Biomedical subjects

O Ishida

Publications and source records attributed to O Ishida.

At least 55 records · Page 3Linked to original sources

PubMed1996

[Effect of a nitric oxide donor on optic nerve head circulation].

Recently the endothelium-derived relaxing factor was proved to be nitric oxide (NO) and it has been found to play an important role in the regulation of local blood flow. In this paper, we studied the effect of S-nitroso-N-acetyl-DL-penicillamine (SNAP), a NO donor, on the optic nerve head (ONH) circulation in rabbits, using a hydrogen gas clearance flowmeter etc. Intravitreal application of SNAP (20 nmol) increased the caliber of the retinal artery at the edge of the ONH 60 to 120 minutes later and capillary blood flow in the ONH 90 to 135 minutes later. A dose-response relation was found between 2 and 20 nmol. These changes were thought to be caused by NO produced from SNAP because they were inhibited by pretreatment with a NO trapping agent. Blood pressure and IOP were reduced 30 to 45 minutes later and 60 to 120 minutes later, respectively. It was considered that intravitreal injection of SNAP first reduced both the resistance of the ONH blood vessels and the perfusion pressure in the ONH and that the latter then rose, followed by an increase of the capillary blood flow in the ONH.

Animals↗

PubMed1996

[Effect of a nitric oxide donor on intraocular pressure].

We examined the effect of nitric oxide (NO) on intraocular pressure (IOP) and aqueous humor dynamics by using a NO donor, S-nitroso-N-acetyl-DL-penicillamine (SNAP) in rabbits. Intravitreal injection of 20 microliters of SNAP solution (10(-4) to 10(-2)M) reduced IOP from 60 to 120 min after injection. The magnitude of IOP reduction was dose-dependent within 10(-4) and 10(-3)M. The IOP reduction was inhibited by pretreatment with a NO trapping agent, carboxy-PTIO, indicating that IOP reduction was induced by NO released from SNAP. The aqueous flare as assessed with a laser cell flare meter was not accompanied with the IOP reduction indicating that no inflammatory response occurred. Neither tonographic outflow facility nor aqueous flow rate was affected by the treatment with SNAP. We conclude that NO reduces IOP through a mechanism which is not directly involved with the change of conventional outflow or aqueous formation in rabbits.

Animals↗

PubMed1995

Immune response to fresh meniscal allografts in mice.

To date, no study of allogeneic meniscal transplantation has investigated both the host cellular immune response and the humoral immune response. Using inbred mice, we examined cellular and humoral immunity to meniscal allografts through the mixed lymphocyte culture reaction and a complement-dependent cytotoxicity test. We also examined the histology of an allogeneic meniscus transplanted subcutaneously. The stimulation index of the mixed lymphocyte culture seen after placing fresh meniscal allografts subcutaneously was not significantly higher than when isograft controls were similarly placed. Following placement of the allografts, no specific antibodies were detected in serum throughout the 24-week period after grafting. Although viable fibrochondrocytes in the allogeneic meniscus decreased in number and lymphocyte infiltration around the allogeneic meniscus was noted at Week 2, no remarkable infiltration of lymphocytes into the meniscus was observed. These results indicate that in our experimental mouse model, a fresh meniscus apparently is not sufficiently immunogenic to induce a systemic reaction. Our results suggest that a fresh allogeneic meniscus can be transplanted without any special treatment to decrease its immunogenicity.

Animals↗

PubMed1995

Bilateral aberrant internal carotid arteries.

An aberrant course of the internal carotid artery is a rare vascular anomaly. This is the only known reported case of bilateral aberrant internal carotid arteries examined with CT and MRI.

Aged↗

PubMed1995

Cranial MRI in chronic thinner intoxication.

We studied a 19-year-old man with thinner and toluene poisoning for 5 years by CT and MRI. Symmetrical lesions were seen in the basal ganglia and cingulate gyri.

Administration, Inhalation↗

PubMed1995

Soluble interleukin-6 receptors in inflammatory bowel disease: relation to circulating interleukin-6.

The in vivo appearance of soluble interleukin (IL)-6 receptor (sIL-6R) in serum from patients with inflammatory bowel disease was examined using an enzyme linked immunosorbent assay (ELISA). The serum sIL-6R concentrations in patients with active disease (ulcerative colitis, 148.4 (5.1); Crohn's disease, 142.3 (9.3) ng/ml; mean (SEM)) were significantly raised compared with those in patients with inactive disease (ulcerative colitis, 116.2 (7.2); Crohn's disease, 114.3 (7.1) ng/ml), some other type of colitis (104.8 (11.6) ng/ml), or in normal subjects (107.3 (2.4) ng/ml). These differences were also seen in paired samples examined during both active and inactive phases. Additionally, serum sIL-6R and IL-6 concentrations correlated significantly with C-reactive protein levels in both ulcerative colitis and Crohn's disease patients (r = 0.23 and 0.56, respectively; p < 0.05 for both). Furthermore, gel filtration analysis of serum from these patients showed two major peaks of immunoreactive IL-6-one peak corresponding to free IL-6 and another peak to sIL-6R-bound IL-6-this was further confirmed by a luminescence sandwich ELISA. These results, together with its in vitro effects, indicate that natural sIL-6R may function as a powerful enhancer of the IL-6-dependent immune processes observed in inflammatory bowel disease.

Adolescent↗

PubMed1995

Siblings with ACTH insensitivity due to lack of ACTH binding to the receptor.

We report two siblings, a 9-year-old boy and 4-year-old girl, with ACTH insensitivity. They were referred to our hospital because of pigmentation of the skin. They had normal plasma cortisol and urinary 17-OHCS levels despite markedly high plasma ACTH, and these did not respond to consecutive 3-day ACTH-Z administration, but plasma aldosterone responded normally to increased plasma renin activity after a low sodium diet. We examined the characteristics of ACTH receptors in peripheral blood mononuclear leukocytes (MNLs) obtained from the patients and their family. Adenylate cyclase generation caused by an addition of ACTH did not occur in MNLs from the patients. In studies on ACTH binding to MNLs, a lack of high-affinity ACTH binding was observed in the patients. These results suggest that the patients have a defect in ACTH binding to the receptors, resulting in ACTH insensitivity. The reason for this defect in ACTH binding remains unclear because no significant mutation in the ACTH receptor DNA sequence was detected in the MNLs of these patients.

17-Hydroxycorticosteroids↗

PubMed1995

Germ line mutation in the RET proto-oncogene associated with familial multiple endocrine neoplasia type 2B: a case report.

Multiple endocrine neoplasia type 2 (MEN 2) is a dominantly inherited cancer syndrome. MEN 2B is characterized by the combined occurrence of medullary thyroid carcinoma (MTC), pheochromocytoma, mucosal neuroma and Marfanoid habitus. Recently, a missense mutation in codon 918 of the proto-RET has been reported in the germ line of apparently distinct families with MEN 2B. In the present paper we first show a familial case of MEN 2B in Japan also to be associated with a germ line mutation in codon 918 of the proto-RET. The mutation was the substitution of a threonine for a methionine in the tyrosine kinase domain of the protein. The germ-like mutations of the proto-RET in MEN 2A and MEN 2B are the first examples of a dominantly acting oncogenic point mutation initiating human hereditary neoplasia.

Adrenal Gland Neoplasms↗

PubMed1995

[Diagnostic assistance system based on possibility for evaluation of long bone tumorous lesions].

We constructed a diagnostic assistance system for long bone lesions using a relational data base management system, in which we categorized radiographic findings of all parameters in various lesions and stored them as degrees of possibility. Possible diagnoses of unknown lesions were listed by max-min calculation between the data base and findings of the lesions. Integration of parameters narrowed the scope of possible diagnoses. Fifty-six cases with long bone lesions were tested. Experts diagnosed correctly up to 64 percent, while the system showed a correct diagnosis rate of 43 percent as the first rank of possibility. However, the system gave 75 percent correct diagnosis when listed up to the third rank, and this increased up to 100 percent at the ninth rank. The rate of true diagnosis by experts did not exceed 73 percent. The diagnostic assistance system based on possibility analysis proved to be useful for suggesting differential diagnoses in diagnosing long bone tumorous lesions from plain radiographs.

Bone Neoplasms↗

PubMed1994

[MR imaging of traumatic head injuries using FLAIR technique].

The visualization of traumatic head injuries was compared between FLAIR images and standard long TR/TE images. FlAIR images were more sensitive than long TR/TE images in the detection of head injuries. We concluded that FLAIR images are better than conventional MR images in the evaluation of traumatic head injuries.

Adolescent↗

PubMed1994

Experimental challenge for the treatment of Duchenne muscular dystrophy using a vascularized free muscle graft.

Following free vascularized normal muscle graft in mice, a study was made to determine whether dystrophin expression is possible in dystrophin-deficient muscles. In this study, dystrophic C57BL/10 ScSn-mdx mice were used as recipients and normal C57BL/10 ScSn mice as donors. A free vascularized quadriceps muscle 8.0 x 6.0 x 6.0 mm in size was orthotopically transplanted into a muscle defect produced in the recipient mouse. The diameter of the sutured vessels was about 0.4 mm. Transplantation was successful in 7 of 20 mice. At 12 weeks after the transplantation, the grafted muscle was examined by immunocytochemical stain using anti-dystrophin antibody. This study showed that dystrophin was expressed in the transplanted muscle but not in the adjacent recipient quadriceps muscle, suggesting that grafted donor cells with dystrophin failed to migrate into dystrophic muscle cells and fuse together. However, since the grafted normal skeletal muscle successfully survived and normal dystrophin was expressed in almost all the grafted muscle fibers, the possibility was suggested that the function of muscular dystrophy muscle can be compensated by complete replacement with a larger muscle.

Animals↗

PubMed1994

Ipsilateral osteochondral grafting for finger joint repair.

A method for reconstructing articular osteochondral defects of the joint surfaces of the fingers is described. An osteochondral graft was harvested from the distal or proximal side of the second or third carpometacarpal joint of the ipsilateral hand. The graft was subsequently transplanted to the site of the defect in the proximal or distal interphalangeal joint. Ten cases with a follow-up period of more than 2 years were reviewed. The mean angular deformity decreased from 33 degrees to 4 degrees, and the mean active range of motion increased from 22 degrees to 38 degrees. Plain x-ray films revealed good joint congruity, and no donor site morbidity was appreciated. This treatment approach may be particularly useful in children.

Adult↗

PubMed1994

The receptor, metabolism and effects of androgen in osteoblastic MC3T3-E1 cells.

We investigated the androgen receptor (AR), metabolism and effects of androgens in osteoblastic MC3T3-E1 cells. AR was proved as a transcript of a 10-kb mRNA and as a 110-kDa protein. An immunocytochemical study showed that AR was located mainly in the nuclei. Specific binding of [3H]DHT was observed in both the nuclear and cytosol fractions. MC3T3-E1 cells possessed approximately 1190 binding sites per cell and most of the sites (1150 sites) situated in the nucleus. The apparent Kd value in the nuclear fraction was 1.35 nM for [3H]DHT binding, and it was similar to that for [3H]testosterone. In the competition analysis, there was not much difference in the displacement of the [3H]DHT binding from AR between the addition of radioinert DHT and testosterone. In studies of 5 alpha-reductase activity and aromatase activity of the cells, both activities were lower than the respective values in classical androgen target tissues. Androgens stimulated the incorporation of [3H]thymidine into the cell, and DHT and testosterone had a similar potency on the cell proliferation. Thus, these results suggest testosterone itself acts mainly on the osteoblasts without conversion to DHT.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

PubMed1994

Adrenal insufficiency in a patient with acquired immunodeficiency syndrome.

A 46-year-old man was admitted because of hypotension and consciousness disturbance. He was a patient with hemophilia B, and diagnosed as having an AIDS-related complex 2 years prior to admission. On admission he had severe hyponatremia. Hormonal studies revealed that he had Addison's disease. Serum cytomegalovirus (CMV) antibody titers were high, and a CMV antigen was detected in his urine, which suggested CMV adrenalitis caused by an active CMV infection. After the administration of hydrocortisone and ganciclovir, his general clinical condition and biochemical test results were back to normal. However, the adrenal dysfunction was irreversible, despite the treatment with ganciclovir. With an increase in the number of AIDS patients, we have to consider adrenal insufficiency due to a CMV infection in patients with AIDS.

AIDS-Related Complex↗

PubMed1994

Familial primary hyperparathyroidism complicated with Wilms' tumor.

We describe a familial occurrence of primary hyperparathyroidism. The proband is a 60-year-old woman who had a parathyroid adenoma. Her older sister had a parathyroid adenoma with cementifying jaw fibroma and her younger sister died of parathyroid adenocarcinoma with pulmonary metastasis at the age of 38. We have not yet obtained evidence for other endocrine disorders suggesting multiple endocrine neoplasia (MEN) in this pedigree. The proband is complicated with Wilms' tumor. It is now widely accepted that respective predisposed genes of MEN type 1 and Wilms' tumor, and PTH gene are located on chromosome 11. The manifestation observed in this case may be related to mutational abnormalities on chromosome 11.

Adenocarcinoma↗

PubMed1993

Cellular and humoral immune responses after fresh meniscal allografts in mice. A preliminary report.

To date, no study of allogeneic meniscal transplantation has investigated both the host cellular immune response and the humoral immune response. Using inbred mice, we examined cellular immunity to meniscal allografts by assaying mixed lymphocyte culture and investigated humoral immunity through a complement-dependent cytotoxicity test. The level of the stimulation index of the mixed lymphocyte culture seen after placing fresh meniscal allografts subcutaneously was not significantly higher than when isograft controls were similarly placed. Following placement of the allografts, no specific antibodies were detected in serum throughout the 24-week period after grafting. Thus, in mice, fresh meniscus apparently is not immunogenic. Our results tentatively suggest that a fresh allogeneic meniscus might be transplanted without any special treatment to decrease its immunogenicity.

Animals↗

PubMed1993

Preventive effect of pyrroloquinoline quinone (PQQ) on biliverdin accumulation of the liver of chick embryo after glucocorticoid administration.

Administration of a high dose of hydrocortisone hemisuccinate sodium (0.25 mumol/egg) to 15-day-old fertilized hen's eggs caused accumulation of biliverdin in the embryonic liver. The responses were 10 to 20-fold higher than controls within 48 hr as a result of stimulation of biliverdin synthesis in the liver and the decrease of biliverdin excretion from the liver. This accumulation was effectively prevented by PQQ, possibly through the enhancement of biliverdin excretion from the liver to the gallbladder. This PQQ action was due to its preventive effect against the decrease of glutathione in the liver caused by glucocorticoid since glutathione is suggested to play a role in elimination of bile components from the liver.

Animals↗

PubMed1993

Long-term results of denervation of the wrist joint for chronic wrist pain.

The results have been evaluated of 29 patients who had wrist denervation for chronic wrist pain between 1979 and 1987. Follow-up ranged from 22 to 86 months (mean 51 months). 17 patients had denervation without a concurrent procedure. Of these, 12% became pain-free and 71% had pain with all activities or had additional surgery; 24% said they were satisfied with their treatment. The results were worse in those who had partial denervation than those who had total denervation. 12 patients had denervation performed concurrently with another pain-relieving procedure. Denervation alone was not reliable in resolving chronic wrist pain.

Adult↗