Biomedical subjects

A Watanabe

Publications and source records attributed to A Watanabe.

At least 559 records · Page 31Linked to original sources

PubMed1993

Ca(2+)-dependent aggregation of rabbit platelets induced by maitotoxin, a potent marine toxin, isolated from a dinoflagellate.

1. Administration of maitotoxin (MTX), a dinoflagellate toxin, caused aggregation of rabbit washed platelets. The cytosolic Ca2+ concentration ([Ca2+]i), measured by fura-2 fluorescence technique, was also increased by the presence of MTX. Rates of aggregation response and [Ca2+]i-increase were dependent on tested concentrations (3-100 ng ml-1) of the toxin. 2. The MTX-induced platelet aggregation and [Ca2+]i-increase were totally abolished in a Ca(2+)-free solution. The successive administration of Ca2+ in the presence of MTX elicited the aggregation and increase in [Ca2+]i. 3. Ba2+ was capable of substituting for Ca2+ in the MTX-induced platelet aggregation. In the presence of external Ca2+, transition metals, Co2+, Cd2+ and Ni2+, inhibited the aggregation response to MTX. 4. Organic calcium antagonists (verapamil and nifedipine) as well as a cyclo-oxygenase-inhibitor (aspirin) did not apparently inhibit the aggregation response to MTX, except for a high concentration (10(-5) M) of verapamil, while procaine (10 mM) reduced the rate of platelet aggregation. 5. MTX also elicited a release of ATP from platelets, which was abolished in the absence of external Ca2+. 6. In contrast, thrombin 0.5 unit ml-1 could elicit platelet shape change, [Ca2+]i-increase and ATP-release in the absence of external Ca2+. 7. These results suggest that the MTX-induced platelet activation is caused by an enhanced Ca(2+)-influx presumably through voltage-independent Ca2+ channels on the plasma membrane.

Adenosine Triphosphate↗

PubMed1993

In situ assay of basic fibroblast growth factor in cultured cells with a specific monoclonal antibody.

The localization of basic fibroblast growth factor (bFGF) in various cultured bFGF-producing cells, including bovine capillary endothelial (BCE) cells and human cholangiocellular carcinoma (HuCC-T1) cells, was determined by measuring binding of 125I-labeled specific monoclonal antibody against bFGF. bFGF on the cell surface and within the cells was determined by counting the radioactivity of the labeled monoclonal antibody bound to the cells before and after increasing their permeability by treatment with alcohol or Triton X-100. The radioactivity bound to these cells decreased with increase in the concentration of unlabeled monoclonal antibody. Scatchard analyses of these data suggested the quantitative localization of bFGF and Kd values showing the specific binding. This method was designated as in situ assay with radio-labeled antibody (ISARA). bFGF detected on the cell surface and within the cells could be partially removed by treatment with heparin or heparinase and with heparin or DNase, respectively. Exogenous bFGF bound to cells not producing bFGF was also quantified by ISARA. Measurements of bFGF in extracts of cells producing bFGF suggested that 8.3-13.3% of the bFGF associated with the cells was detected by ISARA. This method should be useful for quantitative confirmation of immunohistochemical results on bFGF.

Animals↗

PubMed1993

[Crystal morphological and habit investigations of crystalline drugs. II. Amobarbital, barbital and ephedrine hydrochloride].

Crystal morphology, habit and refractive indices necessary for the analyses of amobarbital, barbital, phase III and ephedrine hydrochloride were studied using a polarizing microscope and partly using a reflexing goniometer. These substances, market products of Japanese Pharmacopoeia XII, were measured for optical properties including key refractive indices to confirm their modifications, and their possible facial angles along the zone of which axis is parallel to the elongated direction was also measured using a goniometer. Stereographic projections were drawn and the crystal habits of market products were shown by orthographic projections. It was also found that one of the key refractive indices of each modification was specially usable for the analyses of crystal habits including their crushed powders.

Amobarbital↗

PubMed1993

Purification and characterization of a thermostable neutral metalloprotease I from Chloroflexus aurantiacus J-10-fl.

Chloroflexus aurantiacus J-10-fl was found to contain two types (protease I and protease II) of thermostable proteases which were separated by Butyl-Toyopearl 650 M chromatography. Protease I was purified to electrophoretic homogeneity from the culture broth of C. aurantiacus J-10-fl. The molecular mass of protease I was estimated to be approximately 66 kDa by SDS-PAGE, and the value of approximately 66 kDa was also obtained by the Hedrick-Smith method, indicating that protease I was a monomer. The isoelectric point was 6.2. Protease I activity was inhibited by metalloprotease inhibitors such as EDTA, EGTA, and o-phenanthroline. The optimum pH for the activity of protease I was around 8.0. Addition of Ca2+ increased the pH and heat stabilities of protease I. The activity was stable between pH 4.0-11.0 and up to 75 degrees C, and the maximum activity was observed at 70 degrees C in the presence of 2 mM CaCl2. Protease I was resistant to the treatment by denaturing reagents (8 M urea or 1% SDS) at pH 8.0 and 20 degrees C for 24 h. The sites of cleavage in oxidized insulin B chain by protease I were similar to those by other microbial neutral metalloproteases. Elastase activity of protease I was not detected.

Amino Acid Sequence↗

PubMed1993

Reduction of increased signal intensity in the basal ganglia on T1-weighted MR images during treatment of hepatic encephalopathy.

A 61-year-old man with liver cirrhosis showed a symmetrical increase in the signal intensity of the basal ganglia on T1-weighted magnetic resonance (MR) images, which was diminished after 3 months of treatment for hepatic encephalopathy. He recovered from encephalopathy with treatment, and liver dysfunction (hyperammonemia and abnormal blood coagulation) as well as the results of quantitative psychometric tests showed a marked improvement. The cause of these high signal intensity changes on T1-weighted images and the reason for their partial reversibility are not known, but hyperammonemia due to portal-systemic shunting might be closely related to these clinical observations.

Ammonia↗

PubMed1993

Clinical significance of serum hepatocyte growth factor levels in liver diseases.

Serum levels of human hepatocyte growth factor (hHGF) in patients with various liver diseases were determined using an ELISA kit to explore its clinical significance. Significantly high levels of serum hHGF were found in patients with acute hepatitis, fulminant hepatitis, liver cirrhosis, and hepatocellular carcinoma. Increased levels of hHGF were observed during severe liver injury in patients who died of fulminant hepatitis. However, the levels returned to normal during the repair process of liver injury in the surviving cases. In patients with liver cirrhosis, serum hHGF levels were negatively correlated with serum albumin (Alb) levels. These results indicate that serum hHGF levels are not useful for detecting repair processes of the injured liver, but serve as an index of the severity of liver dysfunction in various liver diseases.

Adult↗

PubMed1993

[Utility of measurement of tumor markers for preoperative staging of gastric cancer].

In 120 operated cases of gastric cancer, nine tumor makers (serum carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 125 (CA125), tissue polypeptide antigen (TPA), serum beta 2-microglobulin (s-BMG), urine beta 2-microglobulin (mu-BMG), serum immunosuppressive acidic protein (IAP) and sialic acid (SA)) were determined before operation, to explore distribution patterns, positive rates, and relationships among these markers. And, we explored tumor markers which would be useful in preoperative assessment of the cancer stage and feasibility of radical treatment. The following results were obtained. 1. The distribution of all tumor markers was close to normal logarithmic distribution. 2. The positive rate was high in the order of IAP > TPA > CEA > CA19-9 >s-BMG > SA > u-BMG > CA125 > AFP. 3. Strong correlations were observed between IAP and SA, between CA125 and TPA. 4. The optimum combination of markers for diagnosis of the cancer stage was IAP + CA19-9 + CA125 and the optimum combination for assessment of the feasibility of radical treatment was IAP + CA125 + TPA.

Adult↗

PubMed1993

Cisplatin, etoposide, and vincristine combination chemotherapy in the treatment of non-small cell lung cancer.

Thirty patients with previously untreated, inoperable non-small cell lung cancer (NSCLC) were treated with cisplatin, etoposide and vincristine. Among twenty-nine evaluable patients, eight patients achieved partial response and the overall response rate was 28%. No patient achieved a complete response. The median survival time was 51 weeks. Myelosuppression was the dose-limiting toxicity. Four patients had a leukocyte nadir of less than 1000/mm3, and one died from severe myelosuppression and sepsis. The other toxicities were nausea/vomiting, peripheral neuropathy, and alopecia. We conclude that cisplatin, etoposide, and vincristine combination chemotherapy offers moderate activity for inoperable non-small cell lung cancer.

Adult↗

PubMed1993

Optical rotation signal of nerve and the Faraday effect.

The polarity of the optical rotation signal, recorded from the lobster nerve, was reversed when the direction of incident light was changed by 180 degrees. This is a property of the Faraday rotation, but the magnetic field by the action current was too small to explain the size of the observed signal.

Action Potentials↗

PubMed1993

[A coronary aneurysm of left main trunk associated with localized dissecting aneurysms of thoracic and abdominal aorta].

A 47-year-old man who had undergone surgery of a dissecting thoracic aortic aneurysm was admitted for a localized, dissecting abdominal aortic aneurysm. Preoperative coronary arteriogram incidentally showed a coronary artery aneurysm (CAA) of the left main trunk. Prior to the operation for abdominal aortic aneurysm, that for the CAA was performed under standard cardiopulmonary bypass conditions with antegrade and retrograde coronary sinus cold blood cardioplegia. A longitudinal incision of the aneurysmal wall was made for the removal of a small thrombus and, the ostia of the left anterior descending artery (LAD), circumflex artery (LCX), intermediate artery (IM) and main trunk were closed from the inside of the aneurysm. The aneurysmal wall was closed without resection of the whole aneurysm. Finally, coronary artery bypass grafting to LAD, LCX and IM was performed. Postoperative course was uneventful with patency of all grafts. The retrograde coronary sinus cardioplagia is effective to prevent thromboembolism of distal coronary arteries due to the antegrade cardioplagia.

Adult↗

PubMed1993

[Identification of Mycobacterium tuberculosis complex and Mycobacterium avium-intracellulare complex by using nonisotopic DNA probes].

A total of 31 clinical isolates of mycobacteria consisting of 21 strains of M. avium-intracellulare complex (ten strains each of M. avium and M. intracellulare identified by specific 125I-labeled DNA probes and one strain of M. avium-intracellulare complex identified by conventional biochemical tests) and 10 strains of M. tuberculosis (identified by a specific 125I-labeled DNA probe) were subjected to identification by hybridization protection assay (HPA) with an acridinium-ester (AE) labeled DNA probe. The results thus obtained were in complete agreement with those obtained by 125I-labeled DNA probes (30 strains) or by conventional biochemical tests (one strain). HPA by the AE-labeled DNA probe is safe, simple and rapid, and can be done with ease in any clinical laboratory.

DNA Probes↗

PubMed1993

[Enkephalinase activity in the guinea pig model of asthma].

Enkephalinase exists in airway epithelial cells, smooth muscle, and submucosa near glands, and cleaves tachykinins to inactive metabolites, thereby reducing there effects. To study the role of enkephalinase in asthmatic response, we measured its activity in guinea pig model of asthma. When compared with the control values, the enkephalinase activity was reduced during in immediate asthmatic response (IAR) and late asthmatic response (LAR). Compared with the control values (100%), each value was 79.7%, 73.4% in the trachea and 74.3%, 55.7% in the lung respectively. Tracheal muscle preparation taken from the control, IAR, and LAR groups were made and mounted in oxygenated modified Krebs-Ringer solution. The response was monitored by isometric transducer. Concentration response curves to NKA with or without phosphoramidon were obtained. The contractile responses of the LAR groups were enhanced in potency and efficiency. Phosphoramidon potentiated the NKA induced contraction of control and the IAR groups but was less potent in enhancing the contractile response in the LAR group, showing less enkephalinase activity in the LAR. These results suggest that the enkephalinase plays an important role in LAR. In LAR, the enkephalinase activity may be inhibited and the responsiveness of the smooth muscle to some bronchoconstrictor, such as tachykinins, may be increased.

Allergens↗

PubMed1993

Development of gastric cancer with special reference to growth and DNA content. Slow and rapid growing types.

We treated two patients with gastric cancer for whom surgery was delayed and the natural course of the tumor could be observed pre and postoperatively. A 70-year-old man with a well differentiated adenocarcinoma in the upper portion of the stomach underwent resection 6 years after the clinical diagnosis. Despite extension upwards towards the lower esophagus during a 6-year period, the tumor could be resected. In a poorly differentiated adenocarcinoma in the lower third of the stomach in a 40-year-old woman, the primary lesion was not distinct on the upper GI series done 6 months before, while at the time of laparotomy, disseminating metastases and pancreas invasion made it impossible to resect the stomach together with the tumor. The tumor in the man had a low DNA ploidy, while the lesion in the woman was characterized by a high ploidy. These findings show the distinct difference in the biological behavior of the tumor in these two patients. The possible correlation between DNA content with speed of growth warrants further attention.

Adenocarcinoma↗

PubMed1993

Polarity reversal of the optical rotation signals with change in direction of impulse conduction along the lobster nerve.

1. The optical rotation signal of nerve associated with excitation was recorded from peripheral nerve taken from a walking leg of a spiny lobster and its properties were analysed. 2. The polarity of the optical rotation signal was reversed when the site of stimulation was changed with reference to the site of optical recording, so that the direction of impulse conduction was reversed, in most of the preparations. 3. Apart from the main response, which is associated with the conducted impulse, a pre-response was found to exist, which manifested itself on anodic stimulation, in a tetrodotoxin-treated nerve, or during the refractory period of the nerve, when the site of stimulation was close to the site of optical recording. The polarity of the pre-response was also reversed when the site of stimulation was changed with reference to the site of optical recording. 4. When the nerve was inclined from the horizontal level, so that the angle of incidence of light to the nerve was changed, the main response changed its amplitude and sometimes its polarity, whereas the pre-response remained practically unchanged. Thus the dependence on the angle of incidence was different between the pre-response and the main response. 5. It is suggested that the dependence of amplitude and polarity of the main response on the angle of incidence of light cannot be explained by the change in molecular axes of the membrane macromolecules, but can only be explained by their conformational change; and therefore the main response can be used as a monitor for the molecular conformation.

Animals↗

PubMed1993

[Cerebral blood flow velocity and electroencephalogram for the evaluation of intraoperative brain function during intrathoracic hyperthermia].

It is well known that progressive hyperthermia exerts fatal damage on the human body. However, there have been few reports on the brain function or the means to provide adequate monitoring during hyperthermia. The purpose of this study was to introduce two new devices, the Life Scan electroencephalogram (EEG) Monitor (Neurometrics) and the TC2-64 (EME) transcranial Doppler sonography (TCD), both for monitoring brain function during hyperthermia. The Life Scan uses aperiodic analysis, which maps each waveform in relation to its frequency, amplitude, and time of occurrence rather than averaging a large number of waveforms over a given period. The Life Scan shows 80% of the whole amplitude of each wave as the activity edge (AE). The flow velocity of the middle cerebral artery was measured by TCD during hyperthermia. After the induction of modified neuroleptanesthesia (fentanyl and midazolam), AE was maintained at 11 Hz. With an increase in body temperature, AE gradually showed a trend toward a slow wave, though the slowing of EEG was interrupted when the patient awoke to slight stimulation. Therefore, it is speculated that the slowing of EEG in this case was caused by fentanyl. The mean cerebral blood flow velocity increased slightly from 28 to 32 cm.sec-1 by hyperthermia. It is concluded that the adoption of EEG and TCD was useful in determining the intraoperative cerebral function during hyperthermia.

Brain↗

PubMed1993

[Identification of Mycobacterium avium-intracellulare complex in Tohoku district of Japan by using DNA probes].

Attempts were made to identify Mycobacterium avium and Mycobacterium intracellulare in the M. avium-intracellulare complex (MAC) isolated in the Tohoku district of Japan by using DNA probes (Gen-Probe; Rapid Diagnostic System) which are specific for M. avium, M. intracellulare and M. tuberculosis complex, respectively. In the Tohoku district, the ratio of M. avium isolates (80%) exceeded that of M. intracellulare isolates. It was thus shown that, in the Tohoku district where no data concerning the ratio of M. avium to M. intracellulare isolates had been available, the ratio of M. avium by far exceeded that of M. intracellulare.

DNA Probes↗

PubMed1992

Measurement of glutamate, aspartate and glycine and its potential precursors in human brain using high-performance liquid chromatography by pre-column derivatization with dimethylaminoazobenzene [correction of diethylaminoazobenzene] sulphonyl chloride.

This paper describes a high-performance liquid chromatographic technique, with dimethylaminoazobenzene sulphonyl chloride derivatization, for the measurement of glutamate, aspartate and glycine and its potential precursors in human brain tissue. The derivatization procedure is simple, sensitive and highly reproducible. The derivatized amino acids are stable and can be analysed by reversed-phase chromatography with visible detection at an absorption wavelength of 436 nm. A preliminary application to the determination of the concentrations of several amino acids in several regions of the human brain is described.

Aged↗

PubMed1992

Prostacyclin administration suppresses the increase in hepatic levels of COL1A(I) and glyceraldehyde-3-phosphate dehydrogenase mRNAs in the rat treated with carbon tetrachloride.

Northern analysis using total RNAs from the component cells of normal rat liver indicated that COL1A(I) mRNA is present in fat-storing cells (Ito cells) and sinusoidal endothelial cells. A fraction for Kupffer cells also contained this mRNA. When CCl4 was given, COL1A(I) mRNA was increased in a factor of 1.5 in the fractions of these component cells. After 48 h of the drug administration, hepatocytes appeared to possess over 60% of liver COL1A(I) mRNA, although in normal hepatocytes its level was below the range detectable by our procedures. Under this injured condition of liver, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA level was elevated, while activity of this enzyme was lowered by 50% of the control value. All the changes were obviously suppressed by the simultaneous administration of prostacyclin.

Animals↗