A rare case of Moraxella lacunata producing combined native mitral and aortic valve endocarditis

We describe a case of infective endocarditis due to Moraxella lacunata involving the native mitral and aortic valves, complicated by cerebral emboli and resultant hemiparesis. The patient was treated with ceftriaxone and gentamicin and improved. This appears to be the first case reported in the medical literature of native multivalvular endocarditis produced by this rare organism.     

Breastfeeding among Turkish Mothers Living in Suburbs of Istanbul and Stockholm–A Comparison

ABSTRACT. The infant feeding pattern among 96 Turkish mothers living in a suburb of Istanbul and 30 living in a suburb of Stockholm, both with working class characteristics, was determined. The duration of breastfeeding among the Turkish immigrant group living in the Stockholm suburb was significantly reduced compared with the group with a similar social background but living in a native urban area. Infant feeding pattern among the Turkish immigrant mothers was more similar to that of Swedish populations. Attitudes to breastfeeding among the immigrant group had changed. Early weaning, reliance on commercially available infant foods and bottle feeding characterized their infant feeding practices. The majority of the infants of this group showed a tendency to overweight.     

Cloning-Free PCR-Based Allele Replacement Methods

Efficient homologous recombination permits the directed introduction of specific mutations into the yeast genome. Here we describe a cloning-free, PCR-based allele replacement method that simplifies allele transfer between yeast strains. The desired allele from one strain is amplified by PCR, along with a selectable/counterselectable marker. After transformation, the resident allele in the target strain is replaced by creating a duplication of the new allele. Selection for direct repeat recombinants results in a single copy of the new allele in the target strain. Specifically, the desired allele is amplified by PCR with a pair of adaptamers, which are chimeric oligonucleotides that are used to amplify the allele and differentially tag its 5′ and 3′ ends. These tags allow the directed fusion to two different, but overlapping, regions of an appropriately tagged selectable/counterselectable marker after a second round of PCR amplification. Following cotransformation of the two fusion fragments into yeast, homologous recombination efficiently generates a duplication of the amplified allele flanking the intact selectable marker in the genome. After counterselection, only the desired allele is retained as a result of direct repeat recombination. A simple modification of this method allows the creation of de novo mutations in the genome.     

Synthesis, characterization and antimicrobial activity of Fe(II), Zn(II), Cd(II) and Hg(II) complexes with 2,6-bis(benzimidazol-2-yl) pyridine ligand

2,6-Bis(benzimidazol-2-yl)pyridine (L) ligand and complexes [M(L)Cl(2)] and [Fe(L)(2)](ClO(4))(2) (M=Zn, Cd, Hg) have been synthesized. The geometries of the [M(L)Cl(2)] complexes were derived from theoretical calculation in DGauss/DFT level (DZVP basis set) on CACHE. The central M(II) ion is penta-coordinated and surrounded by N(3)Cl(2) environment, adopting a distorted trigonal bipyramidal geometry. The ligand is tridentate, via three nitrogen atoms to metal centre and two chloride ions lie on each side of the distorted benzimidazole ring. In the [Fe(L)(2)](ClO(4))(2) complex, the central Fe(II) ion is surrounded by two (3N) units, adopting a octahedral geometry. The elemental analysis, molecular conductivity, FT-Raman, FT-IR (mid-, far-IR), (1)H, and (13)C NMR were reported. The antimicrobial activities of the free ligand, its hydrochloride salt, and the complexes were evaluated using the disk diffusion method in dimethyl sulfoxide (DMSO) as well as the minimal inhibitory concentration (MIC) dilution method, against 10 bacteria and the results compared with that for gentamycin. Antifungal activities were reported for Candida albicans, Kluyveromyces fragilis, Rhodotorula rubra, Debaryomyces hansenii, Hanseniaspora guilliermondii, and the results were referenced against nystatin, ketaconazole, and clotrimazole antifungal agents. In most cases, the compounds tested showed broad-spectrum (Gram positive and Gram negative bacteria) activities that were either more effective than or as potent as the references. The binding of two most biologically effective compounds of zinc and mercury to calf thymus DNA has also been investigated by absorption spectra.     

Antiidiotypic antibodies to sperm in sera of fertile women that neutralize antisperm antibodies.

The presence of antiidiotypic antibodies (ab-2) to sperm was investigated in the sera of fertile, infertile, and virgin women using sperm-specific anti-FA-1 monoclonal antibody Fab'.ab-2 were detected in 71% (17/24) of sera from fertile women and in none (0/12) of the sera from virgin females by the enzyme-linked immunosorbent assay, Western blot procedure, and immunoprecipitation procedure. Sera from infertile women that had antisperm antibodies showed a minimal presence of ab-2, with only three sera (13%, 3/23) demonstrating the presence of low levels of ab-2. The ab-2 present in fertile women were capable of neutralizing the fertilization-inhibitory activity of anti-FA-1 antibody in a concentration-dependent manner in a human sperm penetration assay (SPA) of zona-free hamster oocytes. ab-2 were also capable of inhibiting the binding of antisperm antibodies to the sperm surface as determined by the immunobead binding technique. This is the first report demonstrating the presence of ab-2 in the sera of fertile women that are capable of neutralizing antisperm antibodies present in sera of infertile women. These findings suggest that the inability to detect antisperm antibody activity in the sera of fertile women may be due to higher levels of ab-2 present in these sera than levels found in sera of infertile women, although both groups may be producing antisperm antibody response after sexual exposure to sperm.     

Selenium prevents interferon-gamma induced activation of TRPM2 channel and inhibits inflammation,mitochondrial oxidative stress,and apoptosis in microglia

Microglia as the primary immune cells of brain act protective effects against injuries and infections in the central nervous system. Inflammation via excessive Ca²⁺ influx and oxygen radical species (ROS) generation is a known factor in many neurodegenerative disorders. Importantly, the Ca²⁺ permeable TRPM2 channel is activated by oxidative stress. Thus, TRPM2 could provide the excessive Ca²⁺ influx in the microglia. Although TRPM2 expression level is high in inflammatory cells, the interplay between mouse microglia and TRPM2 channel during inflammation is not fully identified. Thus, it is important to understand the mechanisms and factors involved in order to enhance neuronal regeneration and repair. The data presented here indicate that TRPM2 channels were activated in microglia cells by interferon-gamma (IFNγ). The IFNγ treatment further increased apoptosis (early and late) and cytokine productions (TNF-α, IL-1β, and IL-6) which were due to increased lipid peroxidation and ROS generations as well as increased activations of caspase −3 (Casp-3) and − 9 (Casp-9). However, selenium treatment diminished activations of TRPM2, cytokine, Casp-3, and Casp-9, and levels of lipid peroxidation and mitochondrial ROS production in the microglia that were treated with IFNγ. Moreover, addition of either PARP1 inhibitors (PJ34 or DPQ) or TRPM2 blockers (2-APB or ACA) potentiated the modulator effects of selenium. These results clearly suggest that IFNγ leads to TRPM2 activation in microglia cells; whereas, selenium prevents IFNγ-mediated TRPM2 activation and cytokine generation. Together the interplay between IFNγ released from microglia cells is importance in brain inflammation and may affect oxidative cytotoxicity in the microglia.

Summary of pathways involved in IFNγ-induced TRPM2 activation and microglia death through excessive reactive oxygen species (ROS): Modulator role of selenium (Se). The IFNγ causes the microglia activation. Nudix box domain of TRPM2 is sensitive to ROS. The ROS induces DNA damage and ADPR-ribose (ADPR) production in the nucleus via PARP1 enzyme activation. ADPR and ROS-induced TRPM2 activation stimulates excessive Ca²⁺ influx. ROS are produced in the mitochondria through the increase of free cytosolic Ca²⁺ (via TRPM2 activation) by the IFNγ treatment, although they are diminished by the TRPM2 channel blocker (ACA and 2-APB) and PARP1 inhibitor treatments. The main mechanism in the cell death and inflammatory effects of IFNγ is mediated by stimulation of ROS-mediated caspase (caspase −3 and − 9) activations and cytokine production (TNF-α, IL-1β, and IL-6) via TRPM2 activation, respectively. The apoptotic, inflammatory, and oxidant actions of IFNγ are modulated through TRPM2 inhibition by the Se treatment

     

Evidence of both ontogeny and transplant dose-regulated expansion of hematopoietic stem cells in vivo

Recent assessment of the long-term repopulating activity of defined subsets of hematopoietic cells has offered new insights into the characteristics of the transplantable stem cells of this system; however, as yet, there is very little known about mechanisms that regulate their self-renewal in vivo. We have now exploited the ability to quantitate these cells using the competitive repopulating unit (CRU) assay to identify the role of both intrinsic (ontological) and extrinsic (transplanted dose-related) variables that may contribute to the regulation of CRU recovery in vivo. Ly5.1 donor cells derived from day-14.5 fetal liver (FL) or the bone marrow (BM) of adult mice injected 4 days previously with 5-fluorouracil were transplanted at doses estimated to contain 10, 100, or 1,000 long-term CRU into irradiated congenic Ly5.2 adult recipient mice. Eight to 12 months after transplantation, there was a complete recovery of BM cellularity and in vitro clonogenic progenitor numbers and a nearly full recovery of day-12 colony-forming unit-spleen numbers irrespective of the number or origin of cells initially transplanted. In contrast, regeneration of Ly5.1+ donor-derived CRU was incomplete in all cases and was dependent on both the origin and dose of the transplant, with FL being markedly superior to that of adult BM. As a result, the final recovery of the adult marrow CRU compartment ranged from 15% to 62% and from 1% to 18% of the normal value in recipients of FL and adult BM transplantation, respectively, with an accompanying maximum CRU amplification of 150- fold for recipients of FL cells and 15-fold for recipients of adult BM cells. Interestingly, the extent of CRU expansion from either source was inversely related to the number of CRU transplanted. These data suggest that recovery of mature blood cell production in vivo may activate negative feedback regulatory mechanisms to prematurely limit stem cell self-renewal ability. Proviral integration analysis of mice receiving retrovirally transduced BM cells confirmed regeneration of totipotent lymphomyeloid repopulating cells and provided evidence for a greater than 300-fold clonal amplification of a single transduced stem cell. These results highlight the differential regenerative capacities of CRU from fetal and adult sources that likely reflect intrinsic, genetically defined determinants of CRU expansion but whose contribution to the magnitude of stem cell amplification ultimately obtained in vivo is also strongly influenced by the initial number of CRU transplanted. Such findings set the stage for attempts to enhance CRU regeneration by administration of agents that may enable full expression of regenerative potential or through the expression of intracellular gene products that may alter intrinsic regenerative capacity.     

Development and application of novel bio-magnetic membrane capsules for the removal of the cationic dye malachite green in wastewater treatment

Novel bio-magnetic membrane capsules (BMMCs) were prepared by a simple two-step titration-gel cross-linking method using a polyvinyl alcohol (PVA) and sodium alginate (SA) matrix to control the disintegration of phytogenic magnetic nanoparticles (PMNPs) in an aqueous environment, and their performance was investigated for adsorbing cationic malachite green (MG) dye from water. The prepared BMMCs were characterized by FTIR, powder XRD, SEM, EDX, XPS, VSM and TGA techniques. The findings revealed that the hysteresis loops had an excellent superparamagnetic nature with saturation magnetization values of 11.02 emu g⁻¹. The prepared BMMCs not only controlled the oxidation of PMNPs but also improved the adsorptive performance with respect to MG dye (500 mg g⁻¹ at 298.15 K and pH 6.5) due to the presence of a large amount of hydrophilic functional groups (hydroxyl/–OH and carboxyl/–COOH) on/in the BMMCs. The smooth encapsulation of PMNPs into the PVA–SA matrix established additional hydrogen bonding among polymer molecular chains, with improved stability, and adsorptive performance was maintained over a wide range of pH values (3–12). Importantly, the prepared BMMCs were easily regenerated just by washing with water, and they could be re-utilized for up to four (4) consecutive treatment cycles without observing any apparent dissolution of iron/Fe⁰ or damage to the morphology. According to the mass balance approach, an estimated amount of 100 mL of treated effluent can be obtained from 160 mL of MG dye solution (25 mg L⁻¹) just by employing a 0.02 g L⁻¹ adsorbent dosage. Finally, a model of BMMCs based on zero-effluent discharge was also proposed for commercial or industrial applications. The prepared BMMCs are greatly needed for improving the water/wastewater treatment process and they can be utilized as an excellent adsorbent to remove cationic pollutants for various environmental applications.

Novel bio-magnetic membrane capsules were prepared by a simple two-step titration-gel cross-linking method using a polyvinyl alcohol and sodium alginate matrix to control the disintegration of phytogenic magnetic nanoparticles in aqueous media.     

Convenient pH-responsive removal of Acid Black 1 by green l-histidine/iron oxide magnetic nanoadsorbent from water: performance and mechanistic studies

This study was aimed at developing green histidine-modified Fe₃O₄ nanoparticles (His-MNPs) for the adsorptive removal of Acid Black 1 (AB1) from aqueous solution. The His-MNPs were characterized by atomic force microscopy, scanning electron microscopy-energy dispersive X-ray spectrometry, infra-red spectra and thermogravimetry. These MNPs were spherical (average diameter 11–28 nm) with polydispersity index of 1.40 and about 13% mass coating of histidine. To optimize AB1 adsorption on His-MNPs and understand its mechanism, the influences of different operational variables (pH, adsorbent amount, temperature, initial AB1 concentration, contact time, ionic strength, etc.) on adsorption were examined with adsorption isotherms, kinetics and thermodynamic studies. The AB1 adsorption from water was fast with equilibrium time ≤ 45 min. The adsorption equilibrium was best fitted to the Langmuir isotherm model (q_max = 166.7 mg g⁻¹ at the adsorbent dose of 0.2 g L⁻¹, temperature 30 °C and pH 4). The linearity order for other isotherms was as follows: Dubinin–Radushkevich (D–R) < Temkin < Freundlich. The kinetics of the AB1 adsorption demonstrated the best compliance with the pseudo-second-order model, predominantly controlled by film diffusion as compared to intraparticle diffusion. Thermodynamic parameters (ΔH° and ΔG°) reflected the exothermic and spontaneous adsorption process. The values of ΔG°, ΔH°, activation energy and D–R free adsorption energy were all consistent with the physisorptive removal of AB1. The spectral (electronic and IR) and pH studies further corroborated the mechanism of AB1 removal by His-MNPs. The His-MNPs showed efficient adsorption, easy regeneration and excellent reusability, assisted by their pH-responsive properties. The prepared adsorbent can provide a safe, effective and economical alternative strategy for removing azo dyes from wastewater.

Effective and eco-friendly separation of Acid Black 1 dye from water by electrostatic adsorption onto reusable Histidine-Fe₃O₄ nanoparticles, credited to their pH-responsiveness.