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Biomedical subjects

M Tsuchiya

Publications and source records attributed to M Tsuchiya.

At least 325 records · Page 18Linked to original sources
PubMed1990

In vitro effect of thymic epithelial culture supernate on cyclic GMP levels in rabbit platelets.

When supernatants of thymic epithelial cell cultures (STEC) or thymosin fraction 5 were incubated with washed platelets (37 degrees C for 30 min), the levels of platelet guanosine 3',5'-cyclic monophosphate (cyclic GMP) were increased in a dose-dependent manner. In contrast the supernatants from Chang, HeLa, or HCC-M cell cultures did not significantly affect the levels of intracellular cyclic GMP. The increment of intracellular cyclic GMP levels following treatment with STEC increased with longer incubation times until a plateau was reached at 30 min. This activity of STEC was found in fractions with a molecular weight below 10,000 daltons. Contents of guanine and guanosine in STEC were lower than those observed in other culture supernatants. STEC did not affect guanylate cyclase activity in platelets, but significantly inhibited cyclic GMP phosphodiesterase activities in platelet soluble and membrane fractions. Thymosin fraction 5 inhibited the phosphodiesterase activity of the soluble but not the membrane fraction.

Animals↗
PubMed1990

Changes in thymocytes due to aging--a study of the effects of thymic hormone on adenine nucleotides and thymocyte DNA.

The number of lymphocytes (especially T-lymphocytes) in peripheral blood decreases with aging. The decline is most evident in the thymus. In this study, total AN in the thymocytes of aged mice clearly decreases from that of young mice. The quantity of thymic hormones secreted by thymic cells decreases with the organism's thymus involution with age. After demonstrating the decrease in total AN (primarily ATP) levels within the thymocytes of aged mice, we attempted to reattain the levels of younger thymocytes by the administration of various thymic hormones. Examination of DNA in the thymocytes of 4 and 58-week-old mice, using flowcytometry, showed no differences in content. However, it is significant that aged mouse thymocytes's energy level can be returned to those of young mice with the application of Th-5.

Adenine Nucleotides↗
PubMed1990

Inflammatory bowel diseases and thymus disorder: reactivity of thymocytes with monoclonal antibodies.

Thymectomy is one of the most effective means of treating myasthenia gravis (MG). Formation of lymphoid follicles in the thymus is seen at high rate in ulcerative colitis (UC) as well as MG. We examined the subsets of lymphocytes in the thymuses taken from patients with inflammatory bowel diseases (IBD), using OK series monoclonal antibodies. Decreases in OKT8 (CD8)-, 6(CD1)- and 10-positive cells and an increase of IA1-positive cells were observed in UC. In contrast, there were no significant changes in Crohn's disease (CD). Therefore, the thymocytes from UC appear to consist of comparatively matured cells under the influence of thymic hormone.

Adult↗
PubMed1990

[An evaluation of 3-dimensional position of mandibular condyle to glenoid fossa using tomogram: an analytical technique and its clinical application].

In recent years, temporomandibular disorder (TMD) is occasionally found among orthodontic patients and has become a great concern in orthodontics. From this point of view, a certain technique has been hopefully anticipated for diagnosis and treatment planning. The purpose of this study was to develop a new method for evaluating three-dimensional position of the mandibular condyle relative to the glenoid fossa and also to investigate its clinical application. Seven-layered tomograms were taken and contours of the condyle and glenoid fossa were traced on an acetate paper. These contours were entered into a personal computer by use of a digitizer and were equally divided into 9 parts for the condyle and 15 parts for the glenoid fossa, consisting of 10 and 16 points on the contours of condyle and glenoid fossa. Three-dimensional configuration of the TMJ was thus constructed by 108 triangles for the condyle and 180 triangles for the glenoid fossa. The shortest distance between the condyle and the glenoid fossa (CGFD) was then calculated along a perpendicular line to center of gravity of a triangle on the condyle. For evaluating the position of the condyle to the glenoid fossa easily in a three dimensional space, surface of the condyle was divided into five areas, i.e. anterior, posterior, middle, lateral and medial areas. In order to investigate whether or not the CGFD is accurate enough to identify the distance between surface of the condyle and glenoid fossa, a model of hemi-spherical solid shell was made, of which the thickness is 3.0 mm. Tomograms of the model were taken to analyze the thickness. Direct measurement of the same area was also made by calipers. Two means were approximately 3.0 mm, which is the thickness itself and no significant differences were indicated at 5% level of confidence. The present technique was applied to diagnosis of an orthodontic patient with painful clicking as TMD. The analyzed CGFDs were coincident with clinical symptom. It is shown that the present approach provides an availability and a possibility to evaluate positional relationship between the mandibular condyle and the glenoid fossa of patients with TMDs.

Humans↗
PubMed1990

[Liquid crystal thermography; a reliable method for detecting soda lime exhaustion].

The dynamic and functional state of soda lime can be more precisely assessed by measuring changes in wall temperatures of the absorption chambers rather than observing color change of the soda lime granules. We demonstrated in this report that the liquid crystal thermometer is an inexpensive and reliable measuring device for this purpose.

Anesthesiology↗
PubMed1990

[Relation between localization of gastric mucosal lesions and microvascular disturbance].

Acute gastric mucosal lesions in the rats were produced by intermittent electrical stimuli to a main trunk of the left gastric artery (LGA), right gastroepiploic artery (RGEA) or a posterior branch of the left gastric artery (PLGA). The image processing analysis was applied to determine the relation between distribution of the lesions and perfusion area of the supplying artery to which electrical stimuli were given. Electrical stimuli of 50 Hz, 5 msec, 100 microA was supplied to the artery for 30 sc three times with 10 sec interval. A series of these stimuli was repeated three times. The mucosal blood flow measured with the laser doppler method in each perfusion area was reduced to less than 35% of the control value during the electrical stimuli for 30 sec. After the repeated electrical stimuli to LGA, 85.8 and 95.4% of the mucosal lesions were found in the mean and maximum perfusion area of LGA, respectively. Electrical stimuli to PLGA caused 84.5% and 95.3 of the lesions in the mean and maximum area of PLGA, respectively. Stimuli to RGEA caused 53.4% and 74.1% of the lesions in the mean and maximum perfusion area of RGEA. In the antrum, electrical stimuli to LGA, PLGA or RGEA produced 0%, 5.4% or 5.0% of the mucosal lesions. It is concluded that the corpus mucosal lesions induced by regional ischemia are distributed in the ischemic area.

Animals↗
PubMed1990

[Let's study pharmacokinetics related to anesthesiology by using computer graphics: inhalation anesthetics].

The pharmacokinetics of inhalation anesthetics has been out of public interest for 20 years. Partition coefficient or solubility of anesthetic, an important determinant of uptake and distribution of inhaled anesthetics, may be the only remains of the pharmacokinetics of inhaled anesthetics. There still, however, are a few evidences which can not be explained by partition coefficient of anesthetic. The authors applied three compartment model to the rise of the blood concentration of anesthetics, i.e., nitrous oxide, enflurane, halothane, and diethyl ether. We revealed that the change in the blood anesthetic concentration may be related to the size of compartments and their time constants. The size of compartments and their time constants may be determined by interaction of partition coefficient of anesthetic and blood distribution to the tissues which may be different with different anesthetic, and may also be different when the blood concentration of anesthetic is different.

Anesthesia, Inhalation↗
PubMed1989

Tissue and species distribution of mRNA encoding two ADP-ribosylation factors, 20-kDa guanine nucleotide binding proteins.

Cholera toxin catalyzed ADP-ribosylation of Gs alpha, the stimulatory guanine nucleotide binding protein of the adenylyl cyclase system, is enhanced by approximately 20-kDa guanine nucleotide binding proteins, termed ADP-ribosylation factors or ARFs. ARF is an allosteric activator of the A1 catalytic protein of the toxin. Bovine ARF cDNA clones, ARF-1 isolated from adrenal (Sewell & Kahn, 1988) and ARF-2B from retina (Price et al., 1988), exhibit nucleotide and deduced amino acid sequences that are 80% and 96% identical, respectively, in the coding region. To determine tissue and species distribution of ARF-like mRNAs, bovine ARF-2B and human ARF-1 cDNAs and 30- or 48-base oligonucleotide probes that distinguish between ARF-1 and ARF-2B cDNAs in coding and 3'-untranslated regions were used for Northern analysis of poly(A+) RNA from different tissues and species. On the basis of hybridization with specific oligonucleotide probes, all bovine tissues contained mRNAs of 1.7 and 2.1 kb that were related to ARF-1 and ARF-2B, respectively. Northern analysis of brain poly(A+) RNA from different species with ARF-2B and ARF-1 cDNAs at low stringency demonstrated several bands varying in size from 0.9 to 3.7 kb. A 1.7-kb band consistently hybridized with an ARF-1 30-base coding-region probe but not with a probe for the 3'-untranslated region. Similar ARF-2B oligonucleotide probes did not hybridize with rat, mouse, rabbit, or human brain mRNA. Cleavage of ARF-2B cDNA with PvuII generated two fragments, one containing coding and the other 3'-noncoding region.(ABSTRACT TRUNCATED AT 250 WORDS)

ADP-Ribosylation Factors↗
PubMed1989

Arginine-specific ADP-ribosyltransferase from rabbit skeletal muscle sarcoplasmic reticulum is solubilized as the active form with trypsin: partial purification and characterization.

Arginine-specific ADP-ribosyltransferase from rabbit skeletal muscle sarcoplasmic reticulum was solubilized as the active form with trypsin. The enzyme was partially purified by subsequent chromatography, successively on DE-52, Con A-Sepharose and Sephadex G-75. An approximately 2,000-fold purification was achieved from the 105,000 x g supernatant of trypsin-treated membrane with a recovery of 2.8%. Dithiothreitol, which activates hen liver nuclear ADP-ribosyltransferase, inhibited the enzyme.

Animals↗
PubMed1989

Establishment of a human cell line (HCC-T) from a patient with hepatoma bearing no evidence of hepatitis B or A virus infection.

A human hepatoma cell line, designated HCC-T, was established. The tumor was surgically obtained from a Japanese male patient with hepatocellular carcinoma (HCC) arising in a cirrhotic liver that had supposedly developed from nonAnonB (NANB) chronic hepatitis. HCC-T exhibited a typical morphology of epithelial cells in culture. Population doubling time was 24 hours and HCC-T cells had characteristics of malignant cells demonstrated by the ability to grow in a soft agar medium and transplantability to nude mice. The histologic condition of the tumor transplanted to a nude mouse showed similarity to the original tumor. A chromosome analysis showed that there were ten identifiable marker chromosomes and sex chromosomes with its modal number of 64. Alpha-fetoprotein (AFP) production was demonstrated by direct immunofluorescence study, but albumin or hepatitis B surface antigen were not detectable. The integration of hepatitis B viral DNA was not demonstrable in the genome of HCC-T cells or the original hepatoma.

Aged↗
PubMed1989

Expression of Go alpha mRNA and protein in bovine tissues.

Go alpha is a 39-kDa guanine nucleotide-binding protein (G protein) similar in structure and function to Gs alpha and Gi alpha of the adenylate cyclase complex and to transducin (Gt alpha) of the retinal photon receptor system. Although expression of Go alpha protein has been reported to be tissue-specific, other workers have found Go alpha mRNA in all rat tissues examined. In order to clarify this contradiction, studies to verify the distribution of Go alpha mRNA and protein in bovine and rat tissues were performed. Tissues were screened for the presence of Go alpha mRNA by use of a series of restriction fragments of a bovine retinal cDNA clone, lambda GO9, and oligonucleotide probes complementary to sequences specific among G alpha subunits for the 5' untranslated and coding regions of Go alpha. These probes hybridized predominantly with mRNA of 4.0 and 3.0 kb in bovine brain and retina. A 2.0-kb mRNA in retina also hybridized strongly with the cDNA but weakly with the oligonucleotide probes. In bovine lung, two mRNAs of 1.6 and 1.8 kb hybridized with the cDNA while only the 1.6-kb species hybridized with the coding-region oligonucleotide. In bovine heart, only a 4.0-kb mRNA was detected and in amounts much less than those in the other tissues. A similar distribution of Go alpha mRNAs was seen in rat tissues. In bovine tissues, Go alpha protein was identified with rabbit polyclonal antibodies directed against purified bovine brain Go alpha. An immunoreactive 39-kDa membrane protein was found principally in retina and brain, and in a lesser amount in heart.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

DNA-dependent mono(ADP-ribosyl)ation of p33, an acceptor protein in hen liver nuclei.

A non-histone acceptor protein for hen liver nuclear ADP-ribosyltransferase was purified to an apparently homogeneous state through salt extraction and chromatography on hydroxyapatite, phenyl-Sepharose, carboxy-methyl-cellulose, Sephadex G-75, phenyl 5-PW, mono S and Radial PAK C18. This protein was termed p33. The ADP-ribosylation of p33 was enhanced more than 60-fold by double-stranded DNA. Single-stranded DNA, RNA and poly(L-glutamate), but not deoxyribonucleotide, were partially effective. DNA-dependent ADP-ribosylation was also observed when whole histones were used as acceptor. DNA required for the maximal ADP-ribosylation depended on the dose of the acceptor protein; the optimal mass ratio of DNA to the acceptor protein was 1:1 with both p33 and whole histones. DNA decreased the Km for NAD and concomitantly increased the Vmax value, but did not alter the Km for p33. These results are consistent with the idea that p33 may participate in chromatin processes such as replication or transcription, through modification by nuclear ADP-ribosyltransferase.

ADP Ribose Transferases↗
PubMed1989

[Radiation therapy of choroidal metastases].

A retrospective study was performed on 30 cases with choroidal metastases referred to the Cancer Institute Hospital between July 1975 and June 1986. Of these 30 cases, 32 eyes of 26 patients were treated with irradiation of 4.3 MV X-rays or 12 MeV electron beam therapy in the range of 20-60 Gy to restore vision and prevent blindness. The tumor response to radiation therapy confirmed by ophthalmoscopic examination was described as complete, partial or no response. Of the 32 eyes, 31% had complete response, and 47% showed partial response. The overall response rate was 78%. A visual response as defined by marked or partial improvement of visual acuity and/or subjective symptoms was obtained in 16 out of 26 patients (62%). All of these patients were free of recurrence of symptoms in their quality of life. This proved radiotherapy to be a useful modality of treatment for choroidal metastases. No obvious radiation injuries were encountered in this series.

Adult↗