Search PubMed⌕ Search

Biomedical subjects

T Tani

Publications and source records attributed to T Tani.

At least 271 records · Page 15Linked to original sources
PubMed1990

Potentiation of anti-platelet aggregating activity of cilostazol with vascular endothelial cells.

We developed the new system in which the platelet aggregation was detected turbidimetrically using glass cuvettes which were coated cultured vascular endothelial cells. Using this system, we evaluated the effect of cilostazol, having a selective inhibitory effect on cAMP-PDE, on the ADP-induced platelet aggregation in the presence of endothelial cells. Cilostazol inhibited the platelet aggregation dose-dependently in the presence or absence of endothelial cells. The inhibitory effect of cilostazol on platelet aggregation was potentiated by the presence of endothelial cells, and the slope of the dose-response curves were identified to be as the same between both experiments in the presence and the absence of endothelial cells. The pretreatment of endothelial cells with aspirin reversed the potentiated inhibitory effect of cilostazol on the platelet aggregation with endothelial cells. The amount of 6-keto-prostaglandin F1 alpha accumulated in the cuvette was reduced in this condition. On the other hand, the inhibitory effect of prostaglandin E1 on the platelet aggregation was not potentiated by the presence of endothelial cells. These results suggest that the endothelium-derived prostacyclin plays a role on the potentiation of anti-platelet aggregatory effect of cilostazol.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1990

An intron-containing Schizosaccharomyces pombe U6 RNA gene can be transcribed by human RNA polymerase III.

A Schizosaccharomyces pombe U6 small nuclear RNA gene containing an intron has been described. We find that the S. pombe U6 gene is transcribed in a human (HeLa) cell S100 extract with an alpha-amanitin sensitivity characteristic of RNA polymerase III. The S. pombe U6 gene is also transcribed after transfection into human cells. The transcription of vertebrate U6 RNA genes by RNA polymerase III does not require intragenic control elements. The intron of the S. pombe U6 gene disrupts a "box A"-like intragenic sequence that is typically an RNA polymerase III transcription control element. This, together with the transcription of the S. pombe U6 gene by human RNA polymerase III, suggests that it is recognized by human U6 gene-specific transcription machinery.

Amanitins↗
PubMed1990

Trial of anticancer immunotherapy with immobilized pokeweed mitogen: immunotherapy by extracorporeal circulation.

For the purpose of activating the immune system in the living body, we made use of pokeweed mitogen (PWM). PWM, a type of lectin, has the potential to induce anticancer cells. In order to utilize this potential and apply it to cancer therapy by hemoperfusion with PWM, the lectin is immobilized on the surface of synthetic polymer beads and these beads are packed into a minicolumn. Human peripheral lymphocytes were activated by circulatory contact stimulation through the PWM column for 1h. After circulatory contact stimulation through the column, lymphocytes were collected and used as effector cells. Cytotoxicity tests were measured by 51Cr-release assay using K-562 cells and Daudi cells for targets. This material could enhance natural killer activity and induce cytotoxicity against natural-killer-resistant Daudi cells. Lymphocytes activated by the PWM column were injected intraregionally into nude mice bearing MKN-1 tumor, and suppression of tumor growth was recognized. Anticancer activities by direct hemoperfusion treatment with a PWM minicolumn were examined in Vx2-tumor-bearing rabbits. A single treatment using the PWM column was performed 6 days after tumor inoculation. Suppression of the tumor growth was observable for 25 days. PWM minicolumns are a likely anticancer material, acting as immunomodulators.

Animals↗
PubMed1990

Effects of free fatty acids on the binding of steroid hormones to bovine serum albumin.

The effects of binding of free fatty acids (FFA) to bovine serum albumin (BSA) on steroid hormone binding to BSA were examined. The FFA studied included myristic, palmitic, stearic, oleic and linoleic acids. The binding coefficient K was estimated from the changes in the equilibrium partition coefficient between the aqueous and the hexane phase caused by the addition to BSA to the aqueous phase. A noticeable effect of FFA binding (molar ratio FFA/BSA, 2:1) on the affinities of alpha-estradiol, ethynylestradiol and dehydroisoandrosterone to BSA was not observed: however, the affinities of progesterone, androsterone and testosterone were distinctly enhanced by FFA binding. Furthermore, the elution profiles of gel filtration chromatography clearly showed that progesterone and testosterone are easily liberated from the hormone/BSA complexes and that stronger binding of these hormones to BSA is caused by binding of FFA to BSA. The affinity of ethynylestradiol to BSA is stronger than that of progesterone and testosterone and is not affected by palmitic acid binding to BSA.

Androgens↗
PubMed1990

Effects of formaldehyde on cardiac function.

This investigation examined the effect of formaldehyde (HCHO) on cardiac function in in vitro cardiac preparations and in situ hearts of guinea pigs and rabbits. Though HCHO (0.2-4 mg/kg, i.v.) produced noticeable bradycardiac and negative inotropic responses in anesthetized guinea pigs and rabbits, the responses to HCHO were far less in isolated guinea pig auricles and perfused hearts (Langendorff's preparations). The inhibitory responses to HCHO in the isolated auricles and perfused hearts were obtained at concentrations 200-400 times and 4-8 times higher than the blood concentrations attained in anesthetized animals, respectively. The responses in the isolated preparations were not significantly affected by propranolol. The bradycardiac response to the intravenously administered HCHO in anesthetized animals was not significantly affected by atropine or vagotomy, but was markedly attenuated by propranolol, reserpine or surgical denervation of the heart. These results indicate that the direct action of HCHO on the heart plays only a small role in the negative chronotropic response to HCHO in anesthetized animals. Furthermore, the negative chronotropic effect of HCHO in animals seems to be caused mainly by the inhibition of sympathetic nervous activity through the central nervous system.

Anesthesia↗
PubMed1990

Effect of gamma-oryzanol on atheroma formation in hypercholesterolemic rabbits.

The anti-oxidant action of ferulic acid in gamma-oryzanol was tested in hypercholesterolemic rabbits to determine its effects on the development of atherosclerosis. Eighteen male New Zealand white rabbits were fed a diet containing 1% cholesterol with or without 1% gamma-oryzanol for 10 weeks. The anti-oxidant effect was assessed by the degree of resistance of low density lipoprotein (LDL) to oxidation by copper sulfate and the effect of the copper oxidized LDL on the incorporation of oleate into cholesteryl ester by mouse peritoneal macrophages. In addition, the levels of plasma cholesterol, triglyceride and lipid peroxide were measured before, during and at the end of cholesterol loading. The amount of free ferulic acid and gamma-oryzanol in plasma and LDL and the area of aortic atherosclerotic plaques were determined. It was found that oleate incorporation into cholesteryl ester by macrophages was significantly reduced in the gamma-oryzanol-treated group compared to the non-treated group, and that the reduction was via a mechanism independent of anti-oxidant action. However, no differences were found in the levels of plasma cholesterol, triglyceride, lipid peroxide or in the areas of atherosclerotic plaques between the two groups. It was concluded that gamma-oryzanol has little or no preventive effects on atherosclerosis in rabbits.

Animals↗
PubMed1990

[The spinal monosynaptic reflexes elicited from the tibialis anterior muscle--standardization of the reflexes and diagnostic use in L5 radiculopathy].

The spinal monosynaptic reflexes evoked in the tibialis anterior muscle were investigated to establish a practical method for assessing L5 radiculopathy. Voluntary contraction and averaging technique made it possible to consistently obtain the H-and T-reflexes from the muscle in which these reflexes are normally unelicitable at rest. Based on the study of fifty normal subjects, formulae were produced by an analysis of the simultaneous regression of the latencies of these reflexes on height and age, because these latencies were highly correlated with them. A side-to-side latency difference of the H-and T-waves greater than 1.5 msec. and 2.3 msec. respectively, and/or low amplitude less than 26% and 39% of the amplitude of the contralateral side respectively, could be considered abnormal. According to these criteria, eight out of twelve patients (67%) with unilateral compressive L5 radiculopathy showed abnormalities.

Electrophysiology↗
PubMed1990

[A case of primary early duodenal cancer].

Reported is a case of a suprapapillary primary early duodenal cancer in a 50 year old male patient who had had a hemicolectomy 15 years earlier for a colon cancer. The patient had undergone upper gastrointestinal endoscopy during a mass screening for abnormalities in the gastro-intestinal tract, and a slightly depressed lesion of the IIa + IIc type, 25 x 20 mm in diameter, was discovered accidentally at the superior duodenal flexure. The subsequent biopsy revealed a well differentiated tubular adenocarcinoma. Thus, the patient underwent a subtotal gastrectomy and a partial duodenectomy with a lymph node dissection. The histology of the resected specimen was the same as that of the biopsy, but only the mucosa was involved. Adenomatous lesions of the colon are known to occasionally accompany upper gastro-intestinal tumor, so that periodic gastro-intestinal scrutiny follow-ups are mandatory.

Adenocarcinoma↗
PubMed1990

[Chronic gastritic changes induced in rats after pyloromyotomy and per os administration of acetic acid-glycerin].

We have experimentally studied whether or not repeated episodes of acute gastric mucosal lesions can induce chronic gastritic changes. Rats received pyloromyotomy and repeated per os administration of acetic acid-glycerin. Gastric mucosal lesions thus induced were studied histopathologically in cardiac glandular areas using morphometric analysis. It was found that pyloromyotomy induced fibrosis between the bottom of the gland and muscularis mucosa. On the other hand, the per os administration of acetic acid-glycerin induced hyperplastic change of mucous neck cells. They were increased in number and in size. Distribution of mucous neck cells were distended vertically to the mucosal surface and towards the bottom of the gland. Greater the amount of acetic acid-glycerin administration, stronger the changes of mucous neck cells, i.e., the distended zone of mucous neck cells spread more and more from the cardiac area. Parietal and chief cells were decreased in number in the course of the mucous neck cell hyperplasia. Branching of glands was occasionally seen in rats receiving greater amount of acetic acid-glycerin. It was concluded that there are basic structural similarity between the gastric mucosal changes induced by repeated episodes of acute gastric mucosal lesions and the change seen in human chronic gastritis. Thus acute gastric mucosal lesions can be one of the cause of chronic gastritis.

Acetates↗
PubMed1990

Therapeutic plasmapheresis for post-operative hepatic failure.

It goes without saying that post-surgical hepatic failure must be treated. But today, the prognosis is very poor. The reasons for this are that HF is usually accompanied by hemostatic disorders and PHF, and the patients have fresh wounds and are under surgical stress. Moreover, there is no treatment, except PE, and this requires an anticoagulant. Nafamostat Mesilate (FUT-175) was invented as a serine protease inhibitor. It is short acting, and its degradation does not require the liver. FUT-175 was applied as an anticoagulant to 15 PHF patients with bleeding. There were no side effects and no aggravation of bleeding. Based on these results, FUT-175 is thought to be an ideal anticoagulant.

Anticoagulants↗
PubMed1990

[Cell proliferation in a triple gastric cancer--a study using the isolated organ perfusion system].

So as to study the cell proliferation in a case with triple gastric cancers, we labeled an operated whole stomach with bromodeoxyuridine (BrdU) by the isolated organ perfusion system using artificial blood. Anti-BrdU immunohistochemical staining of sections from every part of the stomach was performed, and 3 separated cancerous lesions were all diagnosed as well differentiated adenocarcinomas. The labeling index (L.I.) of the cancerous lesions were found to differ from part to part. However, the L.I. tended to be higher in the superficial mucosal areas and in the cell-dense areas of the submucosa. In the almost normal fundic glands, the labeled zone was localized in the neck of the glands. The more metaplastic gastritis was advanced, the more the labeled zone shifted irregularly toward the bottom of the glands. Whenever the interstinal metaplasia was completed, the labeled zone was localized in the bottom of the glands. This method was found useful in studying the cell proliferation in the stomach without causing any harm to the human body.

Adenocarcinoma↗
PubMed1990

[Changes in arterial thromboxane B2 and 6-keto-prostaglandin-F1 alpha levels in cirrhotic and non-cirrhotic patients after hepatectomy].

Following hepatectomy, arterial concentrations of thromboxane B2(TXB2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), which are stable metabolites of thromboxane A2(TXA2) and prostaglandin I2(PGI2), were measured by radioimmunoassay in 17 cirrhotic and 9 non-cirrhotic patients to assess the role of TXB2 and PGI2 in patients with liver dysfunction during hepatectomy. In both cirrhotic and non-cirrhotic patients, arterial TXB2 and 6-keto-PGF1 alpha levels significantly increased during hepatectomy and decreased to preoperative levels at the 1st postoperative day (1-POD). The TXB2/6-keto-PGF1 alpha ratio significantly decreased during hepatectomy and at 1-POD. There were no significant differences in changes of TXB2 and PGI2 levels between cirrhotic and non-cirrhotic patients. In cirrhotic patients with poor hepatic reserve, whose ICG K values were less than 0.08, arterial 6-keto-PGF1 alpha levels were significantly higher and the ratio were significantly lower than in cirrhotic patients with good hepatic reserve and non-cirrhotic patients before and after operation. Based on these results, it is concluded that the TXA2/PGI2 ratio becomes low after hepatectomy and the ratio is lower in cirrhotic patients with poor hepatic reserve.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

The gene for the U6 small nuclear RNA in fission yeast has an intron.

The small nuclear RNAs (snRNAs) are a class of metabolically stable small RNAs present in the nuclei of eukaryotic cells. In mammalian cells, there are six major molecular species (U1 to U6 snRNA), which are complexed with proteins, forming small nuclear ribonucleoprotein particles, snRNPs. Of these, the U1, U2, U4, U5, U6 snRNPs are thought to participate in pre-mRNA splicing as part of the spliceosome. Here, we describe the characterization of the gene coding for the Schizosaccharomyces pombe U6 snRNA. Unexpectedly, the Schiz. pombe U6 RNA gene was found to contain an intron-like sequence of 50 base pairs. Northern blot analysis and RNA sequencing revealed that this intron-like sequence is precisely removed from the transcript. The mature U6 RNA of Schiz. pombe has 77% sequence homology with the mammalian U6 RNA. In Schiz. pombe, it is possible that U6 RNA is not only involved in pre-mRNA splicing, but is also a splicing substrate. This is the first report of an intron in a snRNA gene.

Base Sequence↗
PubMed1989

Postoperative instability of cervical OPLL and cervical radiculomyelopathy.

The presence of cervical spine instability with respect to preoperative and postoperative changes in angular, horizontal, and rotational displacement of the vertebral body were studied. With the anterior approach, the instability in the remaining unfused segments, and their relation to the kyphotic or lordotic fused segment were studied. With the posterior approach, postoperative ROM (range of motion) could be better maintained, and horizontal displacement was improved in more cases by laminoplasty compared with laminectomy. With the anterior approach, the compensatory function for the loss of motion of the segments resulting from fusion was most remarkable at the levels of C2-3 and C6-7. In the alignment of the anterior fused segments, it appears important that the physiologic lordotic position be maintained.

Adult↗
PubMed1989

Experimental study on the adsorption of excess heparin with anion exchange resin fiber.

Anion exchange resin fiber (Ionex) was used as a heparin adsorbent. Ionex has the adsorption capacity of 70 mg/g (weight by desiccation) for heparin, and was used in an attempt to remove the heparin from blood-perfused artificial organs, before the blood was transfused back into the patients. In the ex vivo study, the 5 systemically heparinized dogs (500 U/kg) were treated with a 35-40 g column of Ionex, by direct hemoperfusion (DHP). The concentration of heparin was significantly reduced, within 15 to 60 minutes, using the Ionex. This suggested the possibility of removing excess heparin from the living body. In in vitro, the relationship between the amount of heparin by Ionex and the blood-flow volume were evaluated. Whole blood taken from dogs was added to 5 U/ml of heparin. This was then introduced into a small column containing 0.9 g Ionex, at blood-flow rates of 0.8, 1.6, and 3.2 ml/min. A good adsorption capacity was shown at the blood-flow rate of 0.8 ml/min. One possible explanation for this is that the heparin dispersed in the blood cells gradually was passed on into the plasma and, so, did not have time to be adsorbed at the faster flow rates.

Adsorption↗
PubMed1989

[Transport of steroid hormones by bovine serum albumin as carrier].

The affinities of bovine serum albumin (BSA) with six kinds of steroid hormones (alpha-estradiol, ethynylestradiol, progesterone, androsterone, dehydroisoandrosterone and testosterone) were studied, and BSA was employed as a carrier to transport these hormones through the liquid membrane system, which consists of a hexane sauce phase (I), a BSA solution phase (1/15 phosphate buffer) and a hexane receiving phase (II). These steroid hormones dissolved in hexane were extensively transferred into a water phase containing BSA compared to the case of control (without added BSA). This suggests that these hormones are bound to BSA in a water phase. The ratio of hormone, BSA-binding form/free-form, is in the following order: ethynylestradiol greater than androsterone greater than testosterone greater than progesterone greater than dehydroisoandrosterone greater than alpha-estradiol in the water phase at the equilibrium conditions. The initial rate of hormone transfer from the hexane phase (I) to the water phase is followed by the first-order kinetics, and BSA induces an increase in the transfer rate except for the case of alpha-estradiol and ethynylestradiol. On the other hand, as for the increase rate of hormone concentration in the hexane phase (II), BSA makes the rate of transfer of progesterone faster than that of control, but it makes the rate of transfer of dehydroisoandrosterone more slowly. The results show the transport behaviors of steroid hormones across a water membrane are governed primarily by the partition coefficient between water and hexane phase and the addition of BSA accelerates the transport of hormones in the case of lower partition coefficients.

Androsterone↗