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Biomedical subjects

Hitoshi Takahashi

Publications and source records attributed to Hitoshi Takahashi.

At least 37 records · Page 2Linked to original sources

Cellular pathology in multiple system atrophy.

Multiple system atrophy (MSA) is a sporadic, adult-onset neurodegenerative disease, which is characterized by striatonigral degeneration, olivopontocerebellar atrophy, and preganglionic autonomic lesions in any combination. The histological hallmark is the presence of argyrophilic fibrillary inclusions in the oligodendrocytes, referred to as glial cytoplasmic inclusions (GCIs). Fibrillary inclusions are also found in the neuronal somata, axons, and nucleus. Neuronal cytoplasmic inclusions are frequently found in the pontine and inferior olivary nuclei. Since the discovery of alpha-synuclein as a major component of glial and neuronal inclusions in MSA, two neurodegenerative processes have been considered in this disease: one is due to the widespread occurrence of GCIs associated with oligodendroglia-myelin degeneration (oligodendrogliopathy) in the central nervous system, and the other is due to the filamentous aggregation of alpha-synuclein in the neurons in several brain regions. These two degenerative processes might synergistically cause neuronal depletion in MSA.

Animals↗

Three-dimensional anisotropy contrast periodically rotated overlapping parallel lines with enhanced reconstruction (3DAC PROPELLER) on a 3.0T system: a new modality for routine clinical neuroimaging.

BACKGROUND: Clinical magnetic resonance imaging (MRI) has recently entered the "high-field" era, and systems equipped with 3.0-4.0T superconductive magnets are becoming the gold standard for diagnostic imaging. While higher signal-to-noise ratio (S/N) is a definite advantage of higher field systems, higher susceptibility effect remains to be a significant trade-off. To take advantage of a higher field system in performing routine clinical images of higher anatomical resolution, we implemented a vector contrast image technique to 3.0T imaging, three-dimensional anisotropy contrast (3DAC), with a PROPELLER (Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction) sequence, a method capable of effectively eliminating undesired artifacts on rapid diffusion imaging sequences. METHODS: One hundred subjects (20 normal volunteers and 80 volunteers with various central nervous system diseases) participated in the study. Anisotropic diffusion-weighted PROPELLER images were obtained on a General Electric (Waukesha, WI, USA) Signa 3.0T for each axis, with b-value of 1100 sec/mm(2). Subsequently, 3DAC images were constructed using in-house software written on MATLAB (MathWorks, Natick, MA, USA). RESULTS: The vector contrast allows for providing exquisite anatomical detail illustrated by clear identification of all major tracts through the entire brain. 3DAC images provide better anatomical resolution for brainstem glioma than higher-resolution T2 reversed images. Degenerative processes of disease-specific tracts were clearly identified as illustrated in cases of multiple system atrophy and Joseph-Machado disease. CONCLUSION: Anatomical images of significantly higher resolution than the best current standard, T2 reversed images, were successfully obtained. As a technique readily applicable under routine clinical setting, 3DAC PROPELLER on a 3.0T system will be a powerful addition to diagnostic imaging.

Anisotropy↗

Bacterial sepsis and chemokines.

Bacterial sepsis causes a high mortality rate when it occurs in patients with compromised host defenses. Severely burned patients, typical immunocompromised hosts, are extremely susceptible to infections from various pathogens, and a local wound infection frequently escalates into sepsis. In these patients, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa are familiar pathogens that cause opportunistic infections. Also, polymicrobial sepsis frequently occurs in these patients. In this review, therefore, the roles of chemokines in thermally injured patients infected with these 3 pathogens and polymicrobial sepsis will be discussed. These infections in thermally injured patients may be controlled immunologically, because immunocompetent hosts are resistant to infections with these pathogens. Classically activated macrophages (M1Mphi) are major effector cells for host innate immune responses against these infections. However, M1Mphi are not generated in thermally injured patients whose alternatively activated macrophages (M2Mphi) predominate. M2Mphi appear in patients early after severe burn injuries. M2Mphi inhibit M1Mphi generation through the secretion of CCL17 and IL-10. As a modulator of Mphi, two different subsets of neutrophils (PMN-I, PMN-II) are described. PMN-I direct the polarization of resident Mphi into M1Mphi through the production of CCL3. M2Mphi are induced from resident Mphi by CCL2 released from PMN-II. Therefore, as an inhibitor of CCL2, glycyrrhizin protects individuals infected with S. aureus. Sepsis stemming from P. aeruginosa wound infection is also influenced by CCL2 released from immature myeloid cells. A large number of immature myeloid cells appear in association with burn injuries. Host resistance to S. aureus, E. faecalis, P. aeruginosa or polymicrobial infections may be improved in thermally injured patients through the induction of M1Mphi, elimination of CCL2 and/or depletion of M2Mphi induced by CCL2.

Animals↗

NUB1 suppresses the formation of Lewy body-like inclusions by proteasomal degradation of synphilin-1.

NUB1 is a potent down-regulator of the ubiquitin-like protein NEDD8, because it targets NEDD8 to the proteasome for proteolytic degradation. From results in this study, we found that NUB1 physically interacts with synphilin-1 through its NEDD8-binding site, implying that NUB1 also targets synphilin-1 to the proteasome for degradation. Synphilin-1 is a major component of inclusion bodies found in the brains of patients with neurodegenerative alpha-synucleinopathies, including Parkinson's disease. In this study, we immunostained sections of brains from patients with Parkinson's disease and other alpha-synucleinopathies and demonstrated that NUB1, as well as synphilin-1, accumulates in the inclusion bodies. To define the role of NUB1 in the formation of these inclusion bodies, we performed a co-transfection assay using cultured HEK293 cells. This assay showed that NUB1 suppresses the formation of synphilin-1-positive inclusions. Further, biochemical assays revealed that NUB1 overexpression leads to the proteasomal degradation of synphilin-1. These results and our previous observations suggest that NUB1 indeed targets synphilin-1 to the proteasome for its efficient degradation, which, because of the resultant reduction in synphilin-1, suppresses the formation of synphilin-1-positive inclusions.

Adaptor Proteins, Signal Transducing↗

Switching to olanzapine after unsuccessful treatment with risperidone during the first episode of schizophrenia: an open-label trial.

BACKGROUND: The efficacy and safety of switching to olanzapine were investigated in patients with first-episode schizophrenia who failed to attain an adequate clinical response to an initial therapeutic trial of risperidone (2-6 mg/day for 12 weeks). METHOD: A total of 58 first-episode patients with DSM-IV schizophrenia who had residual symptoms following treatment with risperidone were enrolled in an open-label, 12-week study of olanzapine. Dosing was determined by clinical judgment. The main efficacy measure was the Brief Psychiatric Rating Scale (BPRS). Patients with a 20% or greater decrease in BPRS total score plus a final Clinical Global Impressions-Severity of Illness scale score of or= 7%) from baseline. CONCLUSION: Although we cannot draw any conclusion from a study without a control group, favorable outcomes and good tolerance were observed after switching to olanzapine from risperidone in our population. In addition, factors that predicted a good overall response included a relative absence of positive symptoms at baseline and the percentage reduction in total BPRS score at 4 weeks of treatment. Double-blind, crossover trials are needed to confirm these observations.

Adolescent↗

[Total gastrectomy of gastric stump carcinomas is more invasive than usual total gastrectomy for gastric carcinomas].

BACKGROUND: It is said that total gastrectomy of gastric stump carcinomas is more invasive than usual total gastrectomy for gastric carcinoma. METHODS: We compared the duration of the surgeries, blood loss, transfusion, and postoperative complications between patients having undergone total gastrectomy of gastric stump carcinomas (Group A, N=9) and those having undergone usual total gastrectomy for gastric carcinomas without remarkable preoperative complication (Group B, N=9). RESULTS: The surgical duration of Group A was significantly longer than that of Group B. The amount of blood loss was larger in Group A than in Group B. Postoperative severe complications occurred more often in Group A than in Group B. CONCLUSIONS: This study showes that total gastrectomy of gastric stump carcinomas is more invasive than usual total gastrectomy without preoperative complications. This seems to have been caused by adhesion of organs around the rest stomachs and carcinomas were very likely to be advanced ones in Group A. We should take the findings into considerations for maximum surgical blood order schedule (MSBOS) and prevention of severe postoperative complications in group A apart from group B.

Adult↗

[Oral cyclophosphamide therapy for multifocal fibrosclerosis with hypertrophic intracranial pachymeningitis].

A 54-year-old man was admitted to our hospital because of a headache, dry cough, low grade fever and hearing loss sustained for 6 months. Physical and neurological examinations revealed bilateral conjunctival hyperemia, fine crackles in the lower lungs, cutaneous scars, horizontal gaze evoked nystagmus, bilateral moderate sensorineural deafness and mild hyperreflexia. Hypertrophic intracranial pachymeningitis (HIP) accompanied by episcleritis, pulmonary fibrosis, subcutaneous fibrosis of the trunk and upper limbs, bilateral chronic otitis media and sinusitis of the paranasal cavities were observed. Histopathological investigation of biopsied tissues from the dura matter, lung, skin and nasal mucosa showed marked fibrosis with lymphocyte and plasma cell infiltrations. The diagnosis of multifocal fibrosclerosis (MF) was made; this is a rare syndrome of unknown etiology characterized by fibrosis involving multiple organ systems. Although steroid pulse therapy and cyclophosphamide (CP) pulse therapy was not effective in his illnesses, the combination therapy of corticosteroid and oral CP was dramatically effective. We concluded that HIP can be a manifestation of MF, and additional oral CP should be considered as a treatment for steroid-resistant MF with HIP.

Administration, Oral↗

[A case of primary central nervous system malignant lymphoma developing from the optic chiasma and hypothalamus].

A 63-year-old woman was admitted to our hospital with a 1-month history of visual field defect and reduced bilateral visual acuity. Neurological examination revealed enlargement of bilateral central scotoma and blurred vision, and brain MRI showed masses in the optic chiasma and right hypothalamus on Ti-weighted image with contrast enhancement. Although the patient was treated with high-doses of methylprednisolone four times, the masses spread to the right internal capsule and the vicinity of the right lateral ventricle. An open biopsy was performed and microscopic examination of the sample revealed lymphoplasmacytic lymphoma. Although primary central nervous system lymphoma (PCNSL) developing from the optic chiasma and hypothalamus is rare, PCNSL should be considered in patients with multiple lesions in the optic chiasma and hypothalamus.

Brain Neoplasms↗

Sporadic four-repeat tauopathy with frontotemporal degeneration, parkinsonism and motor neuron disease.

We report a sporadic tauopathy of 6-year duration in a 76-year-old woman. Her initial symptoms were asymmetrical parkinsonism and muscle weakness, with apraxia appearing 2 years later. The brain showed frontal and temporal cerebral atrophy; severe neuronal loss and gliosis were observed in the precentral cortex (loss of Betz cells was also evident) and premotor area, and in the medial temporal lobe, including the temporal tip, amygdala, and hippocampal CA1-subiculum border zone. The substantia nigra showed moderate neuronal loss and gliosis. In the spinal cord, loss of the anterior horn cells and degeneration of the corticospinal tracts were a characteristic feature. In addition, in the affected regions, the remaining neurons were often found to contain intracytoplasmic inclusions resembling neurofibrillary tangles. Tau immunostaining revealed widespread glial-predominant lesions in the cerebral gray and white matter. In contrast, predominance of neuronal lesions (pretangles/tangles) was a feature in the subcortical gray matter, including the spinal cord. The remaining upper and lower motor neurons were also affected by tau pathology. Accumulated tau in these glial cells and neurons was clearly recognized by a specific antibody against four-repeat (4R) tau. The ultrastructural presence of tau-positive tubular structures was confirmed in the glial cells and neurons (tangles). Immunoblotting of a frozen frontal lobe sample revealed accumulation of 4R-predominant tau isoforms. No mutations were found in the tau gene. These findings indicate that a sporadic 4R tauopathy can cause frontotemporal degeneration, parkinsonism, and motor neuron disease. The present case could represent a new clinicopathological phenotype of non-familial tauopathy.

Aged↗

Cardiac sympathetic denervation precedes neuronal loss in the sympathetic ganglia in Lewy body disease.

Decreased cardiac uptake of meta-iodobenzylguanidine (MIBG) on [123I]MIBG myocardial scintigraphy has been reported in Parkinson's disease (PD) and dementia with Lewy bodies (DLB). We hypothesized that cardiac sympathetic denervation might account for the pathomechanism. To elucidate the extent, frequency and pattern of cardiac sympathetic nerve involvement in Lewy body disease and related neurodegenerative disorders, we immunohistochemically examined heart tissues from patients with PD (n=11), DLB (n=7), DLB with Alzheimer's disease (DLB/AD; n=4), multiple system atrophy (MSA; n=8), progressive supranuclear palsy (PSP; n=5), pure AD (n=10) and control subjects (n=5) together with sympathetic ganglia from patients with PD (n=5) and control subjects (n=4), using an antibody against tyrosine hydroxylase (TH). TH-immunoreactive nerve fibers in the hearts had almost entirely disappeared in nearly all the patients with PD, DLB and DLB/AD, whereas they were well preserved in all the patients with PSP and pure AD as well as in all except for one patient with MSA. In PD, neurons in the sympathetic ganglia were preserved in all except for one patient. Decreased cardiac uptake of MIBG in Lewy body disease reflects actual cardiac sympathetic denervation, which precedes the neuronal loss in the sympathetic ganglia.

3-Iodobenzylguanidine↗

Modified ProMACE-MOPP hybrid regimen with moderate-dose methotrexate for patients with primary CNS lymphoma.

The object of this study was to assess the estimation of 2- and 5-year overall survival and tumor response and the frequency and severity of treatment morbidity with a modified ProMACE-MOPP hybrid protocol in patients with primary CNS lymphoma (PCNSL). Thirty-two immunocompetent patients were treated with a regimen of pirarubicin, cyclophosphamide, etoposide, vincristine, and methotrexate (500 mg/m(2)) administered in 21-day cycles. Intraventricular 10 mg of methotrexate was given for eight cycles once a week. Patients received 20 Gy of whole brain radiotherapy after three cycles of chemotherapy. A single cycle of chemotherapy was repeated every 4 months for 2 years. Older patients (aged >60) received a reduced dose of chemotherapeutic agents. Eighteen patients were followed up with neuroimaging and neuropsychological assessments for evidence of CNS toxicity. Sixteen patients completed the regimen as planned. The response rate was 87.5% after the initial chemoradiotherapy. The cumulative survival and progression-free survival rates at 5 years were 56 and 31%, respectively. The median survival time was 68 months. The median progression-free survival time was 39 months. Toxicity included grade 3 or 4 leukopenia in 33% of the cycles administered. There were eight grade 3 or 4 pulmonary toxicities. There were three deaths during chemotherapy: one as a result of sepsis and two of pneumonitis. Three patients (25%) experienced delayed neurologic toxicity while on the complete regimen. Maintaining the dose of methotrexate while adding chemotherapeutic agents improved disease control and overall survival in patients with PCNSL, but early toxicity and delayed neurotoxicity are still a risk of this approach.

Adult↗

Contribution of the sympathetic nervous system on the burn-associated impairment of CCL3 production.

Previously, we have reported that the susceptibility of burned patients to infectious complications is increased when the production of CC-chemokine ligand 3 (CCL3) is impaired. In this study, the role of the sympathetic nervous system on impaired CCL3 production and antibacterial resistance following burn injuries was investigated. Normal mice were resistant (65% survival) to cecal ligation and puncture (CLP)-induced sepsis, while the same CLP killed 90% of thermally injured mice (TI-mice). However, TI-mice resisted CLP-induced sepsis (60% survival) when they were previously treated with CCL3 or sympathectomized with 6-hydroxydopamine (6-OHDA). Augmentation of host resistance against CLP-induced sepsis by 6-OHDA was abrogated by anti-CCL3 mAb treatment. Norepinephrine (NE) production was increased in circulation of TI-mice, and treatment of TI-mice with 6-OHDA resulted in the inhibition of NE secretion. CCL3 production was impaired in cultures of T cells from TI-mice or normal T cells treated with NE, even when stimulated with anti-CD3 mAb. However, CCL3 was produced by mAb-stimulated T cells from TI-mice previously treated with 6-OHDA. These results indicated that by inhibiting CCL3 production the sympathetic nervous system contributes to the increased susceptibility of TI-mice to sepsis.

Animals↗

A mutant PSEN1 causes dementia with Lewy bodies and variant Alzheimer's disease.

We report early-onset parkinsonism and dementia of 18 years' duration in a 52-year-old man whose grandfather and father had suffered from a similar neurological disease. In this patient, we found neuronal loss in various brain regions including the substantia nigra and cerebral cortex, Lewy bodies, cotton wool plaques, corticospinal tract degeneration, cerebral amyloid angiopathy, and a novel three-base pair deletion in exon 12 of the presenilin-1 (PSEN1) gene. We considered that the mutant PSEN1 might play an important role in the pathogenetic process of both aggregation of alpha-synuclein into Lewy bodies and deposition of beta-amyloid into cotton wool plaques.

Alzheimer Disease↗

Preserved cardiac sympathetic nerve accounts for normal cardiac uptake of MIBG in PARK2.

We performed [123I] MIBG myocardial scintigraphy in two of three patients with PARK2 from unrelated families and examined the heart tissues from the three patients immunohistochemically using an antibody against tyrosine hydroxylase (TH) to see whether cardiac sympathetic nerve is involved. Cardiac uptake of MIBG was normal except for a slight decrease in the late phase in one of the patients. Postmortem examination revealed that TH-immunoreactive nerve fibers in the epicardium were well preserved in all three patients. The present study confirmed that cardiac sympathetic nerve is well preserved in PARK2 with a homozygous exon deletion, which accounts for normal cardiac uptake of MIBG. Moreover, normal cardiac uptake of MIBG might be of potential diagnostic value to indicate the absence of Lewy body pathology, even in patients with levodopa-responsive Parkinsonism, as in PARK2.

3-Iodobenzylguanidine↗

Is motor neuron disease-inclusion dementia a forme fruste of amyotrophic lateral sclerosis with dementia? An autopsy case further supporting the disease concept.

We report the autopsy findings of a 62-year-old man who exhibited progressive FTD 10 years before the appearance of muscle weakness and wasting, and who died approximately 11 years after onset of the symptoms. Degeneration and atrophy of the frontal and temporal lobes, which contained ubiquitin-positive neuronal inclusions and dystrophic neurites, were evident. Circumscribed degeneration affecting the hippocampal CA1-subiculum border zone was also a feature. Moreover, degeneration was present in both the upper and lower motor neuron systems, the latter being more severely affected. A few lower motor neurons were found to contain the cytoplasmic inclusions characteristic of ALS (i.e. Bunina bodies and ubiquitin-positive skeins). Also of interest was the presence of pallidonigroluysian atrophy, which appeared to be responsible for the chorea-like involuntary movements that developed in this patient approximately 2 months before death. The clinical and pathological features of our patient further support the idea that motor neuron disease-inclusion dementia (MND-ID), which has been classified as a pathological subgroup of FTD, is a forme fruste of ALS with dementia. In other words, if patients with MND-ID live long enough, they may develop ALS.

Amyotrophic Lateral Sclerosis↗

Sporadic fatal insomnia with spongiform degeneration in the thalamus and widespread PrPSc deposits in the brain.

We report a case of human prion disease of 29 months duration in a 74-year-old Japanese man. The disease started with progressive sleeplessness and dementia. MRI showed gradually progressive cerebral atrophy. Neuronal loss, spongiform change and gliosis were evident in the thalamus and cerebral cortex, as well as in the striatum and amygdaloid nucleus. In the cerebellar cortex, mild-to-moderate depletion of Pukinje cells and spongiform change were observed. Mild neuronal loss in the inferior olivary nucleus was also seen. Immunohistochemistry revealed widespread perivacuolar deposits of abnormal prion protein (PrPsc) in the cerebral cortex, thalamus, basal ganglia, and brainstem, and minimal plaque-like deposits of PrPSc in the cerebellar cortex. In the cerebellar plaque-like deposits, the presence of amyloid fibrils was confirmed ultrastructurally. The entire pathology appeared to lie halfway between those of CJD and fatal insomnia, and further demonstrated the relationship between spongiform degeneration and PrPSc deposits, especially in the diseased thalamus. By immunoblotting, the thalamus was shown to contain the lowest amount of PrPSc among the brain regions examined. The PrPSc of type 2, in which the ratio of the three glycoforms was compatible with that of sporadic fatal insomnia (MM2-thalamic variant) reported previously, was also demonstrated. Analysis of the prion protein gene (PRNP) showed no mutation, and homozygosity for methionine at codon 129. In conclusion, we considered that this patient had been suffering from sporadic, pathologically atypical fatal insomnia.

Aged↗

Influences of dopaminergic lesion on epidermal growth factor-ErbB signals in Parkinson's disease and its model: neurotrophic implication in nigrostriatal neurons.

Epidermal growth factor (EGF) is a member of a structurally related family containing heparin-binding EGF-like growth factor (HB-EGF) and transforming growth factor alpha (TGFalpha) that exerts neurotrophic activity on midbrain dopaminergic neurons. To examine neurotrophic abnormality in Parkinson's disease (PD), we measured the protein content of EGF, TGFalpha, and HB-EGF in post-mortem brains of patients with Parkinson's disease and age-matched control subjects. Protein levels of EGF and tyrosine hydroxylase were decreased in the prefrontal cortex and the striatum of patients. In contrast, HB-EGF and TGFalpha levels were not significantly altered in either region. The expression of EGF receptors (ErbB1 and ErbB2, but not ErbB3 or ErbB4) was down-regulated significantly in the same forebrain regions. The same phenomenon was mimicked in rats by dopaminergic lesions induced by nigral 6-hydroxydopamine infusion. EGF and ErbB1 levels in the striatum of the PD model were markedly reduced on the lesioned side, compared with the control hemisphere. Subchronic supplement of EGF in the striatum of the PD model locally prevented the dopaminergic neurodegeration as measured by tyrosine hydroxylase immunoreactivity. These findings suggest that the neurotrophic activity of EGF is maintained by afferent signals of midbrain dopaminergic neurons and is impaired in patients with Parkinson's disease.

Adrenergic Agents↗