Occurrence and characterization of plasmid-encoded qnr genes in quinolone-resistant bacteria across diverse aquatic environments in southern Ontario.

Antimicrobial resistance is an ever-increasing threat. The widespread usage of ciprofloxacin has led to the manifestation of resistance due to chromosomal mutations or the acquisition of plasmid-mediated quinolone resistance (PMQR) traits. Some particular PMQR traits, qnr genes, have been identified globally in clinical and environmental isolates. This study aimed to determine the prevalence of ciprofloxacin-resistant bacteria in aquatic environments in southern Ontario and investigate the extent of dissemination of ciprofloxacin resistance traits among the bacterial communities. We surveyed the prevalence of plasmid encoding qnr genes using a multiplex PCR assay of associated PMQR genes, qnrA, qnrB, and qnrS, on 202 isolates. Despite the absence of significant impacts on minimum inhibitory concentration levels, the presence of qnr genes correlates with heightened resistance to quinolones and nalidixic acid in some isolates. Taxonomic analysis highlights distinct differences in the composition and diversity of ciprofloxacin-sensitive (CipS) and ciprofloxacin-resistant (CipR) populations, with Proteobacteria dominating both groups. Importantly, CipR populations exhibit lower genetic diversity but higher prevalence of multiple antibiotic resistances, suggesting co-selection mechanisms. Co-occurrence analysis highlights significant associations between ciprofloxacin resistance and other antibiotic resistances, implicating complex genetic linkages. The results of our study signified the critical role of environmental monitoring in public health.

Synthesis of New 3-Heteroarylindoles as Potential Anticancer Agents.

2-(3-(1H-Indol-3-yl)-5-(p-tolyl)-4,5-dihydro-1H-pyrazol-1-yl)-4-substituted-5-(substituted diazenyl)thiazoles and 2-(1H-indol-3-yl)-9-substituted-4,7-disubstituted pyrido[3,2-e][1,2,4]triazolo[4,3-a]pyrimidin-5(7H)-ones were synthesized via reaction of hydrazonoyl halides with each of 3-(1H-indol-2-yl)-5-(p-tolyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide and 7-(1H-indol-3-yl)-2- thioxo-5-substituted-2,3-dihydropyrido[2,3-d]pyrimidin-4(1H)-ones, respectively. Also, hydrazonoyl halides were reacted with N'-(1-(1H-indol-3-yl)ethylidene)-2-cyanoacetohydrazide to afford 1,3,4-thiadiazole derivatives. Structures of the new synthesis were elucidated on the basis of elemental analysis, spectral data, and alternative synthetic routes whenever possible. Fifteen of the new compounds have been evaluated for their antitumor activity against the MCF-7 human breast carcinoma cell line. The results indicated that many of the tested compounds showed moderate to high anticancer activity when compared with doxorubicin as a reference drug.

Design, construction and field testing of a manually feeding semiautomatic sugarcane dud chipper.

Sugarcane is the main sugar crop, and sugar is an important agricultural product in Egypt. There are many problems with the technology used in the current planting method of sugarcane, which has a great impact on the planting quality of sugarcane, which have a series of problems, such as low cutting efficiency and poor quality. Therefore, the aim of the current study was to design, construct, and field testing of a semiautomatic sugarcane bud chipper assisted with pivot knives for cutting sugarcane buds and germinating them in plastic trays inside a greenhouse until they reached an average length of 35 cm, and then planting them in the field. In the field tests five cutting speeds (35, 40, 45, 50, and 56 rpm. (Revolution Per minute), three cutting knives (1.5, 2.0, and 2.5 mm) were used for cutting sugarcane stalks with four different diameters (1.32, 1.82, 2.43, and 2.68 cm). The obtained results showed that the values of the damage index and invisible losses were within acceptable limits (ranging between - 1.0 and 0.0) for all the variables under the test. Still, the lowest damage index and invisible losses were recorded with the buds that were cut with a knife of 1.5 mm thickness and cutting speeds less than 50 rpm. The skipping rate increases with the increase in cutting speed and stalk diameter, ranging between 0.0 to 13%. The maximum machine productivity was 110 Buds per minute at a cutting speed of 35 rpm and stalk diameter of 1.32 cm. The paper's findings have important application values for promoting the designing and development of sugarcane bud chipper and sugarcane planting technology in the future.

Role of Mitochondrial Iron Overload in Mediating Cell Death in H9c2 Cells.

Iron overload (IO) is associated with cardiovascular diseases, including heart failure. Our study's aim was to examine the mechanism by which IO triggers cell death in H9c2 cells. IO caused accumulation of intracellular and mitochondrial iron as shown by the use of iron-binding fluorescent reporters, FerroOrange and MitoFerroFluor. Expression of cytosolic and mitochondrial isoforms of Ferritin was also induced by IO. IO-induced iron accumulation and cellular ROS was rapid and temporally linked. ROS accumulation was detected in the cytosol and mitochondrial compartments with CellROX, DCF-DA and MitoSOX fluorescent dyes and partly reversed by the general antioxidant N-acetyl cysteine or the mitochondrial antioxidant SkQ1. Antioxidants also reduced the downstream activation of apoptosis and lytic cell death quantified by Caspase 3 cleavage/activation, mitochondrial Cytochrome c release, Annexin V/Propidium iodide staining and LDH release of IO-treated cells. Finally, overexpression of MitoNEET, an outer mitochondrial membrane protein involved in the transfer of Fe-S clusters between mitochondrial and cytosol, was observed to lower iron and ROS accumulation in the mitochondria. These alterations were correlated with reduced IO-induced cell death by apoptosis in MitoNEET-overexpressing cells. In conclusion, IO mediates H9c2 cell death by causing mitochondrial iron accumulation and subsequent general and mitochondrial ROS upregulation.

All-optical optoacoustic microscopy based on probe beam deflection technique.

Optoacoustic (OA) microscopy using an all-optical system based on the probe beam deflection technique (PBDT) for detection of laser-induced acoustic signals was investigated as an alternative to conventional piezoelectric transducers. PBDT provides a number of advantages for OA microscopy including (i) efficient coupling of laser excitation energy to the samples being imaged through the probing laser beam, (ii) undistorted coupling of acoustic waves to the detector without the need for separation of the optical and acoustic paths, (iii) high sensitivity and (iv) ultrawide bandwidth. Because of the unimpeded optical path in PBDT, diffraction-limited lateral resolution can be readily achieved. The sensitivity of the current PBDT sensor of 22 µV/Pa and its noise equivalent pressure (NEP) of 11.4 Pa are comparable with these parameters of the optical micro-ring resonator and commercial piezoelectric ultrasonic transducers. Benefits of the present prototype OA microscope were demonstrated by successfully resolving micron-size details in histological sections of cardiac muscle.

Photodynamic actions of indocyanine green and trypan blue on human lens epithelial cells in vitro.

PURPOSE: The purpose of this study was to evaluate the toxicity and photodynamic activity of indocyanine green (ICG) and trypan blue (TryB) on cultured human lensepithelial cells (LECs). DESIGN: Experimental study. METHODS: Lens epithelial cell viability was assessed after treatment with ICG and TryB concentrations ranging from 0.025 to 5.0 mg/ml, and exposure to 806 nm diode laser. RESULTS: At ICG concentrations below 0.5 mg/ml, there was > or =75% cell viability; at higher ICG concentrations there was dose-dependent cytotoxicity in addition to loss of cellular viability due to ICG photosensitization. TryB had little cytotoxicity to the LECs: >80% cells were viable irrespective of the dye concentration or laser treatment. CONCLUSIONS: These data indicate that ICG may have application as a photosensitizer in the selective eradication of residual LECs after cataract surgery to reduce the incidence of posterior capsule opacification.

Characterization of Pressure Transients Generated by Nanosecond Electrical Pulse (nsEP) Exposure.

The mechanism(s) responsible for the breakdown (nanoporation) of cell plasma membranes after nanosecond pulse (nsEP) exposure remains poorly understood. Current theories focus exclusively on the electrical field, citing electrostriction, water dipole alignment and/or electrodeformation as the primary mechanisms for pore formation. However, the delivery of a high-voltage nsEP to cells by tungsten electrodes creates a multitude of biophysical phenomena, including electrohydraulic cavitation, electrochemical interactions, thermoelastic expansion, and others. To date, very limited research has investigated non-electric phenomena occurring during nsEP exposures and their potential effect on cell nanoporation. Of primary interest is the production of acoustic shock waves during nsEP exposure, as it is known that acoustic shock waves can cause membrane poration (sonoporation). Based on these observations, our group characterized the acoustic pressure transients generated by nsEP and determined if such transients played any role in nanoporation. In this paper, we show that nsEP exposures, equivalent to those used in cellular studies, are capable of generating high-frequency (2.5 MHz), high-intensity (>13 kPa) pressure transients. Using confocal microscopy to measure cell uptake of YO-PRO®-1 (indicator of nanoporation of the plasma membrane) and changing the electrode geometry, we determined that acoustic waves alone are not responsible for poration of the membrane.

Dose-dependent suppression by ethanol of transient auditory 40-Hz response.

RATIONALE: Acute alcohol (ethanol) challenge is known to induce various cognitive disturbances, yet the neural basis of the effect is poorly known. The auditory transient evoked gamma-band (40-Hz) oscillatory responses have been suggested to be associated with various perceptual and cognitive functions in humans; however, alcohol effects on auditory 40-Hz responses have not been investigated to date. OBJECTIVES: The objective of the study was to test the dose-related impact of alcohol on auditory transient evoked 40-Hz responses during a selective-attention task. METHODS: Ten healthy social drinkers ingested, in four separate sessions, 0.00, 0. 25, 0.50, or 0.75 g/kg of 10% (v/v) alcohol solution. The order of the sessions was randomized and a double-blind procedure was employed. During a selective attention task, 300-Hz standard and 330-Hz deviant tones were presented to the left ear, and 1000-Hz standards and 1100-Hz deviants to the right ear of the subjects (P=0. 425 for each standard, P=0.075 for each deviant). The subjects attended to a designated ear, and were to detect the deviants therein while ignoring tones to the other ear. RESULTS: The auditory transient evoked 40-Hz responses elicited by both the attended and unattended standard tones were significantly suppressed by the 0.50 and 0.75 g/kg alcohol doses. CONCLUSIONS: Alcohol suppresses auditory transient evoked 40-Hz oscillations already with moderate blood alcohol concentrations. Given the putative role of gamma-band oscillations in cognition, this finding could be associated with certain alcohol-induced cognitive deficits.

Effects of spectral complexity and sound duration on automatic complex-sound pitch processing in humans - a mismatch negativity study.

The pitch of a spectrally rich sound is known to be more easily perceived than that of a sinusoidal tone. The present study compared the importance of spectral complexity and sound duration in facilitated pitch discrimination. The mismatch negativity (MMN), which reflects automatic neural discrimination, was recorded to a 2. 5% pitch change in pure tones with only one sinusoidal frequency component (500 Hz) and in spectrally rich tones with three (500-1500 Hz) and five (500-2500 Hz) harmonic partials. During the recordings, subjects concentrated on watching a silent movie. In separate blocks, stimuli were of 100 and 250 ms in duration. The MMN amplitude was enhanced with both spectrally rich sounds when compared with pure tones. The prolonged sound duration did not significantly enhance the MMN. This suggests that increased spectral rather than temporal information facilitates pitch processing of spectrally rich sounds.

Benzodiazepine temazepam suppresses the transient auditory 40-Hz response amplitude in humans.

To discern the role of the GABA(A) receptors in the generation and attentive modulation of the transient auditory 40-Hz response, the effects of the benzodiazepine temazepam (10 mg) were studied in 10 healthy social drinkers, using a double-blind placebo-controlled design. Three hundred Hertz standard and 330 Hz rare deviant tones were presented to the left, and 1000 Hz standards and 1100 Hz deviants to the right ear of the subjects. Subjects attended to a designated ear and were to detect deviants therein while ignoring tones to the other. Temazepam significantly suppressed the amplitude of the 40-Hz response, the effect being equal for attended and non-attended tone responses. This suggests involvement of GABA(A) receptors in transient auditory 40-Hz response generation, however, not in the attentive modulation of the 40-Hz response.

Temperature mapping of laser-induced hyperthermia in an ocular phantom using magnetic resonance thermography.

Laser-induced heating in an ocular phantom is measured with magnetic resonance thermography (MRT) using temperature-dependent phase changes in proton resonance frequency. The ocular phantom contains a layer of melanosomes isolated from bovine retinal pigment epithelium. The phantom is heated by the 806-nm output of a continuous wave diode laser with an irradiance of 2.4 to 21.6 W/cm2 in a beam radius of 0.8 or 2.4 mm, depending on the experiment. MRT is performed with a 2 T magnet, and a two-turn, 6-cm-diam, circular radio frequency coil. Two-dimensional temperature gradients are measured within the plane of the melanin layer, as well as normal to it, with a temperature resolution of 1 degrees C or better. The temperature gradients extending within the melanin layer are broader than those orthogonal to the layer, consistent with the higher optical absorption and consequent heating in the melanin. The temperature gradients in the phantom measured by MRT closely approximate the predictions of a classical heat diffusion model. Three-dimensional temperature maps with a spatial resolution of 0.25 mm in all directions are also made. Although the temporal resolution is limited in the prototype system (22.9 s for a single image "slice"), improvements in future implementations are likely. These results indicate that MRT has sufficient spatial and temperature resolution to monitor target tissue temperature during transpupillary thermotherapy in the human eye.

An investigation of CO2 laser scleral buckling using moiré interferometry.

BACKGROUND AND OBJECTIVE: To demonstrate suitability of moiré interferometry to assess and quantify laser-induced shrinkage of scleral collagen for buckling procedures. MATERIALS AND METHODS: Scleral buckling of human cadaver eyes was investigated using a Coherent Ultrapulse CO2 laser. Projection moiré interferometry was employed to determine the out-of plane displacement produced by laser exposure, and in-situ optical microscopy of reference markers on the eye was used to measure in-plane shrinkage. RESULTS: Measurements based on moiré interferometry allow a three dimensional view of shape changes in the eye surface as laser treatment proceeds. Out-of-plane displacement reaches up to 1.5 mm with a single laser spot exposure. In-plane shrinkage reached a maximum of around 30%, which is similar to that reported by Sasoh et al (Ophthalmic Surg Lasers. 1998;29:410) for a Tm:YAG laser. CONCLUSION: The moiré technique is found to be suitable for quantifying the effects of CO2 laser scleral shrinkage and buckling. This can be further developed to provide a standardized method for experimental investigations of other laser sources for scleral shrinkage.

Association of tumor necrosis factor-alpha polymorphisms with susceptibility and clinical outcomes of rheumatic heart disease.

OBJECTIVE: To examine the association of tumor necrosis factor-alpha (TNF-alpha) gene polymorphisms with rheumatic heart disease (RHD) and valve damage, and their influence on TNF-alpha production and disease outcome. METHODS: We performed this cross-sectional study at Kasr El-Aini Hospital, Cairo University, Cairo, Egypt, from December 2008 to October 2009. Eighty children with chronic RHD and valve affection, and 50 controls were included. Patients with any other diseases or complications were excluded. Blood samples (5 ml) were collected. Genotyping for TNF-alpha polymorphisms was performed by the polymerase chain reaction-restriction fragment length polymorphism method. Serum TNF-alpha was measured by enzyme-linked immunosorbent assay. RESULTS: Serum TNF-alpha was significantly increased in RHD compared with controls (p=0.00003). The TNF-alpha -238 adenine (AA) (p=0.036) and -308AA (p=0.003) genotypes were more frequent in RHD patients than in controls, and were associated with increased production of TNF-alpha (p=0.00001 for 238AA) and (p=0.001 for 308AA). Both polymorphisms contributed to increased susceptibility for RHD (-308AA and adenine guanine (AG), odds ratio [OR]=4.72 [95% confidence interval [CI] 2.03-11.05], p=0.0001); (-238 AA and AG, OR=2.33 [CI: 1.05-5.19], p=0.035). The presence of -308AA was associated with mitral (p=0.001) and multivalvular (p=0.003) lesions and was more prevalent in moderate (p=0.001), and severe (p<0.001) cases than in controls. The -238AA variant was associated with mitral lesions (p=0.04) and severe cases (p=0.05) as compared with controls. CONCLUSION: The TNF-alpha-238G/A and -308G/A polymorphisms were associated with susceptibility to RHD and increased production of TNF-alpha. Both polymorphisms were related to valve damage, and a more severe outcome of RHD.

Precipitating factors and therapeutic outcome in epilepsy with generalized tonic-clonic seizures.

OBJECTIVES: The aim of the study was to evaluate the influence of precipitating factors and therapy on the outcome of epilepsy with generalized tonic-clonic seizures. PATIENTS AND METHODS: Retrospective analysis of data from 34 patients (mean age at seizure onset 19 years; mean duration of follow-up 9.2 years) suffering from epilepsy of either cryptogenic or remote symptomatic (n = 19), or idiopathic (n = 15) etiology. The total number of seizures in all patients was 146. RESULTS: Without treatment 97 seizures manifested during 90.5 years without treatment (1.07 seizures/year), during treatment with carbamazepine or valproate 49 seizures occurred within 224 years (0.2 seizures/year). The frequency of seizures was significantly lower during treatment. Precipitating factors were found in relation to 31% of seizures in patients with remote symptomatic or cryptogenic epilepsy, and for 51% of seizures in patients with idiopathic epilepsy. CONCLUSIONS: There was a low frequency of seizures in patients with generalized tonic-clonic seizures. Precipitating factors are common. Antiepileptic drug treatment is effective.