Plasminogen activators in dextran sulfate-activated euglobulin fractions: a molecular analysis of factor XII- and prekallikrein- dependent fibrinolysis

To elucidate the mechanism by which activation of the contact system of blood coagulation leads to expression of fibrinolytic activity, we have determined the molecular characteristics of the plasminogen activators present in dextran sulfate-treated euglobulin fractions by electrophoretic-zymographic analysis and specific immunoadsorption. In addition to free and protease inhibitor-bound tissue-type plasminogen activator (t-PA), dextran sulfate precipitates of euglobulins contained the complex formed between plasma kallikrein and C1-inhibitor, an indicator of prekallikrein activation. These precipitates also contained substantial fibrinolytic activity related to urinary-type plasminogen activator (u-PA). Autoradiographic analysis was then used to evaluate the cleavage of 125I-single-chain u-PA (prourokinase) in dextran sulfate euglobulins as well as after exposure to kallikrein or beta-factor XIIa. This analysis supported the conclusion that plasma kallikrein-mediated cleavage and activation of single-chain u-PA is the mechanism operative for the development of lytic activity in euglobulin precipitates following activation of the contact system.     

PBL Core Skills Faculty Development Workshop 3: understanding PBL process assessment and feedback via scenario-based discussions, observation, and role-play

Tutorial assessment in PBL is thought to be a valid assessment approach and is believed to exert a positive impact on the learning process. Reports, however, have demonstrated that assessment by the facilitator can be unreliable. Training of faculty to conduct this type of assessment has tended to be lacking and is a likely contributor to this inconsistency. This report describes the final in a series of foundation-building faculty development workshops focused on the instructional methodology of PBL. The PBL Assessment and Feedback workshop reported here introduced the theory and practice of conducting process-based assessment accompanied by formative feedback. Scenario-based discussions, mock group demonstration, role-modeling, and role-play were utilized as adult learning-appropriate strategies to familiarize participants with process-based assessment and feedback. Evaluation of the workshop by participants provided evidence that the majority of participants were satisfied with the methods and content of the workshop. Suggestions for additional training in these assessment methods included additional examples, practice, workshops, or observation and mentoring.     

A phase I open-label, dose-escalation, multi-institutional trial of injection with an E1B-Attenuated adenovirus, ONYX-015, into the peritumoral region of recurrent malignant gliomas, in the adjuvant setting.

ONYX-015 is an oncolytic virus untested as a treatment for malignant glioma. The NABTT CNS Consortium conducted a dose-escalation trial of intracerebral injections of ONYX-015. Cohorts of six patients at each dose level received doses of vector from 10(7) plaque-forming units (pfu) to 10(10) pfu into a total of 10 sites within the resected glioma cavity. Adverse events were identified on physical exams and testing of hematologic, renal, and liver functions. Efficacy data were obtained from serial MRI scans. None of the 24 patients experienced serious adverse events related to ONYX-015. The maximum tolerated dose was not reached at 10(10) pfu. The median time to progression after treatment with ONYX-015 was 46 days (range 13 to 452 + days). The median survival time was 6.2 months (range 1.3 to 28.0 + months). One patient has not progressed and 1 patient showed regression of interval-increased enhancement. With more than 19 months of follow-up, 1/6 recipients at a dose of 10(9) and 2/6 at a dose of 10(10) pfu remain alive. In 2 patients who underwent a second resection 3 months after ONYX-015 injection, a lymphocytic and plasmacytoid cell infiltrate was observed. Injection of ONYX-015 into glioma cavities is well tolerated at doses up to 10(10) pfu.     

Ti6Al4V-AlTiN涂层材料在模拟生理环境中的耐蚀性能

目的:通过电化学腐蚀实验和浸泡实验对AlTiN涂层进行耐蚀性能检测,评价其作为一种新型生物材料的可行性。方法:实验于2006-06/08在贵州省材料结构与强度重点实验室完成。AlTiN涂层的制备:采用高度离子化脉冲工艺(H.I.P)在医用Ti6Al4V合金表面沉积AlTiN涂层。实验评估:①运用电化学腐蚀方法对Ti6Al4V-AlTiN涂层材料在模拟人体生理环境中的耐蚀性与Ti6Al4V合金进行对比,光学显微镜下观察Ti6Al4V-AlTiN涂层材料的表面形貌。②借助等离子发射光谱仪检测化学浸泡实验后的溶液中Al,V离子含量,EPMA-1600电子探针观察Ti6Al4V-AlTiN涂层材料的表面形貌。结果:①电化学腐蚀实验:Ti6Al4V-AlTiN涂层材料电流密度在-0.4～0.25A/m2基本处于钝化状态,Ti6Al4V合金在电位为0.5V时电流密度陡然增加,其氧化膜被击穿。光学显微镜观察Ti6Al4V合金表面凹凸不平,有不均匀氧化膜存在;Ti6Al4V-AlTiN涂层材料表面较为均匀,表现出更好的耐蚀性。②化学浸泡实验:Ti6Al4V-AlTiN涂层材料有效地阻止了Al,V离子的释放。化学浸泡7d后EPMA-1600电子探针观察Ti6Al4V-AlTiN涂层材料表面有Ca/P层沉积。结论:Ti6Al4V-AlTiN涂层材料具有一定生物陶瓷材料的耐蚀性能,有可能成为一种新型生物材料。     

Adenoid cystic carcinoma metastasizing before detection of the primary lesion

Although adenoid cystic carcinomas are occasionally manifested in atypical ways, metastatic disease preceding detection of the primary tumor has not been previously reported. We have described a patient in whom multiple pulmonary metastatic nodules were found one year before identification of primary adenoid cystic carcinoma of the maxilla. This case illustrates the need to include adenoid cystic carcinoma in the differential diagnosis of patients with metastatic disease and an unknown primary lesion. The use of special stains and electron microscopy can be helpful in confirming a diagnosis of adenoid cystic carcinoma.     

Influence of lipoproteins on renal cytotoxicity and antifungal activity of amphotericin B.

We examined the influence of high-density lipoproteins (HDLs) and low-density lipoproteins (LDLs) on the toxicity of amphotericin B (AmpB) to fungal and renal cells. Candida albicans was incubated for 18 h at 37 degrees C with AmpB and deoxycholate (Fungizone) or liposomal AmpB (L-AmpB) (0.1 to 2.0 micrograms of AmpB per ml) in the presence or absence of HDLs or LDLs (0.5 mg of protein per ml). The MICs of AmpB and L-AmpB, whether or not HDLs or LDLs were present, were similar. LLC PK1 renal cells, derived from primary cultures of pig proximal tubular cells, were incubated for 18 h at 37 degrees C in serum-free medium that contained AmpB and deoxycholate or L-AmpB at 20 micrograms of AmpB per ml, HDLs or LDLs at 0.5 mg of protein per ml, mixtures of AmpB with HDLs or LDLs, and mixtures of L-AmpB with HDLs or LDLs. HDL-associated AmpB was less toxic than AmB to LLC PK1 cells (53.0% +/- 2.5% versus 81.3% +/- 3.6% cytotoxicity; P = 0.01), while LDL-associated AmpB was as toxic as AmpB. L-AmpB, HDL-associated L-AmpB, and LDL-associated L-AmpB were less toxic to LLC PK1 cells than was AmpB (48.3% +/- 1.5%, 25.5% +/- 2.2%, and 52.2% +/- 2.5% versus 81.3% +/- 3.6% cytotoxicity; P = 0.02). To further understand why HDL-associated AmpB reduced renal cytotoxic effects, the LLC PK1 cells were examined for the presence of HDL and LDL receptors. LLC PK1 cells expressed high-affinity (K(d) = 0.0538 nanograms/ml; 96,000 sites per cell) and low-affinity (K(d) = 222.22 nanograms/ml; 77 sites per cell) LDL receptors but only a low-affinity HDL receptor (K(d) = 71.43 nanograms/ml; 2 sites per cell). HDL-associated AmpB and LDL-associated AmpB were less toxic than AmpB to trypsinized LLC PK1 cells (46.6% +/- 10.9% and 16.8% +/- 15.98% versus 74.7% +/- 7.7% cytotoxicity; P = 0.02). HDL-associated AmB and LDL-associated L-AmpB were also less toxic than AmpB to the cells (20.4% +/- 6.2% and 13.5% +/- 8.6% versus 74.7% cytotoxicity; P = 0.01). The antifungal activities of AmpB and L-AmpB were not altered in the presence of HDLs or LDLs. We conclude that the reduced nephrotoxicity associated with the use of L-AmpB is related to a decreased uptake of AmpB by renal cells when AmpB is associated with HDLs because of the low level of expression of HDL receptors in these cells.     

The rGel/BLyS fusion toxin specifically targets malignant B cells expressing the BLyS receptors BAFF-R, TACI, and BCMA

B lymphocyte stimulator (BLyS) is crucial for B-cell survival, and the biological effects of BLyS are mediated by three cell surface receptors designated B cell-activating factor receptor (BAFF-R), transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI), and B-cell maturation antibody (BCMA). Increased expression of BLyS and its receptors has been identified in numerous B-cell malignancies. We generated a fusion toxin designated rGel/BLyS for receptor-mediated delivery of the recombinant gelonin (rGel) toxin to neoplastic B cells, and we characterized its activity against various B-cell tumor lines. Three mantle cell lymphoma (MCL) cell lines (JeKo-1, Mino, and SP53) and two diffuse large B-cell lymphoma (DLBCL) cell lines (SUDHL-6 and OCI-Ly3) expressing all three distinct BLyS receptors were found to be the most sensitive to the fusion toxin (IC(50) = 2-5 pmol/L and 0.001-5 nmol/L for MCL and DLBCL, respectively). The rGel/BLyS fusion toxin showed specific binding to cells expressing BLyS receptors and rapid internalization of the rGel component into target cells. The cytotoxic effects of rGel/BLyS were inhibited by pretreatment with free BLyS or with soluble BAFF-R, TACI, and BCMA decoy receptors. This suggests that the cytotoxic effects of the fusion toxin are mediated through BLyS receptors. The rGel/BLyS fusion toxin inhibited MCL cell growth through induction of apoptosis associated with caspase-3 activation and poly (ADP-ribose) polymerase cleavage. Our results suggest that BLyS has the potential to serve as an excellent targeting ligand for the specific delivery of cytotoxic molecules to neoplastic B cells expressing the BLyS receptors, and that the rGel/BLyS fusion toxin may be an excellent candidate for the treatment of B-cell malignancies especially MCL and DLBCL.     

Brief Report: Empirical audit and review and an assessment of evidentiary value in research on the psychological consequences of scarcity

Empirical audit and review is an approach to assessing the evidentiary value of a research area. It involves identifying a topic and selecting a cross-section of studies for replication. We apply the method to research on the psychological consequences of scarcity. Starting with the papers citing a seminal publication in the field, we conducted replications of 20 studies that evaluate the role of scarcity priming in pain sensitivity, resource allocation, materialism, and many other domains. There was considerable variability in the replicability, with some strong successes and other undeniable failures. Empirical audit and review does not attempt to assign an overall replication rate for a heterogeneous field, but rather facilitates researchers seeking to incorporate strength of evidence as they refine theories and plan new investigations in the research area. This method allows for an integration of qualitative and quantitative approaches to review and enables the growth of a cumulative science.     

Interleukin-2-induced skin inflammation

Recombinant human IL-2 has been used to treat inflammatory diseases and cancer; however, side effects like skin rashes limit the use of this therapeutic. To identify key molecules and cells inducing this side effect, we characterized IL-2-induced cutaneous immune reactions and investigated the relevance of CD25 (IL-2 receptor α) in the process. We injected IL-2 intradermally into WT mice and observed increases in immune cell subsets in the skin with preferential increases in frequencies of IL-4- and IL-13-producing group 2 innate lymphoid cells and IL-17-producing dermal γδ T cells. This overall led to a shift toward type 2/type 17 immune responses. In addition, using a novel topical genetic deletion approach, we reduced CD25 on skin, specifically on all cutaneous cells, and found that IL-2-dependent effects were reduced, hinting that CD25 — at least partly — induces this skin inflammation. Reduction of CD25 specifically on skin Tregs further augmented IL-2-induced immune cell infiltration, hinting that CD25 on skin Tregs is crucial to restrain IL-2-induced inflammation. Overall, our data support that innate lymphoid immune cells are key cells inducing side effects during IL-2 therapy and underline the significance of CD25 in this process.