Developmental regulation of beta-carboline-induced inhibition of glycine-evoked responses depends on glycine receptor beta subunit expression

In this work, we show that beta-carbolines, which are known negative allosteric modulators of GABA(A) receptors, inhibit glycine-induced currents of embryonic mouse spinal cord and hippocampal neurons. In both cell types, beta-carboline-induced inhibition of glycine receptor (GlyR)-mediated responses decreases with time in culture. Single-channel recordings show that the major conductance levels of GlyR unitary currents shifts from high levels (> or = 50 pS) in 2 to 3 days in vitro (DIV) neurons to low levels (<50 pS) in 11 to 14 DIV neurons, assessing the replacement of functional homomeric GlyR by heteromeric GlyR. In cultured spinal cord neurons, the disappearance of beta-carboline inhibition of glycine responses and high conductance levels is almost complete in mature neurons, whereas a weaker decrease in beta-carboline-evoked glycine response inhibition and high conductance level proportion is observed in hippocampal neurons. To confirm the hypothesis that the decreased sensitivity of GlyR to beta-carbolines depends on beta subunit expression, Chinese hamster ovary cells were permanently transfected either with GlyR alpha2 subunit alone or in combination with GlyR beta subunit. Single-channel recordings revealed that the major conductance levels shifted from high levels (> or = 50 pS) in GlyR-alpha2-transfected cells to low levels (<50 pS) in GlyR-alpha2+beta-containing cells. Consistently, both picrotoxin- and beta-carboline-induced inhibition of glycine-gated currents were significantly decreased in GlyR-alpha2+beta-transfected cells compared with GlyR-alpha2-containing cells. In summary, we demonstrate that the incorporation of beta subunits in GlyRs confers resistance not only to picrotoxin but also to beta-carboline-induced inhibition. Furthermore, we also provide evidence that hippocampal neurons undergo in vitro a partial maturation process of their GlyR-mediated responses.     

Striatal PSA-NCAM(+) precursor cells from the newborn rat express functional glycine receptors

Immunocytochemical analysis showed that ionotropic glycine receptors are expressed in neurogenic progenitors purified from the newborn rat striatum and expressing the polysialylated form of the neural cell adhesion molecule, both in vitro and in situ. To ascertain whether glycine receptors were functional in vitro, whole-cell patch-clamp recordings demonstrated that glycine triggers inward strychnine-sensitive currents in the majority of these cells. Moreover, we found that glycine receptors expressed by these neurogenic progenitors display intermediate electrophysiological characteristics between those of glycine receptors expressed by neural stem cells and by mature interneurons from the rat striatum. Altogether, the present data show that functional strychnine-sensitive glycine receptors are expressed in neurogenic progenitors purified from the newborn rat striatum.     

Magnetite nanoparticle decorated reduced graphene oxide for adsorptive removal of crystal violet and antifungal activities

This work reports the synthesis and application of magnetic rGO/Fe₃O₄ NCs using a pod extract of Dolichos lablab L. as areducing agent. GO was synthesized by a modified Hummers method, however GO was reduced using the plant extract to produce rGO. The as-synthesized rGO/Fe₃O₄ NCs were characterized by UV-vis spectrophotometer, Fourier transform infrared (FT-IR) spectroscopy, FT-Raman spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy supported with energy dispersed X-ray spectroscopy (FESEM-EDX), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The synthesis of magnetic rGO/Fe₃O₄ NCs was confirmed from characterization results of FT-Raman, TEM and VSM. The FT-Raman results showed the D and G bands at 1306.92 cm⁻¹ and 1591 cm⁻¹ due to rGO and a peak at around 589 cm⁻¹ due to Fe₃O₄ NPs that were anchored on rGO sheets; TEM results showed the synthesis of Fe₃O₄ with an average particle size of 8.86 nm anchored on the surface of rGO sheets. The VSM result confirmed the superparamagnetic properties of the rGO/Fe₃O₄ NCs with a saturation magnetization of 42 emu g⁻¹. The adsorption capacity of rGO/Fe₃O₄ NCs towards crystal violet (CV) dye was calculated to be 62 mg g⁻¹. The dye removal behavior fitted well with the Freundlich isotherm and the pseudo-second-order kinetic model implies possible chemisorption. Besides, rGO/Fe₃O₄ NCs showed antifungal activities against Trichophyton mentagrophytes and Candida albicans by agar-well diffusion method with a zone inhibition of 24 mm and 21 mm, respectively. Therefore, rGO/Fe₃O₄ NCs can be used as an excellent adsorbent to remove organic dye pollutants and kill pathogens.

This work reports synthesis of magnetic rGO/Fe₃O₄ NCs using pod extract of Dolichos lablab L. as a reducing agent and its applications.     

Green synthesis of zinc oxide nanostructures and investigation of their photocatalytic and bactericidal applications

We report a facile one-pot green synthesis of zinc oxide (ZnO) nanostructures using aqueous leaf extract of Dolichos Lablab L. as the reducing and capping agent. The optical properties, structure and morphology of the as-synthesized ZnO nanostructures have been characterized by UV-Visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) supported with energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). TEM analysis revealed that the as-synthesized ZnO nanostructures have an average particle diameter of 29 nm. XRD patterns confirmed the formation of phase-pure ZnO nanostructures with a hexagonal wurtzite structure. The synthesized ZnO nanostructures were used as a catalyst in the photodegradation of methylene blue (MB), rhodamine B (RhB) and orange II (OII) under visible and near-UV irradiation. The results showed the highest efficiency of photodegradation of ZnO nanostructures for MB (80%), RhB (95%) and OII (66%) at pH values of 11, 9 and 5, respectively, in a 210 min time interval. In addition, the antimicrobial activity of the ZnO nanostructures using the agar well diffusion method against Bacillus pumilus and Sphingomonas paucimobilis showed the highest zones of inhibition of 18 mm and 20 mm, respectively. Hence, ZnO nanostructures have the potential to be used as a photocatalyst and bactericidal component.

We report a facile one-pot green synthesis of zinc oxide (ZnO) nanostructures using aqueous leaf extract of Dolichos Lablab L. as the reducing and capping agent.     

Maternal nutritional status mediates the association between maternal age and birth outcomes

Young maternal age during pregnancy is linked with adverse birth outcomes. This study examined the role of maternal nutritional status in the association between maternal age and small for gestational age (SGA) delivery and birth length. We used data from a birth cohort study in Ethiopia, involving women who were 15–24 years of age and their newborns. A mediation analysis was fitted in a sample of 1,422 mother infant dyads for whom data on birth length were available, and 777 dyads for whom gestational age and birth weight was measured. We used commands, medeff for the mediation analysis and medsens for sensitivity analysis in STATA 14. Maternal nutritional status, measured by mid‐upper arm circumference, mediated 21% of the association between maternal age and birth length and 14% of the association with SGA delivery. The average direct effect (ADE) of maternal age on birth length was (β = 0.45, 95% CI [0.17, 0.99]) and the average causal mediated effect (ACME) was (β = 0.12, 95% CI [0.02, 0.15]). We also found an ADE (β = 0.31, 95% CI [0.09, 0.47]) and an ACME of (β = 0.05, 95% CI [0.003, 0.205]) of maternal age on SGA delivery. The sensitivity analysis suggests an unmeasured confounder with a positive correlation of 0.15 and 0.20 between the mediator and the outcome could explain the observed ACME for birth length and SGA, respectively. We cannot make strong causal assertions as the findings suggest the mediator partly explained the total effect of maternal age on both outcomes.     

Long-term results of laparoscopic adjustable gastric banding for the treatment of morbid obesity

Background: Since the first laparoscopic adjustable gastric banding (LAGB) operation on September 1, 1993, there have been important publications related to this procedure. The majority of the articles reported surgical technique and short-term results. Long-term results of LAGB are lacking. The authors report long-term data (at least 4 years) from 3 major bariatric centers in Belgium that perform LAGB routinely. Methods: The 3 centers applied the same patient selection criteria, the same standard surgical technique, the same laparoscopic band (Lap-Band?) and the same follow-up program. 763 patients have been enrolled. Sex ratio was 22% male/78% female. Mean age was 34 years, and mean preoperative BMI was 42 kg/m². Results:The follow-up rate was 90%, and the minimum follow-up time was 4 years. The average BMI after 4 years was 30 kg/m². Early complications were: gastric perforation 4 (0.5%); large bowel perforation 1 (0.1%); bleeding 1 (0.1%); and conversion to open 10 (1.3%). Late complications were: erosion 7 (0.9%); total food intolerance 59 (8%); access port problems 20 (2.5%); re-operations 80 (11.1%); death 1 (0.1%). Conclusion: Long-term results of LAGB have been rarely reported, although publications on the procedure are copious. Our long-term data found that BMI evolution is good, the complication and re-operation rates are acceptable and the overall long-term results of the Lap-Band? system are good.     

Green syntheses of silver nanoparticle decorated reduced graphene oxide using l-methionine as a reducing and stabilizing agent for enhanced catalytic hydrogenation of 4-nitrophenol and antibacterial activity

Herein, we have reported a facile and green synthesis approach of Ag NP decorated reduced graphene oxide (RGO) through an in situ self-assembly method in the presence of l-methionine (l-Met) as reducing and stabilizing agent. The electronic properties, crystal structure, and morphology of the as-synthesized RGO–Ag nanocomposite were investigated by UV-Visible (UV-Vis) spectroscopy, Fourier transform-infrared (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) techniques. UV-Vis and FTIR show the effective reduction of GO and the formation of Ag NPs using l-Met. FESEM, TEM, and XRD analysis show the successful impregnation of Ag NPs into RGO with a 23 nm average crystallite size. The RGO–Ag nanocomposite with NaBH₄ shows a fast-catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AMP). The enhanced catalytic activity of RGO–Ag nanocomposites can be attributed to the synergistic effect of improved adsorption capacity and the absence of agglomeration of Ag nanoparticles. Moreover, RGO–Ag showed strong antibacterial activity against B. subtilis and E. coli.

Herein, we have reported a facile and green synthesis approach of Ag NP decorated reduced graphene oxide (RGO) through an in situ self-assembly method in the presence of l-methionine (l-Met) as reducing and stabilizing agent.