Abstract Objective: To know the epidemiological behavior and associations of AF in Mexican population. Material and methods: 8,686 patients from 38 cardiologists participating in REMECAR were analyzed. They were divided by gender and age, the comorbidities studied were obesity, chronic kidney disease (CKD), high blood pressure (HBP), diabetes mellitus (DM), dyslipidemia, stroke, chronic obstructive pulmonary disease (COPD), hypothyroidism, heart failure (HF) and ischemic heart disease (IHD). Program used: IBM SPSS Statistic. Results: AF was diagnosed in 498 patients (5.7%), with higher prevalence in men (6.1% vs. 5.3%) and older age in women (74.3 ± 12.1 vs. 70.5 + -12.3 years, p<0.0001). In those under 60 years, AF was associated in women with HF, in men with CKD, DM, stroke, hypothyroidism and HF. In women older than 60 years, AF was associated with CKD, dyslipidemia, stroke, chronic COPD and HF, in men with CKD, stroke, COPD, hypothyroidism, HF and IHD. AF in women increase the probability 1.13 for obesity, 1.13 for HBP, 2.8 for CKD, 2.9 for COPD, 4.3 for stroke and 6.5 for HF, in men increase the probability 1.05 for HBP, 1.4 for DM, 2.1 for CKD, 2.4 for COPD, 3.0 for hypothyroidism, 4.7 for stroke and 6.0 for HF. Conclusions: AF is a very common arrhythmia, with a higher prevalence in patients attending the cardiology consultation, in men and with an older age of presentation in women. The older the age, the higher the prevalence of AF and comorbidities, HF is the most frequent condition associated with AF.

Resumen Objetivo: Conocer el comportamiento epidemiológico y asociaciones de la FA en población mexicana. Material y métodos: Analizamos 8,686 pacientes de 38 cardiólogos inscritos en REMECAR, divididos por edad y sexo. Comorbilidades estudiadas: obesidad, ERC, HTA, DM, dislipidemia, EVC, EPOC, hipotiroidismo, IC y CI. Programa: IBM SPSS. Resultados: FA en 498 pacientes (5.7%), mayor prevalencia en hombres (6.1 vs. 5.3%), mayor edad en mujeres (74.3 ± 12.1 vs. 70.5 ± 12.3 años, p < 0.0001). En mujeres menores de 60 años la FA se asoció con IC (p = 0.041), en hombres con ERC (p = 0.43), DM (p = 0.009), EVC (p = 0.001), hipotiroidismo (p = 0.001) e IC (p = 0.001). En mujeres mayores de 60 años se asoció con ERC (p = 0.001), dislipidemia (p = 0.001), EVC (p = 0.001), EPOC (p = 0.001) e IC (p = 0.001), en hombres con ERC (p = 0.002), EVC (p = 0.001), EPOC (p = 0.002), hipotiroidismo (p = 0.002), IC (p = 0.001) y CI (p = 0.033). En mujeres la FA se asoció con 1.13 veces mayor probabilidad de obesidad, 1.13 de HTA, 2.8 de ERC, 2.9 de EPOC, 4.3 de EVC y 6.5 de IC, en hombres la FA se asoció con 1.05 veces mas probabilidad de HTA, 1.4 de DM, 2.1 de ERC, 2.4 de EPOC, 3 de hipotiroidismo, 4.7 de EVC y 6 de IC. Conclusiones: La FA es una arritmia muy frecuente, con mayor prevalencia en pacientes que acuden a consulta de cardiología, en hombres y mayor edad de presentación en las mujeres. A mayor edad, mayor prevalencia de FA y de comorbilidades, la IC es la condición más frecuente con la que se asoció la FA.

ABSTRACT Introduction: COVID-19 is a disease in which mechanical ventilation acquires vital importance. It is estimated that 50 % of the serious and critical patients requiring management in intensive care units die. Objectives: to assess the impact of the ventilation modes used in patients with COVID-19 in Lombardy, Italy, on oxygenation, hemodynamics and mortality. Materials and methods: a retrospective, longitudinal, analytic study was carried out in 86 critical patients with COVID-19 who entered the Main Hospital of Crema, in Lombardy, Italy, from April 1st to May 20, 2020. Results: the survival was 76.7 %. The used mode showed the same behavior in deceased patients (BiPAP-3, PCV-4, VCRP-4, APRV-5, VCV-4) and in alive patients (BiPAP-10, PCV-17, VCRP-14, APRV-15, VCV-10). X2 = 0.59. ANOVA test index PO2/FIO2 (PCV = 132), (BiPAP = 132) (VCV=115) p = 0.924. PEEP (BiPAP-12, PCV-13, VCRP-13, APRV-13, VCV-14) p = 0.205. PCO2 (BiPAP-55, PCV-52, VCRP-57, APRV-59, VCV-57) p = 0.512. Average blood pressure (BiPAP-84, PCV-83, VCRP-84, APRV-82, VCV-83) p = 0.988. PEEP models according to ventilation mode: BiPAP: PEEP = -0.0331 (PO2/FiO2 index) +18.215. PCV: PEEP = -0.0047 (PO2/FiO2 index) + 13.717; VCRP: PEEP = -0.0204 (PO2/FiO2 index) + 15.678; APRV: PEEP = -0.0092 (PO2/FiO2 index) +14.889. Conclusion: the evolution of the critical patient with COVID-19 is determined mostly by the invasive mechanical ventilation; but we did not find evidence enough to recommend one or the other ventilation mode. The success stands in knowing accurately the characteristics of the ventilator, the ventilation modes and the patient.

RESUMEN Introducción: la covid-19 es una enfermedad donde la ventilación mecánica artificial cobra vital importancia. Se estima que el 50 % de los casos graves o críticos que requieren manejo en unidades de cuidados intensivos fallecen. Objetivos: se evaluó el impacto de los modos ventilatorios usados en pacientes con covid-19 en Lombardía, Italia, en la oxigenación, la hemodinámica y la mortalidad. Materiales y métodos: se realizó un estudio analítico longitudinal retrospectivo en 86 pacientes críticos con covid-19, en el Hospital Mayor de Crema, en Lombardía, Italia, desde el 1 de abril al 20 de mayo de 2020. Se realizaron análisis no paramétrico y de la varianza. Resultados: Hubo una supervivencia del 76,7 %. El modo utilizado tuvo igual comportamiento en occisos (BiPAP-3, PCV-4, VCRP-4, APRV-5, VCV-4) y en vivos (BiPAP-10, PCV-17, VCRP-14, APRV-15, VCV-10); test de x2 = 0,59; test de análisis de la varianza media índice PO2/FIO2 (PCV = 132), (BiPAP = 132) (VCV = 115) p = 0,924. La presión de final de espiración positiva (BiPAP-12, PCV-13, VCRP-13, APRV-13, VCV-14) con p = 0,205. PCO2 (BiPAP-55, PCV-52, VCRP-57, APRV-59, VCV-57) con p = 0,512. La tensión arterial media (BiPAP-84, PCV-83, VCRP-84, APRV-82, VCV-83) con p = 0,988. Modelos de cálculo de la presión de final de espiración positiva, según modo ventilatorio: BiPAP: PEEP = -0,0331 (índice PO2/FiO2) +18,215; PCV: PEEP = -0,0047 (índice PO2/FiO2) +13,717; VCRP: PEEP = -0,0204 (índice PO2/FiO2) +15,678; APRV: PEEP = -0,0092 (índice PO2/FiO2) +14,889. Conclusiones: la evolución del paciente crítico con covid-19 está determinada en gran medida por la ventilación mecánica invasiva; sin embargo, no existió suficiente evidencia para recomendar una u otra modalidad ventilatoria. El éxito está en conocer con exactitud las características del respirador, su modalidad y el paciente en cuestión.

ABSTRACT 27. Background: non-carious cervical lesions are the pathological loss of dental tissue, where bruxism plays an important role as a risk factor that, by transmitting damaging forces, causes the fracture of dental tissues and subsequent aesthetic involvement. Objective: to characterize non-carious cervical lesions in bruxopathic patients. Methods: a descriptive, cross-sectional study was carried out in the patients treated at the dental prosthesis consultation of the Nuevitas municipality, Camagüey province in the period from January to July 2019, the universe was made up of 157 patients diagnosed with bruxism, who presented at least a type of non-carious cervical lesions, the sample was probabilistic by the simple random method, and consisted of 97 patients. Results: of the bruxopathic patients examined with non-carious cervical lesions, the female sex and the age group between 34 and 48 years predominated. The main non-carious cervical lesion in general in patients with bruxism was abfraction and was more frequently associated in patients with grinding bruxism. The dental group of upper premolars were the most affected. Conclusions: during the characterization of non-carious cervical lesions in the patient with bruxism, the female sex predominated and between the third and fourth decade of life, abfraction was the main non-carious cervical lesion, with the highest frequency in grinding bruxism and the premolar dental group the most affected.

RESUMEN 20. Fundamento: las lesiones cervicales no cariosas son la pérdida patológica del tejido dentario, donde el bruxismo juega un rol importante como factor de riesgo que al transmitir fuerzas lesivas provoca la fractura de los tejidos dentarios y la posterior afectación estética. Objetivo: caracterizar las lesiones cervicales no cariosas en pacientes bruxópatas. Métodos: se realizó un estudio descriptivo, transversal en los pacientes atendidos en la consulta de Prótesis Estomatológica del municipio Nuevitas, provincia Camagüey en el período de enero a julio de 2019, el universo lo constituyeron los 157 pacientes diagnosticados con bruxismo, que presentaran al menos un tipo de las lesiones cervicales no cariosas, la muestra fue de tipo probabilístico por el método aleatorio simple y quedó constituida por 97 pacientes. Resultados: de los pacientes bruxópatas examinados con lesiones cervicales no cariosas predominó el sexo femenino y el grupo de edad entre 34 a 48 años. La principal lesión cervical no cariosa de forma general en los pacientes con bruxismo fue la abfracción y se relacionó con mayor frecuencia en los pacientes con bruxismo de rechinamiento. El grupo dentario de premolares superiores fueron los más afectados. Conclusiones: durante la caracterización de las lesiones cervicales no cariosas en el paciente con bruxismo, predominó el sexo femenino y entre la tercera y cuarta década de vida, la abfracción fue la principal lesión cervical no cariosa, de mayor frecuencia en el bruxismo por rechinamiento y el grupo dentario premolar el más afectado.

Abstract 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.

Resumen 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.

RESUMO Antecedentes: A endocardite infecciosa (IE) da válvula tricúspide é rara e está associado com pacientes idosos, os utilizadores de drogas intravenosas ou pacientes que necessitam de dispositivos intracardíaca, cateteres ou próteses, infecção por HIV, diabetes mellitus (DM), neoplasias e hemodiálise. Apresentação do caso: caso clínico de uma mulher de 31 anos com uma história de saúde, o que foi admitido por síndrome febril prolongada e estudo anemia descrito; sinais de admissão de insuficiência cardíaca hipertensão dominância direita e estreia diabetes mellitus foram testados. Discussão: endocardite válvula tricúspide devido a Staphylococcus aureus foi confirmada. complicações graves, tais como insuficiência cardíaca, broncopneumonia bacteriana recorrente por êmbolos sépticos pulmonar, insuficiência renal aguda e glomerulonefrite aguda necrose tubular aguda; anemia hemolítica aguda e neurorretinite devido a êmbolos sépticos ou vasculite cerebral caracterizado sua torpid. Ele necessário suporte hemodinâmico e CPR bem sucedida após várias paradas cardiorrespiratórias sustentada taquicardia ventricular polimórfica e fibrilação ventricular devido a distúrbios graves e ambiente interno sepse. Ampicilina 12 grm / dia e.v + rifampicina 600 mg / dia durante 6 semanas v.o, foi eficaz para eliminar a septicemia. Conclusões: O tratamento cirúrgico foi aplicado (prótese de metal tricúspide substituição da válvula) sem complicações.

ABSTRACT Introduction: tricuspid valve infectious endocarditis (IE) is rare and is associated with older patients, intravenous drug users or patients requiring intracardiac devices, catheters or prostheses, human immunodeficiency virus infection, diabetes mellitus (DM), neoplasms and hemodialysis. Case presentation: a case report of a 31-year-old woman with a history of health, who was admitted for prolonged febrile syndrome and anemia under study, is described; On admission, signs of heart failure were found, predominantly right, with arterial hypertension and diabetes mellitus onset. Discussion: tricuspid valve infective endocarditis was confirmed by Staphylococcus aureus. Serious complications such as: heart failure, recurrent bacterial bronchopneumonia due to pulmonary septic emboli, acute renal failure due to acute glomerulonephritis and acute tubular necrosis; Hemolytic anemia and acute neuroretinitis due to vasculitis or septic brain embolus characterized its torpid evolution. It required hemodynamic support and successful cardiopulmonary resuscitation after multiple cardiorespiratory stops due to polymorphic sustained ventricular tachycardia and ventricular fibrillation due to severe internal environment disorders and sepsis. Ampicillin 12 grm / day e.v + rifampicin 600 mg / day v.o for 6 weeks, was effective in eliminating septicemia. Conclusions: surgical treatment was applied (valvular replacement by metallic tricuspid prosthesis) without complications.

RESUMEN Introducción: la endocarditis infecciosa (EI) de válvula tricúspide es rara y se asocia a pacientes de mayor edad, usuarios de drogas endovenosas o pacientes que requieren dispositivos intracardiacos, catéteres o prótesis, infección por virus de la inmunodeficiencia humana, diabetes mellitus (DM), neoplasias y hemodiálisis. Presentación de caso: se describe caso clínico de una mujer de 31 años con antecedentes de salud, que se admitió por síndrome febril prolongado y anemia en estudio; al ingreso se comprobaron signos de insuficiencia cardiaca a predominio derecho con hipertensión arterial y diabetes mellitus de debut. Discusión: se confirmó endocarditis infecciosa de válvula tricúspide por Staphylococcus aureus. Complicaciones graves como: insuficiencia cardiaca, bronconeumonía bacteriana recurrente por émbolos sépticos pulmonares, insuficiencia renal aguda por glomerulonefritis aguda y necrosis tubular aguda; anemia hemolítica y neuroretinitis aguda debido a vasculitis o émbolos sépticos cerebrales caracterizaron su evolución tórpida. Requirió soporte hemodinámico y resucitación cardiopulmonar exitosa tras múltiples paradas cardiorespiratorias por taquicardia ventricular sostenida polimórfica y fibrilación ventricular debido a severos trastornos del medio interno y sepsis. Ampicilina 12 grm/día e.v + rifampicina 600 mg/dia v.o por 6 semanas, resultó efectiva para eliminar la septicemia. Conclusiones: se aplicó tratamiento quirúrgico (sustitución valvular por prótesis tricúspide metálica) sin complicaciones.

Abstract: The objective of this study was to determine the physiological, endocrine and productive response in lactating dairy cows under several series of artificial cooling at the beginning of the summer (June to July, 2011). Fourteen multiparous Holstein cows were assigned in one of two treatments: Cooling (C) before milking (0700 and 1700 h) and additional cooling (AC) each 2 h (from 0700 to 1700h) in the holding pen of the milking parlor. Milk yield (MY), and serum levels of prolactin (PRL) and IGF1 were measured. Rectal temperature and respiratory rate were registered and included as physiological markers of heat stress. Ambient temperature and relative humidity were also collected and used to calculate temperature-humidity index (THI). Both markers of heat stress showed a significant interaction (P<0.001) between treatment and time/week, which were lower in AC treatment (-3.8 breaths per minute and -0.2 °C) during wk 6 and 7. Serum levels of PRL were higher under additional cooling (AC: 35.1 vs C: 29.4 ng/ml; P=0.004), while IGF1 serum levels showed variation only through the sampling weeks (P=0.014). The MY increased (P<0.05) in AC only during wk 6 (+3.1 kg/d) and 7 (+3.1 kg/d). It was concluded that additional cooling at the beginning of the summer reduced heat stress in dairy cows allowing a better productive performance at the end of the study because such effect relied on the variable time/week.

Resumen: El objetivo de este estudio fue determinar la respuesta fisiológica, endócrina y productiva en vacas lactantes sometidas a varias series de enfriamiento artificial al inicio de verano (junio a julio de 2011). Se asignaron 14 vacas Holstein multíparas a uno de dos tratamientos: enfriamiento (E) antes de la ordeña (0700 y 1700 h) y enfriamiento adicional (EA) cada 2 h de 0700 a 1700 h en el corral de espera a la ordeña. Se midió la producción de leche (PL), niveles de prolactina (PRL) e IGF1, mientras que la temperatura rectal y frecuencia respiratoria fueron registradas y consideradas como indicadores fisiológicos de estrés por calor. La temperatura ambiental y humedad relativa también fueron registradas y utilizadas para calcular el índice de temperatura-humedad (ITH). Los indicadores de estrés calórico mostraron una interacción significativa (P<0.001) entre tratamiento y tiempo/semana, los cuales fueron menores con EA (-3.8 respiraciones por minuto y -0.2 °C) sólo durante las semanas 6 y 7. Los niveles séricos de PRL fueron mayores bajo enfriamiento adicional (EA: 35.1 vs E: 29.4 ng/ml; P=0.004), mientras que los de IGF1 solo variaron através de las semanas de muestreo (P=0.014). La PL se incrementó (P<0.05) en EA durante las semanas 6 (+3.1 kg/día) y 7 (+3.1 kg/día). Se concluye que la mayor frecuencia de baños mitigó la condición de estrés calórico al inicio de verano, permitiéndole a la vaca expresar un mejor desempeño productivo al final del estudio, ya que dicho efecto dependió de la variable tiempo/semana.

OBJECTIVE: To identify the prevalence and factors associated with cervical human papillomavirus infection in women with systemic lupus erythematosus METHODS: This cross-sectional study collected traditional and systemic lupus erythematosus-related disease risk factors, including conventional and biologic therapies. A gynecological evaluation and cervical cytology screen were performed. Human papillomavirus detection and genotyping were undertaken by PCR and linear array assay. RESULTS: A total of 148 patients were included, with a mean age and disease duration of 42.5±11.8 years and 9.7±5.3 years, respectively. The prevalence of squamous intraepithelial lesions was 6.8%. The prevalence of human papillomavirus infection was 29%, with human papillomavirus subtype 59 being the most frequent. Patients with human papillomavirus were younger than those without the infection (38.2±11.2 vs. 44.2±11.5 years, respectively; p = 0.05), and patients with the virus had higher daily prednisone doses (12.8±6.8 vs. 9.7±6.7 mg, respectively; p = 0.01) and cumulative glucocorticoid doses (14.2±9.8 vs. 9.7±7.3 g, respectively; p = 0.005) compared with patients without. Patients with human papillomavirus infection more frequently received rituximab than those without (20.9% vs. 8.5%, respectively; p = 0.03). In the multivariate analysis, only the cumulative glucocorticoid dose was associated with human papillomavirus infection. CONCLUSIONS: The cumulative glucocorticoid dose may increase the risk of human papillomavirus infection. Although rituximab administration was more frequent in patients with human papillomavirus infection, no association was found. Screening for human papillomavirus infection is recommended in women with systemic lupus erythematosus.

Porcine rubulavirus (PoRV) is an emerging virus causing meningo-encephalitis and reproductive failures in pigs. Little is known about the pathogenesis and immune evasion of this virus; therefore research on the mechanisms underlying tissue damage during infection is essential. To explore these mechanisms, the effect of PoRV on the transcription of interferon (IFN) pathway members was analyzed in vitro by semi-quantitative RT-PCR. Ten TCID50 of PoRV stimulated transcription of IFNα, IFNβ, STAT1, STAT2, p48 and OAS genes in neuroblastoma cells, whereas infection with 100 TCID50 did not stimulate transcription levels more than non-infected cells. When the cells were primed with IFNα, infection with 1 TCDI50 of PoRV sufficed to stimulate the transcription of the same genes, but 10 and 100 TCID50 did not modify the transcription level of those genes as compared with non-infected and primed controls. MxA gene transcription was observed only when the cells were primed with IFNα and stimulated with 10 TCID50, whereas 100 TCID50 of PoRV did not modify the MxA transcription level as compared to non-infected and primed cells. Our results show that PoRV replication at low titers stimulates the expression of IFN-responsive genes in neuroblastoma cells, and suggest that replication of PoRV at higher titers inhibits the transcription of several members of the IFN pathway. These findings may contribute to the understanding of the pathogenesis of PoRV.

Avian influenza viruses produce mainly respiratory and intestinal diseases. Their relevance in the generation of pandemic strains has led to a large amount of research to understand their distribution in nature, as well as the relations that become established for the effective transmission among different hosts. Waterfowl have been recognized as their natural reservoir and they play an important role in the propagation and generation of the diversity of these viruses. The emergence of new influenza viruses with pandemic potential among the human population (H5N1 of avian origin or recombinant H1N1 with avian segments) point our lack of information on many aspects of the ecology and epidemiology of these viruses in their natural hosts to enable the implementation of more effective prevention and control measures. In this review, we attempt to make a critical essay on the current state of knowledge on the biotic and abiotic factors that influence the ecology and epidemiology of the influenza A viruses in wild birds.

Los virus influenza ocasionan enfermedades respiratorias e intestinales. Su importancia en la generación de cepas pandémicas ha conducido a la realización de intensa investigación científica para entender y conocer su distribución en la naturaleza, así como las relaciones que se establecen para la transmisión efectiva entre diferentes hospederos. Las aves acuáticas principalmente del orden Anseriformes, se han reconocido como el reservorio de estos virus y tienen una participación crucial en la propagación y generación de diversidad de estos virus. La emergencia de nuevos virus influenza con potencial pandémico entre la población humana (H5N1 de origen aviar y el actual virus pandémico H1N1 que presenta segmentos aviares), resalta la falta de información sobre muchos aspectos de la ecología y epidemiología de estos virus en sus hospederos naturales, que permitan la implementación de medidas más efectivas de prevención y control. En esta contribución revisamos el estado del arte del conocimiento sobre los factores bióticos y abióticos que influyen en la ecología y epidemiología de los virus influenza en aves silvestres.

Cervical cancer is an important health problem in women living in developing countries. Infection with some genotypes of human papillomavirus (HPV) is the most important risk factor associated with cervical cancer. Little information exists about HPV genotype distribution in rural and suburban regions of Mexico. Thus, we determined the prevalence of HPV genotypes in women from Tlaxcala, one of the poorest states in central Mexico, and we evaluated age infection prevalence and risk factors associated with cervical neoplasm. A cross-sectional study was conducted in 236 women seeking gynecological care at the Mexican Institute for Social Security in Tlaxcala, Mexico. Cervical scrapings were diagnosed as normal, low-grade, and high-grade squamous intraepithelial lesions (LGSIL, HGSIL). Parallel samples were used to detect HPV genotypes by PCR assays using type-specific primers for HPV 6, 11, 16, 18, and 31. An epidemiological questionnaire was applied. Prevalence of HPV infection was 31.3%. From the infected samples, prevalence of HPV 16 was 45.9%; HPV 18, 31.1%; HPV 31, 16.2%; HPV 6, 10.8%; HPV 11, 6.7%. With regard to age, the highest HPV prevalence (43.5%) was found in the 18- to 24-year-old group and the lowest (19%) in the 45- to 54-year-old group. None of the risk factors showed association with cervical neoplasia grade. HPV 16 was the most common in cervical lesions. HPV was present in 22% of normal samples and, of these, 82.6% represented high-risk HPVs. Tlaxcala showed HPV prevalence comparable to that of the largest cities in Mexico, with higher prevalence for HPV 31.

La sialilación alterada que se ha detectado durante la transformación maligna, en los tumores con invasión y metástasis ha sido asociada con un incremento en la transcripción de sialiltransferasas (STs). En carcinoma escamoso cervical invasor ha sido detectado un incremento en la expresión del ARNm de STs (ST3Gal III y ST6Gal I). Un estudio realizado en muestras de cérvix mostró un ligero incremento en la expresión de ácido siálico en lesiones inflamatorias benignas y un incremento moderado en neoplasia severa, con respecto al tejido normal, sin embargo, a la fecha la expresión alterada de STs en la neoplasia intraepitelial cervical no ha sido evaluada. Este estudio tuvo como finalidad investigar los cambios en el nivel de transcripción de tres STs (ST3Gal III, ST3Gal IV y ST6Gal I) en la neoplasia intraepitelial cervical (NIC). Para ello se analizaron 35 biopsias de cérvix clasificadas como: normal, NIC 1, NIC 2 y NIC 3, mediante ensayos semicuantitativos de RT-PCR. El nivel de transcripción de las tres STs se incrementó en las muestras con diagnóstico de neoplasia intraepitelial cervical con respecto al tejido normal, con una diferencia significativa de p < 0.001 (Mann-Whitney U test) para todas las enzimas. Nuestros resultados sugieren que la expresión alterada de las STs: ST3Gal III, ST3Gal IV y ST6Gal I, en la neoplasia intraepitelial cervical puede tener un papel importante durante la transformación maligna y estar relacionada con los incrementos en la expresión de ácido siálico detectado en tejido con neoplasia cervical.

Altered sialylation observed during oncogenic transformation, tumor metastases and invasion, has been associated with enhanced sialyltransferases (STs) transcription. Increased mRNA expression of STs (ST6Gal I, ST3Gal III) has been detected in invasive cervical squamous cell carcinoma. A study of the sialic acid concentration in local tissue of cervix and in serum showed a slight elevation in benign inflammatory lesions and a moderate elevation in severe neoplasia, but to date, altered expression of STs in cervical intraepithelial neoplasia has not yet been evaluated. This study investigates the changes in mRNA expression of three STs (ST6Gal I, ST3Gal III, and ST3Gal IV) in cervical intraepithelial lesions (CIN). Alterations of these STs mRNA expression were examined in 35 cervix specimens classified as normal, CIN 1, CIN 2 and CIN 3, by semiquantitative reverse transcription-polymerase chain reaction. mRNA expression of the three STs was enhanced in CIN 1, CIN 2 and CIN 3 with respect to normal tissue, with a significant difference of p < 0.001 (Mann-Whitney U test) for all the enzymes. Our results suggest that altered expression of ST3Gal III, ST3Gal IV and ST6Gal I in CIN could play an important role during malignant transformation and could be related with the enhanced sialic acid expression detected in neoplasic tissues.

Highly pathogenic avian influenza virus (HPAI) H5N1 is a global threat due to its zoonotic and pandemic potential. Then, concern arises and the need to have early detection tools to minimize the impact on human and animal health. In this work, a molecular detection method was implemented to detect matrix (M), hemagglutinin (H5) and neuraminidase (N1) genes of HPAI avian influenza virus H5N1, based on real time RT-PCR (RRT-PCR). Positive controls were constructed from reference RNA viral A/Vietnam/1203/2004 (H5N1), cloned into plasmidic vectors and sequenced. Assay detection sensitivity was assessed with standard curves for each gene. Assay sensitivity was 10² DNA copies/μl in all cases. Curves showed amplification efficiency higher than 90% and R²>0.99. This method could be useful for bird monitoring campaigns and as a screening procedure for clinical samples.

El virus de la influenza aviar H5N1 de alta patogenicidad mantiene el alerta mundial debido a su potencial zoonótico y pandémico. Surge entonces la necesidad de contar con herramientas para la detección temprana y de esta forma reducir el impacto potencial a la salud humana y animal. En este estudio se estandarizó un método de detección molecular de los genes de la matriz (M), hemaglutinina (H5) y neuraminidasa (N1) del virus de la influenza aviar H5N1 de alta patogenicidad de linaje asiático, mediante transcripción-reversa y reacción en cadena de la polimerasa en tiempo real (RRT-PCR). A partir de un ARN viral de referencia cepa A/Vietnam/1203/2004 (H5N1) se construyeron controles positivos mediante clonación de productos de PCR. Los estándares de naturaleza plasmídica se emplearon en la obtención de curvas estándar para determinar los límites de detección de la técnica. La sensibilidad observada para todos los genes analizados fue de 10² copias de ADN/μL. Las curvas mostraron una eficiencia superior al 90%, y R²>0,99. Este método puede ser útil en las campañas de monitoreo del virus en aves migratorias, así como para el tamizaje de muestras clínicas de humanos, en una emergencia de salud.

A point mutation from guanine (G) to adenine (A) at nucleotide position 1081 in the hemagglutinin-neuraminidase (HN) gene has been associated with neurovirulence of Urabe AM9 mumps virus vaccine. This mutation corresponds to a glutamic acid (E) to lysine (K) change at position 335 in the HN glycoprotein. We have experimentally demonstrated that two variants of Urabe AM9 strain (HN-A1081 and HN-G1081) differ in neurotropism, sialic acidbinding affinity and neuraminidase activity. In the present study, we performed a structure-function analysis of that amino acid substitution; the structures of HN protein of both Urabe AM9 strain variants were predicted. Based on our analysis, the E/K mutation changes the protein surface properties and to a lesser extent their conformations, which in turn reflects in activity changes. Our modeling results suggest that this E/K interchange does not affect the structure of the sialic acid binding motif; however, the electrostatic surface differs drastically due to an exposed short alpha helix. Consequently, this mutation may affect the accessibility of HN to substrates and membrane receptors of the host cells. Our findings appear to explain the observed differences in neurotropism of these vaccine strains.

El Rubulavirus porcino causa un síndrome neurológico y reproductivo en cerdos, hasta ahora reportado sólo en México. Los virus aislados se agrupan de acuerdo con los síntomas principales observados durante los brotes en: a) neutrópicos en lechones, b) neurotrópicos en lechones/gonadotrópicos en adultos y c) gonadotrópicos en adultos. En este trabajo se estudiaron tres cepas: La Piedad Michoacán (LPM) y Producción Animal "Cerdos" 1 (PAC1) y 3 (PAC3), ubicadas respectivamente en cada grupo. Las propiedades estudiadas se relacionan principalmente con dos proteínas de la envoltura viral, la hemaglutinina-neuraminidasa (HN) y la proteína de fusión (F). Se cuantificaron el efecto citopático y las actividades de hemólisis, hemaglutinación (HA) y neuraminidasa (NA). En cultivo celular la cepa PAC1 presentó una mayor actividad fusogénica, sin embargo PAC3 presentó la mayor actividad citolítica. La cepa PAC3 fue la primera en ser detectada en sobrenadante de células infectadas (HA, NA y genoma), lo que muestra que sus viriones son liberados al medio antes que las otras dos cepas. PAC3 tuvo las actividades más altas de HA y NA, sin embargo, PAC1 presentó una mayor termoestabilidad en estas actividades de HN y un perfil de substrato algo distinto de los observados para LPM y PAC3. Estos datos sugieren que la actividad de NA está relacionada con la virulencia del RVP.

Biological characterization of three natural isolates of the porcine rubulavirus (Mexico). Porcine rubulavirus (PoRV) produces a neurological and reproductive syndrome in pigs called the blue-eye disease, known only from Mexico. Several isolates were grouped by the main symptoms presented during outbreaks: a) neurotropic in piglets, b) broadly neurotropic in piglets and gonadotropic in adults, and c) gonadotropic in adults. We studied some biological properties of three strains, which fall in one of each virus group: La Piedad Michoacán (LPM) and Producción Animal Cerdos 1 (PAC1) and 3 (PAC3), respectively. The analyzed viral properties are mainly related with the trans-membrane hemagglutinin-neuraminidase (HN) and fusion (F) proteins, such as cytopathic effect, hemolysis, hemagglutinating (HA) and neuraminidase (NA) activities. In the infection assays PAC1 strain presented the highest fusogenicity level; however, the most cytolytic strain was PAC3. In addition, HA and NA activities and viral genome of PAC3 strain was detected in supernatants during cell infection earlier than in the other two strains, which shows that PAC3 virions release from the host cell earlier than LPM and PAC1. Experimental determination in purified viruses shows that PAC3 presented a higher HA and NA activities; however, PAC1 shows other interesting properties, such as a high thermostability of HN and differences about substrate profile respect to LPM and PAC3. Our data suggest that NA activity is associated with the virulence of RVP. Rev. Biol. Trop. 56 (2): 487-499. Epub 2008 June 30.