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Biomedical subjects

Y Shibata

Publications and source records attributed to Y Shibata.

At least 613 records · Page 34Linked to original sources
PubMed1988

[Epidemiological study of periodontal disease. Mass examination in university students with CPITN].

The purpose of this study was to investigate the prevalence and treatment needs of periodontal disease in the 1,150 university students (male: 726, female: 424) by using simplified Community Periodontal Index of Treatment Needs (CPITN-S). The results were as follows: 1. Approximately 85% of all the subjects have something wrong in periodontal tissue. If examined in detail; 1) Code 4: a group (1.6%) who had a deep pocket more than 6 mm. 2) Code 3: a group (20.1%) who had a shallow pocket 4 to 5 mm. 3) Code 2: a group (55.9%) who had supra- or subgingival calculus. 4) Code 1: a group (7.5%) who had bleeding on probing only. 2. As for treatment needs (TN), approximately 78% of the subjects need to receive professional prophylaxis and more complex treatment including periodontal surgery (TN 2-3). 3. Average time required to examine one subject was about one minute, so we could cut down the measuring time. From this point, we have understood that simplified CPITN was greatly effective to curtail the time for the primary screening of periodontal disease in the young age group.

Female↗
PubMed1988

Growth inhibitor of calcium oxalate monohydrate crystal in vitamin B6-deficient rat urine and kidney.

Urinary and renal inhibitory activities of calcium oxalate monohydrate crystal growth in normal or vitamin B6-deficient rats were investigated. Renal inhibitory activity in vitamin B6-deficient rats was lower than that in normal rats. Renal inhibitory activity in vitamin B6-deficient rats was about 74% of normal level. Urinary inhibitory activity did not show a significant difference between normal and vitamin B6-deficient rats.

Animals↗
PubMed1988

Marked acceleration of the autoimmune disease in MRL-lpr/lpr mice by the influence of the Yaa gene from BXSB mice.

MRL-lpr, Yaa males were developed by the transfer of the Yaa gene from BXSB males to the MRL-lpr strain. The early-onset autoimmune disease of MRL-lpr males was accelerated further by the action of Yaa. All the serological parameters of autoimmune disease examined, i.e., anti-DNA antibodies, rheumatoid factors and circulating immune complexes were elevated earlier in MRL-lpr, Yaa males than in MRL-lpr males. Consequently, the MRL-lpr, Yaa males showed the clinical signs of an earlier and more rapidly progressive glomerulonephritis as compared with MRL-lpr males. The lifespan of MRL-lpr, Yaa males was shortened by about 50% in comparison to MRL-lpr males, with 90% of MRL-lpr, Yaa males dead by about 4 months of age. The clinical features and overall intensity of the autoimmune responses in the terminal stages appeared to be similar in both MRL-lpr, Yaa and MRL-lpr males. Thus, Yaa appeared merely to accelerate the disease course of MRL-lpr males, without altering the essential nature of the disease.

Animals↗
PubMed1987

Diversity in the effects of extracellular ATP and adenosine on the cellular processing and physiologic actions of insulin in rat adipocytes.

ATP or adenosine (1 mM) added to extracellular buffer abolished both chloroquine- and monensin-dependent accumulation of [125I]iodoinsulin in isolated rat adipocytes. The effects of ATP were not secondary to its conversion to adenosine and were mimicked by beta, gamma-methyleneadenosine 5'-triphosphate. ATP, but not adenosine, partially inhibited the binding of insulin to the cellular receptor. Neither ATP nor adenosine had any significant effect on both internalization of cell-bound insulin and externalization of the internalized hormone. The degradation of cell-bound insulin was reduced to a considerable extent by both 0.1 mM chloroquine and 5 mM ATP, to a lesser degree by 1 mM ATP, and not significantly by 1 or 5 mM adenosine. Physiologically, (a) 1 mM ATP had a strong, while 1 mM adenosine had a mild inhibitory effect on the insulin-stimulated glucose transport without affecting its basal activity, (b) both ATP and adenosine moderately stimulated basal as well as insulin-stimulated glycogen synthase, and (c) ATP, but not adenosine, transiently stimulated basal cAMP phosphodiesterase without affecting the insulin-stimulated enzyme. Phosphodiesterase in cells that had been exposed to ATP for 30 min was refractory to ATP added afresh, but not to insulin. These data suggest that (a) extracellular ATP may block the degradative pathway of insulin processing, (b) adenosine might render the ordinarily irreversible intracellular traffic of insulin reversible or modulate a pathway which is yet to be identified, (c) the previously reported effect of ATP on glycogen synthase may not involve phosphorylation, (d) ATP stimulates cAMP phosphodiesterase by a mechanism which is distinct from that of insulin, and (e) the degradative pathway of insulin processing may not be involved in the physiologic actions of the hormone on glycogen synthase and phosphodiesterase.

2,4-Dinitrophenol↗
PubMed1987

rec-A protein-promoted recombination reaction consists of two independent processes, homologous matching and processive unwinding. A study involving an anti-rec-A protein-monoclonal IgG.

recA protein promotes the formation and processing of joint molecules of homologous double-stranded DNA and single-stranded DNA. We studied the effects of an anti-recA protein monoclonal IgG (ARM193) on two processes carried out by the recA protein. The homologous matching, i.e. pairing of double-stranded DNA and single-stranded DNA by forming intermolecular base-pairing at homologous regions was found to occur even in the presence of an excess amount of antibody ARM193. On the other hand, processive unwinding, i.e. the propagation of the unwinding of double-stranded DNA through a processive reaction of recA protein, which occurs even in the absence of single-stranded DNA, was found to be very sensitive to the inhibition by antibody ARM193. Therefore, we conclude that homologous matching and processive unwinding are independent of each other. Analysis of the effect of antibody ARM193 on the various activities of recA protein suggests that the entire reaction of the formation of joint molecules and their processing can be rationalized in terms of these two underlying processes, homologous matching and processive unwinding. This analysis also suggests that homologous matching seems to require only the binding itself of active units of recA protein to single-stranded DNA but not necessarily either the cooperativity of the protein or unwinding.

Animals↗
PubMed1987

Sedimentation characteristics of vesicles associated with insulin-sensitive intracellular glucose transporter from rat adipocytes.

The sedimentation characteristics of vesicles associated with the insulin-sensitive intracellular glucose transporter from rat adipocytes were studied. The method used was sucrose density gradient centrifugation, which was carried out under non-equilibrium and equilibrium (isopycnic) conditions. The glucose transport activity was determined by the reconstitution method. As reported previously, the sedimentation velocity of the intracellular glucose-transport activity was considerably slower than that of the counterpart in the plasma membrane. It was found, however, that the specific gravity of the slow-sedimenting glucose-transport activity was almost identical to that of the activity in the plasma membrane (d = 1.118-1.122). It is concluded that the intracellular glucose transport activity is associated not with low-density microsomal vesicles, but with unidentified slow-sedimenting vesicles that have a specific gravity similar to that of the plasma membrane.

Adipose Tissue↗
PubMed1987

Endothelial vesicular system in rapid-frozen muscle capillaries revealed by serial sectioning and deep etching.

Endothelial plasmalemmal vesicles were examined in serial sections and in deep-etch replicas of rapid-frozen rat muscle capillary endothelium. Numerous fused vesicles were observed in both preparations. The morphology of the vesicles in rapid-frozen capillaries differed from that in the chemically fixed ones; rapid-frozen vesicles were spherical rather than ovoid, and the necks of caveolae and the connecting portion of fused vesicles were wider than those of chemically fixed ones. In the serial sections, true free vesicles were rarely identified (1.6%). In the deep-etch replicas, some of the cytoplasmic surface of vesicles had a mulberrylike appearance and intracytoplasmic fine fibrils appeared to connect the vesicles either to other vesicles or to the plasmalemma proper. Two transendothelial channels were found among 250 capillary profiles. Almost all endothelial "vesicles" proved to be invaginations of the surface membrane, and chemical fixatives did not seem to induce any substantial membrane fusion. These observations suggest that transendothelial transport of large macromolecules across continuous capillary endothelium is carried out mainly by diffusion through transendothelial channels.

Animals↗
PubMed1987

Rapid formation of myometrial gap junctions during parturition in the unilaterally implanted rat uterus.

In uterine smooth muscles, gap junction plaques rapidly form during the final stages of gestation. To investigate the related mechanisms, regional differences in myometrial gap junction development in rat uterus were examined quantitatively during delivery, using thin-section and freeze-fracture techniques in combination with light- and electron microscopy. Examination of implanted and nonimplanted horns in the unilaterally ligated rat bicornuate uteri, revealed no differences in the occurrence of gap junction plaques, but after 2 to 4 pups had been delivered, the contracted segments contained more gap junction plaques than did noncontracted segments examined immediately before delivery. In all segments, gap junctions were found more frequently in the circular muscle layers than in the longitudinal muscle layers. Gap junctions ranged in size from 0.002 micron 2 to 0.52 micron 2, but two-thirds were less than 0.1 micron 2. The frequency of small gap junction plaques (less than 0.1 micron 2) was higher in the noncontracted segment. These results suggest that gap junctions are dynamic structures, and that their formation is controlled not only by general hormonal factors, possibly involved in gap junction increases in the myometrium before delivery, but also by local factors, possibly related to the contraction, that may accelerate an increase in gap junction formation during delivery.

Animals↗
PubMed1987

Rapid procedure for preparation of macrophage plasma membrane.

This report describes a simple and efficient procedure for the isolation of plasma membrane from guinea pig peritoneal macrophages. The use of polycationic beads (Affi-gel 731 beads) facilitates rapid and high-clear separation of plasma membrane within 30 min. The final plasma membrane coated beads fraction has high specific activities of marker enzymes with little contamination with mitochondrial, lysosomal or cytoplasmal markers.

Animals↗
PubMed1987

Upside-down etching; a simple method for reducing unetchable sediment during deep-etching of fresh untreated tissues.

A simple new method of deep-etching, 'upside-down etching', has been developed in an attempt to obtain clearer images or replicas, especially of fresh, untreated biological tissues. During etching, specimens were kept facing downwards and shaken periodically so that non-volatile materials in the subliming ice could fall out of the frozen tissue. This improvement leads to a considerable reduction of sedimented debris of unetchable materials on 'true' membrane surfaces, as well as in the cytoplasm exposed by deep-etching.

Animals↗
PubMed1987

Identification of the Yukb allo-antigen on platelet glycoprotein IIIa.

The glycoprotein (GP) localization of a new platelet-specific allo-antigen Yukb is described. The antibody was isolated from serum of a patient with neonatal allo-immune thrombocytopenia. In immunoblot procedure, it bound exclusively to platelet GP IIIa, like anti-PlA1, while the known anti-Baka and anti-Leka reacted with GP IIb. Analysis of GP from chymotrypsin-treated platelets with anti-Yukb revealed no binding in the 68-kilodalton position while anti-PlA1 did. Thus, unlike the PlA1 antigen, the Yukb determinant either resides on the 30-kilodalton fragment of GP IIIa or it is destroyed by chymotrypsin treatment.

Antibody Specificity↗
PubMed1987

Expression of heterophile, Paul-Bunnell and Hanganutziu-Deicher antigens on human melanoma cell lines.

Expression of heterophile antigens was studied on 6 human melanoma cell lines. Paul-Bunnell and Hanganutziu-Deicher (H-D) antigens, but not Forssman antigen, were demonstrated on these cell lines. H-D antigen was also demonstrated on melanoma cells isolated from primary and metastatic lesions. Evidence was also presented that HLA class I but not class II (DR and DQ) molecules are expressed on these cell lines. H-D antibodies of IgG class were detected in 10 of 23 (42%) melanoma patients suggesting the possibility that H-D antigen might have been expressed in an immunogenic form in the patients.

Antibodies, Heterophile↗