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Rifampicin was inactivated by Nocardia otitidiscaviarum to yield two products designated RIP-3 and RIP-4. The full structures of RIP-3 and RIP-4 were determined to be 21-(O-phosphoryl) rifampicin and 3-formyl-21-(O-phosphoryl) rifamycin SV, respectively, but neither product had any antimicrobial activity. [ABSTRACT FROM AUTHOR]

MICs of two new carbapenems, meropenem and L-627, and imipenem were determined against 98 strains of the Nocardia asteroides group (i.e. N. asteroides sensu stricto, Nocardia farcinica and Nocardia nova), 46 strains of Nocardia brasiliensis and 17 strains of Nocardia otitidiscaviarum. Meropenem and L-627 were less active against the N. asteroides group than imipenem. Among the three species of the N. asteroides group, N. nova was the most sensitive to all the carbapenems. Meropenem was more active than imipenem against both N. brasiliensis and N. otitidiscaviarum with MIC50 values of 28.3-53.3 mg/L. L-627 was less active than meropenem. [ABSTRACT FROM AUTHOR]

Auditors' propensity to issue Going Concern Audit Reports (GCARs) is one of the proxies often used for audit quality. Although this propensity is a distinguishing characteristic of auditors, it does not indicate quality according to both theory and practice. In theory, higher quality auditors make fewer audit errors; they are more likely to issue GCARs to clients that deserve them and less likely to issue GCARs to clients that do not. Therefore, the propensity itself does not indicate quality. In practice, Public Company Accounting Oversight Board (PCAOB) inspection reports reveal that the GCAR is rarely mentioned as a deficiency, and in the few cases in which it is discussed, the deficiency is attributed to evidence gathering and estimations, rather than to the GCAR decision itself. The theory and practice motivate our study. This article investigates the empirical ability of the GCAR propensity to proxy for audit quality and finds that different samples and different models yield different determinations of auditor quality. Our findings caution against the use of the propensity to issue GCARs as a proxy for audit quality. [ABSTRACT FROM AUTHOR]

We propose and analyze an electrothermal energy converter using volumetric changes in nonequilibrium electron gas inside semiconductors. The geometric concentration of electron gas under an electric field increases the effective pressure of the electrons, and then a barrier filters out cold electrons, acting like a valve. Nano- and micro-scale features enable hot electrons to arrive at the contact in a short enough time to avoid thermalization with the lattice. Key length and time scales, preliminary device geometry, and anticipated efficiency are estimated for electronic analogs of Otto and Brayton power generators and Joule-Thomson micro refrigerators on a chip. The power generators convert the energy of incident photons from the heat source to electrical current, and the refrigerator can reduce the temperature of electrons in a semiconductor device. The analytic calculations show that a large energy conversion efficiency or coefficient of performance may be possible. [ABSTRACT FROM AUTHOR]

Background: Upper gastrointestinal endoscopy (UGIE) may cause some cardiac stress. The effect of sedation on hemodynamics during UGIE has not been fully studied, and therefore the aim of this study was to clarify whether or not sedation can reduce cardiac stress during UGIE. Methods: Eight normal male volunteers undergoing UGIE with sedation (0.1 mg/kg of midazolam) and without it (two endoscopies per volunteer in random order) were monitored throughout the procedure by means of electrocardiogram, blood pressure and peripheral oxygen saturation (SpO[sub 2]). Cardiac output was measured at six points before, during and after endoscopy from automated cardiac flow measurement by color Doppler echocardiography. Serum norepinephrine, epinephrine, dopamine and ACTH concentrations were measured before and after the examination. Results: No significant differences in heart rate, systolic blood pressure, rate-pressure product, cardiac output and left ventricular work index were observed between the sedated and non-sedated groups. SpO[sub 2] hardly changed during endoscopy in the non-sedated group, but decreased slightly in the sedated group (P = 0.075). Although all serum catecholamine concentration changes were within normal limits in both groups, after endoscopy only epinephrine concentration was significantly lower in the sedated group than in the non-sedated group (P = 0.0027). Conclusions: Conscious sedation with midazolam does not reduce the cardiac stress during UGIE. [ABSTRACT FROM AUTHOR]

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The new fluoroquinolone grepafloxacin exhibited MICs of 0.6 to 20 mg/L against 134 pathogenic spp including and and was 2–20 times more active than norfloxacin, ofloxacin, tosufloxacin and ciprofloxacin against these bacteria. [ABSTRACT FROM PUBLISHER]

The in-vitro postantifungal effect (PAFE) of 5-fluorocytosine for for short periods of time was investigated. Yeast cells were exposed for 0·5,1 or 2 h to a range of concentrations (0·1–3·2 mg/L) of 5-fluorocytosine. The PAFE was quantitated by determinations of the number of colony forming units at hourly intervals (0–10 h) after removal of the drug by dilution. The length of the PAFE was dependent upon the concentration of 5-fluorocytosine and the duration of exposure. An exposure time of 0·5 h resulted in PAFE's ranging from 0 to 4·2 h. Exposure times of 1 and 2 h resulted in longer PAFEs and in many instances suppression of cell growth was seen for the entire evaluation period (up to ten hours). [ABSTRACT FROM PUBLISHER]

The susceptibility of 113 strains of pathogenic Nocardia, N. asteroides, N. farcinica, N. nova, N. brasiliensis and N. otitidiscaviarum to a new oxacephem antibiotic flomoxef was determined by an agar dilution method in comparison with those of 13 other cephalosporins. Flomoxef was two to 50 times more active against these pathogenic Nocardia than other cephalopsorins tested. However, there were differences in susceptibility to this antibiotic among these Nocardia strains. N. asteroides was the most sensitive species, followed by N. farcinica and N. nova. N. brasiliensis was moderately sensitive and N. otitidiscaviarum was resistant. [ABSTRACT FROM AUTHOR]

Docosahexaenoic acid (DHA), a major component of fish oil, suppresses the formation and growth of aberrant crypt foci induced by 1,2-dimethylhydrazine and azoxymethane. In the present study we examined the effects of intragastric gavage administration of DHA on the yield of rat colonic aberrant crypt foci due to treatment with a heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), which induces colon cancer in male F344 rats and is considered to be a possible human colon carcinogen. Male F344 rats were given a standard diet (AIN-76A) and received 10 doses of PhIP (75 mg/kg body wt, by intragastric intubation, on days 1-5 and 8-12) with or without intragastric application of 1 ml DHA 4 h prior to each carcinogen treatment, followed by further DHA dosing. The numbers of PhIP-induced aberrant crypt foci per colon after 4 and 12 weeks DHA administration were significantly reduced to 47 and 38% respectively of the values obtained when PhIP alone was used. The mean number of aberrant crypts per focus was also decreased by DHA treatment. At week 4 the PhIP-DNA adduct levels in the colon of rats from the PhIP+DHA group were approximately two thirds of the PhIP group value. The results thus suggest that DHA exerts a preventive effect on PhIP-induced colon carcinogenesis. [ABSTRACT FROM PUBLISHER]

The effects of intragastric gavage administration of docosahexaenoic acid (DNA) , a major component of fish oil, on azoxymethane (AOM)-induced colon carcinogenesis in rats was investigated. Male F344 rats were treated with 15 mg/kg body wt of AOM once a week, for two weeks. The animals were given either 1 ml of DHA or water intragastrically 5 times a week, starting the day before the first carcinogen treatment. The numbers of AOM-induced aberrant crypt foci in the rats given DHA were 76% and 62% of the control values, at 4 and 12 weeks, respectively. After 36 weeks of DHA treatment, colon tumors were counted and examined histologically. The blood plasma levels of prostaglandin E2 (PGE2) and polyunsaturated fatty acids were also quantified. The incidences of colon cancer did not differ, being 96% and 92% in the AOM and AOM+DHA groups, respectively. Colon cancer multiplicity was, however, significantly decreased by the DHA treatment; 3.65 +/- 2.18 in the AOM group and 2.41 +/- 1.58 in the AOM+DHA group (P <0.01). Notably, the numbers of moderately differentiated adenocarcinomas in the middle and distal colon in the DHA-treated group were lower than in the AOM group. The levels of PGE2 and arachidonic acid in the blood plasma of DHA-treated rats were also significantly lower than in the AOM group. These results suggest that DHA exerts its inhibitory effect on colon carcinogenesis by modulating lipid metabolism and inhibiting the arachidonic cascade. [ABSTRACT FROM PUBLISHER]

Simulations of dusty plasmas were performed using GRAPE-6, a special-purpose computer designed for gravitational N-body problems. The collective behavior of dust particles, which are injected into the plasma, was studied by means of three-dimensional computer simulations. As an example of a dusty plasma simulation, experiments on Coulomb crystals in plasmas are simulated. Formation of a quasi-two-dimensional Coulomb crystal has been observed under typical laboratory conditions. Another example was to simulate movement of dust particles in plasmas under microgravity conditions. Fully three-dimensional spherical structures of dust clouds have been observed. For the simulation of a dusty plasma in microgravity with 3×104 particles, GRAPE-6 can perform the whole operation 1000 times faster than by using a Pentium 4 1.6 GHz processor. [ABSTRACT FROM AUTHOR]