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J Yoshida

Publications and source records attributed to J Yoshida.

At least 91 records · Page 5Linked to original sources
PubMed2000

Involvement of tyrosine kinase in citrate-stimulated aldosterone production in bovine glomerulosa cells.

The present study was designed to assess whether citrate stimulates aldosterone production by isolated bovine adrenal glomerulosa cells in vitro. When the cells were incubated with graded concentrations of citrate up to 4.0 mM, basal aldosterone production was significantly elevated, with a gradual reduction of extracellular ionized calcium concentration. Without citrate, however, adding increasing amounts of calcium chloride to a calcium-free medium did not reproduce the citrate's effect on basal aldosterone production. Genistein, an inhibitor of tyrosine kinases, inhibited the citrate (4 mM)-induced aldosterone production in a dose-dependent manner, with 89.8% of inhibition at a concentration of 10 microM. When the cells were exposed to citrate (4 mM) for 5, 10, and 30 min, tyrosine in Mr 105,000 endogenous protein was dominantly phosphorylated. This study demonstrates for the first time that citrate stimulates aldosterone production in bovine adrenal glomerulosa cells in vitro and also suggests a crucial involvement of protein tyrosine kinase in the steroidogenic action of citrate in the cells.

Aldosterone↗
PubMed2000

Interactions of cyclodextrins with dipalmitoyl, distearoyl, and dimyristoyl phosphatidyl choline liposomes. A study by leakage of carboxyfluorescein in inner aqueous phase of unilamellar liposomes.

The interaction of cyclodextrins (CDs) with L-alpha-dipalmitoyl phopsatidyl choline (DPPC), L-alpha-distearoyl phosphatidyl choline (DSPC), and L-alpha-dimyristoyl phosphatidyl choline (DMPC) unilamellar liposomes was investigated by the leakage of carboxylfluorescein (CF) entrapped in the inner aqueous phase of liposomes, at 25 degrees C (DPPC and DSPC liposomes) and at 5 degrees C (DMPC liposomes). The efficiency of CDs for CF leakage was remarkable in the order of heptakis (2,6-di-O-methyl)-beta-CD (DOM-beta-CD) > alpha-CD > heptakis (2,3,6-tri-O-methy)-beta-CD (TOM-beta-CD) from DPPC liposomes, in the order of DOM-beta-CD > TOM-beta-CD > alpha-CD from DSPC liposomes and in the order of alpha-CD > DOM-beta-CD > TOM-beta-CD from DMPC liposomes. The other CDs used in the present studies, beta-CD, 2-hydroxylpropyl beta-CD, and gamma-CD scarcely induced the CF leakage from above the three liposomes. From the profiles of % CF leakage, together with measurements of differential scanning calorimetry, it was found that hydrophobic DOM-beta-CD penetrates the matrix of the liposomes to interact with them as well as TOM-beta-CD, and that less hydrophobic alpha-CD exists at the surface of the membrane to interact with the liposomes. Further, it was found that the interaction of CDs with liposomes changes depending not only on the length of fatty acid chain of phospholipid (condensation force and hydrophobicity) but also the hydrophobicity and the cavity size of CD.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2000

Association of p53 expression with second primary tumour development in hypopharyngeal carcinoma.

Abnormalities of p53 tumour suppressor gene are detected in a diversity of malignancies and play an important role in their pathogenesis. Hypopharyngeal carcinoma is the most morbid among head and neck squamous cell carcinomas because of the high incidence of treatment failures and because a biological marker predictive of the treatment failures remains elusive. The expression of p53 protein in 46 hypopharyngeal squamous cell carcinomas was examined histochemically and p53 immunoreactivity was found in 19 of 46 cases (41.3 per cent). The rate of second primary tumour development was significantly higher in the p53-positive group than in the p53-negative group (p = 0.039), whereas that of tumour recurrence was not significantly different between the two. Moreover, there was no statistically significant difference in either overall or disease-free survival between the p53-positive and -negative groups. These results indicate that although p53 expression significantly correlates with second primary tumour development in patients with hypopharyngeal squamous cell carcinomas, it is not predictive of the clinical outcome.

Biomarkers, Tumor↗
PubMed2000

Endoscopic treatment of vesicoureteral reflux in children with glutaraldehyde cross-linked bovine dermal collagen. Short-term results.

BACKGROUND: Endoscopic treatment using glutaraldehyde cross-linked (GAX) collagen was conducted on 4 children with bilateral primary vesicoureteral reflux (VUR)..... a 1-year-old boy and three 5- to 8-year-old girls $B!D (Ball having a history of repeated hospitalization for fever due to acute pyelonephritis, visiting as pediatric outpatients regularly and receiving antibiotics continuously. By international VUR classification, 4 ureters were grade 3, 2 grade 4, and 2 grade 5. METHODS: After nonallergy to GAX collagen was confirmed intracutaneously, a needle was used through a 9.5 Fr cystoscope channel to puncture bladder mucosa 4 to 5 mm from the affected ureteral orifice at 6 o'clock under general anesthesia; 1.1 to 1.9 ml of GAX collagen was injected immediately below affected orifices. RESULTS: Three months after surgery, voiding cystourethrography showed reflux had disappeared in 6 ureters, for a short-term success rate of 75%. VUR in the Remaining 2 ureters improved from grade 3 to 1 and from grade 5 to 4. No postoperative urinary tract infection occurred and antibiotics were stopped. CONCLUSION: Since GAX collagen is less viscous than Teflon paste, it is easily injected into submucosa, does not form granuloma or migrate to other organs, and is noncarcinogenic. Endoscopic VUR treatment using GAX collagen is indicated when less invasion and shorter hospitalization are considered, although it requires general anesthesia, which itself involves some risk.

Child↗
PubMed2000

Clinical predictors of N2 disease in non-small cell lung cancer.

OBJECTIVES: To identify clinical or radiologic predictors of mediastinal lymph node involvement in patients with non-small cell lung cancer, and to define the indications of preoperative mediastinoscopy. METHODS: From August 1992 through April 1997, 387 patients with lung cancer (290 adenocarcinoma and 97 squamous cell carcinoma) underwent surgical resection. We retrospectively measured all mediastinal lymph node sizes both in the shortest and longest axes on contrast-enhanced CT scan to determine the optimal size criteria. Using multivariate logistic regression analysis, we identified clinical or radiologic predictors of N2 disease. RESULTS: We could not identify reliable size criteria for nodal involvement. We found two significant predictive factors of N2 disease on the basis of multivariable analysis: maximum tumor dimension and serum carcinoembryonic antigen (CEA) concentrations. The lymph node size did not prove to be a significant factor. Among 50 patients with serum CEA concentrations < 5.0 ng/mL and maximum tumor dimension < 20 mm, pathologic N2 disease was proven only in three patients (6%), regardless of the lymph node size on CT scan. Among 140 patients with serum CEA concentrations > or = 5.0 ng/mL and maximum tumor dimension > or = 20 mm, approximately one third (n = 46) showed N2 disease. CONCLUSION: Serum CEA concentrations and maximum tumor dimension were more valuable in predicting N2 disease than the lymph node size on CT scan. Mediastinoscopy is indicated in patients with serum CEA concentrations > or = 5.0 ng/mL and maximum tumor dimension > or = 20 mm, and not indicated in patients with serum CEA concentrations < 5.0 ng/mL and maximum tumor dimension < 20 mm.

Adult↗
PubMed2000

Transduction efficiency of adenoviral vectors into human glioma cells increased by association with cationic liposomes.

Replication-deficient adenoviral vectors are promising agents for human gene therapy of the greater transduction efficiency than other vectors. However, there are distinct disadvantages, including high immunogenicity, which limits the administration to human organs, particularly the brain. Injection of adenoviral vectors into the human brain causes inflammatory responses and induces cerebral edema. The combined effect of adenoviral vectors and cationic liposomes in vitro was investigated in an effort to reduce the immune reaction against the antigens of adenoviral vectors. No toxicity of adenoviral vector-associated liposomes was observed within optimal lipid concentration. The transduction efficiency of the adenoviral vectors containing the beta-galactosidase gene increased almost 10-fold when associated with the cationic liposomes. Furthermore, greater cytotoxicity was induced when the adenoviral vector containing herpes simplex virus-thymidine kinase gene was combined with cationic liposomes than with only the adenoviral vector. These results suggest that the combination of adenoviral vectors and cationic liposomes allows the doses of adenoviral vectors to be reduced while maintaining transduction efficiency.

Adenoviridae↗
PubMed2000

Cerebral blood flow during plateau waves in a patient with benign intracranial hypertension--case report.

A 50-year-old male presented with benign intracranial hypertension (BIH). He was admitted to our hospital for headache and papilledema. The diagnosis was BIH as continuous monitoring of lumbar cerebrospinal fluid pressure (CSFP) showed high basal pressure with intermittent plateau waves. Ten months after successful ventriculoperitoneal shunting, he presented with headache again due to shunt malfunction. CSFP monitoring showed the same findings as before. Regional cerebral blood flow (rCBF) was measured by positron emission tomography (PET) using the 15O-labeled water autoradiographic method with simultaneous recording of lumbar CSFP. The rCBF values of the cerebral cortex, white matter, thalamus, cerebellar cortex, and pons were evaluated during both the plateau waves and the intervals. In spite of severely reduced cerebral perfusion pressure, rCBF during the plateau waves was not reduced when compared with the rCBF of normal volunteers in all regions. This result might explain why patients with BIH show no impairment of consciousness or focal signs during the plateau waves.

Autoradiography↗
PubMed2000

Percutaneous microcompression of the trigeminal ganglion for elderly patients with trigeminal neuralgia and patients with atypical trigeminal neuralgia.

Percutaneous microcompression of the trigeminal ganglion (PMTG) was performed in nine elderly patients (> 70 years) with trigeminal neuralgia and six patients with atypical neuralgia under short-acting anesthesia using propofol. Two patients had postherpetic neuralgia and two had postoperative neuralgia following removal of a posterior fossa neurinoma. Four patients had recurrent neuralgia following microvascular decompression (MVD). PMTG provided complete relief in 10 patients and the other five patients reported at least 50% improvement. No major complications occurred. PMTG is effective for typical trigeminal neuralgia in elderly patients, patients with atypical trigeminal neuralgia, and patients with recurrence after MVD.

Aged↗
PubMed2000

Sarcomatous transformation of a prolactinoma associated with development of a fatal internal carotid artery pseudoaneurysm--case report.

A 21-year-old female with a 5-year history of prolactinoma was referred to our hospital because of cerebrospinal fluid leakage and meningitis immediately following a third transsphenoidal operation for a rapidly growing tumor. Histological examination of the tumor removed at the second transsphenoidal operation found atypical epithelial and sarcomatous components. Administration of bromocriptine, radiotherapy, and chemotherapy were initiated. Emergent craniotomy was required for rapid regrowth of the tumor. Histological examination found predominant sarcomatous components. Tumor growth was difficult to control. The patient died of subarachnoid hemorrhage due to rupture of a pseudoaneurysm involving the C1 portion of the right internal carotid artery. Pituitary adenoma rarely shows malignant transformation. In this case, prolactinoma underwent malignant change to sarcoma. Development of the pseudoaneurysm may have resulted from surgical manipulation, radiotherapy, or tumor invasion.

Adult↗
PubMed2000

Immunogenetic background of patients with autoimmune fatigue syndrome.

We have previously reported that approximately 50% of children with chronic nonspecific complaints were positive for antinuclear antibodies (ANA), and that a novel autoantibody to a 62 kD protein (anti-Sa) was found in 40% of these ANA-positive patients. Therefore, we proposed a distinct disease entity termed autoimmune fatigue syndrome (AIFS). We hypothesized that if autoimmune mechanisms did play an important role in the pathogenesis of AIFS, it is possible that it is immunogenetically regulated as observed in other autoimmune disorders. In order to examine the immunogenetic background of AIFS patients, HLA-A, -B, -C, and -DR loci were analyzed serologically in 61 AIFS patients. AIFS was found to be positively associated with the class I antigen HLA-B61 and with the class II antigen HLA-DR9, with odds ratios of 2.77 (p = 0.015, Pcorr = 0.48) and 2.60 (p= 0.012, Pcorr = 0.17), respectively. A negative association was also found between AIFS and HLA-DR2 with odds ratio of 0.25 (p = 0.029, Pcorr = 0.041). When comparing anti-Sa positive AIFS patients with healthy controls, the odds ratios associated with HLA-B61, DR9, and DR2 were 3.42 (p = 0.021, Pcorr = 0.22), 3.96 (p = 0.0011, Pcorr = 0.015), and 0.16 (p = 0.0022, Porr = 0.031), respectively. Thus, the HLA associations observed in this study suggested that immunogenetic background might play a role in AIFS.

Adolescent↗
PubMed2000

Protein kinase inhibition by fasudil hydrochloride promotes neurological recovery after spinal cord injury in rats.

OBJECT: In Japan fasudil hydrochloride (HA1077), a protein kinase inhibitor, is widely administered to prevent vasospasm in patients after subarachnoid hemorrhage. The effects of fasudil on experimental spinal cord injury (SCI) were investigated and compared with those obtained using methylprednisolone. METHODS: Spinal cord contusion was induced in rats by applying an aneurysm clip extradurally to the spinal cord at T-3 for 1 minute. After injury three groups of rats were treated with intravenously administered saline (control), intraperitoneally administered fasudil (10 mg/kg), or intravenously administered methylprednisolone (four 30 mg/kg injections). Neurological recovery was evaluated periodically over 1 month by using a modified combined behavioral scale and histopathological examination. Leukocyte infiltration near the injury site was evaluated by measuring myeloperoxidase (MPO) activity at 24 hours. Spinal cord blood flow was measured at intervals up to 3 hours after injury by using laser Doppler flowmetry. In rats in the fasudil-treated group significant improvement in modified combined behavioral score was demonstrated at each time point, whereas in the methylprednisolone-treated rats no beneficial effects were shown. In the fasudil-treated group, reduction of traumatic spinal cord damage was evident histologically in the caudal portion of the injured areas, and tissue MPO activity in tissue samples was reduced. Spinal cord blood flow was not significantly different between fasudil-treated and control group rats. CONCLUSIONS: Fasudil hydrochloride showed promise of effectiveness in promoting neurological recovery after traumatic SCI. Possible mechanisms of this effect include protein kinase inhibition and decreased infiltration by neutrophils.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2000

[Intramedullary spinal cord metastasis associated with hemorrhage: a case report].

A rare case of intramedullary spinal cord metastasis associated with hemorrhage was reported. A 74-year-old man had a subacute onset of paraparesis. He became almost paraplegic within a few days. MRI revealed an intramedullary spinal lesion in the epiconus at the Th 11 and Th 12 level, but spinal angiography did not show any abnormality. Since repeated MRI showed enlargement of the lesion, surgery was performed under the diagnosis of an intramedullary spinal cord tumor. Under general anesthesia, a midline myelotomy of about 3 cm was performed and a grayish, elastic and circumscribed tumor as well as a liquefied hematoma in the caudal part was observed. Both the tumor and the hematoma were removed almost totally. The patient's paraparesis improved slightly after surgery. The histological diagnosis was adenocarcinoma. The primary source was unknown, but multiple small metastatic tumors were found in the lung, liver and brain, etc. Hemorrhage from intramedullary spinal cord metastasis is extremely rare with only 6 reported cases in the recent literature. Rapid deterioration of symptoms caused by the hematoma may make the diagnosis more difficult. Indication of surgical treatment should be carefully determined because prognosis of intramedullary spinal cord metastasis is generally very poor.

Adenocarcinoma↗
PubMed2000

[Proposed mechanism of action of metalloendopeptidase-F in the treatment of patients with chronic hepatitis B or C infection].

Chronic hepatitis B and C virus infections have been characterized by the pathophysiological features with a high incidence of progression to cirrhosis and development of hepatocellular carcinoma. The viral persistence produced by escape mutations from virus-specific cytotoxic T lymphocytes (CTL) response may lead to upregulation of delayed-type hypersensitivity immune response, which causes hepatic tissue damage through non specific macrophage activation and CTL response and promotes pathogenesis of hepatic fibrosis. In a preliminary clinical study, a novel metalloendopeptidase-F (MEP-F) has been shown to be effective in the treatment of patients with either chronic hepatitis B or C infection. Oral administration of MEP-F resulted in a significant reduction of the serum levels of HBs antigen and HCV RNA and improvement in the liver function abnormalities. However, the mechanism of action of MEP-F is not yet well understood. There are accumulating evidences showing an important role of alpha 2-macroglobulin-proteinase complexes in regulatory mechanisms of immune response and repairing within impaired and inflammatory tissues. In this article, reviewing the pharmacological and biological properties of alpha 2-macroglobulin-proteinase complexes, the mechanism of anti-viral effect of MEP-F is examined based on the clinical findings. It is indicated that alpha 2-macroglobulin-MEP-F complexes may induce macrophage/Kuppfer cell activation and proliferation through binding their receptors on the cells and activating signaling cascades, which enhance both anti-viral specific and nonspecific immune responses. alpha 2-Macroglobulin-MEP-F complexes may also augment cellular immunity and hepatic regeneration by neutralizing the immunosuppressive and fibrogenic activities of transforming growth factor-beta.

Animals↗
PubMed2000

[Surgical resection of lung cancer in a patient with von Willebrand's disease].

Von Willebrand's disease (vWD) is one of the most common inherited hemorrhagic disorders, and there have been few reports on major thoracic surgery performed in a patient with the disease. We report a vWD patient who underwent of surgical resection of lung cancer. A 67-year-old gentleman, was diagnosed to have vWD when he was an infant, but he needed no medical treatment. Abnormal shadow in the lung was detected on a mass screening chest X-ray. We performed open biopsy, which proved the shadow to be large cell cancer, and performed right upper lobectomy and lymph node dissection. We used Contact-F, monitoring factor VIII, vWD factor and factor VIII-related antigen, during and after the operation, with a successful result.

Aged↗
PubMed2000

[Correlation between DNA topoisomerase II alpha expression and sensitivity to etoposide in human glioma cell lines].

The expression of topoisomerase II alpha (Topo II alpha) was investigated in six human glioma cell lines as a function of doubling time, cell cycle distribution, and sensitivity to an antineoplastic agent, etoposide (ETP). The Topo II alpha level was determined by immunohistochemical and flow cytometric studies using monoclonal antibody, 8D2, specific for Topo II alpha. In all cell lines, the Topo II alpha level correlated directly with sensitivity to ETP, but not with doubling time or percentage of cells in any phase of the cell cycle. These findings suggest that the cytocidal activity of ETP may be mediated by qualitative and quantitative changes in Topo II alpha in human glioma cells. We speculate that better knowledge of Topo II alpha expression in surgical specimens may lead to more individualized use of ETP in patients with malignant glioma.

Antigens, Neoplasm↗
PubMed2000

Human visual motion areas determined individually by magnetoencephalography and 3D magnetic resonance imaging.

We used magnetoencephalography to study inter-individual locational difference in the extrastriate region which responds to visual motion. Magnetic responses to visual motion onset from the right temporo-occipital area were recorded from 12 subjects. All the subjects had clear responses to apparent or random dot coherent motion. The origins of these responses was investigated by use of the single equivalent current dipole model. The nearest scalp to the origin also was identified for each subject, which may be useful in transcranial stimulation studies. Although the magnetic responses of all the subjects should have the same functional properties; be related to neural activities synchronized exclusively to the onset of motion, the estimated origins varied greatly among the subjects. The location of origin could be classified as one of three types: temporo-occipital, occipital, or parietal, according to the sulcal anatomy investigated in the individual's three-dimensional magnetic resonance image. Temporo-occipital types were found for seven subjects, and anatomically the regions were around human MT/V5. Two subjects had the occipital type, with regions posterior to the anatomical MT/V5 and corresponding to V3A anatomically. The other three subjects had origins classified as the parietal type dorso-rostral to the anatomical MT/V5, with regions around the posterior end of the superior temporal sulcus. Although all these cortical regions appear to be related to the neural process of visual motion, whether they correspond functionally to the same names or migrated MT/V5 must now be determined.

Adult↗