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Biomedical subjects

T Okano

Publications and source records attributed to T Okano.

At least 325 records · Page 18Linked to original sources
PubMed1991

Metabolism and transporting system of 22-oxacalcitriol.

The binding potencies of OCT to chick intestinal calcitriol receptor and vitamin DBP were approximately 1/8 and 1/600 of the respective values of calcitriol. OCT is circulating mainly as an intact form bound to chylomicrons and/or lipoproteins. Intravenously injected [3H]-OCT to normal rats was quickly decreased from blood and rapid excretion of OCT as a glucuronate into bile was observed. However, significant amounts of radioactivities were recovered in the intact form in liver and intestine even after 24 h. The separation of calcemic and immune and/or differentiation activities may be derived from the rapid turnover and the nonspecific transporting system.

Animals↗
PubMed1991

Serum immunosuppressive acidic protein as a tumor marker for renal cell carcinoma.

Since there are no reliable tumor markers in renal cell carcinoma, the present study was undertaken to evaluate immunosuppressive acidic protein (IAP) in patients with this tumor. Serum IAP levels were measured in 143 consecutive patients before and/or after nephrectomy by turbidimetric immunoassay. IAP levels had increased according to tumor diameter. Positivity rates of IAP were noticed as 45%, 75%, and 100% for patients with stage I/II, stage III, and stage IV diseases, respectively. Three-year survival rates also correlated with IAP: 96%, 81%, and 44% in preoperative levels below 500, of 501-1,000, and of more than 1,001 micrograms/ml, respectively. Serum IAP levels decreased within 3 months after the operation and increased with recurrence. These results suggest that serum IAP may serve as a tumor marker in patients with renal cell carcinoma.

Adult↗
PubMed1991

Preparation and biological activity of 2-[4-(thiazol-2-yl)phenyl]propionic acid derivatives inhibiting cyclooxygenase.

A series of 2-[4-(thiazol-2-yl)phenyl]propionic acids substituted at various positions were prepared by the reaction of diethyl 2-methyl-2-(4-thiocarbamoylphenyl)malonates with alpha-bromoaldehyde diethyl acetals or alpha-haloketones followed by hydrolysis of esters. The inhibition of prostaglandin H synthetase (cyclooxygenase) was assayed by use of an enzyme preparation from guinea pig polymorphonuclear leukocytes. Examination of the structure-activity relationship of these compounds indicated that the substitution pattern with halogens at position 3 (R1) of the benzene ring and a methyl group in position 4 (R2) and/or 5 (R3) of the thiazole ring were favorable for inhibitory activity. The compounds bearing bulky alkyl or polar functional groups at the R2 position were weak inhibitors. The potent inhibitors of cyclooxygenase were tested for their ability to reduce carrageenin-induced inflammation of rat paws. These derivatives had strong anti-inflammatory activity based on their strong inhibition of cyclooxygenase, with some exceptions, including those with a thiomethyl group at R1.

Animals↗
PubMed1991

Separation of mounting-inducing pheromones of vaginal mucus from estrual heifers.

There is evidence that mucus of the female bovine genital tract contains pheromones that induce physiological and behavioral responses in other animals. To study these pheromones, vaginal mucus was collected from heifers either at estrus or during diestrus. The mucus was then applied to the hindquarters of the same animal during diestrus or to the hindquarters of herdmates during diestrus. The behaviors of the treated animal and its herdmates were then observed. To attempt to isolate the mounting-inducing substance, mucus was dialyzed or separated on ion-exchange resins. Diestrous heifers to which their own estrual mucus has been applied were nearly always mounted by herdmates (P less than .01). But, heifers to which another's estrous mucus had been applied were not mounted. This suggests that vaginal mucus contains not only estrus-related pheromones, but also individual distinctive odors. The dialyzable fraction of vaginal mucus and the neutral fraction, prepared by ion-exchange chromatography of the dialyzable solution of vaginal mucus, had a mounting-inducing activity on the herdmates, as did the application of an animal's own vaginal mucus. These findings suggest that mounting-inducing pheromones are relatively low molecular weight, neutral substances.

Animals↗
PubMed1991

Self-regulated delivery of insulin from microcapsules.

We previously developed self-regulating insulin delivery systems using concanavalin A (Con A)-bound succinyl-amidophenyl-glucopyranoside insulin (SAPG-insulin) in pouch membrane which exhibited long lag times for exchange diffusion in response to glucose changes. We report here the preparation of a new system with a short exchange diffusion onset composed of hydrophilic nylon microcapsules containing Con A and SAPG-insulin in vitro. It is considered that this SAPG-insulin system can quickly respond to glucose changes when it is composed of at least two layers which include active Con A and where unbound SAPG-insulin permeation is the rate limiting step.

Blood Glucose↗
PubMed1991

[Urinary cytology in patients with urolithiasis].

Urinary cytological examination was performed on 1032 patients of urolithiasis at the Department of Urology, Chiba University Hospital between 1980 and 1990. Seven hundred twenty-four were male and 308 were female, and the mean age was 44 years. The results of cytological examination of I-II and IV-V were classified as negative and positive, respectively. Eleven patients (1.1%) were positive, 2 of whom were found to be with renal pelvic tumor. False-positive findings were noticed in 9 cases (0.9%), and the abnormal cytologic changes in these cases disappeared after the calculi were removed. In negative cytological cases, 2 cases of renal pelvic tumor were found, one at nephrectomy and the other at percutaneous nephrolithotripsy. These cases were with staghorn calculi with hydronephrosis. The significance of cytological examination in management of calculous diseases were discussed.

Aged↗
PubMed1991

[Regional lymphadenectomy for renal pelvic and ureteral cancers].

Thirty-four patients with renal pelvic and ureteral cancers received regional lymphadenectomy since 1980. The patients consisted of 21 with renal pelvic cancers, 10 with ureteral and 3 with renal pelvic and ipsilateral ureteral. Fifteen patients (44.1%) had metastatic nodes: 13 with renal hilar or para-aortic metastases and 2 with pelvic nodal involvements only. Thirteen of these 15 patients with nodal metastasis had high grade tumors and 14 had high stage tumors. The 5-year survival rate of these 15 patients was 26.3% which was considerably poor when compared with 19 patients without metastasis. Twenty patients with high grade and high stage tumors who received respective operations with regional lymphadenectomy had significantly better prognosis compared with the historical control group (15 patients, from 1961 to 1979). Additional regional lymphadenectomy for renal pelvic and ureteral cancers appears to be a valuable operation for improving prognosis.

Adult↗
PubMed1991

Superoxide generation in leukocytes and vitamin E.

Superoxide generation in polymorphonuclear cells (PMNs) can be detected through determination of chemiluminescence by stimulation with opsonized zymosan in association with the Cypridina luciferin analogue, 2 methyl-6-phenyl-3,7-dihydroimidazol[1,2-a]pyradin-3-one. Following the addition of vitamin E to cell suspensions, chemiluminescence was suppressed by a vitamin E concentration of more than 80 micrograms/10(9) cells. Superoxide production in PMNs was suppressed by both very low and very high levels of vitamin E (less than 2 micrograms/10(9) cells and more than 50 micrograms/10(9) cells, respectively). The high level of more than 50 micrograms/10(9) cells, which may be a dangerous level, was attained only by the intramuscular administration of 50 mg/kg/day for three days in rats. Young human adults (who received 600 mg/day for 3 months) or premature infants (who received 40 mg/kg/day for 8-14 days) developed PMN vitamin E concentrations not exceeding 30 micrograms/10(9) cells, and chemiluminescence was not affected. This indicates that oral administration of vitamin E does not impair PMN function, even in preterm infants. On the other hand, there was no enhancement of PMN function in premature infants and adults after vitamin E supplementation.

Administration, Oral↗
PubMed1991

[Removal of renal cell carcinoma extending into the right atrium: report of a case].

A 65-year old man presented with a seven-month history of macrohematuria and left back pain. Abdominal ultrasonography, enhanced computed tomographic (CT) scanning, magnetic resonance imaging (MRI), selective renal angiography and vena cavography revealed a left renal tumor extending into the inferior vena cava and right atrium. Surgery was performed using the cardiopulmonary bypass and the whole tumor was resected grossly except for the tumor invading into the lumbar vein. The patient recovered promptly but died from cancer metastasis six months after operation.

Aged↗
PubMed1991

[Results of radical nephrectomy associated with regional lymphadenectomy for renal cell carcinoma].

Between January, 1975 and December, 1989, 86 patients with renal cell carcinoma received radical nephrectomy associated with lymphadenectomy at our institutions. Pathological examination revealed lymph node metastasis in 15 patients (17.4%). The incidence of lymph node metastasis increased in accordance with the aggravation of tumor stage (p less than 0.01) and grade (p less than 0.05). Patients with a rapidly growing tumor showed higher incidence of lymph node metastasis than patients with a slow growing tumor (p less than 0.01). Regional lymph node metastases were found in 3 of the 41 patients with a slow growing tumor. Since these 3 patients are surviving with no evidence of disease for 38.7 months on average, the regional lymphadenectomy was considered to have been effective for their survival. Nine of the 25 patients with a rapid growing tumor had progressive lymph node metastasis. Four of them had apparent tumor thrombi as well as lymph node metastasis, and 2 of them had distant metastasis. These patients showed poor prognosis even after operation. Lymphadenectomy was of no value to the patients with apparent tumor thrombi and/or distant metastasis.

Adult↗
PubMed1991

[A case report of anomalous left brachiocephalic vein].

An anomalous case of a left brachiocephalic vein passing behind the ascending aorta was observed in a 49-year Japanese man. This is known as anomalous left brachiocephalic vein. The anomalous left brachiocephalic vein descended along the left mediastinum in a position identical to that of a persistent left superior vena cava, so the diagnosis of this venous abnormally require carefully considered. Many cases of anomalous left brachiocephalic vein have been reported based on autopsy findings, but this venous anomaly was recently demonstrated by ultrasonography, CT, and MRI.

Brachiocephalic Veins↗
PubMed1991

[A case of cystic hygroma of the chest wall].

Hygroma is generally regarded as a benign tumor occurring favoritely in the cervical region of a child. Recently we have experienced a case of hygroma which was initially detected as a right chest wall tumor in a 16-year-old man, then was surgically diagnosed as cystic hygroma; chest roentgenography on a check up examination in his senior high school pointed out some anomaly, leading to his hospitalization. On admission, he had no subjective symptom, but chest roentgenography and CT confirmed an abnormal shadow in the right pulmonary area and a tumor with calcification on the right chest wall, respectively, so he was operated on for excisional biopsy. The tumor was extirpated together with the 7th intercostal muscle adhered to the tumor, and postoperative pathohistological examination led to diagnosis as cystic hygroma. Cystic hygroma of the chest wall is so rare that we would like to report this case, together with some addition consideration of related literature.

Adolescent↗
PubMed1990

Phosphorylation of iodopsin, chicken red-sensitive cone visual pigment.

The amino acid sequence has been determined for the carboxyl-terminal 41 amino acids of chicken red-sensitive cone pigment, iodopsin. This sequence is distinct from but structurally homologous to that of other visual pigments. It contains a region rich in the hydroxy amino acids serine and threonine. In the related rod cell visual pigment, rhodopsin, such serines and threonines have previously been identified as sites for phosphorylation by rhodopsin kinase. Phosphorylation of photolyzed rhodopsin serves to terminate its ability to function in visual transduction as an activator of G-protein. We have purified and reconstituted both chicken rhodopsin and chicken iodopsin and shown them to be phosphorylated by bovine rhodopsin kinase. Chicken iodopsin has a Km and Vmax similar to but distinguishably different from that for bovine rhodopsin. These results, in conjunction with other data, suggest that visual pigments in cone cells, upon absorption of light, undergo functional processes similar to those of the visual pigments in rod cells.

Amino Acid Sequence↗
PubMed1990

The primary structure of iodopsin, a chicken red-sensitive cone pigment.

A purified iodopsin was digested by CNBr or several proteolytic enzymes into fragments, the amino acid sequences of which were determined. A partial sequence of the C-terminal fragment was utilized for synthesizing an oligonucleotide probe which identified the iodopsin cDNA (1339 bases). The deduced amino acid sequence (362 residues) had 80%, 42%, or 43% homology to that of human red-sensitive cone pigment, cattle or chicken rhodospin, respectively. Although the hydropathy profile implies that iodopsin, like rhodopsin, has 7 transmembrane alpha-helical segments, iodopsin may have a hydrophilic pocket near the seventh segment on the basis of the unexpected cleavages in the middle of the segment VII by chymotrypsin under nondenaturing conditions.

Amino Acid Sequence↗
PubMed1990

Comparative study on the chromophore binding sites of rod and red-sensitive cone visual pigments by use of synthetic retinal isomers and analogues.

A comparative study on the chromophore (retinal) binding sites of the opsin (R-photopsin) from chicken red-sensitive cone visual pigment (iodopsin) and that scotopsin) from bovine rod pigment (rhodopsin) was made by the aid of geometric isomers of retinal (all-trans, 13-cis, 11-cis, 9-cis, and 7-cis) and retinal analogues including fluorinated (14-F, 12-F, 10-F, and 8-F) and methylated (12-methyl) 11-cis-retinals. The stereoselectivity of R-photopsin for the retinal isomers and analogues was almost identical with that of scotopsin, indicating that the shapes of the chromophore binding sites of both opsins are similar, although the former appears to be somewhat more restricted than the latter. The rates of pigment formation from R-photopsin were considerably greater than those from scotopsin. In addition, all the iodopsin isomers and analogues were more susceptible to hydroxylamine than were the rhodopsin ones. These observations suggest that the retinal binding site of iodopsin is located near the protein surface. On the basis of the spectral properties of fluorinated analogues, a polar group in the chromophore binding site of iodopsin as well as rhodopsin was estimated to be located near the hydrogen atom at the C10 position of the retinylidene chromophore. A large difference in wavelength between the absorption maxima of iodopsin and rhodopsin was significantly reduced in the 9-cis and 7-cis pigments. On the assumption that the retinylidene chromophore is anchored rigidly at the alpha-carbon of the lysine residue and loosely at the cyclohexenyl ring, each of the two isomers would have the Schiff-base nitrogen at a position altered from that of the 11-cis pigments.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗