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Biomedical subjects

A Watanabe

Publications and source records attributed to A Watanabe.

At least 631 records · Page 35Linked to original sources
PubMed1991

Determination of calcium ions tightly bound to proteins.

A rapid and sensitive procedure is described for the determination of calcium ions tightly bound to proteins using high-performance gel filtration chromatography, followed by the destabilization of the protein conformation and fluorimetric analysis with Quin-2. With this method, contaminating, unbound calcium can be eliminated simultaneously and one can determine the content of a calcium ion in a protein utilizing less than 200 pmol of the protein.

Animals↗
PubMed1991

Nuclear DNA content, tumor cell aggregation, and metastatic events in patients with poorly differentiated adenocarcinoma of the stomach.

Data on 100 patients who had undergone resection for poorly differentiated adenocarcinoma of the stomach with serosal invasion were examined to assess the prognostic significance of the DNA distribution pattern in relation to the histologic tumor cell aggregation pattern. DNA distribution patterns were classified into low and high ploidies and tumor cell aggregation patterns were classified into free-cell, small nest, and large nest types. The rates of high ploidy in the free-cell, small nest, and large nest types were 23.1%, 48.0%, and 66.7%, respectively, with a significant increase according to the degree of aggregation. The high ploidy group and large nest type had a higher incidence of lymphogenous and hematogenous metastasis than the low ploidy group and free-cell type, respectively. DNA ploidy had no prognostic value for the free-cell type of tumor, but differences in prognosis and the incidence of metastasis between the DNA ploidies were evident in the nest-forming type. Aneuploid tumors consisting of a poorly differentiated adenocarcinoma were those with nest formation, from the standpoint of histologic structure and metastatic behavior. The DNA analysis of poorly differentiated adenocarcinomas was of prognostic value, especially in the nest-forming type.

Adenocarcinoma↗
PubMed1991

Clinical management of gastric cancer and concomitant esophagogastric varices.

We report the late results of treatment of 13 consecutive patients with gastric cancer and concomitant esophagogastric varices. Of seven good-risk patients classified as Child's class A or B, gastrectomy together with selective shunt operation was performed in two, total gastrectomy with splenectomy in three, and distal partial gastrectomy with paraesophageal devascularization without splenectomy in one. The remaining patient with early gastric cancer underwent distal partial gastrectomy following repeated endoscopic injection sclerotherapy (EIS) for treatment of the esophageal varices. Although the majority of patients who underwent surgical repair of varices (i.e., shunt, splenectomy, or devascularization) died, total gastrectomy with splenectomy was the only procedure that led to control of the esophageal varices. Since partial gastrectomy combined with EIS limits the morbidity and mortality of an extensive resection and at the same time controls esophageal variceal bleeding, it is probably the procedure of choice for patients with a carcinoma in the lower two-thirds of the stomach. Concerning non-surgical cases, two patients were effectively treated using laser endoscopy and EIS, without the occurrence of variceal bleeding. The remaining four patients, given chemotherapy or irradiation for treatment of gastric carcinoma, died within 4 months with variceal bleeding or liver failure. For the poor-risk patients with evidence of severe liver dysfunction, laser treatment and EIS would be the treatment of choice.

Aged↗
PubMed1991

Synergistic effect of bile acid, endotoxin, and ammonia on brain edema.

The effects of cytotoxic substances such as ammonia, bile acids and endotoxin, all of which increase in the circulating blood during fulminant hepatic failure (FHF), on the blood-brain barrier (BBB) permeability and development of brain edema were examined in the rats. Direct intracarotid injection of various bile acids resulted in the staining of the cerebral hemisphere with Evans blue as well as the increase of brain water contents. Elevation of ammonia was also observed in the cerebral hemisphere where the reversible opening of the BBB was induced by deoxycholate under hyperammonemic conditions. To see the synergistic significance of cytotoxic substances (ammonia, bile acid and endotoxin) under the more physiological condition as FHF, they were simultaneously injected into a peripheral vein. Brain uptake index of 14C-inulin and brain water content increased, and electron micrographs showed the swollen astrocytic foot processes surrounded brain capillary, but not opening of tight junction, the same as an animal model of fulminant hepatic failure. The results suggest that ammonia, bile acids and endotoxin might have a possible synergistic role in the pathogenesis of the brain edema, mainly cytotoxic, and vasogenic due to acceleration of vesicular transport, in FHF.

Ammonia↗
PubMed1991

Once daily versus every two week multidose ofloxacin in patients with acute exacerbations of chronic respiratory disease.

Two different oral ofloxacin regimens, daily single-dose treatment with 200 mg (Regimen I) and every two week multidose treatment with 3 x 200 mg/day (Regimen II), were compared to evaluate the efficacy of quinolone regimens in controlling acute exacerbations of chronic respiratory tract infections. Fifty-one patients were evaluated in the study: 28 in Regimen I and 23 in Regimen II. The corrected mean incidence of exacerbation per case during the six months before and during the study was reduced from 2.45 to 0.48 in Regimen I, and from 2.79 to 1.0 in Regimen II. The development of resistant strains was not found to be a problem. We conclude that the long-term administration of new quinolones, especially the daily single-dose regimen with 200 mg of ofloxacin, is useful in controlling acute exacerbations of chronic respiratory tract infections.

Acute Disease↗
PubMed1991

Cell-kinetic analysis of pancreatic cancers in Syrian golden hamsters.

Cell-kinetic analysis of pancreatic cancers using bromodeoxyuridine (BrdU) was performed on four transplantable pancreatic ductal adenocarcinomas, which were experimentally induced by giving N-nitrosobis (2-hydroxypropyl) amine (BHP) to Syrian golden hamsters. The volume-doubling time (Td) of the tumor was 0.43, 1.03, 2.30, and 3.50 d for tumor lines J, D, B, and F, respectively. In the pulse-labeling study, the labeling index was 15.8, 23.3, 27.9, and 31.7, respectively. The most rapidly growing tumor line, J, unexpectedly showed the lowest BrdU-labeling index (LI). The further study of tumor using the cumulative-labeling method revealed that the duration of S phase (Ts), the generation time (Tg) and the growth fraction (GF) were 2 h, 14 h, and 90% for tumor J and 12 h, 37 h, and 85% for slowly growing tumor B, respectively. Cells of limited life span (CLLS) of these lines did not differ from each other. These results conclude that the marked difference of Tg between tumor lines J and B resulted in a distinction of their growth rates. The disagreement of Ts/Tg also lead to a reversion of LI between the two lines. Furthermore, LI of BrdU with one-point pulse labeling did not seem to be a sufficient indicator of the growth characteristics, at least, in the present experiment.

Adenocarcinoma↗
PubMed1991

Interaction between phospholipids and biocompatible polymers containing a phosphorylcholine moiety.

Random and block copolymers containing a phospholipid polar group in their side chain were synthesized by the copolymerization between 2-methacryloyloxyethyl phosphorylcholine and styrene. These copolymers showed amphiphilic character, especially poly(methacryloyloxyethyl phosphorylcholine-block-styrene) formed stable polymer micelles in water. The interaction between natural phospholipid, dipalmitoylphosphatidylcholine and methacryloyloxyethyl phosphorylcholine copolymers was investigated. The amount absorbed of dipalmitoylphosphatidylcholine from its liposomal solution on to the poly(methacryloyloxyethyl phosphorylcholine-co-styrene) surface increased with increase of methacryloyloxyethyl phosphorylcholine composition. Moreover, when poly(methacryloyloxyethyl phosphorylcholine-block-styrene) was added to dipalmitoylphosphatidylcholine solution, organization of dipalmitoylphosphatidylcholine molecules and stabilization of bilayer structure of dipalmitoylphosphatidylcholine liposome were found. This means that methacryloyloxyethyl phosphorylcholine moieties in the copolymer have a strong affinity to dipalmitoylphosphatidylcholine molecules. The blood compatibility of methacryloyloxyethyl phosphorylcholine copolymers was also investigated with particular attention to the aggregation ability of platelets after contacting methacryloyloxyethyl phosphorylcholine copolymers; this ability decreased when platelets were put in contact with polymers without a methacryloyloxyethyl phosphorylcholine moiety. On the other hand, aggregation ability remained at almost the same level to that of original platelets after contact with methacryloyloxyethyl phosphorylcholine copolymers. From these findings, we concluded that methacryloyloxyethyl phosphorylcholine copolymers show excellent blood compatibility due to adsorption of lipids from plasma and the formation of an organized adsorption layer of lipids on the surface of the methacryloyloxyethyl phosphorylcholine copolymers.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1991

Elevation of bovine serum C-reactive protein and serum amyloid P component levels by lactation.

C-reactive protein (CRP) and serum amyloid P component (SAP), which are known to increase in sera from humans and many other animals with acute inflammation caused by infection, toxic drug administration or injury, were previously purified from bovine serum. These serum levels were determined by enzyme-linked immunosorbent assay (ELISA) using specific antiserum to bovine CRP or SAP which was prepared by immunizing rabbits and goats with each purified protein. Among 68 healthy Holstein cows, 45 non-lactating cows had levels of CRP and SAP of 20.6 +/- 1.4 and 27.6 +/- 1.3 micrograms/ml respectively; 23 lactating cows had higher levels of CRP and SAP (76.0 +/- 13.6 and 38.3 +/- 5.5 micrograms/ml respectively). In the latter group, there was a high correlation between milk yield and serum CRP levels (P less than 0.001). From these observations, it was assumed that lactation might stimulate CRP synthesis rather than SAP synthesis in bovine liver as an acute phase reaction, and that CRP might be called a lactation-associated protein.

Animals↗
PubMed1991

Evidence for a senescence-associated gene induced by darkness.

A nearly full-length cDNA was isolated from a cDNA library prepared from incipiently senescent radish (Raphanus sativus L.) cotyledons using a previously isolated cDNA clone for dark-inducible mRNA as a probe (A Watanabe, N Kawakami, Y Azumi [1989] In Cell Separation in Plants, NATO ASI Series, Vol H35, pp 31-38. Springer-Verlag, Berlin). The clone detected transcripts of 800 bases which increased more than 100-fold after 24 hours of darkness. The transcripts also accumulated under light when plants were exposed to ethylene or heat stress, and (6)N-benzyladenine partially repressed its accumulation in the dark. These responses of the gene to physiological stimuli closely paralleled the effects of the stimuli on the progress of senescence of the cotyledons. We have named the gene din 1 (dark inducible gene 1). The cDNA encodes a polypeptide of 20 kilodaltons, and its nucleotide sequence shows a high (49%) similarity to a subfamily of pathogenesis-related proteins of tobacco. The predicted amino acid sequence of the product, however, shows only 20% homology to the pathogenesis-related protein.

Journal Article↗
PubMed1991

The use of modified constellation graph method for computer-aided classification of congenital heart diseases.

This paper describes a new method of data reduction and classification in a multidimensional symptom space for diagnostic aid of congenital heart diseases. The algorithm developed here is to reduce interactively a multidimensional symptom space to sectorial regions representing each disease in a semicircle using the modified constellation graph method. This method enables us to classify patients using the angle in the semicircle as a single classifying parameter with an accuracy of about 90%, that is, with little overlapping between disease sectors. Comparing this method with conventional factor analysis, we have found the former far more effective than the latter for disease region separation.

Algorithms↗
PubMed1991

Ultrastructural localization of type IV collagen and laminin in the Disse space of rat liver with carbon tetrachloride induced fibrosis.

Monospecific antibodies, directed against type IV collagen and laminin, were used to clarify the process of sinusoidal capillarization in rats after carbon tetrachloride (CCl4) intoxication by the direct immunoperoxidase method. After acute intoxication, both type IV collagen and laminin were increased in the area of hepatic necrosis, adjacent to the central veins; however, sinusoidal capillarization was not found. During chronic intoxication, deposition of laminin was co-distributed with that of type IV collagen, but deposition proceeded more slowly than that of the type IV collagen. Deposition of laminin was increased in the Disse space. Sinusoidal capillarization was noted as thick deposition of both antigens by light microscopy. Immunoelectron microscopy showed that both components were continuously present in the Disse space. Intracellularly, both antigens were found in the rough endoplasmic reticulum (RER) of fat-storing cells (FSC) and endothelial cells, and these cells showed morphological changes, becoming slender and flattened. In contrast, few immunoreactive products of the two components were observed in the hepatocytes. These findings suggest that type IV collagen and laminin are indispensable for the establishment of sinusoidal capillarization, and that FSC play an important role in the production of both components.

Animals↗
PubMed1991

Protein adsorption on biomedical polymers with a phosphorylcholine moiety adsorbed with phospholipid.

The effects of phospholipid adsorption onto the polymer surface during adsorption of plasma proteins were investigated. When a polymer with the phosphorylcholine moiety, 2-methacryloyloxyethyl phosphorylcholine (MPC) co-polymer, was treated with dipalmitoylphosphatidylcholine (DPPC) liposome solution, an organized adsorption layer of DPPC was formed on the MPC co-polymer surface, which was confirmed by differential scanning calorimetric analysis and X-ray photoelectron spectroscopy. On the other hand, an organized layer of DPPC on poly(n-butyl methacrylate) and poly(2-hydroxyethyl methacrylate) could not be found. The amount of albumin adsorbed on the polymer surfaces was decreased by pretreatment of the surface with DPPC liposome solution in every polymer case. The smallest amount of adsorbed proteins was found on the MPC co-polymer. Protein adsorption on the surface of MPC co-polymers from the plasma was also small. The difference in protein adsorption on the polymers probably reflects the difference in the orientation of the phospholipid molecules which cover the polymer surface.

Adsorption↗
PubMed1991

Syntheses and biological properties of new 8-fluorocarbapenem derivatives.

8-Fluorocarbapenem derivatives having various C-3 side chains were synthesized to study for the structure-activity relationship of carbapenems by in vitro biological evaluation. The introduction of fluorine at C-8 of racemic PS-5 led to slight improvements of the antimicrobial activity and the stability to renal dehydropeptidase-I. When D-cysteine was additionally introduced to the C-3 position of (+/-)-8-fluorocarbapenem, the diastereomeric separation of the 8-fluorocarbapenems became feasible. As expected from penicillins and cephalosporins, (+)-8-fluoro-3-D-cysteinylcarbapenem (+)-7a was antimicrobially active, whereas (-)-7b was inactive. It is worth noting, however, that (+)-7a was significantly more sensitive to renal dehydropeptidase-I than (-)-7b. Irrespective of the presence of fluorine at C-8, basic S-side chains at C-3, such as the pyridyl and pyrrolidyl groups, significantly improved in antimicrobial activity and dehydropeptidase-I stability. The combination of 8-fluorination with C-3 basic side chains in 7c--g resulted in a marked improvement of antimicrobial activity and dehydropeptidase-I stability.

Anti-Bacterial Agents↗
PubMed1991

Acute left main coronary artery occlusion--a case report and review of the literature.

Acute left main coronary artery (LMCA) occlusion is rare and typically fatal. According to the recent literature, only three cases have been reported surviving emergent coronary artery bypass grafting (CABG) for acute myocardial infarction (AMI) caused by total LMCA occlusion. We report the case of a 52-year-old man presenting with total occlusion of the LMCA associated with acute anterolateral myocardial infarction and cardiogenic shock. The patient's dominant right coronary artery did not supply the collaterals to the left coronary system. After ineffective thrombolysis the patient underwent successful emergent CABG for the management of uncontrollable cardiogenic shock. Emergent CABG, though controversial, appears to be a feasible approach for patients with AMI in life-threatening situations, when other attempts at reperfusion have been unsuccessful.

Acute Disease↗
PubMed1991

Check-valve mechanism as a cause of bilateral spontaneous pneumothorax complicating bronchioloalveolar cell carcinoma.

We present a rare case of simultaneous bilateral pneumothorax complicating bronchioloalveolar cell carcinoma. Autopsy revealed that numerous subpleural alveolar spaces were distended and most of the small airways were narrowed by cancer cells. We conclude that a check-valve mechanism may be responsible for pneumothorax in patients with bronchioloalveolar cell carcinoma.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1991

Detection of methicillin-resistant Staphylococcus aureus (MRSA) using polymerase chain reaction amplification.

Polymerase chain reaction (PCR) was applied for the detection of methicillin-resistant Staphylococcus aureus (MRSA). This procedure amplified a segment of MRSA-PBP (penicillin-binding protein) gene of DNA extract from the clinical isolates of S. aureus. A 1339-base-pair fragment of MRSA-PBP gene in DNA from S. aureus (MIC of methicillin, greater than or equal to 16 micrograms/ml) was amplified and detected by a specific oligonucleotide probe. Moreover, a 4.3 kb HindIII fragment containing MRSA-PBP gene was detected by using the same oligonucleotide probe. On the other hand, no PCR-amplified product was detected in DNA from methicillin-sensitive S. aureus (MIC of methicillin, less than 16 micrograms/ml).

Base Sequence↗