Search PubMed⌕ Search

Biomedical subjects

K Wada

Publications and source records attributed to K Wada.

At least 325 records · Page 18Linked to original sources
PubMed1997

Effect of plaunotol on gastric injury induced by ischaemia-reperfusion in rats.

Plaunatol, an anti-ulcer drug, increases prostaglandin content in gastric tissue but its effect on radical-mediated gastric damage or activity against reactive oxygen species is unknown. We examined the effects of oral administration of plaunotol (Kelnac) on the acute gastric mucosal lesion and its progression to ulcer lesion induced by ischaemia-reperfusion in rats. Plaunotol (30 and 100 mg kg-1, 15 min before ischaemia) significantly reduced the total erosion area observed immediately after ischaemia-reperfusion. When plaunotol (30 and 100 mg kg-1, once a day) was administrated orally 60 min after reperfusion, it prevented the progression from erosion to ulcer. At 72 h after ischaemia-reperfusion, the total area of ulcers lesions was significantly reduced compared with that without plaunotol administration. Furthermore, treatment with plaunotol (100 mg kg-1) significantly increased prostaglandin E2 content in gastric tissues of both acute gastric mucosal lesion and gastric ulcer lesion. In in-vitro experiments, plaunotol (1-3 mg mL-1) reduced the superoxide radicals generated by leucocytes, but not by xanthine oxidase. These results indicate that plaunotol has protective effects on both the onset of acute gastric mucosal injury and its progression to ulcer lesion induced by ischaemia-reperfusion. Both effects of plaunotol on increase in prostaglandin content in gastric tissues and inhibition of superoxide radical from leucocytes may play important roles on the protection against gastric mucosal injury.

Animals↗
PubMed1997

[Usefulness of 7 day therapy with cefluprenam in the management of respiratory tract infections].

Efficacy and safety of a newer injectable cephalosporin, cefluprenam (CFLP) on cases with bacterial pneumonia and chronic respiratory tract infections were evaluated at a dose of 1g (potency), d.i.d for 7 days. 1. Of 130 cases in total, 116 cases were enrolled for the clinical efficacy evaluation. The efficacy rate (excellent and good responses) was 94.8% (110/116). The efficacy rate was 93.8% (60/64) for cases with bacterial pneumonia, and 96.2% (50/52) for cases with chronic respiratory tract infections. The recurrence was noted in 1.2% (1/82). The bacteriological response rate was 100.0% (32/32) for gram positive cocci, 93.8% (15/16) for gram negative rods and 97.9% (47/48) in total. 2. Adverse drug reactions were noted in 3.9% (5/129), consisting of 2 cases with skin rash, 1 case with drug fever, 1 case with skin rash and skin itching and 1 case with drug fever and headache. The abnormal laboratory changes were noted in 23.6% (30/127), mainly containing the elevation in GPT and GOT, and eosinophylia. The safety rate (no problem evaluation) was 74.8% (95/127). 3. The usefulness rate (very useful and useful evaluations) was 93.1% (108/116). As suggested by the evaluation on the secondary endpoint in the phase III comparative studies with both bacterial pneumonia and chronic respiratory tract infections, it was confirmed that the 7 day therapy of CFLP was promising for treatment of moderate bacterial pneumonia and chronic respiratory tract infections, because the high clinical efficacy was obtained and also the incidence of allergic reactions with CFLP was almost the same as that of ceftazidime (CAZ) evaluated highly safe. Based on these results, it was concluded that CFLP was useful in the management of moderate respiratory tract infections and also the recommended therapeutic period with CFLP was within 7 days.

Adult↗
PubMed1997

Tidal volume effects on surfactant treatment responses with the initiation of ventilation in preterm lambs.

We hypothesized that initiation of ventilation in preterm lambs with high volumes would cause lung injury and decrease the subsequent response to surfactant treatment. Preterm lambs were randomized to ventilation for 30 min after birth with 5 ml/kg (VT5), 10 ml/kg (VT10), or 20 ml/kg (VT20) tidal volumes and then ventilated with approximately 10 ml/kg tidal volumes to achieve arterial PCO2 values of approximately 50 Torr to 6 h of age. VT20 lambs had lower compliances, lower ventilatory efficiencies, higher recoveries of protein, and lower recoveries of surfactant in alveolar lavages and in surfactant that had decreased compliances when tested in preterm rabbits than VT5 or VT10 lambs. Other lambs randomized to treatment with surfactant at birth and ventilation with 6, 12, or 20 ml/kg tidal volumes for 30 min had no indicators of lung injury. An initial tidal volume of 20 ml/kg decreased the subsequent response to surfactant treatment, an effect that was prevented with surfactant treatment at birth.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1997

Effects of sucralfate on acute gastric mucosal injury and gastric ulcer induced by ischemia-reperfusion in rats.

We have revealed that acute gastric mucosal injury induced by a single ischemia-reperfusion (I-R) treatment develops into an ulcerative lesion within a few days. In the present studies, we examined the effects of oral administration of sucralfate on gastric damage induced by I-R. Sucralfate (1-100 mg/kg, 15 min before I-R) significantly reduced the total erosion area observed immediately after I-R. A high dose of sucralfate (30-100 mg/kg) inhibited the increase in the thiobarbituric acid-reactive substances, an index of lipid peroxidation, induced by I-R, although a low dose of it failed. When sucralfate (30 mg/kg, once a day) was orally administered after I-R, it prevented mucosal damage from developing into gastric ulcers: the total area of the ulcers was significantly reduced compared to that without sucralfate administration 72 h after I-R. High concentrations of sucralfate (3-10 mg/ml) reduced the superoxide radicals generated by leukocytes or xanthine-xanthine oxidase, and protected erythrocyte membrane ghosts against lipid peroxidation induced by hydrogen peroxide and Fe2+ in vitro. These results indicate that sucralfate may prohibit both the generation of acute gastric mucosal injury and its progression to ulcer induced by I-R, probably due to a cytoprotective action on the mucosal surface. However, the protective mechanism may involve an inhibitory action on superoxide and hydroxyl radicals at high doses.

Animals↗
PubMed1997

Protective effect of acetaminophen against acute gastric mucosal lesions induced by ischemia-reperfusion in the rat.

We examined the effect of acetaminophen, an analgesic and antipyretic drug, on acute gastric mucosal injury induced by ischemia-reperfusion in rats. Ischemia-reperfusion was induced by clamping the celiac artery for 30 min with a small clip. Sixty minutes after reperfusion, the total area of erosions was measured. Acetaminophen (300 and 500 mg/kg) administered intraperitoneally 90 min before the ischemia significantly reduced the total area of erosions. The drug also inhibited the increase in lipid peroxide levels induced by ischemia-reperfusion in the gastric tissue and the increase in lipid peroxidation caused by the hydroxyl radical, OH., in vitro. Gastric prostaglandin E2 (PGE2) contents tended to increase after ischemia-reperfusion in both control and acetaminophen-treated groups. A significant difference in gastric PGE2 contents between control and acetaminophen-treated groups was not observed. The results indicate that acetaminophen may protect the gastric mucosa against ischemia-reperfusion injury, probably by blocking hydroxyl-radical-induced membrane damage.

Acetaminophen↗
PubMed1997

Effects of cimetidine on acute gastric mucosal injury induced by ischemia-reperfusion in rats.

We investigated the effects of cimetidine on acute gastric mucosal injury induced by ischemia-reperfusion in rats. Under pentobarbital anesthesia, the celiac artery was clamped for 30 min and reperfused for 60 min. Cimetidine, famotidine and omeprazole caused a dose-dependent suppression in the total area of erosions that were induced by ischemia-reperfusion. Whereas, none of them inhibited the increase in thiobarbituric acid-reactive substances in the stomach, as an index of lipid peroxidation. The inhibitory effect of intraperitoneally administered cimetidine on mucosal damage was abolished by continuous luminal perfusion with HCl solution (pH 1.5, 1 ml/min) during ischemia-reperfusion, while luminal perfusion with the solution containing HCl and cimetidine (3 mmol/l) significantly reduced the total area of erosions compared to luminal perfusion with HCl solution alone. Cimetidine (3 mmol/l) inhibited hydroxyl radical-induced lipid peroxidation of human erythrocyte membranes by 60% in vitro. These results indicate that cimetidine possesses a protective effect against acute gastric mucosal injury induced by ischemia-reperfusion not only due to the suppression in gastric acid secretion, but also due to the antioxidant action when it is present at a high concentration in the intragastric environment.

Animals↗
PubMed1997

Cytomegalovirus glycoprotein B sequence variation among Japanese bone marrow transplant recipients.

Glycoprotein B (gB) of human cytomegalovirus (CMV) is the major target protein of neutralizing antibodies, and four variant types are known. A previously reported polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method was modified by eliminating the cell culture step and amplifying a CMV fragment (corresponding to a.a. 441-450 of gB) by nested PCR. DNA was extracted from the sera of 27 pediatric bone marrow transplant recipients and subjected to nested PCR. Of the samples, 20 yielded PCR products, and the gB type was determined by RFLP. Of the 20 patients, 4 (20%) had gB type 1 (Towne type), 15 patients (75%) had gB type 2 (AD 169 type), and 1 patient (5%) had gB type 3. Previous studies showed that gB type was most common among Caucasians [Chou and Dennison: J Infect Dis 1991;163:1229-1234; Fries et al: J Infect Dis 1994;169:769-774]. Thus, gB genotypes seem to be distributed differently in Caucasians and Japanese. Further, nucleotide sequence analysis of the amplified region revealed that all the type 2 viruses had the same amino acid sequences. The type 3 sample had a novel amino acid substitution at position 498. Of the type 1 samples, 3 had amino acid substitutions in various positions: 1 sample at position 493, 1 sample at position 447 and 1 sample at position 452, 493 and 498.

Bone Marrow Transplantation↗
PubMed1997

Bronchial anti-spasmogenic effects and selectivity of T-440, phosphodiesterase type 4 inhibitor, in the dog.

We investigated the selectivity of T-440 for the inhibition of phosphodiesterases (PDEs) in vitro and for bronchial anti-spasmogenic effects in vivo. Using a fast protein liquid chromatography system, five PDE isozymes, PDE 1, PDE 2, PDE 3, PDE 4 and PDE 5 were prepared from guinea pig and dog tissues. T-440 selectively inhibited PDE 4 with an IC50 of 0.071 microM and 0.13 microM for guinea pig lung and dog trachea, respectively. The IC50 values for all other PDE isozymes were over 20 microM. In contrast, theophylline nonselectively inhibited all the tested PDE isozymes, and the inhibition did not exceed 50%, even at 100 microM. T-440 inhibited the histamine-induced bronchoconstriction of anesthetized dogs in a dose-dependent manner with an ED50 of 0.029 mg/kg, indicating that T-440 is 600 times more potent than theophylline. Both T-440 and theophylline increased LV dp/dt/P (LVP; left ventricular pressure) in anesthetized dogs with ED50 values of 3.6 mg/kg and 4.4 mg/kg, respectively. This potency was 1/125 times the bronchial anti-spasmogenic effects for T-440 and 4.2 times that of theophylline. Rolipram, a PDE 4 inhibitor, also showed selective bronchial anti-spasmogenic effects in anesthetized dogs. These results suggest that T-440, which specifically inhibits PDE 4 activity, has potent and selective bronchial anti-spasmogenic effects.

Animals↗
PubMed1997

Effects of alkaloids from Aconitum yesoense var. macroyesoense on cutaneous blood flow in mice.

Nine alkaloid constituents in the root of Aconitum yesoense var. macroyesoense, as well as three acetylated derivatives, were examined for their peripheral vaso-activities by measuring laser-flowmetrically the cutaneous blood flow in the hind foot of mice after intravenous administration. The major constitutive delcosine (1), 14-acetyldelcosine (2) and lucidusculine (3), respectively, had little or very mild vaso-activity. Kobusine (4) and pseudokobusine (5) and three minor constituents, luciculine (6), 1-acetylluciculine (7) and dehydroluciculine (8), together exhibited a rapid increase in blood flow reaching a peak with a magnitude almost equal to that produced by hydralazine, when administered intravenously at the same dosage level of 20 mg/kg. Among them, 4 was characterized by successive reversal of the increase to a decrease in blood flow, while 7 produced a flow with a more delayed peak time. Dehydrolucidusculine (9) exhibited a transient decrease in blood flow prior to occurrence of the increase, as did papaverine. Consequently, it is assumed that the alkaloids, especially those of the C20-diterpenoid type, in the root of this Aconitum plant have peripherally vaso-dilating activities to varying degrees in mice, probably due to their direct action on the cutaneous microvasculature in a similar fashion to that shown by hydralazine. The laser blood flowmetric method would be useful as an in vivo means of qualitative as well as quantitative screening of chemically modified derivatives of peripherally vasoactive agents in mice.

Alkaloids↗
PubMed1997

Incidence of dogs possessing red blood cells with high K in Japan and East Asia.

The phenotype of high K (HK) red blood cells, which is an autosomal recessive, was found in dog groups from 10 of 13 breeds or populations in Japan. The incidence of HK was 26 to 38% in the San'in-Shiba, Shinshu-Shiba and Akita breeds, and the gene frequencies of HK ranged from 0.513 to 0.612. The highest incidence (42%) was found in the Jindo breed from Korea, and the gene frequency was 0.652. Two other groups from Korea also possessed this HK variation. However, although HK cells were not found in dogs from Taiwan, Indonesia, Mongolia and Sakhalin, Russia, the HK phenotype is clearly distributed now throughout Japan and Korea.

Animals↗
PubMed1997

Bilobalide, a constituent of Ginkgo biloba L., potentiates drug-metabolizing enzyme activities in mice: possible mechanism for anticonvulsant activity against 4-O-methylpyridoxine-induced convulsions.

Anticonvulsant effects of bilobalide, one of the constituents of Ginkgo biloba L., on the convulsions induced by 4-O-methylpyridoxine (MPN) were investigated in mice. Bilobalide reduced the duration and incidence of MPN-induced convulsions depending on its dose and the period of treatment. In addition, the anticonvulsant effect was manifested more than 24 hours after treatment and the effect lasted for 7 days after its withdrawal. In mice treated with bilobalide (30 mg/kg, p.o., once a day for 4 days), hepatic 7-methoxycoumarin O-demethylase activity was potentiated, and the disappearance of MPN in blood after MPN injection was faster than in controls. From these results, it is assumed that the anticonvulsant effect of bilobalide against convulsions induced by MPN partly involves modulation of hepatic drug-metabolizing enzyme activity, which leads to accelerated elimination of MPN.

Administration, Oral↗
PubMed1997

[Susceptibilities of bacteria isolated from patients with respiratory infectious diseases to antibiotics (1995)].

The bacteria isolated from the patients with lower respiratory tract infections were collected by institutions located throughout Japan, since 1981. Ikemoto et al. have been investigating susceptibilities of these isolates to various antibacterial agents and antibiotics, and characteristics of the patients and isolates from them each year. Results obtained from these investigations are discussed. In 23 institutions around the entire Japan, 567 strains of presumably etiological bacteria were isolated mainly from the sputa of 459 patients with lower respiratory tract infections during the period from October 1995 to September 1996. MICs of various antibacterial agents and antibiotics were determined against 74 strains of Staphylococcus aureus, 82 strains of Streptococcus pneumoniae, 104 strains of Haemophilus influenzae, 85 strains of Pseudomonas aeruginosa (non-mucoid strains), 18 strains of Pseudomonas aeruginosa (mucoid strains), 52 strains of Moraxella subgenus Branhamella catarrhalis, 25 strains of Klebsiella pneumoniae etc., and the drug susceptibilities of these strains were assessed except for those strains that died during transportation. 1) S. aureus. S. aureus strains for which MICs of oxacillin (MPIPC) were higher than 4 micrograms/ml (methicillin-resistant S. aureus) accounted for 52.7%. Arbekacin (ABK) showed the most highest activity against S. aureus with MIC80 of 0.5 micrograms/ml. Vancomycin (VCM) showed the next highest activity with MIC80 of 1 microgram/ml. These drugs showed the high activities against MRSA with MIC80S of 1 microgram/ml. 2) S. pneumoniae. Most of drugs tested showed potent activities against S. pneumoniae. Imipenem (IPM) and panipenem (PAPM), carbapenems, showed the most potent activity with MIC80S of 0.063 microgram/ml. Cefotaxime (CTX), cefmenoxime (CMX) and cefpirome (CPR) of cephems showed the next most potent activities with MIC80S of 0.25 microgram/ml. Erythromycin (EM) and clindamycin (CLDM) showed low activities with MIC80S 128 micrograms/ml or high. Among these strains, however, 48.8% and 65.9% of respective strains were quite toward sensitive these agents with MICs of 0.063 microgram/ml. 3) H. influenzae. The activities of all drugs were potent against H. influenzae test with all MICs at 4 micrograms/ml or below. Cefotiam (CTM), CMX, cefditoren (CDTR) and ofloxacin (OFLX) showed the most potent activity with MIC90S to 0.063 microgram/ml. 4) P. aeruginosa. (mucoid strains) IPM and tobramycin (TOB) showed the most potent activity against P. aeruginosa (mucoid strains) with MIC80S of 1 microgram/ml. Ceftazidime (CAZ), cefsulodin (CFS) and carumonam (CRMN) showed next potent activity, with MIC80S of 2 micrograms/ml. The MIC80S of the other drugs ranged from 4 micrograms/ml to 32 micrograms/ml. 5) P. aeruginosa (non-mucoid strains). TOB and ciprofloxacin (CPFX) showed the most potent activities against P. aeruginosa (non-mucoid strains) with MIC80S of 1 microgram/ml. The MIC80 of ampicillin (ABPC) was 128 micrograms/ml in 1994, it was 16 micrograms/ml in 1995. 6) K. pneumoniae. All drugs except ABPC were active against K. pneumoniae. CPR and CRMN showed the most potent activities against K. pneumoniae with MIC80S of 0.063 microgram/ml. The MIC80S of the other drugs ranged from 0.125 microgram/ml to 2 micrograms/ml. 7) M. (B.) catarrhalis. Against M. (B.) catarrhalis, all the drugs showed good activities with MIC80S at 4 micrograms/ml or below. And MICs of all strains were 8 micrograms/ml or below. IPM, OFLX and minocycline (MINO) showed the most potent activity with MIC80S of 0.063 microgram/ml. Also, we investigated year to year changes in the characteristics of patients, their respiratory infectious diseases, and the etiology. Patients' backgrounds were examine for 567 isolates from 459 cases. The examination of age distribution found that the proportion of patients with ages over 60 years was 66.3% of all the patients showing a slight increase over that in 1994. Proportion of differe

Adolescent↗
PubMed1997

[Epstein-Barr virus-infected T-cell malignancy in an adult patient with Behçet's disease-like symptoms].

A 20-year-old woman was hospitalized on November 11, 1994 with Behçet's disease-like symptoms (fever, genital ulcer and aphtha in the oral cavity). Bilateral cervical lymph node swelling was also noted and diagnosed as lymphadenitis on biopsy. Chronic active Epstein-Barr virus infection (CAEBV) was diagnosed based on the high titer of antibodies to the EBV capsid antigen, early antigen, and nuclear antigen. She was treated with prednisolone and acyclovir and all symptoms improved. However, ten months after onset of symptoms, T-cell malignancy was diagnosed on bone marrow aspiration, which revealed 34.9% blast cells that had rearrangement of TCR-beta. She died on May 8, 1995, despite anticancer therapy. In analyzing the blast cells, the monoclonal junctional DNA structure of the EBV terminal repeat was analyzed by Southern blotting and provided definitive evidence for the monoclonality of EBV-infected T cells. These findings strongly suggest that EBV plays a pathogenic role in T-cell malignancy. EBV-infected T-cell malignancy, such as this case, is very rare in Japan, especially in adult.

Adult↗
PubMed1997

Two differential effects of cyclic adenosine 3',5'-monophosphate on IL-5 production by antigen-specific human T cell line.

It has been proven that increasing cyclic adenosine 3',5'-monophosphate (cAMP) in human helper T cells results in decreased production of interleukin (IL)-2. As we have recently found that IL-2 stimulates IL-5 production, the effects of cAMP on IL-5 synthesis of T cells was investigated in this study. Prostaglandin E2 and forskolin raised intracellular cAMP level of Dermatophagoides farinae extract-reactive human T cell line and inhibited T cell receptor-stimulated IL-5 production. The cAMP analog, dibutyryl-cAMP, also inhibited IL-5 production, whereas the protein kinase A inhibitor, H-89, enhanced IL-5 production. The IL-5 production was completely suppressed by anti-IL-2 neutralizing antibody. Recombinant human IL-2 itself induced IL-5 production, suggesting that IL-5 production stimulated through T cell receptor is dependent on the autocrine production of IL-2. Prostaglandin E2, forskolin and dibutyryl-cAMP enhanced but H-89 suppressed recombinant human IL-2-induced IL-5 production. Prostaglandin E2 suppressed T cell receptor-stimulated mRNA expression of IL-2 as well as IL-5 in the T cell line, whereas it potentiated IL-5 mRNA expression stimulated by recombinant human IL-2. These results suggest that the inhibitory effect of cAMP on IL-5 production is mediated by the suppression of IL-2 production. On the contrary, IL-2-induced IL-5 synthesis is enhanced by increasing cAMP. Our study clearly indicated that cAMP regulates IL-5 production of human T cells by two differential effects.

Allergens↗
PubMed1997

Increased expression of S100A4, a metastasis-associated gene, in human colorectal adenocarcinomas.

The S100A4 gene (also known as pEL98/mts1/p9Ka/18A2/42A/calvasculin /FSP1/CAPL) encoding an S100-related calcium-binding protein is implied to be involved in the invasion and metastasis of murine tumor cells. In the present study, the expression of S100A4 in human colorectal adenocarcinoma cell lines (SW837, LoVo, DLD-1, HT-29, SW480, SW620, WiDr, and Colo201) and surgically resected neoplastic tissues was examined to investigate whether S100A4 plays a role in the invasion and metastasis of human tumor cells. Northern blot analysis using total RNA isolated from the adenocarcinoma cell lines revealed that five of the eight cell lines expressed substantial amounts of S100A4 mRNA. Normal colon fibroblasts (CCD-18Co) expressed little of the RNA. Using surgically resected specimens, it seemed that the amount of S100A4 mRNA in adenomas was nearly equal to that in normal colonic mucosa, whereas adenocarcinomas expressed a significantly higher amount of the RNA than did the adjacent normal colonic mucosa. Immunohistochemical analysis using formalin-fixed paraffin-embedded surgical specimens and monoclonal anti-S100A4 antibody demonstrated that none of 12 adenoma specimens were immunopositive, whereas 8 of 18 (44%) focal carcinomas in carcinoma in adenoma specimens and 50 of 53 (94%) adenocarcinoma specimens were immunopositive. Interestingly, the incidence of immunopositive cells increased according to the depth of invasion, and nearly all of the carcinoma cells in 14 metastases in the liver were positive. These results suggest that S100A4 may be involved in the progression and the metastatic process of human colorectal neoplastic cells.

Adenocarcinoma↗
PubMed1996

SHP-2 is involved in neurotrophin signaling.

To investigate the involvement of SHP-2 in the signal transduction pathway stimulated by neurotrophins, the association of SHP-2 with components of the pathway was examined. Following NGF stimulation of PC12 cells, SHP-2 was found to be associated with the p85 subunit of PI3-kinase and the Shc proteins. In retinoic acid-differentiated SH-SY5Y cells and primary cultures of rat cortical neurons, BDNF treatment similarly caused the association of SHP-2 with p85. In addition, a tyrosine-phosphorylated protein, which is probably TrkB, was coimmunoprecipitated with SHP-2 in both cultures. These results show that SHP-2 becomes associated with signaling proteins after treatment with neurotrophins and suggest that SHP-2 plays a fundamental role in neurotrophin signaling.

Animals↗