Oxygen torus and its coincidence with EMIC wave in the deep inner magnetosphere: Van Allen Probe B and Arase observations.

We investigate the longitudinal structure of the oxygen torus in the inner magnetosphere for a specific event found on 12 September 2017, using simultaneous observations from the Van Allen Probe B and Arase satellites. It is found that Probe B observed a clear enhancement in the average plasma mass (M) up to 3-4 amu at L = 3.3-3.6 and magnetic local time (MLT) = 9.0 h. In the afternoon sector at MLT ~ 16.0 h, both Probe B and Arase found no clear enhancements in M. This result suggests that the oxygen torus does not extend over all MLT but is skewed toward the dawn. Since a similar result has been reported for another event of the oxygen torus in a previous study, a crescent-shaped torus or a pinched torus centered around dawn may be a general feature of the O+ density enhancement in the inner magnetosphere. We newly find that an electromagnetic ion cyclotron (EMIC) wave in the H+ band appeared coincidently with the oxygen torus. From the lower cutoff frequency of the EMIC wave, the ion composition of the oxygen torus is estimated to be 80.6% H+, 3.4% He+, and 16.0% O+. According to the linearized dispersion relation for EMIC waves, both He+ and O+ ions inhibit EMIC wave growth and the stabilizing effect is stronger for He+ than O+. Therefore, when the H+ fraction or M is constant, the denser O+ ions are naturally accompanied by the more tenuous He+ ions, resulting in a weaker stabilizing effect (i.e., larger growth rate). From the Probe B observations, we find that the growth rate becomes larger in the oxygen torus than in the adjacent regions in the plasma trough and the plasmasphere.

Coexpression of an unusual form of the EWS-WT1 fusion transcript and interleukin 2/15 receptor betamRNA in a desmoplastic small round cell tumour.

BACKGROUND: The beta chain of the interleukin 2/15 receptor (IL-2/15Rbeta) is induced by the expression of the EWS-WT1. A case of desmoplastic small round cell tumour (DSRCT) expressing only an unusual EWS-WT1 treated by us is reported here. AIM: To characterise an unusual form of EWS-WT1. METHODS: Frozen tissue sections of the axillary tumour were examined using a laser-assisted microdissection technique and reverse transcriptase polymerase chain reaction. RESULTS: The novel fusion of exon 8 of EWS and the defective exon 10 of WT1 (-KTS) was detected. Although it was an unusual form, the coexpression of the present EWS-WT1, IL-2/15Rbeta and Janus kinase (JAK1) mRNA was detected in the tumour cells. IL-2 and signal transducers and activators of transcription (STAT5) mRNA were detected in both tumour and stromal cells. CONCLUSION: The induction of the IL-2/15 receptor signalling pathway may contribute to tumorigenesis in DSRCT through a paracrine or an autocrine system, even though the EWS-WT1 was an unusual form.

The virulence of Enterobacter cloacae and Serratia marcescens in experimental bladder infection in diabetic mice.

Diabetic mice were significantly more susceptible than normal mice to bladder infection with Enterobacter cloacae or Serratia marcescens but not to intraperitoneal infection. Normal urine inhibited the growth of E. cloacae and S. marcescens, whereas urine from diabetic mice permitted multiplication. The addition of urea to urine from diabetic mice restored its antibacterial properties for E. cloacae and S. marcescens. We consider that the decreased urea content of the urine of diabetic mice was responsible for their increased susceptibility to bacterial infection of the bladder.

Adherence of Serratia marcescens in the pathogenesis of urinary tract infections in diabetic mice.

The adherence of Serratia marcescens to bladder epithelial cells of mice with alloxan-induced diabetes was studied. S. marcescens adhered more strongly to the bladder epithelial cells of diabetic mice than to those of normal mice both in vitro and in vivo. The susceptibility of diabetic mice to urinary tract infection may be due to an increased adhesive capacity of bladder epithelial cells.

Therapeutic efficacy of beta-lactam and aminoglycoside antibiotics on experimental pneumonia caused by Klebsiella pneumoniae B-54 in diabetic mice.

The therapeutic efficacy of six beta-lactam and aminoglycoside antibiotics were compared in diabetic mice with experimentally induced Klebsiella pneumoniae pneumonia. beta-Lactams caused a reduction in the numbers of bacteria, with clearance of bacteria from the lungs of diabetic and normal mice. The effect in diabetic mice, however, was very poor. In contrast thereto, no remarkable difference was seen between diabetic and normal mice when treated with aminoglycosides. The concentration of the test antibiotics to the lungs in diabetic mice was lower than in normal mice. The aminoglycosides were more effective than the beta-lactams. These data suggest that in treating acute and more chronic forms of pulmonary infection caused by K. pneumoniae in diabetic mice aminoglycoside antibiotics are particularly valuable, whereas beta-lactams must be given in large quantities using multiple administrations.

In vitro and in vivo antibacterial activity of KY-109, a new orally active cephalosporin.

The in vitro and in vivo antimicrobial potencies of KY-109, a pro-drug of KY-087, were compared with those of amoxicillin, cephalexin (CEX), and cefaclor (CCL). The following results were obtained. KY-087, which is the active form of KY-109, had broad antimicrobial spectrum against Gram-positive and Gram-negative organisms, but showed low antimicrobial activity against Enterobacter sp., Serratia, and Pseudomonas sp. The antimicrobial activities of KY-087 against clinically isolated Gram-positive organisms were superior to those of CEX and CCL. The antimicrobial activities of KY-087 against Gram-negative organisms, such as Enterobacter sp., Serratia, and Pseudomonas sp., were less active. KY-087 showed dose-related bactericidal activity against Staphylococcus aureus and Escherichia coli. The therapeutic efficacy of KY-109 against experimental intraperitoneal infections caused by Gram-positive and Gram-negative organisms in mice was comparable to that of CEX but inferior to that of CCL. In experimental granuloma pouch models in rats and kidney infection in rabbits, therapeutic efficacy of KY-109 was either comparable or superior to that of CEX and CCL.

Therapeutic efficacy of ofloxacin, ciprofloxacin and NY-198 in experimentally infected normal and alloxan-induced diabetic mice.

The therapeutic efficacy of ofloxacin, ciprofloxacin and NY-198 was compared in alloxan-induced diabetic mice with experimental respiratory and urinary tract infections. Respiratory infection due to Klebsiella pneumoniae DT-S was well controlled by treatment with all compounds tested both in normal and diabetic mice. Similar observations were made in a model of urinary tract infection due to Serratia marcescens T-55. There was no difference between normal and diabetic mice in therapeutic efficacy of these compounds. They appear to be highly active antibacterial drugs in vitro under conditions which stimulate normal and diabetic states. There was no difference between normal and diabetic mice in the serum, lung and kidney concentrations. These observations suggest that ofloxacin, ciprofloxacin and NY-198 may be effective drugs in the treatment of bacterial respiratory and urinary tract infections which may occur in diabetic conditions.

In vivo activity of ciprofloxacin, ofloxacin, norfloxacin and pipemidic acid against Escherichia coli infections in mice.

The therapeutic efficacy of four quinolones, i.e. ciprofloxacin, ofloxacin, norfloxacin and pipemidic acid, was investigated in experimental infections in mice caused by pipemidic acid-susceptible and -resistant E. coli. For intraperitoneal infections caused by E. coli strain 444 and 23, the efficacy of ciprofloxacin, ofloxacin and norfloxacin was superior to that of pipemidic acid. Furthermore, ciprofloxacin and ofloxacin had higher activity than norfloxacin and pipemidic acid in urinary tract and uterine infections. Serum and uterus levels of ciprofloxacin and ofloxacin in normal mice were higher and more durable than those of norfloxacin.

[Studies on the biological activity of slime isolated from staphylococci].

The biological characteristic and activity of slime isolated from Staphylococcus aureus No. 71 and Staphylococcus epidermidis No. 2 was studied. The slime isolated from both strains had high contents of protein, RNA (orcinol reaction-positive substances) and sugar. The slime showed low toxic effect when it was injected intravenously and intraperitoneally into mice. It, however, exhibited potent cytotoxic effect against mouse neutrophils in both ex vivo and in vivo experiments. The enhancement of virulence of Escherichia coli by slime isolated from staphylococci was due to neutrophil-impairing effect. It is suggested that the slime isolated from S. aureus and S. epidermidis may act as an virulence factor.

Virulence of Escherichia coli strains with R-plasmid mediated penicillin resistance in mice infections.

Penicillinase I-, II- and III-producing R-plasmid of Escherichia coli were transferred to Escherichia coli 177, KC-14, and 444. These strains are highly virulent in mice. This study was conducted to investigate the influence of conjugative R-plasmid on the virulence of its host strains. Escherichia coli 177 after penicillinase I- or III-producing R-plasmids transfer retained parental levels of virulence. On the other hand, penicillinase II-producing transconjugants showed reduced virulence in mice. The virulence of its revertants, in which R-plasmid was eliminated by heat, were equivalent to that of the host strain. It is suggested that the decrease in the virulence of transconjugants was not due to transferred R-plasmid. The reduced virulence of the these transconjugants may be due to alterations in their components such as the lipopolysaccharides in the cell envelope.

[The infectivity of Enterococcus faecalis in experimental urinary tract infection in mice: II].

The infectivity of Enterococcus faecalis was compared with that of Escherichia coli in the urinary tract in mice. The infectivity of E. faecalis in normal mice was found to be equal to that of E. coli. The mice previously treated with cyclophosphamide, carrageenin or alloxan as the immunosuppressive drug, and restricted water supply, were more susceptible to enterococcal infection than non-treated ones. These data were confirmed with histological examinations. E. faecalis is a pathogenic organism in the urinary tract and therefore cautions should be given to the treatment in clinical practice.

[Effect of insulin on the incidence of experimental Serratia marcescens cystitis in diabetic mice--relationship between insulin therapy and urea nitrogen content].

The effect of insulin on the incidence of experimental Serratia marcescens cystitis in alloxan-induced diabetic mice was studied. The symptoms in diabetes were improved by injection of insulin (1 I.U./b.i.d.) for 3 days. Diabetic mice treated with insulin showed lower susceptibility to cystitis with S. marcescens than non-treated diabetic mice, but slightly higher than normal mice. It was, therefore, suggested that the insulin treatment was important for prevention of S. marcescens cystitis. The prevention of cystitis in insulin-treated diabetic mice was possibly due to the increase of urea nitrogen that inhibits the growth of S. marcescens in urine.

[The virulence of Enterococcus faecalis in experimental urinary tract infection in mice].

The virulence of Enterococcus faecalis in the urinary tract in mice was studied. Pyelonephritis was distinctly caused by E. faecalis which have a high affinity to mouse kidneys. This infection was continuous, but did not turn into sepsis. The relationship between the production of hemolysin or protease and the virulence in the urinary tract was investigated without finding any distinct association. It is concluded that E. faecalis is a pathogenic organism in the urinary tract and presumably induces a severe infection in the compromised host.

[Antifungal susceptibility of clinically isolated Candida albicans by broth microdilution method].

In this study we investigated the antifungal susceptibility of 285 strains of Candida albicans isolates at Kinki University Hospital from March 1995 to December 1996. The antifungal agents tested were fluconazole, miconazole, intraconazole, amphotericin B and flucytosine. The susceptibility testing were performed according to the broth microdilution method standardized by National Committee for Clinical Laboratory Standards (M27-T). Most isolates of C. albicans showed relatively a low MIC value and the MIC90S were calculated at 1 microgram/ml; fluconazole, 0.125 microgram/mg; miconazole, 0.06 microgram/ml; itraconazole, 1 microgram/ml; amphotericin B, 0.25 microgram/ml; flucytosine. There was only one strain that showed high resistance against fluconazole and it showed cross-resistance against miconazole and itraconazole. There were two flucytosine resistant strains. The MICs of amphotericin B were tightly clustered and resistant strain were not observed.

[Retrospective analysis of deep-seated candidiasis among cases autopsied between 1982 to 1991].

Candida is present in the flora of the oral cavity, skin, intestinal tract and vagina, and is also known to be an opportunistic pathogen. Infection with this fungus has been increasing annually along with wide spread use of broad-spectrum antimicrobial agents. The subjects included 95 patients (48 males and 47 females) who had been diagnosed as having had deep-seated candidiasis, among patients autopsied between 1982 to 1991. In regard to annual changes in deep-seated candidiasis, the incidence reached a peak in the 1985 to 1988 period, and thereafter decreased. The number of cases with leukemia as the underlying disease was the largest, 36 (37.9%), followed by malignant lymphoma in 10, and aplastic anemia 5. The number of cases with infection of the stomach was largest, 42 (44.2%), followed by the esophagus in 33 (34.7%), the lung and kidney. The cases with deep-seated candidiasis showed low values of or level of lymphocyte, hemoglobin, CRP, total protein and cholesterol and high values or levels of LDH, urea N, creatinine and total bilirubin. Cases with marked decrease in neutrophils showed no regional infiltration of inflammatory cells in any of the organs infected with Candida. Cases with disseminated candidiasis showed vascular invasion by Candida. The laboratory findings also showed that most of the cases had been undernourished and had high values of CRP which supports the presence of inflammation. Common sites of infection are the esophagus, stomach, and intestinal tract. In the presence of granulocytopenia and immunodeficiency, tissue invasion become severe and associated with vascular invasion.

[Antibacterial action of cefoperazone and piperacillin against Escherichia coli].

A study of the antibacterial action of cefoperazone (CPZ) and piperacillin (PIPC) against E. coli demonstrated clear differences between these 2 drugs. CPZ showed higher bactericidal and lytic activity which was dose dependent and not greatly influenced by inoculum size. In contrast, the activity of PIPC was strongly influenced by inoculum size and showed high bactericidal activity only against a low inoculum size. The activity of CPZ was not related to the pH of the culture medium, whereas PIPC showed increased activity in an acid medium. In a study of the drug sensitive phase of a synchronous culture, CPZ was highly effective during the period of cell division showing strong bactericidal activity at that time. The bactericidal action of CPZ was inhibited by the addition of chloramphenicol. In contrast, PIPC which by itself demonstrated only weak bactericidal activity was not effective during the period of cell division. Although CPZ and PIPC both activate autolysin activity, CPZ was more active in this regard.

[Therapeutic efficacies of suppository of ceftizoxime against experimental infections in mice].

In experimental infections in mice, the therapeutic efficacies of rectal administration of ceftizoxime (CZX) were compared with those of subcutaneous administration. The efficacies of rectal administration were equivalent to those of subcutaneous administration against intraperitoneal infections due to Streptococcus pneumoniae and Escherichia coli. Against Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae, Enterobacter cloacae, Proteus mirabilis, Morganella morganii and Serratia marcescens, the efficacies of rectal administration were inferior to those of subcutaneous administration. Against urinary tract and respiratory tract infections, the efficacies of rectal administration were slightly inferior to those of subcutaneous administration. Serum concentrations of CZX for rectal administration were less than those of subcutaneous administration.

[Combination antibacterial effects between aztreonam and eight other antibiotics].

In vitro interactions between aztreonam (AZT) and 8 other antibiotics were studied using the agar dilution checkerboard technique against 88 clinical isolates of Escherichia coli, Proteus vulgaris, Serratia marcescens and Pseudomonas aeruginosa. Combinations of AZT with 8 other antibiotics were generally additive or indifferent. Synergism was occasionally seen against S. marcescens or P. aeruginosa with AZT plus isepamicin (ISP). Antagonism was observed only between AZT and latamoxef against P. vulgaris. In a phase-contrast microscopic study, synergistic effects between AZT and aspoxicillin or ISP were confirmed against E. coli 177 and P. aeruginosa 15846. AZT in combination with ISP demonstrated a synergy against experimental urinary tract infection in mice caused by P. aeruginosa 15846. We believe that combinations of several antibiotics with AZT should be considered for initial therapy of infections because synergism and additive action were observed and antagonism was rarely found in our study.

[Experimental studies on administration method of chemotherapeutic agents. 16. Effect of polymyxin B against Pseudomonas aeruginosa (author's transl)].

The most effective administration method of polymyxin B (PL-B), a peptide antibiotic, has been studied in the experimental mice infection with Pseudomonas aeruginosa. 1) Pseudomonas aeruginosa damaged by PL-B, when the drug was free, immediately began to regrow in vitro. 2) the therapeutic efficacy of PL-B on multiple administration was less effective than its single administration. 3) An important factor to decide the therapeutic efficacy of PL-B was the high drug concentration in plasma and peritoneal fluid.

[Bacterial combination effect between carumonam and eight other antibiotics].

In vitro interactions between carumonam (CRMN) and 8 other antibiotics were studied using the agar dilution checkerboard technique against 88 clinical isolates of Escherichia coli, Proteus vulgaris, Serratia marcescens and Pseudomonas aeruginosa. Combinations of CRMN with 8 other antibiotics were generally additive or indifferent. Synergism was found against S. marcescens or P. aeruginosa with CRMN plus fosfomycin, gentamicin (GM) or dibekacin. Antagonism was not observed with CRMN plus any of the 8 other antibiotics tested. In a phase-contrast microscopic study, the synergism of CRMN in combination with GM were confirmed against P. aeruginosa 15846. CRMN in combination with GM demonstrated a in vivo synergy against experimental urinary tract infection caused by P. aeruginosa 15846 in mice. We think that combinations of several antibiotics with CRMN should be appropriate for initial therapy of infections because no antagonism appeared to occur with other antibiotic agents.