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Biomedical subjects

Takao Mitsui

Publications and source records attributed to Takao Mitsui.

29 records · Page 2Linked to original sources
PubMed2003

Complicated paraneoplastic neurological syndromes: a report of two patients with small cell or non-small cell lung cancer.

Paraneoplastic neurological syndromes are frequently associated in patients with small cell lung cancer (SCLC) and antineuronal antibodies are involved in the autoimmune mechanism. Multiple syndromes are sometimes complicated in a single patient with SCLC. However, little is known about non-SCLC-associated neurological manifestations. We report two patients with complicated paraneoplastic neurological syndromes. Patient 1 showed paraneoplastic limbic encephalitis (PLE), paraneoplastic sensory neuropathy (PSN) and Lambert-Eaton myasthenic syndrome (LEMS) associated with SCLC. Patient 2 developed opsoclonus-ataxia and probable PLE associated with non-SCLC. Analysis of various antineuronal antibodies revealed that anti-Hu and P/Q-type voltage-gated calcium channel (VGCC) antibodies were positive in Patient 1 but any antibodies were not in Patient 2. Brain MRI demonstrated high intensity signals in temporal lobes particularly on fluid-attenuated inversion recovery (FLAIR) or diffusion-weighted images. These findings suggest that complicated paraneoplastic neurological syndromes occur in non-SCLC as well as SCLC and that unidentified antineuronal autoantibodies may underlie the pathophysiology.

Autoantibodies↗
PubMed2003

Beneficial effect of steroid pulse therapy on acute viral encephalitis.

Corticosteroids are often used in the treatment of acute viral encephalitis, although the efficacy of corticosteroid therapy has not been proven. We examined the effects of high-dose corticosteroid therapy on acute viral encephalitis in 5 patients with progressive disturbances of consciousness. In 3 patients who were treated within 5 days after the onset of illness, pulse therapy dramatically reduced the degree of consciousness disturbance. They became alert within 24 h, and then neurological symptoms gradually improved. Corticosteroid therapy in the other 2 patients, in whom treatment was started more than 3 weeks after the onset of illness, was not as effective, but repeated therapy at 2-week intervals resulted in complete recovery. These findings suggest that high-dose corticosteroid therapy is effective, particularly for disturbances of consciousness, an important prognostic factor in acute viral encephalitis.

Acute Disease↗
PubMed2003

Dermatomyositis with peripheral nervous system involvement: activation of vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR) in vasculitic lesions.

We describe two cases of dermatomyositis (DM) with nervous system involvement. Polyneuropathy was observed in both patients, and cerebral vasculitis was suspected in one patient. Histological examination of biopsied specimens of skeletal muscles, skin and sural nerves revealed vasculitis. Furthermore, vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFRs) were overexpressed in vasculitic lesions. Although, VEGF and VEGFRs were not detected in biopsied specimens of skeletal muscle from normal subjects, they were observed in one of two patients with DM who did not exhibit neuropathy. These findings suggest the possibility that VEGF overproduction is associated with development of vasculitis in some cases of DM complicated with peripheral neuropathy.

Aged↗
PubMed2003

Motor neuron involvement in a patient with long-term corticosteroid administration.

An asthmatic patient with corticosteroid treatment for 45 years presented with slowly progressive limb muscle atrophy. His muscle symptoms were involved in four limbs and tongue, and deep tendon reflexes were exaggerated. Biopsied muscle pathology indicated the presence of neurogenic muscular atrophy in combination with corticosteroid myopathy. Furthermore, 8-hydroxy-deoxyguanosine (8-OH-dG) was prominently increased in mitochondrial and nuclear DNA. An aerobic exercise test demonstrated remarkable serum lactate elevation, which was attenuated by the administration of coenzyme Q10. These findings are consistent with the assumption that long-term corticosteroid administration potentially induces not only myopathy but also motor neuron involvement as in mitochondrial diseases.

Aged↗
PubMed2003

[Cerebrospinal fluid in multiple sclerosis].

Recently, a revised diagnostic criteria for multiple sclerosis(MS) was published. In this paper, the cerebrospinal fluid(CSF) findings in MS were reviewed, with reference to this criteria. CSF abnormality was defined by the presence of oligoclonal IgG bands and/or the presence of an elevated IgG index in the criteria. Some differences in the grade of pleocytosis and protein content, and the frequency of IgG abnormalities were revealed between Japanese and western MS patients. Other CSF findings such as antibodies against myelin proteins, cytokines and chemokines were also discussed.

Animals↗
PubMed2002

Mitochondrial damage in patients with long-term corticosteroid therapy: development of oculoskeletal symptoms similar to mitochondrial disease.

Two patients with long-term corticosteroid administration sporadically developed limb muscle wasting followed by ophthalmoplegia, and the skeletal muscle pathology revealed ragged-red fibers (RRFs) with abnormal mitochondria, in addition to the findings of corticosteroid myopathy. The oculoskeletal symptoms of the present cases resemble those of chronic progressive external ophthalmoplegia, a type of mitochondrial disease. The ocular muscles have more RRFs than limb muscles, and large multiple deletions of mitochondrial DNA was detected in ocular and limb muscles of the two patients by PCR but not by Southern blotting. Immunohistochemistry demonstrated that 8-hydroxy-deoxyguanosine (8-OH-dG) and 4-hydroxy-2-nonenal were intensely stained in skeletal muscles of these patients particularly in RRFs. High-performance liquid chromatography with electrochemical detection analysis revealed an increase in 8-OH-dG from mitochondrial DNA. These findings may suggest that long-term corticosteroid administration potentially induces oxidative stress-mediated mitochondrial damage, resulting in the development of the oculoskeletal symptoms in some patients.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2002

Chronic corticosteroid administration causes mitochondrial dysfunction in skeletal muscle.

Corticosteroid myopathy is a major clinical problem in patients undergoing chronic corticosteroid treatment and shows insidious and progressive muscle atrophy in proximal limbs. Although several mechanisms underlying the pathophysiology of muscle injury have been postulated, precise pathogenesis is still not clear. We evaluated the mitochondrial functions in patients receiving corticosteroids compared with those in healthy controls or patients not receiving corticosteroids. The serum levels and total production of lactate were investigated by an aerobic exercise test using a bicycle ergometer. Mitochondrial respiratory activities and oxidative damage in biopsied skeletal muscles were also studied. The results of aerobic exercise tests revealed a significant overproduction of lactate in patients treated with corticosteroids ( p < 0.005), which was positively correlated with total corticosteroid doses administered ( p < 0.0001). In these patients, mitochondrial enzyme activity in complex I was significantly decreased ( p < 0.05) and oxidative damage of biopsied skeletal muscle was remarkable both in mitochondrial and nuclear DNAs ( p < 0.001). The results suggest that chronic corticosteroid administration induces mitochondrial dysfunction and oxidative damage in skeletal muscles, which may be the pathogenesis, at least in part, of corticosteroid-induced myopathy.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2002

Loss of postural reflexes in long-term occupational solvent exposure.

Inhalation of organic solvents has long been known to damage various nervous systems, including cerebellum, brainstem, and pyramidal tract. However, little is known about the damage of the dopaminergic system. We report two patients with occupational long-term solvent exposure who developed postural instability without other features of parkinsonism. The concentration of HVA in CSF was decreased and the retropulsion was dramatically improved after the administration of levodopa. These findings indicate that the nigrostriatal dopaminergic neurons were disturbed by chronic solvent exposure, resulting in the loss of postural reflexes.

Adult↗
PubMed2002

Diurnal fluctuation of edema synchronized with plasma VEGF concentration in a patient with POEMS syndrome.

A case of POEMS syndrome in a 49-year-old Japanese woman is reported. The patient exhibited prominent edema in her legs at night, but her edema usually improved by the following morning. The plasma concentrations of VEGF in the patient showed diurnal fluctuations; plasma VEGF levels peaked at night and decreased in the daytime. Immunocytochemical study demonstrated the expression of VEGF in IgA- and lambda-positive plasma cells in bone marrow. The results indicate that VEGF was produced at least by plasma cells and that VEGF production was regulated by circadian rhythm in synchronization with the development of edema.

Anti-Inflammatory Agents↗
PubMed2001

Apoptosis-related changes in skeletal muscles of patients with mitochondrial diseases.

Much interest has recently been shown in apoptosis-mediated roles in the pathophysiology of mitochondrial diseases, because mitochondrial defects are implicated in a wide variety of degenerative diseases. We investigated whether apoptotic events occurred in skeletal muscles of patients with mitochondrial diseases, including chronic progressive external ophthalmoplegia (CPEO), Kearns-Sayer syndrome (KSS), and mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). In a immunohistochemical study, stainings for 8-hydroxy-deoxyguanosine (8-OH-dG), 4-hydroxy-nonenal (4-HNE), Mn-SOD, Bcl-2, cytochrome c, DNase I and Bcl-x L showed a pronounced granular distribution in the cytochrome c oxidase (COX)-negative ragged-red fibers (RRFs). On the other hand, the signals for Bax, p53, Fas and caspase 3 were not obviously increased in RRFs. In situ labeling of DNA breaks demonstrated preferential signals not only in myonuclei but also in subsarcolemmal regions of RRFs, indicating that mitochondrial as well as myonuclear DNA is fragmented in RRFs. An immunoblotting study demonstrated that cytochrome c was increased in the cytosol of diseased muscles and that DNase I was increased in mitochondria, compared to that of normal muscles. No difference was observed between protein bands at 20 kDa corresponding to caspase 3 in diseased and normal muscles. These findings demonstrate that these mitochondrial diseases harbor unique apoptosis-related changes that differ from caspase 3-dependent apoptosis. It is thought that these changes are induced by superoxide overproduction and cytochrome c release resulting from an inherent mitochondrial defect and that the events are associated with DNase I activation.

Adult↗