Risk of dengue virus infection according to serostatus in individuals from dengue endemic areas of Mexico.

The variability in the host immune response directed against dengue virus (DENV) has demonstrated the need to understand the immune response associated with protection in incident infection. The objective was to estimate the association between serostatus and the risk of incident DENV infection. We used a prospective study from 2014 to 2016 in the localities of Axochiapan and Tepalcingo, Morelos, Mexico. We recruited 966 participants, of which, according to their infection history registered were categorized in four groups. To accomplish the objectives of this study, we selected to 400 participants older than 5 years of age were followed for 2.5 years. Blood samples were taken every 6 months to measure serological status and infection by ELISA. In individuals with at least two previous infections the risk of new infection was lower compared to a seronegative group (hazard ratio adjusted 0.49, 95% CI 0.24-0.98), adjusted for age and locality. Therefore, individuals who have been exposed two times or more to a DENV infection have a lower risk of re-infection, thus showing the role of cross-immunity and its association with protection.

[Functional results and complications of the use of the proximal femoral nail in the treatment of intertrochanteric hip fractures]. / Resultados funcionales y complicaciones del uso del clavo cefalomedular en el tratamiento de las fracturas de cadera.

INTRODUCTION: Cephalomedullary nails are used for the treatment of hip fractures; however, there are few studies that allow identifying data on the complications of the use of these devices and the results in terms of restoration of the functionality of the patient. METHODS: A cross-sectional study of patients with femur fracture was conducted during the period from January 2008 to December 2012. Data on demographic and clinical variables were collected. Telephone follow-up was performed up to six postoperative months. A descriptive analysis was done using absolute and relative frequency measurements. Quantitative variables are presented with averages and standard deviation or median and interquartile range, according to the normality of the data. RESULTS: 82.9% of the patients managed to walk with or without help within six months after surgery; anemia (16.2%), urinary tract infection (9.7%), pneumonia (9.5%) and myocardial infarction (0.7%) were the main complications. Of the patients included, 57.1% had an ASA level 3; a mortality rate of 16% was identified. DISCUSSION: Cephalomedullary nails show positive results regarding recovery of functional mobility and a low prevalence of complications, with similar mortality to that reported in the literature at 6 months of follow up.

INTRODUCCIÓN: El clavo cefalomedular es utilizado para el tratamiento de la fractura de cadera; sin embargo, existen pocos estudios que permitan identificar datos sobre las complicaciones del uso de estos dispositivos y los resultados en términos de restauración de la funcionalidad del paciente. MÉTODOS: Se realizó un estudio de corte transversal en pacientes con fractura de fémur durante el período de Enero de 2008 a Diciembre de 2012. Se recopiló información de variables demográficas y clínicas. Se llevó a cabo un seguimiento telefónico hasta seis meses postoperatorios. Se efectuó un análisis descriptivo utilizando medidas de frecuencia absolutas y relativas. Las variables cuantitativas se presentan con promedios y desviación estándar o mediana y rango intercuartil, según la normalidad de los datos. RESULTADOS: De los pacientes, 82.9% logró caminar con o sin ayuda dentro de los seis meses posteriores a la cirugía. El tiempo de hospitalización fue de cuatro días en promedio; las principales complicaciones fueron anemia (16.2%), infección urinaria (9.7%), neumonía (9.5%) e infarto del miocardio (0.7%). De quienes fueron incluidos, 57.1% tenían un nivel ASA 3; se identificó una mortalidad de 16% en ellos. DISCUSIÓN: El clavo cefalomedular muestra resultados positivos en cuanto a recuperación funcional de la movilidad y una baja prevalencia de complicaciones, con una mortalidad similar a la reportada en la literatura dentro de los primeros 6 meses de nuestro seguimiento.

Resultados funcionales y complicaciones del uso del clavo cefalomedular en el tratamiento de las fracturas de cadera / Functional results and complications of the use of the proximal femoral nail in the treatment of intertrochanteric hip fractures

Resumen: Introducción: El clavo cefalomedular es utilizado para el tratamiento de la fractura de cadera; sin embargo, existen pocos estudios que permitan identificar datos sobre las complicaciones del uso de estos dispositivos y los resultados en términos de restauración de la funcionalidad del paciente. Métodos: Se realizó un estudio de corte transversal en pacientes con fractura de fémur durante el período de Enero de 2008 a Diciembre de 2012. Se recopiló información de variables demográficas y clínicas. Se llevó a cabo un seguimiento telefónico hasta seis meses postoperatorios. Se efectuó un análisis descriptivo utilizando medidas de frecuencia absolutas y relativas. Las variables cuantitativas se presentan con promedios y desviación estándar o mediana y rango intercuartil, según la normalidad de los datos. Resultados: De los pacientes, 82.9% logró caminar con o sin ayuda dentro de los seis meses posteriores a la cirugía. El tiempo de hospitalización fue de cuatro días en promedio; las principales complicaciones fueron anemia (16.2%), infección urinaria (9.7%), neumonía (9.5%) e infarto del miocardio (0.7%). De quienes fueron incluidos, 57.1% tenían un nivel ASA ≥ 3; se identificó una mortalidad de 16% en ellos. Discusión: El clavo cefalomedular muestra resultados positivos en cuanto a recuperación funcional de la movilidad y una baja prevalencia de complicaciones, con una mortalidad similar a la reportada en la literatura dentro de los primeros 6 meses de nuestro seguimiento.

Abstract: Introduction: Cephalomedullary nails are used for the treatment of hip fractures; however, there are few studies that allow identifying data on the complications of the use of these devices and the results in terms of restoration of the functionality of the patient. Methods: A cross-sectional study of patients with femur fracture was conducted during the period from January 2008 to December 2012. Data on demographic and clinical variables were collected. Telephone follow-up was performed up to six postoperative months. A descriptive analysis was done using absolute and relative frequency measurements. Quantitative variables are presented with averages and standard deviation or median and interquartile range, according to the normality of the data. Results: 82.9% of the patients managed to walk with or without help within six months after surgery; anemia (16.2%), urinary tract infection (9.7%), pneumonia (9.5%) and myocardial infarction (0.7%) were the main complications. Of the patients included, 57.1% had an ASA level ≥ 3; a mortality rate of 16% was identified. Discussion: Cephalomedullary nails show positive results regarding recovery of functional mobility and a low prevalence of complications, with similar mortality to that reported in the literature at 6 months of follow up.

Transmission dynamics of two dengue serotypes with vaccination scenarios.

In this work we present a mathematical model that incorporates two Dengue serotypes. The model has been constructed to study both the epidemiological trends of the disease and conditions that allow coexistence in competing strains under vaccination. We consider two viral strains and temporary cross-immunity with one vector mosquito population. Results suggest that vaccination scenarios will not only reduce disease incidence but will also modify the transmission dynamics. Indeed, vaccination and cross immunity period are seen to decrease the frequency and magnitude of outbreaks but in a differentiated manner with specific effects depending upon the interaction vaccine and strain type.

Neonatal respiratory syncytial virus infection has an effect on lung inflammation and the CD4(+) CD25(+) T cell subpopulation during ovalbumin sensitization in adult mice.

In BALB/c adult mice, respiratory syncytial virus (RSV) infection enhances the degree of lung inflammation before and/or after ovalbumin (OVA) respiratory sensitization. However, it is unclear whether RSV infection in newborn mice has an effect on the immune response to OVA respiratory sensitization in adult mice. The aim of this study was to determine if RSV neonatal infection alters T CD4(+) population and lung inflammation during OVA respiratory sensitization in adult mice. BALB/c mice were infected with RSV on the fourth day of life and challenged by OVA 4 weeks later. We found that in adult mice, RSV neonatal infection prior to OVA sensitization reduces the CD4(+) CD25(+) and CD4(+) CD25(+) forkhead protein 3 (FoxP3)(+) cell populations in the lungs and bronchoalveolar lavage. Furthermore, it also attenuates the inflammatory infiltrate and cytokine/chemokine expression levels in the mouse airways. In conclusion, the magnitude of the immune response to a non-viral respiratory perturbation in adult mice is not enhanced by a neonatal RSV infection.

Recombinant scorpine: a multifunctional antimicrobial peptide with activity against different pathogens.

Scorpine is an antimicrobial peptide whose structure resembles a hybrid between a defensin and a cecropin. It exhibits antibacterial activity and inhibits the sporogonic development of parasites responsible for murine malaria. In this communication we report the production of scorpine in a heterelogous system, using a specific vector containing its cloned gene. The recombinantly expressed scorpine (RScp) in (Anopheles gambie) cells showed antibacterial activity against (Bacillus subtilis) and (Klebsiella pneumoniae), at 5 and 10 microM, respectively. It also produced 98% mortality in sexual stages of (Plasmodium berghei) at 15 microM and 100% reduction in (Plasmodium falciparum) parasitemia at 5 microM. RScp also inhibited virus dengue-2 replication in C6/36 mosquito cells. In addition, we generated viable and fertile transgenic (Drosophila) that overexpresses and correctly secretes RScp into the insect hemolymph, suggesting that the generation of transgenic mosquitoes resistant to different pathogens may be viable.

A 65-kDa trypsin-sensible membrane cell protein as a possible receptor for dengue virus in cultured neuroblastoma cells.

Dengue virus infects primary neurons in mouse experimental model and tissue culture cells of the central nervous system (CNS). In the present work, a mouse neuroblastoma cell line (N1E-115) and a human neuroblastoma cell line (SK-N-SH), susceptible to dengue virus infection were used to study the presence of cell membrane receptor for dengue-2. By day 5 postinfection (pi), viral antigen was detected by immunofluorescence in the cytoplasm and surrounding the nucleus of N1E-115 cells, while on day 7 pi, it was also present along neural extensions. Infection of N1E-115 cells was diminished with trypsin treatment but not with neuraminidase or endoglycosidase H. Partially purified cell membrane proteins from neuroblastoma cells were analyzed by the Virus Overlay Protein Blot Assay (VOPBA), and a single band migrating at 65 kDa was detected in mouse and human neuroblastoma cells but not in C6, a non-susceptible rat glial cell line which was included as a negative control. The 65 kDa protein was eliminated only when nitrocellulose membranes were treated with trypsin. Analysis of neuronal cell infection by dengue virus provides a useful tool to understand the nature of cellular receptors and mechanisms involved in the infection of the nervous system by dengue viruses.

Detection of dengue virus from mosquito cell cultures inoculated with human serum in the presence of actinomycin D.

We report the use of cultures of mosquito cells (TRA-284) to detect dengue virus in serum from cases of dengue fever in the state of Puebla, México. Using the conventional procedure 56 of 171 samples (32.7%) were positive. The negative sera (67.3%) were passaged 'blind' in mosquito cell cultures but no virus was detected. However, when these sera were incubated in the presence of actinomycin D (an inhibitor of deoxyribonucleic acid transcription) 20 of the 115 samples (17.4%) became positive. This procedure increased the virus detection rate from 32.7% to 44.4%. Serotypes 1 and 4 were identified for the first time in the state of Puebla, where the transmission of dengue virus is increasing. The addition of actinomycin D to mosquito cell cultures may improve the detection of dengue virus and could be a useful tool for virological surveillance in endemic countries.

Dengue virus infects mouse cultured neurons but not astrocytes.

Cultures of mouse brain cells containing a high proportion either neurons or astrocytes were inoculated with various strains of dengue virus. At analysis by double immunofluorescence, all strains of dengue virus studied were tropic for neurons. In no case were the astrocytes infected. Only approximately 10% of all neurons were infected, suggesting that the virus may enter the cell through a membrane receptor present only in a subgroup of neurons.

Dengue virus. Detection and pathogeny.

Sequences front a cDNA of dengue virus type 4 were cloned into transcription vectors. These sequences included the E, NS1, NS2A, NS2B, NS3 genes. RNA transcripts produced in vitro from these plasmids were used in hybridization assays to detect dengue viral sequences. With these RNA-probes we have been able to detect molecules of serotype-specific dengue 4 viral RNA. Moreover, the riboprobes detected viral sequences of other serotypes in the following order of sensitivity 4 > 2 > 3 > 1, and might be useful to differentiate serotypes.

Synaptophysin and neurofilament expression in neurons infected with dengue virus.

The expression of two genes encoding the neuronal specific proteins synaptophysin and high molecular weight neurofilaments was investigated in primary cell cultures of embryonic mouse brain infected with dengue virus type 2, using immunocytochemistry and Western blot analysis with monoclonal antibodies. The viral infection leads to a 20-fold induction in the expression of the mentioned synaptogenesis-related proteins. These results suggest a correlation between virus infection and neuropathology of immature neurons in vivo.