Moving to a healthier city? An analysis from China's internal population migration.

A healthy urban environment is considered as an important issue for the amenity and equity of migrants. China has one of the largest internal population movements in the world, and the environmental health of its migrants becomes a growing concern. Based on the 1‰ microdata from the 2015 1% population sample survey, this study uses the spatial visualization and spatial econometric interaction model to reveal intercity population migration patterns and the role of environmental health in China. The results are as follows. First, the main direction of population migration is toward economically developed high class cities, especially the eastern coast where the intercity population migration is most active. However, these major destinations are not necessarily the healthiest areas for the environment. Second, environmentally friendly cities are mainly located in the southern region. Among them, the areas with less serious atmospheric pollution are mainly distributed in the south, climate comfort zones are mainly located in the southeastern region, but areas with more urban green space are mainly distributed in the northwestern region. Third, compared with socioeconomic factors, environmental health factors have not yet become a major driver of population migration. Migrants often place higher value on income than on environmental health. The government should focus not only on the public service wellbeing of migrant workers, but also on their environmental health vulnerability.

Resection arthrodesis using distraction osteogenesis then plating as a hybrid surgical technique for the management of bone sarcomas of the distal tibia.

PURPOSE: We report the oncological and functional results of limb salvage for bone sarcomas involving the distal tibia using hybrid surgical technique of resection arthrodesis by bone transport then plating. METHODS: Five patients (mean age 18.6 years) with primary distal tibial sarcomas (two Ewing's sarcomas and three osteosarcomas) were treated by this method. The average duration of follow-up is 53 months. All patients accepted distraction osteogenesis with a standard technique using external fixator after wide (four cases) or marginal (one case) resection in the first operation. They were re-admitted for the second surgical treatment (plate insertion and removal of the external fixator) one to two months after they achieved the necessary limb length and desired alignment. RESULTS: Solid union of the lengthening site and sound fusion of the ankle were achieved in all five patients with full and unassisted weight bearing. The mean lengthening was 11.8 cm (range 8-14 cm) and the external fixation index (EFI) was 29.3 days/cm (range 22.8-36.3 days/cm). The mean functional score according to the rating system of the Musculoskeletal Tumour Society was 88% (83-90%). One patient showed poor response to chemotherapy, had local recurrence of sarcoma one year after plating, and was treated with above-knee amputation. CONCLUSIONS: In carefully selected patients with primary distal tibial sarcomas, this hybrid method can effectively eliminate tumor lesion, reconstruct function, and shorten the length of wearing an external fixator by a meticulous conversion to internal fixator.

Arcus venosus dorsalis pedis graft to restore the superficial palmar arch in devascularized hands.

For complex amputation injuries and anatomical characteristic of the metacarpus, restoration to the superficial palmar arch in severe devascularized or amputated hands remains a daunting challenge. In this article, we treated a series of five cases using an arcus venosus dorsalis pedis (AVDP) graft to restore the superficial palmar arches in devascularized hands. All hands survived and satisfying function was gained. The AVDP graft may be a suitable option to restore the superficial palmar arch in devascularized hands.

The free peroneal perforator-based sural neurofasciocutaneous flap: a novel tool for reconstruction of large soft-tissue defects in the upper limb.

BACKGROUND: The sural neurofasciocutaneous flap has been widely used for reconstruction of soft-tissue defects in the lower leg, ankle, and foot. It can provide a large amount of tissue without compromising the function of the leg. The authors report the applications of the free peroneal perforator-based sural neurofasciocutaneous flap. METHODS: The free sural neurofasciocutaneous flap based on a single peroneal perforator is described. The peroneal perforator, which emerges from the posterior crural septum at the junction of middle and lower thirds of the fibula, was chosen as the pedicle of the flap. Six perforator-based sural neurofasciocutaneous flaps were transferred to resurface large soft-tissue defects in the upper limb. The size of the defects ranged from 15 × 6 cm to 45 × 10 cm. RESULTS: All six flaps survived completely without necrosis. The area of the flaps ranged from 16 × 8 cm to 30 × 10 cm. The average diameter of the peroneal perforator ranged from 1.0 to 1.5 mm, and the length of the perforator pedicles ranged from 4 to 6 cm. One patient developed arterial thrombosis after surgery, which was treated by removal of the thrombus and reanastomosis. No severe venous congestion was observed. All the patients were satisfied with the aesthetic outcome postoperatively at 3 to 12 months' follow-up. There were no serious donor-site complications. CONCLUSION: The free perforator-based sural neurofasciocutaneous flap is a good alternative for reconstruction of extensive soft-tissue defects in the upper limb.

Competition between TRAF2 and TRAF6 regulates NF-kappaB activation in human B lymphocytes / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the role of TNF receptor-associated factor 2 (TRAF-2) and TRAF6 in CD40-induced nuclear factor-kappaB (NF-kappaB) signaling pathway and whether CD40 signaling requires TRAF2.</p><p><b>METHODS</b>Human B cell lines were transfected with plasmids expressing wild type TRAF2 or dominant negative TRAF2, TRAF2-shRNA, or TRAF6-shRNA. The activation of NF-kappaB was detected by Western blot, kinase assay, transfactor enzyme-linked immunosorbent assay (ELISA), and fluorescence resonance energy transfer (FRET). Analysis of the role of TRAF-2 and TRAF-6 in CD40-mediated NF-kappaB activity was examined following stimulation with recombinant CD154.</p><p><b>RESULTS</b>TRAF2 induced activity of IkappaB-kinases (IKKalpha, IKKi/epsilon), phosphorylation of IkappaBalpha, as well as nuclear translocation and phosphorylation of p65/RelA. In contrast, TRAF6 strongly induced NF-kappaB activation and nuclear translocation of p65 as well as p50 and c-Rel. Engagement of CD154-induced nuclear translocation of p65 was inhibited by a TRAF6-shRNA, but conversely was enhanced by a TRAF2-shRNA. Examination of direct interactions between CD40 and TRAFs by FRET documented that both TRAF2 and TRAF6 directly interacted with CD40. However, the two TRAFs competed for CD40 binding.</p><p><b>CONCLUSIONS</b>These results indicate that TRAF2 can signal in human B cells, but it is not essential for CD40-mediated NF-kappaB activation. Moreover, TRAF2 can compete with TRAF6 for CD40 binding, and thereby limit the capacity of CD40 engagement to induce NF-kappaB activation.</p>

Free peroneal perforator-based sural neurofasciocutaneous flaps for reconstruction of hand and forearm.

BACKGROUND: Sural neurofasciocutaneous flap has been popularly used as an excellent option for the coverage of soft tissue defects in the lower third of leg, ankle and foot, but its free transplantation has been rarely reported. The objective of our work was to investigate the operative technique and clinical results of repairing the soft tissue defects of hand and forearm with free peroneal perforator-based sural neurofasciocutaneous flap. METHODS: Between May 2006 and March 2007, 10 patients including 7 men and 3 women were treated. Their ages ranged from 22 to 51 years. They presented to emergency with large soft tissue defects of 16 cm x 7 cm to 24 cm x 10 cm in size in hand and forearm after injured by motor vehicle accidents (2 cases) or crushed by machine (8 cases). Thorough debridements and primary treatments to associated tendon ruptures or bone fractures were performed on emergency. And free peroneal perforator-based sural neurofasciocutaneous flaps were transplanted when the wound areas were stable at 5 to 7 days after emergency treatment. The flaps were designed along the axis of the sural nerve according to the shape and size of the soft tissue defects, with the peroneal perforator above the lateral malleolus as the pedicle and along with a part of the peroneal artery for vascular anastomosis. Then the flaps were harvested to repair the recipient sites with the peroneal artery anastomosed to the radial (or ulnar) artery and the peroneal veins to one of the radial (or ulnar) veins and the cephalic vein respectively. The flap sizes ranged from 18 cm x 8 cm to 25 cm x 12 cm. The donor areas were closed by skin grafts. RESULTS: All of the 10 flaps survived after surgeries. Marginal necrosis occurred in only 2 cases. The skin grafts survived entirely in the donor sites, and no obvious influence on the donor legs was observed. All of the transplanted flaps presented favourable contours and good functions at 9 to 12 months' follow-up. CONCLUSIONS: Peroneal perforator-based sural neurofasciocutaneous flap has favourable appearance, constant vascular pedicle, reliable blood supply, large size of elevation, and minimal influence on the donor site. The free transplantation of this flap offers a satisfactory alternative for repairing the large soft tissue defects of forearm and hand.

[Improvement of blood compatibility of small intestinal submucosa used as engineering vascular scaffolds by nano-bionic surface modification].

OBJECTIVE: To investigate the effects of nano-bionic surface modification in improving the blood compatibility of small intestinal submucosa (SIS) used as engineering vascular scaffolds. METHODS: SIS films were obtained from pig and underwent nano-bionic surface modification with plasma initiation technique. Scanning electron microscopy (SEM) was used to observe the morphological features, including water contact angle, of the SIS films after nano-bionic surface modification. Modified SIS films were immersed into human platelet-rich plasma for 10 s and then observed for the adhesion of platelet on the surface thereof. Another modified SIS films were immersed into anticoagulant human blood to test the prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT). Twenty dogs were randomly divided into 2 equal groups to undergo cutting of bilateral femoral arteries and anastomosis with tube-like scaffolds made of modified or un-modified SIS films. Color Doppler ultrasonography was used to examine the blood flow 1, 3, and 6 weeks after operation. The dogs were killed in batches 2 and 6 weeks after operation to take out the SIS vessels to observe the existence of mural thrombus and undergo microscopy. RESULTS: SEM showed island-like and groove-like surface morphology in the modified SIS films, and the water contact angle decreased from 105.3 degrees to 62.0 degrees. After treatment by anticoagulant human blood the PT, APTT, and TT of the modified SIS films increased from 30.5 s, 9.8 s, and 13.6 s to 81.5 s, 39.6 s, and 50.2 s respectively. SEM showed that the number of adhering platelets was less on the surface of the modified SIS films than on the surface of un-modified SIS films. Animal experiment showed that 4 blood vessels anastomosed with un-modified SIS tube became completely thrombosed within 3 hours, and the other 6 became completely thrombosed 3 days later, and the 10 blood vessels anastomosed with modified SIS tube remained patent till 6 weeks after operation. Gross observation showed that the implanted scaffolds made of modified SIS films had become biological tube-like 2 weeks after operation, and became integrated tubes with their inner walls covered with endothelial cells 6 weeks post-operatively. CONCLUSION: Nano-bionic surface modified SIS film possesses good and persistent antithrombogenicity and shows excellent blood compatibility.