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Biomedical subjects

M Pauschinger

Publications and source records attributed to M Pauschinger.

At least 37 records · Page 2Linked to original sources

Human coxsackie-adenovirus receptor is colocalized with integrins alpha(v)beta(3) and alpha(v)beta(5) on the cardiomyocyte sarcolemma and upregulated in dilated cardiomyopathy: implications for cardiotropic viral infections.

BACKGROUND: The coxsackievirus and adenovirus receptor (CAR) was identified as a common cellular receptor for both viruses, but its biological and pathogenic relevance is uncertain. Knowledge of CAR localization in the human cardiovascular system is limited but important with respect to CAR-dependent viral infections and gene transfer using CAR-dependent viral vectors. METHODS AND RESULTS: Explanted failing hearts from 13 patients (8 with dilated cardiomyopathy [DCM] and 5 with other heart diseases [non-DCM]) and normal donor hearts (n=7) were investigated for the expression levels and subcellular localization of CAR and the adenovirus coreceptors alpha(v)beta(3) and alpha(v)beta(5) integrins. CAR immunoreactivity was very low in normal and non-DCM hearts, whereas strong CAR signals occurred at the intercalated discs and sarcolemma in 5 of the 8 DCM hearts (62.5%); these strong signals colocalized with both integrins. In all hearts, CAR was detectable in subendothelial layers of the vessel wall, but not on the luminal endothelial surface, and on interstitial cells. Human CAR (hCAR) expressed in rat cardiomyocytes was targeted to cell-cell contacts, which resembled CAR localization in DCM hearts and resulted in 15-fold increased adenovirus uptake. CONCLUSIONS: Low hCAR abundance may render normal human myocardium resistant to CAR-dependent viruses, whereas re-expression of hCAR, such as that observed in DCM, may be a key determinant of cardiac susceptibility to viral infections. Asymmetric expression of hCAR in the vessel wall may be an important determinant of adenovirus tropism in humans. hCAR subcellular localization in human myocardium and hCAR targeting to cell-cell contacts in cardiomyocyte cultures suggest that hCAR may play a role in cell-cell contact formation.

Adenoviridae↗

Enteroviral and immune mediated myocarditis in SCID mice.

Severe combined immune deficiency (SCID) mice have been used as an animal model to study both the direct cytopathic effect of enteroviruses on the heart in the absence of an effective immune system and to investigate the role of immune mediated processes in the pathogenesis of human myocarditis. The infection of SCID mice with coxsackievirus B3 resulted in severe myocarditis with very high titers of the virus in the myocardium and severe necrosis of myocytes. This direct cytopathic effect caused an impairment of the myocardial function and resulted in a high mortality rate of the infected animals. For the study of the immune mechanisms in human myocarditis, peripheral blood leukocytes of patients with myocarditis, having an impaired left ventricular function without viral persistence in the myocardium, were transferred into SCID mice. As controls peripheral blood leukocytes of normal donors were used. At 60 days after transfer, human immunoglobulines could be demonstrated in the peripheral blood of the SCID mice, however, human autoantibodies against the adenine nucleotide translocator, a myocardial autoantigen, were only present in the animals receiving peripheral blood leukocytes from patients with myocarditis. Cellular infiltrates of human leukocytes in the myocardium and an impaired left ventricular function were also only observed in animals reconstituted with peripheral blood leukocytes from patients. These effects were T cell dependent as shown by differential transfer. These results are of interest for the treatment of human myocarditis, suggesting the avoidance of an immunosuppressive therapy in acute or chronic myocarditis with viral persistence to prevent a direct cytopathic effect in the absence of an effective immune system. However, in the setting of a chronic, (auto-)immunological myocarditis with the proven absence of entero- or adenoviral sequences an immunomodulatory therapy seems to be effective and safe.

Animals↗

The shift in the myocardial adenine nucleotide translocator isoform expression pattern is associated with an enteroviral infection in the absence of an active T-cell dependent immune response in human inflammatory heart disease.

OBJECTIVES: This study evaluates the relevance of an enteroviral infection and the intramyocardial T-cell immune response for the alteration in the adenine nucleotide translocator isoform transcription pattern (ANTitp) in patients suspected of having myocardial inflammation. BACKGROUND: The ANT, the only mitochondrial carrier for ADP and ATP, plays a significant role in the energy metabolism and is involved in the apoptosis process. Its function and expression were found to be altered in the myocardium of patients with dilated cardiomyopathy and myocarditis. METHODS: The ANTitp was analyzed in endomyocardial biopsies from 53 patients with clinically suspected inflammatory heart disease (csIHD). Enteroviral RNA was detected in the biopsies using the reverse transcripted polymerase chain reaction technique. The activation of the cellular immune system was assessed by the quantification of T-lymphocytes employing immunohistochemistry. RESULTS: The ANTitp was found to be altered in 21 csIHD patients. Enteroviral genome was found in the heart of 71.4% of these patients, but only 37.5% of the patients with a normal ANTitp were virus-positive (p < 0.02). The infiltration with CD3+, CD45R0+ and CD8+ T-cells was substantially lower in myocardial specimens with an altered ANTitp than in biopsies with a normal ANTitp. Combining the data, an altered ANTitp was primarily found in virus-positive heart tissue, which was less infiltrated with lymphocytes or not at all. CONCLUSIONS: An enteroviral infection is linked to changes in the ANT isoform expression in human heart tissue, which shows little or no evidence of an active T-cell dependent immune response. These results make a contribution to a better understanding of the pathophysiology of enterovirus-induced human inflammatory heart disease.

Adult↗

Trans-complementation of vector replication versus Coxsackie-adenovirus-receptor overexpression to improve transgene expression in poorly permissive cancer cells.

Gene therapy of cancer requires high-level expression of therapeutic transgenes in the target cells. Poor gene transfer is an important limitation to adenovector-mediated cancer gene therapy. We investigated two fundamentally different approaches to improve transgene expression in poorly permissive cancer cells. First, overexpression of the adenovirus attachment receptor CAR to facilitate receptor-mediated adenovector (AdV) uptake into the target cells; second, co-infection of this vector together with traces of replication competent adenovirus (RCA) accidentally arising by back-recombination during large-scale vector preparation. Among eight gastrointestinal cancer cell lines, the colorectal cancer lines showed particularly poor vector-mediated transgene expression (down to 67-fold lower than in HeLa cells). Expression of the adenovirus receptors CAR, alpha(v)beta5- and alpha(v)beta3-integrin were highly variable between cell lines. AdV uptake was significantly associated with CAR levels on the cell surface, but not with those of the integrins. AdV-mediated CAR overexpression increased CAR density on the surface of all investigated tumor cells and led to enhancement of transgene expression by 1.8- to 6.7-fold. The other principle to enhance transgene expression was 'trans-complementation' of the therapeutic vector, ie induction of its replication within the target cells. Traces of RCA in a vector preparation, as well as purified RCA were found to provide sufficient E1-region transcripts to induce replication of the therapeutic vector genome. The number of adenovector-based transgene expression cassettes was greatly amplified by this principle, notably without any influence on the rate of vector entry. Co-infection of four colorectal cancer cell lines with marker vector plus RCA (at around 240:1 particle ratio) resulted in far stronger enhancement of transgene expression (up to 46-fold) as compared with CAR overexpression, even in cancers almost refractory to standard adenovector-mediated gene transfer. Whereas RCAs need to be strictly avoided in gene therapy of non-malignant diseases for safety reasons, the magnitude of helper virus-induced therapeutic transgene expression could possibly warrant application of this principle to overcome the resistance of highly malignant cancers against gene therapy.

Adenoviridae↗

The possible role of myocardial biopsy in systemic sclerosis.

The histopathological features of heart involvement in systemic sclerosis (SSc) are not widely known. In internal and transplantation medicine, myocardial biopsies are increasingly used to diagnose cardiomyopathies including myocarditis. In two SSc patients presenting with dyspnoea with no evidence of pulmonary involvement, the cause of the compromised heart function was sought by myocardial biopsy. Immunohistological analysis revealed an increased number of CD3+ + T cells indicating myocarditis in one, and increased amounts of fibroblasts in both SSc patients. The authors think that myocardial involvement in SSc should be differentially evaluated and they propose the use of myocardial biopsies as a tool to distinguish between inflammatory and fibrotic forms of heart involvement in SSc patients.

Biopsy↗

Dilated cardiomyopathy is associated with significant changes in collagen type I/III ratio.

BACKGROUND: It is controversial whether myocardial fibrosis in end-stage dilated cardiomyopathy (DCM) is associated with altered collagen type I/type III (Col I/Col III) ratio. METHODS AND RESULTS: Patients with DCM (ejection fraction [EF] <50%, n=12) and with mild global left ventricular dysfunction (EF >50%, n=18) were examined. Col I, Col III, and transforming growth factors-beta1 (TGF-beta1) and -beta2 (TGF-beta2) gene expression in endomyocardial biopsies was evaluated by quantitative competitive reverse transcriptase-polymerase chain reaction (qRT-PCR). Collagen content was quantified after picrosirius red and immunohistological staining and by hydroxyproline assay. In patients with EF <50%, there was a pronounced 2- to 6-fold increase of myocardial Col I mRNA abundance (P<0.01), with a corresponding 1.6-fold increase at the protein level versus that found in patients with EF >50%. The Col III mRNA abundance showed a 2.0-fold increase (P<0.04). There was a relevant shift in the Col I/Col III mRNA ratio for DCM patients (Col I/Col III, 8.2) compared with patients with an EF >50% (Col I/Col III, 6. 4). In addition, total collagen content was increased in patients with EF <50% (n=3) (4.3+/-0.1%) compared with patients with EF >50% (n=8) (2.7+/-0.9%) (P<0.004). The biochemically determined ratio of hydroxyproline/total protein (n=12) was correlated to the Col I mRNA abundance (P<0.05, r=0.77). TGF-beta1 and TGF-beta2 showed elevated myocardial mRNA abundances (1- to 7-fold and 4- to 5-fold, respectively) in DCM patients. CONCLUSIONS: Differential increase of Col I and Col III leads to an increased Col I/Col III ratio in DCM myocardium. Because Col I provides substantial tensile strength and stiffness, this may contribute to systolic and in particular diastolic dysfunction in DCM.

Biopsy↗

Detection of adenoviral genome in the myocardium of adult patients with idiopathic left ventricular dysfunction.

BACKGROUND: The use of molecular biological techniques has demonstrated the importance of enteroviral infection of the myocardium in the pathogenesis of myocarditis and dilated cardiomyopathy in adults and adenovirus and enterovirus infection in children. The aim of this study was to determine the frequency of adenoviral infection of the myocardium of adults with impaired left ventricular function of unknown origin. METHODS AND RESULTS: Nested polymerase chain reaction (nPCR) was used to determine the frequency of detection of adenoviral DNA and enteroviral RNA in myocardial tissue samples from 94 adult patients with idiopathic left ventricular dysfunction and 14 control patients. Histological and immunohistological analyses were performed to detect myocardial inflammation. Adenoviral genomic DNA was detected by nPCR in 12 of the 94 patients with left ventricular dysfunction (in each case, adenovirus type 2), whereas enteroviral RNA was detected in another 12 patients. All control samples were negative for both viruses. In all patients, active myocarditis was excluded according to the Dallas criteria. However, there was significantly decreased CD2, CD3, and CD45RO T lymphocyte counts in the adenovirus-positive group compared with the adenovirus-negative group (P<0.05), whereas no differences were associated with enterovirus infection. CONCLUSIONS: Although enteroviruses are an important causative agent in the pathogenesis of myocarditis and dilated cardiomyopathy, this study shows that adenovirus infection is also important in the pathogenesis of left ventricular failure in adults. However, the pathogenetic basis of disease associated with adenovirus infection may be different than that after infection with other agents, particularly with respect to activation of the host immune response.

Adenoviridae Infections↗

Enteroviral RNA replication in the myocardium of patients with left ventricular dysfunction and clinically suspected myocarditis.

BACKGROUND: Previous studies dealing with the detection of enteroviral RNA in human endomyocardial biopsies have not differentiated between latent persistence of the enteroviral genome and active viral replication. Enteroviruses that are considered important factors for the development of myocarditis have a single-strand RNA genome of positive polarity that is transcribed by a virus-encoded RNA polymerase into a minus-strand mRNA during active viral replication. The synthesis of multiple copies of minus-strand enteroviral RNA therefore occurs only at sites of active viral replication but not in tissues with mere persistence of the viral genome. METHODS AND RESULTS: We investigated enteroviral RNA replication versus enteroviral RNA persistence in endomyocardial biopsies of 45 patients with left ventricular dysfunction and clinically suspected myocarditis. Using reverse-transcriptase polymerase chain reaction in conjunction with Southern blot hybridization, we established a highly sensitive assay to specifically detect plus-strand versus minus-strand enteroviral RNA in the biopsies. Plus-strand enteroviral RNA was detected in endomyocardial biopsies of 18 (40%) of 45 patients, whereas minus-strand RNA as an indication of active enteroviral RNA replication was detected in only 10 (56%) of these 18 plus-strand-positive patients. Enteroviral RNA was not found in biopsies of the control group (n=26). CONCLUSIONS: These data demonstrate that a significant fraction of patients with left ventricular dysfunction and clinically suspected myocarditis had active enteroviral RNA replication in their myocardium (22%). Differentiation between patients with active viral replication and latent viral persistence should be particularly important in future studies evaluating different therapeutic strategies. In addition, molecular genetic detection of enteroviral genome and differentiation between replicating versus persistent viruses is possible in a single endomyocardial biopsy.

Adult↗

Transcription of the adenine nucleotide translocase isoforms in various types of tissues in the rat.

Two different isoforms of the adenine nucleotide translocase (ANT1 and ANT2) have been identified in the rat. In order to obtain enhanced knowledge of the ANT isoform expression, we analyzed the transcription pattern of both isoforms and their mRNA levels in various tissues of the rat using the PCR technique. A predominant ANT1 mRNA percentage was recorded in the skeletal muscle, heart and brain, ranging from 81 to 58%. In contrast to these tissues, the percentages of ANT2 were dominant with a range from 59 to 75% in the kidney, lung, spleen and liver. The level of total ANT mRNA varied markedly in the various organs. Tissues with a dominant ANT1 percentage simultaneously showed a high level of total ANT transcription (24-41 attomol/ng total RNA). In comparison to the latter, tissues with a prevalent ANT2 transcription were shown to have an even lower ANT transcription level (2-5 attomol/ng total RNA). The predominance of the ANT1 expression appeared to be restricted to tissues with an inability to regenerate by means of mitotic division, whereas a prevalent ANT2 transcription is found in cell types able to proliferate. The level of total ANT transcription but not the individual ANT isoform expression depends to a great extent on the energy requirements of the tissue.

Animals↗

Expression of coxsackie adenovirus receptor and alphav-integrin does not correlate with adenovector targeting in vivo indicating anatomical vector barriers.

Recombinant adenoviral vectors are broadly applied in gene therapy protocols. However, adenovector-mediated gene transfer has limitations in vivo. One of these is the low gene transfer rate into organs other than the liver after systemic intravenous vector injection. Local direct injection into the target organ has been used as one possible solution, but increases necessary equipment and methodology and is traumatic to the target. Wild-type adenovirus infection as well as adenovector-mediated gene transfer depends on virus interaction with the Coxsackie adenovirus receptor (CAR) mediating virus attachment to the cell surface, and on interaction with alphavbeta3 and alphavbeta5 integrins mediating virus entry into the cell. In order to assess the receptor-associated potential of different tissues to act as adenovector targets, we have therefore determined CAR and alphav-integrin expression in multiple organs from different species. In addition, we have newly determined several human, rat, pig and dog CAR-mRNA sequences. Sequence comparison and structural analyses of known and of newly determined sequences suggests a potential adenovirus binding site between amino acids 29 and 128 of the CAR. With respect to the virus receptor expression patterns we found that CAR-mRNA expression was extremely variable between different tissues, with the highest levels in the liver, whereas alphav-integrin expression was far more homogenous among different organs. Both CAR and alphav-integrin showed similar expression patterns among different species. There was no correlation, however, between the adenovector expression patterns after intravenous, intracardiac and aortic root injection, respectively, and the virus receptor patterns. In summary, many organs carry both receptors required to make them potential adenovector targets. In sharp contrast, their actual targeting clearly indicates that adenovirus receptor expression is necessary but not sufficient for vector transfer after systemic injection. The apparently very important role of anatomical barriers, in particular the endothelium, requires close attention when developing non-traumatic, organ-specific gene therapy protocols.

Adenoviridae↗

[Syncope in 3rd degree atrioventricular block. Detection of virus genome in the myocardium].

HISTORY AND CLINICAL FINDINGS: A 28-year-old woman was admitted after syncope which had been preceded by several flulike episodes. There was no history of any other serious disease. Physical examination was unremarkable. Heart sounds were regular and normal, there were no murmurs. INVESTIGATIONS: White cell count was 9400/microliter, with a normal differential count. Erythrocyte sedimentation rate and C-reactive protein were also normal. Virus serology revealed no abnormality. The electrocardiogram (ECG) showed complete (third degree) atrioventricular (AV) block with an idioventricular rhythm of 38 beats/min and right bundle branch block pattern. TREATMENT AND COURSE: A temporary transvenous pacemaker was inserted on the first hospital day. As myocarditis was suspected a right ventricular endomyocardial biopsy was obtained. Histological and immunohistological examinations demonstrated no unequivocal findings. But molecular-biological tests revealed. Coxsackie-B3 virus genome. The pacemaker was removed on the 6th day, when the ECG had shown intermittent second degree AV block. Regular sinus rhythm with a PR interval of 0.18 s was recorded on day 12, and 24-hour ECG monitoring for several days until her discharge on the 18th day confirmed this rhythm throughout. CONCLUSION: In aetiologically undetermined disease molecular-biological techniques can be indispensable for the exact diagnosis and may be decisive for administering specific treatment.

Adult↗

[Pathogenesis of inflammatory cardiomyopathies].

The development of dilated cardiomyopathy from chronic myocarditis is caused by the persistence of enteroviral infections and chronic myocardial inflammation. New molecularbiological and immunohistochemical techniques improve diagnosis and allow predictions of the development of the disease. This facilitates the decision for a specific immunomodulatory therapy.

Adjuvants, Immunologic↗

[Cardiac troponin T in the diagnosis and follow up of suspected myocarditis].

BACKGROUND AND OBJECTIVE: Results of routine laboratory tests for demonstrating myocardial damage in patients suspected of having myocarditis are often negative. This study was undertaken to ascertain (1) whether measuring Tropinin T (cTnT) in these patients can sensitively determine myocardial cell death, (2) to what extent this correlates with the findings of endomyocardial biopsy, and (3) whether measurement of cTnT can provide noninvasive assessment of the course of myocarditis. PATIENTS AND METHODS: 80 consecutive patients (52 men, 28 women) with clinically suspected myocarditis were investigated. The main clinical symptoms were heart failure (n = 45), angina pectoris (n = 25) or cardiac arrhythmias (n = 10). In most patients the symptoms had developed in temporal relation to a viral infection. Coronary heart disease was excluded in all by coronary angiography. Interventricular septal endomyocardial biopsies were examined histologically and immunohistologically. cTnT was measured with a highly sensitive sandwich-immunoassay. RESULTS: An increased level of cTnT (> 0.1 ng/ml) was demonstrated in 28 of the 80 patients (35%). Myocarditis was diagnosed histologically in only 5 patients, but immunohistologically in 26 of 28 (93%) with a raised cTnT level and in 23 of 52 (44%) with a normal cTnT level. The cTnT level was more frequently elevated in patients with a brief rather than a long history of myocarditis. After 6 months the cTnT level was elevated in only 4 of 28 patients with myocarditis, but the myocardial biopsy showed persisting myocarditis in 14 patients. CONCLUSION: Measurement of cTnT is a very sensitive way of demonstrating myocardial cell damage in patients clinically suspected of having myocarditis. Immunohistological analysis can often provide positive results even if the histological findings are unremarkable. The sensitivity in diagnosing of cTnT is greatest when the patient is tested shortly after the onset of symptoms.

Acute Disease↗

[Biphasic course of left ventricular dysfunction in a 22-year-old female with acute myocarditis].

HISTORY AND CLINICAL FINDINGS: Two days before admission a 22-year-old woman developed general fatigue, nausea, headache and retrosternal pain. Physical examination was unremarkable. INVESTIGATIONS: Erythrocyte sedimentation rate was increased to 20/48, C-reactive protein to 3.3 mg/dl, and there was evidence of myocardial damage (creatine kinase 609 U/l, creatine kinase-MB 42 U/l, troponine T 8.39 ng/ml); ST-segment elevations in I, II, III, aVF and V-V6 of the ECG. Echocardiography revealed clearly thickened myocardium, moderate but haemodynamically not significant pericardial effusion, as well as impaired left ventricular function. Antimyosin scintigraphy was very abnormal. Cardiac catheterization confirmed the left ventricular dysfunction, rise of left ventricular enddiastolic pressure to 17 mm Hg, and a markedly reduced cardiac output of 2.4 l/min. Myocardial biopsy showed severe myocarditis with marked myocytolysis and considerable lymphocytic infiltrations. Enteroviral RNA was demonstrated in the myocardium by polymerase chain reaction. TREATMENT AND COURSE: The haemodynamics became normal within only 3 days. Myocardial biopsy after 6 months was unremarkable histologically and immunohistologically, and left ventricular function was also normal. However, while after a further 12 months myocardial biopsy remained normal and no virus was demonstrated, there was definite, though moderate, impairment in left ventricular function, indicating a dilated cardiomyopathy. INTERPRETATION: Even when histological and immunohistological evidence of healing of an acute viral myocarditis has been achieved, with complete normalization of left ventricular function, a dilated cardiomyopathy may subsequently develop. The pathophysiological mechanism of this occurrence remains unknown.

Acute Disease↗

[Detection of enteroviral RNA in endomyocardial biopsies in inflammatory cardiomyopathy and idiopathic dilated cardiomyopathy].

The role of enteroviral myocardial infection in the development of dilated cardiomyopathy could only be substantiated after the introduction of molecular biological techniques (polymerase chain reaction, in-situ hybridization) in virological diagnostics of dilated cardiomyopathy. By using histological and especially immunohistological techniques for the detection of myocardial inflammation in patients with the tentative clinical diagnosis of dilated cardiomyopathy, a differentiation between inflammatory cardiomyopathy and idiopathic dilated cardiomyopathy on the basis of the WHO classification 1995 (31) was made. Inflammatory cardiomyopathy is defined by myocarditis in association with cardiac dysfunction and is diagnosed by established histological and especially immunohistological techniques. The combination of histological, immunohistological, and molecularbiological techniques enabled a subgroup analysis of the incidence of enteroviral myocardial RNA in patients with inflammatory cardiomyopathy in comparison to patients with idiopathic dilated cardiomyopathy. The study involved a total of 75 patients with impaired left ventricular function (EF < 50%) and the tentative clinical diagnosis of dilated cardiomyopathy. Right ventricular endomyocardial biopsies were obtained from all patients for further clarification of the cause of left ventricular functional disorder. All biopsies were analyzed for the presence of acute and chronic inflammatory myocardial alterations by histological ("Dallas" criteria) and immunohistological techniques (lymphocytic infiltrates, MHC antigen expression). Furthermore, each biopsy was examined by reverse transcriptase polymerase chain reaction (RT-PCR) in combination with Southern blot hybridization for the presence of enteroviral RNA. Active myocarditis was excluded in all patients by histological examination according to the "Dallas" criteria. Using immunohistological techniques, 26/75 patients (35%) had evidence for chronic inflammatory myocardial alterations in the sense of lymphocytic infiltrates (> or = 2,0 CD3 T-lymphocytes/ visual field at 400 magnification (HPF); > or = 7 CD3 T-lymphocytes/mm2). These patients were diagnosed as having inflammatory cardiomyopathy. To differentiate between patients with and without myocardial inflammation, cases with focal cellular infiltration and an average cell number between 2.5 and 2.0 CD3 T-lymphocytes/HPF and an increased expression of additional immune markers, i.e., MHC antigens, were not addressed in the group of patients with inflammatory cardiomyopathy. This is in contrast to Kühl et al (19). Consequently these patients were classified as patients with idiopathic dilated cardiomyopathy. These criteria of diagnosing myocardial inflammation were based on published results (20, 23, 26, 27, 49) and on our own control group (n = 85) (19) in which mean CD3 T-lymphocyte count/HPF in normal myocardial tissue were 0.7 (range 0.0-1.4). In addition, a subgroup analysis was performed of patients with a CD3 T-lymphocyte count > or = 3 CD3 T-lymphocytes/HPF (> or + 11 CD3 T-lymphocytes/mm2). The other 49/75 patients without myocardial inflammation (< 2.0 CD3 T-lymphocytes /HPF) were diagnosed as having idiopathic dilated cardiomyopathy. In 27/75 patients (36%), RT-PCR in combination with Southern blot hybridization revealed enteroviral RNA in the endomyocardial biopsies. The detection rate of enteroviral RNA did not differ between inflammatory cardiomyopathy (8/26 (31%)) and idiopathic dilated cardiomyopathy (19/49 39%)). In the subgroups of patients with a CD3 T-lymphocyte cell count > or = 3 CD3 T-lymphocytes/HPF (> or = 11 CD3 T-lymphocytes/mm2) (mean 4.4 +/-2.1 CD3 T-lymphocytes/HPF), three of the ten patients were enteroviral RNA positive (30%). In summary, the introduction of histological and immunohistological techniques in the extended diagnostics of dilated cardiomyopathy enables a subgroup analysis of the incidence of enteroviral myocardial RNA in

Adult↗

Differential myocardial abundance of collagen type I and type III mRNA in dilated cardiomyopathy: effects of myocardial inflammation.

OBJECTIVE: The collagen subtypes I (Col I) and III (Col III) are essential components of the cardiac extracellular matrix (ECM) maintaining the functional integrity of the heart. Histological, immunohistological, and biochemical studies, however, demonstrate characteristical changes of the ECM in dilated cardiomyopathy, myocarditis, ischemic cardiomyopathy, and hypertensive heart disease. METHODS: In order to investigate possible effects of inflammatory processes on mRNA abundance of Col I and Col III, we examined 24 patients with the presumptive clinical diagnosis of dilated cardiomyopathy (EF = 30 +/- 11%). 12 Patients were classified as idiopathic dilated cardiomyopathy without any evidence of myocardial inflammation; the remaining 12 patients were classified as inflammatory cardiomyopathy due to the immunohistologically documented inflammatory myocardial process. RESULTS: Quantification of reverse transcription polymerase chain reaction (RT-PCR) products revealed significant differences as to the mRNA abundance ratio Col III/Col I between subgroups of patients with inflammatory cardiomyopathy (1.16 +/- 0.18) and idiopathic dilated cardiomyopathy (2.77 +/- 0.65) regardless of left ventricular dysfunction (p < or = 0.05). CONCLUSION: It is not yet known, whether different Col III/Col I ratios differentially influence diastolic compliance. Our data suggest that inflammatory mechanisms seen in inflammatory cardiomyopathy influence the mRNA abundance of collagen subtypes I and III.

Adult↗

Cardiac troponin T in patients with clinically suspected myocarditis.

OBJECTIVES: The present study investigated whether myocyte injury can be assessed sensitively by measurement of serum levels of cardiac troponin T (cTnT) in patients with clinically suspected myocarditis and whether cTnT levels may predict the results of histologic and immunohistologic analysis of endomyocardial biopsy specimens. BACKGROUND: Conventionally used laboratory variables often fail to show myocyte injury in patients with clinically suspected myocarditis, possibly because of a low extent of myocardial injury in these patients. Sensitive variables for myocyte injury have not yet been investigated. METHODS: Eighty patients with clinically suspected myocarditis were screened for creatine kinase (CK) activity, MB isoform of CK (CK-MB) activity and cTnT. Endomyocardial biopsy specimens were examined histologically and immunohistologically. RESULTS: cTnT was elevated in 28 of 80 patients with clinically suspected myocarditis, CK in 4 and CK-MB in 1. Histologic analysis alone of the endomyocardial biopsy specimen revealed evidence of myocarditis in only five patients, all with elevated cTnT levels. Twenty-three of 28 patients with elevated cTnT levels had histologically negative findings for myocarditis. Additional immunohistologic analysis revealed evidence of myocarditis in 26 (93%) of 28 patients with elevated cTnT levels and in 23 (44%) of 52 patients with normal cTnT levels. Mean cTnT levels were higher in patients with myocarditis proved histologically or immunohistologically, or both, than in patients without myocarditis (0.59 +/- 1.68 vs. 0.04 +/- 0.05, p < 0.001). CONCLUSIONS: Measurement of serum levels of cTnT provides evidence of myocyte injury in patients with clinically suspected myocarditis more sensitively than does conventional determination of cardiac enzyme levels. Myocardial cell damage may be present even in the absence of histologic signs of myocarditis. Additional immunohistologic analysis often shows lymphocytic infiltrates in these patients. Elevated levels of cTnT are highly predictive for myocarditis in this group.

Adolescent↗

Tissue-specific transcription pattern of the adenine nucleotide translocase isoforms in humans.

Three adenine nucleotide translocase isoforms (ANT1, ANT2 and ANT3) are coded by different genes. The relative amounts of the three ANT isoform mRNAs were determined in detail in various human tissues. ANT isoforms were co-expressed in all tested tissues revealing tissue-specific transcription patterns. The highest ANT1 mRNA proportions were found in terminally differentiated tissues like skeletal muscle, heart and brain, whereas ANT2 was mainly expressed in tissues capable of proliferation and regeneration as in the kidneys, spleen, liver, fibroblasts and lymphocytes. The ANT3 mRNA proportion was not prominently expressed in any of the tissues tested. In conclusion, tissue-specific expression of ANT isoforms is strongly related to the state of cellular differentiation.

Brain↗