Biomedical subjects

Y Masuda

Publications and source records attributed to Y Masuda.

At least 181 records · Page 10Linked to original sources

PubMed1999

[Levofloxacin-induced neurological adverse effects such as convulsion, involuntary movement (tremor, myoclonus and chorea like), visual hallucination in two elderly patients].

Levofloxacin-induced-neurological adverse events such as convulsion, involuntary movement (tremor, myoclonus and chorea-like) and visual hallucination in two elderly patients are reported. A 67-year-old man with minor alcoholism and a past-history of gastrectomy and cholecystectomy was given 300 mg/day of oral levofloxacin and fulfenamic acid for an upper respiratory infection. On the 4th day, he reported gradual exacerbation of hand tremor which resembled chorea-like involuntary movement and gait disturbance. He also experienced visual hallucinations. On the 7th day, he suffered generalized convulsions and was admitted. Serum concentration of levofloxacin at this time (3 hours after last administration of a 100 mg tablet of levofloxacin) was 3.6 micrograms/ml. Cessation of the agents promoted complete recovery of these neurological adverse effects within a week. Another 85-year-old man with chronic bronchitis and slight renal impairment received long term administration of 200 mg/day of levofloxacin. On the 68th day of administration, gradual exacerbation of gait disturbance, dysarthria and chorea-like involuntary movement occurred. On the day of admission, 76 days after the start of administration, the serum level of levofloxacin was 2.55 micrograms/ml and that of spinal fluid was 1.12 micrograms/ml (3 hours after the last administration of a 100 mg tablet of levofloxacin). Cessation of the agents promoted complete recovery of these neurological adverse effects within the next two weeks. Both patients had no apparent neurological disorders except age-related brain atrophy. Age-related renal and brain impairment might have contributed to the neurological adverse effects of levofloxacin.

Aged↗

PubMed1999

[Results of a survey of the relationship between palatine tonsil and IgA nephropathy].

To investigate the relationship between palatine tonsil and IgA nephropathy, a survey was performed by questionnaire to 154 non-ENT medical doctors who had reported case of IgA nephropathy. The questionnaire was sent in February 1997, and answers were obtained within one month from 93 doctors (79 internal physicians, 12 pediatricians and 2 pathologists); a 60.4% response rate. A total of 72.0% of doctors answered that renal pathology was the most important prognostic factor for IgA nephropathy. A total of 73.1% of doctors thought that the administration of corticosteroid was the most effective therapy for IgA nephropathy, whereas only one doctor answered that tonsillectomy was most effective. Urine protein was the most useful factor for the estimation of the treatment, according to 37.6% of doctors. The majority of doctors who replied to the questionnaire thought that palatine tonsil seemed to be involved in the pathophysiology of IgA nephropathy in less than half of patients with IgA nephropathy. In addition, they answered that the rate of patients with IgA nephropathy to whom tonsillectomy was effective was also less than 50%. The tonsillar provocation test was rarely performed for the diagnosis of tonsillar focal infection in IgA nephropathy. Furthermore, 51.6% doctors answered that urine protein was the most important factor in any estimation of the provocation test.

Glomerulonephritis, IGA↗

PubMed1999

[Analysis of 209 PCB congeners by high separation gas chromatography/low resolution mass spectrometer].

All PCB congeners were analyzed by high separation gas chromatography/low resolution mass spectrometer, using 209 PCB congeners as standards. They were separated into 169 peaks, including 28 peaks containing 2 PCBs and 8 peaks containing 3 PCBs. The rice oil samples of Fukuoka and Taiwan Poisonings were analyzed for PCB congeners. They showed 115 separated peaks of PCB congeners. Total PCB concentrations were 879 and 769 ppm in 2 samples of Fukuoka rice oil and 57 and 83 ppm in 2 samples of Taiwan rice oil.

Environmental Pollutants↗

PubMed1999

[Analysis of all PCB congeners in breast milk and blood of Yusho patients].

Breast milk and blood of Yusho patients were analyzed for polychlorinated biphenyl (PCB) congeners by High separation gas chromatography/Low resolution mass spectrometer. Seventy-one and forty-nine PCB congeners were identified and quantified in the breast milk and blood, respectively. Total PCB concentrations (Whole base) in breast milk of 2 Yusho patients were 69.9 and 15.1 ppb, respectively, being 11.6 and 2.5 times higher than those of 4 control breast milk. Average total PCB concentration of 5.0 ppb in whole blood of 13 Yusho patients was 3.6 times higher than those of control persons. Fourteen PCB congeners, such as 99, 117, 130, 137, 138, 156, 157, 164, 170, 171, 172, 189, 191 and 195, were particularly higher concentration in breast milk and blood of Yusho patients than in those of control persons. Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and coplanar PCBs were also analyzed in the breast milk of Yusho patients and control persons. Large portions, 83 and 74%, of Dioxin toxic equivalency (TEQ) in the 2 Yusho breast milk were consisted of TEQ of 2,3,4,7,8-pentaCDF only, while total TEQ in the breast milk of control persons was consisted of PCDFs 48%. PCDDs 29% and coplanar PCBs 23%.

Environmental Pollutants↗

PubMed1999

[Metabolism of 3,3',4,4',5-penta- and 2,2',3,3',4,4'-hexachlorobiphenyls in rats].

Following the i.p. administration of 3,3',4,4',5-pentachlorobiphenyl (CB126) and 2,2',3,3',4,4'-hexachlorobiphenyl (CB128) to rats, blood, liver, lung, kidney, adipose tissue and feces were analyzed for the metabolites. CB126 was biotransformed to three hydroxylated metabolites identified as 4-OH-3,3',4',5'-tetraCB, 4-OH-3,3',4',5,5'-pentaCB and 5-OH-3,3',4,4',5'-pentaCB at about 1:7:2 ratio, whereas to two methylthio metabolites as 5-MeS- and 6-MeS-3,3',4,4',5'-pentaCBs at 1:2 ratio. Among the metabolites, only 4-OH-3,3',4',5,5'-pentaCB was detected in all tissues and blood. The ratio of metabolite/unchanged CB126 was 1:1.3 in blood and 1:162 in liver, indicating the high blood affinity of this metabolite. Trace amounts of 5-methylsulfonyl-3,3',4,4',5'-pentaCB was also detected in the liver. CB128 was biotransformed to 5-OH-, 5-MeS- and 6-MeS-2,2',3,3',4,4' hexaCBs which were excreted to feces in about 5:5:1 ratio. No metabolites were detected in blood and any tissues except for liver where trace amounts of 5-hydroxylated metabolite was present, indicating the low tissue affinity of hydroxylated metabolites from CB128.

Animals↗

PubMed1999

[Effect of PCBs on mouse lung tumorigenesis induced by 1-nitropyrene: a preliminary report].

We have analyzed the effect of polychlorinated biphenyls (PCB, Kanechlor-400) on 1-nitropyrene (1-NP) induced lung tumor. Male A/J mice (6 weeks old) were used for the experiment. A total of 2.5 mg/kg PCB was administered intraperitoneally (PCB group), a total of 0.38 mmol/kg 1-NP was administered intraperitoneally for 17 times (1-NP group), PCB was administered followed by i.p. injection of 1-NP (PCB + 1-NP group), and only vehicle was administered (control group). The lung lesions induced were examined 18 weeks after the final treatment with 1-NP or vehicle. In control group, no neoplastic lesion in the lung was induced. In PCB group, only one lesion with adenoma was induced. In 1-NP group, various kinds of lung neoplastic lesions including hyperplasia, adenoma and adenocarcinoma were induced. In PCB + 1-NP group, both the number and size of tumors induced were significantly more than those in 1-NP group. In addition, the number of adenocarcinoma formed was more in PCB + 1-NP group than in 1-NP group. Each lesion was microdissected to collect and analyze DNA of the targeted tissue. K-ras gene mutation was detected in part of adenoma lesions and all the carcinoma lesions. The mutation was found in either 1-NP or PCB + 1-NP group, but not in control and PCB group. The pattern of K-ras mutation was CAA to CGA in codon 61 or GGT to GAT in codon 12. There was no difference in the pattern of K-ras mutation despite of the pretreatment with PCB. Although the present data are from small sample size, it was suggested that PCB may promote (but not initiate) 1-NP induced lung tumorigenesis, and may not induce K-ras mutation directly in the experimental system.

Adenocarcinoma↗

PubMed1999

Induction of sister chromatid exchanges in cultured human lymphocytes with methylsulphonyl PCB congeners.

Methylsulphonyl polychlorinated biphenyls (MSF-PCBs) have already contaminated at relatively high concentration in the lungs and blood of Yusho patients and healthy Japanese people. Therefore, we should give due attention to their biological and toxicological effects to man. In this study, in order to evaluate S-dependent genotoxicity of five MSF-PCB congeners, namely, 3-MSF-4,5,3',4'-tetrachlorobiphenyl (TCB), 3-MSF-4,5,2',3'-TCB, 3-MSF-2,5,2',4',5'-pentachlorobiphenyl (PenCB), 4-MSF-2,5,2',3',4'-PenCB and 4-MSF-2,5,2',3',5',6'-hexachlorobiphenyl (HCB), we have examined their effects on the induction of sister chromatid exchanges (SCEs), which has been frequently used to estimate the dose of S-dependent clastogens, in cultured human lymphocytes in the absence or presence of 2,3,4,7,8-pentachlorodibenzofuran (PenCDF), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 3,4,5,3',4'-pentachlorobiphenyl (Co-PenCB) and the following results were obtained. 1) 4 x 10(-5)M, 7,8-benzoflavone (ANF) and two of the five MSF-PCB congeners, namely, 3-MSF-2,5,2',4',5'- and 4-MSF-2,5,2',3',4'-PenCB at respective doses of 5.2 and 5.8 ppm, which were about 35,000 times higher than the concentrations in the lungs and adipose tissue of healthy Japanese people, significantly enhanced the frequency of SCEs. 2) In the simultaneous treatment of one of the five MSF-PCB congeners and PenCDF (3.9 ppb), TCDD (1.5 ppb) or Co-PenCB (8.8 ppb), the combination of 3-MSF-4,5,3',4'-TCB (6.8 ppb) or 4-MSF-2,5,2',3',5',6'-HCB and one of the three highly toxic chemicals significantly promoted the formation of SCEs. We have already studied whether these MSF-PCBs are non-S-dependent genotoxic compounds or not and have obtained the results that they seemed not to be or very weak ones. Therefore, based on the results of this and our former studies, the five MSF-PCB congeners examined are considered rather potent S-dependent genotoxic chemicals than non-S-dependent ones.

Cells, Cultured↗

PubMed1999

Surgical management of infants with mitral valve stenosis or atresia without diminutive ascending aorta.

The surgical strategy in infants with mitral valve stenosis or atresia without diminutive ascending aorta remains to be established, including the potential for biventricular repair as a definitive operation. Our surgical experience of six infants with mitral valve stenosis (4 patients) or atresia (2 patients) without diminutive ascending aorta was evaluated based on three important factors: left ventricular volume; the nature of the systemic outflow obstruction; and the type of mitral valve anomaly. Two patients with systemic outflow tract diameter less than 65% of normal underwent systemic outflow tract reconstruction, and the other patients with outflow tract diameter more than 68% of normal were able to maintain systemic circulation without repair. Only one patient with mitral valve stenosis without left ventricular outflow tract obstruction underwent a successful open mitral valvotomy as a biventricular repair after first-stage palliation. The left ventricle of the other patients did not grow after first-stage palliation. Due to progressive subaortic narrowing, pulmonary artery banding should be avoided in patients with mitral atresia due to absent atrioventricular connection who are future Fontan candidates. Most patients with this lesion can be expected to become candidates for safe Fontan-type repair.

Aorta↗

PubMed1999

Calbindin and calmodulin localization in the developing vestibular organ of the musk shrew (Suncus murinus).

The distribution of the Ca(2+)-binding proteins, calbindin and calmodulin, in the adult inner ear has been described previously. We undertook immunohistochemical investigation of developmental changes in the distribution of calbindin and calmodulin in the vestibular organ of the musk shrew (Suncus murinus). Expression of calbindin was seen first in the hair cells and the vestibular ganglion on gestational day (GD) 19, in nerve fibres on GD23 and in the otoconia on GD26. On GD19 calmodulin was demonstrable only in the hair cells. On GD26 both Ca(2+)-binding proteins showed a distribution of immunoreactivity in hair cells similar to that seen in adults. The developmental differences in distribution of these binding proteins may suggest different roles in the vestibule. Additionally, Ca(2+)-binding proteins may be a useful index of hair cell maturity.

Animals↗

PubMed1999

Cochlear implantation for symptomatic hereditary deafness.

Recently, the effectiveness of cochlear implantation for hereditary deafness has been reported. We performed cochlear implantation for two patients with symptomatic hereditary deafness. Deafness in one patient was thought to be a result of albinism-deafness syndrome and in the other patient, a result of chronic progressive external ophthalmoplegia syndrome. Since their speech perception abilities improved dramatically, we believe that cochlear implantation should be actively performed for these two syndromes.

Adult↗

PubMed1999

Surgical management and its post-operative complications in congenital aural atresia.

The post-operative complications and hearing results of surgical intervention for congenital aural atresia were investigated. Seventy-five ears with congenital aural atresia were operated on for hearing loss from 1982 to 1996. Tympanoplasty was performed on 37 ears and canaloplasty on the remaining 38. Hearing improvement rates were 70.3% and 31.6%, respectively. The post-operative complications included stenosis of the created auditory canal (29.3%), deterioration of the improved hearing (21.3%) and infection (12.0%). Reoperations were performed on 6 cases for restoring hearing, 16 for stenosis and 6 for infection. Reoperative findings demonstrated that scar formation in the canal caused the stenosis of the newly formed external canal and that lateralization of the new tympanic membrane and subsequent detachment from the ossicles caused the deterioration of improved hearing. Using cartilage and pedicled skin flap prevented stenosis at the orifice of the newly formed external canal. Maintaining hearing improvement requires creating a wide ear canal using as many pedicle flaps as possible and attaching a new tympanic membrane firmly to the ossicles.

Child↗

PubMed1999

Volume quantification of healthy paranasal cavity by three-dimensional CT imaging.

The volume of the air cavities in the paranasal sinuses is, even at present, not only the simplest but also the most important index employed in the evaluation of the paranasal sinus. We have measured the size of the paranasal cavities in 20 healthy Japanese subjects by reconstructing three-dimensional (3-D) computed tomography (CT) images. To avoid any bias in determining the cavity margin, we first measured bilateral maxillary sinuses of a macaque both by silicone injection and by 3-D reconstruction. Then the CT value for 3-D reconstruction was determined by comparison with the volume measured by direct injection. Each sinus of the healthy volunteers was then measured by 3-D reconstruction imaging. Paranasal sinuses were, individually and on the whole, apparently larger than previously reported: 90.1 ml in males and 72.5 ml in females, on average. Comparing with other body size indices, the increment of the size was quite apparent and the lower prevalence of sinusitis was assumed to play a role in this increased volume of paranasal sinuses in the modern Japanese population.

Adult↗

PubMed1999

Prognosis of tonsillectomy in patients with IgA nephropathy.

IgA nephropathy (IgAN) is a type of chronic glomerulonephritis characterized by IgA deposits mainly in the mesangial area. It does not have so favourable a prognosis as was initially thought. This nephropathy is one of the diseases affected by tonsillar focal infections, and there have been patients in whom tonsillectomy has been effective. In this study, 24 patients with IgAN were followed for more than 2 years after tonsillectomy and studied clinicopathologically. Remission of proteinuria was observed in 41.7% of the patients 6 months after surgery and in 50.0% 2 years after surgery. At 2 years after surgery, patients with minor and focal segmental renal lesions showed a significantly higher rate of remission of proteinuria than patients with diffuse renal lesions. There was no statistically significant difference between positive and negative patients in the rate of remission of proteinuria based on any parameter of the tonsillar provocation test at any time after surgery.

Adult↗

PubMed1999

The alteration of penicillin-binding proteins (PBPs) in drug-resistant Streptococcus pneumoniae isolated from acute otitis media.

Streptococcus pneumoniae is the micro-organism most frequently isolated from acute otitis media (AOM). Recently, drug-resistant or insensitive strains have been prevalent among pneumococcal AOM cases and were reportedly associated with persistent or recurrent otitis media. The purpose of this study was to examine the alterations of penicillin-binding proteins (PBPs) in Streptococcus pneumoniae isolated from AOM. The PBP samples from 21 clinically isolated strains were examined by 14C-penicillin binding assay and also by adding CCL and CDTR as competitors of 14C-penicillin. Reduced signals in PBP1A and PBP2X/2A were typically observed with the penicillin-resistant Streptococcus pneumoniae samples, while widely different PBP profiles were obtained in each strain of penicillin-insensitive Streptococcus pneumoniae. The competitive binding assay with penicillin-insensitive strains revealed the reduced affinity of CCL to PBPs in comparison with that of CDTR. The results of the penicillin-binding assay were consistent with the results from minimal inhibitory concentration analysis, and its potential usefulness for the prediction of drug resistance was demonstrated.

Acute Disease↗

PubMed1999

Human papillomavirus as a risk factor for head and neck cancers--a case-control study.

A retrospective, case-control study was conducted to examine the relationship between the presence of human papillomavirus types 16 and 18 (HPV16/18) DNA and the risk of head and neck cancers. Twelve out of 74 (16.2%) head and neck cancers contained HPV16/18 DNA, while 3 out of 70 (4.2%) non-cancer controls showed HPV16/18 positivity by polymerase chain reaction. The presence of HPV16/18 DNA was associated with an increased risk of head and neck cancer formation, showing an odds ratio of 4.32, with a 95% confidence interval of 1.26-14.78. Although its epidemiological impact might be smaller than that of other factors like cigarette smoking, the presence of HPV16/18 DNA in the aerodigestive tract is suggested to be a risk factor for human head and neck cancers.

Carcinoma, Squamous Cell↗

PubMed1999

Involvement of carbohydrate on phospholipase A2, a bee-venom allergen, in in vivo antigen-specific IgE synthesis in mice.

BACKGROUND: Carbohydrates on allergens are known to be important for allergenicity. However, most findings have been made with epitope analysis. In this study, we investigated the involvement of N-glycan on phospholipase A2 (PLA2), the major allergen of honeybee venom, in in vivo synthesis of specific IgE in mice. METHODS: CBA/J and C57BL/6 mice were sensitized intranasally with either native or deglycosylated PLA2 in the absence of adjuvant. After repeated sensitization, serum Ab titers against PLA2 were determined. PLA2 was deglycosylated chemically with anhydrous trifluoromethanesulfonic acid (TFMS). RESULTS: CBA/J mice showed PLA2-specific IgE production after repeated sensitization with native PLA2. They also produced PLA2-specific IgG1 predominantly, suggesting that Th2-type Ab production was induced. When we used deglycosylated PLA2 as a competitor in ELISA for detecting PLA2-specific IgE, deglycosylated PLA2 completely inhibited the binding between native PLA2 and IgE. Deglycosylated PLA2 had the same potential for inducing specific IgE synthesis as native PLA2, since sensitization with deglycosylated PLA2 also elicited IgE production in CBA/J mice. CONCLUSIONS: These results suggest that carbohydrate on PLA2 is less important than previously thought not only as a dominant IgE epitope but also in synthesis of PLA2-specific IgE in vivo.

Allergens↗

PubMed1999

Redo cardiac surgery for atrial septal defect in a patient with idiopathic thrombocytopenic purpura. Preoperative management with high-dose intravenous gamma-globulin.

A 58-year-old woman with idiopathic thrombocytopenic purpura required redo cardiac surgery of atrial septal defect closure, mitral annuloplasty, and tricuspid annuloplasty. Preoperative high-dose intravenous gamma-globulin and platelet transfusion after termination of cardiopulmonary bypass allowed successful redo cardiac surgery. Management of a patient with idiopathic thrombocytopenic purpura undergoing open heart surgery are discussed.

Female↗

PubMed1999

[A simple method for regional cerebral blood flow measurement by one-point arterial blood sampling and 123I-IMP microsphere model (Part 2): A study of time correction of one-point blood sample count].

In our previous paper regarding determination of the regional cerebral blood flow (rCBF) using the 123I-IMP microsphere model, we reported that the accuracy of determination of the integrated value of the input function from one-point arterial blood sampling can be increased by performing correction using the 5 min: 29 min ratio for the whole-brain count. However, failure to carry out the arterial blood collection at exactly 5 minutes after 123I-IMP injection causes errors with this method, and there is thus a time limitation. We have now revised our method so that the one-point arterial blood sampling can be performed at any time during the interval between 5 minutes and 20 minutes after 123I-IMP injection, with addition of a correction step for the sampling time. This revised method permits more accurate estimation of the integral of the input functions. This method was then applied to 174 experimental subjects: one-point blood samples collected at random times between 5 and 20 minutes, and the estimated values for the continuous arterial octanol extraction count (COC) were determined. The mean error rate between the COC and the actual measured continuous arterial octanol extraction count (OC) was 3.6%, and the standard deviation was 12.7%. Accordingly, in 70% of the cases, the rCBF was able to be estimated within an error rate of 13%, while estimation was possible in 95% of the cases within an error rate of 25%. This improved method is a simple technique for determination of the rCBF by 123I-IMP microsphere model and one-point arterial blood sampling which no longer shows a time limitation and does not require any octanol extraction step.

Adult↗