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Biomedical subjects

H Kawano

Publications and source records attributed to H Kawano.

At least 19 recordsLinked to original sources
PubMed1992

Met-enkephalin-Arg6-Gly7-Leu8- and substance P-containing projections from the nucleus preopticus medianus to the paraventricular hypothalamic nucleus.

The nucleus preopticus medianus (POMe) is known to be important for the regulation of fluid balance and cardiovascular control. Direct projections from the POMe to the paraventricular hypothalamic nucleus (PVN), where vasopressin-containing neurons exist, were examined in the rat using immunohistochemistry combined with a retrograde tract tracing method. After injection of WGA-HRP-colloidal gold into the PVN, many neurons were retrogradely labeled in the POMe; some of them were immunoreactive to Met-enkephalin-Arg6-Gly7-Leu8 (mE8) or substance P (SP). The results indicate that mE8- and SP-immunoreactive neurons in the POMe send their axons to the PVN.

Animals↗
PubMed1992

Mapping of the antigenic determinants recognized by monoclonal antibodies against the M2 protein of rabies virus.

Twenty-one hybridomas producing monoclonal antibodies (moAbs) against the M2 protein of the Nishigahara (RECH) strain of rabies virus were prepared using the SDS-polyacrylamide gel-purified M2 protein as the immunogen. All moAbs reacted with the protein after Western blotting of rabies virus. By combinations of competitive binding assays, examination of the reactivity of moAbs to the cells infected with parent RCEH and two other strains, CVS and HEP-Flury, and immunoprecipitation with in vitro translation products derived from full-length and truncated cDNAs of the M2 gene, these moAbs could be classified into seven epitope groups. Of these, 20 moAbs belonging to six epitope groups were suggested to recognize an antigenic determinant in the amino-terminal region, from the 1st to the 72nd amino acid of the protein (8 moAbs from two groups directed to amino acids 1 to 72; 2 moAbs from a group directed to amino acids 9 to 72; 5 moAbs from a group directed to amino acids 17-72; 5 moAbs from two groups directed to amino acids 32 to 72). The antigenic determinant recognized by the remaining 1 moAb was shown to be located in the amino acid region from 50 to 171. These moAbs should be useful for further studies on the biological functions of the M2 protein of rabies virus.

Antibodies, Monoclonal↗
PubMed1992

Heterozygosity of the major histocompatibility complex controls the autoimmune disease in (NZW x BXSB) F1 mice.

In the F1 hybrid of phenotypically normal NZW (H-2z) and systemic lupus erythematosus (SLE)-prone BXSB mice (H-2b), features of the disease became more severe than those seen in the BXSB mice, regardless of the presence or absence of the Yaa (Y-chromosome-linked autoimmune acceleration) mutant gene. To determine whether the gene(s) linked to the major histocompatibility complex (MHC) of NZW mice is involved in this event, we developed the H-2-congenic NZW.H-2d strain and compared the severity of autoimmune disease between (NZW x BXSB) F1 (H-2z/b) and (NZW.H-2d x BXSB) F1 mice (H-2d/b). The H-2z/b, but not H-2d/b, heterozygous F1 mice of both sexes showed an accelerated, higher incidence of proteinuria and a more severe thrombocytopenia than did the BXSB mice. In NZW x (NZW x BXSB) F1 backcross mice, the H-2z/b heterozygous progeny showed more severe disease than did the H-2z/z homozygotes. Thus, disease-accelerating events in (NZW x BXSB) F1 mice are linked to the H-2z/b heterozygosity. Because H-2d/z heterozygosity plays a crucial role for SLE in (NZB x NZW) F1 mice, in which SLE features differ from those in (NZW x BXSB) F1 mice, the present observations may imply that the different but related MHC heterozygosity acts as a predisposing genetic element in these different SLE syndromes.

Age Factors↗
PubMed1992

Monoclonal antibodies reveal molecular differences between terminal fields in the rat dentate gyrus.

We have derived a number of monoclonal antibodies which detect molecular differences correlating with the afferent inputs to the molecular layer of the adult rat hippocampal dentate gyrus. One group, dubbed OM-1 to OM-4, strongly stain the outer zone of the molecular layer, which receives its major innervation from the ipsilateral entorhinal cortex. A second group, IM-1 and IM-2, show a complementary pattern and preferentially stain the inner molecular layer, which receives inputs from the ipsilateral and contralateral hippocampus. These antigens are not, however, restricted to these layers, being found outside the hippocampus in several other areas of neuropil in the adult brain. In the developing brain the IM-1 antigen appears ubiquitously from the earliest age studied, embryonic day 12. Within the dentate gyrus, its restriction to the inner terminal field of the molecular layer only occurs during the second postnatal week. In contrast, OM staining appears only sparsely and late in the prenatal brain, appearing in developing cortical white matter between embryonic days 18 and 20. The outer dentate molecular layer becomes OM-positive from birth onwards, corresponding to the time of arrival of entorhinal axons during the first postnatal week. These two groups of monoclonal antibodies recognize a number of different glycoproteins. Ultrastructural immunohistochemistry shows they are cell surface molecules, and as such may be involved in the recognition events required for the establishment of specific patterns of neuronal connectivity.

Animals↗
PubMed1992

The OM series of terminal field-specific monoclonal antibodies demonstrate reinnervation of the adult rat dentate gyrus by embryonic entorhinal transplants.

Monoclonal antibodies OM-1 to OM-4 and IM-1 [Woodhams et al. (1991) Neuroscience 46, 57-69] have complementary immunostaining patterns in the molecular (dendritic) layer of the adult rat dentate gyrus, with OM-1 to OM-4 selectively recognizing the outer (distal) two-thirds (i.e. the entorhinal afferent zone), and IM-1 the inner (proximal) one-third (i.e. the hippocampal commissural/associational zone). Immunoblotting suggests that OM-1 recognizes a single glycoprotein antigen of mol. wt around 93,000, and OM-2, OM-3, and OM-4 all recognize a second glycoprotein antigen of mol. wt around 36,000. At four weeks after removal of the ipsilateral entorhinal cortex the background OM immunostaining of the entorhinal afferent zone is abolished and replaced by a network of densely stained granules, which we interpret as degenerating entorhinal afferent axons. At the same time, the proximal, IM immunoreactive zone expands by about 10 microns in width (while the distal deafferented zone shrinks by about 80 microns). Attempts were made to restore the OM immunoreactivity of the distal zone by grafting either small pieces or cell suspensions of embryonic day 18 entorhinal cortex directly into the dentate molecular layer of entorhinally deafferented adult hosts. About half (14/26) of the animals with successfully positioned grafts showed restoration of OM-2 to OM-4 immunostaining throughout the entire width of the outer two-thirds (entorhinal afferent zone) of the dentate molecular layer. Strikingly, however, in adjacent serial sections the restoration of OM-1 immunoreactivity was restricted to the "middle" molecular layer, i.e. the most proximal part of the distal (entorhinal) two-thirds of the dentate molecular layer. In no case did the OM-1 immunoreactivity extend to the outer margin of the molecular layer. This did not appear to be associated with incompleteness of the removal of the host entorhinal projection, since it occurred in grafted cases where the hippocampus had been completely isolated from the entorhinal area. The simplest explanation of the observed pattern of OM loss and restitution is that the epitopes are located on the entorhinodentate axons, but it is not clear whether the antigens recognized by OM-1 and OM-2 to OM-4 are expressed in different parts of the same group of axons, or in different subsets of entorhinodentate axons. Nor is it clear why the pattern of OM-1 is only restored to the "middle" molecular layer, while that of OM-2 to OM-4 is restored to the entire outer two-thirds.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

Suppression of cell-mediated immunity by street rabies virus infection.

An attempt to define a severe suppression of cell-mediated immunity by street rabies virus infection was undertaken by using the mice lethally and peripherally infected with a street rabies virus (1088 strain). The cell-mediated cytotoxic (CMC) activity of the spleen cells from those mice once slightly increased until day 4 after infection but declined rapidly thereafter until their death on days 10 to 12 after infection. In parallel with a decrease of CMC response of the spleen cells from 1088-infected mice, proliferative response to Con A, IL-2 activity in the culture supernatants of Con A-induced proliferation, responsiveness to exogenously added IL-2 and to Con A to express IL-2R, of those cells became suppressed, and the marked decrease of the total number of spleen cells was observed. Selective depletion of CD4+ and CD8+ cells in the spleens, abnormalities of IL-1 and E-type prostaglandins (PGE2) production or production of inhibitory component able to block IL-2 activity by spleen cells were not observed and these factors did not appear to be associated with the suppression of proliferative response to Con A. However, an apparent association of CD8+ cells in the suppression of differentiation of pre-cytotoxic lymphocytes (CTL) into CTL was demonstrated in the co-culture experiments of the spleen cells from 1088-infected mice with spleen cells of mice infected with an attenuated rabies virus (ERA strain) which can induce higher levels of CMC response. There was no evidence of the productive replication of rabies virus in thymus and spleen of 1088-infected mice. The relationship of these observations to current theories on virus-induced immunosuppression was discussed.

Animals↗
PubMed1992

Prevalence and etiology of dementia in a Japanese community.

BACKGROUND AND PURPOSE: We sought to determine the type-specific prevalence of dementia and its risk factors in elderly persons from the Japanese community of Hisayama. METHODS: We studied the prevalence of dementia in 887 Hisayama residents (353 men and 534 women) aged 65 years or older (screening rate, 94.6%) using various items of clinical information, neurological examination, and dementia scales. We also studied brain morphology in 50 of 59 determined to have dementia by computed tomography or autopsy during the subsequent 54-month period. Factors relevant to dementia were compared between 27 patients with vascular dementia and 789 control subjects without dementia in a retrospective fashion. RESULTS: The prevalence rate of dementia among Hisayama residents aged 65 or older was estimated at 6.7%, with a females to males ratio of 1:2. Among 50 cases of dementia in which brain morphology was examined, the frequency of vascular dementia was 56%; this rate was 2.2 times higher than that for senile dementia of the Alzheimer type. Aging, hypertension, electrocardiographic abnormalities, and high hematocrit were significantly (p less than 0.05) and independently associated with the occurrence of vascular dementia. CONCLUSIONS: Prevalence of dementia among the Hisayama residents was relatively identical to that previously reported, but vascular dementia was more predominant. Risk factors for vascular dementia were similar to those for lacunar infarcts. Control of hypertension may be a key to reducing dementia among the Japanese population.

Age Factors↗
PubMed1992

Light stimulation of the hypothalamic neuroendocrine system.

This paper demonstrates that, in the mediation of light, the suprachiasmatic nucleus (SCN) functionally associates with the anterior periventricular and parvocellular paraventricular neuron systems in rats. Intact rats (group 1) and rats undergoing a hemicomplete cutting of the SCN (group 2) were housed in a dark room (2-3 weeks) and killed after an exposure to light for 10, 30 or 60 min. Other intact animals (group 3) kept in a dark room (2 weeks) were exposed to light for 10 min, then stored 60 min in the dark room, and killed in darkness. The SCN, anterior periventricular nucleus, and parvocellular paraventricular nucleus were examined immunohistochemically using antisera for vasoactive intestinal polypeptide (VIP), arginine vasopressin, somatostatin, rat corticotropin releasing factor (rCRF), and c-fos protein. In comparison with animals kept in darkness, animals exposed for 10 and 30 min to light indicated a remarkable reduction of VIP immunoreactivity in the SCN and some increase of CRF immunoreactivity in the parvocellular paraventricular nucleus. The diminution of VIP immunoreactivity did not occur in the isolated SCN of group 2 animals. In group 3, a 10 min-light exposure induced a remarkable enhancement of nuclear c-fos immunoreactivity in neurons in the ventrolateral region of the SCN, in the anterior periventricular nucleus, and in the parvocellular paraventricular nucleus, most strongly in the SCN. Double immunolabeling methods have shown that VIP, somatostatin, and CRF neurons in the respective nuclei were c-fos positive.

Animals↗
PubMed1992

Time course of the impairment of cerebral autoregulation during chronic cerebral vasospasm after subarachnoid hemorrhage in primates.

The time course of the impairment of cerebral autoregulation during chronic cerebral vasospasm after subarachnoid hemorrhage was studied in 18 monkeys. Changes in cerebral blood flow (CBF) at the regional level and central conduction times during either graded hypo- or hypertension were evaluated in these animals at three stages (3, 7, and 14 days) following the introduction of an autologous blood clot around the right middle cerebral artery (MCA). Angiograms revealed a reduction in vessel caliber (compared to the baseline level in the involved MCA) of 30% at 3 days, 50% at 7 days, and 10% at 14 days. At all stages, CBF remained constant at mean arterial blood pressures (MABP) of 60 to 160 mm Hg in the noninvolved hemisphere. In contrast, at the 3- and 7-day stages, there was an impairment of autoregulation in the involved hemisphere at MABP of 40 to 180 mm Hg. The right hemispheric CBF was significantly (p less than 0.05) lower than that in the left throughout the period of investigation at MABP below 120 mm Hg, but rose to exceed the left CBF at MABP above 180 mm Hg at the 7-day stage and 160 mm Hg at the 14-day stage. The right-sided central conduction time showed significant (p less than 0.05) prolongation at MABP below 60 mm Hg at the 3-day stage and 40 mm Hg at the 7-day stage. It is suggested that these results may help to develop guidelines for hemodynamic therapy for vasospasm in its various stages.

Analysis of Variance↗
PubMed1992

Histopathology of eighth cranial nerve of mass stranded dolphins at Goto Islands, Japan.

We examined four dolphins (Grampus griseus) of 582 mass-stranded. Almost no contents were found in the alimentary canal. Nasitrema gondo and Crassicauda grampicola were found in the tympanic cavity. Severe degeneration of the eighth cranial nerve was observed microscopically in all animals and an egg of Nasitrema was found in a tissue crevice of the nerve. We propose that the nerves were damaged directly by Nasitrema.

Animals↗
PubMed1992

Postnatal changes in development of serotonin-, neuropeptide Y-, Leu-enkephalin- and substance P- terminals in the rat locus coeruleus; a quantitative immunohistochemical study.

Postnatal developmental changes were investigated in afferent terminals immunoreactive to serotonin (5-HT), neuropeptide Y (NPY), Leu-Enkephalin (ENK) and substance P (SP) within the locus coeruleus from postnatal rat from day 1 (1 D) to 9 week (9 W) adult using immunohistochemical techniques. Quantitative study using a light microscopic image analyzing system revealed that the number of immunoreactive terminals increased after birth to reach a peak at 5 W, then decreased by 26% of this value and stabilized at 7 W; terminals immunoreactive to 5-HT or NPY increased gradually after birth, while those immunoreactive to ENK or SP increased suddenly at 3 W. Electron microscopic analysis revealed similar changes in the total terminal number during development. Synaptic terminals, on the other hand, increased sharply from 1 D to 3 W, then gradually until 5 W, and remained stable thereafter. These results suggest that surplus afferent terminals are eliminated prior to the establishment of afferent innervation and that 5 W postnatal is the critical time for maturation of the afferent system. Electron microscopy also demonstrated morphological characteristics of terminals immunoreactive to each peptide or 5-HT and developmental changes in their characteristics.

Aging↗
PubMed1992

Immobilization of nucleoside on silica gel and specific separation of oligonucleotides.

Deoxyadenosine was immobilized on silica gel, in order to use as HPLC resins for selective separation of oligonucleotides. The longest retention time was observed for the complementary pd(T)4, and increased with decrease of temperature. This fact suggested that the main separation factor was the base pairing between complementary nucleic acid bases. These resins may be useful for separation of components of nucleic acids and polynucleotides as a specific separation system.

Chromatography, High Pressure Liquid↗
PubMed1992

[Vagal innervation in the human atrioventricular valves].

Innervation of the human atrioventricular (AV) valves is microscopically studied by histopathological methods. The tricuspid and mitral valves of 4 autopsied hearts of adult men (age range from 50 to 74 years old) without any cardiovascular diseases were stained for acetylcholine-esterase by histochemical method in the medium containing acetylthiocholine iodide. Acetylcholine-esterase positive nerve fibers of 2 to 50 microns in diameter were widely distributed in the subepicardial space of the atrial of the AV valve. They formed a coarse network of the nerve elements from the valve base to the anatomical edge. The nerve network was more dense at the valve ring and base, as well as at the commissure, than at the edge and body. Some thick nerve fibers ran in the chordae tendineae. The thick fibers were intercalated with varicose-like special structures at several places in the leaflets, which seemed to be a kind of sensory apparatus. The thin nerve fibers ended, as usual, at small dot or brush-like apparatus. It is widely accepted that the acetylcholine-esterase positive nerve fibers are identical with vagal nerves which are insisted on participating in development of mitral valve prolapse syndrome. We suggest that the vagal innervation in the AV valves could play an important role for valvular function.

Acetylcholinesterase↗
PubMed1992

Exposure to hepatitis B virus in the general population of Hisayama, Japan: significance of isolated antibody to hepatitis B surface antigen in general population.

Cross-sectional survey on the prevalence of hepatitis B serological markers was performed in 2,411 residents who accounted for 74.4% of the population aged 40 and over and living in Hisayama Town, Japan, in 1983. Overall prevalences were 40.7% for both anti-HBs and anti-HBc, 6.1% for isolated anti-HBs and 5.4% for isolated anti-HBc. The condition with isolated anti-HBs was different from those with isolated anti-HBc and both anti-HBc and anti-HBs as follows. The titer of anti-HBs in isolated anti-HBs positive samples was significantly lower than that in both anti-HBs and anti-HBc positive ones (46.2 +/- 5.4 vs. 83.2 +/- 2.8, mean +/- SE, p less than 0.001). The presence of isolated anti-HBs was neither significantly more frequent in males nor related to the risk of liver damages in contrast with that of anti-HBc with or without anti-HBs. These findings suggest that isolated anti-HBs pattern with the absence of anti-HBc in general population was not due to prior HBV infection, but due to natural immunization with HBsAg.

Adult↗
PubMed1992

Prevalences of hepatitis B surface antigen carriers and liver damages in the general population of Hisayama, Japan.

The prevalences of hepatitis B surface antigen (HBsAg) carriers and liver damages were studied in 2,411 residents aged 40 and over and living in Hisayama, Japan in 1983. Hepatitis B virus (HBV) associated markers were all measured by radioimmunoassay. HBsAg carriers were found in 2.3 per cent of the residents. Hepatitis B e antigen and antibody to hepatitis B e antigen were positive in 8.9 per cent and 80.4 per cent, respectively, of HBsAg carriers. The prevalences of liver damages in HBsAg carriers were compared with 1095 who had none of HBV markers (neither anti-HBc nor anti-HBs). The prevalences of abnormal aminotransferase level in sera were not different between HBsAg carriers and those who had none of HBV markers. A history of jaundice and/or hepatitis was evident in 32.3 per cent of male carriers and 24.0 per cent of female ones, being significantly more than those without HBV markers (13.1 per cent and 5.8 per cent, p less than 0.05 and p less than 0.005, respectively). These results indicate that, among HBsAg carriers aged 40 and over, few have active clinical signs of hepatitis, although about 20 per cent of them have histories of symptomatic hepatitis due to hepatitis B.

Adult↗