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Biomedical subjects

Y Uchida

Publications and source records attributed to Y Uchida.

At least 433 records · Page 24Linked to original sources
PubMed1992

Accumulation of amyloid precursor protein and beta-protein immunoreactivities in axons injured by cerebral infarct.

To determine the distribution of amyloid precursor protein (APP), monoclonal antibodies against APP45-62 (APP1-28-9) and beta1-17 (4A18 and 4A61) were produced. In the sections of Alzheimer's disease (AD) brain, APP1-28-9 was reactive with neurites around senile plaques and a few neurons but not with amyloid cores. This antibody also immunostained the axons in the ischemic lesions of brain tissues from cases with cerebral infarct. 4A18 and 4A61 were reactive with amyloid plaques but not with neurites and neurons. The latter two antibodies also immunostained axons in ischemic lesions. These findings suggest that APP, transported by the fast axonal flows, accumulated in the injured axons in the central nervous system. The beta immunoreactivity appearing in those axons may provide a clue to the mechanism of amyloidogenesis.

Alzheimer Disease↗
PubMed1992

[The vasospasmolytic effects of nicorandil, cromakalim and pinacidil on 3,4-diaminopyridine-induced phasic contractions in canine coronary arteries as an experimental vasospasm model].

The spasmolytic mechanisms of nicorandil, a novel antianginal drug, were investigated using 3,4-diaminopyridine (3,4-DAP)-induced phasic contractions of isolated canine coronary arteries in comparison with those of cromakalim and pinacidil. Nicorandil (10(-4) M), cromakalim (10(-6) M) and pinacidil (10(-5) M) suppressed the phasic contractions. Pretreatment with glibenclamide (10(-6) M), a specific blocking agent of ATP-sensitive K+ channel, eliminated the suppression of phasic contractions by these drugs; glibenclamide completely eliminated the suppression by cromakalim, while the eliminations against nicorandil and pinacidil were incomplete. The recoveries of peak tensions were only 56.8% and 76.1% for nicorandil and pinacidil, respectively. Nicorandil and pinacidil may suppress the phasic contractions via K+ channel opening and additional mechanisms. Methylene blue (10(-7)-10(-5) M) alone, a guanylate cyclase inhibitor, had no effect on the suppression of phasic contractions by nicorandil. In the presence of glibenclamide (10(-6) M), however, the pretreatment with methylene blue significantly augmented the recovery of peak tension for nicorandil. These results indicate that K+ channel openers may suppress the phasic contractions induced by 3,4-DAP via ATP-sensitive K+ channels, and that additionally, nicorandil may suppress the phasic contractility through guanylate cyclase stimulation, as a nitrate.

4-Aminopyridine↗
PubMed1992

Otitis externa induced with Malassezia pachydermatis in dogs and the efficacy of pimaricin.

Eight beagles were experimentally inoculated intraotally with Malassezia pachydermatis to induce acute otitis externa. Three or 4 days after the inoculation, the animals showed the symptoms of otitis externa. All ear canals were erythematous and the dogs were shaking their heads. A large number of M. pachydermatis was noticed in exudate taken from every ear canal. Clinical signs of otitis externa were reduced after treatment with 0.1 ml (per canal) of 1% pimaricin suspension twice a day for 3 days. The amount of exudate decreased gradually and 12 of the 16 ear swabs examined, thereafter, were found to be negative for M. pachydermatis within 10 days. No side effects were observed in all the treated cases. These results suggested that M. pachydermatis could induce the canine otitis externa, and that pimaricin is effective agent for M. pachydermatis infection in ear canals.

Animals↗
PubMed1992

Anatomically corrected malposition (ACM) with subpulmonary infundibulum in a calf: clinico-morphologic case report.

A Japanese black calf with cyanosis, tachycardia, tachypnea and systolic murmur died of hypoxemia and cardiac insufficiency on the 38th day after birth. We could not establish the diagnosis during it's life. However, anatomically corrected malposition (ACM) with ventricular septal defect was confirmed at autopsy. There was situs solitus of the viscera and atria with atrio-ventricular discordance and ventriculo-arterial concordance. The ventricles demonstrated l-loop, i.e. on the right-sided ventricle there was a markedly enlarged morphologic left ventricle, and on the left-sided ventricle there was a hypoplastic morphologic right ventricle with a stenotic tricuspid valve and Ebstein-like deformity. The right posterior aorta originated from the left ventricle. The pulmonary artery arose from the left-sided right ventricle via infundibulum. There was a fibrous continuity between the aortic and mitral valve. We considered that this is the first reported case of bovine ACM.

Animals↗
PubMed1992

Effect of interferon (IFN) on refractory idiopathic thrombocytopenic purpura: administration of 6 million units of recombinant IFN alpha-2b.

Five patients (six courses) with refractory idiopathic thrombocytopenic purpura (ITP) were given 6 million units of recombinant interferon (IFN) alpha-2b in 12 doses to achieve an improved response rate compared to previous studies using 3 million units. From the initial IFN administration, the platelet count increased from a pre-treatment level of 20.7 +/- 17.7 x 10(3)/microliters (mean +/- SD) and reached its first peak in weeks 2 or 3 of therapy (p < 0.05). In week 5, the platelet count made its second and maximum peak (66.5 +/- 57.9 x 10(3)/microliters; p < 0.05). A relatively good response of the platelet count (an increase to > 50 x 10(3)/microliters) was observed in three patients (four courses) out of five. These responses were not much faster or more improved than in previous reports, and a dose of 6 million units may be too large to treat some ITP patients. The platelet-associated IgG level showed a tendency to be reduced with IFN therapy. The mechanism for the increase of the platelet count may be the modification of platelet autoantibody production.

Adult↗
PubMed1992

[New reconstruction method for defect of chest wall using composite graft].

In the case of a 64-year-old man squamous cell carcinoma in the left lung with metastasis to the rib, we excised the affected portion of the chest wall and used a composite graft, a combination hydroxyapatite (HAP) filler, for reconstruction with good results. HAP filler is a ceramic that combines the calcium phosphate apatite hydroxide with 3-calcium phosphate. The Dacron fabric used was made of polyethylene terephthalate fiber. Two layers of Dacron fabric were laid together, stitched to the rib with nylon thread, and the resulting tubular cavity packed with HAP filler to create an artificial rib. The intercostal muscle was sandwiched between the layers of Dacron fabric and the ends of the natural rib laid across those of the artificial one. We used the periosteum and intercostal muscle to integrate the graft and complete reconstruction. Postoperative recovery was good, and there was no visible sign of deformation at the graft site. Even in palpation we were unable to tell that the rib was artificial.

Biocompatible Materials↗
PubMed1992

Respiratory dyskinesia: a variety of clinical forms differentially diagnosed by using a spirograph.

Four cases of respiratory dyskinesia were investigated by using a spirograph before and after biperiden injection. The abnormal respiratory patterns in four cases appeared to be in two types and these abnormalities were abolished after biperiden injection. The present study showed that respiratory dyskinesia could be defined more clearly by using a spirograph and these results are useful for the diagnosis of patients with respiratory discomfort while undergoing neuroleptic drug treatment.

Adult↗
PubMed1992

Endothelins constrict guinea pig tracheas by multiple mechanisms.

When tracheal rings isolated from guinea pigs were treated with endothelins (ETs), a dose-dependent constriction was observed and measured isometrically. ET potencies were ET-1 = ET-2 greater than ET-3. Dose-response curves of epithelium-denuded tracheas were shifted to the left by approximately one order of magnitude. Lung tissue contained saturable binding sites to 125I-labeled ET-1. These binding sites were replaced by ET-1 = ET-2 greater than ET-3. Because the airway tissue contained primarily ET-1 as measured by immunoassay after high-performance liquid chromatography separation, we investigated the mechanism of ET-1-induced tracheal constriction. Tracheal constriction induced by ET-1 required Ca++ in the medium. Because suppression of the contractile response by nicardipine and diltiazem was small, Ca++ entry appeared to be gated primarily through Ca++ channels rather than via voltage-dependent ones. FPL55712, SC47014A, indomethacin and OKY046 suppressed the dose-response curves, suggesting that lipid mediators are formed in response to ET-1. Diphenhydramine also altered dose-response curves, suggesting that histamine release from mast cells was partially responsible for the constriction. Pretreatment of tracheas with compound 48/80 resulted in suppression of the contractile responses. Furthermore, the combination of indomethacin, FPL55712 and diphenhydramine gave essentially identical effects. Our observations suggest that ET-1 provokes the contractile response of guinea pig tracheas not only by direct actions on smooth muscle but also by indirect actions through production of chemical mediators in mast cells and other inflammatory cells.

Animals↗
PubMed1992

[Visualization of the female breast in bone scintigraphy].

Breast cancer incidence rates in Japan have more than doubled in the decade between 1975 and 1985 due to a well-established and affluent Western life-style. One hundred patients having breast cancer, 107 patients having mastectomies, and 243 patients having no breast cancer were reviewed for whole body and spot views of bone scintigraphy with 99mTc-MDP. The frequency of positive breast uptake in patients with no breast cancer showed a maximum in those patients between the ages of 30 and 40, with a progressive rise and fall before and after the peak, respectively. Patients between the ages of 50 and 60 with breast cancer showed a maximum uptake of 83%, while those patients between the ages of 70 and 80 with breast cancer showed an uptake higher than 50%. There was a markedly higher breast uptake ratio in the breast cancer group compared to the breast cancer free group. Although this scanning agent was of no value in recognition of tumor localization from breast uptake, we have to suspect a high incidence of cancer existence whenever there was unilateral increased breast activity. Even though the mechanism of 99mTc-MDP uptake by breast tissue is unknown, breast concentration of 99mTc-MDP appears to be influenced by hormones, especially estrogen.

Adolescent↗
PubMed1992

[Effect of enkephalinase inhibitor on endothelin-1 induced bronchoconstriction in guinea pigs].

Endothelin-1 (ET-1) is one of the most potent bronchoconstrictors in the guinea pig. The mechanism of its metabolism is still unclear. Phosphoramidon is known to be an enkephalinase inhibitor. We studied the effect of phosphoramidon on bronchoconstriction induced by ET-1. In the first in vitro study, a tracheal preparation was mounted in oxygenated Krebs-Ringer solution. The response was monitored by isometric transducer. Dose-response curves to ET-1 with or without phosphoramidon were obtained. Phosphoramidon potentiated ET-1 induced bronchoconstriction significantly. Next, the specific airway conductance (sGaw) was measured in conscious guinea pigs exposed to an aerosol of phosphoramidon or saline, followed by ET-1 aerosol inhalation. The ET-1 dose was increased by successively doubling the concentration. sGaw, after inhalation of phosphoramidon, was significantly reduced when exposed to ET-1. Phosphoramidon also potentiated ET-1 induced bronchoconstriction in vivo. Next, lung parenchymal tissues were prepared and placed in oxygenated Krebs-Ringer solution with or without phosphoramidon. ET-1 was added and incubated, and samples were injected into a high performance liquid chromatography column. Phosphoramidon inhibited an analysis of ET-1. These data suggest that enkephalinase plays a role in the break down of ET-1 in the airway of the guinea pig. Under the condition of decreased enkephalinase, ET-1 would potentiate bronchoconstriction.

Animals↗
PubMed1992

[Anesthetic management of a patient with severe hyponatremia].

A 79 year old man, with left femoral neck fracture, was scheduled for an elective operation. After admission, severe hyponatremia probably due to diuretics developed. No neurological abnormalities were observed before surgery. He recovered from anesthesia with no problems. But on the 5th postoperative day he showed transient unresponsiveness. Grand mal seizures were also seen after the serum Na level had recovered to around 130 mEq.l-1. This case shows that in the management of severe hyponatremia, the discrimination between acute and chronic hyponatremia seems to be important.

Aged↗
PubMed1992

[Effects of steroid therapy in IgA nephropathy].

In order to estimate the effects of corticosteroid therapy in IgA nephropathy cases with daily urinary protein excretion of 1.0 g/day or more. 26 patients (8 men and 18 women, aged 32.6 +/- 14.0 years old) were subjected to this study. The results obtained were as follows: Urinary protein excretion after 1 year from the beginning of steroid therapy (1.56 +/- 1.14 g/day) was significantly (p less than 0.05) lower than that at the beginning of the therapy (4.61 +/- 6.01 g/day). In serum creatinine levels, there was no statistically significant difference with them between at the beginning (1.15 +/- 0.48 mg/dl) of steroid therapy and at the time of 1 year after (1.05 +/- 0.34 mg/dl) the therapy. As for the outcome at the end of this study setting (mean follow-up duration: 3.7 +/- 2.6 years), complete remission was attained in 7 cases, improvement in 5 cases, unchanged condition in 11 cases, increased urinary protein excretion in 2 cases and aggravated renal function in 1 case. In clinical findings at the renal biopsy, duration of the disease (3.4 +/- 1.6 months) in complete remission cases before biopsy was significantly (p less than 0.01) shorter than that in unchanged cases (65.0 +/- 40.0 months). In histological findings, rate of global sclerosing glomeruli (2.6 +/- 4.6%) in complete remission cases was significantly (p less than 0.05) lower than that (24.6 +/- 23.1%) in unchanged cases. These results suggest that steroid therapy in IgA nephropathy with persistent proteinuria of 1.0 g/day or more is beneficial, especially in cases that are in early stage of the disease with lower rate of global sclerosing glomeruli.

Adolescent↗
PubMed1991

Endotoxin stimulates endothelin release from cultured epithelial cells of guinea-pig trachea.

We examined the release of endothelin from cultured epithelial cells of guinea-pig trachea in response to treatment with endotoxin, using a sandwich-enzyme immunoassay. Cultured epithelial cells released endothelin in a time-dependent fashion (3, 6, 12, 24 h), and endotoxin (4-40 micrograms/ml) significantly increased endothelin release. Endotoxin (4-10 micrograms/ml) showed no cytotoxicity against epithelial cells. These results suggest that guinea-pig airway epithelial cells are capable of producing endothelin and this peptide may be related to the pathophysiological effects of endotoxin.

Animals↗