Biomedical subjects

S Yamamoto

Publications and source records attributed to S Yamamoto.

At least 91 records · Page 5Linked to original sources

PubMed2004

Inferior mesenteric venous left renal vein shunting for decompression of excessive portal hypertension in adult living related liver transplantation.

In the present study, we investigated the effect of decompression of excessive portal hypertension by inferior mesenteric venous (IMV) left renal vein shunting in 7 cirrhotic patients with esophago-gastric varices and 2 patients who underwent adult living related donor liver transplantation (ALRDLT). The portal pressure remarkably decreased after shunting in all patients with esophago-gastric varices (388 +/- 42 mm H2O vs. 247 +/- 57 mm H2O; P < .05). It also decreased after a shunt operation in patients who had undergone liver transplantation. We report that the excessive shear stress by portal hypertension after small-for-size LRDLT induces a liver injury and the decompression of portal hypertension by splenic arterial ligation or splenectomy prevents postoperative liver injury following massive hepatectomy and small-for-size LRDLT. Our present studies suggested that IMV left renal vein shunting might prevent postoperative liver injury by partial decompression of excessive portal hypertension following small-for-size LRDLT.

Angiography↗

PubMed2004

Nationwide survey of human Listeria monocytogenes infection in Japan.

Listeriosis, caused by Listeria monocytogenes, is a significant public-health concern as a result of its clinical severity and high mortality. Large foodborne outbreaks of listeriosis have occurred during the last two decades in Europe and the United States, but to date there have been no food-mediated epidemics of the disease and very little information is available on the number of cases of listeriosis in Japan. We performed a nationwide surveillance study of listeriosis. The data were collected between 1980 and 2002, and 95 case reports were identified from 1996 to 2002. We divided 13.6 (cases per year between 1996 and 2002) by the ratio of the number of beds in hospitals that replied to the questionnaire, to that of all the hospitals in Japan and estimated that there is an average of 83 cases of listeriosis per year and an incidence of 0.65 cases per million of the population in Japan.

Adolescent↗

PubMed2004

Poor nutritional status of younger Tibetan children living at high altitudes.

BACKGROUND: The growth, development and nutrition of children in Tibet with high-altitude and unique traditional culture have recently gained attention. However, few researches are available on the nutritional status of younger children of Tibet. OBJECTIVE: The objective of the study was to evaluate the nutritional status of children below 36 months old in Tibet by means of anthropometry. DESIGN: The cross-sectional survey was conducted between August and September in 1999 and a sample of 1655 children below 36 months old was obtained using a stratified multistage cluster random sampling method from a total of seven districts of Tibet. Height, weight and hemoglobin concentration were measured and at the same time related sociodemographic and environmental information were collected. NCHS/CDC/WHO reference data were used to evaluate the nutritional status of the entire study children population and estimate the prevalence of stunting, underweight and wasting. RESULTS: Compared with the reference of NCHS/CDC/WHO, the distributions of HAZ and WAZ shifted to the left significantly and the means of HAZ and WAZ were -1.53 and -1.05, respectively, which were significantly lower than the reference value. The distribution of WHZ, however, was close to that of the reference. The reduction of Z-scores for height and weight occurred very early in life and was greatest in the second year after birth. The prevalence of malnutrition of children was 39.0% for stunting, 23.7% for underweight and 5.6% for wasting, respectively. Rural children had prevalence of stunting of 41.4% and underweight of 24.7%, as compared with prevalence of stunting of 25.3% and underweight of 18.1% for urban children. Stunting and underweight were associated with altitudes. The mean of hemoglobin (Hb) of children was 120.4 g/l and rural children had a significantly lower Hb concentration (119.9 g/l) than urban children (123.3 g/l). The prevalence of anemia seemed higher when using different altitude corrections for Hb to estimate the prevalence, but the consequences were uneven. CONCLUSIONS: For Tibetan young children, the nutritional status of the entire population is poor and the prevalence of malnutrition is higher, especially for stunting. Malnutrition is related to high altitudes. Although the Hb concentration is higher induced by high altitude, there must be quite a lot of anemic children at high altitudes. The relationship between altitude and Hb for children on the Tibetan plateau requires further study in order to determine correctly the magnitude of anemia of children.

Altitude↗

PubMed2004

Development of efficient plasmid DNA transfer into adult rat central nervous system using microbubble-enhanced ultrasound.

Although gene therapy might become a promising approach for central nervous system diseases, the safety issue is a serious consideration in human gene therapy. To overcome this problem, we developed an efficient gene transfer method into the adult rat brain based on plasmid DNA using a microbubble-enhanced ultrasound method, since microbubble-enhanced ultrasound has shown promise for transfecting genes into other tissues such as blood vessels. Using the microbubble-enhanced ultrasound method, luciferase expression was increased approximately 10-fold as compared to injection of naked plasmid DNA alone. Interestingly, the site of gene expression was limited to the site of insonation with intracisternal injection, in contrast to previous studies using viruses. Expression of the reporter gene, Venus, was readily detected in the central nervous system. The transfected cells were mainly detected in meningeal cells with intracisternal injection, and in glial cells with intrastriatal injection. There was no obvious evidence of tissue damage by microbubble-enhanced ultrasound. Overall, the present study demonstrated the feasibility of efficient plasmid DNA transfer into the central nervous system, providing a new option for treating various diseases such as tumors.

Animals↗

PubMed2004

Changes in Helicobacter pylori status in patients with rheumatoid arthritis under non-steroidal anti-inflammatory drugs.

BACKGROUND: The role of Helicobacter pylori infection in rheumatoid arthritis (RA) patients during treatment with non-steroidal anti-inflammatory drugs (NSAID) is still unclear. METHODS: By means of endoscopy and biopsy, gastroduodenal lesions and H. pylori status were repeatedly examined in 88 RA patients at intervals ranging from 26 to 49 months. Histology and culture were applied to determine H. pylori status. Serial changes in gastroduodenal lesions and histologic score for mucosal atrophy were compared among groups classified by initial and second H. pylori status. RESULTS: There were 28 patients with continuously positive H. pylori infection (CP group), 33 patients with continuously negative H. pylori infection (CN group), 7 patients in whom H. pylori status became negative (PN group), and 20 patients in whom H. pylori status could not be determined (UD group). Age, duration and species of NSAID, disease activity of RA, gastroprotective drugs applied and the prevalence of gastroduodenal mucosal lesions were not different among the groups at either the initial or the second examination. In the PN group, the score for mucosal atrophy at the second examination was significantly lower than at the initial examination, whereas no difference was found for the CP, CN and UD groups. Overall, histologic score for mucosal atrophy was higher in H. pylori-positive patients than in H. pylori-negative patients at both initial and second examination. CONCLUSIONS: In RA patients using NSAIDs, H. pylori infection may not affect the course of gastroduodenal lesions and activity of RA, but the infection contributes to mucosal atrophy.

Adult↗

PubMed2004

Pathological study of naturally occurring adenocarcinomas demonstrating differentiation in ducks.

Case 1, a mucinous adenocarcinoma, was in the pancreas of a 5-year-old male mandarin duck. The tumour comprised a single layer of duct-like structures with abundant fibrous stroma. The neoplastic cells produced a large amount of mucin, and dense or moderately dense mucin granules were observed ultrastructurally. Case 2 was a 1-year-old male mandarin duck, which had a type II pneumocytoid carcinoma within the thoracic air sacs. Light microscopy revealed papillary growths composed of stratified neoplastic epithelium. At the ultrastructural level, the tumour cells had osmiophilic lamellar granules in the cytoplasm. Case 3, a ciliated cell adenocarcinoma with squamous metaplasia, was detected in the right lung of a 2-year-old male domestic duck (Anas platyrhynchos forma domestica). The neoplasm consisted of tubular structures with areas of squamous differentiation in places. The presence of cilia was confirmed by electron microscopy. The three adenocarcinomas appeared high-grade or moderate-grade malignant tumours in some aspects, but showed granules or cilia that are suggestive of their origin. The presence of cells retaining the capacity for differentiating into well-differentiated cells may be characteristic of sporadically occurring avian adenocarcinomas.

Adenocarcinoma↗

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

Expression level of valosin-containing protein (VCP) as a prognostic marker for gingival squamous cell carcinoma.

BACKGROUND: Valosin-containing protein (VCP) is associated with anti-apoptotic function and metastasis via activation of the nuclear factor-kappaB signaling pathway. In the present study, association of VCP expression with prognosis of gingival squamous cell carcinoma (GSCC) was examined. PATIENTS AND METHODS: VCP expression in 74 patients with GSCC (34 males and 40 females) with ages ranging from 42 to 85 (median 66) years was evaluated by immunohistochemistry, in which staining intensity in tumor cells was categorized as either weaker (level 1) or equal to/stronger (level 2) than that in the endothelial cells. RESULTS: Twenty-four (32.4%) cases showed level 1 and 50 (67.6%) level 2 VCP expression. Patients with level 1 GSCC showed a significantly better 5-year survival rate than those with level 2 GSCC (5-year overall survival: 100% versus 84.9%, P < 0.05). Multivariate analysis revealed VCP expression level, lymph node metastasis and pT(TNM) to be independent factors for overall survival. Patients with GSCC at stages I and II showed favorable prognosis regardless of VCP expression status, whereas at stages III and IV, patients with level 1 VCP expression showed better survival rates than those with level 2 expression. CONCLUSION: Prognostic significance of VCP expression level in GSCC was demonstrated.

Adenosine Triphosphatases↗

PubMed2004

Heterogeneous genetic structure in a Fagus crenata population in an old-growth beech forest revealed by microsatellite markers.

The within-population genetic structure of Fagus crenata in a 4-ha plot (200 x 200 m) of an old-growth beech forest was analysed using microsatellite markers. To assess the genetic structure, Moran's I spatial autocorrelation coefficient was calculated. Correlograms of Moran's I showed significant positive values less than 0.100 for short-distance classes, indicating weak genetic structure. The genetic structure within the population is created by limited seed dispersal, and is probably weakened by overlapping seed shadow, secondary seed dispersal, extensive pollen flow and the thinning process. Genetic structure was detected in a western subplot of 50 x 200 m with immature soils and almost no dwarf bamboos (Sasa spp.), where small and intermediate-sized individuals were distributed in aggregations with high density because of successful regeneration. By contrast, genetic structure was not found in an eastern subplot of the same size with mature soils and Sasa cover, where successful regeneration was prevented, and the density of the small and intermediate-sized individuals was low. Moreover, genetic structure of individuals in a small-size class (diameter at breast height < 12 cm) was more obvious than in a large-size class (diameter at breast height >/= 12 cm). The apparent genetic structure detected in the 4-ha plot was therefore probably the result of the structure in the western portion of the plot and in small and intermediate-sized individuals that successfully regenerated under the favourable environment. The heterogeneity in genetic structure presumably reflects variation in the density that should be affected by differences in regeneration dynamics associated with heterogeneity in environmental conditions.

Demography↗

PubMed2004

Prevalence and risk factors for diabetes in Ho Chi Minh City, Vietnam.

AIMS: To determine the prevalence of diabetes and associated risk factors in Ho Chi Minh City, Vietnam. METHODS: A total of 2932 participants aged 15 and above in Ho Chi Minh City were screened for diabetes in a cross-sectional study. The study was conducted from March-May 2001. Demographic, occupation, anthropometry and blood pressure were recorded. Blood glucose was calculated on fasting capillary and venous blood. The classification of diabetes and impaired fasting glucose (IFG) was carried out according to WHO and American Diabetes Association criteria. RESULTS: The crude prevalence of diabetes and IFG were 6.6 and 3.2%, respectively. After age, sex-adjustment to the Vietnam population census, the prevalence was 3.8 and 2.5%, respectively; approximately 40% of cases were found to be newly diagnosed diabetes. The crude prevalence of diabetes in the urban area was approximately 2.8 times higher than that recorded in the 1993 study (6.9 vs. 2.5%, respectively). In this study, there was a positive association between diabetes and sex, age, overweight, waist hip ratio (WHR), and having a history of delivering large for gestational age child; there was a negative association between diabetes and physical activity and occupation. CONCLUSIONS: This study found that the age, sex-adjusted prevalence of diabetes and IFG in Ho Chi Minh City were 3.8 and 2.5%, respectively, a rapid increase in the recent decade. Our study also indicates that ageing, a high WHR level, overweight and a sedentary lifestyle may be important determinants of the increased prevalence of diabetes during this transition period in Vietnam.

Adolescent↗

PubMed2004

Features of retinal arterial macroaneurysms in patients with uveitis.

AIM: To determine the frequency and clinical characteristics of retinal arterial macroaneurysms in patients with uveitis. METHODS: A retrospective review of the clinical, photographic, and angiographic records of 1007 patients with uveitis, examined at the Osaka University Hospital uveitis clinic between January 1995 and April 2002, was performed. All of the records were examined to determine whether macroaneurysms were present, and when present, to determine the laterality, type, location, clinical course, and the presence of associated systemic and ocular diseases. RESULTS: Of the 1007 patients with uveitis, only 14 (1.4%) had macroaneurysms. 12 of these 14 patients had peripheral multifocal chorioretinitis (PMC), and five of these 12 were diagnosed with sarcoidosis and the other seven without sarcoidosis. There was only one case with sarcoidosis without PMC, and the remaining case was uveitis of unknown origin. There were 18 macroaneurysms in all cases and 17 (94.4%) were the exudative type, and the remaining one was the haemorrhagic type. Two patients had been treated for systemic hypertension but the others had no signs of systemic hypertension or cardiovascular disease. CONCLUSIONS: Macroaneurysms are not characteristically found in patients with uveitis, but the majority are found in patients with PMC. The majority of the macroaneurysms were the exudative type, and the conclusion is that patients with PMC should be carefully examined for exudative macroaneurysms.

Adult↗

PubMed2004

Identification of novel MUNC13-4 mutations in familial haemophagocytic lymphohistiocytosis and functional analysis of MUNC13-4-deficient cytotoxic T lymphocytes.

BACKGROUND: Familial haemophagocytic lymphohistiocytosis (FHL) has an autosomal recessive mode of inheritance and consists of at least three subtypes. FHL2 subtype with perforin (PRF1) mutation accounts for 30% of all FHL cases, while FHL with MUNC13-4 mutation was recently identified and designated as FHL3 subtype. OBJECTIVE: To examine MUNC13-4 mutations and the cytotoxic function of MUNC13-4 deficient T lymphocytes in Japanese FHL patients METHODS: Mutations of MUNC13-4 and the cytotoxicity of MUNC13-4-deficient cytotoxic T lymphocytes (CTL) were analysed in 16 Japanese families with non-FHL2 subtype. RESULTS: Five new mutations of the MUNC13-4 gene were identified in six families. The mutations were in the introns 4, 9, and 18, and exons 8 and 19. Two families had homozygous mutations, while the remaining four had compound heterozygous mutations. Cytotoxicity of MUNC13-4 deficient CTL was low compared with control CTL, but was still present. Clinically, the onset of disease tended to occur late; moreover, natural killer cell activity was not deficient in some FHL3 patients. CONCLUSIONS: MUNC13-4 mutations play a role in the development of FHL3 through a defective cytotoxic pathway.

Age of Onset↗

PubMed2004

G2 chromatid damage and repair kinetics in normal human fibroblast cells exposed to low- or high-LET radiation.

Radiation-induced chromosome damage can be measured in interphase using the Premature Chromosome Condensation (PCC) technique. With the introduction of a new PCC technique using the potent phosphatase inhibitor calyculin-A, chromosomes can be condensed within five minutes, and it is now possible to examine the early damage induced by radiation. Using this method, it has been shown that high-LET radiation induces a higher frequency of chromatid breaks and a much higher frequency of isochromatid breaks than low-LET radiation. The kinetics of chromatid break rejoining consists of two exponential components representing a rapid and a slow time constant, which appears to be similar for low- and high-LET radiations. However, after high-LET radiation exposures, the rejoining process for isochromatid breaks influences the repair kinetics of chromatid-type breaks, and this plays an important role in the assessment of chromatid break rejoining in the G2 phase of the cell cycle.

Animals↗

PubMed2004

Serum amyloid A, C-reactive protein and remnant-like lipoprotein particle cholesterol in type 2 diabetic patients with coronary heart disease.

BACKGROUND: Serum amyloid A (SAA) and C-reactive protein (CRP) have been suggested to be involved in the process of coronary heart disease (CHD) and to be potential markers and/or predictors of CHD. Remnant-like lipoprotein particles (RLPs), which are regarded as atherogenic remnant lipoprotein, are reported to be increased in type 2 diabetic patients. We assessed the association of CHD with SAA, CRP and RLP-cholesterol in type 2 diabetic patients. METHODS: One hundred and twenty-six diabetic patients without CHD and 41 patients with CHD were recruited from our hospital. Plasma SAA was measured by the latex agglutination nephelometric immunoassay. Plasma high-sensitivity CRP was measured by a latex immunoturbidity method. Plasma RLP-cholesterol was measured by an immunoabsorption enzyme method. RESULTS: The mean standard deviation values of RLP-cholesterol in patients with and without CHD were 0.22 (0.26) mmol/L and 0.15 (0.10) mmol/L, respectively (P <0.05). Median (interquartile ranges) for SAA in patients with and without CHD were 7.4 (4.2-11.2) mg/L and 3.9 (2.2-5.9) mg/L, respectively (P <0.001). Median (interquartile ranges) for CRP in patients with and without CHD was 1.14 (0.45-2.08) mg/L and 0.43 (0.19-1.25) mg/L, respectively (P <0.001). For all patients, the Spearman rank correlation statistics for RLP-cholesterol compared with SAA and with CRP were 0.213 (P <0.05) and 0.301 (P <0.01), respectively. CONCLUSION: These data suggest that SAA, CRP and RLP-cholesterol are increased in type 2 diabetic patients with CHD, and that the inflammatory proteins correlate with remnant lipoprotein.

Aged↗

PubMed2004

Invasive ability of Escherichia coli O18 isolated from swine neonatal diarrhea.

Neonatal diarrhea occurred at two swine breeding farms in Hokkaido. Ten piglets aged 2 to 4 days were examined. Grossly, significant changes were confined to the small intestine. The mucous membrane was muddy and thickened. The intraluminal contents from the jejunum to the colon were liquid and yellow. In the small intestine, numerous Gram-negative bacilli preferentially adhered to the apex of villi. The mucosa was erosive with villous atrophy. There were bacilli also in the lamina propria and in the cytoplasm of degenerated enterocytes. Nonhemolytic Escherichia coli strains, belonging to serogroup E. coli O18 and possessing K88 fimbriae, were isolated from the small intestine. They could not be classified into any of the diarrheagenic E. coli groups because of the absence of genes of LT, STh, STp, VT1, VT2, eae, invE, and ipaH. After inoculation of the isolates on HEp-2 cells, some bacilli were engulfed by cytoplasmic projections resembling membrane ruffles and subsequently were localized in cytoplasmic vacuoles or free in the cytoplasm. These findings support the view that the present E. coli O18 is a new invasive strain enteropathogenic to piglets.

Agglutination Tests↗

PubMed2004

[Postoperative temporal elevation of tumor marker in primary lung cancer patients].

Serum tumor marker measurement in addition to radiological examination is useful to detect postoperative recurrence and metastasis. Surgically treated 8 primary non-small cell lung cancer patients who showed negative serum tumor marker postoperatively elevated their markers temporally. Five of the 8 patients did not show recurrence or metastasis in their last confirmation days. These 5 patients had inflammatory disease when the postoperative marker became positive temporally. Remaining 3 patients did not have inflammatory disease when the marker elevated temporally. The marker of the 3 patients became negative again, however, the 3 patients showed recurrence or metastasis during 1 year after temporally elevated day. In conclusion, if there is no inflammatory disease when the negative marker becomes positive temporally, the recurrence or metastasis may be observed during 1 year after temporally elevated day. And when the recurrence or metastasis is observed radiologically, the marker may become negative.

Adult↗

PubMed2004

[Operation on acute type A aortic dissection using transapical aortic cannulation].

We experienced a case of operation for acute type A aortic dissection using transapical aortic cannulation (TAC). A 62-year-old male with chest and back pain admitted to our hospital. The chest computed tomography (CT) showed the dissection of total aorta. Hemiarch repair (circulatory arrest time: 64 min, pump time: 152 min) was performed by cardiopulmonary bypass (CPB) established with bicaval cannulation and TAC in this case. The reason why we use TAC is that retrograde perfusion by femoral artery has a high-risk of malperfusion and cerebral embolism because of atheromatous change in aorta, and the use of the axillary artery can be troublesome because of the vessel's small diameter. We considered that in cases of acute aortic dissection, TAC is much safer and simpler than femoral or axillary cannulation.

Acute Disease↗

PubMed2004

[Chest wall epithelioid sarcoma].

Two relatively rare cases of epithelioid sarcoma located in the chest wall are reported herein. The first was a tumor, 3.8 x 5.5 x 2.4 cm in size, originating in the left erector spinae muscle of a man 64 years of age. He experienced local recurrence 3 times even after wide resections, and he died of systemic metastasis 22 months after the initial surgery. The second was a tumor, 2.2 x 2.0 x 1.5 cm in size, originating in the left seventh intercostal muscle of a woman 24 years of age. A metastatic tumor occurred in the same muscle, and wide resection including the seventh and eighth intercostal muscles was performed. There has been no recurrence for 1.5 years since surgery. Metastasis of chest wall epithelioid sarcoma in the muscle in which the primary lesion resides should be considered, even if the primary lesion is small.

Adult↗