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Biomedical subjects

M Kanno

Publications and source records attributed to M Kanno.

At least 271 records · Page 15Linked to original sources
PubMed1988

Clinical experience of intrahepatic cholangiocarcinoma associated with hepatolithiasis.

Between 1960 and 1986, seven patients with intrahepatic cholangiocarcinoma and one patient with intrahepatic bile duct adenoma, related to hepatolithiasis, were seen among 112 cases of hepatolithiasis. Histopathologically, the tumors associated with hepatolithiasis arose from the periphery of the stone-containing bile duct, spread chiefly along the luminal surface, and invaded the ductal wall or periductal tissue. The tumors showed papillary to papillo-tubular proliferation and were diagnosed as the intraductal or periductal spreading type of cholangiocarcinoma. In addition, atypical epithelial hyperplasia was noted in the vicinity of the tumor area. These findings suggest that chronic relapsing cholangitis in patients with hepatolithiasis can induce progressive changes to atypical epithelial hyperplasia which may develop into cholangiocarcinoma.

Adenoma, Bile Duct↗
PubMed1988

Bone trabecular pattern analysis in Down's syndrome with the use of computed panoramic tomography with a laser scan system. Quantitative analysis with the power spectrum method.

A quantitative analysis of the mandibular bone trabeculae of 44 patients with Down's syndrome and 68 normal persons by means of panoramic tomography was performed with a laser scan system. The results showed that the normal persons exhibited a correlation between the trabecular pattern and aging, whereas the patients with Down's syndrome showed no such correlation. These findings were consistent with geromorphism, which is one of the systemic features of Down's syndrome.

Adult↗
PubMed1988

Isolation of genomic DNA controlling mouse melanoma antigen defined by monoclonal antibody.

We have isolated the genomic DNA controlling the expression of murine specific melanoma antigen by employing cosmid shuttle vector and monoclonal antibody. Transfection of the cosmid library derived from mouse melanoma cells into human melanomas and repeated cell sortings of the fluorescence-bright population enabled us to enrich the antigen-positive transfectants. We rescued a 34.8 kb DNA fragment from the transfectants by in vitro packaging and showed it to be responsible for the antigen expression. However, we noticed instability of the antigen expression when the selection pressure imposed by the cell sorting was removed. This seemed to be due to the fact that the insert DNA was preferentially deleted from this cosmid vector without loss of the vector sequence itself.

Animals↗
PubMed1988

Frequency- and voltage-dependent depression of maximum upstroke velocity of action potentials by pirmenol in guinea pig ventricular muscles.

The frequency-dependency and voltage-dependency of the suppressing effect of pirmenol, a novel antiarrhythmic agent, on the maximum upstroke velocity (Vmax) of action potentials were examined and compared with those of disopyramide in guinea pig papillary muscles. Pirmenol in concentrations higher than 3 microM decreased Vmax with a slight increase in action potential duration. The reduction of Vmax by pirmenol was enhanced in a frequency-dependent manner over the range of 0.1-2.0 Hz. Pirmenol (30 microM) produced a small resting block (5.5%), whereas disopyramide (100 microM) produced a greater one (25.8%). The onset of frequency-dependent Vmax reduction at 2.0 Hz followed a monoexponential function with a slow rate constant (0.308 +/- 0.055 AP-1). The time constant for the recovery from the frequency-dependent block by pirmenol was also slow (33.5 +/- 5.4 sec), but faster than that of disopyramide (82.5 +/- 12.3 sec). At 1.0 Hz, pirmenol caused a shift (9.5 mV) of the curve relating the resting membrane potential and Vmax along the voltage axis in the hyperpolarizing direction. Thus, pirmenol is a Class Ia drug that has frequency- and voltage-dependent inhibitory actions on Vmax, and its onset and offset kinetics are relatively slow.

Action Potentials↗
PubMed1988

[Clinical trial of high-dose etoposide].

In eleven patients with recurrent or refractory malignant lymphomas or lung cancers, a phase I study of high-dose etoposide without autologous bone marrow transplantation was performed. As a starting dose of etoposide 200 mg/m2 was administered for five consecutive days and the daily dose was increased step by step to a dose of 50 mg/m2. The dose of etoposide was escalated in order to define dose-limiting extramedullary toxicity, which was oropharyngeal mucositis and arrhythmias (PVC) at a dose level of 350 mg/m2/day. Bone marrow toxicity was completely reversible, supported by thrombocyte transfusion and antibiotics. Of nine evaluable patients with malignant lymphomas, two complete remissions and one partial remission were obtained. However, some patients unresponsive to standard-dose etoposide did not exhibit any response to the augmented dose of etoposide. Etoposide is thus a suitable drug for high-dose chemotherapy.

Adult↗
PubMed1988

[Relation between plasma Ara-C and intracellular Ara-CTP levels by intermediate dose and high dose Ara-C administration in the treatment of AML].

Plasma level of cytosine arabinoside (Ara-C) and intracellular cytosine arabinoside triphosphate (Ara-CTP) in peripheral blood and bone marrow were measured in 8 patients with non treated acute myelogenous leukemia. Ara-C was administered by 1 hr infusion (3 g/m2 and 500 mg/m2) and was followed for 12 hrs. The AUC of Ara-C in plasma following 3 g/m2 infusion were greater than the 500 mg/m2 (p less than 0.05). Intracellular Ara-CTP in peripheral blood following 3 g/m2 and 500 mg/m2 infusions were on the same level, after 1 hr. But AUC of intracellular Ara-CTP following 3 g/m2 infusion was greater than 500 mg/m2. There was a correlation between AUC of Ara-C in the peripheral blood (p less than 0.01). Intracellular Ara-CTP in the bone marrow and peripheral blood showed a similar level. Intracellular Ara-CTP in bone marrow was lower than in peripheral blood, however, there was no correlation between intracellular Ara-CTP in bone marrow and in peripheral blood.

Adult↗
PubMed1987

Effects of alpha-adrenoceptor stimulation on electrophysiological properties and mechanics in rat papillary muscle.

1. Electrophysiological and inotropic responses to stimulation of alpha-adrenoceptors were examined in isolated rat papillary muscles. 2. Stimulation of alpha-adrenoceptors caused two major electrophysiological changes, i.e. prolongation of action potential duration (APD) and hyperpolarization of resting membrane potential. 3. The time course of the inotropic responses to alpha-adrenoceptor stimulation was composed of an initial, short-lasting and small positive phase followed by a negative phase and then a second increasing phase. 4. Nifedipine abolished the alpha-adrenoceptor-mediated positive inotropic effect whereas unaffecting the negative inotropic effect, the APD prolongation and the hyperpolarization. 5. In quiescent muscles alpha-adrenoceptor stimulation also produced hyperpolarization, which was blocked by Ba2+.

Action Potentials↗
PubMed1987

Application and limitations of differential hybridization in the isolation of T cell-specific cDNA clones.

We investigated the limitations and effectiveness of differential hybridization in the cloning of T cell-specific cDNA (complementary DNA) molecular clones. By using the technique with T cell and B cell cDNA probes, together with Northern blot analysis, we successfully isolated cDNA clones exclusively expressed in T cells from 1 X 10(4) plaque-forming units of a T cell hybridoma. These clones represent 0.068% of the mass of the cytoplasmic mRNA. Our result shows that differential hybridization is an effective procedure when used in combination with Northern blot analysis for screening of genes selectively expressed in T cells.

Animals↗
PubMed1987

Electrophysiological derangements induced by lipid peroxidation in cardiac tissue.

Recently it has been postulated that oxygen-derived free radicals may be involved in reperfusion-induced arrhythmias. This study was undertaken to evaluate cellular electrophysiological alterations produced by peroxidation of membrane lipids in isolated cardiac tissues. In retrogradely perfused guinea pig hearts, perfusion of organic hydroperoxides, cumene hydroperoxide (CH), and tert-butyl hydroperoxide (TBH) caused conduction disturbances and arrhythmias, concomitantly with an increase in malondialdehyde (MDA) content of the myocardium. The hydroperoxides decreased the maximum diastolic potential, action potential amplitude, and maximum upstroke velocity of phase 0 in both canine Purkinje fibers and guinea pig papillary muscles. They also induced abnormal automaticity, such as depolarization-induced automaticity, delayed afterdepolarizations, and triggered activity. Mechanical abnormalities including increased resting tension and aftercontractions, presumably resulting from intracellular Ca2+ overload, were produced by the hydroperoxides. Pretreatment with butylated hydroxytoluene, an antioxidant, significantly inhibited the hydroperoxide-induced electrophysiological derangements and MDA accumulation in the myocardium. These results suggest that lipid peroxidation of membranes causes various electrophysiological and mechanical abnormalities and may play a role in the genesis of reperfusion-induced arrhythmias.

Animals↗
PubMed1987

Pharmacological analysis of the cardiac actions of xamoterol, a beta adrenoceptor antagonist with partial agonistic activity, in guinea pig heart: evidence for involvement of adenylate cyclase system in its cardiac stimulant actions.

The pharmacological effects of xamoterol, a beta adrenoceptor antagonist with partial agonistic activity, were examined in guinea pig cardiac preparations and compared with those of isoproterenol to assess possible mechanisms of its cardiac stimulant actions. Xamoterol produced a positive inotropic effect in the papillary muscles and a positive chronotropic effect in the spontaneously beating right atria in a concentration-dependent manner. The maximum inotropic and chronotropic effects of xamoterol were about 33 and 35% of those of isoproterenol, respectively. Although xamoterol failed to produce a consistent increase in contractile force in the left atria, the positive inotropic effect of the agent was observed clearly in preparations obtained from reserpine-pretreated animals. The positive inotropic and chronotropic effects of xamoterol were antagonized by atenolol, but not by ICI 118,551. On the other hand, xamoterol antagonized competitively the positive inotropic and chronotropic responses to isoproterenol. In papillary muscles the increases in contractile force induced by xamoterol and isoproterenol were depressed markedly in the presence of carbachol or adenosine. In all of left atria, right atria and papillary muscles obtained from reserpine-pretreated animals, xamoterol caused a significant elevation in cyclic AMP levels, while inhibiting the isoproterenol-induced increase in cyclic AMP levels. Computer-assisted analysis of concentration-response curves for the inhibition by xamoterol of the binding of [125I]iodocyanopindolol in the membranes from guinea pig ventricles showed the existence of the 5'-guanylylimidodiphosphate sensitive, highly affinity site of beta adrenoceptors for xamoterol, suggesting that xamoterol may induce the formation of a ternary complex with the beta adrenoceptor and a stimulatory guanine nucleotide regulatory protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1987

[Results of combined radiochemotherapy of intracranial ependymoma].

Thirty patients with intracranial ependymoma were treated in our clinic from 1965 through 1984. They were 13 children and 17 adults. As for the location of tumor, 9 were in the lateral ventricle, 8 in the cerebral hemisphere, 12 in the fourth ventricle and one in the third ventricle. Histologically, 18 were benign and 12 were anaplastic. The clinical course was analyzed in 24 cases. Out of the 24 cases, surgical treatment with postoperative radiation therapy was done in 16 cases, surgical treatment with postoperative radiochemotherapy in 6, and radiochemotherapy alone in two. Five-year survival rate of patients treated by surgery with radiation therapy and with radiochemotherapy was 35.7% and 66.7%, respectively. Patients treated by surgery not only with radiation therapy but also with chemotherapy took a better outcome. Recurrence was observed in 9 cases. Four cases of the 9 were benign ependymoma. The recurrence was observed within 3 years after the initial treatment in all cases. Even if histologically benign, the recurrence occurred in a relatively high rate as reported in the past literature. It should, therefore, be stressed that the initial treatment is important not only for a malignant ependymoma but also for a benign one, and the postoperative radiochemotherapy is useful for the improvement of the results.

Adolescent↗
PubMed1987

[Clinical and pharmacokinetic studies of high dose N4-behenoyl-1-beta-D-arabinofuranosylcytosine].

Effect of high dose of N4-behenoyl-1-beta-D-arabinofuranosylcytosine (BH-AC) was studied clinically and pharmacologically in non-Hodgkin's lymphoma and acute leukemia. The schedule of drug administration consisted of daily i.v. infusion for 5 consecutive days. The daily close was initiated with 500 mg/m2 which was escalated up to 1300 mg/m2. Eruption was found to be dose-limiting toxicity and there was no myelosuppression. The plasma concentration curve of BH-AC showed a biphasic curve. The half-lives of the initial phase (t1/2 alpha) and the second phase (t1/2 beta) by the administration (1 hr iv infusion) of 700 mg/m2 were 1.08 and 3.65 h respectively. The plasma 1-beta-D-arabinofuranosylcytosine was detected for 12-24 hr after infusion (Cmax: 0.26 microgram/ml).

Antineoplastic Agents↗