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Biomedical subjects

M Fujiwara

Publications and source records attributed to M Fujiwara.

At least 703 records · Page 39Linked to original sources

Capsaicin and bradykinin-induced substance P-ergic responses in the iris sphincter muscle of the rabbit.

Exogenously applied capsaicin and bradykinin produced contractile responses in the rabbit iris sphincter muscle and responses were suppressed remarkably by [D-Pro2, D-Trp7,9]-substance P, a substance P antagonist, and disappeared in trigeminally denervated preparations. Thus, the responses to capsaicin or bradykinin were considered to be mediated by substance P released from the trigeminal nerve. Repetitive application of capsaicin or bradykinin produced a gradual decline in the responses, thereby indicating the development of tachyphylaxis. Furthermore, bradykinin failed to induce any response after the development of capsaicin-induced tachyphylaxis, but after the development of tachyphylaxis to bradykinin, responses to capsaicin persisted. Electrical transmural stimulation produced cholinergic and substance P-ergic responses in the rabbit iris sphincter muscle. Substance P-ergic response to electrical transmural stimulation also was abolished after development of tachyphylaxis to capsaicin, but not to bradykinin. The contractile response to exogenously applied substance P was not affected by the development of tachyphylaxis to capsaicin and bradykinin. These results suggest that capsaicin and bradykinin produce substance P-ergic contractile responses mediated by the trigeminal nerve and that the mechanisms of action differ between the two drugs. These effects of capsaicin and bradykinin are discussed in relation to occurrence of neurogenic inflammation in the eye.

Animals↗

Induction of immunoglobulin-secreting cells by 2-mercaptoethanol in in vitro culture of B cells from autoimmune mice.

Splenic B cells from older MRL/Mp-lpr/lpr (MRL/1) and male BXSB mice responded to 2-mercaptoethanol (2-ME) in in vitro culture and generated immunoglobulin-secreting cells (IgSC). Optimal concentration of 2-ME to induce IgSC was 5 X 10(-5) M. Kinetic studies revealed that the generation of IgSC was already apparent after 24 hr of culture and peak response was attained on the 2nd day. The response of B cells to 2 ME was enhanced in the presence of splenic T cells. Irradiation of B cells reduced the generation of IgSC. The B cell population of autoimmune mice responding to 2-ME to generate IgSC seems to be in a terminal stage of differentiation. This increased B cell differentiation was characteristic of autoimmune mice and assumed to have some significance in the development of autoimmune diseases.

Aging↗

One-way occurrence of graft-versus-host disease in bone marrow chimaeras between congenic MRL mice.

Bone marrow cells (BMCs) of MRL/Mp-lpr/lpr (MRL/l) mice, when infused into irradiated MRL/Mp-+/+ (MRL/n) mice, induced graft-versus-host disease (GVHD) and recipients died of wasting syndromes beginning around a few weeks later. Protracted appearance of GVHD was observed when (MRL/n X MRL/l) F1 mice were used as recipients of MRL/l BMSs. On the other hand, MRL/n BMCs did not elicit GVHD in irradiated MRL/l mice. Treatment of MRL/l BMCs with anti-Thy-l antiserum plus complement did not eliminate GVHD-provoking capacity. Thymectomy of the recipents reduced the incidence of GVHD. No apparent reaction was observed in mutual mixed lymphocyte culture of spleen cells from MRL/l and MRL/n mice. These data suggest that injected T cell precursors of MRL/l mice become mature through the host (MRL/n mice) thymus and appear in the periphery as functioning T cells, resulting in the appearance of GVHD.

Animals↗

[A case of intrasellar arachnoid cyst].

Intrasellar arachnoid cyst is very rare. We report a case of intrasellar arachnoid cyst and review 15 cases which were previously reported. A 58-year-old male was admitted for evaluation of visual disturbance on April 24, 1981. Neurological examination revealed bilateral decreased visual acuity, optic atrophy and bitemporal hemianopsia. X-ray film of the skull showed a balloon-shaped sella turcica with thinning of the cortex of the sella floor. Axial and coronal CT scan showed a cystic lesion with water-density occupying the intrasellar and suprasellar region. After administration of contrast medium, no enhancement was noted. Bilateral carotid angiographies demonstrated that the carotid siphons were stretched and displaced laterally, the A1 portions of the anterior cerebral arteries were raised. Pneumoencephalography revealed the upward displacement of the floor of the third ventricle indicating the presence of the suprasellar mass. On May 7, 1981, the sella turcica was reached via the transsphenoidal rhinoseptal approach. A cyst with a white colored thin wall which contained water-like fluid was encountered, and a biopsy was taken of the cyst wall. The roof of the cyst pulsated downward and ruptured spontaneously. Cerebrospinal fluid flowed out. The cavity was filled with muscle and adipose tissue. Postoperative course was uneventful during the first few days and the visual disturbance improved. On the fourth postoperative day cerebrospinal fluid rhinorrhea occurred, but it subsided in nine days. The patient was discharged on June 26 with satisfactory improvement of visual field and visual acuity. Histological examination of the biopsied specimen revealed arachnoid membrane consisting of collagen fibers and scattered cells. Symptoms, signs and radiological findings of the intrasellar archnoid cyst are similar to that of various sellar lesions including pituitary adenoma, craniopharyngioma and the other space occupying mass in the sellar region. Intrasellar arachnoid cysts can be treated by a transsphenoidal approach as well as a subfrontal approach with craniotomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Arachnoid↗

[A case of renal cell carcinoma in tuberous sclerosis followed by basic fetoprotein--a new carcinoembryonic protein].

There have been very few reports on renal malignancies in tuberous sclerosis and only 9 cases have been reported in the Japanese literature. A second case of renal cell carcinoma in tuberous sclerosis in Japan is reported. The present case is a 29-year-old male who visited our clinic with the chief complaint of right flank mass. The excretory urogram, and renal selective angiography suggested right benign renal tumor, possibly angiomyolipoma. But surgical exploration was performed because of the possibility of renal malignancy. The histological findings revealed renal cell carcinoma. At 18 months after operation, the patient died of multiple visceral metastasis, i.e., to lungs, left kidney and liver. In this case basic fetoprotein - a new carcinoembryonic protein - was measured and its level elevated gradually as the disease progressed. Judging from the measurement of basic fetoprotein in this patient it may be an efficient new tumor marker for renal cell carcinoma.

Adenocarcinoma↗

Long term administration of cyclophosphamide in MRL/1 mice. I. The effects on the development of immunological abnormalities and lupus nephritis.

Weekly injection of cyclophosphamide (Cy) into MRL/Mp-lpr/lpr (MRL/l) mice, at a dose of 10-20 mg/kg, from 1 month of age prevented the development of generalized lymph node enlargement, decreased serum levels of anti-DNA antibodies and immune complexes, and markedly prolonged their life span. Cy effectively suppressed enhanced differentiation of B cells, as evidenced by decreased number of immunoglobulin secreting cells in the spleen. Cy was also shown to suppress abnormal expansion of Thy-1 positive cells in lymphoid organs of MRL/1 mice. These results suggested that Cy prevented the development of murine lupus like syndrome in MRL/1 mice through suppression of spontaneous polyclonal B cell activation and also by reducing the number of T cells to exert excessive helper activity on B cells.

Animals↗

Long term administration of cyclophosphamide into MRL/1 mice. II. The effects on the isotype of anti-DNA antibodies and immunoglobulin secreting cells in the spleen.

Weekly injections of cyclophosphamide (Cy) at a dose of 20 mg/kg body weight prevented IgM to IgG class switch of serum anti-DNA antibodies and also immunoglobulin secreting cells in the spleen of MRL/Mp-lpr/lpr (MRL/1) mice. Culture experiments revealed that splenic B cells of Cy treated mice gave rise to more IgM and less IgG secreting cells than those of untreated mice in response to lipopolysaccharide. These results suggested that Cy suppressed enhanced differentiation of B cells into IgG secreting cells in MRL/1 mice, which would result in reduction of IgG anti-single stranded DNA antibodies and improvement of murine lupus like syndrome.

Aging↗

Calcium-dependent regulation of phospholipid methylation in rabbit platelets.

Effects of Ca2+ on phospholipid methylation in rabbit platelet membranes were studied using S-adenosyl-L-[3H-methyl]methionine as a substrate. The methylation was inhibited to 30% of the basal activity with 100 microM Ca2+. The inhibition was completely counteracted by various calmodulin antagonists. Their concentrations, i.e., N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide, chlorpromazine and trifluoperazine, to be required for half maximal recovery were 32, 47 and 29 microM, respectively. In contrast, N-(6-aminohexyl)-1-naphthalenesulfonamide, a weaker calmodulin antagonist, did not lead to a sufficient recovery of the inhibition. Addition of exogenous phosphatidyl-N-monomethylethanolamine (PMME) and phosphatidyl-N,N-dimethylethanolamine, intermediates of phosphatidylcholine synthesis by successive methylation of phosphatidylethanolamine (PE), enhanced the formation of 3H-methylated products. However, the increased amount of 3H-methylated products by the addition of those intermediates was much the same either in the presence or absence of Ca2+. These results suggest that the Ca2+-induced inhibition of methylation in platelets is mediated either by calmodulin itself or by a site which has calmodulin antagonist binding properties similar to this protein and that Ca2+ seems to inhibit the first step of the methylation to form PMME from PE.

Animals↗

Do the substance P-ergic vagus afferents in cats reinnervate the deafferented superior cervical ganglion?

By ligating specific nerves in the cat, the central processes of the nodose ganglion (NG) cells containing substance P-like immunoreactive materials were shown, immunohistochemically, to run through the cross-anastomosis made between the cranial end of the NG and the caudal end of the superior cervical ganglion (SCG), and to reach the portions cranial to the SCG without making synaptic contacts with the SCG cells.

Afferent Pathways↗