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Biomedical subjects

W Stremmel

Publications and source records attributed to W Stremmel.

At least 37 records · Page 2Linked to original sources
PubMed2003

CpG immuno-stimulatory motifs enhance humoral immune responses against hepatitis C virus core protein after DNA-based immunization.

Chronic HCV infection is associated with a high morbidity and mortality rate, and currently a prophylactic or therapeutic vaccine is not available. DNA-based immunization is a powerful method to generate cellular and humoral immune responses. However, DNA immunization against HCV core results only in a weak humoral immune response demonstrated in several studies. Therefore, co-immunization with a novel adjuvant may enhance such potentially important immune responses. We examined whether unmethylated CpG motifs in the form of oligodeoxynucleotides (ODN) or E. coli DNA can act as adjuvants for a DNA vaccination approach, since CpG motifs have been shown to stimulate the innate immune system as well as B and T cell immune reactivity. The present study demonstrates that CpG motifs enhance in vivo antibody levels after DNA immunization against HCV core. However, despite some in vitro activity of CpG motifs, no enhancement of T cell responses in vivo was observed after immunization with HCV plasmid DNA and CpG motifs in mice. Our results suggest that co-immunization with CpG-ODN may strengthen humoral immune responses but show no potential effect as an adjuvant to induce cellular immunity against HCV core.

Adjuvants, Immunologic↗
PubMed2003

[NASH -- nonalcoholic steatohepatitis].

Nonalcoholic steatohepatitis describes a hepatic disorder with the typical characteristics of an alcoholic pathogenesis without alcohol consumption. It was first described in 1962 and named NASH by Ludwig et al. 1980. Many researchers worked on this disease since this time. It represents the hepatic manifestation of the syndrome X. The pathogenesis is a two-hit phenomenon. The first hit leads to steatosis hepatis and makes the liver vulnerable to the second hit. Central factors of the second hit are oxygen-radicals, oxidative stress, lipid-peroxidation and cytokines. The exact pathogenic mechanisms are still unknown. NASH is a hepatic disease which can end up in liver cirrhosis and liver failure. Up to now a curative drug therapy does not exist. The poor prognosis in some cases, the increasing incidence in western populations and the lack of therapeutic options renders NASH to a serious problem. The aim of this article is to show the actual knowledge of this disease, especially focussed on the pathogenesis, by review of the literature from 1979 up to the present time.

Biopsy↗
PubMed2003

Procalcitonin is a valid marker of infection in decompensated cirrhosis.

BACKGROUND/AIMS: Bacterial infections are life-threatening complications in cirrhosis and early diagnosis is mandatory. Procalcitonin, a 116 amino acid propeptide of calcitonin, is an early marker of infection. The aim was to evaluate prospectively procalcitonin in the diagnosis of bacterial infection in cirrhosis. 127 patients with liver cirrhosis were analysed and stratified into three groups according bacteriological and morphological findings; decompensated patients with (group I = 36) and without (group II = 64) infection, and 27 non-decompensated and non-infected (group III). METHODS: Diagnosis of infection was made using standard criteria. Serum procalcitonin, tumour necrosis factor alpha, interleukin-6 and C-reactive protein were measured using commercially available methods. RESULTS: PCT serum levels were significantly different between group I (2.8 ng/ml [0.4 - 20.4]), group II (0.6 ng/ml [0.1 - 5.9]) and group III (0.4 ng/ml [0.1 - 1.2]), respectively. Levels above 0.58 ng/ml had a sensitivity of 92 % and specificity of 78 % for the diagnosis of infection and were associated with a 50 % mortality in the first two months. Interleukin-6, tumour necrosis factor alpha and C-reactive protein were less sensitive and specific for the diagnosis of infection. CONCLUSION: In decompensated cirrhosis procalcitonin serum levels provided the most sensitive and specific tool for the initial diagnosis of bacterial infection.

Adult↗
PubMed2003

[Clinical usefulness and diagnostic value of percutaneous liver biopsy in patients with chronically elevated liver enzymes of non-viral origin].

BACKGROUND: In the context of increasing non-invasive diagnostic techniques the purpose of the present study was to determine the clinical usefulness and the diagnostic value of percutaneous liver biopsy in patients with chronically elevated liver enzymes of non-viral origin. PATIENTS AND METHODS: 100 patients from the outpatient clinic of the department of gastroenterology and hepatology who had a liver biopsy in the years 1996 to 1998 because of chronically elevated alanine-aminotransferase (ALT) and/or gamma-glutamyltransferase (gamma-GT) levels were included. Exclusion criteria were as follows: chronic hepatitis B or C infection, focal liver disease and clinical signs of hepatic decompensation. Retrospectively gained clinical data were independently evaluated by two experienced hepatologists. Initially, both examiners made a preliminary clinical diagnosis prior to knowing results from liver histology. With the results from liver histology both examiners were asked to make a final diagnosis. For each patient, the preliminary clinical diagnoses of both examiners were then correlated with the corresponding final diagnoses. RESULTS: Liver histology led in 71 % respectively 74 % of the patients to confirmation or specification of the clinical diagnosis. Liver biopsy was particularly helpful in differentiating non-decompensated liver cirrhosis, cryptogenic hepatitis, auto-immune hepatitis and biliary diseases. CONCLUSION: Despite improved non-invasive diagnostic tools including a broad spectrum of serologic tests liver biopsy is often indispensable for differentiating primary liver from biliary diseases and for the early detection of patients with liver cirrhosis.

Adult↗
PubMed2003

Measurement of gastric emptying by 13C-octanoic acid breath test versus scintigraphy in diabetics.

In this prospective study, we compared the assessment of gastric emptying by the 13C-octanoic acid breath test to gastric emptying scintigraphy in diabetics. We also examined the relationship between gastric emptying parameters and gastric symptoms and cardiovascular autonomic function. The 13C-octanoic acid breath test and scintigraphy were performed simultaneously in 24 diabetics with a solid test meal (1 egg, doubly labelled with 91 mg 13C-octanoic acid and 50 MBq 99mTechnetium-Nanocoll, 60 g white bread, 5 g margarine and 150 ml water). At fifteen-minute intervals, breath samples were taken over 4 hours and examined by mass spectrometry. In parallel, scintigraphy was performed for 2 hours at one minute intervals. Using breath test data, gastric emptying half time (t (1/2) ), lag-phase (t lag ) and gastric emptying coefficient (GEC) were calculated. Subsequently, the correlation of these results with the equivalent data from scintigraphy were determined employing a regression method. To detect a cardiovascular autonomic neuropathy, a 24-h ECG recording was performed. The prevalence of gastrointestinal symptoms in our collective was assessed by a standardized questionnaire. There was a highly significant positive correlation of both 13C-octanoic acid breath test t (1/2) and scintigraphic t (1/2) (r = 0.8257; p < 0.0001) and 13C-octanoic acid breath test t lag and scintigraphic t lag (r = 0.6302; p < 0.001). The sensitivity of the 13C-octanoic acid breath test was 1 and the specificity was 0.73. In our study, there was no significant association of cardiovascular and gastrointestinal autonomic neuropathy. Furthermore, there was no significant relationship between the prevalence of gastrointestinal symptoms and gastric emptying disorders. We conclude that the 13C-octanoic acid breath test represents a suitable method to measure disordered gastric emptying in diabetics due to its highly significant positive correlation to scintigraphy and due to its validity. It is not possible to predict diabetic gastroparesis on the basis of other autonomic function disorders or because of dyspeptic symptoms.

Adult↗
PubMed2003

Immunogenicity of an accelerated vaccination regime with a combined hepatitis a/b vaccine in patients with chronic hepatitis C.

OBJECTIVES: Hepatitis A (HAV) and B (HBV) vaccinations are recommended in patients with chronic liver diseases. METHODS: We prospectively investigated immunogenicity and safety of an accelerated vaccination protocol (0-7-21 days) with the combined hepatitis A/B vaccine (Twinrix(R)) versus the standard vaccination scheme (0-1-6 months) in hepatitis C virus-infected patients versus healthy volunteers. RESULTS: Local and general symptoms were mostly mild in all groups. One month after completion of the accelerated vaccination or standard vaccination, with the combined hepatitis A/B vaccine anti-HAV seroconversion rates (>33 IU/l) were 89 % and 88 % in HCV-infected patients. Initial HCV-nonresponders developed protective anti-HAV antibodies in 94 % and 96 % after a booster dose. According to the anti-HBs seroprotection rate, HCV-infected patients developed protective anti-HBs titres (>10 IU/l) in 77 % and 82 % of cases one month after the accelerated and the standard vaccination scheme-at month 2 and 7, respectively. This anti-HBs seroprotection rate could even be increased to 84 % and 85 % when initial HCV-infected nonresponders where given a booster dose with the combined hepatitis A/B vaccine. Protective anti-HAV and anti-HBs titers were achieved as early as month 2 after the accelerated vaccination schedule in the majority of HCV-infected patients. Healthy subjects developed protective anti-HAV titers and anti-HBs titers in 100 % and 98 % after the accelerated and standard vaccination protocol. CONCLUSIONS: This study is the first to have demonstrated that the accelerated combined hepatitis A/B vaccination is both safe and highly immunogenic against HAV and HBV in HCV-infected patients with well compensated liver disease.

Adolescent↗
PubMed2003

Progressive sclerosing cholangitis after septic shock: a new variant of vanishing bile duct disorders.

BACKGROUND: We present nine patients with progressive sclerosing cholangitis after septic shock. PATIENTS: All nine patients had previously required long term treatment in an intensive care unit for septic shock: two patients with polytrauma, five with burn injury, and two with extensive surgery. They were admitted to our hospital because of cholangitis. Endoscopic retrograde cholangiography revealed severe intrahepatic stenoses in all patients and liver biopsies showed typical signs of sclerosing cholangitis. No patient had pre-existing liver disease. RESULTS: Mean follow up time was 35 months. In patients with major bile duct stenoses (3/9), 12 endoscopic dilations were performed in total. In one patient, concrements were extracted and intermittent stenting was necessary. To date, 4/9 patients have rapidly developed liver cirrhosis. During follow up, 5/9 patients died: two after fulminant cholangitis, one after liver failure, one due to liver transplantation associated problems, and one after cerebral ischaemia. One patient has been registered for transplantation and the remaining three patients show no acute signs of liver failure. CONCLUSIONS: Patients with sclerosing cholangitis, following septic shock, represent a new variant of vanishing bile duct disorders. In such patients liver disease rapidly progresses to cirrhosis. Endoscopic treatment may only transiently improve the course of the disease. Orthotopic liver transplantation is indicated in end stage disease.

Adolescent↗
PubMed2003

Peritoneal tuberculosis with negative polymerase chain reaction results: report of two cases.

Peritoneal tuberculosis is rarely observed in European countries. We report on peritoneal tuberculosis in two female immigrants from Somalia and Columbia who presented with diffuse abdominal pain, fever, weight loss and exudative, lymphocytic ascites. Laboratory investigations showed an increase in C-reactive protein and carcinoma antigen 125 serum levels. Nodular peritoneal lesions and adhesions were detected by ultrasound and computed tomography. In both patients, peritoneal biopsy from laparoscopy revealed epitheloid granulomas with central necrosis and multinucleate giant cells. Microscopy and PCR analysis were, however, negative for Mycobacterium tuberculosis in both patients. Despite repeated testing, ascites culture became positive for M. tuberculosis in only one patient. Shortly after starting antituberculous drug treatment, both patients improved, ascitic fluid disappeared and C-reactive protein and carcinoma antigen 125 serum levels returned to normal. Even in Western countries, peritoneal tuberculosis should be considered in any febrile patient with abdominal signs and symptoms, particularly if ascites is present. Empirical antituberculous treatment is justified in patients with clinical and histological features highly suggestive of peritoneal tuberculosis, even in cases with negative results from microscopy, culture and PCR analysis.

Adult↗
PubMed2002

Chances and shortcomins of adenovirus-mediated ATP7B gene transfer in Wilson disease: proof of principle demonstrated in a pilot study with LEC rats.

BACKGROUND & AIMS: Wilson disease (WD) is an autosomal recessively inherited copper storage disease due to mutations in the ATP7B gene. It results in impaired biliary copper excretion followed by liver injury leading to cirrhosis. In parallel, copper accumulates in other tissues e. g. basal ganglia of the brain inducing motoric disorders. Phenotypical cure of Wilson disease by liver transplantation raised the question whether gene therapy may represent a successful alternative treatment procedure. To examine the principle feasibility of this approach we investigated the effects of gene transfer using an adenoviral vector construct expressing the human ATP7B cDNA in an established rodent model for WD, the Long-Evans Cinnemon rat (LEC). METHODS: Transduction efficiency was assessed by RT-PCR, Western blot and immunofluorescence analysis. The therapeutic effect was estimated by analyzing holoceruloplasmin and its ferroxidase activity in serum, and the copper content of excrements. Changes in copper homeostasis were determined by positron emission tomography (PET). RESULTS: Successful, but temporary gene transfer was clearly detectable on RNA and protein levels. In parallel the temporary therapeutic effect was documented by restoration of serum holoceruloplasmin and of its ferroxidase activity. Additionally the Ad-ATP7B treated LEC rat revealed a higher (64)Cu content in stool. PET was able to visualize differences in (64)Cu distribution between wild type and LEC rats, indicating its principle usefulness as analytical tool. CONCLUSION: The data demonstrate proof of principle of successful gene therapy in an experimental model of WD. As a consequence of successful but only transient therapeutic effect of adenoviral gene transfer we can now focus more efficient and permanent gene transfer strategies.

Adenosine Triphosphatases↗
PubMed2002

Endoscopic variceal ligation plus propranolol vs. transjugular intrahepatic portosystemic stent shunt: a long-term randomized trial.

BACKGROUND AND STUDY AIMS: After a first variceal bleeding episode in patients with cirrhosis of the liver, treatment with transjugular intrahepatic portosystemic stent shunt (TIPS) and endoscopic variceal ligation (EVL) plus propranolol were compared, with regard to prevention of variceal rebleeding, complications, and mortality. PATIENTS AND METHODS: 85 patients were randomly allocated to receive TIPS (n = 43) or EVL (n = 42). The groups were comparable regarding age, sex, etiology of liver cirrhosis, and liver function. RESULTS: The mean observation times were 4.1 years in the TIPS group and 3.6 years in the EVL group. Although the probability of rebleeding was higher in the EVL group (29.9%) than in the TIPS group (19.4%), the difference was not statistically significant. Three of five patients of the EVL group successfully underwent TIPS placement after treatment failure. The probability of TIPS dysfunction requiring shunt revision was 89 %. Hepatic encephalopathy was observed more often in the TIPS group (40.5%) than in the EVL group (20.5%; P < 0.05). The probability of survival was similar in both groups (TIPS group 75.9%, EVL group 82.2%; n.s.). CONCLUSIONS: In view of its good efficacy and the lower cost of treatment, endoscopic ligation plus propranolol may be recommended as initial procedure for prevention of recurrent variceal hemorrhage, whereas TIPS seems to be the preferable procedure in patients with recurrent bleeding after adequate endoscopic and pharmacological treatment.

Adrenergic beta-Antagonists↗
PubMed2001

[Imported tropical malaria after a sojourn in Kenya. Serious consequences of neglected chemoprophylaxis and delayed diagnosis].

HISTORY AND ADMISSION FINDINGS: A 56-year-old man was admitted to the hospital 11 days after returning from Kenya because of recurrent fever attacks. The patient had not taken malaria chemoprophylaxis and had previously received symptomatic treatment for suspected viral infection by his general practitioner. Physical findings on admission included enlargement of liver and spleen, marked dehydration and a body temperature of 40.1 degrees C. INVESTIGATIONS: Initial chest radiography showed no abnormalities. Thick and thin blood smears were positive for Plasmodium falciparum. Initial parasitemia was 0.5 per thousand. TREATMENT AND COURSE: Despite immediate quinine therapy including loading dose and intensive care treatment complicated malaria with multiorgan failure developed. The patient required mechanical ventilation, high-dose catecholamine treatment and hemodialysis for several days. The course of parasitemia peaked on treatment day 2 at a level of 31.1 per thousand. CONCLUSION: Our case shows serious consequences and important complications of Plasmodium falciparum malaria in a patient without chemoprophylaxis and with delayed diagnosis. Fever following a stay in the tropics requires immediate testing for malaria infection.

Animals↗
PubMed2001

Mouse fatty acid transport protein 4 (FATP4): characterization of the gene and functional assessment as a very long chain acyl-CoA synthetase.

FATP4 (SLC27A4) is a member of the fatty acid transport protein (FATP) family, a group of evolutionarily conserved proteins that are involved in cellular uptake and metabolism of long and very long chain fatty acids. We cloned and characterized the murine FATP4 gene and its cDNA. From database analysis we identified the human FATP4 genomic sequence. The FATP4 gene was assigned to mouse chromosome 2 band B, syntenic to the region 9q34 encompassing the human gene. The open reading frame was determined to be 1929 bp in length, encoding a polypeptide of 643 amino acids. Within the coding region, the exon-intron structures of the murine FATP4 gene and its human counterpart are identical, revealing a high similarity to the FATP1 gene. The overall amino acid identity between the deduced murine and human FATP4 polypeptides is 92.2%, and between the murine FATP1 and FATP4 polypeptides is 60.3%. Northern analysis showed that FATP4 mRNA was expressed most abundantly in small intestine, brain, kidney, liver, skin and heart. Transfection of FATP4 cDNA into COS1 cells resulted in a 2-fold increase in palmitoyl-CoA synthetase (C16:0) and a 5-fold increase in lignoceroyl-CoA synthetase (C24:0) activity from membrane extracts, indicating that the FATP4 gene encodes an acyl-CoA synthetase with substrate specificity biased towards very long chain fatty acids.

Amino Acid Sequence↗
PubMed2001

Copper in disorders with neurological symptoms: Alzheimer's, Menkes, and Wilson diseases.

Copper is an essential element for the activity of a number of physiologically important enzymes. Enzyme-related malfunctions may contribute to severe neurological symptoms and neurological diseases: copper is a component of cytochrome c oxidase, which catalyzes the reduction of oxygen to water, the essential step in cellular respiration. Copper is a cofactor of Cu/Zn-superoxide-dismutase which plays a key role in the cellular response to oxidative stress by scavenging reactive oxygen species. Furthermore, copper is a constituent of dopamine-beta-hydroxylase, a critical enzyme in the catecholamine biosynthetic pathway. A detailed exploration of the biological importance and functional properties of proteins associated with neurological symptoms will have an important impact on understanding disease mechanisms and may accelerate development and testing of new therapeutic approaches. Copper binding proteins play important roles in the establishment and maintenance of metal-ion homeostasis, in deficiency disorders with neurological symptoms (Menkes disease, Wilson disease) and in neurodegenerative diseases (Alzheimer's disease). The Menkes and Wilson proteins have been characterized as copper transporters and the amyloid precursor protein (APP) of Alzheimer's disease has been proposed to work as a Cu(II) and/or Zn(II) transporter. Experimental, clinical and epidemiological observations in neurodegenerative disorders like Alzheimer's disease and in the genetically inherited copper-dependent disorders Menkes and Wilson disease are summarized. This could provide a rationale for a link between severely dysregulated metal-ion homeostasis and the selective neuronal pathology.

Alzheimer Disease↗
PubMed2001

IRP1 activation by extracellular oxidative stress in the perfused rat liver.

The expression of several proteins with critical functions in iron metabolism is regulated post-transcriptionally by the binding of iron regulatory proteins, IRP1 and IRP2, to mRNA iron responsive elements (IREs). In iron-deficient tissues and cultured cells, both IRP1 and IRP2 are activated for high affinity IRE binding. Previous work showed that IRP1 is also activated when cultured cells are exposed to H(2)O(2). The well established role of iron and H(2)O(2) in tissue injury (based on Fenton chemistry) suggests that this response may have important pathophysiological implications. This is particularly relevant in inflammation, where cytotoxic immune cells release large amounts of reactive oxygen species. Here, we describe a rat liver perfusion model to study IRP1 activation under H(2)O(2) generation conditions that mimic a physiological inflammatory response, using steady-state concentrations of H(2)O(2) produced by a glucose/ glucose oxidase/catalase system. We show first that stimulated neutrophils are able to increase serum levels of H(2)O(2) by a factor of 10, even in the presence of H(2)O(2)-degrading erythrocytes. We further show that perfusion of rat liver with glucose oxidase leads to a rapid activation of IRE binding activity in the intact organ. Mobility shift assays with liver extracts and IRP1 or IRP2-specific probes indicate that only IRP1 responds to H(2)O(2). Our study demonstrates a principal existence of iron regulation by oxidative stress at the intact organ level. It also provides a link between iron metabolism and the inflammatory response, as H(2)O(2) is a major product of the oxidative burst of neutrophils and macrophages.

Animals↗