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Biomedical subjects

S Kaneko

Publications and source records attributed to S Kaneko.

At least 109 records · Page 6Linked to original sources
PubMed2001

[Brain abscess developed five years after splenectomy in a patient with idiopathic thrombocytopenic purpura].

The increased susceptibility to infection following splenectomy has been well documented. We report here, a case of brain abscess developed five years after splenectomy in a patient with idiopathic thrombocytopenic purpura (ITP). A 65-year-old woman was admitted to our hospital because of fever, mental disorientation, and weakness in August, 1999. She had been followed with diagnoses of essential hypertension and type 2 diabetes mellitus (DM) since 1988. The patient was diagnosed as having ITP in 1992, and then underwent splenectomy in 1994. Monoclonal gammopathy of undetermined significance (MGUS) of IgG, lambda type was found in February 1999. Though high grade fever persisted after admission, blood cultures were negative. Antibiotics were given without a satisfactory effect. Right hemiparesis and worsening of consciousness developed subsequently. Contrast enhanced cranial computed tomography (CT) disclosed a ringed enhanced low density mass in the left parieto-occipital lobe compatible with a diagnosis of brain abscess. Surgical drainage was performed and 20 ml of pus was obtained. No primary infectious focus of the brain abscess was detected with intensive examinations.

Aged↗
PubMed2001

[A case of bilateral renal cell carcinoma showing a rapid course of death in a long-term hemodialysis patient due to polycystic kidney].

A case of bilateral renal cell carcinoma in a 42-year-old polycystic kidney male is reported. He had been treated with hemodialysis for 22 years. An abnormal small mass was found in one of the left renal cystic lesions by screening ultrasonography and CT scan at the 19th year of the hemodialysis. Left radical nephrectomy was performed and the histological diagnosis was a renal cell carcinoma (RCC). There was no evidence of recurrence and metastasis, however, he presented with asymptomatic macrohematuria two years after the operation. CT scan demonstrated the rapidly progressing right renal tumor and multiple para-aortic lymph node swelling. Right nephrectomy and lymphadenectomy were performed and pathological examination showed the advanced RCC with multiple lymph node metastasis. Eleven months after the second operation followed by interferon therapy. he died of multiorgan metastasis of the RCC. This is the first bilateral RCC case in polycystic kidney patient treated with hemodialysis in Japan.

Adult↗
PubMed2001

Early stage of urolithiasis formation in experimental hyperparathyroidism.

PURPOSE: We have previously noted marked acceleration in the proliferative activity of parathyroid cells in rats with spontaneous hypercholesterolemia and secondary hyperparathyroidism. Using this proliferative potential we investigated whether transplantation of these enlarged parathyroids into normal rats would induce hyperparathyroidism and renal stones. MATERIALS AND METHODS: We used 26-week-old male rats with spontaneous hypercholesterolemia as donors, and 5-week-old normal male Sprague-Dawley rats and rats with spontaneous hypercholesterolemia as recipients. Enlarged parathyroid glands were transplanted into group 1--Sprague-Dawley rats with no treatment, group 2--Sprague-Dawley rats that received FK-506 as an immuno-suppressor, group 3--rats with spontaneous hypercholesterolemia rats that underwent parathyroidectomy plus FK-506 administration and group 4--Sprague-Dawley rats that underwent parathyroidectomy plus FK-506 administration. Parathyroidectomy was performed in recipients before transplantation to ensure a low calcium condition. RESULTS: Grafts were rejected within 11 and 15 weeks in groups 1 and 2, respectively. In group 3, 78% of the grafts were successful even after 19 weeks. In group 4 graft survival was 30% at 15 weeks with complete rejection at 19 weeks. In group 3 gradually elevated serum parathyroid hormone was observed as well as stone plaques containing calcium oxalate and calcium phosphate in renal tubules located mainly in the corticomedullary junction. An increased number of plaques was associated with higher parathyroid hormone. CONCLUSIONS: Our study shows that transplanted parathyroid glands function with an immunosuppressive agent and the maintenance of hypocalcemic conditions, and they secrete sufficient parathyroid hormone to demonstrate hyperparathyroidism. Plaque in these kidneys indicates an early stage of urolithiasis caused by hyperparathyroidism.

Animals↗
PubMed2001

[Detection of underlying causes of death among the deceased of Yusho patients by linkage to the national vital statistics data].

As of January 31, 1996, 292 deaths among registered patients of Yusho were identified by three follow-up studies conducted in 1986, 1990, and 1996. In this study, we attempted to identify underlying causes of death by linkage of the registered data to the National Vital Statistics Data provided by the Management and Coordination Agency of Japan, which included 15 million deaths between 1978 and 1996. The two datasets were linked by matching for six variables; birth year/month/day, death year/month, and sex, along with a variable of death day or death place, or both. The matched cases were 203 among 235 deaths between 1978 and 1996 (matching rate was 86%). Among the 203 deaths, 58 underlying causes of death were newly identified, 146 causes of death were already grasped by the follow-up studies, and 31 deaths did not have matching pair in the National Vital Statistics data. Among the 146 deaths, 110 causes of death were concordant with each other, however, 35 causes of death were completely discord. The reason of the discordance and the unmatched deaths might be due to difference in information of the matching variables in the two datasets. In order to conduct an efficient follow-up study of Yusho patients, identification of underlying causes of death by linkage to the National Vital Statistics Date is evitable. For that, we need to substitute basic information in the Yusho database to those compatible to the National civil registration system.

Cause of Death↗
PubMed2001

[Immunoadsorption therapy for HCV infected chimpanzee].

Response of Interferon therapy to chronic hepatitis C patients are poor who infected high titer of hepatitis C virus(HCV) RNA. It has been reported that HCV particles coexist low density lipoprotein(LDL) or anti-HCV antibodies as antigen-antibody complex in chronic hepatitis C patients. We demonstrated the ability of removal HCV particles by these adsorbents and the efficacy of HCV RNA reduction by immunoadsorption therapy for HCV infected chimpanzee. By batch method, IgG and LDL adsorbent showed 66% HCV RNA reduction and IgG adsorbents kept better adsorption ability than that of others when adsorbent: serum ratio was increased. Immunoadsorption therapy to chronic HCV infected chimpanzee was carried out on-line with a plasma separator. HCV RNA titer of this chimpanzee decreased 35% immediately after therapy, but after 4.5 hours, it recovered as same level as that of before procedure.

Animals↗
PubMed2001

Arsenic contamination of groundwater and prevalence of arsenical dermatosis in the Hetao plain area, Inner Mongolia, China.

An investigation was carried out on arsenic contamination of groundwater and prevalence of arsenical dermatosis in the Hetao plain of Inner Mongolia Autonomous Region, China. Based on the screening of water samples from 96 randomly selected wells in this Region, two areas (Wuyuan and Alashan) were chosen as highly contaminated areas because arsenic in the water samples was higher than 50 microg/l. Arsenic was measured using an arsenic silver diethyl dithiocarbamate method for 326 water samples from all the wells in these areas. The results show arsenic contaminated groundwater from tubule-type wells of depths about 15-30 m was serious compared with open-type wells where depth is about 3-5 m. In the Wuyuan area, 96.2% of water samples from tubule-type wells contained arsenic above 50 microg/l and 69.3% in Alashan area; the highest value was 1354 microg/l and 1088 microg/l, respectively. In these two areas, a health survey was carried out for arsenical dermatosis. The results show the prevalence of arsenical dermatosis in the Wuyuan area was 44.8%, higher than 37.1% prevalence of arsenical dermatosis in the Alashan area. The prevalence of arsenical dermatosis was highest in the over 40-year-old age group. There was no sex difference in the prevalence. Further investigation is needed to clarify the actual situation of arsenic pollution of groundwater in Inner Mongolia, China in order to reduce the adverse health effect among residents exposed to arsenic.

Adolescent↗
PubMed2001

[A case of endobronchial tuberculosis associated with bronchial asthma treated with high doses of inhaled corticosteroid].

A 46-year-old woman had been treated with 1,600-2,000 micrograms/day of beclomethasone dipropionate (BDP) and oral theophylline on the basis of a diagnosis of bronchial asthma in 1993. Eosinophilic pneumonia was diagnosed in June 1999, and she was then treated with 40 mg/day of oral prednisolone (PSL), which was gradually tapered off, and then stopped in October 1999. She was referred to our hospital because acid-fast bacilli were found in the sputum on January 18, 2000. Her chest radiographs and CT scans showed partial atelectasis of the right upper lobe, and fiberoptic bronchoscopy revealed bronchial inflammatory changes and whitish mucosal nodular lesions in the walls of the lower trachea, the right main bronchus and the orifice of the right upper lobe bronchus. She was found to have endobronchial tuberculosis. Anti-tuberculosis treatment with isoniazid, rifampicin, streptomycin and pyrazinamide was started. Serum levels of interferon-gamma were markedly elevated on admission. Asthma symptoms improved for a period of one month after the beginning of anti-tuberculosis treatment, despite the termination of inhaled corticosteroid. However, as the tuberculosis improved, the frequency and severity of the asthma increased and so corticosteroid inhalation was started again. Four months after administration of the anti-tuberculosis drug, fiberoptic bronchoscopy revealed that the endobronchial lesions had improved without any stenosis or constrictive changes. It was speculated that high doses of inhaled corticosteroid may have the potential to cause endobronchial tuberculosis whilst, ironically, at the same time preventing bronchial stenosis by endobronchial tuberculosis. This is an interesting case in which the asthma symptoms first decreased during the acute phase of endobronchial tuberculosis and then increased again after the tuberculosis improved.

Administration, Inhalation↗
PubMed2000

Ion implantation into collagen-coated surfaces for the development of small diameter artificial grafts.

Ion implantation into collagen (Type I) coated inner surfaces of test tubes with a length of 50 mm and an inner diameter of 2 and 3 mm were performed to develop hybrid type small diameter artificial vascular grafts. To obtain information about the cellular response and chemical and physical structure of those collagen surfaces, several experiments such as platelets adhesion test, endothelial cell culture, analysis of amino acids and animal study were performed. He(+) ion implanted collagen coated specimen exhibited cell attachment and inhibit platelet adhesion. From these results, it was assumed that He(+) ions broke the ligands that correspond to platelet, and the ligands that correspond to endothelial cell adhesion still existed after ion implantation. It was suggested that platelets and cell attachment could be control individually by ion implantation into collagen.

Journal Article↗
PubMed2000

The effect of deviant stimulus probability on the human mismatch process.

The present study addresses the separate activities of frontal and temporal MMN generators which might be differentially affected by a change in the probability of standard stimuli. As the probability of standard stimuli was increased, the frontal MMN component significantly increased in amplitude, while the temporal one was not affected. Correspondingly, the scalp current density (SCD) maps showed that the temporal MMN generator was activated even at low probability of standard stimuli, suggesting that even the weak memory trace could start the automatic mismatch process, whereas the frontal MMN generator was activated only with increased probabilities of standard stimuli, suggesting that the stronger the memory trace is, the easier it might trigger the involuntary switching of attention to stimulus change.

Acoustic Stimulation↗
PubMed2000

Dysfunction of M-channel enhances propagation of neuronal excitability in rat hippocampus monitored by multielectrode dish and microdialysis systems.

To explore the pathogenesis of benign familial neonatal convulsions (BFNC), we determined effects of KCNQ-related M-channels (KCNQ-channels) on hippocampal glutamate (Glu) and gamma-aminobutyric acid (GABA) releases using microdialysis, and propagation of evoked field-potentials (FP) using multielectrode (64-ch)-dish system as two-dimensional monitoring. KCNQ-channel inhibitor, Dup996, enhanced hippocampal K(+)-evoked Glu and GABA releases without affecting basal releases of them. Dup996 unaffected FP-amplitude, but enhanced FP-propagation. The GABA(A)-receptor antagonist, bicuculline, enhanced the stimulatory effects of Dup996 on FP-propagation, however, this stimulatory effects of Dup996 were abolished by the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)/glutamate-receptor antagonist, DNQX. These results suggest that the occurrence of BFNC cannot be produced by KCNQ-channel dysfunction alone, but by reciprocal action between impaired KCNQ-channel and other unknown elements (possibly dysfunction of inhibitory neurotransmission system).

Action Potentials↗
PubMed2000

Novel sugar-binding specificity of the type XIII xylan-binding domain of a family F/10 xylanase from Streptomyces olivaceoviridis E-86.

The type XIII xylan-binding domain (XBD) of a family F/10 xylanase (FXYN) from Streptomyces olivaceoviridis E-86 was found to be structurally similar to the ricin B chain which recognizes the non-reducing end of galactose and specifically binds to galactose containing sugars. The crystal structure of XBD [Fujimoto, Z. et al. (2000) J. Mol. Biol. 300, 575-585] indicated that the whole structure of XBD is very similar to the ricin B chain and the amino acids which form the galactose-binding sites are highly conserved between the XBD and the ricin B chain. However, our investigation of the binding abilities of wt FXYN and its truncated mutants towards xylan demonstrated that the XBD bound xylose-based polysaccharides. Moreover, it was found that the sugar-binding unit of the XBD was a trimer, which was demonstrated in a releasing assay using sugar ranging in size from xylose to xyloheptaose. These results indicated that the binding specificity of the XBD was different from those of the same family lectins such as the ricin B chain. Somewhat surprisingly, it was found that lactose could release the XBD from insoluble xylan to a level half of that observed for xylobiose, indicating that the XBD also possessed the same galactose recognition site as the ricin B chain. It appears that the sugar-binding pocket of the XBD has evolved from the ancient ricin super family lectins to bind additional sugar targets, resulting in the differences observed in the sugar-binding specificities between the lectin group (containing the ricin B chain) and the enzyme group.

Binding Sites↗
PubMed2000

Involvement of direct inhibition of NMDA receptors in the effects of sigma-receptor ligands on glutamate neurotoxicity in vitro.

This study was performed to examine the roles of the N-methyl-D-aspartate (NMDA) receptor/phencyclidine (PCP) channel complex in the protective effects of sigma-receptor ligands against glutamate neurotoxicity in cultured cortical neurons derived from fetal rats. A 1-h exposure of cultures to glutamate caused a marked loss of viability, as determined by Trypan blue exclusion. This acute neurotoxicity of glutamate was prevented by NMDA receptor antagonists. Expression of sigma(1) receptor mRNA in cortical cultures was confirmed by reverse transcription polymerase chain reaction (RT-PCR). sigma Receptor ligands with affinity for NMDA receptor channels including the PCP site, such as (+)-N-allylnormetazocine ((+)-SKF10,047), haloperidol, and R(-)-N-(3-phenyl-1-propyl)-1-phenyl-2-aminopropane ((-)-PPAP), prevented glutamate neurotoxicity in a concentration-dependent manner. In contrast, other sigma-receptor ligands without affinity for NMDA receptors, such as carbetapentane and R(+)-3-(3-hydroxyphenyl)-N-propylpiperidine ((+)-3-PPP), did not show neuroprotective effects. Putative endogenous sigma receptor ligands such as pregnenolone, progesterone, and dehydroepiandrosterone did not affect glutamate neurotoxicity. The protective effects of (+)-SKF10,047, haloperidol, and (-)-PPAP were not affected by the sigma(1) receptor antagonist rimcazole. These results suggested that a direct interaction with NMDA receptors but not with sigma receptors plays a crucial role in the neuroprotective effects of sigma receptor ligands with affinity for NMDA receptors.

Animals↗