1/5. in situ hybridization of mitochondrial dna in the heart of a patient with kearns-sayre syndrome and dilatative cardiomyopathy.Previous studies have revealed cytochrome-c-oxidase-deficient cardiomyocytes and the 4,977 base pair deletion ("common deletion") of mitochondrial dna (position 8,482-13,459) in the heart of a patient with dilatative cardiomyopathy and kearns-sayre syndrome. In the present investigation the co-localization of the enzymatic and genomic defects was studied. in situ hybridization of mitochondrial dna (mtDNA) revealed different hybridization patterns in the cytochrome-c-oxidase-deficient cells: (1) a selective reduction of the hybridization signal with an mtDNA probe recognizing the common deletion, indicating predominance of the deleted over the nondeleted mtDNA molecules in the cytochrome-c-oxidase-deficient cells; (2) a reduced hybridization signal with different mtDNA probes, indicating depletion of mtDNA; and (3) normal hybridization signals with different probes in single cytochrome-c-oxidase-deficient cardiomyocytes. These results indicate that different mechanisms may co-exist in kearns-sayre syndrome and may lead to defective respiratory chain function. The question of the pathogenetic interrelationship is discussed.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/5. Successful management of recurrent Epstein-Barr virus-associated multilocular leiomyosarcoma after cardiac transplantation.BACKGROUND: In contrast to Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disorders (PTLD), EBV-associated leiomyomatous tumors have thus far only rarely been described. CASE REPORT: Two years after heart transplantation with ATG induction, cyclosporine (CsA; trough levels of 250 ng/mL)-based triple drug immunosuppression), a 23-year-old patient developed a small round lesion within the left lateral liver segment. The patient underwent ultrasound-guided biopsy followed by liver resection. Histological and immunohistological examination showed a leiomyosarcoma. in situ hybridization using EBV-specific EB endoplasmic reticulum-rna showed an intensive signal in almost all tumor cells. The tumor stained for EB nuclear antigen (EBNA)-2-protein. immunosuppression was drastically reduced, namely, CsA levels <100 ng/dL, prednisolone 5 mg, azathioprine withdrawn, and antiviral chemotherapy initiated with 10 days of IV gancyclovir and acyclovir followed by oral famcyclovir. During the follow-up, anti-EBV-IgM, anti-early antigen antibodies, and anti-EBNA antibodies were continuously monitored excluding significant EBV replication. Eighteen months post-liver resection, and high-resolution computed tomography scan demonstrated two paravertebral tumors. These lesions and a small nodule at the left ankle were resected revealing identical leiomyosarcomata. immunosuppression was further reduced (CsA levels 75 ng/dL) and famcyclovir maintenance therapy started. Nevertheless, 2 years later the patient again developed tumor recurrence (perirectal, liver, and right adrenal gland); the tumors were surgically removed. The therapy was switched to Rapamycin and famcyclovir was continued. Three years after the last surgical intervention, the patient is well and recurrence-free. CONCLUSION: Long-term survival in patients with posttransplant EBV-associated leiomyosarcoma can be achieved by combined surgical intervention, reduction of immunosuppression, switch to sirolimus, and antiviral chemotherapy.- - - - - - - - - - ranking = 0.11111111111111keywords = hybridization (Clic here for more details about this article) |
3/5. enterovirus-induced myocarditis: hemodynamic deterioration with immunosuppressive therapy and successful application of interferon-alpha.In 1985, myocarditis was diagnosed by endomyocardial biopsy in a 53-year-old woman who was free of symptoms of heart insufficiency. Immunosuppressive therapy with azathioprine and prednisolone was prescribed as the patient had deteriorated to NYHA II heart insufficiency in March 1986. When application of immunosuppressive agents was terminated in 1987, serial endomyocardial biopsies revealed no signs of myocarditis, thus indicating effectiveness of immunosuppression. Nevertheless, the patient had worsened clinically and hemodynamically. At follow-up in 1991, the patient had progressed to dilated cardiomyopathy resulting in NYHA III heart insufficiency. enterovirus infection of the heart was detected by in situ nucleic acid hybridization. In addition, retrospective serology indicated a significant increase of coxsackievirus B2 antibodies between 1985 and 1991. Investigational antiviral therapy with recombinant interferon alpha-2a was tolerated well and a favorable clinical, hemodynamic, and virologic response was observed. Thus, progression of biopsy-proven myocarditis to dilated cardiomyopathy may have been facilitated by immunosuppressive therapy in enterovirus infection. Antiviral therapy might be advantageous in patients with enterovirus myocarditis and dilated cardiomyopathy.- - - - - - - - - - ranking = 0.11111111111111keywords = hybridization (Clic here for more details about this article) |
4/5. A new congenital muscular dystrophy with mitochondrial structural abnormalities.We report a new form of congenital muscular dystrophy (CMD) in 4 patients from three unrelated families with probable autosomal-recessive inheritance. All patients had the clinical characteristics of merosin-positive congenital muscular dystrophy, but had marked mental retardation. The disease was slowly progressive and 1 patient died from dilated cardiomyopathy at the age of 13 years. In addition to dystrophic changes with necrosis and regeneration in muscle, the most striking finding was mitochondrial depletion in the center of the sarcoplasm. mitochondria at the periphery of fibers were markedly enlarged ("megaconial" appearance) with complicated cristae, and contained a normal amount of mitochondrial dna by in situ hybridization. Mitochondrial enlargement may represent functional compensation for mitochondrial depletion in the central sarcoplasm, where myofibrillar degeneration occurred.- - - - - - - - - - ranking = 0.11111111111111keywords = hybridization (Clic here for more details about this article) |
5/5. Detection of enteroviral rna in end-stage dilated cardiomyopathy in children and adolescents.medical records and archival myocardial specimens of 33 children and adolescents with end-stage idiopathic dilated cardiomyopathy (IDCM) were collected to evaluate retrospectively the potential role of enteroviral persistence in the pathogenesis of IDCM. The clinical history and laboratory assessment of each patient were reviewed carefully in order to obtain information on the nature and etiology of infections in the past and at the time of diagnosis of cardiomyopathy. Sixty-four formaldehyde-fixed, paraffin-embedded myocardial specimens, obtained from endomyocardial biopsies (n = 5), explanted hearts (n = 10), or autopsies (n = 49), were studied by the polymerase chain reaction (PCR) and by in situ hybridization to detect enteroviral rna in the specimens. Control specimens included 34 formaldehyde-fixed, paraffin-embedded myocardial specimens from children with other cardiomyopathies, metabolic diseases, structural heart defects, or various noncardiac malignancies. The presence of cellular rna in the specimens was confirmed by amplification of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA or beta-actin mRNA as positive controls. Only one specimen from the 32 IDCM patients with appropriate myocardial specimens was positive for enteroviral rna by PCR. sequence analysis of the amplified viral segment showed a significant degree of homology between the viral sequence and echovirus 1. One specimen from the control patients also appeared positive by PCR, but sequence analysis of the amplified viral segment revealed it as rhinovirus 16. The results do not indicate any significant role for enteroviral persistence in end-stage childhood IDCM, although they need to be confirmed using a prospective study with fresh frozen specimens. However, mechanisms other than viral persistence may be more important in the progression of IDCM to end-stage heart failure in this age group.- - - - - - - - - - ranking = 0.11111111111111keywords = hybridization (Clic here for more details about this article) |