Intracapsular accommodation mechanism in terms of lens curvature gradient.

The intracapsular accommodation mechanism (IAM) may be understood as an increase in the lens equivalent refractive index as the eye accommodates. Our goal was to evaluate the existence of an IAM by analysing observed changes in the inner curvature gradient of the lens. To this end, we fitted a gradient index and curvature lens model to published experimental data on external and nucleus geometry changes during accommodation. For each case analysed, we computed the refractive power and equivalent index for each accommodative state using a ray transfer matrix. All data sets showed an increase in the effective refractive index, indicating a positive IAM, which was stronger for older lenses. These results suggest a strong dependence of the lens equivalent refractive index on the inner curvature gradient.

The influence of variations in ocular biometric and optical parameters on differences in refractive error.

PURPOSE: To present a paraxial method to estimate the influence of variations in ocular biometry on changes in refractive error (S) at a population level and apply this method to literature data. METHODS: Error propagation was applied to two methods of eye modelling, referred to as the simple method and the matrix method. The simple method defines S as the difference between the axial power and the whole-eye power, while the matrix method uses more accurate ray transfer matrices. These methods were applied to literature data, containing the mean ocular biometry data from the SyntEyes model, as well as populations of premature infants with or without retinopathy, full-term infants, school children and healthy and diabetic adults. RESULTS: Applying these equations to 1000 SyntEyes showed that changes in axial length provided the most important contribution to the variations in refractive error (57%-64%), followed by lens power/gradient index power (16%-31%) and the anterior corneal radius of curvature (10%-13%). All other components of the eye contributed <4%. For young children, the largest contributions were made by variations in axial length, lens and corneal power for the simple method (67%, 23% and 8%, respectively) and by variations in axial length, gradient lens power and anterior corneal curvature for the matrix method (55%, 21% and 14%, respectively). During myopisation, the influence of variations in axial length increased from 54.5% to 73.4%, while changes in corneal power decreased from 9.82% to 6.32%. Similarly, for the other data sets, the largest contribution was related to axial length. CONCLUSIONS: This analysis confirms that the changes in ocular refraction were mostly associated with variations in axial length, lens and corneal power. The relative contributions of the latter two varied, depending on the particular population.

Antiviral resistance in influenza viruses.

Influenza represents a major threat to public health worldwide, vaccination is the most effective strategy to reduce infections. However, achieving adequate vaccination rates is challenging and vaccination does not always guarantee complete protection. For this reason, antiviral drugs represent an important measure to reduce the risk of complications in high-risk patients. However, influenza viruses have a high mutation rate which causes genetic, biochemical, and pathogenic changes that represent a challenge both for the constant replacement of vaccines and reduce their susceptibility to antiviral action. This makes it necessary to determine the mechanisms of these processes, as well as their epidemiological surveillance and, of course, the development of new therapeutic options that may be available in the event of a widespread resistance phenomenon. In this article we review some of the relevant aspects of the replicative cycle of influenza viruses, the antivirals currently used, as well as their resistance mechanisms.

Use of fine capillaries for cryopreservation of Caenorhabditis elegans by vitrification.

Caenorhabditis elegans is an exceptional model organism. More than twenty thousand different strains have been developed, increasing knowledge on countless topics. However, the traditional method to cryopreserve this nematode, based on slow freezing, usually reaches recovery rates of around 35% for the L1 and L2 larval stages. Here, we propose two alternative methods to cryopreserve this nematode based on vitrification that are applicable in common laboratories and allow the selective individual cryopreservation of this organism. These new methods require ultra-high warming rates, which are achieved by employing very thin capillaries as the nematode container, and a very low final concentration of cryoprotectants, which, as compared to slow freezing, reduce toxicity damage. The recovery rate was 98.5% for larvae (L1 - L4) and 84.3% for adults. Given these results, our procedures offer an alternative to cryopreserve this nematode (larvae and adults) with higher recovery rates, avoiding expensive requirements. Indeed, it only needed a container with liquid nitrogen and a warming bath for water at 37 °C. The high performance of this approach has been revealed by preserving the long-term memory and, probably, the connectome of this nematode.

Sildenafil prevents right ventricular hypertrophy and improves heart rate variability in rats with pulmonary hypertension secondary to experimental diabetes.

Chronic treatment with sildenafil (SILD) is an effective protector on the development of cardiovascular complications of pulmonary hypertension (PH) and diabetes. However, to date, no studies have evaluated the effect of SILD on cardiopulmonary pathophysiology during PH secondary to type 1 diabetes. AIM: The present study aimed to evaluate the beneficial effects of chronic SILD treatment on pulmonary arterial pressure, right ventricular hypertrophy (RVH) and cardiac autonomic dysfunction in rats with PH secondary to diabetes. METODOLOGY: Male Sprague Dawley rats were randomly distributed into the control group (saline), diabetic group (60 mg/kg with streptozotocin), SILD-treated control group (20 mg/kg) and SILD-treated diabetic group. RESULTS: After 8 weeks the type 1 diabetic animals presented PH, endothelial dysfunction of the pulmonary arteries, electrocardiographic alterations, RVH and overexpression of phosphodiesterase type 5 in the heart. In type 1 diabetic animals, SILD treatment prevented the development of PH, endothelial dysfunction and RVH. SILD treatment also prevented alterations in the corrected QT period and heart rate variability and prevented overexpression of phosphodiesterase type 5. CONCLUSION: Our results indicate for the first time that SILD treatment prevents pulmonary arterial endothelial dysfunction, pulmonary hypertension, right ventricular hypertrophy and improves heart rate variability in type 1 diabetic rats.

Chloroquine Induces ROS-mediated Macrophage Migration Inhibitory Factor Secretion and Epithelial to Mesenchymal Transition in ER-positive Breast Cancer Cell Lines.

Breast cancer (BC) is the leading cause of cancer-related death in women in the world. Since tumor cells employ autophagy as a survival pathway, it has been proposed that autophagy inhibition could be beneficial for cancer treatment. There are several onging clinical trials where autophagy is being inhibited (using chloroquine, CQ or hydroxychloroquine, HCQ) along with chemotherapy with promising results. However, there is also in vitro evidence in which autophagy inhibition can induce epithelial to mesenchymal transition (EMT) in cancer cells, indicating that, at least in some cases, this strategy could be detrimental for cancer patients. In this study, we found that the genetic inhibition of autophagy primed cells for EMT by inducing a decrease in E-cadherin protein levels, while CQ treatment decreased E-cadherin levels, induced morphological changes related to EMT, increased EMT-related transcription factor (EMT-TF) expression and migration in estrogen receptor positive (ER +) BC cell lines. Importantly, CQ treatment increased intracellular reactive oxygen species (ROS) which induced the secretion of macrophage migration inhibitory factor (MIF), a pro-inflammatory cytokine related to malignancy. Both ROS production and MIF secretion were responsible for the mesenchymal morphology and increased migratory capacity induced by CQ. Our results indicate that CQ treatment increased malignancy by inducing ROS production, MIF secretion and EMT and suggest that autophagy inhibition in ER + BC patients might have detrimental effects. Our data indicates that a careful selection of patients should be performed in order to determine who will benefit the most from autophagy inhibition with available pharmacological agents for the treatment of breast cancer.

Effect of an Intensive Weight-Loss Lifestyle Intervention on Kidney Function: A Randomized Controlled Trial.

INTRODUCTION: Large randomized trials testing the effect of a multifactorial weight-loss lifestyle intervention including Mediterranean diet (MedDiet) on renal function are lacking. Here, we evaluated the 1-year efficacy of an intensive weight-loss intervention with an energy-reduced MedDiet (erMedDiet) plus increased physical activity (PA) on renal function. METHODS: Randomized controlled "PREvención con DIeta MEDiterránea-Plus" (PREDIMED-Plus) trial is conducted in 23 Spanish centers comprising 208 primary care clinics. Overweight/obese (n = 6,719) adults aged 55-75 years with metabolic syndrome were randomly assigned (1:1) to an intensive weight-loss lifestyle intervention with an erMedDiet, PA promotion, and behavioral support (intervention) or usual-care advice to adhere to an energy-unrestricted MedDiet (control) between September 2013 and December 2016. The primary outcome was 1-year change in estimated glomerular filtration rate (eGFR). Secondary outcomes were changes in urine albumin-to-creatinine ratio (UACR), incidence of moderately/severely impaired eGFR (<60 mL/min/1.73 m2) and micro- to macroalbuminuria (UACR ≥30 mg/g), and reversion of moderately (45 to <60 mL/min/1.73 m2) to mildly impaired GFR (60 to <90 mL/min/1.73 m2) or micro- to macroalbuminuria. RESULTS: After 1 year, eGFR declined by 0.66 and 1.25 mL/min/1.73 m2 in the intervention and control groups, respectively (mean difference, 0.58 mL/min/1.73 m2; 95% CI: 0.15-1.02). There were no between-group differences in mean UACR or micro- to macroalbuminuria changes. Moderately/severely impaired eGFR incidence and reversion of moderately to mildly impaired GFR were 40% lower (HR 0.60; 0.44-0.82) and 92% higher (HR 1.92; 1.35-2.73), respectively, in the intervention group. CONCLUSIONS: The PREDIMED-Plus lifestyle intervention approach may preserve renal function and delay CKD progression in overweight/obese adults.

An Update on Phytochemicals and Pharmacological Activities of the Genus Persicaria and Polygonum.

The discovery of new pharmaceutical identities, particularly anti-infective agents, represents an urgent need due to the increase in immunocompromised patients and the ineffectiveness/toxicity of the drugs currently used. The scientific community has recognized in the last decades the importance of the plant kingdom as a huge source of novel molecules which could act against different type of infections or illness. However, the great diversity of plant species makes it difficult to select them with probabilities of success, adding to the fact that existing information is difficult to find, it is atomized or disordered. Persicaria and Polygonum constitute two of the main representatives of the Polygonaceae family, which have been extensively used in traditional medicine worldwide. Important and structurally diverse bioactive compounds have been isolated from these genera of wild plants; among them, sesquiterpenes and flavonoids should be remarked. In this article, we firstly mention all the species reported with pharmacological use and their geographical distribution. Moreover, a number of tables which summarize an update detailing the type of natural product (extract or isolated compound), applied doses, displayed bioassays and the results obtained for the main bioactivities of these genera cited in the literature during the past 40 years. Antimicrobial, antioxidant, analgesic and anti-inflammatory, antinociceptive, anticancer, antiviral, antiparasitic, anti-diabetic, antipyretic, hepatoprotective, diuretic, gastroprotective and neuropharmacological activities were explored and reviewed in this work, concluding that both genera could be the source for upcoming molecules to treat different human diseases.

SARS-CoV-2: basic concepts, origin and treatment advances.

The first cases of COVID-19, caused by the virus called SARS-CoV-2, were recorded in Wuhan, China, in December 2019; however, its transmission ability caused for the infection to be practically present throughout the world six months later. The origin of the virus appears to be zoonotic; it has been proposed that it comes from a bat and that it may have had an intermediate host that led to its introduction in the human population. SARS-CoV-2 is an enveloped virus, with a positive single-stranded RNA genome, and it binds to the angiotensin-converting enzyme, present in susceptible cells, to infect the human respiratory system. Although other coronaviruses have been previously known, they have not had the same impact, and, therefore, research on pharmacological treatments is not sufficiently developed to face the current challenge. Almost since the beginning of the epidemic, several molecules have been proposed for the treatment of infection; however, there is not yet a drug available with sufficient effectiveness for treatment. This review describes SARS-CoV-2 main characteristics, its replicative cycle, its possible origin and some advances in the development of antiviral treatments.

Los primeros casos de COVID-19, causada por el virus denominado SARS-CoV-2, se registraron en Wuhan, China, en diciembre de 2019; sin embargo, su capacidad de transmisión ocasionó que seis meses después la infección prácticamente estuviera presente en todo el mundo. El origen del virus parece ser zoonótico; se propone que proviene del murciélago y podría haber tenido un hospedero intermediario que llevó a su introducción en la población humana. SARS-CoV-2 es un virus envuelto, con genoma de ARN de cadena sencilla en sentido positivo y se ancla a la enzima convertidora de angiotensina, presente en las células susceptibles para infectar el sistema respiratorio de los humanos. Aunque previamente se han conocido otros coronavirus, no han tenido el mismo impacto, por lo que la investigación en tratamientos farmacológicos no tiene el desarrollo suficiente para afrontar el reto actual. Casi desde el comienzo de la epidemia se han propuesto moléculas para el tratamiento de la infección, sin embargo, aún no se cuenta con un fármaco con suficiente efectividad terapéutica. En esta revisión se describen las características principales de SARS-CoV-2, su ciclo replicativo, su posible origen y algunos avances en el desarrollo de tratamientos antivirales.

Alteration of Fermentative Metabolism Enhances Mucor circinelloides Virulence.

The fungus Mucor circinelloides undergoes yeast-mold dimorphism, a developmental process associated with its capability as a human opportunistic pathogen. Dimorphism is strongly influenced by carbon metabolism, and hence the type of metabolism likely affects fungus virulence. We investigated the role of ethanol metabolism in M. circinelloides virulence. A mutant in the adh1 gene (M5 strain) exhibited higher virulence than the wild-type (R7B) and the complemented (M5/pEUKA-adh1+) strains, which were nonvirulent when tested in a mouse infection model. Cell-free culture supernatant (SS) from the M5 mutant showed increased toxic effect on nematodes compared to that from R7B and M5/pEUKA-adh1+ strains. The concentration of acetaldehyde excreted by strain M5 in the SS was higher than that from R7B, which correlated with the acute toxic effect on nematodes. Remarkably, strain M5 showed higher resistance to H2O2, resistance to phagocytosis, and invasiveness in mouse tissues and induced an enhanced systemic inflammatory response compared with R7B. The mice infected with strain M5 under disulfiram treatment exhibited only half the life expectancy of those infected with M5 alone, suggesting that acetaldehyde produced by M. circinelloides contributes to the toxic effect in mice. These results demonstrate that the failure in fermentative metabolism, in the step of the production of ethanol in M. circinelloides, contributes to its virulence, inducing a more severe tissue burden and inflammatory response in mice as a consequence of acetaldehyde overproduction.

Pretreatment HIV drug resistance spread within transmission clusters in Mexico City.

BACKGROUND: Pretreatment HIV drug resistance (HIVDR) to NNRTIs has consistently increased in Mexico City during the last decade. OBJECTIVES: To infer the HIV genetic transmission network in Mexico City to describe the dynamics of the local HIV epidemic and spread of HIVDR. PATIENTS AND METHODS: HIV pol sequences were obtained by next-generation sequencing from 2447 individuals before initiation of ART at the largest HIV clinic in Mexico City (April 2016 to June 2018). Pretreatment HIVDR was estimated using the Stanford algorithm at a Sanger-like threshold (≥20%). Genetic networks were inferred with HIV-TRACE, establishing putative transmission links with genetic distances <1.5%. We examined demographic associations among linked individuals with shared drug resistance mutations (DRMs) using a ≥ 2% threshold to include low-frequency variants. RESULTS: Pretreatment HIVDR reached 14.8% (95% CI 13.4%-16.2%) in the cohort overall and 9.6% (8.5%-10.8%) to NNRTIs. Putative links with at least one other sequence were found for 963/2447 (39%) sequences, forming 326 clusters (2-20 individuals). The inferred network was assortative by age and municipality (P < 0.001). Clustering individuals were younger [adjusted OR (aOR) per year = 0.96, 95% CI 0.95-0.97, P < 0.001] and less likely to include women (aOR = 0.46, 95% CI 0.28-0.75, P = 0.002). Among clustering individuals, 175/963 (18%) shared DRMs (involving 66 clusters), of which 66/175 (38%) shared K103N/S (24 clusters). Eight municipalities (out of 75) harboured 65% of persons sharing DRMs. Among all persons sharing DRMs, those sharing K103N were younger (aOR = 0.93, 95% CI 0.88-0.98, P = 0.003). CONCLUSIONS: Our analyses suggest age- and geographically associated transmission of DRMs within the HIV genetic network in Mexico City, warranting continuous monitoring and focused interventions.

Comparing cytology, colposcopy and human papillomavirus cervical intraepithelial lesion screening methods in women with systemic lupus erythematosus.

OBJECTIVE: To compare the performance of cytology, colposcopy and human papillomavirus in detecting cervical intraepithelial lesions in women with systemic lupus erythematosus. METHODS: Papanicolaou smears (normal, low-grade squamous intraepithelial lesion, high grade squamous intraepithelial lesion), colposcopy findings, human papillomavirus and co-testing (Papanicolaou smear + human papillomavirus) were compared with cervical biopsy findings in women with systemic lupus erythematosus. Sensitivity, specificity, false-positive and false-negative rates, positive and negative predictive values and likelihood ratios of cytologic smears, colposcopy findings, human papillomavirus and co-testing were determined. RESULTS: Cytology and colposcopy were performed in 170 systemic lupus erythematosus women (mean age and disease duration of 43.7±12.1 years and 9.7±5.3 years, respectively) and biopsies were performed in 55 patients (38.2% normal, 60.0% low-grade squamous intraepithelial lesion and 1.8% high grade squamous intraepithelial lesion). The sensitivity, specificity, positive predictive value and negative predictive value of cytology were 14.7% (95% confidence interval 5.5-31.8%), 95.2% (95% confidence interval 74.1-99.7%), 83.3% (95% confidence interval 36.4-99.1%) and 40.8% (95% confidence interval 27.3-55.7%), respectively. The sensitivity, specificity and positive predictive value of colposcopy findings were 100.0% (95% confidence interval 87.3-100.0%), 0.0% (95% confidence interval 0.0-19.2%) and 61.8% (95% confidence interval 47.7-74.2%), respectively. The sensitivity and specificity of co-testing were 8.0% (95% confidence interval 1.3-27.5%) and 100.0% (95% confidence interval 71.6-100.0%). The positive predictive value and negative predictive values were 100.0% (95% confidence interval 19.7-100.0%) and 36.1% (95% confidence interval 33.5-38.8%), respectively. CONCLUSIONS: In systemic lupus erythematosus patients, colposcopy impressions were more sensitive than cytology and co-testing. However, cytology and co-testing were the most specific tests. The results should be interpreted with caution due to the small sample size.

MOLECULAR MARKERS FOR THE DIAGNOSIS OF HIGH-RISK HUMAN PAPILLOMAVIRUS INFECTION AND TRIAGE OF HUMAN PAPILLOMAVIRUS-POSITIVE WOMEN.

Infection with high-risk human papillomavirus (HPV) increases the likelihood of developing cervical cancer (CC). A plethora of cellular processes is required to produce pre-malignant lesions, which in turn may become malignant if left untreated. Those changes are induced by viral oncoproteins, which represent an ideal target to identify the viral presence, or by some particularities of the host that ultimately promote the establishment of CC. This article describes the different methods used for HPV detection and quantification, as well as the current trend of secondary screening approaches to detect premalignant lesions and CC. In addition, we analyzed validated biomarkers and those under clinical investigation for the classification (triage) of women at risk of developing CC after an initial positive HPV test and that could be used as prognostic biomarkers for CC. The use of molecular biomarkers, together with the detection of HPV DNA sequences, provides a high impact diagnostic and prognostic tool in the detection of patients at increased risk of developing CC and also may guide their clinical management. In addition, some of those biomarkers could represent pharmacological targets for the future design of therapeutic approaches to CC treatment.

Taraxacum officinale and Urtica dioica extracts inhibit dengue virus serotype 2 replication in vitro.

BACKGROUND: Urtica dioica, Taraxacum officinale, Calea integrifolia and Caesalpinia pulcherrima are widely used all over the world for treatment of different illnesses. In Mexico, these plants are traditionally used to alleviate or counteract rheumatism and inflammatory muscle diseases. In the present study we evaluated the activity of aqueous and methanolic extracts of these four plants, on the replication of dengue virus serotype 2 (DENV2). METHODS: Extraction process was carried out in a Soxtherm® system at 60, 85 and 120 °C; a chemical fractionation in silica gel chromatography was performed and compounds present in the active fractions were identified by HPLC-DAD-ESI/MSn. The cytotoxic concentration and the inhibitory effect of extracts or fractions on the DENV2 replication were analyzed in the BHK-21 cell line (plaque forming assay). The half maximal inhibitory concentration (IC50) and the selectivity index (SI) were calculated for the extracts and fractions. RESULTS: The methanolic extracts at 60 °C of T. officinale and U. dioica showed the higher inhibitory effects on DENV2 replication. After the chemical fractionation, the higher activity fraction was found for U. dioica and T. officinale, presenting IC50 values of 165.7 ± 3.85 and 126.1 ± 2.80 µg/ml, respectively; SI values were 5.59 and 6.01 for each fraction. The compounds present in T. officinale, were luteolin and caffeoylquinic acids derivatives and quercertin diclycosides. The compounds in the active fraction of U. dioica, were, chlorogenic acid, quercertin derivatives and flavonol glycosides (quercetin and kaempferol). CONCLUSIONS: Two fractions from U. dioica and T. officinale methanolic extracts with anti-dengue activity were found. The compounds present in both fractions were identified, several recognized molecules have demonstrated activity against other viral species. Subsequent biological analysis of the molecules, alone or in combination, contained in the extracts will be carried out to develop therapeutics against DENV2.

Human papillomavirus infections in Mexican women with normal cytology, precancerous lesions, and cervical cancer: type-specific prevalence and HPV coinfections.

The prevalence and genotype distribution of human papillomavirus (HPV) provides the basis for designing HPV prevention programs. The prevalence rates of type-specific HPV and coinfections in samples of Mexican women were investigated in 822 women aged 18-87 years. HPV detection was performed using a Linear Array™ genotyping test. HPV infection was found in 12.4% of controls, 46.3% of those with cervical intraepithelial neoplasia 1, and 100% of those with cervical intraepithelial neoplasia 3 or cervical cancer. HPV 16 was the most prevalent type in all diagnosis groups. The HPV types most frequently found in cervical cancers were 16, 18, 45, 52, 58, and 39; HPV types 16, 62, 51, 84, 18, 53, and CP6108 were the most prevalent in control women. Considering HPV-positive samples only, coinfections occurred most often in controls (63%) and were less frequent in those with cervical cancer (26%). The most frequent viral types in coinfections with HPV 16 in control women were HPV 62, 51, and 84; in women with cervical cancers, HPV 18, 39, and 70 were most common. In conclusion, in addition to HPV types 16 and 18, types 45, 39, 58, 52, and 71 were found in cervical cancers in Mexican women (78%); among them, only 65% were attributable to HPV types 16 and 18. Therefore, it is necessary to consider these viral types in the design of new vaccines, and to determine whether certain HPV types coinfecting with HPV 16 in precursor lesions determine tumor progression or regression.

Human papillomavirus genotyping by Linear Array and Next-Generation Sequencing in cervical samples from Western Mexico.

BACKGROUND: The Linear Array® (LA) genotyping test is one of the most used methodologies for Human papillomavirus (HPV) genotyping, in that it is able to detect 37 HPV genotypes and co-infections in the same sample. However, the assay is limited to a restricted number of HPV, and sequence variations in the detection region of the HPV probes could give false negatives results. Recently, 454 Next-Generation sequencing (NGS) technology has been efficiently used also for HPV genotyping; this methodology is based on massive sequencing of HPV fragments and is expected to be highly specific and sensitive. In this work, we studied HPV prevalence in cervixes of women in Western Mexico by LA and confirmed the genotypes found by NGS. METHODS: Two hundred thirty three cervical samples from women Without cervical lesions (WCL, n = 48), with Cervical intraepithelial neoplasia grade 1 (CIN I, n = 98), or with Cervical cancer (CC, n = 87) were recruited, DNA was extracted, and HPV positivity was determined by PCR amplification using PGMY09/11 primers. All HPV- positive samples were genotyped individually by LA. Additionally, pools of amplicons from the PGMY-PCR products were sequenced using 454 NGS technology. Results obtained by NGS were compared with those of LA for each group of samples. RESULTS: We identified 35 HPV genotypes, among which 30 were identified by both technologies; in addition, the HPV genotypes 32, 44, 74, 102 and 114 were detected by NGS. These latter genotypes, to our knowledge, have not been previously reported in Mexican population. Furthermore, we found that LA did not detect, in some diagnosis groups, certain HPV genotypes included in the test, such as 6, 11, 16, 26, 35, 51, 58, 68, 73, and 89, which indicates possible variations at the species level. CONCLUSIONS: There are HPV genotypes in Mexican population that cannot be detected by LA, which is, at present, the most complete commercial genotyping test. More studies are necessary to determine the impact of HPV-44, 74, 102 and 114 on the risk of developing CC. A greater number of samples must be analyzed by NGS for the most accurate determination of Mexican HPV variants.

Interferon lambda inhibits dengue virus replication in epithelial cells.

BACKGROUND: In viral disease, infection is controlled at the cellular level by type I interferon (IFN-I), but dengue virus (DENV) has the ability to inhibit this response. Type III interferon, also known as lambda IFN (IFN-III or IFN-λ), is a complementary pathway to the antiviral response by IFN-I. This work analyzed the IFN-λ (IFN-III) mediated antiviral response against DENV serotype 2 (DENV-2) infection. METHODS: Dengue fever patients were sampled to determine their IFN-λ levels by ELISA. To study the IFN-λ response during DENV infection we selected the epithelial cell line C33-A, and we demonstrated that it is permissive to DENV-2 infection. The effect of IFN-λ on virus replication was determined in these cells, in parallel to the expression of IFN-stimulated genes (ISGs), and Suppressor of Cytokine Signaling (SOCS), genes measured by RT-qPCR. RESULTS: We found increased (~1.8 times) serological IFN-λ in dengue fever patients compared to healthy blood donors. IFN-λ inhibited DENV-2 replication in a dose-dependent manner in vitro. The reduction of viral titer corresponded with increased ISG mRNA levels (MX1 and OAS1), with the highest inhibition occurring at ISG's peak expression. Presence of IFN-negative regulators, SOCS1 and SOCS3, during DENV-2 infection was associated with reduced IFN-λ1 expression. CONCLUSIONS: Evidence described here suggests that IFN-λ is a good candidate inhibitor of viral replication in dengue infection. Mechanisms for the cellular and organismal interplay between DENV and IFN- λ need to be further studied as they could provide insights into strategies to treat this disease. Furthermore, we report a novel epithelial model to study dengue infection in vitro.

Detection of hepatitis C virus RNA in saliva of patients with active infection not associated with periodontal or liver disease severity.

BACKGROUND: Hepatitis C virus (HCV) is mainly transmitted by parenteral route, being blood transfusion and intravenous drug use the most frequent risk factors. However, it has been suggested that there are other routes of transmission. There are several studies where HCV RNA has been detected in saliva of patients infected with HCV, and epidemiological studies have proposed the dental treatments as possible risk factors for HCV transmission. The purpose of this study was to detect the presence of HCV RNA in saliva of patients with active infection and associating with periodontal or liver disease. METHODS: Patients with quantifiable HCV-RNA in serum were enrolled in the study. Periodontal disease was assessed using the modified gingival index (MGI). Presence of dental plaque was assessed with the use of disclosing tablets. Patients were clinically and laboratory evaluated to identify the stage of liver disease, the HCV RNA was determinate in saliva by nested RT-PCR. To determine associations between different parameters univariate and multivariate analysis were used. RESULTS: A total of 45 patients were included. Of these patients, 21 (46.6%) had hepatitis, 23 (51.1%) had cirrhosis and one patient (2.4%) presented hepatocellular carcinoma (HCC). Viral loads in serum ranged from 2.31-6.68 log IU/ml with a mean of 5.46 log IU/ml (95% CI 5.23-5.70). HCV RNA was positive in saliva of 29 patients (64.4%) and was not detected in 16 (35.6%). For univariate analysis three independent variables were associated with the detection of HCV-RNA in saliva: gender, viral load and dental plaque and multivariate analysis only one independent variable viral load >5.17 log IU/mL remained significantly associated with the detection of HCV in saliva (p = 0.0002). A statistical difference was observed when viral load was analyzed, log 5.85 IU/mL (95% CI 5.67-6.02) for patients with HCV in saliva vs. log 4.77 IU/mL (95% CI 4.35-5.19) for patients without HCV in saliva (p = 0.0001). The detection of HCV-RNA in saliva was more frequent in patients with relatively high serum viral loads. CONCLUSION: HCV-RNA in saliva was associated with the level of serum viral load but not with periodontal or liver disease severity.

Detection of Sialic Acid to Differentiate Cervical Cancer Cell Lines Using a Sambucus nigra Lectin Biosensor.

Pap smear screening is a widespread technique used to detect premalignant lesions of cervical cancer (CC); however, it lacks sensitivity, leading to identifying biomarkers that improve early diagnosis sensitivity. A characteristic of cancer is the aberrant sialylation that involves the abnormal expression of α2,6 sialic acid, a specific carbohydrate linked to glycoproteins and glycolipids on the cell surface, which has been reported in premalignant CC lesions. This work aimed to develop a method to differentiate CC cell lines and primary fibroblasts using a novel lectin-based biosensor to detect α2,6 sialic acid based on attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and chemometric. The biosensor was developed by conjugating gold nanoparticles (AuNPs) with 5 µg of Sambucus nigra (SNA) lectin as the biorecognition element. Sialic acid detection was associated with the signal amplification in the 1500-1350 cm-1 region observed by the surface-enhanced infrared absorption spectroscopy (SEIRA) effect from ATR-FTIR results. This region was further analyzed for the clustering of samples by applying principal component analysis (PCA) and confidence ellipses at a 95% interval. This work demonstrates the feasibility of employing SNA biosensors to discriminate between tumoral and non-tumoral cells, that have the potential for the early detection of premalignant lesions of CC.