Bactericidal and fungicidal capacity of Ag2O/Ag nanoparticles synthesized with Aloe vera extract.

This research aims to provide an alternative eco-friendly way to obtain silver species and assess their bactericidal activity. This study reports the synthesis of Ag2O nanoparticles and Ag nanoparticles reduced with a green synthesis method, using a low-cost and commercial Aloe vera extract. The crystalline phases of Ag and Ag2O nanoparticles were analyzed by X-ray diffraction. The oxidation states for both species were determined by X-ray photoelectron spectroscopy. The optical properties of the material were studied through optical absorption, which resulted in well-defined band centered at 545 nm. This result is attributed to the morphology and size of the silver nanoparticles. In addition, antibacterial tests were performed on AgNPs biosynthesized with A. vera with the Kirby-Bauer protocol on Gram-negative and Gram-positive bacteria Escherichia coli and Staphylococcus aureaus, respectively. Moreover, antifungal tests were performed with various species from Candida.

Development and characterization of three-dimensional antibacterial nanocomposite sponges of chitosan, silver nanoparticles and halloysite nanotubes.

In this work, we developed novel nanocomposite three-dimensional (3D) scaffolds composed of chitosan (CTS), halloysite nanotubes (HNTs) and silver nanoparticles (AgNPs) with enhanced antimicrobial activity and fibroblast cell compatibility for their potential use in wound dressing applications. A stock CTS-HNT solution was obtained by mixing water-dispersed HNTs with CTS aqueous-acid solution, and then, AgNPs, in different concentrations, were synthesized in the CTS-HNT solution via a CTS-mediated in situ reduction method. Finally, freeze-gelation was used to obtain CTS-HNT-AgNP 3D porous scaffolds (sponges). Morphology analysis showed that synthesized AgNPs were spherical with an average diameter of 11 nm. HNTs' presence did not affect the AgNPs morphology or size but improved the mechanical properties of the scaffolds, where CTS-HNT sponges exhibited a 5 times larger compression stress than bare-CTS sponges. AgNPs in the scaffolds further increased their mechanical strength in correlation to the AgNP concentration, and conferred them improved antibacterial activity against Gram-negative and Gram-positive bacteria, inhibiting the planktonic proliferation and adhesion of bacteria in a AgNP concentration depending on manner. In vitro cell viability and immunofluorescence assays exhibited that human fibroblast (HF) culture was supported by the sponges, where HF retained their phenotype upon culture on the sponges. Present CTS-HNT-AgNP sponges showed promising mechanical, antibacterial and cytocompatibility properties to be used as potential scaffolds for wound dressing applications.

Correction: Development and characterization of three-dimensional antibacterial nanocomposite sponges of chitosan, silver nanoparticles and halloysite nanotubes.

[This corrects the article DOI: 10.1039/D4RA04274C.].

Human papillomavirus 16/18 infections in lung cancer patients in Mexico.

BACKGROUND/AIMS: Human papillomavirus (HPV) is an epitheliotropic, double-stranded DNA virus, and its high-risk genotypes are associated with human cancer. HPV genome has been detected in lung carcinomas in certain places around the world, including Mexico; however, the prevalence of this is unclear. In this study, we examine the frequency of high-risk HPV 16/18 in lung cancer tissues from a Mexican population. METHODS: 39 lung cancer specimens were analyzed by polymerase chain reaction (PCR) using HPV GP5+/GP6+ primers and then were genotyped using specific primers to HPV 16/18. Additionally, in situ hybridization (ISH) was performed using BIO-labeled oligonucleotide probes. RESULTS: Our results identified 15 positive cases (38.46%) for HPV 16 and 1 positive case (2.56%) for HPV 18 by PCR. ISH showed the presence of HPV DNA in 13 of 16 (81%) samples, in agreement with the PCR results. CONCLUSIONS: In this study, we detected HPV 16/18 gene sequences in lung cancer samples obtained from Mexican patients by PCR and ISH. We found the highest prevalence of HPV 16 infection in lung adenocarcinomas, suggesting that HPV infection may be associated with lung cancer. However, further studies are needed to elucidate the role of HPV in lung carcinogenesis.

PhysiCan - a device for automatic CPM exercises implementation over canines: Design and analysis.

Continuous Passive Motion (CPM) devices have been used to assist physicians conducting human rehabilitation; however, similar machines specific for canine rehabilitation have not been found in the reviewed literature. This research performed a physical analysis of the hind limb of dogs to design a device for implementing automated CPM exercises. The device proved to comply with the guidelines to perform CPM exercises, allowing a proper setting of parameters to generate rehabilitation routines customized for different rehabilitation requirements. Also, an electromyography acquisition module was incorporated into the system, with surface electrodes to visualize and provide feedback to the user for muscle activation. Limitations were encountered with a range of motion of 80° and an error of approximately 2% for angular position accuracy.

Caspase 3 blocking avoids the expression of autoantigens triggered by apoptosis in neonatal Balb/c mice skin.

OBJECTIVE: To assess the effect of caspase 3 inhibition, in the expression of intracellular antigens induced by apoptosis. MATERIAL AND METHODS: Skin explants of neonatal Balb/c mice were used to assess the autoantigen expression. Skin was obtained by punch biopsies, tissues were cultured in DMEM; cell death was induced by chemicals and assessed by TUNEL. The expression of La, Ro, Sm, RNP, Cajal Bodies and NuMa antigens were monitored by immunohistochemistry using autoantibodies or monoclonal antibodies against these antigens. RESULTS: Chemicals used to induce cell death, successfully produced apoptosis or necrosis in more than 60% of keratinocytes, and viability was significantly decreased when it was compared with those in controls. An increased expression of all skin intracellular antigens in skin biopsies treated with chemicals, major antigenic expression was detected with anti-La and anti-Ro antibodies. The caspase 3 inhibitor DEVD-CMK significantly decreased the expression of antigens induced by chemicals. CONCLUSION: By this result we can infer that caspase inhibitors modify apoptosis and decrease the autoantigens associated to cell death.

Widespread expression of inducible NOS and citrulline in lupus nephritis tissues.

OBJECTIVE: Examine the presence of functional inducible nitric oxide synthase (iNOS) in lupus nephritis lesions. METHODS: Seventeen kidney biopsies from patients with lupus nephritis and an equal number of normal control kidney biopsies were examined for the presence of iNOS and endothelial nitric oxide synthase (eNOS) and citrulline by using immunohistochemical methods. Additionally, iNOS and eNOS mRNAs were examined by reverse transcription -PCR amplification of total renal RNA. RESULTS: All biopsies expressed constitutive eNOS, but in contrast to normal kidney biopsies, 70% of the lupus biopsies also expressed iNOS mRNA and the cognate protein. Eight positive biopsies corresponded to class IV lupus nephritis, which also had a high degree of citrullination. CONCLUSIONS: The data indicate that functional iNOS activity is present in glomeruli as part of the inflammatory process in the kidney; therefore the products of iNOS could play a role in the pathogenesis of lupus nephritis.

The final destiny of acantholytic cells in pemphigus is Fas mediated.

BACKGROUND: Pemphigus is an autoimmune disease characterized by the formation of intra-epidermal blisters. Patients develop auto-antibodies against desmoglein 1 and 3 proteins and induce acantholysis. OBJECTIVE: This work addresses the issue of whether the Fas pathway mediates acantholysis. Furthermore, the possible suppliers of the Fas pathway were investigated. METHODS: Seventeen biopsies of pemphigus patients were studied by haematoxylin and eosin staining, and apoptosis was defined by TUNEL. The expression of Fas, FasL and caspase 3 was studied by in situ hybridization and immunohistochemistry. Cell infiltrates were studied by immunofluorescence with monoclonal anti-CD3, CD4, CD8, CD19 and CD69. RESULTS: All of the biopsies showed intra-epidermal blisters, acantholytic cells and inflammatory infiltrates. The blisters expressed Fas, FasL and caspase 3. Cell infiltrates were composed of CD8 and a few CD4(+)CD69(+) cells. Additionally, CD19(+) cells were detected. Interestingly, the Fas expression was increased in acantholytic cells and perilesional keratinocytes. Incidentally, these cells exhibited apoptotic features. Interestingly, the CD8 cells expressed FasL. CONCLUSION: This paper presents the morphological evidence that apoptosis and acantholysis are linked. Therefore, the Fas pathway is associated with CD8 cells in pemphigus lesions.

Infliximab treatment in a case of rheumatoid scleromalacia perforans.

Ocular rheumatoid disease manifests as hyperemia of the conjunctiva and episclera, and in severe cases, episcleritis can result in nodular sclerotic and scleromalacia perforans. A clinical case of scleromalacia perforans in a 56-year-old woman with 20 years of seropositive rheumatoid arthritis of functional class IV is presented here. During that period, she received exclusively non-steroidal anti-inflammatory drugs (NSAIDs). She developed acute episcleritis of the left ocular globe, which rapidly progressed to scleromalacia perforans. Since the left eye became perforated, it was surgically enucleated, and the patient was maintained with steroidal therapy. Nevertheless, two months later she developed new-onset episcleritis of the right eye followed by scleromalacia. She was first evaluated by a rheumatologist and treated with 200 mg/dose of infliximab, which was administered monthly for the following four months. The biological treatment was accompanied by methotrexate and prednisone. With this therapy, the ocular lesion dramatically improved, and complete remission of rheumatoid arthritis and scleritis was archived four months later. In conclusion, tumour necrosis factor (TNF) blockers are effective therapeutic agents in ocular complications of rheumatoid arthritis.

Catalytic and antibacterial properties of gold nanoparticles synthesized by a green approach for bioremediation applications.

In this work, we are proposing the green synthesis of gold nanoparticles (AuNPs) using aqueous extracts of A. triphylla and evaluating their antibacterial and catalytic properties. Characterization was performed by UV-Vis and FT-IR spectroscopies, X-ray diffraction, and transmission electron microscopy (TEM). Antibacterial activity of AuNPs was analyzed using E. coli and S. Aureus and catalytic activity was determined by the degradation of methylene blue and congo red. UV-Vis analysis showed an increase in AuNPs concentration by increasing the extract concentration, volume extract, and precursor salt concentration. The crystalline nature of AuNPs was corroborated by X-ray diffraction. TEM analysis showed nanoparticles with spherical morphology (mostly) and size between 40 and 60 nm. These results are novel because they showed a homogeneous morphology and a narrow size distribution which is difficult to obtain in green synthesis processes. Results of antibacterial activity showed inhibition zones of 11.3 mm and 10.6 mm for S. Aureus and E. coli, respectively, indicating the bactericidal capacity of the nanoparticles. The degradation periods for methylene blue and congo red were 5 and 11 min, respectively, which are very short compared with previous reports. These results are of great significance for catalytic applications. Therefore, A. triphylla extracts made possible AuNPs synthesis and the nanoparticles obtained can be used as catalytic and antibacterial materials for water remediation.

Intracellular antigens released from Balb/c mice kidneys under chemically induced apoptosis and/or necrosis.

The present investigation assesses the possible role of apoptosis and necrosis in intracellular antigen exposure of kidneys from Balb/c mice. Renal tissues were cultured and treated with chemicals to induce apoptosis and /or necrosis. The expression of intracellular antigens Sm, RNP, Ro and La were monitored with antibodies against these antigens. Main results confirm that renal intracellular antigens are released and exposed onto the surface of apoptotic and necrotic cells, therefore these antigens become an easy target of autoantibodies. This mechanism may be important in the lupus nephritis pathogenesis.

A dermatomyositis and scleroderma overlap syndrome with a remarkable high titer of anti-exosome antibodies.

An overlap syndrome of dermatomyositis and scleroderma is reported. The case corresponded to a 27-year-old female with a clinical picture of 14 months evolution, characterized by proximal muscles weakness, erythematous rash in wrists, knees, ankles, Gottron sign, heliotrope periorbital rash and dysphagia. A muscle biopsy was compatible with dermatomyositis; meanwhile the skin biopsy was compatible with scleroderma. Muscle enzymes were increased. Interestingly, the antinuclear antibody determination in HEp-2 cells was positive with a remarkable titer of 81,920 exhibiting a nucleolar pattern. Anti-Jo1 antibody was negative, but anti-PM/Scl-100 positive. The patient received methylprednisolone and cyclophosphamide pulses, with gradual improvement. Present report constitutes a case of overlap dermatomyositis-scleroderma syndrome, with anti-PM/Scl autoantibodies (anti-exosome). The remarkable of this case was the exceptional high antinucleolar antibody titer.

Effect of chemical modification of titanium dioxide surface with dicarboxylic acid on the crystalline parameters and rheology behavior in polypropylene composites.

In this document, we present the effect of the surface modification of titanium dioxide particles with dicarboxylic acid on the rheological behavior of isotactic polypropylene composites. In addition to evaluating the effect of this type of modified fillers on the crystalline parameters such as long period, crystalline thickness and amorphous thickness, comparing it with unmodified fillers and pure polymer.

The role of apoptosis in autoantibody production.

Apoptosis is the physiologic process that guarantees the cellular exchange; after apoptosis the cellular remains are cleared by phagocytosis. In autoimmunity, some mechanisms in apoptosis fail and may result in disease. For instance, a failure in the Fas pathway during lymphoid ontogeny may allow the survival of autoimmune clones; equally the lack of clearance of apoptotic corps containing self-antigens may activate pre-existent auto-reactive clones and may result in autoantibody production. The role of apoptosis in autoimmunity is reviewed.

Ro60 and La ribonucleoproteins become self-aggregated by cell stress.

Ro and La antigens are of clinical interest in subacute cutaneous lupus erythematosus because skin lesions appear after UV irradiation, which induces the translocation of intracellular Ro and La ribonucleoproteins and trigger autoantibody production. Present studies address the question whether cellular stressors modify molecular characteristics and distribution of Ro60 and La proteins. To accomplish our goal HEp-2 cells were stressed by heat and UV irradiation and Ro and La expression was studied by indirect immunofluorescence and Western blot and crossed-immunoprecipitation using monoclonal anti-Ro/La or anti-HSP70 linked to CNBr-Sepharose 4B. Results of present studies confirm that Ro60 and La were located in the nuclei of non stressed cells; however under stress, both ribonucleoproteins were redistributed within cytoplasm and nucleoplasm, interestingly the stress induces self aggregation of both ribonucleoproteins, as demonstrated the Western blot assays. Ro and La proteins interact with the cytoskeleton protein via HSP70. In conclusion, the cell stress redistributes Ro and La proteins whiting nucleo-cytoplasmic compartments. This redistribution is accompanied by self aggregation of Ro and La which became associated with HSP70. Finally, the cell stress is an important factor for antigenic redistribution.

Effects of extraction solvents on photoluminescent properties of eysenhardtia polystachia and their potential usage as biomarker.

Currently, nanomaterials had been used for several applications; one of them is as bio-markers. These nanomaterials contain fluorescent compounds as effective indicators for imaging and other applications in Biotechnology. In previous studies, we proposed a functionalized nanomaterial-based biomarker from silica and Eysenhardtia Polystachia, a medicinal tree known in Mexico as "palo azul" (Kidneywood). Our previous results showed the feasibility of the nanomaterial obtained as bio-marker. In this article, our purpose is to evaluate the effects of extraction solvents on fluorescence of that biomarker. The photoluminescence (PL) effect was evaluated at different pH (4, 7.4 and 8); four extraction solvents, ethanol, methanol, methanol-ethanol and methanol-ethanol-water were evaluated. A molecular dynamics simulation was performed to recognize molecular interaction between the compounds of the extracts with solvent molecules and to investigate the solvent molecules effect on photoluminescence spectra. The results were also compared with rhodamine 6G and we found that, at physiological pH (7.4), the fluorescent-coated silica nanoparticles obtained were also stable. We found that extraction solvents could be used for obtaining different nanomaterials for specific applications, and also found the best extraction solvent for obtaining EP nanomaterials for health care applications, specifically for imaging techniques.

Interaction between poly(ethylene glycol) and two surfactants investigated by diffusion coefficient measurements.

Dynamic light scattering (DLS) and fluorescence recovery after pattern photobleaching (FRAPP) were used to study the interaction of low molecular weight poly(ethylene glycol) (PEG) with micelles of two different surfactants: tetradecyldimethyl aminoxide (C(14)DMAO, zwitterionic) and pentaethylene glycol n-dodecyl monoether (C(12)E(5), non-ionic). By using an amphiphilic fluorescent probe or a fluorescent-labeled PEG molecule, FRAPP experiments allowed to follow the diffusion of the surfactant-polymer complex either by looking at the micelle diffusion or at the polymer diffusion. Experiments performed with both fluorescent probes gave the same diffusion coefficient showing that the micelles and the polymer form a complex in dilute solutions. Similar experiments showed that PEG interacts as well with pentaethylene glycol n-dodecyl monoether (C(12)E(5)).

Structure, stability and catalytic activity of chemically synthesized Pt, Au, and Au-Pt nanoparticles.

Small (1-5 nm) metallic nanoparticles of Pt, Au, and Au/Pt of different nominal compositions in colloidal form were synthesized by a chemical reduction method using polymer (PVP) as protecting agent. Analytical techniques like HREM and UV-vis spectroscopy have been used to characterize the morphology and structural properties of these small particles. Theoretical simulations based on molecular dynamical have been used to interpret the experimental structural results and analyze the macroscopic properties like stability and catalytic selectivity of these nanoparticles based on the morphology and atomic distribution in the clusters.