ABSTRACT
Cadherins are adhesion molecules that play a crucial role in tissue morphogenesis. Studies on N-cadherin and E-cadherin in the ovary of fetal hamster suggest that these adhesion molecules are involved in primordial follicle formation. In chicken embryo, present results demonstrate that N-cadherin is located on the surface epithelium and in the cortical cords of the ovary. Moreover, N-cadherin is identified in germ cells on day 14 of chicken embryo development. Quantification of mRNA of N-cadherin and E-cadherin demonstrates that treatments with follicle-stimulating hormone (FSH) or human chorionic gonadotropin (hCG), increase N-cadherin expression. Whereas, E-cadherin expression is decreased by gonadotropin treatments. The negative correlation between both cadherins expression is demonstrated after 18 h of hormonal treatment. Regulation of cadherin expression by gonadotropins and the presence of N-cadherin in the ovarian cortex suggest that these adhesion molecules are involved in ovarian morphogenesis in the chicken embryo.
Subject(s)
Cadherins/genetics , Chick Embryo/metabolism , Gonadotropins/physiology , Ovary/metabolism , Animals , Cadherins/metabolism , Cells, Cultured , Chorionic Gonadotropin/pharmacology , Female , Fluorescent Antibody Technique , Gene Expression Regulation, Developmental/drug effects , Gonadotropins/pharmacology , Humans , Morphogenesis/drug effects , Morphogenesis/genetics , Morphogenesis/physiology , Ovary/cytology , Ovary/drug effects , Ovary/embryology , Primary Cell Culture , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
BACKGROUND: Dengue virus infection is an emergent viral disease and the most important transmitted by a vector worldwide. In Mexico it has been an important public health problem since 1995 and Oaxaca is one of the most affected states in the country. OBJECTIVE: To determine the geographic distribution of confirmed dengue cases in the state of Oaxaca, Mexico, the serotypes circulating, and the main gender and age groups affected. STUDY DESIGN: Information about confirmed dengue cases obtained by LESPO during the period 2004-2006 was classified, sorted, and analysed. A RT-PCR technique was used to determine the serotype of the virus in serum samples. RESULTS: A substantial increment in the number of dengue cases was noticed during the period of this study. The most affected sanitary jurisdiction was located on the coast where the climatic conditions were ideal for vector development and where there is significant migratory activity. The most affected group was the 11-15-year-old group. Dengue haemorrhagic fever was more frequent in men than in women over 16 years old, with a significant difference evaluated by chi(2)-test (p<0.001). Four serotypes of the virus were detected in the state and two co-infections with DEN2-3 and DEN3-4 were identified. CONCLUSIONS: The increment in the number of dengue cases in the state of Oaxaca could be explained by several factors such as the presence of the four serotypes of the virus, the migratory phenomenon, the climatic conditions and the socioeconomic level of the population.
Subject(s)
Dengue Virus/isolation & purification , Dengue/epidemiology , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Child , Child, Preschool , Dengue Virus/classification , Female , Humans , Infant , Infant, Newborn , Male , Mexico/epidemiology , Middle Aged , Risk Factors , Serotyping , Sex Factors , Young AdultABSTRACT
BACKGROUND: Dengue virus is spread in tropical areas of the world and is the causative agent of dengue fever and dengue hemorrhagic fever. It is horizontally transmitted to humans by infected Aedes mosquitoes, but it is also able to be vertically or transovarially transmitted to insect progeny. OBJECTIVE: In this work, we analyzed the vertical transmission of dengue virus in Aedes aegypti mosquitoes collected in two endemic localities in the state of Oaxaca, Mexico. METHODS: The collected larvae were grown in the laboratory and transovarial transmission of dengue virus, either in larvae or newly emerged mosquitoes, was investigated using a semi-nested reverse transcription-polymerase chain reaction method. RESULTS: Although the presence of dengue virus in larvae could not be demonstrated, the viral genome was amplified in 4 out of 43 pools of in-cage born mosquitoes: DEN 2, 3 and 4 serotypes were detected in 2 pools from Tuxtepec and two from Juchitán. CONCLUSION: The results presented here strongly suggest that dengue virus can be vertically transmitted in mosquitoes from Oaxaca, but more studies will be necessary to analyze the epidemiological impact of this mechanism of transmission.
