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Biomedical subjects

T Masuda

Publications and source records attributed to T Masuda.

At least 433 records · Page 24Linked to original sources
PubMed1991

Immunohistochemical characterization, distribution and ultrastructure of lymphocytes bearing the gamma/delta T-cell receptor in the human gut.

The phenotypic characterization and distribution of lymphocytes bearing the gamma/delta T-cell receptor (TCR) in the human gut were investigated by an immunohistochemical technique. A mirror section technique and double staining method were used for the phenotypic analysis. Intraepithelial delta-positive cells were almost all CD8-positive and rarely negative for both CD4 and CD8. On the other hand, lymphocytes bearing TCR gamma/delta in the lamina propria were largely negative for both CD4 and CD8. The ratio of delta-positive to CD3-positive cells amongst intraepithelial lymphocytes was larger in the lower intestine. Delta-positive cells were also observed in paracortical areas of lymphoid follicles. Immunoelectron microscopic observation revealed granular structures in these delta-positive cells, which are also present in large granular lymphocytes. The role of lymphocytes bearing TCR gamma/delta in mucosal immune responses in the human gut are discussed.

Adult↗
PubMed1991

The parietal cell autoantigens recognized in neonatal thymectomy-induced murine gastritis are the alpha and beta subunits of the gastric proton pump [corrected].

Murine autoimmune gastritis, induced by neonatal thymectomy, bears a striking similarity in pathology to the human autoimmune disease, pernicious anemia. Autoantibodies to parietal cells are found in both murine and human diseases. Monoclonal immunoglobulin G autoantibodies, obtained from neonatally thymectomized mice, have previously been shown to recognize two groups of gastric parietal cell antigens. In the present study, it is shown that two of these monoclonal autoantibodies, designated 1H9 and 2B6, are directed against the alpha subunit and beta subunit, respectively, of the gastric hydrogen-potassium-stimulated adenosine triphosphatase (H+,K(+)-ATPase; proton pump). Monoclonal antibody 1H9 showed reactivity by immunoblotting with a 95-kilodalton component of dog gastric tubulovesicular membranes and with a fusion protein containing the hydrophilic domain of the alpha subunit of the H+,K(+)-ATPase. Monoclonal antibody 2B6 reacted by immunoblotting with the 60-90-kilodalton glycoprotein (beta subunit) of the tomato lectin-purified dog H+,K(+)-ATPase and with the 60-90-kilodalton autoantigen purified with human parietal cell autoantibodies. Monoclonal antibody 2B6 also reacted with the deglycosylated 35-kilodalton core protein of the tomato lectin-purified 60-90-kilodalton beta subunit and of the purified 60-90-kilodalton autoantigen. Parietal cell autoantibody-positive sera from 20 mice with experimentally induced gastritis showed reactivity predominantly with the alpha and/or beta subunit of the gastric H+,K(+)-ATPase. Therefore, it is concluded that the major molecules targeted by parietal cell autoantibodies from mice with neonatal thymectomy-induced murine autoimmune gastritis and from humans with pernicious anemia are identical.

Adenosine Triphosphatases↗
PubMed1991

Immunohistochemical characterization, distribution, and ultrastructure of lymphocytes bearing T-cell receptor gamma/delta in inflammatory bowel disease.

Phenotypic characterization and distribution of gamma/delta T lymphocytes in the intestinal mucosa were investigated in ulcerative colitis and Crohn's disease by immunohistochemistry. The ratio of delta(+) cells to CD3(+) cells in the intraepithelial space of colon was decreased in Crohn's disease (13%) and strikingly decreased in ulcerative colitis (8%) compared with the control (36%). Delta(+) cells in the lamina propria were also decreased, particularly in the distal ileum of Crohn's disease (4%), compared with the control (15%). On the contrary, the cells gathered at the severe inflammatory sites with other inflammatory cells, including beta(+) cells, and were densely distributed in the T-cell zone around lymphoid follicles. Phenotypic characterization showed that delta(+) lamina proprial lymphocytes of colon were mainly CD4(-)CD8(-) in the control (80%) and Crohn's disease (59%). However, in ulcerative colitis, CD4(-)CD8(-) delta(+) lymphocytes were rarely found (3%). This reflects the difference of immunologic background between the two diseases. Immunoelectron microscopically, these cells in inflammatory bowel disease were rich with vesicular structures in cytoplasms, whereas those in the control group contained electron-opaque granules. The decrease and the morphological change may be closely related to the weakness of mucosal defense.

Adult↗
PubMed1991

Transformation of mammalian cells by luteoskyrin.

The transforming activity of luteoskyrin (LS), a bis-anthraquinoid mycotoxin produced by Penicillium islandicum Sopp., and a hepatocarcinogen in rodents, was examined by an in vitro transformation assay using mouse embryonal Balb/3T3 A31-1-1 cells. The results revealed that LS induced type III foci at 0.5 micrograms/ml, and that the cells selected from these foci by soft-agar cloning grew with a high saturation density. Thus, it was confirmed that LS not only induces hepatic tumours in laboratory animals, but also transforms in vitro cultured mammalian cells. The tumorigenicity of the transformants obtained was confirmed by transplantation into nude mice and by image analysis with IIIIn. A transfection assay, using calcium phosphate co-precipitation, demonstrated that the DNA of the cloned cells transformed NIH3T3 cells. Northern blot also revealed transcriptional activation of c-myc and c-Ha-ras oncogenes. The possible participation of LS-derived hydroxy radicals in the formation of genetic lesions was discussed.

Animals↗
PubMed1991

Formation of the 8-hydroxydeoxyguanosine moiety in hepatic DNA of mice orally administered with luteoskyrin, a bis-anthraquinoid mycotoxin.

Following oral administration of luteoskyrin (LS), a bis-anthraquinone and hepatocarcinogenic mycotoxin of Penicillium islandicum Sopp, to ddY male mice, significant increases in serum GOT and GPT activities, 8-hydroxydeoxyguanosine (8-OH-dG) residues in hepatic DNA, and hepatic lipid peroxide level were observed. alpha-Tocopherol (alpha-TP) depressed the hepatic lipid peroxide content but did not decrease the 8-OH-dG level. These findings indicate that hydroxy radicals derived from LS are involved in the peroxidation of hepatic lipids followed by liver injury, and that the hydroxylation reaction of deoxyguanosine (dG) residues of hepatic DNA at the 8-position was unsusceptible to alpha-TP.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1991

Parathyroid gland adenoma in primary hyperparathyroidism: report of two cases--chief and oxyphil cell adenoma.

Parathyroid adenomas are classified into two types: chief cell and oxyphil cell variants. In this report two types of parathyroid adenoma in association with hyperparathyroidism were examined. Both cases had suffered from renal calculi, and underwent operation. The laboratory tests showed high serum calcium and parathyroid hormone (PTH) levels. An exploratory surgery revealed a solitary tumor in each case. After extirpation of the parathyroid tumor these data returned to normal values. Electronmicroscopically, oxyphil cell adenoma in this report was characterized by numerous mitochondria and annulate lamellae in the cytoplasm. In some tumor cells secretory-like granules were observed.

Adenoma↗
PubMed1991

Response of plasma atrial natriuretic factor to experimentally induced aortic and mitral regurgitation in dogs.

STUDY OBJECTIVE: The correlations between the plasma concentration of atrial natriuretic factor and right atrial or left atrial pressure were studied in experimentally induced aortic regurgitation and mitral regurgitation in dogs. DESIGN: Aortic regurgitation was created by opening the tip of a basket wire catheter placed at the aortic annulus via the left ventricular wall, and terminated by pulling back the catheter. To create mitral regurgitation a basket catheter was inserted into the mitral annular position via a pulmonary vein. Regurgitation was induced by opening the tip of the catheter, and terminated promptly by closing it. EXPERIMENTAL MATERIAL: Seven beagle dogs were prepared for the aortic regurgitation model and six for the mitral regurgitation model (weights 11.5 to 14.5 kg). MEASUREMENTS AND MAIN RESULTS: The plasma concentration of atrial natriuretic factor was highly correlated with right atrial pressure (r = 0.78, SD = 0.07, n = 7) and left atrial pressure (r = 0.82, SD = 0.05, n = 7) in aortic regurgitation; and with right atrial pressure (r = 0.82, SD = 0.05, n = 6) and left atrial pressure (r = 0.84, SD = 0.05, n = 6) in mitral regurgitation. Further evaluation of the molecular forms of plasma atrial natriuretic factor revealed the alpha form in all 13 dogs and the gamma form in two (one with aortic and the other with mitral regurgitation); no evidence of the beta form was seen. CONCLUSIONS: Atrial natriuretic factor secretion responds rapidly to the circulatory changes caused by valvular incompetence.

Animals↗
PubMed1991

Protease II from Escherichia coli: sequencing and expression of the enzyme gene and characterization of the expressed enzyme.

Protease II gene of Escherichia coli HB101 was cloned and expressed in E. coli JM83. The transformant harboring a hybrid plasmid, pPROII-12, with a 2.4 kbp fragment showed 90-fold higher enzyme activity than the host. The whole nucleotide sequence of the inserted fragment of plasmid pPROII-12 was clarified by the dideoxy chain-terminating method. The sequence that encoded the mature enzyme protein was found to start at an ATG codon, as judged by comparison with amino terminal protein sequencing. The molecular weight of the enzyme was estimated to be 81,858 from the nucleotide sequence. The reactive serine residue of protease II was identified as Ser-532 with tritium DFP. The sequence around the serine residue is coincident with the common sequence of Gly-X-Ser-X-Gly, which has been found in the active site of serine proteases. Except for this region, protease II showed no significant sequence homology with E. coli serine proteases, protease IV and protease La (lon gene), or other known families of serine proteases. However, 25.3% homology was observed between protease II and prolyl endopeptidase from porcine brain. Although the substrate specificities of these two enzymes are quite different, it seems possible to classify protease II as a member of the prolyl endopeptidase family from the structural point of view.

Amino Acid Sequence↗
PubMed1991

Congenital laminar defect of the upper lumbar spine associated with pars defect. A report of eleven cases.

Lumbar spondylolysis generally is considered to be a fatigue fracture of the pars interarticularis, and no unequivocal case of congenital spondylolysis has been reported. The authors describe 11 cases of unilateral spondylolysis (possibly congenital laminar defect associated with pars defect) of the upper lumbar spine. They have roentgenographic characteristics distinct from conventional spondylolysis of the lumbar spine, including hypoplasia of the spinal accessory process, rotation of the spinous process contralaterally to the spondylolysis, and prominent ipsilateral lamina. The anomaly found in these 11 patients probably is congenital, and its clinical significance is not known.

Adolescent↗
PubMed1991

Inhibition of autoimmune diabetes in NOD mice with serum from streptococcal preparation (OK-432)-injected mice.

We have recently reported that systemic and chronic administration of recombinant tumour necrosis factor alpha (TNF-alpha), as well as streptococcal preparation (OK-432), inhibits development of insulin-dependent diabetes mellitus (IDDM) in NOD mice and BB rats, models of IDDM. In this study we examined whether serum containing endogenous TNF induced by OK-432 injection could inhibit IDDM in NOD mice. Treatment twice a week from 4 weeks of age with OK-432-injected mouse serum, which contained endogenous TNF (75U), but not IL-1, IL-2 and interferon-gamma (IFN-gamma) activity, reduced the intensity of insulitis and significantly inhibited the cumulative incidence of diabetes by 28 weeks of age in NOD mice, as compared with the incidence in non-treated mice (P less than 0.01) and in mice treated with control serum (P less than 0.02). This inhibitory effect of the serum was diminished, although not significantly, by neutralization of serum TNF activity with anti-mouse TNF antibody. In the mice treated with the serum from OK-432-injected mice, Thy-1.2+ or CD8+ spleen cells decreased (P less than 0.01) and surface-Ig+ (S-Ig+) cells increased (P less than 0.05), whereas the proliferative response of spleen cells to concanavalin A (P less than 0.01) and lipopolysaccharide (P less than 0.05) increased. The results indicate that the inhibition by OK-432 treatment of IDDM in NOD mice was partially mediated by serum factors including endogenous TNF.

Animals↗
PubMed1991

Genetic studies on experimental autoimmune gastritis induced by neonatal thymectomy using recombinant inbred strains between a high-incidence strain, BALB/c, and a low-incidence strain, DBA/2.

Thymectomy on day 3 after birth induced autoimmune gastritis (AIG) at the age of 2 months in 51-73% of BALB/c mice, and in only 3-5% of DBA/2 mice. AIG was detected by histological and serological (immunofluorescence staining for detecting anti-parietal cell autoantibody) examination. However, autoantibody was weakly positive in almost all of these DBA/2 mice when measured by ELISA using extract of murine gastric mucosa as the antigen. To investigate genetically the mechanism controlling the incidence of AIG, II recombinant inbred strains established by brother-sister mating of (BALB/c x DBA/2) F2 mice (C x D2 strains) were used. Among 26 markers tested, the Mls-1 locus on BALB/c chromosome 1 and the Hc locus coding a complement component (C5) on BALB/c chromosome 2 were found to be associated with high susceptibility to AIG. However, if one or both of the loci were of DBA/2 origin, mice showed medium or low susceptibility to AIG. For further analysis, F1, F2 and back-cross generations of these two strains were tested, but segregation of a single susceptibility or insusceptibility gene was not obtained. Taken together, it seems probable that two or more genes are involved in the induction mechanism of AIG. We did not detect C5 deposition in AIG lesions, nor complement-dependent cytotoxic antibody to parietal cells in serum from AIG mice. However, injection of irradiated spleen cells of DBA/2 mice into BALB/c mice thymectomized on day 3 augmented the incidence of AIG from 71 to 100%, but not that of oophoritis (33%). A relationship between Mls-1a determinants and the pathogenesis of AIG was further suggested from the fact that V beta 6 TcR-expressing T cells increased in number in AIG-bearing compared with normal BALB/c mice.

Animals↗
PubMed1991

HLA-DR expression on M cells overlying Peyer's patches is a common feature of human small intestine.

The expression of major histocompatibility complex (MHC) class II (HLA-DR) antigens on M cells within follicle-associated epithelial cells (FAE) covering Peyer's patches was analyzed immunohistochemically. HLA-DR antigens were strongly expressed on M cells and cells with dendritic morphology, whereas other FAE covering Peyer's patches showed weak, but definite staining. Dendritic cells were also positive for S-100 protein and IL-1. These findings suggest that M cells as well as dendritic cells within FAE form an antigen-presenting cell system and contribute to the first information releaser for the mucosal immune system.

Dendritic Cells↗
PubMed1991

[Biohazard in clinical laboratories in Japan].

This survey of occupationally acquired infections in clinical laboratory workers was made by questionnaires to 306 hospitals in which 698 doctors and 8654 technicians worked. There were 177 probable infections during the previous decade (1979-88). In both doctors and technicians annual incidence rate of infection was 0.2% on an average. These included 77 cases of tuberculosis, 59 cases of HBV hepatitis, 24 cases of non-A, non-B hepatitis, 6 cases of rubella, 5 cases of HAV hepatitis, 2 cases of mycoplasmal pneumonia, one case of campylobacter enteritis, one case of paratyphus, one case of salmonellosis and one case of chicken pox. There were no fatal cases. In the recent two years the occurrence of HBV hepatitis among the clinical laboratory workers apparently has decreased, but tuberculosis and non-A, non-B hepatitis occurred unchangedly. Tuberculosis occurred frequently among the staff of the pathology laboratory (40 cases) and in bacteriology (25 cases), but rarely in biochemistry (3 cases) and in hematology (one case). On the other hand, HBV hepatitis occurred frequently among the staff of the biochemistry laboratory (33 cases) and in hematology (11 cases), but rarely in bacteriology (one case). These differences showed the existence of occupational exposure, but only 20% of these cases were due to recognized accidents. According to these results infection control practices for diminishing laboratory-associated infection must be performed.

Containment of Biohazards↗
PubMed1991

Effect of calcium on rat gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine.

The effect of calcium carbonate (CaCO3) on the initiation of gastroduodenal carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was examined under the conditions with and without sodium chloride. Male Wistar rats were given drinking water containing MNNG (100 mg/liter) and one of the following diets during the first 20 weeks ad libitum. Group 1 was given basal diet; group 2, diet with 10% NaCl; group 3, diet with 10% NaCl and 2.5% CaCO3; group 4, diet with 10% NaCl and 7.5% CaCO3; group 5, diet with 7.5% CaCO3. During the next 20 weeks, all groups were fed with the basal diet and tap water. The carcinogenic incidences of glandular stomach between the nonsalted diet groups, 1 and 5 (15% and 16% respectively), were not significantly different at the 40th week. The incidences in the salted diet groups 2, 3, and 4 were 59, 63, and 43%, respectively, indicating no statistical difference among them. Thus, CaCO3 showed no anticarcinogenic effect on gastroduodenal carcinogenesis. In the groups 3 and 4, however, increased incidence of duodenal cancer was observed.

Animals↗
PubMed1991

Pharmacological properties of the new non-steroidal anti-inflammatory agent etodolac.

The anti-inflammatory, analgesic, antipyretic and ulcerogenic activities of etodolac (CAS 41340-25-4), a new nonsteroidal anti-inflammatory agent, were compared with those of indometacin and other anti-inflammatory drugs in experimental animals. Etodolac had a remarkable anti-inflammatory effect in various experimental models: ultraviolet erythema, carrageenin-induced edema and swelling of adjuvant arthritis. In these models, the effective dose of etodolac was several fold that of indometacin. Etodolac inhibited prostaglandin E2 formation in a concentration-dependent manner, and its inhibitory potency was about 1/5 of that of indometacin. Etodolac also caused marked inhibition of granuloma formation and leucocyte functions such as chemotaxis, lysosomal enzyme release and active oxygen generation. These effects of etodolac were observed at similar doses of indometacin. Etodolac suppressed inflammatory pain but not non-inflammatory pain, and had an antipyretic effect but did not lower normal rectal temperature. Etodolac had no effect on delayed hypersensitivity reactions and was much less ulcerogenic than indometacin. These results indicate that etodolac is a low ulcerogenic anti-inflammatory agent with suppressing activities on leucocyte functions to the same extent as indometacin and prostaglandin biosynthesis.

Animals↗
PubMed1991

[Immunoelectron microscopic localization of herpes simplex virus glycoprotein D in infected culture cells using the indirect peroxidase-labeled antibody method].

Ultrastructural localization of herpes simplex virus (HSV) glycoprotein D was studied using HSV infected monolayers of rabbit corneal cells. The pre-embedding indirect peroxidase-labeled antibody method was employed. Immediately after viral adsorption, deposits of reaction products were seen on the viral envelope. The cytoplasmic membrane showed focal positive staining at the sites of virus attachment. At 1 hour after infection, reaction products were found on the envelope of the virus in the phagocytic vacuoles and on the walls of these vacuoles. The localization of the staining did not alter until 4 hours after infection. At 5 hours after infection the nuclear envelope and parts of the membranous structures in the cytoplasm were stained. At 6 hours after infection, when capsid assembly began, the cell surfaces were stained throughout. At 12 hours after infection, when enveloped particles were released into the extracellular space, viral particles were enveloped by the nuclear membrane or membranous structures in the cytoplasm. These membranes were stained positively.

Animals↗
PubMed1991

[Is the new WHO's histological typing clinically useful for the diagnosis of follicular cancer of the thyroid?].

We tried to re-diagnose our 57 cases of thyroid follicular cancer between 1965 and 1988 in accordance with Histological Typing of Thyroid Tumours published by WHO in 1988. 1) The incidence of follicular cancer in differentiated cancers was decreased from 17.9% to 8.3% (26 cases). The number of widely invasive type and minimally invasive type was 13 cases equally. 2) Twenty four cases were diagnosed as papillary cancer. The reason was that 20 cases had a small focus of papillary structure, and other 4 cases had features of follicular variant type of papillary cancer. These 24 cases had good prognosis as our 262 cases of papillary cancer, in contrast to 26 cases of follicular cancer having worse prognosis. 3) The incidence of distant metastasis in follicular carcinoma was increased from 28.1% to 42.3%; 23.9% in minimally invasive type and 61.5% in widely invasive type, respectively. New WHO classification is acceptable according to this clinical study of our cases. We would have to treat more aggressively the patient diagnosed follicular cancer by WHO classification because of high incidence of distant metastasis.

Adenocarcinoma↗