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Biomedical subjects

T Matsubara

Publications and source records attributed to T Matsubara.

At least 505 records · Page 28Linked to original sources

Distribution of break points in human structural rearrangements.

We attempted to resolve the issue on the location of breakages in patients with structural rearrangements, that is, whether they are located within the light band or are at the interface between a G-dark and a G-light band. Three types of structural rearrangements (inverted duplications, isodicentrics, and rings) were studied as they are capable of providing information not obtainable from other rearrangements because of reasons given in the RATIONALE. We found that break points are primarily located within the G-light bands; a small number of breaks are located in G-dark bands. Breakages at the interface were exceedingly rare. The possibility that they are, in fact, located at the interface of subbands within either light or dark bands appears tenuous. Contrary to what is described in the literature, terminal deletions are not useful in the determining of break points.

Chromosome Aberrations↗

[T gamma lymphocytes in rheumatoid synovial membrane].

The proportion of T lymphocytes with receptors for the Fc portion of IgG (T gamma cells), revealed by mixed rosette assay, was determined in the synovial membrane and peripheral blood of 11 patients with rheumatoid arthritis. The percentage of T gamma cells in the lymphocytic infiltration of rheumatoid synovium was significantly lower than that found in peripheral blood (p less than 0.005). There was no significant difference between the percentage of T lymphocytes in the synovial tissue and that in peripheral blood. Depressed supressor activity of T lymphocytes in rheumatoid synovial membrane might lead B-lymphocytes to blastic transformation to the plasma cell series with consequent production of large amounts of immunoglobulins in the joint.

Adult↗

[Surgical treatment of pulmonary metastasis].

We carried out a study on the surgical treatment and indications, and organ specificities of metastatic pulmonary cancer treated in this hospital until 1981. As for the indications for surgical treatment, the conditions that the primary lesion should be controlled, and that there are no metastases to parts other than the lungs are the same as before. However, in the case of the uterus and colon, it is considered that the indications may be further extended to include bilateral resection should there be only 1-2 lesions on both side. Recently, we carried bilateral resection on several cases, and managed to obtain satisfactory results.

Breast Neoplasms↗

Modulation by copper of the products of nitrite respiration in Pseudomonas perfectomarinus.

A synthetic growth medium was purified with the chelator 1,5-diphenylthiocarbazone to study the effects of copper on partial reactions and product formation of nitrite respiration in Pseudomonas perfectomarinus. This organism grew anaerobically in a copper-deficient medium with nitrate or nitrite as the terminal electron acceptor. Copper-deficient cells had high activity for reduction of nitrate, nitrite, and nitric oxide, but little activity for nitrous oxide reduction. High rates of nitrous oxide reduction were observed only in cells grown on a copper-sufficient (1 micro M) medium. Copper-deficient cells converted nitrate or nitrite initially to nitrous oxide instead of dinitrogen, the normal end product of nitrite respiration in this organism. In agreement with this was the finding that anaerobic growth of P. perfectomarinus with nitrous oxide as the terminal electron acceptor required copper. This requirement was not satisfied by substitution of molybdenum, zinc, nickel, cobalt, or manganese for copper. Reconstitution of nitrous oxide reduction in copper-deficient cells was rapid on addition of a small amount of copper, even though protein synthesis was inhibited. The results indicate an involvement of copper protein(s) in the last step of nitrite respiration in P. perfectomarinus. In addition we found that nitric oxide, a presumed intermediate of nitrite respiration, inhibited nitrous oxide reduction.

Copper↗

Spontaneous reactivation of fenitro-oxon-inhibited plasma cholinesterase in various mammals.

It was investigated as to whether a spontaneous reactivation was also observed in fenitro-oxon-inhibited plasma cholinesterase (ChE) of human and several animals, such as mice, guinea pigs and rabbits, as previously reported in rat plasma ChE. It was found from the results that a marked spontaneous reactivation took place during storage at 37 degrees C or 24 degrees C in all of human and the animals, while these reactivations of animals were to some extent slower and slighter than that of rat. Moreover, there was little significant difference between the spontaneous reactivations observed in using acetylthiocholine and butyrylthiocholine as a substrate, although the use of the latter substrate resulted in somewhat faster and greater spontaneous reactivation only in rat. These results suggest that the spontaneous reactivation takes place in plasma pseudo ChE of various animals after inhibition with fenitro-oxon.

Acetylthiocholine↗

Biotransformation of coumarin derivatives (1). 7-alkoxycoumarin O-dealkylase in liver microsomes.

The in vitro metabolic fate of 7-alkoxycoumarin was studied using liver microsomes. Microsomal enzyme catalyzed dealkylation of 7-alkoxycoumarin to 7-hydroxycoumarin in the presence of NADPH and molecular oxygen as cofactors was found to be one of the metabolic pathways. The metabolite 7-hydroxycoumarin was further metabolized to unidentified metabolite(s) in the presence of NADPH and O2 at a very slow rate, while the formation of the conjugate of 7-hydroxycoumarin with glucuronic acid was observed in the presence of UDPGA. Microsomal 7-alkoxycoumarin O-dealkylase activity was altered by the substitution of the alkyl group of the substrate, and the substitutions to either an O-propyl or an O-butyl group resulted in a decrease of the enzyme activity. Species differences were observed in the substrate specificity of microsomal O-dealkylation. The O-dealkylase activities in rat liver microsomes were stimulated by pretreatment of the animals with phenobarbital, regardless of the O-alkyl substituent at the 7 position of the coumarin ring. On the other hand, pretreatment with 3-methylcholanthrene or beta-naphthoflavone resulted in marked increase of O-deethylation. O-depropylation and O-debutylation activities, but not of O-demethylation activity. Pretreatment of animals with beta-naphthoflavone also resulted in remarkable stimulation of 7-hydroxycoumarin-glucuronide formation by the microsomal enzyme, while the conversion of 7-hydroxycoumarin to unidentified metabolite(s) was activated by the pretreatment of rats with only phenobarbital. The O-dealkylation activities in liver microsomes from intact and phenobarbital pretreated rats were inhibited markedly by the addition of hexobarbital to the incubation mixture, but no inhibition was observed with alpha-naphthoflavone. On the other hand, the O-dealkylation activities in microsomes from beta-naphthoflavone-pretreated rats were inhibited remarkably by alpha-naphthoflavone. These results confirmed that several microsomal enzymes, including the cytochrome P-450's and UDP-glucuronyltransferase, participate in the biotransformation of 7-alkoxycoumarin, and these enzymes are regulated differently by inducers.

7-Alkoxycoumarin O-Dealkylase↗

Heterogeneous distribution of the cytochrome P-450 monooxygenase system in rat liver lobes.

Enzyme distribution in rat liver lobes was investigated using liver homogenate as the enzyme source. When the content or the activity was expressed on the basis of unit (gram) wet weight of liver tissue, the protein concentration was almost the same throughout the liver, but several enzymes were distributed heterogeneously within the liver. Cytochrome P-450 monooxygenase activity was higher in the median and right lobes of livers, while the left lobe contained a higher concentration of mitochondrial enzymes. Phenobarbital induced cytochrome P-450 monooxygenase, and the activity was still higher in the median and right lobes even after the pretreatment of rats with phenobarbital. On the other hand, administration of beta-naphthoflavone resulted in a uniform increase of cytochrome P-450 (P-448) content throughout the liver to almost the same concentration. Increase of cytochrome P-448-dependent O-dealkylation activity of 7-alkoxycoumarin by the administration of beta-naphthoflavone was much greater in the left lobe compared to that in the median and the right lobes. Heterogeneous distribution of the enzymes in various liver lobes was also determined employing liver samples obtained from various physiological states of rats (fasting, glucose refeeding after fasting and hyperthyroidism), although the cytochrome P-450 content and drug-metabolizing activity were altered markedly depending upon the physiological states of the rats.

Animals↗

Cross-sectional echocardiographic study on atrial septal defect: pre- and postoperative considerations.

The interatrial septum (IAS) has not been readily appreciated by M-mode echocardiography, but cross-sectional echocardiography has the capability of recording the shape and location of the IAS. Thirty-five patients with secundum atrial septal defect (ASD) were studied with cross-sectional echocardiography for detection of the ASD defect and demonstration of the IAS features following ASD closure. The ASD was shown as an echo dropout at the mid-portion of the septum in those patients examined in the present study in the horizontal cross-sections at the fourth intercostal space. The edge of the remaining IAS sharply demarcated and the defect was constantly demonstrated. In the postoperative patients, the IAS was recognized as a smooth series of echoes and the defect was no longer recognized. A notch echo was demonstrated in patients who underwent direct suture of the defect, and two notch echoes were recorded in patients who had a patch closure from a cardiac operation. The size of the defect at cardiac operation ranged from 1.5 to 5.0 cm with an average of 3.3 +/- 0.2 cm. The defect was slightly smaller on cross-sectional echocardiograms than at the time of operation. As the defect grew larger, the right ventricular dimension and the Qp/Qs became larger as well. Postoperatively, the right ventricular dimension was remarkably decreased, and the paradoxical movement of the interventricular septum (IVS) was normalized in the majority of the patients. Cross-sectional echocardiography is useful to diagnose ASD, to measure the size of the IAS defect, and to follow the clinical course.

Adolescent↗

Histologic and histochemical investigation of Gaucher cells.

Electron microscopic investigations suggest that morphologically, Gaucher cells and histiocytes are very similar. The fact that there are tubular elements in the lysosomes strongly suggests the possibility of lysosomes as the precursors of Gaucher bodies. By means of the lectin staining methods, the localization of glucocerebroside is clearly demonstrable in Gaucher cells. Lectin staining is the significant diagnostic feature of both Gaucher's and Krabbe's diseases.

Biopsy↗