Methods for culture ofBombyx mori wing discs

Summary A culture method forBombyx wing discs is described. Grace's insect medium,Bombyx hemolymph, and moderate doses of ecdysterone (0.02 to 0.1 µg/ml) were necessary for complete imaginal differentiation ofBombyx wing discs. This procedure is useful for understanding ecdysteroid action on insect imaginal differentiation and metamorphosis.     

Somatostatin inhibits the centrally mediated hypertensive response to clonidine in freely moving rats.

The effect of somatostatin on the hypertensive response induced by intracerebroventricular (i.c.v.) injection of clonidine was investigated in freely moving rats. A 10 micrograms i.c.v. injection of clonidine produced a marked pressor response and a decrease in heart rate. No depressor response was induced by clonidine. The i.c.v. pretreatment with somatostatin (2 and 5 micrograms) dose-dependently inhibited the pressor response to i.c.v. injected clonidine (10 micrograms), and a long-lasting depressor response was observed. Systemic (i.v.) treatment with somatostatin had no such effect. These results suggest that brain somatostatin modulates the centrally-mediated pressor response to clonidine.     

Neurosteroid modulation of dendrodendritic inhibition in the mouse olfactory bulb

The present report describes neurosteroid modulation of olfactory bulb function by examining the effects of intrabulbar infusion of dehydroepiandrosterone sulfate (DHEAS), a neurohormone discovered in rat brain, on field potentials in the granule cell layer evoked by paired-pulse stimulation of the mouse lateral olfactory tract. Infusion of DHEAS (5 nmol) significantly decreased the test response without affecting the conditioning response. As a consequence, DHEAS selectively potentiated paired-pulse depression, which is believed to be due to granule cell-mediated inhibition of the mitral/tufted cells. The granule-to-mitral/tufted dendrodendritic synapse is GABAergic. Taken together, these results suggest that DHEAS potentiates the GABAergic dendrodendritic inhibition exerted by the granule cells on the mitral/tufted cells.     

Natural antibodies against the immunoglobulin F(ab′)2 fragment cause elimination of antigens recognized by the F(ab′)2 from the circulation

A humanized monoclonal IgG1 antibody, designated hC4G1, recognizes the fibrinogen receptor glycoprotein (GP)IIb/IIIa on platelets and inhibits platelet aggregation. When the F(ab′)₂ fragment of hC4G1 (F(ab′)₂ hC4G1) was administered to cynomolgus monkeys, all the monkeys showed inhibition of platelet aggregation ex vivo. Unexpectedly, a significant decrease in platelet count was observed in 5 of 18 monkeys. Antibodies against F(ab′)₂ hC4G1 were detected in the plasma of these monkeys by ELISA. Antibody activity in the plasma of these monkeys was significantly correlated with the intensity of platelet decrease (r = 0.84). The natural monkey antibodies to F(ab′)₂ hC4G1 were directed against the C-terminal region of F(ab′)₂ fragment common to all human and humanized IgG antibodies. Natural homo-reactive antibodies were also detected in human plasma from 15 of 40 healthy volunteers. Specificity was closely similar to that of the monkey antibodies. Affinity-purified human homo-reactive antibodies enhanced phagocytosis of platelets treated with the F(ab′)₂ hC4G1. Monkey plasma with high homo-reactive antibody activity was confirmed to decrease platelet count when administered together with F(ab′)₂ hC4G1 to a monkey with low antibody activity. These results suggest that F(ab′)₂ of humanized and human antibodies causes elimination of the corresponding antigens from the circulation by homo-reactive antibodies.     

Morphological brain changes associated with Schneider's first-rank symptoms in schizophrenia: a MRI study

BACKGROUND: Schneider's first-rank symptoms involve an alienated feature of the sense of one's own mental or physical activity. To clarify the brain morphological basis for the production of these symptoms, volumes of the frontal and medial temporal regions and their clinical correlates were examined in patients with schizophrenia. METHOD: Twenty-two patients with schizophrenia and 44 age- and gender-matched healthy control subjects were included. All patients were in their psychotic episodes with definite Schneiderian symptoms, rated by using the Scale for Assessment of Positive Symptoms. Volumetric measurements of high-resolution magnetic resonance imaging were performed in the prefrontal area, cingulate gyrus, and precentral gyrus, and the medial temporal structures such as the amygdala, hippocampus, and parahippocampal gyrus. RESULTS: Patients had significantly decreased volumes in the cingulate gray matter and the amygdala compared to controls. In the patient group, Schneiderian symptom severity showed significant inverse correlations with volumes of the right posterior cingulate gray matter and of the left anterior parahippocampal gyrus. CONCLUSIONS: Schneiderian symptoms may be associated with morphological abnormalities in the limbic-paralimbic regions such as the cingulate gyrus and parahippocampal gyrus, which possibly serve the self-monitoring function and the coherent storage and reactivation of information.     

Inhibition of passive cutaneous anaphylaxis-associated scratching behavior by mu-opioid receptor antagonists in ICR mice

BACKGROUND: Itching in humans is attenuated by mu-opioid receptor antagonists. ICR mice display increases in scratching behavior upon induction of IgE-mediated passive cutaneous anaphylaxis (PCA), or intradermal injection of compound 48/80 or histamine. METHODS: Cutaneous reactions were induced in ICR mice by IgE-mediated PCA, compound 48/80 and histamine, and the scratching behavior associated with the cutaneous reactions was evaluated. RESULTS: Naloxone and nalmefene reduced the incidence of scratching behavior associated with PCA. Naloxone also inhibited the induction of scratching behavior caused by compound 48/80 and histamine. Naloxone did not affect the increase in vascular permeability caused by PCA and injection of compound 48/80. CONCLUSION: Scratching behavior in mice may be induced by a sensation or a mechanism similar to itching in humans and should become a useful model for examining itching in humans.     

The Role of Polymorphonuclear Leukocytes in Rat Chronic Serum Sickness-type Nephritis

In order to investigate the role of polymorphonuclear leukocytes (PMN) in the distribution of antigen in various organs and in the development of nephritis, chronic serum sickness type nephritis was induced in both anti rat PMN rabbit serum (APS) treated and normal rabbit serum (NRS) treated rats by preimmunization with bovine serum albumin (BSA) and subsequent daily intravenous administration of BSA for 4 weeks. Kinetic studies using radiolabeled BSA showed that accumulation of BSA after the first intravenous administration was reduced by APS treatment in the liver, lungs and spleen and increased in the circulation, but was not affected in the kidneys and glomeruli. Histological studies supported the above findings. After 4 weeks of BSA administration, the BSA accumulation in the kidneys and glomeruli was significantly less in APS treated rats than in NRS treated ones, while amounts of BSA in the circulation and other organs were not different between the two groups. Furthermore, APS treatment reduced proteinuria, PMN infiltration and IC deposition in the glomeruli. These observations indicate that PMN play a partial role in IC deposition in the glomerular capillary walls and subsequent destruction of glomerular permeability in chronic serum sickness-type nephritis. Acta Pathol Jpn 39 : 619-629, 1989.     

Chemical and biological properties of a peptidoglycan isolated from Treponema pallidum kazan.

A peptidoglycan layer of Treponema pallidum kazan was isolated by solubilization of whole cells with 1% warm sodium dodecyl sulfate and subsequent digestion of an insoluble residue with proteases. Electron microscopy revealed that the peptidoglycan was isolated as a single-layered sacculus of less than 5 nm in thickness, freed from axial filaments and an envelope sheath. An isolated peptidoglycan fraction was mainly composed of glucosamine, muramic acid, alanine, glutamic acid, ornithine, and glycine in molar ratios of 0.65:0.68:1.63:1.00:0.75:1.03. Amino (N)- and carboxyl (C)-terminal amino acid analyses suggested the involvement of at least a part of the glycine residue in cross-linking between the amino group of ornithine residue at one strand of the stem peptide subunit and the carboxyl group of alanine of the neighboring strand. The treponemal peptidoglycan lacked the immunoadjuvant activity both to stimulate antibody production and to induce delayed-type hypersensitivity against ovalbumin, as well as the properties necessary to stimulate guinea pig and mouse splenocytes and guinea pigs peritoneal macrophages, unlike the cell walls or peptidoglycans (group A type of Schleifer and Kandler's classification, Bacteriol. Rev. 36:407-477, 1972) isolated from many bacterial species parasitic to the mammal. However, the peptidoglycan activated the human complement system through the alternative pathway, as well as the classical one, and caused a liberation of 5-hydroxytryptamine in rabbit blood platelets in a similar manner to the cell wall peptidoglycans of both group A and B types.