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.

Multidimensional beta-diversity across local and regional scales in a Chinese subtropical forest: The role of forest structure.

Beta-diversity, or the spatio-temporal variation in community composition, can be partitioned into turnover and nestedness components in a multidimensional framework. Forest structure, including comprehensive characteristics of vertical and horizontal complexity, strongly affects species composition and its spatial variation. However, the effects of forest structure on beta-diversity patterns in multidimensional and multiple-scale contexts are poorly understood. Here, we assessed beta-diversity at local (a 20-ha forest dynamics plot) and regional (a plot network composed of 19 1-ha plots) scales in a Chinese subtropical evergreen broad-leaved forest. We then evaluated the relative importance of forest structure, topography, and spatial structure on beta-diversity and its turnover and nestedness components in taxonomic, functional, and phylogenetic dimensions at local and regional scales. We derived forest structural parameters from both unmanned aerial vehicle light detection and ranging (UAV LiDAR) data and plot inventory data. Turnover component dominated total beta-diversity for all dimensions at the two scales. With the exception of some components (taxonomic and functional turnover at the local scale; functional nestedness at the regional scale), environmental factors (i.e., topography and forest structure) contributed more than pure spatial variation. Explanations of forest structure for beta-diversity and its component patterns at the local scale were higher than those at the regional scale. The joint effects of spatial structure and forest structure influenced component patterns in all dimensions (except for functional turnover) to some extent at the local scale, while pure forest structure influenced taxonomic and phylogenetic nestedness patterns to some extent at the regional scale. Our results highlight the importance and scale dependence of forest structure in shaping multidimensional beta-diversity and its component patterns. Clearly, further studies need to link forest structure directly to ecological processes (e.g., asymmetric light competition and disturbance dynamics) and explore its roles in biodiversity maintenance.

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.

PBOV1 promotes prostate cancer proliferation by promoting G1/S transition.

Prostate cancer (PC) is one of the leading causes of cancer death in men, and thus, finding new regulators is critical for PC therapy. Prostate and breast cancer overexpressed 1 (PBOV1) is overexpressed in breast, prostate, and bladder cancers, as it is upregulated in the serum of patients with PC, but the role of PBOV1 in PC has not been studied. In this article, we found that PBOV1 was indeed overexpressed in PC cells; PBOV1 overexpression promoted cell proliferation and colony formation ability and arrested cell cycle in the G0/G1 phase and tumorigenicity ability in vitro, whereas knockdown of PBOV1 reduced these effects. Further analysis of PBOV1 overexpression inhibited cell cycle inhibitors, P21 and P27, and increased the phosphorylation level of Rb and cyclin D1 expression, suggesting that PBOV1 promoted cell proliferation through promoting G1/S transition.

Flank-suspended versus prone percutaneous nephrolithotomy: changes of haemodynamics, arterial blood gases and subjective feelings.

BACKGROUND: The flank-suspended position was adopted in percutaneous nephrolithotomy (PCNL), and haemodynamics, blood gas variables and subjective feelings were examined with an attempt to explore the effect of the operative position in PCNL on the body's inner environment and patient comfort. OBJECTIVE: The influence of the flank-suspended and prone position on haemodynamics, arterial blood gases and subjective feelings in patients receiving PCNL was examined. DESIGN, SETTING AND PARTICIPANTS: A total of 100 patients with kidney stones who underwent PCNL during January 2010 to January 2011 were divided into flank-suspended groups (n = 50) and prone groups (n = 50) at random in terms of the operative position. The blood pressure, heart rate, respiratory frequency and oxyhaemoglobin saturation and blood gas variables were determined at different time points (before the operation, after position change, 30 min after the start the operation and immediately after the operation). Visual analogue scale (VAS) scoring system was employed to define the posture comfort, dyspnoea and puncture-site pain 24 h postoperation in the patients. All the measures were compared between patients in different positions at different time points. STATISTICAL ANALYSIS: Paired t-test was employed in the comparison of measures detected at different time points in the same group. Two-group comparison was subjected to t-test. A p value less than 0.05 was considered statistically significant. RESULTS AND LIMITATIONS: The blood pressure was decreased within and after the operation in both groups, substantially in the prone group, significantly lower than that before the operation (p<0.05). No significant differences in the heart rate, respiratory frequency and oxyhaemoglobin saturation were noted among the different time points in the same group. Blood gas analysis showed that pH value and base excess were profoundly reduced within and after the operation in the two groups, significantly lower than those before the operation, and the decrease was most manifest in the prone group. There was no difference in the blood sodium and potassium among the different time points in each group. The flank-suspended group was superior to the prone group with regard to posture comfort and dyspnoea degree but not puncture-site pain 24 h postoperation. CONCLUSIONS: Flank-suspended and prone PCNL affects the haemodynamics, blood gas variables and subjective feelings of patients to a varying degree. The flank-suspended PCNL possesses advantages over prone PCNL such as little influence on haemodynamics and blood gas variables, satisfactory posture comfort, less dyspnoea and easy access to vital sign observation.

Elevated expression of glutaminase confers glucose utilization via glutaminolysis in prostate cancer.

Cancer cells reprogram their metabolism towards aerobic glycolysis and elevated glutaminolysis, which contributes to the aggressive phenotype. Understanding how these metabolic pathways are regulated may provide critical targets for therapeutic intervention. Glutaminase (GLS1) is a key enzyme that converts glutamine to glutamate. In this study, we show the loss of GLS1 function by RNA interference or inhibitor diminished the rates of glucose utilization, growth and invasiveness of prostate cancer cells. We propose that GLS1 positively regulates glucose uptake in addition to glutaminolysis. Further, GLS1 involves the transcriptional repression of thioredoxin interacting protein (TXNIP), which is a potent negative regulator of glucose uptake and aerobic glycolysis. Most importantly, we provided direct evidence that elevated GLS1 expression was highly correlated with the tumor stage and progression in prostate cancer patients. Together, we defined a key role for GLS1 in coupling glutaminolysis of the TCA cycle with elevated glucose uptake and consequently the growth of prostate cancer cells. These data extends the role of GLS1 in regulating cell metabolism and the clinical utility of GLS1 inhibitors in the restriction of essential nutrients.

[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.