Biomedical subjects

H Sakaguchi

Publications and source records attributed to H Sakaguchi.

At least 19 recordsLinked to original sources

PubMed2006

Intravitreal injection of bevacizumab for choroidal neovascularisation associated with pathological myopia.

AIM: To assess the efficacy and safety of an intravitreal injection of bevacizumab (Avastin(R)) for myopic choroidal neovascularisation (mCNV). METHODS: Intravitreal bevacizumab (1 mg) was injected into eight eyes of eight patients with mCNV in this non-randomised, interventional case series. The best-corrected visual acuity (BCVA) was measured and the optical coherence tomography (OCT) and fluorescein angiography findings were examined before and after treatment. The minimum follow-up time was 3 months. RESULTS: The mean BCVA was 0.26 before treatment and 0.51 at the last visit (p = 0.009). The BCVA improved to two or more lines in six eyes (75%) and remained the same in two eyes (25%). Leakage from the mCNV on fluorescein angiography decreased in seven eyes (87.5%). The choroidal neovascularisation area on fluorescein angiography (p = 0.049) and the foveal thickness on OCT images decreased significantly (p = 0.027) after the treatment. No major complications developed. CONCLUSION: Intravitreal injection of bevacizumab seems to be an effective and safe treatment for mCNV.

Adult↗

PubMed2006

[Primary biventricular repair for interrupted aortic arch with left ventricular outflow tract obstruction and tricuspid valve regurgitation; report of a case].

An interrupted aortic arch was diagnosed in a 10-day-old girl weighing 3.3 kg, as was perimembranous ventricular septal defect (VSD) and severe tricuspid valve regurgitation (TR). The subaortic diameter was 3.6 mm and the aortic valve (3.7 mm in diameter) was bicuspid. We chose definitive repair, modified Yasui procedure, because of severe TR and no straddling of mitral valve. In primary biventricular repair, we undertook extended aortic arch anastomosis. Left ventricular outflow tract reconstruction consisted of intracardiac rerouting from the VSD to the pulmonary artery by using expanded-polytetrafluoroethylene (ePTFE) and Damus-Kaye-Stansel (DKS) anastomosis. Right ventricular outflow tract reconstruction was performed by the Rastelli procedure with an ePTFE valved conduit. Moreover, we carried out semicircular annuloplasty for severe TR.

Anastomosis, Surgical↗

PubMed2005

Development of an in vitro skin sensitization test using human cell lines; human Cell Line Activation Test (h-CLAT). II. An inter-laboratory study of the h-CLAT.

Recent regulatory changes have placed a major emphasis on in vitro safety testing and alternative models. In regard to skin sensitization tests, dendritic cells (DCs) derived from human peripheral blood have been considered in the development of new in vitro alternatives. Human cell lines have been also reported recently. In our previous study, we suggested that measuring CD86 and/or CD54 expression on THP-1 cells (human monocytic leukemia cell line) could be used as an in vitro skin sensitization method. An inter-laboratory study among two laboratories was undertaken in Japan in order to further develop an in vitro skin sensitization model. In the present study, we used two human cell lines: THP-1 and U-937 (human histiocytic lymphoma cell line). First we optimized our test protocol (refer to the related paper entitled "optimization of the h-CLAT protocol" within this journal) and then we did an inter-laboratory validation with nine chemicals using the optimized protocol. We measured the expression of CD86 and CD54 on the above cells using flow cytometry after a 24h and 48h exposure to six known allergens (e.g., DNCB, pPD, NiSO(4)) and three non-allergens (e.g., SLS, tween 80). For the sample test concentration, four doses (0.1x, 0.5x, 1x, and 2x of the 50% inhibitory concentration (IC(50))) were evaluated. IC(50) was calculated using MTT assay. We found that allergens/non-allergens were better predicted using THP-1 cells compared to U-937 cells following a 24 h and a 48 h exposure. We also found that the 24h treatment time tended to have a better accuracy than the 48 h treatment time for THP-1 cells. Expression of CD86 and CD54 were good predictive markers for THP-1 cells, but for U-937 cells, expression of CD86 was a better predictor than CD54, at the 24h and the 48 h treatment time. The accuracy also improved when both markers (CD86 and CD54) were used as compared with a single marker for THP-1 cells. Both laboratories gave a good prediction of allergen/non-allergen, especially using THP-1 cells. These results suggest that our method, human Cell Line Activation Test (h-CLAT), using human cell lines THP-1 and U-937, but especially THP-1 cells at 24h treatment, may be a useful in vitro skin sensitization model to predict various contact allergens.

Allergens↗

PubMed2005

Development of an in vitro skin sensitization test using human cell lines: the human Cell Line Activation Test (h-CLAT). I. Optimization of the h-CLAT protocol.

The aim of this study is to optimize the experimental conditions for an in vitro skin sensitization test using the human cell lines THP-1 and U-937. As regards pre-culturing time, the expression of CD86 on DNCB-treated THP-1 cells tended to be higher after 48h and 72h pre-culture compared with other time points evaluated. Next, we investigated the effect of chemical treatment time, and found that induction of CD86 expression on THP-1 cells by DNCB reached a plateau after 24h. Augmentation of CD86 expression is often observed when cells are treated with a subtoxic dose of allergens. To determine the appropriate dose of test samples, the cytotoxicity of test samples to THP-1 and U-937 cells was assessed with MTT assay, and the 50% inhibitory concentration (IC50) of each test sample was calculated. Based on the cytotoxicity assay data, four concentrations in the range between toxic and non-toxic were selected (0.1x, 0.5x, 1x and 2x IC50). Several kinds of antibodies were tested for staining THP-1 and U-937 cells treated with allergens/non-allergens (e.g., DNCB, Ni/SLS), and suitable antibodies for staining CD86 and CD54 were selected. We confirmed that the working dilutions of the selected CD86 and CD54 antibodies were appropriate for use in our method. The effect of an FcR blocking procedure was also evaluated. The mean fluorescence intensity (MFI value) was decreased by the FcR blocking procedure, which indicated that non-specific staining was blocked. Therefore, this procedure should be included in the method. Based on our findings, the protocol for this assay was optimized and the experimental conditions to be used in a future validation study were identified. We propose to call this kind of in vitro skin sensitization test h-CLAT, which is short for human Cell Line Activation Test.

Allergens↗

PubMed2005

Renormalization-group and numerical analysis of a noisy Kuramoto-Sivashinsky equation in 1 + 1 dimensions.

The long-wavelength properties of a noisy Kuramoto-Sivashinsky (KS) equation in 1 + 1 dimensions are investigated by use of the dynamic renormalization group (RG) and direct numerical simulations. It is shown that the noisy KS equation is in the same universality class as the Kardar-Parisi-Zhang (KPZ) equation in the sense that they have scale invariant solutions with the same scaling exponents in the long-wavelength limit. The RG analysis reveals that the RG flow for the parameters of the noisy KS equation rapidly approach the KPZ fixed point with increasing strength of the noise. This is supplemented by numerical simulations of the KS equation with a stochastic noise, in which scaling behavior close to the KPZ scaling can be observed even in a moderate system size and time.

Journal Article↗

PubMed2005

Five-year survival of patients with hepatocellular carcinoma treated with laparoscopic microwave coagulation therapy.

BACKGROUND AND STUDY AIM: Hepatocellular carcinomas (HCCs) that are located near the liver surface are difficult to treat with percutaneous locoregional therapies, so we have performed laparoscopic microwave coagulation therapy (LMCT) for these HCCs. We assessed the long-term survival of patients with HCCs treated with LMCT, the factors related to their survival, and the rates and causes of local and distant recurrences. PATIENTS AND METHODS: Participants were 68 patients with HCC treated in the past 8 years with LMCT under local or general anesthesia. LMCT was done using microwave electrodes with tips ranging from 15 to 45 mm in length; the effectiveness of LMCT was confirmed using contrast-enhanced computed tomography (CT) within 2 weeks of the LMCT procedure while patients were still in hospital, and within 1-3 months after the procedure in an outpatient setting; and the follow-up study was performed periodically by CT, ultrasonography, or magnetic resonance imaging (MRI) in addition to estimation of alpha fetoprotein. Factors contributing to survival were analyzed statistically. RESULTS: The mean lengths of the major and minor axes of the 71 HCC nodules in 68 patients were 20 mm and 18 mm, respectively, and the mean lengths of the major and minor axes of the coagulated areas were 43 mm and 29 mm, respectively. At dynamic CT after the LMCT procedure, treatment in 62 of the 68 patients (91%) was judged to have been completely effective; the remaining six patients underwent additional therapy while still in hospital. Eight of the 68 patients (12%) had local recurrences, 39 of them (57%) had distant recurrences, and 21 of them (31%) had no recurrence up to December 31, 2003. A total of 14 patients (21%) died during the 16-56 months after LMCT. When the survival rate was assessed for all patients treated with LMCT, 1-year survival was 97 %, 3-year survival was 81%, and 5-year survival was 43%. Whether the therapy was for primary or secondary HCC strongly influenced survival. CONCLUSIONS: LMCT is a useful modality in clinical practice for treatment of HCC nodules located near the liver surface, and it can be safely performed, in its entirety, under direct visual guidance.

Aged↗

PubMed2005

Clinical implications of expression of cyclooxygenase-2 related to angiogenesis in uterine endometrial cancers.

BACKGROUND: Angiogenesis is essential for development, growth and advancement of solid tumors. Cyclooxygenase (cox)-2 is recognized as an angiogenic factor in various tumors. This prompted us to study the clinical implications of cox-2 expression and angiogenesis in uterine endometrial cancers. PATIENTS AND METHODS: Fifty patients underwent curative resection for uterine endometrial cancers. In uterine endometrial cancers, cox-2 levels were determined by enzyme immunoassay, and the localization and counts of microvessels were determined by immunohistochemistry. RESULTS: There was a significant correlation between microvessel counts and cox-2 levels in uterine endometrial cancers. Cox-2 localized in the cancer cells, but not in the stromal cells of uterine endometrial cancer tissues. Cox-2 levels decreased with the advancement. Furthermore, cox-2 levels significantly correlated with VEGF levels in uterine endometrial cancers. CONCLUSIONS: VEGF associated with cox-2 might work on angiogenesis at an early status in growth. Therefore, long-term administration of cox-2 inhibitors might be effective in the suppression of recurrent initiation of uterine endometrial cancers after curative resection.

Adult↗

PubMed2005

Inhibitory effects of anti-oxidants on apoptosis of a human polyclonal T-cell line, MT-2, induced by an asbestos, chrysotile-A.

To clarify the effects of silica and silicates on cellular features of lymphocytes, a human T-lymphotropic virus type-1-immortalized polyclonal T-cell line, MT-2, was exposed to various concentrations of chrysotile-A, an asbestos classified as silicate. MT-2 cells underwent apoptosis in a dose- and time-dependent manner. The mitochondrial apoptotic pathway was activated during chrysotile-A-induced apoptosis of MT-2 cells, because of the phosphorylation of JNK and p38, increase of BAX and release of cytochrome-c from mitochondria to cytoplasma. In addition, anti-oxidants such as hydroxyl-radical excluders and capturers of superoxide and inhibitors of superoxide production effectively reduced the size of the apoptotic fraction in MT-2 cells cultured with chrysotile-A. These results indicate that the activation of reactive oxygen species may play a central role in asbestos-induced T-cell apoptosis, and anti-oxidants may help to prevent complications of pneumoconiosis.

Apoptosis↗

PubMed2005

[Autologous fibrin sealant preparing system in coronary artery bypass grafting].

Autologous fibrin sealant (AFS) which is not based on the conventional method of co-administering fibrinogen, thrombin and aprotinin was prepared by Vivostat system, and was used in coronary artery bypass grafting (CABG). The purpose of this study was to investigate the safety and efficacy of the AFS prepared by the Vivostat system. In 6 of 68 cases of CABG, normal AFS was not prepared due to device failures. AFS was prepared and sprayed in 62 cases. There were the total of 230 anastomosis sprayed AFS and the bleeding could not seen in 225 anastomosis. Surgical hemostatic procedures (4 cases) were or other sealant usage (1 case) was performed 5 bleeding anastomosis sites. The rate of hemostasis at the anastomosis using AFS was 97.8%. This study was conducted in patients undergoing CABG. In this group of patients, a number of commercial available fibrin sealant products are routinely used. The usefulness of Vivostat as medical device to prepare and administer AFS was confirmed in this study.

Adult↗

PubMed2005

Characterization of T-cell clones specific to ovomucoid from patients with egg-white allergy.

BACKGROUND: Allergic reactions to foods are specific problems for infants and young children. Ovomucoid (OM) is one of the major allergens found in egg-white. We previously established several T-cell clones (TCCs) specific to OM in non-polarizing conditions from 4 patients (TM and YN are immediate-type, IH and YT are non-immediate-type) with egg-white allergy. We characterized their reactive epitopes, antigen-presenting molecules (HLA class II), and usage of TCR alpha and beta genes and the CDR3 loop sequence. OBJECTIVE: The objective of this study was to characterize these seven clones (TM 1.3, TM1.4,YN 1.1, YN1.5, IH3.1, IH3.3 and YT6.1) for cytokine production patterns and cell-surface-marker phenotypes. METHODS: We measured the production of cytokines, namely interleukin (IL)-4, IL-5 and interferon-gamma (IFN-gamma) by stimulation with ovomucoid peptides and stained intracellular IL-4 and IFN-gamma, and determined cell-surface markers using anti-interleukin-12 receptor (IL-12R) beta1, anti-IL-12Rbeta2 and anti-interleukin-18 receptor alpha (IL-18Ralpha). RESULTS: Most TCCs secreted both IL-4 and IFN-gamma in response to the OM peptide mixture, but the secretion patterns were variable; an IFN-gamma dominant pattern was seen in IH3.1 andYT6.1, an IFN-gamma>IL-4 pattern in TM1.3 and TM1.4, an IL-4> IFN-gamma pattern in YN1.5. In intracellular IFN-gamma and IL-4 staining, IFN-gamma single-positive cells were predominant in TM1.3, TM1.4, IH3.1 and YT6.1 and IFN-gamma and IL-4 double-positive cells were predominant in YN1.1, YN1.5 and IH3.3. All TCCs were IL-12Rbeta1-positive, and TM1.3, IH3.1, IH3.3 and YT6.1 were both IL-12Rbeta2- and IL-18Ralpha-positive. TM1.4 and YN1.1 were both IL-12Rbeta2- and IL-18Ralpha-negative. Based on these results, TM1.3 and TM1.4, IH3.1 and YT6.1 had a predominantly Th1 character and YN1.1, YN1.5, and IH3.3 possessed a predominantly Th0 character. CONCLUSIONS: The phenotypes of TCCs were not in accordance with their clinical manifestations. TCCs established from patients with immediate-type hypersensitivity had either the Th1 or Th0 phenotype as well as those with non-immediate-type hypersensitivity.

Egg Hypersensitivity↗

PubMed2005

[Early and late results and problems of coronary artery bypass grafting in patients over 80-year-old].

This study evaluated the validity of coronary artery bypass grafting (CABG) in patients over 80-year-old investigating the early and late result, patient's opinion to the surgery, and change of activities of daily living scale. From July 1993 to September 2002, consecutive 94 patients over 80-year-old were performed CABG in our institution. The group consisted of 43 female patients, and mean age of 82.6 years. Of these patients, 36 were operated conventional CABG (CABG group) and 58 patients were operated with off-pump CABG (OPCAB) group. There were no significant differences between 2 groups in preoperative characteristics except for anemia and hypertension. Operative results, including mortality, number of distal anastomoses, operative time had no significant differences between 2 groups. But maximum CK-MB fraction was higher in CABG group. There were 4 operative deaths, indicating operative mortality was 4.3%. Late results showed overall survival rate at 3 years was 81.1% and cardiac event free survival rate at 3 years was 88.8%. Questionnaire revealed over 80% patients were satisfied with the surgery but less than 40% patients felt activities of daily living (ADL) scale was improved. Operative results of CABG in octogenarians were satisfied, but more efforts to remain patient's high ADL were mandatory.

Activities of Daily Living↗

PubMed2004

Clinical implication of expression of vascular endothelial growth factor-C in metastatic lymph nodes of uterine cervical cancers.

Vascular endothelial cell growth factor (VEGF)-C levels were significantly (P<0.05) increased in 24 out of 40 metastatic lymph node lesions of uterine cervical cancers. The prognosis of the 24 patients with increased VEGF-C level in metastatic lymph node lesions was poor and the 24-month survival rate was 38%, while the rate of the 16 patients with no change in VEGF-C level in metastatic lymph node lesions was 81%. There was a significant (P<0.01) difference in the 24-month survival rates between the two groups. This is novel, direct evidence that VEGF-C might contribute to the aggressive lymphangitic metastasis in uterine cervical cancers, and that the increase in VEGF-C level from primary tumour to metastatic lymph node might be a prognostic indicator.

Adult↗

PubMed2004

Successful treatment of acute Budd-Chiari syndrome with percutaneous transluminal angioplasty.

A 26-year-old man developed progressive, massive ascites and hematemesis due to rupture of esophageal varices. Combination diagnostic modalities of color doppler ultrasonography, enhanced computed tomography, and magnetic resonance imaging led to the case being diagnosed as acute Budd-Chiari syndrome with severe stricture of the intrahepatic inferior vena cava. Percutaneous transluminal angioplasty this resulted in great improvement of the clinical manifestations.

Acute Disease↗

PubMed2004

Photoluminescence studies of oligothiophene self-assembled monolayers at low excitation energy.

Photoluminescence spectroscopy studies have been performed on self-assembled monolayers (SAMs) on Au(111) of thiophene oligomers with the number of thiophen rings N=3 and N=4. Photoluminescence spectra of SAMs reveal excitonic behavior with different band resolution and temperature dependence. These differences are attributed to different SAMs structure (degree of ordering).

Journal Article↗

PubMed2004

Relationship between immunological rejection and matrix GLA protein in cryopreserved vascular allografts.

INTRODUCTION: Cryopreserved tissue allografts used for cardiovascular diseases become calcified as a late complication after transplantation, probably caused by immunological rejection. Recent attention has been focused on the inhibitory effect of matrix Gla protein (MGP) on ectopic vascular calcification, but the behavior of MGP in cryopreserved allografts is uncertain. In this study we examined the relationship between immunological rejection and MGP in cryopreserved rat aortic grafts after transplantation. METHODS: Cryopreserved rat aortae were isografted or allografted intraperitoneally. Fresh isografts were also tested. The grafts were retrieved 9 days after transplantation and the intragraft MGP mRNA was measured by a real-time quantitative PCR method. The effect of daily administration of FK506 on MGP mRNA levels in cryopreserved isografts and allografts after transplantation was also evaluated. RESULTS: There was no significant difference in intragraft MGP mRNA levels between fresh and cryopreserved isografts 9 days after transplantation. MGP expression levels in cryopreserved allografts were significantly lower as compared to those in cryopreserved isografts (P < .01). Daily administration of FK506 enhanced intragraft MGP mRNA (ninefold) in cryopreserved allografts (P < .01), but not in cryopreserved isografts. CONCLUSIONS: Immunological rejection is likely to inhibit MGP expression in cryopreserved vascular allografts, resulting in late-onset calcification.

Animals↗

PubMed2004

Expression of protein gene product 9.5 (PGP9.5)/ubiquitin-C-terminal hydrolase 1 (UCHL-1) in human myeloma cells.

The neuron cytoplasmic protein gene product 9.5 (PGP9.5)/ubiquitin-C-terminal hydrolase 1 (UCHL-1) protein is a thiol protease that recognizes and hydrolyzes a peptide bond at the C-terminal of ubiquitin, and is involved in the processing of ubiquitin precursors and ubiquinated proteins. Although this molecule is known as a specific tissue marker for the neuroendocrine system, many reports have indicated that PGP9.5 is a marker for certain tumour types, such as cancer of the lung, colon, and pancreas. The expression of PGP9.5 in myeloma cells was examined. PGP9.5 seemed to be expressed specifically in myeloma cells as compared with other haematological malignant cells. In addition, in myeloma cells subjected to growth-factor starvation, the upregulation of PGP9.5 was observed in association with that of p27(Kip1), a cyclin-dependent-kinase inhibitor, although the upregulation caused by irradiation was milder. In contrast, the hypoxic culture of myeloma cells induced down-regulation of PGP9.5. These results suggested that PGP9.5 may be a good marker for myeloma among haematological malignancies. In addition, it may indicate certain cellular features of myeloma cells, such as sensitivity to proteasome inhibitors.

Biomarkers, Tumor↗

PubMed2004

Application of femtosecond ultrashort pulse laser to photodynamic therapy mediated by indocyanine green.

BACKGROUND/AIMS: To evaluate treatment with high peak power pulse energy by femtosecond ultrashort pulse laser (titanium sapphire laser) delivered at an 800 nm wavelength for corneal neovascularisation using photodynamic therapy (PDT) mediated by indocyanine green (ICG). METHODS: Using a gelatin solid as an in vitro corneal model, the safety of laser power was studied to determine if it degenerated gelatin with or without ICG. The authors then induced corneal neovascularisation in rabbit eyes by an intracorneal suturing technique. Fluorescein angiography was used to evaluate occlusion before PDT and 0, 1, 3, and 10 days after PDT. The authors performed light microscopy with haematoxylin eosin staining and transmission electron microscopy to determine thrombosis formation in the neovascular regions. RESULTS: The threshold of peak laser power density ranged from 39 to 53 W/cm(2). Laser irradiation was started 30 seconds after a 10 mg/kg ICG injection, and all irradiated segments were occluded at 0, 1, 3, and 10 days at 3.8 J/cm(2). Light and electron microscopy documented thrombosis formation in the neovascular region. CONCLUSION: Femtosecond pulse laser enhanced by ICG can be used for PDT. Because of effective closure of corneal neovascularisation at a low energy level, the high peak power pulse energy of the femtosecond pulse laser might be more efficacious than continuous wave laser for use with PDT.

Animals↗

PubMed2004

The expression of oestrogen receptor (ER)-beta and its variants, but not ERalpha, in adult human mammary fibroblasts.

Whilst oestrogen receptor (ER)-alpha and ERbeta have been shown to be important in the development of the mammary gland, the cell-specific expression pattern of these two receptors within the human breast is not clear. Although it is well established that in the developing rodent mammary gland stromal ERalpha mediates the secretion of growth factors which stimulate the proliferation of the ductal epithelium, the expression of ERalpha in human adult breast stromal fibroblasts is controversial, and the expression of ERbeta has not been properly defined. In the present study, we have evaluated the expression of ERalpha and ERbeta by immunohistochemistry in normal tissue samples, and in purified human breast fibroblasts by Western blotting, RT-PCR analysis and ligand-binding sucrose gradient assay. Our data clearly demonstrated that ERbeta variants, including ERbeta1, ERbeta2, ERbeta5, ERbetadelta and ERbetains, but not ERalpha, are expressed in human adult mammary fibroblasts. These results are supported by the findings that an ERbeta-selective ligand, BAG, but not the ERalpha high-affinity ligand oestradiol, can induce fibroblast growth factor-7 release and activate transcription from an oestrogen-responsive element promoter in these adult human mammary fibroblasts. Together, these observations revealed that, in the adult breast and in breast cancer, the proliferative signals derived from the stroma of adult mammary glands in response to oestrogen are not mediated by ERalpha and provide new insights into the nature of stromal-epithelial interactions in the adult mammary gland. In addition, the expression of these ERbeta variants in cells where there is no ERalpha suggested that these ERbeta splice forms may have functions other than that of modulating ERalpha activity.

Animals↗