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Biomedical subjects

Y Taniguchi

Publications and source records attributed to Y Taniguchi.

At least 163 records · Page 9Linked to original sources
PubMed1998

Isolation and characterization of a new member of the human Ly6 gene family (LY6H).

The Ly6 family of genes encodes glycosylphosphatidylinositol-anchored cell surface glycoproteins expressed on various types of cells. Intriguing patterns of expression of Ly6 genes on specific subpopulations of lymphoid and myeloid cells suggest that Ly6 molecules may be involved in the development and homeostasis of hematopoietic cells. We have isolated a new member of the human Ly6 gene family, LY6H, from a human fetal brain cDNA library. Fluorescence in situ hybridization and radiation hybrid analyses assigned LY6H to chromosome 8, where other members of the Ly6 gene family are also located. Northern analysis revealed that LY6H is highly expressed in particular subdivisions of human brain and also in MOLT-3 and -4 acute lymphoblastic leukemia cells. These data suggest that LY6H may play a role(s) in both the central nervous system and the immune system.

Amino Acid Sequence↗
PubMed1998

Nucleotide sequence of the ring3 gene in the class II region of the mouse MHC and its abundant expression in testicular germ cells.

The RING3 (NAT) gene is the first and only locus with no obvious function associated with the immune system in the class II region of the human major histocompatibility complex. This gene is a homologue of the Drosophila homeotic gene female sterile homeotic (fsh) and encodes a nuclear serine-threonine kinase. To study more about the physiological function of the RING3 gene, we isolated a mouse homologue from a genomic library, determined its gene structure, and investigated its expression profile. The mouse Ring3 gene spans approximately 8 kb and consists of 12 exons encoding a 798-amino-acid protein, sharing as high as 96% amino acid identity with the human RING3 protein. Northern hybridization revealed that the Ring3 gene abundantly produced 3.8- and 3.0-kb transcripts in the testis but was weakly expressed with 4.6- and 3.8-kb transcripts in somatic tissues. It appears that testis-specific 3.0-kb transcript gives rise to a smaller size Ring3 protein resulting from the usage of the second ATG codon for translational initiation compared to the almost ubiquitous 4.6-kb transcript. In RNAs isolated from fractionated testicular germ cells, the two testicular mRNAs were detected exclusively in the fractions containing a large population of round spermatids and pachytene spermatocytes. Furthermore, in situ hybridization on cross sections of seminiferous tubules in the testis showed that the expression of the Ring3 gene was initiated at the pachytene spermatocyte stage during meiosis and persisted throughout the round spermatid stage during spermiogenesis. These results suggest that the Ring3 gene plays an important role in spermatogenesis.

Amino Acid Sequence↗
PubMed1998

Determinants of tachycardia recurrences after radiofrequency ablation of idiopathic ventricular tachycardia.

Clinical and electrophysiologic parameters were analyzed to define the factors potentially related to tachycardia recurrences in 79 patients undergoing successful radiofrequency ablation of idiopathic right or left ventricular tachycardia. It was found that the endocardial activation time at the successful ablation site was the only independent predictor of tachycardia recurrences.

Adolescent↗
PubMed1998

Pressure-induced structural rearrangements of bovine pancreatic trypsin inhibitor studied by FTIR spectroscopy.

Fourier transform infrared (FTIR) spectroscopy combined with resolution enhancement techniques, second-derivative and difference spectroscopies, have been used to characterize pressure-induced changes in the structural rearrangements of bovine pancreatic trypsin inhibitor (BPTI) in D2O solution at 25.0 degrees C. According to the observed changes in the amide I' band up to 550 MPa, the secondary structure elements of BPTI, such as the alpha-helix, 3(10)-helix, beta-sheet, and beta-turn, are scarcely rearranged except for the loop structure of residues of 9-17 and 36-43. The polypeptide backbone is not extensively unfolded up to 550 MPa. The minor pressure-induced structural rearrangements are completely reversible. A further increase in pressure above 1000 MPa associated with the precipitation of BPTI in D2O buffer solution induces the partial structural rearrangements of the alpha-helix, beta-turn and/or 3(10)-helix, and beta-sheet. The polypeptide backbone of BPTI is not fully unfolded even above 1000 MPa. Most of the protected backbone amide protons involved in the beta-sheet remain intact in the pressure range where BPTI is not precipitated, while those involved in the alpha-helix and beta-turn and/or 3(10)-helix are exchanged with solvent deuterons. The protected backbone amide protons located near the surface regions are more easily exchanged with solvent deuterons by application of high pressure than those involved in the core.

Animals↗
PubMed1998

Effect of exercise-induced activation of sympathetic nerve activity on clearance of 123I-MIBG from the myocardium.

The effect of exercise on the cardiac kinetics of 123I-MIBG was investigated in the present study. 123I-MIBG was administered intravenously at rest in 6 healthy male volunteers, and anterior planar and SPECT images were obtained 15 minutes, and 2 and 4 hours after administration (protocol A). After 4 weeks, 123I-MIBG was again administered intravenously at rest, and images were obtained 15 minutes later. After imaging, the subjects ran 10 km in approximately 1 hour, and anterior planar and SPECT images were obtained 2 and 4 hours after administration of 123I-MIBG (protocol B). The heart-to-mediastinum uptake ratio (H/M) was calculated from each anterior planar image, and the mean 123I-MIBG clearance from 15 minutes to 2 hours, and from 2 hours to 4 hours was calculated with a bull's eye display. The H/M was much lower after exercise. The mean clearance rate between 15 minutes and 2 hours in protocol B was significantly higher than that between 2 hours and 4 hours, and that between 15 minutes and 2 hours in protocol A. It was concluded that the clearance rate of 123I-MIBG may be a useful index of cardiac sympathetic nerve activity.

3-Iodobenzylguanidine↗
PubMed1998

Early and delayed Tc-99m-tetrofosmin myocardial SPECT in patients with left bundle branch block.

UNLABELLED: To determine the utility of the myocardial tracer Tc-99m-tetrofosmin in the examination of patients with left bundle branch block (LBBB) and to investigate Tc-99m-tetrofosmin uptake and retention in the myocardium, early and delayed Tc-99m-tetrofosmin SPECT was performed in 10 patients having LBBB without coronary stenosis. METHODS: After 740 MBq of Tc-99m-tetrofosmin injection in the resting state, the early and delayed SPECT imaging was done at 30 min and 180 min, respectively. RESULTS: Decreased Tc-99m-tetrofosmin uptake in the septal segments was observed in 4 patients (40%) at 30 min and in 9 (90%) at 180 min. Reverse redistribution was seen in 9 of 10 patients. In patients with LBBB, the septal-to-lateral uptake ratio was lower in the delayed images than in the early images (0.80 +/- 0.09 vs. 0.89 +/- 0.09, p < 0.001). In patients with LBBB, the washout rate of Tc-99m-tetrofosmin was higher in the septal segments than in the lateral segments (28.3 +/- 4.3% vs. 22.8 +/- 3.3%, p < 0.001). CONCLUSION: The SPECT data indicate that in LBBB without coronary stenosis, the uptake of Tc-99m-tetrofosmin is decreased in the septal wall, and that reverse redistribution occurs frequently. Our results contribute to the elucidation of both the cellular biokinetics of Tc-99m-tetrofosmin in the myocardium and the hemodynamics of the septum in LBBB, and indicate the possible clinical utility of Tc-99m-tetrofosmin.

Adult↗
PubMed1998

Reverse redistribution of Tc-99m-tetrofosmin in exercise myocardial SPECT in patients with hypertrophic cardiomyopathy.

We examined the usefulness of Tc-99m-tetrofosmin in detecting exercise induced perfusion abnormalities in patients with hypertrophic cardiomyopathy (HCM) and to clarify time-related changes in myocardial distribution of Tc-99m-tetrofosmin after a single injection. We studied 44 consecutive patients with HCM by means of exercise/rest Tc-99m-tetrofosmin single photon emission computed tomography (SPECT). After injecting 370 MBq of Tc-99m-tetrofosmin at the peak exercise, the early SPECT imaging was performed at 30 min (EX-30) and the delayed imaging at 180 min (EX- 180). Immediately after the delayed imaging, 740 MBq of Tc-99m-tetrofosmin was injected in the resting state, and the rest SPECT imaging was performed 30 min later. Exercise-induced regional perfusion defects and/or apparent reversible left ventricular cavity dilation were identified in 26 (68.2%) of the 44 patients. When EX-30 images and EX-180 images were compared, reverse redistribution was confirmed in 36 patients (81.8%). Reverse redistribution was detected most frequently in the septal portion of the anterior wall, followed by the septal portion of the posterior wall and the septum. Exercise/rest Tc-99m-tetrofosmin myocardial imaging was a useful method for assessing myocardial perfusion abnormalities in patients with HCM. Reverse redistribution was detected very frequently on early and delayed images of exercise. We assumed that reverse redistribution may reflect a retention disorder of Tc-99m-tetrofosmin caused by some metabolic dysfunction of myocytes.

Cardiomyopathy, Hypertrophic↗
PubMed1998

Effects of diltiazem on myocardial perfusion abnormalities during exercise in patients with hypertrophic cardiomyopathy.

The effect of diltiazem on myocardial ischemia in patients with hypertrophic cardiomyopathy (HCM) was evaluated by exercise myocardial 201Tl single photon emission computed tomography (SPECT). Exercise myocardial SPECT was performed before and 8 weeks after oral administration of diltiazem (180 mg/day) in 20 patients with HCM who showed transient perfusion defects on exercise myocardial 201Tl SPECT under control conditions. SPECT images were divided into 17 segments. The 201Tl perfusion defects were visually scored and evaluated as the defect score. The transient dilation index was calculated as an index of subendocardial ischemia. Improvement of the defect score was demonstrated in 15 patients after the administration of diltiazem. The mean defect score decreased significantly from 9.90 +/- 5.17 to 5.50 +/- 4.89 (p < 0.0001). Although 16 of 20 patients showed an abnormal transient dilation index before diltiazem treatment, 16 showed improvement and 13 of these normalized after diltiazem therapy. The mean transient dilation index decreased from 1.16 +/- 0.10 to 1.02 +/- 0.09 (p < 0.0001). In conclusion, diltiazem prevents or diminishes myocardial ischemia in patients with HCM.

Adult↗
PubMed1998

[Microcirculation of kidney and skin during left ventricular assisted circulation--comparative studies of pulsatile and nonpulsatile assists].

We examined microcirculation of the kidney and skin over a six-hour period in an acute myocardial infarction model in pigs. The outflow cannula was placed in the ascending aorta, the inflow cannula was placed the in left atrium, and a pump was connected to each (pulsatile group, Zeon Medical pneumatic pump; nonpulsatile group, Nikkiso HPM-15). Items examined included the regional blood flow of the cortex and medulla in the kidney and skin, renal and carotid arterial flow, arterial ketone body ratio (AKBR), lactate/pyruvic acid (L/P), BUN, creatinine, and beta 2-microglobulin. After the experimental study, the major organs were removed and a pathological study was performed. The mean aortic pressure after the assist could be maintained at about 100 mmHg. There were no significant differences between the two groups in mean aortic pressure and total cardiac output. Under assisted circulation, the pulse pressure was maintained at about 15 mmHg in the nonpulsatile group and about 40 mmHg in the pulsatile group. After the assist, there were no significant differences in the carotid arterial blood flow between the two groups. However, there were significant differences between the two groups in the renal arterial, renal cortical, and regional skin blood flows. In the laboratory data, there were significant differences between the two groups in AKBR, L/P, and beta 2-microglobulin. Pathological findings on the kidney in the nonpulsatile group showed expansion of the proximal tubes, retention of red blood cells, and expansion of blood capillaries within the glomerulus. On the other hand, the pulsatile group showed almost normal formation. In the lungs, the nonpulsatile group showed edematous change in the air cells and the pulsatile group showed almost normal formation. The results of the previous and current study indicated that the pulsatile assist produced superior circulation in the kidney and peripheral organs and superior cellular metabolism in the early treatment of acute left cardiac failure. On the other hand, nonpulsatile assisted circulation was found to be ineffective in maintaining the circulation in the body, and to be potentially capable of causing irreversible damage of major organs if continuous for more than three hours. The results also indicated that pulsatility was necessary to maintain normal circulation in the peripheral organs and cellular metabolism in the early treatment of acute left cardiac failure.

Animals↗
PubMed1998

Relationship between the modifications of bilateral deficit in upper and lower limbs by resistance training in humans.

Maximal voluntary strength of simultaneous bilateral exertion is known to be small compared to the sum of the unilateral exertions. This phenomenon is called bilateral deficit and the purpose of this study was to investigate whether it operates in both upper and lower limbs. A group of 7 female and 32 male students were divided into 4 training groups and a control group. The unilateral arm or leg training group performed maximal isokinetic arm or leg extensions using each arm or leg unilaterally. The bilateral arm or leg training group trained using bilateral extensions of both arms or legs. The groups in training continued these two types of resistance exercise 3 days a week, for 6 weeks. The control subjects did not train. The improvement in power brought about by training was compared from the viewpoint of whether the limbs (arms or legs) were trained or not and whether the mode of test power exertion (bilateral or unilateral) was the same as performed during training or not. The power in the trained limbs using the same regime as that during training (3.0% after 3 weeks, 7.7% after 6 weeks) showed the largest improvement ratio. This agrees with the specificity, theory in resistance training. The increase in power in untrained limbs using the same regime as during training (2.1% after 3 weeks, 3.5% after 6 weeks; P < 0.01) and the increase in power in the untrained limbs after the opposing mode of training (1.2% after 3 weeks, 2.2% after 6 weeks; P < 0.05) were larger than that of the controls (-2.5% after 3 weeks, -1.1% after 6 weeks). This suggests that the effect of resistance training was transferred to the untrained limbs (i.e. to the legs in the arm training group and to the arms in the leg training group). The degree of bilateral deficit (bilateral index, BI) in the trained limbs of the bilateral training group was shifted in a positive direction (4.2% after 3 weeks, 3.7% after 6 weeks) and that in the trained limbs of unilateral training group was shifted in a negative direction (-3.0% after 3 weeks, -5.4% after 6 weeks) by 6 weeks of training. The BI in the untrained limbs of the unilateral training group was shifted in a negative direction (-1.9% after 3 weeks, -4.5% after 6 weeks) by 6 weeks of training, whereas that in the untrained limbs of the bilateral training group was not shifted in a positive direction (-0.1% after 3 weeks, -2.4% after 6 weeks). These results would suggest that bilateral deficits in the upper and lower limbs are at least partially affected by some common mechanism at a supraspinal level.

Adult↗
PubMed1998

Bilateral Kienböck's disease.

Bilateral Kienböck's disease is very rare. We report here five cases of bilateral Kienböck's disease in the wrist. Of the five patients, two were manual workers and one was a housewife. The two other patients were retired and had received steroids for long periods to control autoimmune disease. The mean ulnar variance was 1. 8 (0-5) mm, and none of the patients had negative variance, indicating that negative ulnar variance was not a major risk factor for the development of bilateral Kienböck's disease.

Adrenal Cortex Hormones↗
PubMed1998

Oral administration of a dominant T-cell determinant peptide inhibits allergen-specific TH1 and TH2 cell responses in Cry j 2-primed mice.

BACKGROUND: Oral immunotherapy with a peptide for allergic immune responses is theoretically a promising therapy but has not been established yet. OBJECTIVE: To evaluate immune suppressive efficacy of oral administration of an immunodominant peptide, we investigated changes in T-cell proliferation, TH1 - and TH2 -cytokine production, and TH1 - and TH2 -mediated antibody production in mice after oral administration of a peptide. METHODS: Peptide p246-259, containing a dominant T-cell determinant of Cry j 2, which is the major allergen in Japanese cedar pollen, was used in this study. Groups of mice received p246-259 or PBS alone before or after they were primed intranasally with Cry j 2 and cholera toxin. In another experiment mice were primed intraperitoneally with Cry j 2 and alum. Proliferative response and cytokine production by nasal-associated lymph node cells against Cry j 2 were investigated. Amounts of systemic anti-Cry j 2 IgE and IgG antibodies were also measured. RESULTS: Oral administration of the peptide to mice before, or even after, the sensitization induced oral tolerance in T-cell responses against the allergen; the tolerance was associated with decreased production of TH1 (IFN-gamma and IL-2) and TH2 (IL-4) cytokines. Allergen-specific TH1 -mediated (IgG2a and IgG2b) and TH2 -mediated (IgG1 and IgE) antibody responses were also inhibited. CONCLUSIONS: Oral administration of a dominant T-cell determinant peptide induces immunologic tolerance in both TH1 and TH2 cell responses against the whole protein allergen. Our study is the first, to our knowledge, to demonstrate the potential for peptide-based oral immunotherapy in order to treat allergic immune responses.

Administration, Intranasal↗
PubMed1998

The role of microglia and tumor-primed lymphocytes in the interaction between T lymphocytes and brain endothelial cells.

We investigated the role of IFN-gamma activated microglia in the passage of T lymphocytes across a monolayer of brain endothelial cells (EC) in vitro. Microglia isolated from Fisher 344 (F344) newborn rats were stimulated with IFN-gamma (100 U/ml) for 48 h. T lymphocytes primed with glioma cells were 51Cr-labeled, and added to the monolayer of F344 brain EC. In the adhesion assay, when EC were cultured in medium containing the supernatant of reactive microglia before the assay was carried out, the number of T lymphocytes adhering was increased. In addition, this adhesion was blocked by the addition of anti-ICAM-1 mAb to the EC. In the migration assay, performed using the double chamber system, when reactive microglia adhered to the other side of EC, the number of T lymphocytes migrating to the underwell was also increased. When T lymphocytes were primed to tumor cells in vivo, both their adhesion and migration were enhanced. These results suggest that some soluble factors from reactive microglia are capable of enhancing the expression of ICAM-1 on the brain EC. As a consequence, large numbers of tumor-primed T lymphocytes can adhere to EC and migrate across the EC monolayer.

Animals↗
PubMed1998

Primary structure and characterization of a bullfrog visual pigment contained in small single cones.

A cDNA fragment encoding a putative visual pigment (FCV pigment) was isolated from the bullfrog, Rana catesbeiana. Its deduced amino acid sequence shows high similarities to those of short wavelength-sensitive pigments such as human blue-, chicken violet- and goldfish ultraviolet-sensitive pigments. An antiserum against its C-terminal amino acid sequence recognized the outer segments of small cone photoreceptor cells without oil droplets. It is suggested that the FCV pigment is a short wavelength-sensitive pigment contained in small single cones which have not been characterized previously.

Amino Acid Sequence↗
PubMed1998

Skin surgery in patients 90 years of age and over.

BACKGROUND: The number of aged people is increasing. It is conceivable that we will be treating considerably more aged patients with more surgical risk factors in the very near future. METHODS: During the period between 1976 and 1996, 212 patients of 80 years of age and older underwent skin surgery at the Mie University Hospital, Japan. Among them, 25 patients of 90 years of age and over were studied. RESULTS: Fourteen patients (56.0%) have undergone skin surgery in the past 5 years; 22 patients (88.0%) had skin tumors on the face and ears; squamous cell carcinoma was found in 17 patients (68.0%), while basal cell carcinoma was seen in four patients (16.0%). Despite their advanced ages, half of the patients had no medical contraindications to performing surgery. CONCLUSIONS: Careful preoperative management may allow more cutaneous surgery to be carried out in aged people.

Aged↗
PubMed1998

Free vascularized fibular graft in the treatment of Salmonella typhi osteomyelitis of the distal radius.

The authors report a rare case of Salmonella typhi osteomyelitis involving the distal radius. The patient was treated successfully by wide resection and reconstruction of the distal radius with a vascularized fibular transfer. Local recurrence of infection did not occur. The free vascularized fibular graft is an effective procedure for the treatment of osteomyelitis of the distal radius.

Aged↗