Sustained intraatrial reentrant tachycardia: Clinical, electrocardiographic and electrophysiologic characteristics and long-term follow-up

Although intraatrial reentry has been traditionally listed as a mechanism for supraventricular tachycardia, few reports describing the clinical features of this arrhythmia exist. Nineteen patients with a clinical history of sustained supraventricular tachycardia were diagnosed as having intraatrial reentrant tachycardia. Seventeen (89%) patients of the 19 had underlying structural heart disease and 17 had echocardiographic evidence of atrial enlargement; the mean left ventricular ejection fraction was 51 ± 16%. A history of concomitant atrial fibrillation or flutter was present in 13 patients (68%). The mean atrial cycle length during tachycardia was 326 ± 57 ms (range 260 to 460). Fourteen patients had 1:1 atrioventricular (AV) conduction during tachycardia, of whom 50% had an RP7RR' ratio >0.5.Intravenous adenosine (dose range 37.5 to 150 µg/kg) and verapamil (dose range 5 to 10 mg) had no effect on atrial tachycardia cycle length in 13 of 14 and 9 of 9 patients, respectively, despite induction of second degree AV block. Type la antiarrhythmic drugs achieved longterm suppression of intraatrial reentrant tachycardia in only 6 patients, whereas amiodarone (326 ± 145 mg/day) was successful in 11 patients during a 32 ± 20 month follow-up period. The remaining two patients and one patient who later developed amiodarone toxicity either progressed to (n = 1) or had (n = 2) catheter-induced high grade AV block and were treated with long-term ventricular pacing.It is concluded that intraatrial reentrant tachycardia is often associated with structural heart disease, particularly of types that cause atrial abnormalities, but left ventricular dysfunction is not a requisite finding. Other arrhythmias are frequently observed in these patients. This arrhythmia responds poorly to type la antiarrhythmic drugs, but is effectively treated with amiodarone. Catheter ablation of the AV junction offers a therapeutic option for patients who are refractory to medical therapy

Use of a regional wall motion score to enhance risk stratification of patients receiving an implantable cardioverter-defibrillator

AbstractObjectives. We postulated that preoperative assessment of both regional wall motion and left ventricular ejection fraction would serve as an accurate prognostic indicator of long-term cardiac mortality and functional outcome in patients treated with an implantable cardioverter-defibrillator.Background. Long-term cardiac mortality has remained high in patients receiving an implantable cardioverter-defibrillator. The ability to risk stratify patients before defibrillator implantation is becoming increasingly important from a medical and economic standpoint.Methods. The hypothesis was retrospectively tested in 74 patients who had received an implantable cardioverterdefibrillator. Left ventricular ejection fraction and regional wall motion score, derived from centerline chord motion analysis, were calculated for each patient from the preoperative right anterior oblique contrast ventriculogram. Wall motion score was the only significant independent predictor of long-term cardiac mortality and functional status by multivariate analysis because of its enhanced prognostic capability in patients with an ejection fraction in the critical range of 30% to 40%.Results. Patients with an ejection fraction >40% had a 3-year cardiac mortality rate of 0% compared with 25% for those with an ejection fraction of 30% to 40% and 48% for those with an ejection fraction <30% (p < 0.05). Similarly, 75% of patients with an ejection fraction >40% were in New York Heart Association functional class I or II during long-term follow-up compared with 59% of those with an ejection fraction 30% to 40% and 29% of those with an ejection fraction <30%. Among patients with an ejection fraction of 30% to 40%, those with a wall motion score >16% had a 3-year cardiac mortality rate of 0% compared with 71% of those with a wall motion score ≤ 16% (p = 0.002). In addition, 86% of patients with a wall motion score >16% were in functional class I or II during long-term follow-up compared with 13% of those with a wall motion score ≤16% (p = 0.001).Conclusions. Long-term cardiac mortality and functional outcome in patients receiving an implantable cardioverterdefibrillator can be predicted if the left ventricular ejection fraction and regional wall motion score are measured preoperatively

Macrophage migration inhibitory factor: a mediator of matrix metalloproteinase-2 production in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by destruction of bone and cartilage, which is mediated, in part, by synovial fibroblasts. Matrix metalloproteinases (MMPs) are a large family of proteolytic enzymes responsible for matrix degradation. Macrophage migration inhibitory factor (MIF) is a cytokine that induces the production of a large number of proinflammatory molecules and has an important role in the pathogenesis of RA by promoting inflammation and angiogenesis. In the present study, we determined the role of MIF in RA synovial fibroblast MMP production and the underlying signaling mechanisms. We found that MIF induces RA synovial fibroblast MMP-2 expression in a time-dependent and concentration-dependent manner. To elucidate the role of MIF in MMP-2 production, we produced zymosan-induced arthritis (ZIA) in MIF gene-deficient and wild-type mice. We found that MMP-2 protein levels were significantly decreased in MIF gene-deficient compared with wild-type mice joint homogenates. The expression of MMP-2 in ZIA was evaluated by immunohistochemistry (IHC). IHC revealed that MMP-2 is highly expressed in wild-type compared with MIF gene-deficient mice ZIA joints. Interestingly, synovial lining cells, endothelial cells, and sublining nonlymphoid mononuclear cells expressed MMP-2 in the ZIA synovium. Consistent with these results, in methylated BSA (mBSA) antigen-induced arthritis (AIA), a model of RA, enhanced MMP-2 expression was also observed in wild-type compared with MIF gene-deficient mice joints. To elucidate the signaling mechanisms in MIF-induced MMP-2 upregulation, RA synovial fibroblasts were stimulated with MIF in the presence of signaling inhibitors. We found that MIF-induced RA synovial fibroblast MMP-2 upregulation required the protein kinase C (PKC), c-jun N-terminal kinase (JNK), and Src signaling pathways. We studied the expression of MMP-2 in the presence of PKC isoform-specific inhibitors and found that the PKCδ inhibitor rottlerin inhibits MIF-induced RA synovial fibroblast MMP-2 production. Consistent with these results, MIF induced phosphorylation of JNK, PKCδ, and c-jun. These results indicate a potential novel role for MIF in tissue destruction in RA

Treading Water: Tools to Help US Coastal Communities Plan for Sea Level Rise Impacts

As communities grapple with rising seas and more frequent flooding events, they need improved projections of future rising and flooding over multiple time horizons, to assist in a multitude of planning efforts. There are currently a few different tools available that communities can use to plan, including the Sea Level Report Card and products generated by a United States. Federal interagency task force on sea level rise. These tools are a start, but it is recognized that they are not necessarily enough at present to provide communities with the type of information needed to support decisions that range from seasonal to decadal in nature, generally over relatively small geographic regions. The largest need seems to come from integrated models and tools. Agencies need to work with communities to develop tools that integrate several aspects (rainfall, tides, etc.) that affect their coastal flooding problems. They also need a formalized relationship with end users that allows agency products to be responsive to the various needs of managers and decision makers. Existing boundary organizations can be leveraged to meet this need. Focusing on addressing these needs will allow agencies to create robust solutions to flood risks, leading to truly resilient communities

Ordered subset linkage analysis supports a susceptibility locus for age-related macular degeneration on chromosome 16p12

BACKGROUND: Age-related macular degeneration (AMD) is a complex disorder that is responsible for the majority of central vision loss in older adults living in developed countries. Phenotypic and genetic heterogeneity complicate the analysis of genome-wide scans for AMD susceptibility loci. The ordered subset analysis (OSA) method is an approach for reducing heterogeneity, increasing statistical power for detecting linkage, and helping to define the most informative data set for follow-up analysis. OSA assesses the linkage evidence in subsets of potentially more homogeneous families by rank-ordering family-specific lod scores with respect to trait-associated covariates or phenotypic features. Here, we present results of incorporating five continuous covariates into our genome-wide linkage analysis of 389 microsatellite markers in 62 multiplex families: Body mass index (BMI), systolic (SBP) and diastolic (DBP) blood pressure, intraocular pressure (IOP), and pack-years of cigarette smoking. Chromosome-wide significance of increases in nonparametric multipoint lod scores in covariate-defined subsets relative to the overall sample was assessed by permutation. RESULTS: Using a correction for testing multiple covariates, statistically significant lod score increases were observed for two chromosomal regions: 14q13 with a lod score of 3.2 in 28 families with average IOP ≤ 15.5 (p = 0.002), and 6q14 with a lod score of 1.6 in eight families with average BMI ≥ 30.1 (p = 0.0004). On chromosome 16p12, nominally significant lod score increases (p ≤ 0.05), up to a lod score of 2.9 in 32 families, were observed with several covariate orderings. While less significant, this was the only region where linkage evidence was associated with multiple clinically meaningful covariates and the only nominally significant finding when analysis was restricted to advanced forms of AMD. Families with linkage to 16p12 had higher averages of SBP, IOP and BMI and were primarily affected with neovascular AMD. For all three regions, linkage signals at or very near the peak marker have previously been reported. CONCLUSION: Our results suggest that a susceptibility gene on chromosome 16p12 may predispose to AMD, particularly to the neovascular form, and that further research into the previously suggested association of neovascular AMD and systemic hypertension is warranted

Detection of 6 November 1997 ground level event by Milagrito

Solar Energetic Particles (SEPs) with energies exceeding 10 GeV associated with the 6 November 1997 solar flare/CME (coronal mass ejection) have been detected with Milagrito, a prototype of the Milagro Gamma Ray Observatory. While SEP acceleration beyond 1 GeV is well established, few data exist for protons or ions beyond 10 GeV. The Milagro observatory, a ground based water Cherenkov detector designed for observing very high energy gamma ray sources, can also be used to study the Sun. Milagrito, which operated for approximately one year in 1997/98, was sensitive to solar proton and neutron fluxes above ∼4 GeV. In its scaler mode, Milagrito registered a rate increase coincident with the 6 November 1997 ground level event observed by Climax and other neutron monitors. A preliminary analysis suggests the presence of \u3e10 GeV particles

Molecular characterization of vaginal microbiota using a new 22-species qRT-PCR test to achieve a relative-abundance and species-based diagnosis of bacterial vaginosis

BackgroundNumerous bacteria are involved in the etiology of bacterial vaginosis (BV). Yet, current tests only focus on a select few. We therefore designed a new test targeting 22 BV-relevant species.MethodsUsing 946 stored vaginal samples, a new qPCR test that quantitatively identifies 22 bacterial species was designed. The distribution and relative abundance of each species, α- and β-diversities, correlation, and species co-existence were determined per sample. A diagnostic index was modeled from the data, trained, and tested to classify samples into BV-positive, BV-negative, or transitional BV.ResultsThe qPCR test identified all 22 targeted species with 95 – 100% sensitivity and specificity within 8 hours (from sample reception). Across most samples, Lactobacillus iners, Lactobacillus crispatus, Lactobacillus jensenii, Gardnerella vaginalis, Fannyhessea (Atopobium) vaginae, Prevotella bivia, and Megasphaera sp. type 1 were relatively abundant. BVAB-1 was more abundant and distributed than BVAB-2 and BVAB-3. No Mycoplasma genitalium was found. The inter-sample similarity was very low, and correlations existed between key species, which were used to model, train, and test a diagnostic index: MDL-BV index. The MDL-BV index, using both species and relative abundance markers, classified samples into three vaginal microbiome states. Testing this index on our samples, 491 were BV-positive, 318 were BV-negative, and 137 were transitional BV. Although important differences in BV status were observed between different age groups, races, and pregnancy status, they were statistically insignificant.ConclusionUsing a diverse and large number of vaginal samples from different races and age groups, including pregnant women, the new qRT-PCR test and MDL-BV index efficiently diagnosed BV within 8 hours (from sample reception), using 22 BV-associated species

The STAGES view of red spirals and dusty red galaxies: Mass-dependent quenching of star-formation in cluster infall

We investigate the properties of optically passive spirals and dusty red galaxies in the A901/2 cluster complex at redshift ~0.17 using restframe near-UV-optical SEDs, 24 micron IR data and HST morphologies from the STAGES dataset. The cluster sample is based on COMBO-17 redshifts with an rms precision of sigma_cz~2000 km/sec. We find that 'dusty red galaxies' and 'optically passive spirals' in A901/2 are largely the same phenomenon, and that they form stars at a substantial rate, which is only 4x lower than that in blue spirals at fixed mass. This star formation is more obscured than in blue galaxies and its optical signatures are weak. They appear predominantly in the stellar mass range of log M*/Msol=[10,11] where they constitute over half of the star-forming galaxies in the cluster; they are thus a vital ingredient for understanding the overall picture of star formation quenching in clusters. We find that the mean specific SFR of star-forming galaxies in the cluster is clearly lower than in the field, in contrast to the specific SFR properties of blue galaxies alone, which appear similar in cluster and field. Such a rich red spiral population is best explained if quenching is a slow process and morphological transformation is delayed even more. At log M*/Msol<10, such galaxies are rare, suggesting that their quenching is fast and accompanied by morphological change. We note, that edge-on spirals play a minor role; despite being dust-reddened they form only a small fraction of spirals independent of environment.Comment: Accepted for publication in MNRA

Systematic review of communication technologies to promote access and engagement of young people with diabetes into healthcare

Background: Research has investigated whether communication technologies (e.g. mobile telephony, forums, email) can be used to transfer digital information between healthcare professionals and young people who live with diabetes. The systematic review evaluates the effectiveness and impact of these technologies on communication. Methods: Nine electronic databases were searched. Technologies were described and a narrative synthesis of all studies was undertaken. Results: Of 20,925 publications identified, 19 met the inclusion criteria, with 18 technologies assessed. Five categories of communication technologies were identified: video-and tele-conferencing (n = 2); mobile telephony (n = 3); telephone support (n = 3); novel electronic communication devices for transferring clinical information (n = 10); and web-based discussion boards (n = 1). Ten studies showed a positive improvement in HbA1c following the intervention with four studies reporting detrimental increases in HbA1c levels. In fifteen studies communication technologies increased the frequency of contact between patient and healthcare professional. Findings were inconsistent of an association between improvements in HbA1c and increased contact. Limited evidence was available concerning behavioural and care coordination outcomes, although improvement in quality of life, patientcaregiver interaction, self-care and metabolic transmission were reported for some communication technologies. Conclusions: The breadth of study design and types of technologies reported make the magnitude of benefit and their effects on health difficult to determine. While communication technologies may increase the frequency of contact between patient and health care professional, it remains unclear whether this results in improved outcomes and is often the basis of the intervention itself. Further research is needed to explore the effectiveness and cost effectiveness of increasing the use of communication technologies between young people and healthcare professionals