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Biomedical subjects

M Kawata

Publications and source records attributed to M Kawata.

At least 235 records · Page 13Linked to original sources
PubMed1985

Urotensin II-immunoreactive neurons in the caudal neurosecretory system of freshwater and seawater fish.

Antiserum generated against synthetic urotensin II of the goby, Gillichthys mirabilis, was used to localize urotensin II in the caudal neurosecretory system in six species of freshwater teleosts: Cyprinus carpio, Carassius auratus, Oreochromis mossambicus, Oreochromis niloticus, Salmo gairdneri and Plecoglossus altivelis, and six species of seawater teleosts: Acanthogobius flavimanus, Pagrus major, Parapristipoma trilineatum, Trachurus japonicus, Seriola dumerili and Seriola quinqueradiata. In the carp, urotensin II-immunoreactive perikarya were classified into three groups according to their size and shape. Small cells were located in the spinal cord dorsal to the urophysis, medium-sized cells immediately anterior to the urophysis, and large cells anterior to the medium-sized cells. In each group, a small number of nonreactive cells was found. Urotensin II-immunoreactive nerve fibers extended toward the urophysis and terminated around the blood vessels. Other species of teleosts showed a similar immunoreaction to that observed in the carp. The immunoreaction of the urophysis was stronger in seawater fish than freshwater fish. Urotensin II-immunoreactive elements could not be detected in the brains of the carp, goldfish and goby.

Animals↗
PubMed1985

Immuohistochemical demonstration of alpha-atrial natriretic plypeptide-containing neurons in the rat brain.

Using the immunoperoxidase technique in conjunction with specific antisera to alpha-atrial natriuretic polypeptide (alpha-ANP), it was shown that immunoreactive cell bodies and varicose fibers are widely distributed throughout the rat brain. The highest concentrations of alpha-ANP-containing neuronal cell bodies and fibers were found in the hypothalamus and septum. This result confirms the radioimmunological determination of alpha-ANP immunoreactivity in the rat brain.

Animals↗
PubMed1985

Immunohistochemical investigations of the influence of reserpine on the serotonin neuron system in the rat brain.

A peroxidase-antiperoxidase immunohistochemical method with serotonin antiserum was employed to investigate the influence of reserpine on serotonin neurons of rats which were sacrificed at various times after injection (10 mg/kg i.p.). The disappearance of serotonin immunoreactivity induced by reserpine was detected only in the perikarya after 15 min, and then rapidly proceeded to the terminals. Between 2 and 4 h, immunoreactivity completely disappeared throughout the brain. The immunoreactivity reappeared in the perikarya after 6 h, and progressed toward the terminals gradually. However, there was an obvious difference in the rate of recovery of immunoreactivity between areas. After 7 days, the immunoreactivity returned to control levels.

Animals↗
PubMed1985

Atrial natriuretic polypeptide: topographical distribution in the rat brain by radioimmunoassay and immunohistochemistry.

The widespread distribution of neurons containing alpha-atrial natriuretic polypeptide-like immunoreactivity in the rat brain was demonstrated using radioimmunoassay and immunohistochemistry in conjunction with specific antisera. The highest concentrations of alpha-atrial natriuretic polypeptide-like immunoreactivity were in the hypothalamus and septum, with low but still appreciable concentrations in the mesencephalon, cerebral cortex, olfactory bulb and thalamus by radioimmunoassay. Immunohistochemical studies clearly showed that the perikarya of immunoreactive neurons are most prevalent in the ventral part of the lateral septal nucleus, periventricular preoptic nucleus, bed nucleus of the stria terminalis, periventricular and dorsal parts of the paraventricular hypothalamic nucleus, ventromedial nucleus, dorsomedial nucleus, arcuate nucleus, median mamillary nucleus, supramamillary nucleus, zona incerta, medial habenular nucleus and the periaqueductal grey matter. Scattered neurons were seen in the cingulate cortex, endopiriform nucleus, lateral hypothalamic area, and pretectal and dorsal thalamic areas. In addition to the areas mentioned above, high concentrations of immunoreactive varicose fibers were seen in the glomerular layer of the olfactory bulb, external layer of the median eminence, central to paramedian parts of the interpeduncular nucleus and the paraventricular hypothalamic nucleus. The globus pallidus, medial and central amygdaloid nuclei, dorsal raphe, dorsal parabrachial nucleus, locus coeruleus, vagal dorsal motor nucleus, solitary nucleus and some circumventricular organs, including the subfornical organ and organum vasculosum laminae terminalis, contained considerable numbers of immunoreactive varicose fibers. In dehydrated rats and homozygous Brattleboro rats, the pattern of alpha-atrial natriuretic polypeptide-immunoreactive neurons and varicose fibers was qualitatively similar to that seen in normal conditioned rats. This study gives an atlas of the distribution of the alpha-atrial natriuretic polypeptide-containing neuronal system in the rat brain and provides the groundwork for studying the influence of this new peptide on various brain functions.

Animals↗
PubMed1985

The double-eyelid operation in Japan: its evolution as related to cultural changes.

Of the many aspects of aesthetic surgery, the double-eyelid operation generates the most interest for Japanese surgeons, as there has been an enormous demand for it by patients who are fashion-conscious. It has been possible to locate 32 operative procedures that have been published in the Japanese literature over the past ninety years. Some of these procedures have been reviewed here in relation to the cultural and social changes which are important factors determining the extent of the demand for the operation and which correlate with various changes in surgical technique. This study chronologically describes each of the principal methods related to these social changes and also considers the influence of cultural fads and fashions.

Asian People↗
PubMed1985

Characterization of human embryonal carcinoma cell lines derived from testicular germ-cell tumors.

Four human embryonal carcinoma (EC) cell lines (ITO, NEC 8, NEC 14, NEC 15) derived independently from testicular germ-cell tumors were established in vitro. In their xenografted tumor tissues, all of them exhibited histological characteristics consistent with EC. The cell-biological characterization of these human EC cell lines was investigated with reference to well-known murine EC cell lines. This included examination of their morphology, growth, tumorigenic potential, karyotype, cell-aggregate formation, HLA expression, large glycopeptides, AFP and HCG production, plasminogen-activator secretion, and LDH profiles. Three (ITO, NEC 14, NEC 15) of these human EC cell lines shared cell-biological characteristics consistent with typical EC, but one of them (NEC 8) differed from the others with respect to its rapid growth, high tumorigenic potential, formation of solid cell aggregates, and less differentiated, solid histological pattern. Thus, it is suggested that there are several developmentally different types of human EC cells. The relationship between the properties of these human EC cell lines and their differentiation potential is discussed.

Adult↗
PubMed1984

Transcriptional control of HLA-A,B,C antigen in human placental cytotrophoblast isolated using trophoblast- and HLA-specific monoclonal antibodies and the fluorescence-activated cell sorter.

Human placental cell suspensions prepared by trypsin digestion were analyzed with several monoclonal antibodies on a multiparameter fluorescence-activated cell sorter (FACS). Five distinct cell populations were isolated on the basis of size and quantitative differences in the coordinate expression of cell surface antigens detected by monoclonal antibodies against an HLA-A,B,C monomorphic determinant (MB40.5) and against human trophoblasts (anti-Trop-2). By FACS analysis and after sorting we clearly identified the major cell population as cytotrophoblasts based on several independent criteria, including presence of trophoblast-specific surface antigens, Trop-1, and Trop-2; absence of all HLA class I, class II, and beta 2-microglobulin (beta 2m) antigens; absence of the pan-leucocyte and monocyte antigens, HLe1 and LeuM1, respectively; presence of Y-chromatin in a male placenta; presence of placental and not liver alkaline phosphatase; and a large, mononuclear morphology. These procedures provide a reproducible method for obtaining highly purified human cytotrophoblast populations for further studies. We measured by molecular hybridization (RNA or Northern blots) the HLA-A,B,C and beta 2m mRNA in total RNA extracted from sorted cytotrophoblasts. We find that normal human cytotrophoblasts have extremely small amounts of HLA-A,B,C mRNA: approximately 300 times less than that in the lymphoid cell line LCL-721 or normal lymphocytes. In contrast, they have approximately 11% the level of beta 2m mRNA present in LCL-721 cells. Thus, HLA-A,B,C antigen expression on human cytotrophoblasts is limited by the level of HLA heavy chain mRNA.

Alkaline Phosphatase↗
PubMed1984

Immunohistochemical demonstration of serotonin-containing nerve fibers in the hypothalamus of the monkey, Macaca fuscata.

The distributional pattern of serotonin-containing nerve fibers in the hypothalamus of the monkey (Macaca fuscata) was analyzed with the use of the peroxidase-antiperoxidase method in conjunction with a highly sensitive and specific anti-serotonin serum. The highest concentrations of serotonin-immunoreactive varicose fibers were found in the nucleus praeopticus medialis, nucleus ventromedialis hypothalami, and the complex of mammillary nuclei (nucleus praemamillaris, supramamillaris, mamillaris medialis et lateralis). However, the nucleus suprachiasmaticus, where numerous serotoninergic fibers have been reported to occur in the rat, appeared to be almost devoid of these fibers. The infundibular stalk and the intermediate and posterior lobes of the pituitary contained considerable numbers of immunoreactive fibers. The present study provides a morphological basis for possible clarification of the influence of serotoninergic projections on various neuroendocrine mechanisms in primates. Furthermore, an attempt was made to clarify the differences and similarities concerning the distributional patterns of serotoninergic nerve fibers within the monkey hypothalamus in contrast to the rat hypothalamus.

Animals↗
PubMed1984

The effect of cadmium, zinc or copper loading on the metabolism of amino acids in mouse liver.

Cadmium (Cd), zinc (Zn), and cupric chlorides (Cu) were injected i.p. into male mice to examine the effect of the metals on the concentration of amino acids in the liver. It is suggested that after injection some of the cysteine released from glutathione in the liver is incorporated into metallothionein and some is catabolized to taurine, while some of the glutamate released from glutathione is metabolized via aspartate. None of the sulfur-containing amino acids (oxidised metabolites of cysteine) were detected except for taurine in the present experiment.

Amino Acids↗
PubMed1984

Protein polymorphisms and their genetic control in the red-backed vole, Clethrionomys rufocanus bedfordiae.

Twenty enzymatic and non-enzymatic proteins in a wild population of red-backed voles, Cletrionomys rufocanus bedfordiae, were investigated by electrophoresis. Seven enzymatic and non-enzymatic protein systems were found to be polymorphic. Breeding data indicated that the mode of inheritance of the enzyme systems ME-1, ME-2, GPD and EST were consistent with a Mendelian law. Two systems, 6 PGD and SOD, were estimated to be genetically controlled from the electrophoretic patterns and mother-offspring comparison of phenotypes. In the Tf system two new additional phenotypes were observed, but their inheritance could not be elucidated. Gene frequencies at seven loci were also investigated in 88 animals. There was no significant deviation from Hardy-Weinberg equilibrium.

Alleles↗
PubMed1984

Psychiatric disorders of pre-adolescence in Japan.

We have classified 200 pre-adolescent patients, with whom we have met during the last three years, into the following four types: school refusal and obsessive behavior, psychosomatic disorders, depressive reactions, and schizophrenic disorders. During our therapeutic process, we realized that even though their symptoms seemed varied and severe, they disappeared after comparatively short periods. The pre-adolescent period is a turning point at which the children depart from their earlier relationships with parents and start to form new ones with friends. We facilitated the patients' developmental process in this period so that they would recover naturally by themselves. However, when we looked at the social phenomena which influence the family and children, we noticed that some factors interfered with the pre-adolescents trying to get over the above-mentioned turning point.

Adjustment Disorders↗
PubMed1984

Limitation of differential expression of HLA-A,B,C antigens on choriocarcinoma cell lines by messenger RNA for HLA heavy chain but not by beta 2-microglobulin.

The relative amounts of HLA-A,B,C antigens, beta 2-microglobulin (beta 2m), and trophoblast antigens (Trop-1 and Trop-2) were determined on nine choriocarcinoma cell lines including seven lines of gestational origin and two lines of nongestational origin (from ovary and stomach) by quantitative immunofluorescence analysis using a fluorescence-activated cell sorter. Most of these lines expressed surface HLA to variable extents, but one had none detectable. However, all lines secreted readily measurable amounts of beta 2m. We analyzed total RNA extracted from these lines using northern blot molecular hybridization with HLA-A,B,C- and beta 2m-specific complementary DNA probes. We found no messenger RNA species which hybridized with the HLA probe in cells with no detectable HLA surface antigen and only small amounts of HLA-specific RNA in cells with low levels of HLA membrane antigen. Cells exhibiting surface HLA levels greater than about 30% of that on lymphocytes had much higher amounts of HLA-specific RNA than did choriocarcinoma cells with no or low HLA antigen expression. In contrast, RNA hybridizing with beta 2m-specific probes was present at the 20% level or higher (relative to lymphocytes) in all the cell lines tested. Thus, the expression of HLA-A,B,C is apparently limited in choriocarcinoma cells by the level of HLA heavy-chain RNA and not by the level of beta 2m RNA. We discuss these findings in relation to the normal trophoblastic or other origins of this tumor type and with respect to the regulation and function of HLA in trophoblasts.

Antibodies, Monoclonal↗