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Biomedical subjects

T Shimazu

Publications and source records attributed to T Shimazu.

At least 37 records · Page 2Linked to original sources
PubMed2001

Caryophyllidean tapeworms (Platyhelminthes: Eucestoda) from freshwater fishes in Japan.

The following caryophyllidean tapeworms were found in freshwater fishes from Japan (species reported from Japan for the first time marked with an asterisk): family Caryophyllaeidae: Paracaryophyllaeus gotoi (Motomura, 1927) from Misgurnus anguillicaudatus (Cantor); Archigetes sieboldi Leuckart, 1878 from Pseudorasbora parva (Temminck et Schlegel) and Sarcocheilichthys variegatus microoculus Mori (new hosts); family Lytocestidae: *Caryophyllaeides ergensi Scholz, 1990 from Tribolodon hakuensis (Günther), T. ezoe Okada et Ikeda, Hemibarbus barbus (Temminck et Schlegel) and Chaenogobius sp. (new hosts); Khawia japonensis (Yamaguti, 1934) from Cyprinus carpio Linnaeus; K. sinensis Hsü, 1935 from H. barbus (new host) and C. carpio; *K. parva (Zmeev, 1936) from Carassius auratus langsdorfii Valenciennes in Cuvier et Valenciennes and Carassius sp. (new hosts); and *Atractolytocestus sagittatus (Kulakovskaya et Akhmerov, 1962) from C. carpio; family Capingentidae: *Breviscolex orientalis Kulakovskaya, 1962 from H. barbus (new host); and Caryophyllidea gen. sp. (probably Breviscolex orientalis) from C. carpio. The validity of C. ergensi, originally described from Leuciscus leuciscus baicalensis from Mongolia, is confirmed on the basis of an evaluation of extensive material from Japan. Atractolytocestus sagittatus (syn. Markevitschia sagittata) is tentatively considered a valid species, differing from the only congener, A. huronensis Anthony, 1958, in its considerably greater number of testes.

Animals↗
PubMed2001

A multicenter prospective randomized controlled trial of the efficacy of mild hypothermia for severely head injured patients with low intracranial pressure. Mild Hypothermia Study Group in Japan.

OBJECT: The criteria for the use of mild hypothermia (34 degrees C) in severely head injured patients have not been standardized. A prospective randomized controlled trial was conducted to determine whether mild hypothermia is essential in the treatment of severely head injured patients with low intracranial pressure (ICP). METHODS: At 11 medical centers, 91 severely head injured patients with an admission Glasgow Coma Scale score of 8 or less in whom ICP could be maintained below 25 mm Hg by conventional therapies were divided randomly into two groups: the mild hypothermia group (HT group, 45 patients) and the normothermia group (NT group, 46 patients). Patients in the HT group were exposed to mild hypothermia (34 degrees C) for 48 hours, followed by rewarming at 1 degrees C per day for 3 days, whereas patients in the NT group were exposed to normothermia (37 degrees C) for 5 days. The two groups were similar with respect to prognostic factors, and there was no difference in clinical outcome at 3 months postinjury. During treatment, there was a significantly greater use of neuromuscular blocking agents in the HT group (p = 0.011). During the initial 2 weeks postinjury, the incidences of pneumonia, meningitis, leukocytopenia, thrombocytopenia, hypernatremia, hypokalemia, and hyperamylasemia were significantly higher in the HT than in the NT group (p < 0.05). CONCLUSIONS: Mild hypothermia should not be used for the treatment of severely head injured patients with low ICP because this therapy conveys no advantage over normothermia in such patients.

Adolescent↗
PubMed2001

Genetic changes induced in human cells in Space Shuttle experiment (STS-95).

BACKGROUND: Results of past space experiments suggest that the biological effect of space radiation could be enhanced under microgravity. To assess the radiation risk for humans during long-term spaceflight, it is very important to clarify whether human cells exhibit a synergistic effect of radiation and microgravity. HYPOTHESIS: If significant synergism occurs in human cells, genetic changes induced during spaceflight may be detected by using human tumor HCT-116 cells which are hypermutable due to a defect in the DNA mismatch repair system. METHODS: Cultured HCT-116 cells were loaded on the Space Shuttle Discovery (STS-95) and grown during the 9-d mission. After landing, many single-cell clones were isolated, microsatellite repetitive sequences in each clone were amplified by PCR, and mutations in the microsatellite loci were detected as changes in the length of PCR fragments. Mutation frequencies of ouabain-resistant phenotype were also analyzed. RESULTS: The frequencies of microsatellite mutations as well as ouabain-resistant mutations in the flight sample were similar to those of the ground control samples. Some cells were treated in space with bleomycin which mimics the action of radiation, but the frequencies of microsatellite mutations were not significantly different between the flight and the ground control samples. CONCLUSION: Under the present flight conditions, neither space radiation (about 20 mSv during this mission) nor microgravity caused excess mutations in human cells.

Bleomycin↗
PubMed2000

Aggravation of chemically-induced injury in perfused rat liver by extracellular ATP.

The effects of purinergic receptor agonists on acute liver damage and hemodynamics were studied using chemically-induced liver injury. Rat livers were perfused in situ 24 h after treatment with D-galactosamine (800 mg/kg, i.p.). In these livers, infusion of ATP (50 microM) into the portal vein caused a rapid increase in the leakage of LDH and AST from perfused liver in a dose dependent manner, accompanied with flow reduction. The similar but less effective responses were also observed by the infusion of ADP. Infusion of adenosine, a P1-receptor agonist, induced only minimal changes of liver damage and flow rate. The ATP-induced changes were almost completely suppressed by P2-receptor antagonist, suramin, but not affected by P1-receptor antagonist, 8-phenyltheophylline. Pretreatment of rats with gadolinium chloride, which depletes Kupffer cells, did not inhibit the potentiation of liver damage caused by ATP, whereas hemodynamic effects of ATP were significantly attenuated by gadolinium. These results indicate that extracellular ATP aggravates acute liver injury mediated by P2-type purinergic receptors.

Adenosine Triphosphate↗
PubMed2000

Control of gravimorphogenesis by auxin: accumulation pattern of CS-IAA1 mRNA in cucumber seedlings grown in space and on the ground.

Cucumber (Cucumis sativus L.) seedlings grown in microgravity developed a peg on each side of the transition zone between hypocotyl and root, whereas seedlings grown in a horizontal position on the ground developed a peg on the concave side of the gravitropically bending transition zone. The morphological features of the space-grown seedlings were similar to those of seedlings grown in a vertical position on the ground with their radicles pointing down: both became two-pegged seedlings. Morphogenesis of cucumber seedlings is thus inhibited by gravity. Analysis by in-situ hybridization of an auxin-inducible gene, CS-IAA1, showed that its mRNA accumulated to a much greater extent on the lower side of the transition zone in the horizontally placed seedlings on the ground just prior to and during the initiation period of peg formation. On the other hand, when seedlings were grown in microgravity or in a vertical position on the ground, accumulation of CS-IAA1 mRNA occurred all around the transition zone. Accumulation of CS-IAA1 mRNA in horizontally grown seedlings appreciably decreased on the upper side of the transition zone and increased on the lower side upon gravistimulation, compared with the two-pegged seedlings. Application of IAA to seedlings in a horizontal position caused the development of a peg on each side of the transition zone, or a collar-like protuberance, depending on the concentration used. These results suggest that upon gravistimulation the auxin concentration on the upper side of the horizontally placed transition zone is reduced to a level below the threshold value necessary for peg formation. Space-grown seedlings of cucumber might develop two pegs symmetrically because the auxin level in the entire transition zone is maintained above the threshold. This spaceflight experiment verified for the first time that auxin does not redistribute in microgravity.

Cucumis sativus↗
PubMed2000

Morphogenesis in cucumber seedlings is negatively controlled by gravity.

Seedlings of most cucurbitaceous plants develop a peg (protuberance caused by cell outgrowth) on the transition zone between the hypocotyl and root. The peg is necessary for removing the seed coat after germination. In our spaceflight experiments on the STS-95 space shuttle, Discovery, we found that cucumber (Cucumis sativus L.) seedlings grown under microgravity conditions developed two pegs symmetrically at the transition zone. Thus, cucumber seedlings potentially develop two pegs and do not require gravity for peg formation itself, but on the ground the development of one peg is suppressed in response to gravity. This may be considered as negative control of morphogenesis by gravity.

Cucumis sativus↗
PubMed2000

Changes in contused lung volume and oxygenation in patients with pulmonary parenchymal injury after blunt chest trauma.

Although it is well known that pulmonary parenchymal injury impairs oxygenation, the relationship between hypoxemia and volume of the contused lung after blunt chest trauma remains unknown. We studied 23 blunt chest trauma patients who underwent thoracic computed tomography (CT) within 24 hours after admission and also underwent follow-up CT at 1-week intervals until abnormal lung findings disappeared. Contused lung volume was determined quantitatively by CT. CT findings of parenchymal injury were either a diffuse lesion that disappeared within 1 week (n = 9 patients, group 1), or a solitary lesion that remained a few weeks after resolution of the diffuse lesion (n = 14 patients, group 2). PaO2/FiO2 was positively correlated with the volume of contused lung during the first 24 hours in both groups, however, there was no significant correlation after 1 week after injury. Degree of impaired oxygenation is related to the volume of the diffuse lesion that is recognized soon after injury.

Adolescent↗
PubMed2000

Does blood type B protect against haemolytic uraemic syndrome? An analysis of the 1996 Sakai outbreak of Escherichia coli O157:H7 (VTEC O157) infection. The Osaka HUS Critical Care Study Group.

OBJECTIVES: Expression of the P1 blood type antigen is suggested to have a protective effect against post-enteropathic haemolytic uraemic syndrome (HUS). The B blood type may also protect against HUS, since terminal trisaccharide sequences similar to those of the B blood type determinants are reported to have an affinity to Vero cytotoxin that is 23% as strong as that of the P1 determinants. Thus, we studied whether ABO blood types were related to the occurrence or severity of HUS. METHODS: We obtained clinical and laboratory data of 49 HUS patients treated in 14 critical care facilities during the 1996 Escherichia coli O157:H7 outbreak in Sakai, Japan. We retrospectively studied whether ABO blood types were related to the occurrence or severity of HUS. RESULTS: The numbers of patients with blood types A, B, O or AB were 29, 8, 12, and 0, respectively. For each blood type, the number of patients with severe renal complications was 16, 6, 9, and 0, respectively. The distribution of blood types among the HUS patients deviated from a population-based distribution of blood types (P<0.05, Chi-squared test); i.e., the frequency of the A blood phenotype was significantly higher among our HUS patients. However, there was no significant difference in the frequency of patients with the A antigen (A and AB blood groups) among our HUS patients, whereas the frequency of B antigen expression was significantly lower (P<0.05, Chi-squared test). The risk of severe renal complications did not appear to be related to ABO blood types. CONCLUSIONS: Our data suggest that expression of the B antigen has a protective effect against the onset of HUS, but that it does not affect the severity of the disease.

ABO Blood-Group System↗
PubMed2000

Effect of growth hormone on brain oedema caused by a cryogenic brain injury model in rats.

Although growth hormone (GH) is a potential agent to counteract the catabolic response to general and head injuries, the complications of GH treatment have been little studied. To evaluate the safety of GH in head trauma patients, it was investigated whether GH affects brain oedema caused by brain injury, using a rat freeze-injury model. Male Wistar rats (n = 28) were divided into four groups according to the substance injected (GH vs. saline) and whether brain was injured or not. GH (0.8 IU/kg) or saline was injected subcutaneously every 24 hours. In the injury groups, immediately before the first injection of GH, an aluminum rod cooled to -50 degrees C was placed on the right parietal region for 4 minutes, under anaesthesia. At 96 hours after the insult, brain and skeletal muscle were excised and their water content was measured, by drying. Freeze injury of the brain caused an increase in water content in skeletal muscle. GH injection augmented this oedema in skeletal muscle. Freeze injury of the brain also caused an increase in water content in the injured and non-injured hemispheres of brain and cerebellum. GH administration did not exacerbate brain oedema caused by brain injury in this model.

Animals↗
PubMed2000

Difference in the responses after administration of granulocyte colony-stimulating factor in septic patients with relative neutropenia.

OBJECTIVE: The objective of this study was to classify the clinical responses after administration of granulocyte colony-stimulating factor (G-CSF) in septic patients with relative neutropenia. PATIENTS AND METHODS: We administered recombinant human G-CSF (2 microg/kg) subcutaneously once a day for 5 days to 30 septic patients with white cell counts below 5,000 cells/mm3. Absolute neutrophil count (ANC), neutrophil differentiation, and serum concentration of G-CSF were determined serially. Bone marrow also was analyzed before and after treatment. RESULTS: Neutrophil responses to G-CSF varied from good (ANC > 10,000/mm3, group G, n = 20) to moderate (ANC < 10,000/mm3, group M, n = 5) to poor (no increase in ANC, group P, n = 5). Before G-CSF administration, the three groups showed no differences in ANC but did show significant differences in serum concentration of G-CSF. G-CSF concentration was 0.16 +/- 0.03 ng/mL in group G, 7.0 +/- 3.0 ng/mL in group M, and 270 +/- 90 ng/mL in group P. Immature neutrophils accounted for 35.0 +/- 3.7% of peripheral leukocytes in group P but only 5.1 +/- 0.6% in group G. Although bone marrow was depressed in all groups before G-CSF treatment, nucleated cell count increased significantly after rhG-CSF treatment in groups G and M. Survival rate after 4 weeks was 90% in group G and 100% in group M; no patient in group P survived. CONCLUSION: G-CSF administration was effective in septic patients with a low percentage of immature neutrophils and insufficient endogenous G-CSF. It had little effect on patients with a high percentage of immature neutrophils whose G-CSF production was up-regulated and whose bone marrow was severely depressed.

APACHE↗
PubMed2000

Half-life of blood carboxyhemoglobin after short-term and long-term exposure to carbon monoxide.

BACKGROUND: In models of smoke inhalation injury and carbon monoxide poisoning blood carboxy-hemoglobin (COHb) levels decrease faster than predicted by the generally recognized half-life of COHb. We studied the effects of duration of exposure to carbon monoxide (CO) on the subsequent CO elimination. METHODS: Each of four sheep were insufflated with CO gas mixtures either for a few minutes (short-term exposure) or for several hours (long-term exposure), then ventilated with air for 3 hours. Serial COHb concentrations were analyzed by using a two-compartment, single central outlet mathematical model. RESULTS: Short-term exposures exhibited biphasic decreases of COHb concentration compatible with a two-compartment model; an initial rapid decrease (half-life 5.7 +/- 1.4 minutes) was followed by a slower phase (103 +/- 20.5 minutes). Long-term exposures exhibited almost monophasic decreases, which were nevertheless compatible with the model (half-life, 21.5 +/- 2.1 and 118 +/- 11.2 minutes). CONCLUSION: This study demonstrated different patterns of CO elimination curve, which suggests distribution of CO to two compartments having different rates of equilibration.

Administration, Inhalation↗