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Biomedical subjects

T Shibata

Publications and source records attributed to T Shibata.

At least 487 records · Page 27Linked to original sources
PubMed1995

[A case of pulmonary metastasis from colon cancer successfully treated with high-dose 5'-DFUR].

We report a case, showing a complete response to high-dose 5'-DFUR, with pulmonary metastasis from colon cancer. A 52-year-old male patient underwent right hemicolectomy for ascending colon cancer in August, 1991. A recurrence of colon cancer developed in the left lower lung 16 months after surgery, and 5'-DFUR was administered at a dose of 1,600 mg/body/day. The pulmonary metastatic lesion was undetectable on chest X-ray film 9 weeks after the start of this therapy. The dose of 5'-DFUR was then reduced to 600 mg/body/day. Although this condition was maintained for 22 weeks, chest X-ray film again showed the metastatic lesion at the same site in the lung as before. The pulmonary metastasis was resected completely in April, 1994. This is suggested to be an effective therapy for pulmonary metastasis from colon cancer.

Adenocarcinoma↗
PubMed1995

A case of unique communication between blind-ending ectopic ureter and ipsilateral hemi-hematocolpometra in uterus didelphys.

Uterus didelphys with double vagina and hemi-vaginal atresia is a rare syndrome of congenital anomalies. A 17-year-old girl had a right blind-ending ectopic ureter, the proximal end of which communicated with the ipsilateral uterine cervix of uterus didelphys. The patient presented with vaginal urinary incontinence after incision of the vaginal wall for right hemi-hematocolpometra. Following various examinations, the ipsilateral kidney was found to be absent. The ectopic ureter and communicating duct were resected, and the fistula was closed. The genesis of malformation of the female genitalia and urinary tract resulting in such a unique communication is discussed. The importance of preoperative meticulous examinations, including cysto-genitography, pelvic magnetic resonance imaging and panendoscopy with the patient under anesthesia, is emphasized.

Abnormalities, Multiple↗
PubMed1995

[Efficacy of simultaneous function and perfusion imaging on 99mTc-tetrofosmin myocardial scintigraphy].

The aim of this study was to determine whether the diagnosis for coronary artery disease (CAD) with 99mTc-tetrofosmin (Tf) myocardial scintigraphy was improved by the combination of function image and perfusion image as compared with perfusion alone. Tf myocardial scintigraphy was performed with one-day protocol (stress/rest) in 51 patients (CAD: 32, Non-CAD: 19) without previous myocardial infarction. Function image was obtained by first pass method, and perfusion image by SPECT. Number of diseased vessels was 14 in right coronary artery (RCA), 18 in left anterior descending (LAD), and 12 in left circumflex (LCX). Ischemia was diagnosed by 2 different parameters 1) perfusion image alone, 2) combination of perfusion image and regional ejection fraction (rEF). On perfusion image, accuracy was 53%, 94% and 86% in RCA, LAD, and LCX respectively. On perfusion + rEF, accuracy was 76%, 90% and 84% in RCA, LAD, and LCX respectively. Specificity in RCA was 45% on perfusion, 84% on perfusion + rEF. Sensitivity in RCA was 77% on perfusion, 54% on perfusion + rEF. LAD and LCX did not change by the addition of function image. By addition of function image, accuracy and specificity of diagnosis in area of RCA improved significantly (p < 0.01). Thus the addition of function image in Tf myocardial scintigraphy would be useful to improve the diagnosis, especially in region of RCA.

Aged↗
PubMed1995

Significance of urinary fibrin/fibrinogen degradation products (FDP) D-dimer measured by a highly sensitive ELISA method with a new monoclonal antibody (D-D E72) in various renal diseases.

To diagnose the abnormalities of coagulation-fibrinolysis in various renal diseases, we developed a new monoclonal antibody (D-D E72) against fibrin/fibrinogen degradation products D-dimer (FDP D-dimer) and established a highly sensitive enzyme-linked immunosorbent assay (ELISA) for its measurement. FDP D-dimer was assessed in 102 patients with various renal diseases, and the following results were obtained: 1. The mean level of urinary FPD D-dimer in 32 normal controls was 0.69 +/- 0.60 ng/ml (mean +/- SD). 2. The level of urinary FDP D-dimer was significantly higher in primary nephrotic syndrome group (NS), chronic renal failure group (CRF) and in the group of diabetic nephropathy (DM) than in the control group. However, no difference was observed in the level of urinary FDP D-dimer between non-nephrotic chronic glomerulonephritis group (CGN) and control group. 3. No significant correlation was revealed between D-dimer and urinary protein in CGN and NS groups. These results suggest that in addition to plasma filtration the urinary FDP D-dimer in NS, CRF and DM may be also related to abnormalities of secondary fibrinolysis in intra-glomerular fibrin deposits.

Adolescent↗
PubMed1995

Capillaries with fenestrae in the rat soleus muscle after experimental limb immobilization.

Capillaries in the rat soleus muscle were examined by electron microscopy 4 weeks after limb immobilization and compared to those in untreated muscle. Immobilized muscles showed degenerative changes such as dissolution of sarcomeres, vacuoles, and a small increase in connective tissues, including collagen fibers, around muscle fibers. Eight percent of the capillaries in these muscles were found to have fenestrae. The non-nuclear portions of the endothelial cells were extremely thin and were perforated by several fenestrae which were bridged by a single-layered diaphragm. The untreated muscles contained only continuous capillaries. These findings suggest that the occurrence of capillaries with fenestrae in the immobilized muscle may be a result of structural changes in the muscle.

Animals↗
PubMed1995

[Estimated production by the official inspection of coal-tar dyes (including dye aluminum lakes) in 1994].

The number of official inspection of coal-tar dyes and their lakes from April in 1994 till March in 1995 were 635 in total. The quantity which passed inspection amounted to 186 ton in Japan. The production of color in each month was summarised in Table 1, and by each producing company in Table 2. The food coal-tar dye produced in the largest quantity was Food Yellow No.4, occupying 40.7% in this period.

Chemical Industry↗
PubMed1995

[A case of Behçet's disease associated with aortic regurgitation and nephrotic syndrome].

A 50-year-old housewife with a main complaint of dyspnea was admitted to our hospital in September, 1992. In 1975, the patient developed aphthous stomatitis, genital aphthous ulcers, uveitis and erythema nodosum appeared and diagnosed as having Behcet's disease at Department of Dermatology of our hospital. Aortic regurgitation was pointed out in 1984. Hyperlipidemia appeared in January and Oral prednisolone was started in May, 1985. From April in 1987, proteinuria appeared. From January, 1988, urinal protein was greater than 300 mg/dl. Orthopnea appeared in July, 1992. Physical examinations revealed systolic and diastolic murmur and pretibial edema. Laboratory findings showed proteinuria (3.8 g/day) and hypoproteinemia (serum total protein 5.1 g/dl, serum albumin 3.1 g/dl). Microscopic findings of renal biopsy revealed mesangial proliferative glomerulonephritis and arteriosclerosis. Immunofluorescent studies demonstrated deposits of Apo B in the basement membrane and the mesangium. She was discharged from our hospital as proteinuria was decreased after a combination treatment with camostat mesilate 600 mg and SAIREITO 9.0 g. This patient developed nephrotic syndrome, which was caused by hypertension and hyperlipidemia in addition to Behcet's disease. This case is noteworthy because Behcet's disease is rarely complicated with nephrotic syndrome.

Anti-Inflammatory Agents↗
PubMed1995

[A case of severe sarin poisoning in the sarin attack in Matsumoto--one-year follow-up of clinical findings, and laboratory data].

A patient severely poisoned with sarin in the Sarin Attack in Matsumoto is described. A 19-year-old man was exposed to sarin at 23:00 on 27 June, 1994. At 1:00 of the following day, a rescue team found and brought him to the hospital. His blood pressure was 150-80mmHg and the heart rate was 120/min with frequent premature ventricular contractions (PVC). His respiration was shallow and copious salivation and excretion from the respiratory tract were observed. Consciousness disturbance, generalized convulsion, severe miosis and fasciculation of tongue, facial muscle and extremities were also marked. Serum cholinesterase was 21 U/l (normal 109-249) and acetylcholinesterase in erythrocyte (E-AchE) was 0.1U/l (normal 1.2-2.0). Electroencephalogram (EEG) 30 hours after exposure showed polispike and wave complexes. Ventilatory assistance, forced urination and injection of diazepam and atropin improved his general condition and he was discharged 18 days after exposure. Three months after exposure, E-AchE was normalized and there was no complaint. But one year after exposure, EEG showed epilecpic discharges during sleep, and Holter electrocardiogram showed frequent PVC. As no clinical cases of severe sarin poisoning like this patient was reported, a longterm follow-up of this patient is very important.

Adult↗
PubMed1994

Changes in chromatin structure at recombination initiation sites during yeast meiosis.

Transient double-strand breaks (DSBs) occur during Saccharomyces cerevisiae meiosis at recombination hot spots and are thought to initiate most, if not all, homologous recombination between chromosomes. To uncover the regulatory mechanisms active in DSB formation, we have monitored the change in local chromatin structure at the ARG4 and CYS3 recombination hot spots over the course of meiosis. Micrococcal nuclease (MNase) digestion of isolated meiotic chromatin followed by indirect end-labeling revealed that the DSB sites in both loci are hypersensitive to MNase and that their sensitivity increases 2- to 4-fold prior to the appearance of meiotic DSBs and recombination products. Other sensitive sites are not significantly altered. The study of hyper- and hypo-recombinogenic constructs at the ARG4 locus, also revealed that the MNase sensitivity at the DSB site correlates with both the extent of DSBs and the rate of gene conversion. These results suggest that the local chromatin structure and its modification in early meiosis play an important role in the positioning and frequency of meiotic DSBs, leading to meiotic recombination.

Argininosuccinate Lyase↗
PubMed1994

Combined cytokinesis-block micronucleus and chromosomal aberration assay for the evaluation of radiosensitizers at low radiation doses.

PURPOSE: Several methods have been tried for evaluating the efficacy of hypoxic cell radiosensitizers at clinically relevant low radiation doses (1-4 Gy). The cytokinesis-block micronucleus assay is known to be useful for both the in vitro and in vivo evaluation of radiosensitizers, while the chromosomal aberration assay has been commonly used to assess the mutagenicity of various agents. In the present study, the chromosomal aberration assay and the cytokinesis-block micronucleus assay were performed simultaneously to assess the radiosensitizing effect of etanidazole and KU-2285 at low radiation doses. The correlation between the two assays was also evaluated. METHODS AND MATERIALS: In vitro study: EMT-6 cells were irradiated at a dose of 1-3 Gy under hypoxic conditions with or without the drugs at 1 mM. In vivo-in vitro study: EMT-6 tumor-bearing BALB/c mice received 2-4 Gy of radiation with or without administration of the drugs at 200 mg/kg. Single-cell suspensions were then obtained in both studies and were used for the cytokinesis-block micronucleus assay and the chromosomal aberration assay. The micronucleus frequency in binucleate cells was evaluated in the former assay, and the frequency of chromosomal aberrations in metaphase cells was evaluated in the latter assay. RESULTS: In vitro study: the sensitizer enhancement ratios of etanidazole and KU-2285 were 1.73 and 2.21, respectively, in the micronucleus assay, and 1.41 and 1.79 in the chromosomal aberration assay. In vivo-in vitro study: the sensitizer enhancement ratios of etanidazole and KU-2285 were 1.18 and 1.31, respectively, in the micronucleus assay, and 1.16 and 1.42 in the chromosomal aberration assay. In both studies, a linear correlation was observed between the micronucleus frequency and the chromosomal aberration frequency. The background (i.e., the frequency at 0 Gy) of the latter assay was considerably lower than that of the former assay, especially in the vivo study. CONCLUSIONS: The chromosomal aberration assay has not yet been established as a method for evaluating the effect of radiosensitizers. However, a combination of the cytokinesis-block micronucleus assay and the chromosomal aberration assay seems to be useful for assessing radiosensitizers at low radiation doses for the following reasons: a) the chromosomal aberration assay is as sensitive as the micronucleus assay and possibly more specific, because chromosomal aberrations can be observed before cells pass through the first metaphase after irradiation and, thus, reflect quite acute damage, even though they reflect only a part of the total damage; b) the combined assay provides relatively more information for the time and labor required.

Aerobiosis↗
PubMed1994

c-erbB-2 gene product associates with catenins in human cancer cells.

Phosphorylation of beta-catenin, an intracytoplasmic cadherin-binding protein, causes disruption of the cadherin-mediated cell adhesion system in cancer cells. A 185-kDa phosphorylated protein, identified as the c-erbB-2 gene product, was co-immunoprecipitated with the E-cadherin-catenin complex. Association of the c-erbB-2 gene product with the cadherin-catenin complex was proven to be mediated through beta-catenin and plakoglobin using an in vitro protein-protein precipitation system. These results indicate that the c-erbB-2 gene product associates with catenins and may regulate the cell adhesion and invasive growth of cancer.

Cadherins↗
PubMed1994

Rapid decrease in ATP content without recovery phase during glutamate-induced cell death in cultured spinal neurons.

Glutamate neurotoxicity in the cultured neurons from rat spinal cord was evaluated on the basis of endogenous ATP content in the cells. A short exposure of the neurons to glutamate induced an immediate and rapid decrease in ATP content. Then, after removal of glutamate, no recovery of ATP content was observed for 24 h, eventually resulting in neuronal death. These findings suggest that the glutamate-induced neuronal death in vitro is apparently similar to but essentially different from so-called 'delayed' neuronal death in vivo after a brief ischemia in hippocampal CA1 neurons in which a transient recovery of ATP level occurs after its dramatic reduction.

Adenosine Triphosphate↗
PubMed1994

Association of plakoglobin with APC, a tumor suppressor gene product, and its regulation by tyrosine phosphorylation.

Plakoglobin is a cytoplasmic protein localized in both adherens junctions and desmosomes. Little is known about its function, but it may play a role in maintaining cell junction integrity. A partly homologous protein, beta catenin, is localized mainly in adherens junctions and plays a key role in cell adhesion by associating with cadherins, a family of Ca2+ dependent cell-to-cell adhesion molecules. Recently the product of APC, a tumor suppressor gene, was found to associate with beta catenin. In this study we demonstrated that plakoglobin also associates with APC and that tyrosine phosphorylated plakoglobin associates with cadherins but not with APC. These results suggest that plakoglobin could play a role in mediating the signals of APC by mutual interaction and that this may be regulated by tyrosine phosphorylation.

Adenocarcinoma↗
PubMed1994

A chimeric Rec-A protein that implicates non-Watson-Crick interactions in homologous pairing.

The helical filament formed by RecA protein on single-stranded DNA plays an important role in homologous recombination and pairs with a complementary single strand or homologous duplex DNA. The RecA nucleoprotein filament also recognizes an identical single strand. The chimeric protein, RecAc38, forms a nucleoprotein filament that recognizes a complementary strand but is defective in recognition of duplex DNA, and is associated with phenotypic defects in repair and recombination. As described here, RecAc38 nucleoprotein filament is also defective in recognition of an identical strand, either when the filament has within it a single strand or duplex DNA. A model that postulates three DNA binding sites rationalizes these observations and suggests that the third binding site mediates non-Watson-Crick interactions that are instrumental in recognition of homology in duplex DNA.

Base Sequence↗
PubMed1994

Fluorinated 2-nitroimidazole derivative hypoxic cell radiosensitizers: radiosensitizing activities and pharmacokinetics.

PURPOSE: To assess the effects of incorporation of a CF2 group into the side chain of a 2-nitroimidazole derivative, we evaluated the in vitro and in vivo radiosensitizing activities of KU-2285 (a 2-nitroimidazole derivative with an N1-substituent of -CH2CF2CONH(CH2)nOH, n = 2) and its related compounds in comparison with those of comparable nonfluorinated compounds. The pharmacokinetics of these compounds in murine tumors was also tested. METHODS AND MATERIALS: KU-2285, KU-3202 (n = 3) and KU-3207 (n = 4) are fluorinated 2-nitroimidazole derivative compounds with similar structures. Etanidazole (a 2-nitroimidazole derivative with an N1-substituent of -CH2CONH(CH2)nOH, n = 2) and its related compounds, KU-3205 (n = 3) and KU-3206 (n = 4) were also tested. The in vitro radiosensitizing activities of each compound for hypoxic cells was evaluated with a standard colony formation method. The in vivo radiosensitizing activities of these compounds were tested in female C3H/He mice bearing SCCVII tumors using an in vivo/in vitro clonogenic assay. The pharmacokinetic studies were performed in C3H/He mice bearing the SCCVII tumor. Samples were analyzed by reverse-phase high-performance liquid chromatography. RESULTS: The in vitro radiosensitizing activities of fluorinated 2-nitroimidazoles were higher than those of the nonfluorinated compounds. Although the in vivo radiosensitizing activity of KU-2285 was higher than that of etanidazole (p < 0.05), other fluorinated 2-nitroimidazoles showed less radiosensitizing activity than the comparable nonfluorinated compounds. The compound was eliminated from serum more rapidly with the increase in the number of CH2 group in the side chain of the compound in each series. CONCLUSION: Although the in vitro sensitizing activity of the fluorinated compounds was higher than that of the comparable nonfluorinated compounds, the in vivo radiosensitizing activity of all fluorinated compounds but KU-2285 was lower than that of comparable etanidazole group compounds, probably due to their lower molecular concentrations in tumor and rapid elimination.

Animals↗
PubMed1994

Reoxygenation in the SCCVII tumor after KU-2285 sensitization plus single or fractionated irradiation.

PURPOSE: Because reoxygenation of solid tumors after irradiation with a hypoxic cell sensitizer has never previously been investigated, we assessed the reoxygenation in SCCVII tumors after treatment with KU-2285 plus single or fractionated irradiation. METHODS AND MATERIALS: KU-2285 (100 mg/kg) was injected intraperitoneally into C3H mice bearing 1-cm SCCVII tumors at 30 min before a single dose of 12 Gy or three fractions of 5 Gy at 12 h intervals. Changes of the hypoxic fraction (HF) were then evaluated by the paired survival curve method. RESULTS: Since the radiosensitizing effect of KU-2285 was relatively persistent, the HF was only evaluable after 6 h of irradiation. The HF of untreated SCCVII tumors was 9.1%. After treatment with KU-2285 and 12 Gy, the HF was 25% at 6 h, 32% at 12 h, 24% at 24 h, and 7.6% at 72 h. The HF was lower at 6 h than that after radiation alone, but was similar at later periods. After three fractions of 5 Gy with or without KU-2285, the HF was 33% at 6 h in both groups, while it was 12% and 13% at 24 h for tumors pretreated with KU-2285 and those receiving radiation alone, respectively. However, a sensitizing effect of KU-2285 was indicated by the downward shift of the survival curves for tumors irradiated after exposure to this agent. CONCLUSION: Reoxygenation occurred quite efficiently in tumors receiving KU-2285 and 12 Gy. After fractionated irradiation, however, reoxygenation was similar in the KU-2285-pretreatment and irradiation alone groups.

Animals↗
PubMed1994

Comparison of radiosensitizing effect of KU-2285 and SR-2508 at low drug concentrations and doses.

PURPOSE: Since the radiosensitizing effect of KU-2285 at relatively low dose levels is not known, we investigated its efficacy at such low concentrations or doses achievable in humans with oral administration of 0.3-1.0 g/m2. METHODS AND MATERIALS: KU-2285 was tested in comparison with SR-2508 at low concentrations (0.05-0.25 mM) in vitro by the cytokinesis-block micronucleus assay and by the colony formation assay, and at low drug doses (12.5-50 mg/kg) in vivo by the in vivo-in vitro assay and by the growth delay assay using SCC VII tumors in C3H/He mice. RESULTS: In the cytokinesis-block micronucleus assay, the sensitizer enhancement ratio (SER) for KU-2285 and SR-2508 was 1.43 and 1.17 at 0.05 mM, 1.75 and 1.27 at 0.10 mM, and 2.14 and 1.69 at 0.25 mM, respectively. In the colony formation assay, the SER for KU-2285 was also greater than that for SR-2508. In the in vivo-in vitro assay, the SER for KU-2285 and SR-2508 was 1.11 and 1.04 at 12.5 mg/kg, 1.21 and 1.04 at 25 mg/kg, and 1.26 and 1.18 at 50 mg/kg, respectively. In the growth delay assay at 50 mg/kg, no tumor regrowth was observed in four of the 18 mice treated with KU-2285 + 25 Gy, although the growth delay time for the remaining mice was similar to that for SR-2508 + 25 Gy. CONCLUSION: KU-2285 was more effective than SR-2508 both at low drug concentrations in vitro and at low drug doses in vivo. These promising findings suggest the potential superiority of KU-2285 over SR-2508 as a radiosensitizer for clinical use.

Animals↗