Search PubMed⌕ Search

Biomedical subjects

T Koike

Publications and source records attributed to T Koike.

At least 37 records · Page 2Linked to original sources
PubMed2004

Chiral bands, dynamical spontaneous symmetry breaking, and the selection rule for electromagnetic transitions in the chiral geometry.

A model for a special configuration in triaxial odd-odd nuclei is constructed which exhibits degenerate chiral bands with a sizable rotation, a manifestation of dynamical spontaneous symmetry breaking. A quantum number obtained from the invariance of the model Hamiltonian, which characterizes observable states, is given and selection rules for electromagnetic transition probabilities in chiral bands is derived in terms of this quantum number. The degeneracy of the lowest two bands is indeed obtained in the numerical diagonalization of the Hamiltonian at an intermediate spin range, over which electromagnetic transitions follow exactly the selection rule expected for the chiral geometry.

Journal Article↗
PubMed2004

Overexpression of lipoprotein lipase improves insulin resistance induced by a high-fat diet in transgenic rabbits.

AIMS/HYPOTHESIS: Dysfunctions of lipoprotein lipase (LPL) have been found to be associated with dyslipidaemias, atherosclerosis, obesity and insulin resistance. There are two conflicting hypotheses regarding the roles of LPL in glucose metabolism and insulin resistance. Whether systemically increased LPL activity would be beneficial or detrimental to insulin sensitivity is yet to be resolved. To address this issue, we studied transgenic rabbits overexpressing human LPL transgene. METHODS: LPL transgenic and control rabbits were fed a 10% high-fat diet (HFD) for 16 weeks. To evaluate glucose metabolism, we compared plasma levels of glucose and insulin in transgenic rabbits with control rabbits and performed an intravenous glucose tolerance test. In addition, we measured adipose tissue accumulation in HFD-fed rabbits. RESULTS: Increased LPL activity in transgenic rabbits resulted in a significant reduction of plasma triglycerides and non-esterified fatty acids, but not in basal levels of glucose and insulin. HFD feeding induced an elevation of plasma glucose levels accompanied by hyperinsulinaemia in control rabbits, but was significantly inhibited in transgenic rabbits. The intravenous glucose tolerance test showed that transgenic rabbits had faster glucose clearance associated with lower levels of insulin secretion than control rabbits. In addition, there was a significant reduction of body adipose tissue in transgenic rabbits compared with in control rabbits fed an HFD. Scanning electron microscopic examination revealed that adipocytes in transgenic rabbits were predominately small cells. CONCLUSIONS/INTERPRETATION: Our results showed that systemically increased LPL activity improves insulin resistance and reduces adipose accumulation in transgenic rabbits, indicating that systemic elevation of LPL may have potential benefits for the treatment of insulin resistance and obesity.

Adipocytes↗
PubMed2004

Long-term effect of Helicobacter pylori eradication on the reversibility of acid secretion in profound hypochlorhydria.

BACKGROUND: Although profound hypochlorhydria is considered to be an important risk factor for development of gastric cancer, long-term effect of Helicobacter pylori eradication on its reversibility remains uncertain. AIM: To clarify the change in acid secretion after eradication in a long-term follow-up over 5 years in patients with profound hypochlorhydria. METHODS: Twenty-three H. pylori-positive patients with hypochlorhydria (<0.6 mmol/10 min) were enrolled prospectively. Assessment of gastrin-stimulated acid output and histologic evaluation of biopsy specimens were performed prior to, and 1, 7 months after eradication. Subsequently, gastric acid secretion was assessed for long-term period over 5 years after eradication in 12 patients. RESULTS: Gastric acid secretion was reversed to normal range in nine of 23 patients (39%) at 7 months after eradication. In the long-term follow-up, gradual and significant recovery in gastric acid secretion was observed up to 2 years post-therapy. However, there was no additional increase during the last 3 years of 5-year follow-up period, leaving the acid secretory levels subnormal in the majority of the patients. CONCLUSIONS: This long-term follow-up study suggests that the pathologic process has already progressed to an irreversible stage in the majority of H. pylori-positive patients with marked body atrophy and profound hypochlorhydria.

Achlorhydria↗
PubMed2004

Chiral degeneracy in triaxial 104Rh.

Chiral doublet bands based on the pi g(9/2) multiply sign in circle nu h(11/2) configuration that achieve degeneracy at spin I=17 in the odd-odd triaxial 104Rh nucleus have been observed. Experimental verification of the interpretation has been tested against specific fingerprints of chirality in the intrinsic system.

Journal Article↗
PubMed2004

Localized relapse in bone marrow of extremities after allogeneic stem cell transplantation for acute lymphoblastic leukemia.

We report a patient with a relapsed in bone marrow of extremities after allogeneic peripheral blood stem cell transplantation for acute lymphoblastic leukemia (ALL). The patient complained of pain in the right upper arm and left leg 15 months after transplantation. Magnetic resonance imaging (MRI) and fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) showed abnormal findings in bone marrow of upper and lower extremities. There were no findings of relapse in aspirates from the sternum and iliac bone marrow. Biopsy specimen from the iliac bone marrow showed normocellular marrow without leukemic cells. Biopsy specimen from the right humerus revealed marked leukemic cell infiltration in the bone marrow. This is apparently the first case of localized relapse of ALL in bone marrow of extremities. Physicians should be aware of unusual relapse sites of leukemia after allogeneic stem cell transplantation. MRI and FDG-PET may be of value in detecting this type of relapse.

Adult↗
PubMed2004

Peripheral blood stem cell mobilization following CHOP plus rituximab therapy combined with G-CSF in patients with B-cell non-Hodgkin's lymphoma.

We mobilized peripheral blood stem cells (PBSC) following CHOP plus rituximab (CHOP-R) therapy, and compared with the findings following CHOP therapy without rituximab. All patients were given G-CSF starting from day 11 after CHOP therapy. Patients in the CHOP-R group (n=8) were given rituximab on day 12. Target CD34(+) cells number was collected in a single leukapheresis on day 14, from all the eight patients in the CHOP-R group. PBSC mobilization kinetics, CD34(+) cells yield and colony-forming ability in the graft collection, toxicity during mobilization, and engraftment after transplantation of CHOP-R group were not significantly different from those in the CHOP group (n=8). In all patients given CHOP-R therapy, CD20(+) cells and immunoglobulin heavy chain (IgH) rearrangement in the graft collection were undetectable by flow-cytometric analysis and Southern blot analysis, respectively, but with PCR analysis two of eight grafts were positive for IgH rearrangement. While further studies are needed to evaluate the efficacy of purging and the outcome of patients undergoing autologous transplantation, CHOP-R therapy can be safely and effectively used in the mobilization phase of PBSC collection, without excess clinical toxicity or deleterious effect on PBSC mobilization kinetics or engraftment time.

Adult↗
PubMed2004

High-dose cytosine arabinoside and etoposide with total body irradiation as a preparatory regimen for allogeneic hematopoietic stem-cell transplantation in patients with acute lymphoblastic leukemia.

One approach to improving the outcome of allogeneic hematopoietic stem-cell transplantation for acute lymphoblastic leukemia (ALL) is to intensify the pretransplant conditioning regimen without increasing toxicity. We used an intensified conditioning regimen consisting of high-dose cytosine arabinoside (3 g/m(2) twice daily i.v. for 3 consecutive days, total six doses), high-dose etoposide (1 g/m(2) once daily i.v. during the first 2 days) and total body irradiation (TBI) (HDACE-TBI) in ALL patients. We retrospectively analyzed 21 patients treated with HDACE-TBI, of whom 18 were in complete remission (CR) and three were in non-CR at transplantation. Although gastrointestinal toxicities were common, critical regimen-related toxicities were not seen in any patients. One patient demonstrated veno-occlusive disease, which could be controlled conservatively. The disease-free survival rate of 18 patients in CR at transplantation was 61%. These results demonstrate that the HDACE-TBI combination regimen is a feasible alternative to other preparatory regimens and does not increase the regimen-related toxicity.

Adolescent↗
PubMed2004

Gastric acid secretion of normal Japanese subjects in relation to Helicobacter pylori infection, aging, and gender.

BACKGROUND: In Japan, where the incidence of gastric cancer is high, Helicobacter pylori infection could affect gastric acid secretion differently from that in Western countries. The aim of this study was to investigate the relationship between H. pylori infection, acid secretion, aging, and gender in normal Japanese subjects. METHODS: The study comprised 193 Japanese subjects who had undergone routine endoscopy. Gastrin-stimulated acid output was performed during the routine endoscopic examination using the endoscopic method of gastric acid secretory testing (EGT: endoscopic gastrin test), which has been reported previously. H. pylori status was determined by histology, rapid urease test, and serology. RESULTS: Mean EGT values were 3.9 +/- 1.5 mEq/10 min in H. pylori-negative men, 1.6 +/- 2.5 in H. pylori-positive men, 2.2 +/- 0.9 in H. pylori-negative women, and 1.5 +/- 1.2 in H. pylori-positive women. Although acid secretion was lower in H. pylori-positive subjects compared with H. pylori-negative subjects in both men and women, the decrease was more marked in men with H. pylori infection. Multiple linear regression analysis showed that aging is positively associated with gastric acid secretion in the H. pylori-negative subjects, whereas a negative association was found between them in the H. pylori-positive subjects. CONCLUSIONS: In Japanese subjects, aging affects gastric acid secretion differently depending on the status of H. pylori infection. H. pylori infection showed a stronger inhibitory effect on the acid secretion in men than in women. This gender-related difference in the susceptibility of acid secretion to H. pylori infection may explain the higher rates of gastric cancer in men in Japan.

Adult↗
PubMed2004

A preliminary analysis of the balance between Th1 and Th2 cells after CD34+ cell-selected autologous PBSC transplantation.

BACKGROUND: CD34+ cell-selected autologous PBSC transplantation (CD34+ APBSCT) is a procedure used for the treatment of patients with malignant disease that is intended to eliminate residual tumor cells from autologous grafts. However, frequent infectious complications after CD34+ APBSCT can occur. A delay of recovery of the absolute number of CD4+ T cells after transplantation was reported to be one disadvantageous factor. As data on T-cell function after CD34+ APBSCT are scanty, we analyzed changes in T-helper cell 1 (Th1) and T-helper cell 2 (Th2) after CD34+ APBSCT to evaluate immune reconstitution. METHODS: Twelve patients underwent APBSCT (CD34+APBSCT group, n=4, and unselected APBSCT, n=8). Peripheral blood (PB) samples were obtained at 2, 4, 8, 12 and 16 weeks after the transplantation. The dynamics of the Th1 and Th2 were analyzed at a single-cell level, using flow cytometry. RESULTS: In the CD34+ APBSCT group, not only the absolute count of CD4+ T cells but also the proportion of Th1 cells in CD4+ T cells and the ratio of Th1 to Th2 after transplantation were significantly decreased at 2 and 4 weeks after transplantation compared with findings in the unselected APBSCT group. DISCUSSION: We suggest that higher rates of infectious complications after CD34+ APBSCT may be due to the inability of residual T cells from the CD34+ cell selection to generate mature T cells that function adequately against infection. Although further study would be required, our preliminary data provide some information on the immune reconstitution after CD34+ APBSCT and differentiation of T lymphocytes into Th1 and Th2 in vivo.

Adult↗
PubMed2004

Allocation of 14C-carbon in two species of larch seedlings infected with ectomycorrhizal fungi.

The flow of labeled carbon in ectomycorrhizal and non-ectomycorrhizal seedlings of Japanese larch (Larix kaempferi Sarg.) and its F1 hybrid (Larix gmelinii Rupr. x L. kaempferi) was studied. Larch seedlings were grown in a greenhouse for 110 days with larch forest soil (FM) or Suillus grevillei (SM) inoculum, or in the absence of ectomycorrhizal fungi (NM). Shoots of colonized and NM seedlings were exposed to a pulse of 14CO2 for 1 h under natural light. Seedlings were harvested following 0, 6 and 24 h of exposure to 14CO2. At the final harvest, SM seedlings of Japanese larch and hybrid larch allocated 2.6 and 2.5% more 14C, respectively, to roots than NM seedlings. In contrast, FM seedlings of Japanese larch and hybrid larch allocated 6.5 and 18.0% more 14C, respectively, to the stem than NM seedlings. Of the total 14C detected in needle, stem and root fractions, FM and SM seedlings allocated a greater proportion than NM seedlings, perhaps because FM and SM seedlings had significantly (P < 0.05) higher photosynthetic rates than NM seedlings. As a result, FM and SM seedlings had greater dry masses than NM seedlings. Concentrations of nitrogen and phosphorus in FM and SM seedlings were significantly (P < 0.05) higher than in NM seedlings, as was stomatal conductance.

Carbon↗
PubMed2004

Synthetic selective inhibitors of coagulation factor Xa strongly inhibit thrombin generation without affecting initial thrombin forming time necessary for platelet activation in hemostasis.

DX-9065a and JTV-803, synthetic selective inhibitors of activated factor X (FXa), have recently been demonstrated as strongly effective antithrombotic agents in animal thrombosis models, yet with a low risk of bleeding. The aim of the present study was to elucidate these characteristics. Using a chromogenic assay with purified coagulation factors, 73.9% of thrombin generation was suppressed by the addition of DX-9065a (0.20 microm) and 75.7% by JTV-803 (0.18 microm). Inhibition by argatroban (0.19 microm) was less (36.0%) and initial thrombin forming time (T50), the time required to generate 50% thrombin activity in vitro, which is considered important for platelet aggregation in hemostasis, was significantly prolonged by argatroban. In contrast, DX-9065a and JTV-803 had no apparent influence on T50, suggesting that initial thrombin was formed immediately, as in the control. We also investigated platelet aggregation in defibrinated plasma induced by tissue factor, to clarify whether initial thrombin contributes to hemostasis. Aggregation was not affected by the addition of either FXa inhibitor, whereas it was significantly reduced by argatroban. Our results suggest that initial thrombin, which is formed despite the presence of a FXa inhibitor, can activate platelets. We concluded that DX-9065a and JTV-803 are able to inhibit thrombin generation significantly without affecting the formation of initial thrombin for platelet activation, which may contribute to hemostasis through the preservation of normal bleeding time.

Anticoagulants↗
PubMed2004

Relationship between temporomandibular joint (TMJ)-related pain and morphological changes of the TMJ condyle in patients with temporomandibular disorders.

OBJECTIVES: The purpose of this study was to analyse the relationship between temporomandibular joint (TMJ)-related pain and morphological change of the TMJ condyle in patients with temporomandibular disorders. METHODS: Data were obtained from 178 joints in 89 patients. The joints were clinically assessed for pain on mandibular function and on lateral palpation of the TMJ. They were also assessed for radiographic evidence of bone change at the articular surface (OAAS) and resorption of the lateral part of the condyle (RLC). RESULTS: A higher prevalence of joint pain on function was observed in joints with OAAS than in those without OAAS (Chi-square test of independence, P < 0.05). Significant relationships were found between palpation pain and OAAS and between palpation pain and RLC (Chi-square test of independence, P < 0.05). In addition, patients with RLC showed a significantly lower pain threshold for external mechanical stimuli than those without RLC (Welch's t-test, P < 0.05). CONCLUSIONS: These results suggest a possible relationship between pain on function and OAAS as well as a relationship between palpation pain and RLC. Pain on lateral palpation may be related to the pathological conditions that induce RLC.

Adolescent↗
PubMed2004

NO-1886 decreases ectopic lipid deposition and protects pancreatic beta cells in diet-induced diabetic swine.

The synthetic compound NO-1886 (ibrolipim) is a lipoprotein lipase activator that has been proven to be highly effective in lowering plasma triglycerides. Recently, we found that NO-1886 also reduced plasma free fatty acids and glucose in high-fat/high-sucrose diet-induced diabetic rabbits. In the current study, we investigated the effects of NO-1886 treatment on ectopic lipid deposition and the islet pathology in miniature swine fed a high-fat/high-sucrose diet. Our results showed that feeding this diet to miniature swine caused insulin resistance, increased lipid deposition in non-adipose tissue, such as in the heart, skeletal muscle, liver and pancreas, and also caused pancreatic beta cell damage. However, supplementing 1% NO-1886 (200 mg/kg per day) into the high-fat/high-sucrose diet decreased ectopic lipid deposition, improved insulin resistance, and alleviated the beta cell damage. These results suggest that improvement of lipid disorder, non-adipose tissue steatosis and insulin resistance may be very important for the protection of beta cell damage. Therefore, NO-1886 is potentially beneficial for the treatment of insulin-resistance syndrome.

Animals↗
PubMed2004

[Intentional limited resection for small adenocarcinoma with ground-glass opacity component more than 50% on computed tomography].

Fifty-eight patients who had small lung tumors 2 cm or less with ground-glass opacity (GGO) component more than 50% on high resolution computed tomography (HRCT) underwent intentional limited resection. After bronchioloalveolar carcinoma without both active fibroblastic proliferation and invasive sign to the stroma was confirmed, limited resection was completed in 50 patients. In 8 patients, procedure was converted lobectomy because of microscopic invasive sign in 4, active fibroblastic proliferation in 2, and other reasons in 2. Unexpected invasive sign was found by detailed post-operative examination in 2 cases. Five-year survival rate was 98% with a mean follow-up period of 48.8 months. A limitation of intra-operative diagnosis was revealed and the accuracy of diagnosis should be improved by not only intra-operative pathological diagnosis but also HRCT images.

Adenocarcinoma↗
PubMed2004

Effects of hypophysectomy and in vivo administration of ACTH or dexamethasone on the level of ACTH receptor mRNA in adrenal glands and adipose tissues of mice.

OBJECTIVE: In rodents, ACTH induces steroidogenesis in the adrenal cortex and also lipolysis in adipose tissues via the sole specific receptor for ACTH. Up-regulation of the ACTH receptor (ACTH-R) mRNA by ACTH was found to be evident in adrenocortical cells. However, a role of in vivo ACTH on ACTH-R mRNA expression in the adrenal cortex is not well understood. In addition, so far less attention has been also paid to the regulation of ACTH-R expression in adipose tissues. We investigated the effects of hypophysectomy and in vivo administration of ACTH or dexamethasone on the level of ACTH-R mRNA in the adrenal gland and adipose tissues of mice. METHODS: ACTH mRNA in the adrenal glands and epididymal adipose tissues of mice sacrificed 10 days after hypophysectomy or sham operation, and 24 hours after ACTH-Z (2 IU i.m.) or physiological saline solution (PSS) injection, and also 3-days after dexamethasone (300 microg/day i.m.) or PSS administration was analysed by Northern blot, and intensities of autoradiographic bands were quantified. RESULTS: In the adrenal gland, in vivo administration of ACTH-Z significantly increased the level of ACTH-R mRNA to 342% of control values, but in vivo administration of dexamethasone or hypophysectomy induced no significant alteration of ACTH-R mRNA. In adipose tissues, these conditions did not significantly alter the level of ACTH-R mRNA. CONCLUSION: Low circulating ACTH may not be a substantial factor for ACTH-R gene expression in the adrenal gland, but a high level of in vivo ACTH dose up-regulated the expression. A different regulation of ACTH-R gene expression exists in the adrenal cortex and adipose tissues of mice.

Adipose Tissue↗
PubMed2003

Successful treatment with rituximab for autoimmune hemolytic anemia concomitant with proliferation of Epstein-Barr virus and monoclonal gammopathy in a post-nonmyeloablative stem cell transplant patient.

A 30-year-old Japanese woman who underwent nonmyeloablative stem cell transplantation from her HLA-matched sister developed autoimmune hemolytic anemia (AIHA). There was proliferation of EBV-DNA in her peripheral blood and monoclonal gammopathy, both predictive factors of post-transplant lymphoproliferative disorder (PTLD). As conventional immunosuppressive therapy for AIHA could lead to overt PTLD, we decided to give her rituximab 375 mg/m(2) once weekly for a total of four doses. After this therapy, both her AIHA and monoclonal gammopathy were resolved and EBV-DNA became undetectable. Rituximab therapy deserves consideration for treatment of post-allogeneic stem cell transplant patients with AIHA, especially for patients who cannot be given immunosuppressive therapy.

Adult↗
PubMed2003

A composite chiral pair of rotational bands in the odd-A nucleus 135Nd.

High-spin states in 135Nd were populated with the 110Pd(30Si,5n)135Nd reaction at a 30Si bombarding energy of 133 MeV. Two DeltaI=1 bands with close excitation energies and the same parity were observed. These bands are directly linked by DeltaI=1 and DeltaI=2 transitions. The chiral nature of these two bands is confirmed by comparison with three-dimensional tilted axis cranking calculations. This is the first observation of a three-quasiparticle chiral structure and establishes the primarily geometric nature of this phenomenon.

Journal Article↗