Biomedical subjects

K Kamiyama

Publications and source records attributed to K Kamiyama.

At least 37 records · Page 2Linked to original sources

PubMed1998

Central nervous system effects of the novel antiallergic agent HSR-609 and typical antiallergic agents using behavioral and electroencephalographic analyses in dogs.

We studied the central nervous system (CNS) effects of 3-[4-(8-fluoro-5, 11-dihydrobenz[b] oxepino[4, 3-b]pyridin-11-ylidene)piperidino]propionic acid dihydrate (HSR-609), a novel amphoteric antiallergic agent having antihistaminic activity. Its effects on gross behavior, spontaneous electroencephalograms (EEG) and some pharmacological parameters of unanesthetized, unrestrained dogs with chronic indwelling brain electrodes after oral administration were compared with typical antiallergic agents and 8-fluoro-5, 11-dihydro-11-(1-methyl-4-piperidylidene)benz[b] oxepino[4,3-b]pyridine (PY-608), a non-amphoteric basic compound having a similar chemical structure to HSR-609. HSR-609 (1, 10 and 100 mg/kg) and terfenadine (100 mg/kg) had no effect on the behavior, EEG patterns, sleep-wakefulness cycles or EEG power spectrum. Cyproheptadine (10 mg/kg), ketotifen (30 mg/kg) and PY-608 (10 mg/kg) increased slow waves with high amplitude in all EEG leads and caused dissociation between the slowing of EEG and waking behavior. Both azelastine (30 mg/kg) and oxatomide (100 mg/kg) caused generalized seizure discharges accompanied by agitation with the former and sedation with the latter. These findings suggest that observations of behavior and EEG in conscious dogs can be useful for clarifying the pharmacological characteristics of various antiallergic agents on the CNS. We were able to show that HSR-609 has no effect on the behavior and EEG of dogs because of its amphoteric chemical structure.

Animals↗

PubMed1998

Effects of PDGF on the migration of rabbit corneal fibroblasts and epithelial cells.

PURPOSE: We investigated the effects of human platelet-derived growth factor (PDGF) isomers on the migration of rabbit corneal fibroblasts and epithelial cells in the presence or absence of fibronectin (FN). METHODS: A modified Boyden's chamber method was used to detect cell migration. Cells placed in the inner chamber were incubated with PDGF in the outer chamber at 37 degrees C at 24 h. In addition, epithelial cells were incubated in the presence or absence of FN. The migrated cells were stained and the cell number counted under a microscope. Checkerboard analysis was used to distinguish chemotaxis from chemokinesis. RESULTS: Natural PDGF and PDGF-BB enhanced the migration of corneal fibroblasts, whereas PDGF-AA did not. As for corneal epithelial cells, all the isomers of PDGF enhanced the migration, but only in the presence of FN, as in the absence of FN or at a low concentration gradient of FN, there was no enhanced cell migration. A checkerboard assay demonstrated that PDGF-BB had a chemotactic effect on the migration of corneal fibroblasts and epithelial cells, whereas PDGF-AA had a chemotactic effect on only corneal epithelial cells. CONCLUSION: These results suggest that PDGF is involved in corneal wound healing by stimulating the migration of corneal epithelial cells in the presence of FN and fibroblasts.

Animals↗

PubMed1997

Pharmacological studies on the novel antiallergic agent HSR-609: its effects on behavior in mice and electroencephalograms in rabbits.

We studied the central nervous system (CNS) effects of HSR-609 (3-[4-(8-fluoro-5,11-dihydrobenz[b]oxepino[4,3-b]pyridin-11- ylidene) piperidino]propionic acid dihydrate), a novel amphoteric antiallergic agent having antihistaminic activity. Its effects on the behavior of mice and the electroencephalograms (EEG) of unanesthetized and unrestrained rabbits after oral administration were compared with those of typical antiallergic agents and the non-amphoteric basic compound PY-608 (8-fluoro-5,11-dihydro-11-(1-methyl-4-piperidylidene)benz [b]oxepino[4,3-b]pyridine), which has chemical structure similar to that of HSR-609. HSR-609 (3-300 mg/kg) had no effect on general behavior, spontaneous locomotor activity, hexobarbital-induced sleeping time and reserpine-induced hypothermia in mice. HSR-609 (10-100 mg/kg) and terfenadine (100 mg/kg) had no effect on spontaneous EEG, sleep-wakefulness cycles and EEG power spectra in rabbits. On the other hand, cyproheptadine (3-30 mg/kg), ketotifen (30-100 mg/kg) and PY-608 (0.3-100 mg/kg) caused increases and/or decreases of spontaneous locomotor activity, prolongation of hexobarbital-induced sleeping time and antagonistic effects on reserpine-induced hypothermia in mice. These agents (30 mg/kg) increased slow wave sleep and enhanced EEG power spectra at low frequency bands such as delta and theta in rabbits. These findings suggest that HSR-609 has no inhibitory effect on the CNS due to its amphoteric chemical structure.

Animals↗

PubMed1996

New method for evaluation of hard contact lens materials with regard to cell injury by dynamic contact.

To establish a new method for evaluation of contact lens materials, we studied the porcine endothelial cell injury caused by dynamic contact (rotatory rubbing) with three kinds of hard contact lenses (HCL). The HCLs used were 1) PMMA HCL, 2) oxygen-permeable HCL composed of a graft copolymer of dextran derivative and methylmethacrylate (MMA) (Suncon Mild II, 12 Dk), and 3) oxygen-permeable-HCL composed of a copolymer of a monomer containing silicone, a monomer containing fluorine, and MMA (RGPL-A, 216 Dk). Cell injury rates were significantly different among these HCLs (Suncon Mild II < PMMA < RGPL-A) although there were no differences in rotatory rubbing forces. The smoothness of HCL surface, the qualities of injured cell layers observed by scanning electron microscopy, and the water wettability of HCLs were not correlated with cell injury rate. These results suggest that physicochemical properties of materials other than rotatory rubbing force, smoothness, and water wettability were involved in the cell injury. Our evaluation method for biomaterials that injure the corneal endothelial cells by dynamic contact should be very useful for the development of biomaterials or medical devices, including HCLs and intracardiac and urethral catheters.

Animals↗

PubMed1996

Effects of calcitonin and parathyroid hormone on the distribution of F-actin in the clear zone of osteoclasts in vivo.

To elucidate the relation between the distribution of F-actin bands in the clear zone and the bone-resorbing activity of osteoclasts in vivo, the endocranial surfaces of calvariae from 7-day-old Wistar rats were stained with F-actin-specific fluorescein isothiocyanate-labeled phalloidin (FITC-phalloidin) with and without the intraperitoneal injection of the calcium-regulating hormones, calcitonin (CT), and parathyroid hormone (PTH). Some specimens were double-stained with FITC-phalloidin and a monoclonal antibody, ED1, which stained monocytes and macrophages. In normal rats, almost 80% of the osteoclasts showed ring-shaped F-actin bands in the clear zone, and the remaining 20% showed arch- or line-shaped F-actin bands. From 15 min to 1 h after the injection of CT (salmon, 10 mg/kg), the number of osteoclasts with ring-shaped F-actin bands decreased significantly. At 1 h, few F-actin bands were detected in osteoclasts, which were still stained by ED1. However, these F-actin bands recovered to the normal level at 6 h. On the other hand, from 15 min to 6 h after the injection of PTH (bovine, 50 mg/kg), the number of osteoclasts with arch- or line-shaped F-actin bands decreased significantly. These results indicate that osteoclasts with arch- or line-shaped F-actin bands in the clear zone had lower bone-resorbing activity than those with ring-shaped F-actin bands, and that the formation of bands could be controlled by calcium-regulating hormones over the course of a few hours. Observation of the endocranial surfaces of calvariae might be useful for examining factors which affect the activities of osteoclasts in vivo.

Actins↗

PubMed1996

Highly virulent strains of herpes simplex virus fail to kill mice following infection via gingival route.

Virulence of herpes simplex virus (HSV) in mice has been demonstrated to be dependent on the site of infection. In this experiment, pathogenesis of HSV was studied in 2 different routes of infection in a mouse model system. When BALB/c mice were infected with 5 x 10(3) plaque-forming units (PFU) of virulent HSV type 1 Miyama GC+ strain (HSV-1-GC+) intraperitoneally, all mice were dead in 6 to 9 days. HSV-1-GC+ was recovered from organs such as the cerebrum, cerebellum, brainstem, and spleen 2 to 5 days after infection, but not from other organs such as trigeminal ganglia. However, if mice were infected in the maxillary gingiva with 1.0 x 10(7) PFU of HSV-1-GC+, all mice survived. HSV-1-GC+ was recovered from the trigeminal ganglia and brainstem 2 to 5 days after infection, but not from other organs tested. When mice were infected in maxillary gingiva with HSV-1-GC+, followed by the intraperitoneal injection of 6 mg of cyclophosphamide 72 hrs after virus infection, all mice were dead within days. Immunofluorescent and hematoxylin-eosin staining of gingival tissue sections revealed that when mice were infected in maxillary gingiva with HSV-1-GC+, 3 times as many gamma delta T-cells and 5 times as many polymorphonuclear cells can be detected in sections of maxillary gingiva when compared with non-infected mice. These data show that the gingiva of mice is considerably more resistant to infection with HSV, compared with the peritoneal cavity, and suggest the possible presence of an oral defense mechanism which might be different from that in the peritoneal cavity.

Animals↗

PubMed1996

Influence of dynamic contact of hard contact lens materials on corneal epithelial cells examined by rose bengal staining.

PURPOSE: To establish a method for evaluation of less irritating contact lens materials by dynamic contact with cornea, we examined epithelial and endothelial cell injury to the porcine cornea caused by rotatory rubbing with four kinds of hard contact lenses (HCL). METHODS: The HCLs used were (1) polymethylmethacrylate (PMMA) HCL, (2) gas-permeable HCL composed of a graft co-polymer of dextran derivative and methylmethacrylate (MMA) (Suncon Mild II(TM), 12 Dk), (3) gas-permeable HCL composed of a graft co-polymer of dextran derivative, a monomer containing silicone, a monomer containing fluorine and MMA (New Dx HCL-136, 32 Dk), and (4) gas-permeable HCL composed of a monomer containing silicone, a monomer containing fluorine and MMA(RGPL-A, 216 Dk). Using a specially designed apparatus, we produced a standardized injury to the epithelium or endothelium of porcine corneas by holding the HCL against the corneal surface while rotating the lens rapidly. RESULTS: After rotatory rubbing of the HCL on the epithelium, the degree of rose bengal staining of the epithelial cells, indicating degeneration of the cells and mucin detachment, were significantly different among these HCLs (New Dx HCL-136 < Suncon Mild II(TM), PPMA < RGPL-A), and the cell injury rates of the endothelium were also significantly different among them (Suncon Mild II(TM) < New Dx HCL-136, PMMA < RGPL-A). The water-wettability of HCLs was not directly correlated with cell injury rates on epithelial and endothelial cells. CONCLUSIONS: Both the New Dx HCL-136 and Suncon Mild II(TM), which have a common composition of graft co-polymer of dextran derivative, are less irritating to the epithelium and to the endothelium. Also a very few patients complaints regarding Suncon Mild II(TM) wearing in individuals with dry eyes have been reported. Therefore, we would expect that the New Dx HCL-136 should be satisfactory for wear by individuals with dry eyes.

Animals↗

PubMed1995

Enhancing effect of platelet-derived growth factors on migration of corneal endothelial cells.

To investigate the role of platelet-derived growth factor (PDGF) in corneal wound healing, we examined the effect of human natural PDGF, recombinant PDGF-BB, and PDGF-AA on the migration of rabbit corneal endothelial cells. In a modified Boyden chamber in fetal bovine serum-free conditions, natural PDGF and PDGF-BB, at a concentration of 1-3 or 10 ng/ml, enhanced the migration of endothelial cells, whereas at a higher concentration (10 or 30 ng/ml), this enhanced migration was suppressed; the optimal concentration range for enhancing migration was 3-10 ng/ml. PDGF-AA did not enhance the migration. Natural PDGF and PDGF-BB activity was found for up to 6 h after the beginning of culture, and was completely blocked by anti-PDGF neutralizing antibodies. A checkerboard assay demonstrated that PDGF-BB had a chemotactic effect on the corneal endothelial cell migration. These results suggest that natural PDGF and PDGF-BB, but not PDGF-AA, are involved in corneal wound healing by stimulating the migration of corneal endothelial cells.

Animals↗

PubMed1995

Cross-sectional comparisons of caries time trends in nursery school children in Sendai, Japan.

The aim of this study was to clarify the trends in caries experience in the primary dentition of nursery school children in Sendai, Japan, over a period of 20 yr. An annual clinical dental examination of children aged 2-5 yr at 13 nursery schools in Sendai City was carried out in 1972, 1977, 1982, 1987 and 1992. Data obtained from all five surveys were compared in each age group respectively. The percentages of 2-, 3- and 4-yr-olds free from caries increased remarkably until 1977, while that in 5-yr-olds started increasing several years later. After such increments, percentages in all age groups except 3-yr-olds remained almost at the same level with slight fluctuations. The mean deft and defs values per child in 2-, 3- and 4-yr-olds decreased remarkably until 1977, but then remained almost at the same level thereafter. That in 5-yr-olds continued decreasing slightly during the 20-yr period. The marked reduction of caries experience in nursery school children shown during the 1970's did not continue through the 1980's or the beginning of the 1990's.

Child, Preschool↗

PubMed1995

Enhancement of growth of rabbit corneal endothelial cells by PDGF.

The effect of platelet-derived growth factor (PDGF) on the growth of rabbit corneal endothelial cells and the expression of PDGF receptor mRNA in these cells were examined in the present study. When rabbit corneal endothelial cells were cultured in the presence of natural PDGF, recombinant PDGF-BB, and PDGF-AA for 1, 3, and 5 days, natural PDGF and recombinant PDGF-BB enhanced the growth of the endothelial cells, but PDGF-AA did not. This growth promotion was suppressed by anti-PDGF antibody. PDGF enhanced also the incorporation of 3H-thymidine into the cells. When PDGF was combined with epidermal growth factor (EGF), the additive effect was recognized. The expression of the PDGF receptor mRNA was found in the endothelial cells by the polymerase chain reaction (PCR) method. It was concluded from these results that PDGF enhanced the growth of the corneal endothelial cells and that the PDGF receptor mRNA was expressed in these cells. These results suggest that PDGF may regulate corneal endothelial cell growth.

Animals↗

PubMed1995

Downbeat nystagmus with compression of the medulla oblongata by the dolichoectatic vertebral arteries.

A case is reported of downbeat nystagmus associated with compression of the caudal brain stem by the dolichoectatic vertebral arteries, which was revealed by magnetic resonance imaging. Before surgery, the patient complained of oscillopsia at rest. Downbeat nystagmus was observed in the primary eye position and was increased in lateral gaze, especially to the left. Surgical repositioning of the left vertebral artery succeeded in resolving the downbeat nystagmus in the primary position within 1 month, and the nystagmus in all the other gaze positions almost completely disappeared over the subsequent months. Other ocular abnormalities also were improved after surgery. Thus, this case shows clear evidence of downbeat nystagmus arising from compression of dolichoectatic vertebral arteries to the medulla oblongata. Surgical neurovascular decompression of the dolichoectasia reverses the progression of symptoms if permanent neurologic damage has not already occurred.

Aged↗

PubMed1994

Enhancement of fibronectin-induced migration of corneal epithelial cells by cytokines.

PURPOSE: To examine the enhancing effect of cytokines on the corneal epithelial cell migration induced by fibronectin (FN). METHODS: A modified Boyden chamber method was used to detect chemotactic cell migration. Cells plated in the inner chamber were incubated with FN, cytokines, or both in the outer chamber at 37 degrees C for 24 hours. Cells that had migrated were stained and counted under a microscope. Checkerboard analysis was used to distinguish chemotaxis from chemokinesis. RESULTS: FN induced epithelial cell migration, but interleukin (IL)-1 alpha, IL-6, tumor necrosis factor (TNF)-alpha, and epidermal growth factor (EGF) alone did not. These cytokines, even at very low concentrations (0.1 to 100 pg/ml), enhanced FN-induced migration to levels about twofold those observed with FN alone. Checkerboard analysis demonstrated that EGF, but not IL-1 alpha, IL-6, or TNF-alpha, stimulated the chemokinesis of corneal epithelial cells in the presence of FN. CONCLUSION: EGF enhanced corneal epithelial cell migration by increasing chemokinesis, whereas IL-1 alpha, IL-6, and TNF-alpha enhanced this migration by increasing the FN-induced chemotactic activity, although these cytokines themselves do not have chemokinetic and chemotactic activity.

Animals↗

PubMed1993

Different clinical features in monozygotic twins: a case of 7q--syndrome.

We present male monozygotic twins who showed quite different clinical features. Blood chromosome analysis revealed 46,XY/46,XY,del(7) (q32-->qter) mosaicism in both twins. However, cultured skin fibroblasts from the twins showed different karyotypes. Twin 1, with a normal phenotype, had normal chromosomes and was 46,XY. Twin 2, on the other hand, had the characteristic manifestations of 7q- syndrome and chromosomes of 46,XY,del(7) (q32-->qter). DNA fingerprint analysis of their peripheral blood samples revealed the same pattern. However, DNA fingerprint patterns of cultured skin fibroblasts and buccal mucosal cells were different when a 7q terminal marker, probe g3, was used. These identical twins with discordant phenotypes can be explained by the occurrence of twinning and simultaneous erroneous mitosis. In addition, there might be a vascular communication which probably resulted in blood exchange and chromosomal mosaicism of the lymphocytes of the monozygotic twins.

Abnormalities, Multiple↗

PubMed1992

[Imprint cytodiagnosis of lymph node metastasis in resected lung cancer].

The cytological examination of lymph node imprints is a rapid and useful method for diagnosis of lymph node metastasis. We applied this technique for the diagnosis of regional lymph node metastasis of resected lung cancer, and compared its diagnostic value with histological examination. The accuracy rate of imprint cytology is 97.3%, and the sensitivity rate is 100%. We conclude that imprint cytology of lymph node for diagnosis of cancer metastasis is highly accurate and simple, and its diagnostic value may be equal to that of routine histological examination.

Adenocarcinoma↗

PubMed1992

[A case of traumatic rupture of the pericardium].

A 59-year-old man was admitted to our hospital because of compression fracture of the lumbar spine and pubic bone fracture following fall from a ladder. On admission the only a little left pleural effusion in the thorax was noted. Two days later, x-ray film of the chest revealed massive left pleural effusion. Under the diagnosis of left hemothorax, left thoracotomy was performed. Then we found incidentally that the left pericardium had ruptured longitudinally over the length. Herniation of the heart was not developed. The ruptured pericardium was repaired using Teflon mesh.

Humans↗

PubMed1990

Biochemical mechanisms of enhanced inhibition of fluoride on the anaerobic sugar metabolism by Streptococcus sanguis.

The effect of fluoride on acid production by Streptococcus sanguis ATCC 10556 was compared under anaerobic and aerobic conditions. The rate of acid production under constant-pH and pH-free-fall conditions was determined during glucose metabolism by resting cells. Anaerobic glycolysis was inhibited more strongly by fluoride than was aerobic glycolysis. Intracellular levels of 3-phosphoglyceric, 2-phosphoglyceric, and phosphoenolpyruvic acids were lower under anaerobic conditions than under aerobic conditions. Thus, S. sanguis had a low phosphoenolpyruvate (PEP) potential under anaerobic conditions. This low PEP potential was suggested to account for the more effective fluoride inhibition of enolase and, consequently, the reduced transport of sugar by the PEP-dependent phosphotransferase system of this micro-organism.

Fluorides↗

PubMed1990

Chiral synthon obtained with pig liver esterase: introduction of chiral centers into cyclohexene skeleton.

A versatile chiral synthon, (1R,6S)-6-methoxycarbonyl-3-cyclohexene-1-carboxylic acid, was obtained by an enantioselective hydrolysis of the corresponding meso diester with pig liver esterase. This enzymatic hydrolysis can easily be carried out on a multi-hundred gram scale. The chiral monoester thus obtained can be further converted into all stereoisomers of 1-amino-2-alkoxycarbonyl-4-cyclohexene derivatives in an enantio- and stereocontrolled manner. These derivatives are considered as potential key intermediates for synthesizing a variety of biologically interesting compounds such as aminocyclitol and carbapenem antibiotics.

Animals↗

PubMed1990

Surgical approach to arteriovenous malformation of the medial temporal lobe--report of three cases.

We report three cases of arteriovenous malformation (AVM) of the medial temporal lobe and the surgical approaches used. The AVM was fed by the anterior choroidal artery (AChA) in two cases (Cases 1 and 2) and by the posterior cerebral artery in one (Case 3). The trans-Sylvian approach was first used for cerebrospinal fluid aspiration to retract the brain in all cases, and for confirming the feeding arteries to prevent premature bleeding from the AVM in Cases 1 and 2. In Case 1, a corticotomy was then made in the fusiform gyrus via the subtemporal approach to avoid the development of speech disturbance and visual field defects, while in Cases 2 and 3, a cortical incision was made in the middle temporal gyrus because visual field defects were preoperatively present. Cases 1 and 2 achieved good recoveries, but Case 3 suffered postoperative speech disturbance and died of rebleeding from a recurrent AVM fed by the AChA 22 months after the operation. This AVM was not demonstrated on the postoperative angiograms. We emphasize the usefulness of the combination of trans-Sylvian and subtemporal approaches for this lesion, because the feeding arteries are easily identified and retraction of the temporal lobe is alleviated. A corticotomy in the fusiform gyrus is also recommended to avoid the development of not only visual field defects but also aphasia.

Adolescent↗