A Middle Eocene lowland humid subtropical "Shangri-La" ecosystem in central Tibet.

Tibet's ancient topography and its role in climatic and biotic evolution remain speculative due to a paucity of quantitative surface-height measurements through time and space, and sparse fossil records. However, newly discovered fossils from a present elevation of ∼4,850 m in central Tibet improve substantially our knowledge of the ancient Tibetan environment. The 70 plant fossil taxa so far recovered include the first occurrences of several modern Asian lineages and represent a Middle Eocene (∼47 Mya) humid subtropical ecosystem. The fossils not only record the diverse composition of the ancient Tibetan biota, but also allow us to constrain the Middle Eocene land surface height in central Tibet to ∼1,500 ± 900 m, and quantify the prevailing thermal and hydrological regime. This "Shangri-La"-like ecosystem experienced monsoon seasonality with a mean annual temperature of ∼19 °C, and frosts were rare. It contained few Gondwanan taxa, yet was compositionally similar to contemporaneous floras in both North America and Europe. Our discovery quantifies a key part of Tibetan Paleogene topography and climate, and highlights the importance of Tibet in regard to the origin of modern Asian plant species and the evolution of global biodiversity.

The oldest Mahonia (Berberidaceae) fossil from East Asia and its biogeographic implications.

Interpretation of the biogeography of the genus Mahonia (Berberidaceae) is limited by the lack of fossil records in East Asia. Compressed fossil foliage, described here as Mahonia mioasiatica sp. nov., were collected from the Upper Miocene Xiaolongtan Formation in Wenshan, Yunnan, southwest China. These specimens represent the oldest reliable fossil record of Mahonia in East Asia. This new fossil species shows a general similarity to Group Orientales and is most similar to the extant eastern Asian Mahonia conferta. Considering other fossil evidence of Mahonia, we propose a migration route of this genus to Asia over the North Atlantic Land Bridge rather than the Bering Land Bridge. Our results also suggest that North America, Europe and East Asia have been successive centers of diversity for the genus, as a consequence of diversification in Group Orientales potentially related to historical climate change.

Identification of key genes associated with the effect of estrogen on ovarian cancer using microarray analysis.

PURPOSE: To identify key genes related to the effect of estrogen on ovarian cancer. METHODS: Microarray data (GSE22600) were downloaded from Gene Expression Omnibus. Eight estrogen and seven placebo treatment samples were obtained using a 2 × 2 factorial designs, which contained 2 cell lines (PEO4 and 2008) and 2 treatments (estrogen and placebo). Differentially expressed genes were identified by Bayesian methods, and the genes with P < 0.05 and |log2FC (fold change)| ≥0.5 were chosen as cut-off criterion. Differentially co-expressed genes (DCGs) and differentially regulated genes (DRGs) were, respectively, identified by DCe function and DRsort function in DCGL package. Topological structure analysis was performed on the important transcriptional factors (TFs) and genes in transcriptional regulatory network using tYNA. Functional enrichment analysis was, respectively, performed for DEGs and the important genes using Gene Ontology and KEGG databases. RESULTS: In total, 465 DEGs were identified. Functional enrichment analysis of DEGs indicated that ACVR2B, LTBP1, BMP7 and MYC involved in TGF-beta signaling pathway. The 2285 DCG pairs and 357 DRGs were identified. Topological structure analysis showed that 52 important TFs and 65 important genes were identified. Functional enrichment analysis of the important genes showed that TP53 and MLH1 participated in DNA damage response and the genes (ACVR2B, LTBP1, BMP7 and MYC) involved in TGF-beta signaling pathway. CONCLUSION: TP53, MLH1, ACVR2B, LTBP1 and BMP7 might participate in the pathogenesis of ovarian cancer.

New Biogeographic insight into Bauhinia s.l. (Leguminosae): integration from fossil records and molecular analyses.

BACKGROUND: Given that most species that have ever existed on earth are extinct, it stands to reason that the evolutionary history can be better understood with fossil taxa. Bauhinia is a typical genus of pantropical intercontinental disjunction among the Asian, African, and American continents. Geographic distribution patterns are better recognized when fossil records and molecular sequences are combined in the analyses. Here, we describe a new macrofossil species of Bauhinia from the Upper Miocene Xiaolongtan Formation in Wenshan County, Southeast Yunnan, China, and elucidate the biogeographic significance through the analyses of molecules and fossils. RESULTS: Morphometric analysis demonstrates that the leaf shapes of B. acuminata, B. championii, B. chalcophylla, B. purpurea, and B. podopetala closely resemble the leaf shapes of the new finding fossil. Phylogenetic relationships among the Bauhinia species were reconstructed using maximum parsimony and Bayesian inference, which inferred that species in Bauhinia species are well-resolved into three main groups. Divergence times were estimated by the Bayesian Markov chain Monte Carlo (MCMC) method under a relaxed clock, and inferred that the stem diversification time of Bauhinia was ca. 62.7 Ma. The Asian lineage first diverged at ca. 59.8 Ma, followed by divergence of the Africa lineage starting during the late Eocene, whereas that of the neotropical lineage starting during the middle Miocene. CONCLUSIONS: Hypotheses relying on vicariance or continental history to explain pantropical disjunct distributions are dismissed because they require mostly Palaeogene and older tectonic events. We suggest that Bauhinia originated in the middle Paleocene in Laurasia, probably in Asia, implying a possible Tethys Seaway origin or an "Out of Tropical Asia", and dispersal of legumes. Its present pantropical disjunction resulted from disruption of the boreotropical flora by climatic cooling after the Paleocene-Eocene Thermal Maximum (PETM). North Atlantic land bridges (NALB) seem the most plausible route for migration of Bauhinia from Asia to America; and additional aspects of the Bauhinia species distribution are explained by migration and long distance dispersal (LDD) from Eurasia to the African and American continents.

Early Oligocene Itea (Iteaceae) leaves from East Asia and their biogeographic implications.

Compressed materials of fossil foliage described here as Itea polyneura sp. nov. (Iteaceae) were collected from the Oligocene of Wenshan, Yunnan Province, southwestern China. The identification is based on the following characters: eucamptodromous secondary veins, strict scalariform tertiary veins, irregular tooth with setaceous apex. The leaf morphology of all modern and fossil species was compared with the new species from Wenshan and show that I. polyneura is most similar to the extant East Asian species Itea omeiensis, which inhabits subtropical forests of southern China. This discovery represents the first unambiguous leaf fossil record of Itea in East Asia. Together with other species in the Wenshan flora and evidence from several other flora in southern China, these findings demonstrate that Itea from East Asia arose with the Paleogene modernization.

Erratum.

Glioma is the most common and lethal malignant intracranial tumor. Long noncoding RNAs (lncRNAs) have been identified as pivotal regulators in the tumorigenesis of glioma. However, the role of lncRNA urothelial carcinoma-associated 1 (UCA1) in glioma genesis is still unknown. The purpose of this study was to investigate the underlying function of UCA1 on glioma genesis. The results demonstrated that UCA1 was upregulated in glioma tissue and indicated a poor prognosis. UCA1 knockdown induced by si-UCA1 significantly suppressed the proliferative, migrative, and invasive activities of glioma cell lines (U87 and U251). Bioinformatics analysis and luciferase reporter assay verified the complementary binding within UCA1 and miR-122 at the 3-UTR. Functional experiments revealed that UCA1 acted as an miR-122 sponge to modulate glioma cell proliferation, migration, and invasion via downregulation of miR-122. Overall, the present study demonstrated that lncRNA UCA1 acts as an endogenous sponge of miR-122 to promote glioma cell proliferation, migration, and invasion, which provides a novel insight and therapeutic target in the tumorigenesis of glioma.

Uplift, climate and biotic changes at the Eocene-Oligocene transition in south-eastern Tibet.

The uplift history of south-eastern Tibet is crucial to understanding processes driving the tectonic evolution of the Tibetan Plateau and surrounding areas. Underpinning existing palaeoaltimetric studies has been regional mapping based in large part on biostratigraphy that assumes a Neogene modernization of the highly diverse, but threatened, Asian biota. Here, with new radiometric dating and newly collected plant-fossil archives, we quantify the surface height of part of the south-eastern margin of Tibet in the latest Eocene (∼34 Ma) to be ∼3 km and rising, possibly attaining its present elevation (3.9 km) in the early Oligocene. We also find that the Eocene-Oligocene transition in south-eastern Tibet witnessed leaf-size diminution and a floral composition change from sub-tropical/warm temperate to cool temperate, likely reflective of both uplift and secular climate change, and that, by the latest Eocene, floral modernization on Tibet had already taken place, implying modernization was deeply rooted in the Palaeogene.

[Determination of rhenium in raffinate and residue from synthesis of methyltrioxorhenium by ICP-AES].

Methyltrioxorhenium is a novel and efficient organometallic catalyst. It has exhibited amazingly high activities in a variety of organic reactions, and can form compounds with Lewis base. Thus, the improvement of its synthesis rate has become a pop topic all over the world. The content of rhenium in raffinate and residue from the synthesis of methyltrioxorhenium is an important standard for the evaluation of synthesis rate and a foundation for the optimization of synthesis condition. UV spectrophotometry is the standard technique for the determination of rhenium. However, this method presents several disadvantanges such as low sensitivity, high interferences, and hard handling. Inductive coupled plasma-atomic emission spectrometry has many advantages such as high precision, rapid analysis speed and good stability, and can determine multi-elements simultaneously. It is widely used in determination in every walk of life. An ICP-AES method for determination of the content of rhenium in raffinate and residue from the synthesis of methyltrioxorhenium was used. The working parameters were optimized. The detection limit was 0.01 mg x L(-1). RSD was in the range of 0.48%-1.12% and recoveries in the range from 97.2%-104% were obtained. The spectrum interference can be neglected. Compared with spectrophotometer, the proposed method was proved to be simple, rapid and accurate, and the result was satisfactory.

Long Noncoding RNA UCA1 Targets miR-122 to Promote Proliferation, Migration, and Invasion of Glioma Cells.

Glioma is the most common and lethal malignant intracranial tumor. Long noncoding RNAs (lncRNAs) have been identified as pivotal regulators in the tumorigenesis of glioma. However, the role of lncRNA urothelial carcinoma-associated 1 (UCA1) in glioma genesis is still unknown. The purpose of this study was to investigate the underlying function of UCA1 on glioma genesis. The results demonstrated that UCA1 was upregulated in glioma tissue and indicated a poor prognosis. UCA1 knockdown induced by si-UCA1 significantly suppressed the proliferative, migrative, and invasive activities of glioma cell lines (U87 and U251). Bioinformatics analysis and luciferase reporter assay verified the complementary binding within UCA1 and miR-122 at the 3'-UTR. Functional experiments revealed that UCA1 acted as an miR-122 "sponge" to modulate glioma cell proliferation, migration, and invasion via downregulation of miR-122. Overall, the present study demonstrated that lncRNA UCA1 acts as an endogenous sponge of miR-122 to promote glioma cell proliferation, migration, and invasion, which provides a novel insight and therapeutic target in the tumorigenesis of glioma.

Hypoglycemic effect and mechanism of isoquercitrin as an inhibitor of dipeptidyl peptidase-4 in type 2 diabetic mice.

Glucagon-like peptide (GLP)-1 is a potent glucose-dependent insulinotropic gut hormone released from intestinal L cells. The aim of this study was to investigate isoquercitrin as an inhibitor of dipeptidyl peptidase IV (DPP-IV) and determine whether it affects GLP-1 release in normal mice and NCI-H716 cells. In vitro, we used chromogenic substrate method detection methods to measure DPP-IV. We found that isoquercitrin was a competitive inhibitor, with IC50 and K i values of 96.8 and 236 µM, respectively. Isoquercitrin and sitagliptin also stimulated GLP-1 release in NCI-H716 cells. In vivo, a type 2 diabetic mouse model was established, and oral treatment with different concentration of isoquercitrin and sitagliptin for 8 weeks significantly decreased the fasting blood glucose level. The weight and the levels of serum GLP-1 and insulin of the mice in the isoquercitrin group were higher than those in the model group (P < 0.001). An oral glucose tolerance test showed that the isoquercitrin significantly inhibited postprandial blood glucose changes in a dose-dependent manner. These findings demonstrated the hypoglycemic effects of isoquercitrin and indicated that isoquercitrin improved insulin sensitivity by targeting DPP-IV.

Effect of Statins on Aneurysmal Subarachnoid Hemorrhage: A Meta-Analysis of Randomized Controlled Trials.

AIM: The role of statins for treating aneurysmal subarachnoid hemorrhage (aSAH) remains uncertain. In this study, the relevance of different end points was evaluated in order to clarify the action and efficacy of statins. MATERIAL AND METHODS: A systematic literature retrieval was carried out to obtain randomized controlled trials (RCTs) from before March 2013 on the use of statins for aSAH. Data extraction and quality evaluation of the studies were performed by 2 investigators. A meta-analysis was performed using Review Manager (RevMan) software version 5.2.3. RESULTS: Seven randomized controlled trials comprising 347 patients that met the inclusion criteria were included in this meta-analysis. Results showed that, in aSAH, statins did not reduce vasospasm on transcranial Doppler (RR=0.80; 95% CI, 0.53-1.21; p=0.29) or improve outcomes (RR=0.92; 95% CI, 0.71-1.20; p=0.54). However, statins were able to decrease delayed ischemic neurological deficits (RR=0.56; 95% CI, 0.41-0.75; p=0.0001) and mortality (RR=0.54; 95% CI, 0.32-0.91; p=0.02) compared with placebo. CONCLUSION: Acute statin treatment might not be a good choice for cerebral vasospasm after aSAH. Further large-scale, well-designed RCTs on this topic are still needed.