Hypothermia induced by central injection of sucralose potentially occurs via monoaminergic pathways in the hypothalamus of chicks.

Oral administration of sucralose has been reported to stimulate food intake through inducing hypothalamic neuropeptide Y (NPY) in mice and fruit flies. However, the underlying mechanisms of action of sucralose in hypothermia and NPY and monoamine regulation remain unknown. The aim of the present study was to investigate central effects of sucralose on body temperature, NPY, and monoamine regulation, as well as its peripheral effects, in chicks. In Experiment 1, 5-day-old chicks were centrally injected with 1 µmol of sucralose, other sweeteners (erythritol and glucose), or saline. In Experiment 2, chicks were centrally injected with 0.2, 0.4, and 1.6 µmol of sucralose or saline. In Experiment 3, chicks were centrally injected with 0.8 µmol of sucralose or saline, with a co-injection of 100 µg fusaric acid (FA), an inhibitor of dopamine-ß-hydroxylase, to examine the role dopamine in sucralose induced hypothermia. In Experiment 4, 7-16-day-old chicks were orally administered with 75, 150, and 300 mg/2 ml distilled water or sucralose, daily. We observed that the central injection of sucralose, but not other sweeteners, decreased body temperature (P < .05) in chicks; however, the oral injection did not influence body temperature, food intake, and body weight gain. Central sucralose administration decreased dopamine and serotonin and stimulated dopamine turnover rate in the hypothalamus significantly (P < .05). Notably, sucralose co-injection with FA impeded sucralose-induced hypothermia. Sucralose decreases body temperature potentially via central monoaminergic pathways in the hypothalamus.

In-plane coupled Fabry-Perot micro-cavities based on Si-air Bragg mirrors: a theoretical and practical study.

In-plane Fabry-Perot cavities based on deeply etched Bragg mirrors are used in many microphotonic applications including sensing, telecom, and swept laser devices. A main limitation to their performance is the small free spectral range (FSR) and low finesse. The FSR limits the dynamic range or the wavelength tuning range, while the linewidth limits the resolution. In this work, we propose coupled Fabry-Perot micro-cavities that greatly enhance the FSR, besides reducing the linewidth, which lead to higher finesse and better performance. The proposed structure is modeled and etched on Si substrate to a depth of 150 µm using the deep reactive ion etching technology. Optical measurements indicate an enhanced FSR of more than 140 nm and a quality factor of 3152 using coupled cavities as compared to only 9 nm FSR for a single cavity of the same length. The over-etching and surface roughness, being the main effective fabrication tolerances, are modeled and extracted from the measurements.

Biodegradation of dairy wastewater using bacterial and fungal local isolates.

Dairy wastewater contains high levels of organics and other pollutants. The present study was carried out to investigate the biodegradation process of dairy effluents using some locally isolated bacteria and fungi. Four different dairy effluent samples were collected from Obour and 6th October industrial cities, Egypt. Five bacterial species (Pseudomonas aeruginosa, Bacillus subtilis, Lactobacillus delbrueckii, Staphylococcus aureus and Enterococcus hirae) and three fungal strains (Alternaria sp., Fusarium sp. and Aspergillus sp.) were isolated from dairy wastewater samples, identified and used for biodegradation process. Bacterial and fungal consortia were prepared separately in the laboratory. Two-stages (aeration and filtration) laboratory scale model was designed. Rice straw and activated carbon layers were used as filtration media. Results indicated the great ability of both studied bacteria and fungi for removal of organics (biological oxygen demand removal percent were 78.7% and 74.7% for bacteria and fungi, respectively) and the improvement of the physicochemical quality (total suspended solids removal percent were 99.3% and 99.0% for bacteria and fungi, respectively) of the dairy effluent. The addition of rice straw and activated carbon increased removal efficiencies. Biodegradation of dairy wastewater depending on local microorganisms is an effective, cheap and eco-friendly technology.

Central NPY-Y5 sub-receptor partially functions as a mediator of NPY-induced hypothermia and affords thermotolerance in heat-exposed fasted chicks.

Exposure of chicks to a high ambient temperature (HT) has previously been shown to increase neuropeptide Y (NPY) mRNA expression in the brain. Furthermore, it was found that NPY has anti-stress functions in heat-exposed fasted chicks. The aim of the study was to reveal the role of central administration of NPY on thermotolerance ability and the induction of heat-shock protein (HSP) and NPY sub-receptors (NPYSRs) in fasted chicks with the contribution of plasma metabolite changes. Six- or seven-day-old chicks were centrally injected with 0 or 375 pmol of NPY and exposed to either HT (35 ± 1°C) or control thermoneutral temperature (CT: 30 ± 1°C) for 60 min while fasted. NPY reduced body temperature under both CT and HT NPY enhanced the brain mRNA expression of HSP-70 and -90, as well as of NPYSRs-Y5, -Y6, and -Y7, but not -Y1, -Y2, and -Y4, under CT and HT A coinjection of an NPYSR-Y5 antagonist (CGP71683) and NPY (375 pmol) attenuated the NPY-induced hypothermia. Furthermore, central NPY decreased plasma glucose and triacylglycerol under CT and HT and kept plasma corticosterone and epinephrine lower under HT NPY increased plasma taurine and anserine concentrations. In conclusion, brain NPYSR-Y5 partially afforded protective thermotolerance in heat-exposed fasted chicks. The NPY-mediated reduction in plasma glucose and stress hormone levels and the increase in free amino acids in plasma further suggest that NPY might potentially play a role in minimizing heat stress in fasted chicks.

Dispersion of the Vancomycin Resistance Genes vanA and vanC of Enterococcus Isolated from Nile Tilapia on Retail Sale: A Public Health Hazard.

Although normally regarded harmless commensals, enterococci may cause a range of different infections in humans, including urinary tract infections, sepsis, and endocarditis. The acquisition of vancomycin resistance by enterococci (VRE) has seriously affected the treatment and infection control of these organisms. VRE are frequently resistant to all antibiotics that are effective treatment for vancomycin-susceptible enterococci, which leaves clinicians treating VRE infections with limited therapeutic options. With VRE emerging as a global threat to public health, we aimed to isolate, identify enterococci species from tilapia and their resistance to van-mediated glycopeptide (vanA and vanC) as well as the presence of enterococcal surface protein (esp) using conventional and molecular methods. The cultural, biochemical (Vitek 2 system) and polymerase chain reaction results revealed eight Enterococcus isolates from the 80 fish samples (10%) to be further identified as E. faecalis (6/8, 75%) and E gallinarum (2/8, 25%). Intraperitoneal injection of healthy Nile tilapia with the eight Enterococcus isolates caused significant morbidity (70%) within 3 days and 100% mortality at 6 days post-injection with general signs of septicemia. All of the eight Enterococcus isolates were found to be resistant to tetracycline. The 6/6 E. faecalis isolates were susceptible for penicillin, nitrofurantoin, gentamicin, and streptomycin. On the other hand 5/6 were susceptible for ampicillin, vancomycin, chloramphenicol, and ciprofloxacin. The two isolates of E. gallinarum were sensitive to rifampicin and ciprofloxacin and resistant to vancomycin, chloramphenicol, and erythromycin. Molecular characterization proved that they all presented the prototypic vanC element. On the whole, one of the two vancomycin resistance gene was present in 3/8 of the enterococci isolates, while the esp virulence gene was present in 1/8 of the enterococci isolates. The results in this study emphasize the potential role that aquatic environments are correlated to proximity to anthropogenic activities in determining the antimicrobial resistance patterns of Enterococcus spp. recovered from fish in the river Nile in Giza, Elmounib, Egypt as a continuation of our larger study on the reservoirs of antibiotic resistance in the environment.