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Biomedical subjects

Shigehiro Sato

Publications and source records attributed to Shigehiro Sato.

12 recordsLinked to original sources

[Study on pollutant pathway of norovirus contamination in oysters].

Noroviruses (NVs) cause human gastroenteritis through person-to-person transmission and via contaminated foods. In food poisoning, a major suspected cause is the consumption of raw oysters. We detected NVs from environmental water and oysters around a closed gulf where oysters are cultivated. We collected oyster and water samples once or twice a month for 30 months from October 2001 to March 2004. We then studied monthly changes in virus occurrence and in genetic relationships among 208 NVs isolated from water and oyster samples and from the feces of children suffering from acute gastroenteritis during the same period in the same region. In the analysis of untreated water flowing into farm sewage, NVs were detected year round. In other water samples -processed sewage, river water, and seawater-, oysters, and children's feces, NVs were detected mainly in winter. A comparison of NV nucleotide sequences showed genetic diversity, but some strains predominated in certain winter seasons. These predominant strains were detected across sample materials. In 2002/03, an identical strain was detected in sewage, river water, seawater, oysters, and feces. We also found that NV genetic types changed at the beginning of the season, in November or December, in both 2001/02 and 2002/03. This study showed a clear relationship between NVs detected in children's feces and those in environmental water and oysters. These results support the idea that NVs are transmitted from the feces of infected persons to oysters by the flow of water through farm sewage, rivers, and the sea, finally accumulating in the mid-gut gland of oysters.

Animals↗

[Serum anti-lPS antibody production in an outbreak of enterohemorrhagic Escherichia coli O157 infection among schoolchildren].

Although there have been many reports of the usefulness of serodiagnosis of enterohemorrhagic Escherichia coli (EHEC) O157, the serotype of the bacteria detected and the increase in anti-LPS antibody have not always been consistent. In this study we investigated the diagnostic significance of measurements of anti-LPS antibody by ELISA in an outbreak of O157 infection among schoolchildren in whom the bacteriological test findings were clarified and the age groups were uniform. The anti-LPS antibody titer was measured in 31 patients (77 serum samples) in an outbreak of EHEC O157 : H7 infection (220 children infected) that occurred in a primary school in Morioka in 1996. The anti-O157 LPS antibody positivity rates of IgM, IgG, and IgA were 98.7%, 85.7%, and 98.7%, respectively. Between the time the meal that caused the outbreak and 19 days later, anti-O157 LPS IgM antibody and IgA antibody were detected in all patients. The specificity was investigated using control serum, and the specificity of IgM, IgG, and IgA was 93.5%, 93.5%, and 97.2%, respectively. Some samples contained antibodies against O111 and O26 LPS, but the titers were lower than the anti-O157 antibody titer. The anti-O111 antibody titer and anti-O26 antibody titer were highly correlated, suggesting that they were crossreactive antibodies for O157 LPS. No significant correlation was found between differences in clinical manifestations and the anti-O157 LPS antibody titer in this O157 outbreak in schoolchildren. It was clarified that an increase in anti-LPS antibody was found to support the diagnosis of mild cases of 0157 infection infection as well as severe cases.

Antibodies, Bacterial↗

Compact monochromatic flash x-ray generator utilizing a disk-cathode molybdenum tube.

The high-voltage condensers in a polarity-inversion two-stage Marx surge generator are charged from -50 to -70 kV by a power supply, and the electric charges in the condensers are discharged to an x-ray tube after closing gap switches in the surge generator with a trigger device. The x-ray tube is a demountable diode, and the turbo molecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Clean molybdenum Kalpha lines are produced using a 20 microm-thick zirconium filter, since the tube utilizes a disk cathode and a rod target, and bremsstrahlung rays are not emitted in the opposite direction to that of electron acceleration. At a charging voltage of -70 kV, the instantaneous tube voltage and current were 120 kV and 1.0 kA, respectively. The x-ray pulse widths were approximately 70 ns, and the generator produced instantaneous number of Kalpha photons was approximately 3 x 10(7) photons/cm2 per pulse at 0.5 m from the source of 3.0 mm in diameter.

Animals↗

Homologous and heterologous antibody responses to lipopolysaccharide after enterohemorrhagic Escherichia coli infection.

To evaluate antibody responses against lipopolysaccharide (LPS: O157, O26, and O111) in enterohemorrhagic Escherichia coli(EHEC) infection, sera of 24 schoolchildren associated with the Morioka outbreak in 1997 and of 74 sporadic patients suspected of having EHEC infection were examined. Using a positive standard serum, quantitative evaluation of LPS antibodies by an enzyme-linked immunosorbent assay (ELISA) was established. High levels of specific IgM and IgA antibodies against homologous E. coli LPS were present in the acute period and are characteristic of EHEC. This could be used for the serological diagnosis of EHEC infection, except for early infants and the elderly. In addition to the specific homologous response, multiple antibody responses against different serotypes other than those isolated were demonstrated in many cases by qualitative analysis using Western blotting.

Adolescent↗

Demonstration of enhanced K-edge angiography using a cerium target x-ray generator.

The cerium target x-ray generator is useful in order to perform enhanced K-edge angiography using a cone beam because K-series characteristic x rays from the cerium target are absorbed effectively by iodine-based contrast mediums. The x-ray generator consists of a main controller, a unit with a Cockcroft-Walton circuit and a fixed anode x-ray tube, and a personal computer. The tube is a glass-enclosed diode with a cerium target and a 0.5-mm-thick beryllium window. The maximum tube voltage and current were 65 kV and 0.4 mA, respectively, and the focal-spot sizes were 1.0 x 1.3 mm. Cerium Kalpha lines were left using a barium sulfate filter, and the x-ray intensity was 0.48 microC/kg at 1.0 m from the source with a tube voltage of 60 kV, a current of 0.40 mA, and an exposure time of 1.0 s. Angiography was performed with a computed radiography system using iodine-based microspheres. In coronary angiography of nonliving animals, we observed fine blood vessels of approximately 100 microm with high contrasts.

Angiography↗

Augmentation effects of lymphocyte activation by antigen-presenting macrophages on FDG uptake.

OBJECTIVE: Research on FDG-uptake by blood cells has revealed that FDG is incorporated by macrophages and granulocytes, as well as activated lymphocytes. These characteristics of FDG suggest the possibility of visualizing the distribution of immunocytes in target organs. The aim of this study was to investigate if mouse spleen-derived lymphocytes, activated by macrophages presenting sheep red blood cell (sRBC) antigens, could be traced by FDG. METHODS: One percent of a sRBC suspension was injected into the peritoneal cavity of mice thereby creating immunity to the sRBC antigen. The splenocytes, consisting mostly of lymphocytes, were isolated, and serum containing the anti-sRBC antibody was mixed with sRBC to prepare sRBC-antibody complexes (sRBC-AbCs). Then five percent of a thioglycolate medium was injected into the peritoneal cavity of the same mice, and macrophages of ascitic cell origin were obtained. These macrophages were added to the sRBC-AbCs to induce sRBC antigen presenting macrophages. These were incubated with splenocytes obtained from sRBC immunized mouse (sRBC immunized splenocytes) or non-immunized splenocytes to induce a T cell immune response. [3H]deoxyglucose ([3H]DG) and FDG were incorporated in splenocytes, and the quantity of their uptake was measured. RESULTS: [3H]DG uptake by sRBC-immunized splenocytes was about eleven times as high as that of non-immunized splenocytes. In contrast, [3H]DG uptake by sRBC-immunized splenocytes, co-cultured with macrophages phagocytizing sRBC-AbCs, was about 40 times higher compared with non-immunized splenocytes. Splenocytes in non-immunized mice picked up very little [3H]DG, despite co-culture with macrophages phagocytizing sRBC-AbCs. Similar tendencies were observed with FDG. CONCLUSIONS: These results suggest that the SUV calculated in PET reflects not only the number of lymphocytes, but also the activation state of the lymphocytes themselves. In addition, the biodistribution of antigen specific lymphocytes, that have been taken up FDG in vitro and returned to the body, can be observed through PET.

Adult↗

Examination of soluble Fas (sFas) and soluble Fas ligand (sFasL) in patients with burns.

The FasL-Fas system is one of the recognized apoptosis-inducing systems, and has been determined to have important functions in relation to homeostasis and biological defense mechanisms. In this study, we investigated the serum levels of soluble Fas (sFas), soluble FasL (sFasL) and tumor necrosis factor alpha (TNF-alpha) in patients with burns. The sFas levels were found to be significantly higher in the patients who eventually died as compared to those in the patients who survived (3.9+/-1.8ng/ml versus 2.6+/-1.0ng/ml). On the other hand, the sFasL levels were significantly higher in the patients who survived (61.5+/-29.9ng/ml versus 37.2+/-14.4ng/ml) than in those who eventually died. A positive correlation was noted between the TNF-alpha level and the sFas level, and a negative correlation was observed between the TNF-alpha level and the sFasL level. These findings suggest that worsening of the condition of a burns patient may be related to changes in the Fas-FasL system.

Adult↗

Matrix metalloproteinase-1 and cytokines in patients with acute pancreatitis.

INTRODUCTION: Hypercytokinemia is known to occur in severe acute pancreatitis, suggesting that the production, deposition, and degradation of the extracellular matrix (ECM) occur actively as a result of the actions of the complicated cytokine network. AIMS AND METHODOLOGY: To examine the influence of cytokines and growth factors on the ECM in acute pancreatitis from the points of view of the severity of the disease, the complication of multiple organ dysfunction syndrome (MODS), and the prognosis, 25 patients with acute pancreatitis were divided into three groups according to the severity of the condition as assessed by the Ranson score. The serum levels of matrix metalloproteinase (MMP)-1, tissue inhibitor of metalloproteinases (TIMP)-1, the MMP-1.TIMP-1 complex, tumor necrosis factor (TNF)-alpha, and transfer growth factor (TGF)-beta1 were determined by enzyme-linked immunosorbent assay. RESULTS: Comparison of the three groups divided according to the severity of the disease revealed significant differences in the levels of MMP-1 and TNF-alpha among the three groups, with the levels being higher in patients with more severe disease. The TIMP-1/MMP-1 ratio and the TGF-beta1 levels were found to be significantly lower in patients with more severe disease. Comparison between the group with the complication of MODS and the group without the complication showed that the levels of MMP-1, the MMP-1.TIMP-1 complex, and TNF-alpha were significantly higher in the former group than in the latter group. The TIMP-1/MMP-1 ratio and the TGF-beta1 levels were significantly lower in the group with the complication of MODS than in the group without the complication. Comparison between the nonsurvivor group and the survivor group revealed significantly higher levels of MMP-1, TIMP-1, and TNF-alpha in the nonsurvivors than in the survivors. The TIMP-1/MMP-1 ratio and the TGF-beta1 levels were significantly higher in the survivors than in the nonsurvivors. A significant correlation was observed between MMP-1 levels and TNF-alpha levels. On the other hand, a significant negative correlation was noted between MMP-1 levels and TGF-beta1 levels. CONCLUSION: The results of our study suggest that the activity of the ECM catabolic enzyme MMP-1 and cytokines are related to the development of acute pancreatitis.

Acute Disease↗

A silkworm larvae plasma test for detecting peptidoglycan in cerebrospinal fluid is useful for the diagnosis of bacterial meningitis.

The silkworm larvae plasma (SLP) test has been established based on a cascade reaction triggered by either peptidoglycan or (1, 3)-beta-D-glucan to produce melanin. We applied this test to the diagnosis of bacterial meningitis. Cerebrospinal fluid (CSF) obtained from patients with bacterial meningitis due to gram-positive bacteria, gram-negative bacteria, or fungi, showed positive reactions to the test. In contrast, CSF from patients with viral meningitis or noninfectious illnesses gave negative reactions. Therefore, this test seems to be useful for diagnosis of bacterial and fungal meningitis. When this test was used together with two types of limulus tests, an endotoxin-specific test, and a conventional test, meningitis was further characterized as gram-positive, gram-negative or fungal meningitis. The SLP test requires a computerized instrument for quantitative colorimetric measurement. A qualitative alternative of this test also can be accomplished by visually observing the darkening color. Thus, this method can be applied for simple and rapid diagnosis of meningitis.

Adolescent↗

First report of CRF03_AB recombinant HIV type 1 in injecting drug users in Ukraine.

It has been reported that subtypes A throughout H of HIV-1 are circulating in the former Soviet Union. In this sequence note, we analyzed the genetic prevalence of HIV-1 among injecting drug users (IDUs) in Ukraine. The subjects studied included two individuals from Kiev and six individuals from Simferopol', the latter located in the Crimean Peninsula. We found that one of eight IDUs was infected with a CRF03 gagA/envB recombinant HIV-1 and was from Simferopol', whereas the others were infected with HIV-1 subtype A. There combinant was closely related to other A/B recombinants reported previously, and had silent mutations Inthe V3 region, the same as other envB strains of HIV-1 circulating among mDUs in the former Soviet Union. The data supported reports that the Russian AIB recombinant HIV-1 was probably from Ukraine. This is the first report of a CRF03 gagA/envB recombinant HIV-1 found in Ukraine.

Amino Acid Sequence↗

Surfactant protein A and D (SP-A, AP-D) levels in patients with septic ARDS.

The levels of surfactant protein-A (SP-A) and surfactant protein-D (SP-D) in the serum of patients with septic acute respiratory distress syndrome (ARDS) were determined. Patients with sepsis without ARDS were examined as controls. The mean serum SP-A level in the former group was 37.6 +/- 16.2 ng/ml and in the latter group was 31.8 +/- 9.6 ng/ml. The difference between the two groups was not statistically significant. The maximum serum SP-D level was 83.0 +/- 33.9 ng/ml in the control group of patients without ARDS, and 476.3 +/- 391.2 ng/ml in the patients with ARDS. The level in the latter population was significantly higher than that in the former population. No significant correlation was observed between the SP-A and SP-D levels. These results suggest that the serum SP-D levels may serve as a good diagnostic indicator of ARDS in patients with sepsis.

Aged↗