神经营养因子信号转导与神经细胞凋亡的分子机制

细胞凋亡(Apoptosis)是一种程序化的细胞死亡过程,其中神经细胞的凋亡对胚胎期神经系统的生长、发育、分化、成熟及生后各种原因所致的脑损伤,神经退行性疾病的发生都起着至关重要的作用。神经营养因子(Neurotrophins,NTS)通过其与相应靶细胞膜受体的活化而引发相关信使分子的级联激活而减缓神经细胞凋亡、促进神经细胞的存活,发挥其生物学功能。对NTS家族信号转导与神经细胞凋亡的分子机制的认识有助于早期干预和治疗各种原因所致神经发育残障,脑损伤及神经退性行疾病。     

Early production of thymic stromal lymphopoietin precedes infiltration of dendritic cells expressing its receptor in allergen-induced late phase cutaneous responses in atopic subjects

Background: Thymic stromal lymphopoietin (TSLP) is an interleukin (IL)‐7‐like cytokine that triggers dendritic cell‐mediated T helper (Th)2 inflammatory responses through a receptor consisting of a heterodimer of the IL‐7 receptor alpha (IL‐7Rα) chain and the TSLP receptor (TSLPR), which resembles the cytokine receptor common gamma chain. Dendritic cells activated by TSLP prime development of CD4⁺ T cells into Th2 cells contributing to the pathogenesis of allergic inflammation. We hypothesized that allergen exposure induces expression of TSLP and results in recruitment of TSLPR bearing cells in the cutaneous allergen‐induced late‐phase reaction (LPR) in atopic subjects. Methods: Skin biopsies were obtained from atopic subjects (n = 9) at various times after cutaneous allergen challenge. In situ hybridization and immunohistochemistry were used to determine TSLP mRNA expression and to measure infiltration of TSLPR⁺ DC in skin LPR. RT‐PCR and flow cytometry were employed to analyse TSLPR expression on isolated blood DC. Results: Allergen‐induced skin TSLP expression occurred as early as 1 h after allergen challenge, whereas TSLPR⁺ and CD11c⁺ cells infiltrated relatively late (24–48 h). The majority of TSLPR⁺ cells were DC co‐expressing blood DC antigen‐1 (BDCA‐1) or BDCA‐2. Freshly isolated blood DC expressed both TSLPR and IL‐7Rα chains. Maturation and stimulation with TSLP or polyriboinosinic–polyribocytidylic acid in vitro upregulated the expression of both TSLPR and IL‐7Rα chains in DC but not in chemoattractant receptor‐homologous molecule expressed on Th2 cells⁺ CD4⁺ T cells. Conclusion: The data suggest that TSLP plays a role in augmenting, through DC recruitment and activation, the development of Th2‐type T cells in allergic inflammation.     

Extensive and interrelated subcortical white and gray matter alterations in preterm-born adults

Preterm birth is a leading cause for impaired neurocognitive development with an increased risk for persistent cognitive deficits in adulthood. In newborns, preterm birth is associated with interrelated white matter (WM) alterations and deep gray matter (GM) loss; however, little is known about the persistence and relevance of these subcortical brain changes. We tested the hypothesis that the pattern of correspondent subcortical WM and GM changes is present in preterm-born adults and has a brain-injury-like nature, i.e., it predicts lowered general cognitive performance. Eighty-five preterm-born and 69 matched term-born adults were assessed by diffusion- and T1-weighted MRI and cognitive testing. Main outcome measures were fractional anisotropy of water diffusion for WM property, GM volume for GM property, and full-scale IQ for cognitive performance. In preterm-born adults, reduced fractional anisotropy was widely distributed ranging from cerebellum to brainstem to hemispheres. GM volume was reduced in the thalamus, striatum, temporal cortices, and increased in the cingulate cortices. Fractional anisotropy reductions were specifically associated with GM loss in thalamus and striatum, with correlation patterns for both regions extensively overlapping in the WM of brainstem and hemispheres. For overlap regions, fractional anisotropy was positively related with both gestational age and full-scale IQ. Results provide evidence for extensive, interrelated, and adverse WM and GM subcortical changes in preterm-born adults. Data suggest persistent brain-injury-like changes of subcortical–cortical connectivity after preterm delivery.     

Second-harmonic imaging of cornea after intrastromal femtosecond laser ablation

Nonlinear laser scanning microscopy is widely used for noninvasive imaging in cell biology and tissue physiology. However, multiphoton fluorescence imaging of dense, transparent connective tissue (e.g., cornea) is challenging since sophisticated labeling or slicing is necessary. High-resolution, high-contrast second harmonic generation (SHG) imaging of corneal tissue based on the intrinsic structure of collagen is discussed. The three-dimensional corneal ultrastructure in depths up to hundreds of microns can be probed noninvasively, without any staining or mechanical slicing. As an important application of second harmonic imaging in ophthalmology, the modification of corneal ultrastructure using femtosecond laser intrastromal ablation is systematically investigated to evaluate next-generation refractive surgical approaches.     

Pneumococcal 6-Phospho-β-Glucosidase (BglA3) Is Involved in Virulence and Nutrient Metabolism

For the generation of energy, the important human pathogen Streptococcus pneumoniae relies on host-derived sugars, including β-glucoside analogs. The catabolism of these nutrients involves the action of 6-phospho-β-glucosidase to convert them into usable monosaccharaides. In this study, we characterized a 6-phospho-β-glucosidase (BglA3) encoded by SPD_0247. We found that this enzyme has a cell membrane localization and is active only against a phosphorylated substrate. A mutated pneumococcal ΔSPD0247 strain had reduced 6-phospho-glucosidase activity and was attenuated in growth on cellobiose and hyaluronic acid compared to the growth of wild-type D39. ΔSPD0247-infected mice survived significantly longer than the wild-type-infected cohort, and the colony counts of the mutant were lower than those of the wild type in the lungs. The expression of SPD_0247 in S. pneumoniae harvested from infected tissues was significantly increased relative to its expression in vitro on glucose. Additionally, ΔSPD0247 is severely impaired in its attachment to an abiotic surface. These results indicate the importance of β-glucoside metabolism in pneumococcal survival and virulence.     

Establishment and characterization of human metastatic hepatocellular carcinoma cell line

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide with a poor prognosis. Recently, we established a HCC cell line from a metastatic HCC tumor. GTG banding analysis was performed and the karyotype showed that this metastatic HCC cell line is a hypertriploid (71-78 chromosomes) with a large marker chromosome containing a long homogeneously staining region (hsr). Comparative genomic hybridization was applied to characterize the chromosomal alterations in this metastatic HCC cell line. The results showed that the hsr was composed of amplified DNA sequences from 11q13. Further characterization of the hsr may lead to the isolation of the putative amplified oncogene at 11q13.     

Morphological and functional plasticity of olfactory ensheathing cells

In the primary olfactory pathway, olfactory ensheathing cells (OECs) extend processes to envelop bundles of olfactory axons as they course towards their termination in the olfactory bulb. The expression of growth-promoting adhesion and extracellular matrix molecules by OECs, and their spatially close association with olfactory axons are consistent with OECs being involved in promoting and guiding olfactory axon growth. Because of this, OECs have been employed as a possible tool for inducing axonal regeneration in the injured adult CNS, resulting in significant functional recovery in some animal models and promising outcomes from early clinical applications. However, fundamental aspects of OEC biology remain unclear. This brief review discusses some of the experimental data that have resulted in conflicting views with regard to the identity of OECs. We present here recent findings which support the notion of OECs as a single but malleable phenotype which demonstrate extensive morphological and functional plasticity depending on the environmental stimuli. The review includes a discussion of the normal functional role of OECs in the developing primary olfactory pathway as well as their interaction with regenerating axons and reactive astrocytes in the novel environment of the injured CNS. The use of OECs to induce repair in the injured nervous system reflects the functional plasticity of these cells. Finally, we will explore the possibility that recent microarray data could point to OECs assuming an innate immune function or playing a role in modulating neuroinflammation.     

利肝消脂颗粒剂治疗脂肪肝患者血清ET和血脂水平的变化

目的:探讨了利肝消脂颗粒剂治疗脂肪肝患者血清ET和血脂水平的变化。方法:应用放免法和生化法对70例脂肪肝患者进行了治疗前后血清ET和血脂水平的变化。结果:治疗后血清ET和血脂水平较治疗前存在显著性差异(P<0.01～0.01)。结论:利肝消脂颗粒剂具有降低血清ET和血脂水平,对脂肪肝的治疗具有重要的临床价值。     

Risk of adverse pregnancy outcomes stratified for pre-pregnancy body mass index

Objective: To estimate the risk of adverse maternal and perinatal outcomes in women with different pre-pregnancy body mass index (BMI).

Methods: We conducted a cohort study with 14?451 singleton pregnancies in 15 medical centers in Beijing between 20 June 2013 and 30 November 2013 using cluster random sampling. We divided participants into four groups based on pre-pregnancy BMI: Group A (underweight): BMI?<?18.5?kg/m², Group B (normal): 18.5–23.9?kg/m², Group C (overweight): 24–27.9?kg/m², Group D (obesity): ≥28?kg/m². We used multivariate analysis to evaluate the association of the risk of adverse pregnancy outcomes and pre-pregnancy BMI.

Results: The prevalence of maternal overweight and obesity was 14.82% (2142/14?451) and 4.71% (680/14?451) in the study population, respectively. Higher pre-pregnancy BMI is associated with higher prevalence of gestational diabetes (GDM), macrosomia, Cesarean section (C-section), preeclampsia and postpartum hemorrhage. Pre-pregnancy overweight or obesity increases the risk of adverse pregnancy outcomes, regardless of GDM status.

Conclusions: Pre-pregnancy overweight or obesity is associated with increased risk of adverse pregnancy outcomes. Nutrition counseling is recommended before pregnancy in women who have overweight or obesity.