青海藏族青少年骨龄与生长发育关系研究

本文报告了青海省境内,世居在海拔3000-4000米地区的728名7-18岁健康藏族青少年学生的手、腕部骨骼发育情况,对骨化中心出现和骨骺愈合求出了50%出现年龄,并对骨龄与青春期身高突增的关系及与月经初衬潮的关系进行了分析。     

Incorporation of β-sitosterol into mitochondrial membrane enhances mitochondrial function by promoting inner mitochondrial membrane fluidity

Recent findings suggest that mitochondrial membrane fluidity could influence mitochondrial energy metabolism. β-sitosterol (BS) is a common plant sterol that is prevalent in plant oils, nuts, cereals and plant food products. Its chemical structure is very similar to that of cholesterol. As a cholesterol analog, BS is highly lipid soluble and largely resides in the membranes of cells or organelles where it may have an influence on the membrane fluidity. The present study reports that, with the cholesterol chelator 2-hydroxypropyl-β-cyclodextrin (HPβCD) as its carrier, BS is able to increase the fluidity of the inner mitochondrial membrane (IMM) without affecting the fluidity of the outer mitochondrial membrane (OMM), and consequently to increase the mitochondrial membrane potential (?Ψm) and mitochondrial ATP content. It has been previously proposed that a therapeutical boost in adenosine triphosphate (ATP) levels in mitochondria may be beneficial for neurodegenerative diseases such as Alzheimer’s disease (AD). Given that dietary administration of plant sterols could increase brain BS concentrations, these results may provide a better understanding of the beneficial effects of plant sterol-enriched nutrients on neurodegenerative diseases such as AD.     

Cryopreservation of mouse embryoid bodies

Cryopreservation of embryonic stem (ES) cells is essential to establish them as a resource for regenerative therapy. We evaluated survival adhesion rate, cell structure, gene expression, and multipotency of frozen and thawed embryoid bodies (EBs) derived from mouse ES cells. EBs were cryopreserved using the BICELL and the Program Freezer. After one week the EBs were thawed and cultured. EBs prepared in the Program Freezer had the highest survival adhesion (Program Freezer; 55-69%, BICELL; 30-38%). Though many cells in the thawed EBs were damaged, some were not, especially those prepared in the Program Freezer. RT-PCR analysis showed that genes characteristic of the three embryonic germ layers were expressed in thawed EBs cultured for one week. EBs transplanted into mice formed teratomas consisting of cells derived from the three germ layers. In conclusion, EBs frozen in the Program Freezer had higher survival adhesion rates compared to the BICELL and formed differentiated cells characteristic of the three embryonic germ layers.     

Differentiation of primate ES cells into retinal cells induced by ES cell-derived pigmented cells

Purpose: Photoreceptors cannot regenerate and recover their functions once disordered. Transplantation of retinal pigment epithelium (RPE) has recently become a possible therapeutic approach for retinal degeneration. In the present study, we investigated the induction of photoreceptors by coculturing primate embryonic stem cells (ESCs) with ESC-derived RPE cells. Methods: RPE cells were derived by coculturing ESCs and Sertoli cells. Photoreceptors were then induced by using ESC-derived RPE cells and retinoic acid (RA) Results: RPE cell generation was confirmed by morphological analysis, which revealed highly pigmented polygonal cells with a compact cell-cell arrangement. After coculturing ESCs and RPE cells, some ESC derivatives became immunopositive for rhodopsin. RT-PCR analysis demonstrated the expression of retina-related gene markers such as Pax6, CRX, IRBP, rhodopsin, rhodopsin kinase, and Muschx10A. When RA was added, a distinct increase in the expression of photoreceptor-specific proteins and genes was found. In addition, the differentiation of bipolar horizontal cells was demonstrated by protein and gene expression. The ESCs that were cocultured with RPE cells and treated with RA were transplanted into the renal capsule or intra-vitreal space of nude mice. Grafted ESC derivatives demonstrated extensive rhodopsin expression, and they survived and organized into recipient tissues, although they formed teratomas. Conclusion: These results indicate that coculturing ESCs with ESC-derived RPE cells is a useful and efficient method for inducing photoreceptors and providing an insight into the use of ESCs for retina regeneration.     

Rotenoids and flavonoids with anti-invasion of HT1080, anti-proliferation of U937, and differentiation-inducing activity in HL-60 from Erycibe expansa

Principal rotenoids (deguelin, tephrosin, rotenone, and 12a-hydroxyrotenone) (3-30microM) isolated from the stems of Erycibe expansa significantly inhibited invasion of human fibrosarcoma HT1080 cells through Matrigel-coated filters and release of proMMPs-2 and 9. In addition, deguelin and tephrosin showed differentiation-inducing activity in human promyelocytic leukemia HL-60 cells. Furthermore, effects of various constituents isolated from the ethyl acetate-soluble fraction on proliferation of human leukemia U937 cells were examined. As a result, most of isoflavones and several flavans as well as rotenoids showed moderate or substantial anti-proliferative activities.     

Gene pathway analysis of the mechanism by which the Rho-associated kinase inhibitor Y-27632 inhibits apoptosis in isolated thawed human embryonic stem cells

Cryopreservation is an essential technique in basic research and clinical applications of human embryonic stem (hES) cells. Cryopreserved hES cells are fragile and undergo post-thaw apoptosis. We performed gene pathway analysis on cryopreserved and thawed hES cells to examine the effect of Y-27632, a Rho-associated kinase (ROCK) inhibitor, on apoptosis and associated molecular events. Y-27632 was added to the cryopreservation solution and/or the post-thaw medium of two hES cell lines (KhES-1, KhES-3). Post-thaw apoptosis was recorded as a function of time using Giemsa staining and the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Apoptosis plateaued 12h after the untreated hES cells were thawed. Gene pathway analysis showed the activation of IL-1β, TGF-β, and their respective receptors (IL-1R, ACVR1C) in the mitogen-activated protein kinase (MAPK) pathway, which resulted in the upregulation of caspase-8 and -10. Quantitative RT-PCR confirmed the upregulation of IL-1β, TGF-β, their respective receptors, and caspase-10 and -3. As these molecules were suppressed by Y-27632, gene pathways involving these molecules probably depend on ROCK activation. The TGF-β receptor antagonist, SB-431542, and an inhibitor of p38MAPK, SB-203580, did not affect apoptosis. Combining Y-27632 with SB-203580, however, resulted in an increase in the survival rate compared with the control. This suggests that the initiation of apoptosis depends on cytokine interactions and multiple ways exist to reduce post-thaw apoptosis in hES cells. Y-27632 can suppress cytokine interactions and the MAPK pathway, thereby reducing the occurrence of apoptosis, and is an effective cryoprotectant for hES cells.     

Difference in feeding behaviors of two invasive whiteflies on host plants with different suitability: implication for competitive displacement

In China, Bemisia tabaci Q (commonly known as biotype Q) has rapidly displaced B (commonly known as biotype B) in the past 6 years. The mechanisms underlying such phenomenon have been studied extensively in recent years; however, we have not come to a definitive conclusion yet. In the present study, the differences in host suitability between B and Q whitefly adults to five host plants (cabbage, cotton, cucumber, poinsettia, and tomato) were evaluated based on their respective feeding behaviors using a direct-current electrical penetration graph (DC-EPG) system. Pair-wise comparisons of B. tabaci B and Q feeding on each of the five host plants clearly indicate that Q feeds better than B on tomato, cotton and poinsettia, while B feeds better than Q on cabbage and cucumber. The EPG parameters related to both phloem and non-phloem phases confirm that cabbage and cucumber are best suited to B, while tomato, cotton, and poinsettia are best suited to Q. Our present results support the contention that host suitability and adult feeding behavior contribute to the competitive displacement of biotype B by biotype Q. The discrepancy between field (previous studies) and laboratory results (this study), however, suggests that 1) whitefly displacement is apparently contributed by multiple factors; and 2) factor(s) other than the host plant suitability may play a vital role in dictating the whitefly biotypes in the field.     

Molecular cloning and expression analysis of rice OsTVLP1, encoding a protein with similarity to TGF-beta receptor interacting proteins and vacuolar assembly Vam6p/Vps39p proteins.

We describe the cloning and identification of a rice cDNA, OsTVLP1, encoding a protein with similarity to TGF-beta receptor interacting proteins and vacuolar assembly Vam6p/Vps39p proteins. OsTVLP1 has an open reading frame of 2955 bp, which encodes a 984 amino acid protein, containing a citron homology (CNH) domain at its N-terminal and a clathrin heavy-chain repeat homology (CLH) domain at its C-terminal. The expression of OsTVLP1 was induced by treatments with benzothiadiazole (BTH), a chemical activator of plant disease resistance responses, and by infection of the blast fungus, Magnaporthe grisea. Importantly, the expression of OsTVLP1 was activated specifically in disease resistance response induced by BTH and in an incompatible interaction between rice and the blast fungus. Our observations suggest that OsTVLP1 may play a role in rice disease resistance response against pathogen infection.     

Synthesis and evaluation of azaindole-alpha-alkyloxyphenylpropionic acid analogues as PPARalpha/gamma agonists

A series of azaindole-alpha-alkyloxyphenylpropionic acid analogues was synthesized and evaluated for PPAR agonist activities. Structure-activity relationship was developed for PPARalpha/gamma dual agonism. One of the synthesized compound 7a was identified as a potent, selective PPARalpha/gamma dual agonist.