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Biomedical subjects

S Arai

Publications and source records attributed to S Arai.

At least 325 records · Page 18Linked to original sources
PubMed1989

In vitro and in vivo effects of combinations of cefotaxime or other beta-lactams with rolitetracycline on methicillin-resistant Staphylococcus aureus.

Combinations of cefotaxime (CTX) or other five beta-lactams with rolitetracycline (RTC) were examined using the checkerboard method for their synergistic effects against 27 strains of methicillin-resistant Staphylococcus aureus (MRSA), and the combination of CTX and RTC was further evaluated for its synergistic effect in vitro and in vivo against 1 or 2 strains. Synergy occurred against 44% of the strains when RTC was combined with CTX, 22 to 30% with cefazolin, methicillin, and ceftizoxime, and 4 to 11% with latamoxef and cefmetazole. No antagonism was found with any combinations tested. Killing curve studies also showed that CTX/RTC was synergistic between 3 and 24 hours after the beginning of exposure, and the synergy was especially strong at 24 hours and potencies of combined bactericidal effect determined at 24 hours were in the following order: the 2 antibiotics given simultaneously, CTX given 2 hours before RTC, and CTX given 2 hours after RTC. In addition, the 2 drugs in combination synergistically inhibited (a) mortality in mice infected intraperitoneally with MRSA and (b) formation of subcutaneous abscess induced by MRSA in mice. The results of our study indicate that beta-lactams, especially CTX, had synergistic effects in vitro when combined with RTC against MRSA and that the combination of CTX and RTC was also synergistic in vivo.

Animals↗
PubMed1989

Experimental autoimmune uveoretinitis (EAU) in rats: abrogation of resistance to the induction and augmentation of the inflammation by pertussis toxin.

The effect of pertussis toxin (PT) on experimental autoimmune uveoretinitis (EAU) induced by immunization with S-antigen was examined in rats. Intravenous administration of PT (2 micrograms/rat) initiated the development of EAU in rats that had been made resistant to the induction of EAU by immunization with S-antigen and complete Freund's adjuvant (CFA). The capacity of PT to promote EAU was also demonstrated by a marked augmentation of the inflammation in EAU eyes of rats susceptible to the induction of EAU. PT was most effective when it was given from the day before to the day after immunization with S-antigen. However the induction of EAU was promoted by the injection of PT even 7 days before and 14 days after immunization. The clinical and histopathological findings of the EAU produced by the additional PT treatment were described and the mechanisms by which PT augmented the induction of EAU were discussed.

Animals↗
PubMed1989

[Laboratory and clinical investigations of cefodizime in infectious diseases in childhood].

In this study, cefodizime (CDZM, THR-221) was administered to 34 children with infections and the efficacy was evaluated in 30 patients. The efficacy rate was 90.0% and CDZM was proved to be a highly effective antibiotic for infectious diseases in childhood. We also demonstrated that CDZM had strong antibacterial activities against both Gram-positive and Gram-negative bacteria. No severe toxicity related to intravenous injection of CDZM was observed in our 34 cases.

Age Factors↗
PubMed1989

Pharmacokinetic study of cefodizime in experimentally infected animals.

Cefodizime, a new cephem antibiotic, was intravenously injected to mice with systemic or urinary tract infection by Escherichia coli and those with respiratory infection by Streptococcus pneumoniae, and the time courses of the plasma and tissue cefodizime levels were determined and compared with those in healthy mice (control group). In mice with systemic infection, the drug level in the plasma, liver, kidneys and lung changed on the basis of the two-compartment model. In this group, disappearance of the drug from plasma and tissues was obviously delayed and decrease in elimination constant (KE) and increase in the apparent volume of distribution (V2) were noted as compared with the control group. In the group with respiratory infection, T1/2(beta) and AUC for the hepatic drug level and T1/2(beta) for the renal drug level increased but in the other organs there was no great difference from the control group. In the urinary tract infection group, T1/2(beta) and AUC in the kidneys (infected site) and liver that mainly participate in elimination of cefodizime considerably increased differently from the control group. Changes of the distribution volume seemed to correspond with a physiological change of increase in body water content in the peripheral tissues (muscle, etc.) of the systemic infection group and in the liver, kidneys, etc. of the urinary tract infection group. Regarding the protein binding ratio, the urinary tract infection group showed a significant decrease as compared with the control group, but no distinct difference was noted in systemic and respiratory infections.

Animals↗
PubMed1989

[Diagnosing the depth of esophageal carcinoma invasion by esophagography scoring].

In patients with an esophageal carcinoma, it was important to determine the depth of the carcinomatous involvement so as to decide on its resectability and prognosis. Thus four measurements of the esophagography findings involving ninety five post-esophagectomy patients were categorized into four grades and scored from point 1 to point 4, depending on the degree of severity, the measurements being the size of the tumor, the circumferential carcinomatous invasion, the degree of stenosis, and the depth of the ulcer. The sum total scores of these four esophagography findings were found to correlate well (P less than 0.01) with the depth of the invasion (submucosa, muscularis propria, adventitia, and the adjacent structures).

Adult↗
PubMed1989

[Mitral valve replacement following myomectomy for idiopathic hypertrophic subaortic stenosis].

A patient is reported with IHSS where mitral valve replacement was performed 3 years following myomectomy because of a residual pressure gradient of left ventricular outflow tract. After mitral valve replacement, the left ventricular outflow tract obstruction was almost completely relieved not only at rest but also at provocation by isoproterenol. The patient successfully returned to work with no symptoms.

Adult↗
PubMed1989

[Emergency surgery for thrombosed Björk-Shiley mitral valve prosthesis].

A case of a thrombosed Björk-Shiley mitral valve with severe pulmonary edema which developed six years following an initial operation was reported. Doppler echocardiography was one of the most useful tools to evaluate prosthetic mitral valve dysfunction. Peak blood flow velocity was high (2.7 m/sec) compared to the data (1.7 m/sec) obtained six months before the reoperation. Emergency surgery disclosed the thrombosed valve prosthesis which was replaced with a St. Jude Medical valve. The patient recovered successfully with no problems.

Adult↗
PubMed1988

The NH2-terminal 21 amino acid residues are not essential for the papain-inhibitory activity of oryzacystatin, a member of the cystatin superfamily. Expression of oryzacystatin cDNA and its truncated fragments in Escherichia coli.

Oryzacystatin, a proteinaceous cysteine proteinase inhibitor (cystatin) in rice, is comprised of 102 residues (Met1-Ala102) (Abe, K., Emori, Y., Kondo, H., Suzuki, K., and Arai, S. (1987) J. Biol. Chem. 262, 16793-16797). We constructed an expression plasmid containing a full length oryzacystatin cDNA at the multi-cloning site of pUC18 and produced a lacZ'-oryzacystatin fusion protein in Escherichia coli. The partially purified expressed protein efficiently inhibits papain activity assayed using N-benzoyl-DL-arginine-2-naphthylamide as a substrate. We also constructed expression plasmids lacking the 5'- and 3'-regions of cDNAs that encode NH2- and COOH-terminally truncated oryzacystatins. An N-truncated oryzacystatin lacking Gly5 and retaining Gln53-Val54-Val55-Ala56-Gly57 inhibited papain as efficiently as the full length oryzacystatin, although both Gly5 and Gln53-Gly57 (oryzacystatin numbering) are conserved among members of most cystatin superfamilies. However, another N-truncated oryzacystatin lacking the NH2-terminal 38 residues was almost completely inactive. On the other hand, a COOH-terminally truncated oryzacystatin lacking the COOH-terminal 11 residues possesses potent papain-inhibitory activity, whereas another COOH-terminally truncated oryzacystatin lacking 35 residues shows much less inhibitory activity, although it retains the two well conserved features Gly5 and Gln53-Gly57. These results indicate that the NH2-terminal 21 residues containing Gly5 and the COOH-terminal 11 residues are not essential, suggesting that a portion of the polypeptide segment containing Gln53-Gly57 is necessary for oryzacystatin to elicite its papain-inhibitory activity efficiently.

Amino Acid Sequence↗
PubMed1988

Sporadic lower motor neuron disease with Lewy body-like inclusions: a new subgroup?

A sporadic case of lower motor neuron disease with Lewy body-like inclusions is presented. A woman of 69, 6 months before death, had a history of muscle weakness and atrophy of the four extremities. Neuropathological examination revealed neuronal loss and associated gliosis in the anterior horns of the whole spinal cord. The cytoplasm of some of the remaining neurons contained Lewy body-like inclusions. Bunina bodies, or both. Spheroids and cord-like thickenings of cell processes were also observed in the anterior horns. A few neurons showed argentophilia of the cytoplasm. No tract degeneration was detectable in the white matter of the spinal cord. The present case and two reported similar cases may constitute a new subgroup of motor neuron disease.

Aged↗
PubMed1988

Enteropathogenic and enterotoxigenic Escherichia coli as aetiological factors of infantile diarrhoea in rural and urban Ghana.

There are 4 recognized classes of Escherichia coli that cause diarrhoeal disease in humans: enteropathogenic (EPEC), enterotoxigenic (ETEC), enteroinvasive (EIEC), and enterohaemorrhagic E. coli (EHEC). Preliminary analysis of enterotoxin production in a rural community in Ghana showed a prevalence of 11.0% LT-ST+, 9.5% LT+ST- and 7.5% EPEC. (LT = heat-labile, and ST = heat-stable, enterotoxin). The results of a similar study in an urban community in Accra, Ghana, showed 10.9% LT-ST+, 5.9% LT+ST-, 1.6% LT+ST+ and 6.5% EPEC. 14 different serotypes of EPEC were isolated in the urban area, whereas 6 serotypes and two untypable strains were isolated in the rural area. The most common serotype isolated in Accra was 0126:K71 and that from the rural area was 0128:K67. Serotypes 0143:KXI and 0155:K59 are reported for the first time in Ghana.

Child, Preschool↗
PubMed1988

Effects of dietary taurine on tissue taurine and free amino acid levels of the chum salmon, Oncorhynchus keta, reared in freshwater and seawater environments.

1. Young chum salmon were fed on the basal and taurine-supplemented diets for 30 days in freshwater (FW) and for 25 days in seawater (SW). Levels of taurine, major free amino acids (FAA) and non-protein nitrogen (NPN) in various tissues were determined. 2. Tissue taurine levels were higher when fish were fed on the taurine-supplemented diets. All tissues of the SW fish did not contain higher taurine levels than those of the FW. 3. Levels of major FAA in the tissues differed little between fish fed on the basal and taurine-supplemented diets and also between the FW and SW fish. 4. No difference was observed in tissue NPN levels between fish ingesting the basal and taurine-supplemented diets; the levels were slightly higher in the SW fish.

Acclimatization↗
PubMed1988

School screening for scoliosis by the Chiba University Medical School screening program. Results of 1.24 million students over an 8-year period.

The screening program for scoliosis started by Chiba University in 1979 consists of using moiré topography, low-dose roentgenography and a final ordinary x-ray examination. The number of children screened through this Chiba University Medical School (CUMS) screening program to 1986 amounted to 1,246,798. The incidence of scoliosis of more than 15 degrees increased linearly according to age from the fifth grade primary school children (0.07% in boys, 0.44% in girls) to the second grade junior high school students (0.25% in boys, 1.77% in girls). The female predominance of scoliosis cases with curvatures of more than 20 degrees detected during the total period was 10:1 and this female predominance was the same for primary school children and junior high school students. According to a study of the incidence of scoliosis by districts, (areas were divided according to population density and urbanization) there were no significant differences in the fifth grade primary school children between the sparsely and densely populated areas. In the cases of children beyond the fifth grade primary school level, however, the incidence in the densely populated areas were significantly higher than those in the sparsely populated districts. The incidence of scoliosis of more than 20 degrees decreased significantly every year among junior high school students, because they were screened periodically in school and the scoliotic students who had already been detected were left out of the next screening. This study establishes that screening for scoliosis by the CUMS screening program is cost-effective with a low risk of radiation hazards.

Adolescent↗
PubMed1988

The mechanisms of cytotoxicity to tumor cells by polymorphonuclear leukocytes stimulated with cytokines.

The mechanisms of tumor cytotoxicity of rat polymorphonuclear leukocytes (PMN) activated with cytokine(s) were studied with the use of supernatants from a rat myelomonocytic leukemia cell line, WRT-7, incubated in the presence of bacterial lipopolysaccharide (LPS) (LPS WRT-7 sup) as a source of cytokine. Rat peritoneal PMN treated with LPS WRT-7 sup showed cytostasis from 3 hr after the start of incubation, while significant cytolysis was first observed after 24 hr. When target tumor cells were separated from PMN at 6 or 12 hr after the start of the assay, 3H-UdR release from the separated target cells comparable to that from the group incubated with PMN for the whole assay time of 40 hr was observed during the following incubation, which indicates that priming for subsequent lysis occurs at a relatively early stage of the assay. None of various scavengers of active oxygens, inhibitors of heme enzymes, and inhibitors of neutral proteinases inhibited cytolysis mediated by PMN stimulated with LPS WRT-7 sup. Heparin inhibited PMN cytolysis only when it was added within 1 hr after the start of the assay. Fractionation of heparin by ion exchange chromatography showed a parallelism between the negative charge and the inhibitory effect of heparin on PMN cytotoxicity.

Animals↗
PubMed1988

Simple assay of beta-lactamase with agar medium containing a chromogenic cephalosporin, pyridinium-2-azo-p-dimethylaniline chromophore (PADAC).

A new beta-lactamase assay method with agar plates containing pyridinium-2-azo-p-dimethylaniline chromophore (PADAC) (50 microM), a beta-lactamase-labile, chromogenic cephalosporin, was examined. On the PADAC plates inoculated with beta-lactamase-producing gram-negative bacteria (10(4) CFU per spot) and incubated at 37 degrees C, a yellow zone showing hydrolysis of PADAC by beta-lactamase was formed around the colony. The zone diameter increased with incubation time. Examination with Enterobacter cloacae GN7471 revealed that beta-lactamase activity was present in the agar around the colony, decreasing exponentially with increasing distance from the colonial margin; this suggests that the PADAC hydrolysis zone is formed by an extracellular enzyme. At 18 h, significant correlations were obtained between the zone diameters of the 10 species (clinical isolates) examined and their periplasmic beta-lactamase activities determined spectrophotometrically. The addition of clavulanic acid (0.5 to 10 micrograms/ml) inhibited zone formation on the PADAC plates inoculated with type IIIa, Va, Vb, PSE-1, and Ic beta-lactamase producers. When the clinical isolates were tested on plates with clavulanic acid (2 micrograms/ml), inhibition was observed in 41 to 58% of the Escherichia coli, Serratia marcescens, and Pseudomonas aeruginosa isolates and in all isolates of Klebsiella pneumoniae, Klebsiella oxytoca, and Proteus vulgaris. Thus, the use of the inhibitor made it possible to detect penicillinase or type Ic cephalosporinase producers. These results proved that the PADAC plate might be a useful tool permitting easy, semiquantitative determination of beta-lactamase activity.

Agar↗
PubMed1988

Distribution of cefpirome (HR 810) to exudate in the croton oil-induced rat granuloma pouch and its therapeutic effects on experimental infections in the pouch.

Therapeutic effects of intravenously administered cefpirome on experimental bacterial infections in croton oil-induced rat granuloma pouches were compared with those of ceftazidime, moxalactam, cefoperazone, and cefotaxime. Its pharmacokinetic profile in pouch exudate was also examined. Cefpirome showed bactericidal effects and long-lasting bacterial growth-inhibitory effects in granuloma pouches infected in Escherichia coli Ec-7, and its effects were almost equal to those of the other antibiotics. Against Pseudomonas aeruginosa TM-11 infection, cefpirome was more active than moxalactam, cefoperazone, and cefotaxime and comparable to ceftazidime. Cefpirome had the strongest activity against Staphylococcus aureus Smith infection among the five antibiotics, showing bactericidal effects and long-lasting bacterial growth-inhibitory effects. The level of cefpirome in pouch exudate peaked at 1 h after administration, with a value of 16.4 micrograms/ml, and declined in a pattern similar to that of ceftazidime. When compared in peak level, the exudate level of cefpirome was 1.8 to 2.6 times higher than the values of moxalactam, cefoperazone, and cefotaxime. The in vitro exudate protein binding of cefpirome was 8.8%, which was the lowest among the antibiotics used.

Animals↗
PubMed1988

Ocular pharmacokinetics of latamoxef and cefaclor in rabbits. Penetration into aqueous humor.

Penetrations of latamoxef (LMOX) and cefaclor (CCL) into the aqueous humor after intravenous or oral administration were investigated in rabbits. Concentrations of antibiotics in plasma and aqueous humor after administration were determined periodically by microbiological assay. LMOX disappeared from plasma in a monoexponential manner with a half-life of 43 min after intravenous administration at a dose of 50 mg/kg. The maximum concentration of LMOX in aqueous humor (6.4 micrograms/ml) was observed 1 h after administration. When CCL was administered orally at a dose of 50 mg/kg, the maximum concentration of CCL in aqueous humor was 1.00 microgram/ml 1.5 h after administration, whereas the maximum plasma concentration of 19.2 micrograms/ml was observed at 30 min. Pharmacokinetic analysis (simultaneous simulation) of plasma and aqueous humor concentration-time courses was made using the best fitted compartment model examined (modified two-compartment model). Prediction of the concentration of antibiotics in aqueous humor from the plasma concentration profile was also examined using the same compartment model in a separate experiment. The predicted concentration in aqueous humor was proved to coincide reasonably well with the measured concentration.

Administration, Oral↗