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Biomedical subjects

T Shibata

Publications and source records attributed to T Shibata.

At least 649 records · Page 36Linked to original sources

[Flower bud differentiation and development of opium poppy (Papaver somniferum L.) II. Effects of daylength and temperature].

We investigated the effect of daylength (from 9 to 15 hours) and cultivation temperature (from about 13 to 25 degrees C) on flower bud differentiation of three strains of Papaver somniferum L. cv. Ikkanshu, which have been cultivated in Nayoro (Hokkaido), Tsukuba (Central Honshu) and Nagasaki (Kyushu) for the last a few decades. 1. The experiment on the effect of daylength on flowering revealed that the longer the photoperiod was, the earlier flowering occurred. 2. Flower bud differentiation was observed at temperatures of 20 degrees C or less but never at 25 degrees C, and it was more quickly induced at lower temperatures. Furthermore, we also found that the optimum temperature for flower bud development following differentiation was 20 degrees C. From these findings, we reached the conclusion that this species has thermosensitivity. 3. Flower bud differentiation clearly occurred later in the Nayoro strain than in the Nagasaki strain or the Tsukuba strain. This seems to indicate that the Nayoro strain is a different ecological type from other strains. 4. When we compared the size and dry weight of the capsules, which are known to be closely related to opium yield, the capsules of the Nagasaki and Tsukuba strains were considerably smaller and lighter than those of the Nayoro strain. This is attributable to the fact that flower bud differentiation occurred at an early stage before the achievement of sufficient vegetative growth in the Nagasaki and Tsukuba strains.

Light↗

[The effects of protease inhibitor upon the ischemia-reperfusion injury].

The purpose of the study is to investigate the effects of protease inhibitor (Nafamostat mesilate: NM) upon myocardial protection. Hearts were subjected to 20 min working control perfusion followed by 3 min cardioplegic infusion with the St. Thomas Cardioplegic Solution (ST) contained various concentrations of NM, and global ischemia for 33 min at 37 degrees C (Exp. 1) or 150 min at 20 degrees C (Exp. 2). Hearts were then converted to Langendorff reperfusion (the leakage of Creatine Kinase (CK) and Cathepsin B (Cat-B) ware measured) and 20 min working reperfusion. Various concentrations of NM added during Langendorff reperfusion (Exp. 3). During working perfusion cardiac functions (aortic flow (AoF), coronary flow (CoF), heart rate (HR), aortic pressure (AoP)) were measured, and expressed as the percent recovery of pre-ischemic control value. Post-ischemic recovery of AoF (%AoF) showed the bell-shaped dose-response curve, and the optimal dose was 3 microM (Exp. 1) and 10 microM (Exp. 2) respectively. There was a significant (p < 0.05) increase of %AoF in optimal dose compared with that in controls (64.2 +/- 1.2% vs 52.3 +/- 2.5% in Exp. 1, 68.9 +/- 3.1% vs 54.1 +/- 1.4% in Exp. 2). These increase of functional recovery reflected in the values for CK and Cat-B leakage. The addition of NM in ST reduced CK and Cat-B leakage significantly in the concentration of 5 microM (in Exp. 1) and 10 microM (in Exp. 2) respectively. But the addition of NM in reperfusate did not reduced CK leakage significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Suppression of intestinal smooth muscle contraction by phenolic compounds.

Wood creosote, a mixture of guaiacol, creosol, and other related phenolic compounds, suppresses the spontaneous longitudinal phasic contractions of an isolated rat ileal segment. Thirty-two phenolic compounds were screened for this activity to identify the active substances in wood creosote. Of the 32 compounds tested, 2,3,6-trimethylphenol, 2,4,6-trimethylphenol, and 4-ethylguaiacol were most effective and their respective IC50 values were 0.035, 0.037, and 0.043 mM. Guaiacol and creosol, the chief constituents of wood creosote, were moderately effective and their respective IC50 values were 0.18 and 0.13 mM. Other phenolic compounds in wood creosote also suppressed the ileal contraction although their IC50 values differed markedly from each other. These results suggest that practically all of its constituent phenolic compounds contribute to wood creosote's capacity to suppress ileal contraction.

Animals↗

[Involvement of allergic mechanism in minimal change nephrotic syndrome (MCNS)].

In this study we evaluated the involvement of allergic mechanisms in patients with adult onset MCNS (17 cases) by measuring serum IgE levels and RAST scores to house dust 1 (H.D.1), house dust 2 (H.D.2), Dermatophagoides farinae (D.f.), Dermatophagoides ptenonyssinus (D.p.). Out of the 17 cases, three cases showed high levels of IgE (more than 1000 IU/ml) and the mean level of serum IgE was 877 IU/ml before treatment. All cases were treated with steroid and/or cyclophosphamide. After the treatment, all cases returned to remission. The level of IgE decreased to the normal range in four out of seven cases which had shown high levels of IgE before treatment. RAST was carried out on seven of the 17 cases. RAST scores for D.f. and D.f. were found to be positive in three cases, but these became negative in two cases after treatment. In five cases relapsed, the all cases showed to have the increased level of serum IgE and two of four cases which were examined RAST score showed to have the increased RAST score for D.f. and D.p. Thus, the data indicated that allergic mechanism, especially against D.f. and D.p. antigen, seemed to play one of the factors in the pathogenesis of MCNS.

Adolescent↗

[The effects of potassium concentration in reperfusion solution upon myocardial protection].

The effects of potassium in reperfusion solution (RS) and the influence of sodium on this effect were studied. Experimental time course was as followed: 20 min working perfusion, 3 min cardioplegic infusion with St. Thomas Cardioplegic Solution followed by global ischemia for 33 or 35 min at 37.5 degrees C, 15 min early Langendorff reperfusion with several different potassium concentration modified with Krebs Henseleit Bicarbonate Buffer (KHBB) containing 145 mM and 110 mM sodium and 5 min late reperfusion with KHBB, followed by 20 min working perfusion. Potassium in RS possessed bell shaped dose response nature with optimal concentration of 10 mM in the condition of 145 mM sodium but 6 m in the condition of 110 mM in terms of percent recovery of aortic flow. Although higher potassium reperfusion produced less Creatine Kinase leakage.

Animals↗

Relationship between pancreatic exocrine function and histological changes in chronic pancreatitis.

To confirm correlation between function and histology of the exocrine pancreas in chronic pancreatitis, we compared exocrine pancreatic function, as estimated by cholecystokinin secretin test (CST), with histological findings in 108 patients. Exocrine pancreatic insufficiency was graded from 0 to 4 according to the number of abnormal CST parameters. Histological findings also were graded from 0 to 4. Results of CST in 108 patients were normal (grade 0) in 52, equivocal (grade 1) in 23, and abnormal (grades 2-4) in 33. Normal histological findings (grade 0) were observed in 54 patients, equivocal (grade 1) in 15, and abnormal (grades 2-4) in 39. We confirmed that there was a significant correlation between histological grading and overall scoring (tau = 0.59, p less than 0.01) or individual parameters (tau = -0.36 for volume, -0.45 for amylase output, and -0.54 for maximal bicarbonate concentration (p less than 0.01) of CST. Sensitivity of CST was 67% in 39 patients with histologically confirmed chronic pancreatitis, specificity was 90% in 69 patients without chronic pancreatitis, based on histological evidence, and efficiency was 81%. In conclusion, we confirmed a highly significant correlation between direct function test (CST) and histology of the exocrine pancreas.

Cholecystokinin↗

[An attempt at intraoperative, ultrasound-guided microwave tissue coagulation for metastatic liver tumors].

Using a microwave tissue coagulator, we attempted intraoperative, ultrasound-guided cauterization and thermocoagulation of metastatic liver tumors. The procedure, safety and efficacy of this therapy were analyzed. During the past 2 years, this therapy was used in 10 patients with unresectable metastatic liver tumors. During surgery, monopolar electrodes were inserted with an ultrasonic guide. One round of cauterization lasted for 10 seconds at 100 W. It was repeated until the tissue around the tumor became hyperechoic. This therapy was used for 67 tumor lesions in total (2-22 lesions/patient). No complications were observed during or after this therapy, except for a case complicated by liver abscess. The anti-tumor effect of the therapy was assessed by histological examination of resected liver tissues. Tumor coagulation and necrosis were observed consistent with the cauterized area. The response to this therapy, assessed by diagnostic imaging, was CR (complete remission) in 3 cases, PR (partial remission) in 3, NC (no change) in 3 and PD (progressive disease) in 1. Thus, the efficacy (the percentage of cases showing CR or PR) was 60%. Since this therapeutic approach acts directly on tumors and is simple and safe, it seems to provide a useful means for intraoperative regional treatment of tumors.

Adult↗

[Management of infected transvenous permanent pacemakers].

Between November, 1980, and January 1991, a total of 115 transvenous pacemakers were implanted in 102 patients at our hospital. Infection at the site of implantation developed in three cases or 2.6%. The median time of the onset of infection postoperatively was eleven and a half months, the range being two and a half to twenty-four months. Coagulase positive Staphylococcus aureus was cultured from the infected site of one patient and coagulase negative Staphylococcus epidermidis and saprophyticus in two patients. Staphylococcus aureus septicemia developed in one patient. Conservative medical treatment consisting of the application of two or more antibiotics was unsuccessful in all three cases. In two patients, removal of the infected pacemaker generator and implantation of a completely new pacemaker system at a new, clean site were conducted. In one of these two patients, the septic pacemaker electrode was withdrawn 3 months after removal of the infected pacemaker generator. In the other patient, limited thoracotomy with incision of the left brachiocephalic vein was performed for removal of the electrode three weeks after removal of the infected pacemaker generator.

Adult↗

[The effects of sodium concentration in reperfusion solution upon myocardial protection].

The effects of several sodium concentrations in reperfusion solution (RS) were studied. Experimental time course was as follows: 20 min working perfusion, 3 min cardioplegic infusion with St. Thomas Cardioplegic Solution followed by global ischemia for 33 min at 37.5 degrees C, 15 min early Langendorff reperfusion with various sodium concentrations modified with Krebs Henseleit Bicarbonate Buffer (KHBB) and 5 min late reperfusion with KHBB, followed by 20 min working perfusion. Percent recoveries of aortic flow and Creatine Kinase leakage showed that 110 mM sodium of RS possessed optimal protective properties with bell shaped dose response characteristics.

Animals↗

[In vivo observation of crystalline lens changes in the early post-vitrectomy stage].

Crystalline lens changes of 17 cases of eye undergoing simple vitrectomy were observed from the post-operative 1st to 21st month. Changes in the crystalline lenses were detected through a slitlamp microscope or by methods of image analysis, the Opacity Lensmeter and the laser scattering spectroscopy. Increases of the scattering light intensity of the anterior and posterior deep cortical layers were observed from the early post-operative stage in 9 cases. Seven cases progressed to nuclear opacification during the observation period, however, one case showed no nuclear changes even at the 12 post-operative month. No relationships were observed between the early cortical changes and surgical invasion, patient age, or cause of vitreous opacification. Quantitative evaluation by image analysis revealed early post-operative crystalline lens changes in cases undergoing vitreous surgery.

Adult↗

[The effects of osmolarity in reperfusion solution upon myocardial protection].

The effects of several different osmolarity in reperfusion solution were studied. Experimental time course was as follows: 20 min working perfusion, 3 min cardioplegic infusion with St. Thomas Cardioplegic Solution (STS) followed by global ischemia for 33 min at 37.5 degrees C, 15 min early Langendorff reperfusion with different osmolarity by adding sucrose and 5 min late reperfusion with Krebs Henseleit bicarbonate buffer, followed by 20 min working perfusion. Percent recoveries of aortic flow showed that 290 mOsm/L in reperfusion solution possessed optimal protective properties with bell shaped dose response characteristics.

Animals↗

[Hairy cell leukemia successfully treated with 2'-deoxycoformycin following refractoriness to splenectomy and alpha-interferon therapy].

A 34-year-old man was admitted in May, 1989 because of severe left upper abdominal pain, which was caused by advanced splenomegaly. On initial examinations, peripheral blood showed leukocytosis (13,400/ml) including 60% hairy cell which also infiltrated in bone marrow (64%). The patient was diagnosed as having hairy cell leukemia (Japanese type) of B-cell lineage. Splenectomy was performed as an initial treatment. The effect of splenectomy was only palliative and transient leukocytosis progressed thereafter. alpha-interferon and bestrabucil (KM 2210) were then adopted for 4 months respectively. The effects were, however, unsatisfactory. Subsequently the patient was treated successfully with 2'-deoxycoformycin (DCF). Complete remission was attained following 12 injections of 7.5 mg/body of DCF during 5 months and durable remission persists for more than 6 months without maintenance therapy. The side effect was minimum.

Adult↗

Assay for type III collagenolytic activity in lung cancer tissue.

We developed a method for measuring the activity of type III collagenolytic enzyme in lung cancer tissue, using as substrate, type III collagen purified from human placenta. In this method [3H]propionate is used for labeling type III collagen, with bacterial collagenase used for making the standard curve. It, therefore, becomes possible to compare type III collagenolytic activity with those of other collagen subtypes (types I and IV). As this method is a fibril assay it is not susceptible to trypsin or other proteases. The average type III collagenolytic enzyme activity was higher in squamous cell carcinoma than in adenocarcinoma, while that of lung cancer tissue exceeded that of normal lung tissue. The activity of type III collagenase increased with the progression from one disease stage to the next.

Adenocarcinoma↗

Sequence-specific complex formation of DNA and a eukaryotic sequence-specific endonuclease, SceI.

Endo.SceI is a eukaryotic sequence-specific endonuclease of 120 kDa that causes sequence-specific double-stranded scission of DNA. Unlike results with restriction enzymes, we found a consensus sequence around the cleavage sites for Endo.SceI instead of a common sequence. We searched for conditions for studying the binding of Endo.SceI to DNA other than cutting. Under optimized conditions including gel mobility shift assay, Endo.SceI exhibited sequence-specific binding to a short double-stranded DNA (41 base pairs) containing a cleavage site and the DNA reisolated from the protein-DNA complex was not cleaved. The analysis of the complex of Endo.SceI and DNA isolated by the gel mobility shift experiments showed that the DNA-binding entity in the Endo.SceI preparation does have Endo.SceI activity and consists of an equal amount of 75-kDa and 50-kDa polypeptides. Based on this observation and those from previous studies, we conclude that Endo.SceI is a heterodimer of the 75-kDa and 50-kDa subunits. Under the present assay conditions, Endo.SceI did not show binding to single-stranded DNA having the same sequence of either plus or minus strand of the double-stranded DNA containing the cleavage site (the 41-bp DNA). Endo.SceI showed significantly higher affinity for the consensus sequence than the major cleavage site in pBR322 DNA. Unlike the cleavage of DNA by Endo.SceI which requires Mg2+, this sequence-specific binding is independent of but stimulated by Mg2+.

Base Sequence↗

Complement activation induces the expression of decay-accelerating factor on human mesangial cells.

In the present study we evaluated the effect of complement activation by immune complexes (IC) on the expression of decay-accelerating factor (DAF) on human mesangial cells (MC). MC in culture were incubated with an Ag (DNP-Gelatin) that binds to fibronectin present in the MC matrix. Subsequently, MC were incubated with anti-DNP antibodies in the presence of human serum. By immunoperoxidase staining we showed that these incubations resulted in IC formation and deposition of human C3 and terminal complement components (C5b-9) on the mesangial matrix and on the surface of MC. By immunoperoxidase staining and by RIA we showed that IC formation and complement activation significantly increased DAF expression on the MC plasma membrane. The induction of DAF expression was a consequence of deposition of terminal complement components on the MC because, zymosan-activated serum and IC formation in the presence of C5- or C8-deficient serum failed to increase MC DAF expression. Furthermore, the observed increased DAF expression was the consequence of increased DAF synthesis by MC. Thus, both cycloheximide and actinomycin D blocked the increase on MC DAF observed after incubation with IC and serum. MC DAF had biophysical and functional characteristics similar to DAF in other cells. Thus, 1) MC DAF was resistant to trypsin but was removed from the MC membrane by pronase; 2) phosphatidylinositol-specific phospholipase C removed 48 +/- 4% of MC DAF indicating that MC DAF is anchored in the cell membrane by phosphatidylinositol groups; 3) DAF isolated from MC-inhibited complement-mediated hemolysis and demonstrated a molecular mass of 83 kDa. In conclusion, deposition of terminal complement components on human MC trigger new synthesis and membrane expression of DAF. Because DAF protects cells against complement-mediated lysis, we postulate that DAF may protect glomerular cells during IC and complement-mediated glomerulonephritis.

CD55 Antigens↗

Murine cryoglobulinemia: pathogenic and protective IgG3 self-associating antibodies.

A murine IgG3 mAb, 6-19, derived from autoimmune MRL-lpr/lpr mice, is a rheumatoid factor (RF) specific for IgG2a and is able to generate cryoglobulins via nonspecific IgG3 Fc-Fc interaction. Intra-peritoneal passive transfer of ascites containing the 6-19 mAb into BALB/c mice induces skin leukocytoclastic vasculitis and acute glomerulonephritis associated with cryoglobulinemia. Because IgG3 interact with each other, we have determined whether noncryoprecipitating IgG3 mAb were able to inhibit the cryoprecipitation of 6-19 mAb and the development of related tissue lesions. In vitro, the cryoprecipitation of 6-19 mAb was almost completely inhibited by a fourfold excess of a noncryoprecipitating non-RF IgG3 (9-106) mAb derived from MRL-lpr/lpr mice. Cryoprecipitation of five other IgG3 mAb was similarly inhibited by the 9-106 mAb, and two other noncryoprecipitating IgG3 mAb, including the 2-6D antinuclear autoantibody, inhibited the cryoprecipitation of 6-19 mAb. In vivo, pretreatment of BALB/c mice with 9-106 or 2-6D mAb prevented the development of skin vasculitis and glomerulonephritis induced by the 6-19 mAb. The cryoglobulin formation was greatly diminished in 9-106 or 2-6D mAb-treated mice, although their serum levels of 6-19 mAb and RF activity were comparable to those of control mice. This indicated that pretreatment with non-cryoglobulin IgG3 inhibited the cryoglobulin generation and cryoglobulin-associated tissue lesions induced by an IgG3 RF cryoglobulin-generating mAb. These results suggest that the balance of formation of IgG3 autoantibodies with or without the cryoglobulin activity may be critical for the development of IgG3 cryoglobulin-mediated tissue lesions in murine lupus, particularly in MRL-lpr/lpr mice.

Animals↗

Magnetic resonance imaging of neurohypophyseal germinomas.

The authors reviewed magnetic resonance (MR) images in seven cases of germinoma in the hypothalamoneurohypophyseal axis (HNA). The intrasellar portions were clearly identified in six germinomas. Two small germinomas of these six were located only in the neurohypophysis. The major parts of the four large germinomas were located below the optic chiasm, and the large intrasellar portions were demonstrated. The remaining one small germinoma was localized from the pituitary stalk to the third ventricular floor. These findings strongly suggest that the primary site of germinomas in the HNA is the neurohypophysis. In the four large germinomas, the tumor shape was similar to that of pituitary adenoma. The authors believe that age (limited to first three decades), symptoms (diabetes insipidus), MR findings (absence of normal hyperintense signal of the posterior pituitary on T1-weighted (T1WI) images, and homogeneous hypointensity to the pons on T1WI images/isointensity on T2-weighted images are important in differential diagnosis.

Adolescent↗