Biomedical subjects

K Horie

Publications and source records attributed to K Horie.

At least 145 records · Page 8Linked to original sources

PubMed1992

Purification of rat megakaryocyte colony-forming cells using a monoclonal antibody against rat platelet glycoprotein IIb/IIIa.

We recently reported the production and characterization of four monoclonal antibodies (MoAbs) against rat platelet glycoprotein IIb/IIIa (GPIIb/IIIa). In this study we developed a simple and efficient three-step procedure, based on positive selection by immunoadsorption (panning) using one MoAb, P55, to purify rat megakaryocyte colony-forming cells (megakaryocyte colony-forming units, CFU-MK) from normal bone marrow. Cells obtained after each step were assayed for their ability to form megakaryocyte colonies in the presence of Concanavalin A (Con A)-stimulated rat spleen cell-conditioned medium in soft agar cultures. Marrow cells were first separated on discontinuous Percoll gradients. Cells sedimented at densities between 1.063 and 1.082 g/ml were depleted of cells adherent to plastic tissue culture dishes. The nonadherent cells were further incubated on dishes coated with P55 MoAb. CFU-MK were enriched about 50-fold in the adsorbed cell fraction. This sequential fractionation procedure resulted in a 345-fold (range 276 to 412-fold) enrichment of rat CFU-MK over whole bone marrow cells. The average cloning efficiency of CFU-MK in the final fraction was about 7% (range 5%-9.2%) of the nucleated cells. The overall recovery of CFU-MK averaged 20% (range 9%-29%). The panning step provided a 46-fold enrichment of megakaryocyte burst-forming cells (megakaryocyte burst-forming units, BFU-MK), whose average cloning efficiency in the post-panning fraction was 0.14% (range 0.07%-0.2%). In addition, erythroid burst-forming cells (erythroid burst-forming units, BFU-E) were also significantly enriched by panning, but to a lesser degree than BFU-MK and CFU-MK. By contrast, granulocyte-macrophage colony-forming cells (granulocyte-macrophage colony-forming units, CFU-GM) and erythroid colony-forming cells (erythroid colony-forming units, CFU-E) were not enriched by panning. CFU-MK obtained after panning formed megakaryocyte colonies in the presence of recombinant rat interleukin 3 (rIL-3), mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF), or human erythropoietin (hEPO), as has been reported for murine CFU-MK in whole marrow cells. The highly enriched populations of rat CFU-MK should thus provide a basis for the further study of the regulation of megakaryocytopoiesis.

Animals↗

PubMed1991

Novel polyfunctional silanes for improved hydrolytic stability at the polymer-silica interface.

Polyfunctional silanes were designed to promote the formation of a stable multisilane layer on the silica surface. The hydrolytic stability of polyfunctional silanes at the interface between silica and polymeric resin was investigated using conventional tensile testing. The specimens were immersed in boiling water and a decrease was observed in the tensile bonding strength of polymeric resin against the silane-treated silica surface as the immersion time increased. The failure mechanism changes from cohesive failure of the matrix resin to failure of the interface. The time necessary to start the interfacial failure is dependent on the silane concentration in the treating solution and the number of silicone functional groups within the silane molecules. The silane with two silicone functional groups is more stable at the interface between silica and polymeric resin than those which have mono- or trisilicone functional groups.

Biocompatible Materials↗

PubMed1991

Heterogeneity of immune complex-derived anti-DNA antibodies associated with lupus nephritis.

The mechanisms responsible for the tissue injuries associated with lupus nephritis have not yet been well explained. We have investigated the characteristics of anti-DNA antibodies in circulating immune complexes (CIC) and in the deposits of renal glomeruli in patients with active lupus nephritis. The CIC-derived antibodies expressed anti-DNA idiotypes (Id) designated as 0-81 Id and NE-1 Id, and bound mainly to single-stranded DNA but never to glomerular basement membrane (GBM) antigens. On the other hand, the immunoglobulins (Ig) eluted from renal glomeruli of lupus patients reacted not only with DNA but also with GBM, proteoglycan, and heparan sulfate. The binding of glomeruli-deposited Ig was markedly low when GBM antigens were used after treatment with heparitinase, suggesting that some anti-DNA antibodies may bind directly to GBM antigens associated with heparan sulfate, and form in situ IC in renal glomeruli. It was also revealed that the renal eluates obtained after passing through GBM antigen-coupled Sepharose lost the binding ability with GBM but still retained DNA-binding and 0-81 Id activity, showing the participation of circulating IC-derived anti-DNA antibodies in the glomerular deposits. Theoretically there may be two mechanisms in the pathogenesis of lupus nephritis through the deposition of circulating IC and through in situ formation of anti-DNA IC in renal glomeruli. The diversity of histological features in lupus kidneys may be attributed to the heterogeneity of the mechanisms.

Antibodies, Antinuclear↗

PubMed1991

The expression of c-kit protein during oogenesis and early embryonic development.

The c-kit proto-oncogene encodes a transmembrane tyrosine kinase receptor and was shown to be allelic with the white-spotting locus (W) of the mouse. Mutations at the W locus have pleiotropic effects on the development of hematopoietic stem cells, melanoblasts, and primordial germ cells. In order to elucidate the role of c-kit protein in gametogenesis and oocyte maturation, we have examined immunohistochemically the expression of c-kit in the ovaries of mice at late fetal and postnatal stages, and in early embryos. By the avidin-biotin-peroxidase (ABC) method using rat anti-mouse c-kit monoclonal antibody, the c-kit protein was detected in ovaries after the time of birth, but not before. The expression of c-kit was observed mainly on the surface of oocytes, but not in granulosa cells nor in interstitial regions. Oocytes of primordial to fully grown Graafian follicles showed the c-kit protein. When ovulation was induced by hCG, the expression of c-kit in ovulated unfertilized oocytes was weaker than in oocytes of Graafian follicles. In 1-cell embryos the c-kit protein was still observed, but with cell division its expression further decreased, and it was not detected in embryos of 4-cell, 8-cell, and morula stages. In summary, the highest expression of c-kit was observed on the surface of oocytes arrested in the diplotene stage of meiotic prophase. With ovulation and the resumption of meiotic maturation, its expression declined. These results suggest that the c-kit protein may play some role in meiotic arrest, oocyte growth, and oocyte maturation.

Animals↗

PubMed1991

Adhesiveness of amide monomers to tooth substrate.

Seven types of amide monomers, methacryloyl tyrosine amide (MTYA), p-methacryloxybenzamide (p-MBA), p-methacryloxybutoxybenzamide (p-MBBA), o-methacryloxybutoxybenzamide (o-MBBA), p-methacryloxybutoxy phenylpropionamide (p-MBPPA), 3,5-dimethacryloxybenzamide (3,5-DMBA), and 3,5-di (methacryloxybutoxy)benzamide (3,5-DMBBA), were prepared for use as bonding agents. The monomers were dissolved in HEMA. Bovine enamel was etched with 40% phosphoric acid, and bovine dentin was etched with 10% citric acid before being primed with MTYA.G.H. The tensile bond strengths between bovine enamel or dentin and experimental adhesives were measured after one day immersion in water at 37 degrees C. HEMA was used as a control adhesive. When bonding to etched enamel, the bond strengths of composite resins with o-MBBA and 3,5-DMBA were significantly higher than those with HEMA. The bond strengths of composites with MTYA, p-MBA, p-MBBA, 3,5-DMBBA and p-MBPPA were almost the same as those with HEMA. When bonding to dentin, the bond strengths of composite resin with MTYA and p-MBBA were significantly higher than those with HEMA.

Acid Etching, Dental↗

PubMed1990

Occurrence in chick embryo vitreous humor of a type IX collagen proteoglycan with an extraordinarily large chondroitin sulfate chain and short alpha 1 polypeptide.

We have prepared a high buoyant density proteoglycan fraction from the vitreous humor of 13-day-old chick embryos. Using immunoblot analysis coupled with chondroitinase digestion, we demonstrate that the purified preparation is composed predominantly of type IX collagen-like chondroitin sulfate proteoglycan with an alpha 1(IX) chain Mr approximately 23,000 shorter than the known alpha 1 in cartilage type IX. Also different from cartilage type IX is the size of the chondroitin sulfate chain attached to the alpha 2(IX) polypeptide; its Mr is approximately 350,000 indicating that it is approximately 10 times larger in vitreous humor than in cartilage. Examination of vitreous bodies at different developmental stages indicates that a transition occurs in the size of alpha 1(IX) in a well defined temporal pattern; at about stage 31, a cartilage-type alpha 1(IX) of Mr 84,000 is the predominant species, whereas at stage 36 and thereafter, a Mr 61,000 species appears with a concomitant disappearance of the Mr 84,000 species. Immunostaining for type IX collagen followed by electron microscopic observation of 13-day-old chick embryo vitreous humor reveals a regular D-periodic arrangement of vitreous type IX collagen proteoglycan along thin fibrils. It seems possible that the chondroitin sulfate chains of extraordinarily high viscosity and high molecular weight may extend away from the fibrils, thus contributing to structural as well as functional properties of this unique matrix.

Aggrecans↗

PubMed1990

Etching of dentin surface with ammonium citrate aqueous solution.

New dentin etchants AC (ammonium citrate) were examined. The pH of the AC solution was 7.3-7.4, and the concentration of the solutions varied from 5% to 30%. The etching of a 10% AC solution was the most effective in improving the adhesion between the composite resin and dentin among the AC solutions employed when MTYA.G.H was used as a dentin primer. The smear layer was removed and the tubules were not generally opened with AC etching. The bond strengths to dentin etched with 10% AC were comparable with those to dentin etched with neutralized 0.5 M EDTA or EDTA 3.2. The bond strengths increased with primers MTYA.H and MTYA.G.H, in that order.

Acid Etching, Dental↗

PubMed1990

[The evaluation of commercially available silane coupling agents for porcelain adhesion].

We investigated the effectiveness of commercially available silane coupling agents on the adhesion between the composite resin and the porcelain. As silane coupling agents, we used Cosmotech primer. Clearfil porcelain bond. Porcelain liner M, and Scotchprime. As porcelain, we used Cosmotech porcelain DA2 which was etched either with hydrofluoric acid or with phosphoric acid gel. The tensile bond strengths between composite resin and the porcelain treated with silane coupling agents were measured after one day immersion in 37 degrees C water. Among the silane coupling agents, Clearfil porcelain bond gave the highest bond strength of about 175 kgf/cm2. When any of these silane coupling agents were used, the bond strengths were increased more by hydrofluoric acid etching than by phosphoric acid etching. Especially in the case of Scotchprime treatment, hydrofluoric acid etching was remarkably effective on the increase in the bond strengths. The value in hydrofluoric acid etching was 3 times higher than that in phosphoric acid etching. From SEM observation, hydrofluoric acid etching gave greater roughness to the porcelain surface, which resulted in greater mechanical interlocking of the resin. In the case of Cosmotech primer treatment, the combination with GC bonding agent did not increase the bond strengths, while combination with Clearfil new bond did. The phosphoric acid ester monomer in Clearfil new bond, which is known as strong acid, was supposed to catalyze the activation of silane coupling agent.

Adhesives↗

PubMed1990

Sites of lymph follicle formation in the draining popliteal lymph nodes of mice locally injected with antigenic and mitogenic substances.

Our previous studies showed that some antigenic and mitogenic substances, when locally injected into mice, efficiently produced new lymph follicles outside pre-existing follicles in draining lymph nodes, whereas others had virtually no effect. In the present experiments, young adult male mice were injected with several antigens and mitogens in the rear footpad, and the number and development sites of newly produced lymph follicles in the draining popliteal nodes were studied using serial sections of the nodes obtained between 5 and 21 days after injection. In the unstimulated state, each popliteal node contained a limited number of lymph follicles which mostly lay in a portion of the peripheral cortex overlaying the deep cortex (this portion is referred to as the PCOU), whereas a portion of the peripheral cortex extending beyond the deep cortex (referred to as the PCBU) was underdeveloped with only occasional follicles. Mice treated with soluble PHA or fluid tetanus toxoid developed germinal centers in association with existing follicles but failed to produce new follicles. The PCBU of the draining nodes remained underdeveloped, and the number and distribution pattern of lymph follicles within a draining node were comparable to those in the control node. Animals treated with LPS (50 micrograms), Con A, alum-precipitated PHA or alum-precipitated tetanus toxoid produced significantly large numbers of new follicles outside pre-existing follicles in the draining nodes, the new follicles produced in the PCBU being generally more numerous than those in the PCOU. In these draining nodes, the peripheral cortex, comprising a number of follicles, was found to overlie the deep cortex and extend beyond the deep cortex towards the hilar region. In animals given a less effective stimulant, such as ferritin or a smaller dose of LPS (10 micrograms), the draining nodes produced a relatively small number of new follicles, most of which were formed in the PCBU. The present results indicate that in the mouse popliteal node, the PCBU is morphologically underdeveloped under normal conditions, but develops lymph follicles in response to exogenous stimuli more readily than the PCOU, and that substances efficient in inducing follicle formation can be regarded as capable of stimulating the development of the peripheral cortex.

Animals↗

PubMed1990

[Transmittance of light-cured composite resins. 1. Measurement of transmittance with time].

The factors that influence the change of the transmittance of light-cured composite resins during polymerization were examined. Six experimental composite resins such as used organic composite filler and fourteen commercial composite resins were investigated using the experimental device for measurement of the transmittance. The transmittance of the experimental composite resins were from 25 to 73%. The transmittance of the experimental composite resins changed with time; a group with increasing transmittance (G1), a group giving a maximum transmittance (G2), and a group with decreasing transmittance (G3). These changes of transmittance were influenced by the difference in the refractive indices between matrix resin and filler, but the refractive index that indicated a maximum transmittance of matrix resin during polymerization could not be observed when the refractive index of the matrix resin and filler was same. The light transmitted through the commercial composite resins was less than half of the irradiation light. This change of transmittance could also be classified into the three groups mentioned above. The commercial composite resins belonged to the group with increasing transmittance (G1).

Composite Resins↗

PubMed1990

[In vivo wear test for posterior composites. 1. Development of wear test predicting composite wear in vivo].

A wear test method based on a new concept was developed for predicting the wear rate of posterior composite restorations in vivo. The concept based on the conclusions derived from our clinical tests on posterior composites that composite restorations would be deteriorated chemically and by repeated compressive stress as well as by abrasion by food passing during mastication. New wear tests were performed on several posterior restorative materials under various conditions to compare the effect of abrasion using the tooth-brush. The results of wear rate using the present test on specimens stored in a 0.1 N-NaOH solution (37 degrees C) for 6 days were parallel to those measured in clinical tests. However, the abrasion test results obtained using a tooth-brush on deteriorated specimens did not match the clinical data. These findings suggested that degradation or aging of specimens and repeated compressive stress are necessary for the wear test to simulate the wear of posterior composites in vivo.

Composite Resins↗

PubMed1990

[A case of a pulmonary large cell carcinoma patient who has still been surviving for four years even with triple carcinoma developed on different occasions (rectum, stomach: resected; lung: nonresected)].

The case occurs on an 86-year-old man. In May 1977, Miles' operation was performed for rectal cancer (papillary tubular adenocarcinoma), together with additional proctostomy. In March 1984, subtotal gastrectomy was performed for an early stomach cancer (moderately-differentiated tubular adenocarcinoma). In September 1985, chemotherapy with 3 courses of CDDP (50 mg x 1) plus VDS (3 mg x 3) and liniac irradiation (60 Gy in total) were performed for pulmonary large cell carcinoma. Restiform shadows and fibrosed foci were left behind, but thereafter only the former was persisted without anticancer therapy. Now in December 1989, he has still been surviving without any sign of local recurrence of remote metastasis. Neither anticancer therapy was tried for the first and second cancers nor a cancer family history was found about him.

Adenocarcinoma↗

PubMed1990

[Metastatic lung tumor of a thyroid cancer origin detected by a periodic health examination--a case of a complete response].

Reports is the case of a 21-year-old student, who received a medical examination at our Department for an abnormal chest shadow that had been detected during a periodic health examination at his university. No special subjective symptoms such as a cough and/or sputa, pyrexia, pectoralgia, and dyspnea were noted. A thyroid tumor was palpable and a 99mTc thyroid scintigram and a 201Tl thyroid tumor scintigram gave cause to suspect thyroid cancer and a metastatic lung tumor. A total thyroidectomy and a right modified neck dissection revealed a tumor (histologically, a papillary cancer), 3.5 cm in diameter, that mainly involved the right lobe. It was found that 131I-100 mCi internal irradiation was very effective for the metastatic lung tumor, and no abnormal shadow was subsequently revealed by chest X-ray. Now, 6 years later, he is alive with no manifestations of a local relapse nor any abnormal chest X-ray findings.

Adult↗

PubMed1989

Induction of glutathione S-transferase by phenobarbital in rat hepatocyte culture.

The in vitro effect of phenobarbital on glutathione S-transferase (GST) activity toward 1-chloro-2,4-dinitrobenzene (CDNB) in rat hepatocyte culture was investigated. Treatment of hepatocytes with a medium containing 6 or 8 mM phenobarbital for 20 h increased the specific activity of GST approx. 140% and 160% of control, respectively. When induction of GST by phenobarbital treatment was observed, the cellular level of phenobarbital determined by HPLC was approx. 10 - 15 micrograms/mg of 20000 x g supernatant protein of hepatocytes. Thus, an inductive effect of phenobarbital on GST was observed in vitro as well as in rat liver. It was suggested that a certain level of cellular phenobarbital was necessary for the induction.

Animals↗

PubMed1989

Predictability of left heart dysfunction from right heart performance--cardiac index-venous pressure plots and cardiac index-mean pulmonary artery wedge pressure plots at rest and their shift during dynamic exercise.

In an attempt to examine the extent to which the right heart performance can predict the left heart performance in heart diseases primarily affecting the left heart, we recorded cardiac index-venous pressure (CI-VP) plot and cardiac index-mean pulmonary artery wedge pressure (CI-PAW) plot at rest and investigated the shift of CI-VP plot and CI-PAW plot that occurred during mild dynamic exercise of the lower limbs. Six patients had normal heart function and 20 patients had heart diseases primarily affecting the left heart. The sensitivity, specificity, positive predictive value and negative predictive value in the estimation of the left heart function with delta CI/delta VP were 80%, 100%, 89% and 100%, respectively, when delta CI/delta PAW was regarded as the golden standard for the estimation of the left heart function. The sensitivity, specificity, positive predictive value and negative predictive value in estimating the left heart function with delta CI/delta RA were 86%, 93%, 92% and 86%, respectively. When the left heart function was estimated by delta VP alone without measuring delta CI, the sensitivity, specificity positive predictive value and negative predictive value were 40%, 100%, 73% and 100%, respectively. In short, it was possible to predict the left heart dysfunction with delta CI/delta VP or delta CI/delta RA, in the presence of the right heart dysfunction. It was also possible to predict a steep heart slope from normal delta CI/delta VP with error of 2/18 (11%), when steep left heart slope was predicted, based on the presence of steep right heart slope. In comparison, delta VP alone was a less sensitive index of the performance of the left heart.

Adolescent↗

PubMed1989

A histological and experimental study on the fate of an increased number of lymph follicles produced in the mouse popliteal lymph node by exogenous antigen stimulation.

Eight-week-old female C57B1/6 mice were injected with endotoxin LPS and/or other antigens into the left hind footpad, and then the number of lymph follicles in the draining popliteal lymph nodes was examined. In untreated mice each popliteal node contained 10-12 lymph follicles at both 8 and 15 weeks of age. Animals given 50 micrograms of LPS at 8 weeks of age showed an increase in the number of lymph follicles 3 weeks later, but this number returned to normal levels by 15 weeks after the LPS injection. After a 2-micrograms-LPS injection at 23 weeks of age, the number of lymph follicles in the draining lymph node was unchanged, but that in animals given the 2-micrograms-injection 15 weeks after the 50-micrograms-LPS injection was significantly increased. In animals receiving 2 Lf of diphtheria toxoid, instead of the 2-micrograms-LPS, at 15 weeks after a 50-micrograms-LPS injection, the number of lymph follicles per draining node was within the normal range. In one group of mice, the initial injection of 50-micrograms-LPS at 8 weeks of age was followed by injections every third week of several kinds of antigens which had been shown to be ineffective in inducing follicle formation. Here, the number of lymph follicles in the draining popliteal node was kept to significantly increased levels at 25 weeks of age. The present results suggest that, while most lymph follicles normally developing in the lymph node are maintained for a long time under normal conditions, many lymph follicles induced by antigenic challenge have a limited life span and undergo atrophy unless they are periodically activated by additional antigenic stimuli, and that atrophied follicles finally become unable to respond to antigenic stimulation. It is also suggested that antigenic materials which trigger the formation of lymph follicles in the primary challenge can evoke follicle formation more efficiently in the secondary challenge.

Animals↗

PubMed1989

Studies on adhesion to tooth substrate. 6. Adhesion of composite resin to dentin mediated by the dentin primer containing MTYA.

The influences of the kinds and concentrations of the aldehydes in the primer on dentin adhesion were investigated. Moreover, the durability of the adhesion to the dentin treated with primer was examined by thermal cycling tests. Among the aldehyde tested here, glutaraldehyde was effective in improving the adhesion to dentin etched with citric acid. When HEMA was substituted with ethanol, the bond strengths decreased. The relationship between the bond strength and the concentration of glutaraldehyde in the primer was studied. In the cases of phosphoric acid or citric acid etching, the bond strengths were affected by the concentration of glutaraldehyde in the primer. The bond strengths decreased after 2000 thermocycles in phosphoric acid etching.

Adhesiveness↗

PubMed1989

[Studies on adhesion to tooth substrate. 5. The relationship between the structure of monomers and their adhesiveness].

The relationship between the structure of monomers with amide groups and their adhesiveness to tooth was investigated. The monomers used were methacrylamide (MA), p-methacryloxybenzamide (p-MBA), and 3,5-dimethacryloxybenzamide (3,5-DMBA). MA was commercially available. p-MBA and 3,5-DMBA were prepared from the reaction of methacryloyl chloride with p-hydroxybenzamide or 3,5-dihydroxybenzamide, respectively, in acetonitrile. The bovine enamel and dentin were etched with 10% citric acid -3% FeCl3 solution. The monomers were dissolved in MMA, and TBB-O was used as a polymerization initiator. The test samples were immersed in 37 degrees C water for 1 day, 1 month, or 3 months. Then the tensile bond strengths were measured. The bond strengths to enamel were almost the same, irrespective of the kinds of monomers after 1 day immersion. Although the bond strengths of MA (1.0%) and 3,5-DMBA (3.0%) decreased after 1 month immersion, those of MA (0.5%) and p-MBA (0.5%) did not decrease after 3 months immersion. There was no relationship between the bond strengths to enamel and the bending strengths of the resins. The bond strengths of 3,5-DMBA (1.0%) and 3,5-DMBA (3.0%) to dentin were about 5-7 MPa. The bond strengths of MA (0.5%) or MA (1.0%) decreased after 3 months or 1 month immersion, respectively. The bond strength of p-MBA (0.5%) did not decrease after 3 months immersion.

Acrylamides↗