33 research outputs found
Cervical epithelial damage promotes Ureaplasma parvum ascending infection, intrauterine inflammation and preterm birth induction in mice
Around 40% of preterm births are attributed to ascending intrauterine infection, and Ureaplasma parvum (UP) is commonly isolated in these cases. Here we present a mouse model of ascending UP infection that resembles human disease, using vaginal inoculation combined with mild cervical injury induced by a common spermicide (Nonoxynol-9, as a surrogate for any mechanism of cervical epithelial damage). We measure bacterial load in a non-invasive manner using a luciferase-expressing UP strain, and post-mortem by qPCR and bacterial titration. Cervical exposure to Nonoxynol-9, 24 h pre-inoculation, facilitates intrauterine UP infection, upregulates pro-inflammatory cytokines, and increases preterm birth rates from 13 to 28%. Our results highlight the crucial role of the cervical epithelium as a barrier against ascending infection. In addition, we expect the mouse model will facilitate further research on the potential links between UP infection and preterm birth
Global report on preterm birth and stillbirth (2 of 7): discovery science
<p>Abstract</p> <p>Background</p> <p>Normal and abnormal processes of pregnancy and childbirth are poorly understood. This second article in a global report explains what is known about the etiologies of preterm births and stillbirths and identifies critical gaps in knowledge. Two important concepts emerge: the continuum of pregnancy, beginning at implantation and ending with uterine involution following birth; and the multifactorial etiologies of preterm birth and stillbirth. Improved tools and data will enable discovery scientists to identify causal pathways and cost-effective interventions.</p> <p>Pregnancy and parturition continuum</p> <p>The biological process of pregnancy and childbirth begins with implantation and, after birth, ends with the return of the uterus to its previous state. The majority of pregnancy is characterized by rapid uterine and fetal growth without contractions. Yet most research has addressed only uterine stimulation (labor) that accounts for <0.5% of pregnancy.</p> <p>Etiologies</p> <p>The etiologies of preterm birth and stillbirth differ by gestational age, genetics, and environmental factors. Approximately 30% of all preterm births are indicated for either maternal or fetal complications, such as maternal illness or fetal growth restriction. Commonly recognized pathways leading to preterm birth occur most often during the gestational ages indicated: (1) inflammation caused by infection (22-32 weeks); (2) decidual hemorrhage caused by uteroplacental thrombosis (early or late preterm birth); (3) stress (32-36 weeks); and (4) uterine overdistention, often caused by multiple fetuses (32-36 weeks). Other contributors include cervical insufficiency, smoking, and systemic infections. Many stillbirths have similar causes and mechanisms. About two-thirds of late fetal deaths occur during the antepartum period; the other third occur during childbirth. Intrapartum asphyxia is a leading cause of stillbirths in low- and middle-income countries.</p> <p>Recommendations</p> <p>Utilizing new systems biology tools, opportunities now exist for researchers to investigate various pathways important to normal and abnormal pregnancies. Improved access to quality data and biological specimens are critical to advancing discovery science. Phenotypes, standardized definitions, and uniform criteria for assessing preterm birth and stillbirth outcomes are other immediate research needs.</p> <p>Conclusion</p> <p>Preterm birth and stillbirth have multifactorial etiologies. More resources must be directed toward accelerating our understanding of these complex processes, and identifying upstream and cost-effective solutions that will improve these pregnancy outcomes.</p
Documento de posición sobre las necesidades y niveles óptimos de vitamina D
IntroducciónEn los últimos años se ha producido un notable interés por la vitamina D, no sólo por su importancia crucial en el metabolismo mineral óseo, sino también por los efectos extraóseos, cada vez mejor conocidos.
Asi mismo, se ha constatado la existencia de valores séricos bajos de vitamina D, por debajo de lo deseable, en diferentes poblaciones, tanto sanas como enfermas, y se discute cuáles serían los niveles óptimos de vitamina D en sangre.
Por todo ello, la Sociedad Española de Investigación Ósea y Metabolismo Mineral (SEIOMM), conjuntamente con todas las Sociedades Científicas implicadas en el estudio del metabolismo óseo, han elaborado el presente documento de posición sobre las necesidades y niveles óptimos de vitamina D
Tropical cyclone statistics in the Northeastern Pacific
The principal area of tropical cyclogenesis in the tropical eastern Pacific Ocean is offshore in the Gulf of Tehuantepec, between 8 and 15° N, and most of these cyclones move towards the west and northwest during their initial phase. Historical analysis of tropical cyclone data in the Northeastern (NE) Pacific over the last 38 years (from 1966 to 2004) shows a mean of 16.3 tropical cyclones per year, consisting of 8.8 hurricanes and 7.4 tropical storms. The analysis shows great geographical variability of cyclone tracks, and that there were a considerable number of hurricane strikes along the Mexican coast. About 50% of the tropical cyclones formed turned north to northeast. It was rare that any passed further north than 30° N in latitude because of the cold California Current. Hurricane tracks that affected the NE Pacific may be separated into 5 groups. We compared the historical record of the sea surface temperature (SST), related with the El Niño events with a data set of tropical cyclones, including frequency, intensity, trajectory, and duration. Although the statistical dependence between the frequencies of tropical cyclones of the most abundant categories, 1 and 2, over this region and SST data was not convincing, the percentage of high intensity hurricanes and hurricanes with a long life-time (greater than 12 days) was more during El Niño years than in non-El Niño years
Enhanced Predictability of Eastern North Pacific Tropical Cyclone Activity Using the ENSO Longitude Index
While El Niño–Southern Oscillation (ENSO) influences eastern North Pacific (ENP) tropical cyclones (TCs) through a variety of atmospheric processes when examined concurrently, ocean pathways dominate at longer lead times. The eastward displacement of the warm pool during an El Niño, which carries warm water into the ENP basin, is the primary oceanic mechanism. Despite this, the question of whether an accurate knowledge of preseason ENSO conditions enhances predictability of ENP TCs has not been addressed specifically. In this study, we show that relative to traditional indices of ENSO, the ENSO Longitude Index (ELI) captures changes in the location of deep convection and associated thermocline processes more accurately. Consequently, the ELI explains more variability in the upper-ocean heat content, and thus TC activity, at lead times of several months in the ENP basin. These results motivate the need to further explore the predictability of ENP TCs associated with ENSO