Biomedical subjects

S Wagner

Publications and source records attributed to S Wagner.

At least 235 records · Page 13Linked to original sources

PubMed1996

Biliary malignancies in primary sclerosing cholangitis: timing for liver transplantation.

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease associated in 10% to 36% of those with hepatobiliary malignancies, which are, in the majority of cases, not known prior to transplantation. Diagnosis of carcinomas in a PSC setting at an early stage has not yet been achieved, because there are no differences in the age of patients or clinical course, particularly with regard to the time between diagnosis of PSC and detection of carcinomas. To assess optimal timing for transplantation in patients with PSC, we applied the Mayo survival model to 48 patients receiving transplants for that disease in our center between 1972 and 1994. Of these patients, 10 had a biliary malignancy, which was incidental in 9. According to the Mayo model, low-, moderate-, and high-risk groups of patients could be formed. The actuarial patient survivals at 1 and 7 years were 100% and 100% (low risk), 68.6% and 68.6% (moderate risk), and 54.6% and 46.8% (high risk), respectively. Patients with a biliary malignancy had a 30% survival at 1 year; none survived 6 years. Local recurrence of the tumor was found in 3 patients, 2 of them with low tumor stages at the time of transplantation. Analysis of the Mayo Model risk scores demonstrated a marked increase in the incidence of biliary malignancies at a score above 4.4. All patients with tumors were found to have a score above 4. Moreover, the prevalence rate rose from 14.3% in the low-risk group to 33.3% in the moderate-risk group. There was no difference in the clinical courses at 6 to 12 months prior to transplantation; in particular, the bilirubin levels (PSC alone, 250 +/- 230 mumol/L; PSC with carcinoma, 288 +/- 182 mumol/L) did not differ significantly (P > .05) between both patient groups. Because the outcome after transplantation is poor even in patients with low-grade malignancies, early timing of transplantation in patients with PSC is suggested to prevent formation of biliary malignancies. Therefore, regular scoring of patients with the Mayo Model risk score is suggested, and transplantation should be taken into consideration at scores above 4.

Actuarial Analysis↗

PubMed1996

Arterial angiography in high-kilovoltage technique with gadolinium as the contrast agent: first clinical experience.

Iodine-containing contrast agents are currently used for angiography. However, due to the relatively low atomic number of iodine, imaging must be performed with a relatively low tube voltage. Gadolinium has been used for several years as a contrast agent in MRI with low adverse side effects. This substance has a higher atomic number as compared with iodine. We investigated whether the use of a gadolinium-containing contrast agent with a higher tube voltage reduces the radiation exposure in angiography, and how the image quality compares with the previous technique. A total of 15 patients were examined with either a survey angiography or a selective angiography. In all patients angiography was performed with an iodine-containing contrast agent with a tube voltage of 75 kV. Then gadolinium-containing contrast agent was administered immediately with a tube voltage of 110 kV. Radiation exposure and image quality were compared. On average, a dose reduction factor of 3.57 times was achieved by using 110 instead of 75 kV. However, the image quality was poorer in the majority of cases as compared with the images taken with iodine as a contrast agent and a tube voltage of 75 kV. The poorer image quality is caused by the relative low concentration (0.5 M) of the used gadolinium solution. A 1 M solution is currently tested for market approval and would probably solve this problem.

Aged↗

PubMed1996

[Contrast media for magnetic resonance tomographic lymph node diagnosis (MR lymphography)].

In MR-imaging, similar to computed tomography, diagnosis of metastatic lymph-node disease is based on lymph-node sizes, and thereby it is non-specific. Super-paramagnetic iron oxide as a potential contrast medium for MR-lymphography accumulate in normal lymph node tissue after endolymphatic, interstitial and, in case of very small particles, after intravenous injection. No accumulation occures in lymph node metastases. Lymph-node metastases can be detected by all three injection techniques. It has been shown experimentally, that in particular small metastases can be detected in normal sized lymph nodes. However, MR-lymphography also has inherent methodologic problems, as there may occure an uneven distribution of the contrast medium between different lymph-node groups. The experimental results with endolymphatic, interstitial, and intravenous MR-lymphography as well as first clinical results with intravenous contrast medium injection are presented and discussed.

Contrast Media↗

PubMed1996

The suprachiasmatic nucleus in stationary organotypic culture.

Suprachiasmatic nuclei, derived from neonate rats, were maintained for several weeks in stationary organotypic culture. Hypothalamic slice explants, supported by Millicell filters and incubated in Petri dishes containing serum-based medium, flattened appreciably, yet preserved the organization of the suprachiasmatic nucleus and the surrounding hypothalamic tissue. After two to three weeks, cultures were fixed, and three neuronal sub-populations were identified as vasopressinergic, vasoactive intestinal peptide-containing, or GABA-containing. The GABAergic component of the cultured suprachiasmatic nucleus was particularly profuse, projecting extensively into the hypothalamic slice. Unilateral ablation of the nucleus in the explant dramatically reduced ipsilateral GABA-immunoreactivity in the slice. Explants in which an incision separated the bilateral suprachiasmatic nucleus from the paraventricular nucleus, deprived the latter of its fine-caliber GABA-immunoreactive input. Extra- or intra-cellular electrophysiological recordings from the suprachiasmatic nucleus were obtained in 51 of 58 cultures. The electrical properties of the long-term cultured suprachiasmatic nucleus were similar to those recorded in acute slices from adult rats. In six cultures recordings were extended for up to 10-24 h. Within long-term stationary organotypic cultures of the suprachiasmatic nucleus, sub-populations of neurons, intrinsic to the nucleus in vivo, were identified immunocytochemically. Lesion studies supported the observation that the main source of the GABAergic innervation within the entire hypothalamic slice explant appeared to be the suprachiasmatic nucleus. Electrophysiological studies confirmed the viability of the long-term cultured nucleus and revealed changes in spontaneous electrical activity that may indicate circadian fluctuation.

Animals↗

PubMed1996

Procedure to predictably seat multiple, hexed abutments onto endosseous implants: a clinical report.

The use of implants to restore the dentition of partially edentulous patients has increased over the past several years. Optimal esthetic results depend on satisfactory implant placement. Occasionally, implants are placed in less than optimal positions, which may require modification in the prosthesis design and increase the technical difficulty. In these instances, preangled or customized abutments can be used. If more than one of these abutments has to be used, accurate orientation of the hexed components to the implants and each other may be a problem. This clinical report illustrated a simple, inexpensive procedure to transfer the orientation of two or more hexed abutments from a master cast to the mouth. This procedure reduced the time needed to orient the hexed abutments correctly in laboratory and clinical situations. It may also reduce the chances of the patient aspirating or swallowing abutments or screws.

Adult↗

PubMed1996

Cognitive-behavioral treatment of anorexia nervosa.

This article outlines a cognitive-behavioral outpatient program for the treatment of anorexia nervosa. The rationale for this treatment is based on two primary assumptions about the anorectic condition: first, that anorexia nervosa develops as a way of coping with life stresses; and second, that anorexia nervosa develops into a self-sustaining "food phobia." Cognitive-behavioral treatment techniques are therefore aimed at (1) confronting the patient's fears and avoidance behaviors, (2) identifying the patient's areas of deficient problem-solving skills, particularly in the interpersonal realm, and (3) cultivating new problem-solving skills.

Adaptation, Psychological↗

PubMed1996

Magnetic resonance lymphography in rats: effects of muscular activity and hyperthermia on the lymph node uptake of intravenously injected superparamagnetic iron oxide particles.

RATIONALE AND OBJECTIVES: We investigated the influence of muscular activity and regional body temperature changes on the accumulation of intravenously (i.v.) administered, dextran-coated superparamagnetic iron oxide (SPIO) particles in the lymph nodes of rats. METHODS: Four groups of rats (N = 21) were used. Five rats were allowed to move freely after i.v. contrast administration (group 1). In another five rats, muscular inactivity (group 2) was induced during i.v. injection of SPIO particles and for up to 2 hr thereafter by anesthesia. In seven rats (likewise anesthetized), the contrast agent was administered while the extremities of one side of the body were warmed in a water bath for 2 hr (group 3). The rats in groups 1-3 received 100 mumol Fe/kg of the contrast agent. Four rats not given SPIO particles served as the control group (group 4). The lymph nodes of all animals were removed 24 hr after SPIO administration and were embedded in an agar matrix for magnetic resonance imaging at 1.5 T using a proton-density-weighted spin-echo (PD-SE) sequence and a T2*-weighted gradient-recalled echo (T2* GRE) sequence. RESULTS: Signal loss varied widely among the different lymph nodes in group 1. A pronounced signal reduction was observed in the mesenteric (PD-SE = 20 +/- 6%, T2* GRE = 55 +/- 19%), iliac (PD-SE = 13 +/- 13%, T2* GRE = 44 +/- 24%), and popliteal (PD-SE = 24 +/- 7%, T2* GRE = 70 +/- 11%) lymph nodes and only a moderate reduction in the mandibular (PD-SE = 4 +/- 7%, T2* GRE = 42 +/- 15%), axillary (PD-SE = 0 +/- 4%, T2* GRE = 8 +/- 7%), and inguinal (PD-SE = 5 +/- 5%, T2* GRE = 34 +/- 18%) lymph nodes. The least pronounced signal loss occurred in the peripheral lymph nodes of group 2, ranging from 0 +/- 3% for PD-SE sequences and 10 +/- 11% for T2* GRE sequences to 13 +/- 15% for PD-SE sequences and 41 +/- 19% for T2* GRE sequences. In group 3, the uptake of contrast material in the peripheral lymph nodes of the hyperthermal side was significantly more pronounced than on the contralateral side (p < .01), and the contrast agent was distributed more evenly to the different lymph node groups than in group 1. CONCLUSION: Muscular activity and regional hyperthermia markedly influence the accumulation of SPIO particles in different lymph node groups in rats. These findings must be considered in preclinical studies and in the clinical administration of MR lymphography.

Anesthesia↗

PubMed1996

Endoscopic management of biliary tract strictures in primary sclerosing cholangitis.

BACKGROUND AND STUDY AIMS: In a subgroup of patients, primary sclerosing cholangitis (PSC) is complicated by high-grade focal strictures of the bile ducts, and this can have an unfavorable influence on the natural course of the disease. The aim of this study was to evaluate the efficacy and safety of endoscopic treatment in this selected patient group. PATIENTS AND METHODS: Twelve symptomatic patients with primary sclerosing cholangitis and major ductal strictures were included in a prospective study of endoscopic treatment. All patients were managed by repeated angioplasty-type balloon dilation and nasobiliary catheter perfusion. A minimum of two treatment sessions was used, and therapy was continued until satisfactory reopening of the strictures was obtained. Routine endoscopic follow-up was performed after three, six, 12, 18, and 24 months, and then at yearly intervals. The efficacy of therapy was assessed by evaluating clinical symptoms, laboratory data, and cholangiograms. RESULTS: The long-term follow-up averaged 23 months (range: 12-50 months). Two to nine (mean: three) treatment sessions were required to obtain satisfactory reopening of major biliary strictures. Eight patients showed considerable and sustained improvement. The mean serum bilirubin, alkaline phosphatase, gamma-glutamyl-transpeptidase, and alanine aminotransferase levels felt significantly by 73% (P = 0.0164), 46% (P = 0.0022), 55% (P = 0.0022), and 58% (P = 0.0022), respectively. The average radiographic stricture score before treatment was 3.2 +/- 0.8 (P = 0.0033). Three patients required liver transplantation seven, 12, and 40 months after the initiation of endoscopic treatment, due to a deterioration in hepatic function or an inability to exclude complex biliary malignancy. No major procedure-related side effects were observed. CONCLUSIONS: Our results suggest that the endoscopic treatment of PSC patients with dominant bile duct strictures is effective, safe, and well-tolerated. However, it is important not to overlook the potential development of cholangiocarcinoma.

Adolescent↗

PubMed1996

Functional hepatobiliary imaging with gadolinium-EOB-DTPA. A comparison of magnetic resonance imaging and 153gadolinium-EOB-DTPA scintigraphy in rats.

RATIONALE AND OBJECTIVES: Gadolinium-EOB-DTPA (Gd-EOB-DTPA) is a hepatobiliary magnetic resonance (MR) imaging contrast medium designed to detect focal liver lesions. The objective of this study was to evaluate dynamic Gd-EOB-DTPA-enhanced MR imaging as a new method for assessing liver excretory function and to compare it with a scintigraphic method, the gold standard. METHODS: Changes in scintigraphic liver activity or MR liver signal intensity were intraindividually monitored over time after intravenous injection of 50 mumol Gd/kg of Gd-EOB-DTPA in controls and rats with common bile duct obstruction or L-ethionine-induced fatty liver (n = 6). RESULTS: A comparison of liver scintigraphy and MR imaging revealed that elimination half-lives of Gd-EOB-DTPA were significantly longer in rats with common bile duct obstruction (scintigraphy: 100 +/- 27 minutes; MR imaging: 59 +/- 18 minutes) or fatty liver (scintigraphy: 94 +/- 30 minutes; MR imaging: 72 +/- 32 minutes) than in controls (scintigraphy: 20 +/- 2 minutes; MR imaging: 18 +/- 3) (P < 0.05). CONCLUSIONS: Like liver scintigraphy, functional MR liver imaging using Gd-EOB-DTPA is feasible and can differentiate normal controls from models of biliary and hepatocyte disease.

Animals↗

PubMed1996

Quantification of lipoprotein(a): comparison of an automated latex-enhanced nephelometric assay with an immunoenzymometric method.

Several studies indicate the relevance of lipoprotein(a) (Lp(a)) in the genesis of premature coronary artery disease. A simple method for determining the concentration of Lp(a) is therefore of great interest for assessing the risk of coronary artery disease in patients. We compared a new latex-enhanced immunonephelometric assay (Behringwerke AG, Marburg, Germany), using the Behring Nephelometer System 100, with an established immunoenzymometric assay (Immuno, Heidelberg, Germany). A total of 163 patients was studied. Intra- and inter-assay coefficients of variation were between 2.2% and 7.1%, and between 3.4% and 8.6%, depending on the concentration of Lp(a). The correlation between the studied assays was excellent (r = 0.93, y = 0.98x -1.57, Spearman rank, Passing & Bablok). When values above 1000 mg/l for Lp(a) were excluded, the correlation was even higher. Increased light scattering with particle size, which hitherto has been a disadvantage of the nephelometric technique, seems to be negligible using the improved latex-enhanced approach. In patients with triacylglycerol values above 4.5 mmol/l (n = 19) there was no interference with the Behring system, i.e. the results of the nephelometric method were not increasing, and they agreed with those of the immunoenzymometric assay. In conclusion, this new latex-enhanced nephelometric immunoassay represents a rapid and precise method for the quantification of Lp(a).

Humans↗

PubMed1996

Spontaneous resolution of a large spinal epidural hematoma: case report.

Spontaneous spinal epidural hematoma is a rare condition that usually requires surgical evacuation of the hematoma. We report a case of spontaneous spinal epidural hematoma that was probably associated with aspirin intake. The initial clinical signs and symptoms included sharp, left-sided neck pain and weakness of the left arm. The initial magnetic resonance image showed a spinal epidural hematoma extending from C2 to C6, with compression of the myelon. This case is remarkable for dramatic clinical improvement within 12 hours and the magnetic resonance imaging documentation of complete resolution within 3 days. For each patient with a stable or improving neurological status, conservative management monitored by magnetic resonance imaging might be the treatment of choice.

Aged↗

PubMed1996

A case of the yellow nail syndrome associated with massive chylous ascites, pleural and pericardial effusions.

A 26-year-old male patient with a history of chronic peripheral lymphedema, yellowish coloured slow growing nails and pleural effusions since early childhood is described. After 23 years he developed a chylous ascites and scintigraphy with technetium-99m labeled albumin clearly demonstrated a diffuse protein loss involving the whole jejunum and ileum. Subsequent jejunal and duodenal biopsies showed the typical histological findings of intestinal lymphangiectasia thereby confirming a diffuse intestinal lymphatic damage. In addition to the gastrointestional symptoms the patient developed a pericardial effusion diagnosed by echocardiographic imaging. Dietary treatment with middle chained triglycerides and intravenous human albumin supplementation was followed by the reduction of the ascites and improvement of the peripheral lymphedema. To our knowledge this is the first description of the yellow nail syndrome associated with a diffuse lymphangiectasia involving the whole small bowel.

Adult↗

PubMed1996

[Prospective study of subjective stress caused by dobutamine stress echocardiography--effect on diagnostic accuracy].

UNLABELLED: We used a standardized questionnaire to assess physical and mental distress caused by dobutamine stress echocardiography (DSE). The examination was performed according to a standardized protocol (5-40 micrograms/kg/min including atropine). 91 patients (pts), 68 men (62 +/- 9 years), 23 women (65 +/- 7 years) were asked to quantify the severity of the following symptoms: palpitations, anxiety, headache, nausea, discomfort of left lateral position, angina pectoris and dyspnea. Numbers on a rating scale from 1-10 defined the degree of distress. Absence of a symptom equalled mark, 1, slight expression marks 2-4. Moderate expression was defined by marks 5-7 and very strong expression by marks 8-10. RESULTS: 86% of pts felt affected by one or more symptoms to a slight to moderate extent (mark 4 +/- 2.17). Palpitations were felt by 85% of the pts (mark 6 +/- 2.83), anxiety by 42% (mark 3 +/- 2.5), headache by 50% (3 +/- 2.54), nausea by 20% (2 +/- 1.72), angina pectoris by 42% (3 +/- 2.5), dyspnea by 30% (2 +/- 2.42) and discomfort of left lateral recumbent position by 43% (mark 3 +/- 2.59). 43 pts underwent coronary angiography. The negative predictive value of DSE to identify pts without a coronary artery stenosis extending a 50% diameter reduction was 85% for the 16 pts who reached their individual submaximal heart rate compared to 60% for those 27 pts who did not reach it. Unspecific symptoms led to test termination in these pts. The positive predictive values were comparable (89 and 94%). CONCLUSION: DSE causes physical and mental distress. If symptoms lead to test termination before age corrected submaximal heart rate is reached, normal wall motion does not exclude significant coronary artery disease.

Angina Pectoris↗

PubMed1996

[Hereditary hemorrhagic telangiectasia with hepatic involvement and including gastric vessels. A case report].

Hereditary hemorrhagic teleangiectasia (HHT) (Osler-Weber-Rendu-disease) is characterized by a combination of muccocutaneous vascular malformations with recurrent spontaneous bleeding and a familiar predisposition. Among visceral manifestations of this disease are only a few descriptions of hepatic involvement. We describe a 53-year-old woman with HHT whose first symptoms of hypercirculatory heart failure developed 1.5 years before the final diagnosis of HHT. We measured a heart-time-volume of 14-151/min. by echocardiography and a flow-volume of 5-9 l/min. in the proper hepatic artery by dopplersonography on admission. We were able to demonstrate multiple intra- and extra-hepatic and gastric arteriovenous malformations by arteriography. Branches of the proper hepatic artery and the left gastric artery were embolized in three serial sessions. By this procedure we were able to reduce the flow-volume in the proper hepatic artery from 5-9l/min. to 1.5l/min. and the heart-time-volume to a minimum of 9.8l/min. and thus stop progression of the hyperdynamic heart failure.

Angiography↗

PubMed1996

[Pseudo-esophagitis in antacid abuse].

The case of a patient with diffuse white furs in the whole esophagus is described. Esophagoscopy was suggestive of the presence of a wide-spread Candida esophagitis. The histologic and cultural examinations excluded Candida esophagitis and did not show unequivocal pathologic alterations. Detailed anamnestic exploration revealed a long existing distinct abuse of an antacid. After discontinuation of the antacid-intake a control gastroscopy was done 4 months later showing completely normal mucosa and disappearance of all furs. The present case demonstrates that antacidum intake must be encountered as differential diagnosis of esophageal white plaques.

Antacids↗

PubMed1996

[Typing, resistance behavior and occurrence of methicillin-resistant Staphylococcus aureus strains in a surgical intensive care unit].

Over a period of three years, the frequency of the appearance of methicillin-resistant S. aureus strains (MRSA) was observed on a surgical intensive care unit. During this above-mentioned period of investigation it came to a heaped occurrence of nosocomial infections on this ICU with altogether 332 S. aureus-stems being isolated from different patient specimen. 204 (61.5%) of these were resistant against methicillin and could be divided into 48 first- and 156 follow-up-isolates. The thereupon accomplished differentiation of the 48 MRSA-first isolates by means of lysotyping and the pioneered GenePath Strain Typing System for a standardized pulsed-field-gel-electrophoresis (PFGE) gave the proof of 7 different MRSA-types. Around 7 different, in part parallel chains of infection on this ICU were observed, which could be led back to different strains. In reference to all analyzed S. aureus, an especially high rate (90%) of MRSA on this ICU could be isolated in taken wound-swabs, followed by 83.3% MRSA at catheter tips and 71,9% in tracheal and bronchial secretion. A consideration of the antibiotic susceptibility yielded, that also gentamicin and the quinolones showed an in-vitro resistance against MRSA, while fosfomycin, fusidic acid, chloramphenicol and trimethoprim/sulfamethoxazole reached positive responding rates between 80 and 100%. On the other hand, presently still 100% of the explored MRSA-strains are susceptible for glycopeptides such as vancomycin and teicoplanin. Because of intensive hospital hygienic measures the number of newly isolated MRSA could be reduced clearly on this ward.

Anti-Bacterial Agents↗

PubMed1995

[Normal values for dobutamine stress echocardiography].

Dobutamine stress echocardiography having established itself as a sensitive method for diagnosing coronary heart disease, even in the absence of normative values, the physiological haemodynamics as well as the physiological values for global and regional left ventricular myocardial function were measured. TEST PERSONS AND METHODS: 14 healthy subjects (ten men, four women; median age 25 [range 21-32] years) underwent dobutamine stress echocardiography according to an internationally practised dosage steps protocol (5-40 micrograms/kg/min with additional 0.5 mg atropine at 40 micrograms). RESULTS: Maximal infusion rate achieved a serum dobutamine level of 1.67 micrograms/ml with minimal quartiles; it did not influence serum electrolytes (especially potassium). Heart rate increased from 64 to 150/min (P < 0.0001), blood pressure from 111/66 to 158/88 mmHg (systolic: P < 0.0001; diastolic P < 0.001) and the double product of systolic pressure and heart rate from 6714 to 24571 (P < 0.001). While the end-diastolic volume index decreased from 50 to 37 ml/m2 (P < 0.05), the end-systolic volume index fell from 20 to 7 ml/m2 (P < 0.0001). Regional wall motion analysis indicated an increase in left ventricular circumferential contractility with little scatter. CONCLUSIONS: The usual protocol for dobutamine stress echocardiography is a sensible one, because the haemodynamic effect occurs already at low dosage and can then be increased significantly with further dosage steps. High serum dobutamine concentrations can be achieved without arrhythmogenic hypokalaemia. Volume index and ejection fraction are especially discriminatory variables. Quantitative analysis of wall motion is justified because of the low scatter of values.

Adult↗

PubMed1995

Extracellular nucleotides increase cytosolic free calcium by activating P2u-receptors in single human gastric mucous cells.

In single human gastric mucous cells extracellular ATP, ATP-gamma-S, ADP and UTP at micromolar concentrations caused a biphasic increase in [Ca2+]i. Consistent with a P2u-receptor the rank-order of potency was ATP > or = UTP > ATP-gamma-S > ADP, and cross-desensitization of the Ca2+ responses occurred between ATP and UTP. The initial transient peak in [Ca2+]i was resistant to extracellular Ca2+ depletion which demonstrates mobilization of internal Ca2+. By contrast, the sustained plateau phase required influx of external Ca2+. Ca2+ influx occurs most likely through a capacitative Ca2+ entry mechanism, which was shown to exist in these cells by experiments performed with thapsigargin. Thus, extracellular ATP and UTP activate a common P2u-receptor most likely coupled to the Ca(2+)-phosphatidylinositol signalling cascade. Extracellular nucleotides from various sources might be an important factor in the regulation of human gastric mucous cells.

Adenosine Diphosphate↗