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Biomedical subjects

T Shibata

Publications and source records attributed to T Shibata.

At least 1,027 records · Page 57Linked to original sources
PubMed1983

[Autologous bone marrow transplantation in solid tumors in children].

Seven children with advanced solid tumors (2 rhabdomyosarcomas, 2 Ewing's sarcomas, 1 astrocytoma, 1 T cell lymphoma and 1 neuroblastoma) received high dose chemotherapy and/or radiotherapy followed by autologous bone marrow transplantation. Four patients achieved complete remissions, two had partial remissions, and one was no response. Side effect of autologous bone marrow transplantation was few compared with that of allogeneic bone marrow transplantation in which graft versus host reaction, profound posttransplantation immunodeficiency and interstitial pneumonitis were unavoidable. In this report methods of bone marrow cryopreservation and elimination of tumor cells from harvested bone marrow were also discussed.

Adolescent↗
PubMed1983

Anti-ATLA (antibody to adult T-cell leukemia virus-associated antigen), highly positive in OKT4-positive mature T-cell malignancies.

Serum or plasma specimens from 252 patients with lymphoid malignancies were screened for reactivity with adult T-cell leukemia virus-associated antigen (ATLA), and the relationship between the immunologic phenotype of the tumor cells and ATLA reactivity was determined. Anti-ATLA antibodies were found in 24 (29.3%) of 82 patients with T-cell malignancy. In contrast, the antibodies were found in none of the 106 patients with B-cell malignancy and only rarely in patients with other lymphoid malignancies without blood transfusions. Among the patients with T-cell malignancy, anti-ATLA antibodies were found in 23 (45.1%) of the 51 patients with OKT4-positive mature T-cell (inducer/helper T-cell) malignancy, but in none of the patients with T-cell malignancy of pre-T, thymic T-cell or OKT8-positive mature T-cell (suppressor/cytotoxic T-cell) phenotype. Furthermore, among the OKT4-positive mature T-cell malignancies, the antibodies were found in 16 (84.2%) of 19 patients with ATL and in 5 (27.8%) of 18 patients with mature (peripheral) T-cell lymphoma, in none of four with typical T-chronic lymphocytic leukemia, in one of nine with mycosis fungoides and in the one patient with small-cell variant of Sézary's syndrome. These results suggest that anti-ATLA positive T-cell malignancies with OKT4-positive mature T-cell phenotype must be the same disease, because it is highly possible that they have the same etiology and the same cellular origin. In the atypical cases, it seems necessary to demonstrate monoclonal integration of proviral DNA of ATLV or HTLV into the tumor cells in order to establish the final diagnosis of ATL.

Antibodies, Viral↗
PubMed1983

[Cerebral blood flow dynamics of spontaneous occlusion of the circle of Willis (Part 1)--comparison between electrophysiological findings and neuroradiological findings].

Four cases (2 children and 2 adults) of spontaneous occlusion of the circle of Willis were studied using EEG, somatosensory evoked potential (SEP), cerebral angiography and CT scan. The following results were obtained. 1) Among the above described parameters, SEP was the most useful to detect the ischemic change in the thalamus when the obstruction of the posterior part of the circle of Willis extends, even before a low density lesion of the thalamus appears on CT. 2) In child cases, a decrease in the amplitude N3 of SEP was observed after hyperventilation. It was speculated that this finding of SEP might be correlated with the mild cortical ischemia due to vasoconstriction and "rebuild up" phenomenon in EEG after hyperventilation.

Adult↗
PubMed1983

Comparative study of protected environment for children with malignant disease.

Thirty-three children with malignancy were investigated to evaluate the effect of reverse isolation with or without decontamination on prevention of infection. They were allocated to three groups: Group A, isolation in a laminar air flow room plus oral nonabsorbable antibiotics and sterile food; group B, isolation in a vertical air flow room without decontamination; group C, isolation in a conventional private room. Infectious episodes were the fewest and the rate of response to cancer chemotherapy was the highest in group A. Pyrexial days (greater than 38 degrees C) and days on systemic antibiotics were significantly fewer in groups A and B. Episodes of infection were also significantly fewer in group A but not in group B, as compared with group C. The usefulness and the necessity of a laminar air flow room as well as a vertical air flow room for management of childhood cancer were demonstrated.

Adolescent↗
PubMed1982

D-loop cycle. A circular reaction sequence which comprises formation and dissociation of D-loops and inactivation and reactivation of superhelical closed circular DNA promoted by recA protein of Escherichia coli.

Excess recA protein, a protein essential to general genetic recombination in Escherichia coli, promotes a sequence of formation and dissociation of D-loops from negative superhelical closed circular double-stranded DNA (form I DNA) and homologous single-stranded fragments in the presence of excess ATP, resulting in inactivation of the form I DNA without apparent damage to the DNA. The dissociation of D-loops is accompanied by hydrolysis of ATP to ADP that apparently depends on homologous DNA molecules (homology-dependent ATP hydrolysis). However, at a lower concentrations of ATP, we observed anomalous kinetics in the formation and dissociation of D-loops; as the concentration of ATP was decreased, there was a progressively smaller dissociation of D-loops and a faster resynthesis in the second phase, without changing the rate of the first formation of D-loops. This anomaly might suggest that, as the increase in the amount of ADP relative to that of ATP, dissociation form I DNA is stimulated before formation of D-loops is inhibited. We found that addition of ADP inhibited competitively both formation and dissociation of D-loops and that the latter process was more sensitive to the inhibition than was the former process. Addition of a sufficient amount of ADP to inhibit both formation and dissociation of D-loops, cessation of homology-dependent hydrolysis of ATP, or incubation at low temperature resulted in reactivation of form I DNA that had been inactivated by the sequence. In the presence of an ATP-regenerating system, we confirmed our previous result that limiting the amount of recA protein also causes anomalous kinetics in the formation and dissociation of D-loops. These observations indicate that the formation and dissociation of D-loops and the inactivation and reactivation of form I DNA make a circular reaction sequence.

Bacterial Proteins↗
PubMed1982

The turnover of molecular species of phosphatidylinositol in Ehrlich ascites tumor cells.

It has been shown previously the 32Pi is incorporated into phosphatidylinositol 30 times faster than into the other phospholipids classes in Ehrlich ascites tumor cells, whereas [1-14C] glycerol is incorporated at almost the same rate (Waku, K., Nakazawa, Y. and MOri, W. (1976) J. Biochem. 79, 407-411). It was therefore suggested that there is a recirculating system (phosphatidylinositol leads to diacylglycerol leads to phosphatidic acid leads to CDP diacylglycerol leads to phosphatidylinositol) of phosphatidylinositol in Ehrlich ascites tumor cells. In this work, 32Pi or [1-3H] glycerol was injected into the peritoneal cavity of mice bearing Ehrlich ascites tumor cells from which the lipids were extracted after selected periods. Phosphatidylinositol was prepared and fractionated in the form of dimethylphosphatidic acid into six molecular species by AgNO3-impregnated TLC. The specific radioactivities of the fractionated species were determined. 32Pi was incorporated into diene molecular species and [1-3H] glycerol into monoene species with a higher rate than the other species and both precursors were incorporated into tetraene species rather slowly. 32P/3H values appeared to be at almost the same for each molecular species, although monoene species showed slightly lower values. These results suggest that there could be a recirculating of the phosphorylinositol moiety in each of the molecular species of phosphatidylinositol.

Animals↗
PubMed1982

Role of superhelicity in homologous pairing of DNA molecules promoted by Escherichia coli recA protein.

In the presence of ATP and an excess of recA protein, superhelical closed circular DNA (form I DNA) and homologous single-stranded fragments paired to form D-loops in the early stage of incubation and dissociated during subsequent incubation. RecA protein that was not bound to single-stranded DNA ("free recA protein") was shown to be responsible for the dissociation of D-loops. Larger amount of free recA protein gave a lower final yield of D-loops. When the concentration of form I DNA was increased in the presence of a fixed amount of single-stranded DNA, larger amounts of free recA protein were required to produce a certain extent of dissociation. When form I DNA, excess recA protein, and ATP were incubated without single-stranded DNA, or with heterologous single-stranded fragments before the addition of homologous single-stranded fragments, formation and subsequent dissociation of D-loops were observed as in the case when all components of the reaction were added from the start. Therefore, the dissociation of D-loops is a result of the stoichiometric interaction between free recA protein and form I DNA bearing D-loops. In the process of formation and dissociation of D-loops, form I DNA was converted to an inactive substrate without any apparent damage to the DNA. The concentration of free recA protein appeared to decrease during the reaction. These observations revealed that formation and dissociation of D-loops are sequential reactions when form I DNA is the substrate and recA protein is present in excess. The dissociation of D-loops and the inactivation of form I DNA can be explained by a model in which recA protein cooperatively binds to form I DNA from the site of D-loop, resulting in stimulation of unidirectional unwinding of the double helix.

Bacterial Proteins↗
PubMed1982

Effects of benzyl alcohol on phosphatidylcholine lamellar phase with different water contents.

Effects of benzyl alcohol (BA) on the bilayer thickness dl and the fluidity of egg phosphatidylcholine (PC) lamellar phase with various water contents have been studied by X-ray diffraction and the proton spin-lattice relaxation rate. At lower water contents, BA causes dl to decrease and the rate of molecular motions to increase. By contrast, with increasing BA at excess water, dl remains nearly unchanged, though the rate of motions increases. Hydration experiment for egg phosphatidylcholine lamellae with BA at a 1 : 1 molar ratio shows that in the range from 15% to 30% water, dl decreases to the value of the fully hydrated sample without BA and is nearly constant above 30% water. The value at full hydration is suggested to be a lower limit of the bilayer thickness, the chain is in the unperturbed state. It is in an extended structure at lower water contents. This leads to the difference in the effect of BA on the bilayer thickness at different water contents.

Anesthetics, Local↗
PubMed1982

Hydrolysis of ATP dependent on homologous double-stranded DNA and single-stranded fragments promoted by RecA protein of Escherichia coli.

RecA protein is essential to general genetic recombination in Escherichia coli. In the presence of ATP, a stoichiometric amount of recA protein forms D-loops from superhelical closed-circular DNA (form I DNA) and homologous single-stranded fragments, and subsequently dissociates the D-loops. Under appropriate conditions, the hydrolysis of ATP by recA protein depends on the presence of both double-stranded DNA and homologous single-stranded fragments (homology-dependent hydrolysis). In the presence of form I DNA, most of the homology-dependent hydrolysis of ATP by recA protein is related to the dissociation of D-loops rather than the formation of D-loops. RecA protein also promoted the homology-dependent hydrolysis of ATP in the presence of nicked-circular DNA (form II DNA), but unlike the case of form I DNA, this hydrolysis was associated with an increase in the amount of mature D-loops that were detected by the D-loop assay. When double-stranded DNA was superhelical, the homology-dependent hydrolysis of ATP continued at the same rate even after all the D-loops were dissociated. This correlates with our earlier observation that in the process of formation and dissociation of D-loops, form I DNA was converted to an inactive substrate without any apparent damage to the DNA, probably by the formation of a complex with recA protein. All of the observations described above can be explained by a model in which a common mechanism causes dissociation of D-loops from form I DNA, inactivation of form I DNA, and growth of D-loops in form II DNA. The mechanism might involve cooperative binding of recA protein to the duplex DNA from the site of the nascent D-loop, resulting in unidirectional unwinding of the duplex DNA.

Adenosine Triphosphate↗
PubMed1982

Posterior fossa subdural hemorrhage in the newborn as a result of birth trauma.

During the past 19 years, 229 autopsies of intracranial hemmorrhages were performed at the Department of Pathology, and 23 cases of posterior fossa subdural hemorrhages were discovered (10.0%). 25 cases of posterior fossa subdural hemorrhages (2 of our own treated surgically and 23 untreated found at autopsy) are described in detail. 2 cases treated surgically responded favorably to surgical treatment. The mechanism of hemorrhage into posterior fossa subdural spaces is investigated and reconsidered following a review of the literature. The necessity for CT is emphasized for early diagnosis of posterior fossa subdural hemorrhage.

Birth Injuries↗