Simultaneous Coating of Electrospun Nanofibers with Bioactive Molecules for Stem Cell Osteogenesis In Vitro.

OBJECTIVE: Mesenchymal stem cells (MSCs) are widely recognized as a promising cell type for therapeutic applications due to their ability to secrete and regenerate bioactive molecules. For effective bone healing, it is crucial to select a scaffold that can support, induce, and restore biological function. Evaluating the scaffold should involve assessing MSC survival, proliferation, and differentiation. The principal aim of this investigation was to formulate composite nanofibrous scaffolds apt for applications in bone tissue engineering. MATERIALS AND METHODS: In this experimental study, nanofibrous scaffolds were fabricated using Poly-L-lactic acid (PLLA) polymer. The PLLA fibers' surface was modified by integrating collagen and hydroxyapatite (HA) nanoparticles. RESULTS: The findings demonstrated that the collagen- and nanohydroxyapatite-modified electrospun PLLA scaffold positively influenced the attachment, growth, and osteogenic differentiation of MSCs. CONCLUSION: Coating the nanofiber scaffold with collagen and nanoparticle HA significantly enhanced the osteogenic differentiation of MSCs on electrospun PLLA scaffolds.

Is bacteriostatic saline superior to normal saline as an echocardiographic contrast agent?

Objective data on the performance characteristics and physical properties of commercially available saline formulations [normal saline (NS) vs. bacteriostatic normal saline (bNS)] are sparse. This study sought to compare the in vitro physical properties and in vivo characteristics of two commonly employed echocardiographic saline contrast agents in an attempt to assess superiority. Nineteen patients undergoing transesophageal echocardiograms were each administered agitated regular NS and bNS injections in random order and in a blinded manner according to a standardized protocol. Video time-intensity (TI) curves were constructed from a representative region of interest, placed paraseptally within the right atrium, in the bicaval view. TI curves were analyzed for maximal plateau acoustic intensity (Vmax, dB) and dwell time (DT, s), defined as time duration between onset of Vmax and decay of video intensity below clinically useful levels, reflecting the duration of homogenous opacification of the right atrium. To further characterize the physical properties of the bubbles in vitro, fixed aliquots of similarly agitated saline were injected into a glass well slide-cover slip assembly and examined using an optical microscope to determine bubble diameter in microns (µm) and concentration [bubble count/high power field (hpf)]. A higher acoustic intensity (a less negative dB level), higher bubble concentration and longer DT were considered properties of a superior contrast agent. For statistical analysis, a paired t test was conducted to evaluate the differences in means of Vmax and DT. Compared to NS, bNS administration was associated with superior opacification (video intensity -8.69 ± 4.7 vs. -10.46 ± 4.1 dB, P = 0.002), longer DT (17.3 ± 6.1 vs. 10.2 ± 3.7 s) in vivo and smaller mean bubble size (43.4 vs. 58.6 µm) and higher bubble concentration (1,002 vs. 298 bubble/hpf) in vitro. bNS provides higher intensity and more sustained opacification of the right atrium compared to NS. Higher bubble concentration and stability appear to be additional desirable rheological characteristics favoring bNS as a contrast agent.

Comparison of patients with peripartum heart failure and normal (≥55%) versus low (<45%) left ventricular ejection fractions.

The current definition of peripartum cardiomyopathy (PC) is restricted to patients with left ventricular systolic dysfunction (ejection fraction [EF]<45%). Data on peripartum heart failure (HF) with normal EF are sparse. We describe clinical characteristics of patients with normal (≥55%) and patients with low (<45%) left ventricular ejection fractions (LVEFs). Electronic medical records (2006 to 2013) of our tertiary care center were retrospectively screened to identify peripartum HF with normal EF, defined as an entity meeting Framingham criteria for HF with symptom onset during the last month of pregnancy or up to 5 months after delivery and with an EF of ≥55%. Clinical characteristics, echocardiographic parameters, and outcomes of these patients were compared with age-matched control patients with traditionally defined PC (EF<45%). A total of 25 patients with PC and EF≥55% were identified. Exclusion of hypertension (n=9), preeclampsia (n=1), and diabetes mellitus (n=2) yielded 13 patients with PC and EF≥55%. Age-matched patients with traditional PC (EF<45%) constituted controls (n=16). Compared with patients with PC and low LVEF, patients with PC and normal LVEF had lower B-type natriuretic peptide levels, systolic and diastolic left ventricular dimensions, left atrial size, and incidence of decompensated HF during delivery (p<0.05). Compared with historical age-matched controls, patients with normal LVEF exhibited attenuated E' mitral annular velocities. On follow-up, these patients were associated with a lower New York Heart Association functional class. In conclusion, peripartum HF with normal LVEF appears to be a distinct entity.

Impact of completeness of revascularization on long-term cardiovascular outcomes in patients with type 2 diabetes mellitus: results from the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D).

BACKGROUND: Patients with diabetes have more extensive coronary disease than those without diabetes, resulting in more challenging percutaneous coronary intervention or surgical (coronary artery bypass graft) revascularization and more residual jeopardized myocardium. The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial provided an opportunity to examine the long-term clinical impact of completeness of revascularization in patients with diabetes. METHODS AND RESULTS: This is a post hoc, nonrandomized analysis of the completeness of revascularization in 751 patients who were randomly assigned to early revascularization, of whom 264 underwent coronary artery bypass graft surgery and 487 underwent percutaneous coronary intervention. The completeness of revascularization was determined by the residual postprocedure myocardial jeopardy index (RMJI). RMJI is a ratio of the number of myocardial territories supplied by a significantly diseased epicardial coronary artery or branch that was not successfully revascularized, divided by the total number of myocardial territories. Mean follow-up for mortality was 5.3 years. Complete revascularization (RMJI=0) was achieved in 37.9% of patients, mildly incomplete revascularization (RMJI >0≤33) in 46.6%, and moderately to severely incomplete revascularization (RMJI >33) in 15.4%. Adjusted event-free survival was higher in patients with more complete revascularization (hazard ratio, 1.14; P=0.0018). CONCLUSIONS: Patients with type 2 diabetes mellitus and less complete revascularization had more long-term cardiovascular events. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00006305.

False ST elevation in a modified 12-lead surface electrocardiogram.

Precise recording of the standard 12-lead electrocardiogram (ECG) is technically time consuming. Placing limb leads on the torso has the major advantages of ease of use, increased speed of application, and decreased artifact. This modified ECG frequently substitutes for the standard 12-lead ECG in intensive care units to detect ischemia, although its implementation should be limited to interpreting arrhythmias. We describe a patient who was misdiagnosed with acute inferior myocardial infarction in a modified 12-lead ECG. To the best of our knowledge, this is the first case report regarding detection of false ST elevations in this setting. Always, a standard 12-lead ECG is recommended to evaluate any ST-T changes.

Prognostic value of the shock index along with transthoracic echocardiography in risk stratification of patients with acute pulmonary embolism.

The initial clinical presentation and echocardiography have key roles in risk stratification of patients with acute pulmonary embolism (PE). To assess the value of shock index and echocardiographic abnormalities as predictors of in-hospital complications and mortality, echocardiographic features of 159 patients diagnosed with acute PE were reviewed. A shock index > or =1, independent of echocardiographic findings, was associated with increased in-hospital mortality. Regardless of shock index, moderate to severe right ventricular (RV) hypokinesis and a ratio of RV to left ventricular (LV) end-diastolic diameter >1 was significantly associated with in-hospital mortality and demonstrated the best predictive values for short-term outcomes. The sensitivity and negative predictive value of diastolic LV impairment (E/A wave <1), RV hypokinesis, RV/LV >1, and end-diastolic RV diameter >3 cm for in-hospital mortality were 100%. Systolic pulmonary artery pressure (PAP) was higher in patients who died before discharge. A cut-off point >50 mm Hg for systolic PAP was significantly associated with increased in-hospital death. In conclusion, among conventional echocardiographic abnormalities attributed to RV dysfunction (E/A wave <1, RV hypokinesis, RV/LV >1, RV end-diastolic diameter >3 cm, and interventricular septal flattening), moderate to severe RV hypokinesis and RV/LV >1 have better predictive values for short-term outcomes of patients with acute PE. In addition, a shock index > or =1 and systolic PAP >50 mm Hg could also be helpful in the triage of these patients.

Electrocardiographic score and short-term outcomes of acute pulmonary embolism.

Risk stratification of patients with a diagnosis of acute pulmonary embolism (PE) is crucial in deciding appropriate management. An electrocardiographic (ECG) scoring system may potentially be useful in identifying patients at high risk of increased hospital morbidity and mortality from acute PE. Electrocardiography and echocardiography of 159 patients with a diagnosis of acute PE using ventilation/perfusion scan or spiral computed tomographic scan at 2 Emory-affiliated hospitals were reviewed. The 21-ECG score was compared with the presence or absence of right ventricular (RV) dysfunction and the 2 major end points of complicated in-hospital course or death. ECG score was significantly higher in patients with RV dysfunction (p <0.001) and a complicated in-hospital course (p <0.05). Although the ECG score was higher in nonsurvivors, it was not significantly different. Based on receiver-operator characteristic curves, an ECG score > or =3 could predict RV dysfunction with sensitivity, specificity, and positive and negative predictive values of 76%, 82%, 76%, and 86%, respectively. An ECG score > or =3 could predict a complicated in-hospital course and mortality with sensitivities of 58% and 59%, specificities of 60% and 58%, positive predictive values of 16% and 10%, and negative predictive values of 89% and 95%, respectively. In conclusion, the current 21-ECG scoring system can predict RV dysfunction in patients with acute PE well. However; its ability to predict an adverse in-hospital course is limited. Nevertheless, an ECG score <3 predicts better short-term outcome in these patients.