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Y Tsuchida

Publications and source records attributed to Y Tsuchida.

At least 73 records · Page 4Linked to original sources
PubMed1998

Cytotoxic effect of accelerated carbon beams on glioblastoma cell lines with p53 mutation: clonogenic survival and cell-cycle analysis.

PURPOSE: The cytotoxic effect of high-LET carbon beams was analysed on p53 mutant and wild-type glioblastoma cell lines. MATERIALS AND METHODS: Three glioblastoma (U251MG, TK-1, A-172) cell lines, one medulloblastoma (ONS-76) and one fibroblast cell line (NB1RGB) were used. U251MG and TK-1 have mutated p53, A-172, ONS-76 and NB1RGB have wild-type p53. Gamma-ray and 290 MeV/u carbon mono-peak beams with average LET values of 20, 40, 81 and 105keV/microm were used. Cytotoxicity was measured by clonogenic survival assay and DNA histograms were analysed by flow cytometry. RESULTS: The RBE values for carbon beams at D10 ranged from approximately 1.5-1.7 (20keV) to 2.9-3.1 (105keV). Although p53 mutants were more resistant than wild-types for all radiation qualities, carbon beams yielded a higher RBE in p53 mutants than in wild-types. Alpha values were significantly smaller in p53 mutants than wild-types for gamma- and 20 keV/microm radiations, while no significant difference was noticed for LET greater than 40 keV/microm. A G1 block was noticed after irradiation with gamma-rays and carbon beams of 20 and 40keV/microm in p53 wild-types. A more pronounced G2 block occurred in p53 mutants than wild-types in proportion to LET up to 105 keV/microm. CONCLUSION: Accelerated carbon beams can yield higher RBE in gamma-resistant glioblastoma cell lines with p53 mutations. High-LET irradiation induces not only disappearance of the p53-dependent G1 block but also a greater G2 block in glioblastoma cell lines.

Cell Cycle↗
PubMed1998

Changes in hemodynamics in jejunal flaps of rabbits due to ischemia, venous congestion, and reperfusion as measured by means of colored microspheres.

The effect on the jejunal hemodynamics of restoration of blood flow of the jejunal artery or vein in the free jejunal flap has not yet been elucidated. In the present study, a model of ischemia and reperfusion in the jejunal flap of rabbits, and that of venous congestion and reperfusion, were prepared. Jejunal blood flow was measured by means of colored microspheres, and changes in jejunal blood flow were analyzed. Three segmental jejunal flaps were designed on each rabbit (n = 16), with one artery and one vein kept intact. Arterial clamp and venous clamp groups were prepared with a control group in which there was no clamping. After clamping for 5 minutes (n = 7), the jejunal blood flow of the arterial clamp group decreased to 1.6 percent of that of the control group (p = 0.0002), and that of the venous clamp group decreased to 31.2 percent of that of the control group (p = 0.0041). At 5 minutes after release of clamping, the jejunal blood flow of the arterial clamp group recovered to only 74.1 percent of that of the control group, with no consistent tendency; that of the venous clamp group recovered to 45.9 percent of that of the control group (p = 0.0194), with an increase of only 14.7 percent over that of the clamped jejunal blood flow group. Thus, injury of the jejunal hemodynamics in the venous clamp group had already begun in response to clamping for 5 minutes. After clamping for 30 minutes (n = 9), the jejunal blood flow of the arterial clamp group decreased to 4.3 percent of that of the control group (p = 0.0060), and that of venous clamp group decreased to 12.5 percent of that of the control group (p = 0.0106). At 5 minutes after release of clamping, jejunal blood flow of the arterial clamp group recovered to 171.0 percent of that of the control group (p = 0.0295), and that of venous clamp group recovered to 41.7 percent of that of the control group (p = 0.0276). Jejunal blood flow of the arterial clamp group recovered to 409.7 percent of that of the venous clamp group (p < 0.0001). When measurement of jejunal blood flow was repeated twice after changing the color of microspheres, jejunal blood flow of the second measurement was approximately 24 percent greater in mean value than that of the first measurement. The histologic results of the jejunum of the arterial clamp group clamped for 30 minutes showed no injury, which was similar to the results of the control group. The jejunum of the venous clamp group clamped for 5 minutes showed injury with severe hemorrhage in the lamina propria, and irreversible injury 30 minutes thereafter, with massive hemorrhage in all layers of the jejunal wall. In conclusion, as microcirculatory hemodynamics and histologic results of the jejunum demonstrated evidence of injury even by venous congestion for 5 minutes, restoration of blood flow of the free jejunal flap must be started from the jejunal vein.

Animals↗
PubMed1998

Effect of autotransplantation of microvessel fragments on experimental random-pattern flaps in the rat.

We examined whether autotransplantation of microvessel fragments (Mvf) and/or myofibroblasts (Mf) into an in vivo skin flap model might improve the survival of the ischemic flap. If so, this could improve blood perfusion, increase blood flow, and improve the survival of the flap. A skin flap was raised on the back of each rat (n = 15 in each group). In the control group, the flap was sutured to the original bed. In the other groups (1) phosphate-buffered saline; (2) autotransplanted Mvf, Mf, or Mvf plus Mf, and (3) a homogenized mixture of Mvf plus Mf was injected into the distal part of the flap. In a further group, Mvf labeled with DiI-acetylated low-density lipoprotein were autotransplanted with Mf into the distal part of the flap, and India ink was perfused through the abdominal aorta 7 days postoperatively. The transplanted Mvf plus Mf group showed better flap survival after 7 days than the other groups (p < 0.02). Labeling with DiI-acetylated low-density lipoprotein showed that transplanted Mvf sent arborizations into the nearby tissue. India ink was found in the lumina within such arborizations. Thus, autotransplanted Mvf may improve the survival of ischemic skin flaps by promoting the early formation of patent connections between Mvf and the host's microcirculatory system. This apparently requires the presence of Mf.

Animals↗
PubMed1998

[TNM classification--pediatric tumors].

The clinical and postsurgical TNM classifications (cTNM and pTNM) for neuroblastoma (NB), nephroblastoma (WT) and soft tissue sarcomas were presented in 1982 by the TNM Committee in UICC in collaboration with SIOP. The Japanese TNM Committee proposed new pTNM systems (J-pTNM) for NB and WT, and new cTNM and pTNM system for primary liver carcinoma in infants and children (HT). These pTNMs were based on the staging systems developed by the Malignant Tumor Committee of the Japanese Society of Pediatric Surgeons. The proposal of subdivision of M category in NB was presented for testing the new telescopic ramifications of TNM. The TNM for HT was added as a new classification recommended for testing. The effectiveness of these TNM systems was assessed using NB, WT and hepatoblastoma (HB) cases which were registered in collaborating institutes. The analyses suggested that pTNM, especially the J-pTNM system in NB, WT and HT were effective for the assessment of prognoses, although cTNM systems were not enough to assess the extent of the disease.

Child↗
PubMed1997

Extensive genetic heterogeneity in the neuroblastoma cell line NB(TU)1.

A neuroblastoma cell line displaying genetically unique features was established from a stage III case of a 20-month-old girl. Southern blotting by the probe pTNB6, which contains exon 1 of the N-myc gene, showed that the primary tumor had in total 4 aberrant bands beside the normal amplified band. The established cell line NB(TU)1 had an aberrant N-myc band (9.0 kb) in addition to the normal band (2.9 kb). Cytogenetic analysis revealed that NB(TU)1 has a composite karyotype composed of at least 7 related karyotypes, which are pseudo-diploid and contain complex chromosomal abnormalities, including translocations, deletions and homogeneously staining regions (HSRs). Such extensive abnormalities were considered to be prominent among known neuroblastoma cell lines, and it was suggested that NB(TU)1 had acquired a certain type of genetic instability. Analysis of N-myc bands in 11 clones of NB(TU)1 showed that the intensity ratio of the normal-sized band (2.9 kb) and the aberrant one (9.0 kb) markedly varied among clones. Moreover, 3 clones showed an additional band with the size of 3.7 kb, which was detectable neither in the parent NB(TU)1 nor in the primary tumor. Thus, NB(TU)1 was shown to be composed of heterogeneous cell components. To further detect such ongoing chromosomal instability, we examined micronuclei formation. NB(TU)1 yielded a larger number of micronuclei than 5 other neuroblastoma cell lines. We conclude that NB(TU)1 has acquired genetic instability detectable by both Southern blotting and cytogenetic analysis.

Abdominal Neoplasms↗
PubMed1997

Isolation of radiosensitive and radioresistant mutants from a medulloblastoma cell line.

Two mutant clones, one radiosensitive (OS-3) and one resistant (OR-5), were isolated from ONS-76 after screening 2400 clones by the replica micro-well technique. These two clones exhibited significantly different radiosensitivity, with D37 values of 4.7Gy in OR-5 and 1.7Gy in OS-3. After gamma irradiation (8Gy), OR-5 exhibited greater G2 arrest than sensitive clone OS-3. Administration of 5mM of caffeine resulted in greater cell killing in OR-5 than in OS-3, with an almost complete release of G2 block. These observations support the notion that the G2 block contributes to the repair process of DNA damage after irradiation. The present results suggest that clones with a large postirradiation G2 block may show a greater reduction in radiosensitivity if the G2 block is released artificially. The study of the mutant clones described herein may provide important clues to the mechanism by which glioma cells acquire radioresistance.

Caffeine↗
PubMed1997

Evaluation of an extracorporeal membrane oxygenation system using a nonporous membrane oxygenator and a new method for heparin coating.

A new heparin binding method was applied to a miniature extracorporeal membrane oxygenation (ECMO) system with a nonporous membrane oxygenator (the priming volume, 45 mL; the membrane surface area, 0.4 m2; maximal flow rate, 2 L/min) that is resistant to plasma leakage. The authors evaluated the stability of the immobilized heparin in vitro and the feasibility of this system in animals. Samples of hollow fibers and tubing were rinsed at 40 degrees C for 4 days in normal saline, Ringer's lactate, and 1 mol/L NaCl solution. Heparin activities on hollow fibers after rinsing were 99 +/- 2.3% (mean +/- SD), 96 +/- 3.9%, and 93 +/- 2.0% of the control in each solution, while those of the tubing were 87 +/- 4.1%, 86 +/- 3.1%, and 76 +/- 8.6%, respectively. Veno-arterial ECMO using this heparin-coated system was performed on five beagles (8 to 12 kg) for 10 hours. Neither major thrombus formation nor plasma leakage was detected during the procedure in spite of a low flow rate (300 mL/min) and a reduced activated clotting time (mean, 128 seconds). Platelets decreased to 52% of the control (P < .01) at 1 hour, but no progressive decrease was seen thereafter. Antithrombin-III decreased (P < .01) and thrombin/antithrombin III complex increased (P < .05 at 4 hours and P < .01 at 6, 8, and 10 hours) during bypass, but the changes of fibrinogen and fibrinopeptide A were not significant. Fibrinogen/fibrin degeneration products, fibrinopeptide B beta 15-42, and plasma-free hemoglobin levels did not rise significantly. O2 transfer of the oxygenators at a flow rate of 300 mL/min were 12.3 +/- 0.4 mL/min at 30 minutes, 14.3 +/- 1.2 mL/min at 5 hours, and 14.7 +/- 1.7 mL/min at 10 hours (no statistical difference). Histological examination of the brains and the kidneys showed no evidence of thromboembolic sequela in any of the animals. These results suggest that this new system is a promising device for long-term ECMO in which the amount of systemic heparinization can be reduced with the minimal possibility of plasma leakage.

Animals↗
PubMed1997

Histopathologic findings of advanced neuroblastoma after intensive induction chemotherapy.

BACKGROUND: Histopathologic findings of advanced neuroblastoma after intensive induction chemotherapy have not been studied well. METHODS: In the present study, all of the surgical specimens from 19 patients who had advanced abdominal neuroblastoma and were pretreated intensively with the protocol of the Study Group of Japan were reviewed. The authors found that dissection of the contralateral lymph nodes is mandatory in advanced neuroblastoma when the goal is the complete dissection of the abdominal disease. Effects of chemotherapy were graded histologically according to the ratio of viable residual neuroblastoma tissue to total areas of the tumor, including neuroblastoma, ganglioneuroblastoma, ganglioneuroma, hemorrhage, necrosis and fibrosis, in five ranks from ( ) to (-). CONCLUSIONS: The newly introduced, highly cytotoxic regimen of the Japanese protocol, designated "A3," appears to be more effective histologically than the conventional regimen, designated "A1" or "new A1." Effects designated ( ) or (++) were prerequisites for survival in stage IV disease, but some stage III patients with the (+) effect survived.

Abdominal Neoplasms↗
PubMed1997

A peculiar form of multiple cystic dilatation of the intrahepatic biliary system found in a patient with biliary atresia.

The authors report a peculiar form of intrahepatic multiple cysts of the biliary system in a patient with biliary atresia (BA). An 11-year-old girl was admitted to our institution to be investigated for repeated cholangitis occurring after the age of 10 years. She underwent a hepaticojejunostomy, caused by Type I (cyst-type) BA, in the neonatal period. The radiological examination results showed multiple cystic dilatation of the intrahepatic biliary system with a vascular structure protruding into the cyst lumen. Such cystic dilatation with a protruding vascular structure has been noted in patients with Caroli's disease and congenital hepatic fibrosis, and ductal plate malformation is shown to be responsible for the cyst formation. The authors postulate that such malformation of the intrahepatic biliary system is related to the cyst formation in our case.

Bile Ducts, Intrahepatic↗
PubMed1997

Further experience with the antireflux valve to prevent ascending cholangitis in biliary atresia.

BACKGROUND/PURPOSE: The intussusception-type antireflux valve is a mechanism introduced by Nakajo, who reported the results of his initial 17 cases in 1990. This report summarizes our further experience with new patients, together with follow-up results of the cases previously reported by Nakajo. METHODS: In total, 46 new patients who had biliary atresia underwent portoenterostomy at the authors' two units. The authors hoped to construct the intussuscepted antireflux valve in the Roux-en-Y loop, whenever possible, at the time of hepatic portoenterostomy. RESULTS: Among the 46 patients, one case each was found to be too young or too old to have the valve constructed during the surgery. In another case, the Roux-en-Y loop became too short after repeated revisions of the portoenterostomy. In another patient, the valve was first constructed but later removed because of jejunal perforation near the valve. In the last patient, the valve was not constructed for unspecified reasons. The authors constructed the antireflux valve in 42 patients, but it was maintained in 41. In one case, the valve truly prevented reflux of the intestinal juice during an episode of intestinal obstruction. The valve was found to be incompetent in one patient 5 years after the initial surgery. CONCLUSION: The incidence of cholangitis was high in patients with postoperative cystic dilatation of the intrahepatic bile ducts, and low in those without it.

Biliary Atresia↗
PubMed1997

The role of subfractionation of alpha-fetoprotein in the treatment of pediatric surgical patients.

Subfractionation of serum alpha-fetoprotein (AFP) is a useful method to discriminate between yolk sac tumors, hepatic malignancies, and benign liver diseases in adults but has not been validated in infants and children. AFP subfractionation was performed on AFP-positive sera from 73 infants and children. AFP subfraction profiles were classified into three common types: (1) yolk sac type, (2) hepatoblastoma type, and (3) benign hepatic type, according to the reactivity of individual AFP samples to lectins. In 68 of 73 samples (93.2%), AFP subfraction profiles were accurately classified into these three types, and an atypical AFP subfraction profile resembling the hepatoblastoma type was found in sera from five infants (6.8%). Differentiation between hepatoblastoma and hepatitis when patients are very young can be difficult. Subfractionation is more accurate when patients are older. This technique was found to be useful in the diagnosis of neonatal ovarian tumors, in recurrent hepatoblastoma/ yolk sac tumor with low serum AFP, and in the differential diagnosis of hepatic mass (malignancy versus hyperplastic nodule) in the liver with long-standing cholestasis. Estimation of serum AFP subfraction profiles facilitates the differential diagnosis of various AFP-positive pediatric diseases, such as hepatoblastoma, hepatoma, hepatitis or germ cell tumors. This test is inexpensive, can be carried out within 48 hours, and should be performed for the differential diagnosis of pediatric liver disease.

Adolescent↗
PubMed1997

The relationship between disturbed transit and dilated bowel, and manometric findings of dilated bowel in patients with duodenal atresia and stenosis.

To determine whether dilated bowel proximal to obstruction associated with duodenal atresia and stenosis is related to feeding problems after a surgical correction of obstruction, the authors reviewed retrospectively the degree of bowel dilatation and disturbed transit as well as other clinical features in 18 duodenal atresia and 12 duodenal stenosis patients. A multivariate analysis was conducted to determine the possible correlation among them. The authors also evaluated the physiological function of the dilated bowel in duodenal atresia and stenosis patients (n = 8) by manometry of dilated bowel. The results were as follows. (1) In multivariate analysis, using the degree of disturbed transit as a dependent variable and using other clinical features as independent variables, the presence of postoperative complication and the existence of bowel dilatation 2 weeks after the operation were risk factors for disturbed transit. (2) One or two episodes of phase 3 were found in six of eight measured patients during the recorded period. The most distinctive manometric finding was the low contraction amplitude of both phase 2 and phase 3. These results indicate that dilated bowel was related to disturbed transit during the postoperative period, and that the low contraction amplitude of the dilated bowel was the main pathophysiological feature. The tapering or plication of dilated bowel might be indicated in patients with a markedly dilated bowel.

Constriction, Pathologic↗
PubMed1997

Limb allografts in rats treated with anti-ICAM-1 and anti-LFA-1 monoclonal antibodies.

This study examined whether administration of anti-ICAM-1 mAb (monoclonal antibody) and anti-LFA-1 mAb were effective for inhibition of the acute rejection reaction in a rat-limb allograft model. The grafts were carried out using major histocompatibility complex mismatch pairs of rats: ACI rats as the donors and Lewis rats as the recipients. The subjects were of species with completely different major histocompatibility complexes. The average length of survival in this combination was 4.7 +/- 0.6 days. When anti-ICAM-1, anti-LFA-1 mAb, or a combination of both were administered intraperitoneally at 1 mg/kg body weight daily for 7 days after the graft, the mean survival times were 4.3 +/- 0.6, 4.7 +/- 0.6, or 4.7 +/- 0.6 days, respectively. The agents were found to exercise no beneficial effects for transplants. Transplants were then carried out with a single intramuscular administration of FK506 at 3mg/kg body weight on the day of the operation to observe the effect of this adjunct therapy. The mean survival time averaged 16.0 +/- 5.5 days with FK506 alone. Administration of anti-ICAM-1, anti-LFA-1, and both antibodies together with FK506 resulted in mean survival times of 15.4 +/- 3.0, 25.0 +/- 5.8 and 13.2 +/- 5.8 days, respectively. Thus, a significant prolongation of survival time was observed when the combination of anti-LFA-1 mAb and FK506 was used. In contrast, anti-ICAM-1 mAb and FK506 or both mAb and FK506 showed no beneficial effects.

Animals↗
PubMed1997

Synthesis and aromatase-inhibitory activity of imidazolyl-1,3,5-triazine derivatives.

Triamino-substituted 1,3,5-triazine derivatives were synthesized and tested for inhibitory activities against the aromatase of human placental microsomes and the cytochrome P450 side chain cleavage of cholesterol (P450SCC) of pig adrenal mitochondria. The compounds having imidazolyl and tertiary amino groups as substituents in the 1,3,5-triazine ring showed significant aromatase-inhibitory activity. Among them, compounds 17, 23, 26, 27 and 28 were more active than the reference compound, CGS 16949A. The inhibitory activities of these compounds against P450SCC were much weaker than their aromatase-inhibitory activities. These compounds may be regarded as selective aromatase inhibitors.

Adrenal Glands↗
PubMed1997

MRI findings in the liver in biliary atresia patients after the Kasai operation.

To evaluate liver function in biliary atresia (BA) patients after the Kasai operation, magnetic resonance imaging (MRI) was carried out 28 times in 19 BA patients. Sixteen of these were divided into three groups on the basis of the serum level of total bilirubin (t-bil), glutamic pyruvic transaminase (GPT) and gamma-glutamyltransferase (gamma-GTP) in the postoperative follow-up period (2-11 years). In group 1 (n = 7) the t-bil was continuously kept under 1 mg/100 ml. In group 2 (n = 4) the t-bil was continuously kept under 1 mg/100 ml, but GPT and gamma-GTP remained high (GPT > 100 IU/liter, gamma-GTP > 200 IU/ liter) for more than 2 years. In group 3 (n = 5) an increase in the t-bil level reappeared (1-2 mg/100 ml; n = 4, > 2 mg/100 ml; n = 1). The differences between MRI finding in the 3 groups, and the correlation between MRI findings and laboratory data (t-bil, cholinesterase; ChE, GPT and gamma-GTP), which were taken around the time of MRI examinations, were studied. The results were as follows: (1) All 19 patients had normal or high signal areas of various sizes on T1 weighted images (WI). (2) Eighteen of 19 patients had high signal areas of various sizes on T2 WI in the portal system areas and/or liver parenchyma, and these areas were enhanced by gadolinium-DTPA in about half of the patients. (3) Ten of 16 patients had atrophic change over one liver lobe. (4) MRI findings for group 1 and the other groups were significantly different, and MRI findings, except for atrophic change, were correlated with the increase or decrease in laboratory data taken around the time of MRI examinations (p < 0.05). These results indicate that a normal or high signal area on T1 WI shows functional tissue, and that a high signal area on T2 WI shows tissue damaged by inflammation and/or progressive fibrosis. MRI is useful for evaluating liver function, especially in terms of morphological features, in BA patients after the Kasai operation, and will be one method for establishing their prognosis.

Alanine Transaminase↗
PubMed1997

[Glucocorticoid].

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Glucocorticoids↗