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T Sakai

Publications and source records attributed to T Sakai.

At least 37 records · Page 2Linked to original sources
PubMed2005

Experimental observation of the 1/3 magnetization plateau in the diamond-chain compound Cu3(CO3)2(OH)2.

The magnetic susceptibility, high field magnetization, and specific heat measurements of Cu3(CO3)2(OH)2, which is a model substance for the frustrating diamond spin chain model, have been performed using single crystals. Two broad peaks are observed at around 20 and 5 K in both magnetic susceptibility and specific heat results. The magnetization curve has a clear plateau at one third of the saturation magnetization. The experimental results are examined in terms of theoretical expectations based on exact diagonalization and density matrix renormalization group methods. An origin of magnetic anisotropy is also discussed.

Journal Article↗
PubMed2005

Subdural accumulation of fluid in a dog after the insertion of a ventriculoperitoneal shunt.

A dog with hydrocephalus as a result of aqueduct stenosis and cerebellar herniation underwent ventriculoperitoneal shunting. Magnetic resonance images and computed tomography scans taken after the surgery revealed subdural accumulations of haemorrhagic fluid and cereberocortical collapse caused by overshunting and leakage of cerebrospinal fluid from the site of insertion of the shunt. However, the degree of cerebellar herniation was reduced after the shunt was inserted, and the dog did not develop any neurological signs and made good progress.

Animals↗
PubMed2005

A parturient with neurofibromatosis type 2: anesthetic and obstetric considerations for delivery.

Neurofibromatosis type 2 is an extremely rare form of neurofibromatosis characterized by central nervous system involvement with bilateral vestibular schwannomas and spinal tumors. Anesthetic management of a parturient with neurofibromatosis type 2 has not been fully reported, and the condition is challenging to obstetric anesthesiologists due to the presence of intracranial and intraspinal canal neurofibromas. We present a case of neurofibromatosis type 2 referred for delivery. Because of central neuraxial involvement, regional anesthesia was avoided, and the patient delivered by cesarean section under general anesthesia. The importance of pre-operative diagnosis and multidisciplinary management for neurofibromatosis type 2 is emphasized and anesthetic and obstetric considerations for delivery are presented.

Adult↗
PubMed2005

Successful islet transplantation from a single pancreas harvested from a young, low-BMI, non-heart-beating cadaver.

BACKGROUND: Young donors, donors with low body mass index (BMI), and non-heart-beating (NHB) donors are considered nonideal for islet transplantation. In this report, we successfully used a pancreas from a young, low-BMI, NHB donor for islet transplantation. METHODS: The donor was a 15-year-old adolescent boy whose cause of death was rupture of a primary brain tumor. According to Japanese regulations, his pancreas was procured after cardiac arrest. Warm ischemic time was 3 minutes and cold ischemic time was 300 minutes. The pancreas was digested by the automated method of Ricordi, followed by purification using continuous Euro-Ficoll gradients on a Cobe 2991 device. The recipient was a 35-year-old woman with unstable type 1 diabetes mellitus. Her pretransplant C-peptide level was null. She suffered frequent hypoglycemic unawareness. Her pretransplant M value, which is a good marker for glucose instability, was 125. Islet yield was 252,816 IEQ. There were no signs of contamination. Viability of islets assessed by FDA/PI staining was 83%. Stimulation index was 2.7. RESULTS: The patient received 5160 IEQ/kg of islets via the portal vein under local anesthesia. There were no transplant-related complications. Although she required minimal exogenous insulin, her C-peptide level increased to 0.7 ng/mL at postoperative day (POD) 14. Her M value at POD 15 to 19 decreased dramatically to 23.6, indicating good glycemic control. At 3 months posttransplant, episodes of hypoglycemia disappeared. CONCLUSIONS: Although an additional transplant is mandatory to wean patients from insulin, this case shows the possibility of using marginal donors, such as a young, low-BMI, NHB donor, for pancreas islet transplantation.

Adolescent↗
PubMed2005

Obesity is associated with increased risk of allergy in Vietnamese adolescents.

BACKGROUND: The prevalence of allergic diseases has remarkably increased in the last decades in tandem with the number of obese individuals. Results of studies on obesity and allergic diseases are controversial, and most of them are related to asthma and asthma-like symptoms. OBJECTIVE: In our study, we evaluated the association of several obesity indices and the prevalence of allergic diseases, including bronchial asthma, allergic rhino-conjunctivitis, atopic dermatitis and food allergy. DESIGN: Cross-sectional study. RESULTS: From a total of 1185 adolescents (49.3% boys) aged 12 to 17 y old, 19.3% reported a physician-diagnosed allergic disease, and 35.3% reported undiagnosed allergic symptoms. Logistic regression analysis revealed a higher risk of allergy in children of middle (OR = 2.02, CI: 1.12-3.64) and high (OR = 2.40, CI: 1.25-4.61) compared to low socioeconomic status, in subjects reporting industrial emissions in the neighborhood (OR = 2.19, CI: 1.40-3.41), and in adolescents with parental history of allergy (OR = 1.92, CI: 1.26-2.92). Body mass index (BMI) and percentage of body fat (%BF) were significantly related to allergy (OR = 1.16, CI: 1.01-1.34 for BMI; OR = 1.03, CI: 1.01-1.06 for %BF). After controlling for socioeconomic status, industrial emissions and parental history of allergy, only %BF remained statistically significant (OR = 1.03, CI: 1.01-1.06). Food allergy was not related to obesity in our study population, and when adolescents with food allergy were excluded from the analysis, the odds of having allergy increased 28% with each increase in SD of BMI (OR = 1.28, CI: 1.05-1.57) and 5% for each unit increase in the percentage of body fat (OR = 1.05, CI: 1.01-1.08). CONCLUSION: In conclusion, being overweight was associated with an increased risk of allergy in our study population. Our results point towards an association between being overweight and rhino-conjunctivitis, but not food allergy. No association was observed with other allergic diseases.

Adolescent↗
PubMed2005

FAO/WHO/UNU equations overestimate resting metabolic rate in Vietnamese adults.

OBJECTIVE: To evaluate the FAO/WHO/UNU equations for predicting resting metabolic rate (RMR) in Vietnamese adults. DESIGN: A cross-sectional study with healthy subjects was carried out at the Basic Nutrition Department, National Institute of Nutrition, Vietnam. RMR was measured by indirect calorimetry, and anthropometric indices were recorded. Equations derived by linear regression of RMR vs body weight were compared to the FAO/WHO/UNU 1985 predictive equations. SUBJECTS: A total of 188 subjects (98 males and 90 females) had a normal body mass index (BMI) and were divided into four groups by sex and age (male and female subjects 18-29 and 30-60 y old). RESULTS: Mean RMR (MJ/kg/day) in males was lightly significant by higher than that in female subjects in the 18-29 y old age group (0.1074+/-0.0100 vs 0.0965+/-0.0123) and the same result was seen in the 30-60 y old group (0.1018+/-0.0114 vs 0.0922+/-0.0129). However, differences were not statistically significant in the two age groups. Compared to the FAO/WHO/UNU equation, our findings were 7.4, 9.0, 11.7, and 13.5% lower in the four groups, respectively (P < 0.001). CONCLUSION: Our findings suggest that the FAO/WHO/UNU equations may overestimate RMR in Vietnamese adults. Further studies examining the relationship between body weight and RMR are needed, and establishing new predictive equations for RMR in Vietnamese should be a priority.

Adolescent↗
PubMed2005

Regeneration of dystrophin-expressing myocytes in the mdx heart by skeletal muscle stem cells.

Cell transplantation holds promise as a potential treatment for cardiac dysfunction. Our group has isolated populations of murine skeletal muscle-derived stem cells (MDSCs) that exhibit stem cell-like properties. Here, we investigated the fate of MDSCs after transplantation into the hearts of dystrophin-deficient mdx mice, which model Duchenne muscular dystrophy (DMD). Transplanted MDSCs generated large grafts consisting primarily of numerous dystrophin-positive myocytes and, to a lesser degree, dystrophin-negative non-myocytes that expressed an endothelial phenotype. Most of the dystrophin-positive myocytes expressed a skeletal muscle phenotype and did not express a cardiac phenotype. However, some donor myocytes, located at the graft-host myocardium border, were observed to express cardiac-specific markers. More than half of these donor cells that exhibited a cardiac phenotype still maintained a skeletal muscle phenotype, demonstrating a hybrid state. Sex-mismatched donors and hosts revealed that many donor-derived cells that acquired a cardiac phenotype did so through fusion with host cardiomyocytes. Connexin43 gap junctions were not expressed by donor-derived myocytes in the graft. Scar tissue formation in the border region may inhibit the fusion and gap junction connections between donor and host cells. This study demonstrates that MDSC transplantation warrants further investigation as a potential therapy for cardiac dysfunction in DMD.

Animals↗
PubMed2005

Comparison of metabolic effects of pioglitazone, metformin, and glimepiride over 1 year in Japanese patients with newly diagnosed Type 2 diabetes.

AIMS: To compare the metabolic effects of pioglitazone, metformin, and glimepiride in the treatment of Japanese patients with newly diagnosed Type 2 diabetes. METHODS: A total of 114 patients with Type 2 diabetes who had never used oral hypoglycaemic drugs were studied for 12 months. Patients were randomly assigned to pioglitazone (30-45 mg/day, n = 38), metformin (750 mg/day, n = 39), or glimepiride (1.0-2.0 mg/day, n = 37). The effect of treatment on fasting plasma glucose (FPG), glycated haemoglobin (HbA(1c)), 1,5-anhydroglucitol (1,5AG), total cholesterol, high-density lipoprotein (HDL)-cholesterol, triglycerides, free fatty acids (FFA), and fasting plasma insulin levels was monitored monthly. Body weight and safety data were also collected. RESULTS: Eight patients withdrew from the study (three in the pioglitazone group, two in the metformin group, and three in the glimepiride group). The rate of reduction of HbA(1c) was fastest in patients receiving glimepiride and slowest in patients receiving pioglitazone. Although there were no significant differences among the three groups in HbA(1c) levels at the end of the study, patients taking pioglitazone had relatively lower FPG and 1,5AG levels than patients taking the other two drugs. These results suggest that pioglitazone acts predominantly on nocturnal metabolism rather than at mealtimes. FFA were reduced significantly in those taking pioglitazone (542.2 microEq/l vs. 237.3 microEq/l; P < 0.01) before a decrease in HbA(1c) was apparent. The change in FFA levels correlated with the change in HbA(1c) (r = 0.409, P < 0.01). There were no significant differences in other lipid parameters among the groups. CONCLUSIONS: Pioglitazone, metformin, and glimepiride are equally effective in reducing blood glucose in patients with newly diagnosed Type 2 diabetes. However, their specific characteristics, such as the rapid action on blood glucose levels of glimepiride and the favourable action on FPG and FFA of pioglitazone, should be considered when choosing an appropriate agent.

Aged↗
PubMed2005

Effective in vivo purging with rituximab and autologous peripheral blood stem cell transplantation in a woman with CD5 positive primary cutaneous diffuse large B-cell lymphoma.

Generalized subcutaneous tumors developed without any other sites of the disease in a Japanese woman. Skin biopsy revealed CD5(+) and CD20(+) atypical diffuse large cells infiltrating subcutaneous tissues. The diagnosis was CD5(+) primary cutaneous diffuse large B-cell lymphoma. Tumor-specific PCR showed the existence of malignant cells in the peripheral blood and bone marrow. After three cycles of chemotherapy, she was remained in partial remission. Peripheral blood stem cells (PBSC) were harvested after the fourth cycles of chemotherapy combined with rituximab for in vivo purging. The contamination of tumor cells in PBSC was negative with PCR. She then underwent autologous peripheral blood stem cell transplantation using purged PBSC and has remained in complete remission for the past 24 month.

Antibodies, Monoclonal↗
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

Performance of bispectral index and auditory evoked potential monitors in detecting loss of consciousness during anaesthetic induction with propofol with and without fentanyl.

BACKGROUND AND OBJECTIVE: To investigate and compare the performance of bispectral index (BIS) and auditory evoked response index (AAI) in detecting the transition from consciousness to unconsciousness during anaesthesia induction by propofol, alone and in combination with fentanyl. METHODS: Anaesthesia was induced with either an intravenous infusion of 30 mg kg(-1)h(-1) of propofol plus 2 microg kg(-1) of fentanyl (Group PF, n = 20) or an intravenous infusion of 30 mg kg(-1) h(-1) of propofol plus normal saline (Group P, n = 20). BIS, AAI and the doses of propofol administered were recorded at the end-point of unresponsiveness to verbal commands. The propofol plasma concentration was also measured. RESULTS: The propofol dose and plasma propofol concentration required to achieve loss of consciousness were significantly lower in patients pretreated with fentanyl (P < 0.001). The mean BIS value at loss of consciousness was significantly different between the two groups (74.10 in Group PF vs. 60.80 in Group P) (P < 0.001). However, no difference in the AAI was seen between the two groups at loss of consciousness (32.90 in Group PF vs. 31.80 in Group P) (P > 0.05). In both groups, the regression analysis values (r-values) between BIS and plasma propofol concentrations at the onset of unconsciousness were higher than those between AAI and propofol concentrations (0.553 vs. 0.180 in Group P; 0.432 vs. 0.308 in Group PF). CONCLUSIONS: These results show that a fentanyl bolus is effective in augmenting the hypnotic effect of propofol during anaesthesia induction. AAI appears to be able to measure the transition from consciousness to unconsciousness at similar values, regardless of whether or not fentanyl pretreatment is used whereas the BIS values were not independent of fentanyl pretreatment. This suggests that AAI may be a better indicator of conscious status during propofol/fentanyl anaesthesia, where it appears to be independent of the anaesthesia regimen.

Adolescent↗
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

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

Urinary leukotriene E4 in Henoch-Schonlein purpura.

BACKGROUND: Children with Henoch-Schonlein purpura (HSP) occasionally have allergic disease. We have previously shown that pranlukast hydrate was effective for purpura in HSP. Pranlukast hydrate is a leukotriene (LT) receptor antagonist; therefore, it is likely that LTs take part in the cause of HSP. Urinary leukotriene E4 (LTE4u) levels are a useful index of whole-body cysteinyl LT production in vivo. In this study, LTE4u was examined in children with HSP. OBJECTIVE: The purpose of this study was to examine the relation between the level of LTE4u and the cause of HSP. METHODS: Eighteen HSP children (six boys and 12 girls) and six healthy children were enrolled. RESULTS: LTE4u levels in patients with HSP were significantly higher (P< 0.05) at the onset than those in healthy children. Four weeks therapy with pranlukast hydrate lowers LTE4u levels in patients with HSP (P< 0.05). There were no differences in LTE4u between the group of HSP patients with purpura nephritis and the group of HSP patients without purpura nephritis. CONCLUSION: These results indicate that csyteinyl LTs may play a role in the pathophysiology of purpura in HSP.

Adolescent↗
PubMed2004

Ghrelin-induced growth hormone release from isolated rat anterior pituitary cells depends on intracellullar and extracellular Ca2+ sources.

Ghrelin, a novel growth hormone (GH)-releasing peptide, was isolated from the rat stomach as an endogenous ligand to the growth hormone secretagogues receptor. It is known that ghrelin stimulates the release of GH from the rat anterior pituitary gland, but the intracellular signal cascade in somatotrophs has not yet been clarified. In this study, using an isolated cell perifusion system, we examined whether ghrelin- and growth hormone-releasing hormone (GHRH)-induced GH secretion from rat pituitary cells depends on intra- and extracellular Ca(2+) and voltage-gated Ca(2+) channels. For this purpose, we first measured ghrelin- or GHRH-stimulated GH concentration following treatment with reduced extracellular Ca(2+) and/or thapsigargin, an endoplasmic reticulum Ca(2+) ATPase inhibitor. Reductions in the extracellular Ca(2+) concentration to 0.25 mM and to 0 mM resulted in decreases in ghrelin-stimulated GH secretion to 81% and 39% and decreases in GHRH-induced GH secretion to 83% and 13%, respectively, compared to the levels in the case of 2.5 mM Ca(2+) concentration, suggesting that extracellular Ca(2+) is essential for both ghrelin- and GHRH-induced GH secretion. Pretreatment with thapsigargin resulted in a reduction in ghrelin-induced GH secretion to approximately 60% of the control level, but GHRH treatment had not effect on the GH secretion. Moreover, preincubation with thapsigargin and 0 mM extracellular Ca(2+) concentration resulted in significant inhibition of GHRH- and ghrelin-induced GH secretion. Subsequently, to determine whether ghrelin-stimulated GH secretion was induced through voltage-gated Ca(2+) channels, we measured the ghrelin-stimulated GH concentration following treatment with nifedipine, an L-type Ca(2+) channel inhibitor, and found that the amount of GH secretion was reduced to 44% of the control level. Furthermore, by replacement of extracellular Na(2+) in the medium with N-methyl-D(-)-glucamine, an impermeable molecule, GH secretion was reduced to 47%. In this study, we demonstrated that the GH-stimulatory effect of ghrelin, unlike that of GHRH, is achieved through both intracellular and extracellular Ca(2+) sources and that ghrelin-induced extracellular Ca(2+) influx involves an L-type voltage-gated Ca(2+) channel and Na(+) influx.

Animals↗
PubMed2004

Cerebellar focal granulomatous meningoencephalitis in a dog: clinical findings and MR imaging.

The authors encountered a dachshund dog, presenting vestibular disorder. On magnetic resonance (MR) imaging, a mass showing isointensity on the T1- and T2-weighted images and enhanced by contrast medium, was observed in the right cerebellum. In addition, the periphery of the mass showed isointensity on the T1-weighted image and hyperintensity on the T2-weighted image, suggesting sever oedema. Although the dog underwent surgery, it died. The mass was diagnosed pathologically as a granulomatous meningoencephalitis.

Animals↗