Biomedical subjects

Y Koike

Publications and source records attributed to Y Koike.

At least 19 recordsLinked to original sources

PubMed2006

Synergistic effects of injection of bone marrow cells into both portal vein and bone marrow on tolerance induction in transplantation of allogeneic pancreatic islets.

We have established a new method for allogeneic pancreatic islet (PI) transplantation: relatively low doses of irradiation followed by simultaneous transplantation of PIs and bone marrow cells (BMCs) via the portal vein (PV). In the present study, we have compared this method with intra-bone marrow (IBM)-bone marrow transplantation (BMT), and with a combination of both methods. Streptozotocin (STZ)-induced diabetic-recipient rats, Fischer 344 (F344, RT1A(l), RT1B(l)), were irradiated 1 day before transplantation. PIs of Brown Norway rats (BN, RT1A(n), RT1B(n)) were transplanted into the liver of the diabetic F344 rats via the PV. BMCs from BN rats were injected into the recipients' bone marrow (IBM), PV or intravenously (IV) or by a simultaneous combination of PV plus IBM (PV+IBM). We compared graft survival among the groups of '9 Gy+IBM'(10/10 accepted), '9 Gy+PV'(7/10 accepted), '9 Gy+IV'(0/7 accepted), '9 Gy+PV+IBM'(8/8 accepted), '8.5 Gy+IBM'(4/9 accepted), '8.5 Gy+PV'(0/7 accepted), '8.5 Gy+IV'(0/7 accepted), '8.5 Gy+PV+IBM'(9/12 accepted), '8 Gy+IBM'(2/10 accepted) and '8 Gy+PV+IBM'(2/8 accepted). As we reported previously, PV-BMT is more effective in inducing the acceptance of allogeneic PIs than IV-BMT. However, IBM-BMT requires less pretreatment than PV-BMT. (PV+IBM)-BMT was found to be the most effective in inducing the acceptance of allogeneic PIs. These results suggest that allogeneic PI-transplantation in conjunction with (PV+IBM)-BMT could become a viable strategy.

Animals↗

PubMed2006

[Surgical fixation for flail chest].

Flail chest occurs by blunt chest trauma and is associated with pulmonary contusion, atelectasis, pneumothorax, hemothorax, and respiratory failure. Because of its severity, it may need internal pneumatic stabilization or surgical fixation. Some patients do not need the internal stabilization and are observed conservatively. Some of these patients, however, increase the flail after palliating the pain and getting up. These patients show inefficient ventilation and surgical fixation is needed. The operation should be performed after the improvement of pulmonary contusion. In this paper, we presented 2 patients who showed such course and clarified the surgical methodology.

Aged↗

PubMed2005

Spin excitations in an anisotropic bond-alternating quantum s = 1 chain in a magnetic field: contrast to haldane spin chains.

Inelastic neutron scattering experiments on the S = 1 quasi-one-dimensional bond-alternating antiferromagnet Ni(C9D24N4)(NO2)ClO4 have been performed under magnetic fields below and above a critical field Hc at which the energy gap closes. Normal field dependence of Zeeman splitting of the excited triplet modes below Hc has been observed, but the highest mode is unusually small and smears out with increasing field. This can be explained by an interaction with a low-lying two magnon continuum at q(parallel) = pi that is present in dimerized chains but absent in uniform ones. Above Hc, we find only one excited mode, in stark contrast with three massive excitations previously observed in the structurally similar Haldane-gap material NDMAP [A. Zheludev, Phys. Rev. B 68, 134438 (2003)].

Journal Article↗

PubMed2005

Analysis of the susceptibility of CD57 T cells to CD3-mediated apoptosis.

After stimulation with anti-CD3 antibody in vitro, CD57(+) T cells showed a greater susceptibility to apoptosis than CD57(-)alphabetaT cell receptor (TCR)(+) T cells (regular alphabeta T cells). The apoptotic fraction of CD57(+) T cells showed an increased production of active caspase-3. An increase in both Fas expression and Fas-ligand (FasL) production was also observed in CD57(+) T cells, whereas the expression of survivin was suppressed in CD57(+) T cells compared to that of regular alphabeta T cells. CD57(+) T cells display a biased expansion of a few Vbeta T cell fractions in individuals, but such Vbeta T cells were not specifically susceptible to CD3-mediated apoptosis. The TCR expression level of CD57(+) T cells was much lower than that of regular T cells and anti-TCR antibody stimulation induced a smaller apoptotic proportion of CD57(+) T cells than did anti-CD3 antibody. Although the CD3epsilon expression levels were similar in both T cell subsets, the CD3zeta level of CD57(+) T cells was significantly higher than that of regular T cells. These results suggest that several apoptotic and anti-apoptotic molecules are involved in the CD3-induced apoptosis of CD57(+) T cells and raise the possibility that the imbalance in expression of the CD3epsilon and CD3zeta chains may also contribute to the susceptibility of CD57(+) T cells to undergo apoptosis.

Adult↗

PubMed2005

Proposal of a new prognostic model for hepatocellular carcinoma: an analysis of 403 patients.

BACKGROUND: The prognosis of hepatocellular carcinoma (HCC) is highly dependent on tumour extension and liver function. Recently, two new prognostic scoring systems-the CLIP score, developed by Italian investigators and the BCLC score, developed in Barcelona-have been widely used to assess prognosis in patients presenting with hepatocellular carcinoma. Each system has its own relative limitations. AIMS: To create a new prognostic scoring system which is simple, easy to calculate, and suitable for estimating prognosis during radical treatment of early HCC. METHODS: A total of 403 consecutive patients with HCC treated by percutaneous ablation at the Department of Gastroenterology, University of Tokyo Hospital, between 1990 and 1997 were used as the training sample to identify prognostic factors for our patients and used to develop the Tokyo score. As a testing sample, 203 independent patients who underwent hepatectomy at the Department of Hepato-Biliary-Pancreatic Surgery were studied. Prognostic factors were analysed by univariate and multivariate Cox proportional hazard regression. RESULTS: The Tokyo score consists of four factors: serum albumin, bilirubin, and size and number of tumours. Five year survival was 78.7%, 62.1%, 40.0%, 27.7%, and 14.3% for Tokyo scores 0, 1, 2, 3, and 4-6, respectively. The discriminatory ability of the Tokyo score was internally validated by bootstrap methods. The Tokyo score, CLIP score, and BCLC staging were compared by Akaike information criterion and Harrell's c index among training and testing samples. In the testing sample, the predictive ability of the Tokyo score was equal to CLIP and better than BCLC staging. CONCLUSIONS: The Tokyo score is a simple system which provides good prediction of prognosis for Japanese patients with HCC requiring radical therapy.

Adolescent↗

PubMed2005

Progression and prognosis in pure autonomic failure (PAF): comparison with multiple system atrophy.

OBJECTIVE: To clarify the progression of autonomic symptoms and functional deterioration in pure autonomic failure (PAF), particularly in comparison with multiple system atrophy (MSA). METHODS: The investigation involved eight patients with PAF (M/F = 7/1; mean age at onset, 57 years) and 22 with probable MSA matched for age at onset (M/F = 14/8; onset 56 years). Subjects were followed up for neurological symptoms, activities of daily living, and autonomic function for more than seven years. Autonomic functional tests were carried out. RESULTS: In PAF, fainting or sudomotor dysfunction occurred first, followed by constipation and syncope. Urinary dysfunction developed late, and respiratory dysfunction was not evident. This clinical course contrasted sharply with that in MSA, where early urinary dysfunction usually proceeded to sudomotor dysfunction or orthostatic hypotension (p = 0.004), followed by respiratory dysfunction (p = 0.0004). Results of pharmacological tests also distinguished PAF from MSA. Progression and prognosis in patients with PAF did not worsen, unlike the steady progressive autonomic dysfunction in MSA (p < 0.0001, p < 0.0001, p = 0.0009, and p = 0.003, for progression to modified Rankin scale grade III, IV, V, and death, respectively). CONCLUSIONS: The time course and pattern of progression of autonomic failure differed significantly between PAF and MSA. Patients with PAF had slower functional deterioration and a better prognosis.

Activities of Daily Living↗

PubMed2004

Decreased bone mineral density at the distal radius, but not at the lumbar spine or the femoral neck, in Japanese type 2 diabetic patients.

The purpose of this study is to assess the association between type 2 diabetes and bone mineral density. This study included 145 Japanese patients (64 men and 81 women) with type 2 diabetes and 95 non-diabetic control subjects (41 men and 54 women) of similar age. We measured bone mineral density (BMD) at the sites with different cortical/cancellous bone ratio (lumbar spine, femoral neck, and distal radius) using dual-energy X-ray absorptiometry. BMD and Z score at the distal radius were significantly lower in type 2 diabetic patients than those in control subjects, and in type 2 diabetic patients, the Z score at the distal radius was lower than that at their own lumbar spine and femoral neck. In type 2 diabetic patients, negative correlation between BMD and the mean HbA1c during the previous 2 years was found significantly at the distal radius in both genders and at the femoral neck in women. These results indicate the selective cortical bone loss in type 2 diabetes and suggest the importance of also determining BMD at the radius and keeping good metabolic control to prevent bone loss in type 2 diabetic patients.

Absorptiometry, Photon↗

PubMed2004

Primary cervical spinal epidural Extra-osseous Ewing's sarcoma.

Cases of primary spinal epidural Extra-osseous Ewing's sarcoma (EES) are rarely seen and a good prognosis for EES cannot be expected since a high incidence of local recurrence and metastasis frequently occur. We present a case of cervical spinal epidural EES in a 7-year-old girl with long survival after tumour resection. She also received adjuvant treatment with peripheral blood stem cell transplantation (PBSCT). This management successfully improved her condition and she was in complete remission without neurological deficit 60 months after surgery. Such a good prognosis of EES in the cervical spine is very rare. It is likely that magnetic resonance imaging (MRI) lead to a diagnosis of this rare type of EES at an early stage of the disease. PBSCT could be useful as an adjuvant to prolong the period of complete remission.

Child↗

PubMed2003

Horticultural characterization of Angelonia salicariifolia plants transformed with wild-type strains of Agrobacterium rhizogenes.

Genetic transformation was carried out with wild-type strains of Agrobacterium rhizogenes for introducing a dwarf trait into the Scrophulariaceous ornamental plant, angelonia (Angelonia salicariifolia). Leaf segments of two angelonia genotypes (Ang.1 and Ang.2) were co-cultivated with mikimopine-type strains of A. rhizogenes. Adventitious roots that showed vigorous growth and increased lateral branching when cultured on half-strength Murashige and Skoog's (MS) basal salts medium lacking plant growth regulators (PGRs) after co-cultivation were selected as putatively transformed lines. All of these selected lines produced mikimopine. Adventitious shoots were efficiently induced from putatively transformed root segments on half-strength MS basal salts medium containing 1 mg l(-1) benzyladenine (BA) under continuous illumination (24-h photoperiod), and the shoots easily rooted following their transfer to half-strength MS basal salts medium lacking PGRs. The transgenic nature of regenerated plants was confirmed by Southern hybridization. Transformed plants frequently died during their acclimatization, and acclimatized plants of eight transformed lines grew very slowly for 1-5 months after transplantation to the greenhouse. Plants of two transformed lines of Ang.2 flowered 4-6 months after transplantation. These transformed plants exhibited phenotypic alterations such as dwarfness and smaller leaves. There were no apparent alterations observed in the number, shape, and size of the flowers. Pollen fertility of the transformed plants was 60-80% based on aceto-carmine staining. These results indicate the possibility of applying A. rhizogenes-mediated transformation for introducing a dwarf trait into angelonia.

Blotting, Southern↗

PubMed2003

Genomic sequence of a 320-kb segment of the Z chromosome of Bombyx mori containing a kettin ortholog.

The sex chromosome constitution of the silkworm, Bombyx mori, is ZW in the female and ZZ in the male. Very little molecular information is available about the Z chromosome in Lepidoptera, although the topic is interesting because of the absence of gene dosage compensation in this chromosome. We constructed a 320-kb BAC contig around the Bmkettin gene on the Z chromosome in Bombyx and determined its nucleotide sequence by the shotgun method. We found 13 novel protein-coding sequences in addition to Bmkettin. All the transposable elements detected in the region were truncated, and no LTR retrotransposons were found, in stark contrast to the situation on the W chromosome. In this 320-kb region, four genes for muscle proteins (Bmkettin, Bmtitin1, Bmtitin2, and Bmprojectin) are clustered, together with another gene (Bmmiple) on the Z chromosome in B. mori; their orthologs are also closely linked on chromosome 3 in Drosophila, suggesting a partial synteny. Real-time RT-PCR experiments demonstrated that transcripts of 13 genes of the 14 Z-linked genes found accumulated in larger amounts in males than in female moths, indicating the absence of gene dosage compensation. The implications of these findings for the evolution and function of the Z chromosome in Lepidoptera are discussed.

Amino Acid Motifs↗

PubMed2003

Characterization of bronchoalveolar lavage T cell subsets in sarcoidosis on the basis of CD57, CD4 and CD8.

T cells expressing CD57 (a natural killer cell marker) with interferon-gamma (IFN-gamma) producing capacity increase under various conditions. CD57+ T cells are also present in the bronchoalveolar lavage fluid (BALF) of sarcoidosis, and several phenotypical and functional analyses of these cells have been reported. In the present study, BALF T cells obtained from 52 patients with sarcoidosis were classified further into CD4+CD57+ T cells, CD4+CD57- T cells, CD8+CD57+ T cells and CD8+CD57- T cells and their phenotypes and functional characteristics were assessed. Substantial proportions of these T cell subsets expressed natural killer cell markers CD161 and CD122. The biased expansion of Vbeta2 T cells was observed in both CD4+CD57+ T cells and CD4+CD57- T cells in BALF from most patients, while the expansion of other Vbeta T cells was also observed in some patients. Unexpectedly, the biased expansion of certain Vbeta T cells was also seen in either CD8+CD57+ T cells or CD8+CD57- T cells, while the expanded Vbeta T cells in CD8+ T cells differed substantially among individuals. BALF T cells showed a remarkably lower T cell receptor (TCR) intensity than that of peripheral blood T cells. Both CD8+ T cell subsets in BALF of sarcoidosis expressed the intracellular perforin/granzyme B, while all four subsets expressed intracellular IFN-gamma after in vitro activation, and CD4+ T cells, especially CD4+CD57+ T cells, expressed tumour necrosis factor-alpha. These findings indicate that CD57+ T cells as well as CD57- T cells in the BALF are phenotypically and functionally different from peripheral blood T cells and may play an important role in the Th1 dominant state and inflammation in pulmonary sarcoidosis.

Antigens, CD↗

PubMed2003

Onset age and severity of motor impairment are associated with reduction of myocardial 123I-MIBG uptake in Parkinson's disease.

OBJECTIVES: To elucidate the factors associated with severity of cardiac sympathetic nerve involvement in idiopathic Parkinson's disease (PD). METHODS: (123)I-metaiodobenzylguanidine uptake was examined in 88 patients with PD. The ratio of the uptake in the heart (H) to that in the mediastinum (M) (the H/M ratio) was calculated and correlated with age at onset, age at examination, and disease severity and duration. Twenty five healthy people were also examined as a control. RESULTS: There was a mild but significant negative correlation between H/M ratio and age at onset (early, r = -0.33, p = 0.002; delayed, r = -0.34, p = 0.001) and between Hoehn and Yahr (H-Y) stage (early, r = -0.30, p = 0.006; delayed, r = -0.32, p = 0.003). There was no significant correlation between disease duration and H/M ratio. When patients with PD were classified into four subgroups on the basis of age at onset (> 62 or < 62 years) and disease severity (H-Y > III or H-Y < or = II), the median H/M ratio of the older and more severe group was significantly lower than that of the younger and less severe group (p = 0.005). CONCLUSION: This study suggests that late onset, high severity PD is associated with myocardial sympathetic dysfunction.

3-Iodobenzylguanidine↗

PubMed2003

Sequential constriction of upper airway and vocal cords in sleep apnoea of multiple system atrophy: low field magnetic resonance fluoroscopic study.

Low field magnetic resonance fluoroscopy was used to clarify temporal and spatial features of airway obstruction in sleep apnoea syndrome (SAS) in multiple system atrophy (MSA), as well as in obstructive SAS (OSAS). 20 patients with OSAS with severe obesity (mean (SD) age 66 (10) years; 16 men, 4 women) and 6 patients with SAS related to probable MSA (60 (9) years; 4 men, 2 women) were studied. In the OSAS group, body mass index, apnoea index, and desaturation index were significantly higher than in the MSA group. In OSAS, simultaneous obstruction extended from the retropalatal pharynx to the retroglossal during sleep on low field magnetic resonance fluoroscopy. In MSA, obstruction of upper airway followed a similar distribution, but obstruction of vocal cords followed upper airway obstruction. In contrast to OSAS, sequentially acting neural mechanisms are suspected in SAS with MSA.

Aged↗

PubMed2002

Magnetic structure, phase diagram, and a new type of spin-flop transition dominated by higher order interaction in a localized 5f system U3Pd20Si6.

The magnetic structure of the localized-5f uranium intermetallic compound U3Pd20Si6 has been determined by means of a neutron diffraction experiment. Our data demonstrate that this compound has a collinear coupling of the sublattice ordering of the uranium spins on the 4a and 8c sites. We conclude that higher-order exchange and/or quadrupole interactions are necessary to stabilize this unique collinear structure. We discovered a new type of spin-flop transition against the uniaxial anisotropy induced by this collinear coupling.

Journal Article↗

PubMed2002

Activation of human T cells with NK cell markers by staphylococcal enterotoxin A via IL-12 but not via IL-18.

We have reported recently that mouse liver NK cells and NK1 x 1+ T cells were activated by bacterial superantigens via the IL-12 production from Kupffer cells. In the present study, we examined the effect of staphyloccoccal enterotoxin A (SEA) on human T cells with NK cell markers, CD56 or CD57 (NK-type T cells). After stimulating peripheral blood mononuclear cells (PBMC) with SEA, PBMC produced a large amount of IFN- and acquired a potent antitumour cytotoxicity. The in vitro depletion of either CD56+ TCR NK cells, CD56+ T cells or 57+ T cells from PBMC significantly inhibited the IFN- production from PBMC. When purified NK-type T cells, NK cells and regular T cells were cultured with monocytes and SEA they all produced IFN-, while the IFN- amounts produced by both NK-type T cells were greater than those produced by NK cells. NK cells as well as CD56+ T cells showed cytotoxicity against NK-sensitive K562 cells, whereas both NK-type T cells showed a more potent cytotoxicity against NK-resistant Raji cells than did NK cells. The IFN- production from each population as well as from whole PBMC was greatly inhibited by anti-IL-12 antibody but not by anti-IL-18 antibody. The antitumour cytotoxicity of whole PBMC was also significantly inhibited by anti-IL-12 antibody while the SEA-induced proliferation of PBMC was not affected by anti-IL-12 antibody. Furthermore, SEA-activated NK-type T cells as well as NK cells showed cytotoxicities against vascular endothelial cells. Our findings suggest that human NK-type T cells are thus involved in bacterial superantigen-induced immune response.

Biomarkers↗

PubMed2002

CD57+ T cells augment IFN-gamma production in a one-way mixed lymphocyte reaction and their expansion after stem cell transplantation in paediatric patients.

To clarify the immune response of CD57+ T cells (most of them are CD8+) in peripheral blood (PB) against alloantigens in order to elucidate the T helper 1 (Th 1) immune response, we assessed the role of CD57+ T cells in IFN-gamma (one of the representative Th 1 cytokines) production in a one-way mixed lymphocyte reaction (MLR). In this study, we showed that CD57+ T cells in responder cells were essential for effective IFN-gamma production in allogeneic MLR due partly to the augmentation of the alloresponse of regular T cells. Furthermore, IFN-gamma production in MLR correlated with the proportions of CD57+ T cells in PB regardless of the responders' age. We also showed that the extent of the expansion of CD57+ T cells in paediatric patients after haematopoietic stem cell transplantation (HSCT) was markedly lower than that in adult patients. In addition, CD57+ T cells purified and activated with a combination of cytokines showed a greater cytotoxicity than regular T cells against human umbilical vein endothelial cells. Because IFN-gamma production in one-way MLR is a useful predictor of graft-versus-host disease (GVHD), especially in the acute phase that occurs after allogeneic HSCT, our findings suggested that CD57+ T cells play a role in the development of GVHD and thus may explain the reason as to why a higher donor age is associated with an increased risk of developing GVHD while, in addition, the incidence of severe GVHD in paediatric patients is lower than that in adult patients.

Adult↗

PubMed2001

The mechanism of a defective IFN-gamma response to bacterial toxins in an atopic dermatitis model, NC/Nga mice, and the therapeutic effect of IFN-gamma, IL-12, or IL-18 on dermatitis.

NC/Nga (NC) mice raised under conventional conditions (Conv. NC mice) spontaneously develop dermatitis similar to human atopic dermatitis, whereas NC mice raised under the specific pathogen-free conditions do not develop dermatitis. In the present study, we show that the representative Th1 cytokine, IFN-gamma levels in the sera of NC mice, injected with either staphylococcal enterotoxin B or endotoxin (LPS), to be severalfold lower than those of normal mice. The low IFN-gamma response to staphylococcal enterotoxin B was correlated to the lack of regular Vbeta8(+) T cells and Vbeta8(+) NK T cells, and the low IFN-gamma response to LPS was correlated to an impaired IL-18 production of macrophages. The CD3-stimulated IL-4 production from liver and spleen T cells from Conv. NC mice in vitro was greatly augmented. The serum IL-4 levels of untreated Conv. NC mice also were higher than those of normal mice and specific pathogen-free NC mice. Treatment of Conv. NC mice either with IFN-gamma, IL-12, or IL-18 twice a week from 4 wk of age substantially inhibited the elevation of the serum IgE levels, serum IL-4 levels, and dermatitis, and IL-12 or IL-18 treatment also reduced the in vitro IL-4 production from CD3-stimulated liver T cells. The systemic deficiency in the Th1 response to bacterial stimulation thus leads to a Th2-dominant state and may induce an abnormal cellular immune response in the skin accompanied with an overproduction of IgE and a susceptibility to dermatitis in NC mice.

Adjuvants, Immunologic↗

PubMed2001

Des-gamma-carboxy prothrombin as a useful predisposing factor for the development of portal venous invasion in patients with hepatocellular carcinoma: a prospective analysis of 227 patients.

BACKGROUND: Portal venous invasion (PVI) in patients with hepatocellular carcinoma (HCC) is an important factor affecting prognosis. The objective of this study was to elucidate predisposing factors for the development of PVI. METHODS: Two hundred twenty-seven patients with HCC who did not show PVI and who received percutaneous ethanol injection therapy and/or microwave coagulation therapy at the time of their first hospital admission were enrolled between 1994 and 1996. After their HCC was treated, the patients were followed for a mean of 19 months. For the detection of HCC recurrence and/or development of PVI, ultrasonography was performed every 3 months, a computed tomography (CT) scan was performed every 6 months, and the biochemical parameters of the patients were measured every month. PVI was defined as protrusion of the tumor into the first and/or second branch or into the main trunk of the portal vein. RESULTS: Of the 227 patients, 24 (11%) later developed PVI. Tabular analysis was performed on these 24 patients and indicated that tumor size, albumin, total bilirubin, prothrombin time, alpha-fetoprotein (AFP) level, and des-gamma-carboxy prothrombin (DCP) level differed significantly between the time of initial admission and the time of PVI development. A univariate analysis performed on the 227 patients indicated that an increase in the numbers of tumors, the histologic tumor grade (differentiation), the AFP level, and the DCP level at the time of initial diagnosis of HCC had a significant correlation with the later development of PVI; and a stepwise, multivariate Cox regression analysis revealed that the DCP level was the strongest predisposing factor (P < 0.0010; risk ratio = 5.65) followed by the histologic grade of tumor differentiation. CONCLUSIONS: The results suggest that the serum DCP level is the most useful predisposing clinical parameter for the development of PVI.

Adult↗