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Biomedical subjects

M Shibata

Publications and source records attributed to M Shibata.

At least 271 records · Page 15Linked to original sources
PubMed1997

[Detection of the thermostable lipase gene (lipAH) in clinical isolates of Aeromonas hydrophila belonging to the major O serogroups O11, O16 and O34].

On the basis of DNA hybridization data and phenotypes, most pathogenic strains of Aeromonas hydrophila are grouped into hybridization group 1 (HG1). These pathogenic strains secret the theromostable lipase, and it's gene (lipAH) has been cloned and sequenced. The present study was performed to identify the pathogenic strains of A. hydrophila by the polymerase chain reaction (PCR) technique to detect the lipAH. Synthetic oligonucleotide primers (lipAH-ns-1 and -na-1) were used in the PCR. The PCR identified 80% of lipAH-positive strains, consisting of seven of the 11 O11 strains (64%), 13 of the 15 O16 strains (87%) and 25 of the 30 O34 strains (83%) in clinical isolates of A. hydrophila used in this study.

Aeromonas hydrophila↗
PubMed1997

[Sporadic diarrhea caused by Vibrio cholerae non-O1 and characteristics of the isolates].

In 1996, we examined five domestic and eight imported cases of sporadic diarrhea caused by Vibrio cholerae non-O1 in Tokyo. The domestic cases occurred during the summer, from June to September, while the imported cases were seen throughout the year. The major clinical symptoms of the patients were watery diarrhea (100%) with an average frequency of 5.5 times/day, abdominal pain (77%), vomiting (31%) and fever (15%). A total of 13 strains isolated from these 13 cases had the typical biochemical characteristics of Vibrio cholerae, and were classified into 11 kinds of serovars (O2, O5, O8, O9, O12, O14, O27, O51, O88, O97, and O161). All strains produced hemolysin, and two strains produced NAG-ST, while no strain produced cholera toxin.

Adult↗
PubMed1997

The selective capsaicin antagonist capsazepine abolishes the antinociceptive action of eugenol and guaiacol.

The dental phenolic medicaments, eugenol and guaiacol, are partly similar in chemical structure to capsaicin, the pungent constituent of chili peppers, which selectively activates sensory neurons via a specific receptor. We have previously demonstrated that these phenolic compounds show capsaicin-like action. In the present study, an attempt was made to investigate the possibility that these compounds interact with the same cellular site as capsaicin, by using capsazepine, a selective and competitive anta-gonist of capsaicin. Intrathecal (i.t.) treatment with eugenol (12.5 to 50 micrograms), guaiacol (25 to 150 micrograms), or capsaicin (1 to 4 micrograms) for 24 h dose-dependently inhibited the formalin-induced nociceptive response. Capsazepine (5, 10 micrograms, i.t.) shifted these dose-response curves in parallel to the right. Similarly, capsazepine abolished antinociceptive effects of eugenol (50 micrograms), guaiacol (150 micrograms), or capsaicin (2 micrograms) in the acetic acid writhing test. These results suggest that eugenol and guaiacol may exert their antinociceptive effects via the capsaicin receptor located on sensory terminals in the spinal cord.

Analgesics, Non-Narcotic↗
PubMed1997

The effects of intraventricular/periventricular blood on cerebral 3',5'-cyclic adenosine monophosphate concentration and cerebrovascular reactivity in newborn pigs.

This study investigated the effects of intraventricular/periventricular blood on cerebral cAMP production and cortical cerebrovascular reactivity. Under halothane and N2O anesthesia, 3 mL of either autologous blood or artificial cerebrospinal fluid (CSF) were injected into the left caudate nucleus; volume was adequate to result in extrusion of fluid or blood into the lateral ventricles of 1-2-d-old piglets. Twenty-four hours later, a closed cranial window was implanted over the left parietal cortex. Pial arteriolar responses to vasodilator and vasoconstrictor stimuli were monitored. Before the application of vasoactive agents, cortical periarachioid CSF was collected for cAMP measurement. Pial arteriolar responses to topical application of endothelin-1 (10(-9) and 10(-8) M) and to leukotriene C4 (10(-10) and 10(-9) M) were similar between the two groups. However, pial arteriolar responses to topical application of cAMP-mediated vasodilators, prostaglandin E2 (10(-6) and 10(-5) M), and histamine (10(-6) and 10(-5) M), respectively, were markedly reduced in the blood group when compared with the artificial CSF (control) group. Mean CSF cAMP level in the blood group was significantly lower than the control group (199 +/- 31 versus 1092 +/- 238 fmol/mL, p = 0.0006). We conclude that in newborn pigs intraventricular/periventricular blood results in a marked reduction of CSF cAMP concentration and attenuation of the cerebrovascular responses to cAMP-mediated vasodilators on the cortical surface remote from the site of blood or hematoma.

Animals↗
PubMed1997

[Effect of a novel tachykinin NK-2-receptor antagonist, TAC-363, on bronchoconstriction and airway hyperresponsiveness in guinea pigs].

We examined the effect of a novel tachykinin NK-2-receptor antagonist, N alpha-(tert-Butylcarbamoyl)-L-glutaminyl-L-tryptophyl-alpha-aza- phenylalanine 2-benzyloxyethylamide (TAC-363), on hyperventilation- and citric acid-induced bronchoconstriction and neurokinin A (NKA)-, capsaicin- and antigen-induced airway hyperresponsiveness in guinea pigs. The i.v. administration of TAC-363 at doses of 0.01-1 mg/kg inhibited hyperventilation- and citric acid-induced bronchoconstriction in a dose-dependent manner, while FK-888, a tachykinin NK-1-receptor antagonist, did not inhibit hyperventilation-induced bronchoconstriction. NKA-induced airway hyperresponsiveness to acetylcholine was attenuated by i.v. injection of TAC-363, but not by the thromboxane A2 synthetase inhibitor ozagrel and the mast cell stabilizer DSCG. Furthermore, TAC-363 prevented the occurrence of capsaicin- and antigen-induced airway hyperresponsiveness to acetylcholine, while FK-888 did not prevent occurrence of capsaicin-induced airway hyperresponsiveness. In summary, TAC-363 inhibits bronchoconstriction and airway hyperresponsiveness induced by various stimuli. These results suggest that NKA mediates bronchoconstriction and airway hyperresponsiveness. Thus, TAC-363 is expected to be useful in the treatment of airway diseases such as asthma.

Animals↗
PubMed1997

[Effect of a novel antiulcer drug, lafutidine, on experimental chronic gastritis in rats].

Oral administration of an ammonia solution (0.01%) or a sodium taurocholate solution (TCA solution, 5 mM) as drinking water for 4 weeks or 13 weeks, respectively, resulted in gastric mucosal thinning and decreased parietal cell numbers. Oral administration of TCA solution also caused cell infiltration in the lamina propria of the mucosa and mucosal fibrosis. When lafutidine (3, 10 mg/kg) was administered orally once daily for one week after the withdrawal of ammonia or TCA solution, the recovery of the mucosal thickness in the fundic gland area and the parietal cell number were significantly accelerated, and the recovery of mucosal thickness in the pyloric gland area also tended to be accelerated. Lafutidine at 10 mg/kg for 1 week had no influence on normal mucosal thickness and parietal cell numbers. At the doses that produce equal or greater acid antisecretory effect than lafutidine, oral administration of cimetidine (30 mg/kg) and famotidine (1 mg/kg) had no effect on either of these atrophy indexes. These results demonstrate that lafutidine, unlike cimetidine and famotidine, can accelerate the healing of mucosal injuries in ammonia- and TCA-induced chronic gastritis models.

Acetamides↗
PubMed1997

A novel metalloproteinase, almelysin, from a marine bacterium, Alteromonas sp. No. 3696: purification and characterization.

We have discovered a novel metalloproteinase, which has high activity at low temperatures, from the culture supernatant of a marine bacterium. The strain was identified as Alteromonas sp. No. 3696. The metalloproteinase, named almelysin, was purified to homogeneity from the cultured supernatant at 10 degrees C by two column chromatographies. About 20 mg of purified almelysin was obtained from 18.4 liters of the culture supernatant. The molecular mass of almelysin was estimated to be 28 kDa by SDS-PAGE and the isoelectric point was 4.3. The optimum pH for activity of almelysin was pH 8.5-9.0 and 6.5 using casein and (7-methoxycoumarin-4-yl)acetyl(MOCAc)-Pro-Leu-Gly-Leu-(N3- [2,4-dinitrophenyl]-L-2,3-diaminopropionyl) [A2pr(Dnp)]-Ala-Arg-NH2 as substrates, respectively. Almelysin was stable between pH 7.5-8.0 and below 40 degrees C. The optimum temperature for the activity was observed to be 40 degrees C using both casein and MOCAc-Pro-Leu-Gly-Leu-A2pr(Dnp)-Ala-Arg-NH2 as substrates. The activity of almelysin was inhibited by such metallo chelators as EDTA and o-phenanthroline, while talopeptin, phosphoramidon, and SMPI, typical metalloproteinase inhibitors, had no effect. Almelysin primarily cleaved the Ala14-Leu15 bond and Phe24-Phe25 bond, and secondarily the Tyr16-Leu17 bond in oxidized insulin B-chain. However, almelysin could not cleave the His5-Leu6, His10-Leu11, and Gly23-Phe24 bonds, which were cleaved by other metalloproteinases. These results indicate that the substrate specificity of almelysin is different from other metalloproteinases. Interestingly, Alteromonas sp. No. 3696 strain produced another proteinase as well as almelysin at 25 degrees C.

Amino Acid Sequence↗
PubMed1997

Effects on endotoxin pathogenicity in pigs with acute septicemia of Haemophilus parasuis infection.

Changes of endotoxin in plasma, and the response of the coagulation system and blood cells in septicemia of Haemophilus parasuis infection were examined by inoculation with H. parasuis in specific pathogen-free (SPF) pigs. Eight pigs were inoculated intratracheally with 10(5), 10(6) and 10(7) colony formation units (CFU) of the strain Nagasaki (serovar 5). All pigs died 28 to 42 hr after inoculation. Haematologically, severe leukopenia occurred 24 hr post inoculation (hpi) until death. Glucose concentration decreased from 24 hpi to death. In the coagulation system, decrease of platelet counts, prolongation of prothrombin time, activated partial thromboplastin time, and increase of fibrinogen-fibrin degradation products were observed in all inoculated pigs. Endotoxin was detected in the plasma of all the inoculated pigs from 16 hpi to death, and its concentration rose dramatically just before death. H. parasuis was re-isolated from the blood of all inoculated pigs from 16 hpi to death, and also from almost all organs and body fluids of the pigs. The pigs had microthrombi in the kidney, liver and lungs, and many also had pneumonia, meningitis and serositis. H. parasuis antigen was detected in the lesions by the immunoperoxidase technique. The results indicated that disseminated intravascular coagulation (DIC) and endotoxin shock involved aggravation of clinical signs and death on the pigs induced to septicemia of H. parasuis.

Animals↗
PubMed1997

Activities of D- and L-xyloascorbic acid and D- and L-araboascorbic acid as a cofactor for dopamine beta-hydroxylase reaction.

L-Xyloascorbic acid (L-xylo-AsA) and its three stereoisomers, D-xyloascorbic acid (D-xylo-AsA), L-araboascorbic acid (L-arabo-AsA) and D-araboascorbic acid (D-arabc-AsA), have been considered to show some differences in vitamin C activity. In this paper the effect of L-xylo-AsA, D-xylo-AsA, L-arabo-AsA and D-arabo-AsA on the activity of dopamine beta-hydroxylase was studied to clarify whether or not the structural specificities of these stereoisomers have different effects on enzyme activity. The maximum velocity (Vmax) of the hydroxylation and Km for ascorbic acid were calculated using double-reciprocal plotting. Vmax for L-xylo-AsA was estimated to be 201 nmol/min/mg protein and those of D-xylo-AsA, L-arabo-AsA and D-arabo-AsA were 157 nmol/min/mg protein, 112 nmol/min/mg protein and 194 nmol/min/mg protein, respectively. Km for L-xylo-AsA was 1.5 mM and those for D-xylo-AsA, L-arabo-AsA and D-arabo-AsA were 2.3 mM, 2.7 mM and 1.4 mM, respectively. The effect of D-arabo-AsA on the activity of dopamine beta-hydroxylase was almost the same as that of L-xylo-AsA, while D-xylo-AsA and L-arabo-AsA showed smaller effects. Our results suggest that the configuration at carbon 4 might be more important than that of the hydroxyl group at carbon 5 for the development of the activity as a cofactor for dopamine beta-hydroxylase reaction.

Animals↗
PubMed1997

[Interferon treatment for hepatitis G virus infection in patients with chronic hepatitis C].

Clinical features of HGV infection as a novel virus infection have not yet been clarified enough. We studied the implication of HGV in the activity of hepatitis and the sensitivity of HGV to IFN. We treated 10 HGV RNA positive patients with chronic hepatitis C with IFN. HGV RNA was identified in serum by RT-PCR method using the primer derived from the base sequences of the NS5 region of HGV genome. HGV RNA became negative in the all of 10 patients during IFN treatment, but returned to be positive again in the all patients after the completion of IFN treatment. In 5 of 10 patients, HCV RNA became persistently negative. In 3 of these 5 patients, ALT was continuously normal and hepatitis subsided biochemically and clinically after IFN treatment. We assume that HGV is sensitive to IFN, but could not be implicated in hepatitis or liver damage.

Adult↗
PubMed1997

Adsorption of levocabastine eye drops by soft contact lenses and its effects in rabbit eyes.

PURPOSE: We evaluated the adsorption of levocabastine (LEV) eye drops onto soft contact lenses in rabbit eyes to confirm the safety of this antihistaminic and antiallergic agent. METHODS: Low- and high- water-content soft contact lenses were placed on the eyes of three rabbits for each type of soft contact lens (total: six rabbits) for 8 hours daily. LEV eye drops and physiological saline solution (used as a control) were instilled into the experimental eye and the fellow eye at a dosage of 0.1 mL per eye, at 1 hour intervals, eight times daily, for 6 consecutive days. Severity of possible eye injury was evaluated before soft contact lens insertion and after removal. RESULTS: After completion of the study, the amounts of LEV and the preservative benzalkonium chloride (BAK) adsorbed onto the soft contact lenses were assayed using high-performance liquid chromatography. There were no significant differences between the experimental solution and the control solution using Draize's method scores or slit lamp evaluation. CONCLUSION: LEV and BAK accumulated only slightly in the soft contact lenses, leading us to conclude that LEV eye drops could be used safely by soft contact lens wearers for about 1 week.

Adsorption↗
PubMed1997

Analysis of mother-to-infant transmission of hepatitis C virus: quasispecies nature and buoyant densities of maternal virus populations.

Mother-to-infant transmission of hepatitis C virus (HCV) was analyzed by sequencing of viral RNA and semiquantitative polymerase chain reaction following ultracentrifugation of maternal sera. In two mother-infant pairs, the hypervariable region 1 (HVR1) and carboxyl terminus of envelope 1 (E1) were sequenced. Both viral sequences in the infants were less diverse than those of their mothers. Although the E1 sequences were almost identical in each mother-infant pair, the HVR1 sequences of the infants were related, but not identical, to those of the mothers. Serial examinations of one infant revealed that the HVR1 nucleotide sequence did not change from 10 days to 3 months of age. In six mothers with uninfected infants, all of the dense fractions of sera contained significant amounts of HCV RNA, whereas in six mothers with infected infants, only two of those fractions contained significant amounts of HCV RNA. These results indicate that the strains of HCV detected in the infants were not dominant in the mothers, but were still transmissible to the infants. As dense fractions are known to contain antibody-bound HCV particles, maternal antibodies against HCV may inhibit viral transmission.

Amino Acid Sequence↗
PubMed1997

[An elderly patient with infectious endocarditis complicated with congestive heart failure due to mitral and tricuspid regurgitation].

A 77-year-old man was referred to our hospital on October 2, 1995 because of fever and left mandibular pain beginning three months before admission. His blood pressure was 90/60 mmHg. A grade III/VI pansystolic murmur was heard over the cardiac apex. The liver was palpable 4 cm below the right costal margin. Lower extremity edema was present bilaterally. White blood cell count was 7,030/mm3 and C-reactive protein was 2.54. Enterococcus faecalis was identified by the blood culture. The diagnosis was infective endocarditis associated with congestive heart failure. He was treated by administration of antibiotics and diuretics. Mitral valve replacement and tricuspid annuloplasty were performed on October 19 because of progressive congestive heart failure with oliguria. The surgical intervention was successful despite the presence of multiple risk factors: high age, emergency, congestive heart failure and active infection. His condition improved dramatically after the operation and he was discharged two months later. Surgical intervention for infective endocarditis was a significant high-risk procedure in this uncontrollable and elderly case. This successful result suggests the indication for the timing of surgery.

Aged↗
PubMed1997

[Combination therapy with 5'-DFUR, MMC and CDDP in patient with far advanced gastric cancer: report of a case].

A 48-year-old man was referred to our hospital for a Borrmann 3 type advanced gastric cancer. Endoscopic biopsy disclosed poorly differentiated adenocarcinoma. Ultrasonography and CT scan revealed left hydronephrosis. Endoscopic retrograde cholangiography detected a stenosis of common bile duct at the hepatic hilum due to lymph nodal metastasis, and laparoscopy revealed peritoneal dissemination. Because the tumor was diagnosed as not for curative resection, the patient was treated by 4 courses of combination therapy with 5'-DFUR, MMC and CDDP. No adverse effect of chemotherapy was observed. As a result, lymph nodal metastasis and peritoneal dissemination were reduced. Curative intent total gastrectomy was performed, together with pancreatico-splenectomy, left hemicolectomy, cholecystectomy, and extended lymph nodal dissection. The patient is well and alive with no sign of recurrence 2 years after operation.

Adenocarcinoma↗
PubMed1997

[A case of esophageal leiomyoma found as mediastinal tumor, diagnosed with endoscopic ultrasonography].

A 20 year-old female was admitted to our department because of an abnormal shadow in chest roentgenogram on a physical check-up. The barium swallowing study revealed an oppression of the middle of the esophagus. Endoscopy, chest CT and MRI failed to distinguish submucosal tumor from mediastinal tumor. Endoscopic ultrasonography showed the mass originated from the esophagus and a diagnosis of esophageal smooth muscle tumor was obtained. The tumor was tried to resect by thoracoscopic surgery but was failed because of its shape like a tortoise shell. The tumor was resected through the right thoracotomy and the diagnosis was confirmed histopathologically.

Adult↗
PubMed1997

[A case of postencephalitic intractable partial epilepsy with multiple brain lesions demonstrated by MRI].

We encountered a case of focal encephalitis. A 5-year-old boy developed high fever and he was admitted to our hospital on the third day with generalized tonic-clonic convulsions. Cerebrospinal fluid showed slight pleocytosis. CT showed diffuse low-density area in the left temporal, parietal and occipital regions. T2 weighed MRI showed swelling and hyperintense regions in the left temporal, parietal and occipital cortex. With the disappearance of generalized convulsion, the cortical swelling improved. But aphasia and intractable complex partial seizures appeared. On MRI, the atrophic findings of the left hippocampus and temporal lesion became developed. We considered this case corresponds to focal encephalitis related to "a peculiar type of post-encephalitic/encephalopathic epilepsy" reported by Awaya et al.

Child↗
PubMed1997

[Western blot analysis of anti-M2 antibodies in anti-mitochondrial antibody-negative primary biliary cirrhosis].

One variety of anti-mitochondrial antibody(AMA) is characteristically found in sera from patients with primary biliary cirrhosis(PBC). The major target antigens of this type of AMA are M2s. It is well known, however, that AMA-negative PBC also exists. An alternative disease concept, called autoimmune cholangiopathy, recently has been advocated. This new concept is defined by the following criteria: 1)the failure to detect AMA and anti-M2, 2)the detection of a diffuse type of anti-nuclear antibody and anti-smooth muscle antibody, 3)pathological findings compatible with PBC, and 4)the effectiveness of prednisolone. However, the difference between AMA-negative PBC and autoimmune cholangiopathy is controversial. Therefore, we analyzed antibodies to four major M2 proteins with Western blotting in 34 cases of immunofluorescent AMA-negative PBC. In 31(91.2%) of these 34 AMA-negative sera, antibodies to at least one of these four major M2 proteins was detected. In serum samples from 34 control patients with AMA-positive PBC, antibodies to at least one of these four proteins were detected in all cases. In addition, we studied the frequency of cases which satisfied the serological criteria of autoimmune cholangiopathy. In only one(0.7%) of 141 cases was the serological criteria met. We conclude that to clarify the serological differences between autoimmune cholangiopathy and AMA-negative PBC, the analysis of M2 proteins by Western blotting is essential.

Adult↗