Procoagulant activity of reversibly acylated human factor Xa

The plasma clotting factors used to treat hemophiliacs who have developed inhibitory antibodies have a shared history of limited clinical safety and utility. To improve on existing bypass factors, we have developed a reversibly acylated form of human plasma factor Xa capable of providing a time-dependent release of procoagulant activity. Factor Xa was treated with p-amidinophenyl p'-anisate to generate anisoyl Xa. The chemical modification of the protein involves acylation of the active site serine residue of factor Xa. Anisoyl Xa deacylated in a time, pH, and temperature-dependent manner. Active factor Xa generated on deacylation of anisoyl Xa exhibited amidolytic and prothrombinase complex activities in in vitro assays, the level being comparable to those of untreated factor Xa. When Anisoyl Xa was infused into rabbits, active factor Xa was generated on deacylation of the acylated enzyme, which shortened the activated partial thromboplastin time (APTT) in a dose-dependent manner. The duration of effect on rabbit APTT could be directly correlated to the level of human plasma factor Xa. Because anisoyl Xa bypasses the "tenase" complex that is compromised in hemophilia A and B and is unaffected by inhibitory antibodies, it has the potential to be used as an effective bypass therapy.     

A multi-systemic disease (lupus-like) preceding bronchioloalveolar carcinoma

Summary A patient with a multi-systemic disease (lupus-like) that preceded the onset of a bronchioloalveolar carcinoma is described, and a brief review of the literature is presented. We suggest that this tumor be listed among the neoplasms responsible for multi-systemic diseases with lupus-like characteristics.     

The role of biomechanics and inflammation in cartilage injury and repair

Osteoarthritis is a painful and debilitating disease characterized by progressive degenerative changes in the articular cartilage and other joint tissues. Biomechanical factors play a critical role in the initiation and progression of this disease, as evidenced by clinical and animal studies of alterations in the mechanical environment of the joint caused by trauma, joint instability, disuse, or obesity. The onset of these changes after joint injury generally has been termed posttraumatic arthritis and can be accelerated by factors such as a displaced articular fracture. Within this context, there is considerable evidence that interactions between biomechanical factors and proinflammatory mediators are involved in the progression of cartilage degeneration in posttraumatic arthritis. In vivo studies have shown increased concentrations of inflammatory cytokines and mediators in the joint in mechanically induced models of osteoarthritis. In vitro explant studies confirm that mechanical load is a potent regulator of matrix metabolism, cell viability, and the production of proinflammatory mediators such as nitric oxide and prostaglandin E2. Knowledge of the interaction of inflammatory and biomechanical factors in regulating cartilage metabolism would be beneficial to an understanding of the etiopathogenesis of posttraumatic osteoarthritis and in the improvement of therapies for joint injury.     

Absence of donor CD40 protects renal allograft epithelium and preserves renal function

Blocking the CD40‐CD154 pathway prevents allograft rejection and induces donor‐specific tolerance in various experimental models. However, the translation to clinical studies has been hampered by unexpected thromboembolic complications of CD154‐blocking antibodies. Thus, blocking CD40 instead is now considered as an alternative strategy. Here, we evaluated the role of donor CD40 in allospecific T‐cell responses in vitro and in an in vivo model for renal transplantation. Fully MHC‐mismatched allografts from CD40‐deficient donors displayed better renal function than wild type. These functional data correlated with a lower level of apoptosis in renal tubular epithelial cells and higher expression of PD‐L1, which is most probably because of a reduced Th17 response in recipients of a CD40‐deficient donor. This hypothesis was supported in vitro, where donor CD40 expression was important for the induction of direct allospecific T‐cell responses. Especially the induction of Th17 cells was critically dependent on donor CD40. IL‐17A in conjunction with interferon‐γ in turn rendered renal tubular epithelial cells to a more costimulatory state by upregulating CD40 and downregulating PD‐L1 expression. In conclusion, CD40 blockade not only reduces the allospecific T‐cell responses, but might also lead to protection of tubular epithelium from apoptosis and thereby preserve kidney allograft function.     

Therapie der septischen Querschnittl?hmung

The frequency of infectious diseases of the spine and associated spinal cord injury are constantly increasing. Affected are multimorbid and elderly patients, mostly after prolonged medical treatment. An acute spinal cord injury due to infection is an emergency. A rapid decision for treatment strategy and if at all possible subtle debridement of the infected tissue with decompression of the spinal cord is paramount. Additionally spinal cord injury necessitates specialized treatment and care of the infection. Spinal cord injured patients in general and these patients in particular are prone to complications and need especially trained nursing personnel. It is therefore recommended that patients with vertebral osteomyelitis associated with spinal cord injury should be transferred to dedicated centres of treatment as soon as possible.Just as in cases of spondylodiscitis without spinal cord injury inconsistent surgical or insufficient antibiotic treatment worsens the prognosis significantly. If it is possible to remit the infection, the prognosis for recovery of motor and sensory function is better than in cases with traumatic spinal cord injury. In many cases at least partial recovery can be observed.     

Selective neck dissection in node-positive squamous cell carcinoma of the head and neck

Objective The optimal type of neck dissection in head and neck squamous cell carcinoma (SCC) with clinical cervical metastases has not been determined. The following study was performed to determine the rate of regional control with selective neck dissection (SND) in these patients. Study Design Case series with planned data collection. Settings Single institution, cancer center. Methods and Subjects Patients with cervical lymph node metastases from mucosal cancers of the head and neck who were treated with SND from 2000 to 2010 were selected. Demographics, tumor characteristics, extent of neck dissection, adjuvant treatments, locoregional control, and survival were recorded. Recurrence in the neck and disease-specific survival (DSS) were primary and secondary end points. Results One hundred eight patients underwent SND. Sixty-nine (64%) were male. Median age was 62 (20-89) years. The most common primary site was the oral cavity (71.3%). Ninety-five (88%) received adjuvant treatment. Median follow-up was 21 months. Six patients (5.5%) had isolated recurrence in the dissected neck. Patients with N2C disease had poorer neck recurrence-free survival. At the end of study, 64 (59.3%) patients had no evidence of disease, and 23 (21.3%) had died of disease. Two-year DSS was 76.9%. Number of positive nodes (P = .026) and positive surgical margins (P = .001), among others, were predictors of poorer DSS. Conclusion In a highly selected group of patients with cervical lymph node metastases from head and neck SCC, selective neck dissection is effective in controlling the disease in the neck when performed in the setting of a multimodality treatment, including adjuvant radiotherapy or radiochemotherapy.     

Transcatheter embolization as the new reference standard for endoscopically unmanageable upper gastrointestinal bleeding

Acute nonvariceal upper gastrointestinal bleeding(UGIB) is a major medical emergency problem associated with significant morbidity and mortality.Endoscopy is considered the first method of choice to detect and treat UGIB.Endoscopic therapy usually achieves primary hemostasis,but 10%-30% of these patients have repeat bleeding.In patients in whom hemostasis is not achieved with endoscopic techniques,treatment with transcatheter angiographic embolization(TAE) or surgery is needed.Surgical intervention is usually an expeditious and gratifying endeavor,but it can be associated with high operative mortality rates.A large number of studies support the use of TAE as salvage therapy as an alternative to surgery.However,few studies have compared the results of TAE with that of emergency surgery in terms of efficiency,the frequency of repeat bleeding,and complications.Recently,Ang et al retrospectively compared the outcome of TAE and surgery as salvage therapy of UGIB after failed endoscopic treatment.There were no significant differences in 30 d mortality,complication rates and length of stay although higher rebleeding rates were observed after TAE compared with surgery.In this commentary,we discuss the advantages and drawbacks of these two therapeutic strategies for UGIB.We also attempt to define the exact role of TAE for acute nonvariceal UGIB.     

Endovascular management of visceral artery aneurysms: When to watch,when to intervene?

Visceral artery aneurysms (VAA) include splanchnic and renal artery aneurysms. They represent a rare clinical entity, although their detection is rising due to an increased use of cross-sectional imaging. Rupture is the most devastating complication, and is associated with a high morbidity and mortality. In addition, increased percutaneous endovascular interventions have raised the incidence of iatrogenic visceral artery pseudoaneurysms (VAPAs). For this reason, elective repair is preferable in the appropriately chosen patient. Controversy still exists regarding their treatment. Over the past decade, there has been steady increase in the utilization of minimally invasive, non-operative interventions, for vascular aneurysmal disease. All VAAs and VAPAs can technically be fixed by endovascular techniques but that does not mean they should. These catheter-based techniques constitute an excellent approach in the elective setting. However, in the emergent setting it may carry a higher morbidity and mortality. The decision for intervention has to take into account the size and the natural history of the lesion, the risk of rupture, which is high during pregnancy, and the relative risk of surgical or radiological intervention. For splanchnic artery aneurysms, we should recognize that we are not, in reality, well informed about their natural history. For most asymptomatic aneurysms, expectant treatment is acceptable. For large, symptomatic or aneurysms with a high risk of rupture, endovascular treatment has become the first-line therapy. Treatment of VAPAs is always mandatory because of the high risk of rupture. We present our point of view on interventional radiology in the splanchnic arteries, focusing on what has been achieved and the remaining challenges.     

Safety and efficacy of pulse and daily calcitriol in patients on CAPD: a randomized trial

Background: Calcitriol therapy is the mainstay of therapy for the treatment of secondary hyperparathyroidism. Oral administration of calcitriol is necessary in CAPD patients, but no studies have directly compared different routes of administration in this patient population. Methods: To determine if the peak serum calcitriol level (pulse therapy) is more important than the total delivered dose, we randomized CAPD patients with mild to moderate secondary hyperparathyroidism to receive either pulse (3.0 &mgr;g twice a week, n=10) or daily (0.75 &mgr;g a day, n=8) oral calcitriol in comparable weekly doses. The main comparison was the rate of decline of serum intact parathyroid hormone (PTH) levels to reach the desired end-point of 100 pg/ml. The patients were dialysed with low-calcium dialysate and received only calcium-containing phosphate binders. Results: Pharmacokinetic analysis after a single dose of 3.0 &mgr;g (pulse) vs 0.75 &mgr;g (daily) revealed 1,25(OH)2-vitamin D levels to be higher in the pulse group at 3 and 6 h, but equivalent by 12 h. The area under the curve for 1 week of daily and 1 week of pulse therapy was equal. The patients in the 2 arms had equivalent basal serum levels of PTH (pulse=562±291 vs daily=454±113 pg/ml), calcium (pulse=2.32±0.20 vs daily=2.32±0.12 mmol/l) and phosphorus (pulse=1.32±0.52 vs daily=1.35±0.26 mmol/l). The time required for the PTH to decrease to 100 pg/ml and rate of decline in PTH were similar (time: pulse=14.2±6.8 weeks, daily=12.2±7 weeks; rate: pulse=7.4±4.2 vs daily=8.4±4.2% PTH/week; P=NS). The serum calcium increased similarly in both groups. Hypercalcaemia (>2.9 mmol/l) was rare (pulse=3, daily=2 episodes). Conclusions: This study demonstrates that pulse and daily calcitriol are similarly effective and safe for the treatment of mild to moderate secondary hyperparathyroidism in CAPD patients despite higher peak levels of 1,25(OH)2-vitamin D with pulse therapy. Key words: calcitriol; calcium balance; CAPD; dialysis; hyperparathyroidism; renal osteodystrophy