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Biomedical subjects

H Kanaya

Publications and source records attributed to H Kanaya.

At least 19 recordsLinked to original sources
PubMed1992

The influence of surface conditions and silane agents on the bond of resin to dental porcelain.

The influence of porcelain surface condition and the application of silane agents on the adhesion between resin and dental porcelain were investigated. The experimental variables included three porcelain surface preparations, as polished, etched with phosphoric acid, or etched with hydrofluoric acid and three kinds of commercially available silane coupling agents. The shear bond strength between the light-cured composite and the dental porcelain was measured after one-day immersion in 37 degrees C water. Samples without the silane agent application were also tested as controls. Without the silane agent, hydrofluoric acid-etched specimens had a higher bond strength than polished or phosphoric acid-etched specimens. The combination of hydrofluoric acid-etching and an application of Cosmotech Porcelain Primer increased the bond strengths more than that of phosphoric acid-etching. With the application of Laminabond Porcelain Primer or Optec Silane Coupling Agent, high bond strengths were obtained regardless of the porcelain surface condition. Therefore, it seems the chemical reactions between the porcelain surface and silane agents were responsible for the high shear bond strengths.

Acid Etching, Dental↗
PubMed1992

Spherical liquefaction necrosis of mitral annular calcification in a chronic dialysis patient--liquefaction necrosis of mitral annular calcification.

A 60-year-old woman on chronic dialysis consulted our department for closer examination of transient atrial fibrillation and a mitral regurgitant murmur. Echocardiography revealed a left atrial abnormal dense echogenic spherical mass, the diameter of which was 2 cm. She died of cerebral bleeding 3 months later. At autopsy, the submitral mass-like structure consisted of light-gray pasty material, which was liquefaction necrosis of a mitral annular calcification. These findings were different from those of the so-called mitral annular calcification found in the elderly or in chronic renal failure patients. The existence of such calcification must be kept in mind and not be mistaken for cardiac tumor.

Atrial Fibrillation↗
PubMed1992

Adhesion between the resin shell and composite resin.

Adhesiveness between the resin shell and composite resin was examined. As the resin shell, SR-PE-ISOCETTE, made from thermosetting crown and bridge resin, was used. The shear bond strengths between the resin shell and photocurable composite resin bonded by various methods were measured after 1-day of immersion in water at 37 degrees C. Super-bond C & B treatment to the resin shell effectively improved the adhesiveness, giving a bond strength of about 14 MPa. Clearfil new bond, Clearfil porcelain bond, Unifast and MMA/TBBO treatment gave almost the same bond strengths of about 7-9 MPa. Silane coupling agents were not effective for improving the bond strength. It was revealed that 4-META was necessary for obtaining good adhesion between SR-PE-ISOCETTE and composite resin.

Boron Compounds↗
PubMed1992

[Measurement of PCNA labeling index in astrocytic tumors].

PCNA (proliferating cell nuclear antigen) is said to be present specifically in the nucleus of proliferating cells. The PCNA labeling index (PCNA LI) of astrocytic tumors was measured and compared with histological types or prognosis. The specimens from 44 patients were fixed in a 10% formalin solution, and embedded in paraffin. The 3 microns-sections were stained immunohistochemically with anti-PCNA monoclonal antibody (PCIO, Novocastra) using an ABC method. The percentage of PCNA-positive-cells was determined by counting 2000 cells, and identified as PCNA LI. All of the PCNA-positive-cells showed diffuse nucleoplasmic staining. The averages of PCNA LIs in each pathological type were calculated and evaluated statistically. Although differences in averages of PCNA LIs among pilocytic, gemistocytic, fibrillary astrocytoma were not significant, there was a significant difference between anaplastic astrocytoma and glioblastoma. The relationship between PCNA LIs and the prognoses for 43 patients was studied. Forty-three patients were classified into 3 groups (over 22%, 7 to less than 22%, and less than 7%) according to PCNA LIs. The survival data in the 3 groups were analyzed, and differed significantly in the survival rates. Furthermore, twenty-three patients of anaplastic astrocytoma and glioblastoma were classified into two groups (over 22% and less than 22%). Likewise, the two groups differed significantly. In summary, pathological type and prognosis were closely related to PCNA LI in astrocytic tumors. Therefore, we thought measurement of PCNA LI would make it more possible to analyze clinically the proliferating activity of astrocytic tumors, and to care for patients more effectively.

Adolescent↗
PubMed1992

[The effect of elastase on aminonucleoside nephrosis--on renal vascular system].

This study was performed to investigated the relationship between cross sectional areas of glomerular arterioles and glomerular volume in rats with puromycin aminonucleoside (PAN)-induced nephrosis, which is an experimental model of glomerular sclerosis. We also evaluated the effect of an anti-arteriosclerotic agent, elastase on these parameters. Six-week-old male Sprague-Dawley rats were divided into 3 groups; control, PAN-treated (70 mg/kg i.p.), or PAN+elastase-treated (5 mg/kg/day i. m.) group. After 12 weeks of experimental period, microvascular cast of the kidney was prepared, and the cross sectional areas of afferent and efferent arterioles as well as glomerular volume were measured using scanning electron microscopy. In the juxtamedullary glomeruli with minor abnormalities, the efferent arteriole was narrower in PAN-treated rats than in the control rats and the elastase-treatment partially corrected it (control 55.7, PAN 35.9, PAN+elastase 43.7 x 10 microns 2). On the other hand, the cross sectional area of afferent arteriole was not different among the 3 groups. In glomeruli showing sclerosis, the cross sectional area of efferent arteriole correlated positively with the glomerular volume. There results suggest that constriction of the efferent arterioles contributes to the development of glomerular sclerosis in PAN-induced nephrosis. In addition, elastase possibly inhibits this process and thereby protect glomeruli from sclerosis.

Animals↗
PubMed1992

Mesangial anionic sites are decreased in human focal glomerular sclerosis.

We studied the mesangial anionic sites in two patients with focal glomerular sclerosis (FGS), using polyethyleneimine as a cationic probe. The mesangial negative charge in the FGS patients was less than that in three control patients. The decrease in negative charge in FGS concerned the central, paramesangial, as well as the subendothelial region of the mesangium; the decrease was most pronounced in the central region. It is proposed that loss of mesangial negative charge may have pathogenic significance in FGS.

Adolescent↗
PubMed1991

Morphometric analysis of the glomerular capillary area--a comparison of minimal change nephrotic syndrome, focal glomerular sclerosis, and pre-eclampsia.

A morphometric analysis was performed to compare the capillary area in non-sclerotic glomeruli in focal glomerular sclerosis (FGS), pre-eclampsia with focal sclerotic change of the glomeruli, and minimal change nephrotic syndrome (MCNS). The mean and standard deviation of the capillary area was greater in FGS than in pre-eclampsia and MCNS. Tubulo-interstitial lesions, such as tubular atrophy, interstitial fibrosis, and lymphocytic infiltration, were more severe in FGS than in pre-eclampsia. The presence of tubulo-interstitial changes including tubular atrophy and interstitial fibrosis with lymphocytic infiltration is thought to be an important prognostic factor in pre-eclampsia as well as in FGS. Unequal dilatation of the glomerular capillaries in non-sclerotic glomeruli may be harmful to the glomeruli and may lead to the development of glomerular sclerosis.

Adolescent↗
PubMed1991

Aneurysm of the distal anterior inferior cerebellar artery unrelated to the cerebellopontine angle: case report.

This is a case report of an unusual aneurysm of the distal anterior inferior cerebellar artery. A 44-year-old woman had a severe frontal headache and vomiting of sudden onset. On the day after admission, the patient began to demonstrate nuchal rigidity and difficulty with upward gaze bilaterally. There were no complaints at this time suggestive of a syndrome of the cerebellopontine angle. A computed tomographic scan revealed an intraventricular hemorrhage of the 3rd and 4th ventricles; however, multiple attempts at four-vessel angiography were required before an aneurysm could be demonstrated. On the 28th hospital day, a suboccipital craniectomy using the retromastoid approach in the lateral position was performed. A saccular aneurysm with a surrounding hematoma in the distal anterior inferior cerebellar artery was found and clipped. The operative findings revealed that the aneurysm was unrelated to the cerebellopontine angle. After surgery, the patient had an uneventful recovery and complete resolution of symptoms.

Adult↗
PubMed1991

Focal segmental glomerular hyalinosis and/or sclerosis in rats with congenital unilateral hydronephrosis.

Focal segmental glomerular hyalinosis and/or sclerosis (FSHS) was observed in five Wistar-Imamichi rats with congenital unilateral hydronephrosis (CUH rats). Marked proteinuria (164.9 +/- 138.4 mg/day) was observed in the CUH rats. Immunoperoxidase staining for IgM, C3 and IgG was positive in the glomeruli, showing in a focal, segmental pattern that corresponded to the areas of FSHS seen by light microscopy. These glomerular findings were extremely similar to those of human focal glomerular sclerosis (FGS). FSHS was found to be common to both the hydronephrotic kidney and the contralateral kidney without hydronephrosis. Morphometry revealed that the glomerular area of the juxtamedullary glomeruli was greater than that of superficial glomeruli in control rats (11,037 micron2 vs. 6,847 microns2). On the other hand, glomerular hypertrophy was observed in non-sclerotic glomeruli of CUH rats (superficial glomeruli; 12,477-16,123 microns2, juxtamedullary glomeruli; 14,635-18,418 microns2). Also, a decreased in the number of glomeruli within the range 1.8-4.1 per unit area (1 mm2) was seen in CUH rats compared with control rats (mean 4.4). These results suggest that the increased rate of development of FSHS is based on hyperfiltration in the remaining functional nephrons.

Animals↗
PubMed1991

Changes of anionic sites in the mesangium with aging in rats: a comparison of the immersion and intravenous PEI methods.

We investigated the changes in anionic sites of the mesangial matrix related to aging in rats, employing polyethyleneimine (PEI) as a cationic probe. We compared the numbers of anionic sites detected by the immersion method and by the intravenous administration of PEI. Analysis of the mean numbers of PEI particles per 0.1 micron2 in the mesangial matrix revealed a significant decrease related to aging. Our results suggested that there was no significant difference in efficacy between the immersion and intravenous methods. Loss of negative charge of the mesangial matrix is believed to promote mesangial dysfunction and the entrapment of macromolecular substances, and so to play an important role in the onset of glomerular sclerosis.

Aging↗
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

[Study on prototype cylindrical HAP].

Hydroxyapatite (HAP) is currently utilized as biomaterials for implantation or reconstruction of bone defect in dentistry. In order to obtain better physical properties and biocompatibility, we have developed cylindrical sintered porous HAP which has longitudinal internal tubules. We measured compressive strength and specific surface area of cylindrical HAP. In the results, compressive strength was more 300MPa on average and specific surface area was 1.7-2.4 folds as HAP ceramics commercially available. This result indicates new bone formation. Cylindrical HAP used was subsequently applied to lower premolars and molars of male beagle dogs (1.5 years). We have implanted cylindrical HAP to bone defect of postextraction of tooth followed to sacrifice six months after. Specimens of bone block were stained with Villanueva bone stain and observed with fluorescence microscope and scanning electron microscope. New tissue formation was observed invading into tubules of 27 microns diameter of cylindrical HAP particles. This new tissue was confirmed to be bone tissue because the proportion of Ca to P was 1.616 obtained by energy dispersive X-ray analyzer.

Alveolar Bone Loss↗
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

[Meningioma of pineal region].

A 58-year-old man was admitted to our hospital upon his request for an operation on a hemifacial spasm that had developed twelve years ago. The hemifacial spasm on the left side was the only positive neurological findings at the time of admission. However, a pre-operative neuroradiological examination revealed a meningioma originating in the falco-tentorial junction. Left neurovascular decompression was initially performed and was followed by the excision of the tumor through a right parietooccipital approach. The pathological diagnosis was meningothelial meningioma. The patient was discharged with no neurological deficit. There have been only a few reports on pineal meningioma and even now this type of tumor is considered to be rare. Some similar cases reported in the literature are reviewed. The clinical aspects, clinical features and the pathological entity are discussed.

Brain Neoplasms↗
PubMed1990

[A case of traumatic syringomyelia which disappeared after anterior decompression: a suggestion for surgical treatment of syringomyelia].

A 37-year-old man had received cervical spinal-cord injury 20 years previously. Recently, he complained of progressive spastic gait and was shown to have fracture dislocation of the C5 vertebral body which compressed the spinal cord posteriorly. He also had a syrinx from the C5 to C2 vertebral level. Postoperatively, this syrinx disappeared after anterior decompression of the C4 and C5 vertebral bodies. Such a case as this has never been reported, and this case may give a suggestion for surgical treatment of syringomyelia, because it is very natural that the most reasonable treatment of any disease is removal of the cause.

Adult↗
PubMed1989

[Transverse sinus thrombosis accompanied by intracerebellar hemorrhage: a case report].

This case report deals with transverse sinus thrombosis accompanied by intracerebellar hemorrhage. A 33-year-old woman had sudden onset of headache, vomiting, and disturbance of consciousness. Computed Tomography (CT) scan showed left intracerebellar hematoma, while vertebral angiography revealed no visualization of the transverse sinus and cerebellar cortical veins on the left side. Evacuation of the intracerebellar hematoma along with decompression of the posterior fossa was carried out. Findings of the histopathological examination of the operation specimen showed the cortical veins to be filled with fresh thrombus and softened cerebellar parenchyma mixed with many small clots. Until now, cases such as hemorrhagic infarction in the cerebellum, due to transverse sinus thrombosis have not yet been reported. It is considered that there is much more collateral circulation in the infratentorial region rather than in the supratentorial region. This indicates that cerebellum hemorrhagic infarction rarely occurs due to transverse sinus thrombosis. In our case, the inflammation of the cortical veins (thrombophlebitis) was thought to have disturbed the collateral circulation in the cerebellum.

Adult↗