Human endometrial receptivity: gene regulation

Endometrial receptivity is a self-limited period in which the endometrial epithelium (EE) acquires a functional and transient ovarian steroid-dependent status that allows blastocyst adhesion. Termed as "the window of implantation", this specific period opens 4-5 days after progesterone production or administration and closes after 9-10 days. Scientific knowledge on the endometrial receptivity process is fundamental for the understanding of human reproduction, but so far none of the proposed biochemical markers for endometrial receptivity has been proven to be clinically useful. In this work, we present strategies of cDNA analysis technologies that aim to clarify the fragmented information in this field. Specifically, the objective is the differential identification, cloning and sequencing of genes linked to endometrial receptivity in humans, combining differential display PCR and cDNA microarray analysis of endometrial epithelial-derived cell lines and endometrial samples obtained in the same patient 2 and 7 days after the luteinizing hormone (LH) surge (day LH+2) and (day LH+7), respectively.     

Reactive oxygen: its sources and significance in Alzheimer disease

Over the past decade, oxidative stress has been established as the earliest cytological feature of Alzheimer disease and an attractive therapeutic target. The major challenges now are establishing the source of the reactive oxygen and what oxidative stress tells us about the etiology of Alzheimer disease. These are complex issues since a variety of enzymatic and non-enzymatic processes are involved in reactive oxygen formation and damage to macromolecules. In this review, we consider disease mechanisms that show the greatest promise for future research.     

Evaluation of an educational module on dengue and Aedes aegypti for schoolchildren in Honduras]

OBJECTIVE: To evaluate the effectiveness of a special course on environmental health and dengue, given to primary school students and intended to promote behavioral changes in the mothers of those students that would lead to the safe handling of water, adequate disposal of trash, and control of household breeding sites of Aedes aegypti, the mosquito vector for dengue. METHODS: In the period from April to November 2002 a community field trial was carried out that included four public schools in the city of Comayaguela, Honduras. Two of the schools formed the intervention group, and the two others made up the comparison or control group. The data collection activities before and after the intervention included knowledge tests for the schoolchildren and the teachers; surveys of the knowledge, attitudes, and practices of the students' mothers; entomological surveys (systematic checking in order to find water containers, to search for mosquito larvae) in the homes of the schoolchildren; in-depth interviews with the students' mothers; observation in the classrooms; and postintervention focus group with the teachers. RESULTS: During the intervention period the largest epidemic of classical dengue ever in the history of Tegucigalpa, the capital of Honduras, occurred. That event prompted the Secretariat of Health to undertake large-scale control activities. In the two intervention schools there was a significant increase in the students' knowledge of the following three variables: dengue caused by a virus, life cycle of the vector, and reduction of breeding sites, which is the most effective measure for controlling the vector (P < 0.0001 for all those increases in knowledge). There were also significant increases in the knowledge of the same variables among the teachers in the intervention schools: dengue caused by a virus (P = 0.03), life cycle of the vector (P = 0.01), and reduction of breeding sites (P = 0.004). Reducing the number of breeding sites as being the best measure for controlling Aedes aegypti was the knowledge variable that showed the greatest change among the mothers in the intervention group (P = 0.02). The values for two of the entomological indices (the House index and the Breteau index) were better in the intervention group than in the control group, but the difference was not statistically significant. However, there was a statistically significant difference in the Breteau index values between the two control group schools and the one intervention school where the education course was implemented more adequately than in the other intervention school. CONCLUSIONS: The application of educational interventions directed to schoolchildren, as a part of a comprehensive plan for controlling Aedes aegypti, is an effective way to raise the awareness of teachers and parents with respect to the problem of dengue, and it also helps in encouraging family members to be involved in reducing breeding sites in the home. In moving to control the dengue vector, this strategy should take into consideration the involvement not only of families but also of civic and public institutions in the community. Given our results, it appears that this approach of using a special course for schoolchildren can constitute a fundamental pillar in the strategy for integrated dengue control.     

A two-hybrid screening of human Tau protein: interactions with Alu-derived domain

The microtubule associated protein tau has been implicated in several neurodegenerative diseases, grouped as tauopathies. To search for tau-associated proteins, the two-hybrid system was used with tau as a bait and an adult human brain cDNA library as a source of putative interacting proteins. We have identified two positive clones consisting of an Alu-derived amino acid sequence that binds to tau and show moderate homology with a motif found in several neuronal proteins related to neurodegenerative disorders. We have also demonstrated that the Alu-derived motif interacts in vitro with tau and may be involved in modulation of its phosphorylation. These findings suggest the existence of tau-binding proteins that are able to bind to tau through their Alu-derived sequence in a direct way. The possible interaction of these proteins with tau could play a role in its cellular localization, regulate the amount of phosphorylated tau and also be involved in the pathological processes of tauopathies.     

Meconium-stained amniotic fluid: a risk factor for microbial invasion of the amniotic cavity

The purpose of this study was to determine whether meconium-stained amniotic fluid is a marker for microbial invasion of the amniotic cavity. Amniocentesis was performed on 707 patients presenting with preterm labor and intact membranes. Meconium-stained amniotic fluid was present in 4.2% (30/707) of patients with preterm labor. The prevalence of positive amniotic fluid cultures was significantly higher in women with meconium-stained amniotic fluid than in women with clear fluid (33% [10/30] vs 11% [75/677]; p = 0.001; odds ratio = 4.01; 95% confidence interval = 1.6 to 9.4). Patients with meconium-stained amniotic fluid were also more likely to have failed tocolysis and delivered a preterm neonate more frequently than patients with clear fluid (83% [25/30] vs 38% (258/677); p = 0.0001; odds ratio = 8.1; 95% confidence interval = 2.9 to 24.4). We conclude that meconium-stained amniotic fluid is a risk factor for microbial invasion of the amniotic cavity and preterm delivery in women with preterm labor and intact membranes.     

Pituitary response to luteinizing hormone-releasing hormone analog at sea level and high altitudes

Two groups of subjects living at different altitudes were stimulated with synthetic luteinizing hormone-releasing hormone (LH-RH) or with an LH-RH analog. One hundred micrograms LH-RH was given subcutaneously to 19 men and 19 women, all normal, of reproductive age, and living at sea level, and to 19 men and 20 women living at a high altitude (2940 m). In neither sex, however, were the differences in peak responses for both gonadotropins significantly different between the sea level and high-altitude groups. Plasma levels of LH and follicle-stimulating hormone (FSH) were also measured after administration of [D-Leu6, des Gly-NH2(10)]-LH-RH ethylamide (25 micrograms subcutaneously) in 32 men and 37 women living at sea level and at high altitude. The analog induced a powerful and protracted stimulation of the release of LH and FSH irrespective of altitude and sex. The responses of men and women to the LH-RH analog, both for LH as well as for FSH, were significantly greater at sea level than at high altitudes.     

Small intestinal development in growth-retarded fetal sheep

The functional maturity of the gastrointestinal system is essential for the survival of the neonate. The effects of reducing placental size and the ensuing fetal growth retardation on the development of the small intestine (SI) of the sheep fetus were investigated. At 140 days of gestation (term is 147 days), fetal body weight, gastrointestinal weight (from the abomasum to the rectum, i.e., the gut), SI weight, and SI length in the growth-retarded fetuses (n = 6) were significantly reduced (p less than 0.05) when compared with age- and breed-matched control fetuses. The SI weight was disproportionately reduced as a fraction of the gut weight or SI length (p less than 0.01). The proximal SI showed marked reductions in the thickness of the wall, muscularis externa, mucosa, villus height, and crypt depth (p less than 0.003). Densities of villi and crypts were also reduced (p less than 0.02). The crypt-to-villus ratio was maintained. Glycogen was accumulated basally in the villus epithelial cells, and their nuclei were located apically. These characteristics are comparable to those of much younger fetuses. In the distal SI, interanimal variation was large; however, the mean thickness of the wall, the muscularis externa, the mucosa, and the villus height were all reduced (p less than 0.05). In this region, the density of villi and crypts, the pattern of glycogen accumulation, and the position of the nuclei did not markedly differ between growth-retarded and control fetuses. Villus cell density was increased (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)