Biomedical subjects
H Kawamura
Publications and source records attributed to H Kawamura.
[Intramedullary hemangiopericytoma of the spinal cord; case report and review of the literature].
Hemangiopericytoma is a rare tumor deriving from capillaries and pericytes. Although it is a well established entity clinically and histologically, its occurrence in the central nervous system adhering to the meninges has been controversial. We described a case of a 39-year-old man with intramedullary hemangiopericytoma. To the best of our knowledge, no previous case of hemangiopericytoma in this location has been reported. We reviewed differential diagnosis of spinal hemangiopericytoma based on neuroradiological points, and clinical findings of the 14 primary cases reported in the literature. The nosological problem of hemangiopericytoma was also discussed.
Plantagoside, a novel alpha-mannosidase inhibitor isolated from the seeds of Plantago asiatica, suppresses immune response.
A hot-water extract from the seed of Plantago asiatica showed a potent inhibitory activity against jack bean alpha-mannosidase, and a flavanone glucoside, plantagoside, was isolated as the inhibitor. Plantagoside was a specific inhibitor for jack bean alpha-mannosidase (IC50 at 5 microM) and appeared to be a non-competitive inhibitor of the enzyme. Whereas, negligible or weak inhibitory activities were observed for beta-mannosidase, beta-glucosidase, and sialidase tested. Plantagoside also inhibited alpha-mannosidase activities in mouse liver lysosomal and microsomal fractions, and the enzyme inhibitory activity in microsomal fraction was enhanced in the presence of glucosidase inhibitor, castanospermine. Plantagoside suppressed antibody response to sheep red blood cells and concanavalin A induced lymphocyte proliferation which was measured by [3H]thymidine incorporation.
First-order phase transition in the fcc Heisenberg antiferromagnet.
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Transplantation of septal cholinergic neurons to the hippocampus improves memory impairments of spatial learning in rats treated with AF64A.
Embryonic septal neurons were transplanted into damaged hippocampus in adult rats which had received lateral ventricular administration of AF64A, a cholinergic neurotoxin. About 3 months after transplantation, the rats with bilateral septal grafts showed significant improvement in the radial maze and T-maze tasks. Many ingrowths of acetylcholinesterase (AChE)-positive fibers originating from the grafts were observed in the hippocampus of the rats which showed good performance in these learning tasks. These results indicate that transplantation of septal cholinergic neurons into the AF64A-treated hippocampus may induce at least partial recovery in learning tasks believed to involve the hippocampus.
Visceral urate deposits in chicks inoculated with avian nephritis virus.
Avian nephritis virus, G-4260 strain, was inoculated orally into one-day-old specific-pathogen-free chicks of two lines. Approximately 20 per cent of the chicks of both lines died with visceral urate deposits from eight to 12 days after infection, and the virus was isolated from the kidneys of the dead chicks. At 14 or 15 days of age the mean liveweight of the surviving infected chicks was approximately 16 per cent less than that of the uninfected control chicks.
Age-related decline of acetylcholine release evoked by depolarizing stimulation.
Release of endogenous acetylcholine (ACh) from the dorsal hippocampus in response to depolarizing stimulation with high-K+ infusion was examined in young and aged rats using the method of in vivo dialysis. ACh content in the dialysate was determined by high-performance liquid chromatography-electrochemical detection (HPCC-ECD). During the high-K+ stimulation, the concentration of ACh in the dialysate only slightly increased in aged rats in contrast with young rats where the ACh content during stimulation increased about 2-fold of the basal level. These results showed that ACh release evoked by depolarizing stimulation declined through aging in the hippocampus.
Recovery of hippocampal cholinergic activity by transplantation of septal neurons in AF64A treated rats.
Embryonic septal neurons were transplanted into the hippocampus of adult rats which had received lateral-ventricular administration of AF64A, a cholinergic neurotoxin, and the effects on hippocampal cholinergic activity were studied. One week after AF64A administration, we injected dissociated septal cell suspension into the dorsal hippocampus, unilaterally. About 3 months after the transplantation, acetylcholine (ACh)-rich septal grafts formed extensive acetylcholinesterase (AChE)-positive fibers into the host hippocampus, recovering choline acetyltransferase (ChAT) level only in the grafted side. These results indicate that septal implants can produce a partial recovery of the cholinergic activity in the chemically damaged hippocampus.
Promotion of calcification by imidazole and its suppression by diltiazem in the growth cartilage of rats with HEBP induced rickets.
The object of our experiments was to determine the effect of imidazole on the growth cartilage of rats with HEBP induced rickets. When HEBP (1-hydroxyethylidene-1, 1-bisphophonic acid) was given to young rats in large doses over a short period, rickets was consistently produced. We found that imidazole had a calcification promoting action in the growth plate cartilage where there had been an increase in thickness due to the inhibition of calcification. In an attempt to clarify the mechanism of accelerated calcification due to imidazole, the effects of diltiazem, a calcium antagonist, were observed; it was found to suppress the accelerated calcification. If diltiazem inhibits the entry of calcium ions into the cells of the growth cartilage, as it does in smooth muscle and myocardial cells, then our results indicate that intracellular concentrations of calcium may play an important role in the accelerated calcification due to imidazole.
Immunopathological and ultrastructural studies on the tonsil of gnotobiotic pigs infected with strain 67N of haemagglutinating encephalomyelitis virus.
The 67N strain of haemagglutinating encephalomyelitis virus (HEV) was inoculated orally or nasally into ten 3-day-old gnotobiotic piglets. Tonsillar changes characterized by epithelial degeneration and lymphatic cell infiltration occurred in the crypt from post-inoculation days (PID) 5 to 7, and HEV was isolated from the tonsil on PID 3 and 5. Ultrastructurally, many HEV particles were found in the cisternae, cytoplasmic vesicules and extracellular spaces of crypt epithelium. Immunohistologically, many HEV particles were observed in the crypt epithelial cells in the early stage of infection. Thereafter, a large number of immunoglobulin (IgG, IgM and IgA)-containing cells were observed in the tonsil. The appearance of IgM-containing cells was coincident with the detection of neutralizing antibody in the serum. These findings suggest that HEV replication in the crypt epithelium stimulates the proliferative response of immunoglobulin (IgG, IgM and IgA)-producing cells.
Demonstration of viral antigen and immunoglobulin (IgG and IgM) in brain tissue of pigs experimentally infected with haemagglutinating encephalomyelitis virus.
Haemagglutinating encephalomyelitis virus (HEV) was inoculated either orally or intranasally into ten 3-day-old gnotobiotic piglets. All infected pigs showed inappetence and listlessness, but there were no clinical signs of nervous disorder. Severe encephalomyelitis, characterized by neuronophagia, focal gliosis and perivascular cuffing, was observed in the brain stem and cerebral cortex. Nasally infected pigs, in particular, developed lesions in the area of the stria olfactoria and tractus olfactorius. Coincident with the encephalitic changes, HEV antigen was observed first in the trigeminal ganglion cells and then in degenerating neurones. Immunoglobulin (IgG and IgM)-containing cells were also found in perivascular cuffs and glial foci. They appeared at first on PID 7 and after that increased in number. These findings suggest that these encephalitic lesions are a specific immune response to HEV following its multiplication in the central nervous system.
Effects of temperature and pH on hemoglobin release from hydrostatic pressure-treated erythrocytes.
The release of hemoglobin from human erythrocytes hemolyzed beforehand by hydrostatic pressure, osmotic pressure, and freeze-thaw methods was examined as a function of temperature (0-45 degrees C) and pH (5.5-8.8) at atmospheric pressure. Only in the case of high pressure (2,000 bar) did the release of hemoglobin increase significantly with decreasing temperature and pH. Maleimide spin label studies showed that the temperature and pH dependences of hemoglobin release were qualitatively explicable in terms of those of the conformational changes of membrane proteins. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of membrane proteins showed the diminution of band intensities corresponding to spectrin, ankyrin, and actin in the erythrocytes hemolyzed by high pressure. Cross-linking of cytoskeletal proteins by diamide stabilized the membrane structure against high pressure and suppressed hemoglobin release. These results indicate that the disruption of cytoskeletal apparatus by high pressure makes the membrane more leaky.
Daily intake of 11 elements in relation to reference Japanese man.
Diet samples were collected by a duplicated portion method from 31 locations in Japan in both the summer and winter of 1981. The ashed samples were analyzed with an inductively coupled plasma atomic-emission spectrometer (ICP-AES) for 11 elements: Na, K, P, Ca, Mg, Zn, Mn, Al, Sr, Cu and Ba. Average daily intake was as follows: Na--4.5 g, K--1.9 g, P--0.92 g, Ca--0.56 g, Mg--0.20 g, Zn--7.1 mg, Al--4.0 mg, Mn--3.4 mg, Sr--2.3 mg, Cu--1.3 mg and Ba--0.36 mg. A tendency for higher mineral intakes was found in central Japan. These were the highest in the Chubu area followed by the Kanto and Kinki areas. Lower mineral intakes, below the averages for Japan, were found in western Japan, especially in the Chugoku and Shikoku areas. Daily intake of most elements, except Na, Mn, and Sr, was found to be 40-70% of the levels of Reference Man, which were reported by International Commission on Radiological Protection (ICRP) for the Western Europeans and North Americans. Daily intake of Na, Mn and Sr was almost the same in both cases.
Event-related potentials (P300) in myotonic dystrophy.
The P300 component of the auditory event-related potential in 8 patients with myotonic dystrophy was studied and compared with that of 13 healthy controls. Abnormalities of P300 (prolongation of the latency and/or decrease of the amplitude) were observed in 6. These observations imply that the function of cognitive and information processing are impaired in myotonic dystrophy.
Evaluation of the pathogenicity and immunogenicity of vaccinia virus to piglets.
The pathogenicity and immunogenicity of vaccinia virus were examined in order to evaluate the possibility of its application as a recombinant viral vaccine in pigs. Following scarification inoculation with vaccinia virus, a mild reddish papulation developed only on the scarified part of the skin. No symptoms of illness such as fever or stunting were noted. Vaccinia virus was recovered in titers from scarified skin 4 and 7 days after inoculation. Control piglets cohabited with inoculated animals remained normal for the whole 5 week observation period. Hemagglutination inhibition and indirect immunofluorescence tests detected antibodies against vaccinia virus in the inoculated piglets, whereas no anti-vaccinia virus antibodies were detected in the contact control animals. Antigen-induced blastogenic tests of peripheral blood lymphocytes from animals, revealed that lymphocytes obtained from inoculated donors 5 weeks after inoculation, had a higher stimulation index (P less than 0.05) than did those from uninoculated piglets. These results suggested that vaccinia virus would be useful as a recombinant viral vector for pigs.
[Evaluation of inferior joint space arthrography for type III temporomandibular arthrosis (internal derangements of temporomandibular joint)].
Inferior joint space arthrographies for the 37 patients with internal derangements of temporomandibular joint or joints were examined clinically. All arthrograms showed various problems of postural and morphological findings of the disc. Clinical diagnosis for the existence of internal derangements of the temporomandibular joint was completely confirmed by lower joint space arthrography. It must be considered, however, that clinical diagnosis for the morphological changes of the disc associated with internal derangements of temporomandibular joint is difficult. Inferior joint space arthrography was very useful to evaluate optically the discal formation in the cases.
[Effect of fluoride releasing composite resin on bovine enamel].
FluorEver is one kind of fluoride releasing composite resin. The first aim of this study was to investigate the amount of fluoride released from FluorEver. The second aim of this study was to determine the uptake of fluoride with bovine enamel, which was immersed in distilled water for 28 days in contact with FluorEver, compared with Fuji Ionomer cement which released fluoride. The results obtained were as follows. 1) A great amount of fluoride was released from FluorEver immediately after immersion. Twenty-four hours after immersion, the amount of released fluoride decreased quickly. From the 3rd day of immersion, the amount of fluoride released decreased gradually. The fluoride could be detected on the 28th day. 2) The amount of fluoride released from FluorEver was almost directly proportional to the volume of FluorEver blocks used. 3) The uptake of fluoride on enamel in contact with FluorEver was significantly high. 4) The release pattern of the fluoride of Fuji Ionomer was similar to that of FluorEver. The amount of fluoride released from Fuji Ionomer was greater than that of FluorEver immediately after immersion. However, from the 7th day of immersion, that of Fuji Ionomer was less than that of FluorEver. 5) The uptake of fluoride from FluorEver on the surface enamel was less than that of Fuji Ionomer. However, the uptake of fluoride from FluorEver on the subsurface enamel was greater than that of Fuji Ionomer.
[Case report on the Ehlers-Danlos syndrome].
The Ehlers-Danlos syndrome is a hereditary disease of the connective tissue, characterized by tendencies of hyperextensibility and fragility of the skin, and hypermobility of the joints. We are reporting in this paper on a 4 year, 4 month old boy with the Ehlers-Danlos syndrome, Type III. The following findings were obtained: 1) In addition to the three main symptoms the complications of exotropia, low position of the auricle, defect of the right musculuspectoralis major, right double thumbs, dislocation of hip joint, right inguinal hernia, right undescended testis and pes planovalgus were found. 2) Based on histopathological tissue examination, hypoplasia of the collagen fibers and the elastic fibers was found. 3) The occlusion was edge to edge, the plate was high arched and the upper and the lower dental arches were contracted. 4) The mesiodistal lengths of all primary teeth and the lengths and widths of the dental arches were smaller than the standard size. 5) The orthopantomo and dental x-rays revealed a tendency toward late calcification of the deciduous teeth and permanent teeth germs, and the stricture of the root canals. 6) According to x-ray cephalometric analysis, retardation of the growth of the upper face as well as the maxilla and mandibula was found.