The role of video-based discussion in model for preparing professional development leaders.

BACKGROUND: This paper describes the Problem-Solving Cycle model of professional development and the Mathematics Leadership Preparation model of PD leader preparation. These models form the backbone of our current research-practice partnership project in which we are working with a large urban district to adapt these models to develop district capacity to support the implementation of a middle school mathematics curriculum aligned with Common Core State Standards (CCSS). We highlight the central role of video in the Problem-Solving Cycle and our approach to preparing teacher leaders to use video-based discussions to understand student thinking and instructional practices. RESULTS: The first phase of the research was designed to identify how the models were adapted to support the district goals for implementing their new CCSS mathematics curriculum and to understand the reasons for the adaptations. The analysis of multiple data sources revealed two overarching categories of adaptations that we made to refine the models to better support the district goals: addressing district priorities and addressing teacher leaders' limited experience. We made adaptations such as incorporating the district curriculum, addressing the needs of English learners, integrating the teacher leaders' learning of the Problem-Solving Cycle model into the leadership preparation session, increasing the emphasis on what it means to be an instructional leader, strengthening the role of modeling and debriefing activities to support leadership development, scaffolding the selection of video clips, and incorporating the use of rehearsals and debriefing activities to support leadership development. CONCLUSION: The implications of this work illustrate the need for researchers to be responsive to the context of their school partners if they expect their work to be meaningful. Using the frame of design-based implementation research proved to be an effective strategy for working with the district STEM leadership team and teacher leaders to adapt the Problem-Solving Cycle and Mathematics Leadership Preparation models to support district implementation of a new curriculum that necessitates shifts in teacher practices and for determining how to make video-based discussions more productive activities in the models.

Preoperative infliximab therapy does not increase morbidity and mortality after laparoscopic resection for inflammatory bowel disease.

BACKGROUND: The impact of infliximab on the postoperative course of patients with IBD is under debate. OBJECTIVE: The aim of this study was to evaluate the influence of infliximab on perioperative outcomes in patients undergoing elective laparoscopic resection for IBD. DESIGN: This study is a retrospective analysis of a prospectively collected, institutional review board-approved database. SETTING, PATIENTS, INTERVENTIONS: Patients undergoing laparoscopic resection on preoperative infliximab (infliximab group) were compared with patients who did not receive infliximab (noninfliximab group). MAIN OUTCOME MEASURES: The short-term and long-term morbidity and mortality rates were assessed. RESULTS: Elective laparoscopic resection for IBD was performed on 518 patients from January 2004 through June 2011; 142 patients were treated with infliximab preoperatively. Both groups had similar demographics, type and severity of IBD, comorbidities, and type of surgery. A significantly higher number of patients in the infliximab group had been on aggressive medical therapy to control symptoms of IBD during the month preceding surgery, including steroids (73.9 vs 58.8%, p = 0.002) and immunosuppressors (32.4 vs 20.5%, p = 0.006). Operative time and blood loss were similar (p = 0.50 and p = 0.34). Intraoperative complication rate was 2.1% in both groups. No significant differences were observed in terms of the conversion rate to laparotomy (6.3% vs 9.3%, p = 0.36), overall 30-day postoperative morbidity (p = 0.93), or mortality (p = 0.61). The rates of anastomotic leak (2.1% vs 1.3%, p = 0.81), infections (12% vs 11.2%, p = 0.92), and thrombotic complications (3.5% vs 5.6%, p = 0.46) were similar. Subgroup analyses confirmed similar rates of overall, infectious, and thrombotic complications regardless of whether patients had ulcerative colitis or Crohn's disease. LIMITATIONS: This study is subject to the limitations of a retrospective design. CONCLUSIONS: Infliximab is not associated with increased rates of postoperative complications after laparoscopic resection.

Does morbid obesity change outcomes after laparoscopic surgery for inflammatory bowel disease? Review of 626 consecutive cases.

BACKGROUND: Little is known about the impact of obesity on morbidity in patients with inflammatory bowel disease (IBD) who are undergoing laparoscopic resections. The aim of this study was to evaluate outcomes in a consecutive series of normal weight (NW), overweight (OW), and obese (OB) patients undergoing elective laparoscopic colorectal surgery for IBD. STUDY DESIGN: This study is a retrospective analysis of a prospectively collected, Institutional Review Board-approved IBD database. RESULTS: Laparoscopic colorectal resection was performed in 626 patients (335 NW, 206 OW, and 85 OB) between August 2002 and December 2011. Operative time and blood loss were significantly higher in the OW and OB groups compared with the NW group (p = 0.001 and p < 0.001). No differences were observed in terms of intraoperative blood transfusions (p = 0.738) or complications (p = 0.196). The OW and OB groups had a significantly higher conversion rate (p = 0.049 and p = 0.037) and a longer incision compared with the NW group (p = 0.002 and p < 0.001). Obesity was an independent predictor of conversion to open surgery. No significant differences between groups were observed in terms of overall 30-day postoperative morbidity (p = 0.294) and mortality (p = 0.796). Long-term complications occurred in 6.3% NW, 7.3% OW, and 4.7% OB patients (p = 0.676). Incisional hernias were more common in the OB group compared with the NW group (p = 0.020). On multivariate analysis, obesity was not an independent risk factor for either early or late postoperative complications. CONCLUSIONS: Obesity increases the complexity of laparoscopic resections in IBD with higher blood loss, operative time, and conversion rates, without worsening outcomes.

Three-dimensional crystallization of the Escherichia coli glycerol-3-phosphate transporter: a member of the major facilitator superfamily.

Here we report the successful three-dimensional crystallization of GlpT, the glycerol-3-phosphate transporter from Escherichia coli inner membrane. GlpT possesses 12 transmembrane alpha-helices and is a member of the major facilitator superfamily. It mediates the exchange of glycerol-3-phosphate for inorganic phosphate across the membrane. Approximately 20 phospholipid molecules per protein, identified as negatively charged phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin, were required for the monodispersity of purified GlpT. Analytical size-exclusion chromatography proved to be efficient in identifying detergents for GlpT monodispersity. Nine such detergents were later used for GlpT crystallization. Screening for crystal nucleation was carried out with a variety of polyethylene glycols as the precipitant over a wide pH range. Subsequent identification of a rigid protein core by limited proteolysis and mass spectroscopy resulted in better-ordered crystals. These crystals exhibited order to 3.7 A resolution in two dimensions. However, the stacking in the third dimension was partially disordered. This stacking problem was overcome by using a detergent mixture and manipulating the ionic interactions in the crystallization solution. The resulting GlpT crystals diffracted isotropically to 3.3 A resolution and were suitable for structure determination by X-ray crystallography.

Oligomeric and conformational properties of a proteolytically mature, disulfide-stabilized human immunodeficiency virus type 1 gp140 envelope glycoprotein.

We describe the further properties of a protein, designated SOS gp140, wherein the association of the gp120 and gp41 subunits of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein is stabilized by an intersubunit disulfide bond. HIV-1(JR-FL) SOS gp140, proteolytically uncleaved gp140 (gp140(UNC)), and gp120 were expressed in stably transfected Chinese hamster ovary cells and analyzed for antigenic and structural properties before and after purification. Compared with gp140(UNC), SOS gp140 reacted more strongly in surface plasmon resonance and radioimmunoprecipitation assays with the neutralizing monoclonal antibodies (MAbs) 2G12 (anti-gp120), 2F5 (anti-gp41), and 17b (to a CD4-induced epitope that overlaps the CCR5-binding site). In contrast, gp140(UNC) displayed the greater reactivity with nonneutralizing anti-gp120 and anti-gp41 MAbs. Immunoelectron microscopy studies suggested a model for SOS gp140 wherein the gp41 ectodomain (gp41(ECTO)) occludes the "nonneutralizing" face of gp120, consistent with the antigenic properties of this protein. We also report the application of Blue Native polyacrylamide gel electrophoresis (BN-PAGE), a high-resolution molecular sizing method, to the study of viral envelope proteins. BN-PAGE and other biophysical studies demonstrated that SOS gp140 was monomeric, whereas gp140(UNC) comprised a mixture of noncovalently associated and disulfide-linked dimers, trimers, and tetramers. The oligomeric and conformational properties of SOS gp140 and gp140(UNC) were largely unaffected by purification. An uncleaved gp140 protein containing the SOS cysteine mutations (SOS gp140(UNC)) was also oligomeric. Surprisingly, variable-loop-deleted SOS gp140 proteins were expressed (although not yet purified) as cleaved, noncovalently associated oligomers that were significantly more stable than the full-length protein. Overall, our findings have relevance for rational vaccine design.