Biomedical subjects

H Yamaguchi

Publications and source records attributed to H Yamaguchi.

At least 883 records · Page 49Linked to original sources

PubMed1993

Calcium mobilization by muscarinic cholinergic stimulation in bovine single airway smooth muscle.

Cellular mechanisms for Ca2+ mobilization by muscarinic cholinergic stimulation were investigated in dispersed bovine airway smooth muscle cells by the fura-2 method. Because the dissociation constant (Kd) of the intracellular fura-2 was not known, we first determined the Kd as 386 +/- 6 nM, which ranged from 368 to 394 nM. By using the Kd, resting intracellular Ca2+ concentration ([Ca2+]i) was calculated to be 177 +/- 11 nM (n = 22). Carbachol (CCh) at 10(-7) - 10(-5) M caused two distinct increases in [Ca2+]i; an initial transient which reached 1.3-2.7 microM followed by a sustained increase in [Ca2+]i of 250-400 nM. The sustained Ca2+ elevation was not observed in the absence of extracellular Ca2+. D 600 (10(-5) - 3 x 10(-5) M) also eliminated this response. An analogue of diacylglycerol (DAG), 1,2-dioctanoyl-sn-glycerol, caused a gradual increase in [Ca2+]i to 303 +/- 24 nM (n = 13), which was equivalent to the sustained response to 10(-7) and 10(-6) M CCh and was again blocked by D 600. These findings are consistent with the idea that inositol 1,4,5-trisphosphate releases stored Ca2+ as the main cause for the initial transient and that activation of DAG by CCh may result in the sustained increase in [Ca2+]i through voltage-dependent Ca2+ channels.

Animals↗

PubMed1993

Venoarterial carbon dioxide tension gradient in acute heart failure.

The venoarterial carbon dioxide tension gradient (P[v-a]CO2) was studied in patients with acute myocardial infarction. Seven patients with congestive heart failure (CHF group) and 10 patients without heart failure (control) were enrolled in this study. In all patients, hemodynamics were continuously monitored. Simultaneously, arterial and mixed venous blood were sampled, and blood gases and lactate concentration were analyzed. At the initial measurement before therapy, arterial and mixed venous pH and bicarbonate values were within the normal range, and there was no significant difference between the CHF group and controls. There was also no difference in arterial oxygen tension under the differential conditions of oxygen inhalation. However, cardiac index and mixed venous oxygen saturation (SvO2) were significantly lower, while the oxygen extraction ratio (OER) and arterial lactate were significantly higher in the CHF group than in the controls. On the other hand, P[v-a]CO2 was significantly higher in the CHF group (7.8 +/- 2.6 vs. 3.5 +/- 2.2 mm Hg, p < 0.01). This finding was due to the elevated mixed venous carbon dioxide tension in the CHF group, since arterial carbon dioxide tension was the same in both groups. Analysis of a total of 42 measurements obtained during the therapeutic course in the CHF group revealed a correlation of P[v-a]CO2 with cardiac index (r = -0.3, p < 0.05), OER (r = 0.57, p < 0.001), SvO2 (r = -0.56, p < 0.001) and lactate (r = 0.62, p < 0.001). The increase in P[v-a]CO2 observed in acute heart failure suggests the evidence of intracellular acidosis despite the absence of acidemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗

PubMed1993

Human smooth muscle myosin heavy chain isoforms as molecular markers for vascular development and atherosclerosis.

Smooth muscle myosin heavy chains (MHCs) exist in multiple isoforms. Rabbit smooth muscles contain at least three types of MHC isoforms: SM1 (204 kD), SM2 (200 kD), and SMemb (200 kD). SM1 and SM2 are specific to smooth muscles, but SMemb is a nonmuscle-type MHC abundantly expressed in the embryonic aorta. We recently reported that these three MHC isoforms are differentially expressed in rabbit during normal vascular development and in experimental arteriosclerosis and atherosclerosis. The purpose of this study was to clarify whether expression of human smooth muscle MHC isoforms is regulated in developing arteries and in atherosclerotic lesions. To accomplish this, we have isolated and characterized three cDNA clones from human smooth muscle: SMHC94 (SM1), SMHC93 (SM2), and HSME6 (SMemb). The expression of SM2 mRNA in the fetal aorta was significantly lower as compared with SM1 mRNA, but the ratio of SM2 to SM1 mRNA was increased after birth. SMemb mRNA in the aorta was decreased after birth but appeared to be increased in the aged. To further examine the MHC expression at the histological level, we have developed three antibodies against human SM1, SM2, and SMemb using the isoform-specific sequences of the carboxyl terminal end. Immunohistologically, SM1 was constitutively positive from the fetal stage to adulthood in the apparently normal media of the aorta and coronary arteries, whereas SM2 was negative in fetal arteries of the early gestational stage. In human, unlike rabbit, aorta or coronary arteries, SMemb was detected even in the adult. However, smaller-sized arteries, like the vasa vasorum of the aorta or intramyocardial coronary arterioles, were negative for SMemb. Diffuse intimal thickening in the major coronary arteries was found to be composed of smooth muscles, reacting equally to three antibodies for MHC isoforms, but reactivities with anti-SM2 antibody were reduced with aging. With progression of atherosclerosis, intimal smooth muscles diminished the expression of not only SM2 but also SM1, whereas alpha-smooth muscle actin was well preserved. We conclude from these results that smooth muscle MHC isoforms are important molecular markers for studying human vascular smooth muscle cell differentiation as well as the cellular mechanisms of atherosclerosis.

Aging↗

PubMed1993

Antitumor agents. II: Regio- and stereospecific syntheses of 1-beta-alkyl-1-desoxypodophyllotoxin derivatives and biological activity.

1-beta-Alkyl derivatives of 1-desoxypodophyllotoxin were synthesized, and their cytotoxicity and inhibitory effects on DNA topoisomerase II (Topo-II) and tubulin polymerization were examined. The reaction of epipodophyllotoxin derivatives (1a-c) with trimethylallylsilane in the presence of boron trifluoride etherate gave 1-beta-allylated compounds (2a-c). The regiochemistry and the beta-stereochemistry of the 1-allyl group were confirmed by comparison of the 13C-NMR spectra and NOE's (%) of 2c, podophyllotoxin (POD) and epipodophyllotoxin (1b). 1-beta-Alkyl-1-desoxypodophyllotoxin derivatives (3-8) were prepared from 2b. None of the tested compounds (3-8) showed any inhibitory effect on Topo-II. 1-beta-Propyl compound (3) and its 4'-demethyl compound (4) inhibited tubulin polymerization and the cytotoxicities of these compounds were equal to that of VP-16. 1-beta-(2,3-Dihydroxypropyl) compounds (5 and 8) and 1-beta-(2,3-diacetoxypropyl) compounds (6 and 7) showed no inhibitory effect on tubulin polymerization. Although 5 did not inhibit either Topo-II activity or tubulin polymerization, it showed a high cytotoxicity against sarcoma 180.

Animals↗

PubMed1993

[Antitumor activity of Enterococcus faecalis FK-23 preparation against murine syngeneic tumors].

The antitumor activity of a preparation of heat-killed cells of Enterococcus faecalis, FK-23. Intraperitoneal injection of the preparation prolonged the lifespan of C3H/He N mice which were intraperitoneally inoculated with MM46 mammary carcinoma. Not only intraperitoneal but also oral administration of the FK-23 preparation inhibited the growth of these carcinomas inoculated intradermally. The tumor-bearing mice produced tumor necrosis factor (TNF) in their sera 2 h after intravenous injection of OK432. This TNF level increased after the mice were fed with food supplemented with the FK-23 preparation. Additionally, the FK-23 preparation inhibited the growth of Meth A fibrosarcoma in cyclophosphamide-treated BALB/c mice.

Animals↗

PubMed1993

Coronary spasm in two sisters.

Coronary spasm was observed in two sisters. Neither of them had significant atheromatous stenosis in the coronary arteries. The 41-year-old elder sister presented with resting morning angina. The stress electrocardiogram showed marked depression of the ST-segment in precordial leads. Diffuse vasospasm in the left anterior descending artery was induced by the intracoronary administration of acetylcholine. The 38-year-old younger sister suffered from acute inferior myocardial infarction after taking methylergonovine following an abortion. Emergent coronary angiography disclosed a thrombus in the proximal right coronary artery which was dissolved with intracoronary administration of urokinase. There was no residual stenosis in the culprit vessel. Although the sisters do have risk factors for coronary spasm, an inherited factor may contribute to the mechanism of the spasm.

Adult↗

PubMed1993

Isolation and characterization of the subunits of a heat-labile alpha-amylase inhibitor from Phaseolus vulgaris white kidney bean.

The heat-labile one of the two alpha-amylase inhibitors of the white kidney bean (Phaseolus vulgaris) was found to be composed of three kinds of subunits, and they were isolated and characterized. The alpha-subunit was free from tryptophan and cysteine and the beta-subunit contained no methionine or cysteine. There was no marked resemblance in tryptic peptide maps between the alpha- and beta-subunit polypeptides. The alpha-subunit contained 30% by weight of carbohydrate, mainly made up of high mannose-oligosaccharides, and the sugar moiety of the beta-subunit amounted 7% and appeared to be predominantly composed of xylomannose-type oligosaccharides. The largest subunit, gamma, was very similar in molecular features to a postulated alpha beta-dimer and its N-terminal sequence coincided with that of the alpha-subunit. The molecular weights of the polypeptides of alpha, beta-, and gamma-subunits were shown to be 7,800, 14,000, and 22,000, respectively, by SDS-PAGE. It seemed likely that the alpha- and beta-subunits are common to both of the inhibitors and that the heat-lability of this inhibitor arises from the gamma-subunit.

Amino Acid Sequence↗

PubMed1993

Long-term prognosis in 990 medically treated Japanese patients with coronary artery disease.

We performed a retrospective analysis of the fate of 990 medically treated Japanese patients with coronary artery disease. Patients were enrolled in this study between September 1973 and February 1984. They were confirmed to have significant coronary artery disease by coronary angiography. There were 924 males and 66 females with a mean age of 54.4 years. The mean duration of follow-up was 9.4 years with a range of 6.5 to 17.0 years. The 5-year and 10-year survival rates for the entire population were 92.1% and 84.4%. The 5-year and 10-year survival rates in patients with single- (SVD), double- (DVD), and triple-vessel disease (TVD) and left main trunk (LMT) disease were as follows: 96.0% and 91.9% for SVD, 93.8% and 87.5% for DVD, 83.2% and 68.3% for TVD, and 89.3% and 84.6% for LMT disease. This was the first large follow-up study of coronary artery disease in Japan. Its results suggest that the prognosis of Japanese patients with coronary artery disease is more favorable than that of patients in Western countries. In addition, the findings should provide a control data base for future studies in Japan and the West.

Coronary Angiography↗

PubMed1993

A case of idiopathic ventricular fibrillation with incomplete right bundle branch block and persistent ST segment elevation.

We report the case of a 42-year-old male who suffered from ventricular fibrillation (VF) without obvious QT prolongation. His electrocardiogram showed incomplete right bundle branch block (IRBBB) and persistent ST segment elevation in the right precordial leads during sinus rhythm. Cardiac catheterization revealed no overt heart disease except moderate endocardial and subendocardial fibrosis in the left ventricle. Mental stress seemed to trigger VF, and ST elevation became prominent just before VF. Propranolol and mexiletine have been effective in preventing VF for over 3 years.

Adult↗

PubMed1993

Acute myocardial infarction induced by ergonovine administration for artificially induced abortion.

Acute myocardial infarction after artificially induced abortion is an uncommon event because such patients are usually young females and are not usually subject to atherosclerosis. This report describes two premenopausal females who developed acute myocardial infarction after administration of ergot derivatives which were used following abortion. Coronary arteries in both cases were angiographically normal. Both patients were smokers. We concluded that the ischemic event was caused by coronary vasospasm which was precipitated by the acute administration of ergot derivatives.

Abortion, Induced↗

PubMed1993

Biological properties of aureobasidin A, a cyclic depsipeptide antifungal antibiotic.

Aureobasidin A (AbA) is a novel cyclic depsipeptide antifungal antibiotic. The antifungal activity of AbA was studied in vitro and in vivo in comparison with clinically effective antifungal agents, amphotericin B and fluconazole. AbA was highly active in vitro against many pathogenic fungi, including Candida albicans, Cryptococcus neoformans, Blastomyces dermatitidis and Histoplasma capsulatum. The activity was superior to amphotericin B in most cases. AbA exhibited fungicidal action toward growing cultures of C. albicans. It was highly tolerated by mice and showed good efficacy in the treatment of murine systemic candidiasis when given orally or subcutaneously. AbA's fungicidal action in mice with candidiasis was more effective than fluconazole and amphotericin B.

Amino Acid Sequence↗

PubMed1993

En(a-) phenotype in a Japanese blood donor.

The first Japanese En(a-) individual (T.N.) was found by screening red cells from 250,000 Japanese blood donors with monoclonal anti-Ena. His serum contained no atypical antibodies and his partial red cell phenotype was M-N-S+s-, although a trypsin- resistant N antigen was detected. His red cells were En(a-) and Wr(b-), as determined by various human and mouse monoclonal antibodies. The absence of glycophorin A (GPA) and the presence of apparently normal glycophorin B (GPB) were demonstrated by immunoblotting with antibodies to the extracellular and cytoplasmic domain of GPA and to epitopes common to GPA and GPB. Sialic acid levels of T.N.'s intact red cells were substantially lower than those of control MN cells. Serologic tests suggested that both of T.N.'s parents were heterozygous for a recessive GPA deficiency gene.

Journal Article↗

PubMed1993

[In vitro susceptibility to fluconazole of fungal strains freshly isolated from child patients with deep-seated mycoses].

The susceptibility to fluconazole (FLCZ) were evaluated for 40 strains of 8 yeast species and 4 strains of 3 Aspergillus species, all of which were isolated from clinical specimens during clinical trials of FLCZ in child patients performed from January 1991 to January 1993 in this country. The in vitro activity of FLCZ against yeast isolates and Aspergillus isolates were measured using the microdilution method with semisolid SAAMF (synthetic amino acid medium fungal) agar and the macrodilution method with Eagle MEM (minimum essential medium), respectively, using amphotericin B (AMPH) and flucytosine as the reference drugs. Out of all yeast species tested, Candida albicans and Candida tropicalis were the most susceptible to FLCZ with geometric mean (GM)-MICs of < 0.4 microgram/ml that were far less than the corresponding values for AMPH or flucytosine. On the other hand, FLCZ showed the lowest activity against Candida krusei and Candida glabrata with GM-MICs of approximately 10 micrograms/ml that were slightly higher than those for AMPH. The susceptibilities to FLCZ of Candida parapsilosis, Candida pelliculosa (anamorph of Hansenula anomala), Candida famata, and Trichosporon cutaneum were intermediate. Antifungal activities of FLCZ and the 2 reference drugs against aspergilli were determined on the basis of the amount of total protein recovered from drug-treated cultures relative to that from drug-free control cultures. Fifty percent and 90% inhibitory concentrations of FLCZ against 2 isolates of Aspergillus fumigatus were 6.25-25 micrograms/ml and 50 micrograms/ml, respectively. Against this and 2 other species of Aspergillus, AMPH appeared more highly active than FLCZ.

Amphotericin B↗

PubMed1993

[Therapeutic efficacies of neticonazole (SS717) cream and solution in experimental cutaneous Candida albicans infection of guinea pigs].

The therapeutic efficacies of 1% neticonazole (SS717) cream and solution on experimental cutaneous Candida albicans infection produced in prednisolone-treated guinea pigs were compared with those of 1% bifonazole (BFZ). Active preparations or blank vehicles were applied once daily for 3 consecutive days starting 5 days postinfection. Therapeutic effects were assessed on the basis of viable counts recovered from the infected loci 9 days postinfection. In animals treated with SS 717 or BFZ cream, a significant mycological improvement was observed when compared to untreated controls. A significant therapeutic efficacy of a SS717 cream compared to cream vehicle was also noted, while there was no significant difference in the recovery of Candida between the untreated control group and the cream vehicle-treated groups. The mycological result of the SS717 solution treated group was significantly superior to those of the untreated control group, the solution vehicle-treated group and the BFZ solution-treated group. The treatment with a solution vehicle or a BFZ solution appeared to lower, though not to a significant level, viable counts at the infected loci. These results led us to the conclusion that both SS717 cream and solution preparations exhibited significantly superior activity to that of BFZ in experimental cutaneous candidasis of guinea pigs.

Animals↗

PubMed1993

[In vitro antifungal activity of omoconazole nitrate, a new imidazole antimycotic].

In vitro antifungal activities of omoconazole nitrate (OMZ), a new topical imidazole antifungal agent, were studied against 364 strains of 22 genera and 47 species of stock cultures of a wide range of medically important fungi. The test was carried out using the agar dilution method with bifonazole (BFZ) as the reference drug. OMZ exhibited a broad spectrum of antifungal activities. Most of yeasts including Malassezia, dimorphic fungi, non-pigmented hyphomycetes and dermatophytes were almost equally or more greatly susceptible to OMZ than to BFZ, although the MIC values of these drugs against Candida and probably some other fungi were influenced differently by testing media. Comparable susceptibility to OMZ were observed for fresh clinical isolates of dermatophytes and Candida albicans. OMZ was also active against Malassezia. These results have encouraged us to proceed in vivo studies using animal models of cutaneous mycoses.

Antifungal Agents↗

PubMed1993

[A 79-year-old man with rapidly progressive tetraparesis].

We report a 79-year-old man who developed progressive gait disturbance and sensory loss. He had been doing well except for hepatitis B virus hepatitis until 72 years of age when he developed angina pectoris for which aorto-coronary bypass operation was performed when he was 73-year-old (1986). In 1990, he developed pulmonary fibrosis for which prednisolone was prescribed. His liver function deteriorated, and the liver function tests suggested liver cirrhosis. He noted an onset of gait disturbance in the middle of June in 1992 when he was 79-year-old. His gait disturbance deteriorated progressively, and he developed edema and loss of sensation in his both legs. He became unable to walk unassisted in the beginning of July. He fractured his right external malleolus after falling down from a chair. He became unable to stand by himself, and he was admitted to the cardiology service of our hospital on July 18, 1992, and the neurology service was asked to see the patient on July 30 of the same month. The patient was well developed and well nourished man in no acute distress. General physical examination revealed slight jaundice, left carotid bruit, and slight pitting pretibial edema. His temperature was 37.3 degrees C. On neurologic examination, he was alert and mentally sound without dementia. He showed a slight weakness in the facial muscles bilaterally and mild dysarthria and dysphagia, however, the other cranial nerves appeared intact. He was unable to stand unassisted. The muscle tone was hypotonic, however, no focal muscle atrophy was noted, nor was observed fasciculatory twitches.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1993

[Percutaneous removal of foreign bodies from the cardiovascular system: two experienced cases in addition to a review of 35 cases reported over the past 9 years in Japan].

From 1984 to 1992 in Japan, 37 cases, including 2 cases of our own, have been reported to involve the percutaneous removal of foreign bodies from the cardiovascular system by catheter. We reviewed the cases of these foreign bodies and the locations, approaches and types of catheters used for removal. The reported foreign bodies were usually iatrogenic in origin and were approximately two times larger than those found in patients who had self-dislodged catheters. The most common catheter approaches were from either the right femoral or saphenous veins.

Aged↗

PubMed1993

[Evaluation of immediate hypersensitivity and environmental factors by intracutaneous skin tests and specific IgE antibodies in allergic children. Part 1. The annual change of immediate hypersensitivity measured by intracutaneous skin tests and radioallergosorbent test].

To evaluate the relation between immediate hypersensitivity and environmental factors, a total of 2,187 allergic children were given the intracutaneous skin tests (IC test) and specific IgE antibodies (RAST) at Kudanzaka Hospital over a period of 21 years (1967-1987). The incidence of positive IC test to house dust (HD) and Japanese cedar pollen (sugi) increased, and that to molds increased transiently in the period 1965-1975. There was no sex difference in the incidence. Asthmatic children with allergic rhinitis scored higher both in IC test and RAST than those with asthma only. The more severely asthmatic children had a higher incidence of positive IC test to HD, molds, sugi, ragweed, cat dander, silk and buckwheat (sobagara). The recent rise of in the number of allergic diseases was partly proved by higher positive IC tests to HD and sugi. The number of positive test to HD mites also increased because twice as many non-wooden houses as wooden houses, have been built since 1969, and there were 3 times as many, high-rise building in 1975 as in 1965. Pollution and the increasing area of sugi forests were also responsible for increased allergic problems.

Animals↗