Synthesis and biological activity of 4-amino-5-chloro-2-ethoxy-3-hydroxybenzamides, metabolites of a new gastroprokinetic agent, mosapride

To confirm the proposed structures of the minor metabolites of a potential gastroprokinetic agent, mosapride, 4-amino-5-chloro-2-ethoxy-3-hydroxy-N-(2-morpholinylmethyl)benzamide (3) and the N-(5-oxo-2-morpholinyl)-methyl analogue 4 were prepared. As the common intermediate, 2-ethoxy-3-hydroxy-4-nitrobenzoic acid (15) was prepared via the regioselective ethylation of 2,3-dihydroxybenzaldehyde (10) and subsequent nitration of the resultant 2-ethoxy-3-hydroxybenzaldehyde (11). The key intermediate 15 was converted into the benzamides 3 and 4. After enzymatic treatment of the isolated metabolites, their structures were identified by comparison with the synthetic compounds. Serotonin-4 receptor binding affinity of these metabolites was found to be lower than that of mosapride.

A mutant trypsin-like enzyme from Streptomyces fradiae, created by site-directed mutagenesis, improves affinity chromatography for protein trypsin inhibitors

The Ser-170 residue of a trypsin-like enzyme from Streptomyces fradiae (SFT), which is considered to be the active-site serine, was replaced with alanine by site-directed mutagenesis to improve the affinity chromatography step for a Kazal-type trypsin inhibitor pancreatic secretory trypsin inhibitor (PSTI). The resulting mutant SFT, designated as [S170A]SFT, was expressed in Streptomyces lividans and purified to homogeneity. [S170A]SFT was catalytically inactive, but still had the ability to bind tightly to PSTI and to soybean trypsin inhibitor with dissociation constants of 3.1 x 10(-7) M and 1.9 x 10(-8) M respectively. We further demonstrated that recombinant human PSTI secreted into Saccharomyces cerevisiae culture broth could be purified to homogeneity with a one-step [S170A]SFT-affinity column. The purified PSTI contained no molecules intramolecularly cleaved by active trypsin, which are found when trypsin-affinity chromatography is used for the purification. This eliminated the need for further separation of intact PSTI from intramolecularly cleaved PSTI by high-performance liquid chromatography, thus simplifying and improving its purification process.

Local gastric and serum concentrations of rebamipide following oral administration to patients with chronic gastritis

The potential anti-ulcer action of rebamipide (CAS 11911-87-6, OPC-12759) on experimental and clinical injury to the gastric mucosa depends on its presence in sufficient concentration in the gastric mucosa. To investigate its local penetration, rebamipide levels in the gastric mucosa and serum were measured. A dose of 100 mg of rebamipide was given orally (tablet) to patients with chronic gastritis (n = 32). Gastroscopy was performed between 22 and 353 min after drug ingestion. Venous blood was sampled for determination of serum concentrations. Samples were analyzed by high-performance liquid chromatography (HPLC). The maximal concentration in the gastric mucosa was reached after 30-60 min, and the concentration remained elevated for about 120 min thereafter. The mean mucosal concentration of rebamipide between 30 and 120 min after ingestion was 60.0 +/- 109.8 micrograms/g of tissue, which was higher than 0.1 mmol/l (37 micrograms/g of tissue). The serum concentration of rebamipide peaked about 30-60 min after drug ingestion and remained elevated for about 5 h thereafter. The mean serum concentration of rebamipide between 30 and 120 min after ingestion was 0.25 +/- 0.23 microgram/ml, being below the level of 1.0 mumol/l (0.37 microgram/ml). Data indicate that the concentration of rebamipide in the gastric mucosa resulted from local penetration, and suggest that the blood level and systemic distribution of rebamipide have little effect on its antioxidative and anti-neutrophilic activities.

Intrathecally administered NMDA receptor antagonists reduce the MAC of isoflurane in rats

PURPOSE

We studied the effects of intrathecal administration of an N-methyl-D-aspartate (NMDA) receptor antagonist and an antagonist of the glycine site of the NMDA receptor on the minimum alveolar anaesthetic concentration (MAC) of isoflurane in rats, and on locomotor activity in conscious rats.

METHODS

In Wistar rats fitted with indwelling intrathecal catheters, we determined the MAC of isoflurane after the administration of saline (control group); the competitive NMDA receptor antagonist 3-(2-carboxypiperazin-4-yl)propyl-1-phosponic acid(CPP) at 0.01, 0.1, and 1.0 nM; and the selective antagonist of the glycine site on the NMDA receptor complex 7-chlorokynurenic acid (7CKA) at 0.1, 1.0, and 10 nM. After measurement of MAC following administration of the antagonist, the equipotent reversal dose of NMDA or D-serine was administered. The rats were examined for the presence of locomotor dysfunction by intrathecal administration of NMDA receptor antagonists, NMDA and D-serine in conscious rats. All of the experiments were performed using randomization and masking of drugs.

RESULTS

CPP at 0.1 and 1.0 nM decreased the MAC of isoflurane by 9.9-17.6% (P < 0.05). 7CKA at 1.0 and 10 nM reduced MAC from 10.5-15.5% (P < 0.05). Intrathecal administration of NMDA or D-serine reversed the decreases in MAC to control values. Locomotor activity was not changed.

CONCLUSIONS

We believe that NMDA receptor plays an important role in determining the MAC of isoflurane in the spinal cord.

Case report: fibrolamellar hepatocellular carcinoma in a Japanese woman: a case report and review of Japanese cases

Fibrolamellar hepatocellular carcinoma (FLHCC) is an entity distinct from ordinary hepatocellular carcinoma and is very rare in Oriental countries. We present here a Japanese case of FLHCC in a 25 year old woman, and review Japanese cases of FLHCC. The patient had mild abdominal pain when the hepatic tumour was revealed by ultrasonography. Hepatitis B surface antigen (HBsAg) and anti-hepatitis C antibody were negative and serum alpha-fetoprotein (AFP) was within the normal limit. Ultrasound-guided fine needle biopsy was performed and the tumour was histologically diagnosed as FLHCC. A right lobectomy of the liver was then performed. Macroscopically, the tumour (10 x 10 x 8 cm) was circumscribed, rather hard and yellowish white. Microscopically, neoplastic hepatocytes were polygonal and large with eosinophilic cytoplasm, which contained pale bodies. A number of fibrous stroma were arranged in thin parallel bands. Consequently, the case was diagnosed as FLHCC. In Japan, approximately 18,000 people die of ordinary hepatocellular carcinoma annually, while only nine cases (including the present case; six males, three females) of FLHCC in Japanese subjects have been reported previously. The mean age of the Japanese cases of FLHCC is 20.9 years old. One case with positive HBsAg, liver cirrhosis and high level of AFP was observed of nine cases. The nature of FLHCC in Japanese subjects may not be significantly different from that in Caucasians, except for male predominance.

Rebamipide protects against activation of neutrophils by Helicobacter pylori

Our objectives were to determine whether rebamipide, a unique antiulcer agent, would inhibit adhesive reactions between neutrophils and endothelial cells as well as the production of active oxygen species from neutrophils elicited by an extract of H. pylori. A water extract of H. pylori that was prepared from biopsy materials obtained from a patient with gastric ulcer increased the surface expression of CD18 on human neutrophils isolated from peripheral blood, the adhesion of neutrophil-endothelial cells, and the production of active oxygen species by neutrophils. Rebamipide, at concentrations of 10(-5) and 10(-6) M, reduced the adherence of neutrophils to endothelial cells as well as the CD18 expression on neutrophils induced by this bacterial extract. Rebamipide also inhibited the production of active oxygen species from neutrophils stimulated by H. pylori extract. These results suggest that rebamipide protects against the gastric mucosal inflammation associated with H. pylori by inhibiting neutrophil function.

Identification of a domain of Trypanosoma cruzi metacyclic trypomastigote surface molecule gp82 required for attachment and invasion of mammalian cells

Recombinant proteins and synthetic peptides representing various sequences of gp82, a surface glycoprotein of Trypanosoma cruzi metacyclic trypomastigotes implicated in mammalian cell invasion, were used in this study aiming at the identification of the domain(s) of this molecule required for interaction with target cells. Invasion of cultured HeLa cells by metacyclic trypomastigotes was inhibited by about 80% in the presence of native gp82 or the corresponding recombinant construct J18. Inhibition by recombinant proteins J18a and J18b, containing respectively the N-terminal and the C-terminal portions of gp82, was on the order of 30% and 65%. As compared to J18b (amino acids 224-516), the truncated gp82 fragments J18b1 (amino acids 303-516) and J18b2 (amino acids 357-516) displayed lower inhibitory effect (approximately 40% and approximately 15%, respectively). Compatible with these observations, we found that the recombinant protein J18b, but not J18a or J18b2, binds to HeLa cells in a dose-dependent and saturable fashion. Experiments with ten overlapping synthetic peptides, representing the gp82 portion spanning amino acids 224-333, showed that peptides 4 (amino acids 254-273) and 8 (amino acids 294-313) have significant inhibitory activity on HeLa cell invasion by metacyclic forms. All these results indicate that the portion of gp82 required for mammalian cell attachment and invasion is located in the central domain of the molecule.

Case report: multiple cancers: hepatocellular carcinoma and adenocarcinomas of the common bile duct and the gall-bladder in a woman with primary biliary cirrhosis

We present a case of primary biliary cirrhosis associated with simultaneous triple cancers: a hepatocellular carcinoma and adenocarcinomas of the common bile duct and gall-bladder. A 70 year old Japanese woman, who had been diagnosed with primary biliary cirrhosis (stage 2 by Scheuer) 15 years before, was admitted to Koseiren Kamo Hospital in a comatose state. Laboratory data were as follows: the ammonia level was high (164.0 micrograms/dL), the antimitochondrial antibody showed a 320-fold increase, a high level of alpha-fetoprotein was indicated (2677 ng/mL), hepatitis B surface antigen was negative and hepatitis C antibody by enzyme immunoassay was negative, although a test for the RNA of hepatitis C virus by polymerase chain reaction was positive (10(3.5) copies/50 microL). The patient's condition gradually worsened and the patient died of liver failure. Autopsy showed triple cancers in the liver (hepatocellular carcinoma; trabecular type, moderately differentiated), the common bile duct (well-differentiated papillary adenocarcinoma) and the gall-bladder (well-differentiated papillary adenocarcinoma) with primary biliary cirrhosis (stage 4). Primary biliary cirrhosis has been believed to be a low risk for the development of hepatocellular carcinoma, despite the high risk of extrahepatic malignancy. The simultaneous occurrence of triple cancers with primary biliary cirrhosis, to the best of our knowledge, has never been reported. The present case may provide additional evidence for a predisposition to malignancy in primary biliary cirrhosis.

Involvement of dopamine D3 receptors in the area postrema in R(+)-7-OH-DPAT-induced emesis in the ferret

We investigated the possible involvement of dopamine D3 receptors in R(+)-7-hydroxy-2-(N,N-di-n-propylamino)tetraline (R(+)-7-OH-DPAT)-induced emesis in the ferret. The R(+)enantiomer of 7-OH-DPAT (0.03-1 mg/kg, s.c.) caused emesis in a dose-dependent manner, whereas the S(-)enantiomer, even at 1 mg/kg s.c. failed to induce emesis. Quinpirole (0.1-1.0 mg/kg) and apomorphine (0.3 mg/kg, s.c. only) also elicited an emetic response. S(-)-Eticlopride, which has a high affinity for the dopamine D3 receptor, antagonized R(+)-7-OH-DPAT (0.3 mg/kg, s.c.)-induced emesis (ID50 1.4 micrograms/kg, s.c.). R(+)-7-OH-DPAT (0.1-1.0 microgram) administered into the 4th cerebral ventricle dose dependently induced emesis within 1 min of dosing in ferrets. Intracerebroventricularly administered S(-)-eticlopride (0.01-1 microgram) also inhibited the emesis induced by s.c. administration of R(+)-7-OH-DPAT. The emetic effect of R(+)-7-OH-DPAT was unaffected by abdominal vagotomy but was markedly reduced by ablation of the area postrema. These results suggest that dopamine D3 receptors in the area postrema play an important role in R(+)-7-OH-DPAT-induced emesis in the ferret.

Essential role of Stat6 in IL-4 signalling

Interleukin-4 (IL-4) is a pleiotropic lymphokine which plays an important role in the immune system. IL-4 activates two distinct signalling pathways through tyrosine phosphorylation of Stat6, a signal transducer and activator of transcription, and of a 170K protein called 4PS. To investigate the functional role of Stat6 in IL-4 signalling, we generated mice deficient in Stat6 by gene targeting. We report here that in the mutant mice, expression of CD23 and major histocompatibility complex (MHC) class II in resting B cells was not enhanced in response to IL-4. IL-4 induced B-cell proliferation costimulated by anti-IgM antibody was abolished. The T-cell proliferative response was also notably reduced. Furthermore, production of Th2 cytokines from T cells as well as IgE and IgG1 responses after nematode infection were profoundly reduced. These findings agreed with those obtained in IL-4 deficient mice or using antibodies to IL-4 and the IL-4 receptor. We conclude that Stat6 plays a central role in exerting IL-4 mediated biological responses.

A recombinant protein based on the Trypanosoma cruzi metacyclic trypomastigote 82-kilodalton antigen that induces and effective immune response to acute infection

To further investigate the immunological properties of the stage-specific 82-kDa glycoprotein (gp82) of Trypanosoma cruzi metacyclic trypomastigotes, previously shown to induce antigen-specific humoral and T-cell responses in mice, we performed a series of experiments with recombinant proteins containing sequences of gp82 fused to glutathione S-transferase. Of five fusion proteins tested, only J18b and J18b1, the carboxyproximal peptides containing amino acids 224 to 516 and 303 to 516, respectively, were recognized by monoclonal antibody 3F6 as well as by various anti-T. cruzi antisera and, when administered to mice, were capable of eliciting antibodies directed to the native gp82. The amino-terminal peptide and other carboxyterminal recombinant proteins lacking the central domain of gp82 (amino acids 224 to 356), which is exposed on the surface of live metacyclic forms, did not display any of these properties. Spleen cells derived from mice immunized with any of the five recombinant proteins proliferated in vitro in the presence of native gp82.J18b was the most stimulatory, whereas J18b3, the peptide containing amino acids 408 to 516, elicited the weakest response. When BALB/c mice immunized with J18b antigen plus A1(OH)3 as adjuvant were challenged 10 5 metacyclic trypomastigotes, 85% of them resisted acute infection, in comparison with control mice that received glutathione S-transferase plus adjuvant. Antibodies induced by J18b protein lacked agglutinating or complement-dependent lytic activity and failed to neutralize parasite infectivity. On the other hand, CD4+T cells from the spleens of J18b-immunized mice displayed an intense proliferative activity upon stimulation with 1.25 microgram of native gp82 per ml, which resulted in increased production of gamma interferon, a cytokine associated with resistance to T. cruzi infection.

Sharp Increase in the Incidence of Mammary Carcinoma in Kagoshima Prefecture, Japan

Between 1986 and 1990, among a female population of about 0.95 million, 1184 women living in Kagoshima Prefecture were diagnosed pathologically as having mammary carcinoma. The number of patients with mammary carcinoma, the crude incidence rate per 100000 women and age-standardized mammary carcinoma incidence rates were 205, 21.29 and 19.42 in 1986, 212, 22.04 and 19.48 in 1987, 238, 24.74 and 21.8 in 1988, 245, 25.47 and 22.33 in 1989 and 284, 29.57 and 25.69 in 1990, respectively. The number of patients with this disease increased annually. The increase in the age-specific incidence rate of this type of cancer between 1986 and 1990 was 1.38-fold in women between 40 and 49 years of age, 1.46-fold in women between 50 and 59, 1.37-fold in the 60-69 age group, 1.48-fold in the 70-79 age group and 1.91-fold in women over 80. In both the urban and rural areas, the incidence increased annually during the course of this study. In 1990, the age-standardized mammary carcinoma incidence rate in urban area was 1.17 times that in rural area.

Enhanced and accelerated lymphoproliferation in Fas-null mice

Fas is a 45-kDa membrane protein that transduces an apoptotic signal. The mouse lymphoproliferation (lpr) mutation is a leaky mutation of Fas. In this study, we examined lymphocyte development in Fas-null mice generated by gene targeting. The Fas-/- mice progressively accumulated abnormal T cells (Thy1+, B220+, CD4-, and CD8-) and developed lymphadenopathy and splenomegaly, which were much more accelerated and pronounced than those in lpr mice. In addition, the Fas-null mice showed lymphocytosis, accompanied by lymphocytic infiltration in the lungs and liver. The number of apparently normal B cells also increased, and large amounts of immunoglobulins, including anti-DNA antibodies, were produced. Thymic clonal deletion, assessed by deletion of T cells reactive to mouse endogenous superantigens, was apparently normal in the Fas-/- mice, whereas the peripheral clonal deletion of mature T cells against a bacterial superantigen was impaired. These results suggested that Fas plays a decisive role in peripheral clonal deletion but not in negative selection in the thymus.

A novel synthesis method for cyclodextrins from maltose in water-organic solvent systems

A novel enzymatic synthesis method of cyclodextrin (CD) from low-mol-wt maltose using cyclomaltodextrin glucanotransferase (CGTase) from Bacillus macerans has been developed in various water-organic solvent systems. A beta-CD was synthesized in a two-phase system consisting of water and cyclohexane. However, no CDs could be synthesized in an aqueous buffer solution. A maximal yield of beta-CD has been obtained at a cyclohexane content volume of 44%. This synthesis has been obtained only at low temperatures, i.e., 7 degrees C, and did not take place at 50 degrees C. In addition, various organic solvents have been used for the enzymatic synthesis of CD from maltose. Consequently, beta-CD could be synthesized in various water-organic solvent systems, e.g., cyclohexane, benzene, xylene, and chloroform, but no enzymatic reaction occurred using aliphatic n-hydrocarbon solvents such as hexane, dodecane, and hexadecane. Furthermore, alpha- and beta-CD could be synthesized in water mixture solutions using organic solvents having an alcoholic group (e.g., ethanol, propanol, butanol, and pentanol) in a wide range of the reaction temperatures, typically 7-50 degrees C. In this temperature range, alpha- and beta-CD were also formed and the maximal yield from maltose to beta-CD of approx 13% was reached in 60 h.

Simultaneous assessment of regional adrenergic activity and perfusion with 123I-MIBG and 201Tl in congestive heart failure

Simultaneous assessment of regional adrenergic activity and perfusion with 123I-meta-iodobenzylguanidine (123I-MIBG) and 201Tl in various organs was performed in 13 patients with congestive heart failure (CHF) and 13 subjects without heart failure. In order to reduce the crosstalk of 201Tl to the 123I energy window to less than 5%, a dose of 123I-MIBG more than five times greater than that of 201Tl was administered following 201Tl scintigraphy. Regional uptake of 201Tl (%dose) was significantly increased in the heart (left ventricle) and lung (both P < 0.01) in the patients with CHF. The increased global cardiac uptake could have been related to the enlarged left ventricle. The patterns of regional uptake of 123I-MIBG (% dose) at 15 min were similar to those of 201Tl, suggesting that early 123I-MIBG uptake could in part depend on regional perfusion in both groups. At 3 h, regional uptake of 123I-MIBG was significantly increased in the heart, lung and kidney (all P < 0.01) in the patients with CHF. The delayed 123I-MIBG uptake indicates the degree of neuronal accumulation of the tracer, and therefore reflects adrenergic activity. Interestingly, the cardiac 123I-MIBG (adrenergic activity) to 201Tl (unit of perfusion) ratio decreased significantly in the heart (P < 0.01) but increased significantly in the kidney (P < 0.01) in the patients with CHF compared with the control group. Cardiac 123I-MIBG washout was also significantly increased in the CHF patients. Moreover, the cardiac 123I-MIBG:201Tl ratio was negatively correlated with plasma norepinephrine concentration (r = -0.74, P < 0.01), but positively correlated with LVEF (r = 0.60, P < 0.01). These data suggest that there may be impairment of both the neuronal uptake function and the vesicular storage function in the failing heart, and an increment in neuronal uptake function in the kidneys in patients with CHF. We suggest that dual-tracer scintigraphy is a useful non-invasive method for the simultaneous assessment of adrenergic activity and perfusion in various organs in patients with heart failure.

Targeted disruption of gp130, a common signal transducer for the interleukin 6 family of cytokines, leads to myocardial and hematological disorders

gp130 is a ubiquitously expressed signal-transducing receptor component shared by interleukin 6, interleukin 11, leukemia inhibitory factor, oncostatin M, ciliary neurotrophic factor, and cardiotrophin 1. To investigate physiological roles of gp130 and to examine pathological consequences of a lack of gp130, mice deficient for gp130 have been prepared. Embryos homozygous for the gp130 mutation progressively die between 12.5 days postcoitum and term. On 16.5 days postcoitum and later, they show hypoplastic ventricular myocardium without septal and trabecular defect. The subcellular ultrastructures in gp130-/- cardiomyocytes appear normal. The mutant embryos have greatly reduced numbers of pluripotential and committed hematopoietic progenitors in the liver and differentiated lineages such as T cells in the thymus. Some gp130-/- embryos show anemia due to impaired development of erythroid lineage cells. These results indicate that gp130 plays a crucial role in myocardial development and hematopoiesis during embryogenesis.

Production of fructosyl lysine oxidase from Fusarium oxysporum S-1F4 on autoclave-browned medium

In Fusarium oxysporum S-1F4, fructosyl lysine oxidase (FLOD) was induced with N epsilon-fructosyl N alpha-Z-lysine (epsilon-FL), which is a model compound of a glycated protein, and the induction was inhibited by the addition of cycloheximide in the growing cells. FLOD formation was greatly enhanced in an autoclave-browned medium containing glucose and L-lysine. Some Amadori compounds formed from glucose and L-lysine during autoclaving were assumed to induce the enzyme. After optimization of the culture conditions, FLOD produced in the browned medium was comparable to that in the medium with epsilon-FL.

Treatment of high-risk acute lymphoblastic leukemia in children using the AL851 and ALHR88 protocols: a report from the Kyushu-Yamaguchi Children's Cancer Study Group in Japan

A total of 125 children, who were diagnosed as having high-risk acute lymphoblastic leukemia (ALL), were treated with two consecutive protocols designated as AL851 (1985-1988) and ALHR88 (1988-1990). All patients received induction therapy consisting of vincristine (VCR), prednisolone (PSL), daunorubicin (DNR), and I-asparaginase (I-Asp). In the ALHR88 protocol, the patients whose blasts in the bone marrow (BM) were > or = 25% on day 14 of induction therapy and who were classified into T-cell type received additional cytosine arabinoside (AraC). After consolidation with intermediate-dose methotrexate (MTX), reinduction therapy including VCR, dexamethasone, and adriamycin followed by high-dose AraC was done for all patients. Intrathecal MTX and 24Gy of cranial irradiation were used to prevent central nervous system leukemia. A maintenance therapy consisting of 6-mercaptopurine, cyclophosphamide, MTX, DNR, VCR, and AraC was administered for 3 years after achieving a complete remission (CR). CR was achieved in 51/55 (92.7%) for AL851 and 68/70 (97.1%) for ALHR88. The 5-year event-free survival rates were 49.1 +/- 6.7% in AL851 and 62.5 +/- 6.1% in ALHR88. The factors related to a poor prognosis were a high initial leukocyte count of greater than 50 x 10(9)/L (P < 0.001), an L2 morphology of leukemic cells by FAB classification (P = 0.009), the chromosomal abnormality (P = 0.004) and high residual leukemic cells in BM (> or = 25%) on day 14 of induction therapy (P < 0.001). Taking these factors into consideration, more intensive protocols were started in 1990 for the patients with high-risk ALL.

Effect of a novel histamine H2 receptor antagonist, IT-066, on acute gastric injury induced by ischemia-reperfusion in rats, and its antioxidative properties

The effect of a novel histamine H2 receptor antagonist IT-066 (3-amino-4-[4-[4-(1-piperidinomethyl)-2-pyridyloxy]-cis-2-++ +butenylamino]- 3-cyclobutene-1,2-dione hydrochloride), on acute gastric mucosal injury induced by ischemia-reperfusion was investigated from the standpoint of oxygen radical-mediated lipid peroxidation in rats. Ischemia-reperfusion injury was produced in the rat stomach by applying a small vascular clamp to the celiac artery for 30 min and subsequent removal of the clamp for 60 min. The decrease in gastric mucosal blood flow was not influenced by treatment with IT-066. The antiulcer activity of IT-066 was demonstrated in this injury after intragastric ingestion as well as after intravenous injection. IT-066 significantly inhibited this injury in the presence of exogenous HCl. The mucosal protection by IT-066 was not reversed by pretreatment with indomethacin or nitric oxide synthase inhibitor. The increase in lipid peroxides in the gastric mucosa after ischemia-reperfusion was significantly inhibited by the intragastric treatment with IT-066 at doses of 1.0 and 3.0 mg/kg. The total area of erosions closely paralleled the accumulation of lipid peroxide with a significant correlation. A spin trapping method using 5,5-dimethyl-1-pyrroline-N-oxide showed that IT-066 scavenged superoxide radical and hydroxyl radical generated by the hypoxanthine-xanthine oxidase system and the hydrogen peroxide-ferrous iron system, respectively. IT-066 also significantly inhibited the in vitro increase of lipid peroxide in the gastric mucosal homogenates induced by a free radical initiator. These results suggest that the protective effect of IT-066 against ischemia/reperfusion-induced gastric mucosal injury may result in part from its antioxidative properties.

Purification and characterization of a new serine proteinase from Bacillus subtilis with specificity for amino acids at P1 and P2 positions

A proteinase was purified 230-fold to apparent homogeneity from culture filtrates of Bacillus subtilis by a series of column chromatographies on DE52, DEAE-Toyopearl, Cellulofine GC200M, and Mono-Q, using Boc-Ala-Ala-Pro-Ser-pNA as a substrate. The molecular weight of the proteinase was estimated to be 42,000 by SDS-PAGE in the presence of 2-mercaptoethanol. Studies on the substrate specificity with peptide p-nitroanilides and natural peptides revealed that this proteinase preferentially hydrolyzed the peptide bond on the carboxyl-terminal side of either serine or alanine residues at the P1 position and hydrophobic bulky amino acids at P2. It was most active at pH 9.5 for the hydrolysis of Boc-Ala-Ala-Pro-Ser-pNA. The enzyme was inactivated by diisopropyl fluorophosphate (DFP), but not by tosyl-L-phenylalanine chloromethylketone (TPCK) or by EDTA. Based on the reactivity toward substrates and inhibitors, this enzyme differs from elastase- or subtilisin-like proteinase, hence it is a new type of proteinase with specificity for amino acids at P1 and P2 positions.

[Subgingival distribution of periodontopathic bacteria in periodontic patients and susceptibility of these bacteria to minocycline-HCl]

The present study was carried out to examine the distribution of six periodontopathic bacteria in deep periodontal pockets and to reconfirm the effect of Periocline on these periodontopathic bacteria. Samples from sixty-two periodontal pockets were collected at pocket depths of over 4 mm in twenty-one periodontitis patients aged 43 to 75 years. After sampling, Periocline was applied topically to the selected pockets once a week for four weeks and reexamined. The detected rates of the periodontopathic bacteria were Capnocytophaga sputigena (37.1%), Prevotella intermedia (22.6%), Porphyromonas gingivalis (22.6%), Fusobacterium nucleatum (20.1%), Actinobacillus actinomycetemcomitans (9.7%) and Eikenella corrodens (4.8%). The distribution of the bacteria was compound because two or three bacterial species were found to coexist. In view of the MIC of minocycline-HCI for these bacteria, increase of most of the measured bacteria was suppressed by the concentration of drugs, including Periocline. However, clinical strains of P. i. were considered to have low susceptibility to minocycline-HCl. In view of the effect of topical application of drugs, no significant differences were found. From these results, it was suggested that Periocline contained effective concentration of minocycline-HCl.