Aedes aegypti, the dengue fever mosquito in Mexico City. Early invasion and its potential risks.

INTRODUCTION: Mexico City has no endemic presence of Aedes aegypti, and it is therefore free of vector-borne diseases, such as dengue fever, Zika and chikungunya. However, evidence has shown the presence of Aedes aegypti eggs in the city since 2015. OBJECTIVE: To report the constant and increasing presence of Aedes aegypti eggs in Mexico City from 2015 to 2018. METHODS: Surveillance was carried out using ovitraps. Eggs were counted and hatched in order to determine the species. RESULTS: From 2015 to 2018, 378 organisms were identified as Ae. aegypti. In total, 76 Aedes aegypti-positive ovitraps were collected at 50 different places in 11 boroughs of the city. Northeastern Mexico City was the area with the highest number of positive traps. CONCLUSIONS: The results may be indicating a period of early colonization and the probable existence of cryptic colonies of the mosquito; Mexico City could be at risk of experiencing vector-borne epidemics.

INTRODUCCIÓN: La Ciudad de México no tiene presencia endémica de Aedes aegypti, por lo que está libre de enfermedades transmitidas por vector como dengue, Zika y chikunguña. Sin embargo, existe evidencia de la presencia de huevecillos en la urbe desde 2015. OBJETIVO: Reportar la presencia constante y en aumento de huevecillos de Aedes aegypti en la Ciudad de México de 2015 a 2018. MÉTODO: Se realizó vigilancia a través de ovitrampas; se contabilizaron y eclosionaron huevecillos para determinar la especie. RESULTADOS: De 2015 a 2018 fueron identificados 378 organismos como Aedes aegypti. En total fueron colectadas 76 ovitrampas positivas a Aedes aegypti en 50 sitios distintos de 11 alcaldías. El noreste de la Ciudad de México fue el área con mayor positividad. CONCLUSIONES: Los resultados pueden estar indicando un periodo de colonización incipiente y la probable la existencia de colonias crípticas del mosquito, por lo que la Ciudad de México podría estar en riesgo de presentar epidemias de enfermedades transmitidas por vector.

Effects of hippocampal high-frequency electrical stimulation in memory formation and their association with amino acid tissue content and release in normal rats.

Hippocampal high frequency electrical stimulation (HFS) at 130 Hz has been proposed as a therapeutical strategy to control neurological disorders such as intractable temporal lobe epilepsy (TLE). This study was carried out to determine the effects of hippocampal HFS on the memory process and the probable involvement of amino acids. Using the autoshaping task, we found that animals receiving hippocampal HFS showed augmented short-term, but not long-term memory formation, an effect blocked by bicuculline pretreatment and associated with enhanced tissue levels of amino acids in hippocampus. In addition, microdialysis experiments revealed high extracellular levels of glutamate, aspartate, glycine, taurine, and alanine during the application of hippocampal HFS. In contrast, GABA release augmented during HFS and remained elevated for more than 1 h after the stimulation was ended. HFS had minimal effects on glutamine release. The present results suggest that HFS has an activating effect on specific amino acids in normal hippocampus that may be involved in the enhanced short-term memory formation. These data further provide experimental support for the concept that hippocampus may be a promising target for focal stimulation to treat intractable seizures in humans.

Temporal lobe epilepsy causes selective changes in mu opioid and nociceptin receptor binding and functional coupling to G-proteins in human temporal neocortex.

There is no information concerning signal transduction mechanisms downstream of the opioid/nociceptin receptors in the human epileptic brain. The aim of this work was to evaluate the level of G-proteins activation mediated by DAMGO (a mu receptor selective peptide) and nociceptin, and the binding to mu and nociceptin (NOP) receptors and adenylyl cyclase (AC) in neocortex of patients with pharmacoresistant temporal lobe epilepsy. Patients with temporal lobe epilepsy associated with mesial sclerosis (MTLE) or secondary to tumor or vascular lesion showed enhanced [3H]DAMGO and [3H]forskolin binding, lower DAMGO-stimulated [35S]GTPgammaS binding and no significant changes in nociceptin-stimulated G-protein. [3H]Nociceptin binding was lower in patients with MTLE. Age of seizure onset correlated positively with [3H]DAMGO binding and DAMGO-stimulated [35S]GTPgammaS binding, whereas epilepsy duration correlated negatively with [3H]DAMGO and [3H]nociceptin binding, and positively with [3H]forskolin binding. In conclusion, our present data obtained from neocortex of epileptic patients provide strong evidence that a) temporal lobe epilepsy is associated with alterations in mu opioid and NOP receptor binding and signal transduction mechanisms downstream of these receptors, and b) clinical aspects may play an important role on these receptor changes.

El mosquito del dengue en la Ciudad de México. Invasión incipiente de Aedes aegypti y sus potenciales riesgos / Aedes aegypti, the dengue fever mosquito in Mexico City. Early invasion and its potential risks

Resumen Introducción: La Ciudad de México no tiene presencia endémica de Aedes aegypti, por lo que está libre de enfermedades transmitidas por vector como dengue, Zika y chikunguña. Sin embargo, existe evidencia de la presencia de huevecillos en la urbe desde 2015. Objetivo: Reportar la presencia constante y en aumento de huevecillos de Aedes aegypti en la Ciudad de México de 2015 a 2018. Método: Se realizó vigilancia a través de ovitrampas; se contabilizaron y eclosionaron huevecillos para determinar la especie. Resultados: De 2015 a 2018 fueron identificados 378 organismos como Aedes aegypti. En total fueron colectadas 76 ovitrampas positivas a Aedes aegypti en 50 sitios distintos de 11 alcaldías. El noreste de la Ciudad de México fue el área con mayor positividad. Conclusiones: Los resultados pueden estar indicando un periodo de colonización incipiente y la probable la existencia de colonias crípticas del mosquito, por lo que la Ciudad de México podría estar en riesgo de presentar epidemias de enfermedades transmitidas por vector.

Abstract Introduction: Mexico City has no endemic presence of Aedes aegypti, and it is therefore free of vector-borne diseases, such as dengue fever, Zika and chikungunya. However, evidence has shown the presence of Aedes aegypti eggs in the city since 2015. Objective: To report the constant and increasing presence of Aedes aegypti eggs in Mexico City from 2015 to 2018. Methods: Surveillance was carried out using ovitraps. Eggs were counted and hatched in order to determine the species. Results: From 2015 to 2018, 378 organisms were identified as Ae. aegypti. In total, 76 Aedes aegypti-positive ovitraps were collected at 50 different places in 11 boroughs of the city. Northeastern Mexico City was the area with the highest number of positive traps. Conclusions: The results may be indicating a period of early colonization and the probable existence of cryptic colonies of the mosquito, and Mexico City could be therefore at risk of experiencing vector-borne epidemics.