Visualizing ribonuclease digestion of RNA-like polymers produced by hot wet-dry cycles.

Polymerization of nucleotides under prebiotic conditions simulating the early Earth has been extensively studied. Several independent methods have been used to verify that RNA-like polymers can be produced by hot wet-dry cycling of nucleotides. However, it has not been shown that these RNA-like polymers are similar to biological RNA with 3'-5' phosphodiester bonds. In the results described here, RNA-like polymers were generated from 5'-monophosphate nucleosides AMP and UMP. To confirm that the polymers resemble biological RNA, ribonuclease A should catalyze hydrolysis of the 3'-5' phosphodiester bonds between pyrimidine nucleotides to each other or to purine nucleotides, but not purine-purine nucleotide bonds. Here we show AFM images of specific polymers produced by hot wet-dry cycling of AMP, UMP and AMP/UMP (1:1) solutions on mica surfaces, before and after exposure to ribonuclease A. AMP polymers were unaffected by ribonuclease A but UMP polymers disappeared. This indicates that a major fraction of the bonds in the UMP polymers is indeed 3'-5' phosphodiester bonds. Some of the polymers generated from the AMP/UMP mixture also showed clear signs of cleavage. Because ribonuclease A recognizes the ester bonds in the polymers, we show for the first time that these prebiotically produced polymers are in fact similar to biological RNA but are likely to be linked by a mixture of 3'-5' and 2'-5' phosphodiester bonds.

Exposure to Dichlorvos pesticide alters the morphology of and lipid metabolism in the ventral prostate of rats.

Organophosphate pesticides are widely used in agriculture, leading to soil, water, and food contamination. Among these compounds is Dichlorvos [O,O-dimethyl O-(2,2-dichlorovinyl)phosphate, DDVP], which is listed as a highly toxic compound by the Environmental Protection Agency and World Health Organization. Exposure to DDVP can result in nervous, respiratory, hepatic, and reproductive abnormalities, in addition to endocrine disrupting, mutagenic, and carcinogenic effects. Little is known about the impacts of DDVP on the reprogramming of lipid metabolism, which is also associated with the development and progression of cancer, since the tumor cells need to recruit, capture, and use fatty acids to compose their building membranes. This study aimed to evaluate the influence of the pesticide DDVP on lipid metabolism in the prostate, after chemical induction by the carcinogen N-methyl-N-nitrosourea (MNU). For this, 32 Fischer rats aged 90 days were randomly divided into four experimental groups: Control, DDVP, MNU, and MNU + DDVP. The MNU and MNU + DDVP groups underwent chemical induction with MNU (15 mg/kg) and the DDVP and MNU + DDVP groups received a diet supplemented with DDVP (10 mg/kg). Histopathological analyses of the rat ventral prostate showed 100% incidence of epithelial hyperplasia in the MNU and MNU + DDVP groups. This finding was accompanied by an increase of the epithelial compartment in the MNU + DDVP group. Immunolocalization of important proteins linked to lipid metabolism has been established. In the MNU + DDVP group, Western blotting analyses pointed out an increased expression of the protein LIMP II (Lysosomal Integral Membrane Protein-II), which is correlated with the capture and distribution of lipids in tumor cells. Together, these results indicate that the association of a low dose of DDVP with MNU was able to promote alterations in the morphology and lipid metabolism of the rat ventral prostate, which may be related to tumor progression in this organ.

Residual contamination in antineoplastic drug packaging.

INTRODUCTION: The handling of antineoplastic drugs should follow strict supervision and safety rules to minimize the occupational exposure risks to professionals involved. The external surface contamination of drug vials is recognized as a health risk. So, our goal was to determine if there is residual contamination on the vials and containers surface of the antineoplastic drugs doxorubicin (DOX) and cyclophosphamide (CP). METHODS: A cross-sectional study was conducted. Samples were collected using a uniform sampling procedure on the inner surfaces of the packages/boxes and the outer surfaces of the vials. The analyzes were executed by high-performance liquid chromatography/mass spectrometry (UHPLC-MS/MS). RESULTS: A total of 209 samples were analyzed, 66 of CP and 143 of DOX. CP levels were detected in nine samples (13.63%), three were below the lower limit of quantification (LLQ) and the other six had contamination levels ranging from 1.24 to 28.04 ng/filter. DOX levels were detected in 36 samples (25.17%), two were below the LLQ and the others had levels between 1.32 and 664.84 ng/filter. The majority of samples with residual contamination were in vials (80.0%), however, boxes also showed contamination. CONCLUSIONS: The results revealed the presence of residual contamination in the vials and packages of CP and DOX drugs. Although the residues found in each sample are small, special care should be taken in the handling and disposal of the antineoplastic drugs. The use of personal protective equipment is fundamental while handling the vials and packaging of cytotoxic drugs.

3D printed nitric oxide-releasing poly(acrylic acid)/F127/cellulose nanocrystal hydrogels.

Hydrogels have been used as matrices for the topical delivery of nitric oxide (NO) for achieving vasodilation, wound healing and analgesic actions. More recently, supramolecular hydrogels comprised of poly(acrylic acid) (PAA) and micellar Pluronic F127 (F127), prepared by thermal reaction, emerged as a suitable matrix for the incorporation of hydrophilic NO donors, such as S-nitrosoglutathione (GSNO). Herein, we describe an innovative method for the three-dimensional (3D) printing of cellulose nanocrystal (CNC)-containing and semi-interpenetrating PAA/F127 hydrogels by PAA photopolymerization via digital light processing (DLP), in the absence of organic solvents. Scanning electron microscopy showed that, differently from typical porous PAA-based hydrogels, the 3D printed PAA/F127/CNC hydrogels have dense morphology. By using transmission electron microscopy we confirmed for the first time the presence of F127 micelles in the printable resin, and their preservation after the photopolymerization process. The F127 micelles conferred compressive recoverability to the 3D printed PAA/F127/CNC hydrogels, widening their potential applications as soft biomaterials. PAA/F127/CNC hydrogels charged with GSNO are shown to release NO spontaneously upon hydration at initial rates that depend on the GSNO charge and are higher in the presence of CNC. As local NO release may exert cell proliferation action, 3D printed PAA/F127/CNC/GSNO hydrogels may serve as a versatile soft biomaterial for local NO delivery in regenerative medicine and other biomedical applications.

Mobility of a Mononucleotide within a Lipid Matrix: A Neutron Scattering Study.

An essential question in studies on the origins of life is how nucleic acids were first synthesized and then incorporated into compartments about 4 billion years ago. A recent discovery is that guided polymerization within organizing matrices could promote a non-enzymatic condensation reaction allowing the formation of RNA-like polymers, followed by encapsulation in lipid membranes. Here, we used neutron scattering and deuterium labelling to investigate 5'-adenosine monophosphate (AMP) molecules captured in a multilamellar phospholipid matrix. The aim of the research was to determine and compare how mononucleotides are captured and differently organized within matrices and multilamellar phospholipid structures and to explore the role of water in organizing the system to determine at which level the system becomes sufficiently anhydrous to lock the AMP molecules into an organized structure and initiate ester bond synthesis. Elastic incoherent neutron scattering experiments were thus employed to investigate the changes of the dynamic properties of AMP induced by embedding the molecules within the lipid matrix. The influence of AMP addition to the lipid membrane organization was determined through diffraction measurement, which also helped us to define the best working Q range for dynamical data analysis with respect to specific hydration. The use of different complementary instruments allowed coverage of a wide time-scale domain, from ns to ps, of atomic mean square fluctuations, providing evidence of a well-defined dependence of the AMP dynamics on the hydration level.

Long-Term Follow-Up of Anterior Pituitary Deficiency after Aneurysmal Subarachnoid Hemorrhage: Prospective Cohort.

OBJECTIVE: The aim of this study was to evaluate the prevalence of hypopituitarism in the acute stage after aneurysmal subarachnoid hemorrhage (SAH) as well at the chronic stage, at least 1 year after bleeding, to assess its implications and correlation with clinical features of the studied population. PATIENTS AND METHODS: This was a prospective cohort study that evaluated patients admitted between December 2009 and May 2011 with a diagnosis of SAH secondary to cerebral aneurysm rupture. Clinical and endocrine assessment was performed during the acute stage after hospital admission and before treatment at a mean of 7.5 days (SD ± 3.8) following SAH, and also at the follow-up visit at a mean of 25.5 months (range: 12-55 months) after the bleeding. RESULTS: Out of the 119 patients initially assessed, 92 were enrolled for acute stage, 82 underwent hormonal levels analysis, and 68 (82.9%) were followed up in both acute and chronic phases. The mean age and median age were lower among patients with dysfunction in the acute phase compared to those without dysfunction (P < .05). The prevalence of dysfunction in the acute phase was higher among patients with hydrocephalus on admission computed tomography (57.9%) than among those without it (P < .05). At chronic phase, there was an association between dysfunction and Hunt & Hess scale score greater than 2 (P < .05). CONCLUSIONS: We believe that there is not enough literature evidence to incorporate routine endocrinological evaluation for patient victims of SAH, but we should always keep this differential diagnosis in mind when conducting long-term assessments of this population.

The involvement of TLR2 and TLR4 in cytokine and nitric oxide production in visceral leishmaniasis patients before and after treatment with anti-leishmanial drugs.

Toll-like receptors (TLRs) have significant involvement in Leishmania infection, although little is known about the relationship between these receptors, cytokines and nitric oxide (NO) in patients with visceral leishmaniasis (VL) before or after treatment with anti-leishmanial drugs. The goal of this study was to evaluate the expression of TLR2 and TLR4 in CD3+ and CD14+ cells and the production of TNF-α, IFN-γ, IL-17, IL-10, TGF-ß and NO in peripheral blood mononuclear cells (PBMCs) from VL patients pre- and post-treatment with anti-leishmanial drugs. In addition, we investigated whether these receptors were involved in the production of these cytokines and NO. In the active VL patients, increased TLR2 and TLR4 expression in lymphocytes and monocytes, increased production of TNF-α, IL-10 and TGF-ß and decreased production of IFN-γ, IL-17 and NO were observed. After treatment, TLR2 and TLR4 were still expressed in lymphocytes and monocytes, the TNF-α and IL-10 levels were lower, the production of IFN-γ, IL-17 and NO was higher, and the TGF-ß level remained high. Before treatment, the production of TNF-α and NO was associated with TLR2 and TLR4 expression, while IL-10 production was only associated with TLR2 expression. After treatment, both receptors were associated with the production of TNF-α, IFN-γ, IL-10 and NO, while the production of IL-17 was associated only with TLR4 expression. The results presented in this study suggest that both TLR2 and TLR4 participate in the modulation of cytokine and NO production in VL patients, contributing to the pathogenesis of VL prior to treatment and the protective immune response after treatment.