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Biomedical subjects

Y Yamada

Publications and source records attributed to Y Yamada.

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

Spontaneous regression of hepatocellular carcinoma with complete necrosis: case report.

Spontaneous regression of hepatocellular carcinoma is rare phenomenon. A 74-year-old man was found to have a hepatocellular carcinoma with intrahepatic metastases in the lateral segment of the liver. Before surgery, he developed severe cholangitis due to choledocholithiasis and was treated endoscopically. The tumor marker level decreased markedly, and hepatectomy was performed. The resected tumor demonstrated complete necrosis.

Aged↗
PubMed2005

Effects of ketamine and propofol on inflammatory responses of primary glial cell cultures stimulated with lipopolysaccharide.

BACKGROUND: Ketamine has been reported to exert anti-inflammatory effects on macrophages stimulated with lipopolysaccharide (LPS) in vitro and in vivo. Several studies have reported conflicting results regarding the effects of propofol on cytokine production from immune cells. However, there have been no reports of the effects of these agents on inflammatory responses in glial cells. We investigated the effects of ketamine and propofol on LPS-induced production of nitric oxide, tumour necrosis factor-alpha (TNF-alpha) and prostaglandin E(2) (PGE(2)) from primary cultures of rat glial cells in vitro. METHODS: Glial cells were stimulated with LPS in the absence and presence of various concentrations of ketamine (30-1000 microM) or propofol (30 and 300 microM). Nitric oxide released into the culture media was determined by measuring nitrite using the Griess reaction, and concentrations of TNF-alpha and PGE(2) were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Ketamine reduced LPS-induced TNF-alpha production without significant inhibition of nitrite release in mixed glial cells, astrocyte cultures and microglial cultures. Ketamine also inhibited LPS-induced production of PGE(2) in astrocyte cultures. In contrast, propofol had no effect on LPS-induced nitrite or TNF-alpha production in mixed glial cells. CONCLUSIONS: The data demonstrate that ketamine inhibited some of the inflammatory responses of both astrocytes and microglial cells treated with LPS without causing major change in nitric oxide release. Propofol had no effect on the production of nitric oxide or TNF-alpha from LPS-stimulated glial cells.

Anesthetics, Dissociative↗
PubMed2005

Microbial synthesis of chiral amines by (R)-specific transamination with Arthrobacter sp. KNK168.

Arthrobacter sp. KNK168 shows (R)-enantioselective transaminase [(R)-transaminase] activity, which converts prochiral ketones into the corresponding chiral (R)-amines in the presence of an amino donor. The cultural conditions and reaction conditions for asymmetric synthesis of chiral amines with this microorganism were examined. The transaminase was inducible, and its production was enhanced by the addition of sec-butylamine and 3-amino-2,2-dimethylbutane to the culture medium. (R)-1-Phenylethylamine was a good amino donor for amination of 3,4-dimethoxyphenylacetone with Arthrobacter sp. KNK168. Under the optimum conditions, 126 mM (R)-3,4-dimethoxyamphetamine (DMA) [>99% enantiomeric excess (ee)] was synthesized from 154 mM 3,4-dimethoxyphenylacetone and 154 mM (R)-1-phenylethylamine through the whole cell reaction with an 82% conversion yield. (R)-Enantiomers of other amines, such as (R)-4-methoxyamphetamine, (R)-1-(3-hydroxyphenyl)ethylamine and (R)-1-(3-hydroxyphenyl)ethylamine, were also synthesized from the corresponding carbonyl compounds through asymmetric amination with Arthrobacter sp. KNK168.

Acetone↗
PubMed2005

Aerobic composting of waste activated sludge: kinetic analysis for microbiological reaction and oxygen consumption.

In order to examine the optimal design and operating parameters, kinetics for microbiological reaction and oxygen consumption in composting of waste activated sludge were quantitatively examined. A series of experiments was conducted to discuss the optimal operating parameters for aerobic composting of waste activated sludge obtained from Kawagoe City Wastewater Treatment Plant (Saitama, Japan) using 4 and 20 L laboratory scale bioreactors. Aeration rate, compositions of compost mixture and height of compost pile were investigated as main design and operating parameters. The optimal aerobic composting of waste activated sludge was found at the aeration rate of 2.0 L/min/kg (initial composting mixture dry weight). A compost pile up to 0.5 m could be operated effectively. A simple model for composting of waste activated sludge in a composting reactor was developed by assuming that a solid phase of compost mixture is well mixed and the kinetics for microbiological reaction is represented by a Monod-type equation. The model predictions could fit the experimental data for decomposition of waste activated sludge with an average deviation of 2.14%. Oxygen consumption during composting was also examined using a simplified model in which the oxygen consumption was represented by a Monod-type equation and the axial distribution of oxygen concentration in the composting pile was described by a plug-flow model. The predictions could satisfactorily simulate the experiment results for the average maximum oxygen consumption rate during aerobic composting with an average deviation of 7.4%.

Aerobiosis↗
PubMed2005

Analysis of risk factors for the development of gallstones after gastrectomy.

BACKGROUND: The incidence of gallstones is higher in people who have undergone gastrectomy than in the general population, but the cause of this is unknown. METHODS: Between January 1992 and January 2003, 749 patients underwent ultrasonography of the gallbladder after gastrectomy for gastric cancer. A total of 2327 examinations were carried out. The incidence of gallstones was compared in subgroups of patients classified according to the type of reconstruction, extent of gastrectomy, whether the duodenum was excluded and type of lymph node dissection. RESULTS: The incidence of gallstones was significantly higher after total compared with partial gastrectomy (27.9 versus 7.8 per cent at 5 years; P < 0.001). Reconstruction with duodenal exclusion was associated with a significantly higher incidence than non-exclusion (25.1 versus 8.2 per cent at 5 years; P < 0.001). Patients who had lymph node dissection in the hepatoduodenal ligament had a significantly higher incidence of gallstones than those who did not (28.2 versus 7.5 per cent at 5 years; P < 0.001). In multivariate analysis that included type of reconstruction and lymph node dissection, lymph node dissection in the hepatoduodenal ligament was identified as the most significant risk factor for gallstone development (odds ratio 3.66 (95 per cent confidence interval 2.16 to 6.22); P < 0.001). CONCLUSION: Lymph node dissection in the hepatoduodenal ligament, total gastrectomy and exclusion of the duodenum are risk factors for gallstones after gastrectomy.

Adult↗
PubMed2005

Analysis of head movements coupled with trunk drift in healthy subjects.

Accelerometers were used to measure sequential head tilt and trunk drift in 14 healthy young subjects while they performed three kinds of head task. First, maximum inclination angles in anterior, posterior, right and left directions were measured to estimate cervical ranges of motion for flexion-extension and lateral bending. The inclination angles measured (61.2 degrees on average for flexion, 51.7 degrees for extension, 42.7 degrees for right bending and 43.9 degrees for left bending) were consistent with previous findings. Secondly, cross-correlation analysis was applied to evaluate the degree of functional coupling between the head and trunk during flexion-extension and lateral bending. Significantly higher correlation coefficients were found between head tilt and trunk drift when these movements were in the same (iso-) directional condition than in a different (allo-) directional condition. The coupled trunk drift in flexion-extension for the iso-directional condition (10.3 degrees on average) was much larger than for the allodirectional condition (2.3 degrees). Finally, head turning was recorded as oval traces in a biaxial plane. In both clockwise and counter-clockwise head turning conditions, the maximum inclination angles of the traces were larger in the anterior-posterior direction (59.8 degrees anterior and 58.2 degrees posterior, in the clockwise condition, and 47.4 degrees and 47.4 degrees in the counter-clockwise condition) than in the right-left direction (36.3 degrees right and 39.0 degrees left, in the clockwise condition, and 40.5 degrees and 36.7 degrees in the counter-clockwise condition), and the angles in the four directions were almost equal to flexion-extension and lateral bending. The characteristics of the traces recorded and a possible application of the present recording system are discussed.

Acceleration↗
PubMed2005

Insulin independence of unstable diabetic patient after single living donor islet transplantation.

BACKGROUND: Current success in islet transplantation will lead to a donor shortage. Living donor islet transplantation could be an alternative approach to expand the potential donor pool. In this study we describe the first successful living donor islet transplantation for unstable diabetes, performed at Kyoto University Hospital on January 19, 2005. METHODS: The donor was a healthy 56-year-old woman and mother of the recipient. The recipient was a 27-year-old woman with insulin-dependent diabetes since the age of 15 years. She experienced frequent hypoglycemic unawareness episodes. Her blood glucose concentration was difficult to control and C-peptide level was negative after glucagon stimulation. She needed an average 28 of units of insulin per day. The donor underwent a distal pancreatectomy and islets were isolated from the resected pancreas graft. The total islet yield was 408,114 islet equivalents and isolated islets were immediately transplanted into the recipient's liver. RESULTS: After transplant, the blood glucose level of the recipient was tightly controlled without hypoglycemic episodes. She was discharged on day 37 with a normal oral glucose tolerance test (OGTT). The recipient remained insulin-independent for >3 months, since day 22 posttransplant. The donor's postoperative clinical course was uneventful. She was discharged on postoperative day 18 and returned to her job within 1 month. CONCLUSIONS: We report the first successful living donor islet transplantation for the treatment of unstable diabetes. We believe that living donor islet transplantation may become an option in the treatment of insulin-dependent diabetes.

Adult↗
PubMed2005

Simple evaluation of engraftment by secretory unit of islet transplant objects for living donor and cadaveric donor fresh or cultured islet transplantation.

BACKGROUND: Evaluation of engraftment is important to assess the success of islet transplantation. Recently we developed secretory unit of islet transplant objects (SUITO) index for simple evaluation of engraftment. Assuming that normal subjects aged <40 years have 100% pancreatic beta-cell function, SUITO index was calculated by the formula: 1500 x fasting C-peptide immunoreactivity [ng/dL]/(fasting blood glucose [mg/dL] - 63). In this study, we compared the efficacy of islet transplantation from cadaveric and living donors using the SUITO index. METHODS: We performed eight islet transplantations with non-heart-beating donors (NHBDs) into five patients. Two patients received fresh islets once, one patient received fresh islets twice, one patient received cultured islets once, and one patient received cultured islets twice plus fresh islets once. In addition, one patient received fresh islets from a living donor. We calculated the SUITO index from postoperative days 3 to 30 for each case. RESULTS: Mean SUITO index after one fresh islet transplant was 11.7 +/- 1.0, after two fresh islet transplants was 28.5 +/- 3.4, after one cultured islet transplant was 2.1 +/- 0.4, after two cultured islet transplant was 12.1 +/- 1.9, and after two cultured islet transplant plus one fresh islet transplant was 26.7 +/- 1.7. The mean SUITO index after single living donor islet transplant was 40.7 +/- 2.6, which was significantly higher compared with all other groups. Insulin independence was obtained when the SUITO index was >26, which might reflect that 26% beta-cell mass was required for insulin independence. CONCLUSION: SUITO index is useful to evaluate islet engraftment and to predict the possibility of insulin independence.

Blood Glucose↗
PubMed2005

Little effects of low dosage of levomepromazine on plasma risperidone levels.

In the present study, we investigated the effects of levomepromazine on plasma risperidone concentrations in a steady state. Twenty patients taking risperidone at a stable dose for more than 2 weeks who were considered to require levomepromazine coadministration were selected. The scores of excitement in BPRS significantly decreased 2 weeks after the coadministration of levomepromazine. Plasma risperidone concentrations and the ratio of risperidone and 9-hydroxyrisperidone (risperidone/9-hydroxyrisperidone) did not change between before and 2 weeks after the coadministration of levomepromazine. The extrapyramidal symptoms were not worsened by the coadministration of levomepromazine. These results suggest that a low dosage of levomepromazine, use as a sedative adjuvant to risperidone treatment, have no statistically significant effect on the trough plasma concentrations of risperidone.

Adolescent↗
PubMed2005

Soluble TNF receptors and albuminuria in non-obese Japanese type 2 diabetic patients.

The aim of this study was to investigate the relationships between albuminuria and tumor necrosis factor (TNF)-alpha or soluble TNF receptors (sTNF-R1, sTNF-R2) in eighty-eight non-obese Japanese type 2 diabetic patients stratified into two groups according to albuminuria status-microalbuminuria or normoalbuminuria. Patients with microalbuminuria were older and had significantly higher concentrations of sTNF-R1 and sTNF-R2 than those with normoalbuminuria. There was, however, no significant difference in sex, diabetes duration, smoking, BMI, systolic and diastolic blood pressure, HbA (1c), serum creatinine, and lipid profile between the two groups. Although serum TNF-alpha was positively correlated to serum sTNF-R1 and sTNF-R2, serum TNF-alpha level did not differ with respect to albuminuria. Univariate regression analysis showed that urinary albumin concentration was positively correlated to age (r=0.380, p<0.001), serum creatinine (r=0.214, p<0.05) and concentrations of sTNF-R1 (r=0.364, p<0.001) and sTNF-R2 (r=0.342, p<0.005). Other variables, including TNF-alpha, were not associated with albuminuria. Multiple regression analyses showed that urinary albumin concentration was independently predicted by the level of sTNF-R1 (F=32.1), which explained 26.3% of the variability of urinary albumin concentration. From these results, it can be concluded that serum soluble TNF receptor is an important independent factor associated with albuminuria in non-obese Japanese type 2 diabetic patients.

Aged↗
PubMed2005

Inactivation of tumor suppressor genes and the progression of adult T-cell leukemia-lymphoma.

Almost three decades have passed since adult T-cell leukemia-lymphoma (ATLL) was proposed as a new disease entity. During this period, its causative agent, human T-cell leukemia virus type-1 (HTLV-1), was found and a crucial role of the viral product Tax in the development of ATLL was disclosed. However, the long latent period after infection with HTLV-1 indicates the need for additional factors for full-blown ATLL, most of which are supposed to be provided by somatic mutations of cellular genes. Recent progress in cell-cycle research has revealed that the uncontrolled and superior proliferative activity of malignant cells is mainly caused by the breakdown of cell-cycle regulation and that most malignancies carry aberrations in p16-pRB and/or p53 pathways. ATLL is not an exception, despite the consistent association of HTLV-1 in primary leukemia cells, and accumulating evidence indicates that the breakdown of these pathways is indeed involved in the leukemogenesis of ATLL, especially in its later steps, which serve as the key events for promotion of indolent ATLL to aggressive ATLL.

Disease Progression↗
PubMed2005

Sensitivity of adult T-cell leukaemia lymphoma cells to tumour necrosis factor-related apoptosis-inducing ligand.

Tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induces apoptosis in many transformed cells, but not in normal cells, and hence TRAIL has recently emerged as a novel anti-cancer agent. Adult T-cell leukaemia lymphoma (ATLL) is a neoplasm of T-lymphocyte origin aetiologically associated with human T-lymphotropic virus type 1 (HTLV-I), and is resistant to standard anti-cancer therapy. We thus characterized the sensitivity of ATLL cells to TRAIL in this study. Although most primary ATLL cells and cell lines expressed TRAIL death receptors on their surface, they showed only restricted sensitivity to TRAIL. Among the 10 ATLL cell lines examined, one was sensitive, but two had insufficient death-receptor expression, two had an unknown resistant mechanism with abrogation of the death signal upstream of caspase-8, and the remaining five showed attenuation of the signal in both extrinsic and intrinsic pathways by X-linked inhibitor of apoptosis and Bcl-2/Bcl-xL respectively. Furthermore, the level of HTLV-I tax expression was significantly correlated to TRAIL resistance. Interestingly, ATLL cells themselves expressed TRAIL on the cell surface. Constitutive production of TRAIL may offer resistance, thus allowing the development of TRAIL-resistant ATLL cells. Consequently, the resistant mechanism in ATLL cells against TRAIL was assigned to multiple factors and was not explained by a definitive single agent.

Antineoplastic Agents↗
PubMed2005

Proviral status of HTLV-1 integrated into the host genomic DNA of adult T-cell leukemia cells.

Human T-cell leukemia virus type-1 (HTLV-1) is the etiological agent of adult T-cell leukemia (ATL), and leukemic cells always carry the proviral genome monoclonally integrated into their host genomes at the same sequence site, designated as the monoclonal integration. Using Southern blot hybridization (SBH) and sequenced tagged site polymerase chain reaction assays, we examined the proviral status in 558 clinical specimens from 350 patients who are suspected to have ATL. A total of 321 specimens (57.5%) from 241 patients showed positive results for the monoclonal integration according to SBH, using EcoR1 and Pst1. The 241 patients consisted of 136 patients (56.4%) with the complete provirus (C-type), 62 patients (25.7%) with a defective provirus (D-type), and 43 patients (17.8%) with multibands (M-type). The incidence of the D- and M-types were in the order of smoldering, chronic, and acute subtypes of ATL, suggesting that such an aberrant proviral status is generated on the way to multistep carcinogenesis and is subsequently clinically important for the malignant behavior of the disease. Moreover, our data showed that the partial deletion of the proviral genome is initiated first at the site of the gag region and spreads into the sites of the pol and env regions, whereas the long terminal repeats and pX regions are almost always conserved. These results suggest that analysis of the proviral status provides useful diagnostic and virologic-oncological information about ATL and HTLV-1 pathology, especially the important role of pX gene in tumorigenesis.

Adult↗
PubMed2005

Acute myocardial infarction caused by a septic coronary embolism diagnosed and treated with a thrombectomy catheter.

Acute myocardial infarctions are common in bacteraemia but are seldom diagnosed during life. A 64 year old man with severe chest pain who had fever for several days due to possible bacteraemia was shown by ECG and echocardiography to have possible lateral infarction. Immediate coronary angiography showed possible thrombus in the left circumflex artery, which was treated by thrombectomy catheter. Bacterial thrombus was removed and was verified by histological examination. A stent was implanted without complications. Acute myocardial infarction caused by septic embolism is usually fatal; however, thrombectomy may be useful in these cases.

Cardiac Catheterization↗
PubMed2005

Comparison of a digital flat-panel versus screen-film, photofluorography and storage-phosphor systems by detection of simulated lung adenocarcinoma lesions using hard copy images.

The purpose of this study was to compare hard copy images from a flat-panel detector digital radiography system with conventional radiography, photofluorographic radiography and storage phosphor radiography for the detection of simulated lung adenocarcinoma lesions and also for radiation dose. To test the diagnostic performance of these four systems, the authors used 15 types of lung adenocarcinoma phantom according to Noguchi's classification and an anthropomorphic chest phantom. The visual evaluation of tumour detectability by four radiologists and two general thoracic surgeons was examined with a five-level confidence scale. Lung doses were measured with glass dosemeters for the chest radiology systems under the conditions used by each hospital and centre. Our results indicated that flat-panel detector digital radiography and storage phosphor radiography are not necessarily superior to conventional radiography and photofluorographic radiography for detecting lung adenocarcinomas when only hard copy images are used, and this suggests a need to carefully optimize chest radiography.

Adenocarcinoma↗