Search PubMed⌕ Search

Biomedical subjects

T Okada

Publications and source records attributed to T Okada.

At least 739 records · Page 41Linked to original sources
PubMed1991

Alkaline phosphatase, 5'-nucleotidase and magnesium-dependent adenosine triphosphatase activities in the transitional epithelium of the rat urinary bladder.

The cerium-based method was used to demonstrate cytochemically the ultrastructural localization of alkaline phosphatase (ALPase), 5'-nucleotidase (5'-Nase) and magnesium-dependent adenosine triphosphatase (Mg-ATPase) on the transitional epithelium of the rat urinary bladder. The reaction product for ALPase was found on the plasma membrane of all epithelial cells, except the luminal surface of superficial cells. The activity of 5'-Nase appeared on the plasma membrane of all bladder transitional epithelial cells, including the free surface of superficial cells. The Mg-ATPase reaction product was seen on the plasma membrane of superficial, intermediate and basal cells, but never on the luminal surface of superficial cells and it was only occasionally seen on the basal surface. The possible functions of these phosphatases have been discussed, and it was emphasized that the 5'-Nase activity present on the luminal surface of superficial cells may play a special role in the membrane movement of these cells in the transitional epithelium.

5'-Nucleotidase↗
PubMed1991

Release of endogenous excitatory amino acids from ON-type bipolar cells isolated from the goldfish retina.

Excitatory amino acids are presumed to be the transmitter of retinal bipolar cells. However, one of the essential criteria for the identification of the transmitter, its release from the cells upon depolarization, has not been demonstrated. This article examines the release of endogenous excitatory amino acids from bipolar cells and correlates this release with the influx of Ca2+. Bipolar cells with a large, bulblike axon terminal (ON-type cells with mixed inputs from rods and cones) were enzymatically isolated from the goldfish retina. Horizontal cells dissociated from the catfish retina were used as a probe of excitatory amino acids, because these cells can detect submicromolar concentrations of L-glutamate with high selectivity. An isolated bipolar cell was closely apposed to a dissociated horizontal cell, and each cell was voltage clamped by a patch pipette in the whole-cell clamp configuration. When the bipolar cell was depolarized from -60 mV to a potential more positive than -40 mV using a 500-msec voltage pulse, an outward current (greater than 20 pA) was recorded from the apposed horizontal cell, which was maintained at +40 mV. The reversal potential of the current induced by the substance released from bipolar cells (Irs) was close to 0 mV and was almost identical to the responses evoked with ionophoretically applied L-glutamate. Both reversal potentials were shifted to the same, more negative value when the external Na+ was replaced with choline. Furthermore, the Irs was suppressed reversibly by the application of kynurenic acid, a glutamate antagonist. When the Ca current (ICa) of the bipolar cell was blocked by Cd2+, the Irs also disappeared. The peak amplitude of Irs was closely related to that of the ICa. We conclude that mixed rod/cone ON-type bipolar cells of the goldfish retina release an endogenous excitatory amino acid or a closely related compound in a Ca(2+)-dependent manner.

Amino Acids↗
PubMed1991

Effect of PUVA radiation on anaphylactic histamine release from rat dermal tissues.

We have devised a new in vitro model of type I cutaneous anaphylaxis. Male albino rats were sensitized with DNP-Ascaris. Abdominal skin was shaved, and thin, split-thickness slices of skin were cut with a dermatome. The dermis was excised and cut into 100 mg pieces. The dermal tissue was incubated with antigen in Tyrode's solution for 30 min at 37 degrees C. Antigen-induced histamine release from dermal tissue was measured fluorimetrically. Using this system, we measured histamine release from PUVA-irradiated and non-irradiated dermal tissues. A single PUVA irradiation inhibited type I cutaneous anaphylaxis, but did not affect spontaneous histamine release or total dermal histamine. Our model is considered to be useful for investigation of the mechanism of suppression of type I cutaneous anaphylaxis by PUVA.

Anaphylaxis↗
PubMed1991

Treatment of persistent sleep-wake schedule disorders in adolescents with methylcobalamin (vitamin B12).

Two adolescent patients suffering from persistent sleep-wake schedule disorders appear to have responded to treatment with vitamin B12 (methylcobalamin). A 15-year-old girl with delayed sleep phase syndrome (DSPS) and a 17-year-old boy with hypernychthemeral syndrome complained of not being able to attend school despite many trials of medication. The improvement of the sleep-wake rhythm disorders appeared immediately after the administration of high doses (3,000 micrograms/day) of methylcobalamin. Neither patient showed any laboratory or clinical evidence of vitamin B12 deficiency or hypothyroidism (which can cause B12 deficiency). Serum concentrations of vitamin B12 during treatment were in the high range of normal or above normal. The duration of the sleep period of the DSPS patient decreased gradually from 10 hours to 7 hours, and the time of sleep onset advanced from 2 a.m. to midnight. The period of the sleep-wake cycle of the hypernychthemeral patient was 24.6 hours before treatment and 24.0 hours after treatment. The relationship between the circadian basis of these disorders and vitamin B12 and its metabolites is discussed.

Achievement↗
PubMed1991

Effect of silicone oil on ocular tissues.

The effect of silicone oil on ocular tissues was investigated histopathologically in rabbit eyes by injecting silicone oil into the anterior chamber or the vitreous cavity after vitrectomy. The eyes were enucleated 3, 6, 9, 12 or 18 months after the injection and various tissues were observed by light and electron microscopy. Silicone oil was first observed in the retrocorneal membrane at 18 months after the injection. In the trabecular meshwork silicone oil was seen for the first time at 12 months after injection. Migrating cells engulfing silicone oil attached to the internal limiting membrane of the retina 3 months after the injection. Twelve and 18 months after the injection, silicone oil passed through the internal limiting membrane and was engulfed by Müller cells. These results indicate that attention should be paid to the effects of silicone oil on ocular tissues when it remains in the eye for a long time since, after a certain period, cells of the trabecular meshwork and retina may engulf silicone oil.

Animals↗
PubMed1991

[Thoracoabdominal aneurysm complicated with disseminated intravascular coagulopathy--a case of surgical treatment following heparin pretreatment].

This article reports a case of a thoracoabdominal aneurysm complicated with disseminated intravascular coagulopathy (DIC). The thoracoabdominal aneurysm was successfully replaced with a prosthetic graft following the short terms of heparin pretreatment. Although heparin pretreatment had been effective for the temporal remission of DIC, a large amount of blood transfusion was necessary because of prolonged bleeding from surgical wound. However, hematological evidence of DIC and bleeding tendency were dramatically arrested in the immediate postoperative period. It was concluded that the definitive treatment for DIC was removal of the aneurysm. Heparin was usefull for the preservation of coagulation factors and platelet, but it did not lessen operative bleeding.

Aorta, Abdominal↗
PubMed1991

[The changes in plasma beta-thromboglobulin (beta-TG), platelet factor 4 (PF4) and thromboxane B2 (TXB2) after a bronchial provocation test (BPT) with house dust (HD) allergen].

In order to investigate the role of platelets in allergic asthma, the time related changes in plasma levels of beta-TG, PF4 and TXB2 were evaluated following BPT with HD in 19 patients with bronchial asthma who were positive in skin test and RAST to HD. The results obtained were as follows. 1) Plasma beta-TG and PF4 levels tended to increase following BPT with HD at the time of immediate asthmatic response (IAR) in patients showing IAR alone. 2) Plasma beta-TG and PF4 levels increased significantly (p less than 0.05) at IAR and tended to increase at the time of late asthmatic response (LAR) in patients showing a dual asthmatic response (DAR). 3) The levels of plasma TXB2 in patients showing IAR alone significantly increased at IAR (p less than 0.05) and gradually decreased and the levels of plasma TXB2 in patients showing a DAR increased in each period of IAR, 3 hr after BPT and LAR, and the peak of TXB2 was observed in 3 hours after BPT. 4) These results suggest that platelets are activated at IAR and there was also a possible activation in platelets at LAR.

Adult↗
PubMed1991

[A case of CA19-9 producing adenocarcinoma of the lung associated with idiopathic interstitial pneumonia].

A 63-year-old female, who had been suffering from idiopathic interstitial pneumonia (IIP) since two years and four months previously, was admitted with general fatigue, body weight loss, bloody sputum and progression of dyspnea. Chest roentgenogram on admission showed diffuse coarse ring shadows in the right middle and lower lung fields and in the left middle lung filed. Chest CT clearly showed honeycombing in bilateral dorso-basal segments of the lung. Serum CA19-9 level was elevated, and continued to increase during her clinical course. Sputum cytology was positive. Autopsy showed papillary adenocarcinoma of the lung (alveolar cell type). Immunohistochemical study of lung tissue showed positive CA19-9 staining on the surface of adenocarcinoma cells.

Adenocarcinoma↗
PubMed1991

[Clinical evaluation of cefpirome in pediatrics and a study on the penetration into cerebrospinal fluid].

Cefpirome (CPR, HR 810), a new cephem antibiotic, was investigated for its penetration into cerebrospinal fluid (CSF), and its clinical efficacy against bacterial infections. 1. CSF concentrations of CPR following intravenous injection was investigated in 2 patients with purulent meningitis. In one of them, the concentrations were 2.11 micrograms/ml and 1.31 micrograms/ml on 3 and 8 days, respectively, after start of administration. In the other patient, they were 24.2 micrograms/ml, and 1.35 micrograms/ml on 2 days and 7 days after administration, respectively. 2. Antibacterial activities of CPR against clinical isolates, Escherichia coli, Haemophilus influenzae, Staphylococcus aureus and Streptococcus pneumoniae, except those against Pseudomonas aeruginosa, were clearly superior to those of ceftazidime. 3. Clinical efficacies evaluated in 15 patients were "excellent" in 9, "good" in 5 and "unknown" in 1. The overall efficacy rate was 93.0%. 4. Clinical efficacies were "excellent" in 1 patient with bacteremia, "excellent" in 6 and "good" in one of 7 patients with pneumonia, and "good" in both of the 2 patients with purulent meningitis. Clinical efficacies against other diseases were "excellent" or "good", in 1 patient with pyothorax, 1 patient with purulent lymphadenitis, and 2 patients with facial cellulitis. In 1 patient with biliary tract infection, the results of treatment with CPR were "unknown" due to insufficient clinical data. 5. No adverse reactions were observed except in 1 patient who showed an increase in platelet count.

Adolescent↗
PubMed1991

[Enzyme immunoassay for secretory immunoglobulin A on skin surface and in sweat].

Recently secretory IgA (S-IgA) was found to be secreted from the eccrine gland. By using a sandwich enzyme immunoassay, we measured the concentration of S-IgA 1) in sweat (sweat S-IgA) and 2) in the extract buffer obtained by pipetting++ on the skin (skin surface S-IgA). Skin surface hydration and skin surface lipid were measured at the sites where the samples of skin surface S-IgA were collected. (These measurements were taken immediately after the buffer was pipetted). The quantity of both sweat S-IgA and skin surface S-IgA differed according to the sites where they were collected. Sites in order of decreasing sweat S-IgA level: face, chest, forearm. Sites in order of decreasing skin surface S-IgA level: face, chest, palm, forearm, sole. (Skin surface S-IgA levels on palm and forearm were approximately equal). Although the amount of skin surface S-IgA was not related to the skin surface hydration, there was a significant correlation between skin surface S-IgA and skin surface lipid.

Adolescent↗
PubMed1991

[P300 latencies in epileptic children: the differences among various epileptic syndromes].

Auditory event-related potentials (ERPs) were recorded from 129 epileptic children of 5 to 20 years of age. To clarify the developmental changes in each of the epileptic syndromes, P300 latencies of ERPs were examined. ERPs were elicited with the auditory oddball paradigm. P300 detection was occasionally difficult in epileptic children. Mean P300 latency in epileptic children (375 +/- 39.7 msec) was significantly prolonged compared with that in normal control children. (355 +/- 39.1 msec). P300 latencies in the children with symptomatic partial epilepsies were prolonged and were not recognized to be shortened with age. In the idiopathic partial epilepsies of 5 to 12 years of age, P300 latencies showed almost the same values with those in the normal children. However, in the idiopathic partial epilepsies of 13 to 15 years of age, P300 latencies were significantly prolonged compared with those in normal children and there were no difference in P300 latencies with other epileptic syndromes. P300 latencies in idiopathic generalized epilepsies showed intermediate values between that in symptomatic partial epilepsies and idiopathic partial epilepsies. Each epileptic syndrome showed different developments in P300 latencies with age. This results suggests that the development and the disturbance of cognitive functions differ among the epileptic syndromes.

Adolescent↗
PubMed1991

[A case of benign pulmonary metastasis from ovarian immature teratoma].

A thirty one-year-old female underwent resection for pulmonary metastatic tumor from immature ovarian teratoma (G-II). Resected specimens from the lung revealed no malignant findings in the cystic teratoma (G-0). We speculated this finding might be due to retroconversion of ovarian immature teratoma. Retroconversion of ovarian immature teratoma is rarely reported and no report was found which dealt with pulmonary metastatic lesion histologically.

Adult↗
PubMed1991

[Regional cerebral blood flow in moyamoya disease using 123-I IMP-SPECT--follow up study before and after therapy].

The recent development of a new radiopharmaceutical 123 I-isopropyl-p-iodoamphetamine (IMP), which is taken up by the brain from the blood flow, has offered a possibility of constructing scintigraphy maps of regional cerebral blood flow (rCBF) using single photon emission CT. We evaluated the clinical utility of this method in moyamoya disease. Five patients with moyamoya disease, who were examined by IMP-SPECT before and after bypass operations, were selected. On the IMP images before operations, all patients showed focal or global decrease of rCBF. There was a good correlation between the area and degree of rCBF abnormalities and severity of clinical symptoms and stage on angiography. The area of rCBF decrease coincided with the dominant area of rebuild-up phenomena on EEG. On the IMP images just after operations, the rCBF changed for the worse transiently in three patients, and the crossed cerebellar diaschisis appeared in two patients. On the IMP images 3 months after operations, the rCBF increased in company with the improvement of clinical symptoms. The increased rCBF on the point of operation was recognized in two patients with good prognosis. These results suggest that IMP-SPECT is a noninvasive and useful method of assessing the effects of therapy as well as the characteristic hemodynamic abnormalities in moyamoya disease.

Amphetamines↗