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Biomedical subjects

Y Komori

Publications and source records attributed to Y Komori.

At least 19 recordsLinked to original sources
PubMed2007

Immunostaining of thymidylate synthase and p53 for predicting chemoresistance to S-1/cisplatin in gastric cancer.

High expression of thymidylate synthase (TS) and inactivation of p53 are allegedly associated with chemoresistance. The authors evaluated TS and p53 expression in gastric cancer treated with neoadjuvant S-1/cisplatin chemotherapy. Paraffin sections of pretreatment biopsy and surgical specimens from 41 gastric cancers were immunostained for TS and p53 protein after appropriate antigen retrieval. Fifty-one cases without neoadjuvant chemotherapy were also studied. In the pretreatment biopsies, high expression of TS was seen in 8% of the histologic responders, in 28% of the nonresponders and in 31% of the controls. High expression of p53 was observed in 56% of the nonresponders, but in 8% of the responders and in 29% of the controls (P<0.01 and P<0.05, respectively). The TS- and/or p53-high phenotype was seen in 76% of the nonresponders and in 54% of the controls, but in 8% of the responders (P<0.0001 and P<0.005, respectively). The data of the surgical specimens were consistent with those of the pretreatment biopsies. These results suggest that immunostaining for TS and p53 protein is useful for pretreatment selection of gastric cancer patients unresponsive to S-1/cisplatin chemotherapy.

Antineoplastic Agents↗
PubMed2001

Construction of a series of mutants lacking all of the four major mex operons for multidrug efflux pumps or possessing each one of the operons from Pseudomonas aeruginosa PAO1: MexCD-OprJ is an inducible pump.

We constructed a series of deletion mutants lacking all of the four major mex operons for Mex multidrug efflux pumps or possessing each one of the operons from Pseudomonas aeruginosa PAO1. The drug specificity of MexAB-OprM, MexXY-OprM and MexCD-OprJ was investigated. Surprisingly, we found that the MexCD-OprJ was an inducible pump, inducers of which were tetraphenylphosphonium chloride, ethidium bromide, rhodamine 6G and acriflavine. Fluoroquinolones, chloramphenicol, erythromycin and tetracycline were not inducers although they were substrates of MexCD-OprJ.

Anti-Bacterial Agents↗
PubMed2001

Laparoscopic side-to-side esophagogastrostomy using a linear stapler after proximal gastrectomy.

In order to improve anastomotic procedures, we performed laparoscopic side-to-side esophagogastrostomy, using a linear stapler, after proximal gastrectomy in two patients with gastric cancer located in the upper third of the stomach. The patients' postoperative courses were excellent. During postoperative recovery, the patients experienced very little pain, used no analgesic medications, and never experienced reflux esophagitis. This procedure is technically feasible and is an excellent option, given the less involved anastomotic procedure and better postoperative quality of life compared with these features in end-to-side anastomosis using a circular stapler.

Anastomosis, Surgical↗
PubMed2001

Laparoscopic right hemicolectomy with radical lymph node dissection using the no-touch isolation technique for advanced colon cancer.

The treatment of advanced right-sided colon cancer presents numerous challenges for the surgeon who must aim to minimize the invasiveness of surgery, achieve curative resection, and prevent port-site recurrences. To overcome these issues, we performed a totally intra-abdominal laparoscopic right hemicolectomy with radical lymph node dissection based on a no-touch isolation technique. To perform this no-touch technique, we initially dissected the lymph nodes along the surgical trunk, then transected the transverse colon, terminal ileum, and mesentery without tumor manipulation. Finally, the right side of the colon was freed retroperitoneally. We performed this surgical technique on three patients and no intraoperative complications were encountered. Curative resection was achieved in all three patients, as curability A according to the Japanese Classification of Colorectal Carcinoma, and their postoperative courses were uneventful. Therefore, this novel technique proved to be both feasible and safe. Furthermore, it enabled us to minimize the invasiveness of surgery, while providing clear access to resect the right-sided advanced colon cancer.

Carcinoma↗
PubMed2001

Hemorrhagic activity and muscle damaging effect of Pseudomonas aeruginosa metalloproteinase (elastase).

Pseudomonas aeruginosa elastase, a Bacillus subtilis thermolysin-like zinc-proteinase was examined for hemorrhagic activity and its effect on muscle and endothelial cells. Subcutaneous and intramuscular injections of elastase into mice caused severe hemorrhage with an acute increase of creatine phosphokinase activity in serum. The elastase also possessed fibrinogenolytic and fibrinolytic activities. The Aalpha and Bbeta chains of fibrinogen were completely hydrolyzed as demonstrated by their electrophoretic disappearance on SDS polyacrylamide gels. The pathological study indicates that elastase induces changes in the structure of the vascular wall and causes leakage of the plasma component and red and white blood cells into the extravascular tissue. This is further supported by results showing injury to cultured endothelial cells and macrophages. These data indicate that P. aeruginosa elastase directly affects endothelial cells and destroys the basement membrane of blood vessels to cause hemorrhage. Since fibrinogenolytic activity is an additional component of this elastase and this activity induces the hemorrhagic tendency, the damage in tissues could become increasingly severe.

Animals↗
PubMed2001

[The trend of the drug eruptions in the last fifteen years].

The drug eruptions are known to often become more severe by the readministration of causative drugs. It is an important theme to prevent the relapse of the drug eruptions. We have been monitoring drug adverse reactions at our hospital since October, 1980. We divided fifteen years from October, 1980 to September, 1995 into three periods; the first period (Oct., 1980-Sep. 1985), the second period (Oct., 1985-Sep., 1990), and the third period (Oct., 1990-Sep., 1995), and discussed the trend of the drug eruptions appeared among these three periods. The number of the drug eruptions increased. But the proportion to the total drug adverse reactions and to the number of patients slightly decreased. The eruptions in women much increased and in the patients of forties or older generations also increased. But in patients of thirties or younger generations decreased. While nonsteroidal anti-inflammatory drugs (NSAIDs) other than pyrines, antibiotics other than penicillins and cephalosporins and drugs affecting the cardiovascular system and the metabolism tend to increase, pyrines, penicillins, iodic and biliary contrast media tend to decrease. The incubation period before the eruption appeared is less than three days in most antibiotics and anti-inflammatory drugs. But it is more than four days in most drugs for chronic diseases. Other symptoms such as nausea, fever and liver dysfunction were shown in 9.2% of the drug eruptions. In 8.9% of the drug eruptions a relapse of allergic reactions included eruptions were also found. In some cases the drug eruptions exacerbate by re-administration of beta-lactam antibiotics. In the case of administration of drugs, it is necessary to pay attention to dermatitis caused by the drugs. And we recognized the importance of the system for the prevention of the relapse of drug eruptions including injections.

Adolescent↗
PubMed2001

Characterization of coagulase from Staphylococcus intermedius.

A protein coagulase was isolated from Staphylococcus intermedius 6131 using bovine prothrombin-Sepharose 4B and Bio-gel P-4 column chromatographies. Homogeneity was demonstrated by the formation of a single band in polyacrylamide gel electrophoresis and isoelectric focusing. The purified preparation possesses a molecular weight of 64,500, an isoelectric point of 4.1, consists of 615 total amino acid residues and demonstrates coagulase activity for human and rabbit fibrinogen, but does not show the activity for rat or guinea pig fibrinogens. This purified protein contains galactose and fucose, and the amino-terminal amino acid sequence was determined. The coagulase activity is inhibited by N-bromosuccinimide (NBS), suggesting that tryptophan is involved in this activity. The coagulase was heat stable to 80 degrees C and stable to pH over the range of 7-9. This is the first report of coagulase from Staphylococcus intermedius.

Animals↗
PubMed2001

Thrombin-like enzyme, flavovilase, with kinin-releasing activity from Trimeresurus flavoviridis (habu) venom.

A thrombin-like enzyme, flavovilase, with kinin-releasing activity was isolated, purified, and characterized from the venom of Trimeresurus flavoviridis (habu) using Sephadex G-100, DEAE-Cellulose, and CM-Cellulose column chromatographies. The final preparation was homogeneous as demonstrated by a single band on polyacrylamide gel electrophoresis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and isoelectric focusing electrophoresis. The enzyme possesses a molecular weight of 26,500, an isoelectric point of 5.0, and consists of 247 total amino acid residues. Specific electrolytic activities of this enzyme on N-tosyl-L-arginine methyl ester (TAME) and N-benzoyl-L-arginine ethyl ester (BAEE) were determined to be 50.9 and 17.4 micromol/min/mg, respectively. The enzyme was inhibited by p-APMSF (p-amidinophenylmethanesulfonyl fluoride hydrochloride), beta-mercaptoethanol, and N-bromosuccinimide. Additionally, the enzyme was found stable to heat treatment. It was also observed that the enzyme cleaved a kininogen analog with the release of bradykinin.

Animals↗
PubMed2000

Laparoscopic pancreas-preserving total gastrectomy for proximal gastric cancer. A case and technical report.

Although total gastrectomy with distal pancreatectomy has been the standard surgical treatment for advanced gastric cancer, this procedure is frequently complicated by leakage of pancreatic juice and postoperative diabetes mellitus. We present the case of a 74-year-old woman with proximal gastric cancer who underwent a laparoscopic modification of an open pancreas-preserving procedure first described by Maruyama et al. in 1995. With this novel technique, there is no pancreatic leakage, and at 12-month follow-up our patient remains free of diabetes. Herein we give the details of our new method and offer some caveats for its performance.

Aged↗
PubMed2000

Involvement of nitric oxide in phencyclidine-induced place aversion and preference in mice.

The present study investigated the involvement of nitric oxide (NO) in phencyclidine (PCP)-induced place aversion and preference in the place conditioning paradigm. PCP-induced place aversion in naive mice was dose-dependently attenuated by administration of N(G)-nitro-L-arginine methyl ester (L-NAME), a NO synthase (NOS) inhibitor, during the conditioning. The NOS activity and dopamine (DA) turnover in the hippocampus in mice showing PCP-induced place aversion were decreased, such changes being restored by administration of L-NAME during the conditioning. On the other hand, PCP-induced place preference in mice pretreated with PCP for 28 days was not attenuated by administration of L-NAME during the conditioning. Although NOS activity was not changed, the DA turnover in the cerebral cortex was increased in mice showing PCP-induced place preference. In mice pretreated with L-NAME and PCP for 28 days before the place conditioning paradigm, PCP neither induced place preference, nor changed the NOS activity or DA turnover. These results suggest that NO is involved in the acquisition of PCP-induced aversive effects, and in the development of PCP-induced preferred effects. Further, the functional change of the DAergic neuronal system mediated by NO in the hippocampus and cerebral cortex may be necessary for the expression of aversive effects and development of preferred effects, respectively, induced by PCP.

Animals↗
PubMed2000

Primary structure and functional characterization of bilitoxin-1, a novel dimeric P-II snake venom metalloproteinase from Agkistrodon bilineatus venom.

The amino acid sequence of the hemorrhagic toxin, bilitoxin-1, isolated from the venom of Agkistrodon bilineatus was determined by the Edman sequencing procedure of peptides derived from digests utilizing cyanogen bromide, clostripain, lysyl endopeptidase, and Staphylococcus aureus V8 protease. A molecular mass of 80,000 Da was observed in the nonreduced state and 48,000 Da was observed in the reduced state, as demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Each subunit consists of 291 amino acid residues and has a calculated molecular mass of 32,276 Da. The toxin contains fucose, galactosamine, glucosamine, galactose, mannose, and N-acetylneuraminic acid and three N-linked glycosylation consensus sites. Hydrazinolysis and ESI mass spectrometry revealed that asparagine was the carboxyl-terminal amino acid. The disintegrin-like domain of bilitoxin-1 lacks the RGD cell-binding sequence, which is substituted by the MGD sequence. Under certain conditions, the disintegrin domain is autoproteolytically processed from the native protein. Studies with the bilitoxin disintegrin demonstrated that it lacks platelet aggregation inhibitory activity, probably reflecting the substitution of RGD by MGD. The hemorrhagic activity of the asialobilitoxin-1 was only 25% of bilitoxin-1, while proteolytic activity was unaffected. The three-dimensional structure of this toxin was modeled and was shown to likely possess a structure similar to that of adamalysin II (Gomis-Rüth et al., EMBO J. 12, 151-157 (1993)) and the disintegrin kistrin (Adler et al., Biochemistry 32, 282-289 (1993)). In summary, here we report the first primary structure of a dimeric, P-II snake venom metalloproteinase and the biological role of bilitoxin-1 glycosylation and the disintegrin domain.

Agkistrodon↗
PubMed2000

Precancerous conditions of biliary tract cancer in patients with pancreaticobiliary maljunction: reappraisal of nationwide survey in Japan.

It is widely known that pancreaticobiliary maljunction (PBM), an anomalous arrangement of the pancreaticobiliary ductal system, is frequently associated with biliary tract cancer in patients with or without bile duct dilatation. In 1985, we surveyed patients with PBM who had been operated on at 133 Japanese institutions. A close relationship was shown between biliary tract carcinogenesis and PBM, according to the type of maljunction and age distribution: PBM patients with cystic dilatation had a high risk of bile duct cancer, even in those who were young (aged less than 20 years); the incidence of gallbladder cancer increased markedly in PBM patients over 40 years old with cystic dilatation, while it gradually increased with age in the PBM patients without cystic dilatation. Therefore, we recommend surgical treatment for patients with PBM even if they have no symptoms.

Age Distribution↗
PubMed2000

[Studies on hemorrhagic toxins from the venoms of Trimeresurus mucrosquamatus, Crotalus ruber ruber, Vipera aspis aspis and Agkistrodon acutus and arginine ester hydrolases from Trimeresurus mucrosquamatus venom].

Venom samples were corrected from several poisonous snakes, such as Bungarus multicinctus, Trimeresurus mucrosquamatus, T. gramineus, T. flavoviridis, and Agkistrodon acutus, and stored in a desiccator at room temperature for 25 to 31 years. Then they were compared with fresh venoms as to their biological activities. The characteristic local symptoms produced by the bite of venomous snakes of Crotalidae and Viperidae are hemorrhage, necrosis and muscular degeneration. Hemorrhagic toxins were purified from Trimeresurus mucrosquamatus, Crotalus ruber ruber, Vipera aspis aspis, and Agkistrodon acutus venoms and their biological, biochemical, and pathological properties were investigated. Arginine ester hydrolases are present in the venoms of Crotalidae and Viperidae, but are not found in the venoms of Elapidae and Hydrophiidae. In this paper we describe the enzymatic and biological activities of arginine ester hydrolases from a Trimeresurus mucrosquamatus venom.

Amino Acid Sequence↗
PubMed2000

Edema factor from the venom of Trimeresurus elegans (Sakishimahabu).

An edema factor was isolated from the venom of Trimeresurus elegans using HW-55, CM-Cellulose, and Mono S column chromatographies. Homogeneity was demonstrated by the formation of a single band in polyacrylamide gel electrophoresis (pH 8.3). The edema factor has a molecular weight of 25,500, an isoelectric point of 7.5, and express edema, proteolytic and capillary permeability-increasing activities. Edema, proteolytic and capillary permeability-increasing activities are inhibited by ethylenediaminetetraacetic acid (EDTA), o-phenanthroline, and N-bromosuccinimide. Additionally, this factor exhibits kinin-releasing activity. The edema factor possesses proteolytic activity as shown by hydrolyzing the Val(3)-Asn(4), His(5)-Leu(6), Ser(9)-His(10), Ala(14)-Leu(15), Leu(15)-Tyr(16), Tyr(16)-Leu(17), and Glu(21)-Arg(22) bonds of oxidized insulin B chain. The A alpha, B beta, and gamma chains of human fibrinogen were also hydrolyzed. The edema factor was found to contain 1 mol of zinc and 2 mols of calcium per mol of protein and the amino-terminal sequence was determined.

Amino Acid Sequence↗
PubMed2000

Gastrointestinal stromal tumor of the stomach successfully treated by laparoscopic proximal gastrectomy with jejunal interposition.

The authors describe a patient with a bleeding gastrointestinal stromal tumor of the stomach who was treated successfully by laparoscopic proximal gastrectomy with jejunal interposition. Immunohistochemically, the tumor was positive for vimentin and CD34 and was diagnosed as a gastrointestinal stromal tumor of low-grade malignancy. Because it is difficult to diagnose this disease preoperatively and a malignant phenotype has been reported, resulting in liver metastasis and peritoneal dissemination, it is desirable to treat this disease with as little manipulation as possible. To achieve this, laparoscopic surgery is a feasible option for the treatment of gastrointestinal stromal tumors.

Gastrectomy↗