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Biomedical subjects

M Fujiwara

Publications and source records attributed to M Fujiwara.

At least 829 records · Page 46Linked to original sources
PubMed1980

Effects of psychotropic drugs on delta 9-tetrahydrocannabinol-induced long-lasting muricide.

The effects of psychotropic drugs on THC-induced long-lasting muricide were investigated in rats. Changes in open field activity (ambulation and rearing) of the rat were concurrently assessed as an index of behavioral toxicity. Imipramine-like antidepressants, atropine, and antiparkinsonism drugs exhibited a selective inhibitory activity on muricide, whereas the effects of neuroleptics, pentobarbital, diazepam, and methamphetamine were nonspecific. It is also suggested that cholinergic, catecholaminergic, and serotonergic mechanisms are involved in THC-induced muricide. This type of induced muricide appears to be a useful experimental model particularly suitable for the evaluation of antidepressants in correlation with brain amine dynamics.

Aggression↗
PubMed1980

Chronic granulomatous disease associated with peculiar Aspergillus lesions. Patho-anatomical report based on two autopsy cases and a brief review of all autopsy cases reported in Japan.

Chronic granulomatous disease (CGD) is based on the dysfunction of phagocytes and characterized by a comparatively uniform granulomatous lesion caused by organisms which do not produce hydrogen peroxide and which are catalase-positive. This report describes two autopsy cases in children, a nine year-two month-old boy and a ten month-old girl, with the clinical manifestations and autopsy findings of CGD and a brief review of all autopsy cases consistent with CGD reported in Japan. In these cases, in addition to the usual CGD lesions, there was a markedly different type of granuloma due to Aspergillus sp., which consisted of multinuclear giant cells alone, or a caseous center surrounded by giant cells. This peculiar type of aspergillosis may correspond to a primary infection, described as pseudotuberculosis aspergillina. It appears that in some CGD patients, macrophages may function normally and sometimes be more activated by these infections than in the normal body. The histochemical and electron microscopic examination of the present cases and a review of the previous cases suggest that the yellowish brown pigment found seems to resemble a ceroid. It is a product of the degradation of leukocytes and tissue elements with subsequent accumulation in phagocytic histiocytes and is not necessarily peculiar to CGD.

Aspergillosis↗
PubMed1980

Effects of Goniopora toxin on guinea-pig blood vessels.

Effects of a marine polypeptide, Goniopora toxin (GPT) (molecular weight 12,000), were examined in isolated blood vessels guinea pigs. GPT, ranging from 10-100 nM, augmented the contractile response to electrical transmural stimulation in the thoracic aorta, portal vein, and mesenteric and femoral arteries. The effects were abolished by tetrodotoxin and bretylium, and were markedly attenuated by phentolamine. As GTP did not affect the resting tension spontaneous rhythmicity or noradrenaline-induced contraction, the toxin appears to act on the neural elements in the vascular wall rather than on the smooth muscle. In the portal vein preloaded with 3H-noradrenaline, GPT enhanced the 3H-efflux in response to electrical transmural stimulation, yet had not effect on the spontaneous efflux. The increase in stimulation-evoked 3H-efflux caused by GPT was more than 15 times larger than the increase seen with cocaine or phentolamine. Tetrodotoxin completely blocked the 3H-efflux induced by electrical transmural stimulation. These data suggest that GPT acts on nerve components in guinea pig blood vessels and increases the release of noradrenaline evoked by electrical stimulation of the nerve fibers. These effects are probably associated with prolongation of the action potential duration and repetitive discharges in the adrenergic nerve fibers.

Action Potentials↗
PubMed1980

Reactivity of isolated canine cerebral arteries to adenine nucleotides and adenosine.

ATP (10(-8)-10(-5) M) produced phasic contraction in the canine basilar artery and relaxation in the middle cerebral artery. At high concentrations (10(-5) and 10(-4) M) a contractile response in the middle cerebral artery occasionally preceded relaxation. ADP, AMP, c-AMP and adenosine (10(-8)-10(-4) M) caused relaxation in all preparations except that ADP produced contraction in both cerebral arteries at high concentrations (10(-5) and 10(-4) M). These effects were observed in the absence or presence of active tension induced by 5-HT. The potency of ADP in producing vasodilation in the middle cerebral artery was greater than in the basilar artery, whereas that of the other agents was reversed. c-AMP showed the lowest potency among the agents tested on both arteries. The relaxing responses, but not contractile responses, to agents used were partially inhibited by theophylline. Phentolamine, propranolol, atropine, tetrodotoxin, ouabain or quinidine had little effect on both the contractile and relaxing responses. From these results, it is concluded that the canine cerebral arteries respond well to adenine nucleotides and adenosine and that the relaxing response is in part caused through theophylline-sensitive receptors.

Adenine Nucleotides↗
PubMed1980

Na,K-, Mg- and HCO3-adenosine triphosphatases in the rabbit brain choroid plexus.

Properties of adenosine triphosphatases (ATPases) in the choroid plexus of rabbit cerebral ventricles were investigated using tissue homogenates and subcellular fractions. Na,K-ATPase or HCO3-ATPase activity of choroid plexus was significantly lower than that of the brain or the kidney, respectively. Among the homogenates of choroid plexus from the lateral, third and fourth ventricles, there were no differences in the activities of Na,K-, Mg- and HCO3-ATPases. In the choroid plexus, Na,K-ATPase activity was demonstrated to be highest in 10,000 X g fraction, while the highest Mg- and HCO3-ATPase activities were observed in 8,000 X g fraction, the so-called mitochondrial fraction. Ion requirement, pH optimum and ouabain sensitivity of Na,K-ATPase in 10,000 X g fraction of choroid plexus were similar to findings in erythrocytes, brain and kidney. However, properties of Mg- and HCO3-ATPases in 8,000 X g fraction were considerably different from those found in the brain and gastric mucosa. In the choroid plexus, thiocyanate ion inhibited Mg-ATPase as well as HCO3-ATPase. These results indicate that characteristics of ATPase systems in the choroid plexus are to some extent different from those in tissues such as brain, kidney and gastric mucosa.

Adenosine Triphosphatases↗
PubMed1980

Immunological properties of athymic nude mice born from homozygous (nu/nu) parents.

No significant differences were observed between nude mice (nu/nu) born of homozygous (nu/nu) parents and those born of heterozygous (nu/+) mothers in the percentage of Thy-1-positive cells or immunoglobulin (Ig)-bearing cells in the spleen as assessed by immunofluorescence. There were no significant differences in the antibody response to thymus-dependent antigen or in the number of background plaque-forming cells to this antigen. The antibody response to thymus-independent antigen was not imparied at all in mice born from homozygous parents as compared with other nude mice or euthymic mice. It was concluded that the Thy-1-bearing (T) cells observed in nu/nu mice and the capacity of these mice to respond to thymus-dependent antigens arose independently of maternal T cells and of the influence of the maternal thymus.

Animals↗
PubMed1980

Primary pineal endodermal sinus tumor with elevated serum and CSF alphafetoprotein levels. Case report.

A 12-year-old girl with an alphafetoprotein-producing brain tumor in the pineal region is presented. The marker was detected in both serum and cerebrospinal fluid. The amount of the marker decreased after irradiation of the tumor and systemic chemotherapy and increased prior to tumor recurrence. At autopsy, the tumor was histopathologically diagnosed as an endodermal sinus tumor, and alphafetoprotein was demonstrated in the tumor cells by the immunofluorescence method. Alphafetoprotein may represent a specific and sensitive marker for predicting tumor histopathology and for monitoring the therapeutic response in patients with primary intracranial germ-cell tumors.

Brain Neoplasms↗
PubMed1980

Humoral and cellular immune response to varicella-zoster virus in children inoculated with live attenuated varicella vaccine.

Twenty-seven hospitalized children without a history of varicella were vaccinated with 500 plaque forming units of live attenuated varicella vaccine (Oka strain) and followed for four to five weeks at weekly intervals for the development of virus-specific cell-mediated immunity (CMI) and neutralizing (NT) antibody activity. These children had suffered from heterogeneous underlying diseases, such as acute leukemia, lymphoma, the nephrotic syndrome, and other chronic illnesses and were in various immunological states. Development of specific CMI, detected by lymphocyte transformation (LTF), was observed in 23 of the 27 children. The appearance of LTF activity in immunologically handicapped patients was delayed and/or rather suppressed compared with that of immunologically normal patients. An antibody response was detected in 26 of the 27 children. All of the vaccinated patients were protected effectively against a subsequent outbreak of varicella in the ward.

Adolescent↗
PubMed1980

Tolerance inducibility and the elicitation of autoantibodies by LPS in aged NZB mice.

Correlation between tolerance inducibility to human IgG and the elicitation of anti-erythrocyte autoantibodies by LPS was investigated in NZB mice. At first, tolerance inducibility to human IgG was examined in various ages of the mice. Straight relationship was found between the age of mice and tolerance inducibility; the older mice became, the more difficult it became to induce tolerance. This age-related change was also shown at the level of B lymphocytes. When LPS was injected into tolerogen-resistant, aged mice, anti-erythrocyte autoantibodies were elicited. On the other hand, autoantibodies were never detected in younger NZB mice or other strains of comparable aged mice. From these results, it is assumed that similar mechanisms are operating in the escape from self-tolerance and the resistance to tolerance to heterologous antigens, thus self-reactive B lymphocytes gradually appear with the age of NZB nice in which the resistance to tolerance induction become apparent.

Aging↗
PubMed1980

[Effects of quinazoline-2, 4(1H, 3H)-dione compound, H-88 and pyridopyrimidine-2, 4(1H, 3H)-dione compound, HN-37 on pituitary-adrenal axis in rats (author's transl)].

Anti-carrageenin paw edema effects of 1-(m-trifluoromethylphenyl)-3-(2-hydroxyethyl)-quinazoline-2, 4(1H, 3H)-dione [H-88] and 1-(m-trifluoromethylphenyl)-3-ethylpyridopyrimidine-2, 4(1H, 3H)-dione [HN-37] in rats were dissipated or reduced markedly by adrenalectomy. The effects of both compounds on the pituitary-adrenal axis were therefore investigated in male Wistar rats at 5-6 weeks of age. Oral treatments with H-88 in a dose of 100 mg/kg and HN-37 at 10 mg/kg induced the same degree of responses in intact animals, namely, a marked increase of blood corticosterone level at one hr of the peak time (360%), a decrease of adrenal ascorbic acid level at 3 hr (52-59%), an increase of blood glucose level at 6-12 hr (25-59%) and of liver glycogen level at 12-4 hr (97-153%). In addition, a significant hypertrophy of the pituitary and adrenals (p less than 0.05) at 6-12 hr and/or atrophy of the thymus and spleen at 3-24 hr were noted. The effect of HN-37 on blood corticosterone level was approximately 10 times as potent as that of H-88 as well as on the carrageenin paw edema. The effects of both compounds on blood corticosterone level were dissipated by adrenalectomy, and those on blood corticosterone level and adrenal ascorbic acid level were abolished by hypophysectomy. These results suggest that hypophysis-adrenal axis stimulation may play an important role in antiedematous effects of N-88 and HN-37.

Adrenal Glands↗
PubMed1980

beta-Bungarotoxin and parasympathetic nerve blocking action.

Autonomic effects of beta-bungarotoxin (beta-BuTX), a presynaptic blocking agent at the neuromuscular junction, were examined with parasympathetic (vagus), sympathetic nerve-atrial preparations isolated from guinea pigs. beta-BuTX in concentrations ranging from 0.01 to 10 micrograms/ml abolished the negative inotropic and chronotropic responses to electrical stimulation of the preganglionic trunks of the vagus nerve. This effect was time- and dose-related and was not restored by repeated washings. Such blocking action of beta-BuTX was also obtained when post-ganglionic stimulation was applied. On the other hand, beta-BuTX failed to block the positive inotropic and chronotropic responses to either pre- or postganglionic sympathetic nerve stimulation. The nicotine-induced negative, then positive inotropic and chronotropic effects, under nerve conduction block with tetrodotoxin, were little affected with the application of beta-BuTX. The negative or positive responses to exogenously applied acetylcholine or norepinephrine were also unaffected by beta-BuTX. Thus, beta-BuTX apparently blocks cholinergic transmission in the vagus nerve innervating the guinea-pig heart, probably by acting on the postganglionic nerve terminals, yet does not interfere with preganglionic cholinergic and postganglionic adrenergic transmissions in the sympathetic nerves.

Acetylcholine↗