Search PubMed⌕ Search

Biomedical subjects

K Loeschke

Publications and source records attributed to K Loeschke.

At least 55 records · Page 3Linked to original sources
PubMed1995

[Recurrent hemorrhage from the small intestine in a patient with type 1 neurofibromatosis].

Patients with NF-1 may exhibit visceral neurofibromas, Schwannomas and other tumors of ectodermal origin beside the classical cutaneous and neuronal manifestations of neurofibromatosis. In a 46-year-old woman with a previous diagnosis of NF-1 and a history of recurrent intestinal bleeding of obscure origin a well vascularized tumor in a branch of the A. messenterica superior was found by use of scintigraphy and angiography. Intraoperatively two inhomogeneons tumors were found in the proximal jejunum. Histologically these tumors were classified as neurofibromas. After partial resection of the jejunum no further intestinal bleeding occurred in this patient. Therefore the intestinal neurofibromas were presumably the source of the recurrent bleeding.

Angiography↗
PubMed1994

Osmotic water flow pathways across Necturus gallbladder: role of the tight junction.

To explore the quantitative significance of passive water flow through tight junctions of leaky epithelia, transepithelial water flow rates were measured in Necturus gallbladder mounted in chambers. Osmotic flows generated by raffinose gradients were asymmetrical with the greater flow in the mucosal-to-serosal direction. In tissue fixed in situ, intercellular spaces were dilated during mucosal-to-serosal flow and closed during serosal-to-mucosal flow. Tight junctions were focally separated (blistered), which correlated with the magnitude of mucosal-to-serosal flow. Blisters were not observed during serosal-to-mucosal flow or in nontransporting gallbladders. In freeze-fracture replicas, blisters appeared as pockets between intramembranous strands. Protamine, which decreases electrical conductance and increases depth and complexity of the tight junction, reduced osmotic water flow by approximately 30% in the mucosal-to-serosal direction (100 mosmol/kg gradient) without altering serosal-to-mucosal flow. We suggest that in the steady state, at least 30% of osmotically driven water passes transjunctionally in the mucosal-to-serosal direction, but flow is transcellular in the serosal-to-mucosal direction. Directionally divergent pathways may account for flow asymmetry.

Animals↗
PubMed1993

[Broad beans as a cause of acute hemolytic anemia].

A previously healthy 17-year-old Greek boy suddenly developed jaundice of sclerae and skin. In addition, physical examination revealed a pale appearance. He also reported feeling tired and weak. The haemoglobin level was 9.6 g/dl, lactate dehydrogenase activity 335 U/l, bilirubin concentration 3.2 mg/dl (direct bilirubin 0.7 mg/dl, indirect bilirubin 2.5 mg/dl), haptoglobin concentration 48.8 mg/dl. As haemolytic anaemia was assumed, direct questioning elicited the fact that the patient had, for the first time in his life, eaten 300 g of broad beans (Vicia faba) on each of two days, namely 3 and 2 days before the appearance of jaundice. Absence of glucose-6-phosphate dehydrogenase activity in the red blood corpuscles confirmed the diagnosis of favism. On symptomatic treatment both the enzyme activities and the bilirubin level fell to normal within one week, and the haemoglobin level was 15.7 g/dl after 4 weeks.

Acute Disease↗
PubMed1991

Effects of n-3 fatty acids on fluid and electrolyte transport in rat intestine in vivo and in vitro.

Potential therapeutic benefits of dietary n-3 fatty acids are presently evaluated in arteriosclerotic and chronic inflammatory diseases. Because some other long-chain fatty acids inhibit intestinal fluid absorption, the effects of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on fluid and electrolyte transport were tested in rat colon and jejunum. In ligated colon loops in vivo, DHA (10(-5)-10(-3) M luminally) diminished net sodium and fluid absorption, and stimulated net potassium secretion. Similar but smaller effects were produced by EPA. In the jejunum, transport parameters were not influenced by DHA and EPA. In isolated distal colonic mucosa in vitro, DHA (10(-4)-10(-3) M on the mucosal side) reduced the electrical resistance, potential difference, short-circuit current and the net absorption of sodium and chloride due to increased unidirectional serosal to mucosal fluxes. These changes were prevented when calcium was replaced by strontium in the bathing solution. The data suggest that n-3 fatty acids increase colonic conductance indirectly by binding luminal calcium.

Animals↗
PubMed1990

Effects of a small bolus dose of ANF in healthy volunteers and in patients with volume retaining disorders.

Thirty-seven patients with volume-retaining disorders (liver cirrhosis with ascites, n = 8; heart failure NYHA III-IV, n = 12; endstage renal failure, n = 17) and twelve healthy age-matched controls were given a small dose (33 micrograms) of hANF (human atrial natriuretic factor). We tested the resulting hemodynamic and renal effects as well as the effect on plasma cyclic GMP levels and compared them with the properties of platelet ANF receptors. The ANF injection evoked an increase in cyclic GMP plasma levels of 19.3 +/- 2.2 nM in healthy controls. This increase tended to be smaller in the cirrhosis group (15.5 +/- 3.3 nM) and in the heart failure group (16.8 +/- 2.3 nM) than in the dialysis group (20.5 +/- 2.5 nM). The invasion rates of cyclic GMP were comparable in all groups, but the evasion rates increased more in the heart failure and endstage renal failure groups (27.9 +/- 7.7 min and 26.1 +/- 3.4 min, respectively) than in the cirrhosis and control groups (14.9 +/- 1.9 min and 14.2 +/- 1.9 min, respectively). Patients with endstage renal failure and congestive heart failure showed a smaller decrease in diastolic blood pressure than controls and patients with liver cirrhosis. Renal actions of ANF were diminished in cirrhosis and heart failure patients. Binding capacities of platelet ANF receptors were higher in the control group (12.2 +/- 1.5 receptors/cell) than in the patient groups (cirrhosis, 7.8 +/- 1.2; endstage renal failure, 8.0 +/- 0.9; heart insufficiency, 8.0 +/- 1.0 receptors/cell), with no differences among the patient groups. Binding affinities were not significantly different. Correlation analysis showed that the relationship between the actions of ANF and the increases in plasma cyclic GMP levels is loose and cannot predict the hemodynamic or renal effects of exogenous ANF in a given patient. Although the behavior of plasma cyclic GMP levels fails to predict the responsiveness of the body to ANF in a given patient, it does reflect the differences between the patient groups and the control group. In contrast, we found no correlation between the properties of platelet ANF receptors and ANF action.

Adult↗
PubMed1989

Inhibition by loperamide of mucus secretion in the rat colon in vivo.

The effect of loperamide on mucus secretion and the net transport of fluid, sodium and potassium was investigated in the perfused rat colon in vivo. Prostaglandin E2 (PGE2, 1 mg/kg per h intraarterially) and deoxycholic acid (2 mM intraluminally) were used as secretagogues. Mucus secretion was determined as the total amount of protein-bound hexose in the effluent. Under basal conditions, loperamide (6 mg/kg subcutaneously) slightly decreased mucus secretion and increased the absorption of fluid and sodium. PGE2 and deoxycholic acid stimulated mucus secretion about 4- and 9-fold, respectively. Loperamide abolished the mucus secretory response to PGE2 and reduced the response to deoxycholic acid by 50%. It also reduced the fluid secretion following PGE2 but did not affect the diminished fluid absorption following deoxycholic acid. Potassium secretion was not significantly influenced by loperamide and therefore was independent of the secretion of mucus. The data suggest that loperamide is a potent inhibitor of colonic mucus secretion, a property that possibly contributes to the antidiarrheal effect of this opiate analogue.

Animals↗
PubMed1989

Supplementation with n-3 fatty acids from fish oil in chronic inflammatory bowel disease--a randomized, placebo-controlled, double-blind cross-over trial.

Thirty-nine patients with chronic inflammatory bowel disease were studied in a 7-month, double-blind, placebo controlled cross-over trial of dietary supplementation with fish oil, which provided about 3.2 g n-3 fatty acids per day. At control, biopsies from inflamed mucosa contained higher levels of arachidonic acid than uninvolved mucosa. Dietary n-3 fatty acids were well tolerated and incorporated into plasma and enteric mucosa phospholipids at the expense of n-6 fatty acids. The arachidonic acid-derived prostanoid generation was reduced by fish oil and the extension and severity of macroscopic bowel involvement was moderately improved. In patients with Crohn's disease, clinical activity was unchanged by fish-oil supplementation. In patients with ulcerative colitis, clinical disease activity fell during fish oil supplementation and thereafter; this was not significant however. Despite a moderate reduction in inflammatory lipid mediators by dietary n-3 fatty acids and limited morphological improvement in chronic inflammatory bowel disease, the clinical benefit seems to be confined to patients with ulcerative colitis.

Adult↗
PubMed1989

[Procollagen-III-peptide in the serum of patients with Crohn disease].

Serum procollagen-III-peptide (PP III) concentrations were measured in 54 patients with Crohn's disease and compared with data obtained from healthy controls and patients with liver fibrosis or ulcerative colitis. Whereas in alcoholic liver cirrhosis and chronic active hepatitis PP III was increased up to 18-fold as described by others, only 3 patients with Crohn's disease had slightly elevated PP III concentrations. In 2 of them, increased PP III could be explained by adolescence. In 5 other patients, PP III levels were at the upper limit of normal. Subgroup analysis showed that high clinical disease activity, recurrence after intestinal resection, presence of strictures and long disease duration did not elevate PP III levels. We therefore conclude that determination of serum PP III is of no value in the follow-up patients with Crohn's disease. In ulcerative colitis, PP III levels were uniformly normal. An additional result was a decreased PP III during corticosteroid therapy, suggesting a direct effect on collagen metabolism.

Adult↗
PubMed1988

Discrepancy between effects of cholera toxin on net fluid movement and cAMP levels in rat jejunum, ileum, and colon.

Regional differences in the response to cholera toxin were evaluated in rat jejunum, ileum, and colon in vivo. Ligated intestinal loops were exposed to a supramaximal concentration of cholera toxin for 5 hr, and net fluid transport, adenosine 3',5'-monophosphate (cAMP) concentrations, and adenylate cyclase and phosphodiesterase activities of mucosal homogenates were determined. The fluid transport response and the specific activities of adenylate cyclase (with and without cholera toxin) and phosphodiesterase declined progressively from the jejunum to the colon. In contrast, cAMP concentrations (with and without cholera toxin) were lowest in the jejunum and highest in the colon. These results demonstrate that cAMP concentrations of the total mucosal homogenate do not parallel cholera toxin-induced fluid secretion in the three intestinal segments. Rather, the activities of adenylate cyclase and phosphodiesterase suggest a relation between fluid secretion and the turnover of cAMP.

Adenylyl Cyclases↗
PubMed1988

Local epinephrine injection improves the therapeutic effect of Nd-YAG laser treatment of arterial peptic ulcer bleeding.

Nd-YAG laser therapy has been shown to be effective in the treatment of gastrointestinal ulcer bleeding. However, a breakdown by bleeding severity shows that its benefit is doubtful in bleeds classified as Forrest Ia and IIa. In a prospective study, we therefore tested a new therapeutic approach combining epinephrine injection into the bleeding site, with subsequent laser coagulation. Thirty-two patients with Forrest Ia and IIa bleeding from gastric or small intestinal ulcers were compared with 51 own historical controls treated by laser coagulation alone. In the combined therapy group, a significantly higher rate of permanent hemostasis was achieved, and mortality and frequency of emergency surgery were significantly reduced. Furthermore bleeding recurred more rarely and only during the later course of the disease. Finally, following epinephrine injection fewer Forrest IIa ulcer bleeds were reactivated by laser treatment, and all of these bleeds were stopped by further laser coagulation. Overall, our results demonstrate a clear-cut therapeutic improvement when laser coagulation is preceded by local epinephrine injection.

Combined Modality Therapy↗
PubMed1987

Influence of vasoactive intestinal peptide, secretin, and Ala4, Val5-secretin on the net movements of electrolytes, fluid, and mucus in the rat colon in vivo.

The effect of vasoactive intestinal peptide (VIP), secretin, and VIP-secretin (Ala4, Val5-secretin) on the net movements of sodium, potassium, fluid, and mucus was investigated in the rat colon perfused in vivo. Peptides (1-100 micrograms/kg.h) were infused intra-arterially. VIP influenced electrolyte and fluid movements at a threshold dose 10- to 100-fold lower than secretin, whereas the secretory efficacy was not significantly different. Replacing the NH2-terminal hexapeptide of secretin by that of VIP did not markedly alter the effect of secretin. Mucus output was stimulated weakly by all three peptides. The results indicate that the larger colonic secretory activity of VIP as compared to secretin is not primarily due to the difference in their NH2-terminal sequence but probably requires the intact molecule.

Animals↗
PubMed1987

Regional distribution of Na-K-ATPase specific activity in the large intestine of the rat and man.

Segmental heterogeneity of colonic electrolyte transport has been demonstrated in rat and man. We determined whether this is reflected by regional differences in Na-K-ATPase activity. In rats, Na-K-ATPase specific activity was significantly lower in the caecum than in the proximal colon, distal colon, and rectum. In man, biopsy specimens of macroscopically intact mucosa in 26 subjects showed no difference in Na-K-ATPase specific activity along the colon axis. We conclude that Na-K-ATPase distribution may contribute to electrolyte transport differences between rat caecum and colon but not between colonic segments in either rat or man. In an additional series of 11 patients with proximal intestinal resections colonic Na-K-ATPase specific activity was slightly but significantly higher than in controls, possibly representing an adaptive process.

Adult↗