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Biomedical subjects

K Yoshida

Publications and source records attributed to K Yoshida.

At least 127 records · Page 7Linked to original sources
PubMed2002

Serological and genetic characterization of newly isolated Peaton virus in Japan. Brief report.

The viruses were isolated from the blood of sentinel cattle and Culicoides biting midges in the Kyushu district, southwestern Japan, in 1999 and identified by neutralization tests as Peaton (PEA) viruses. Before this study, PEA virus had been isolated in Australia only. The nucleotide identity of the nucleocapsid (N) protein encoded by the S segment ranged from 91.1 to 91.6% between the Australian and Japanese strains. A phylogenetic analysis of the N protein sequence revealed that the PEA virus strains are closely related to Aino (AIN) virus and suggested reassortment events for PEA and AIN viruses.

Amino Acid Sequence↗
PubMed2002

Nucleotide sequence of a Japanese isolate of Squash mosaic virus. Brief report.

The complete nucleotide sequence of the RNA-1 of Squash mosaic virus (SqMV) was determined using a Japanese isolate (Y-SqMV). The sequence consisted of 5865 nucleotides excluding the poly (A) at the 3' terminus and contained a single long open reading frame with a coding capacity for a protein of Mr209971. Analysis of the deduced amino acid sequence suggested a genomic organization typical of comoviruses. The nucleotide sequence of the RNA-2 of Y-SqMV was also determined and compared with the SqMV isolates from the United States. The larger and smaller capsid protein (CP) coding region was compared to those of K-SqMV and Z-SqMV, which represent two subgroups of SqMV. The larger CP gene of Y-SqMV showed 93.0% and 88.0% identities with those of K-SqMV and Z-SqMV, respectively at the nucleotide level. The smaller CP gene of Y-SqMV was 94.1% and 88.4% identical with those of K-SqMV and Z-SqMV. The results suggested that the Japanese SqMV isolate (Y-SqMV) is distinct from those in the United States, and might represent a third subgroup.

Comovirus↗
PubMed2002

Joint strength of laser-welded titanium.

OBJECTIVE: The objective of this study was to examine the joint strength of titanium laser-welding using several levels of laser output energy [current (A)]. METHODS: Cast titanium plates (0.5 x 3.0 x 40 and 1.0 x 3.0 x 40 mm(3)) were prepared and perpendicularly cut at the center of the plate. After the cut halves were fixed in a jig, they were laser-welded using a Nd: YAG laser at several levels of output energy in increments of 30A from 180 to 300A. The penetration depths of laser to titanium were measured under various conditions for output energy, pulse duration, and spot diameter to determine the appropriate conditions for these parameters. Based on the correlation between the results obtained for penetration depth and the size of the specimens (thickness: 0.5 and 1.0 mm, width: 3.0 mm), the pulse duration and spot diameter employed in this study were 10 ms and 1.0 mm, respectively. Three laser pulses (spot diameter: 1.0 mm) were applied from one side to weld the entire joint width (3.0 mm) of the specimens. Uncut specimens served as the non-welded control specimens. Tensile testing was conducted at a crosshead speed of 2 mm/min and a gage length of 10 mm. The breaking force (N) was recorded, and the data (n=5) were statistically analyzed. RESULTS: For the 0.5 mm thick specimens, the breaking force of the specimens laser-welded at currents of 240, 270, and 300A were not statistically (P>0.05) different from the non-welded control specimens. There were no significant differences in breaking force among the 1.0mm thick specimens laser-welded at currents of 270 and 300A, and the non-welded control specimens. SIGNIFICANCE: Under appropriate conditions, joint strengths similar to the strength of the non-welded parent metal were achieved.

Aluminum Silicates↗
PubMed2002

Caffeine test in predicting flutamide-induced hepatic injury in patients with prostate cancer.

The caffeine test measures the activity of cytochrome p450 (CYP1A2) which is a major enzyme involved in the activation of flutamide. The usefulness of this test in predicting flutamide-induced hepatic injury in patients with prostate cancer was examined. The subjects were: (1). five patients whose aspartate aminotransferase (AST) or alanine aminotransferase (ALT) level rose to 100 IU/l or higher following the start of flutamide (moderately injured group); (2). four patients whose AST and ALT levels were higher than normal but less than 100 IU/l (mildly injured group); and (3). two patients whose hepatic function remained normal (normal group). The subjects were each given canned coffee to drink. Urinary caffeine (137X), paraxanthine (17X) and 1, 7-dimethyluric acid (17U) levels were measured 4-5 h later. The metabolite ratio, (17U+17X)/137X, was calculated to serve as an indicator of CYP1A2 activity. The metabolite ratio for the moderately injured group (3.98+/-1.56) and the mildly injured group (5.55+/-1.42) were lower than that for the normal group (9.56). The results suggest that a decrease in CYP1A2 activity is involved in the onset of flutamide-induced hepatic injury, and that the caffeine test seems to provide a useful means of its prediction.

Aged↗
PubMed2002

Lymphoepithelial lesion of the parotid gland.

We describe a case of lymphoepithelial lesion of the parotid gland, also known as salivary lymphoepithelial lesion. Lymphoepithelial lesions are usually seen in conjunction with autoimmune disease of the salivary glands and these lesions do not always remain benign. Our case consisted of two masses that had different imaging features. Moreover, we could investigate the changes of the size and internal architecture on imaging due to the postponement of surgical intervention on the masses. At review 6 months later, the size of the masses had increased. The aims of this paper were to: (1) investigate the contribution of gray-scale sonography, power Doppler sonography, magnetic resonance imaging, and computed tomography to the diagnosis; and (2) consider the appropriate imaging modality to follow-up this case to monitor for recurrence or malignant transformation.

Diagnosis, Differential↗
PubMed2002

Factors influencing the therapeutic effect of muscle afferent block for oromandibular dystonia and dyskinesia: implications for their distinct pathophysiology.

Oromandibular dystonia (OMD) is a focal dystonia manifested by involuntary masticatory and/or lingual muscle contractions. Muscle afferent block (MAB) by injecting anaesthetic and alcohol intramuscularly is recently used for the treatment of OMD. To study the factors affecting the efficacy of MAB, 44 patients with OMD were treated by local injection of lidocaine and ethanol. They were divided into four groups (spastic, rhythmic, dyskinetic, and task-specific) according to the pattern of incisal movement and involuntary contraction. We used a clinical scaling protocol in terms of four parameters (mastication, speech, pain, and discomfort) to evaluate the change of symptoms objectively. The relationship of improvement in clinical scores with various parameters was assessed statistically. The overall objective improvement was 60.2 +/- 29.5%. The scores decreased significantly (P<0.0001, paired t-test) after MAB. The maximal incisal velocity significantly correlated inversely with the clinical improvement, and MAB was particularly effective for spastic contraction. Dyskinetic and rhythmic groups showed variable and significantly less improvements than the spastic group. MAB is highly effective for OMD, but not for the patients with dyskinetic symptoms. The jaw movement pattern is an important factor for predicting the outcome. The difference in the response to MAB in OMD and oral and/or orofacial dyskinesia suggests the distinct pathophysiology between the two.

Adolescent↗
PubMed2002

Pharmacokinetics of a benzodithiin (RD3-0028) following aerosol treatment in rat.

1. RD3-0028, a benzodithiin compound, has potent antiviral activity against respiratory syncytial virus (RSV) in cell culture. The compound also inhibits growth of RSV and improves pathologic changes of interstitial pneumonia in the immunosuppressed mouse when delivered by small-particle aerosol. 2. In the present study, the absorption, distribution and excretion of 14C-RD3-0028 were compared in rat following either a single aerosol treatment or oral administration. 3. The plasma concentration was maintained at the same level from 5 min to 1 h, and decreased with a half-life of 2.2 +/- 0.1 h for 1-8 h. 4. The excretion of radioactivity in the urine and faeces at 24 h after aerosol treatment was 89.3 and 4.5%, respectively, indicating that almost all the radioactivity was rapidly excreted in the urine. The excretion of total radioactivity was 98.9% within 168 h. 5. The concentrations of radioactivity in the lung and trachea following aerosol treatment were higher than those in other tissues, and were detected even at 72 h. 6. These results suggest that the aerosol treatment might be useful for delivering RD3-0028 to the respiratory tract of RSV-infected patients.

Administration, Oral↗
PubMed2002

Cytogenetic and cellular events during radiation-induced thymic lymphomagenesis in the p53 heterozygous (+/-) B10 mouse.

PURPOSE: Cellular and cytogenetic events in radiation-induced thymic lymphomagenesis were investigated in the p53 heterozygous (+/-) mouse following a single dose of whole-body irradiation. MATERIALS AND METHODS: The loss of the wild-type p53 allele and microsatellite markers of chromosome 11 in thymic lymphomas that developed in the p53 heterozygous (+/-) mouse after irradiation, and the stage at which prelymphoma cells appeared were analysed. RESULTS: The p53 heterozygous mouse developed thymic lymphomas in a dose-dependent manner. The loss of the wild-type p53 allele (loss of heterozygosity; LOH) occurred in almost all thymic lymphomas induced in the irradiated p53 heterozygous mouse. Cytogenetic analysis for the mechanism of LOH strongly suggested that the loss of the wild-type p53 gene in the lymphomas was caused by duplication of the disrupted allele through either homologous recombination or non-disjunctional chromosome duplication. The assay for prelymphoma cells suggested that a critical event in the development of prelymphoma cells occurred at least 3 weeks after irradiation. CONCLUSIONS: The loss of the wild-type p53 gene in thymocytes of the p53 heterozygous mouse may precede the development of prelymphoma cells after irradiation and be a valuable marker of radiation-induced leukemogenesis.

Animals↗
PubMed2002

Cyclic changes of granulocyte colony-stimulating factor (G-CSF) mRNA in the human follicle during the normal menstrual cycle and immunolocalization of G-CSF protein.

BACKGROUND: Ovulation has several similarities with inflammation and is closely connected to the activity of leukocytes and inflammatory cytokines. Since granulocytes are one of the major leukocytes, we focused our attention on the presence and local production of granulocyte colony-stimulating factor (G-CSF) in the human ovary. METHODS: The presence of G-CSF protein in the follicular fluid and perifollicular tissues was examined by Western blot analysis (n = 5) and immunohistochemical staining (n = 10). The relative expression levels of G-CSF mRNA in relation to GAPDH in granulosa, theca and luteal cells during the menstrual cycle were measured by quantitative RT-PCR using TaqMan technology (n = 15). RESULTS: G-CSF protein was detected in all follicular fluid and located mainly in granulosa cells of the follicle and luteal cells. The expression level of G-CSF mRNA in the late follicular phase was 137.6 +/- 18.5, which was approximately 10-fold greater than other phases during the menstrual cycle (P < 0.05). CONCLUSIONS: These results demonstrate that G-CSF is produced in the human follicle shortly before the ovulatory phase and may play an important role in the mechanism of ovulation.

Adult↗
PubMed2002

NOR-1: a nitric oxide releasing agent for calibrating low levels of nitric oxide by the chemiluminescence method.

Nitric oxide (NO) is formed in small amounts in vivo and is rapidly oxidized by interacting with oxygen, making measurement of its level difficult. The chemiluminescence assay is the most widely used method for detecting NO and is extremely sensitive to very small amounts of NO. However, it is difficult to prepare small amounts of NO to be used as a standard for NO analysis. NOR-1, a derivative of NOR-3, is a newly discovered NO donor with rapid NO-releasing activity. We assessed the dynamics of NO release and decomposition using NOR-1. Our results demonstrate that NOR-1 is stable in dimethylsulfoxide (DMSO) and is able to dilute at lower concentration (to picomolar levels) by DMSO without decomposition. NOR-1 released persistently 1.4 more excess of NO with 15 min of incubation. There was a linear relationship between the concentration of NOR-1 and that of NO released from NOR-1 (r=0.997) These findings suggest that NOR-1 is a useful reagent for the calibration of lower NO detection.

Benzoates↗
PubMed2002

Non-invasive automated assessment of the ratio of pulmonary to systemic flow in patients with atrial septal defects by the colour Doppler velocity profile integration method.

BACKGROUND: The recent introduction of the automated cardiac flow measurement (ACM) method, using spatiotemporal integration of the Doppler velocity profile, provides a quick and accurate automated calculation of cardiac output. OBJECTIVE: To evaluate the ACM method against oximetry during cardiac catheterisation for estimating the Qp/Qs (pulmonary to systemic flow) ratio in patients with an atrial septal defect. METHODS: Left and right ventricular stroke volume (LVSV, RVSV) were calculated by ACM in 22 patients with an atrial septal defect who underwent cardiac catheterisation and in 11 patients without heart disease (control group). With ACM, the Qp/Qs ratio was estimated from RVSV divided by LVSV. In the patients with an atrial septal defect, the Qp/Qs ratio was assessed by oximetry at the time of cardiac catheterisation. RESULTS: There was a good correlation between LVSV and RVSV obtained by ACM in the control group (r = 0.98, y = 0.97x + 0.25, SEE = 2.9 ml). The mean difference between LVSV and RVSV by ACM was -1.25 (2.76) ml. The Qp/Qs ratio obtained by ACM in the control group was 0.98 (0.06). The Qp/Qs ratio in patients with an atrial septal defect was significantly higher than in the control group (3.11 (1.20), p < 0.001). ACM determination of the Qp/Qs ratio correlated well with oximetry determination (r = 0.86, y = 0.75x + 0.55, SEE = 0.64). The mean difference between ACM and oximetry for the measurement of the Qp/Qs ratio was -0.28 (0.69). CONCLUSIONS: The newly developed ACM method is clinically useful for non-invasive automated estimations of the Qp/Qs ratio in patients with an atrial septal defect.

Adult↗
PubMed2002

Automated quantification of aortic regurgitant volume and regurgitant fraction using the digital colour Doppler velocity profile integration method in patients with aortic regurgitation.

BACKGROUND: The recently introduced automated cardiac flow measurement (ACM) technique provides a quick and an accurate automated calculation of stroke volume and cardiac output. This is obtained by spatio-temporal integration of digital Doppler velocity profile data. OBJECTIVE: To evaluate the use of the ACM method in the non-invasive assessment of aortic regurgitant volume and per cent regurgitant fraction (%RF) in patients with aortic regurgitation. METHODS: Aortic outflow volume and mitral inflow volume were calculated by the ACM method in 22 patients with isolated aortic regurgitation. Aortic regurgitant volume and %RF were calculated using the following equations: aortic regurgitant volume = [aortic outflow volume] - [mitral inflow volume]; %RF = [aortic regurgitant volume]/[aortic outflow volume] x 100. The results were compared with those obtained using pulsed Doppler cross sectional echocardiography (PD-2D). RESULTS: Aortic regurgitant volumes measured by the ACM method showed a good correlation with the PD-2D measurements (r = 0.95, y = 0.9x + 3.9, SEE = 8.6 ml); the mean (SD) difference between the two methods was -1.5 (8.5) ml. %RF estimated by the ACM method also correlated well with the values obtained by the PD-2D method (r = 0.91, y = 0.9x + 4.9, SEE = 6.0%); the mean difference between the two methods was -1.5 (6.0)%. Total time required for aortic regurgitant volume (for one cardiac cycle) by the ACM method was significantly shorter than by the PD-2D method (130 (16) v 230 (32) s, p < 0.01). CONCLUSIONS: The newly developed the ACM method is quick and accurate in the automated assessment of aortic regurgitant volume and per cent regurgitant fraction in patients with isolated aortic regurgitation.

Adult↗
PubMed2002

Seroepidemiology of Chlamydia pneumoniae in Japan between 1991 and 2000.

AIM: To clarify the endemic and epidemic status of Chlamydia pneumoniae in Japan, the incidence of anti-C pneumoniae antibody was evaluated over a period of 10 years. METHOD: Serum samples were collected from 4756 healthy individuals aged 6 months to 88 years (2488 male and 2268 female individuals) between 1991 and 2000. The antibody titre was determined by a microimmunofluorescence test. RESULTS: After stratification by age and sex in each year, distinct peaks with prevalences of 73.3% and 73.0% were noted in 1993 and 1999, respectively. The lowest prevalence rate was seen in 1996 (59.0%). The epidemic cycle has been estimated to be almost six years in this geographical area. CONCLUSIONS: Chlamydia pneumoniae infection is highly endemic in Japan, as it is in Western countries, and there is a year to year variability. Long term studies in Japan are needed to clarify the epidemic occurrence of C pneumoniae infection.

Adolescent↗
PubMed2002

Recent outbreaks of foot and mouth disease in countries of east Asia.

Japan regained the status of freedom from foot and mouth disease (FMD) without vaccination in September 2000 and the Republic of Korea likewise obtained this status in September 2001. However, new outbreaks of FMD caused by the pan-Asian topotype have occurred in pigs in the Republic of Korea since May 2002. Taipei China has not experienced an outbreak of FMD since February 2001 and the country is currently implementing an eradication programme. These countries had been free from FMD for many decades when in 1997, the FMD virus (FMDV) once again invaded the region, particularly in 2000; this resulted in widespread occurrence of the disease. The types of FMDV were investigated by genome analysis, and in each case the virus concerned was found to be a member of the pan-Asian O lineage. The authors present the recent situations and the characteristics of FMD in countries of east Asia.

Animals↗
PubMed2002

Genetic polymorphisms of cytochrome P450 1A1 and risk of gallbladder cancer.

The relation between cytochrome P4501A1 (CYP1A1) gene polymorphisms and the risk of gallbladder cancer was examined. To clarify individual differences in susceptibility to gallbladder carcinogenesis, we investigated the frequency of the Mspl and Ile-Val polymorphisms of the CYP1A1 gene, in 52 patients with gallbladder cancer (32 females, 20 males) and 104 healthy controls (64 females, 40 males). We then examined the relationship between the CYP1A1 polymorphisms and the development of gallbladder cancer in members of both sexes. A statistical difference in the frequencies of the MspI and Ile-Val polymorphisms or their alleles (ml, m2 and Ile, Val) was not observed in the male patients and controls. Among females, however, the frequencies of genotypes C and Ile/Val were significantly higher (p < 0.05) in the patients than in their controls. Moreover, the frequency of the hetero genotype Ile/Val was statistically higher (p < 0.05) in the female patients than in the male patients. This study demonstrated a significant over-representation of genotypes C and Ile/Val in female patients with gallbladder cancer. Females with genotypes C and/or Ile/Val may have a high genetic susceptibility to the development of gallbladder cancer.

Alleles↗