Biomedical subjects

S Ando

Publications and source records attributed to S Ando.

At least 127 records · Page 7Linked to original sources

PubMed1997

Therapeutic experience of venomous snakebites by the Japanese viper (Agkistrodon halys Blomhoffii) with low dose of antivenin: report of 43 consecutive cases.

Forty-three consecutive patients of venomous snakebite by the Japanese viper (Agkistrodon halys Blomhoffii, "Mamushi" in Japanese) were treated with an uniformly scheduled therapy from 1990 and 1994. The therapy was mainly composed of minimal dose of antivenin, methylprednisolon and cepharanthin. There were two clinical courses, i.e., the minimal envenomation course (Group A, n = 14) and the severe one (Group B, n = 29). Our treatment was so satisfactory that all patients of both groups fully recovered activities of daily living with neither organic disorders nor sequelae of the bitten extremities. The high appearance ratio of atypical lymphocytes (P < 0.05) and the increased ratio of lymphocyte count to White blood cell count (P < 0.02) could be indicators that predict which clinical courses the patients take.

Adolescent↗

PubMed1997

Sympathetic alternans. Evidence for arterial baroreflex control of muscle sympathetic nerve activity in congestive heart failure.

Alternation in the amplitude of muscle sympathetic nerve activity (MSNA) was documented in three patients with severe heart failure. In the index patient with pulsus alternans, the amplitude of MSNA was inversely related to changes in the preceding diastolic pressure with a lag time of 1.2 to 1.3 seconds, indicating that oscillations in burst amplitude are determined primarily by changes in this component of blood pressure. Spectral analysis of the blood pressure and MSNA signals identified two spectral peaks, one at the cardiac frequency and a second peak, with greater spectral power, at the alternans frequency (ie, at half the heart rate). The latter peak for both blood pressure and MSNA disappeared when alternans was abolished by nitroglycerin. The presence of sympathetic alternans in synchrony with pulsus alternans and the rapid transduction of changes in the diastolic blood pressure afferent signal to the amplitude of sympathetic outflow indicate that the arterial baroreflex control of MSNA must be active and rapidly responsive in human heart failure.

Adult↗

PubMed1997

A method for determining the distribution of fluoride, calcium and phosphorus in human dental plaque and the effect of a single in vivo fluoride rinse.

A new sampling method, capable of sampling plaque from its surface to its interior for quantitative studies, was modified to meet some of the requirements for the determination of the fluoride and mineral (Ca and P) profiles within dental plaque formed in vivo. Plaque samples were repeatedly collected from the same individual, using special devices, before a single fluoride rinse (900 parts/10(6) fluoride) and 10 min and 24 hr after rinse. The method allowed examination of fluoride, calcium and phosphorus distribution along the entire thickness of plaque. Fluoride content significantly increased throughout the sample 10 min after rinsing, indicating the fluoride had rapidly penetrated into the plaque. Although the elevated fluoride concentrations diminished almost to baseline with 24 hr, a high correlation was found between fluoride and minerals in each plaque fraction. It is concluded that this technique will be useful for evaluating the fluoride and mineral behaviour in the saliva/plaque and plaque/enamel interfaces, and the anti caries efficacy of fluoride applications.

Calcium↗

PubMed1997

Isolation of low density lipoprotein subfraction containing apolipoprotein B-like protein from Japanese eel Anguilla japonica plasma using dextran sulfate cellulose.

Japanese eel (Anguilla japonica) possessed a unique lipoprotein profile in their plasma, reflecting high utilization of lipids. Low density lipoprotein (LDL) fraction isolated at the densities from 1.006 to 1.085 g/ml comprised the heterogeneous components with molecular weight (Mr) 1200 K, 470 K, and 250 K. LDL subfraction with Mr 1200 K was completely adsorbed to dextran sulfate cellulose (DSC) column which had been developed for LDL apheresis treatment of the patients with familial hypercholesterolemia, while LDL subfractions with Mr 470 K and 250 K had no affinity for the DSC column. LDL subfractions with Mr 470 K and 250 K were floated and settled, respectively, by centrifuging the unbound fraction of DSC column at a density of 1.063 g/ml. LDL subfraction with Mr 1200 K possessed apolipoprotein (apo) B-like protein of Mr 230 K, while apo A-I- and A-II-like proteins of Mr 25 K and 14 K were the main components in LDL subfractions with Mr 470 K and 250 K. The presence of apo B-like protein seemed to be responsible for the adsorption of LDL subfraction with Mr 1200 K for the DSC column. LDL subfractions with Mr 470 K and 250 K seemed to belong to high density lipoprotein (HDL) with respect to molecular weights and apolipoprotein features. To our knowledge, this is the first report of the separation of LDL and HDL from the plasma of Japanese eels using the DSC column.

Anguilla↗

PubMed1997

Fractal component of variability of heart rate and systolic blood pressure in congestive heart failure.

1. There is a substantial non-harmonic or fractal component to the variability of both heart rate and blood pressure in normal subjects. Heart rate is the more complex of these two signals, with respect to the slope, beta, of the 1/f beta relationship. In congestive heart failure, heart rate spectral power is attenuated, but the fractal and harmonic components of heart rate and systolic blood pressure variability have not been characterized. 2. Two groups, each comprising 20 men, were studied during 15 min of supine rest and spontaneous respiration: one with functional class II-IV heart failure (age 52 +/- 2 years; mean +/- SEM) and a second group of healthy men (age 46 +/- 2 years). 3. Total spectral power for heart rate was significantly reduced in heart failure (P < 0.02), whereas total spectral power for systolic blood pressure was similar in the two groups. In both heart failure and normal subjects, 65-80% of total spectral power in these two signals displayed fractal characteristics. 4. In heart failure, the slope of the 1/f beta relationship for heart rate was significantly steeper than in normal subjects (1.40 +/- 0.08 compared with 1.14 +/- 0.05; P < 0.05), indicating reduced complexity of the fractal component of heart rate variability. There was no significant difference in the 1/f beta slope for systolic blood pressure variability between these two groups, but the blood pressure signals were less complex than heart rate variations in both heart failure (2.31 +/- 0.15; P < 0.006) and normal subjects (2.47 +/- 0.15; P < 0.0001). 5. Parasympathetic nervous system activity, as estimated from heart rate variability was reduced (P < 0.01) in patients with heart failure, whereas trends towards increased sympathetic nervous system activity and decreased non-harmonic power were not significant. 6. The non-harmonic components of cardiac frequency are reduced in heart failure. Non-harmonic power is not attenuated, but the complexity of the heart rate signal is less than in subjects with normal ventricular function. A reduction in parasympathetic modulation appears to contribute to this loss of complexity of heart rate. Consequently, the heart rate signal comes to resemble that of blood pressure. In contrast, the variability and complexity of the systolic blood pressure signal is similar in heart failure and normal subjects. This reduced complexity of heart rate variability may have adverse implications for patients with heart failure.

Blood Pressure↗

PubMed1997

Role of the pyrrolidine ring of proline in determining the substrate specificity of cdc2 kinase or cdk5.

To examine structural features of proline which are essential for the proline-directed phosphorylation by cdc2 kinase or cdk5, we prepared the peptide representing the cdc2 kinase phosphorylation site at Ser-55 in vimentin [Ser-Leu-Tyr-Ser-Ser-Ser55-Pro56-Gly-Gly58-Ala-Tyr-NH2], the peptide containing arginine in place of Gly-58, and their derivatives containing various N-methylamino acids or proline homologs in place of Pro-56, and tested them as substrates for the kinases. While substitution of the proline by proline homologs (L-pipecolic acid or L-azetidine-2-carboxylic acid) increased the K(m) value 2- to 4-fold at utmost, substitution by N-methylamino acids (sarcosine, L-N-methylalanine, L-N-methylvaline, or L-N-methylleucine) increased the K(m) value 7- to 40-fold for cdc2 kinase. For cdk5, these substitutions led to parallel effects on the K(m) value to those found for cdc2 kinase; cdk5 recognized the peptides with a proline specificity similar to that for cdc2 kinase. These results suggest that the pyrrolidine ring of proline is important for substrate recognition by cdc2 kinase or cdk5. Molecular dynamics and molecular mechanics simulations indicated that the pyrrolidine ring of proline is optimal to stabilize a beta-turn at the phosphorylation site and that the K(m) values of the peptides for the enzymes might be related to the probability of the turn structure. The results obtained here also suggest that the pyrrolidine ring of proline is required to maintain a high V(max) value for cdc2 kinase or especially for cdk5. These will aid in designing specific substrates or inhibitors for cdc2 kinase or cdk5.

CDC2 Protein Kinase↗

PubMed1997

Rfc5, a replication factor C component, is required for regulation of Rad53 protein kinase in the yeast checkpoint pathway.

The RFC5 gene encodes a small subunit of replication factor C (RFC) complex in Saccharomyces cerevisiae. We have previously shown that a temperature-sensitive (ts) rfc5-1 mutation is impaired in the S-phase checkpoint. In this report, we show that the rfc5-1 mutation is sensitive to DNA-damaging agents. RFC5 is necessary for slowing the S-phase progression in response to DNA damage. The phosphorylation of the essential central transducer, Rad53 protein kinase, is reduced in response to DNA damage in rfc5-1 mutants during the S phase. Furthermore, the inducibility of RNR3 transcription in response to DNA damage is dependent on RFC5. It has been shown that phosphorylation of Rad53 is controlled by Mec1 and Tel1, members of the subfamily of ataxia-telangiectasia mutated (ATM) kinases. We also demonstrate that overexpression of TEL1 suppresses the ts growth defect and DNA damage sensitivity of rfc5-1 mutants and restores phosphorylation of Rad53 and RNR3 induction in response to DNA damage in rfc5-1. Our results, together with the observation that overexpression of RAD53 suppresses the defects of the rfc5-1 mutation, suggest that Rfc5 is part of a mechanism transducing the DNA damage signal to the activation of the central transducer Rad53.

Cell Cycle Proteins↗

PubMed1997

Frequency domain characteristics of muscle sympathetic nerve activity in heart failure and healthy humans.

The purpose of this study was to characterize oscillations in muscle sympathetic nerve activity (MSNA) in the frequency domain in healthy subjects and patients with congestive heart failure (CHF) and to relate these to blood pressure (BP), heart rate (HR), and breathing frequency. MSNA burst frequency was significantly greater in CHF [52 +/- 21 (n = 12) vs. 35 +/- 11 (n = 19) bursts/min, P < 0.05], whereas breathing frequency and HR were similar. There was no significant difference between CHF and healthy subjects in total power, harmonic power, and nonharmonic power in the MSNA spectrum from 0 to 0.5 Hz, but low frequency power (LF, 0.05-0.15 Hz, P < 0.05) was reduced in heart failure patients. There was less coherence between BP and MSNA in the LF range, but similar spectral power in both groups in the very LF (VLF, 0-0.05 Hz) and high frequency (0.15-0.5 Hz) ranges. The transfer of MSNA oscillations into BP in the VLF (P < 0.05) and LF (P < 0.02) ranges was significantly lower in CHF, but gains in the transfer function and in the coherence between BP and MSNA and in the coherence between respiration and MSNA were similar in the two groups. These observations indicate that modulation of MSNA by the arterial baroreflex and respiration is preserved in CHF. The loss of LF power in the MSNA signal may be due to impaired neuroeffector transduction. The higher sympathetic nerve firing rate in CHF would therefore appear to be caused by factors other than the loss of regulation by these two inhibitory influences.

Adult↗

PubMed1997

Ca(2+)-regulated expression of aldosterone synthase is mediated by calmodulin and calmodulin-dependent protein kinases.

The chronic maintenance of aldosterone production in the adrenal zona glomerulosa is associated with increased expression of aldosterone synthase (P450aldo), the enzyme responsible for the conversion of 11-deoxycorticosterone to aldosterone. The major physiologic regulators of aldosterone production are angiotensin II (ANG II) and (K+) which act in part through increasing intracellular calcium ([Ca2+]i). Recently we demonstrated that increased [Ca2+]i is associated with K+ induction of P450aldo expression. To determine whether Ca2+ regulation of P450aldo is mediated through calmodulin or calmodulin-dependent kinases (CaMK), we investigated the actions of calmidazolium (a calmodulin inhibitor) and KN93 (an inhibitor of CaMK) on expression of P450aldo in human adrenocortical H295R cell line. Treatment with either calmidazolium or KN93 completely inhibited K(+)-stimulated expression of P450aldo mRNA with little effect on ANG II or dibutyryl cyclic AMP-stimulated induction of this transcript. Cellular calcium levels were also increased using the calcium ionophore ionomycin and calcium channel agonist Bay K 8644. These compounds increased P450aldo mRNA and this calcium induction was inhibited by calmidazolium and KN93. These data show that K(+)-stimulated expression of P450aldo mRNA is regulated in a Ca2+ sensitive manner through mechanisms involving calmodulin and CaMK.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1997

L-arginine increases exercise-induced vasodilation of the forearm in patients with heart failure.

To determine whether L-arginine, a precursor of nitric oxide, can improve exercise-induced vasodilation of the forearm in patients with heart failure, we measured forearm blood flow in 9 patients with heart failure and in 7 age-matched control subjects before and after intra-arterial infusion of L-arginine. Resting forearm blood flow was significantly lower in patients with heart failure than in control subjects (2.34 +/- 0.85 (SD) vs 4.76 +/- 0.77 ml/min per 100 ml, p < 0.001). Endothelium-dependent vasodilation induced by acetylcholine was attenuated in patients with heart failure (p < 0.05). Exercise-induced vasodilation after handgrip exercise was significantly lower in patients with heart failure (p < 0.05). Intra-arterial infusion of L-arginine did not change basal forearm blood flow but significantly augmented acetylcholine-induced vasodilation in both patients with heart failure and control subjects (p < 0.05). Although L-arginine did not affect maximum forearm blood flow after handgrip exercise in control subjects (before, 26.2 +/- 13.5; after, 25.7 +/- 14.3; p = NS), it was increased in patients with heart failure (from 15.2 +/- 4.9 to 24.7 +/- 14.6, p < 0.01). The finding that L-arginine increased both acetylcholine- and exercise-induced vasodilation in patients with heart failure suggests that endothelial dysfunction might play an important role in impaired exercise-induced vasodilation in patients with heart failure.

Aged↗

PubMed1997

Comparison of hemodynamic and sympathoneural responses to adenosine and lower body negative pressure in man.

Adenosine increases heart rate and sympathetic nerve activity reflexively in conscious humans through several mechanisms. The purpose of this study was to assess the relative contributions of arterial baroreceptor unloading, carotid chemoreceptor stimulation, and other adenosine-sensitive afferent nerves to these responses. In 12 healthy men, the effect on blood pressure, heart rate (HR), and muscle sympathetic nerve activity (MSNA; peroneal nerve) of lower body negative pressure (LBNP; -15 mmHg (1 mmHg = 133.3 Pa)) was compared with the effect of intravenous adenosine (35, 70, and l40 micrograms.kg-1.min-1). In eight subjects, the highest dose was reinfused during 100% oxygen to suppress arterial chemoreceptors. Blood pressure reductions during LBNP and adenosine (140 micrograms.kg-1.min-1) were similar. HR did not change significantly during LBNP (+2 +/- 2 beats/min; mean +/- SE) but increased at the highest adenosine dose (+25 +/- 3 beats/min; p < 0.05). MSNA increased significantly (p < 0.05) during both interventions (+255 +/- 82 and +247 +/- 58 units/100 beats for adenosine and LBNP, respectively), and there was no difference in the MSNA response to these two stimuli (p > 0.1). Oxygen inhibited adenosine-induced increases in HR and MSNA (from +305 +/- 99 to +198 +/- 75 units/100 beats and from +26 +/- 4 to +18 +/- 3 beats/min; p < 0.05 for both comparisons). The MSNA response to these combined stimuli was similar to that observed during LBNP. In contrast, the residual HR response (+18 +/- 3 beats/min) was significantly greter than the response to LBNP (+2 +/- 2 beats/min; p < 0.05). These data indicate that arterial baroreceptor unloading cannot account for the marked adenosine-induced increase in HR, but may be sufficient to explain its effect on MSNA. The effect of 100% oxygen confirms that stimulation of carotid chemoreceptors accounts for approximately one-third of the HR and MSNA response to adenosine. However, other mechanisms, such as stimulation of adenosine-sensitive afferent nerves in other vascular beds, are involved in the HR and possibly the MSNA response.

Adenosine↗

PubMed1997

[Effect of extracellular magnesium on reperfused rat heart and intracellular calcium concentration of the myocardium].

Isolated rat hearts were subjected to 30 min global ischemia followed 20 min reperfusion with various concentration of Mg2+ Krebs-Henseleit-bicarbonate buffer (KHB buffer) (Mg2+:1.2 mM, 2.5 mM, 5 mM, 10 mM) and 20 min reperfusion with original KHB buffer (Mg2+:1.2 mM) at 37 degrees C, respectively. Cardiac function and the incidence of ventricular arrhythmia were measured during pre-ischemia and reperfusion, and intracellular Ca2+ concentration was measured during pre-ischemia, ischemia and reperfusion period. The hearts reperfused with 1.2 mM Mg2+ presented a significantly higher frequency of ventricular fibrillation (VF) and ventricular tachycardia (VT) than the other groups. Percent recoveries of LVDP (Left ventricular developed pressure) at the Mg2+ concentration of 1.2, 2.5, 5, 10 mM after 40 min reperfusion were 64.3 +/- 5.7%, 108.4 +/- 6.1%, 100.4 +/- 6.1%, 101.5 +/- 5.5%, respectively. Intracellular Ca2+ concentration of the hearts with Mg2+ 1.2 mM revealed 248.9 +/- 15.6% at reperfusion, and that the other groups did not increased during reperfusion. These data suggest that extracellular Mg2+ inhibits reperfusion arrhythmia and Ca2+ overload during reperfusion, and improves cardiac function of reperfused heart.

Animals↗

PubMed1997

[Successful 5'-DFUR, CDDP and MMC combination therapy and 5'-DFUR and carboplatin combination therapy for a patient with inoperable advanced gastric cancer with peritonitis carcinomatosa].

A 71-year-old man with Borrmann type 3 gastric cancer and peritonitis carcinomatosa was treated with 5'-DFUR 600 mg/body p.o. daily, CDDP 50-80 mg/m2 i.v. on day 1 and MMC 6 mg/m2 i.v. on day 2 after intraperitoneal injection of CDDP and OK-432. The cycle of CDDP and MMC was repeated every 4 or 5 weeks. After 15 cycles of treatment, the primary gastric lesion disappeared and regional lymph node metastasis was reduced. Because of relapsing of the original lesion and concomitant renal dysfunction, a changed regimen of CDDP and Carboplatin was tried. Then the gastric lesion was reduced and lymph node metastasis disappeared. The patient has lived for about 3 years after diagnosis, but his gastric lesion is gradually worsening with duodenal invasion. This case indicates that these combination chemotherapies are quite promising as an effective treatment for advanced gastric cancer and good quality of patient's life.

Aged↗

PubMed1997

[Right atrial thrombus recognized 18 years after tricuspid valve replacement: a case report].

A 53-year-old man, who had undergone tricuspid valve replacement with Hancock valve and direct closure of a ventricular septal defect when aged 34 years, was admitted with signs of right heart failure. Two-dimensional echocardiography showed bioprosthetic tricuspid valve malfunction with right atrial thrombus. He was treated by tricuspid valve replacement using a Hancock II valve and removal of the right atrial thrombus with remarkable improvement. Transesophageal echocardiography was the most useful method for recognizing the presence of right atrial thrombus and assessing its actual or potential hemodynamic effects.

Echocardiography↗

PubMed1997

Influence of environmental conditions on bond strength of a resin-modified glass ionomer.

PURPOSE: To investigate the influence of temperature and relative humidity (RH) on the dentin bond strength of a resin-modified glass ionomer cement (Fuji II LC) and to evaluate the bonding efficacy of dentin primer. MATERIALS AND METHODS: Four environmental conditions: (A) 25 +/- 1 degrees C, 50 +/- 5% RH, (B) 25 +/- 1 degrees C, 95 +/- 5% RH, (C) 37 +/- 1 degrees C, 50 +/- 5% RH, (D) 37 +/- 1 degrees C, 95 +/- 5% RH, were used to make the specimens. Bovine mandibular incisors were mounted in self-curing resin and the facial surfaces were ground on wet #600 SiC paper to expose dentin. Dentin Conditioner and OptiBond Prime were employed as treatment agents. After treating the dentin surface, the cement was condensed into a vinyl mold (4 x 2 mm) placed on the dentin and light cured. Ten samples per test group were stored in 37 degrees C water for 24 hours, then shear tested at a crosshead speed of 1.0 mm/minute. One-way ANOVA followed by Duncan test (P < 0.05) were done. RESULTS: The dentin bond strengths of the no-conditioning group and Dentin Conditioner treatment group increased with increasing temperature but were not influenced by RH. With the use of the dentin primer, increased bond strengths and no influence of environmental conditions were observed. These data suggest the efficacy of employing dentin primer for application of the resin-modified glass ionomer cement regardless of temperature or RH.

Analysis of Variance↗

PubMed1996

Gangliosides expressed in human breast cancer.

Breast tumors that were histopathologically diagnosed as invasive ductal carcinoma were examined in relation to their abnormal expression of gangliosides. Total ganglioside levels that were expressed as lipid-bound sialic acids were significantly higher in breast tumor tissues than in normal mammary tissues. Two kinds of unusual gangliosides were found to be expressed in many cases of breast tumors. One was a group of O-acetylated gangliosides, such as O-acetyl-GD3 and O-acetyl-GT3. They are known as fetal gangliosides, which appear in fetal brains. The other was an N-glycolylneuraminic acid-containing ganglioside, N-glycolyl-GM3, which had not been previously found in normal human tissues. The finding that unusual gangliosides are expressed in breast tumors may provide the basis for their immunological diagnosis and vaccine therapy.

Breast Neoplasms↗

PubMed1996

Characterization of a T cell line specific to an anti-Id antibody related to the carbohydrate antigen, sialyl SSEA-1, and the immundominant T cell antigenic site of the antibody.

The stage-specific embryonic Ag-1 (SSEA-1) is a carbohydrate Ag and regarded as an onco-developmental Ag. Sialyl SSEA-1 Ag, the sialylated form of SSEA-1, is frequently expressed in human cancer cells as well as in murine cancer cells. A mAb, FH-6, was shown to specifically recognize the Ag. We have generated five anti-Id Abs directed to the paratope-related idiotopes of the FH-6 Ab. One of these anti-Id Abs, Id-F2, increased the survival of host mice that were inoculated with Meth-A cells expressing the sialyl SSEA-1 Ag. To clarify the exact mechanism underlying the antitumor effect of the anti-Id Ab, we established a T cell line that recognized Id-F2 in association with MHC class II molecules. The T cell line was CD4+V beta 8+, and produced IL-2, exhibiting helper activity for B cells. The VH CDR2 region of the Id-F2 amino acid sequences turned out to be strongly immunogenic to T cells. When the immune complexes, consisting of the sialyl SSEA-1 Ag, FH-6, and Id-F2, were formed at the Meth-A cell-surface, the T cell line showed a strong proliferative response. The possible roles played by such T cell subsets in the anti-tumor effect are discussed.

Amino Acid Sequence↗

PubMed1996

Keratin 8 phosphorylation in vitro by cAMP-dependent protein kinase occurs within the amino- and carboxyl-terminal end domains.

We reported earlier that phosphorylation in vitro of keratin filaments reconstituted from rat type I keratin 18 and type II keratin 8 by cAPM-dependent protein kinase induces disassembly of the keratin filament structure. Keratin 8 rather than keratin 18 was the major target of the kinase. We have now identified the sites on rat keratin 8 for cAMP-dependent protein kinase. Sequential analysis of the purified phosphoropeptides, together with the known primary sequence, revealed that four major sites, Ser-12, Ser-23, Ser-36, and Ser-50, and three minor sites, Ser-8, Ser-33, Ser-42, are located in the amino-terminal head domain, while three minor sites, Ser-416, Ser-423 and Ser-425 locate in the carboxyl-terminal tail domain.

Amino Acid Sequence↗