Search PubMed⌕ Search

Biomedical subjects

H Kojima

Publications and source records attributed to H Kojima.

At least 559 records · Page 31Linked to original sources

Cholinergic innervation of the main and the accessory olfactory bulbs of the rat as revealed by a monoclonal antibody against choline acetyltransferase.

The main and accessory olfactory bulbs (MOB and AOB) of the rat were immunohistochemically stained with a monoclonal antibody against choline acetyltransferase (ChAT) in order to know the difference in the distribution patterns of cholinergic fibers between these two structures. A few ChAT-immunoreactive cell bodies were found in the superficial and middle parts of the external plexiform layer (EPL) of the MOB, in the granule cell layer (GCL) of the MOB, and in the GCL of the AOB. The frequency in appearance of these cells was 0.9 cells/section in the MOB and 0.3 cells/section in the AOB. While the glomerular layer (GL) and the superficial part of the EPL were most densely innervated in the MOB, the internal plexiform layer received the richest innervation in the AOB. There were no immunoreactive structures in the olfactory nerve layer of the MOB and in the vomeronasal nerve layer and glomerular layer of the AOB. In addition to a relatively homogenous distribution of cholinergic fibers in the MOB and AOB, there were several foci of very dense network of immunoreactive fibers at the posterior level of the OB. These foci formed a part of the modified glomerular complex that was recently identified using 2-deoxyglucose method and was presumed to be related to suckling behaviour in the neonatal rat.

Animals↗

Enhancement of dopamine release from striatal slices of rats that were subchronically treated with methamphetamine.

The effect of dopamine (DA) uptake inhibitors (methamphetamine, nomifensine, and phenylethylamine) on the release of endogenous DA from striatal slices of rats pretreated with methamphetamine (6 mg/kg/day for 9 days) was investigated. The exposure of methamphetamine-pretreated rat striatal slices to a low concentration (10(-7) M, 5 X 10(-7) M) of methamphetamine caused a greater increase in DA efflux than that of saline-treated rat striatal slices. The drug-treated rats displayed an enhanced stereotyped behavioral response to a small dose of methamphetamine (1 mg/kg). Removal of Ca2+ from the superfusion medium did not affect the difference in the rates of methamphetamine (10(-7) M) induced DA release between methamphetamine-treated and saline-treated rat striatal slices. Nomifensine- and phenylethylamine-induced DA release from striatal slices was also enhanced by repeated administration of methamphetamine. On the other hand, there was no difference in K+-induced DA release between the two groups. Moreover, repeated administration of methamphetamine caused a significant increase in 3H-dopamine uptake in rat striatal synaptosomes. These results suggest that the behavioral sensitization produced by the repeated administration of methamphetamine is accompanied by an enhancement in the release of DA induced by methamphetamine, nomifensine, and phenylethylamine in vitro and is also accompanied by increased DA uptake into striatal synaptosomes.

Animals↗

Local antibody in semen for rapid diagnosis of Chlamydia trachomatis epididymitis.

Etiologic studies including micro-immunofluorescence serology for Chlamydia trachomatis were done on 45 consecutive men with acute epididymitis. Of the men 21, all less than 35 years old, had type specific Chlamydia trachomatis antibody in the semen. All patients with semen antibody also had Chlamydia trachomatis antibody in the serum, while only a few of the patients without semen antibody had serum antibody. Chlamydia antibody titers in the semen specimens were higher than those in the sera and they persisted longer. In only 1 patient with semen antibody was another potential etiological agent for epididymitis demonstrated, while most of the patients without semen antibody had bacterial causes for the epididymitis. It was concluded that measurement of Chlamydia trachomatis antibody in semen offered a noninvasive, sensitive and specific method, useful despite prior antibiotic therapy, for diagnosis of the etiology of epididymitis in young men.

Acute Disease↗

Thermotropic behavior and electronmicroscopic structures of mixtures of gangliosides and dipalmitoylphosphatidylcholine.

The calorimetric properties and morphological structures of dispersed mixtures of 1, 2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and highly purified human brain gangliosides, GM2, GM1, GD1a, GD1b, and GT1b, were studied using a high-sensitivity differential scanning calorimeter and an electron-microscope, as a function of the ganglioside molar fraction. No thermal phase transitions of pure gangliosides in aqueous dispersions could be detected. In the mixtures of DPPC and gangliosides, the gel to liquid crystalline phase transition occurred at a higher temperature than in pure DPPC dispersions and progressed over a wide temperature range. As increasing amounts of the pure ganglioside species were added to DPPC, the temperature for the main transition gradually increased. The phase transition progressed differently among different gangliosides/DPPC mixtures. The enthalpy values were found to decrease linearly as the number of sialic acid residues increased. Electron-microscopically the ganglioside/DPPC mixtures formed multilamellar structures at lower concentrations of the gangliosides, and the structures changed to cylindrical and spherical micelles as the ganglioside concentration was increased. The polysialoganglioside/DPPC mixtures showed the micellar form even at lower ganglioside concentrations, contrary to the case of the monosialoganglioside/DPPC mixtures. The morphological changes of gangliosides/DPPC mixtures corresponded with changes in the calorimetric properties. These results show that individual gangliosides have different physicochemical effects on model membranes, possibly because of the interaction of their negatively charged head groups.

1,2-Dipalmitoylphosphatidylcholine↗

Immunohistochemical conditions for staining choline acetyltransferase-containing axon terminals in the rat.

Immunohistochemical conditions for staining cholinergic axon terminals using a commercially available anticholine acetyltransferase (anti-ChAT) monoclonal antibody were determined in the rat. A number of variations of procedures including fixative composition, fixation time, and incubation time and temperature in the anti-ChAT antibody solution were tested. Optimal procedures for minimizing the chance of negative staining of ChAT-containing axon terminals consisted of perfusion with a mixture of 4% paraformaldehyde and 0.2% glutaraldehyde for 3 min followed by a fixative containing only 4% paraformaldehyde for 10 min, and reaction with the anti-ChAT antibody for 2 days at 37 C. The distribution patterns of axon terminals stained in the cerebral cortex and the hippocampal formation were comparable to those reported by other investigators using different monoclonal antibodies.

Animals↗

Glomerular deposition of food antigens in IgA nephropathy.

Recently, we reported on the importance of food antigens on the pathogenesis of an experimentally-induced model of, and some patients with, IgA nephropathy. In this paper, the glomerular deposition of food antigens (casein, lactalbumin, peanut protein, soy bean protein, rice protein, ovalbumin) was investigated by an immunofluorescence technique in 28 patients with IgA nephropathy and 32 controls (ten with lupus nephritis, three with Henoch-Schoenlein purpura nephritis and 19 with other glomerulonephritis). Glomerular IgA deposition was demonstrated in all IgA nephropathy and Henoch-Schoenlein purpura nephritis, and in four lupus nephritis. Positive findings of food antigens, observed as mesangial pattern, were obtained in eleven cases (39.3%) with casein, 21 (75.0%) with soy bean protein and one (3.6%) with rice protein in IgA nephropathy, even though no such findings were seen in the control group. Eleven of 28 patients with IgA nephropathy were positive with soy bean protein alone, nine were positive with soy bean protein + casein, one was positive with soy bean protein + casein + rice protein, and one was positive with casein alone. The deposition of food antigens was not observed in six cases only. Furthermore, no correlation was noted between the deposition of food antigens and the deposition of IgA1, IgA2 or J chain, in vitro binding of the secretory component, or histopathological grades. These results suggest that the exact meanings of glomerular deposition are unclear. Food antigens are postulated, however, as possibly participating strongly in the pathogenesis and as being localized in the glomerular mesangium as an antigen in some patients with IgA nephropathy.

Adolescent↗

Primary malignant astrocytoma of the cerebellum in children. Report of a case with electron microscopic and cytofluorometric DNA evaluation.

The case of a 1-year-old girl with primary malignant astrocytoma of the cerebellum is presented with special reference to ultramicroscopic study and cytofluorometric DNA analysis. The routine light microscopic study was not pathognomonic because of the immaturity of the composing cells. The glial fibrillary microfilaments characteristic of astroglial cells were confirmed by means of electron microscopy. Cytofluorometrically, the DNA histogram of this case revealed a prominent peak in the 4C region, with considerable dispersion to the 8C region, indicating the polyploidic and heterogeneic pattern of malignant tumors.

Astrocytoma↗

General pharmacological properties of muroctasin.

General pharmacological effects of N2-[(N-acetyl-muramoyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-ly sine MDP-Lys(L18), muroctasin) were examined and the following results were obtained. 1. Central nervous system: MDP-Lys(L18) had no effect on behavior, spontaneous motor activity, electroshock- and chemoshock-induced convulsions, hexobarbital sleeping time, pain threshold (mice), conditioned avoidance response (rats) at a dose of 0.4 mg/kg, s.c. and EEG as well as spinal reflex (cats) at a dose of 0.4 mg/kg, i.v. It produced a significant elevation in body temperature (rabbits) at doses of 13 micrograms/kg, s.c. and greater. 2. Respiratory and cardiovascular system (dogs): MDP-Lys(L18) did not show any significant effect on respiratory and cardiovascular functions at a dose of 0.4 mg/kg i.v. 3. Autonomic nervous system: MDP-Lys(L18) induced a miosis (rabbits) at doses of 13 micrograms/kg s.c. and greater. It did not affect norepinephrine-induced pressor and acetylcholine-induced depressor responses (dogs) and contraction of the nictitating membrane induced by electrical stimulation (cats) at a dose of 0.4 mg/kg i.v. 4. Smooth muscles: In the experiments using the isolated ileum, vas deferens, trachea (guinea pigs) and uterus (rats), MDP-Lys(L18) showed neither spasmogenic nor spasmolytic activity at a concentration of 4 x 10(-6) g/ml. Gastrointestinal propulsion (mice), gastric mucosa, gastric emptying rate and gastric secretion (rats) were not affected by this drug at a dose of 0.4 mg/kg s.c. MDP-Lys(L18) did not influence gastrointestinal motility (dogs) at a dose of 0.4 mg/kg, i.v. 5. Miscellaneous: MDP(L-18) suppressed carrageenan-induced edema (rats) at doses of 0.13 mg/kg s.c. and greater.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylmuramyl-Alanyl-Isoglutamine↗