Low antiviral resistance in Influenza A and B viruses isolated in Mexico from 2010 to 2023.

The most widely used class of antivirals available for Influenza treatment are the neuraminidase inhibitors (NAI) Oseltamivir and Zanamivir. However, amino acid (AA) substitutions in the neuraminidase may cause reduced inhibition or high antiviral resistance. In Mexico, the current state of knowledge about NAI susceptibility is scarce, in this study we report the results of 14 years of Influenza surveillance by phenotypic and genotypic methods. A total of 255 isolates were assessed with the NAI assay, including Influenza A(H1N1)pdm09, A(H3N2) and Influenza B (IBV). Furthermore, 827 sequences contained in the GISAID platform were analyzed in search of relevant mutations.Overall, five isolates showed highly reduced inhibition or reduced inhibition to Oseltamivir, and two showed reduced inhibition to Zanamivir in the NAI assays. Additionally, five A(H1N1)pdm09 sequences from the GISAID possessed AA substitutions associated to reduced inhibition to Oseltamivir and none to Zanamivir. Oseltamivir resistant A(H1N1)pdm09 harbored the H275Y mutation. No genetic mutations were identified in Influenza A(H3N2) and IBV. Overall, these results show that in Mexico the rate of NAI resistance is low (0.6%), but it is essential to continue the Influenza surveillance in order to understand the drug susceptibility of circulating strains.

Exportin-mediated nucleocytoplasmic transport maintains Pch2 homeostasis during meiosis.

The meiotic recombination checkpoint reinforces the order of events during meiotic prophase I, ensuring the accurate distribution of chromosomes to the gametes. The AAA+ ATPase Pch2 remodels the Hop1 axial protein enabling adequate levels of Hop1-T318 phosphorylation to support the ensuing checkpoint response. While these events are localized at chromosome axes, the checkpoint activating function of Pch2 relies on its cytoplasmic population. In contrast, forced nuclear accumulation of Pch2 leads to checkpoint inactivation. Here, we reveal the mechanism by which Pch2 travels from the cell nucleus to the cytoplasm to maintain Pch2 cellular homeostasis. Leptomycin B treatment provokes the nuclear accumulation of Pch2, indicating that its nucleocytoplasmic transport is mediated by the Crm1 exportin recognizing proteins containing Nuclear Export Signals (NESs). Consistently, leptomycin B leads to checkpoint inactivation and impaired Hop1 axial localization. Pch2 nucleocytoplasmic traffic is independent of its association with Zip1 and Orc1. We also identify a functional NES in the non-catalytic N-terminal domain of Pch2 that is required for its nucleocytoplasmic trafficking and proper checkpoint activity. In sum, we unveil another layer of control of Pch2 function during meiosis involving nuclear export via the exportin pathway that is crucial to maintain the critical balance of Pch2 distribution among different cellular compartments.

Design of a data set of qPCR primers for the early region of Human Papillomavirus oncogenic types 16 and 18.

High-Risk Human Papillomavirus (HR-HPV) types 16 and 18 are estimated to be responsible for 72.4% of all HPV-related cancers worldwide in both men and women, including cervical, anal, penile, vulval, vaginal and head and neck cancers [1]. Important efforts worldwide have devoted to the study of these genotypes, throughout epidemiology and basic science approaches. Of particular interest are the genes from the early region (E), coding non-structural proteins. Early genes E1 and E2 products are involved in replication and transcription regulation, while E6 and E7 proteins are recognised for their oncogenic potential. In this data report, we described a set of primers based on reference sequences from HPV16 and HPV18 designed to cover the early region of these oncogenic genotypes. The design was based on multiple sequences alignment to identify the less conserved regions along the open reading frames (ORFs) E6, E7, E1 and E2. The design allows a highly stringent real time PCR essay ranged from 123 to 598 bp overlapping products for HPV16 (12 products in total) and from 183 to 526 bp for HPV18 (11 products in total), both spanning the early genomic region. The high annealing temperatures (Ta) and regions selected for primer bind were intended for genotypic specificity, without compromising the qPCR amplification efficiency (≥ 90%). Evaluation of qPCR conditions for primer set was performed using DNA standards as controls, generated from the HPV16 and 18 genomes clones. This provides relevant information for further multiple quantitative real-time PCR analysis (qPCR), using the SYBR green chemistry, which is is more affordable than generating multiple fluorescently labeled probes.

Human Papillomavirus Genotypes Infecting the Anal Canal and Cervix in HIV+ Men and Women, Anal Cytology, and Risk Factors for Anal Infection.

The incidence of anal intraepithelial neoplasias associated with HPV is rising worldwide. In the general population, this pathology is rare, but individuals living with HIV/AIDS are at a significantly higher risk. We aimed to study HPV infection and performed cytological screening to study the epidemiological and behavioral determinants in a group of men and women living with HIV from a region in Mexico with high HIV incidence. This was a cross-sectional study including adults living with HIV/AIDS performed in Merida (Mexico). We invited patients of public HIV/STD clinics and those affiliated with social organizations of people living with HIV to participate in the study. Participants responded to an instrument to assess their risky behaviors and clinical history. Swabs from the anal canal and cervix and anal cytology specimens were obtained by medical staff from women and by self-sampling from men. For the 200 participants, 169 men and 31 women, anal HPV PCR tests resulted in 59.8% positivity (62.6% of men and 45.2% of women), and 17 genotypes were identified. The most frequent high-risk (HR) types for the anal canal were: HPV33 (35.3%), HPV58 (20.6%), HPV66 (18.6%), HPV45 (17.6%), and HPV16 (14.7%). Multiple genotypes were found in over 80% of the participants. Receptive anal intercourse in the previous 12 months, inconsistent condom use, and detectable HIV titers (≥50 cc/mL) were associated with HPV infection (p < 0.05). Cytology (smears and liquid-based) identified that 34.6% of the participants had low-grade squamous intraepithelial lesions (LSILs), and 3.5% had high-grade squamous intraepithelial lesions (HSILs). Neither HPV nor lesions were associated with low CD4+ counts (<200 cells/mm3, p > 0.05). Of the women, 60% were infected in the cervix and 45% in the anal canal, with an agreement of at least one genotype in 90%. The HR-HPV types associated with HSILs were HPV66, 33, 52, 51, 45, 18, and 68.

Human IgG antibody responses to severe acute respiratory syndrome coronavirus 2 viral antigens receptor-binding domain, spike, and nucleocapsid, in vaccinated adults from Merida, Mexico.

Several vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been approved for controlling the coronavirus disease 2019 (COVID-19) pandemic worldwide. Antibody response is essential to understand the immune response to different viral targets after vaccination with different vaccine platforms. Thus, the main aim of this study was to describe how vaccination with two distinct SARS-CoV-2 vaccine preparations elicit IgG antibody specific responses against two antigenically relevant SARS-CoV-2 viral proteins: the receptor-binding domain (RBD) and the full-length spike (S). To do so, SARS-CoV-2 protein specific in-house enzyme-linked immunosorbent assays (ELISAs) were standardized and tested against serum samples collected from 89 adults, recipients of either a single-dose of the Spike-encoding mRNA-based Pfizer/BioNTech (Pf-BNT) (70%, 62/89) or the Spike-encoding-Adenovirus-5-based CanSino Biologics Inc. (CSBIO) (30%, 27/89) in Merida, Mexico. Overall, we identified an IgG seroconversion rate of 88% (68/78) in all vaccinees after more than 25 days post-vaccination (dpv). Anti-RBD IgG-specific responses ranged from 90% (46/51) in the Pf-BNT vaccine at 25 dpv to 74% (20/27) in the CSBIO vaccine at 42 dpv. Compared to the S, the RBD IgG reactivity was significantly higher in both Pf-BNT (p < 0.004) and CSBIO (p < 0.003) vaccinees. Interestingly, in more than 50% of vaccine recipients, with no history of COVID-19 infection, antibodies against the nucleocapsid (N) protein were detected. Thus, participants were grouped either as naïve or pre-exposed vaccinees. Seroconversion rates after 25 and more dpv varies between 100% in Pf-BNT (22/22) and 75% (9/12) in CSBIO pre-exposed vaccinees, and 89% (26/29) and 73% (11/15) in Pf-BNT and CSBIO naïve vaccine recipients, respectively. In summary, observed seroconversion rates varied depending on the type of vaccine, previous infection with SARS-CoV-2, and the target viral antigen. Our results indicate that both vaccine preparations can induce detectable levels of IgG against the RBD or Spike in both naïve and SARS-CoV-2 pre-exposed vaccinees. Our study provides valuable and novel information about the serodiagnosis and the antibody response to vaccines in Mexico.

A Key Metabolic Regulator of Bone and Cartilage Health.

Taurine, a cysteine-derived zwitterionic sulfonic acid, is a common ingredient in energy drinks and is naturally found in fish and other seafood. In humans, taurine is produced mainly in the liver, and it can also be obtained from food. In target tissues, such as the retina, heart, and skeletal muscle, it functions as an essential antioxidant, osmolyte, and antiapoptotic agent. Taurine is also involved in energy metabolism and calcium homeostasis. Taurine plays a considerable role in bone growth and development, and high-profile reports have demonstrated the importance of its metabolism for bone health. However, these reports have not been collated for more than 10 years. Therefore, this review focuses on taurine-bone interactions and covers recently discovered aspects of taurine's effects on osteoblastogenesis, osteoclastogenesis, bone structure, and bone pathologies (e.g., osteoporosis and fracture healing), with due attention to the taurine-cartilage relationship.

[Molecular detection of human papillomavirus among patients with benign prostatic hyperplasia and prostate cáncer.] / Detección molecular del virus de papiloma humano en pacientes con hiperplasia prostática benigna y cáncer de próstata.

OBJECTIVE: To analyze the presenceof human papillomavirus in prostate and its associationwith prostate cancer. METHODS: A case-control study was conducted.Tissue samples with benign hyperplasia and prostatecancer were collected. Risk factors related to prostatecancer and human papillomavirus were assessedby a medical interview. Prostate tissue was obtainedby transrectal biopsy or transurethral resection. Theidentification of viral genome was assessed by the amplificationof 450 pb., from L1 gene. Real time PCR wasused to identified HPV genotypes 16 and 18. For dataanalysis, the χ2 test, Student's T test or Mann-WhitneyU test and OR were computed. RESULTS: Thirty and 99 with benign prostatehyperplasia were included in a 1:3 ratio, with a meanage of 69.44±9.22 years. The global prevalence of humanpapillomavirus was 15.2% being similar in bothcases (15.6%) and controls (15.1%) with no significantdifference (p = 0.572). Forty percent of the infectionswere persistent. From all positive samples, only in the40% were identified some of the genotypes analyzed(16 and 18). The group of patients with Gleason scorede > 7 had a virus prevalence of 16%. CONCLUSIONS: The results show the presence ofthe human papillomavirus genome in prostate tissuewith and without neoplasia; no association was foundbetween infection and prostate cancer.

OBJETIVOS: Analizar la presencia delvirus de papiloma humano en próstata y su asociacióncon cáncer.MATERIAL Y MÉTODOS: Se realizó un estudiode casos y controles, para lo cual se colectaronmuestras de tejido con hiperplasia benigna y concáncer de próstata. Se realizó una historia clínicapara conocer la presencia de los factores de riesgoasociados al cáncer de próstata, así como los relacionadoscon el virus. El tejido prostático fue obtenidopor biopsia transrectal o resección transuretral.La identificación del genoma viral se realizó amplificandoun fragmento de 450 del gen L1 por mediode una PCR clásica. Para la identificación de los genotipos16 y 18, se utilizó PCR tiempo real. Para elanálisis de los datos se utilizó la prueba de χ2, pruebade T de Student o U de Mann-Whitney y cálculode OR. RESULTADOS: Se incluyeron 32 pacientes concáncer de próstata y 99 con hiperplasia benigna depróstata en una relación 1:3. La media de edad fuede 69.44±9.22 años. La prevalencia global del virusde papiloma humano fue de 15.2% siendo similar en los casos y entre casos (15.6%) y controles (15.1%),no existiendo diferencia significativa (p=0.572). El40% de las infecciones eran persistentes. Del totalde las muestras positivas, solamente en el 40% seencontró alguno de los dos genotipos analizados (16y 18). Los pacientes con un puntaje de Gleason > 7tuvieron una prevalencia del virus de 16%. CONCLUSIONES: Los resultados ponen de manifiestola presencia del genoma del virus del papilomahumano en próstata con y sin neoplasia, no se encontróasociación entre la infección y el cáncer de próstata.

Detección molecular del Virus de Papiloma Humano en pacientes con hiperplasia prostática benigna y cáncer de próstata / Molecular detection of human papillomavirus among patients with benign prostatic hyperplasia and prostate cáncer

OBJETIVOS: Analizar la presencia delvirus de papiloma humano en próstata y su asociacióncon cáncer.MATERIAL Y MÉTODOS: Se realizó un estudio de casos y controles, para lo cual se colectaronmuestras de tejido con hiperplasia benigna y concáncer de próstata. Se realizó una historia clínicapara conocer la presencia de los factores de riesgoasociados al cáncer de próstata, así como los relacionados con el virus. El tejido prostático fue obtenido por biopsia transrectal o resección transuretral.La identificación del genoma viral se realizó amplificando un fragmento de 450 del gen L1 por mediode una PCR clásica. Para la identificación de los genotipos 16 y 18, se utilizó PCR tiempo real. Para elanálisis de los datos se utilizó la prueba de χ2, prueba de T de Student o U de Mann-Whitney y cálculode OR.RESULTADOS: Se incluyeron 32 pacientes concáncer de próstata y 99 con hiperplasia benigna depróstata en una relación 1:3. La media de edad fuede 69.44±9.22 años. La prevalencia global del virusde papiloma humano fue de 15.2% siendo similar en los casos y entre casos (15.6%) y controles (15.1%),no existiendo diferencia significativa (p=0.572). El40% de las infecciones eran persistentes. Del totalde las muestras positivas, solamente en el 40% seencontró alguno de los dos genotipos analizados (16y 18). Los pacientes con un puntaje de Gleason > 7tuvieron una prevalencia del virus de 16%.CONCLUSIONES: Los resultados ponen de manifiesto la presencia del genoma del virus del papilomahumano en próstata con y sin neoplasia, no se encontróasociación entre la infección y el cáncer de próstata.

OBJECTIVE: To analyze the presenceof human papillomavirus in prostate and its associationwith prostate cancer.METHODS: A case-control study was conducted.Tissue samples with benign hyperplasia and prostatecancer were collected. Risk factors related to prostate cancer and human papillomavirus were assessedby a medical interview. Prostate tissue was obtainedby transrectal biopsy or transurethral resection. Theidentification of viral genome was assessed by the amplification of 450 pb., from L1 gene. Real time PCR wasused to identified HPV genotypes 16 and 18. For dataanalysis, the χ2 test, Student’s T test or Mann-WhitneyU test and OR were computed. RESULTS: Thirty and 99 with benign prostatehyperplasia were included in a 1:3 ratio, with a meanage of 69.44±9.22 years. The global prevalence of human papillomavirus was 15.2% being similar in bothcases (15.6%) and controls (15.1%) with no significantdifference (p = 0.572). Forty percent of the infectionswere persistent. From all positive samples, only in the40% were identified some of the genotypes analyzed(16 and 18). The group of patients with Gleason scorede > 7 had a virus prevalence of 16%CONCLUSIONS: The results show the presence ofthe human papillomavirus genome in prostate tissuewith and without neoplasia; no association was foundbetween infection and prostate cancer.

The N-Terminal Region of the Polo Kinase Cdc5 Is Required for Downregulation of the Meiotic Recombination Checkpoint.

During meiosis, the budding yeast polo-like kinase Cdc5 is a crucial driver of the prophase I to meiosis I (G2/M) transition. The meiotic recombination checkpoint restrains cell cycle progression in response to defective recombination to ensure proper distribution of intact chromosomes to the gametes. This checkpoint detects unrepaired DSBs and initiates a signaling cascade that ultimately inhibits Ndt80, a transcription factor required for CDC5 gene expression. Previous work revealed that overexpression of CDC5 partially alleviates the checkpoint-imposed meiotic delay in the synaptonemal complex-defective zip1Δ mutant. Here, we show that overproduction of a Cdc5 version (Cdc5-ΔN70), lacking the N-terminal region required for targeted degradation of the protein by the APC/C complex, fails to relieve the zip1Δ-induced meiotic delay, despite being more stable and reaching increased protein levels. However, precise mutation of the consensus motifs for APC/C recognition (D-boxes and KEN) has no effect on Cdc5 stability or function during meiosis. Compared to the zip1Δ single mutant, the zip1Δ cdc5-ΔN70 double mutant exhibits an exacerbated meiotic block and reduced levels of Ndt80 consistent with persistent checkpoint activity. Finally, using a CDC5-inducible system, we demonstrate that the N-terminal region of Cdc5 is essential for its checkpoint erasing function. Thus, our results unveil an additional layer of regulation of polo-like kinase function in meiotic cell cycle control.

The Cdc14 Phosphatase Controls Resolution of Recombination Intermediates and Crossover Formation during Meiosis.

Meiotic defects derived from incorrect DNA repair during gametogenesis can lead to mutations, aneuploidies and infertility. The coordinated resolution of meiotic recombination intermediates is required for crossover formation, ultimately necessary for the accurate completion of both rounds of chromosome segregation. Numerous master kinases orchestrate the correct assembly and activity of the repair machinery. Although much less is known, the reversal of phosphorylation events in meiosis must also be key to coordinate the timing and functionality of repair enzymes. Cdc14 is a crucial phosphatase required for the dephosphorylation of multiple CDK1 targets in many eukaryotes. Mutations that inactivate this phosphatase lead to meiotic failure, but until now it was unknown if Cdc14 plays a direct role in meiotic recombination. Here, we show that the elimination of Cdc14 leads to severe defects in the processing and resolution of recombination intermediates, causing a drastic depletion in crossovers when other repair pathways are compromised. We also show that Cdc14 is required for the correct activity and localization of the Holliday Junction resolvase Yen1/GEN1. We reveal that Cdc14 regulates Yen1 activity from meiosis I onwards, and this function is essential for crossover resolution in the absence of other repair pathways. We also demonstrate that Cdc14 and Yen1 are required to safeguard sister chromatid segregation during the second meiotic division, a late action that is independent of the earlier role in crossover formation. Thus, this work uncovers previously undescribed functions of the evolutionary conserved Cdc14 phosphatase in the regulation of meiotic recombination.

Pch2 orchestrates the meiotic recombination checkpoint from the cytoplasm.

During meiosis, defects in critical events trigger checkpoint activation and restrict cell cycle progression. The budding yeast Pch2 AAA+ ATPase orchestrates the checkpoint response launched by synapsis deficiency; deletion of PCH2 or mutation of the ATPase catalytic sites suppress the meiotic block of the zip1Δ mutant lacking the central region of the synaptonemal complex. Pch2 action enables adequate levels of phosphorylation of the Hop1 axial component at threonine 318, which in turn promotes activation of the Mek1 effector kinase and the ensuing checkpoint response. In zip1Δ chromosomes, Pch2 is exclusively associated to the rDNA region, but this nucleolar fraction is not required for checkpoint activation, implying that another yet uncharacterized Pch2 population must be responsible for this function. Here, we have artificially redirected Pch2 to different subcellular compartments by adding ectopic Nuclear Export (NES) or Nuclear Localization (NLS) sequences, or by trapping Pch2 in an immobile extranuclear domain, and we have evaluated the effect on Hop1 chromosomal distribution and checkpoint activity. We have also deciphered the spatial and functional impact of Pch2 regulators including Orc1, Dot1 and Nup2. We conclude that the cytoplasmic pool of Pch2 is sufficient to support the meiotic recombination checkpoint involving the subsequent Hop1-Mek1 activation on chromosomes, whereas the nuclear accumulation of Pch2 has pathological consequences. We propose that cytoplasmic Pch2 provokes a conformational change in Hop1 that poises it for its chromosomal incorporation and phosphorylation. Our discoveries shed light into the intricate regulatory network controlling the accurate balance of Pch2 distribution among different cellular compartments, which is essential for proper meiotic outcomes.

Human papillomavirus type 13: Genome amplification and characterization data.

As for 2020 only two complete genomes of Human papillomavirus type 13 (HPV13) are publicly available in GenBank database. In addition, reports of partial sequences of genetic regions are very limited. Therefore, genomic research that contributes to knowledge of viral components involved in HPV13 pathogenesis, and molecular mechanisms associated to multifocal epithelial hyperplasia (MEH) disease are urged. In the accompanying paper [1], we aimed to obtain the complete genome sequence of HPV13 associated to MEH disease, obtained from a Mayan boy living in Yucatan, Mexico. Coding sequences were annotated, and viral proteins traduced and deposited in GenBank with accession number MT068446. In this data report, we present the oligonucleotide list used to amplify the complete genome, a graphical abstract of process employed for the amplification of circular HPV13 genome, a representative figure of PCR products obtained for sequencing and multiple sequence alignments with the translated coding sequences of the existing genomes: X62843 is the first HPV13 genome reported [2]; it was generated from a clone obtained from a Turkish patient; DQ344807 was originally obtained from a patient in the Amazonian region [3]. The multiple sequence alignments show the main viral proteins (predicted). This provides relevant information for future molecular analysis and epidemiological studies because HPV13 is an understudied genotype associated to a neglected disease that appears more commonly in children. Additionally, the description of the methods can help in future sequencing of HPV genomes. We hope that our solutions will help researchers who do not have next-generation sequencing (NGS) platforms. A more comprehensive analysis of this data may be obtained from "Genomic characterization of Human papillomavirus type 13, associated to Multifocal Epithelial Hyperplasia, in a Mayan community" [1].

Genomic characterization of human papillomavirus type 13, associated to multifocal epithelial hyperplasia, in a Mayan community.

Human papillomavirus type 13 (HPV13) is a low-risk HPV type associated with Multifocal Epithelial Hyperplasia (MEH). It is considered a rare pathology of oral mucosa, more prevalent in certain ethnical groups, such as the Maya from Yucatan in Mexico. As for 2020 only two complete genomes of HPV13 are publicly available in Genbank database (one from Turkey one from the Amazonian). We aimed to obtain the complete genome sequence of HPV13 associated to MEH, obtained from a community in the Mayan area from Mexico. A bank of oral swabs from children with MEH were used. To enrich the sample, a Rolling Cycle Amplification (RCA) method was performed followed by overlapping end-point PCR of 500 bp fragments, Sanger sequencing and assembly. Eight open reading frames (ORFs) were annotated (E1, E2, E4, E5, E6, E7, L1 and L2 genes). When compared with the other two previously reported genomes the identity at nucleotide level is high 98.9% and 99.6%, respectively. The phylogenetic tree shows that Yucatan HPV13 is more closely related to HPV13 obtained from the Amazonian. Most changes identified at amino acid level are substitutions derived from nucleotide variations or SNPs in coding regions. Amino-acid changes were observed in E2 and E1 proteins (n ≥ 8), and in L1, L2, E6 and E5 proteins (n ≤ 5). E7 protein from Yucatan has 100% identity with the reported from Amazonian and differs (94.1% identity) with the one from Turkey due to 3 substitutions and three missing amino acids. In conclusion, the genome from HPV13 (7831 bp, 49 nt missing) associated to MEH in the Mayan area from Yucatan was obtained from stored swabs; this is the first effort in Mexico, the second in Latin America, and the third of the world. More research that contributes to the knowledge of the determinants underlying this neglected pathology are urged.

SWR1-Independent Association of H2A.Z to the LINC Complex Promotes Meiotic Chromosome Motion.

The H2A.Z histone variant is deposited into the chromatin by the SWR1 complex, affecting multiple aspects of meiosis. We describe here a SWR1-independent localization of H2A.Z at meiotic telomeres and the centrosome. We demonstrate that H2A.Z colocalizes and interacts with Mps3, the SUN component of the linker of nucleoskeleton, and cytoskeleton (LINC) complex that spans the nuclear envelope and links meiotic telomeres to the cytoskeleton, promoting meiotic chromosome movement. H2A.Z also interacts with the meiosis-specific Ndj1 protein that anchors telomeres to the nuclear periphery via Mps3. Telomeric localization of H2A.Z depends on Ndj1 and the N-terminal domain of Mps3. Although telomeric attachment to the nuclear envelope is maintained in the absence of H2A.Z, the distribution of Mps3 is altered. The velocity of chromosome movement during the meiotic prophase is reduced in the htz1Δ mutant lacking H2A.Z, but it is unaffected in swr1Δ cells. We reveal that H2A.Z is an additional LINC-associated factor that contributes to promote telomere-driven chromosome motion critical for error-free gametogenesis.

Characterization of Pch2 localization determinants reveals a nucleolar-independent role in the meiotic recombination checkpoint.

The meiotic recombination checkpoint blocks meiotic cell cycle progression in response to synapsis and/or recombination defects to prevent aberrant chromosome segregation. The evolutionarily conserved budding yeast Pch2TRIP13 AAA+ ATPase participates in this pathway by supporting phosphorylation of the Hop1HORMAD adaptor at T318. In the wild type, Pch2 localizes to synapsed chromosomes and to the unsynapsed rDNA region (nucleolus), excluding Hop1. In contrast, in synaptonemal complex (SC)-defective zip1Δ mutants, which undergo checkpoint activation, Pch2 is detected only on the nucleolus. Alterations in some epigenetic marks that lead to Pch2 dispersion from the nucleolus suppress zip1Δ-induced checkpoint arrest. These observations have led to the notion that Pch2 nucleolar localization could be important for the meiotic recombination checkpoint. Here we investigate how Pch2 chromosomal distribution impacts checkpoint function. We have generated and characterized several mutations that alter Pch2 localization pattern resulting in aberrant Hop1 distribution and compromised meiotic checkpoint response. Besides the AAA+ signature, we have identified a basic motif in the extended N-terminal domain critical for Pch2's checkpoint function and localization. We have also examined the functional relevance of the described Orc1-Pch2 interaction. Both proteins colocalize in the rDNA, and Orc1 depletion during meiotic prophase prevents Pch2 targeting to the rDNA allowing unwanted Hop1 accumulation on this region. However, Pch2 association with SC components remains intact in the absence of Orc1. We finally show that checkpoint activation is not affected by the lack of Orc1 demonstrating that, in contrast to previous hypotheses, nucleolar localization of Pch2 is actually dispensable for the meiotic checkpoint.

Posterior cornea and thickness changes after scleral lens wear in keratoconus patients.

PURPOSE: To evaluate the changes in the corneal thickness, anterior chamber depth and posterior corneal curvature and aberrations after scleral lens wear in keratoconus patients with and without intrastromal corneal ring segments (ICRS). METHODS: Twenty-six keratoconus subjects (36.95 ±â€¯8.95 years) were evaluated after 8 h of scleral lens wear. The subjects were divided into two groups: those with ICRS (ICRS group) and without ICRS (KC group). The study variables evaluated before and immediately after scleral lens wear included corneal thickness evaluated in different quadrants, posterior corneal curvature at 2, 4, 6 and 8 mm of corneal diameter, posterior corneal aberrations for 4, 6 and 8 mm of pupil size and anterior chamber depth. RESULTS: There was a statistically significant corneal thinning (p < 0.05) in the inferior region of the KC group and in the superior region of the ICRS group. No change (p > 0.05) in the anterior chamber depth was found. The KC group showed a steepening (p < 0.05) in the temporal quadrant and a flattening that mainly affected to the superior-nasal quadrant. The ICRS group showed a steepening (p < 0.05) that mainly affected to the superior-nasal quadrant. Regarding posterior corneal aberrations, only changes (p < 0.05) in Z4 for 8 mm and Z8 for 4 mm were found in the KC group. CONCLUSIONS: Short-term scleral lens wear showed a thinning of the cornea and changes in the posterior corneal curvature affects different regions in keratoconus patients with and without ICRS.

In vitro evaluation of anthraquinones from Aloe vera (Aloe barbadensis Miller) roots and several derivatives against strains of influenza virus.

Aloe vera is a crop of wide economic value of worldwide distribution, and a rich source of quinone components. Recently, antiviral aloe anthraquinones had been reported against human influenza virus. In the present work two anthraquinones, aloesaponarin-I (1) and aloesaponarin-II (2) were isolated from A. vera roots, and six derivatives were obtained by methylation (3), acetylation (4) and O-glycosyl (5-6) reactions starting from (1). Additionally, a new Tetra-O-acetyl-ß-d-glucopyranosyl derivative from 2 was also prepared. All compounds were evaluated against two strains of influenza virus AH1N1 by cytopathic effect reduction assay (CPE). The antiviral activity was determined by the ability of compounds to inhibit virus replication on Madin Darby Canine Kidney cells (MDCK). New derivatives 3-(2´,3´,4´,6´-Tetra-O-acetyl-ß-d-glucopyranosyl-aloesaponarin-I (5) and 3-(2´,3´,4´,6´-Tetra-O-acetyl-ß-d-glucopyranosyl- aloesaponarin-II (7) showed a cytopathic reduction effect against influenza strain A/Yucatán/2370/09 with IC50 of 30.77 and 13.70 µM, and against the virus A/Mexico/InDRE797/10 with IC50 of 62.28 and 19.47 µM, respectively. To assess the effect of derivatives 5 and 7 during one cycle of replication (0-10 h), a time-of-addition experiment was performed. As a result it was found that both compounds were most effective when added 6-10 h post-infection and significantly inhibited viral titre (> 70%) at the concentrations of 50 and 100 µM. Based on the structural analysis of the compounds, it was suggested that the Tetra-O-acetyl-ß-d-glucopyranosyl substituent at the C3 position of the anthraquinone might have an effect against the influenza AH1N1 virus.

Anterior Corneal Curvature and Aberration Changes After Scleral Lens Wear in Keratoconus Patients With and Without Ring Segments.

OBJECTIVE: To evaluate changes in the anterior corneal curvature and aberrometry after scleral contact lens wear in keratoconus (KC) subjects with and without intracorneal ring segments (ICRS). METHODS: Twenty-six subjects diagnosed with keratoconus were selected to participate in the study. Subjects were divided into 2 groups, those with ICRS (KC-ICRS group) and those without ICRS (KC group). Subjects were instructed to wear 16.5-mm scleral lenses for 8 hours. Topographic and aberrometric parameters were evaluated before lens wear and immediately after lens removal. Anterior corneal curvature was evaluated at corneal diameters of 2, 4, 6, and 8 mm, and corneal aberrations were measured at 4-, 6-, and 8-mm pupil diameters. RESULTS: The mean age of subjects was 36.95±8.95 years. In KC group, there was a statistically significant flattening of the central corneal curvature, from 6.98 to 7.09 mm (P<0.05). No changes were found in the central corneal curvature in the KC-ICRS group. The KC group showed anterior corneal curvature flattening, mainly in the nasal quadrant. The KC-ICRS group showed flattening primarily in the inferior hemisphere. In the KC group, spherical aberration for 6-mm pupil increased significantly. In the KC-ICRS group, changes in aberrations were significant for high-order root mean square at 4- and 6-mm pupil diameters (P<0.05), for oblique astigmatism for 4 mm and 6 mm, and for vertical coma for 4-mm pupil (P<0.05). CONCLUSION: Short-term scleral lens wear showed flattening of the anterior corneal surface in all subjects. In the KC group, the flattening was more pronounced in the nasal quadrant while changes were more pronounced inferiorly in KC-ICRS group.

Temporal distribution and genetic variants in influenza A(H1N1)pdm09 virus circulating in Mexico, seasons 2012 and 2013.

The 2012 and 2013 annual influenza epidemics in Mexico were characterized by presenting different seasonal patterns. In 2012 the A(H1N1)pdm09 virus caused a high incidence of influenza infections after a two-year period of low circulation; whereas the 2013 epidemic presented circulation of the A(H1N1)pdm09 virus throughout the year. We have characterized the molecular composition of the Hemagglutinin (HA) and Neuraminidase (NA) genes of the A(H1N1)pdm09 virus from both epidemic seasons, emphasizing the genetic characteristics of viruses isolated from Yucatan in Southern Mexico. The molecular analysis of viruses from the 2012 revealed that all viruses from Mexico were predominantly grouped in clade 7. Strikingly, the molecular characterization of viruses from 2013 revealed that viruses circulating in Yucatan were genetically different to viruses from other regions of Mexico. In fact, we identified the occurrence of two genetic variants containing relevant mutations at both the HA and NA surface antigens. There was a difference on the temporal circulation of each genetic variant, viruses containing the mutations HA-A141T / NA-N341S were detected in May, June and July; whereas viruses containing the mutations HA-S162I / NA-L206S circulated in August and September. We discuss the significance of these novel genetic changes.

Epidemiología de la infección oral por VPH en sujetos jóvenes sanos / Epidemiology of oral HPV infection in young healthy individuals

Resumen Introducción: La infección por VPH es la infección viral de transmisión sexual más frecuente, y se encuentra asociada a diversas neoplasias. Objetivo: Describir la epidemiología, historia natural y factores de riesgo asociados a la infección oral por VPH en adultos jóvenes asintomáticos. Métodos: Se realizó un estudio prospectivo de corte longitudinal, que incluyó sujetos sin patología oral, a los que se les tomó una muestra de la mucosa bucal. A todos los sujetos con resultados positivos se les realizó un nuevo muestreo seis meses después. Se identificó la presencia del virus por RPC; los datos demográficos y de conducta sexual fueron obtenidos con una encuesta que respondieron sin intervención del investigador. Resultados: Se recolectaron 102 muestras de sujetos de 18-26 años de edad, 60 (58,8%) correspondieron al sexo masculino. La prevalencia del virus fue de 6,9%; todos los sujetos positivos tenían vida sexual. Las relaciones sexuales entre personas del mismo sexo fue la única variable asociada a la presencia del virus (p < 0,05). A los seis meses, todos los sujetos habían eliminado al virus. Conclusión: La infección oral por VPH es transitoria y está asociada a relaciones sexuales entre personas del mismo sexo, principalmente mujeres que tienen sexo con mujeres.

Background: HPV infection is the most common sexually transmitted viral infection, and is associated with several neoplasms. Aim: To describe the epidemiology, natural history and risk factors associated with oral HPV infection in asymptomatic young adults. Methods: A prospective and longitudinal study was conducted, including subjects without oral pathology, who were sampled from the oral mucosa. All subjects with positive results were re-sampled 6 months later. The presence of HPV was identified by PCR. Demographic and sexual behavior data were obtained with a survey that was responded without the intervention of the researcher. Results: 102 samples were collected from subject of 18-26 years old, 60 (58.8%) were male. The prevalence of the virus was 6.9%; all positive subjects had active sexual life. Same-gender relationships were the only variable associated with the presence of the virus (p < 0.05). At six months all subjects had eliminated the virus. Conclusion: Oral HPV infection is transient and is associated to same-gender relationships, mainly women who have sex with women.