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Biomedical subjects

Y Taguchi

Publications and source records attributed to Y Taguchi.

At least 55 records · Page 3Linked to original sources
PubMed2000

Chemoselective oxidative polymerization of m-ethynylphenol by peroxidase catalyst to a new reactive polyphenol.

Enzymatic oxidative polymerization of m-ethynylphenol possessing two reactive groups, phenol and acetylene moieties, was carried out in aqueous methanol under air. Horseradish peroxidase and hydrogen peroxide were used as catalyst and oxidizing agent, respectively. 1H NMR and IR analysis showed that only the phenolic moiety was polymerized to produce the polymer having the ethynyl group in the side chain. The reaction of the monomer using a copper/amine catalyst, a conventional catalyst for oxidative coupling, exclusively produced a diacetylene derivative. From these data, it was found that the peroxidase catalysis induced the chemoselective polymerization of the monomer. The resulting polymer was converted to carbonized polymer in a much higher yield than enzymatically synthesized poly(m-cresol) and is expected to have potential applications as a reactive starting polymer.

Catalysis↗
PubMed1999

Meltrin-alpha, a fusion protein involved in multinucleated giant cell and osteoclast formation.

The formation of multinucleated cells such as myotubes, macrophage-derived giant cells (MGC), and osteoclasts is the result of cell-cell fusion of mononuclear precursors. Meltrin-alpha, -beta, and -gamma are members of a recently discovered family of proteins that contain disintegrin and metalloprotease domains and are related to fertilin, a protein involved in egg-sperm fusion. Based on this and evidence implicating meltrin-alpha in myoblast formation, we have investigated the possibility that meltrins may also play a role in the formation of MGC and osteoclasts. Using in situ RT-PCR, we have determined that murine mononuclear alveolar macrophages cultured under basal conditions express the transcript for meltrin-beta, but not for meltrin-alpha. However, meltrin-alpha mRNA appeared in mononuclear cells before cell fusion after treatment with 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], a potent inducer of giant cell and osteoclast formation. Moreover, addition of meltrin-alpha antisense oligonucleotides to the cultures caused a 50% inhibition of giant cell formation. Similarly, meltrin-alpha antisense oligonucleotides inhibited by 70% the formation of multinucleated osteoclast-like cells expressing tartrate-resistant acid phosphatase (TRAP) in co-cultures of bone marrow cells and osteoblastic cells (2107) in the presence of 1,25(OH)2D3. Mononucleated TRAP-positive cells, induced by 1,25(OH)2D3 in the co-cultures, also expressed meltrin-alpha mRNA, but their number was not changed in the presence of meltrin-alpha antisense oligonucleotide. In contrast to mononuclear macrophages and osteoclast-like cells, murine bone marrow stroma and calvaria derived-cell lines (+/+ LDA.11 and 2107), primary cultures of calvaria cells, and primary cultures of bone marrow cells expressed both meltrin-alpha and -beta mRNA under basal conditions; whereas embryonic fibroblasts (NIH3T3) expressed only the meltrin-beta transcript. Upregulation of meltrin-alpha protein expression during cell fusion in alveolar macrophages and expression in osteoblastic cell lines were confirmed by Western blot analysis. These observations demonstrate that meltrins play a role in MGC and osteoclast formation from mononuclear precursors, as in the case with myotubes.

ADAM Proteins↗
PubMed1999

Early postmenopausal bone loss is prevented by estrogen and partially by 1alpha-OH-vitamin D3: therapeutic effects of estrogen and/or 1alpha-OH-vitamin D3.

A total of 79 Japanese women who were within 5 years of menopause were randomly assigned 1alpha-hydroxyvitamin D3 [1alpha(OH)D3] 1.0 microg/day, conjugated estrogens 0.625 mg/day, a combination of both, or control (no treatment). Lumbar spine and proximal femur bone mineral density (BMD) and biochemical indices were monitored over 2 years. In the 1alpha(OH)D3-treated group, there was a nonsignificant decrease in lumbar spine BMD compared with controls, and no significant loss in the femoral neck compared with controls. In the estrogen-treated group, there was a nonsignificant increase in spine BMD (+2.17% in the first year and +1.71% in the second year), and no loss in femoral neck BMD. The combination of conjugated estrogens +1alpha(OH)D3 was more effective in increasing BMD in the spine (+3. 68% in the first year and +3.63% in the second year) and femur (+2. 56% in the first year and +4.44% in the second year) BMD. There was a significant difference in lumbar spine BMD in both the first and second years between the combination-treated group and the 1alpha(OH)D3-treated and control groups (P < 0.01). Serum osteocalcin (OC) significantly decreased in the combination-treated group (-23.8% in the first year) and the estrogen-treated group (-37. 6% and -41.2% at 6 and 18 months, respectively), and serum alkaline phosphatase (Alp) decreased significantly in the first year in the combination-treated (-31.5%), estrogen-treated (-27.3%), and 1alpha(OH)D3-treated (-7.9%) groups, whereas serum OC increased (+45. 4% in the first year) in women without treatment. The results of this study indicate that early postmenopausal bone loss in the femoral neck is prevented by conjugated estrogens, 1alpha(OH)D3, or both, whereas bone loss in the spine is not prevented by 1alpha(OH)D3. Estrogen proves effective in preventing early postmenopausal bone loss by markedly inhibiting bone turnover. Moreover, a synergistic bone-sparing effect can be expected when estrogen is administered concomitantly with 1alpha(OH)D3 rather than when used alone.

Adult↗
PubMed1999

Transient mutism resolving into cerebellar speech after brain stem infarction following a traumatic injury of the vertebral artery in a child.

A 3.7-year-old girl presented with an anterior neck injury followed by progressive subcutaneous emphysema and loss of consciousness. After resuscitation, a laceration on the first tracheal cartilage was closed surgically. As she was extubated one week later, she was found to have right hemiplegia and muteness. MRI showed a T2-bright lesion on the tegmentum of the left midbrain down to the upper pons. Right vertebral angiography disclosed an intimal flap with stenosis at the C3 vertebral level presumably caused by a fracture of the right C3 transverse process later confirmed in a cervical 3D-CT scan. Her muteness lasted for 10 days, after which she began to utter some comprehensible words in a dysarthric fashion. Her neurological deficits showed improvement within 3 months of her admission. Transient mutism after brain stem infarction has not been reported previously. We discuss the anatomical bases for this unusual reversible disorder in the light of previous observations and conclude that bilateral damage to the dentatothalamocortical fibers at the decussation of the superior cerebellar peduncle may have been responsible for her transient mutism.

Brain Mapping↗
PubMed1999

Capillary changes with fenestrations in the contralateral soleus muscle of the rat following unilateral limb immobilization.

Using electron microscopy, we examined structural changes in the capillaries of the immobilized and contralateral soleus muscles in the rat after the unilateral limb had been immobilized for 4 weeks. Individual contralateral muscle fibers showed a normal structure, compared with the structure in the immobilized muscle fibers. Most capillaries in the contralateral muscle were of the continuous type. However, about 5% of the examined capillaries in these muscles in each rat had fenestrations. The non-nuclear portions of the endothelial cells in these capillaries were extremely thin and were perforated by several fenestrations that were bridged by a single-layered diaphragm. The fenestration of capillaries in the contralateral muscle may have been caused by some the unilateral limb immobilization.

Animals↗
PubMed1999

Association of diffuse panbronchiolitis with microsatellite polymorphism of the human interleukin 8 (IL-8) gene.

Diffuse panbronchiolitis (DPB) is a distinctive chronic inflammatory lung disease predominantly found in Asian populations. Although its etiology is unknown, DPB is considered to be a multifactorial disease of whose susceptibility is determined by genetic predisposition unique to Asians. We and others have previously reported that the B*5401 allele of the human leukocyte antigen (HLA)-B gene or a closely linked gene in the HLA region on 6p21.3 is one of the major genetic factors in susceptibility to this disease. However, the association with B*5401 is not absolute and the contribution of other genetic or environmental factors should also be considered. Here, four candidate genes that are postulated to play a role in the pathophysiology of DPB, namely, RON-kinase, CYP3A4, motilin, and interleukin (IL)-8, were chosen, and association studies between microsatellite markers at these loci and DPB were conducted. We demonstrated the presence of a specific allele at the IL-8 locus was associated with the disease (c2 = 9.13; P = 0.0025; corrected P [Pc] < 0.05). Although further studies are needed to examine whether neutrophil accumulation in the airways of patients with DPB is controlled by a possible genetic variation of IL-8 or other chemokine genes located in the region 4q12-q13, our data suggest that genes other than those of the HLA system may also contribute to a genetic predisposition to DPB.

Asian People↗
PubMed1999

Contribution of TAP genes to genetic predisposition for diffuse panbronchiolitis.

Diffuse panbronchiolitis is a chronic obstructive pulmonary disease found in Asian populations. Although diffuse panbronchiolitis is considered to be a multifactorial disease of unknown etiology, the disease susceptibility appears to be determined by a genetic predisposition unique to Asians. An earlier study showed that human leukocyte antigen (HLA)-B54 predominantly found in East Asians was strongly associated with the disease. A possible interpretation of this association is that the class I molecule or class I antigen presenting system is directly involved in its pathogenesis. Recent observations in which impaired expression of class I molecules causes a syndrome resembling diffuse panbronchiolitis further prompted us to test this possibility. Genes of the molecules implicated in the class I pathway, TAP1, TAP2 and LMP2, which are located in the HLA region of the sixth chromosome were analyzed in 76 patients with diffuse panbronchiolitis and 120 normal controls. The combination of Ala-665 and Gln-687 in exon 11 of the TAP2 gene was associated with the disease (P=0.0028, Pc<0.05). Although this positive association might be partly explained by linkage disequilibrium with HLA-B*5401, this TAP2 variation was associated with the disease even in the B*5401-negative subgroup. On the other hand, the His-60 substitution within the LMP2 gene exhibited a negative association with the disease. This negative association, however, could be explained by a strong linkage disequilibrium with HLA-B44 which showed a negative association with the disease in the previous study. These results support the notion that diffuse panbronchiolitis is influenced by genetic factors in the HLA region. Besides the class I gene itself, genes relevant to the class I antigen presenting system might contribute to its genetic predisposition.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Flowcytometric analysis of bronchoalveolar lavage fluid cells in polymyositis/dermatomyositis with interstitial pneumonia.

OBJECTIVE: Interstitial lung disease (ILD) is a complication occurring in 10-30% of patients with polymyositis/dermatomyositis (PM/DM) as well as in those with progressive systemic sclerosis (PSS). Clinical features are different between these two disease states, notably with respect to the duration of manifestations, pathological findings, response to steroid therapy etc. However, dissimilarities in pulmonary inflammatory cell characteristics, which, if present at all, would be of critical importance, remain as yet to be clarified. METHODOLOGY: The phenotypes of lymphocytes and alveolar macrophages in bronchoalveolar lavage fluid (BALF) were analysed to elucidate phenotypic peculiarity of pulmonary inflammatory cells of ILD in PM/DM. Eight PM/DM patients with ILD (mean age 47.9 years) were examined by bronchofibrescopy under local anaesthesia. Bronchoalveolar lavage was performed from the right middle lobe using four 50 mL aliquots of normal saline and the recovered fluid was compared with BALF of ILD in PSS. RESULTS: Bronchoalveolar lavage fluid cells of PM/DM patients with ILD showed an increased percentage of CD8+ lymphocytes, in particular CD8+ histocompatibility leucocyte antigen-DR positive lymphocytes and CD8+ CD11b-lymphocytes, both of which represent cytotoxic T cells. However, phenotypic differences in these lymphocytes were not found between PM and DM. The percentage of alveolar macrophages with expression of histocompatibility leucocyte antigen-DQ was significantly different among the three groups (PM/DM, PSS, healthy volunteers). CONCLUSIONS: Cytotoxic T cells may be major pulmonary inflammatory cells of ILD in PM/DM with no apparent difference between PM and DM. In contrast, ILD in PSS was suggested as being likely to be characterized by activated macrophage.

Adult↗
PubMed1999

Eruption disturbances of maxillary permanent central incisors associated with anomalous adjacent permanent lateral incisors.

Several causes of eruption disturbances in upper permanent central incisors have been described. This report describes six cases in which the failure of maxillary permanent central incisors to erupt appears to be associated with developmental anomalies in the adjacent permanent lateral incisors. The root formation of the unerupted central incisors was delayed in comparison to the contralateral incisors as was the development of the adjacent lateral incisors. The shapes of the crowns were abnormal and in five cases out of the six described, the primary predecessors of the unerupted incisors were fused.

Child↗
PubMed1999

[Multicenter screening of Chlamydia pneumoniae pneumonia by ELISA method].

We prospectively investigated the etiology of community-acquired pneumonia among adult patients admitted to three general hospitals over one year. Antibody titers to Chlamydia pneumoniae were also measured by ELISA method to investigate the incidence and clinical pictures of C. pneumoniae pneumonia in Japan. Two hundred and fourteen patients were enrolled in the study. Seventeen patients (7.9%) satisfied the criteria for diagnosis of acute infection due to C. pneumoniae by ELISA method. C. pneumoniae was the 3rd leading causative agent following Streptococcus pneumoniae (21.5%) and Haemophilus influenzae (8.4%). Preexisting antibodies were detected in 62.1% of the patients. Most of the patients with C. pneumoniae pneumonia were aged, and had comorbidities of respiratory system. Superinfection with bacterial pneumonia was recognized in some patients. Though there are several problems, ELISA method is thought to be useful to diagnose C. pneumoniae pneumonia, and is suitable for screening tests.

Aged↗
PubMed1999

[Disappearance of globus pallidus hyperintensity in a patient with portal-systemic encephalopathy after occlusion of the shunt vessel].

A 67-year-old woman was admitted to our hospital with confusion and asterixis on January 23, 1994. She had had the same symptoms repeatedly. On admission she was disorientated, and had slurred speech and asterixis. Laboratory data showed hyperammonemia (84 micrograms/dl) with a poor ICG hepatic clearance (ICG15min = 32%), although hepatic failure did not exist. Abdominal ultrasonography, CT scan and liver biopsy showed no evidence of cirrhosis. Celiac arteriography revealed a large shunt vessel connecting the portal vein to the left renal vein. A 1.5 T magnetic resonance imaging (MRI) demonstrated a bilateral and symmetrical hyperintensity of the globus pallidus in the T1-weighted images. Portal-systemic encephalopathy recurred repeatedly in spite of the conservative therapy, and there was no evidence of the portal hypertension. Therefore, the operative procedure of ligation of the shunt vessel was done on February 21, 1995. After the operation, blood ammonia level and ICG hepatic clearance were normalized. She became free from encephalopathy. Twenty-seven months after the operation, the hyperintensity of the globus pallidus in the T1-weighted images completely disappeared. There have been several reports describing that the globus pallidus alterations on the T1-weighted images in patients with liver cirrhosis, manganese intoxication and portal-systemic encephalopathy. To our knowledge, this is the first case that the hyperintense signal of the basal ganglia in a patient with portal-systemic encephalopathy disappeared completely after occlusion of the shunt vessel.

Aged↗
PubMed1999

[Endoscopic diagnosis of ulcerative colitis].

Endoscopic findings of ulcerative colitis are classified into three groups according to the degree of inflammation, i.e. mild, moderate and severe. 1)mild: Edema, erythema, yellow spots, fine granular appearance are conspicuous signs of early disease. The mucosal vascular pattern disappears. 2)moderate: Coarse mucosa with mucous, pus, blood are characteristic findings. Erosions or shallow ulcers are scattered. The erythematous mucosa is friable and bleeds easily. 3)severe: There are deep, widespread ulcers. Marked bleeding is seen from granulation tissue of ulcer base. We remind that inflammation often take a turn for the worse due to endoscopic examination. Total colonoscopy is not always necessary in the cases of ulcerative colitis.

Colitis, Ulcerative↗
PubMed1998

Non-equivalent cooperation between the two nucleotide-binding folds of P-glycoprotein.

To identify the roles of the two nucleotide-binding folds (NBFs) in the function of human P-glycoprotein, a multidrug transporter, we mutated the key lysine residues to methionines and the cysteine residues to alanines in the Walker A (WA) motifs (the core consensus sequence) in the NBFs. We examined the effects of these mutations on N-ethylmaleimide (NEM) and ATP binding, as well as on the vanadate-induced nucleotide trapping with 8-azido-[alpha-32P]ATP. Mutation of the WA lysine or NEM binding cysteine in either of the NBFs blocked vanadate-induced nucleotide trapping of P-glycoprotein. These results suggest that if one NBF is non-functional, there is no ATP hydrolysis even if the other functional NBF contains a bound nucleotide, further indicating the strong cooperation between the two NBFs of P-glycoprotein. However, we found that the effect of NEM modification at one NBF on ATP binding at the other NBF was not equivalent, suggesting a non-equivalency of the role of the two NBFs in P-glycoprotein function.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Effects of endothelin-1 on norepinephrine-induced vasoconstriction in deoxycorticosterone acetate-salt hypertensive rats.

We investigated the effects of endothelin-1 on pressor responses to norepinephrine in perfused mesenteric arteries of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. The response to norepinephrine (10(-6) M) was significantly increased in DOCA-salt rats compared with that in uninephrectomized control rats. Perfusion of the arteries with subpressor dose of endothelin-1 (3 x 10(-10) M) for 15 min markedly enhanced the pressor responses to norepinephrine (10(-6) and 3 x 10(-6) M) in control rats and this effect was significantly prevented by BQ788 [N-cis-2,6-dimethylpiperidinocarbonyl-L-gamma-methylleucyl-D -1-methoxycarbonyl-tryptophanyl-D-norleucine] (10(-6) M), but not by FR139317 ((R)2-[(R)-2-[(S)-2-[[1-(hexahydro-1H-azepinyl)]carbonyl]amino-4-+ ++methylpentanoyl]amino-3-[3-(1-methyl-1H-indoyl)]propionyl]ami no-3-(2-pyridyl)propionic acid) (10(-6) M). In DOCA-salt hypertensive rats, increased pressor response to norepinephrine was declined to the level of control rats by BQ788, but not by FR139317. In contrast to the case seen with control rat, exogenous endothelin-1 had little effect on pressor responses to norepinephrine in the arteries of DOCA-salt hypertensive rats. Total immunoreactive endothelin content in the arteries of DOCA-salt hypertensive rats was significantly higher than that of uninephrectomized control rats. These results suggest that endothelin-1 enhances contractile responses to norepinephrine through endothelin ETB receptor. Moreover, this phenomenon is stimulated tonically by endogenous endothelin-1 in DOCA-salt hypertensive rats and may contribute to the maintenance of hypertension in DOCA-salt rats.

Animals↗
PubMed1998

Intranasal administration of denatured type II collagen and its fragments can delay the onset of collagen-induced arthritis.

Collagen-induced arthritis (CIA) is an autoimmune animal model for some types of human rheumatoid arthritis (RA). We have evaluated the effectiveness of intranasal administration of antigen in inhibiting CIA in DBA/1 mice. The intranasal administration of heat-denatured or trypsin-digested bovine type II collagen (CII) before immunization with CII strongly delayed the onset of CIA, whereas administration of native CII did not do so. The mice administered denatured or digested CII possessed much lower titers of anti-CII IgG2a than the control mice, whereas titers of anti-CII IgG1 and IgG2b were unchanged or slightly decreased. Responding to CII and peptides containing immunodominant T cell determinants, lymph node cells from mice administered denatured CII produced less IFN-gamma. These results suggest that intranasal administration of antigen downregulated preferentially Th1-type responses, whereas an enhanced Th2-type response was not observed. We demonstrate that the methods shown here are a possible treatment for rheumatoid arthritis.

Administration, Intranasal↗
PubMed1998

Differences in bone resorption after menopause in Japanese women with normal or low bone mineral density: quantitation of urinary cross-linked N-telopeptides.

The objective of this study was to examine the value of NTx, a urinary cross-linked N-telopeptides of type I collagen, as a marker of bone resorption. We assessed changes in pre- and postmenopausal bone resorption by evaluating the correlation of NTx with L2-4 bone mineral density (BMD) in a total of 1100 Japanese women, aged 19-80 years [272 premenopausal (45.2 +/- 6.2 years) and 828 postmenopausal (59.5 +/- 6.2 years)]. Postmenopausal women were divided into three groups based on the range of BMD (normal, osteopenic, and osteoporotic). Within each group, subjects were further segregated according to years since menopause (YSM). NTx values were then evaluated for each group. Our results showed that BMD was significantly decreased (P < 0.05) and NTx was significantly increased (P < 0.01) after menopause in age-matched analysis. Consistent with a previous report, NTx was inversely correlated with BMD for the entire cohort of study subjects (r = -0.299), although NTx correlated better with premenopausal than postmenopausal BMD (r = -0.240 versus r = -0.086). This may have been due to the fact that elevated values of NTx were exhibited over the entire range of BMD present in the postmenopausal women, suggesting that NTx might respond faster to the estrogen withdrawal than BMD. In all postmenopausal women, regardless of the range of BMD, the increase in NTx reached a peak within 5 YSM. After 11 YSM, however, NTx remained elevated in the osteoporotic group but it decreased in the osteopenic group, and showed no significant change in the group of postmenopausal women with normal BMD. These findings suggest that bone resorption is dramatically increased within 5 years after menopause but remains increased only in osteoporotic women.

Absorptiometry, Photon↗
PubMed1998

A heterogeneity in serum osteocalcin N-terminal fragments in Paget's disease: a comparison with other biochemical indices in pre- and postmenopause.

An osteocalcin (OC) nitrogen (N)-terminal sandwich enzyme immunoassay that employs anit-N-20 (amino acids 1-20) polyclonal and monoclonal antibodies has been developed. This assay has demonstrated the existence of a heterogeneity in the OC N-terminal fragments observed in the serum of a patient with Paget's disease and a normal child. The elevation of the serum OC N-terminal value that occurs in Paget's disease was considered to be comparable to the serum alkaline phosphatase (ALP) elevations that also occur. The size of the peaks corresponding to N-terminal OC fragments in Paget's serum decreased 3 months after bisphosphonate treatment. Serum levels of OC N-terminals, and other biochemical indices, were determined for 67 premenopausal and 181 postmenopausal Japanese women. Serum OC N-terminal levels increased significantly (41.2%) in postmenopausal women compared with age-matched premenopausal women. These results strongly suggest that serum OC N-terminal levels reflect bone turnover rates when bone resorption is dominant.

Adolescent↗