The Generalist Model: Where do the Micro and Macro Converge?

Although macro issues are integral to social work, students continue to struggle with the acquisition of knowledge and skills pertaining to larger systems. Educators have developed innovative methods to integrate learning across systems of various sizes however it appears an imbalance persists. This challenge is supported by baccalaureate student responses to a social work program evaluation. Four years of data from 295 undergraduate students revealed that they felt less prepared to practice with larger, macro systems. Changes in curriculum to reflect collaboration and holism, and more research are needed to adequately provide macro learning and macro practice opportunities within the generalist model and in the context of the current socio-economic-political environment

Intimal Hyperplasia in Balloon Dilated Coronary Arteries is Reduced by Local Delivery of the NO Donor, SIN-1 Via a cGMP-Dependent Pathway

<p>Abstract</p> <p>Background</p> <p>To elucidate the mechanism by which local delivery of 3-morpholino-sydnonimine (SIN-1) affects intimal hyperplasia after percutaneous transluminal coronary angioplasty (PTCA).</p> <p>Methods</p> <p>Porcine coronary arteries were treated with PTCA and immediately afterwards locally treated for 5 minutes, with a selective cytosolic guanylate cyclase inhibitor, 1 H-(1,2,4)oxadiazole(4,3-alpha)quinoxaline-1-one (ODQ) + SIN-1 or only SIN-1 using a drug delivery-balloon. Arteries were angiographically depicted, morphologically evaluated and analyzed after one and eight weeks for actin, myosin and intermediate filaments (IF) and nitric oxide synthase (NOS) contents.</p> <p>Results</p> <p>Luminal diameter after PCI in arteries treated with SIN-1 alone and corrected for age-growth was significantly larger as compared to ODQ + SIN-1 or to controls (p < 0.01). IF/actin ratio after one week in SIN-1 treated segments was not different compared to untreated segments, but was significantly reduced compared to ODQ + SIN-1 treated vessels (p < 0.05). Expression of endothelial NADPH diaphorase activity was significantly lower in untreated segments and in SIN-1 treated segments compared to controls and SIN-1 + ODQ treated arteries (p < 0.01). Restenosis index (p < 0.01) and intimal hyperplasia (p < 0.01) were significantly reduced while the residual lumen was increased (p < 0.01) in SIN-1 segments compared to controls and ODQ + SIN-1 treated vessels.</p> <p>Conclusions</p> <p>After PTCA local delivery of high concentrations of the NO donor SIN-1 for 5 minutes inhibited injury induced neointimal hyperplasia. This favorable effect was abolished by inhibition of guanylyl cyclase indicating mediation of a cyclic guanosine 3',5'-monophosphate (cGMP)-dependent pathway. The momentary events at the time of injury play crucial role in the ensuring development of intimal hyperplasia.</p

Evaluation of coronary blood flow velocity during cardiac arrest with circulation maintained through mechanical chest compressions in a porcine model

<p>Abstract</p> <p>Background</p> <p>Mechanical chest compressions (CCs) have been shown capable of maintaining circulation in humans suffering cardiac arrest for extensive periods of time. Reports have documented a visually normalized coronary blood flow during angiography in such cases (TIMI III flow), but it has never been actually measured. Only indirect measurements of the coronary circulation during cardiac arrest with on-going mechanical CCs have been performed previously through measurement of the coronary perfusion pressure (CPP). In this study our aim was to correlate average peak coronary flow velocity (APV) to CPP during mechanical CCs.</p> <p>Methods</p> <p>In a closed chest porcine model, cardiac arrest was established through electrically induced ventricular fibrillation (VF) in eleven pigs. After one minute, mechanical chest compressions were initiated and then maintained for 10 minutes upon which the pigs were defibrillated. Measurements of coronary blood flow in the left anterior descending artery were made at baseline and during VF with a catheter based Doppler flow fire measuring APV. Furthermore measurements of central (thoracic) venous and arterial pressures were also made in order to calculate the theoretical CPP.</p> <p>Results</p> <p>Average peak coronary flow velocity was significantly higher compared to baseline during mechanical chests compressions and this was observed during the entire period of mechanical chest compressions (12 - 39% above baseline). The APV slowly declined during the 10 min period of mechanical chest compressions, but was still higher than baseline at the end of mechanical chest compressions. CPP was simultaneously maintained at > 20 mmHg during the 10 minute episode of cardiac arrest.</p> <p>Conclusion</p> <p>Our study showed good correlation between CPP and APV which was highly significant, during cardiac arrest with on-going mechanical CCs in a closed chest porcine model. In addition APV was even higher during mechanical CCs compared to baseline. Mechanical CCs can, at minimum, re-establish coronary blood flow in non-diseased coronary arteries during cardiac arrest.</p

Mild hypothermia reduces cardiac post-ischemic reactive hyperemia

BACKGROUND: In experimentally induced myocardial infarction, mild hypothermia (33–35°C) is beneficial if applied prior to ischemia or reperfusion. Hypothermia, when applied after reperfusion seems to confer little or no benefit. The mechanism by which hypothermia exerts its cell-protective effect during cardiac ischemia remains unclear. It has been hypothesized that hypothermia reduces the reperfusion damage; the additional damage incurred upon the myocardium during reperfusion. Reperfusion results in a massive increase in blood flow, reactive hyperemia, which may contribute to reperfusion damage. We postulated that hypothermia could attenuate the post-ischemic reactive hyperemia. METHODS: Sixteen 25–30 kg pigs, in a closed chest model, were anesthetized and temperature was established in all pigs at 37°C using an intravascular cooling catheter. The 16 pigs were then randomized to hypothermia (34°C) or control (37°C). The left main coronary artery was then catheterized with a PCI guiding catheter. A Doppler flow wire was placed in the mid part of the LAD and a PCI balloon was then positioned proximal to the Doppler wire but distal to the first diagonal branch. The LAD was then occluded for ten minutes in all pigs. Coronary blood flow was measured before, during and after ischemia/reperfusion. RESULTS: The peak flow seen during post-ischemic reactive hyperemia (during the first minutes of reperfusion) was significantly reduced by 43 % (p < 0.01) in hypothermic pigs compared to controls. CONCLUSION: Mild hypothermia significantly reduces post-ischemic hyperemia in a closed chest pig model. The reduction of reactive hyperemia during reperfusion may have an impact on cardiac reperfusion injury

Design, Analysis and Testing of a Novel Mitral Valve for Transcatheter Implantation

Mitral regurgitation is a common mitral valve dysfunction which may lead to heart failure. Because of the rapid aging of the population, conventional surgical repair and replacement of the pathological valve are often unsuitable for about half of symptomatic patients, who are judged high-risk. Transcatheter valve implantation could represent an effective solution. However, currently available aortic valve devices are inapt for the mitral position. This paper presents the design, development and hydrodynamic assessment of a novel bi-leaflet mitral valve suitable for transcatheter implantation. The device consists of two leaflets and a sealing component made from bovine pericardium, supported by a self-expanding wireframe made from superelastic NiTi alloy. A parametric design procedure based on numerical simulations was implemented to identify design parameters providing acceptable stress levels and maximum coaptation area for the leaflets. The wireframe was designed to host the leaflets and was optimised numerically to minimise the stresses for crimping in an 8 mm sheath for percutaneous delivery. Prototypes were built and their hydrodynamic performances were tested on a cardiac pulse duplicator, in compliance with the ISO5840-3:2013 standard. The numerical results and hydrodynamic tests show the feasibility of the device to be adopted as a transcatheter valve implant for treating mitral regurgitation

Haemodynamics and flow modification stents for peripheral arterial disease:a review

Endovascular stents are widely used for the treatment of peripheral arterial disease (PAD). However, the development of in-stent restenosis and downstream PAD progression remain a challenge. Stent revascularisation of PAD causes arterial trauma and introduces abnormal haemodynamics, which initiate complicated biological processes detrimental to the arterial wall. The interaction between stent struts and arterial cells in contact, and the blood flow field created in a stented region, are highly affected by stent design. Spiral flow is known as a normal physiologic characteristic of arterial circulation and is believed to prevent the development of flow disturbances. This secondary flow motion is lost in atheromatous disease and its re-introduction after endovascular treatment of PAD has been suggested as a method to induce stabilised and coherent haemodynamics. Stent designs able to generate spiral flow may support endothelial function and therefore increase patency rates. This review is focused on secondary flow phenomena in arteries and the development of flow modification stent technologies for the treatment of PAD

Predictors of Paravalvular Regurgitation Following Implantation of the Fully Repositionable and Retrievable Lotus Transcatheter Aortic Valve (From the REPRISE II Trial Extended Cohort)

Paravalvular leak (PVL) following transcatheter aortic valve replacement (TAVR) is associated with worse long-term outcomes. The Lotus Valve incorporates an innovative adaptive seal designed to minimize PVL. This analysis evaluated the incidence and predictors of PVL following implantation of the Lotus transcatheter aortic valve. The REPRISE II study with Extended Cohort enrolled 250 high-surgical risk patients with severe symptomatic aortic stenosis. Aortic regurgitation was assessed by echocardiography pre-procedure, at discharge and 30 days by an independent core lab. Baseline and procedural predictors of mild or greater PVL at 30 days (or at discharge if 30-day data were not available) were determined using a multivariate regression model (N=229). Among 229 patients, 197 (86%) had no/trace PVL, 30 had mild, and 2 had moderate PVL; no patient had severe PVL. Significant predictors of mild/moderate PVL included device:annulus area ratio (odds ratio [OR]: 0.87 (95% CI: 0.83-0.92); P&lt;0.001), LVOT calcium volume (OR:2.85;(1.44-5.63); P=0.003), and annulus area (OR:0.89(0.82-0.96); P=0.002). When the device:annulus area ratio was &lt;1, the rate of mild/moderate PVL was 53.1% (17/32). The rates of mild/moderate PVL with 0-5%, 5-10%, and &gt;10% annular oversizing by area were 17.5% (11/63), 2.9% (2/70), and 3.2% (2/63), respectively. Significant independent predictors of PVL included device:annulus area ratio and LVOT calcium volume. When the prosthetic valve was oversized by ≥5%, the rate of mild or greater PVL was only 3%. In conclusion, the overall rates of PVL with the Lotus Valve are low and predominantly related to device/annulus areas and calcium; these findings have implications for optimal device sizing

Cardiac arrest in the catheterisation laboratory: A 5-year experience of using mechanical chest compressions to facilitate PCI during prolonged resuscitation efforts.

PURPOSE: Lengthy resuscitations in the catheterisation laboratory carry extremely high rates of mortality because it is essentially impossible to perform effective chest compressions during percutaneous coronary intervention (PCI). The purpose of this study was to evaluate the use of a mechanical chest compression device, LUCAS, in the catheterisation laboratory, in patients who suffered circulatory arrest requiring prolonged resuscitation. MATERIALS AND METHODS: The study population was comprised of patients who arrived alive to the catheterisation laboratory and then required mechanical chest compression at some time during the angiogram, PCI or pericardiocentesis between 2004 and 2008 at the Lund University Hospital. This is a retrospective registry analysis. RESULTS: During the study period, a total of 3058 patients were treated with PCI for ST-elevation myocardial infarction (STEMI) of whom 118 were in cardiogenic shock and 81 required defibrillations. LUCAS was used in 43 patients (33 STEMI, 7 non-ST-elevation myocardial infarction (NSTEMI), 2 elective PCIs and 1 patient with tamponade). Five patients had tamponade due to myocardial rupture prior to PCI that was revealed at the start of the PCI, and all five died. Of the remaining 38 patients, 1 patient underwent a successful pericardiocentesis and 36 were treated with PCI. Eleven of these patients were discharged alive in good neurological condition. CONCLUSION: The use of mechanical chest compressions in the catheterisation laboratory allows for continued PCI or pericardiocentesis despite ongoing cardiac or circulatory arrest with artificially sustained circulation. It is unlikely that few, if any, of the patients would have survived without the use of mechanical chest compressions in the catheterisation laboratory