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U Pfeifer

Publications and source records attributed to U Pfeifer.

At least 19 recordsLinked to original sources
PubMed2005

Immunohistochemical differentiation of eosinophilic heart diseases using antibodies against eosinophil activation markers.

AIMS: Eosinophilic heart syndromes are rare in Western countries and include endocarditis parietalis fibroplastica (EPF) and hypersensitivity myocarditis (HM). There are striking differences in natural history and morphological findings. Since diagnosis can be difficult when analysing small myocardial biopsies lacking the characteristic histological features, we studied a set of immunohistochemical markers in order to characterize the activation status of the infiltrating eosinophils to distinguish between these two entities. METHODS AND RESULTS: This study is based on the investigation of seven explanted hearts and one left ventricular specimen collected during implantation of a left ventricular assist device from a total of seven patients with HM. Also investigated were three right and three left ventricular specimens from five patients with EPF. We used antibodies (Ab) against EG1, and EG2, CD44, and CD69 which have been described as markers to distinguish between resting and activated eosinophils. The EG1 to EG2 ratio of eosinophils and the immunoreactivity against CD44 showed no differences between the two entities. However, eosinophils in the EPF were completely negative for CD69, whereas eosinophils reacted positively within the HM group. CONCLUSION: The immunohistochemical investigation of eosinophilic heart diseases using antibodies against CD69 can be a useful tool to distinguish between hypersensitivity myocarditis and endocarditis parietalis fibroplastica.

Aged↗
PubMed2003

[Interlaboratory trial 2000 " Immunohistochemistry" of the German Society for Pathology and the Professional Association of German Pathologists].

Early in 2000 an interlaboratory trial on immunohistochemistry was held in Germany in which 172 pathologists took part. Each pathologist received one H&E stained and five unstained slides of five different tumors to reach a diagnosis based on immunohistochemical stains. Additionally, the diagnosis-independent staining quality was assessed by using a multi-tissue block. Altogether, 828 diagnoses were made, among which 57% (468) were correct. The individual steps of immunohistochemistry (tentative morphological diagnosis, choice of primary antibodies, technical staining quality, conclusions from the diagnosis and rendering a final diagnosis) were assessed independently. Although each of these steps was correlated to the correct final diagnosis, in the multivariate analysis only the tentative diagnosis, choice of primary antibodies and the conclusions drawn from individual stains were independent factors to reach the correct final diagnosis. In the diagnostic part of the interlaboratory trial, the technical quality of the immunostaining was not an independent variable to reach a correct diagnosis. In contrast, the results of the multi-tissue block proved that the immunohistochemical staining quality has to be standardized to reach reproducible results in defining the estrogen receptor expression as a basis for therapeutic decisions.

Coloring Agents↗
PubMed2003

Small-fragment genomic libraries for the display of putative epitopes from clinically significant pathogens.

Taking advantage of whole genome sequences of bacterial pathogens in many thriving diseases with global impact, we developed a comprehensive screening procedure for the identification of putative vaccine candidate antigens. Importantly, this procedure relies on highly representative small-fragment genomic libraries that are expressed to display frame-selected epitope-size peptides on a bacterial cell surface and to interact directly with carefully selected disease-relevant high-titer sera. Here we describe the generation of small-fragment genomic libraries of Gram-positive and Gram-negative clinically significant pathogens, including Staphylococcus aureus and Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus agalactiae, and Streptococcus pneumoniae, Enterococcus faecalis, Helicobacter pylori, Chlamydia pneumoniae, the enterotoxigenic Escherichia coli, and Campylobacter jejuni. Large-scale sequencing revealed that the libraries, which provide an average of 20-fold coverage, were random and, as demonstrated with two S. aureus libraries, highly representative. Consistent with the comprehensive nature of this approach is the identification of epitopes that reside in both annotated and putatively novel open reading frames. The use of these libraries therefore allows for the rapid and direct identification of immunogenic epitopes with no apparent bias or difficulty that often associate with conventional expression methods.

Bacterial Proteins↗
PubMed2002

Quality assurance in immunohistochemistry: results of an interlaboratory trial involving 172 pathologists.

The practicability of quality assurance in immunohistochemistry and its integration into the diagnostic process were both tested in this Germany-wide interlaboratory trial. One hundred seventy-two pathologists received one hematoxylin and eosin and five unstained slides from five cases; all cases were selected by a panel because immunohistochemistry was required for their final diagnosis. Participants rendered a morphologic diagnosis and then substantiated it immunohistochemically. Stained slides and evaluation sheets were reviewed by the panel, and the diagnostic process was analyzed in individual steps: morphologic diagnosis, selection of antibodies, staining quality, interpretation of stained slides, conclusions, and final diagnosis. Diagnosis-independent immunohistochemical performance was tested using a multisample tissue block (30 samples) that was stained and evaluated for six common antigens. For individual cases, corresponding to their difficulty, 21-89% of the final diagnoses (altogether 57% from 828 diagnoses) were correct. In a statistical analysis, the tentative diagnosis, the interpretation of stains and conclusions drawn from immunohistochemistry, were independent factors in reaching the diagnosis. Sensitivity to detect estrogen receptors on the multisample tissue block was only 48%. However, 24% of the stains were interpreted as falsely negative. The low staining sensitivity was not correlated to the number of correct diagnoses. The major problem of applying immunohistochemistry in surgical pathology appears to be its integration into the diagnostic process and not the staining quality. Both future quality control projects and training will have to regard these integrative requirements. Multisample tissue blocks provide a promising tool to standardize quantitative immunohistochemical parameters, such as receptor or proliferation scores.

Coloring Agents↗
PubMed2001

Cell hydration controls autophagosome formation in rat liver in a microtubule-dependent way downstream from p38MAPK activation.

Autophagic proteolysis in rat liver is under the control of the cellular hydration state. Because the morphological site of swelling-dependent proteolysis regulation has not yet been identified, the formation of autophagosomes was investigated with transmission electron microscopy in slices from perfused livers. In livers from fed rats, hypo-osmotic exposure (185 mosmol/l) led within 30 min to a decrease in fractional cytoplasmic autophagosome volume that was sensitive to colchicine and p38(MAPK) inhibition. Similarly, the decrease in autophagosome volume, but not the increase in cell volume caused by insulin or glutamine/glycine, was strongly inhibited by colchicine and SB 203580, an inhibition of p38(MAPK) activation. Immune complex assays from perfused liver showed that hypo-osmotic activation of p38(MAPK) was not inhibited by colchicine. Further, experiments using confocal laser microscopy in cultivated hepatocytes incubated with mouse-derived anti-(alpha-tubulin) showed that microtubular structures were not influenced by the inhibition of p38(MAPK) by SB 203580. It is concluded that the sequestration of autophagic vacuoles is a major site of proteolysis regulation by cell hydration. Swelling-induced activation of p38(MAPK) is required for this process and occurs upstream of the putative microtubule regulation site.

Animals↗
PubMed2001

Adverse health effects related to mercury exposure from dental amalgam fillings: toxicological or psychological causes?

BACKGROUND: Possible adverse health effects due to mercury released by amalgam fillings have been discussed in several studies of patients who attribute various symptoms to the effects of amalgam fillings. No systematic relation of specific symptoms to increased mercury levels could be established in any of these studies. Thus, a psychosomatic aetiology of the complaints should be considered and psychological factors contributing to their aetiology should be identified. METHODS: A screening questionnaire was used to identify subjects who were convinced that their health had already been affected seriously by their amalgam fillings (N = 40). These amalgam sensitive subjects were compared to amalgam non-sensitive subjects (N = 43). All participants were subjected to dental, general health, toxicological and psychological examinations. RESULTS: The two groups did not differ with respect to the number of amalgam fillings, amalgam surfaces or mercury levels assessed in blood, urine or saliva. However, amalgam sensitive subjects had significantly higher symptom scores both in a screening instrument for medically unexplained somatic symptoms (SOMS) and in the SCL-90-R Somatization scale. Additionally, more subjects from this group (50% versus 4.7%) had severe somatization syndromes. With respect to psychological risk factors, amalgam sensitive subjects had a self-concept of being weak and unable to tolerate stress, more cognitions of environmental threat, and increased habitual anxiety. These psychological factors were significantly correlated with the number and intensity of the reported somatic symptoms. CONCLUSIONS: While our results do not support an organic explanation of the reported symptoms, they are well in accord with the notion of a psychological aetiology of the reported symptoms and complaints. The findings suggest that self-diagnosed 'amalgam illness' is a label for a general tendency toward somatization.

Adult↗
PubMed2000

Segmental hepatic vein thrombosis associated with heparin-induced thrombocytopenia II.

We report the case of a 55-year-old man who developed heparin-induced thrombocytopenia II after a vertebral fracture. Autopsy revealed segmental hepatic vein thrombosis of the right lobe with subacute congestion and an activation of hepatic stellate cells. This case shows that heparin-induced thrombocytopenia II is a possible cause of the Budd-Chiari syndrome.

Anticoagulants↗
PubMed2000

[Perforation of mucocele-like transformed Hartmann stump].

We report an unusual complication in a 53-year-old woman following ileostomy for Crohn's disease 22 years previously. A stenosis of the distal colonic segment was the reason for the formation and subsequent rupture of a huge colonic mucocele. To our knowledge, this is the first report of a ruptured mucocele of colonic origin after ileostomy.

Colon↗
PubMed2000

Fatal pneumonia in an AIDS patient coinfected with adenovirus and Pneumocystis carinii.

BACKGROUND: Adenovirus infections are common in immunocompromised hosts. However, pulmonary adenovirus infections rarely cause significant morbidity in HIV-infected patients. PATIENT: Here we describe a 27-year-old man with AIDS who presented with tachypnea, hypoxemia and an infiltrate in the upper left lobe on chest X-ray. Bronchoscopy was performed and Pneumocystis carinii was detected in bronchoalveolar lavage (BAL) fluid. Treatment with cotrimoxazole and prednisone initially resulted in improvement, but after 10 days the patient's clinical condition deteriorated rapidly and he died after 23 days due to respiratory failure. RESULTS: On autopsy histopathologic examination showed abundant "smudge cells," suggestive of adenoviral infection. Electron microscopy revealed adenovirus-like particles arrayed in a paracrystalline manner. Subsequent immunohistochemistry confirmed the extensive presence of adenovirus in addition to P. carinii. CONCLUSION: This case demonstrates a pathogenetic role for adenovirus coinfection in P. carinii pneumonia (PCP). Earlier diagnosis, e.g. by PCR analysis of the BAL fluid or transbronchial biopsy, might have led to the consideration of ribavirin treatment.

AIDS-Related Opportunistic Infections↗
PubMed2000

Hepatocellular alterations after intraportal transplantation of ovarian tissue in ovariectomized rats.

The mechanisms of hepatocarcinogenesis by certain synthetic estrogens seem to involve both nongenotoxic and indirect genotoxic effects. However, the natural estrogen estradiol did not exert any carcinogenic effects in established experimental protocols. To elucidate specific long-term effects of natural estrogens on hepatocytes, small pieces of ovarian tissue were transplanted via the portal vein into the livers of ovariectomized female rats. One week, 3 weeks, and 3 months after transplantation the transplants were found to proliferate and to secrete estradiol. Three weeks after transplantation the hepatocytes of the liver acini downstream of the stimulated transplants already showed a remarkable loss of glycogen, distinct cytoplasmic amphophilia, enlargement of their nuclei, a strong increase in the number and size of peroxisomes, an increase in proliferative activity and apoptotic elimination, and changes in the activity of certain key enzymes of energy metabolism. All hepatocellular alterations could be inhibited by the estrogen receptor antagonist toremifene and are, therefore, attributed to specific effects of estradiol produced by the transplants. The observed alterations resemble in some respects amphophilic preneoplastic liver foci, which particularly occur after long-term administration of nongenotoxic hepatocarcinogens, including the adrenal steroid hormone dehydroepiandrosterone. In a preliminary experiment three of six animals exhibited a hepatocellular carcinoma, and another animal developed a hepatocellular adenoma 18 months after intrahepatic ovarian tissue transplantation.

Adenoma↗
PubMed2000

Angiotropic large-cell lymphoma presenting as pulmonary small vessel occlusive disease.

Angiotropic lymphoma (AL) is an unusual variant of extranodal lymphoma, characterized by massive proliferation of neoplastic lymphoid cells almost exclusively within blood vessels. Whereas the lymphoid origin of this disease is widely accepted it still remains unclear whether AL is a distinct entity that originates in the blood vessels or whether it represents a form of secondary intravascular dissemination of a primary solid lymphoma. The present case is unusual because death by right heart failure owing to extensive intravascular proliferation of neoplastic cells and subsequent occlusion of pulmonary blood vessels has not been described so far. In addition, the patient had suffered from a solid deposit of a large-cell B-lymphoma months before the angiotropic manifestation, suggesting that AL might develop out of more common types of non-Hodgkin's lymphomas.

Aged↗
PubMed2000

Breast MR imaging screening in 192 women proved or suspected to be carriers of a breast cancer susceptibility gene: preliminary results.

PURPOSE: To compare magnetic resonance (MR) imaging with conventional imaging in screening high-risk women. MATERIALS AND METHODS: This prospective trial included 192 asymptomatic and six symptomatic women who, on the basis of personal or family history or genetic analysis, were suspected or proved to carry a breast cancer susceptibility gene. RESULTS: Fifteen breast cancers were identified: nine in the 192 asymptomatic women (six in the first and three in the second screening round) and six in the symptomatic patients. Concerning the asymptomatic women, four of the nine breast cancers were detected and correctly classified with mammography and ultrasonography (US) combined; another two cancers were visible as well-circumscribed masses and were diagnosed as fibroadenomas. MR imaging allowed the correct classification and local staging of all nine cancers. In 105 asymptomatic women with validation of the 1st-year screening results, the sensitivities of mammography, US, and MR imaging were 33%, 33% (mammography and US combined, 44%), and 100%, respectively; the positive predictive values were 30%, 12%, and 64%, respectively. CONCLUSION: The accuracy of MR imaging is significantly higher than that of conventional imaging in screening high-risk women. Difficulties can be caused by an atypical manifestation of hereditary breast cancers at both conventional and MR imaging and by contrast material enhancement associated with hormonal stimulation.

Adult↗
PubMed2000

Are morphological or functional changes in the carotid artery wall associated with Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, or herpes simplex virus infection?

BACKGROUND AND PURPOSE: Chronic infection with Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus (CMV), and herpes simplex virus (HSV) has been implicated in the pathogenesis of atherosclerosis. The carotid intima-media thickness (IMT) can be taken to indicate early atherosclerosis, the presence of a carotid stenosis is a marker of a manifest carotid atherosclerosis, and an increase in arterial stiffness is used as marker of structural and functional changes in an atherosclerotic vessel wall. METHODS: In 504 patients (75% men; mean age 62.9 [SD 10] years), we measured the IMT and the elastic pressure modulus (EP; n=445) of the common carotid artery and the prevalence of a internal or external carotid artery stenosis. Blood samples were taken, and antibodies against C pneumoniae, H pylori, CMV, and HSV types 1 and 2 were evaluated. Statistical evaluation was performed with regression procedures and multivariate logistic regression analyses. RESULTS: Seropositivity for C pneumoniae was an independent predictor for a combined end point of highest category of IMT and carotid artery stenosis (OR 1.8, 95% CI 1.1 to 3.1; adjusted) for IgG titers. Independently, CMV increased the risk for the combined end point (OR 1.7, 95% CI 1.1 to 2.8; adjusted) for IgG titers and for IgA titers (OR 2.3, 95% CI 1.1 to 4. 9; adjusted). We found a significant correlation between IgG antibodies against CMV and EP; HSV type 2 IgG titers were associated with IMT and carotid stenosis, but the latter results were no longer significant after adjustment. There was no association with H pylori or HSV type 1. CONCLUSIONS: We found a significant association of IgG antibodies against C pneumoniae and CMV with early and advanced carotid atherosclerosis. CMV was also correlated to functional changes of the carotid artery, but this could not be confirmed after adjustment.

Arteriosclerosis↗
PubMed1999

Evaluation of different models of experimentally induced liver cirrhosis for MRI research with correlation to histopathologic findings.

RATIONALE AND OBJECTIVES: Three models of experimentally induced liver cirrhosis were evaluated for MRI research on chronic liver disease. The influence of different histopathologic changes in liver fibrosis and cirrhosis on relaxation times and signal intensities was studied in vitro and in vivo. METHODS: Liver fibrosis and cirrhosis in rats was induced by oral or subcutaneous administration of carbon tetrachloride (CCl4) or by thioacetamide (TAA) in drinking water. On histology, the degree of liver fibrosis and cirrhosis, fatty infiltration, iron accumulation, and inflammatory changes were measured semiquantitatively. The amount of connective tissue was quantitatively determined by morphometry. The results were correlated with T1 and T2 relaxation times and signal intensities of the liver studied in vitro by relaxometry and in vivo by MRI. RESULTS: In both groups with CCl4 administration, histology revealed different degrees of liver fibrosis and cirrhosis. Subcutaneous injection of CCl4 also resulted in increased fatty infiltration. On the contrary, TAA produced complete liver cirrhosis in all animals. Overall, there was a good correlation between the liver T2 relaxation time and the amount of connective tissue in liver fibrosis and cirrhosis. However, the degree of liver fibrosis and cirrhosis was also strongly correlated with the degree of inflammatory changes. In the group with CCl4 administration, there was a good correlation between the fatty infiltration and the T1 relaxation time, as well as with the liver signal intensity on the T1-weighted gradient echo sequence. An increased iron accumulation was also correlated with the degree of liver fibrosis/cirrhosis; however, there was no significant influence of the iron on relaxation times or signal intensities. CONCLUSIONS: The TAA model is easier to perform and more reliable in liver cirrhosis induction than the CCl4 models. Although there is a positive correlation between the T2 relaxation times and the degree of liver fibrosis/cirrhosis, this probably results from the associated inflammatory changes and is not caused by the increased amount of connective tissue.

Animals↗
PubMed1998

[Löffler fibroblastic endocarditis in the thrombotic stages in isolated right ventricular tissue eosinophilia].

We report on a male, 31 year old, Turkish patient with an intracardiac mass in the right ventricle, reduction of performance and weight, as well as intermittent fever. No eosinophilia was documented in the peripheral blood; cardiac function was primarily normal. Besides the differential diagnosis of Löffer's endocarditis (endomyocardial fibrosis) an inflammatory disease and a malignant cardiac tumor were suggested. The diagnosis of Löffler's endocarditis could not be confirmed morphologically by echocardiography nor histologically by right ventricular biopsy. Operative removal of the mass lesion was necessary because of fast tumor progression, fulminant pulmonary embolism, and infiltration of the tricuspid valve. Only then, histologically Löffler's eosinophilic endocarditis of thrombotic stage was diagnosed. Antiphlogistic therapy with cortisone was initially performed. With a dose reduction after 6 months, a relapse of the thrombotic mass occurred. Therefore, continuous treatment with cortisone and azathioprine was induced followed by further tumor regression and further clinical stabilization since 8 months of treatment.

Adult↗
PubMed1998

Argyrophilic nucleolar organizer region counts in squamous cell carcinomas of the head and neck after irradiation and chemotherapy.

After irradiation or chemotherapy of tumors of the head and neck, histological alterations might be difficult to assess. In 30 cases of squamous cell carcinomas of the pharynx, changes in argyrophilic nucleolar organizer region (AgNOR) counts were investigated after therapy. After treatment a significant decrease of AgNOR counts was detected (P < 0.001). No significant differences could be found between groups treated with radiotherapy, chemotherapy or a combination of radiotherapy and chemotherapy. These findings suggest that AgNOR counts might be useful to assess cytotoxic effects on a subcellular level.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Nonparenchymal cells in chronically hyperinsulinemic liver acini of diabetic rats, with special regard to hepatic stellate cells.

BACKGROUND/AIMS: An increase in proliferative activity and other distinct hepatocellular alterations--resembling preneoplastic foci and progressing to hepatocellular tumors--have been shown to develop in liver acini draining the blood from islets of Langerhans, transplanted through the portal vein into the liver of streptozotocin-diabetic rats. METHODS: Altered and unaltered liver acini were investigated for possible changes in hepatic stellate cells 4-76 days after islet transplantation. RESULTS: Corresponding to a significant increase in the hepatocellular volume, the volume density of total nonparenchymal cells was significantly reduced in altered compared to unaltered liver acini. With regard to the total nonparenchymal cell volume, the hepatic stellate cell fraction was not different, whereas the fraction of Kupffer cells was significantly reduced and the fraction of sinusoidal endothelial cells was significantly increased in altered compared to unaltered liver acini, respectively. The volume density as well as the single volume of the hepatic stellate cell mitochondria increased significantly in altered compared to unaltered liver acini. Hepatic stellate cell lipid droplets did not show significant differences between altered and unaltered liver acini. In situ hybridization for hepatocyte growth factor mRNA showed no differences in intensity of the specific signals in hepatic stellate cells of altered versus unaltered liver acini. The transplanted islets were negative for hepatic growth factor mRNA. CONCLUSIONS: The results suggest that hepatic growth factor production by hepatic stellate cells or by islet cells is not relevant to hepatocellular proliferative activity in altered liver acini.

Animals↗