Magnetic resonance assessment of aortic pulse wave velocity, aortic distensibility, and cardiac function in uncomplicated type 2 diabetes mellitus.

BACKGROUND: Type 2 diabetes mellitus (DM2) may augment arterial stiffening and thereby modulates left ventricular (LV) function. Cardiovascular magnetic resonance (CMR) is well suited to assess aortic pulse wave velocity (PWV) and aortic distensibility, both markers of arterial stiffness, without the use of geometric assumptions. Furthermore, CMR is a reliable method for assessing left ventricular (LV) function. The purpose of this study was to assess LV function, PWV, and aortic distensibility in patients with DM2 using MR. METHODS: Fourteen patients with well controlled, uncomplicated DM2, and 16 age and gender matched healthy subjects were included. PWV was calculated based on MR velocity mapping at two predefined aortic locations. Aortic distensibility was measured in the mid ascending aorta. LV volumes were measured by fast gradient-echo imaging to assess systolic function. Furthermore, mitral inflow was measured by MR velocity mapping to assess diastolic LV function. RESULTS: Mean PWV was higher in patients as compared to healthy subjects (6.83 +/- 1.60 m/s vs. 5.65 +/- 0.75 m/s, p < 0.05). This difference was independent of blood pressure. PWV correlated significantly (p < 0.05) with fasting plasma glucose and insulin levels. Aortic distensibility was lower in patients as compared to healthy subjects (4.50 x 10(- 3)+/- 2.24 x 10(- 3) mmHg(- 1) vs. 7.42 x 10(- 3)+/- 3.34 x 10(- 3) mmHg(- 1), p < 0.05). Distensibility correlated negatively with PWV and positively with LV diastolic function (p < 0.05). CONCLUSION: A combined CMR assessment of aortic PWV, aortic distensibility, and heart function reveals abnormal PWV and distensibility in patients with DM2, independent of blood pressure. Furthermore, aortic distensibility correlates with diastolic left ventricular function.     

Early viral replication in lymph nodes provides HIV with a means by which to escape NK-cell-mediated control

Acute HIV infection is marked by dramatic viral replication associated with preferential replication within secondary lymphoid tissues, such as lymph nodes (LNs), that is rapidly but incompletely contained to a viral setpoint. Accumulating evidence supports a role for natural killer (NK) cells in the early control of HIV infection; however, little is known about the location of their antiviral control. Given that HIV replicates profusely in LNs during early infection, we sought to define whether changes occurred in the NK cell infiltrate within these sites during the first year of HIV infection. Surprisingly, NK cell numbers and distribution were unaltered during early HIV infection. LN NK cells expressed decreased inhibitory receptors, were more highly activated, and expressed elevated TRAIL, potentially conferring a superior capacity for NK cells to become activated and control infection. Most noticeably, KIR(+) NK cells were rarely detected in the LN during HIV infection, associated with diminished migratory capacity in the setting of reduced expression of CX3CR1 and CXCR1. Thus, incomplete control of HIV viral replication during early disease may be due to the inefficient recruitment of KIR(+) NK cells to this vulnerable site, providing HIV a niche where it can replicate unabated by early NK-cell-mediated innate pressure.     

The crown of love: intimate relations and alcohol use in adolescence

Background  Remarkably, little attention has been paid to the role of intimate partners and their drinking behavior in relation to adolescent alcohol use. In the current study, we examined associations between adolescent alcohol use and romantic partners’ drinking behavior. Methods  A total of 428 families, consisting of both parents and two adolescents (aged 13.4 and 15.2 at Time 1) participated in a prospective study with four annual waves. Correlations and multivariate regressions were used to examine (1) similarity in drinking behaviors of adolescents and intimate partners, (2) whether alcohol use of partners prospectively predicts adolescent alcohol consumption, and (3) whether adolescents who consume alcohol select partners over time who show similar drinking behaviors. Results  (1) Frequency of alcohol consumption of adolescents and of their romantic partners correlated significantly. (2) Alcohol use of partners was not predictive of adolescent alcohol consumption over time, if previous levels of alcohol consumption were taken into account. (3) Adolescents acquired partners with similar drinking behaviors. Gender effects were found; adolescent girls, but not boys, were more likely to become involved with partners who also frequently consumed alcohol. Conclusions  Regarding alcohol consumption, adolescents and their intimate partners were relatively similar in alcohol use. This resemblance is best explained by adolescents’ selection of future partner on the basis of alcohol consumption. Less indication was found for influence effects, perhaps due to the transient nature of most adolescent romantic relationships.

Parenting styles, coping strategies, and the expression of homesickness

The present study examined the role of parenting styles in the experience and expression of homesickness, and the way of coping with the feelings involved. Using a sample of 670 first year college and university students, aged 16 to 25, we tested three hypotheses: (1) authoritarian, permissive as well as uninvolved parenting are associated with the experience of homesickness, contrary to students with authoritative parents who are less likely to have feelings of homesickness; (2) students with authoritarian, permissive or uninvolved parents show their homesickness by internalizing and externalizing problems; and (3) students raised by authoritative or permissive parents use more effective coping strategies to deal with homesickness. Results indicated that students raised by authoritative and permissive parents experienced more homesickness with stronger feelings of homesickness than students raised by authoritarian or uninvolved parents. However, they hardly express homesickness by internalizing or externalizing problems when they use effective ways of coping, namely support-seeking and/or problem-solving. Students with parents endorsing an authoritarian or uninvolved parenting style, on the other hand, showed more internalizing and externalizing problems in reaction to feelings of homesickness. They also use less effective coping strategies. The results revealed the importance of a loving and accepting home environment for the development and expression of homesickness, as well as the importance of the way in which students learn to cope with their problems.     

Stability and change in personality type membership and anxiety in adolescence

Although the stability and changeability of personality has long been debated, many studies now agree that personality changes over the life course. Although the changes in rank-order and mean-level stability are well established, the stability in personality type membership during adolescence is not yet clear. Little research has been conducted on the associations between change in personality type membership and anxiety. A total of 827 adolescents (10-20 years) completed personality and anxiety questionnaires on 2 waves of the CONflict And Management Of RElationships study (CONAMORE). We found that the stability in personality type membership was moderate. The change from undercontroller to overcontroller was the most frequently occurring change. Furthermore, the stability in type membership was related to stability in anxiety level and change in type membership was related to anxiety change. More specifically, the resilient-overcontroller group demonstrated an increase in anxiety level, whereas the overcontroller-resilient group demonstrated a decrease.     

Complementarity determining regions of an anti-prion protein scFv fragment orchestrate conformation specificity and antiprion activity

The prion protein, PrP, exists in several stable conformations, with the presence of one conformation, PrP(Sc), associated with transmissible neurodegenerative diseases. Targeting PrP by high-affinity ligands has been proven to be an effective way of preventing peripheral prion infections. Here, we have generated bacterially expressed single chain fragments of the variable domains (scFv) of a monoclonal antibody in Escherichia coli, originally raised against purified PrP(Sc) that recognizes both PrP(C) and PrP(Sc). This scFv fragment had a dissociation constant (K(D)) with recombinant PrP of 2 nM and cleared prions in ScN2a cells at 4 nM, as demonstrated by a mouse prion bioassay. A peptide corresponding to the complementarity determining region 3 of the heavy chain (CDR3H) selectively bound PrP(Sc) but had lost antiprion activity. However, synthesis and application of an improved peptide mimicking side chain topology of CDR3H while exhibiting increased protease resistance, a retro-inverso d-peptide of CDR3H, still bound PrP(Sc) and reinstated antiprion activity. We conclude that (1) scFvW226 is so far the smallest polypeptide with bioassay confirmed antiprion activity, and (2) differential conformation specificity and bioactivity can be regulated by orchestrating the participation of different CDRs.     

Antimicrobial effects of an NO-releasing poly(ethylene vinylacetate) coating on soft-tissue implants in vitro and in a murine model

Infection of surgical meshes used in abdominal wall reconstructions often leads to removal of the implant and increases patient morbidity due to repetitive operations and hospital administrations. Treatment with antibiotics is ineffective due to the biofilm mode of growth of the infecting bacteria and bears the risk of inducing antibiotic resistance. Hence there is a need for alternative methods to prevent and treat mesh infection. Nitric oxide (NO)-releasing coatings have been demonstrated to possess bactericidal properties in vitro. It is the aim of this study to assess possible benefits of a low concentration NO-releasing carbon-based coating on monofilament polypropylene meshes with respect to infection control in vitro and in vivo. When applied on surgical meshes, NO-releasing coatings showed significant bactericidal effect on in vitro biofilms of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and CNS. However, using bioluminescent in vivo imaging, no beneficial effects of this NO-releasing coating on subcutaneously implanted surgical meshes in mice could be observed.