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S Shigeta

Publications and source records attributed to S Shigeta.

At least 253 records · Page 14Linked to original sources
PubMed1987

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from urinary tract infections (1985). III. Secular changes in susceptibility].

Sensitivities to antimicrobial agents of Escherichia coli, Klebsiella spp., Citrobacter spp., Enterobacter spp., Proteus spp., Pseudomonas aeruginosa and Serratia marcescens isolated from infected patients were evaluated and compared according to the types of their infections, i.e., simple and complicated urinary tract infections with or without indwelling catheter. There were no apparent decreases in the sensitivity of E. coli isolated from patients with simple urinary tract infections. When data obtained in 1982-1985 were summarized, it was found that a new quinoline derivative, ofloxacin (OFLX), showed the strongest activity among oral antimicrobial and antibiotic agents. This agent inhibited 100% of bacterial growth at MIC of 1.56 micrograms/ml. The next strongest activity was found with mecillinam (MPC) which showed 89.3% growth inhibition at the same concentration. Cefaclor (CCL) also showed 84.9% growth inhibition at the same concentration. When sensitivities of E. coli isolated from patients with complicated urinary tract infections with or without indwelling catheter to first and second generation cephems were determined, cefotiam (CTM), which inhibited 88.9%: 91.4% bacterial growth at MIC of 0.39 micrograms/ml, had the strongest activity among CTM, cefazolin (CEZ), cefoxitin (CFX) and cefmetazole (CMZ). Among third generation cephems, including cefmenoxime (CMX), latamoxef (LMOX), ceftizoxime (CZX), cefotaxime (CTX) and cefoperazone (CPZ), the strongest activity was observed with CZX, and the agent having the next strongest activity was CMX. LMOX and CPZ showed relatively low activities. Carumonam (CRMN) and aztreonam (AZT), monobactams, showed strong activities against E. coli. As for Klebsiella spp., activities of pencillins against these strains were low. When activities of oral cephems (cephalexin (CEX) and CCL) and of a quinoline derivative OFLX against these strains were determined, OFLX showed strong activity; i.e., the growth of Klebsiella spp. isolated from complicated urinary tract infections was inhibited at 87.2%: 82.1% at MIC of 0.20 micrograms/ml.(ABSTRACT TRUNCATED AT 400 WORDS)

Anti-Bacterial Agents↗
PubMed1986

Characterization of a varicella-zoster virus variant with altered thymidine kinase activity.

A varicella-zoster virus (VZV) strain resistant to 5-iodo-2'-deoxyuridine (IdUrd) and 5-bromo-2'-deoxyuridine (BrdUrd) but sensitive to (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVdUrd) and (E)-5-(2-iodovinyl)-2'-deoxyuridine (IVdUrd) was isolated. The 2'-deoxythymidine (dThd) kinase of this mutant (Ito) strain was characterized; it was much less efficient in phosphorylating dThd, 2'-deoxycytidine, and BrdUrd than were the dThd kinases from wild-type (CaQu, Kobayashi) VZV strains. The Ito dThd kinase had a markedly decreased affinity for dThd, 2'-deoxycytidine, and BrdUrd but only a slightly decreased affinity for IVdUrd than had the wild-type VZV dThd kinase. BrdUrd was incorporated to a much lesser extent in VZV (Ito strain)-infected cells than wild-type VZV-infected cells, but IVdUrd was incorporated in Ito VZV-infected cells as efficiently as in wild-type VZV-infected cells. While resistant to IdUrd and BrdUrd, the Ito strain was susceptible to inhibitors of de novo thymidylate biosynthesis such as aminopterin.

Aminopterin↗
PubMed1986

Serological classification of Pseudomonas cepacia by somatic antigen.

Ten samples of antiserum against Pseudomonas cepacia were prepared by the intravenous immunization of rabbits with heat-killed organisms. Ten P. cepacia strains used for immunization were proven unique antigenic strains. Using these antisera, we serogrouped 127 strains of P. cepacia, and 114 strains (89.8%) fell under one of the ten serogroup. The most prevalent serogroup was C (26.8), the second most prevalent being D (18.1%). When we compared our serogroups with the serogroups of Monteil et al. (H. Monteil, C. Richard, and A. Heidt, Med. Mal. Infect. 11:544-547, 1981) and Heidt et al. (A. Heidt, H. Monteil, and C. Richard, J. Clin. Microbiol. 18:738-740, 1983), five out of seven of their serogroups were represented by our antisera.

Animals↗
PubMed1986

Importance of anticomplement immunofluorescence antibody titration for diagnosing varicella-zoster virus infection in Bell's palsy.

Anticomplement Immunofluorescence was used for antibody titration against varicella-zoster virus (VZV) in 43 patients with peripheral facial palsy. Nine of 31 patients (29%) with Bell's palsy and eight of 12 patients (75%) with Ramsey-Hunt syndrome had anticomplement immunofluorescence antibody titres of greater than or equal to 1/10. On the other hand, none of 14 patients with herpes simplex virus (HSV) infection and 51 healthy adults showed anticomplement immunofluorescence antibody titres of greater than or equal to 1/10. The anticomplement immunofluorescence antibody titre in two patients with Ramsey-Hunt syndrome increased later and decreased sooner than the indirect immunofluorescence antibody titre, becoming undetectable at 66 and 104 days, respectively, after onset of the disease. There was no cross reaction between anti-VZV and anti-HSV antibodies in the patients who showed a positive antibody rise for VZV. As the acute stage of VZV infection is obscure in the patients with peripheral facial palsy without herpes the screening of anticomplement immunofluorescence antibody to VZV at titres greater than or equal to 1/10 may be useful for the diagnosis of VZV infection in patients with peripheral facial palsy.

Adult↗
PubMed1986

[An experimental study of work load on VDT performance. Part 1. Effects of polarity of screen and color of display].

Study were made on the effects of polarity of screen and color of display on work load of VDT tasks. The subjects of the present experiment were eight healthy male college students (age: 21-23 yr) having a naked binocular vision of not less than 0.7 and no astigmatism nor hyperopia. The test consisted of an experimental word processing task in which the subjects visually searched e's in given sequences of alphabetical letters displayed on the CRT and converted them to 5's through keyboard operation. As for experimental conditions, four levels of screen image, that is, positive and negative screens and green and white colored displays were adopted and 2 hr were given for each operation time. Critical flicker fusion (CFF), near point distance, accommodation time, subjective fatigue symptoms, heart rate, electromyogram in upper limbs and performance score were measured. The following results were obtained. Decrease in C.F.F. and extension of near point distance were observed in all experimental conditions during the operating time. Increase in complaints of subjective fatigue related to visual function was observed in all experimental conditions after two hour VDT task. Greater extension of near point distance and larger complaints of subjective fatigue were observed in subjects using the green colored display than in those using the white colored display. This suggests that the visual load using the green colored display is larger than that using the white colored display. A larger decreased in C.F.F. and greater complaints of subjective fatigue were demonstrated in subjects using negative screen than those using positive screen. This suggests that the visual load using the negative screen is larger than that using the positive screen.

Adult↗
PubMed1986

[Effects of peri- and postnatal lead administration on learning of high avoider rats].

Effects of administration of lead acetate on Sidman avoidance behavior were assessed in juvenile and adult rats which were obtained by continued selective breeding and which have a high level avoidance ability and small individual differences (THA rat: Tokai high avoider rat). THA rats were administered lead acetate solution at 200-300 mg/kg/day as Pb until 7 wk of age through maternal milk before weaning from mothers which had been administered lead acetate from the 13th day of gestation and per os by gastric tube after weaning. Three series of Sidman avoidance behavior tests were conducted from 49th, 100th and 150th day after birth each for 10 d, 1 h every day. In the first series, a significant delay of shock avoidance acquisition was observed in lead-administered male rats compared with the control subjects, while no acquisition delay was seen in female rats. The lead administered male rats could be divided into two groups with different response patterns; a low susceptible group (LSG) which exhibited as good acquisition rate from the beginning similar to the control rats and a high susceptible group (HSG) which showed a significant delay and individual differences. In the 2nd test series, very high avoidance rates were obtained in all the test groups except in male HSG, but in the 3rd test series, male HSG also attained a final acquisition of high avoidance rate. There was no developmental variation between the groups nor difference in lead contents of the organs of the exposed group. Useful characteristics of THA rats for behavioral toxicology are discussed.

Animals↗
PubMed1986

[Effects of low level toluene exposure during the developing stage of the brain on learning in high avoider rats].

THA (Tokai High Avoiders) rats were exposed in the exposure chambers to 100 and 500 ppm of toluene and air for 7 h every day from 13th day of gestation to 48 d of age. After the termination of toluene exposure, Sidman avoidance test was conducted on the rats for 10 d from 49 d of age (first test series), 100 d of age (second test series) and 150 d of age (third test series). The results obtained are as follows. No difference could be observed between the toluene exposed groups and controls in the initiation of pinna detachment, primary coat of downy hair, incisor eruption and eye opening. The body weight of the 100 ppm exposed group was slightly greater than that of the control and the 500 ppm exposed group. No difference was indicated between these three groups in reflex and locomotor activity. Avoidance learning: Avoidance rate in the two exposed groups of male rats was significantly lower than those in the control during the 60 min of the test in the first test series. The magnitude of individual variations of avoidance rate in the two exposed groups of male rats was also remarkably greater than that of the control. No difference was seen between the two exposed groups in both avoidance rate and magnitude of avoidance variation. In the second and third test series, the avoidance rate of the two exposed groups still did not attain the control levels during the period of the test series. In female rats, the avoidance rate of the two exposed groups during the first 30 min of the test in the first test series was slightly lower than the control. This difference in avoidance rate observed between the exposed groups and the control disappeared during the latter 30 min of the test. In the second and third test series, the avoidance rate of both exposed groups reached the control level during the test period. It may be concluded from the foregoing findings that 100 ppm and 500 ppm toluene exposure during the fetal and suckling periods affects learning in the rats after termination of the growth period, and that the learning disorder still remained as long as 100 days after the end of toluene exposure, although the effect decreased gradually. It was also observed that this learning disorder appeared more distinctly in male rats than in female rats.

Animals↗
PubMed1986

[An experimental study of work load on VDT performance. Part 2. Effects of difference in input devices].

Effects of the difference in input device on work load of VDT task were studied. The subjects of the experiment were eight healthy male college students (age: 21-22 yr) having a binocular vision of not less than 0.7 and no astigmatism or hyperopia. The test consisted of an experimental word processing task in which the subjects visually searched e's in given sequences of alphabetical letters displayed on the CRT and converted them to 5's through input device operation. As for experimental conditions, two kinds of input devices, namely, keyboard and lightpen were adopted and 1 h was provided as each operation time. Critical flicker fusion (CFF), near point distance, accommodation time, subjective fatigue symptoms, blinking counts, pupillary reflex, electromyogram in upper limb, neck and shoulder and performance score were measured. The results were as follows. Decrease in C.F.F. was observed in two experimental conditions during the process of operating time. Increments in complaints of subjective fatigue related to visual function were seen in the two experimental conditions after 1 h VDT task. A higher error rate in performance was observed in the subjects using the lightpen compared to the one using the keyboard. The frequency of both blinking and pupil-size changes were lower in the subjects using the lightpen compared to those using the keyboard. This suggests that the gaze time of the VDT screen with lightpen-condition is longer than that in keyboard-condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Accommodation, Ocular↗
PubMed1986

Inhibitory effects of selected antiviral compounds on newly isolated clinical varicella-zoster virus strains.

Nine anti-herpes compounds, idoxuridine (IDU), bromovinyldeoxyuridine (BVDU), bromovinylarabinofuranosylurasil (BVaraU), carbocyclic bromovinyldeoxyuridine (C-BVDU), chloroethyldeoxyuridine (CEDU), acyclovir (ACV), dihydroxypropoxymethylguanine (DHPG), adenine arabinoside (Ara-A), and phosphonoformate (PFA) were examined for their inhibitory activities against the replication of twenty-six newly isolated clinical strains of varicella-zoster virus (VZV) in human embryonic fibroblast cell cultures. The order of (decreasing) efficacy was: BVaraU greater than BVDU greater than or equal to C-BVDU greater than CEDU greater than or equal to IDU greater than ACV greater than Ara-A greater than DHPG greater than PFA. There was little variation in the susceptibility of the 26 VZV strains to each particular compound, except for one strain which was resistant to IDU.

Antiviral Agents↗
PubMed1986

[Comparative studies of antimicrobial agents against causative organisms isolated from urinary tract infections (1984). I. Susceptibility distribution].

Our research group was engaged for 3 years (1979-1981) in a study on sensitivities to antibiotics of 4 bacterial groups including representative pathogenic bacteria found in cases of urinary tract infections; i.e. E. coli, Klebsiella spp., Citrobacter spp., and Proteus spp. Since 1982, all the bacterial strains isolated by our group from patients with urinary tract infections and deemed by doctors in charge as pathogens were sent to the Laboratory of Clinical Pathology of Juntendo University, where they were refixed and subjected to MIC determination. This is the third year of the new study. E. coli was detected most frequently from patients with urinary tract infections and the detection frequency was 28% (323/1,153) this year (1984), whereas it was 35.3% (304/860) last year, showing a 7% decline from last year to this year. E. faecalis was next frequent organism (12.7% or 147/1,153) followed by P. aeruginosa (10.8% or 124/1,153). This order, however, was reversed from last year. Other pathogens, in a decreasing order of isolation frequencies following the above three, were as follows: Proteus spp. (9.5% or 109/1,153), S. marcescens (6.2% or 71/1,153), S. epidermidis (5.4% or 62/1,153), K. pneumoniae (4.9% or 56/1,153), Enterobacter spp. (2.4% or 28/1,153) and Citrobacter spp. (2.3% or 27/1,153). The results of the determination of the sensitivity of bacterial strains to the antibiotics are described below. Of all the oral antibacterial and antibiotic agents used against E. coli, mecillinam (MPC), cefaclor (CCL) and pipemidic acid (PPA) proved to have high antibacterial potency, and their MIC90 (the concentration to inhibit growths of 90% of the objective bacteria) was 3.13 micrograms/ml. The MIC90's of cefotiam (CTM), cefotaxime (CTX), ceftizoxime (CZX), cefmenoxime (CMX) and latamoxef (LMOX) were less than 0.39 microgram/ml. The MIC90's of cefmetazole (CMZ) and cefoperazone (CPZ) were invariably 1.56 micrograms/ml. K. pneumoniae was not sensitive to ampicillin (ABPC) and did not show much sensitivity to other oral antibacterial and antibiotic agents also. Of all the injectable preparations of antibiotics, cephem antibiotics of the third generation showed the most potent antibacterial effects against K. pneumoniae, and their MIC90's were lower than 0.10 microgram/ml for CZX, 0.20 microgram/ml for CTX, 0.39 microgram/ml for CMX, and 0.78 microgram/ml for LMOX, while MIC90's of CPZ was 6.25 micrograms/ml, which was equal to that of CMZ. The MIC90 of CTM was 0.78 microgram/ml which was identical to that of LMOX.(ABSTRACT TRUNCATED AT 400 WORDS)

Anti-Bacterial Agents↗
PubMed1986

[Comparative studies of antimicrobial agents against causative organisms isolated from urinary tract infections (1984). III. Secular changes in susceptibility].

Cases with infections of urinary tracts were divided into 3 groups of the simple infections, and complicated infections without indwelling of catheter, and complicated infections with indwelling of catheter. Susceptibilities to antimicrobial agents of Escherichia coli, Klebsiella spp., Proteus spp., Citrobacter spp., Enterobacter spp., Pseudomonas aeruginosa and Serratia marcescens which were isolated from patients with these infections were determined. There was no tendency of decline in the susceptibilities of E. coli isolated from the patients with simple urinary tract infections (UTI). Susceptibilities of E. coli isolated from the patients with complicated UTI without and with indwelling of catheter to cephem antibiotics of the third generation were examined. The susceptibility of E. coli strains isolated from patients with complicated UTI without and with indwelling of catheter remained the same. More specifically, cefmenoxime (CMX) at a concentration of less than 0.10 microgram/ml inhibited the growth of E. coli isolated from cases without: with catheter at 74.1%: 78.3% in 1982, 75.4%: 73.3% in 1983, and 81.3%: 84.8% in 1984. Also, ceftizoxime (CZX) at a concentration of less than 0.10 microgram/ml inhibited the growth at 83.3%: 95.7% in 1982, 89.2%: 86.7% in 1983, and 91.7%: 97.0% in 1984. Latamoxef (LMOX) at less than 0.10 microgram/ml inhibited the growth at 59.3%: 43.5% in 1982, 47.7%: 40.0% in 1983, and 47.9%: 42.4% in 1984. The antibacterial effect of penicillin against Klebsiella spp. was found to be poor, while those of oral cephem antibiotics, cephalexin (CEX), cefaclor (CCL), and cefazolin (CEZ) which is the cephem antibiotics of the so-called first generation and cefotiam (CTM) among other cephem antibiotics of the so-called second generation were relatively good. A study of susceptibilities of Klebsiella spp. isolated from patients with complicated UTI without and with indwelling of catheter revealed inhibition of growth by CTM at a concentration of 0.39 microgram/ml at 84.0%: 75.9% in 1982, 70.6%: 75.0% in 1983, and 95.8%: 77.8% in 1984. Cefmetazole (CMZ) at a concentration of 0.39 microgram/ml showed a relatively lower rate of growth inhibition of Klebsiella spp., while at 0.78 microgram/ml it inhibited the growth at 88.0%: 72.4% in 1982, 52.9%: 50.0% in 1983, and 70.8%: 66.7% in 1984. The antibacterial effects of both CTM and CMZ against Klebsiella spp. isolated from patients with indwelling of catheter were found to be poor, and some of the bacterial strains showed a MIC over than 100 micrograms/ml.(ABSTRACT TRUNCATED AT 400 WORDS)

Anti-Bacterial Agents↗
PubMed1986

[Comparative studies of antimicrobial agents against causative organisms isolated from urinary tract infections (1984). II. Background of patients].

Groups of bacteria were isolated from patients with infections of urinary tracts, and backgrounds of these isolates and patients have been studied in terms of the sexual distribution, and distributions of sexes versus age of the patients relationships between bacterial types and sexual and age distribution of the patients from whom the isolates were obtained correlation ages of patients and types of infections, the association of certain types of bacteria with certain infections and the effect of antibacterial treatments on these types of bacteria, approximately 20% of simple infections of urinary tracts occurred in males and approximately 80% in females on average from 1981 to 1984. This ratio showed hardly any changes during this period. Likewise, male patients comprised approximately 60-70% of all the cases with complicated infections of urinary tracts regardless of indwelling or without indwelling of catheters. In terms of age, the ratio of urinary tract infections was almost universally observed, e.g., for patients in 40's: 10.0% in 1981, 11.0% in 1984, while in those in 70's: 25.5% and 21.2%, respectively. Consequently, background factors of the cases with infections of urinary tracts, such as sexes, age, or simple or complicated, remained almost stable, whereas bacteria involved showed considerable variations. In 1982 and 1983, the frequency of isolations of Enterococcus spp. was approximately 8% in both males and females. However, in 1984, the frequency of isolation of Enterococcus spp. was 22.5% in the males 17.9% in the females. The frequency of isolation of Enterococcus spp. increased in all age groups, but the frequency was not particularly high among the aged. A study on variations and isolation frequencies of bacteria before the administration of antibiotic agents revealed that isolation frequencies of Enterococcus spp. sharply increased in 1983, and this high frequency remained in 1984. The frequency of isolation of E. coli tended to decrease year after year. This finding represents that the frequency of isolations of E. coli from materials of cases with simple infections of urinary tracts has decreased, showing that pathogenic bacteria from simple infections of urinary tracts were becoming similar to that of the complicated infections of urinary tracts. These findings seem to be worth mentioning here. In cases receiving administrations of antibacterial and antibiotic agents for more than 8 days. Frequencies of isolation from cases without catheter retention and from those with catheter retention were similar.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1986

Strain difference in learning impairment in rats following lead administration during brain development.

High and stable avoidance with low variability (THA) rats and non-select Wistar rats were administered 2 mg/ml lead acetate solution (0.2-0.27 g/Kg/day as lead) up to seven weeks of age; via placenta from the 13th day of gestation and from maternal milk before weaning, and per os after weaning. Results were as follows. 1) Significant differences were not observed between the lead-exposed rats and the controls regarding the developmental landmarks in both the Wistar rats and THA rats. Body weight of the exposed rats, however, were significantly less than that of the controls of the two rat strains. 2) Low rate of avoidance, slow acquisition of learning and large individual variabilities were exhibited in both the controls and the exposed rats of the Wistar strain throughout the test sessions. No significant difference was indicated between the controls and the exposed rats of the Wistar strain. In the control THA rats, avoidance learning was acquired rapidly, and a high level and very small individual variabilities of avoidance were demonstrated during the latter sessions of the test. Meanwhile, in the exposed THA rats, slow learning acquisition and large individual variabilities were displayed. It is thought that the learning impairment appearing in the THA exposed rats was induced primarily by lead.

Animals↗