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Biomedical subjects

Y Wada

Publications and source records attributed to Y Wada.

At least 271 records · Page 15Linked to original sources
PubMed1999

Regeneration process of mechanoreceptors in the reconstructed anterior cruciate ligament.

We performed reconstructive surgery on the anterior cruciate ligament (ACL) of the rabbit using a free bone-patellar tendon-bone (BTB) graft and evaluated nerve regeneration in the graft. The right ACL of 15 Japanese white rabbits was resected and reconstructed using a BTB graft. The BTB and ACL from the contralateral knee served as controls. The graft and control BTB were collected at 2, 4, and 8 weeks after the operation. We measured the number of mechanoreceptors in the ligaments using a modified gold chloride method. In the control patellar tendon, mechanoreceptors were present in all the samples. At 2 weeks after the operation, mechanoreceptors were not observed in the reconstructed ligaments. They were observed at 4 weeks but in lower numbers than in the control knees. At 8 weeks, the total number of mechanoreceptors did not differ significantly in the reconstructed and control tendons. The appearance of mechanoreceptors in the graft between 2 and 4 weeks postoperatively suggests that regeneration of mechanoreceptors occurred during this time period. At 4 and 8 weeks postoperatively, there was no significant difference in the number of mechanoreceptors between the intra-articular portion of grafted tendon and the contralateral ACL. The further increase between 4 and 8 weeks to control levels suggests that this regeneration may restore mechanoreceptors in BTB grafts to normal levels.

Animals↗
PubMed1999

Effects of hyaluronan on periosteal grafts for large full-thickness defects in rabbit articular cartilage.

We studied the effects of hyaluronan (HA) on chondrogenesis in periosteal grafts in rabbit knees to elucidate the effects of this agent in the repair of articular cartilage. Large full-thickness defects of the articular cartilage were created in the anteromedial part of the femoral articular surface of bilateral knee joints. Periosteal grafts were then harvested and sutured onto the defects. HA was injected in the right knee immediately after the operation and then once a week for 4 weeks (HA group). The same volume of saline was injected in the left knee in the control group. The animals were killed 2, 5, 8, and 12 weeks after the operation. Macroscopic and histological findings of the regenerated tissue were evaluated with a semiquantitative histological grading system. The total histological scores of the HA group were better than those in the control group at each time examination point. At 12 weeks, in particular, the scores for surface regularity and integration to adjacent articular cartilage were significantly better in the HA group than in the control group (P < 0.05). No significant differences were observed between the two groups in regard to the area healed (%). HA may have beneficial effects on the repair of large full-thickness defects of the articular cartilage with autologous periosteal grafts.

Adjuvants, Immunologic↗
PubMed1999

A clinical and molecular study of a patient with Simpson-Golabi-Behmel syndrome.

Simpson-Golabi-Behmel syndrome (SGBS) is one of the overgrowth syndromes. Microdeletions of the glypican-3 (GPC3) gene were described by Pilia et al. (1996). Glypican-3 encodes a putative extracellular proteoglycan which is expressed in embryonic mesodermal tissues and plays an important role in embryonal growth. We report a Japanese patient with SGBS who had a single base deletion in the exon 7 of the GPC3 gene. This is the first report of a single base deletion of the GPC3 gene.

Abnormalities, Multiple↗
PubMed1999

Diffuse central nervous system lupus involving white matter, basal ganglia, thalami and brainstem.

We described an 11-year-old girl with acute central nervous system lupus showing diffuse lesions. She developed generalized convulsions followed by prolonged coma, and her psychomotor ability recovered fully after 3 months of steroid therapy. Cranial magnetic resonance imaging (MRI) showed high signal intensity in the cerebral deep white matter, bilateral basal ganglia, thalami, and brainstem on T2-weighted image. These lesions resolved over 1 month with residual atrophic change in the heads of the caudate nucleus on MRI. Acute SLE leukoencephalopathy may be recognized as a subtype of CNS lupus.

Basal Ganglia↗
PubMed1999

Serial electroencephalographic findings in patients with MELAS.

To clarify the electroencephalographic characteristics of mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS), the medical records and electroencephalograms of six patients with MELAS and two of their relatives with MELA (mitochondrial myopathy, encephalopathy, and lactic acidosis, without strokelike episodes) were retrospectively reviewed. All have a point mutation in the mitochondrial DNA at nucleotide position 3243. The electroencephalograms (n = 79) were divided into four groups according to the time relation to the strokelike episode: (1) before the first strokelike episode, (2) within 5 days after the strokelike episode (acute stage), (3) between 6 days and 1 month after the strokelike episode (subacute stage), and (4) more than 1 month after the strokelike episode (chronic stage). In the acute stage, 10 of the 11 electroencephalograms (9 strokelike episodes in four patients) revealed focal high-voltage delta waves with polyspikes (FHDPS), which were recognized as ictal electroencephalogram. Ictal events during FHDPS included focal clonic or myoclonic seizure and migrainous headache. In the subacute and chronic stages, focal spikes or sharp waves and 14- and 6-Hz positive bursts were frequently recorded. The authors' results suggest that FHDPSs present a reliable and accurate indicator of a strokelike episode in patients with MELAS.

Adolescent↗
PubMed1999

Syntelencephaly associated with connected transhemispheric cleft of focal cortical dysplasia.

The authors report a female with syntelencephaly associated with a connected transhemispheric cleft of focal cortical dysplasia. Syntelencephaly is a rare anomaly characterized by fusion of the hemispheres in the posterior frontal and parietal regions and is considered a new variant of holoprosencephaly. Cranial magnetic resonance imaging of the patient revealed syntelencephaly associated with bilateral fused clefts of focal cortical dysplasia without the pial-ependymal seam, which was regarded as an incomplete type of schizencephaly. The underlying mechanism is discussed.

Developmental Disabilities↗
PubMed1999

Erythropoietin impairs endothelium-dependent vasorelaxation through cyclooxygenase-dependent mechanisms in humans.

Hypertension is a major complication of recombinant human erythropoietin therapy in patients with end-stage renal disease. Although the mechanisms for this pressor effect remain unknown, in vitro and ex vivo experiments suggest that erythropoietin stimulates release of cyclooxygenase-dependent endothelium-derived contracting factors (EDCFs) and attenuates endothelium-dependent vasorelaxation. To investigate the effect of erythropoietin on human endothelial function, we measured forearm blood flow by strain gauge plethysmography before and after intraarterial incremental administration of erythropoietin (10 to 300 IU/min, total 3000 U), while infusing acetylcholine (4 to 24 microg/min) and sodium nitroprusside (0.2 to 1.2 microg/min) in healthy male volunteers (n = 12). To examine a possible role of EDCFs, we repeated the same protocol under the pretreatment with oral indomethacin (50 mg), a cyclooxygenase inhibitor (n = 8). Infusion of erythropoietin into the brachial artery increased the erythropoietin blood concentration of venous effluents significantly (P < .0001) without changes in blood pressure and basal forearm blood flow. Acetylcholine and sodium nitroprusside increased forearm blood flow dose dependently before and after erythropoietin administration. However, acetylcholine-induced vasodilation (endothelium dependent) was significantly attenuated (P < .001) after erythropoietin administration, whereas vasodilation to sodium nitroprusside (endothelium independent) was unchanged. After indomethacin pretreatment, erythropoietin no longer attenuated endothelium-dependent vasorelaxation. Our results indicate that erythropoietin may impair endothelial function acutely, probably through cyclooxygenase-dependent EDCFs in humans. Long-term effects of erythropoietin on endothelial function in uremic patients remain to be elucidated.

Acetylcholine↗
PubMed1999

Improvements in the hygroscopic properties of cotton cellulose by treatment with an endo-type cellulase from Streptomyces sp. KSM-26.

The effect of enzymatic cellulolysis on the moisture-adsorbing properties of cotton cellulose was investigated, using a highly purified endo-type cellulase from Streptomyces sp. KSM-26. The time course of changes in the hygroscopicity of cotton reflected the time course of changes in the extent of the amorphous state of cotton, which was estimated from the amount of water that could bind to cotton, as determined by differential scanning calorimetry, during the hydrolytic process. The endo-type cellulase increased the degree of freedom of cellulose chains in the amorphous regions of cotton at the initial stage of the hydrolytic reaction, leading to major improvements in the moisture-adsorbing properties of cotton. The cellulase then caused the rapid decrease in the size of the amorphous regions with the release of reducing sugars as endo-cleavages in the amorphous regions increased, which reduced the hygroscopicity. The decrease in the hygroscopicity of cotton during enzymatic hydrolysis was followed by a second increase, as the cotton became more amorphous as a consequence of further hydrolysis of the crystalline regions of cotton. The effect of cellulase on the apparent degree of polymerization and the physical strength of cotton became detectable at the later stage of cellulolysis.

Journal Article↗
PubMed1999

Structure-physicochemical function relationships of soybean beta-conglycinin constituent subunits.

Beta-conglycinin, one of the dominant storage proteins of soybean, has a trimeric structure, being composed of three subunits alpha, alpha', and beta. The alpha and alpha' subunits contain the extension regions in addition to the core regions common to all subunits, which are N-glycosylated. Physicochemical functions of recombinant nonglycosylated individual subunits and deletion mutants (alpha(c) and alpha'(c)) lacking the extension regions of the alpha and alpha' subunits were examined at pH 7.6 and 3.7 at low (mu = 0.08) and high (mu = 0.5) ionic strengths. Although individual recombinant subunits exhibited different properties at all conditions, there were some consistencies. Surface hydrophobicities and thermal stabilities of the individual subunits were likely to be conferred by their core regions, and the carbohydrate moieties did not contribute to these properties at any conditions examined here. Solubility at mu = 0.08, heat-induced association, and emulsifying ability remarkably depended on the extension regions and the carbohydrate moieties in addition to the structural features of the core regions. These findings indicate that various end products could be produced by the selection of soybean varieties containing beta-conglycinin with different subunit compositions and suggest a direction for a principle of soybean breeding.

Antigens, Plant↗
PubMed1999

Binding specificity of hydrolytic catalytic antibody: lessons from the diverse immune system.

The diverse immune system has the potential to provide numerous antibodies that catalyze a great variety of reactions and exhibit diversity in mechanism and substrate specificity. However, to find such an antibody is not practical, unless we understand the immune response precisely and utilize it. We applied an alternative screening methodology based on the binding specificity of antibodies for the structure of the transition-state analog p-nitrophenyl phosphonate in order to study the built-in diversity of the immune response. This study uncovered the unpredictable binding and substrate specificity of catalytic antibodies derived from the diverse immune response.

Animals↗
PubMed1999

A novel minor histocompatibility antigen recognized by HLA-A31 restricted cytotoxic T lymphocytes generated from HLA-identical bone marrow donor lymphocytes.

Bulk cytotoxic T lymphocytes (CTL) were generated by in vitro stimulation of BMT donor lymphocytes with Philadelphia chromosome (Ph)-positive leukemic cells from an HLA-identical sibling patient. CTL were cytotoxic against the patient's leukemic cells as well as the EBV-lymphoblastoid cell line (EBV-LCL) generated from the patient's cells, suggesting that they recognize a minor histocompatibility antigen (mHAg). Subsequently, several CTL lines were established by a limiting dilution method and analyzed. One of these CTL lines, 16C12 CTL which used a single TCRbetaV3S1 for CD8 cells, lysed HLA-A31-positive leukemic cells and EBV-LCL, but not fibroblasts. The cytotoxicity against the patient's leukemic cells and EBV-LCL was blocked by anti-HLA-A31 moAb, anti-HLA-class I moAb, and anti-CD8 moAb, suggesting that this mHAg was presented with HLA-A31. The antigen recognized by 16C12 CTL seemed to be a novel mHAg, since HLA-A31 restricted antigen has not been reported to date and 16C12 CTL showed no cytotoxicity against EBV-LCL which probably express known mHAgs. CTL detecting this mHAg may play an important role in the GVL effect in HLA-A31-positive BMT patients.

Bone Marrow Transplantation↗
PubMed1999

A linkage map of 243 DNA markers in an intercross of Göttingen miniature and Meishan pigs.

A resource family of pigs has been constructed by using a boar of Göttingen miniature pig and two sows of Meishan pig as parents. In the construction of the family, two F1 males and 18 F1 females were intercrossed to generate 143 F2 offspring. The members of the family were genotyped using 243 genetic markers including 26 markers developed in our laboratory in order to generate a linkage map of markers for use in detecting quantitative trait loci (QTLs) in the family. The markers consisted of 237 microsatellites, five PRE-1 markers, and one RFLP marker. The linkage map was revealed to cover all 18 autosomes and the X chromosome; and the total length of the sex-averaged linkage map was calculated to be 2561.9 CM. Four out of the 26 markers developed in our laboratory exended the current linkage map at the termini of chromosomes 1p, 5p, 11p, and Xq. The linkage maps of all the chromosomes except for chromosome 1 were found to be longer in females than in males. Concerning chromosome 1, the length of the linkage map showed no difference between females and males, which was attributed to low recombination rates between markers localized in the centromeric region in females. The average ratio of female-to-male recombination was calculated to be 1.55.

Animals↗
PubMed1999

Reliability of the omeprazole hydroxylation index for CYP2C19 phenotyping: possible effect of age, liver disease and length of therapy.

AIMS: To evaluate the reliability of the omeprazole hydroxylation index as a marker for polymorphic CYP2C19 activity in a Japanese population of healthy young subjects (n = 78) and patients with peptic ulcer (n = 72). METHODS: Healthy subjects were administered a single dose of omeprazole (20 mg), whereas patients received 20 mg daily for at least 1 week. The ratio of the serum concentration of omeprazole to hydroxyomeprazole at 3 h postdose was determined and used as a measure of CYP2C19 activity. The CYP2C19 wild type (wt) gene and four mutant alleles associated with the poor metaboliser phenotype of (S)-mephenytoin, CYP2C19*2 in exon 5, CYP2C19*3 in exon 4, CYP2C19m4 in exon 9, and CYP2C19m3 in the initial codon were analysed. RESULTS: In the healthy volunteer study there was complete concordance between genotype and phenotype. However, eight of the patients who had the EM genotype had a high value for their hydroxylation index, and were classified as phenotypic PMs. No CYP2C19m4 and CYP2C19m3 mutations were detected in the eight mismatched patients. They were all genotypic heterozygous EMs, elderly (> or = 65 years) and/or had hepatic disease. Therefore, impaired CYP2C19 activity combined with partial saturation of omeprazole metabolism during multiple dosing may have contributed to the discrepancy between CYP2C19 genotyping and phenotyping. CONCLUSION: Although omeprazole has been used instead of mephenytoin as a probe for polymorphic CYP2C19, it does not appear to be reliable enough for clinical application in Japanese patients.

Adult↗