A Revised Time Tree of the Asterids: Establishing a Temporal Framework For Evolutionary Studies of the Coffee Family (Rubiaceae)

Divergence time analyses in the coffee family (Rubiaceae) have all relied on the same Gentianales crown group age estimate, reported by an earlier analysis of the asterids, for defining the upper age bound of the root node in their analyses. However, not only did the asterid analysis suffer from several analytical shortcomings, but the estimate itself has been used in highly inconsistent ways in these Rubiaceae analyses. Based on the original data, we here reanalyze the divergence times of the asterids using relaxed-clock models and 14 fossil-based minimum age constraints. We also expand the data set to include an additional 67 taxa from Rubiaceae sampled across all three subfamilies recognized in the family. Three analyses are conducted: a separate analysis of the asterids, which completely mirrors the original asterid analysis in terms of taxon sample and data; a separate analysis of the Gentianales, where the result from the first analysis is used for defining a secondary root calibration point; and a combined analysis where all taxa are analyzed simultaneously. Results are presented in the form of a time-calibrated phylogeny, and age estimates for asterid groups, Gentianales, and major groups of Rubiaceae are compared and discussed in relation to previously published estimates. Our updated age estimates for major groups of Rubiaceae provide a significant step forward towards the long term goal of establishing a robust temporal framework for the divergence of this biologically diverse and fascinating group of plants.     

Decline in Coronary Mortality in Sweden between 1986 and 2002: Comparing Contributions from Primary and Secondary Prevention

BackgroundThe relative importance of risk factor reduction in healthy people (primary prevention) versus that in patients with coronary heart disease (secondary prevention) has been debated. We aimed to quantify the contribution of the two.MethodologyWe used the previously validated IMPACT model to estimate contributions from primary prevention (reducing risk factors in the population, particularly smoking, cholesterol and systolic blood pressure) and from secondary prevention (reducing risk factors in coronary heart disease patients) in the Swedish population.ConclusionsThe largest effects on mortality came from primary prevention, giving markedly larger mortality reductions than secondary prevention.     

BCG Skin Infection Triggers IL-1R-MyD88-Dependent Migration of EpCAMlow CD11bhigh Skin Dendritic cells to Draining Lymph Node During CD4+ T-Cell Priming

The transport of antigen from the periphery to the draining lymph node (DLN) is critical for T-cell priming but remains poorly studied during infection with Mycobacterium bovis Bacille Calmette-Guérin (BCG). To address this we employed a mouse model to track the traffic of Dendritic cells (DCs) and mycobacteria from the BCG inoculation site in the skin to the DLN. Detection of BCG in the DLN was concomitant with the priming of antigen-specific CD4⁺ T cells at that site. We found EpCAM^low CD11b^high migratory skin DCs to be mobilized during the transport of BCG to the DLN. Migratory skin DCs distributed to the T-cell area of the LN, co-localized with BCG and were found in close apposition to antigen-specific CD4⁺ T cells. Consequently, blockade of skin DC traffic into DLN dramatically reduced mycobacterial entry into DLN and muted T-cell priming. Interestingly, DC and mycobacterial entry into the DLN was dependent on IL-1R-I, MyD88, TNFR-I and IL-12p40. In addition, we found using DC adoptive transfers that the requirement for MyD88 in BCG-triggered migration was not restricted to the migrating DC itself and that hematopoietic expression of MyD88 was needed in part for full-fledged migration. Our observations thus identify a population of DCs that contribute towards the priming of CD4⁺ T cells to BCG infection by transporting bacilli into the DLN in an IL-1R-MyD88-dependent manner and reveal both DC-intrinsic and -extrinsic requirements for MyD88 in DC migration.     

Views of Swedish Commissioning Parents Relating to the Exploitation Discourse in Using Transnational Surrogacy

Transnational surrogacy, when people travel abroad for reproduction with the help of a surrogate mother, is a heavily debated phenomenon. One of the most salient discourses on surrogacy is the one affirming that Westerners, in their quest for having a child, exploit poor women in countries such as India. As surrogacy within the Swedish health care system is not permitted, Swedish commissioning parents have used transnational surrogacy, and the majority has turned to India. This interview study aimed to explore how commissioning parents negotiate the present discourses on surrogacy. Findings from the study suggest that the commissioning parents’ views on using surrogacy are influenced by competing discourses on surrogacy represented by media and surrogacy agencies. The use of this reproductive method resulted, then, in some ambiguity. Although commissioning parents defy the exploitation discourse by referring to what they have learnt about the surrogate mother’s life situation and by pointing at the significant benefits for her, they still had a request for regulation of surrogacy in Sweden, to better protect all parties involved. This study, then, gives a complex view on surrogacy, where the commissioning parents simultaneously argue against the exploitation discourse but at the same time are uncertain if the surrogate mothers are well protected in the surrogacy arrangements. Their responses to the situation endorse the need for regulation both in Sweden and India.     

Influence of Thin Slice Reconstruction on CT Brain Perfusion Analysis

Objectives

Although CT scanners generally allow dynamic acquisition of thin slices (1 mm), thick slice (≥5 mm) reconstruction is commonly used for stroke imaging to reduce data, processing time, and noise level. Thin slice CT perfusion (CTP) reconstruction may suffer less from partial volume effects, and thus yield more accurate quantitative results with increased resolution. Before thin slice protocols are to be introduced clinically, it needs to be ensured that this does not affect overall CTP constancy. We studied the influence of thin slice reconstruction on average perfusion values by comparing it with standard thick slice reconstruction.

Materials and Methods

From 50 patient studies, absolute and relative hemisphere averaged estimates of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and permeability-surface area product (PS) were analyzed using 0.8, 2.4, 4.8, and 9.6 mm slice reconstructions. Specifically, the influence of Gaussian and bilateral filtering, the arterial input function (AIF), and motion correction on the perfusion values was investigated.

Results

Bilateral filtering gave noise levels comparable to isotropic Gaussian filtering, with less partial volume effects. Absolute CBF, CBV and PS were 22%, 14% and 46% lower with 0.8 mm than with 4.8 mm slices. If the AIF and motion correction were based on thin slices prior to reconstruction of thicker slices, these differences reduced to 3%, 4% and 3%. The effect of slice thickness on relative values was very small.

Conclusions

This study shows that thin slice reconstruction for CTP with unaltered acquisition protocol gives relative perfusion values without clinically relevant bias. It does however affect absolute perfusion values, of which CBF and CBV are most sensitive. Partial volume effects in large arteries and veins lead to overestimation of these values. The effects of reconstruction slice thickness should be taken into account when absolute perfusion values are used for clinical decision making.     

Rolling circle amplification-based detection of human topoisomerase I activity on magnetic beads

A high-sensitivity assay has been developed for the detection of human topoisomerase I with single molecule resolution. The method uses magnetic sepharose beads to concentrate rolling circle products, produced by the amplification of DNA molecules circularized by topoisomerase I and detectable with a confocal microscope as single and discrete dots, once reacted with fluorescent probes. Each dot, corresponding to a single cleavage–religation event mediated by the enzyme, can be counted due to its high signal/noise ratio, allowing detection of 0.3 pM enzyme and representing a valid method to detect the enzyme activity in highly diluted samples.     

Teaching acid/base physiology in the laboratory

Acid/base homeostasis is one of the most difficult subdisciplines of physiology for medical students to master. A different approach, where theory and practice are linked, might help students develop a deeper understanding of acid/base homeostasis. We therefore set out to develop a laboratory exercise in acid/base physiology that would provide students with unambiguous and reproducible data that clearly would illustrate the theory in practice. The laboratory exercise was developed to include both metabolic acidosis and respiratory alkalosis. Data were collected from 56 groups of medical students that had participated in this laboratory exercise. The acquired data showed very consistent and solid findings after the development of both metabolic acidosis and respiratory alkalosis. All results were consistent with the appropriate diagnosis of the acid/base disorder. Not one single group failed to obtain data that were compatible with the diagnosis; it was only the degree of acidosis/alkalosis and compensation that varied.     

Molecular systematics and morphological character evolution of the Condamineeae (Rubiaceae)

? Premise of the study: The Condamineeae have in previous molecular studies been shown to be part of an early-divergent clade within the subfamily Ixoroideae, together with the tribes Calycophylleae, and Hippotideae, and genera of the former Cinchoneae and Rondeletieae. Generic relationships within this clade have, however, remained largely unresolved. ? Methods: In this study, the systematics of the Condamineeae was further examined by phylogenetic reconstruction of six cpDNA regions and one nrDNA region using parsimony and Bayesian Markov chain Monte Carlo inference. Morphological character evolution within the tribe was assessed by ancestral state reconstruction using likelihood optimization of characters onto Bayesian trees. ? Key results: Calycophylleae appears polyphyletic. "Hippotideae" is monophyletic but nested within the Condamineeae. The phylogenetic hypotheses presented support a resurrection of the genera Holtonia, Schizocalyx, and Semaphyllanthe. Furthermore, Bathysa is found to be polyphyletic, Tresanthera is found nested within Rustia, and the taxonomically disputed genus Dialypetalanthus is here shown to be sister to a Bothriospora-Wittmackanthus clade. Morphological ancestral state reconstructions indicate that protogyny have evolved at least two times within the tribe and that indehiscent fruits, loculicidal fruit dehiscence, and intrapetiolar stipules have evolved independently several times. The occurrence of calycophylls (leaf-like calyx lobes), poricidal anthers, and winged seeds also appear homoplastic within the tribe. ? Conclusions: A diagnosis and delimitation of the tribe Condamineeae is presented, with taxonomic proposals to synonymize Tresanthera and to transfer several species of Bathysa as well as Phitopis to a resurrected Schizocalyx.