Nuclear DNA origin of mitochondrial complex I deficiency in fatal infantile lactic acidosis evidenced by transnuclear complementation of cultured fibroblasts.
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We have studied complex I (NADH-ubiquinone reductase) defects of the mitochondrial respiratory chain in 2 infants who died in the neonatal period from 2 different neurological forms of severe neonatal lactic acidosis. Specific and marked decrease in complex I activity was documented in muscle, liver, and cultured skin fibroblasts. Biochemical characterization and study of the genetic origin of this defect were performed using cultured fibroblasts. Immunodetection of 6 nuclear DNA-encoded (20, 23, 24, 30, 49, and 51 kDa) and 1 mitochondrial DNA-encoded (ND1) complex I subunits in fibroblast mitochondria revealed 2 distinct patterns. In 1 patient, complex I contained reduced amounts of the 24- and 51-kDa subunits and normal amounts of all the other investigated subunits. In the second patient, amounts of all the investigated subunits were severely decreased. The data suggest partial or extensive impairment of complex I assembly in both patients. Cell fusion experiments between 143B206 rho degrees cells, fully depleted of mitochondrial DNA, and fibroblasts from both patients led to phenotypic complementation of the complex I defects in mitochondria of the resulting cybrid cells. These results indicate that the complex I defects in the 2 reported cases are due to nuclear gene mutations. (+info)
Gangrenous cystitis: a rare cause of colovesical fistula.
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A case of gangrenous cystitis presenting as a colovesical fistula in an elderly woman is described. The literature on this rare condition is reviewed. (+info)
Recurrent thrombo-embolic episodes: the association of cholangiocarcinoma with antiphospholipid syndrome.
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Antiphospholipid syndrome is a disorder of recurrent vascular thrombosis, pregnancy loss and thrombocytopenia associated with persistently elevated levels of antiphospholipid antibodies. It was first described in a group of patients with systemic lupus erythematosus but has since been associated with a wide range of conditions, including other autoimmune disorders and malignancy. It can also occur in isolation, the so-called primary antiphospholipid syndrome. We describe an elderly woman with the antiphospholipid syndrome thought to be associated with a cholangiocarcinoma. (+info)
Enoyl-CoA hydratase deficiency: identification of a new type of D-bifunctional protein deficiency.
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D-bifunctional protein is involved in the peroxisomal beta-oxidation of very long chain fatty acids, branched chain fatty acids and bile acid intermediates. In line with the central role of D-bifunctional protein in the beta-oxidation of these three types of fatty acids, all patients with D-bifunctional protein deficiency so far reported in the literature show elevated levels of very long chain fatty acids, branched chain fatty acids and bile acid inter-mediates. In contrast, we now report two novel patients with D-bifunctional protein deficiency who both have normal levels of bile acid intermediates. Complementation analysis and D-bifunctional protein activity measurements revealed that both patients had an isolated defect in the enoyl-CoA hydratase domain of D-bifunctional protein. Subsequent mutation analysis showed that both patients are homozygous for a missense mutation (N457Y), which is located in the enoyl-CoA hydratase coding part of the D-bifunctional protein gene. Expression of the mutant protein in the yeast Saccharomyces cerevisiae confirmed that the N457Y mutation is the disease-causing mutation. Immunoblot analysis of patient fibroblast homogenates showed that the protein levels of full-length D-bifunctional protein were strongly reduced while the enoyl-CoA hydratase component produced after processing within the peroxisome was undetectable, which indicates that the mutation leads to an unstable protein. (+info)
Identification and characterization of three novel missense mutations in mevalonate kinase cDNA causing mevalonic aciduria, a disorder of isoprene biosynthesis.
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Mevalonic aciduria is a rare autosomal recessive metabolic disorder, characterized by psychomotor retardation, failure to thrive, hepatosplenomegaly, anemia and recurrent febrile crises. The disorder is caused by a deficient activity of mevalonate kinase due to mutations in the encoding gene. Thus far, only two disease-causing mutations have been identified. We now report four different missense mutations including three novel ones, which were identified by sequence analysis of mevalonate kinase cDNA from three mevalonic aciduria patients. All mutations affect conserved amino acids. Heterologous expression of the corresponding mutant mevalonate kinases as fusion proteins with glutathione S -transferase in Escherichia coli showed a profound effect of each of the mutations on enzyme activity. In addition, immunoblot analysis of fibroblast lysates from patients using specific antibodies against mevalonate kinase identified virtually no protein. These results demonstrate that the mutations affect not only the activity but also the stability of the mutant proteins. (+info)
Four cases of therapy-related leukemia.
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Combination chemotherapy and radiation therapy have contributed to the successful treatment of various cancer patients. But the development of second malignancies is an inevitable complication of long-term cytotoxic treatment. The most serious and frequent of such complications is acute myelogenous leukemia (AML). Therapy-related leukemia is generally fatal. Since the number of patients exposed to chemotherapy is increasing each year, the clinical significance of this entity cannot be underestimated. There have been many investigations of therapy-related leukemia, but in Korea published reports are rare. We describe four such cases, involving one older female with lung cancer and three children with acute lymphoblastic leukemia (ALL) and malignant lymphoma. Alkylating agents were used for chemotherapy, and in one case, topoisomerase II inhibitor. Irrespective of the causative agents, the latency periods were relatively short, and despite induction chemotherapy in two, all survived for only a few months. During the follow-up of patients treated for primary malignancies, the possibility of therapy-related leukemia should always be borne in mind. (+info)
Giant cell arteritis of the cervical radicular vessels presenting with diaphragmatic weakness.
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The clinical and histopathological details of a patient who succumbed to giant cell arteritis (GCA) of the cervical radicular vessels are described. The initial clinical presentation, with diaphragmatic weakness, has not previously been reported. Normal inflammatory indices and the unusual presentation prevented diagnosis during life, but GCA should be considered in the differential diagnosis of any unexplained neuropathic or radiculopathic syndrome, as corticosteroid therapy may lead to recovery. This is the first account of the pathological findings in cervical radiculopathy associated with GCA. (+info)
Herpes simplex encephalitis after brain surgery: case report and review of the literature.
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Intracranial infection after neurosurgical intervention most often is caused by bacteria. A rare case of fatal herpes simplex encephalitis after removal of a meningioma is described and similar cases reported in the literature are reviewed. Recent diagnostic tools, including detection of herpes viral DNA sequences by polymerase chain reaction, complement clinical suspicion and facilitate mandatory early diagnosis, because herpes encephalitis, without rapid initiation of treatment, may lead to severe disability or death. (+info)