Neutralization of Different Variants of SARS-CoV-2 by a F(ab')2 Preparation from Sera of Horses Immunized with the Viral Receptor Binding Domain.

The Receptor Binding Domain (RBD) of SARS-CoV-2, the virus responsible for the COVID-19 pandemic, is the functional region of the viral Spike protein (S), which is involved in cell attachment to target cells. The virus has accumulated progressively mutations in its genome, particularly in the RBD region, many of them associated with immune evasion of the host neutralizing antibodies. Some of the viral lineages derived from this evolution have been classified as Variant of Interest (VOI) or Concern (VOC). The neutralizing capacity of a F(ab')2 preparation from sera of horses immunized with viral RBD was evaluated by lytic plaque reduction assay against different SARS-CoV-2 variants. A F(ab')2 preparation of a hyperimmune serum after nine immunizations with RBD exhibited a high titer of neutralizing antibodies against the ancestral-like strain (1/18,528). A reduction in the titer of the F(ab')2 preparation was observed against the different variants tested compared to the neutralizing activity against the ancestral-like strain. The highest reduction in the neutralization titer was observed for the Omicron VOC (4.7-fold), followed by the Mu VOI (2.6), Delta VOC (1.8-fold), and Gamma VOC (1.5). Even if a progressive reduction in the neutralizing antibodies titer against the different variants evaluated was observed, the serum still exhibited a neutralizing titer against the Mu VOI and the Omicron VOC (1/7113 and 1/3918, respectively), the evaluated strains most resistant to neutralization. Therefore, the preparation retained neutralizing activity against all the strains tested.

Hepatitis B eradication: vaccine as a key player.

OBJECTIVE: Despite the availability of a highly effective and safe vaccine against hepatitis B virus (HBV) infection for 40 years, still almost 300 million persons are estimated to be chronically infected by this virus worldwide. The World Health Organization (WHO) has proposed a plan for hepatitis elimination by 2030. However, several factors, such as the reduction and limitation in vaccination campaigns or vaccine hesitancy (VH) in some regions of the World, might have played a role in limiting the worldwide coverage of hepatitis B prophylaxis. This review aims to describe which factors, such as VH, may be hampering the WHO 2030 goal for hepatitis B eradication. METHODS: The review describes the development and characteristics of the HBV vaccine, from the first plasma-derived to the recombinant one. Eventual limitations in its effectiveness and particularly VH were reviewed. RESULTS: The apparent pitfalls of the HBV vaccine, such as long-term effectiveness, vaccine-escape mutants, and adverse effects, were proven not to be a concern for this vaccine. However, VH persists and was even intensified by the COVID-19 pandemic. CONCLUSIONS: Many barriers still exist, such as vaccine availability, lack of awareness of the benefits of HBV vaccination, and VH. HBV VH seems to be eventually overcome in many settings with active education campaigns and information, stressing the importance of developing these strategies to achieve the 2030 goal of the WHO.

The Hepatitis B Virus Genotypes E to J: The Overlooked Genotypes.

Hepatitis B virus (HBV) genotypes E to J are understudied genotypes. Genotype E is found almost exclusively in West Africa. Genotypes F and H are found in America and are rare in other parts of the world. The distribution of genotype G is not completely known. Genotypes I and J are found in Asia and probably result from recombination events with other genotypes. The number of reported sequences for HBV genotypes E to J is small compared to other genotypes, which could impact phylogenetic and pairwise distance analyses. Genotype F is the most divergent of the HBV genotypes and is subdivided into six subgenotypes F1 to F6. Genotype E may be a recent genotype circulating almost exclusively in sub-Saharan Africa. Genotype J is a putative genotype originating from a single Japanese patient. The paucity of data from sub-Saharan Africa and Latin America is due to the under-representation of these regions in clinical and research cohorts. The purpose of this review is to highlight the need for further research on HBV genotypes E to J, which appear to be overlooked genotypes.

Performance of molecular methods for identification of unusual subtypes of hepatitis C virus genotype 2

Introduction: Hepatitis C virus (HCV) displays high genetic variability, with seven genotypes and numerous subtypes. The determination of the viral type has been essential for the selection and timing of antiviral treatment. In Venezuela, HCV genotype 2 is relatively diverse, being particularly prevalent subtype 2j. Objective: To evaluate the performance of methodologies for genotyping HCV, particularly for identification of subtype 2j. Materials and methods: HCV genotype and subtype were determined by reverse hybridization technique (LiPA) and sequencing of the HCV 5'UTR and NS5B regions. Results: A total of 65 samples from HCV-infected patients were analyzed. PCR amplifications of the 5'UTR region exhibited the highest sensitivity (100% vs 91% for LiPA and 77% for NS5B). Genotype determination, taking as reference test NS5B, showed 100% concordance with the other methods, and 67% and 59% for subtypes with 5´NC and LiPA, respectively. NS5B sequencing allowed the identification of subtypes 2j and 2s, which were not detected by the other methods. A specific LiPA pattern was not observed for HCV subtype 2j. Conclusion: Although being the methodology with lowest sensitivity for amplification of HCV RNA, sequencing NS5B region remains a powerful tool for correct discrimination of the different HCV subtypes, which is of epidemiological relevance.

Desempeño de métodos moleculares para la identificación de subtipos poco comunes del virus de la hepatitis C, genotipo 2 / Performance of molecular methods for identification of unusual subtypes of hepatitis C virus genotype 2

Resumen Introducción. El virus de la hepatitis C (HCV) presenta una gran variabilidad genética, con siete genotipos y numerosos subtipos. La determinación del tipo viral ha sido fundamental para la escogencia y la duración del tratamiento antiviral adecuado. En Venezuela, el genotipo 2 del HCV es relativamente diverso, siendo particularmente prevalente el subtipo 2j. Objetivo. Evaluar el desempeño de las metodologías para la determinación del genotipo del HCV, particularmente para la identificación del subtipo 2j. Materiales y métodos. Se determinaron el genotipo y el subtipo del HCV mediante la técnica de hibridación inversa LiPA (Line Probe Assay) y secuenciación de las regiones genómicas 5'NC y NS5B del virus. Resultados. En 65 muestras analizadas, la metodología basada en la amplificación de la región 5'NC mostró mayor sensibilidad (100 %), en comparación con la técnica LiPA (91 %) y la secuenciación de la región NS5B (77 %). La determinación de genotipo, tomando como método de referencia la secuenciación de NS5B, mostró un alto grado de concordancia para la secuenciación de la región 5´NC y la hibridación inversa LiPA, con 100 % en la asignación de genotipos, comparado con 70 % y 66 % para los subtipos, respectivamente. La secuenciación de la región NS5B permitió identificar los subtipos 2j y 2s, los cuales no fueron detectados por las otras metodologías. No se observó un patrón característico para las muestras subtipo 2j en la hibridación inversa LiPA. Conclusión. Aunque es la metodología con menor sensibilidad, la secuenciación de la región NS5B es una herramienta poderosa para la correcta discriminación de los distintos subtipos circulantes del HCV, lo cual reviste importancia epidemiológica.

Abstract Introduction: Hepatitis C virus (HCV) displays high genetic variability, with seven genotypes and numerous subtypes. The determination of the viral type has been essential for the selection and timing of antiviral treatment. In Venezuela, HCV genotype 2 is relatively diverse, being particularly prevalent subtype 2j. Objective: To evaluate the performance of methodologies for genotyping HCV, particularly for identification of subtype 2j. Materials and methods: HCV genotype and subtype were determined by reverse hybridization technique (LiPA) and sequencing of the HCV 5'UTR and NS5B regions. Results: A total of 65 samples from HCV-infected patients were analyzed. PCR amplifications of the 5'UTR region exhibited the highest sensitivity (100% vs 91% for LiPA and 77% for NS5B). Genotype determination, taking as reference test NS5B, showed 100% concordance with the other methods, and 67% and 59% for subtypes with 5´NC and LiPA, respectively. NS5B sequencing allowed the identification of subtypes 2j and 2s, which were not detected by the other methods. A specific LiPA pattern was not observed for HCV subtype 2j. Conclusion: Although being the methodology with lowest sensitivity for amplification of HCV RNA, sequencing NS5B region remains a powerful tool for correct discrimination of the different HCV subtypes, which is of epidemiological relevance.

Mutaciones K130M y V131I del gen X en aislados venezolanos del virus de hepatitis B / K130M and V131L Mutations on the X gene of hepatitis B virus in Venezuelan isolates

Aproximadamente el 50% de los carcinomas hepatocelulares (CHC) en el mundo están etiológicamente asociados con la infección por el virus de hepatitis B (VHB). Se han descrito 10 genotipos del VHB (A-J). En Venezuela y en varios países latinoamericanos predomina el genotipo F. Las mutaciones K130M y V131I presentes en la proteína HBx del VHB han sido asociadas al desarrollo del CHC. El objetivo de este trabajo fue estudiar la variabilidad genética de la proteína HBx del VHB circulante en pacientes venezolanos, con el fin de correlacionar estas mutaciones con los parámetros clínicos y virológicos de la enfermedad. Se analizó la secuencia del gen X del VHB, mediante amplificación por PCR de un fragmento de ese gen, en 45 pacientes infectados (35 crónicos y 10 agudos). Se observó una mayor frecuencia de las mutaciones K130M y V131I en pacientes de 25 o más años y con infección crónica. La presencia de estas mutaciones fue significativamente menor en el subgenotipo F3, comparado con el genotipo C. Estos resultados refuerzan la hipótesis de que el subgenotipo F3, predominante en Venezuela, podría estar asociado a una progresión menos severa de la enfermedad que la descrita para otros subgenotipos americanos, como F1b o F2.

Approximately 50% of the hepatocellular carcinomas (HCC) in the world are etiologically associated to hepatitis B virus (HBV) infection. Ten HBV genotypes (A-J) have been described in Venezuela and in other Latin American countries where the F genotype predominates. The K130M and V131I mutations present in the HBx protein of HBV have been associated with the development of HCC. The aim of this work was to study the genetic variability of HBx protein from HBV circulating in Venezuelan patients, in order to correlate these mutations with clinical and virus factors involved in the disease. The X HBV gene sequence was analyzed by PCR amplification of that gene in 45 infected patients (35 with chronic and 10 with acute stages of hepatitis). A higher frequency K130M and V131I mutations was observed in subjects 25 years of age and older with chronic infection. The presence of these mutations was significantly lower in the F3 subgenotype compared with genotype C. These results support the hypothesis that the F3 subgenotype, predominant in Venezuela, could be associated with a less severe progression of the disease than that described for other American subgenotypes, such as F1b or F2.

[Molecular characterization of hepatitis C virus in patients referred to a reference laboratory of public health, University Hospital "Antonio Patricio de Alcalá", Cumani, Venezuela]. / Caracterización molecular del virus de la Hepatitis C en pacientes remitidos al Laboratorio Regional de Salud Pública del Hospital Universitario "Antonio Patricio de Alcalá", Cumaná, Venezuela.

The World Health Organization estimates that approximately 170 million people are chronically infected with hepatitis C virus (HCV). This study evaluated the presence of antibodies against HCV by two immunoassays. HCV genotypes were analyzed by phylogenetic analysis of viral genome fragments amplified from the 5 'non-coding (5'NC) region and non-structural region 5b (NS5b), using reverse transcription and nested polymerase chain reaction (RT-PCR), in patients referred from January 2010 to February 2013 to the Reference Laboratory of Public Health, University Hospital "Antonio Patricio de Alcalá". The prevalence of anti-HCV antibodies was 0.57% (17/3005), being the group of patients older than 41 years the most affected (0.9%). A total of 16 samples were found positive for HCV RNA by RT-PCR in the 5'NC region (16/17, 94%). Phylogenetic analysis of the 5'NC region allowed to identify the circulation of genotypes 2 and 1, and one genotype 3 and one 4. By phylogenetic analysis of the NS5b region, diverse subtypes of HCV genotype 2 were identified (2a, 2j and 2s). This finding is in accordance with previous studies that indicate that this genotype is relatively diverse in our country.

Caracterización molecular del virus de la Hepatitis C en pacientes remitidos al Laboratorio Regional de Salud Pública del Hospital Universitario “Antonio Patricio de Alcalá”, Cumaná, Venezuela / Molecular characterization of hepatitis C virus in patients referred to a reference laboratory of public health, University Hospital “Antonio Patricio de Alcalá”, Cumaná, Venezuela

La Organización Mundial de la Salud estima que aproximadamente 170 millones de personas están crónicamente infectadas por el virus de la hepatitis C (VHC). En este estudio se evaluó la presencia de anticuerpos contra el VHC en pacientes remitidos durante enero de 2010 a febrero de 2013, al Laboratorio Regional de Salud Pública del Hospital Universitario “Antonio Patricio de Alcalᔠen Cumaná, Venezuela. La presencia de anticuerpos se hizo mediante dos ensayos de ELISA y se determinaron los genotipos circulantes a través de análisis filogenéticos de fragmentos de genoma viral amplificados por la región 5’ no codificante (5’NC) y región no estructural 5b (NS5b) usando la transcripción reversa y reacción en cadena de la polimerasa en dos rondas (RT-PCR). Se encontró una prevalencia de anticuerpos contra el VHC del 0,57 % (17/3005), siendo el grupo etario mayor de 41 años el más afectado (0,9 %). Un total de 16 muestras resultaron positivas para la presencia del ARN viral por RT-PCR en la región 5´NC (16/17, 94 %). El análisis filogenético de la región 5´NC permitió identificar la circulación del genotipo 2 y 1 y de un genotipo 3 y uno 4. Mediante análisis filogenéticos de la región NS5b, se observó la presencia de diversos subtipos dentro del genotipo 2 (2a, 2j y 2s), lo que concuerda con estudios anteriores que muestran que este genotipo es relativamente diverso en nuestro país.

The World Health Organization estimates that approximately 170 million people are chronically infected with hepatitis C virus (HCV). This study evaluated the presence of antibodies against HCV by two immunoassays. HCV genotypes were analyzed by phylogenetic analysis of viral genome fragments amplified from the 5 ‘non-coding (5’NC) region and non-structural region 5b (NS5b), using reverse transcription and nested polymerase chain reaction (RT-PCR), in patients referred from January 2010 to February 2013 to the Reference Laboratory of Public Health, University Hospital “Antonio Patricio de Alcalá”. The prevalence of anti-HCV antibodies was 0.57% (17/3005), being the group of patients older than 41 years the most affected (0.9%). A total of 16 samples were found positive for HCV RNA by RT-PCR in the 5’NC region (16/17, 94%). Phylogenetic analysis of the 5´NC region allowed to identify the circulation of genotypes 2 and 1, and one genotype 3 and one 4. By phylogenetic analysis of the NS5b region, diverse subtypes of HCV genotype 2 were identified (2a, 2j and 2s). This finding is in accordance with previous studies that indicate that this genotype is relatively diverse in our country.

HIV-1 and GBV-C co-infection in Venezuela.

INTRODUCTION: Co-infection with GB virus C (GBV-C) in patients infected with human immunodeficiency virus 1 (HIV-1) has been associated with prolonged survival. The aim of this study was to evaluate the prevalence of GBV-C infection among HIV-1-infected patients in Venezuela, and to determine the effects of the co-infection on the levels of relevant cytokines. METHODOLOGY: Plasma samples were collected from 270 HIV-1-seronegative and 255 HIV-1-seropositive individuals. GBV-C infection was determined by RT-PCR of the NS5 region and genotyped by sequence analysis of the 5´UTR region. HIV-1 strains were characterized by sequence analysis of pol, vif, env, and nef genes. Selected cytokines were evaluated by ELISA. RESULTS: Ninety-seven of 525 (18.5%) plasma samples tested positive for GBV-C RNA. A significantly higher prevalence of GBV-C was found among HIV-1 patients compared to HIV-1-seronegative individuals (67/255, 26% versus 30/270, 11%; p < 0.001). Statistical difference was observed in the viral load between HIV-1+GBV-C+ and HIV-1+GBV-C- (p = 0.014), although no differences in CD4+ cell counts were found between both groups. TNFα concentration was higher in HIV-1+GBV-C- than in HIV-1+GBV-C+ patients (25.9 pg/mL versus 17.3 pg/mL; p = 0.02); RANTES expression levels were more variable in GBV-C co-infected patients and more frequently elevated in HIV-1 mono-infected patients compared to patients co-infected with GBV-C. CONCLUSIONS: The previously observed beneficial effect of co-infection with HIV-1 and GBV-C on disease progression is complex and might be due in part to a change in the cytokine environment. More studies are required to understand the interaction between both viruses.

Human papillomavirus in invasive cervical cancer and cervical intraepithelial neoplasia 2 and 3 in Venezuela: a cross-sectional study.

BACKGROUND: This study investigated the distribution of human papillomavirus (HPV) types in invasive cervical cancer (ICC), cervical intraepithelial neoplasia 2 (CIN2) and cervical intraepithelial neoplasia 3 (CIN3) in Venezuela. METHODS: Paraffin-embedded samples from 329 women from 29 medical centers of the 24 states of Venezuela were analyzed to determine the distribution of HPV types for ICC, CIN2, and CIN3, the prevalence of single and multiple infection, and the association of HPV types with severity of lesion, comparing CIN2 versus CIN3+ (CIN3 and ICC). The samples were analyzed with the polymerase chain reaction (PCR) followed by reverse hybridization for the identification of HPV types. RESULTS: HPV was identified in 95/96 ICC specimens (98.9%), in 142/149 CIN3 (95.3%) and in 78/84 CIN2 samples (92.8%). The most common types for ICC and CIN3 were: HPV16, 18, 31, and 33, and for CIN2 were HPV16, 31, 51, 52, and 18. HPV single infection was found in 82.1% of ICC cases, in 79.4% of CIN2 cases, and in 77.4% of CIN3 cases. HPV16 was identified as a single infection more frequently in women with CIN3+ than in those with CIN2 (68.6% versus 46.7%, P=0.002), and HPV16 or HPV18 types were more prevalent in CIN3+ than in CIN2 (73.4% versus 50%, P=0.0006). CONCLUSION: this is the first study of the distribution of HPV types in ICC, CIN2, and CIN3 conducted throughout the territory of Venezuela. HPV16 and HPV18 were the most frequent HPV types identified in single and multiple infections in both ICC and CIN3 groups, and are associated with severity of lesion. The knowledge of the distribution of HPV types would allow organization of an HPV-DNA-based screening test, and consideration of the implementation of prophylactic vaccination in Venezuela.

Etiology and Viral Genotype in Patients with End-Stage Liver Diseases admitted to a Hepatology Unit in Colombia.

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are the principal risk factor associated to end-stage liver diseases in the world. A study was carried out on end-stage liver disease cases admitted to an important hepatology unit in Medellin, the second largest city in Colombia. From 131 patients recruited in this prospective study, 71% of cases were diagnosed as cirrhosis, 12.2% as HCC, and 16.8% as cirrhosis and HCC. Regarding the risk factors of these patients, alcohol consumption was the most frequent (37.4%), followed by viral etiology (17.6%). Blood and/or hepatic tissue samples from patients with serological markers for HCV or HBV infection were characterized; on the basis of the phylogenetic analysis of HCV 5' UTR and HBV S gene, isolates belonged to HCV/1 and HBV/F3, respectively. These results confirm the presence of strains associated with poor clinical outcome, in patients with liver disease in Colombia; additionally, HBV basal core promoter double mutant was identified in HCC cases. Here we show the first study of cirrhosis and/or HCC in Colombian and HBV and HCV molecular characterization of these patients. Viral aetiology was not the main risk factor in this cohort but alcohol consumption.

Desempeño de estuches comerciales para el diagnóstico serológico de las hepatitis virales B y C en poblaciones yanomami y piaroa del estado Amazonas / Performance of commercial kits for serologic diagnosis of viral hepatitis B and C in yanomami and piaroa populations from Amazonas State

Los virus de hepatitis son una causa importante de morbilidad y mortalidad en la cuenca amazónica. El objetivo de este estudio fue evaluar el desempeño de estuches serológicos para la determinación de marcadores de VHB y VHC en población indígena. Se determinó la presencia de anti-HBc, agsHB, anti-VHC y de genomas virales en sueros de individuos piaroa y yanomami. Más de 50% de las muestras reactivas por un inmunoensayo comercial no resultaron positivas al usar otros estuches. El marcador serológico para el cual se observó una mayor concordancia entre los estuches comerciales fue el anti-HBc, posiblemente porque se trata de un ensayo de inhibición. La concordancia entre los ensayos para agsHB con la positividad de la PCR fue de pobre a moderada, coincidiendo sólo dos de los ensayos con los resultados de la PCR. No existió concordancia entre los distintos ensayos inmunoezimáticos, ni con la presencia del ARN viral para VHC. Las discrepancias inesperadas entre distintos estuches comerciales pudieran deberse a características inherentes a estas poblaciones, tales como múltiples coinfecciones, en especial parasitarias. Estos factores pudiesen estar afectando la especificidad de los estuches diagnósticos, situación observada con menor frecuencia en otras poblaciones venezolanas. Estos estudios refuerzan la importancia de la validación de pruebas serológicas en estas poblaciones, con ensayos confirmatorios y moleculares.

Hepatitis viruses are an important morbility and mortality cause in the Amazon basin. The goal of this study was to evaluate the performance of commercial serologic kits for determination of HVB and HVC markers in indigenous populations. Presence of anti-HBc, HBags, anti-HVC and viral genomes was determined in sera from piaroa and yanomami individuals. Over 50% of the samples reactive with one of the commercial kits were not positive when using other kits. The serologic marker which showed the highest concordance among the commercial kits was anti-HBc, possibly because it is an inhibition assay. Concordance among assays for HBags and PCR positivity varied between poor and moderate; only two of the tests coincided with the PCR results. There was no concordance among the various immunoenzymatic assays, nor in viral RNA presence for HVC. The unexpected discrepancies among the various commercial kits could be due to inherent characteristics of these populations such as multiple co-infections, especially parasitic. These factors could be affecting the specificity of the diagnostic kits, situation less frequently observed in other Venezuelan populations. This study emphasizes the importance of validating serologic tests in these populations, through confirmation and molecular assays.

Mutation analysis of the HFE gene associated with hereditary hemochromatosis in a Venezuelan sample.

The frequency of the C282Y, H63D and S65C alleles of the HFE gene was determined in a sample of the Venezuelan population. Two new sets of primers were tested for amplifying the regions mapping these mutations, and genotyping was performed by restriction fragment length polymorphism (RFLP). DNA sequencing was used to validate the RFLP analysis. Serum ferritin levels were also determined. Two hundred and fourteen individuals were tested, extracting DNA from whole blood cells (n=177) or from serum (n=37). The frequency of heterozygous subjects was 3.7, 18.2 and 1.7% for the C282Y, H63D and S65C mutations, respectively, and the allele frequencies were 0.019+/-0.01 for C282Y, 0.119+/-0.016 for H63D and 0.009+/-0.005 for S65C. The results suggest that the admixture of native populations with subjects of South European origin might have had an important role in the diffusion of HFE alleles in Venezuela. C282Y homozygous subjects were not found in this study. No HFE genotype studied here was associated with a significant elevation of serum ferritin concentrations, except for C282Y/H63D compound heterozygote found in one asymptomatic male. This finding supports the theory that the H63D mutation could be involved in alterations of iron parameters when inherited together with C282Y. Our results indicate that C282Y homozygotes will be rarely detected. Performance of HFE mutation analysis in individuals with high iron determinations would be recommended.

Molecular and serological evaluation of surface antigen negative hepatitis B virus infection in blood donors from Venezuela.

Surface antigen negative hepatitis B virus (HBV) infection was evaluated in Venezuela, by molecular characterization of blood samples positive for antibodies to core antigen (anti-HBc) and negative for surface antigen (HBsAg) in blood donors (residual infections). HBV DNA was found in 11/258 samples (4.3%), and was significantly associated with high levels of anti-HBc antibodies (>25 UI/ml, P < 0.05), while no correlation was found between the presence of HBV DNA and the levels of anti-HBs. Synonymous and non-synonymous mutations were found in the HBV surface region (but not vaccine escape mutants) and in the precore/core region (precore mutants in 2/7 samples and 33-45 bp deletions near the N-terminal core region in 4/19 samples). While HBV genotype F prevails among HBsAg positive samples from blood donors in Venezuela, residual infection isolates were mainly genotypes A and D. Phylogenetic analysis of viral surface and core region revealed discrepancies in genotype designation in 6/9 samples, suggesting the presence of mixed infection or recombination. In conclusion, HBV residual infection in Venezuela does not seem to be frequently observed in HBV genotype F. This type of infection is frequently associated with variants exhibiting mutations in the surface gene that might be affecting the correct recognition by commercial tests, with precore mutants and with core internal deletions. These variants do not seem to cause severe liver disease, and on the contrary, were found circulating at low viremia.

Follicular fluid antibodies to Chlamydia trachomatis and human heat shock protein-60 kDa and infertility in women.

BACKGROUND: The objective of this study was to establish the relationship between presence of anti-Chlamydia trachomatis and anti-HSP60 antibodies in serum and follicular fluid of infertile women. METHODS: Serum IgG and follicular fluid IgA to Chlamydia trachomatis and human heat shock protein 60 (HSP60) were determined in 41 women undergoing in vitro fertilization (IVF). RESULTS: A significant association was found between presence of bacterial antibodies in serum and IgA anti-HSP60 in follicular fluid. CONCLUSIONS: Chlamydia trachomatis infection might be triggering an autoimmune process that could negatively affect the success of IVF.

Modulación de la liberación del transmisor y de su interacción con el receptor en la unión neuro-muscular / Modulation of transmitter release and of its receptor interaction in the neuromuscular junction

La aparición reciente de técnicas de control de potencial en parches de membrana está permitiendo entender con mejor detalle el funcionamiento de los canales iónicos pre y post-sinápticos y su vinculación con la regulación del tamaño cuántico durante la liberación sincrónica (evocada) o asincrónica (espontánea) del neurotransmisor. La técnica de control de potencial en macroparches, aplicada a sistemas sinápticos adultos o en desarrollo tiene ventajas sobre otras técnicas para el registro de corrientes macroscopicas tal como, la producida durante un miniatura (corriente miniatura de placa terminal, cmpt) ya que los registros se hacen de una manera focalizada. De esta forma, se impide la contaminación de los eventos originados en lugares distantes, como cuando se registra en una área extensa de sitios de liberación de neurotransmisor. La regulación de la respuesta cuántica, es importante en el proceso de plasticidad sináptica en sistemas adultos y en desarrollo. Aquí, se analizarán algunos aspectos de la regulación pre y post-sináptica de la respuesta cuántica durante la liberación asincrónica del neurotransmisor y se hará énfasis en la unión neuromuscular "en desarrollo" del músculo caudal de renacuajos de anfibios