Body surface mapping using an ECG belt to characterize electrical heterogeneity for different left ventricular pacing sites during cardiac resynchronization: Relationship with acute hemodynamic improvement.

Background: Electrical heterogeneity (EH) during cardiac resynchronization therapy may vary with different left ventricular (LV) pacing sites.

Objective: The purpose of this study was to evaluate the relationship between such changes and acute hemodynamic response (AHR).

Methods: Two EH metrics-standard deviation of activation times and mean left thorax activation times-were computed from isochronal maps based on 53-electrode body surface mapping during baseline AAI pacing and biventricular (BiV) pacing from different pacing sites in coronary veins in 40 cardiac resynchronization therapy-indicated patients.

The Proliferative Activity of Mammary Epithelial Cells in Normal Tissue Predicts Breast Cancer Risk in Premenopausal Women.

The frequency and proliferative activity of tissue-specific stem and progenitor cells are suggested to correlate with cancer risk. In this study, we investigated the association between breast cancer risk and the frequency of mammary epithelial cells expressing p27, estrogen receptor (ER), and Ki67 in normal breast tissue. We performed a nested case-control study of 302 women (69 breast cancer cases, 233 controls) who had been initially diagnosed with benign breast disease according to the Nurses' Health Studies.

Ultrasound for routine lumbar puncture.

Objectives: The objective was to determine if use of ultrasound (US) by emergency physicians (EPs) to localize spinal landmarks improves the performance of lumbar puncture (LP).

Methods: This was a prospective, randomized, controlled study conducted in a county teaching hospital. Subjects, adults 18 years of age or older who were to receive LPs for routine clinical care in the emergency department (ED), were randomized either to undergo US localization of the puncture site or to have the puncture site determined by palpation of spinal landmarks.

Transcription factor genes Smad4 and Gata4 cooperatively regulate cardiac valve development. [corrected].

We report that the dominant human missense mutations G303E and G296S in GATA4, a cardiac-specific transcription factor gene, cause atrioventricular septal defects and valve abnormalities by disrupting a signaling cascade involved in endocardial cushion development. These GATA4 missense mutations, but not a mutation causing secundum atrial septal defects (S52F), demonstrated impaired protein interactions with SMAD4, a transcription factor required for canonical bone morphogenetic protein/transforming growth factor-β (BMP/TGF-β) signaling. Gata4 and Smad4 genetically interact in vivo: atrioventricular septal defects result from endothelial-specific Gata4 and Smad4 compound haploinsufficiency.

Genome-wide identification of mouse congenital heart disease loci.

Empirical evidence supporting a genetic basis for the etiology of congenital heart disease (CHD) is limited and few disease-causing mutations have been identified. To identify novel CHD genes, we performed a forward genetic screen to identify mutant mouse lines with heritable CHD. Lines with recessive N-ethyl-N-nitrsourea-induced CHD-causing mutations were identified using a three-generation backcross.

sonic hedgehog is required in pulmonary endoderm for atrial septation.

The genesis of the septal structures of the mammalian heart is central to understanding the ontogeny of congenital heart disease and the evolution of cardiac organogenesis. We found that Hedgehog (Hh) signaling marked a subset of cardiac progenitors specific to the atrial septum and the pulmonary trunk in the mouse. Using genetic inducible fate mapping with Gli1(CreERT2), we marked Hh-receiving progenitors in anterior and posterior second heart field splanchnic mesoderm between E8 and E10.

A molecular pathway including Id2, Tbx5, and Nkx2-5 required for cardiac conduction system development.

The cardiac conduction system is an anatomically discrete segment of specialized myocardium that initiates and propagates electrical impulses to coordinate myocardial contraction. To define the molecular composition of the mouse ventricular conduction system we used microdissection and transcriptional profiling by serial analysis of gene expression (SAGE). Conduction-system-specific expression for Id2, a member of the Id gene family of transcriptional repressors, was identified.

Bedside ultrasound for difficult lumbar puncture.

Lumbar puncture is a common procedure performed in the emergency department for evaluation of several life-threatening conditions, including meningitis and subarachnoid hemorrhage. We describe the use of bedside ultrasound to assist in performance of the lumbar puncture in situations where the standard "blind" technique of needle insertion using palpable spinal landmarks is likely to be difficult or to fail. Use of ultrasound to guide lumbar puncture needle placement was originally reported 30 years ago in the Russian literature.

Hydrogen sulfide consumption measured at low steady state concentrations using a sulfidostat.

Although >10 microM hydrogen sulfide typically is toxic to eukaryotic cells, <1 microM sulfide is rapidly consumed and oxidized. To measure sulfide consumption in such low concentrations, we built a "Sulfidostat." The apparatus uses a sulfide-specific electrode to measure the concentration of free sulfide.

Impact of normalized myocardial perfusion after successful angioplasty in acute myocardial infarction.

Objectives: We sought to evaluate and validate the ability of the angiographic myocardial blush grade to risk stratify patients after successful angioplasty in acute myocardial infarction (AMI).

Background: Although epicardial Thrombolysis In Myocardial Infarction (TIMI)-3 flow is restored in >90% of patients undergoing primary percutaneous coronary intervention (PCI), normal myocardial perfusion may be present less frequently and may detrimentally impact survival.

Methods: A cohort of 173 consecutive patients undergoing intervention within 24 h of AMI onset were studied.

The Principle of Maximum Chiral Discrimination: Chiral Recognition in Permethyl-beta-cyclodextrin.

Five guest molecules, isomenthone, pulegone, 1-fluoro-1-phenylethane, 1-phenylethanol, and 2-methylbutanoic acid, binding to permethyl-beta-cyclodextrin, a chiral host molecule, have been simulated by molecular dynamics techniques. From the simulations we find the preferred binding site to be the interior of the macrocyclic cavity. A new technique was used for locating the host's most enantiodiscriminating domain, which was also found to be inside the macrocyclic cavity.