CH bond activation in aromatic ketones mediated by iridium-tris(pyrazolyl)borate complexes.

Reaction of complex [TpMe2Ir(η4-CH2C(Me)C(Me)C2)] (1) with a series of aromatic ketones at 130 °C renders, by means of a selective ortho-CH activation, Ir(III)-metallacycles 2-5, which display an Ir-H bond. When [TpMe2Ir(C6H5)2N2] (6) is treated with 2-(trifluoromethyl)acetophenone and 2-fluoroacetophenone at 80 °C, the formation of dimeric (7) and trimeric architectures (8) is achieved through the meta- and para-CH activation of the aromatic ketone, respectively. The generation of complexes 2-5 is proposed to occur by the initial formation of Ir(III) η1-ketone adducts as key intermediates, followed by aromatic CH activations and the release of a butadiene ligand. The formation of complexes 7 and 8 involves an assisted process in which a metal center activation of the less sterically hindered C-H bond of the aromatic ketone takes place (releasing a benzene molecule), followed by the coordination of the carbonyl group, which generates the respective dimeric and trimeric structures. Complexes 7 and 8 are efficient catalysts for the transfer hydrogenation of ketones and aldehydes using isopropanol as the hydrogen source. All complexes have been fully characterized by NMR spectroscopy, FT-IR, elemental analysis and, in the cases of 7 and 8, X-ray crystallography. Details of the reaction conditions, isolation of the products, and proposals for the pathways of formation of complexes 2-5 and 7-8 are discussed.

Distribution of Hg and Se in Muscle and Liver of the Thornback Guitarfish Platyrhinoidis triseriata from the Eastern Pacific Ocean.

Human consumption of the thornback guitarfish (Platyrhinoidis triseriata) is concentrated in coastal populations of the Pacific coast of Mexico as its meat is prized for its high quality. This study analyzes the distribution of mercury and selenium in the muscle and liver of Platyrhinoidis triseriata and the risk to human health associated with its consumption. In order to conduct these estimates, specimens were collected from the Eastern Pacific Ocean in 2015 and 2016 and found mean concentrations (µg g-1 wet weight) of mercury ranging from 0.02 to 0.58 in muscle and 0.10 to 0.31 in liver. Selenium ranged from 0.14 to 1.31 in muscle and from 0.93 to 4.52 in liver. Mercury levels in the muscle of P. triseriata were significantly correlated (positive correlation) with the total length of the specimens. The predominant prey of P. triseriata was the shrimp Pleuroncodes planipes and according to the biomagnification factor, only mercury was biomagnified. The risk to consumers associated with the simultaneous presence of mercury and selenium in the muscle and liver of rays under the selenium health benefit value approach indicated that consumption of P. triseriata from this area is beneficial to human health.

Severe Cutaneous Adverse Reactions to Drugs in Latin America: The RACGRAD Study.

BACKGROUND AND OBJECTIVE: Severe cutaneous adverse reactions to drugs (SCARs) are associated with high morbidity and mortality and with sequelae. Objective: To characterize patients with SCARs in 8 health care institutions in Latin America. METHODS: We performed a cross-sectional, descriptive, multicenter study of patients diagnosed with SCARs in Latin America between January 2009 and December 2018. The analysis was carried out using a database in BD Clinic. RESULTS: We collected 70 patients, of whom 42 (60%) were women. Mean age was 38.7 years. Forty-two patients (60%) had DRESS-DIHS, 12 (17.1%) TEN, 5 (7.1%) SJS, 6 (8.5%) AGEP, 4 (5.7%) other reactions not classified as SCARs, and 1 (1.4%) overlapping SJS-TEN. The main causative drugs were aromatic anticonvulsants in 31 cases (44.3%), ß-lactam antibiotics in 11 cases (15.7%), and non-ß-lactam antibiotics in 6 cases (8.6%). In all of the cases, the suspected drug was withdrawn at the first sign of a SCAR. Sixty-six patients (94.2%) received anti-inflammatory treatment, mostly systemic corticosteroids. Complications occurred in 53 cases (75.7%), and 3 patients died (4.3%). Thirteen patients (18.6%) had sequelae. CONCLUSIONS: This is the first multicenter report on SCARs in Latin America. DRESS-DIHS was the most frequently reported clinical entity, and anticonvulsants were the main triggers. Most of the patients received systemic corticosteroids. Complications were frequent, and 3 patients died.

Recycling of polymeric composites from industrial waste by pyrolysis: Deep evaluation for carbon fibers reuse.

The use of polymeric composite on transport applications as reinforcement material has been increased due to the low fuel consumption when replacing heavier materials. It is estimated that 170,000 tons of polymeric composites will be discarded by 2025, and recycling processing for carbon fibers recovery is required to save primary energy and reduce waste. Among the current techniques, pyrolysis processing has been most effective. On the other hand, innovation must maintain the structure for reuse since physical and mechanical properties are important for recycled materials. For this reason, the goal of the present study was the recycling of polymeric composite by pyrolysis. The recovered carbon fibers were analyzed in SEM and EDS to verify surface defects compared with virgin carbon fibers. The effect of temperature, time, and atmosphere were investigated. Results showed that at 550 °C for 1 h, it was possible to obtain free carbon fibers from the polymeric matrix. After the pyrolysis process in this condition, the fibers had no pores, material fracture, and carbonization. This paper contributes to the widening and systematizing knowledge on effectiveness and understanding polymeric composites recycling for carbon fiber recovery, maintaining its structure for reuse.

Severe Cutaneous Adverse Reactions to Drugs in Latin America: The RACGRAD Study

Background: Severe cutaneous adverse reactions to drugs (SCARs) are associated with high morbidity and mortality and with sequelae. Objective: To characterize patients with SCARs in 8 health care institutions in Latin America. Methods: We performed a cross-sectional, descriptive, multicenter study of patients diagnosed with SCARs in Latin America between January 2009 and December 2018. The analysis was carried out using a database in BD Clinic. Results: We collected 70 patients, of whom 42 (60%) were women. Mean age was 38.7 years. Forty-two patients (60%) had DRESS-DIHS, 12 (17.1%) TEN, 5 (7.1%) SJS, 6 (8.5%) AGEP, 4 (5.7%) other reactions not classified as SCARs, and 1 (1.4%) overlapping SJS-TEN. The main causative drugs were aromatic anticonvulsants in 31 cases (44.3%), ß-lactam antibiotics in 11 cases (15.7%), and non–ß-lactam antibiotics in 6 cases (8.6%). In all of the cases, the suspected drug was withdrawn at the first sign of a SCAR. Sixty-six patients (94.2%) received anti-inflammatory treatment, mostly systemic corticosteroids. Complications occurred in 53 cases (75.7%), and 3 patients died (4.3%). Thirteen patients (18.6%) had sequelae. Conclusions: This is the first multicenter report on SCARs in Latin America. DRESS-DIHS was the most frequently reported clinical entity, and anticonvulsants were the main triggers. Most of the patients received systemic corticosteroids. Complications were frequent, and 3 patients died (AU)

Presence of Newcastle disease viruses of sub-genotypes Vc and VIn in backyard chickens and in apparently healthy wild birds from Mexico in 2017.

Virulent Newcastle disease viruses (NDV) have been present in Mexico since 1946, and recently, multiple outbreaks have been reported in the country. Here, we characterized eleven NDV isolated from apparently healthy wild birds and backyard chickens in three different locations of Jalisco, Mexico in 2017. Total RNA from NDV was reverse-transcribed, and 1285 nucleotides, which includes 3/4 of the fusion gene, was amplified and sequenced using a long-read MinION sequencing method. The sequences were 99.99-100% identical to the corresponding region obtained using the Illumina MiSeq. Phylogenetic analysis using MinION sequences demonstrated that nine virulent NDV from wild birds belonged to sub-genotypes Vc and VIn, and two backyard chicken isolates were of sub-genotype Vc. The sub-genotype Vc viruses had nucleotide sequence identity that ranged from 97.7 to 98% to a virus of the same sub-genotype isolated from a chicken in Mexico in 2010. Three viruses from pigeons had 96.3-98.7% nucleotide identity to sub-genotype VIn pigeon viruses, commonly referred to as pigeon paramyxovirus, isolated in the USA during 2000-2016. This study demonstrates that viruses of sub-genotype Vc are still present in Mexico, and the detection of this sub-genotype in both chickens and wild birds suggests that transmission among these species may represent a biosecurity risk. This is the first detection and complete genome sequencing of genotype VI NDV from Mexico. In addition, the utilization of an optimized long-read sequencing method for rapid virulence and genotype identification using the Oxford nanopore MinION system is demonstrated.

In vitro Validation of Quantitative Light-Induced Fluorescence for the Diagnosis of Enamel Fluorosis in Permanent Teeth.

This study aimed to validate quantitative light-induced fluorescence (QLF) as a diagnostic tool for mild and moderate enamel fluorosis in permanent teeth, comparing it to visual diagnosis and histological assessment completed using polarized light microscopy (PLM). The buccal surfaces of 139 teeth were visually classified using the Thylstrup and Fejerskov Index (TFI) into sound (TFI 0; n = 17), mild (TFI 1-2; n = 69), and moderate (TFI 3-4; n = 43) fluorosis. Fluorosis was then assessed with QLF (variables ΔF, A, and ΔQ at 5-, 15-, and 30-radiance thresholds) using as reference areas the entire surface and a region of interest (ROI), identified as the most representative region of a fluorosis lesion. PLM images of longitudinal thin sections including the ROI were assessed for histological changes. Correlations among TFI, PLM, and QLF were determined. A receiver-operating characteristic curve was conducted to determine QLF's diagnostic accuracy when compared to the TFI and PLM assessments. This was used to assess the probability that the images were correctly ranked according to severity as determined by PLM and TFI. A positive correlation was found between QLF and PLM, and between QLF and TFI. QLF showed the highest sensitivity and specificity for the diagnosis of mild fluorosis. There was also a strong agreement between TFI and PLM. The selection of a ROI resulted in a stronger correlation with TFI and PLM than when the entire surface was used. The study results indicate that defining an ROI for QLF assessments is a valid method for the diagnosis of mild and moderate enamel fluorosis.

Large scale, prospective screening of EGFR mutations in the blood of advanced NSCLC patients to guide treatment decisions.

BACKGROUND: In a significant percentage of advanced non-small-cell lung cancer (NSCLC) patients, tumor tissue is unavailable or insufficient for genetic analyses. We prospectively analyzed if circulating-free DNA (cfDNA) purified from blood can be used as a surrogate in this setting to select patients for treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). PATIENTS AND METHODS: Blood samples were collected in 119 hospitals from 1138 advanced NSCLC patients at presentation (n = 1033) or at progression to EGFR-TKIs (n = 105) with no biopsy or insufficient tumor tissue. Serum and plasma were sent to a central laboratory, cfDNA purified and EGFR mutations analyzed and quantified using a real-time PCR assay. Response data from a subset of patients (n = 18) were retrospectively collected. RESULTS: Of 1033 NSCLC patients at presentation, 1026 were assessable; with a prevalence of males and former or current smokers. Sensitizing mutations were found in the cfDNA of 113 patients (11%); with a majority of females, never smokers and exon 19 deletions. Thirty-one patients were positive only in plasma and 11 in serum alone and mutation load was higher in plasma and in cases with exon 19 deletions. More than 50% of samples had <10 pg mutated genomes/µl with allelic fractions below 0.25%. Patients treated first line with TKIs based exclusively on EGFR positivity in blood had an ORR of 72% and a median PFS of 11 months. Of 105 patients screened after progression to EGFR-TKIs, sensitizing mutations were found in 56.2% and the p.T790M resistance mutation in 35.2%. CONCLUSIONS: Large-scale EGFR testing in the blood of unselected advanced NSCLC patients is feasible and can be used to select patients for targeted therapy when testing cannot be done in tissue. The characteristics and clinical outcomes to TKI treatment of the EGFR-mutated patients identified are undistinguishable from those positive in tumor.

Potential of Entomopathogenic Fungi as Biological Control Agents of Diamondback Moth (Lepidoptera: Plutellidae) and Compatibility With Chemical Insecticides.

The objectives were to evaluate the efficiency of entomopathogenic fungi against Plutella xylostella (L.) and the compatibility of the most virulent isolates with some of the insecticides registered for use on cabbage crops. Pathogenicity tests used isolates of Beauveria bassiana, Metarhizium rileyi, Isaria fumosorosea, Isaria sinclairii, and Lecanicillium muscarium standardized at a concentration of 10(7) conidia/ml. Cabbage leaf discs were immersed in these suspensions, and after evaporation of the excess water, were placed 10 second-instar larvae of P. xylostella, totaling 10 leaf discs per treatment. Mortality was assessed 7 d after treatment, and the isolates that caused mortality>80% were used to estimate LC50 and LT50. The compatibilities of the most virulent isolates and the insecticides were tested from the mixture of these into the culture medium, and after solidifying, the medium was inoculated with an aliquot of the isolated suspension. The following parameters were evaluated: growth of the colony, number and viability of conidia after 7 d. The isolated IBCB01, IBCB18, IBCB66, and IBCB87 of B. bassiana, LCMAP101 of M. rileyi, and ARSEF7973 of I. sinclairii caused mortality between 80 and 100%, with LC50 and LT50 between 2.504 to 6.775×10(4) conidia/ml and 52.22 to 112.13 h, respectively. The active ingredients thiamethoxam and azadirachtin were compatible with the entomopathogenic fungi. The results suggest that the use of these isolates is an important alternative in the pesticidal management of P. xylostella, with the possible exception of the associated use of chemical controls using the active ingredients thiamethoxam or azadirachtin.

Current status of prenatal diagnosis in Cuba: causes of low prevalence of Down syndrome.

OBJECTIVES: To analyze trends in cytogenetic prenatal diagnosis in Cuba and to analyze possible causes leading to a low Down syndrome prevalence in a country where the triple test is not available. METHODS: An analysis of the Cuban program in prenatal cytogenetic diagnosis from 1984 to 2012 was conducted. Results are described, with particular emphasis on indications, abnormal results, types of invasive procedures, and terminations of pregnancy. RESULTS: Cytogenetic prenatal diagnostic analyses (n = 75,095) were conducted; maternal age was the indication for 77.9% of the amniocenteses and chorionic villus samplings. The detection rate of chromosomally abnormal pregnancies was 2.3% for maternal age and increased to 8-9% for other indications. When a chromosomal abnormality was identified, 88.5% terminated the pregnancy. In 2002, the live birth prevalence of Down syndrome was 8.4 per 10,000 live births, and in 2012, 7 per 10,000. CONCLUSION: Prenatal diagnosis in Cuba has contributed to a significant reduction in chromosomal aberrations. The impact increased because of the demographic trends of the population, the high index of terminations of pregnancy, and the establishment of a network of cytogenetic laboratories throughout Cuba.

Mercury levels in myliobatid stingrays (Batoidea) from the Gulf of California: tissue distribution and health risk assessment.

With the aim of knowing Hg distribution in selected tissues of myliobatid stingrays and assessing health risk to Mexican population, Hg concentration was determined in the muscle and liver of four ray species. Total Hg levels were determined by cold vapor atomic absorption spectrophotometry. With respect to the muscle, devil rays (Mobula spp.) showed lower Hg levels (<0.22 µg g(-1)) than Rhinoptera steindachneri (0.37 ± 0.25 µg g(-1) wet weight). In the case of the liver, the highest Hg concentration was found in Mobula japanica (0.22 ± 0.01 µg g(-1)). Hg levels in the muscle and liver varied according to the species; in some case, the liver accumulated more Hg than the muscle and the opposite pattern in other cases. R. steindachneri showed a significant difference between both tissues. No significant differences of Hg levels between males and females and between juveniles and adult specimens of R. steindachneri were found. Positive correlation between Hg concentrations and disc width and total weight was not significant for R. steindachneri (Rs < 0.36, p > 0.05). Batoids showed Hg values below the Mexican (NOM-027-SSA1-1993) limits (1.0 µg g(-1)) in fishes for human consumption. The species with the highest potential of Hg transfer to human population is R. steindachneri; however, an adult (70 kg) could consume approximately 943 g per week without representing a health risk. Nevertheless, further and continuous monitoring is needed since batoids support an important fishery in Mexican waters, being a food resource and income to coastal communities.

Influence of nanoparticle size on the nonlinear optical properties of magnetite ferrofluids.

The nonlinear index of refraction (n_{2}) and the two-photon absorption coefficient (ß) of water-based ferrofluids made of magnetite nanocrystals of different sizes and with different coatings have been measured through the Z-scan technique, with ultrashort (femtoseconds) laser pulses. Their third-order susceptibility is calculated from the values of n_{2} and ß. The influence of different particles' coatings and sizes on these nonlinear optical properties are investigated. The values of n_{2} and ß depend more significantly on the nanoparticles' size than on the particular coating. We observe a decrease of ß as the nanoparticles' diameters decrease, although the optical gap is found to be the same for all samples. The results are interpreted considering modifications in the electronic orbital shape due to the particles' nanosize effect.

Mercury in muscle and liver of ten ray species from Northwest Mexico.

We determined total mercury (Hg) distribution in muscle and liver of ten ray species and assessed health risk considering Hg levels in muscle and average consumption of rays in Mexico. Rays were collected from five sites in NW Mexico between March and November 2012. Hg concentrations ranged from 4.465 µg g(-1) in muscle of the longtail stingray Dasyatis longa to 0.036 µg g(-1) in liver of the diamond stingray Dasyatis dipterura. Considering all the individuals, Hg in muscle (1.612±1.322 µg g(-1)) was significantly (p<0.05) higher than in liver (0.745±0.616 µg g(-1)). Regarding local health risk assessment, none of the ray species may cause adverse effects on consumers.

Immunotherapeutic effects of recombinant adenovirus encoding granulocyte-macrophage colony-stimulating factor in experimental pulmonary tuberculosis.

BALB/c mice with pulmonary tuberculosis (TB) develop a T helper cell type 1 that temporarily controls bacterial growth. Bacterial proliferation increases, accompanied by decreasing expression of interferon (IFN)-γ, tumour necrosis factor (TNF)-α and inducible nitric oxide synthase (iNOS). Activation of dendritic cells (DCs) is delayed. Intratracheal administration of only one dose of recombinant adenoviruses encoding granulocyte-macrophage colony-stimulating factor (AdGM-CSF) 1 day before Mycobacterium tuberculosis (Mtb) infection produced a significant decrease of pulmonary bacterial loads, higher activated DCs and increased expression of TNF-α, IFN-γ and iNOS. When AdGM-CSF was given in female mice B6D2F1 (C57BL/6J X DBA/2J) infected with a low Mtb dose to induce chronic infection similar to latent infection and corticosterone was used to induce reactivation, a very low bacilli burden in lungs was detected, and the same effect was observed in healthy mice co-housed with mice infected with mild and highly virulent bacteria in a model of transmissibility. Thus, GM-CSF is a significant cytokine in the immune protection against Mtb and gene therapy with AdGM-CSF increased protective immunity when administered in a single dose 1 day before Mtb infection in a model of progressive disease, and when used to prevent reactivation of latent infection or transmission.

Lung volume reduction surgery after lung transplantation for emphysema-chronic obstructive pulmonary disease.

Lung Volume Reduction Surgery (LVRS) has become a palliative treatment for patients with advanced emphysema and disabling dyspnea. After single lung transplantation in chronic obstructive pulmonary disease, LVRS may be indicated to improve graft dysfunction caused by native lung hyperinflation compressing the grafted lung. This common complication is the subject of our study, which showed LVRS to be helpful to manage this situation. We performed an observational retrospective and descriptive study using the data of 293 patients transplanted in our center between January 1996 and October 2011. Some of the patients who underwent a single lung transplantation developed native lung hyperinflation years after the transplantation, interfering with respiratory function due to graft compression.

Lung cancer in patients with lung transplants.

OBJECTIVE: The aim of our study was to describe the incidence of lung cancer in patients after lung transplantation (LT). MATERIALS AND METHODS: We performed an observational, retrospective, descriptive study based on data from 340 patients undergoing lung transplantation between October 1993 and December 2010. We collected data about the donors, recipients, intra- and postoperative periods, and survivals. RESULTS: We identified 9 (2.6%) patients who developed lung cancer after LT. Their average age was 56 ± 9.3 years (range, 18-63). All cases were men with 8/9 (88.8%) having received a single lung transplant. All cancers developed in the native lung. The indications for transplantation were: emphysema type chronic obstructive pulmonary disease (COPD; n = 5), idiopathic pulmonary fibrosis (n = 3), or cystic fibrosis (n = 1); 77% of them were former smokers. All of the COPD patient were affected. The interval from transplantation to diagnosis was 53.3 ± 12 months (range 24-86). Survival after cancer diagnosis was 49.3 ± 6.3 (range = 0-180) months. CONCLUSIONS: LT was associated with a relatively high incidence of lung cancer, particularly in the native lung. In our series, lung cancer was related more to patients with emphysema-type COPD and a history of smoking. We believe that these patients should be closely followed to establish the diagnosis and apply early treatment.

Hematological and biochemical blood values in wild populations of black howler monkeys (Alouatta pigra) of Campeche, México.

BACKGROUND: The clinical analyses of free-ranging New World primates are extremely limited. The aim of this study was to obtain baseline data of blood chemistry and hematological values of free-ranging Alouatta pigra. METHOD: 17 males and 17 females were captured. We collected blood from the caudal tail vein; conventional techniques were used to analyze the samples RESULTS: Hemoglobin, hematocrit, and erythrocytes were significantly higher in males than in females. In relation to biochemical blood values, albumin/globulin ratio, cholesterol, triglycerides, calcium, phosphorus, magnesium, and iron were significantly higher in males than in females, while creatinine was significantly higher in females than in males. CONCLUSIONS: In general, measured parameters are similar to those of other primates and will be used as reference values for futures studies.

Use of mouse models to study the variability in virulence associated with specific genotypic lineages of Mycobacterium tuberculosis.

The host response against Mycobacterium tuberculosis show a wide spectrum of clinical manifestations in those patients who fail to control the infection. The course of the infection and its epidemiological consequences depend upon a complex interplay of host, environmental and bacterial factors. Experimental animal models have helped to define the influence of bacterial genetic diversity on virulence and on the immune response that is induced. For this purpose, experimental animals such as mice, guinea pigs and rabbits have been infected with selected clinical isolates obtained from outbreaks or from clinical epidemiology settings. Here we review the contribution of mouse models to defining the variability in virulence and immune response in relation to mycobacterial genetic diversity. Low dose aerosol infection in C57Bl mice or high dose intratracheal infection in BALB/c mice have demonstrated wide variability in virulence and immune responses induced by different bacterial genotypes, and each genotype has different phenotypes, with high and low virulence variants. In general, these studies have shown that high prevalent strains from big clusters are more virulent than low prevalent sporadic clinical isolates, and highly virulent strains induce non-protective immune responses with some correlation with clinical-epidemiological data. In the future selected strains from these types of studies should be analyzed with molecular technologies. These kinds of study will contribute to the identification of mycobacterial genes associated with virulence and immunogenicity.

Variation in the Extraction Efficiency of Estradiol and Progesterone in Moist and Lyophilized Feces of the Black Howler Monkey (Alouatta pigra): Alternative Methods.

Several fecal steroid extraction techniques have been developed to measure the ovary function in different species of mammals. However, regardless of the method of extraction and the sample type chosen, it has been observed that they can yield results with different percentages of recuperation. The objective of this study was to determine whether the type of substratum, solvent and extraction method used have any influence on the extraction efficiency in the feces of Alouatta pigra (black howler monkey). For this purpose we used two methods: agitation and ebullition. With each method, we utilized moist and lyophilized feces. The validation of radioimmunoassay method was accurate and precise for quantify estradiol and progesterone in lyophilized feces of A. pigra. To both of which ethanol and methanol, absolute and at 80%, were added, besides the hormones (125)I-Estradiol and (125)I-Progesterone. The extraction efficiency for (125)I-Estradiol was from 87.72 ± 3.97 to 41.24 ± 2.67%, and for (125)I-Progesterone from 71.15 ± 4.24 to 42.30 ± 1.19% when we used the agitation method. Whereas with the ebullition method, the extraction efficiency for (125)I-Estradiol ranged from 86.89 ± 2.66 to 71.68 ± 3.02% and for (125)I-Progesterone from 98.31 ± 1.26 to 85.40 ± 1.98%. Due to the differences found in these assays, which depend on the method used, the type of feces employed and the type of solvent added to them, we recommend the ebullition method and the lyophilized feces of A. pigra for extracting the hormones, since in moist feces there may exist variables which might interfere in the quantification of (125)I-Estradiol and (125)I-Progesterone.