PHR1 involved in the regulation of low phosphate-induced leaf senescence by modulating phosphorus homeostasis in Arabidopsis.

Phosphorus (P) is a crucial macronutrient for plant growth, development, and reproduction. The effects of low P (LP) stress on leaf senescence and the role of PHR1 in LP-induced leaf senescence are still unknown. Here, we report that PHR1 plays a crucial role in LP-induced leaf senescence, showing delayed leaf senescence in phr1 mutant and accelerated leaf senescence in 35S:PHR1 transgenic Arabidopsis under LP stress. The transcriptional profiles indicate that 763 differentially expressed SAGs (DE-SAGs) were upregulated and 134 DE-SAGs were downregulated by LP stress. Of the 405 DE-SAGs regulated by PHR1, 27 DE-SAGs were involved in P metabolism and transport. PHR1 could bind to the promoters of six DE-SAGs (RNS1, PAP17, SAG113, NPC5, PLDζ2, and Pht1;5), and modulate them in LP-induced senescing leaves. The analysis of RNA content, phospholipase activity, acid phosphatase activity, total P and phosphate content also revealed that PHR1 promotes P liberation from senescing leaves and transport to young tissues under LP stress. Our results indicated that PHR1 is one of the crucial modulators for P recycling and redistribution under LP stress, and the drastic decline of P level is at least one of the causes of early senescence in P-deficient leaves.

[Treatment of intertrochanteric fractures over age of 80 years old patients with proximal femur intramedullary nail].

OBJECTIVE: To explore the clinical effects of proximal femur intramedullary nail (PFNA) in treating intertrochanteric fracture in elderly patients. METHODS: From January,2008 to December,2010,the data of 86 elderly patients (aged, 80 to 93 years) with intertrochanteric fracture who underwent internal fixation were retrospectively analyzed. Of them, 54 patients (22 males and 32 females) were treated with close reduction and PFNA internal fixation(PFNA group),and 32 patients (12 males and 20 females) were treated with open reduction and nail-plate internal fixation (control group). Operation time, volume of blood loss, postoperative complications, time of hospitalization and bone union, hip function were compared between two groups. RESULTS: All patients were followed up more than 2 years. Operation time, volume of blood loss, postoperative complications,time of hospitalization in PFNA group were less than that of control group (P<0.01). There was no significant difference in time of bone union between two groups (P>0.05). According to Harris score to evaluate the function of hip joint, PFNA group was better than that of control group (P<0.01). CONCLUSION: Treatment of elderly patients with intertrochanteric fractures with PFNA internal fixations can obtain satisfactory results, the method is better than that of traditional method.

[Risk early warning and multimodal prevention of postoperative venous thromboembolism for hip fractures].

OBJECTIVE: To study the efficacy and safety of multimodal prevention of postoperative venous thromboembolism for hip fractures. METHODS: From March 2009 to July 2011, preoperatively, patients were assigned to two groups on the basis of an assessment of their risk factors. One hundred and twelve patients were considered to be low risk, involving 47 males and 65 females,with an average age of (72.40 +/- 13.29) years ranging from 42 to 88,and were managed with aspirin (100 mg once daily for 14 days) as well as intermittent gasing compression devices. Twenty-six patients were considered to be high risk, involving 12 males and 14 females with an average age of (78.50 +/- 12.76) years ranging from 65 to 84,and were managed with low-molecular-weight heparin (0.4 ml,subcutaneous injection once daily for 14 days) and intermittent gasing compression. All patients were underwent Doppler ultrasonography within 24 hours before hospital discharge. All patients were followed-up for 3 months postoperatively. The incidence of deep venous thrombosis of lower limb, pulmonary embolism, gastrointestinal hemorrhage were recorded. RESULTS: Overall, there were no fatal pulmonary embolism, 1 case of symptomatic pulmonary emboli in low risk group, and none were detected in the high-risk group. Deep venous thrombosis was detected in association with 6 (6.25%) of the 112 procedures in the low-risk group and 2 (7.69%) of the 26 operations in the high-risk group. Paitents were selected in opened reduction and internal fixation, the quantity of bleeding, decrease of hemoglobin, hematoma rate, and gastrointestinal hemorrhage rate of low risk group were (538.10 +/- 390.20) ml, (30 +/- 19) g/L, 0, and 1 (1.03%) respectively; those of the high-risk group were (585.95 +/- 403.96) mL, (32 +/- 20) g/L,1 (4.76%), (4.76%), there were no significant different between the two groups, all P > 0.05. CONCLUSION: There were no statistic significances between the aspirin as well as intermittent gasing compression devices and the low-molecular-weight heparin and intermittent gasing compression in preventing venous thromboembolism (VTE) in postoperative postoperative venous thromboembolism for hip fractures. However, there are potential advantages to reduce complications of bleeding and cardiovascular disease. Multimodal prevention of postoperative venous thromboembolism can protect postoperative patients with hip fractures.