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Biomedical subjects

S Wagner

Publications and source records attributed to S Wagner.

At least 325 records · Page 18Linked to original sources
PubMed1992

Effect of Helicobacter pylori infection on 24 hour intragastric acidity in patients with gastritis and duodenal ulcer.

Helicobacter pylori status, gastric histology, and 24 hour acidity were studied in 35 gastritis patients, 21 duodenal ulcer patients, and 14 subjects with normal gastric mucosa. H pylori was identified in 21 of 35 patients with chronic active gastritis and in 19 of 21 duodenal ulcer patients, but in none of those with normal gastric mucosa. Mean scores of activity of gastritis were similar in H pylori positive gastritis and duodenal ulcer patients, but were significantly lower in H pylori negative gastritis patients (2.1 (0.8) and 2.3 (0.9) v 1.4 (0.7); p < 0.01, respectively). Median 24 hour hydrogen ion activity (interquartile range) was 21 (8.9-38.0) mmol/l in normal subjects and 23 (11.2-49.0) mmol/l, 19 (7.1-33.1) mmol/l, 44 (25.1-63.1) mmol/l, and 36 (31.6-39.8) mmol/l respectively in gastritis and duodenal ulcer patients with and without H pylori infection. During all predefined time periods, intragastric acidity was significantly higher in patients with H pylori positive duodenal ulcers compared with gastritis patients and normal subjects. However, there was no significant difference in intragastric acidity between the H pylori positive and negative gastritis patients. These results suggest that most of the subjects with chronic H pylori infection have normal gastric acidity.

Adult↗
PubMed1992

MR lymphography with iron oxide particles: dose-response studies and pulse sequence optimization in rabbits.

Superparamagnetic iron oxide (SPIO) particles are a promising contrast agent for MR lymphography. The effect of SPIO on MR imaging of normal lymph nodes and the impact of the size of the dose have not yet been investigated in detail. Therefore, we performed dose-response and pulse sequence optimization studies. MR images of the iliac lymph nodes of 15 normal rabbits were obtained at 1.5 T with 12 different spin-echo (SE) and gradient-echo (GRE) sequences before and after SPIO administration. The contrast agent was injected into a femoral lymph vessel at five different doses (0.02-2.0 mumol Fe/animal). The dose that reduced signal intensity by half (ED50) was determined for each sequence, and images were evaluated qualitatively. Doses of 0.2 and 1.0 mumol Fe caused a complete signal loss throughout the lymph node. In this dose range, proton density-weighted SE sequences showed a profound signal loss (ED50, 0.132 mumol Fe), and lymph nodes were sharply demarcated. The GRE sequences (ED50, 0.027-0.070 mumol Fe) and the T2-weighted SE sequence (ED50, 0.014 mumol Fe) showed an even more pronounced signal loss but insufficient anatomic resolution. Underdosing (less than or equal to 0.1 mumol Fe) caused only a focal signal loss in the lymph nodes. Oversaturation (2.0 mumol Fe for SE sequences, greater than or equal to 1.0 mumol Fe for GRE sequences) led to image distortion and did not allow assessment of lymph node morphology. Our results show that optimal contrast enhancement of normal lymph nodes with SPIO can be achieved in the dose range of 0.2-1.0 mumol Fe on proton density-weighted SE sequences. Our results may serve as a basis for further development of noninvasive MR lymphography.

Animals↗
PubMed1992

Sonographic evaluation of gallbladder motility in patients with end-stage renal disease on haemodialysis.

Thirty nine patients with end-stage renal disease on haemodialysis therapy with upper gastrointestinal symptoms were investigated for gallbladder motor function as the cause of their symptoms using cholecystosonography in fasting state, after a cholecystokinetic agent (BILOPTIN fatty meal) and after a smooth muscle relaxant (BUSCOPAN). Forty healthy individuals served as a control group. No significant difference was found between dialysis patients and healthy controls regarding the gallbladder area during fasting state, or the variation in the area of gallbladder during maximal contraction and dilatation. However, the patients on dialysis therapy of longer duration had stronger gallbladder contraction in response to a cholecystokinetic agent. Serum gastrin concentrations were increased in haemodialysis patients, but there was no consistent relationship between serum gastrin and gallbladder motility. The upper gastrointestinal symptoms of dialysis patients are unlikely to be due to disturbed gallbladder motility.

Adult↗
PubMed1992

Specialized extended hospital treatment for borderline patients.

The intensive psychoanalytically oriented hospital treatment described by the authors was developed specifically for borderline patients. This unique treatment, an integrated multimodal approach, is based on the theory that the disturbed behaviors and relationships of borderline patients are manifestations of intrapsychic impairment. The authors use a detailed case report to illustrate how the theory is transformed into technical precepts and applied to all aspects of the treatment.

Activities of Daily Living↗
PubMed1992

[Differential diagnosis of peptic ulcer].

Although new pathogenetic findings of peptic ulcers have been detected, there still remain some open questions. Accurate anamnestic evaluation will find out risk factors as cigarette-smoking, stress and therapy with nonsteroidal antiinflammatory drugs (NSAIDs), and will be helpful in differential diagnosis. Endoscopy is the diagnostic means of choice, and enables to easy helicobacter pylori detection. Since some gastric ulcers are actually carcinomas, it is absolutely necessary to obtain multiple biopsies. The Zollinger-Ellison syndrome and symptoms of other rare diseases of the upper intestine are discussed.

Diagnosis, Differential↗
PubMed1992

[Helicobacter pylori. New apsects in the pathogenesis of peptic ulcer disease].

Antral gastritis and peptic ulcer disease are closely related to gastric Helicobacter pylori (HP) infection. HP possesses several pathogenic features which point to a causal role of HP in the development of gastroduodenal lesions. It is now generally accepted that HP causes type B gastritis, while its role in the pathogenesis of peptic ulcers is still unsolved. According to the classical ulcer concept, peptic ulceration is the result of an imbalance between protective mucosal mechanisms and aggressive digestive factors. The identification of HP does not disprove this concept, however, HP has to be added as a major pathogenic factor.

Gastric Mucosa↗
PubMed1992

[Methodology and clinical significance of intragastric long-term pH measurement].

Intragastric long-term pH-metry is a suitable method of assessing gastric acidity under conditions of real life. The pH-metry system consists of three components: pH electrode, solid state recorder, and data analyzing system. Combined glass electrodes are recommended for gastric pH studies. Up to now, there are no generally accepted normal values in gastric pH-metry and thus data analyzing is not uniformly standardized. Intragastric pH-metry is the method of choice for monitoring of antisecretory treatment. This method enables the recognition of non-responders and improves dosing of antisecretory drugs. The prognostic value of gastric pH-metry in the assessment of acid-related diseases, if any, has still to be defined.

Gastric Acidity Determination↗
PubMed1992

[Complications of peptic ulcer].

The complication rate of peptic ulcer disease is 2 to 5% a year. Hemorrhage occurs four times more often than perforation and penetration. High age and the use of nonsteroidal antiinflammatory drugs (NSAID) are the most important risk factors. The incidence of rebleeding is twice as high after a first complication. About 15 to 30% of bleeding patients die because of this complication. Endoscopy is the means of choice in diagnosis and primary therapy. Gastric retention and vomiting of stale food are typical symptoms of gastric outlet obstruction.

Humans↗
PubMed1992

Factors influencing virus inactivation and retention of platelet properties following treatment with aminomethyltrimethylpsoralen and ultraviolet A light.

A wide variety of viruses are inactivated by psoralen compounds in the presence of ultraviolet A light (UVA). Use of aminomethyltrimethylpsoralen (AMT) and UVA is being evaluated as a method to inactivate viruses that may be present in platelet suspensions prepared for transfusion. Studies have been conducted to assess how variation in various environmental parameters influences the extent of viral inactivation and the retention of platelet properties. Most notably, it was determined that increasing levels of plasma progressively inhibited the inactivation of model viruses. As a result, experiments were routinely conducted at a plasma level of approximately 14.5%, using 40 micrograms/ml AMT, which was determined to be optimal when using this reduced plasma level. The reduced plasma level was achieved by dilution with a nonplasma medium that has been shown to be satisfactory for storage of platelets. Under these conditions, about 5 logs of vesicular stomatitis virus (VSV), pseudorabies, and phi 6 inactivation were achieved. Variation of platelet and leukocyte counts, within normal levels, had a minimal effect on extent of viral inactivation. Although oxygen level (mean levels, 97.9 mm Hg versus 19.2 mm Hg) had only a small influence on viral inactivation with 2.4, 4.8, and 7.2 J/cm2 of UVA (equivalent to 1-3 minutes of exposure), in vitro platelet properties, such as medium pH, morphology characteristics, and aggregation response, were better retained with a longer exposure time at the reduced oxygen level. With normal oxygen (97.9 mm Hg), platelet properties declined substantially relative to untreated controls (no UVA, no AMT) on exposure to 4.8 J/cm2. Our studies have identified two sets of conditions that provide about 5 logs of virus inactivation without extensively altering platelet in vitro properties.

Blood↗
PubMed1991

Electrophysiological evidence for the existence of receptors for endothelin and vasopressin on cultured astrocytes of rat spinal cord and brainstem.

By means of intracellular recordings we have studied the actions of the vasoactive peptides endothelin-1 and -3 (ET-1, ET-3) and arginine vasopressin (AVP) on the membrane potential of astrocytes in explant cultures of rat spinal cord and brainstem. Addition of ET-1, ET-3 or AVP to the bathing solution at concentrations of 10(-8)-10(-6) M depolarized the membrane of the majority of glial cells studied. The AVP antagonist d(CH2)5(1), Tyr(Me)2, Arg8-vasopressin reversibly blocked the depolarizations by AVP. Our electrophysiological findings together with autoradiographic binding studies strongly suggest the existence of ET and AVP receptors on astrocytes.

Animals↗
PubMed1991

Pathophysiology and clinical basis of prevention and treatment of complications of chronic liver disease.

Chronic liver failure is characterized by the appearance of jaundice, ascites, encephalopathy and/or gastrointestinal bleeding. Acute episodes of hepatic decompensation are frequently precipitated by additional events, e.g. septicaemia, diuretic therapy or excessive protein intake. Identification, correction and treatment of these precipitating factors are first steps in the management of chronic liver failure. Nutritional support is important in the treatment of cirrhotic patients, because malnutrition is one of the major determinants of patient outcome. Management of encephalopathy reduces the appearance of gut-derived nitrogenous toxins and corrects imbalances in amino acid metabolism. Treatment of ascites is salt restriction supported by gentle and incremental administration of diuretics. Ursodesoxycholic acid has become a new and promising modality in the management of cholestatic liver diseases. If conservative therapy fails to recompensate liver function, liver transplantation may be indicated.

Ascites↗
PubMed1991

Follow-up study of sensory-motor polyneuropathy in type 1 (insulin-dependent) diabetic subjects after simultaneous pancreas and kidney transplantation and after graft rejection.

The influence of successful simultaneous pancreas and kidney transplantation on peripheral polyneuropathy was investigated in 53 patients for a mean observation period of 40.3 months. Seventeen patients were followed-up for more than 3 years. Symptoms and signs were assessed every 6 months using a standard questionnaire, neurological examination and measurement of sensory and motor nerve conduction velocities. While symptoms of polyneuropathy improved (pain, paraesthesia, cramps, restless-legs) and nerve conduction velocity increased, there was no change of clinical signs (sensation, muscle-force, tendon-reflexes). Following kidney-graft-rejection there was a slight decrease of nerve conduction velocity during the first year, which was not statistically significant. Following pancreas-graft rejection there was no change of nerve conduction velocity during the first year. Comparing the maximum nerve conduction velocity of the patients with pancreas-graft-rejection to the nerve conduction velocities of these patients at the end of the study, there was a statistically significant decrease of 6.5 m/s. In conclusion, we believe that strict normalization of glucose metabolism alters the progressive course of diabetic polyneuropathy. It may be stabilized or partly reversed after successful grafting even in long-term diabetic patients.

Adult↗
PubMed1991

Noninvasive determination of left ventricular output and wall stress in volume overload and in myocardial disease by cine magnetic resonance imaging.

The current study used cine magnetic resonance imaging to determine the effect of increasing severity of valvular regurgitation on systolic wall stress and to demonstrate that wall stress was disproportionately increased in relation to the severity of regurgitation in patients with myocardial disease. A total of 39 patients with predominantly mitral (n = 22) or aortic (n = 17) regurgitation with (n = 13) and without (n = 26) myocardial disease and 10 normal volunteers were examined with cine magnetic resonance imaging (MRI) at 1.5 T. Left ventricular (LV) cardiac output (CO) and peak systolic (PS) wall stress (WS) and end-systolic (ES) WS were calculated from blood pressure recordings, carotid pulse tracings, and wall thickness (h) and diameter (D) measurements obtained from cine MRI. Patients were classified into three degrees of severity according to their LV regurgitant volume (RV). Myocardial disease was defined by an ejection fraction (EF) of less than 40%. Mean LV EF was 61 +/- 3% in normal volunteers, 64 +/- 3% in patients with regurgitation, and 25 +/- 2% in patients with myocardial disease. LV CO was directly related to RV in patients without myocardial disease, whereas it was disproportionately low in relation to RV in patients with myocardial disease. PS WS was significantly higher in severe mitral and/or aortic regurgitation compared with moderate, mild, and no mitral and/or aortic regurgitation. Compared with the degree of regurgitation, PS WS was disproportionately higher in patients with myocardial disease. Thus LV CO and WS rise progressively with increasing severity of regurgitation. Disproportionately high systolic WS relative to RV indicates the presence of myocardial disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Preparation and maintenance of chronic esophagostomized rats: an update.

We report significant improvements in our procedures for preparing and maintaining rats with esophageal fistulas and gastric cannulas. The most important of these are 1) a new cannula assembly, 2) a two-stage surgical procedure, 3) a modified diet, and 4) a less stringent maintenance regimen.

Animals↗
PubMed1991

All-or-none suppression of glucose sham feeding by an intragastric mixed meal in rats.

Rats were permitted to sham feed a 1 M glucose solution after varying delays (0-40 min) following the intragastric (IG) infusion of a large, nutritionally adequate meal. (a) The meal affected sham feeding in an all-or-none way. After such a meal, sham feeding was either suppressed almost entirely, or it was not suppressed at all as compared with a no-meal control condition. (b) When it occurred, the suppression was short-lived: As little as a 20-min delay after the meal could suffice to change its suppressant effect from "all" to "none." This implies in turn that the much longer suppression found under other conditions is not a product of systemic inhibition on readiness to ingest. (c) The duration of the suppression appeared to decrease with successive exposures to the experimental conditions. After several such exposures, some rats showed no postprandial suppression at all, even immediately after the IG meal.

Animals↗
PubMed1991

The Q300 gene: a novel transcription unit induced in simian virus 40-infected and -transformed mouse cells.

The Q300 element is a single-copy 233-bp genomic mouse DNA fragment carrying a high-affinity binding site for the simian virus 40 (SV40) large T antigen. This element was used to screen an EMBL3 mouse genomic library. We could identify a genomic clone containing an approximately 500-bp transcribed region flanking the Q300 element. The transcribed region, termed the Q300 transcription unit or Q300 gene, is overexpressed in acutely SV40-infected or SV40-transformed mouse and rat cells. The Q300 gene includes an open reading frame which has the coding potential for a small polypeptide with an extremely hydrophobic N terminus and a hydrophilic C terminus. The deduced polypeptide has some similarity with the papillomavirus E5 oncoprotein.

Amino Acid Sequence↗