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Biomedical subjects

J Kikuchi

Publications and source records attributed to J Kikuchi.

At least 91 records · Page 5Linked to original sources
PubMed1989

Analysis of structural features of dihydropyridine analogs needed to reverse multidrug resistance and to inhibit photoaffinity labeling of P-glycoprotein.

Synthetic dihydropyridine analogs were screened to determine whether they would reverse multidrug resistance of a multidrug-resistant human KB carcinoma cell line, KB-C1. Among twenty-four dihydropyridine analogs examined, thirteen almost completely overcame drug resistance (group A), nine partially overcame resistance (group B) and two did not reverse resistance (group C). The twenty-two compounds that reversed drug-resistance (groups A and B) were hydrophobic dihydropyridine derivatives. Three compounds that reversed resistance, NK-113, NK-138 and NK-194, increased the accumulation of [3H]vincristine in the resistant KB-C1 cells, but not in the parental KB cells, nor in a revertant cell line, KB-C1-R2. NK-101 (group C), which did not reverse resistance, had no effect on drug accumulation. Enhanced efflux of vincristine from the resistant cells was inhibited completely by NK-194, but NK-194 did not affect vincristine influx. Nine of the twenty-four compounds were screened to determine whether they inhibited photoaffinity labeling of the cell surface protein gp170 (P-glycoprotein) in KB-C1 cells by N-(p-azido-[3-125I]-salicyl)-N'-beta-aminoethylvindesine [( 125I]NASV). All five compounds of group A, NK-138, NK-194, NK-200, NK-203 and NK-220, inhibited the photoaffinity labeling of gp170 at less than 10-100 microM, whereas NK-113 and NK-196 of group B inhibited the labeling at 100-200 microM. By contrast, NK-101 and NK-102 of group C did not inhibit labeling even at 2000 microM. These studies confirm the relationship among reversal of multidrug resistance, decreased efflux of vincristine, and inhibition of [125I]NASV labeling of P-glycoprotein.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1989

The response of normal and failing heart to externally applied vibration in the canine open chest preparation.

We examined the left ventricular functional response to externally applied vibration using four canine open chest preparations. A sinusoidal 30 Hz vibration (2.7 mm in amplitude) was applied to the ventricular epicardium at each level of propranolol-induced myocardial depression. External vibration in control conditions induced no significant change either in peak left ventricular pressure (LVP) or in stroke volume (SV). With propranolol, 0.1 and 0.3 mg/kg, peak LVP and SV were depressed by the application of external vibration, even though there was no significant change of these values in the nonvibrating condition compared to control. We conclude that the ventricular response to vibration depends on the underlying myocardial viability.

Animals↗
PubMed1989

Effect of left ventricular volume on the magnitude of functional depression by external minute vibration.

We examined the effect of the left ventricular (LV) volume on the magnitude of the vibration induced functional depression (VID) using four canine cross-circulated isovolumically beating LV preparations. A sinusoidal, 50 Hz vibration (1.5 mm in amplitude) was applied to the ventricular anterior epicardium at different values of LV volume which was stepwisely increased by 1-2 ml from 0 to 30 ml. VID was estimated as the difference of the peak LV pressure between control and during external vibration. VID increased as an increment in LV volume when the volume was below 7-8 ml and when peak LV pressure was less than 70 mmHg. However, VID remained constant when the volume increased further. We concluded that VID was independent of LV volume at physiological range.

Animals↗
PubMed1989

The improvement of systolic function of depressed left ventricle by external vibration at diastole.

The left ventricular (LV) incomplete relaxation (IR) has been reported to play an important role in the pathophysiology of the congestive heart failure such as causing higher diastolic pressure and/or impeding the coronary perfusion during diastole. Therefore, using open chest canine preparations (n = 4), we examined 1) whether the minute external vibration during diastole could release IR and 2) what occurred to LV systolic function in this perturbation. LV failure with IR was induced by propranolol administration and, if necessary, by rapid atrial pacing up to 180 beats/min. When we applied a 50 Hz, sinusoidal vibration of 2.1 mm magnitude during diastole to the epicardium of LV with complete relaxation, there was no significant change in the ventricular function. However, the systolic functional improvement (3.8 +/- 1.1 mmHg elevation in LV systolic pressure) was observed when the vibration was applied to LV with IR. We concluded that external vibration at diastole could release IR and would be useful to improve the systolic function of the depressed heart with IR.

Animals↗
PubMed1989

Clinical demonstration of vibration-induced depression of left ventricular function.

In experimental studies, minute sinusoidal vibration has been reported to induce functional depression of the left ventricle and to be an index for evaluation of myocardial crossbridge kinetics. Therefore, to examine whether or not this vibration-induced functional depression could also be observed in the human ventricle, motion of the left ventricular (LV) wall or LV pressure was measured by echocardiography (n = 16) or by left heart catheterization (n = 4), in which 100 Hz, 2.07 mm-amplitude sinusoidal vibration was applied to the subject's precordium. In the echocardiographic study, left ventricular wall shortening did not change by vibration in nine healthy volunteers, but was depressed in two patients with aortic regurgitation (AR) and in one patient with ischemic heart disease (IHD). In measurement of LV pressure, the decrease in LV systolic pressure caused by vibration was obviously observed in two patients (AR and IHD) but was not observed in two patients with hypertrophic cardiomyopathy. These results suggest that we might be able to extend previously proposed experimental idea on early detection of the abnormality in myocardial crossbridge kinetics to the clinical setting.

Adult↗
PubMed1989

Quaternary ammonium glucuronide of croconazole in rabbits.

1. A water-soluble croconazole glucuronide was isolated from the urine of rabbits dosed intravenously with croconazole, using XAD-2 column chromatography, reversed-phase RP-8 column chromatography and h.p.l.c. 2. beta-Glucuronidase hydrolysis liberated unchanged croconazole from the glucuronide. 3. Secondary ion mass spectra, i.r. and n.m.r. spectroscopic studies, including two-dimensional n.m.r. techniques (ROESY and HETCOR), showed the metabolite to be a quaternary ammonium glucuronide of croconazole: i.e. a chemical bond exists between a nitrogen, having sp2 type orbital, in the imidazole ring of croconazole and the anomeric carbon of glucuronic acid. 4. The urinary excretion of the glucuronide amounted to 2.8 +/- 0.7% of dose (mean +/- SD, n = 4) in rabbits.

Animals↗
PubMed1989

Disposition of acetone, methyl ethyl ketone and cyclohexanone in acute poisoning.

A case of coma due to the drinking of a liquid cement for polyvinyl chloride resin, containing acetone, methyl ethyl ketone, cyclohexanone and polyvinyl chloride is described. The patient also simultaneously ingested the alcoholic beverage, sake. After gastric lavage, plasma exchanges and direct hemoperfusions, the patient recovered. The concentrations of these chemicals in plasma and urine were analyzed at various time intervals to estimate the clearance. The elimination half lives for acetone and methyl ethyl ketone were 18 hours and 10 hours, respectively. Although cyclohexanone made up the largest component in the solvents, the blood level was extremely low and a large amount of cyclohexanol, a metabolite of cyclohexanone was detected in the blood and urine. The glucuronide metabolite of cyclohexanol was also estimated after the hydrolysis with beta-glucuronidase. Since the conversion of cyclohexanone to cyclohexanol is known to be catalyzed by alcohol dehydrogenase, possible interactions between sake ingestion and cyclohexanone metabolism is proposed.

Acetone↗
PubMed1989

Isolation of CB-25-I, an antifungal antibiotic, from Serratia plymuthica.

A new antifungal antibiotic, CB-25-I, was isolated from the culture broth of a strain of Serratia plymuthica. The antibiotic, a water-soluble dipeptide, is structurally related to Sch 37137 and A 19009, both produced by strains of Actinomycetales. The antibiotic exhibits inhibitory activity against Candida albicans in YNB medium (a synthetic medium), but the activity is significantly reduced in Sabouroud dextrose medium.

Amino Acids↗
PubMed1988

Vincristine-resistant human cancer KB cell line and increased expression of multidrug-resistance gene.

A multidrug-resistant clone of human cancer KB cells was isolated by stepwise selection on exposure to increasing doses of vincristine. The final clone, VJ-300, obtained after ethylmethane sulfonate mutagenesis showed 400-fold higher resistance to vincristine than did KB cells. Cellular accumulation of vincristine in VJ-300 was decreased to less than one-tenth of that in KB. The cells were also cross-resistant to daunomycin, adriamycin, actinomycin D, colchicine and VP-16. During continuous culturing in the absence of any drug for several months, a different colchicine-resistant and multidrug-resistant clone, KB-C1, reverted almost completely to drug sensitivity, whereas drug resistance in VJ-300 was stably maintained. Amplification of the multidrug-resistance-1 (mdr-1) gene was more than 20-fold in KB-C1, but less than 2-fold in VJ-300. mdr-1 mRNA was, however, expressed in VJ-300 at a rate comparable to KB-C1. Acquisition of high multidrug resistance in VJ-300 might be correlated with both activated transcription of mdr-1 gene and amplification.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1988

Dependence of instantaneous transfer function on regional ischemic myocardial volume.

To obtain the instantaneous left ventricular transfer function curve (instantaneous TFC) under conditions of regional ischemia, sinusoidal accelerations ranging from 30 to 150 Hz were applied to a small area of the epicardium of cross-circulated isovolumic canine left ventricle, and the contralateral acceleration was measured under control and during regional coronary occlusion (n = 11). The TFC is the ratio of the output to input acceleration amplitudes. The instantaneous TFC was characterized as a single-peaked configuration under control coronary perfusion. However, TFCs progressively changed from a single-peaked to a double-peaked configuration during regional ischemia. To quantify this change in instantaneous TFC, we defined an index D as the mean squared difference of TFC during ischemia from TFC during control. Index D was linearly related to the percent mass of the ischemic region at 40 minutes after onset of ischemia. We conclude that 1) transfer function curves are sensitive measures of myocardial heterogeneity and 2) the fractional ischemic weight of the ventricle is a major factor in determination of the deformation in instantaneous TFC at the later stages of regional ischemia.

Animals↗
PubMed1988

The structures of katanosins A and B.

1H and 13C NMR studies on katanosin A confirmed the presence of eight usual amino acid residues which were previously deduced by amino acid analysis and suggested the presence of beta-hydroxyaspartic acid, beta-hydroxyleucine and beta-phenylserine residues. These amino acids were isolated and confirmed, including their stereochemistries, by comparison with the respective authentic specimens. Stereochemistries of the usual amino acids were determined by comparing the L-leucylated amino acids with reference compounds by HPLC. Lithium borohydride reduction and chromic acid oxidation of katanosin A and alkali-treated katanosin A elucidated a lactone linkage between the C-terminal Ser and phenylserine residues. Edman degradation on alkali-treated katanosin A clarified the total amino acid sequence. The difference in katanosins A and B was determined to be replacement of Val in A by Ile in B. Thus, the structures of katanosins A and B were elucidated.

Amino Acid Sequence↗
PubMed1988

The left ventricular vibration mode in the ventricular transfer function method and at the moment of the first heart sound.

Several investigators have aimed to clarify the patient's left ventricular (LV) physical properties by free vibration analysis of heart sound. Recently we have developed a transfer function (TF) method to calculate the LV viscoelasticity. To clarify whether this TF method and a clinical first heart sound (1 HS) analysis are based on the identical ventricular vibration mode analysis, we examined (1) the visualized LV vibration image in the TF method and (2) the quantitative relationship between the peak frequency of the 1 HS spectrum and that of TF curve in the early and late phase of the 1 HS. Isolated isovolumic potassium arrested canine left ventricles were used to visualize the vibration mode in describing the TF (N = 2). Examination of stroboscopically illuminated, slow-motion images revealed the oscillation of the ventricle to be of mode 2 behavior. To analyze the quantitative relation between the TF method and 1 HS analysis we used ten open-chest dogs. The correlation was good (r = 0.917) when the peak frequency of the TF curve at the early phase of the 1 HS was compared to the peak frequency of the 1 HS. We concluded that both the TF method and 1 HS analysis were based on the common, second-order ventricular vibration mode. Therefore, some information on the ventricular physical properties suggeted by the TF method could also be included in the clinical data obtained by 1 HS analysis.

Animals↗
PubMed1988

[Reductive effect on ascites, of neocarzinostatin in patients with ovarian cancer].

Neocarzinostatin (NCS) was administered intravenously by drop infusion to 16 patients with ovarian cancer, and intrathoracically to one patient. In addition to evaluation of the efficacy of the chemotherapy, we mainly investigated its effect on ascites and pleural effusion, and carried out continuous measurements of the abdominal circumference in 3 patients. NCS relieved thoracic effusion in 1 patient. We observed that abdominal circumference decreased in 10 patients after administration of NCS. The results obtained from continuous measurement of abdominal circumference revealed that NCS significantly reduced ascitic retention in ovarian cancer.

Adult↗