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Biomedical subjects

T Tani

Publications and source records attributed to T Tani.

At least 289 records · Page 16Linked to original sources
PubMed1989

Effects of S-312, a new calcium antagonist, on the mechanical and electrophysiological responses of isolated cardiovascular preparations.

S-312, a new calcium antagonist with a bicyclic dihydrothienopyridine structure, potently relaxed the helical strips of various isolated rabbit arteries precontracted with high K+-depolarization, serotonin (5-HT) and U46619 (thromboxane A2 analogue), and it competitively inhibited Ca++-induced contractions in depolarized basilar and femoral arteries. These effects of S-312 were more potent than nifedipine and almost comparable to or slightly more potent than those of nicardipine. In comparison with nifedipine and nicardipine, the calcium antagonistic effect and the relaxant effect on 5-HT-induced contractions of S-312 were most prominent in the basilar artery. The potent vasodilating action of S-312 in the high K+-depolarized basilar artery was not easily reversed by washing. S-312 did not affect Ca++-induced contraction in the skinned fiber of guinea pig taenia caecum. The negative inotropic effect of S-312 in isolated guinea pig left atria was much less potent than those of nifedipine and nicardipine. S-312 above 10(-7) M preferentially increased AV nodal conduction time in Langendorff-perfused isolated rabbit hearts; and above 3 x 10(-8) M, it mainly decreased the maximum upstroke velocity of the action potential in isolated rabbit sinus node preparations. In summary, the present results indicate that S-312 is a potent new calcium antagonist possessing vasculoselectivity, especially for cerebral vessels.

Animals↗
PubMed1989

Effects of S-1389 (711389-S), a new antiarrhythmic agent, on the conduction in perfused guinea pig hearts.

In the His bundle and ventricular electrograms of Langendorff-perfused guinea pig hearts driven at a cycle length of 450 or 700 msec, S-1389 (711389-S), a new antiarrhythmic agent, above 3 x 10(-7) or 10(-6) M increased the basal conduction times in the following order: His-Purkinje system greater than ventricular and atrial muscles greater than atrioventricular (AV) node. Slowing of the ventricular and AV nodal conduction of extrasystoles with variable coupling intervals was also caused by S-1389. S-1389 above 10(-6) or 3 x 10(-6) M significantly prolonged the functional and/or effective refractory periods of the AV node and ventricle. Disopyramide (3 x 10(-6)-3 x 10(-5) M) also produced similar effects, but they were much less potent than those of S-1389. Although disopyramide did not produce the rate-dependent increases in the atrial and AV nodal conduction times and in the AV nodal refractory period, S-1389 increased these parameters rate-dependently.

Animals↗
PubMed1989

New approach to endotoxic and septic shock by means of polymyxin B immobilized fiber.

Endotoxin shock therapy has not been successfully dealt with pharmacologically. Circulation of endotoxins in the blood is an important factor in the pathogenesis and clinical symptoms of endotoxic shock. We have recently developed polymyxin immobilized fiber (PMX-F) as a biomaterial for selectively detoxifying endotoxins. In ex vivo experiments, direct hemoperfusion (DHP) by PMX-F was performed on dogs injected with purified endotoxin. Only one of eight survived in the control group, but ten of 12 survived in the group receiving DHP with PMX-F. Mortality in the treated group decreased remarkably. Thus, the results indicate the efficacy of PMX-F in neutralizing endotoxins. By the same method as already mentioned, DHP with PMX-F was carried out on live dogs with Escherichia coli induced sepsis. All of the dogs in the control group died within 18 hours after bacterial infusion. All of the dogs in the treated group, however, survived for more than three days. Two of the five dogs are still alive. One of the remaining two survived for seven days and the other, 14. We found that PMX-F treatment prolonged or increased the survival rate in the endotoxic and septic dogs.

Animals↗
PubMed1989

[Analysis of prognostic factors in patients with hepatocellular cancer treated by hepatic arterial infusion chemotherapy].

Analyses of the prognoses of thirty-four patients with hepatocellular cancer, who were treated by hepatic arterial infusion chemotherapy and/or transcatheter arterial embolization (TAE) and/or hyperthermotherapy, were performed by multivariate analysis using Cox's proportional hazard model and generalized Wilcoxon test. In the multivariate analysis on the conditions of patients, nine of fifteen variables were associated with the prognosis of patients who received regional cancer chemotherapy. The variables are: sex, liver cirrhosis, esophageal varices, GOT, GPT, albumin and gamma-globulin. One of three variables was associated with the prognosis in the therapy analysis, and the variable is TAE. Significant differences in survival curves which were estimated by generalized Wilcoxon test were noted in age, portal vein invasion, ascites, GOT and TAE. From these results it is suggested that the conditions of patients with unresectable hepatocellular cancer must be carefully investigated before regional cancer chemotherapy and the good therapy effects is obtained by hepatic arterial infusion chemotherapy combined with transcatheter arterial embolization therapy.

Aged↗
PubMed1989

[Usefulness of endotoxin removal from the septic blood with direct hemoperfusion using PMX-F].

UNLABELLED: Sepsis and septic shock have been drugs difficult to treat despite many our therapeutic methods. There are many drugs for sepsis, but few can remove or detoxify such sabstances as endotoxin. The polystyrene fiber immobilized polymyxin B (PMX-F) have been invented and it was already confirmed the stability of its bonding. In this paper, mass-productive PMX-F for the clinical application were estimated. IN VITRO STUDIES: PMX-F adsorbed endotoxin (10ng/ml) from the calf serum, and recombinant tumor necrosis factor (80U/ml) from the serine solution. PMX-F maintained an antimicrobial activities against E.coli sufficiently. Those activities of PMX-F showed significant difference between PMX-F and carrier fiber. But PMX-F could not adsorb histamine and thromboxane B2. In vivo studies: The treatment of endotoxic mongrel dogs showed early recovery in arterial blood pressure, and ameliorated survival rate significantly. In human study, 77-year old male patients who had obstructive jaundice due to recurrent stomach cancer and biliary tract infection by Klebsiella showed sepsis and DIC. During DHP with PMX-F, the change of blood pressure was remarkable better, and platelet counts decreased, but next morning this count recovered completely and he had no hemorrhagic tendency. We believe clinical application of PMX-F is safe and useful.

Adsorption↗
PubMed1989

[A case report of reflex sympathetic dystrophy treated with nifedipine].

Reflex sympathetic dystrophy (RSD) refers to a symptom complex observed after nerve injury and consists primarily of severe burning pain associated with sensory, vasomotor and trophic phenomena. A 54-year-old male had undergone nephrectomy. At surgery left XIth intercostal nerve had been injured by cautery. After a few weeks following surgery, the patient developed progressive deep burning pain, stabbing sensation and dysesthesia in the left abdominal region. Analgesics and narcotics were ineffective. We diagnosed his case as RSD. He received nifedipine 10mg sublingually. Pain relief was obtained within 10min and lasted for 6hs. Consequently, nifedipine therapy was started at a daily dose of 30 to 60mg. His symptoms were markedly improved within 4 weeks. After 3 months his pain resolved. At the present, some pain often returns, but nifedipine is effective. Nifedipine may be useful as a drug for the management of reflex sympathetic dystrophy.

Humans↗
PubMed1988

Identification of a novel class of elastase isozyme, human pancreatic elastase III, by cDNA and genomic gene cloning.

By using porcine elastase I cDNA as a probe, we have isolated two different but closely related cDNAs encoding elastase-like proteases from a human pancreatic cDNA library. The amino acid sequences deduced from the cloned cDNA sequences showed 56-61% identity with those of both pancreatic elastases I and II, similar to the homology between elastases I and II. The active form of the elastase-like proteases appeared to be composed of 242 amino acids and preceded by a signal peptide and propeptide of 28 amino acids. Dot blot analysis of various tissue mRNAs demonstrated that the genes for the cloned cDNAs are expressed at a high level only in the pancreas. In addition, sequence analysis of the cloned genomic genes corresponding to one of the cDNAs showed that they are members of the elastase gene family. These results indicate that the two enzymes encoded by the cDNAs should be classified into a third class of elastase isozyme. Therefore, we designated them as human pancreatic elastases IIIA and IIIB. They strongly resembled cholesterol-binding pancreatic protease, suggesting that they may possess not only a digestive function but also function(s) related to cholesterol metabolism or transport in the intestine.

Amino Acid Sequence↗
PubMed1988

[Clinicopathological evaluation of angiograms in hepatocellular carcinoma].

Hepatocellular carcinoma (HCC) was classified into the three types of expansive type "Exp", mixed type "Mix" and infiltrative type "Inf" according to the preoperative angiographic characteristics, referred to clinicopathological features. "Exp" type had less incidence of accompanied portal venous invasion and daughter nodules in comparison to "Inf" type. And "Exp" type had a better prognosis in the cumulative survival rate than "Inf" type (p less than 0.001). Thus, the present typing essentially classified by tumor vascular architecture represents "malignancy grade" of HCC. In addition, "Inf" type may be recommended more extensive resection or multidisciplinary therapy (for example TAE) for better prognosis.

Adult↗
PubMed1988

Development of artificial mastication system. Construction of one degree of freedom antagonistic muscle model WJ-O.

The authors have determined that there are 2 levels of control systems in mastication; the muscle control system as the lower level system and the mastication control system as the upper level system. And the authors made an experiment of the muscle control system as the first step of an artificial mastication system. The purpose of this paper is to propose the artificial muscle model which uses as DC motor under the control of position, velocity and force feedback.

Humans↗
PubMed1988

[An experimental study of spinal cord traction syndrome].

An experimental study was carried out on the pathophysiology of spinal cord traction syndrome. In fifty dogs, spinal cord traction impairment was created by gradual lumbosacral cord traction. Physiological integrity of the spinal cord was monitored and recorded by the spinal evoked potentials. The earliest change of the spinal evoked potentials and lumbar roots potentials was transient augmentation of the amplitude. With greater traction force, the potentials gradually decreased in amplitude. The spinal cord vulnerability to compression was increased by spinal cord traction. Under 200 g traction, the vulnerability of the lower thoracic cord was most increased while those of the upper thoracic and lumbar cord were unchanged. The authors conclude that tethered cord syndrome is caused by the impairment of the spinal cord and lumbosacral roots due to traction, and that spinal cord traction not only causes spinal cord impairment but increases the spinal cord vulnerability to compression.

Animals↗
PubMed1987

A sensitive method for quantitation of steroid hydroxylase activities of individual P-450 in tissue homogenates.

Assay methods which allow measurements of the level of individual P-450's in a homogenate of steroidogenic tissues have been developed. The assay is based simply on the determination of the specific products of steroid monooxygenase reactions under conditions in which sufficient amounts of the purified electron-donating components as well as lipids and detergents are supplemented so that the membrane-associated P-450 is able to exhibit its maximum activity. Under these conditions, an at least 10-fold increase in the NADPH-dependent monooxygenase activity of P-450 occurred as compared to that measured in the unenriched system. In addition, the present assay used ascorbate as an O2- -scavenger which effectively prevented possible inhibition caused by initiation of O2- -formation. Under the present assay conditions, nearly quantitative recovery of activities was accomplished of each purified P-450 that had been added to the homogenates as an internal standard. Furthermore, the high sensitivity of this assay allows the measurement of P-450 in small specimens (at least 100 mg of tissues), and could be used for measurements in autopsied cases or the glands of small animals.

Adrenal Glands↗
PubMed1987

Characterization of pancreatic elastase II cDNAs: two elastase II mRNAs are expressed in human pancreas.

The primary structures of porcine and human pancreatic elastase II precursors were elucidated by molecular cloning and cDNA sequence analysis. The sequences of the cDNAs cloned from a human pancreatic cDNA library indicate that at least two elastases II are expressed in this tissue. These two human elastases II have been designated elastases IIA and IIB. All the cDNA sequences obtained, including porcine elastase II cDNA, reveal that elastase II is synthesized as a preproenzyme of 269 amino acids, including a predicted signal peptide of 16 amino acids and a predicted activation peptide of 12 amino acids. Human elastase IIA contains the published amino-terminal sequence (16 residues) for human pancreatic proelastase II, whereas elastase IIB shares 50% homology with the published 16-residue sequence. However, there is 90% homology between the overall amino acid sequences of elastases IIA and IIB. Blot hybridization analysis of the poly-adenylated RNAs isolated from various human tissues demonstrates that the human elastase II mRNAs are specifically detected in the pancreas.

Amino Acid Sequence↗
PubMed1987

Characterization of a silent gene for human pancreatic elastase I: structure of the 5'-flanking region.

A cDNA for porcine pancreatic elastase I has been cloned and used as a probe for blot hybridization analysis. Southern blot analysis of total DNA demonstrated that the elastase I gene is conserved among the porcine, rat, calf, and human genomes. Northern blot analysis, however, indicated that the elastase I gene is not expressed in the human adult pancreas, even though abundant expression is observed in the rat and porcine pancreas. Sequence analysis of the cloned human elastase I gene revealed that the proximal 5'-flanking region from -1 to -200 shows 78% identity with that of the actively transcribed rat elastase I gene, and contains a consensus TATA box and a putative tissue specific enhancer sequence. The transcriptional activity of the human elastase I gene appears to be suppressed in the human adult pancreas.

Amino Acid Sequence↗
PubMed1987

Antimicrobial activity of tertiary amine covalently bonded to a polystyrene fiber.

Tertiary amine was covalently bonded to a polystyrene fiber and examined for antibacterial activity. The tertiary amine covalently bonded to a polystyrene fiber (TAF) showed a high antimicrobial activity against Escherichia coli. TAF exhibited a stronger antibacterial activity against gram-negative bacteria (E. coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhimurium, and Serratia marcescens) than against gram-positive bacteria (Staphylococcus aureus and Streptococcus faecalis) or Candida albicans. This activity against E. coli was accentuated by 0.1% deoxycholate or 10 mg of actinomycin D per ml, to which E. coli is normally not susceptible. This implies that TAF causes an increase of the bacterial outer membrane permeability. On the other hand, the antimicrobial activity was inhibited by adding Mg2+ or by lowering the pH. This suggest an electrostatic interaction between the bacterial cell wall and TAF. Scanning electron microscopy showed that E. coli cells were initially attached to TAF, with many projections on the cell surface, but then were apparently lysed after contact for 4 h. Taken together, these results imply that bacteria initially interact with TAF by an electrostatic force between the anionic bacterial outer membrane and the cationic tertiary amine residues of TAF and that longer contact with TAF damages the bacterial outer membrane structure and increases its permeability.

Anti-Bacterial Agents↗