3056Orthogonal P wave morphology, traditional P wave indices, and the risk of atrial fibrillation in the general population

Background

A substantial portion of the risk of atrial fibrillation (AF) remains unexplained by the established risk markers. However, accurate assessment of AF risk would be beneficial, especially among stroke patients and subjects with symptoms attributable to arrhythmia.

Purpose

To study the associations of P-wave indices with AF risk in the general population.

Methods

Electrocardiograms, including orthogonal leads, of 7217 Finnish subjects aged over 30 years who took part in the baseline examinations of the Mini-Finland Health Survey in 1978–80, were digitized. P-wave duration, third-degree interatrial block (IAB), and P terminal force (PTF) were assessed manually. PTF was considered abnormal when the amplitude of the negative terminal part of the P wave in lead V1 was ≥0.1mV and duration ≥40ms. Third-degree IAB was defined as P-wave duration ≥120ms and the presence of ≥2 +/− biphasic P-waves in the inferior leads. Orthogonal P-wave morphology, which is related to left atrial breakthrough site and affected by atrial fibrosis (1 being considered benign, 2 borderline, and 3 shown to be associated with adverse events), was assessed with an automated algorithm, and ascertained manually. Subjects were followed 10 years for AF hospitalization and mortality. The risk of AF associated with P wave parameters was assessed using Cox proportional hazards models. Model discrimination improvement was quantified by the change in C index, integrated discrimination improvement (IDI), and continuous net reclassification improvement (cNRI).

Results

There were 5489 subjects (47.8% male, mean age 50.5 years) with a readable ECG, sinus rhythm, no missing data, and a predefined orthogonal P-wave morphology. Type 3 orthogonal P morphology (n=216, multivariate adjusted HR [maHR] 3.01, 95% confidence interval [CI] 1.66–5.45, p<0.001), P-wave duration ≥120ms (n=752, maHR 1.67, 95% CI 1.06–2.64, p=0.027), and third-degree IAB (n=103, maHR 3.18, 95% CI 1.66–6.13, p=0.001) were independently associated with the risk of AF in separate models. PTF did not independently predict AF. Subjects presenting with both Type 1 orthogonal P-wave morphology and P-wave duration <110ms (n=2074) were at low risk of AF (maHR 0.46, 95% CI 0.26–0.83, p=0.006) when compared to the rest of the subjects. The inclusion of variables combining orthogonal P-wave morphology and P-wave duration to a multivariate model including conventional AF risk factors improved C index from 0.815 to 0.832 (change 0.017, 95% CI 0.001–0.033), IDI was 0.012 (95% CI 0.006–0.051), and cNRI was 0.220 (95% CI 0.048–0.357).

Conclusions

P-wave indices and orthogonal P-wave morphology can be used to identify subjects at high and low risk for AF and possibly direct extensive AF screening protocols towards high-risk subjects in the general population in order to decrease the risk of cardioembolic stroke. However, more research is needed in this topic.

Acknowledgement/Funding

Finnish Medical Foundation, Onni and Hilja Tuovinen's Foundation, Orion Research Foundation, Paavo Nurmi's Foundation, Veritas Foundation

Predictive capacity of prodromal symptoms in first-episode psychosis of recent onset

BACKGROUND

Both the nature and number of a wide range of prodromal symptoms have been related to the severity and type of psychopathology in the psychotic phase. However, at present there is an incomplete picture focused mainly on the positive pre-psychotic dimension.

AIM

To characterize the prodromal phase retrospectively, examining the number and nature of prodromal symptoms as well as their relationship with psychopathology at the onset of first-episode psychosis.

METHODS

Retrospective study of 79 patients experiencing a first-episode psychosis of less than 1 year from the onset of full-blown psychosis. All patients were evaluated with a comprehensive battery of instruments including socio-demographic and clinical questionnaire, IRAOS interview, PANSS, stressful life events scale (PERI) and WAIS/WISC (vocabulary subtest). Bivariate associations and multiple regression analysis were performed.

RESULTS

Regression models revealed that several prodromal dimensions of IRAOS (delusions, affect, language, behaviour and non-hallucinatory disturbances of perception) predicted the onset of psychosis, with positive (22.4% of the variance) and disorganized (25.6% of the variance) dimensions being the most widely explained.

CONCLUSION

In addition to attenuated positive symptoms, other symptoms such as affective, behavioural and language disturbances should also be considered in the definitions criteria of at-high-risk people.

Interatrial block in prediction of all-cause mortality after first-ever ischemic stroke

Background

Interatrial block (IAB) is an ECG indicator of atrial fibrosis related to atrial remodeling and thrombus formation thus leading to embolic stroke and increasing mortality. We aimed to assess weather IAB predicted all-cause mortality during 10 years after ischemic stroke.

Methods

The study sample comprised 235 patients (median age 74 (interquartile range 25–75% 65–81) years, 95 female) included in the Lund Stroke Register in 2001–2002, who had sinus rhythm ECGs at stroke admission. IAB was defined as a P-wave duration ≥120 ms without = partial IAB (n = 56) or with = advanced IAB (n = 41) biphasic morphology (±) in the inferior ECG leads. All-cause mortality was assessed via linkage with the Swedish Causes of Death Register.

Results

During follow-up 126 patients died (54%). Advanced IAB, but not partial, was associated with all-cause mortality in univariate Cox regression analysis (hazard ratio (HR) 1.98, 95% CI 1.27–3.09, p = 0.003). After adjustment for age, gender, severity of stroke measured by NIHSS scale and smoking status in patients without additional comorbidities advanced IAB independently predicted all-cause mortality (HR 7.89, 95% CI 2.01–30.98, p = 0.003), while in patients with comorbidities it did not (HR 1.01 95% CI 0.59–1.72, p = 0.966).

Conclusion

Advanced IAB predicted all-cause mortality after ischemic stroke, but mostly in patients without additional cardiovascular comorbidities.

Properties of Nuclei up to A=16 using Local Chiral Interactions

We report accurate quantum Monte Carlo calculations of nuclei up to A=16 based on local chiral two- and three-nucleon interactions up to next-to-next-to-leading order. We examine the theoretical uncertainties associated with the chiral expansion and the cutoff in the theory, as well as the associated operator choices in the three-nucleon interactions. While in light nuclei the cutoff variation and systematic uncertainties are rather small, in ^{16}O these can be significant for large coordinate-space cutoffs. Overall, we show that chiral interactions constructed to reproduce properties of very light systems and nucleon-nucleon scattering give an excellent description of binding energies, charge radii, and form factors for all these nuclei, including open-shell systems in A=6 and 12.

Ground-State Properties of Unitary Bosons: From Clusters to Matter

The properties of cold Bose gases at unitarity have been extensively investigated in the last few years both theoretically and experimentally. In this Letter we use a family of interactions tuned to two-body unitarity and very weak three-body binding to demonstrate the universal properties of both clusters and matter. We determine the universal properties of finite clusters up to 60 particles and, for the first time, explicitly demonstrate the saturation of energy and density with particle number and compare with bulk properties. At saturation in the bulk we determine the energy, density, two- and three-body contacts, and the condensate fraction. We find that uniform matter is more bound than three-body clusters by nearly 2 orders of magnitude, the two-body contact is very large in absolute terms, and yet the condensate fraction is also very large, greater than 90%. Equilibrium properties of these systems may be experimentally accessible through rapid quenching of weakly interacting boson superfluids.

Detection and prevalence of Haemoproteus archilochus (Haemosporida, Haemoproteidae) in two species of California hummingbirds

Haemosporidian blood parasites are transmitted to a wide range of avian hosts via blood-sucking dipteran vectors. Microscopy has revealed an impressive diversity of avian haemosporidia with more than 250 species described. Moreover, PCR and subsequent sequence analyses have suggested a much greater diversity of haemosporidia than morphological analyses alone. Given the importance of these parasites, very few studies have focused on the charismatic hummingbirds. To date, three Haemoproteus species (Haemoproteus archilochus, Haemoproteus trochili, and Haemoproteus witti) and one Leucocytozoon species (Leucocytozoon quynzae) have been described in blood samples taken from hummingbirds (Trochilidae). Unconfirmed Plasmodium lineages have also been detected in hummingbirds. Here, we report the detection of H. archilochus in two hummingbird species (Calypte anna and Archilochus alexandri) sampled in Northern California and perform a phylogenetic analysis of mitochondrial cytochrome b (cyt b) gene lineages. A total of 261 hummingbirds (157 C. anna, 104 A. alexandri) were sampled and screened for blood parasites using PCR and microscopy techniques. Combining both methods, 4 (2.55%) haemosporidian infections were detected in C. anna and 18 (17.31%) haemosporidian infections were detected in A. alexandri. Molecular analyses revealed four distinct H. archilocus cyt b lineages, which clustered as a monophyletic clade. No species of Plasmodium or Leucocytozoon were detected in this study, raising the possibility of specific vector associations with hummingbirds. These results provide resources for future studies of haemosporidian prevalence, diversity, and pathogenicity in California hummingbird populations.

Does the social environment moderate associations of the built environment with Latinas' objectively-measured neighborhood outdoor physical activity?

Favorable perceptions of the built and social neighborhood environment may promote outdoor physical activity (PA). However, little is known about their independent and interactive effects on neighborhood-specific outdoor PA. We examined associations of perceived built and social neighborhood environment factors, and their interactions, with objectively-measured neighborhood outdoor moderate-to-vigorous physical activity (MVPA) among a sample of Latina women in San Diego, CA. Analyses included baseline data collected in 2011-2013 from 86 Latinas with ≥ 2 days of combined accelerometer and global positioning system data and complete survey measures. We examined objective neighborhood outdoor MVPA within 500-meter home buffers. Generalized linear mixed models examined associations of 3 perceived built (e.g., sidewalk maintenance) and 3 social environmental (e.g., safety from crime) factors with engaging in any daily neighborhood outdoor MVPA. Models tested interactions between the built and social environmental factors. Although the perceived neighborhood environmental factors were not significantly related to daily neighborhood outdoor MVPA, we found 2 significant interactions: perceived sidewalk maintenance x safety from crime (p = 0.05) and neighborhood aesthetics x neighborhood social cohesion (p = 0.03). Sidewalk maintenance was positively related to daily neighborhood outdoor MVPA only among Latinas that reported low levels of safety from crime. Neighborhood aesthetics was positively related to daily neighborhood outdoor MVPA only among Latinas with high neighborhood social cohesion. Findings suggest several built and social environmental factors interact to influence Latinas' neighborhood outdoor MVPA. Interventions are needed targeting both built and social neighborhood environmental factors favorable to outdoor PA in the neighborhood.

Liver Transplantation in a Patient at Psychosocial Risk

Psychosocial assessment of transplant candidates is a challenging task. Securing adequate information is made more difficult when patients present with fulminant hepatic failure. When the patient cannot be interviewed and the family is reluctant to provide vital information, a comprehensive pretransplant psychosocial evaluation is virtually impossible. However, even the most difficult cases have the potential for a positive result when a good psychosocial profile of the patient is obtained after transplantation, a team treatment plan is developed and carried out which addresses current and anticipated problems, and the patient obtains mental health treatment.

Paediatric non-progression following grandmother-to-child HIV transmission

Background

In contrast to adult HIV infection, where slow disease progression is strongly linked to immune control of HIV mediated by protective HLA class I molecules such as HLA-B*81:01, the mechanisms by which a minority of HIV-infected children maintain normal-for-age CD4 counts and remain clinically healthy appear to be HLA class I-independent and are largely unknown. To better understand these mechanisms, we here studied a HIV-infected South African female, who remained a non-progressor throughout childhood.

Results

Phylogenetic analysis of viral sequences in the HIV-infected family members, together with the history of grand-maternal breast-feeding, indicated that, unusually, the non-progressor child had been infected via grandmother-to-child transmission. Although HLA-B*81:01 was expressed by both grandmother and grand-daughter, autologous virus in each subject encoded an escape mutation L188F within the immunodominant HLA-B*81:01-restricted Gag-specific epitope TL9 (TPQDLNTML, Gag 180–188). Since the transmitted virus can influence paediatric and adult HIV disease progression, we investigated the impact of the L188F mutant on replicative capacity. When this variant was introduced into three distinct HIV clones in vitro, viral replicative capacity was abrogated altogether. However, a virus constructed using the gag sequence of the non-progressor child replicated as efficiently as wildtype virus.

Conclusion

These findings suggest alternative sequences of events: the transmission of the uncompensated low fitness L188F to both children, potentially contributing to slow progression in both, consistent with previous studies indicating that disease progression in children can be influenced by the replicative capacity of the transmitted virus; or the transmission of fully compensated virus, and slow progression here principally the result of HLA-independent host-specific factors, yet to be defined.

Electronic supplementary material

The online version of this article (doi:10.1186/s12977-016-0300-y) contains supplementary material, which is available to authorized users.

Electromagnetic Response of ^{12}C: A First-Principles Calculation

The longitudinal and transverse electromagnetic response functions of ^{12}C are computed in a "first-principles" Green's function Monte Carlo calculation, based on realistic two- and three-nucleon interactions and associated one- and two-body currents. We find excellent agreement between theory and experiment and, in particular, no evidence for the quenching of the measured versus calculated longitudinal response. This is further corroborated by a reanalysis of the Coulomb sum rule, in which the contributions from the low-lying J^{π}=2^{+}, 0_{2}^{+} (Hoyle), and 4^{+} states in ^{12}C are accounted for explicitly in evaluating the total inelastic strength.

Phosphatidylserine is a global immunosuppressive signal in efferocytosis, infectious disease, and cancer

Apoptosis is an evolutionarily conserved and tightly regulated cell death modality. It serves important roles in physiology by sculpting complex tissues during embryogenesis and by removing effete cells that have reached advanced age or whose genomes have been irreparably damaged. Apoptosis culminates in the rapid and decisive removal of cell corpses by efferocytosis, a term used to distinguish the engulfment of apoptotic cells from other phagocytic processes. Over the past decades, the molecular and cell biological events associated with efferocytosis have been rigorously studied, and many eat-me signals and receptors have been identified. The externalization of phosphatidylserine (PS) is arguably the most emblematic eat-me signal that is in turn bound by a large number of serum proteins and opsonins that facilitate efferocytosis. Under physiological conditions, externalized PS functions as a dominant and evolutionarily conserved immunosuppressive signal that promotes tolerance and prevents local and systemic immune activation. Pathologically, the innate immunosuppressive effect of externalized PS has been hijacked by numerous viruses, microorganisms, and parasites to facilitate infection, and in many cases, establish infection latency. PS is also profoundly dysregulated in the tumor microenvironment and antagonizes the development of tumor immunity. In this review, we discuss the biology of PS with respect to its role as a global immunosuppressive signal and how PS is exploited to drive diverse pathological processes such as infection and cancer. Finally, we outline the rationale that agents targeting PS could have significant value in cancer and infectious disease therapeutics.