Frustrated and Confused: The American Public Rates its Cancer-Related Information-Seeking Experiences

BACKGROUND Ensuring access to high-quality cancer-related information is important for the success of cancer prevention and control efforts. OBJECTIVE We conducted a population-based assessment of the barriers faced by people searching for cancer information. DESIGN Cross-sectional data from the National Cancer Institute’s 2003 Health Information National Trends Survey. PARTICIPANTS A nationally representative sample of individuals in the USA (n = 6,369). MEASUREMENTS We assessed whether respondents had ever sought cancer-related information and examined ratings of their information-seeking experiences and beliefs regarding causes of cancer and its prevention. Linear and logistic regression models were estimated to determine predictors of negative experiences and associations between experiences and cancer beliefs. RESULTS Nearly one half (44.9%) of Americans had searched for cancer information. Many reported negative experiences, including the search process requiring a lot of effort (47.7%), expressing frustration (41.3%), and concerns about the quality of the information found (57.7%). Respondents lacking health insurance or a high school education experienced the greatest difficulty. Compared to those reporting the most positive experiences, information seekers reporting more negative experiences were more likely to report that almost everything caused cancer [odds ratio (OR) 2.0, 95% confidence interval (CI) 1.5–2.6], that not much can be done to prevent cancer (OR 2.7, 95% CI 1.9–3.8), and that it is hard to know which cancer prevention recommendations to follow (OR 3.2, 95% CI 2.3–4.5). CONCLUSIONS While a significant proportion of the American public searches for cancer information, suboptimal experiences are common. Facilitation of information seeking will be critical for promoting informed decision making in cancer prevention and control.     

Atrial Electrophysiologic Remodeling: Another Vicious Circle?

AF-Induced Electrophysiologic Remodeling. Introduction : With few exceptions, acquired heart di.sease is the result of (gradual changes in the heart, progressing during several months or years. This also includes certain cardiac arrhythmias, as for instance atrial fihrillation (AF). In spite of the important role of slowly progressing pathologic processes, most of our knowledge about mechanisms of cardiac arrhythmias is hased on acute experiments. Only recently, the attention also is more focused on long-term adaptation processes like cardiac memory, electrical remodeling, and tachycardia-induced cardiomyopathy. In experimental animal models, it has heen shown that AF induces a vicious circle of electrophysiologic and structural changes that inevitahly leads to "domestication" of the arrhythmia ("AF begets AF"). In this article, the studies on AF-induced electrophysiologic and cellular remodeling are discussed.     

Analysis of the thrombopoietin receptor (MPL) promoter implicates GATA and Ets proteins in the coregulation of megakaryocyte-specific genes

The MPL gene codes for the thrombopoietin receptor, whose ligand specifically controls megakaryocytic differentiation. To understand the molecular basis for the megakaryocyte-specific expression of MPL, we analyzed the promoter of this gene. A 200 bp fragment is sufficient for high-level specific expression. This fragment can bind several trans- acting factors in vitro, including GATA-1 and members of the Ets family. GATA-1 binds with low affinity to a unique GATA motif at -70 in the MPL promoter, and destruction of this site yields only a modest decrease in expression level in HEL cells. Ets proteins also bind with low affinity to two sites. One is located at position -15 and its destruction reduces expression to 50%; the other is located immediately downstream of the GATA motif and plays a crucial role in expression of the promoter in HEL cells, as its inactivation reduces expression to 15%. Furthermore, GATA-1 and two Ets proteins, Ets-1 and Fli-1, can trans-activate the MPL promoter in heterologous cells. The effects of GATA-1 and these two Ets proteins are additive. Together with our previous results on the glycoprotein IIb (GpIIb) promoter, this study indicates a molecular basis for the coregulation of early markers of megakaryocyte differentiation.     

Genome sequence of the deep-sea gamma-proteobacterium Idiomarina loihiensis reveals amino acid fermentation as a source of carbon and energy

We report the complete genome sequence of the deep-sea gamma-proteobacterium, Idiomarina loihiensis, isolated recently from a hydrothermal vent at 1,300-m depth on the Loihi submarine volcano, Hawaii. The I. loihiensis genome comprises a single chromosome of 2,839,318 base pairs, encoding 2,640 proteins, four rRNA operons, and 56 tRNA genes. A comparison of I. loihiensis to the genomes of other gamma-proteobacteria reveals abundance of amino acid transport and degradation enzymes, but a loss of sugar transport systems and certain enzymes of sugar metabolism. This finding suggests that I. loihiensis relies primarily on amino acid catabolism, rather than on sugar fermentation, for carbon and energy. Enzymes for biosynthesis of purines, pyrimidines, the majority of amino acids, and coenzymes are encoded in the genome, but biosynthetic pathways for Leu, Ile, Val, Thr, and Met are incomplete. Auxotrophy for Val and Thr was confirmed by in vivo experiments. The I. loihiensis genome contains a cluster of 32 genes encoding enzymes for exopolysaccharide and capsular polysaccharide synthesis. It also encodes diverse peptidases, a variety of peptide and amino acid uptake systems, and versatile signal transduction machinery. We propose that the source of amino acids for I. loihiensis growth are the proteinaceous particles present in the deep sea hydrothermal vent waters. I. loihiensis would colonize these particles by using the secreted exopolysaccharide, digest these proteins, and metabolize the resulting peptides and amino acids. In summary, the I. loihiensis genome reveals an integrated mechanism of metabolic adaptation to the constantly changing deep-sea hydrothermal ecosystem.     

Localization of the SRC oncogene to chromosome band 20q11.2 and loss of this gene with deletion (20q) in two leukemic patients

In situ hybridization of the pHul-c-src probe to metaphase cells from three normal donors and two leukemic patients showed significant labeling in the proximal region of the long arm of chromosome 20q, with modal peaks of grains consistently at band 20q11.2. A secondary peak of grains was detected in the region 20q13.2-qter, the localization of SRC suggested by previous in situ studies. The exact localization of SRC is important for understanding the del(20q) chromosomal abnormality in myeloid neoplasias. Chromosome in situ hybridization and genomic studies showed loss of one allele of SRC in two patients with the deletion (20q). These results differ from previously published findings and suggest heterogeneity of the breakpoint at 20q11.2 in interstitial deletions of 20q, which characterize myeloid disorders.     

In vitro establishment and characterization of two acquired immunodeficiency syndrome-related lymphoma cell lines (BC-1 and BC-2) containing Kaposi's sarcoma-associated herpesvirus-like (KSHV) DNA sequences

Two unique DNA fragments were recently identified in over 90% of acquired immunodeficiency syndrome (AIDS)-related Kaposi's sarcoma tissues. Sequence analysis suggests that these fragments belong to a previously unidentified human herpesvirus, Kaposi's sarcoma-associated herpesvirus (KSHV). These fragments have also been identified in a subset of non-Hodgkin's lymphomas in human immunodeficiency virus- positive patients; specifically, in body cavity-based lymphomas (AIDS- BCBLs). We have established two cell lines derived from AIDS-BCBLs, BC- 1 and BC-2, which retain the KSHV sequences, and have used them to further characterize this putative viral genome. In this report, we demonstrate that the KSHV sequences represent a portion of a much larger DNA molecule that is located predominantly in the nucleus of the infected cells. In situ hybridization of metaphase spreads made from both of these cell lines show these sequences in episomal structures. Their presence in the cells as large nuclear episomes supports previous sequence homology data suggesting that KSHV belongs to the herpesvirus family. These cell lines provide a continuous source of KSHV sequences. Thus, they represent an important tool for future studies of this recently described human herpesvirus that may be involved in the pathogenesis of Kaposi's sarcoma and some AIDS-related non-Hodgkin's lymphomas.     

Comparison of ECG Variables of Dispersion of Ventricular Repolarization with Direct Myocardial Repolarization Measurements in the Human Heart

Validation of ECG Variables of Dispersion. Introduction: QT dispersion (QTD) from the 12-tead ECG has been widely adopted as a noninvasive index of dispersion of ventricular repolarization (DVR). QTD, however, has never been validated by direct comparison with myocardial DVR in the human heart. Methods and Results: Monophasic action potential (MAP) recordings obtained in an earlier study were retrospectively matched with 12-lead ECGs available from within 24 hours of the invasive procedure. MAPs were available from an average of 8 ± 3 left endocardial sites in 4 patients with left ventricular hypertrophy (LVH) and 7 patients with normal ECGs, and 6 ± 2 epicardial sites in 3 patients of each group during normal ventricular activation. Local repolarization time (RT) was determined as MAP duration at 90% repolarization plus the local activation time. Dispersion of RT was calculated as the difference between the earliest and latest RT. ECGs were digitized and analyzed with recently described interactive QTD analysis software. In addition to standard QTD (defined as QT_max– QT_min), all currently proposed ECG dispersion variables were compared and correlated with the invasive measurements of DVR. QTD exhibited a reasonable correlation with dispersion of RT (R = 0.67; P < 0.01). Several other variables designed to measure DVR exhibited a similar, but not better, correlation. Among them, the QT peak/QT end ratio in V₃ (R =?0.72; P < 0.01) and averaged over all analyzableleads (R =?0.59; P < 0.01) exhibited a good correlation with dispersion of RT, which was further improved when endocardial measurements were considered alone. T area measures did not correlate with dispersion of RT, but discriminated LVH. Conclusion: DVR can he assessed by means of a 12-lead surface ECG. Several of the variables under study exhibit a similar accuracy in determination of true myocardial dispersion of repolarization. Variables involving the terminal part of repolarization, such as the QT peak/QT ratio, even from a single lead, may add to the determination of DVR from the human heart.     

Retrograde Coronary Venous Infusion of Ethanol for Ablation of Canine Ventricular Myocardium

Retrograde Coronary Venous Ethanol Infusion for Ablation. Introduction : Permanent cure of reentrant ventricular tachycardia (VT) associated with coronary artery disease is difficult to achieve. Retrograde coronary venous infusion of ethanol for ablation of ventricular myocardium associated with reentrant tachyarrhythmias has several potential advantages, including use of physiologic mapping techniques and production of deeper, wider necrotic zones.
Methods and Results: Nine anesthetized dogs had baseline hemodynamic measurement, left ventriculography, coronary arteriography, occlusive coronary venography, and programmed electrical stimulation of the right ventricular apex and outflow tract. A balloon-tipped infusion catheter was advanced into a distal coronary venous branch, the balloon slowly inflated, and pure ethanol infused at volumes of 1.5, 3, or 5 cc. Hemodynamic measurements, angiography, ventriculography, and programmed electrical stimulation were repeated immediately and 1 week following ablation. Formalin-perfused hearts were serially sectioned and lesion volumes determined. Histologic examination of ablation beds then was performed. No significant difference was found in any hemodynamic measurement before or after ablation. Coronary arteriograms and left ventriculograms were unchanged after ablation. Nonsustained VT occurred in eight dogs during ethanol infusion; however, VT was not inducible in any dog before or after ablation. Infusion volumes of 3 cc or more were required to produce transmural lesions.
Conclusion : Retrograde coronary venous infusions of ethanol using a balloon-tipped infusion catheter were effective in ablating ventricular myocardium. Retrograde chemical ablation did not itself result in inducible VT or adversely affect hemodynamic measurements or coronary arteries. Transmural myocardial necrosis, necessary in the ablation of VT associated with coronary artery disease, can be produced by higher infusion volumes.