Ruben Lopez Revilla

Airborne viruses cause millions of deaths and significant economic losses around the world, especially in developing countries. Since viral particles are transmitted through airborne routes and can remain viable for hours, monitoring and timely detection of airborne viruses is a crucial strategy to prevent and control outbreaks of respiratory infections. This review compares various sampling devices and methods used for detecting infectious airborne viruses.

Peptides binding overexpressed breast and cervical cancer cell surface proteins can be isolated by phage display technology, and their affinity to their potential receptors can be assessed by molecular docking. We isolated 44 phage clones displaying dodecapeptides with high affinity to HeLa cervical cancer and MDA-MB-231 (MDA) breast cancer cells by repeated biopanning of an MK13 phage library and explored their affinity to specific proteins by molecular docking. Six peptides appeared repeatedly during biopanning: two with affinity to HeLa (H5/H21), and four with affinity to MDA cells (M3/M7/M15/M17). Peptide pairs M3/H5 and H1/M17 had affinity to both cell lines. A systematic review identified Annexin A2, EGFR, CD44, CD146, and Integrin alpha V as potential protein targets in HeLa cells, and Vimentin, Galectin-1, and Annexins A1 and A5 in MDA cells. Via virtual screening, we selected six peptides with the highest total docking scores: H1 (-916.32), H6 (-979.21), H19 (-1093.24), M6 (-732.21), M16 (-745.5), and M19 (-739.64), and identified that docking scores were strengthened by the protein type, the interacting amino acid side chains, and the polarity of peptides. This approach facilitates the selection of relevant peptides that could be further explored for active targeting in cancer diagnosis and treatment.

This study aims to evaluate a structural equation model to explore statistical relationships between the Body Mass Index (BMI) percentile, the neuroendocrine response to neighbourhood aesthetics, and physical activity among elementary school children residing in a Mexican community. 103 children (mid‐childhood mean age = 9.02 years, SD = 1.05, range 7–11 years; 51.5% boys) participated in the study. The neuroendocrine response to chronic stress was assessed by hair cortisol concentration over 3 months. The model shows that neighbourhood aesthetics is negatively associated with children’s Body Mass Index scores and contributes positively to the practice of children’s physical activity. Likewise, environment-based physical activity has a positive relationship with lower scores of Body Mass Index and children’s hair cortisol concentration (restorative effects). The positive association between neighbourhood aesthetics on children’s physical activity and children’s hair cortisol concentration (chronic stress) was in line with the positive relationship between hair cortisol concentration and children’s obesity, suggesting that neighbourhood aesthetics has a positive influence on health indicators, diminishing chronic stress biomarkers and obesity indicators. These findings document the relevance of a psycho-environmental approach to better understand the synergistic links of a positive environment and behavioral transactions in relation to weight gain and obesity.

Amarissinin F (1) and its 16-epimer (2) are two neo-clerodane diterpenoids isolated from the leaves and flowers of Salvia amarissima that occur as an unresolved epimeric mixture by chromatographic methods. The molecular structures of these compounds were deduced by the extensive analyses of their HRESIMS and their 1D/2D NMR data. Both compounds co-exist in the solid state as confirmed by single-crystal X-ray diffraction. In solution, both isolates appeared as the major compounds, which was corroborated by derivatization with Mosher reagents. However, the 1H and 13C NMR spectra demonstrated evidence for epimerization at C-20 and the possible interconversion of the 16-hydroxy-15,16-furanone to a 15-hydroxy-16,15-furanone, which was supported by a variable temperature 1H NMR analysis. The absolute configuration of compounds 1 and 2 was established by single-crystal X-ray diffraction and NMR. The cytotoxic effects of the isolated epimeric mixture (1 and 2) against a set of human cancer cells and the MDR modulatory activity in resistant MCF-7 breast cancer cells were explored.

Tumors of the central nervous system (CNS) are due to the abnormal growth of cells in the brain or spinal cord that can become malignant and spread by metastases.Gliomas are the most frequent malignant tumors of the CNS, characterized by their heterogeneity and invasiveness.The high lethality of gliomas is due, among other causes, to the low efficacy of current treatments.The few biomarkers effective for the classification, prognosis, and treatment of the various types of gliomas are a useful tool for their management.New markers are currently being sought to make a more accurate diagnosis and for their potential as therapeutic targets.In this review, we describe the traditional biomarkers and other biomarkers that could be used to improve the diagnosis, prognosis, and treatment of gliomas.

Photothermal tumor ablation might be carried out with multibranched gold nanoparticles (MBAuNPs) having maximum absorbance (Amax) in the infrared region and functionalized with ligands that would bind them to the target tumor markers. However, in nanomedicine applications, the nanostructures must reach their target tissues to be effective, but the corona of serum proteins they instantaneously acquire when administered by intravenous injection may affect their activity; for this reason, we decided to analyze the effect that exposing MBAuNPs to bovine serum albumin (BSA) and human serum (HS) have on their protein corona and physical properties. The synthesized spherical Au seeds stoichiometrically generate piñata-like MBAuNPs of 8–20 peaks potentially useful for photothermal tumor ablation since they induce hyperthermia of more than 4 °C in phantom gels mimicking the skin irradiated with an 808 nm laser at 0.75 W/cm2. The calculated surface area of MBAuNPs ranges from 24 984 nm2 to 40 669 nm2, depending on the number of peaks we use for modeling the NPs. When MBAuNPs are exposed to BSA, they acquire a protein corona with an internal “hard” portion composed by one or two layers of BSA containing ∼1000–4000 molecules covalently bound to their surface, and an external “soft” portion formed by agglomerated BSA molecules linked by non-covalent bonds. Functionalization with BSA decreases the tendency of MBAuNPs to agglomerate and increases their size dispersion. MBAuNPs and MBAuNPs–BSA exposed to HS bind HS albumin and other HS proteins ranging from 25 kDa to 180 kDa that increase their hydrodynamic diameter and decrease their stability. We conclude that MBAuNPs exposed to serum albumin and HS instantaneously acquire a hard and soft protein corona that may affect prior or subsequent functionalization aiming to direct them to specific cell or tissue targets.

Cutaneous adverse drug reactions include maculopapular exanthema, Stevens-Johnson syndrome, and toxic epidermal necrolysis and are a global public health problem associated with the use of antiepileptic drugs (AEDs).Lamotrigine (LTG) stands out among AEDs because it does not cause sedation and does not affect cognition.Cutaneous adverse reactions (cADRs) to LTG occur in patients carrying certain allele variants of the human leukocyte antigen (HLA) system; although infrequent, they are alarming because they put the life at risk and force discontinuation of the treatment.The fear of neurologists to cADRs to LTG decreases its prescription despite its therapeutic advantages.Here, we review the allele variants of the HLA system that have been associated with cADRs to LTG in Mexican mestizos and other ethnic groups; identification of these variants would serve to select the patients that may be treated with LTG.

PURPOSE: To develop a fast and inexpensive genotyping assay to identify the Mycobacterium tuberculosis complex (MTC) species most prevalent in human tuberculosis (TB), based on the thermal denaturation profiles of PCR products from mycobacterial 16S rDNA and three MTC genomic regions of difference (RD). METHODOLOGY: Genotypes were determined by the presence and thermal denaturation profiles of the amplicons generated in the 'preliminary' PCR mixture (16S rDNA), followed by those of the simultaneous D1 (RD9+, RD1-) and D2 (RD4+, RD4-) PCR mixtures. The 16S rDNA profile identifies the genus Mycobacterium; the absence of any additional RD profile identifies Mycobacterium non-tuberculous (MNT) strains; additional RD4+ and RD9+ profiles without RD1- identify M. tuberculosis; an additional RD4+ profile per se identifies M. africanum; an additional RD4- profile per se identifies Mycobaterium bovis; additional RD1- and RD4- profiles identify M. bovis BCG. RESULTS: Genotypes of a panel with 44 mycobacterial strains coincided in 16 MB and five non-MTC strains; in the remaining 23 MTC strains, 17 MTB and five MA concordant genotypes and one discordant MB genotype were resolved. The genotypes of 13 human and bovine MTC isolates coincided in all four MB and eight of the nine MTB isolates. CONCLUSION: Sensitivity, specificity and positive and negative predictive values of the method are 100 % for the genus Mycobacterium, which resolves MB, MTB and MA genotypes. Species/genotype agreement is 97.7 % for the panel and 92.3 % for the MTC isolates. This method may be advantageously used to identify the most prevalent MTC species in humans.

BACKGROUND: The association of human papillomavirus (HPV) types to neoplastic lesions increase as a function of their oncogenicity and the duration of the infection since lesion severity progresses from low-grade to high-grade and cancer. In an outbreak, the prevalence of the HPV type involved would increase and the proportion of the associated low-grade lesions would predominate over severe lesions. In this study, the prevalence of HPV types and their association to neoplastic lesions was determined in women subjected to colposcopy in San Luis Potosí, Mexico. METHODS: DNA from high-risk (HR) and low-risk (LR) HPV types was identified by E6 nested multiplex PCR in cervical scrapes from 700 women with normal cytology, atypical squamous cells of undetermined significance (ASCUS), low-grade squamous intraepithelial lesions (LSIL), high-grade squamous intraepithelial lesions (HSIL) or invasive cervical cancer (CC). RESULTS: Overall HPV-DNA prevalence was 67.7 %, that of HR-HPV was 63.1 %, and that of LR-HPV was 21.3 %. The highest prevalence (78.2 %) occurred in the 15-24 year group, whereas that of single infections was 52 % and that of multiple infections (i.e., by 2-6 HPV types) was 48 %. The most prevalent HR types were HPV33 (33.1 %), HPV16 (16.6 %), HPV18 and HPV51 (6.7 % each). HR-HPV prevalence was 29.6 % in normal cytology, 26.7 % in ASCUS, 63.3 % in LSIL, 68.2 % in HSIL, and 90.5 % in CC. Three prevalence trends for HR-HPV types were found in neoplastic lesions of increasing severity: increasing (LSIL < HSIL < CC) for HPV16, HPV39, HPV18, HPV58, HPV31 and HPV35; asymptotic (LSIL < HSIL ≈ CC) for HPV51 and HPV68; U-shaped (LSIL < HSIL > CC) for HPV33. CONCLUSIONS: Two-thirds of the women subjected to colposcopy from 2007 to 2010 in San Luis Potosí have HPV infections which predominate in the 15-24 years group. Around half of the infections are by one viral type and the rest by 2-6 types. HPV33 is the most prevalent type, followed by HPV16. Overall HR-HPV prevalence increases with the severity of neoplastic lesions. HPV33 prevalence is highest in LSIL and its U-shaped trend with progressing neoplastic lesions differs from the growing/asymptotic trends of other HR-HPV types. An ongoing or recent HPV33 outbreak is consistent with its high prevalence and anomalous association to LSIL.

[This corrects the article DOI: 10.1186/s13027-015-0027-8.].

BACKGROUND: We conducted a large international study to estimate fractions of head and neck cancers (HNCs) attributable to human papillomavirus (HPV-AFs) using six HPV-related biomarkers of viral detection, transcription, and cellular transformation. METHODS: Formalin-fixed, paraffin-embedded cancer tissues of the oral cavity (OC), pharynx, and larynx were collected from pathology archives in 29 countries. All samples were subject to histopathological evaluation, DNA quality control, and HPV-DNA detection. Samples containing HPV-DNA were further subject to HPV E6*I mRNA detection and to p16(INK4a), pRb, p53, and Cyclin D1 immunohistochemistry. Final estimates of HPV-AFs were based on HPV-DNA, HPV E6*I mRNA, and/or p16(INK4a) results. RESULTS: A total of 3680 samples yielded valid results: 1374 pharyngeal, 1264 OC, and 1042 laryngeal cancers. HPV-AF estimates based on positivity for HPV-DNA, and for either HPV E6*I mRNA or p16(INK4a), were 22.4%, 4.4%, and 3.5% for cancers of the oropharynx, OC, and larynx, respectively, and 18.5%, 3.0%, and 1.5% when requiring simultaneous positivity for all three markers. HPV16 was largely the most common type. Estimates of HPV-AF in the oropharynx were highest in South America, Central and Eastern Europe, and Northern Europe, and lowest in Southern Europe. Women showed higher HPV-AFs than men for cancers of the oropharynx in Europe and for the larynx in Central-South America. CONCLUSIONS: HPV contribution to HNCs is substantial but highly heterogeneous by cancer site, region, and sex. This study, the largest exploring HPV attribution in HNCs, confirms the important role of HPVs in oropharyngeal cancer and drastically downplays the previously reported involvement of HPVs in the other HNCs.

BACKGROUND: Viral infections and the burden of high-grade intraepithelial neoplasias (HIN) and invasive carcinomas (IC) associated to infections by human papillomavirus (HPV) types may be prevented by type-specific anti-HPV vaccines. This study determined the prevalence of HPV types in non-cervical HIN and IC diagnosed from 1999 to 2011 at a general hospital in San Luis Potosí, Mexico. METHODS: Review of the 67 formaldehyde-fixed paraffin-embedded non-cervical specimens initially diagnosed as HIN (n = 28) or IC (n = 39) confirmed the presence of tumor tissue in 63 of them and changed the diagnosis of 24 from HIN to low-grade intraepithelial neoplasias, that were excluded from the study. HPV DNA was detected with the SPF10-DNA enzyme immunoassay in the 39 cases included, and viral types in the HPV-positive tumors were identified with the INNO-LiPA linear probe array. RESULTS: Among the cases included, four HIN were located in the vagina (n = 3) and vulva (n = 1), and 35 IC in the oral cavity (n = 19), penis (n = 8), vagina (n = 7) and vulva (n = 1). There were 13 HPV-positive cases from the vagina (n = 7), vulva (n = 1), penis (n = 1) and oral cavity (n = 1). The viral types identified were the high-risk types HPV16 in the vagina (n = 3) and vulva (n = 3), HPV45 in the vagina (n = 2), HPV59 in the vagina (n = 1) and penis (n = 1), HPV33 in the vagina (n = 1),and HPV35 in the tongue(n = 1); and the low-risk types HPV54 in the vagina (n = 1), and HPV11 in the vulva (n = 1). CONCLUSIONS: Five high-risk viral types (HPV16, 45, 59, 33 and 35) and two low-risk types (HPV11 and 54) infect one third of the non-cervical HIN and IC included. Most infections are by a single HPV high-risk type, the most prevalent one being HPV16. Vagina is the most frequent location of the HPV-positive tumors. Vaccination against HPV16 and HPV18 could have prevented around half of the HPV-positive tumors.

BACKGROUND: Although epidemiologic and socioeconomic criteria and biomedical risk factors indicate high-priority for tuberculosis (TB) control in Mexico, molecular epidemiology studies of the disease in the country are scarce. METHODS: Complete sociodemographic and clinical data were obtained from 248 of the 432 pulmonary TB (PTB) cases confirmed from 2006 to 2010 on the population under epidemiological surveillance in the state of San Luis Potosí, México. From most PTB cases with complete data Mycobacterium tuberculosis complex (MTC) isolates were recovered and their spoligotypes, lineages and families, geographic distribution and drug resistance determined. RESULTS: Pulmonary tuberculosis incidence ranged from 2.4 to 33.4 (cases per 100,000 inhabitants) in the six state sanitary jurisdictions that were grouped in regions of low (jurisdictions I-II-III), intermediate (jurisdictions IV-V) and high incidence (jurisdiction VI) with 6.2, 17.3 and 33.4 rates, respectively. Most patients were poor, 50-years-median-age males and housewives. Among the 237 MTC spoligotyped isolates, 232 corresponded to M. tuberculosis (104 spoligotypes in 24 clusters) and five to M. bovis. The predominant Euro-American lineage was distributed all over the state, the East-Asian lineage (Beijing family) in the capital city, the Indo-Oceanic (Manila family) in eastern localities, and M. bovis in rural localities. CONCLUSIONS: In San Luis Potosí TB affects mainly poor male adults and is caused by M. tuberculosis and to a minor extent by M. bovis. There is great genotypic diversity among M. tuberculosis strains, the Euro-American lineage being much more prevalent than the Indo-Oceanic and East-Asian lineages. The frequency of resistant strains is relatively low and not associated to any particular lineage.

Los loci SRCRSP (Small Ruminant Collaborative Research Support Program) son secuencias de microsatélites polimórficos de 100-300 pares de bases de dinucleótidos repetidos que pueden ser amplificados por la reacción en cadena de la polimerasa (PCR).Los alelos de un determinado locus son los productos de PCR de longitud única amplificados con iniciadores específicos.Los loci SRCRSP se han utilizado para identificar individuos, pero no para determinar la paternidad en el ganado caprino.En el presente trabajo se reporta el desarrollo de un método para evaluar la paternidad en caprinos mediante el análisis del polimorfismo de loci SRCRSP en un rebaño de 20 animales, que incluía nueve de raza Nubia y 11 Boer.Se amplificaron 36 alelos: 6 del SRCRSP-1, 5 del SRCRSP-2, 4 del SRCRSP-3, 5 del SRCRSP-4, 5 del SRCRSP-5, 6 del SRCRSP-6 y 5 del SRCRSP-9.Cuatro alelos aparecieron exclusivamente en el grupo Nubia, mientras que sólo ocho en el grupo Boer.El análisis del polimorfismo llegó a 0.995 de certeza en la exclusión correcta del segundo padre.Los loci descritos en este trabajo podrían ser utilizados para controlar la paternidad así como para identificar a los individuos en ganado caprino.

BACKGROUND: We have developed an ultrasensitive method based on conventional PCR preamplification followed by nested amplification through real time PCR (qPCR) in the presence of the DNA intercalating agent EvaGreen. RESULTS: Amplification mixtures calibrated with a known number of pHV101 copies carrying a 645 base pair (bp)-long insert of the human papillomavirus type 16 (HPV16) E6 oncogene were used to generate the E6-1 amplicon of 645 bp by conventional PCR and then the E6-2 amplicon of 237 bp by nested qPCR. Direct and nested qPCR mixtures for E6-2 amplification corresponding to 2.5 x 102-2.5 x 106 initial pHV101 copies had threshold cycle (Ct) values in the ranges of 18.7-29.0 and 10.0-25.0, respectively. The Ct of qPCR mixtures prepared with 1/50 volumes of preamplified mixtures containing 50 ng of DNA of the SiHa cell line (derived from an invasive cervical cancer with one HPV16 genome per cell) was 19.9. Thermal fluorescence extinction profiles of E6-2 amplicons generated from pHV101 and SiHa DNA were identical, with a peak at 85.5 degrees C. CONCLUSIONS: Our method based on conventional preamplification for 15 cycles increased 10,750 times the sensitivity of nested qPCR for the quantitation of the E6 viral oncogene and confirmed that the SiHa cell line contains one E6-HPV16 copy per cell.

OBJECTIVE: To carry out the phenotypic characterization of Staphylococcus epidermidis isolated from endophthalmitis developed after cataract extraction and implantation of an intraocular lens. This bacteria produces a biofilm, adheres to polystyrene and host proteins such as collagen and fibronectine, significant virulence factors. METHODS: Five S. epidermidis strains were isolated from cases of endophthalmitis, they developed after crystalline extraction and implantation of an intraocular lens. We assessed if these strains adhere to polystyrene, to Type I collagen and to fibronectine and if bacteria produced biofilm. Finally, the bacterial surface proteins were obtained and analyzed using polyacrylamide gel electrophoresis. RESULTS: All five bacterial strains adhered to polystyrene, with a maximum adherence time of 105 min; they also displayed adherence to fibronectine but only two to collagen. Only two strains were weak biofilm producers. We identified proteins that by molecular weight are similar to those identified in the literature as proteins binding to biomaterials. CONCLUSIONS: As the strains that we studied were not biofilm-forming they should be considered as non-pathogenic. Nevertheless, they meet the initial criteria of pathogenicity and adherence, aside from being isolated from an intraocular infectious process and being able to provoke endophtalmitis when inoculated in rabbit eyes.

BACKGROUND: In San Luis Potosí City cervical infection by human papillomavirus type 16 (HPV16) associated to dysplastic lesions is more prevalent in younger women. In this work HPV16 subtypes and variants associated to low-grade intraepithelial lesions (LSIL), high-grade intraepithelial lesions (HSIL) and invasive cervical cancer (ICC) of 38 women residing in San Luis Potosí City were identified by comparing their E6 open reading frame sequences. RESULTS: Three European (E) variants (E-P, n = 27; E-T350G, n = 7; E-C188G, n = 2) and one AA-a variant (n = 2) were identified among the 38 HPV16 sequences analyzed. E-P variant sequences contained 23 single nucleotide changes, two of which (A334G, A404T) had not been described before and allowed the phylogenetic separation from the other variants. E-P A334G sequences were the most prevalent (22 cases, 57.9%), followed by the E-P Ref prototype (8 cases, 21.1%) and E-P A404T (1 case, 2.6%) sequences. The HSIL + ICC fraction was 0.21 for the E-P A334G variants and 0.00 for the E-P Ref variants. CONCLUSION: We conclude that in the women included in this study the HPV16 E subtype is 19 times more frequent than the AA subtype; that the circulating E variants are E-P (71.1%) > E-T350G (18.4%) > E-C188G (5.3%); that 71.0% of the E-P sequences carry the A334G single nucleotide change and appear to correspond to a HPV16 variant characteristic of San Luis Potosi City more oncogenic than the E-P Ref prototype.