Antibody-mediated rejection is a major complication in renal transplantation. The pathologic manifestations of acute antibody-mediated rejection that has progressed to functional impairment of a renal transplant have been defined in clinical biopsy specimens. However, the initial stages of the process are difficult to resolve with the unavoidable variables of clinical studies. We devised a model of renal transplantation to elucidate the initial stages of humoral rejection. Kidneys were orthotopically allografted to immunodeficient mice. After perioperative inflammation subsided, donor-specific alloantibodies were passively transferred to the recipient. Within 1 hour after a single transfer of antibodies, C4d was deposited diffusely on capillaries, and von Willebrand factor released from endothelial cells coated intravascular platelet aggregates. Platelet-transported inflammatory mediators platelet factor 4 and serotonin accumulated in the graft at 100- to 1000-fold higher concentrations compared with other platelet-transported chemokines. Activated platelets that expressed P-selectin attached to vascular endothelium and macrophages. These intragraft inflammatory changes were accompanied by evidence of acute endothelial injury. Repeated transfers of alloantibodies over 1 week sustained high levels of platelet factor 4 and serotonin. Platelet depletion decreased platelet mediators and altered the accumulation of macrophages. These data indicate that platelets augment early inflammation in response to donor-specific antibodies and that platelet-derived mediators may be markers of evolving alloantibody responses. 相似文献
Past research suggests that as many as 50% of onward human immunodeficiency virus (HIV) transmissions occur during acute and recent HIV infection. It is clearly important to develop interventions which focus on this highly infectious stage of HIV infection to prevent further transmission in the risk networks of acutely and recently infected individuals. Project Protect tries to find recently and acutely infected individuals and prevents HIV transmission in their risk networks. Participants are recruited by community health outreach workers at community-based HIV testing sites and drug users' community venues, by coupon referrals and through referrals from AIDS clinics. When a network with acute/recent infection is identified, network members are interviewed about their risky behaviors, network information is collected, and blood is drawn for HIV testing. Participants are also educated and given prevention materials (condoms, syringes, educational materials); HIV-infected participants are referred to AIDS clinics and are assisted with access to care. Community alerts about elevated risk of HIV transmission are distributed within the risk networks of recently infected. Overall, 342 people were recruited to the project and screened for acute/recent HIV infection. Only six index cases of recent infection (2.3% of all people screened) were found through primary screening at voluntary counseling and testing (VCT) sites, but six cases of recent infection were found through contact tracing of these recently infected participants (7% of network members who came to the interview). Combining screening at VCT sites and contact tracing the number of recently infected people we located as compared to VCT screening alone. No adverse events were encountered. These first results provide evidence for the theory behind the intervention, i.e., in the risk networks of recently infected people there are other people with recent HIV infection and they can be successfully located without increasing stigma for project participants. 相似文献
BACKGROUNDGuillain-Barré syndrome (GBS) is a rare disorder that typically presents with ascending weakness, pain, paraesthesias, and numbness, which mimic the findings in lumbar spinal stenosis. Here, we report a case of severe lumbar spinal stenosis combined with GBS.CASE SUMMARYA 70-year-old man with a history of lumbar spinal stenosis presented to our emergency department with severe lower back pain and lower extremity numbness. Magnetic resonance imaging confirmed the diagnosis of severe lumbar spinal stenosis. However, his symptoms did not improve postoperatively and he developed dysphagia and upper extremity numbness. An electromyogram was performed. Based on his symptoms, physical examination, and electromyogram, he was diagnosed with GBS. After 5 d of intravenous immunoglobulin (0.4 g/kg/d for 5 d) therapy, he gained 4/5 of strength in his upper and lower extremities and denied paraesthesias. He had regained 5/5 of strength in his extremities when he was discharged and had no symptoms during follow-up.CONCLUSIONGBS should be considered in the differential diagnosis of spinal disorder, even though magnetic resonance imaging shows severe lumbar spinal stenosis. This case highlights the importance of a careful diagnosis when a patient has a history of a disease and comes to the hospital with the same or similar symptoms. 相似文献
Chlorpyrifos is the most used insecticide in Argentina. Cnesterodon decemmaculatus is a widely distributed, endemic fish from Neotropical America. It attains high densities in the shallow water assemblages of Argentina and Brazil. The aim of this study was to assess the acute toxicity of chlorpyrifos to C. decemmaculatus. The mean 96-h LC50 of three independent determinations was 105.3 (±?3.1) μg/L. Sublethal effects were observed. Swimming behavioral changes at each chlorpyrifos exposure concentration were reported. C. decemmaculatus represents a good model for ecotoxicological risk assessment. 相似文献
While use of large heads in total hip arthroplasty (THA) continues to grow, concerns have been raised regarding anterior hip pain resulting from impingement of the prosthetic head against soft-tissues like the iliopsoas. To address these concerns, a new anatomically contoured head (ACH) was developed. In this study cadaver tests were utilized to show that iliopsoas impingement/tenting caused by conventional heads is significantly relieved with the more rounded and reduced distal profile of the ACH. Thus, the ACH implant may be able to decrease the risk of soft-tissue impingement with conventional heads, particularly in the smaller hip. 相似文献
Objective: To evaluate the long-term clinical effect of high-intensity focussed ultrasound (HIFU) as a non-invasive modality for ablation of abdominal wall endometriosis (AWE) foci.
Methods: All women who were diagnosed with cutaneous endometriosis and underwent HIFU ablation and 4-year follow-up were included. Patient symptoms, imaging performed, HIFU ablation, recurrence, lesion location, size and number were collected and analyzed.
Results: A total of 51 women with 57 painful abdominal wall masses with a median volume of 4.00?cm3 and a mean age of 30.5±2.12 years were treated with HIFU. The main symptoms were a palpable painful abdominal mass (93%), protrusion of the skin (28.1%, 16) or lack of protrusion of the skin (71.9%, 41). Ultrasound was initially performed in 100% (51) of women, whereas 6% (3) required MRI examinations to distinguish the features and range of the masses. Ablation was performed with a median 300?s of sonication time, 40?min treatment time, 150?W of power and 41800?J of total energy to treat lesions that were a median volume of 3.83?cm3. No severe complications occurred, except in one patient with a first-degree skin burn, during the 48-month follow-up period. The pooled recurrence of cutaneous endometriosis occurred in 3.9% (2) of women.
Conclusion: The diagnosis of AWE should be confirmed with imaging of the lesion number, location, size and features before HIFU ablation. HIFU should be the first choice for the treatment of AWE as it is a non-invasive method, with high efficiency and safety and rapid postoperative recovery. 相似文献