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Biomedical subjects

H Wada

Publications and source records attributed to H Wada.

At least 847 records · Page 47Linked to original sources
PubMed1989

[A case of squamous cell carcinoma of the thymus].

A case of squamous cell carcinoma of the thymus was reported. A 60-year-old female was admitted because of swelling of left cervical and left axillary lymph nodes. Chest X-ray revealed left anterior mediastinal mass shadow. The histological examination on the excised left axillary lymph nodes revealed well differentiated squamous cell carcinoma. After radiotherapy, the operation was performed with median sternotomy and then the mediastinal tumor was diagnosed squamous cell carcinoma originated from the thymus. The postoperative course of the patient was unfavorable, though adjacent postoperative radiotherapy and chemotherapy. Compared with ordinary thymoma, squamous cell carcinoma of the thymus commonly metastasizes outside the thorax and has poor prognosis. In view of these differences, it should be separated histologically from ordinary thymoma.

Carcinoma, Squamous Cell↗
PubMed1989

[A cyclic thrombocytopenia associated with Sjögren syndrome].

A 51-year-old women in menopause was admitted because of intermittent purpura. She was diagnosed as having cyclic thrombocytopenia. One platelet cycle lasted for about 22 days with platelet count fluctuating from 1.0 X 10(4)/microliters to 31.0 X 10(4)/microliters. The platelet-associated immunoglobulin was correlated with the platelet cycle. The rheumatic factor, antinuclear antibody, antimicrosome antibody, anti-thyroglobulin antibody and platelet binding immunoglobulin were all positive but did not fluctuate during the cycle. The platelet life-span was shortened. The mean platelet volume fluctuated during each cycle. The lipid emulsion test was prolonged. Symptoms of Sjögren syndrome and purpura appeared at the same time. It was strongly suggested that purpura was caused by cyclical destruction of platelets by reticuloendothelial system.

Autoantibodies↗
PubMed1989

[Adjuvant surgery for lung cancer].

Recently several trials of adjuvant surgery or so-called neo-adjuvant chemotherapy have been reported about lung cancer. The indication of this therapy contains not only small cell lung cancers but also non-small cell lung cancers in most recent report. However, the therapeutic outcome is not satisfactory especially in N2 cases, better local control and, even a few, long time survivors were reported with this therapy. In our own experience of 10 cases since 1981, same tendency was recognized. So several type of controlled studies are necessary for the evaluation of adjuvant surgery to lung cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Effect of neurotoxic lesions in the mammillary bodies on the distribution of brain histamine.

Unilateral lesions with ibotenic acid in the vicinity of the mammillary bodies where the histamine (HA)-secreting neurons are located induced bilateral reductions in the levels of HA in the posterior hypothalamus (40-60%), anterior hypothalamus (45%), and frontal cortex (30%) as well as in the ipsilateral hippocampus (40%) 7 days after injection. Changes in the concentration of HA in the median eminence and adenohypophysis were not significant, but in the neurohypophysis the content of HA increased by 80%. These results seem to indicate that intrahypothalamic and cortical HA pathways are bilateral in origin while hippocampal HA pathways are predominantly ipsilateral.

Animals↗
PubMed1988

Organization of histaminergic fibers in the rat brain.

Detailed information on innervation of the histaminergic system in the brain is essential to an understanding of the physiological roles of this system. In a previous immunocytochemical study with antihistidine decarboxylase (HDC) antibody, we detected extensive networks of histaminergic fibers in many areas of the rat brain (Watanabe et al., '84). In the present study, we improved the immunocytochemical procedure and examined the detailed distribution of histaminergic innervation in the rat brain with anti-HDC antibody. As reported previously, the highest concentrations of fibers were found in the hypothalamic nuclei and medial forebrain bundle. With the modified procedure, we detected more dense networks of HDC-immunoreactive (HDCI) fibers. Furthermore, we demonstrated for the first time the existence of HDCI fibers in other regions, namely, the thalamic nuclei, median eminence, fimbria of the hippocampus, habenular nuclei, superior colliculus, nucleus of the optic tract, parabrachial nuclei, mesencephalic trigeminal nucleus, superior, lateral, and spinal vestibular nuclei, posterior lobe of the hypophysis, and vascular organ of the lamina terminalis. We also found dense transverse fibers in the retrochiasmatic area and supraoptic decussation, which suggests bilateral innervation of the histaminergic system. These results indicate that innervation of the rat brain by the histaminergic system is more extensive than observed previously.

Animals↗
PubMed1988

[Physiological significance of plasma free and conjugated dopamine in healthy volunteers--with special reference to sympathetic nerve activity].

In order to elucidate the physiological significance of plasma dopamine, blood pressure, pulse rate (PR), plasma concentrations of free or conjugated dopamine (free or conjugated pDA), noradrenaline (pNA) and adrenaline (pAd) were measured in 9 healthy volunteers. Blood sampling for the measurements was performed at a basal condition maintaining a supine position for 60 minutes, after twenty minutes 60 degrees head-up tilt (tilt) and an intravenous infusion of 1000 ml 0.9% saline for 2 hours. Following tilt, mean values in diastolic and mean blood pressure, PR, pNA and pAd were significantly increased, while free, conjugated and total pDA were decreased. On the other hand, saline infusion yielded significant decreases in hematocrit, pNA, free, conjugated and total pDA, but blood pressure, PR and pAd remained at the same level. Free/conjugated pDA ratio did not change during tilt or saline infusion. The basal value of free, conjugated or total pDA did not significantly correlate with blood pressure, PR, pNA or pAd, respectively. Furthermore, no significant correlations between the changes in pDAs and hemodynamic parameters, pNA or pAd by tilt or saline infusion were observed. From these results, it was suggested that plasma free or conjugated dopamine in physiological conditions may not be released from sympathetic nerve endings or adrenomedullary glands. Further investigations are needed to clarify the physiological significance of plasma dopamine in humans.

Adult↗
PubMed1988

Autoradiographic visualization in rat brain of receptors for omega-conotoxin GVIA, a newly discovered calcium antagonist.

Putative N-type voltage-sensitive calcium channels were localized autoradiographically in thaw-mounted rat brain slices using [125I]omega-conotoxin GVIA as a ligand. Density of the toxin binding sites were highly heterogeneous throughout the brain. The highest density of the binding sites was observed in the glomerular layer of the olfactory bulb, cerebral cortex, molecular layer of the hippocampus, amygdaloid complex, reticular part of the substantia nigra, molecular layer of the cerebellar cortex, and nucleus of the solitary tract. White matter tract regions such as the internal capsule, corpus callosum, fimbria of the hippocampus, fornix, and fasciculus retroflexus showed an extremely low density.

Animals↗
PubMed1988

Induction of cytosolic aspartate aminotransferase by glucagon in primary cultured rat hepatocytes.

The activity and the mRNA content of cytosolic aspartate aminotransferase (EC 2.6.1.1) were examined in cultured rat hepatocytes. Addition of glucagon (1 x 10(-7) M) in the presence of dexamethasone (1 x 10(-7) M) caused about 2-fold increase in the activity and mRNA content. Dibutyryl cAMP (1 x 10(-4) M) could replace glucagon for this effect. Maximal induction of cytosolic aspartate aminotransferase mRNA was observed 8 h after their additions. Insulin (1 x 10(-7) M) did not inhibit the enzyme induction by glucagon or dibutyryl cAMP. These results suggest that the cytosolic aspartate aminotransferase gene is regulated by cAMP, and not by insulin.

Animals↗
PubMed1988

Anticoagulant activity in cell homogenate of adult T cell leukemia.

The hemostatic abnormality in 18 patients with adult T cell leukemia (ATL) was studied. Activated partial thromboplastin time (APTT) was slightly prolonged and prekallikrein activity was markedly low in these patients. The leukemic cell homogenate from these patients prolonged the recalcification time (RCT) of normal plasma; homogenates containing more than 3 x 10(3) cells/microliter prolonged it, although a lower cell concentration shortened it. The crude anticoagulant fraction from the gel filtration, with a molecular weight of about 34,000, prolonged RCT. The crude anticoagulant did not affect prothrombin time (PT), thrombin activity or activated X activity at any concentration, but prolonged the contact activation test, inhibited the activation of prekallikrein and prolonged RCT of Fletcher trait, Fitzgerald trait and F XII deficient plasma. These effects of ATL cell homogenate were stronger on platelet poor plasma than on platelet rich plasma. Although ATL cells had low procoagulant activity, increase of leukemic cells made anticoagulant activity predominant, might be the cause of hemostatic abnormality or amplify the bleeding tendency in patients with ATL.

Adult↗
PubMed1988

Impaired catecholamine secretion as a cause of diabetic autonomic neuropathy.

Human and animal studies were performed to investigate the causes of diabetic autonomic neuropathy. Human diabetics, with and without autonomic neuropathy, were measured for plasma catecholamine response to insulin hypoglycemia and for urinary catecholamine excretion. In streptozotocin-diabetic rats, plasma catecholamine response and tissue catecholamine concentrations were measured at various stages of the disease. As the duration of the diabetic state lengthens in rats, there is a time-proportional stepwise decrease in plasma catecholamine response. This is similar to the clinical course observed in human diabetics, which also includes a reduction of catecholamine excretion after the appearance of autonomic neuropathy. After 6 weeks of diabetes, rat tissue is found to have an increased concentration of catecholamines; this may represent a compensatory reaction to the difficulties of secretion. At 13 weeks of diabetes, tissue catecholamine concentrations return to almost normal, when plasma responses have disappeared. These results suggest that the impaired secretion of catecholamines in diabetics may be a cause of diabetic autonomic neuropathy.

Animals↗
PubMed1988

Induction of histidine decarboxylase of rat basophilic leukemia (2H3) cells stimulated by higher oligomeric IgE or phorbol myristate acetate.

When rat basophilic leukemia (2H3) cells were stimulated by higher oligomer, the chemically cross-linked oligomers of IgE, in the presence of calcium the activity of histidine decarboxylase (HDC, L-histidine carboxylase, E.C.4.1.1.22), a histamine-forming enzyme, was increased by 1 hr, reaching maximum activity by 2 hr, and returning to the original level by 8 hr. A similar increase in enzyme activity was observed in cells treated with phorbol myristate acetate (PMA) or oleoyl-acetylglycerol (OAG), which are known activators of protein kinase C. Removal of calcium from medium abolished the increase in HDC activity in response to higher oligomer but not that induced by PMA or OAG, suggesting that the increase in HDC activity may be mediated by protein kinase C. The increase in the HDC activity probably required induction of enzyme synthesis, because it was prevented by cycloheximide.

Animals↗
PubMed1988

Histamine H1-receptor in endothelial and smooth muscle cells of guinea-pig aorta.

The location of histamine H1-receptors in the thoracic aorta of guinea-pigs was studied with a [3H]mepyramine binding assay. [3H]Mepyramine binding studies of whole and rubbed aortas, and of cultured endothelial and smooth muscle cells showed that the Kd values were all in the range 0.53-0.76 nM, but that the Bmax values were 19.1, 10.1, 63.3 and 11.6 fmol/mg protein, respectively. Thus, the whole aorta contained more H1-receptors than the rubbed one (free of endothelium), and cultured endothelial cells contained more H1-receptors than smooth muscle cells. These results indicate that more histamine H1-receptors were concentrated in the endothelial cells than in the smooth muscle cells in guinea-pig aorta.

Animals↗
PubMed1988

Feeding induced by blockade of histamine H1-receptor in rat brain.

Histamine antagonists were infused into the third ventricle of the cerebrum in rats. All the H1-, but none of the H2-antagonists tested, induced initial feeding during the early portion of the light phase when histamine level was highest. No periprandial drinking was observed. Ambulation increased during feeding. The effect on feeding was attenuated when brain histamine was normally low during the early portion of the dark phase, or was decreased by alpha-fluoromethylhistidine. Hypothalamic neuronal histamine may suppress food intake through H1-receptors, and diurnal fluctuations of food intake may mirror neuronal histamine levels.

Animals↗
PubMed1988

Changes in the electrical activity of locus coeruleus neurons in pregnant rats.

Under urethane anesthesia, unit activity of locus coeruleus (LC) neurons was recorded extracellularly in pregnant and non-pregnant rats. The spontaneous firing of LC neurons was found to be reduced in pregnant rats. In addition, biochemical studies indicated that noradrenaline contents in the cerebral cortex, one of the major projection sites of LC neurons, were significantly higher in pregnant than non-pregnant rats. These results suggest that the electrical activity of noradrenergic neurons in the LC is reduced during gestation.

Action Potentials↗
PubMed1988

Blockade of the histamine H1-receptor in the rat ventromedial hypothalamus and feeding elicitation.

All H1-, but no H2-antagonists infused into the rat third cerebroventricle, induced feeding during the early light, but not during the early dark, reflecting a concentration of hypothalamic histamine. Bilateral microinfusion identified the ventromedial hypothalamus (VMH), but not the lateral hypothalamus or the paraventricular nucleus, as a main locus for the induction of feeding by an H1-antagonist. The effect was completely abolished when brain histamine was decreased by pretreatment with alpha-fluoromethylhistidine. Hypothalamic neuronal histamine suppresses food intake, at least in part, through H1-receptors in the VMH.

Animals↗
PubMed1988

Histaminergic nerve fibers in the median eminence and hypophysis of rats demonstrated immunocytochemically with antibodies against histidine decarboxylase and histamine.

Histaminergic fibers in the median eminence and hypophysis of rats were examined immunocytochemically with antibodies against histidine decarboxylase (HDC), the sole histamine-synthesizing enzyme, and against histamine itself. A similar distribution of immunoreactive fibers was observed with these two antibodies. In the median eminence, immunoreactive fibers were mainly located in the internal layer and could be traced to the posterior lobe of the hypophysis. A few fibers were detected in the external layer of the median eminence, but none in the anterior or intermediate lobe of the hypophysis. These observations suggest that neuronal histamine may take part in regulation of the hypothalamo-neurohypophysial neuroendocrine system in rats.

Animals↗