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Biomedical subjects

S Kawabata

Publications and source records attributed to S Kawabata.

At least 145 records · Page 8Linked to original sources

A sapecin homologue of Holotrichia diomphalia: purification, sequencing and determination of disulfide pairs.

We purified and characterized a sapecin homologue, named holotricin 1, from the hemolymph of immunized larvae of a coleopteran insect, Holotrichia diomphalia. We determined its complete amino acid sequence and three disulfide pairs. Holotricin 1 consisted of 43 amino acid residues and showed potent antibacterial activity against gram-positive bacteria, but antibacterial activity against gram-negative bacteria was not obvious.

Amino Acid Sequence↗

Clinical experience with the ACS RX Lifestream coronary dilatation catheter: a new low profile perfusion balloon catheter.

BACKGROUND: Although the use of the perfusion balloon catheter (PBC) has been widely accepted, there are some indicational limitations in percutaneous transluminal coronary angioplasty (PTCA). A new low profile perfusion balloon catheter, the ACS RX Lifestream Coronary Dilatation Catheter, was developed by Advanced Cardiovascular Systems, Inc. in which material and structures were improved to reduce previous limitations. PURPOSE AND STUDY DESIGN: In order to evaluate the ACS RX Lifestream Catheter's performance not only in PTCA but also in stent implantation, we used the catheter in 45 consecutive patients (male = 35, mean age 66 years) with combined use of 6F guiding catheter. Exclusions included total occlusions, long diffuse and acute MI lesions. There were 4 with Left Main Trunk Disease (LMTD), 15 with single vessel disease, 26 with multi-vessel disease, 20 with prior MI, 4 with prior CABG, and 10 with unstable angina. In bare stent procedures, a Johnson & Johnson metal stent was mounted on an ACS RX Lifestream Catheter previously used for predilation. Stent delivery and post-dilatation were performed using the same balloon. RESULTS: Forty-nine lesions in 45 cases (de novo lesion-31) including 7 of Type A, 15 of Type B1, 19 of Type B2, and 8 of Type C lesions were successfully dilated without any complications. Primary guiding catheter use was 6F in 40, 7F in 2 and 8F in 3 cases. The perfusion balloon was used alone in 30 cases and combined with stent placement in 15 cases. In 40 cases of 6F use, the ACS RX Lifestream Catheter could not cross the lesion in 3 cases at first attempt, of which 2 cases were successfully dilated with the balloon after predilatation with standard low-profile balloon catheters. Two cases with 7F use were bail-out cases after PTCA for long diffuse lesions. In one case of 8F guide use, flow patterns of ACS RX Lifestream Catheters and ACS RX Flowtrack Coronary Dilatation Catheters were examined with a flow-wire in the same lesion for comparison. All 15 stent cases performed using bare technique (10 with 6F, 2 with 7F and 3 with 8F guiding catheters) including 7 primary and 8 secondary use, were successful. Percent diameter stenosis pre-dilatation was 81% and 12.8% post-procedure. CONCLUSION: ACS RX Lifestream Catheter is a useful device in both PTCA and bare stent procedures. Consequently, it is possible to expand its indications to more difficult types of lesions.

Aged↗

[A case of unresectable advanced gastric cancer responding remarkably to combined chemotherapy with 5-fluorouracil and low-dose cisplatin].

A 62-year-old male patient complaining epigastralgia was diagnosed as having Borrmann type 2 gastric concer (por). The primary lesion was unresectable, so the patient was treated by combined chemotherapy with 5-fluorouracil and low-dose cisplatin for 4 weeks, which resulted in the disappearance of primary tumor and a remarkable reduction of metastatic lymph nodes. The patient has a good quality of life without any sign of recurrence now.

Antineoplastic Combined Chemotherapy Protocols↗

Annexin V is localized in association with Z-line of rat cardiac myocytes.

OBJECTIVE: The aim of this study was to characterize a 33-kDa protein (p33) isolated from bovine liver and to determine the subcellular localization of the protein in rat cardiocytes as well as in non-cardiac tissues. METHODS: Cycles of calcium-induced precipitation coupled with EGTA-resolubilization were used to isolate crude annexins from bovine and rat tissues. Column chromatography was performed to purify the p33 from the crude annexins. The protein was identified as annexin V by partial amino acid sequence determination. Specificity of anti-annexin V antibody was examined by using Western blotting after one- or two-dimensional electrophoresis. For characterization of the protein, immunofluorescence microscopy and actin-binding assays were carried out. RESULTS: Immunofluorescence microscopy showed that annexin V was stained as a striated pattern along myofibrils on frozen sections of both atria and ventricles of adult rats. The striations were seen more clearly in cultured rat atrial myocytes. Examination of doubly stained cardiocytes with anti-annexin V and anti-alpha-actinin by a confocal laser scanning microscope suggests that annexin V is localized in association with the Z-line of rat cardiac myocytes. We also found that annexin V was stained intensely in actin-rich regions of non-cardiac tissues such as bile canaliculi of rat liver and brush border-terminal web region in the epithelial cells of both small intestine and kidney proximal tubular cells. F-actin binding experiments revealed that annexin V failed to bind to F-actin directly in vitro. CONCLUSION: Our results suggest that annexin V is a new component of the Z-line in rat cardiocytes and might be involved in regulation of its organization.

Actins↗

[Pulmonary complications in patients with rheumatoid arthritis].

Pulmonary manifestations of rheumatoid arthritis were studied in 26 patients. Pulmonary complications could be divided into four subgroups: Interstitial pneumonia/Pulmonary fibrosis (n = 18), Bronchiolitis Obliterans Organizing Pneumonia (n = 4), Bronchiolitis Obliterans (n = 2), and Pleuritis/Pericarditis (n = 1). Analysis of cells in broncho-alveolar lavage fluid (BALF) revealed abnormally high percentages of lymphocytes in one-half of the patients and abnormally high percentages of neutrophils in one-third of the patients. The percent of BALF cells that were neutrophils was higher with higher chest radiograph grades. Analysis of soluble constituents of BALF indicated local production of IgG in two cases, but IgM-rheumatic factor was not detected. In 18 of 26 patients corticosteroid or immunosuppressive drugs were needed, and most of the patients responded to the therapy and had good outcomes. The conditions of 6 patients with interstitial pneumonia/pulmonary fibrosis deteriorated and 4 patients died of progressive respiratory failure. The subclassification of rheumatoid lung was useful for predicting its outcome.

Aged↗

Evidence for the regulation of small intestinal Na+/glucose cotransporter by insulin.

The small intestinal sodium dependent absorption of D-glucose has been known to be increased by diabetes mellitus. Furthermore, we previously showed that the enhanced activity of Na+/glucose cotransporter (SGLT1) was restored by the treatment with insulin. The present study was designed to investigate the mechanism by which diabetes mellitus and insulin regulated the activity of the small intestinal SGLT1. The acute diabetes at 2 weeks after the injection of streptozotocin increased the expression of SGLT1 protein in rat small intestinal brush border membrane vesicles without changing the mRNA level for SGLT1. In addition, we showed that the increased content of SGLT1 protein was restored by the subcutaneous treatment with insulin. In contrast, there was no change of the mRNA level for SGLT1 in diabetic and insulin-treated diabetic rats. These results suggest that rat intestinal SGLT1 activity is under the translational or posttranslational controls by insulin.

Animals↗

Cloning and sequencing of the cDNA encoding human glutaredoxin.

Glutaredoxin (thioltransferase) is a small, heat-stable protein, which is involved in thiol/disulfide exchange reactions. We have isolated a cDNA that encodes glutaredoxin from a human brain cDNA library. The encoded protein contains 106 amino acids with a calculated molecular mass of 11.76 kDa and an isoelectric point of 8.09. The amino acid sequence deduced from the cDNA is more than 80% identical to those of other mammalian glutaredoxins.

Amino Acid Sequence↗

Activation peptide of human factor IX has oligosaccharides O-glycosidically linked to threonine residues at 159 and 169.

O-Linked oligosaccharide chains were identified in the activation peptide (AP) of human blood coagulation factor IX. The peptide obtained from human factor IX was separated into three molecular species (AP alpha, AP beta, and AP gamma) by reversed-phase high-performance liquid chromatography. Amino acid analysis showed that AP alpha, but not AP beta and AP gamma, contained galactosamine in addition to glucosamine, thereby suggesting the presence of an O-linked sugar chain(s) in the molecule of AP alpha. A nonapeptide (AP alpha-D4, residues 157-165) and an undecapeptide (AP alpha-D5, 166-176) derived from AP alpha contained Thr-159 and Thr-169, neither of which could be identified using a gas-phase protein sequencer. All other serine and threonine residues present in AP alpha were identified by peptide sequencing. Component sugar and sialic acid analyses of AP alpha-D4 and AP alpha-D5 revealed that they contained 1 mol each of N-acetyl-D-galactosamine (GalNAc), D-galactose (Gal), and sialic acid. Fast atom bombardment tandem mass spectrometric analysis of AP alpha-D4 suggested the existence of Gal-GalNAc-Thr, NeuNAc-(Gal-)GalNAc-Thr, and NeuNAc-Gal-GalNAc-Thr structures. On the basis of amino acid analysis after the isolation of AP alpha, it accounted for approximately 35% of the total activation peptide obtained. From these results, it was concluded that a part of the activation peptide of human factor IX in circulating blood has tri- and tetrasaccharides O-glycosidically linked to the threonine residues at 159 and 169.

Amino Acid Sequence↗

Role of hemocyte-derived granular components in invertebrate defense.

Figure 2 illustrates an outline of the cellular and humoral defense systems in limulus. On the basis of the knowledge described above, it is suggested that granular components present in L and S granules in the hemocytes play a decisive role in the biological defense for this animal. The isolated L granules contain at least three clotting factors plus coagulogen as the major component. The known anti-LPS factor and a number of additional unknown protein components are also present in the L granules. On the other hand, the isolated S granules contain antimicrobial tachyplesins as the major component, in addition to six unidentified proteins. We speculate that the L-granule-derived protein components, which probably contain all the factors essential for the Limulus clotting system participate, in immobilizing invading microbes, and that the S-granule-derived tachyplesins contribute to a self-defense system against invaders. Although we have not mentioned hemolymph plasma components, there are many humoral factors, such as proteinase inhibitors, alpha 2-macroglobulin, various lectins, C-reactive protein, and polyphemin, all of which are important for antimicrobial defense. Furthermore, Liu and colleagues have reported several endotoxin-binding proteins and a cell-adhesion protein found in the Limulus hemocytes. Although the exact functions of these substances are unknown, they may act in concert with other components to provide biological defense for the animal. Nevertheless, compared to our knowledge of mammalian blood cells, much less remains to be learned of biological/physiological events in horseshoe crab hemocytes.

Amino Acid Sequence↗

A Limulus intracellular coagulation inhibitor with characteristics of the serpin superfamily. Purification, characterization, and cDNA cloning.

A Limulus intracellular coagulation inhibitor, designated LICI, was isolated from hemocytes of the Japanese horseshoe crab (Tachypleus tridentatus), using three steps of chromatography, including dextran sulfate-Sepharose CL-6B, Sephacryl S-200, and Mono S. LICI is a single-chain glycoprotein with an apparent M(r) = 48,000 estimated by SDS-polyacrylamide gel electrophoresis. It blocks the amidolytic activities of Limulus lipopolysaccharide-sensitive serine protease, factor C, by forming a covalent 1:1 complex with the protease. The second-order rate constant for inhibition of factor C was 2.5 x 10(6) M-1 s-1 at 37 degrees C. LICI also inhibited human alpha-thrombin, rat salivary kallikrein, bovine plasmin, and trypsin but not Limulus clotting enzyme, Limulus factor B, bovine factor Xa, human factor XIa, human tissue plasminogen activator, human urokinase, chymotrypsin, elastase, and papain. Glycosaminoglycans such as heparin and heparan sulfate had no effect on the inhibitory activity. A cDNA coding for LICI was isolated from a hemocyte cDNA library. The open reading frame of the 1,257-base pair cDNA codes for the mature protein of 394 amino acids, of which 223 residues were confirmed by amino acid sequence analysis. LICI shows significant sequence identities to members of the serpin superfamily, such as human plasminogen activator inhibitor type 2 (40%) and human monocyte/neutrophil elastase inhibitor (39%). LICI contains a putative reactive site, -Arg-Ser-, at the corresponding position present in several inhibitors of the serpin superfamily. The subcellular localization, determined using an anti-LICI polyclonal antibody, indicated that LICI colocates with the Limulus serine protease zymogens in large granules in the hemocyte.

Amino Acid Sequence↗

Structure-function relationships of tachyplesins and their analogues.

Haemocytes of the horseshoe crab (Limulus) contain a new family of arthropodous peptide antibiotics, termed the tachyplesin family. These cationic peptides are composed of 17-18 amino acid residues with a C-terminal arginine alpha-amide. Tachyplesin I takes on a fairly rigid conformation constrained by two disulphide bridges and adopts a conformation consisting of an antiparallel beta-sheet connected by a beta-turn. Isopeptides of tachyplesin I with amino acid replacements, tachyplesins II and III, and polyphemusins I and II have also been found in the haemocytes of the South-East Asian species and Limulus polyphemus. These peptides are present in abundance in the small granules of the haemocytes and inhibit strongly the growth of not only Gram-negative and Gram-positive bacteria but also fungi such as Candida albicans. Tachyplesin exists in the prepro form consisting of 77 residues; this precursor is probably processed by intracellular proteases and an amidation enzyme before incorporation into the small granules of the haemocytes. We examined the mode of action of tachyplesin I on biomembranes, comparing it with that of gramicidin S. Tachyplesin caused an efflux of K+ from Staphylococcus aureus and Escherichia coli cells similar to that caused by gramicidin S. Another antimicrobial substance, anti-LPS factor, has been isolated from haemocytes.

Amino Acid Sequence↗

cDNA cloning and characterization of mitochondrial import stimulation factor (MSF) purified from rat liver cytosol.

We identified a liver cytosolic protein factor that stimulated the import of wheat germ lysate-synthesized precursor proteins into mitochondria. It was termed mitochondrial import stimulation factor or MSF [Hachiya, N. et al. (1993) EMBO J. 12, 1579-1586]. It consisted of 32-kDa (MSFL) and 30-kDa (MSFS) polypeptides as assessed by SDS-PAGE. MSF recognized the presequence portion of mitochondrial precursor proteins and catalyzed the depolymerization and unfolding of in vitro synthesized mitochondrial precursor proteins in an ATP-dependent manner. We report here the cDNA cloning and characterization of MSF. Microsequencing of MSFL and MSFS showed that they belonged to a highly conserved, widely distributed eukaryotic protein family, collectively designated as 14-3-3 proteins. We cloned the cDNA of MSFL and that of one component of MSFS (MSFS1) from a rat liver cDNA library. The cloned cDNAs were separately expressed in Escherichia coli and the expressed proteins were purified to homogeneity. The purified recombinant MSFL and MSFS1 stimulated mitochondrial import of adrenodoxin precursor (pAd) synthesized in vitro with wheat germ lysate translation system. Recombinant MSFL or MSFS1 had the ability to bind with denatured pAd and they kept the precursor in an import-competent state. Rabbit polyclonal antibodies raised against the recombinant proteins inhibited the import-stimulation activity of rat liver cytosol as well as that of authentic purified MSF. Identification of MSF as 14-3-3 proteins establishes a novel function for this family of proteins and indicates their role as cytosolic chaperones to aid many important cellular events.

14-3-3 Proteins↗

Sensitivity of Staphylococcus aureus and Streptococcus pyogenes isolated from skin infections in 1992 to antimicrobial agents.

We studied the efficacy of antimicrobial agents against Staphylococcus aureus (S. aureus) and Streptococcus pyogenes (S. pyogenes) isolated from skin infections in 1992. For S. aureus, we measured the minimum inhibitory concentrations (MICs) of the following 10 drugs: methicillin (DMPPC), cefaclor (CCL), gentamicin (GM), erythromycin (EM), clindamycin (CLDM), minocycline (MINO), vancomycin (VAN), fusidic acid (FA), ofloxacin (OFLX) and nadifloxacin (NDFX); for S. pyogenes, we determined the MICs of the following 9 drugs: ampicillin (ABPC), amoxicillin (AMPC), cefpodoxime proxetil (CPDX-PR), erythromycin (EM), clindamycin (CLDM), minocycline (MINO), norfloxacin (NFLX), of loxacin (OFLX) and nadifloxacin (NDFX). These drugs are frequently used to treat skin infections, either systemically or topically. NDFX is a new synthetic fluoroquinolone, recently developed for use as a topical acne medication in Japan. It is used NDFX for acne, but not for skin infections. There were no strains of S. aureus resistant to NDFX, VAN or FA. The resistance (> or = 12.5 micrograms/ml) of S. aureus was highest to GM and lowest to OFLX. Four strains of methicillin-resistant (> or = 12.5 micrograms/ml) S. aureus (MRSA) were found. In contrast, no resistant strains of S. pyogenes were found except to MINO. Only two strains of S. pyogenes were susceptible to MINO. The sensitivity of S. pyogenes to ABPC, AMPC, CPDX-PR, EM and CLDM was very good. All the strains were susceptible at a MIC below > or = 0.05 microgram/ml. However, the S. pyogenes strains were not very sensitive to the new quinolones, especially NFLX. We concluded that penicillins, cephalosporins and macrolides are still effective against streptococcal infections.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗

Interleukin-1 beta inhibits gastric histamine secretion and synthesis in the rat.

Interleukin-1 beta (IL-1 beta) is the most potent inhibitor of gastric acid secretion known at present. Although histamine has been shown to be an important mediator of gastric acid secretion, the effect of IL-1 beta on gastric histamine mobilization has not been studied. In the present study, the effects of IL-1 beta on gastric acid secretion and gastric histamine mobilization were investigated in conscious rats with both gastric and vesical fistulas. IL-1 beta (5 micrograms/kg iv) significantly inhibited basal acid secretion but did not affect basal urinary histamine excretion and fundic histidine decarboxylase (HDC) activity. Gastrin-17-I (1 nmol.kg-1.h-1) caused a marked increase in acid secretion, urinary histamine secretion, and fundic HDC activity. IL-1 beta (5 micrograms/kg iv) completely inhibited gastrin-induced acid secretion and partially inhibited urinary histamine excretion and fundic HDC activity. Pretreatment with indomethacin (10 mg/kg ip) partially reversed the inhibitory effects of IL-1 beta on gastrin-stimulated fundic HDC activity and acid secretion. These findings indicate that IL-1 beta inhibits gastric histamine mobilization through both prostaglandin-dependent and prostaglandin-independent pathways. Furthermore, it is suggested that the inhibitory action of IL-1 beta on gastric acid secretion is mediated by the inhibition of gastric histamine mobilization.

Animals↗