Leaf nitrogen and phosphorus resorption efficiencies are related to drought resistance across woody species in a Chinese savanna.

Leaf nutrient resorption and drought resistance are crucial for the growth and survival of plants. However, our understanding of the relationships between leaf nutrient resorption and plant drought resistance is still limited. In this study, we investigated the nitrogen and phosphorus resorption efficiencies (NRE and PRE), leaf structural traits, leaf osmotic potential at full hydration (Ψosm), xylem water potential at 50% loss of xylem-specific hydraulic conductivity (P50) and seasonal minimum water potential (Ψmin) for 18 shrub and tree species in a semiarid savanna ecosystem, in Southwest China. Our results showed that NRE and PRE exhibited trade-off against drought resistance traits (Ψosm and P50) across woody species. Moreover, this relationship was modulated by leaf structural investment. Species with low structural investment (e.g., leaf mass per area, leaf dry mass content and leaf construction cost [LCC]) tend to have high NRE and PRE, while those with high LCCs show high drought resistance, showing more negative Ψosm and P50.These results indicate that species with a lower leaf structural investment may have a greater need to recycle their nutrients, thus exhibiting higher nutrient resorption efficiencies, and vice versa. In conclusion, nutrient resorption efficiency may be a crucial adaptation strategy for coexisting plants in semiarid ecosystems, highlighting the importance of understanding the complex relationships between nutrient cycling and plant survival strategies.

Ontogenetic trait variation and metacommunity effects influence species relative abundances during tree community assembly.

Predicting species abundance is one of the most fundamental pursuits of ecology. Combining the information encoded in functional traits and metacommunities provides a new perspective to predict the abundance of species in communities. We applied a community assembly via trait selection model to predict quadrat-scale species abundances using functional trait variation on ontogenetic stages and metacommunity information for over 490 plant species in a subtropical forest and a lowland tropical forest in Yunnan, China. The relative importance of trait-based selection, mass effects, and stochasticity in shaping local species abundances is evaluated using different null models. We found both mass effects and trait selection contribute to local abundance patterns. Trait selection was detectable at all studied spatial scales (0.04-1 ha), with its strength stronger at larger scales and in the subtropical forest. In contrast, the importance of stochasticity decreased with spatial scale. A significant mass effect of the metacommunity was observed at small spatial scales. Our results indicate that tree community assembly is primarily driven by ontogenetic traits and metacommunity effects. Our findings also demonstrate that including ontogenetic trait variation into predictive frameworks allows ecologists to infer ecological mechanisms operating in community assembly at the individual level.

[Effects of adenovirus-mediated PTEN on the proliferation of prostate cancer PC-3 cells and expressions of cyclin D1 and p21].

OBJECTIVE: To construct a recombinant adenovirus expression vector containing the anti-oncogene PTEN and to investigate the effects of the PTEN gene on the proliferation of prostate cancer PC-3 cells and the expressions of cyclin D1 and p21 in the PC-3 cells. METHODS: The PTEN gene was amplified from the rat hippocampus by RT-PCR and cloned into the shuttle plasmid pEN-TR2A. The plasmids were constructed and amplified in 293A cells. Prostate cancer PC-3 cells were cultured in vitro and infected with the adenoviral vector carrying the PTEN gene (Ad-PTEN). The up-regulation of the PTEN protein was measured by indirect immuno-fluorescence assay; the expressions of PTEN, cyclin D1 and p21 in the cells infected with Ad-PTEN and Ad-LacZ were determined by RESULTS: The Western blot; and the effect of PTEN on the cell proliferation was detected by MTT assay and plate colony formation. recombinant adenoviral vector Ad-PTEN was successfully constructed. Western blot showed a significantly increased expression of the PTEN protein in the PC-3 cells infected with Ad-PTIEN (0.215 +/-0.065) as compared with that in the control ([0.052 +/-0.009], t = 4. 30, P <0.05) and the Ad-LacZ group ( [0. 056 +/- 0.008 ] , t =4.21, P <0.05). The expression of cyclin D1 was significantly lower in the Ad-PTEN-infected PC-3 cells (0. 256 +/- 0. 072) than in the control ( [0. 502 +/- 0. 087 ], t = 3.77, P < 0.05) and the Ad-LacZ group ([0.498 +/-0.081] , t =3.87, P <0.05), while the expression of p21 remarkably higher in the Ad-PTEN-infected PC-3 cells (0.589 +/-0. 076) than in the control ([0. 146 +/-0.026] , t = 9.55, P<0. 01) and the Ad-LacZ group ([0. 163 +/-0. 024] , t = 9.26, P <0.01). Ad-PTEN significantly inhibited the growth of the PC-3 cells (21.98%) at 48 h (t = 6.80, P <0.01). The colony formation rate of the PC-3 cells was (37.4 +/-4. 18)% in the Ad-PTEN group, significantly lower than (54.9 +/-4.81)% in the control (t =4.76, P<0.01) and (56.5 +/- 5.42)% in the Ad-LacZ group (t=4.83, P<0.01). CONCLUSION: The expression of PTEN induced by Ad-PTEN can significantly inhibit the proliferation of PC-3 cells, down-regulate the expression of cyclin D1, and up-regulate the expression of p21.

Flank suspended supine position for percutaneous nephrolithotomy.

AIMS: Prone and supine positions for percutaneous nephrolithotomy are widely used but have their drawbacks. We report a new positioning method called "flank suspended supine position" (FSSP) for PCNL and describe our experience with PCNL in this position to evaluate its safety and efficacy. METHODS: Retrospective study of 150 cases of renal stone patients treated with PCNL in a new position called flank suspended supine position (FSSP) from June 2009 to July 2010. All patients were treated with PCNL in FSSP under epidural anesthesia. Operation time, bleeding rate, stone free rate, and complications were recorded. RESULTS: All patients tolerated FSSP. Mean operation time was 78.29±26.13 min. Initial stone-free rate was 83%. For those with residual stones (26 cases), 18 were stone-free after a second PCNL, 8 after extracorporeal shock wave lithotripsy (ESWL). Mean hospital stay was 7.63±2.39 days. No penetrating injury of the pleural cavity or injury to visceral organs was reported. SUMMARY: FSSP is an effective and safe position for PCNL in our hands and its effectiveness relative to traditional prone position needs to be determined in future randomized studies.

[Effects of intraprostatic injection of botulinum toxin A (BTX-A) on benign prostate hyperplasia].

OBJECTIVE: To investigate the effects of intraprostatic injection of botulinum toxin A (BTX-A) on benign prostate hyperplasia (BPH) in rats. METHODS: Models of BPH were established in adult male Sprague-Dawley rats by injection of testosterone propionate, and then divided into three BTX-A groups, injected with BTX-A into the ventral prostate at the doses of 5 U, 10 U and 20 U, a negative control group, injected with saline only, and a sham operation group, with 12 in each. The prostates of the animals were harvested at 2 or 4 weeks after the injection, their volumes and weights measured, histological changes examined by HE staining, and glandular and interstitial areas semi-quantified by the image analysis system. RESULTS: Two rats died in the 20 U group within 3 days after BTX-A injection. Compared with the saline group, the 5 U, 10 U and 20 U BTX-A groups showed significant decreases in prostatic volume (P < 0.01, 0.01 and 0.05), weight, and glandular and interstitial areas as well as atrophic epithelia in the glandular tube at 2 weeks. These changes were lessened at 4 weeks, especially in the 5 U group. CONCLUSION: Intraprostatic injection of BTX-A induces obvious atrophy and histological changes of the prostate, but meanwhile may potentially result in death at a large dose.

Application study on inversion diagnosis of F8 gene in hemophilia A / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To establish an effective method of genetic diagnosis on hemophilia A (HA) by detecting the inversion mutation in intron 22 of F8 gene.</p><p><b>METHODS</b>Intron 22 inversion mutation in F8 gene was detected by using long distance-polymerase chain reaction (LD-PCR) and inversion-PCR (I-PCR) in 31 HA patients. The mothers of HA patients with intron 22 inversion mutation were selected to carrier diagnosis and amniotic fluid of the pregnant women with inversion mutation was collected at intermediate stage of gestation, and used to prenatal genetic diagnosis.</p><p><b>RESULTS</b>Seven patients showed F8 gene inversion mutation in thirty-one patients. Three in four mothers of HA patients with intron 22 inversion mutation were diagnosed as carriers. The prenatal diagnosis result indicated that the fetus conceived in the HA-carrier woman was normal individual.</p><p><b>CONCLUSION</b>The detection of intron 22 inversion mutation by LD-PCR and I-PCR is time-saving, and can be used in prenatal diagnosis on HA.</p>