Fate of Zinc Oxide Nanoparticles Coated onto Macronutrient Fertilizers in an Alkaline Calcareous Soil

Zinc oxide (ZnO) nanoparticles may provide a more soluble and plant available source of Zn in Zn fertilizers due to their greater reactivity compared to equivalent micron- or millimetre-sized (bulk) particles. However, the effect of soil on solubility, spatial distribution and speciation of ZnO nanoparticles has not yet been investigated. In this study, we examined the diffusion and solid phase speciation of Zn in an alkaline calcareous soil following application of nanoparticulate and bulk ZnO coated fertilizer products (monoammonium phosphate (MAP) and urea) using laboratory-based x-ray techniques and synchrotron-based μ-x-ray fluorescence (μ–XRF) mapping and absorption fine structure spectroscopy (μ–XAFS). Mapping of the soil-fertilizer reaction zones revealed that most of the applied Zn for all treatments remained on the coated fertilizer granule or close to the point of application after five weeks of incubation in soil. Zinc precipitated mainly as scholzite (CaZn₂(PO₄)₂.2H₂O) and zinc ammonium phosphate (Zn(NH₄)PO₄) species at the surface of MAP granules. These reactions reduced dissolution and diffusion of Zn from the MAP granules. Although Zn remained as zincite (ZnO) at the surface of urea granules, limited diffusion of Zn from ZnO-coated urea granules was also observed for both bulk and nanoparticulate ZnO treatments. This might be due to either the high pH of urea granules, which reduced solubility of Zn, or aggregation (due to high ionic strength) of released ZnO nanoparticles around the granule/point of application. The relative proportion of Zn(OH)₂ and ZnCO₃ species increased for all Zn treatments with increasing distance from coated MAP and urea granules in the calcareous soil. When coated on macronutrient fertilizers, Zn from ZnO nanoparticles (without surface modifiers) was not more mobile or diffusible compared to bulk forms of ZnO. The results also suggest that risk associated with the presence of ZnO NPs in calcareous soils would be the same as bulk sources of ZnO.     

Curcumin can prevent the loss of sinoatrial node cells in methionine-treated rats: A stereological study

Methionine (MET) rich diets, smoking, coffee and alcohol consumption, low physical activity, and aging are related to high plasma concentrations of homocysteine, which can jeopardize the heart health. Although hyperhomocysteinemia has been considered a recognized risk factor for cardiac dysrhythmia, the structural changes of the conductive system, including Sinoatrial (SA) node of the heart involved in the disorder, have not been completely clarified. Curcumin is the main component of turmeric and has shown some cardioprotective effects.This study aimed to evaluate the effect of curcumin on the structural changes of the SA node in L-MET-treated rats. These alterations were evaluated by means of stereological techniques, namely cavalieri principle for volume estimation and optical disector counting technique for cell counting. Both techniques used two-dimensional images for obtaining three-dimensional parameters. The rats were divided into four groups, including control, MET-treated (1 g/kg/day), curcumin-treated, (100 mg/kg/day), and MET + curcumin. The treatments were performed for 28 days. On the final day, SA nodes were dissected out for stereological investigation. Compared to the control rats, the volume of SA node, total volume of grape-like cell clusters, and number of SA node cells were respectively decreased by 42%, 34%, and 37% in the MET-treated group (p < 0.04). However, collagen density remained constant in all the study groups. Furthermore, treatment with curcumin could protect the SA node from cellular decline in the MET + curcumin group (p < 0.01).It can be concluded that curcumin could prevent the structural changes of the SA node in the rats treated with methionine.     

Synthesis and Characterization of Time-resolved Fluorescence Probes for Evaluation of Competitive Binding to Melanocortin Receptors

Probes for use in time-resolved fluorescence competitive binding assays at melanocortin receptors based on the parental ligands MSH(4), MSH(7), and NDP-α-MSH were prepared by solid phase synthesis methods, purified, and characterized. The saturation binding of these probes was studied using HEK-293 cells engineered to overexpress the human melanocortin 4 receptor (hMC4R) as well as the human cholecystokinin 2 receptor (hCCK2R). The ratios of non-specific binding to total binding approached unity at high concentrations for each probe. At low probe concentrations, receptor-mediated binding and uptake was discernable, and so probe concentrations were kept as low as possible in determining K_d values. The Eu-DTPA-PEGO-MSH(4) probe exhibited low specific binding relative to non-specific binding, even at low nanomolar concentrations, and was deemed unsuitable for use in competition binding assays. The Eu-DTPA-PEGO probes based on MSH(7) and NDP-α-MSH exhibited K_d values of 27 ± 3.9 nM and 4.2 ± 0.48 nM, respectively, for binding with hMC4R. These probes were employed in competitive binding assays to characterize the interactions of hMC4R with monovalent and divalent MSH(4), MSH(7), and NDP-α-MSH constructs derived from squalene. Results from assays with both probes reflected only statistical enhancements, suggesting improper ligand spacing on the squalene scaffold for the divalent constructs. The K_i values from competitive binding assays that employed the MSH(7)-based probe were generally lower than the K_i values obtained when the probe based on NDP-α-MSH was employed, which is consistent with the greater potency of the latter probe. The probe based on MSH(7) was also competed with monovalent, divalent, and trivalent MSH(4) constructs that previously demonstrated multivalent binding in competitive binding assays against a variant of the probe based on NDP-α-MSH. Results from these assays confirm multivalent binding, but suggest a more modest increase in avidity for these MSH(4) constructs than was previously reported.     

A review of drug therapy for sporadic fatal insomnia

Background: Sporadic fatal insomnia (sFI) is a rapid progressive neurodegenerative disease characterised by gradual to perpetual insomnia, followed by dysautonomia, coma and death.¹ Lugaresi E, Medori R, Montagna P, Baruzzi A, Cortelli P, Lugaresi A, Tinuper P, Zucconi M, Gambetti P. Fatal familial insomnia and dysautonomia with selective degeneration of thalamic nuclei. New England J of Med. 1986;315:997–1003. doi:10.1056/NEJM198610163151605.[Crossref], [PubMed], [Web of Science ®] [Google Scholar] The cause of sFI was recently mapped to a mutation in a protein, the prion, found in the human brain. It is the unfolding of the prion that leads to the generation of toxic oligomers that destroy brain tissue and function. Recent studies have confirmed that a methionine mutation at codon 129 of the human Prion is characteristic of sFI. Current treatment slows down the progression of the disease, but no cure has been found, yet. Methods: We used Molecular Docking and Molecular Dynamics simulation methods, to study the toxic Fatal-Insomnia-prion conformations at local unfolding. The idea was to determine these sites and to stabilise these regions against unfolding and miss-folding, using a small ligand, based on a phenothiazine "moiety". Conclusion: As a result we here discuss current fatal insomnia therapy and present seven novel possible compounds for in vitro and in vivo screening.     

Prevalence of congenital hypothyroidism in Isfahan, Iran: results of a survey on 20,000 neonates

AIMS: To evaluate the prevalence of congenital hypothyroidism (CH) in a screening program performed for the first time in Isfahan, Iran. METHODS: From May 2002 to December 2002, T4 and TSH serum concentrations of 20,000 3- to 7-day-old newborns, born in all 17 hospitals of the city, were measured by radioimmunoassay and immunoradiometric assay, respectively. The newborns with abnormal screening results (TSH >20 mIU/l, T4 <6.5 microg/dl and based on the weight) were re-examined. RESULTS: Of 531 recalled subjects (recall rate 2.6%), 54 were confirmed to be hypothyroid, showing a prevalence of 1:370 for CH. CONCLUSION: Considering the high frequency of CH, the necessity of implementing a routine screening program in the healthcare system of Isfahan Province is emphasized.     

Modeling transmission of directly transmitted infectious diseases using colored stochastic Petri nets

In order to improve our understanding of directly transmitted pathogens within host populations, epidemic models should take into account individual heterogeneities as well as stochastic fluctuations in individual parameters. The associated cost results in an increasing level of complexity of the mathematical models which generally lack consistent formalisms. In this paper, we demonstrate that complex epidemic models could be expressed as colored stochastic Petri nets (CSPN). CSPN is a mathematical tool developed in computer science. The concept is based on the Markov Chain theory and on a standard well codified graphical formalism. This approach presents an alternative to other computer simulation methods since it offers both a theoretical formalism and a graphical representation that facilitate the implementation, the understanding and thus the replication or modification of the model. We explain how common concepts of epidemic models--such as the incidence function--can be easily translated into an individual based point of view in the CSPN formalism. We then illustrate this approach by using the well documented susceptible-infected model with recruitment and death.     

Behavioral plasticity and virus propagation: the FIV-cat population example

A new theoretical approach is proposed to investigate the effect of intra-individual variability in behavior on the spread of directly transmitted diseases within host populations. The classical hawk-dove game is used to describe interactions between individuals on a fast time scale (the day). Individuals may exhibit both tactics according to their own experience, to environment conditions, and to the opponent. They are not able to recognize the epidemiological state of their opponents. This fast-time part of the model is coupled to a classical compartmental epidemic model describing the demography of the population and the transmission of the disease from an infected individual to a healthy one on a slow time scale (the year). The model is applied to the case of feline immunodeficiency virus (FIV)-domestic cat population system. Our model gives rise to different predictions according to values of cost and gain due to fights: extinction of the epidemic, FIV endemicity at low, intermediate and high prevalence. These predictions are in good agreement with results from domestic cat populations living in different environmental conditions.     

Comparison of Acyclovir and Multistrain <Emphasis Type="Italic">Lactobacillus brevis</Emphasis> in Women with Recurrent Genital Herpes Infections: a Double-Blind,Randomized, Controlled Study

We performed a randomized double-blind controlled trial to compare the efficacy and safety of multistrain probiotic and acyclovir in women patients with recurrent genital herpes simplex virus type 2 (HSV-2) infections. Eighty-one patients enrolled in the study were being treated with multistrain Lactobacillus brevis one vaginal capsule every 12 h and oral acyclovir 400 mg twice daily for 6 months. Of 53 patients who completed both treatment courses, no important differences were identified between acyclovir and probiotic for the primary and secondary efficacy endpoint, resolution of episode (hazard ratio, 0.60; 95% CI, 0.3429 to 1.0663; P = 0.08), lesion healing time (hazard ratio, 0.57; 95% CI, 0.3034 to 1.0717, P = 0.08), viral shedding (hazard ratio, 0.54; 95% CI, 0.3027 to 0.9750, P = 0.04), and percentage of pain (hazard ratio, 0.48; 95% CI, 0.2708 to 0.8545, P = 0.01). The median time to first and second recurrence after treatment were 43 and 121 days in patients receiving acyclovir and 33 and 118 days in patients receiving probiotic (HR 2.61; 95% CI, 1.4427 to 4.7546, P = 0.001, and HR 0.62; 95% CI, 0.3500 to 1.1133, P = 0.1, respectively). No clinically important effects happened during the probiotic treatment but some of adverse events reported in patients taking acyclovir. Easy availability, low cost, and no side effect of L. brevis are valuable properties of probiotic therapy compared with acyclovir. Therefore, we concluded that multistrain L. brevis could play an important role in suppression of recurrent genital herpes simplex virus infection.     

Identification of two major direct repeat unit clusters, 8i and 11ce,among methicillin resistant Staphylococcus aureus strains: the emergence of novel dru types and repeats

Molecular Biology Reports - The changing epidemiology and decreasing susceptibility to first-line antibiotics, such as vancomycin and linezolid, leave clinicians with few therapeutic options for...