Selenium nanoparticles based on Amphipterygium glaucum extract with antibacterial, antioxidant, and plant biostimulant properties.

BACKGROUND: In recent years, crop production has expanded due to the variety of commercially available species. This increase in production has led to global competition and the search for biostimulant products that improve crop quality and yield. At the same time, agricultural products that protect against diseases caused by phytopathogenic microorganisms are needed. Thus, the green synthesis of selenium nanoparticles (SeNPs) is a proposal for achieving these needs. In this research, SeNPs were synthesized from methanolic extract of Amphipterygium glaucum leaves, and chemically and biologically characterized. RESULTS: The characterization of SeNPs was conducted by ultraviolet-visible spectrophotometry (UV-Vis), scanning electron microscopy (SEM), electron microscopy transmission (TEM), Dynamic Light Scattering (DLS), energy dispersion X-ray spectroscopy (EDX), and infrared spectrophotometry (FTIR) techniques. SeNPs with an average size of 40-60 nm and spherical and needle-shaped morphologies were obtained. The antibacterial activity of SeNPs against Serratia marcescens, Enterobacter cloacae, and Alcaligenes faecalis was evaluated. The results indicate that the methanolic extracts of A. glaucum and SeNPs presented a high antioxidant activity. The biostimulant effect of SeNPs (10, 20, 50, and 100 µM) was evaluated in vinca (Catharanthus roseus), and calendula (Calendula officinalis) plants under greenhouse conditions, and they improved growth parameters such as the height, the fresh and dry weight of roots, stems, and leaves; and the number of flowers of vinca and calendula. CONCLUSIONS: The antibacterial, antioxidant, and biostimulant properties of SeNPs synthesized from A. glaucum extract demonstrated in this study support their use as a promising tool in crop production.

Antifungal Activity of Selenium Nanoparticles Obtained by Plant-Mediated Synthesis.

The continuous need to satisfy world food demand has led to the search for new alternatives to combat economic losses in agriculture caused by phytopathogenic fungi. These organisms cause plant diseases, reducing their productivity and decreasing fruit quality. Among the new tools being explored is nanotechnology. Nanoparticles with antimicrobial properties could be an excellent alternative to address this problem. In this work, selenium nanoparticles (SeNPs) were obtained using plant extracts of Amphipterygium glaucum leaves (SeNPs-AGL) and Calendula officinalis flowers (SeNPs-COF). Characterization of the SeNPs was performed and their ability as antifungal agents against two commercially relevant plant pathogenic fungi, Fusarium oxysporum and Colletotrichum gloeosporioides, was evaluated. Assays were performed with different concentrations of SeNPs (0, 0.25, 0.5, 1.0, and 1.7 mg/mL). It was observed that both SeNPs had antifungal activity against both plant pathogens at concentrations of 0.25 mg/mL and above. SeNPs-AGL demonstrated better antifungal activity and smaller size (around 8.0 nm) than SeNPs-COF (134.0 nm). FTIR analysis evidenced the existence of different functional groups that constitute both types of SeNPs. There are factors that have to be considered in the antimicrobial activity of SeNPs such as nanoparticle size and phytochemical composition of the plant extracts used, as these may affect their bioavailability.

The Role of Selenium Nanoparticles in Agriculture and Food Technology.

Selenium (Se) is an essential micronutrient for diverse organisms such as mammals, bacteria, some insects and nematodes, archaea, and algae, as it is involved in a large number of physiological and metabolic processes and is part of approximately 25 selenoproteins in mammals. In plants, Se has no essential metabolic role, high concentrations of inorganic Se can lead to the formation of Se-amino acids, and its incorporation into selenoproteins can generate toxicity. Conversely, low doses of Se can trigger a variety of beneficial effects as an antioxidant, antimicrobial, or stress-modulating agent without being an essential element. Therefore, Se can generate toxicity depending on the dose and the chemical form in which it is supplied. Selenium nanoparticles (SeNPs) have emerged as an approach to reduce this negative effect and improve its biological properties. In turn, SeNPs have a wide range of potential advantages, making them an alternative for areas such as agriculture and food technology. This review focuses on the use of SeNPs and their different applications as antimicrobial agents, growth promoters, crop biofortification, and nutraceuticals in agriculture. In addition, the utilization of SeNPs in the generation of packaging with antioxidant and antimicrobial traits and Se enrichment of animal source foods for human consumption as part of food technology is addressed. Additionally, possible action mechanisms and potential adverse effects are discussed. The concentration, size, and synthesis method of SeNPs are determining factors of their biological properties.

Chronic wound healing by controlled release of chitosan hydrogels loaded with silver nanoparticles and calendula extract.

As the skin is the main protective organ of the body, it is exposed to wounds or injuries which carry out a healing process during a period of approximately 15 days depending on the severity of the injury. In the present research, the development of chitosan-based hydrogels loaded with silver nanoparticles and calendula extract (Ch-AgNPs-Ce) was proposed. This can be used to fulfill the hemostatic, anti-infective, antibacterial, healing and anti-inflammatory functions through controlled release of the nanoparticles and calendula extract in substitution of commonly used drugs. The physical properties of the silver nanoparticles were analyzed by UV-visible spectroscopy, scanning and transmission electron microscopy, showing a size between 50 and 100 nm. The antibacterial properties were evaluated by the agar well diffusion method. Antimicrobial testing of the hydrogels showed that the inclusion of silver nanoparticles provides concentration-dependent antibacterial behavior against E. coli and S. aureus. The healing properties of the system were tested in two diabetic patients to whom said hydrogels were placed, obtaining a positive curative result after a few weeks. Therefore, it can be concluded that Ch-AgNPs-Ce hydrogels can achieve healing in chronic or exposed wounds after a period of time which can be used in alternative treatments in patients with poor healing capacity.

A narrative review of biosimilars: a continued journey from the scientific evidence to practice implementation.

Biologic agents have revolutionized the management of serious health conditions in the last two decades. The use of "targeted therapy" brings not only better progression free survivals and overall survivals, but also better toxicity profiles and quality of life benefits, compared to empirical palliative chemotherapy. However, given the high cost associated with biologic drugs and the sharp increases in biologic drug utilization, this drug category has significantly raised healthcare cost over the years. A similar phenomenon was previously experienced with branded simple chemical compound drugs, including chemotherapeutic agents, which was largely mitigated by the introduction of a generic approval pathway, decreasing the costs of the drugs, making them more affordable, given to the increase in competition among the drug makers. A similar opportunity presents years later with the completion of the full patent exclusivity period of many biologics. However, the ending of patent exclusivity, although enables more market competition, does not guarantee market penetration. Stakeholders, such as patients, providers and payers, must build trust and confidence in the science of biosimilars and the product specific studies leading to FDA approval in order to incorporate these products to practice and enable the biosimilar market at large to reach the potential to significantly contribute to reductions in drug cost. Dissemination of scientific and emerging biosimilar evidence is paramount in order to support stakeholder informed decision making and enable each to benefit from expanded treatment options. This paper describes the biosimilar development, approval process, and reviews a number of challenges with the marketing implementation of biosimilars.

Bifunctional colorimetric chemosensing of fluoride and cyanide ions by nickel-POCOP pincer receptors.

Three Ni(ii)-POCOP pincer complexes [NiCl{C6H2-4-OH-2,6-(OPPh2)2}], 1; [NiCl{C6H2-4-OH-2,6-(OPtBu2)2}], 2 and [NiCl{C6H2-4-OH-2,6-(OPiPr2)2}], 3 were studied as bifunctional molecular sensors for inorganic anions and acetate. In CH3CN, fluoride generates a bathochromic shift with a colorimetric change for 1-3 with a simultaneous fluorescence turn on, this optical effect is based on deprotonation of the para-hydroxy group of the POCOP ligand. On the other hand, in a neutral aqueous solution of 80 vol% CH3CN, additions of cyanide produce a distinct change of color by forming very stable complexes with the nickel-based receptors 1-3 with log Ka in the range of 4.38-5.03 M-1 and pronounced selectivity over other common anions such as iodide, phosphate, and acetate. Additionally, bromide shows a modest spectral change and affinity, but lower than those observed for cyanide. On the basis of 1H NMR experiments, UV-vis titrations, ESI-MS experiments, and the crystal structure of the neutral bromo complex of 1, it is proposed that the colorimetric change involves an exchange of chloride by CN- on the Ni(ii) atom. The Ni(ii)-based sensor 1 allows the fluorescent selective detection of fluoride with a limit of 5.66 µmol L-1 and colorimetric sensing of cyanide in aqueous medium in the micromolar concentration range.

The Labor Games.

OBJECTIVE: To develop and evaluate a simulation laboratory designed to stimulate learning and increase medical students' preparedness for an obstetrics and gynecology clinical clerkship. METHODS: Ninety-seven medical students participated in the games during their obstetrics and gynecology clerkship in 1 year. Using the resident-as-teacher model, students rotated through seven stations, each with a simulated obstetric task. Points were awarded at each station, and the student with the highest score won. Self-perceived proficiency level and general preparedness for the clerkship were evaluated through paired pregame and postgame assessments. RESULTS: Postassessment results showed statistically significant (P<.001) increases in self-perceived competence performing all tested skills including reading fetal heart tracings, knot-tying, measuring cervical dilation, amniotomy, estimating fetal weight, and estimating blood loss. Approximately 97% enjoyed The Labor Games, 97.9% reported increased knowledge, and 96.9% learned valuable skills. Students also reported feeling more prepared for the obstetrics and gynecology rotation (2.6 compared with 3.3, P<.001). DISCUSSION: The Labor Games improved medical students' self-confidence and self-perceived skill level on obstetric tasks. Students also felt more prepared for the obstetrics and gynecology clerkship. This study creates a low-cost and reproducible simulation laboratory that is identified as effective by medical students in teaching skills, knowledge, and preparedness for an obstetrics and gynecology clerkship.

Knowledge and Acceptability of Anal Cytology Screening Among Women.

OBJECTIVE: Medical providers have initiated anal cytology screening among women to detect anal neoplasia early. Lack of knowledge of the human papillomavirus (HPV) and anticipated screening discomfort may limit patient acceptance. This study investigates attitudes toward anal cytology screening among women. MATERIALS AND METHODS: Women seen for gynecologic care at an urban university medical center were invited to complete an anonymous survey assessing their understanding of HPV and interest in anal cytology screening. Subjects reported the level of pain, discomfort, and embarrassment they expected from screening on a 100-mm visual analog scale. RESULTS: Four hundred four women with mean (SD) age 36 (13) years met criteria for participation. Three hundred thirty-five women reported their race: 52% were white and 36% were African American. Three hundred forty-eight women reported their ethnicities: 76% were Hispanic and 12% were Haitian. Twenty-two percent had never heard of HPV, 57% were not familiar with anal cytology screening, 67% acknowledged that screening was very helpful in detecting anal neoplasia early, and 28% were very interested in undergoing screening. Mean (SD) level of anticipated pain, discomfort, and embarrassment during screening was 62 (32), 68 (30), and 58 (34) mm, respectively. Level of familiarity with anal cytology screening (p < .001), belief in its utility in detecting anal neoplasia (p < .001), and level of anticipated pain (p = .004) were significant predictors of acceptability. CONCLUSIONS: Medical providers should improve counseling about anal cytology screening among at-risk women to familiarize them with the procedure, describe its role in detecting anal neoplasia, and address expectations surrounding pain to increase its acceptability.

Raf kinase inhibitor protein expression in a survival analysis of colorectal cancer patients.

PURPOSE: Raf kinase inhibitor protein (RKIP) inhibits the Raf and nuclear factor kappa B signaling pathways, and suppresses metastasis in animal models. We examined whether RKIP expression in primary colorectal cancers (CRCs) correlates with the risk of metastasis and overall survival. PATIENTS AND METHODS: RKIP expression was examined immunohistochemically in three separate cohorts: a tissue microarray containing 276 samples from human tumors and normal tissues, and retrospective studies of 268 CRC patients and 65 early-stage CRCs. Overall and metastasis-free survival rates were measured. RESULTS: RKIP was expressed in normal epithelia but was reduced in metastatic tumors. RKIP expression in primary CRC was an independent prognostic marker for survival using multivariate Cox regression analysis (hazard ratio, 2.808; 95% CI, 1.58 to 4.96; P = .0002), independent of Dukes' stage. Patients with Dukes' C RKIP-positive tumors had similar 5-year survival rates as early-stage patients if tumors had equivalent RKIP expression levels. An independent study of early-stage CRCs confirmed that reduced RKIP expression predicted metastatic recurrence and reduced disease-free survival (hazard ratio, 4.5; 95% CI, 1.7 to 12.3; P = .003). RKIP expression was independent of sex, age, mitotic index, lymphatic and vascular invasion, depth of invasion, and tumor site, but correlated positively with apoptotic index (P = .024). Weak or loss of RKIP expression was the most significant and independent prognostic marker using a multivariate regression equation (hazard ratio, 4.5; 95% CI, 1.7 to 12.3; P = .003). CONCLUSION: RKIP expression in primary CRCs correlates with overall and disease-free survival, and can be useful for identifying early-stage CRC patients at risk of relapse.

Recursos en pacientes con secuelas neoplásticas de cabeza y cuello tratados por cáncer de esa región. Manejo con colgajos microquirúrgicos / Treatment of head and neck recurrences. Microvascular reconstruction

Los cirujanos plásticos han invertido considerable esfuerzo en el tratamiento de las secuelas posquirúrgicas en tumores de cabeza y cuello. La reconstrucción de las disfunciones y deformidades sufridas ya sea por los efectos creados por la resección, lesiones residuales o por secuelas de la radioterapia conlleva la participación de la cirugía plástica y del cirujano oncológico como equipo multidisciplinario. La utilización de colgajos microquirúrgicos como recurso en el tratamiento de estas secuelas fue un método de elección para nuestros pacientes. Entre 1999 y 2002 se presentaron 5 casos, 4 pacientes con lesiones residuales y uno con pérdida de sustancia posradioterapia

Recursos en pacientes con secuelas neoplásticas de cabeza y cuello tratados por cáncer de esa región. Manejo con colgajos microquirúrgicos / Treatment of head and neck recurrences. Microvascular reconstruction

Los cirujanos plásticos han invertido considerable esfuerzo en el tratamiento de las secuelas posquirúrgicas en tumores de cabeza y cuello. La reconstrucción de las disfunciones y deformidades sufridas ya sea por los efectos creados por la resección, lesiones residuales o por secuelas de la radioterapia conlleva la participación de la cirugía plástica y del cirujano oncológico como equipo multidisciplinario. La utilización de colgajos microquirúrgicos como recurso en el tratamiento de estas secuelas fue un método de elección para nuestros pacientes. Entre 1999 y 2002 se presentaron 5 casos, 4 pacientes con lesiones residuales y uno con pérdida de sustancia posradioterapia

Reduction of Raf-1 kinase inhibitor protein expression correlates with breast cancer metastasis.

PURPOSE: Raf-1 kinase inhibitor protein (RKIP) was originally identified as the first physiologic inhibitor of the Raf/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (ERK) pathway. This pathway regulates fundamental cellular functions, including those that are subverted in cancer cells, such as proliferation, transformation, survival, and metastasis. Recently, RKIP has been recognized as a strong candidate for a metastasis suppressor gene in cell and animal model systems. Therefore, we investigated whether RKIP expression is altered in clinical specimens of human primary breast cancers and their lymph node metastases. EXPERIMENTAL DESIGN: Paraffin-embedded tumor samples from 103 breast cancer patients were examined immunohistochemically for the expression of RKIP, activated ERK, and apoptosis. The specificity of the antibodies used was validated by competition experiments with purified recombinant RKIP protein. RESULTS: RKIP expression was high in breast duct epithelia and retained to varying degrees in primary breast tumors. However, in lymph node metastases, RKIP expression was highly significantly reduced or lost (P = 0.000003). No significant correlations were observed between RKIP expression and histologic type, tumor differentiation grade, size, or estrogen receptor status. CONCLUSION: This is the first study of RKIP expression in a large clinical cohort. It confirms the results of cell culture and animal studies, suggesting that in human breast cancer, RKIP is a metastasis suppressor gene whose expression must be down-regulated for metastases to develop. RKIP expression is independent of other markers for breast cancer progression and prognosis.