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S Hori

Publications and source records attributed to S Hori.

At least 19 recordsLinked to original sources
PubMed2006

Risk evaluation of outcome of vitreous surgery based on vitreous levels of cytokines.

AIM: To ascertain whether vitreous and plasma levels of vascular endothelial growth factor (VEGF), interleukin-6 (IL-6) and fundus findings could predict the outcome of vitreous surgery in patients with proliferative diabetic retinopathy (PDR). METHODS: Vitreous fluid samples were obtained during vitreoretinal surgery from 73 consecutive eyes with PDR. The levels of VEGF and IL-6 in vitreous fluid and plasma were determined by enzyme-linked immunosorbent assay. Patients were prospectively followed for 6 months and the postoperative outcome was analysed by logistic regression analysis. RESULTS: No improvement and/or progression of PDR occurred in 23 (32%) of the 73 eyes (progression group). The vitreous levels of VEGF and IL-6 were significantly higher in eyes from the progression group than in eyes with regression of PDR (regression group) (P=0.0032 and 0.0088, respectively). Multivariate logistic regression analysis showed that higher vitreous levels of VEGF were associated with the progression of PDR after vitreous surgery (odds ratio 2.72, P=0.0003). CONCLUSIONS: High vitreous levels of VEGF identified as a significant risk factor for the outcome of vitreous surgery in patients with PDR. A model was developed to predict the probability of PDR progression and measurement of the vitreous level of VEGF may be useful for predicting the outcome of surgery.

Adult↗
PubMed2005

Cytoplasmic and mitochondrial Ca levels in brown adipocytes.

AIM: We elucidated the mitochondrial functions of brown adipocytes in intracellular signalling, paying attention to mitochondrial activity and noradrenaline- and forskolin-induced Ca(2+) mobilizations in cold-acclimated rats. METHODS: A confocal laser-scanning microscope of brown adipocytes from warm- or cold-acclimated rats was employed using probes rhodamine 123 which is a mitochondria-specific cationic dye, and the cytoplasmic and mitochondrial Ca(2+) probes fluo-3 and rhod-2. X-ray microanalysis was also studied. RESULTS: The signal of rhodamine 123 in the cells was decreased by antimycin A which effect was less in cold-acclimated cells than warm-acclimated cells. Cytoplasmic and mitochondrial Ca(2+) in cold-acclimated brown adipocytes double-loaded with fluo-3 and rhod-2 were measured. Noradrenaline induced the rise in cytoplasmic Ca(2+) ([Ca(2+)](cyto)) followed by mitochondrial Ca(2+) ([Ca(2+)](mito)), the effect being transformed into an increase in [Ca(2+)](cyto) whereas a decrease in [Ca(2+)](mito) by antimycin A or carbonyl cyanide m-chlorophenylhydrazone (CCCP). Antimycin A induced small Ca(2+) release from mitochondria. CCCP induced Ca(2+) release from mitochondria only after the cells were stimulated with noradrenaline. Further, forskolin also elicited an elevation in [Ca(2+)](cyto) followed by [Ca(2+)](mito) in the cells. The Ca measured by X-ray microanalysis was higher both in the cytoplasm and mitochondria whereas K was higher in the mitochondria of cold-acclimated cells in comparison to warm-acclimated cells. CONCLUSIONS: These results suggest that noradrenaline and forskolin evoked an elevation in [Ca(2+)](cyto) followed by [Ca(2+)](mito), in which H(+) gradient across the inner membrane is responsible for the accumulation of calcium on mitochondria. Moreover, cAMP also plays a role in intracellular and mitochondrial Ca(2+) signalling in cold-acclimated brown adipocytes.

Adipocytes↗
PubMed2004

Determination of di(2-ethylhexyl)phthalate and mono(2-ethylhexyl)phthalate in human serum using liquid chromatography-tandem mass spectrometry.

Concentrations of mono(2-ethylhexyl)phthalate (MEHP), and di(2-ethylhexyl)phthalate (DEHP), in serum of healthy volunteers were determined by high performance liquid chromatography (HPLC) with tandem mass spectrometry (LC/MS/MS). The serum was extracted with acetone, followed by hexane extraction under acidic conditions, and then applied to the LC/MS/MS. Recoveries of 20 ng/ml of MEHP and DEHP were 101+/-5.7 (n=6) and 102+/-6.5% (n=6), respectively. The limits of quantification (LOQ) of MEHP and DEHP in the method were 5.0 and 14.0 ng/ml, respectively. The concentration of MEHP in the serum was at or less than the LOQ. The concentration of DEHP in the serum was less than the LOQ. Contaminations of MEHP and DEHP from experimental reagents, apparatus and air during the procedure were less than the LOQ and were estimated to be <1.0 and 2.2+/-0.6 ng/ml, respectively. After subtraction of the contamination, the net concentrations of MEHP and DEHP in the serum were estimated at or <5 and <2 ng/ml, respectively. To decrease contamination by DEHP, the cleanup steps and the apparatus and solvent usage were minimized in the sample preparation procedures. The high selectivity of LC/MS/MS is the key for obtaining reliable experimental data from in the matrix-rich analytical samples and for maintaining a low level contamination of MEHP and DEHP in this experimental system. This method would be a useful tool for the detection of MEHP and DEHP in serum.

Chromatography, High Pressure Liquid↗
PubMed2004

Effect of hematocrit on pharmacokinetics of tacrolimus in adult living donor liver transplant recipients.

OBJECTIVE: Plasma drug concentrations are generally considered to reflect efficacy and pharmacokinetics more directly than those in whole blood. However, whole blood has been selected as the matrix to monitor concentrations of tacrolimus (FK506), because it is difficult to accurately measure plasma FK506 concentrations. Because FK506 highly and saturably binds in blood cells, a change in hematocrit value (Hct) may affect FK506 pharmacokinetics. Therefore, we investigated effects of Hct on FK506 pharmacokinetics. METHODS: First, we analyzed data on FK506 distribution among human blood cells in vitro. Briefly, we employed an equation, which describes saturable binding of FK506 to blood cells, and simulated plasma FK506 concentrations and clearances using the above equation with respect to a variable Hct. Subsequently, we retrospectively analyzed dosages and whole blood FK506 concentrations to predict plasma FK506 concentrations in living donor transplant recipients. RESULTS: In the simulation study, the Hct changed plasma FK506 concentrations and clearances based in whole blood. In living donor liver transplant recipients, whole blood FK506 concentrations were maintained within a therapeutic range, while the Hct varied after transplantation. The correlation of Hct with the ratio of dose/trough concentrations of FK506 (D/C) in plasma (D/Cp) (R = -0.23, n = 343) was weaker than that for D/C in whole blood (D/CWB) (R = -0.53, n = 343). CONCLUSION: Hct may be an important factor affecting the pharmacokinetics of FK506 in living donor liver transplantation recipients. It may be necessary to take Hct into consideration in the FK506 dosing regimen, especially when the Hct is low.

Adult↗
PubMed2004

[3H]alpha,beta-methylene ATP binding to P2X purinoceptor is unaffected by volatile anaesthetics.

BACKGROUND AND OBJECTIVE: The P2X receptor is responsible for fast excitatory neurotransmission in the central nervous system. This receptor is suggested as one of the targets of volatile anaesthetics. The study was undertaken to examine the site of action of volatile anaesthetics, especially for P2X purinoceptor-mediated neurotransmission. METHODS: The effect of sevoflurane and isoflurane on [3H]alpha,beta-methylene ATP binding was investigated in rat crude synaptic membranes. The crude synaptic membranes were prepared from Sprague-Dawley rat brains by centrifugation and then incubated with volatile anaesthetics or P2 receptor antagonists. RESULTS: [3H]alpha,beta-methylene ATP binding was unchanged by either sevoflurane or isoflurane at clinically relevant concentrations. Suramin, a P2 antagonist, significantly (P < 0.05) decreased the binding of [3H]alpha,beta-methylene ATP in a dose-dependent manner (68.7 +/- 14.7% at 10 micromol, 49.5 +/- 6.4% at 50 micromol, 24.3 +/- 5.7% at 100 micromol, n = 10, mean +/- SD), whereas pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), another P2 antagonist, did not affect the binding. CONCLUSIONS: The suppressive effect of volatile anaesthetics on ATP-mediated excitatory synaptic transmission could be one site of action. However, the blockade of ATP binding to P2X receptors is not a mechanism of action of volatile anaesthetics.

Adenosine Triphosphate↗
PubMed2004

Effective treatment of advanced solid tumors by the combination of arsenic trioxide and L-buthionine-sulfoximine.

Clinical application of anticancer agents has been often hampered by toxicity against normal cells, so the achievement of their cancer-specific action is still one of the major challenges to be addressed. Previously, we reported that arsenic trioxide (As2O3) could be a promising new drug against not only leukemia but also solid tumors. The cytotoxicity of As2O3 occurred through the generation of reactive oxygen species (ROS), thus inhibiting radical scavenging systems would enhance the therapeutic efficacy of As2O3 provided that normal cells were relatively resistant to such a measure. Here, we report that the combination therapy of As2O3 with L-buthionine-sulfoximine (BSO), which inhibits a critical step in glutathione synthesis, effectively enhanced in vitro growth inhibition effect of As2O3 on all 11 investigated cell lines arising from prostate, breast, lung, colon, cervix, bladder, and kidney cancers, compared with As2O3 treatment alone. Furthermore, this combination enhanced cytotoxicity to cell lines from prostate cancer with less toxicity to those from normal prostate. In vitro cytotoxic assay using ROS-related compounds demonstrated that hydrogen peroxide (H2O2) is a major cytotoxic mediator among ROS molecules. Biochemical analysis showed that combined use of As2O3 and BSO blocked H2O2-scavenging systems including glutathione, catalase, and glutathione peroxidase, and that the degree of this blockade was well correlated with intracellular ROS levels and sensitivity to this treatment. Finally, the effectiveness of the combination therapy of As2O3 with BSO was demonstrated with an orthotopic model of prostate cancer metastasis. We propose that the combination therapy of As2O3 with BSO is a valid means of blockade of H2O2-scavenging system, and that the combination of a ROS-generating agent with an inhibitor of major scavenging systems is effective in terms of both efficacy and selectivity. Furthermore, because the effective doses of both compounds are within clinically achievable range, this report will lead to immediate benefit for the development of a new cancer therapy.

Animals↗
PubMed2004

Development and progression of diabetic retinopathy in patients with Type 1 diabetes who are positive for GAD autoantibody.

AIMS: To investigate the relationship between autoantibodies to glutamic acid decarboxylase (GAD) and proliferative diabetic retinopathy (PDR) to assess the role of autoimmunity in retinopathy. METHODS: Patients with Type 1 diabetes for more than 10 years who had been diagnosed under age 30 (13-28 years) were studied. They were classified into three groups. The PDR group consisted of 22 patients, the pre-PDR group was 26 patients, while the non-DR group was 32 patients who had Type 1 diabetes without retinopathy. Blood was collected to measure autoantibodies to GAD, and the relationship between PDR and GAD positivity was investigated in a cross-sectional study. RESULTS: The highest positivity rate of GAD autoantibodies was 50.0% in the non-DR group, followed by the pre-PDR group (30.8%) and the PDR group (18.2%). CONCLUSIONS: Production or existence of GAD autoantibodies may contribute to the prevention of retinopathy.

Adolescent↗
PubMed2004

Risk evaluation of outcome of vitreous surgery for proliferative diabetic retinopathy based on vitreous level of vascular endothelial growth factor and angiotensin II.

AIMS: To ascertain whether measurement of the vitreous fluid levels of vascular endothelial growth factor (VEGF) or angiotensin II (Ang II) could predict the outcome of vitreous surgery in patients with proliferative diabetic retinopathy (PDR). METHODS: A prospective observational case study was performed in 61 consecutive patients (61 eyes) with PDR who underwent vitreoretinal surgery. Vitreous fluid samples were obtained during surgery. The VEGF level in vitreous fluid and plasma was determined by enzyme linked immunosorbent assay, while the Ang II level was measured by radioimmunoassay. Patients were prospectively followed for 6 months and the postoperative outcome was analysed by logistic regression analysis. RESULTS: No improvement and/or progression of PDR was seen in 15 (25%) of the 61 eyes. Vitreous levels of VEGF and Ang II were significantly higher in eyes with progression of PDR than in eyes with regression of PDR (p = 0.0044, and p = 0.0178, respectively). Multivariate logistic regression analysis showed that the vitreous VEGF level increased along with the progression of PDR after vitreous surgery (odds ratio 2.48, p = 0.0008). CONCLUSION: A high vitreous fluid VEGF level is associated with a significant risk of postoperative progression of PDR. The vitreous level of VEGF at the time of surgery may be a useful predictor of the outcome.

Adult↗
PubMed2004

Changes in the axonal membrane potential and Ca2+ concentration associated with peripheral nerve grafting after spinal cord injury.

We performed peripheral nerve allografting in rats with spinal cord injury, and measured motor function and axonal membrane potential as well as Ca(2+) concentration of the nerve grafting spinal cord area by using a behavior observation system and a confocal laser-scanning microscope, respectively. In our experiments, we produced a model of peripheral nerve grafting after spinal cord injury by peripheral nerve allografting (sciatic nerve) in rats with spinal cord injury (thoracic cord hemisection). The group with spinal cord injury that underwent peripheral nerve grafting showed improvement in motor function, a significant increase in the axonal action potential, and a slight increase in the Ca(2+) concentration compared with the group that did not undergo nerve grafting.

Animals↗
PubMed2003

Motor evoked potentials following transcranial magnetic stimulation after middle cerebral artery and/or basilar artery occlusions in rats.

To clarify the significance of motor evoked potentials following transcranial magnetic stimulation (MMEPs) in acute stage of cerebral ischemia, MMEPs were recorded in rats with the right middle cerebral artery (MCA) and/or the basilar (BA) artery occlusions. MMEPs from bilateral forelimb muscle and regional cerebral blood flow (rCBF) of the pons were recorded simultaneously. After MCA occlusion, the amplitudes of MMEPs from left forelimb were increased up to approximately 184-221% of the pre-ischemic value for 60 min, though the latencies were unchanged. On the other hand, in the rats of BA occlusion and both BA and MCA occlusion groups, MMEPs amplitudes were decreased to 8-25% of the pre-ischemic value for 60 min. Pontine rCBF was decreased to 28-44% in both groups. As a mechanism of the facilitation of MMEPs after MCA occlusion, the affection of the inhibitory mechanism between the cerebral cortex and the generator of MMEPs by MCA occlusion is speculated.

Animals↗
PubMed2003

Prognostic significance of the number of metastatic lymph nodes in early gastric cancer.

BACKGROUND: The prognostic value of the number of metastatic lymph nodes in early gastric cancer has not been evaluated much, although the significance of metastatic lymph nodes is defined by the location of positive nodes, according to the JRSGC for gastric cancer. METHODS: The postoperative courses of 305 early gastric cancer patients who had undergone D2-extended lymphadenectomy were followed up for a median of 108 months to evaluate the significance of the number of metastatic lymph nodes on recurrence of the disease. RESULTS: Recurrence of gastric cancer was more frequently observed in submucosal cancer than in mucosal cancer. All patients but one who revealed recurrence had nodal metastasis at the time of surgery. In cases with 1-3 metastatic lymph nodes, no patient had revealed any sign of recurrence; however, in cases with 4 or more metastatic lymph nodes, 6 of 7 patients died of recurrent disease. There were 3 cases of bone metastases, 2 of peritoneal dissemination, and 1 each of both recurrent diseases. CONCLUSIONS: These data suggest that in n-positive cases, in which there are 4 or more metastatic lymph nodes, there is a high probability of recurrence of early gastric cancer, and especially of hematogenic metastasis.

Adenocarcinoma↗
PubMed2003

[Development of computerized method for automated classification of the body parts in digital radiographs].

PURPOSE: In picture archiving and communication systems (PACS), the information on the body parts included in radiographs is often not or incorrectly recorded in an image header. In order to apply the computer-aided diagnosis (CAD) system in the PACS environment, the body parts in radiographs need to be recognized correctly by computer. The purpose of this study is to develop a computerized method for correctly classifying the body parts in digital radiographs based on a template matching technique. METHODS/MATERIALS: The image database used in this study was 1032 digital radiographs (14 x 17 inches) obtained with a computed radiography, and included 505 chest of postetroanterior view, 39 chest of lateral view, 241 abdomen, 108 pelvis, 10 upper limbs, 125 lower limbs, and 4 thoracic spine. In this method, test images were classified into four body parts, i.e., (1) chest, (2) abdomen, (3) pelvis, and (4) upper/lower limbs and thoracic spine. This computerized method was tested with 852 images, since 180 images were employed for creation of 98 templates, which represented the average radiographs for various body parts. Our approach was to examine the similarity of a given test image with templates by use of the cross-correlation values as the similarity measures. The body part of the test image was identified as the body part in the template yielding the maximum correlation value. Our method consisted of the following five steps. First, test images were classified into one of three groups; i.e. 1) chest and abdomen, 2) pelvis, and 3) upper/lower limbs and thoracic spine by using the templates obtained from images with the average size and position. Second, the remaining uncertain images were classified by using additional templates in various directions. Third, the chest and abdomen group was separated into two subgroups; i.e.chest and abdomen. Fourth, in order to classify some uncertain images, templates were shifted horizontally and vertically. Fifth, outer pixels of templates were eliminated to avoid the misclassification due to x-ray collimation. RESULTS: Our preliminary results indicated that the body parts for 850 cases (99.8%) were correctly classified with our method. CONCLUSIONS: This method would be useful for automated identification of the body parts in radiographs when various CAD systems would be implemented in the PACS environment.

Diagnosis, Computer-Assisted↗
PubMed2002

Process of apoptosis induced by TNF-alpha in murine fibroblast Ltk-cells: continuous observation with video enhanced contrast microscopy.

Apoptosis is originally defined by unique morphological changes of dying cells, and the biochemical hallmark associated with apoptosis is internucleosomal DNA fragmentation. However, few report has shown the precise time course of the apoptotic events. The present study was designed to try to clarify apoptotic processes using a video-enhanced contrast-differential interference contrast (VEC-DIC) microscopy. The morphological changes of murine fibroblast Ltk-cells treated with TNF-alpha were divided into four stages: (i) pre-apoptotic, (ii) cytoplasmic shrinkage, (iii) membrane blebbing, and (iv) ballooning. Almost of the cells underwent cytoplasmic shrinkage and membrane blebbing within 6 hours after TNF-alpha exposure, and at about 9 hours, they were in the ballooning stage. Based on these data, we investigated the relationship between morphological changes and other biochemical features. The earliest event was exposure of phosphatidyl-serine at the cytoplasmic membrane, which was already observed in the pre-apoptotic stage. Loss of mitochondrial membrane potential was observed in the cytoplasmic shrinkage stage. Caspase-8/-3 activities already started increasing in the pre-apoptotic stage, and reached their peak at 6 hours after TNF-alpha exposure. DNA fragmentation occurred in the late phase of the membrane blebbing.

Animals↗
PubMed2002

The Nottingham Staphylococcus aureus population study: prevalence of MRSA among the elderly in a university hospital.

A prevalence survey of methicillin-resistant Staphylococcus aureus (MRSA) in elderly patients (65 years and older) three weeks after admission to a university hospital was performed. Risk factors associated with hospital MRSA carriage were determined. The design was a cross-sectional patient-based study and all adult wards at the University Hospital Nottingham (1600 beds) were included. Three hundred and forty-two elderly individuals (65 years and older) were enrolled into the study on day 21 after admission. One hundred and twenty patients [35.08% (95% confidence intervals 29.93-40.25%)] carried S. aureus. MRSA was isolated from 54 patients. The MRSA prevalence was 158/1000 (95% CI 119-197/1000 patients). Independent risk factors for MRSA carriage in the hospital were exposure to ampicillin [adjusted odds ratio 4.1 (95% CI 1.28-13.14)] and ciprofloxacin [17.1 (95% CI 2.91-99.90)]. Forty-one MRSA isolates (75.9%) belonged to the epidemic type EMRSA 15, seven isolates to EMRSA 16 (12.9%) and six isolates were sporadic strains as determined by genetic typing. It can be expected that among this defined risk group, between 187 and 331 patients carried MRSA on discharge in the year 2000. MRSA carriage is frequent and detected in only 15% of actual carriers amongst elderly patients by routine clinical investigations three weeks after admission. The only significant risk factor identified by multivariate logistic regression was antibiotic chemotherapy. The repeated finding of a strong association between MRSA colonization and previous ciprofloxacin exposure demands attention and indicates that fluoroquinolones should be used prudently in institutions where MRSA is endemic.

Aged↗
PubMed2002

Angiotensin II and vascular endothelial growth factor in the vitreous fluid of patients with proliferative diabetic retinopathy.

AIMS: To investigate the correlation between the level of angiotensin II and vascular endothelial growth factor (VEGF) in the vitreous fluid and the severity of proliferative diabetic retinopathy (PDR). METHODS: During vitreoretinal surgery at the Tokyo Women's Medical University, vitreous fluid samples were obtained from 51 eyes of diabetic patients with PDR, six eyes of diabetic patients without retinopathy, and 16 eyes of non-diabetic patients with ocular disease (controls). The VEGF levels in vitreous fluid and plasma were determined by enzyme linked immunosorbent assay, while angiotensin II levels were measured by radioimmunoassay. RESULTS: The vitreous fluid levels of VEGF and angiotensin II were significantly higher in patients with PDR than in non-diabetic patients or diabetic patients without retinopathy (all p<0.0001). The vitreous fluid level of angiotensin II was significantly correlated with that of VEGF (p<0.0001), and the vitreous concentrations of both VEGF and angiotensin II were significantly higher in patients with active PDR than in those with quiescent PDR (p<0.0001 and p=0.0005, respectively). CONCLUSION: The authors found that both angiotensin II and VEGF levels were significantly higher in the vitreous fluid of patients with PDR than in that of non-diabetic patients or diabetic patients without retinopathy, and that the levels of both angiotensin II and VEGF were elevated in the active stage of PDR. These findings suggest that angiotensin II contributes to the development and progression of PDR in combination with VEGF.

Angiotensin II↗
PubMed2002

Personality, social support, coping and emotional distress after repeated spontaneous abortions.

Systematic investigations on the emotional impacts of repeated spontaneous abortions have been few. We mounted a prospective study of a cohort of couples who had experienced two consecutive first trimester spontaneous abortions and for whom no clearly identifiable causes were found. The present report is based on the first part of the study and examines: (1) emotional distress reported by the miscarrying women at six months (median, range 1-12 months) after two abortions; and (2) psychosocial predictors influencing such distress. The mean score of the women on the Symptom Checklist 90-Revised--one of the most popular self-report scales for psychopathology--was 0.38, whereas that for the general population is reported to be 0.26 (the higher the score, the more psychopathology). Fourteen percent of the cohort scored above the cutoff point for mental disorders screening. Factors examined and found non-influential upon the level of emotional distress include: the maternal age; whether the last pregnancy was planned and wished for or not; and coping styles of the women after the abortions. Control by the husbands over the marital relationship and neurotic personality traits of the women increased the emotional distress, whereas the social support the women perceive decreased it. These findings suggest that martial and social support are important in determining the level of psychiatric morbidity after repeated abortions.

Abortion, Spontaneous↗