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Biomedical subjects

Kurenai Tanji

Publications and source records attributed to Kurenai Tanji.

13 recordsLinked to original sources
PubMed2007

Use of stents to treat intracranial cerebrovascular disease.

Intracranial atherosclerosis is a common cause of stroke. Although it has been recognized for decades, the lack of successful treatment strategies has limited clinical interest until recently. We review the natural history and pathophysiology of intracranial atherosclerosis. Vascular biomechanics are important to define differences between cerebral arteries and extracranial vessels and partly explain the technical challenges facing cerebral artery revascularization as compared with revascularization of coronary arteries. Pharmacological interventions to prevent stroke have had limited success, but technological developments offer improved methods for endovascular revascularization of symptomatic and asymptomatic cerebral artery stenosis. Identification of appropriate candidates for treatment also remains a challenge, and our knowledge about the natural history of the disease is limited. At this time, patients with significant intracranial stenosis should receive information on the benefits and risks of revascularization therapy. Determining which patients should undergo revascularization procedures will require carefully planned, randomized clinical trials.

Angioplasty, Balloon↗
PubMed2006

Navajo neurohepatopathy is caused by a mutation in the MPV17 gene.

Navajo neurohepatopathy (NNH) is an autosomal recessive disease that is prevalent among Navajo children in the southwestern United States. The major clinical features are hepatopathy, peripheral neuropathy, corneal anesthesia and scarring, acral mutilation, cerebral leukoencephalopathy, failure to thrive, and recurrent metabolic acidosis with intercurrent infections. Infantile, childhood, and classic forms of NNH have been described. Mitochondrial DNA (mtDNA) depletion was detected in the livers of two patients, suggesting a primary defect in mtDNA maintenance. Homozygosity mapping of two families with NNH suggested linkage to chromosome 2p24. This locus includes the MPV17 gene, which, when mutated, causes a hepatocerebral form of mtDNA depletion. Sequencing of the MPV17 gene in six patients with NNH from five families revealed the homozygous R50Q mutation described elsewhere. Identification of a single missense mutation in patients with NNH confirms that the disease is probably due to a founder effect and extends the phenotypic spectrum associated with MPV17 mutations.

Adult↗
PubMed2005

The transformation of pediatric gliomatosis cerebri to cerebellar glioblastoma multiforme presenting as supra- and infratentorial acute disseminated encephalomyelitis. Case report.

Cerebellar glioblastoma multiforme (GBM) is a rare entity in adults and an extremely rare entity in children. Approximately 30 cases have been reported in the literature. The authors report the case of a histologically confirmed cerebellar GBM presenting initially as supra- and infratentorial gliomatosis cerebri. Acute disseminated encephalomyelitis had been diagnosed in the patient and that diagnosis remained until near the end of his treatment. This case underscores the need for recognizing the clinical presentation of gliomatosis cerebri and multifocal GBM in the pediatric subpopulation thought to harbor demyelinating disease.

Cerebellar Neoplasms↗
PubMed2004

Fatal infantile neuromuscular presentation of glycogen storage disease type IV.

Glycogen storage disease type IV or Andersen disease is an autosomal recessive disorder due to deficiency of glycogen branching enzyme. Typically, glycogen storage disease type IV presents with rapidly progressive liver cirrhosis and death in childhood. Variants include a cardiopathic form of childhood, a relatively benign myopathic form of young adults, and a late-onset neurodegenerative disorder (adult polyglucosan body disease). A severe neuromuscular variant resembling Werdnig-Hoffmann disease has also been described in two patients. The objective was to describe two additional infants with the neuromuscular variant and novel mutations in the GBE1 gene. Branching enzyme assay, Western blot, RT-PCR and sequencing were performed in muscle biopsies from both patients. The cDNA of patient 1 was subcloned and sequenced to define the mutations. Muscle biopsies showed accumulation of periodic acid Schiff-positive, diastase-resistant storage material in both patients and increased lysosomal enzyme activity in patient 1. Branching enzyme activity in muscle was negligible in both patients, and Western blot showed decreased branching enzyme protein. Patient 1 had two single base pair deletions, one in exon 10 (1238delT) and the other in exon 12 (1467delC), and each parent was heterozygous for one of the deletions. Patient 2 had a large homozygous deletion that spanned 627 bp and included exons 8-12. Patient 1, who died at 41 days, had neurophysiological and neuropathological features of Spinal Muscular Atrophy. Patient 2, who died at 5(1/2) weeks, had a predominantly myopathic process. The infantile neuromuscular form of glycogen storage disease type IV is considered extremely rare, but our encountering two patients in close succession suggests that the disease may be underdiagnosed.

1,4-alpha-Glucan Branching Enzyme↗
PubMed2004

Mitochondrial DNA deletion in a child with megaloblastic anemia and recurrent encephalopathy.

A 3 1/2-year-old boy presented with megaloblastic anemia and recurrent episodes of severe lactic acidosis and coma. At age 4 years, he developed sepsis and died; postmortem examination failed to show any gross abnormality in any tissue. Biochemical analysis of muscle showed decreased activities for all respiratory chain enzymes except complex II. Muscle histochemistry revealed diffuse cytochrome c oxidase deficiency. Southern blot analysis of mitochondrial DNA from muscle, liver, and blood showed a heteroplasmic single mitochindrial DNA deletion of 2.4 kb, which removed the genes for cytochrome c oxidase I and II and the transfer ribonucleic acid genes for serine and aspartic acid. Single large-scale deletions in mitochondrial DNA have been associated with Pearson's syndrome, Kearns-Sayre syndrome, and progressive external ophthalmoplegia. This patient's presentation is unusual and suggests an overlap between Pearson's syndrome and Kearns-Sayre syndrome.

Acidosis, Lactic↗
PubMed2003

Histopathological evaluation of middle cerebral artery after percutaneous intracranial transluminal angioplasty.

BACKGROUND: Intracranial atherosclerosis accounts for 8% to 10% of all ischemic strokes, and intracranial angioplasty is increasingly performed to treat stenotic lesions. We report an autopsy case and discuss the effects of intracranial angioplasty for atherosclerotic arteries. CASE DESCRIPTION: A 77-year-old patient died 9 days after angioplasty of the left middle cerebral artery as a result of cardiorespiratory failure. The patient was anticoagulated before, during, and after the procedure with heparin, aspirin, and clopidogrel. At the site of angioplasty, the densely fibrotic eccentric plaque was displaced from the adjacent media into the lumen, distorting it and forming elongated projections. No local thrombosis, plaque compression, or inflammation was observed. Additionally, an intramural hemorrhage extended from the site of angioplasty into the stenotic proximal inferior division of the left middle cerebral artery. CONCLUSIONS: Histopathological findings after intracranial angioplasty parallel those in other arterial territories. The implications of these pathological findings on the medical and endovascular treatment of intracranial atherosclerosis are discussed.

Aged↗
PubMed2003

Mitochondrial DNA dysfunction in oncocytic hepatocytes.

Hepatic oncocytes with abundant granular, eosinophilic cytoplasm due to mitochondrial hyperplasia are seen in various chronic liver diseases, particularly chronic hepatitis and cirrhosis. Increased mitochondria in oncocytes are thought to be a compensatory mechanism for deficiencies in the hepatocellular respiratory chain, although the pathogenesis of these deficiencies has been uncertain. We selected seven cases of cirrhosis (six with oncocytes, one without) for the following analysis: histoenzymatic and immunohistochemical staining of several mitochondrial DNA (mtDNA)- and nuclear DNA (nDNA)-encoded respiratory chain enzymes; immunostaining using antibodies against double-strand-DNA (anti-DNA) and against Ki-67 (a cell proliferation marker); and Southern blot analysis for mtDNA and nDNA. Eighty percent of oncocytes showed histoenzymatic and immunohistochemical deficiencies of cytochrome c oxidase and the mtDNA-encoded subunit I of complex IV, with preserved expression of nDNA-encoded succinate dehydrogenase and the iron-sulfur subunit of complex III (FeS). Cytoplasmic (but not nuclear) anti-DNA staining was partially or completely absent in approximately 50% of oncocytes. Three cases with oncocytes studied by Southern blot showed mtDNA reductions of 66%, 71%, and 85%. In conclusion, hepatic oncocytes demonstrate significant deficiencies of mtDNA and mtDNA-encoded respiratory chain enzymes. We propose that mtDNA depletion plays an important role in hepatocellular oncocytic transformation.

Adult↗
PubMed2002

The A8344G mutation in mitochondrial DNA associated with stroke-like episodes and gastrointestinal dysfunction.

We report an unusual case of encephalo-entero-myopathy associated with the A8344G mutation in the tRNA(Lys) gene of mitochondrial DNA (mtDNA). This patient had mitochondrial myopathy, multiple lipomatosis, mild hearing loss, stroke-like episodes, and paralytic ileus, but she lacked the canonical clinical features of MERRF, myoclonus, epilepsy, or ataxia. We conducted genetic, biochemical, histochemical, and immunohistochemical studies in skeletal muscle, brain, intestine, and lipoma tissue. The mutation was abundant in all tissues, and cytochrome c oxidase (COX) activity was selectively decreased in brain and small intestine. COX deficiency was also documented histochemically and immunohistochemically in the small intestine, suggesting that mitochondrial dysfunction played a role in the pathogenesis of paralytic ileus. This case illustrates an unusual and dramatic clinical phenotype of the A8344G mutation, characterized by stroke-like episodes and acute ileus.

Adult↗
PubMed2002

Identical mitochondrial DNA deletion in a woman with ocular myopathy and in her son with pearson syndrome.

Single deletions of mitochondrial DNA (mtDNA) are associated with three major clinical conditions: Kearns-Sayre syndrome, a multisystem disorder; Pearson syndrome (PS), a disorder of the hematopoietic system; and progressive external ophthalmoplegia (PEO), primarily affecting the ocular muscles. Typically, single mtDNA deletions are sporadic events, since the mothers, siblings, and offspring of affected individuals are unaffected. We studied a woman who presented with PEO, ptosis, and weakness of pharyngeal, facial, neck, and limb muscles. She had two unaffected children, but another of her children, an infant son, had sideroblastic anemia, was diagnosed with PS, and died at age 1 year. Morphological analysis of a muscle biopsy sample from the mother showed cytochrome c oxidase-negative ragged-red fibers-a typical pattern in patients with mtDNA deletions. Southern blot analysis using multiple restriction endonucleases and probed with multiple mtDNA fragments showed that both the mother and her infant son harbored an identical 5,355-bp single deletion in mtDNA, without flanking direct repeats. The deletion was the only abnormal species of mtDNA identified in both patients, and there was no evidence for duplications. We conclude that, although the vast majority of single large-scale deletions in mtDNA are sporadic, in rare cases, single deletions can be transmitted through the germline.

Adolescent↗
PubMed2002

Mitochondrial abnormalities in muscle and other aging cells: classification, causes, and effects.

The involvement of mitochondria and of mitochondrial DNA (mtDNA) in the aging process has generated much interest and even more controversy. The mitochondrial theory of aging considers a vicious circle consisting of: (1) accumulation of somatic mtDNA mutations; (2) impairment of respiratory chain function; (3) increased production of reactive oxygen species (ROS) in mitochondria; and (4) further damage to mtDNA. We review the evidence for and against the belief that these steps occur in aging muscle and brain, considering separately morphological, biochemical, and molecular data. The relationship between mitochondrial aging and late-onset neurodegenerative diseases is briefly reviewed. We conclude that mitochondrial dysfunction does play a crucial role in the aging process of both muscle and brain, but it remains unclear whether mitochondria are the culprits or mere accomplices.

Animals↗