Evaluation of the GenoType MTBDR assay for detection of rifampicin and isoniazid resistance in Mycobacterium tuberculosis complex isolates.

Detection of drug resistance plays a critical role in tuberculosis treatment. The aim of this study was to evaluate the performance of GenoType Mycobacteria Drug Resistance (MTBDR) assay (Hain Lifescience, Germany) and to compare it with radiometric BACTEC 460 TB system (Becton Dickinson, USA) for the detection of rifampicin (RIF) and isoniazid (INH) resistance in 84 Mycobacterium tuberculosis complex (MTBC) isolates. RIF resistance was identified in 6 of 7 (85.7%) isolates and INH resistance was identified in 8 of 14 (57.1%) isolates by the GenoType MTBDR assay. Compared with BACTEC system, the sensitivity, specificity, positive predictive value and negative predictive values were 85.7%, 98.7%, 85.7% and 98.7% for RIF resistance; and 57.1%, 100%, 100% and 92.1% for INH resistance, respectively. GenoType MTBDR assay is reliable when tested specimen is resistant to the tested drugs. Although test was more successful in the detection of RIF resistance, it exhibited low sensitivity for the detection of INH resistance.

Correlation between broth microdilution and disk diffusion methods for antifungal susceptibility testing of caspofungin, voriconazole, amphotericin B, itraconazole and fluconazole against Candida glabrata.

Candida glabrata is one of the most frequent organisms isolated from superficial and invasive fungal infections, after Candida albicans. This organism also exhibits intrinsically low susceptibility to azole antifungals and treatment often fails. The microdilution method is not very practical for use in routine susceptibility testing in the clinical laboratory, thus necessitating the use of other methods. In this study, we compared the in vitro activity of five antifungal agents in three different groups (echinocandin, polyene and azole) against 50 C. glabrata isolates by broth microdilution and disk diffusion methods recommended by Clinical Laboratory Standards Institute CLSI M27-A3 and CLSI M44-A, respectively. All the isolates were susceptible to amphotericin B (100%) and 98% of the isolates were susceptible to caspofungin by the broth microdilution method. Within the azole group drugs, voriconazole was the most active followed by fluconazole and itraconazole in vitro. The highest rate of resistance was obtained against itraconazole with a high number of isolates defined as susceptible-dose dependent or resistant. Although the disk diffusion method is easy to use in clinical laboratories, it shows very poor agreement with the reference method for fluconazole and itraconazole against C. glabrata (8% and 14%, respectively).

Mismatch management for optical and matter-wave quadratic solitons.

We propose a way to control solitons in chi(2) (quadratically nonlinear) systems by means of periodic modulation imposed on the phase-mismatch parameter ("mismatch management," MM). It may be realized in the cotransmission of fundamental-frequency (FF) and second-harmonic (SH) waves in a planar optical waveguide via a long-period modulation of the usual quasi-phase-matching pattern of ferroelectric domains. In an altogether different physical setting, the MM may also be implemented by dint of the Feshbach resonance in a harmonically modulated magnetic field in a hybrid atomic-molecular Bose-Einstein condensate (BEC), with the atomic and molecular mean fields (MFs) playing the roles of the FF and SH, respectively. Accordingly, the problem is analyzed in two different ways. First, in the optical model, we identify stability regions for spatial solitons in the MM system, in terms of the MM amplitude and period, using the MF equations for spatially inhomogeneous configurations. In particular, an instability enclave is found inside the stability area. The robustness of the solitons is also tested against variation of the shape of the input pulse, and a threshold for the formation of stable solitons is found in terms of the power. Interactions between stable solitons are virtually unaffected by the MM. The second method (parametric approximation), going beyond the MF description, is developed for spatially homogeneous states in the BEC model. It demonstrates that the MF description is valid for large modulation periods, while, at smaller periods, non-MF components acquire gain, which implies destruction of the MF under the action of the high-frequency MM.

Preemptive effect of fentanyl and ketamine on postoperative pain and wound hyperalgesia.

The aim of this study was to test the hypothesis that the induction and maintenance of anesthesia with the use of fentanyl or ketamine reduces postoperative pain and wound hyperalgesia beyond the period when these effects can be explained by the direct analgesic action of these drugs. Twenty-seven patients scheduled for elective hysterectomy were investigated in a double-blind, randomized study. Patients were divided into three groups. In the fentanyl group, anesthesia was induced with fentanyl 5 micrograms/kg combined with thiopental 3 mg/kg and maintained with isoflurane and fentanyl 0.02 microgram.kg-1.min-1. In the ketamine group, anesthesia was induced with ketamine 2 mg/kg in combination with thiopental 3 mg/kg and maintained with isoflurane and ketamine 20 micrograms.kg-1.min-1. In the control group, anesthesia was induced with thiopental 5 mg/kg and maintained with isoflurane only. Patients in all three groups received identical postoperative pain treatment. The intensity of spontaneous incisional pain and movement-associated pain was measured with a visual analog self-rating method. The surgical wound hyperalgesia was assessed by measuring pain threshold to pressure on the wound by using an algometer, and also by measuring the intensity of pain to suprathreshold pressure on the wound with the visual analog self-rating method. Forty-eight hours after surgery, the pain threshold was 0.90 +/- 0.06 kg in controls, 1.69 +/- 0.19 kg (P < 0.001) in the fentanyl group, and 1.49 +/- 0.15 kg (P < 0.01) in the ketamine group.(ABSTRACT TRUNCATED AT 250 WORDS)