Increased adhesion of erythrocytes to components of the extracellular matrix: isolation and characterization of a red blood cell lipid that binds thrombospondin and laminin

Red blood cell (RBC) adhesion to the vascular endothelium is increased in several pathologic conditions, including sickle cell disease and malaria. However, RBC interactions with components of the subendothelial matrix are not well-characterized. Under in vitro flow conditions of 1 dyne/cm2, washed RBCs bound to the purified adhesive molecules thrombospondin (TSP) and laminin. Sickle RBCs had the greatest adhesion of all tested RBCs. The adhesion of sickle RBCs to immobilized TSP was inhibited by the anionic polysaccharides high molecular weight (MW) dextran sulfate and chondroitin sulfate A, but not other anionic polysaccharides of similar structure and/or charge density. These data were consistent with the RBC adhesive molecule being a sulfated glycolipid. Therefore, TSP-binding lipids from normal and sickle RBCs were isolated and characterized. The TSP-binding lipid was purified by alkaline methanolysis, anion exchange chromatography and preparative thin layer chromatography (TLC). A homogeneous band on TLC was identified using a specific overlay TSP-binding assay. TSP binding to the purified lipid was stable to bass and neuraminidase treatment, labile to acid treatment, and was inhibited by high MW dextran sulfate, similar to that seen with intact RBCs binding to immobilized TSP under conditions of flow. In addition, soluble laminin bound to the purified RBC lipid. This acidic TSP- and laminin-binding lipid(s) isolated from both sickle and normal RBC membranes may contribute to erythrocyte interactions with the subendothelial matrix, hereby participating in the pathogenesis of vaso-occlusive diseases.     

Controlled insect-sting challenge in 55 patients: correlation between activation of plasminogen and the development of anaphylactic shock

The pathogenesis of anaphylactic shock is not completely understood. Mast cell degranulation products may stimulate endothelial cells, leading to activation of fibrinolytic and coagulation systems. We investigated the activation of these systems in insect-sting anaphylaxis. Fifty-five patients with a previous insect-sting anaphylactic reaction and 8 volunteers were challenged with an in- hospital sting. Plasma levels of von Willebrand factor (vWF), coagulation, and fibrinolytic parameters were assessed. After the sting challenge, 20 patients developed anaphylactic symptoms, 7 of whom developed hypotension. In only these 7 patients, but not in the volunteers or in the other patients with no or mild anaphylactic symptoms, vWF levels increased from 107% +/- 33% (mean +/- SD) before, to 235% +/- 134% 60 minutes after the onset of clinical symptoms. This increase of vWF was accompanied by an increase of circulating tissue- type plasminogen-activator (tPA) levels from 5 +/- 3 micrograms/L to 50 +/- 59 micrograms/L and of plasminogen-alpha 2-antiplasmin complex (PAP- c) levels from 6 +/- 3 nmol/L to 297 +/- 225 nmol/L. Both tPA and PAP-c levels peaked 5 minutes after the onset of clinical symptoms. Such increases of tPA and PAP-c were not observed in the volunteers or in the patients who did not develop shock. The increase of tPA and PAP-c levels in the hypotensive patients correlated positively with the degree of mast cell degranulation and inversely with the mean arterial pressure. We conclude that activation of plasminogen may be involved in the pathogenesis of anaphylactic shock induced by insect venom.     

Observations on the Chromium Labelling of ACD-Stored and Previously Frozen Red Cells

Chromium labelling characteristics of both ACD-stored and previously frozen red cells were evaluated. The chromium uptake of previously frozen red cells processed by agglomeration was inversely related to the hemoglobin level of the suspending fluid. Ascorbic acid was not needed for the labelling of previously frozen, agglomerated red cells.
Cellular injury, as measured by increase in supernatant hemoglobin during post-thaw storage at 4 C, occurred with the agglomerated, previously frozen red cells when: (1) Na₂ EDTA was present in the glycerolizing solution; (2) the disaggregation of the agglomerated red cell mass was carried out with 75 rather than 250 ml of isotonic saline; and (3) the storage temperature of the glycerolized red cells was interrupted for one week with a storage interim at either 4 C or −20 C.
By use of a phthalate ester technic, red cells were separated into three fractions on the basis of cellular density. Preferential chromium labelling of red cells was noted: the lightest fraction contained significantly more radioactivity than the heaviest fraction.     

Reduced length of hospital stay after the introduction of a rapid recovery protocol for primary THA procedures

Background and purpose Rapid recovery protocols after total hip arthroplasty (THA) have been introduced worldwide in the last few years and they have reduced the length of hospital stay. We show the results of the introduction of a rapid recovery protocol for primary THA for unselected patients in our large teaching hospital.

Patients and methods In a retrospective cohort study, we included all 1,180 patients who underwent a primary THA between July 1, 2008 and June 30, 2012. These patients were divided into 3 groups: patients operated before, during, and after the introduction of the rapid recovery protocol. There were no exclusion criteria. All complications, re-admissions, and reoperations were registered and analyzed.

Results The mean length of hospital stay decreased from 4.6 to 2.9 nights after the introduction of the rapid recovery protocol. There were no statistically significant differences in the rate of complications, re-admissions, or reoperations between the 3 groups.

Interpretation In a large teaching hospital, the length of hospital stay decreased after introduction of our protocol for rapid recovery after THA in unselected patients, without any increase in complications, re-admissions, or reoperation rate.     

Two-year analysis of efficacy and safety of deferasirox treatment for transfusional iron overload in sickle cell anemia patients

The efficacy and safety of a 2-year treatment with deferasirox was evaluated in 31 patients with sickle cell anemia and transfusional iron overload. At 24 months, there were significant decreases from baseline in mean serum ferritin (from 2,344.6 to 1,986.3 μg/l; p = 0.040) and in mean liver iron concentration (from 13.0 ± 5.4 to 9.3 ± 5.7 mg Fe/g dry weight; p < 0.001). Myocardial T2* values were normal (>20 ms) in all patients at baseline and did not change significantly over the course of the study. However, there was a significant improvement from baseline in left ventricular ejection fraction at 24 months (62.2-64.6%; p = 0.02). Deferasirox was generally well tolerated with no progressive increases in serum creatinine or renal failure observed. These data confirm that deferasirox is effective in reducing body iron burden in patients with sickle cell anemia and transfusional iron overload.     

Future research and collaboration: the “SINERGIE” project on HCV (<Emphasis Type="Italic">South Italian Network for Rational Guidelines and International Epidemiology</Emphasis>)

The SINERGIE (South Italian Network for Rational Guidelines and International Epidemiology) project is intended to set up a collaborative network comprising virologists, clinicians and public health officials dealing with patients affected by HCV disease in the Calabria Region. A prospective observational data-base of HCV infection will be developed and used for studies on HCV natural history, response to treatment, pharmaco-economics, disease complications, and HCV epidemiology (including phylogenetic analysis). With this approach, we aim at improving the identification and care of patients, focusing on upcoming research questions. The final objective is to assist in improving care delivery and inform Public Health Authorities on how to optimize resource allocation in this area.     

Spatial Heterogeneity in the Response of the Proximal Femur to Two Lower‐Body Resistance Exercise Regimens

Understanding the skeletal effects of resistance exercise involves delineating the spatially heterogeneous response of bone to load distributions from different muscle contractions. Bone mineral density (BMD) analyses may obscure these patterns by averaging data from tissues with variable mechanoresponse. To assess the proximal femoral response to resistance exercise, we acquired pretraining and posttraining quantitative computed tomography (QCT) images in 22 subjects (25–55 years, 9 males, 13 females) performing two resistance exercises for 16 weeks. One group (SQDL, n = 7) performed 4 sets each of squats and deadlifts, a second group (ABADD, n = 8) performed 4 sets each of standing hip abductions and adductions, and a third group (COMBO, n = 7) performed two sets each of squat/deadlift and abduction/adduction exercise. Subjects exercised three times weekly, and the load was adjusted each session to maximum effort. We used voxel‐based morphometry (VBM) to visualize BMD distributions. Hip strength computations used finite element modeling (FEM) with stance and fall loading conditions. We used QCT analysis for cortical and trabecular BMD, and cortical tissue volume. For muscle size and density, we analyzed the cross‐sectional area (CSA) and mean Hounsfield unit (HU) in the hip extensor, flexor, abductor, and adductor muscle groups. Whereas SQDL increased vertebral BMD, femoral neck cortical BMD and volume, and stance hip strength, ABADD increased trochanteric cortical volume. The COMBO group showed no changes in any parameter. VBM showed different effects of ABADD and SQDL exercise, with the former causing focal changes of trochanteric cortical bone, and the latter showing diffuse changes in the femoral neck and head. ABADD exercise increased adductor CSA and HU, whereas SQDL exercise increased the hip extensor CSA and HU. In conclusion, we observed different proximal femoral bone and muscle tissue responses to SQDL and ABADD exercise. This study supports VBM and volumetric QCT (vQCT) to quantify the spatially heterogeneous effects of types of muscle contractions on bone. © 2014 American Society for Bone and Mineral Research.     

Identification of promising strategies to sustain improvements in hospital practice: a qualitative case study

Background

A quality improvement collaborative is an intensive project involving a combination of implementation strategies applied in a limited “breakthrough” time window. After an implementation project, it is generally difficult to sustain its success. In the current study, sustainability was described as maintaining an implemented innovation and its benefits over a longer period of time after the implementation project has ended. The aim of the study was to explore potentially promising strategies for sustaining the Enhanced Recovery After Surgery (ERAS) programme in colonic surgery as perceived by professionals, three to six years after the hospital had successfully finished a quality improvement collaborative.

Methods

A qualitative case study was performed to identify promising strategies to sustain key outcome variables related to the ERAS programme in terms of adherence, time needed for functional recovery and hospital length of stay (LOS), as achieved immediately after implementation. Ten hospitals were selected which had successfully implemented the ERAS programme in colonic surgery (2006–2009), with success defined as a median LOS of 6 days or less and protocol adherence rates above 70%. Fourteen semi-structured interviews were held with eighteen key participants of the care process three to six years after implementation, starting with the project leader in every hospital. The interviews started by confronting them with the level of sustained implementation results. A direct content analysis with an inductive coding approach was used to identify promising strategies. The mean duration of the interviews was 37 minutes (min 26 minutes – max 51 minutes).

Results

The current study revealed strategies targeting professionals and the organisation. They comprised internal audit and feedback on outcomes, small-scale educational booster meetings, reminders, changing the physical structure of the organisation, changing the care process, making work agreements and delegating responsibility, and involving a coordinator. A multifaceted self-driven promising strategy was applied in most hospitals, and in most hospitals promising strategies were suggested to sustain the ERAS programme.

Conclusions

Joining a quality improvement collaborative may not be enough to achieve long-term normalisation of transformed care, and additional investments may be needed. The findings suggest that certain post-implementation strategies are valuable in sustaining implementation successes achieved after joining a quality improvement collaborative.