Assessment of injuries patterns produced by a 9mm P.A.K "rubber ball" blank firing weapon: porcine model

The use of less lethal weapons aims to mitigate civilian casualties caused by firearm use. However, due to numerous cases in which these weapons caused serious injuries, even lethal injuries, both legislation and the forensic field are interested in characterizing and regulating them better. In the forensic field, there is a lack of strong research about injury patterns of these weapons which makes it difficult to identify the type of weapon employed. In this study, the main objective was to characterize the injury pattern produced by the impact of the 9 mm P.A.K. projectile. A porcine model was used. Four different distances were studied: firm contact, 10 cm, 60 cm and 110 cm, using 3 of the more representative anatomical sites: the head, the hind leg and the ribs. The average measurement of the entrance orifice varied according to the anatomical site, being 6.67 mm wide and 6.25 mm long in the thorax, 7.3 mm wide and 8.8 mm long in the hind legs, and 7.62 mm wide and 7.54 mm long in the head. The variation in width and length measurements was not found to be directly related to the shot distance. The gunshot residues had similar characteristics to those of conventional lead projectiles, however there was more unburned powder deposit near the wounds, with a less dense soot and more dense powder tattoo. Depth varied widely regardless of tissue and firing distance, although loss of penetrating power and injury is observed as one moves away from the target.

Transradial approach to endovascular Infrarenal aortic repair

Atherosclerotic disease of the abdominal aorta is relatively common. However chronic stenosis of the infrarenal aorta is a fairly rare condition that has been traditionally treated with open endarterectomy and aorto-bifemoral bypass surgery. These surgeries may be associated with a significant increase in mortality and morbidity. Using 2 case examples we describe the feasibility of endovascular treatment of severely calcified infra-abdominal aortic lesion using a transradial endovascular approach that greatly reduce both vascular and access site complications.

Synergistic Effects of Combined Cell Therapy for Chronic Ischemic Cardiomyopathy

BACKGROUND

Both bone marrow-derived mesenchymal stem cells (MSCs) and c-kit(+) cardiac stem cells (CSCs) improve left ventricular remodeling in porcine models and clinical trials. Using xenogeneic (human) cells in immunosuppressed animals with acute ischemic heart disease, we previously showed that these 2 cell types act synergistically.

OBJECTIVES

To more accurately model clinical applications for heart failure, this study tested whether the combination of autologous MSCs and CSCs produce greater improvement in cardiac performance than MSCs alone in a nonimmunosuppressed porcine model of chronic ischemic cardiomyopathy.

METHODS

Three months after ischemia/reperfusion injury, Göttingen swine received transendocardial injections with MSCs alone (n = 6) or in combination with cardiac-derived CSCs (n = 8), or placebo (vehicle; n = 6). Cardiac functional and anatomic parameters were assessed using cardiac magnetic resonance at baseline and before and after therapy.

RESULTS

Both groups of cell-treated animals exhibited significantly reduced scar size (MSCs -44.1 ± 6.8%; CSC/MSC -37.2 ± 5.4%; placebo -12.9 ± 4.2%; p < 0.0001), increased viable tissue, and improved wall motion relative to placebo 3 months post-injection. Ejection fraction (EF) improved (MSCs 2.9 ± 1.6 EF units; CSC/MSC 6.9 ± 2.8 EF units; placebo 2.5 ± 1.6 EF units; p = 0.0009), as did stroke volume, cardiac output, and diastolic strain only in the combination-treated animals, which also exhibited increased cardiomyocyte mitotic activity.

CONCLUSIONS

These findings illustrate that interactions between MSCs and CSCs enhance cardiac performance more than MSCs alone, establish the safety of autologous cell combination strategies, and support the development of second-generation cell therapeutic products.

Autologous mesenchymal stem cells produce concordant improvements in regional function, tissue perfusion, and fibrotic burden when administered to patients undergoing coronary artery bypass grafting: The Prospective Randomized Study of Mesenchymal Stem Cell Therapy in Patients Undergoing Cardiac Surgery (PROMETHEUS) trial

RATIONALE

Although accumulating data support the efficacy of intramyocardial cell-based therapy to improve left ventricular (LV) function in patients with chronic ischemic cardiomyopathy undergoing CABG, the underlying mechanism and impact of cell injection site remain controversial. Mesenchymal stem cells (MSCs) improve LV structure and function through several effects including reducing fibrosis, neoangiogenesis, and neomyogenesis.

OBJECTIVE

To test the hypothesis that the impact on cardiac structure and function after intramyocardial injections of autologous MSCs results from a concordance of prorecovery phenotypic effects.

METHODS AND RESULTS

Six patients were injected with autologous MSCs into akinetic/hypokinetic myocardial territories not receiving bypass graft for clinical reasons. MRI was used to measure scar, perfusion, wall thickness, and contractility at baseline, at 3, 6, and 18 months and to compare structural and functional recovery in regions that received MSC injections alone, revascularization alone, or neither. A composite score of MRI variables was used to assess concordance of antifibrotic effects, perfusion, and contraction at different regions. After 18 months, subjects receiving MSCs exhibited increased LV ejection fraction (+9.4 ± 1.7%, P=0.0002) and decreased scar mass (-47.5 ± 8.1%; P<0.0001) compared with baseline. MSC-injected segments had concordant reduction in scar size, perfusion, and contractile improvement (concordant score: 2.93 ± 0.07), whereas revascularized (0.5 ± 0.21) and nontreated segments (-0.07 ± 0.34) demonstrated nonconcordant changes (P<0.0001 versus injected segments).

CONCLUSIONS

Intramyocardial injection of autologous MSCs into akinetic yet nonrevascularized segments produces comprehensive regional functional restitution, which in turn drives improvement in global LV function. These findings, although inconclusive because of lack of placebo group, have important therapeutic and mechanistic hypothesis-generating implications.

CLINICAL TRIAL REGISTRATION URL

http://clinicaltrials.gov/show/NCT00587990. Unique identifier: NCT00587990.

Does transendocardial injection of mesenchymal stem cells improve myocardial function locally or globally?: An analysis from the Percutaneous Stem Cell Injection Delivery Effects on Neomyogenesis (POSEIDON) randomized trial

RATIONALE

Transendocardial stem cell injection (TESI) with mesenchymal stem cells improves remodeling in chronic ischemic cardiomyopathy, but the effect of the injection site remains unknown.

OBJECTIVE

To address whether TESI exerts its effects at the site of injection only or also in remote areas, we hypothesized that segmental myocardial scar and segmental ejection fraction improve to a greater extent in injected than in noninjected segments.

METHODS AND RESULTS

Biplane ventriculographic and endocardial tracings were recorded. TESI was guided to 10 sites in infarct-border zones. Sites were mapped according to the 17-myocardial segment model. As a result, 510 segments were analyzed in 30 patients before and 13 months after TESI. Segmental early enhancement defect (a measure of scar size) was reduced by TESI in both injected (-43.7 ± 4.4%; n=95; P<0.01) and noninjected segments (-25.1 ± 7.8%; n=148; P<0.001; between-group comparison P<0.05). Conversely, segmental ejection fraction (a measure of contractile performance) improved in injected scar segments (19.9 ± 3.3-26.3 ± 3.5%; P=0.003) but not in noninjected scar segments (21.3 ± 2.6-23.5 ± 3.2%; P=0.20; between-group comparison P<0.05). Furthermore, segmental ejection fraction in injected scar segments improved to a greater degree in patients with baseline segmental ejection fraction <20% (12.1 ± 1.2-19.9 ± 2.7%; n=18; P=0.003), versus <20% (31.7 ± 3.4-35.5 ± 3.3%; n=12; P=0.33, between-group comparison P<0.0001).

CONCLUSIONS

These findings illustrate a dichotomy in regional responses to TESI. Although scar size reduction was evident in all scar segments, scar size reduction and ventricular functional responses preferentially occurred at the sites of TESI versus non-TESI sites. Furthermore, improvement was greatest when segmental left ventricular dysfunction was severe.

Rationale and design of the Transendocardial Injection of Autologous Human Cells (bone marrow or mesenchymal) in Chronic Ischemic Left Ventricular Dysfunction and Heart Failure Secondary to Myocardial Infarction (TAC-HFT) trial: A randomized, double-blind, placebo-controlled study of safety and efficacy

Although there is tremendous interest in stem cell (SC)-based therapies for cardiomyopathy caused by chronic myocardial infarction, many unanswered questions regarding the best approach remain. The TAC-HFT study is a phase I/II randomized, double-blind, placebo-controlled trial designed to address several of these questions, including the optimal cell type, delivery technique, and population. This trial compares autologous mesenchymal SCs (MSCs) and whole bone marrow mononuclear cells (BMCs). In addition, the study will use a novel helical catheter to deliver cells transendocardially. Although most trials have used intracoronary delivery, the optimal method is unknown and data suggest that the transendocardial approach may have important advantages. Several trials support the benefit of SCs in patients with chronic ischemic cardiomyopathy (ICMP), although the sample sizes have been small and the number of trials sparse. After a pilot phase of 8 patients, 60 patients with ICMP (left ventricular ejection fraction 15%-50%) will be randomized to group A (30 patients further randomized to receive MSC injection or placebo in a 2:1 fashion) or group B (30 patients further randomized to BMCs or placebo in a 2:1 fashion). All patients will undergo bone marrow aspiration and transendocardial injection of SCs or placebo. The primary and secondary objectives are, respectively, to demonstrate the safety and efficacy (determined primarily by cardiac magnetic resonance imaging) of BMCs and MSCs administered transendocardially in patients with ICMP.

Is TEE useful in patients with small subcortical strokes?

Although the role of transesophageal echocardiography (TEE) in the investigation of stroke mechanism is well established, the value of this test in patients with lacunar presentation is unclear. Review of 214 patients with acute cerebral ischemia referred for TEE to exclude cardioaortic sources of embolism after non-diagnostic basic work-up including carotid ultrasound and transthoracic echocardiography. TEE was considered positive when it showed large or complex aortic arch plaques, left atrial thrombus, mitral or aortic valve vegetations, or patent foramen ovale with atrial septal aneurysm. Multivariate regression analysis was performed to assess the value of lacunar syndrome and radiological small subcortical infarctions in predicting TEE result. Predictive values and likelihood ratios for these variables were calculated. Fifty-two patients (24%) had positive TEE. The most common embolic source was large or complex aortic plaques in 19% of patients. Neither clinical presentation with lacunar syndrome nor the presence of small subcortical infarction on CT scan predicted a negative TEE result on univariate or multivariate analysis. However, the combination of lacunar syndrome with radiological small subcortical infarction was uniformly associated with negative TEE (P=0.01; negative predictive value 100%). The combination of lacunar syndrome with small subcortical radiological infarct predicts the absence of cardioaortic sources of embolism on TEE in patients with acute cerebral ischemia.

Digoxin use is associated with increased platelet and endothelial cell activation in patients with nonvalvular atrial fibrillation

OBJECTIVES

The purpose of this study was to determine whether digoxin use is associated with increased flow cytometric markers of endothelial cell and platelet activation in patients with nonvalvular atrial fibrillation (AF).

BACKGROUND

Increased intracellular calcium is a key event in platelet activation, and several studies have demonstrated that digitalis activates platelets in vitro. Intracellular calcium also is a key regulator of endothelial cell function, and endogenous digitalis-like substances have been shown to affect biologic processes in endothelial cells.

METHODS

We studied 30 patients with nonvalvular AF. We measured the levels of (1) platelet expression of P-selectin (CD62P), (2) platelet microparticles (PMP); and (3) endothelial microparticles (EMP) identified by anti-CD31 (EMP31) and by anti-E-selectin antibodies (EMP62E).

RESULTS

Patients who were taking digoxin (n = 16; mean digoxin level = 0.93 ng/dL) did not demonstrate any significant differences in clinical or echocardiographic characteristics compared with patients not taking digoxin (n = 14). Patients taking digoxin had significantly increased levels of CD62P expression in platelets and platelet-leukocyte conjugates and markedly increased markers of endothelial activation: EMP62E and EMP31. After adjusting for potential confounders (including age, congestive heart failure, coronary artery disease, ejection fraction, antiplatelet, beta-blocker, and calcium channel blocker use), the differences persisted.

CONCLUSIONS

Digoxin use in patients with AF is associated with increased levels of endothelial and platelet activation. If digitalis activates endothelial cells and platelets at pharmacologic doses, use of digitalis in conditions such as AF could predispose to thrombosis and vascular events.

Percutaneous stenting of bilateral pulmonary artery stenosis caused by malignant extrinsic compression

Percutaneous stenting of the pulmonary arteries (PAs) represents a potential option in cases of PA compression due to a variety of conditions. We present the first reported case of successful bilateral percutaneous stenting of the PAs in a patient with non-small cell lung cancer and severe right ventricular hypertension due to mediastinal lymphadenopathy compressing both PAs. Although the natural course of the disease was not altered, the patient had significant symptomatic relief without adverse effects. Additionally, there was objective evidence of improvement. This case suggests that endovascular stenting is a feasible palliative management option in patients with right ventricular failure due to malignant extrinsic compression of the PAs.