The evolutionary heritage and ecological uniqueness of Scots pine in the Caucasus ecoregion is at risk of climate changes.

Scots pine is one of the most widely occurring pines, but future projections suggest a large reduction in its range, mostly at the southern European limits. A significant part of its range is located in the Caucasus, a global hot-spot of diversity. Pine forests are an important reservoir of biodiversity and endemism in this region. We explored demographic and biogeographical processes that shaped the genetic diversity of Scots pine in the Caucasus ecoregion and its probable future distribution under different climate scenarios. We found that the high genetic variability of the Caucasian populations mirrors a complex glacial and postglacial history that had a unique evolutionary trajectory compared to the main range in Europe. Scots pine currently grows under a broad spectrum of climatic conditions in the Caucasus, which implies high adaptive potential in the past. However, the current genetic resources of Scots pine are under high pressure from climate change. From our predictions, over 90% of the current distribution of Scots pine may be lost in this century. By threatening the stability of the forest ecosystems, this would dramatically affect the biodiversity of the Caucasus hot-spot.

Trichorionic and dichorionic triplet pregnancies at 10-14 weeks: outcome after embryo reduction compared to expectant management.

OBJECTIVE: To compare the outcome of trichorionic triplet (TCT) and dichorionic triplet (DCT) pregnancies managed expectantly and those with embryo reduction (ER) at 10-14 weeks to twins or singletons. METHODS: This was a retrospective study of triplet pregnancies with 3 live fetuses managed expectantly or by ER. Data were combined with the results of previous studies that used similar entry criteria and outcome measures. The management options were compared for rates of miscarriage and preterm birth <33 weeks. RESULTS: In TCTs managed expectantly (n = 358), the rates of miscarriage and preterm birth were 3.1 and 35.1%. Compared to the expectantly managed TCTs, the rate of miscarriage was higher and preterm birth lower in TCTs with ER to 2 fetuses (n = 833, 7.3 and 13.1%, respectively) and TCTs with ER to 1 fetus (n = 78, 11.5 and 8.7%). In DCTs managed expectantly (n = 136), the rates of miscarriage and preterm birth were 8.8 and 46.0%. In DCTs with ER to 2 fetuses (n = 15) or ER to 1 fetus (n = 42), there was a non-significant increase in miscarriage (13.3 and 16.7%, respectively) and decrease in preterm birth (23.1 and 8%, respectively). CONCLUSIONS: In TCT and DCT pregnancies, ER increases the rate of miscarriage but reduces the rate of preterm birth.

Meta-analysis of second-trimester markers for trisomy 21.

OBJECTIVE: To summarize by meta-analysis the accumulated data on the screening performance of second-trimester sonographic markers for fetal trisomy 21. METHODS: We conducted a literature search to identify studies between 1995 and September 2012 that provided data on the incidence of sonographic markers in trisomy 21 and euploid fetuses at 14-24 weeks' gestation. Weighted independent estimates of detection rate, false-positive rate and positive and negative likelihood ratios (LR) of markers were calculated. RESULTS: A total of 48 studies was included in the analysis. The pooled estimates of positive and negative LR were, respectively: 5.83 (95% CI, 5.02-6.77) and 0.80 (95% CI, 0.75-0.86) for intracardiac echogenic focus; 27.52 (95% CI, 13.61-55.68) and 0.94 (95% CI, 0.91-0.98) for ventriculomegaly; 23.30 (95% CI, 14.35-37.83) and 0.80 (95% CI, 0.74-0.85) for increased nuchal fold; 11.44 (95% CI, 9.05-14.47) and 0.90 (95% CI, 0.86-0.94) for hyperechogenic bowel; 7.63 (95% CI, 6.11-9.51) and 0.92 (95% CI, 0.89-0.96) for mild hydronephrosis; 3.72 (95% CI, 2.79-4.97) and 0.80 (95% CI, 0.73-0.88) for short femur; 4.81 (95% CI, 3.49-6.62) and 0.74 (95% CI, 0.63-0.88) for short humerus; 21.48 (95% CI, 11.48-40.19) and 0.71 (95% CI, 0.57-0.88) for aberrant right subclavian artery (ARSA); and 23.27 (95% CI, 14.23-38.06) and 0.46 (95% CI, 0.36-0.58) for absent or hypoplastic nasal bone. The combined negative LR, obtained by multiplying the values of individual markers, was 0.13 (95% CI, 0.05-0.29) when short femur but not short humerus was included and 0.12 (95% CI, 0.06-0.29) when short humerus but not short femur was included. CONCLUSION: The presence of sonographic markers increases, and absence of such markers decreases, the risk for trisomy 21. In the case of most isolated markers there is only a small effect on modifying the pre-test odds for trisomy 21, but with ventriculomegaly, nuchal fold thickness and ARSA there is a 3-4-fold increase in risk and with hypoplastic nasal bone a 6-7-fold increase.

Identification of a complex that binds to the CD154 3' untranslated region: implications for a role in message stability during T cell activation.

CD154 expression is regulated throughout a time course of CD3-dependent T cell activation by differential mRNA decay. To understand the molecular basis of the "stability" phase of this pathway, experiments were conducted to identify sequences and specific complexes important in this regulation. Gel retardation assays using extracts from both Jurkat T cells and CD3-activated CD4(+) T cells revealed a major complex (complex I) that bound a 65-bp highly CU-rich region of the CD154 3' untranslated region. The specificity of the CU-rich element for complex-I formation was confirmed by disruption of this complex by oligo(dCT) competition. Formation of complex I strongly correlated with CD154 mRNA stability across a time course of T cell activation. UV cross-linking identified a major oligo(dCT)-sensitive species at approximately 90 kDa that showed induced and increased expression in extracts from 24- and 48-hr anti-CD3-activated T cells, respectively. This protein was absent in equivalent extracts from resting or 2-h-activated T cells. Using an in vitro decay assay, we found that a CD154-specific transcript was more rapidly degraded in 2-h-activated extract and stabilized in the 24- and 48-h extracts compared to extracts from resting T cells. Disruption of complex I resulted in the rapid decay of a CD154-specific transcript demonstrating a functional role for complex I in mRNA stabilization in vitro. These studies support a model of posttranscriptional regulation of CD154 expression being controlled in part by the interaction of a poly(CU)-binding complex with a specific sequence in the 3' untranslated region.