to the stimulation in active sodium transport reported earlier. Recalculation of parallel Na-K-ATPase data on the basis of DNA demonstrated a doubling of Na-K-ATPase activity per mg DNA in the fully adapted cell.

Adaptation, Physiological↗
PubMed1975

[Intestinal adaptation of electrolyte and water resorption].

The mammalian intestine is capable of adjusting electrolyte and water transport to the diet by modifying not only total mucosal cell mass but also the functional properties of the absorbing cell. This was demonstrated in the rat cecum where oral application of the polymer polyethylene glycol induced epithelial cell hyperplasia and - functionally - a stimulation of active sodium transport per cell, a higher transmural electrical potential difference and an increased specific activity of the Na-K-ATPase.

Adenosine Triphosphatases↗
PubMed1975

Hormones and the stimulated sodium transport in cecum hypertrophy.

Sodium transport per unit tissue is stimulated in dietetically produced cecum hypertrophy of the rat. Presumably this reflects an adaptive process. The possibility was tested whether transport adaptation was mediated by hormones, particularly by the pituitary-adrenal system, Cecum hypertrophy was induced by dissolving polyethylene glycol in the drinking water, and cecal sodium and water net absorption was measured in vivo. In both the adapted and normal mucosa, sodium and water absorption per unit macrosurface or dry weight was increased by aldosterone and decreased by adrenalectomy, hypophysectomy and volume expansion while the decrease following adrenalectomy was reversed by cortisol and the absence of antidiuretic hormone in hereditary diabetes insipidus rats had little effect on absorption. However, none of the test conditions abolished the relatively larger absorption of the adapted compared to the normal mucosa. It is concluded that the hormonal effects were additive but not causally related to transport adaptation.

Adrenalectomy↗