Ball mill abrasion test (BMAT): Method development and statistical evaluations.

High-stress abrasive wear is a major material consumption process in mining and ore beneficiation industries. The common laboratory high-stress abrasion apparatuses suffer from lack of capability of closely simulating the service conditions of grinding media and mill liners, being the main consumables in these sectors. The ball mill abrasion test (BMAT) is a versatile abrasive wear tester that facilitates reliable modelling of kinematics and contact mechanics of the industrial mills. Unlike 'standard' test devices, natural rocks of any type and/or blend with desired particles size distributions can be charged into the BMAT for testings under various ranges of liquids, grinding media and durations. It is simple to design, low-cost to manufacture, reliable to evaluate alloys performance and reproducible to rank abrasion-resistant materials. In this work, BMAT's two operation modes, BMAT-T (tumbling mode) and BMAT-C (cassette mode) are introduced. The performed comprehensive analysis on the method development, statistical assessment and further procedures refinement showed that:•In the BMAT-T, 20-hour tests using the planned operational parameters and normalisation method result in statistically reliable and reproducible outcomes.•In the BMAT-C, four 20-hr intervals, different operational parameters and specific specimen distribution pattern are needed to obtain high quality measurements.•The maximum observed relative standard deviation in the all statistical and alloy-performance evaluation campaigns was 6.6% - an excellent quality dimension for an abrasion test.

Traumatic right atrial rupture bridge to definitive repair with extra-corporeal life support.

Cardiac injury secondary to non-penetrating trauma is more common than thought, albeit, the injury is usually minor and goes undiagnosed without significant sequelae in most cases. Blunt cardiac rupture is much rarer accounting for <0.05% of all trauma cases but lethal in most circumstances. We present a case report of a young trauma victim who presented with both right atrial rupture and traumatic atrial septal disruption (ASD) requiring extra-corporeal life support (ECLS) and surgical repair. Blunt cardiac trauma with chamber rupture and septal disruption is a devastating injury. Stopping the hemorrhage and using ECLS gave our patient time to stabilize before definitive management of her traumatic ASD.

Monitoring circulating tumor cells in cancer vaccine trials.

The presence of circulating tumor cells (CTC) from various cancers has provided a wealth of information and possibilities. As the role of CTC detection in the treatment assessment of metastatic breast cancer becomes standard, there is interest in applying this tool in cancer vaccine development and clinical trial monitoring. Since we lack a proven immunologic assay that correlates with clinical response, CTC detection, quantification and phenotypic characterization may be a useful surrogate for clinical outcome. The Cancer Vaccine Development Program is involved in the development of HER2/neu peptide based vaccine development for the prevention of recurrence in HER2/neu expressing cancers like breast cancer. The CellSearch System (Veridex, LLC Warren, NJ) has been used by our lab in conjunction with in vivo and/or in vitro immunologic measurements to define a monitoring tool that could predict clinical response. Once validated, this assay could significantly shorten clinical trials and lead to more efficient assessment of potentially promising cancer vaccines.

Prospective study of blunt aortic injury: Multicenter Trial of the American Association for the Surgery of Trauma.

BACKGROUND: Blunt aortic injury is a major cause of death from blunt trauma. Evolution of diagnostic techniques and methods of operative repair have altered the management and posed new questions in recent years. METHODS: This study was a prospectively conducted multi-center trial involving 50 trauma centers in North America under the direction of the Multi-institutional Trial Committee of the American Association for the Surgery of Trauma. RESULTS: There were 274 blunt aortic injury cases studied over 2.5 years, of which 81% were caused by automobile crashes. Chest computed tomography and transesophageal echocardiography were applied in 88 and 30 cases, respectively, and were 75 and 80% diagnostic, respectively. Two hundred seven stable patients underwent planned thoracotomy and repair. Clamp and sew technique was used in 73 (35%) and bypass techniques in 134 (65%). Overall mortality was 31%, with 63% of deaths being attributable to aortic rupture; mortality was not affected by method of repair. Paraplegia occurred postoperatively in 8.7%. Logistic regression analysis demonstrated clamp and sew (p = 0.002) and aortic cross clamp time of > or = 30 minutes (p = 0.01) to be associated with development of postoperative paraplegia. CONCLUSIONS: Rupture after hospital admission remains a major problem. Although newer diagnostic techniques are being applied, at this time aortography remains the diagnostic standard. Aortic cross clamp time beyond 30 minutes was associated with paraplegia; bypass techniques, which provide distal aortic perfusion, produced significantly lower paraplegia rates than the clamp and sew approach.

A simple technique for repositioning the intra-aortic balloon catheter associated with ipsilateral limb ischemia.

Occasionally, ipsilateral ischemia develops following the groin insertion of an intra-aortic balloon catheter. Various treatment options have evolved, and include replacing the catheter in the opposite groin, removing it completely, or performing a femorofemoral bypass to deliver blood flow below the catheter. Outlined in this paper is a simple method to restore blood flow to a threatened limb, during femoral artery exploration, in the presence of an intra-aortic balloon. This method is also appropriate for optimal positioning of the balloon catheter prior to femorofemoral bypass.

Thigh ischemia complicating femoral vessel cannulation for cardiopulmonary bypass.

Compartment syndrome of the lower leg is an occasional complication of prolonged ischemia and reperfusion. Compartment syndrome of the thigh is a less well-recognized complication. We present 2 patients with compartment syndrome of the ipsilateral thigh after femoral arterial and venous cannulation for cardiopulmonary bypass. Early diagnosis and urgent decompressive fasciotomy may limit the extent of local tissue damage and subsequent myonephropathic syndrome.

Axillary artery injuries secondary to anterior dislocation of the shoulder.

We describe a case report of an axillary artery injury after recurrent anterior dislocation of the shoulder. Review of 22 reported cases reveals that 27% are recurrent dislocations, 86% occurred in patients older than 50, 86% of the injuries are in the third part of the axillary artery, and 68% presented with an axillary mass.

The management of combined skeletal and arterial injuries of the lower extremity.

Combined skeletal, soft-tissue, and arterial injuries in lower extremity trauma are relatively common. Controversy has surrounded the priority of management of these limb- and life-threatening injuries. There are proponents for initial skeletal stabilization, and an equal number in favor of initial revascularization. The management of a multiply-traumatized patient with an ischemic limb and other life-threatening injuries, and a literature review, are presented to examine some of the issues and describe the use of vascular shunts as a method for rapid temporary revascularization of a damaged limb.

Efficacy of subcutaneous heparin in prevention of venous thromboembolic events in trauma patients.

Trauma patients have an incidence of deep venous thrombosis (DVT) of 7% to 65%. Conflicting data exists regarding the impact of prophylactic anticoagulant therapy. The purpose of this study is to assess the efficacy of DVT prophylaxis based upon our data and a meta-analysis of the current literature. Literature review revealed five recent studies that met the following criteria: 1) Adult patients sustaining major trauma (injury severity score (ISS) > 10), 2) prospective surveillance for DVT using lower extremity duplex examinations, 3) clear documentation of method of DVT prophylaxis with particular attention to the use of anticoagulation and the corresponding incidence of DVT or pulmonary embolus (PE). Additionally, 66 trauma patients in our intensive care unit were prospectively identified and followed with duplex examinations. Patients received either anticoagulation DVT prophylaxis or pneumatic compression boots. An unpaired Student t test was used to compare the characteristics of patients with and without DVT. A Mantel-Haenszel chi-square meta-analysis was performed on the five recent studies and our own data to compare the incidence of DVT/PE in patients with and without anticoagulation. Meta-analysis of the literature included 1102 patients and demonstrated no benefit from anticoagulation for DVT prophylaxis in trauma patients (10% DVT/PE with anticoagulation versus 7 per cent DVT/PE without anticoagulation, P = 0.771). Our own population had a mean age of 38 +/- 17 years, ISS of 29 +/- 11 and a length of stay (LOS) of 34 +/- 22 days. Sixteen events occurred with 13 (20%) DVTs and three (4%) pulmonary emboli.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppressors of oxygen metabolites fail to reduce vein graft intimal hyperplasia.

OBJECTIVE: To evaluate the role of reactive oxygen metabolites in the initiation of intimal hyperplasia of vein grafts inserted into the arterial circulation. SETTING: University pathologic research laboratory. ANIMALS: Sprague-Dawley rats. INTERVENTION: Animals were randomized to receive either the xanthine oxidase inhibitor allopurinol, the iron chelating agent starch-conjugated deferoxamine, or the free-radical scavenger 21-aminosteroid U74389G. Control animals were included for each group. The epigastric vein was inserted into the right common femoral artery. Vein grafts were harvested 30 days postoperatively. The degree of intimal hyperplasia at the two anastomoses as well as at the midgraft was calculated. MAIN OUTCOME MEASURES: The vein grafts were divided into three sections designated proximal anastomosis, midgraft, and distal anastomosis. Intimal and medial areas were determined in an observer-blind fashion and expressed as intimal area-medial area ratios. RESULTS: Pretreatment of the animals with any of these agents resulted in no significant reduction in the degree of intimal hyperplasia in any treated groups compared with the control animals 30 days postoperatively. CONCLUSIONS: Arterial reconstruction often involves interposition of vein segments into the arterial circulation. These veins are subject to ischemia and reperfusion, with the potential for generation of reactive oxygen metabolites and subsequent vein graft injury, resulting in intimal hyperplasia. We hypothesized that perioperative pharmacologic intervention either to scavenge or to reduce the production of reactive oxygen metabolites would attenuate the initial vein graft injury and thus limit the subsequent development of intimal hyperplasia. These data create doubt as to the influence of reactive oxygen metabolites in the initiation of intimal hyperplasia in the vein graft.

Educational characteristics of tumor conferences in teaching and non-teaching hospitals.

Hospital tumor conferences (tumor boards) were observed and evaluated over an 18-month period to determine their organizational and educational characteristics as well as their impact on conference participants. In conjunction with a previous nationwide survey of tumor conferences, this study was designed to identify features that would facilitate the learning that occurs in conference sessions. Study investigators observed a regional sample of 43 tumor boards in 37 participating hospitals, which included 513 sessions at general (hospital-wide) conferences and 198 sessions at specialty conferences. A total of 1,866 tumor cases were presented during these 711 conferences. Participants completed questionnaires to supplement the investigators' evaluations. Session observations revealed several ways in which tumor boards could increase their educational impact on participants, including combining case presentations with presentations of related didactic material and using the method of progressive disclosure to promote increased participation in discussions related to retrospective case presentations. Improvements can be made in session organization and case presentation with the potential for increasing participant learning with little increase in the effort or expense associated with tumor conferences.

An educational intervention to improve hospital tumor conferences.

Hospital tumor conferences exist to improve patient care through the application of a multidisciplinary approach to cancer management decisions and to provide continuing medical education for physicians and other health professionals who participate in cancer care. Based on educational needs identified by means of direct observation of conference sessions, this study implemented an experimental intervention designed to increase the educational benefits associated with participation in these conferences. Participating hospitals were randomly assigned either to a study group that received an "educational case" intervention (emphasizing progressive disclosure of cases, an active leadership style, and use of educational principles such as stating objectives at the beginning of sessions) or to a control group receiving no intervention. Each of the nine experimental and nine control group hospitals had multiple tumor sessions and case presentations with sessions observed and coded before and after intervention. Results showed significant differences in the specific educational procedures emphasized in the educational case intervention, such as use of the progressive disclosure method of presentation, and quality of session leadership. No difference, however, was found in other factors such as participation rates by major categories of specialists. The study has thus shown that educational interventions of this type can have a significant impact on the clinical and educational effectiveness of ongoing hospital conferences.

Penetrating wounds of the extremities. Methods of identifying arterial injury.

Controversy surrounds the optimal management of a wound in proximity to a major vascular structure without clinical evidence of arterial injury. Current data suggest that physical examination alone can detect significant arterial injuries. If an arterial lesion is clinically silent on initial presentation, the natural history is most likely benign. In the rare case in which the arterial lesion degenerates into a more significant lesion, then it will do so slowly and can be repaired electively. In certain instances, there may be a penetrating wound that presents with a pulse deficit that resolves completely with observation. At this time, this is considered a hard sign of vascular injury and warrants aggressive preoperative evaluation.

Delayed hemorrhage with free rupture complicating the nonsurgical management of blunt hepatic trauma: a case report and review of the literature.

The nonsurgical approach for the management of blunt hepatic injuries is appropriate for a select subset of patients. An acceptable number of complications of the biliary tract and intraparenchymal hematomas have been reported. Delayed hepatic hemorrhage has been described, however, scant data are available in the literature to dictate management once this complication has developed. A review of the recent literature indicates that nonsurgical management of this complication remains a safe alternative.

Thoracic aortic dissection with renal artery involvement following blunt thoracic trauma: case report.

Blunt thoracic aortic injury most often occurs beyond the left subclavian artery with subsequent transection and exsanguination. We present a case of an unrestrained driver involved in a high-speed motor vehicle crash who had a traumatic mid-thoracic aortic dissection involving the orifices of both renal arteries, resulting in anuria. This diagnosis should be considered in the presence of anuria following chest trauma.

Improving HIV/AIDS care through education.

It is essential that primary healthcare providers, including dentists, be able to screen and counsel their patients for AIDS and exposure to HIV. This article reviews efforts of the AIDS Education and Training Center for Southern California to train healthcare providers.