Emotion regulation ability varies in relation to intrinsic functional brain architecture

This study investigated the neural basis of individual variation in emotion regulation, specifically the ability to reappraise negative stimuli so as to down-regulate negative affect. Brain functions in young adults were measured with functional Magnetic Resonance Imaging during three conditions: (i) attending to neutral pictures; (ii) attending to negative pictures and (iii) reappraising negative pictures. Resting-state functional connectivity was measured with amygdala and dorsolateral prefrontal cortical (DLPFC) seed regions frequently associated with emotion regulation. Participants reported more negative affect after attending to negative than neutral pictures, and less negative affect following reappraisal. Both attending to negative vs neutral pictures and reappraising vs attending to negative pictures yielded widespread activations that were significantly right-lateralized for attending to negative pictures and left-lateralized for reappraising negative pictures. Across participants, more successful reappraisal correlated with less trait anxiety and more positive daily emotion, greater activation in medial and lateral prefrontal regions, and lesser resting-state functional connectivity between (a) right amygdala and both medial prefrontal and posterior cingulate cortices, and (b) bilateral DLPFC and posterior visual cortices. The ability to regulate emotion, a source of resilience or of risk for distress, appears to vary in relation to differences in intrinsic functional brain architecture.     

Nitric oxide/cGMP signaling inhibits TSH-stimulated iodide uptake and expression of thyroid peroxidase and thyroglobulin mRNA in FRTL-5 thyroid cells.

OBJECTIVE: Nitric oxide (NO) induces morphological and functional alterations in primary cultured thyroid cells. The aim of this paper was to analyze the direct influence of a long-term exposition to NO on parameters of thyroid hormone biosynthesis in FRTL-5 cells. DESIGN: Cells were treated with the NO donor sodium nitroprusside (SNP) for 24-72 h. MAIN OUTCOME: SNP (50-500 micromol/L) reduced iodide uptake in a concentration-dependent manner. The inhibition of iodide uptake increased progressively with time and matched nitrite accumulation. SNP inhibited thyroperoxidase (TPO) and thyroglobulin (TG) mRNA expression in a concentration-dependent manner. SNP enhanced 3',5'-cyclic guanosine monophosphate (cGMP) production. 3',5'-cyclic adenosine phosphate (cAMP) generation was reduced by a high SNP concentration after 48 h. 8-Bromoguanosine 3',5'-cyclic monophosphate (8-Br-cGMP), a cGMP analog, inhibited iodide uptake as well as TPO and TG mRNA expression. The cGMP-dependent protein kinase (cGK) inhibitor KT-5823 reversed SNP or 8-Br-cGMP-inhibited iodide uptake. Thyroid-stimulating hormone pretreatment for 24-48 h prevented SNP-reduced iodide uptake although nitrite levels remained unaffected. CONCLUSION: These findings favor a long-term inhibitory role of the NO/cGMP pathway on parameters of thyroid hormone biosynthesis. A novel property of NO to inhibit TPO and TG mRNA expression is supported. The NO action on iodide uptake could involve cGK mediation. The long-term inhibition of steps of thyroid hormonogenesis by NO could be of interest in thyroid pathophysiology.     

From the Cover: Contrasting drivers of diversity in hosts and parasites across the tropical Andes

Geographic turnover in community composition is created and maintained by eco-evolutionary forces that limit the ranges of species. One such force may be antagonistic interactions among hosts and parasites, but its general importance is unknown. Understanding the processes that underpin turnover requires distinguishing the contributions of key abiotic and biotic drivers over a range of spatial and temporal scales. Here, we address these challenges using flexible, nonlinear models to identify the factors that underlie richness (alpha diversity) and turnover (beta diversity) patterns of interacting host and parasite communities in a global biodiversity hot spot. We sampled 18 communities in the Peruvian Andes, encompassing ∼1,350 bird species and ∼400 hemosporidian parasite lineages, and spanning broad ranges of elevation, climate, primary productivity, and species richness. Turnover in both parasite and host communities was most strongly predicted by variation in precipitation, but secondary predictors differed between parasites and hosts, and between contemporary and phylogenetic timescales. Host communities shaped parasite diversity patterns, but there was little evidence for reciprocal effects. The results for parasite communities contradicted the prevailing view that biotic interactions filter communities at local scales while environmental filtering and dispersal barriers shape regional communities. Rather, subtle differences in precipitation had strong, fine-scale effects on parasite turnover while host–community effects only manifested at broad scales. We used these models to map bird and parasite turnover onto the ecological gradients of the Andean landscape, illustrating beta-diversity hot spots and their mechanistic underpinnings.

Turnover in community composition across space, or “beta diversity,” reflects eco-evolutionary processes that determine range limits of species (1–3). These processes include adaptive specialization on particular habitats, barriers to dispersal, and interactions among species (4–6). Antagonistic interactions between hosts and parasites may have an underappreciated effect on turnover (7), as evidenced by the sensitivity of host populations to novel parasites. For example, introductions of avian malaria (Plasmodium relictum) and avian pox (Avipoxvirus) led to extinctions or range contractions for dozens of endemic Hawaiian honeycreeper species (8). Introduced parasites have also driven shifts in community composition when competing hosts differ in susceptibility to infection (9). While these cases highlight extreme impacts of parasites on host communities, it remains unclear whether host–parasite interactions generally drive turnover in continental faunas, whether such effects are reciprocal or unidirectional, and whether these interactions also impact diversity patterns at regional scales or over evolutionary time.A persistent challenge in studying the factors that underlie community assembly is that turnover is dynamic and exhibits nonlinear variation over space and time (10). As a result, different processes may underlie turnover, depending on the scale at which the community is defined (11–13). For instance, numerous studies have asserted that adaptive specialization on abiotic conditions and barriers to dispersal drive regional turnover patterns while biotic interactions filter communities locally (2, 14). Still, the spatial scales of these various processes are uncertain (11, 15, 16), and empirical tests are complicated by the fact that potential drivers of turnover tend to be spatially autocorrelated (17).To determine the drivers and scale of community turnover in complex systems, we need appropriate, nonlinear analytical tools. Generalized dissimilarity models (GDMs) are an extension of matrix regression that provides two notable innovations: 1) GDMs can incorporate various biotic and abiotic predictors into a single model, and 2) GDMs explicitly model the curvilinear relationship between community dissimilarity and ecological or geographic distance (4, 10, 18). This modeling framework is better suited than linear matrix regression to identifying key factors underlying turnover in complex environments (19–21). In addition, by incorporating phylogenetic measures of community diversity and similarity, we can use GDMs to test how drivers of turnover have varied over evolutionary time (22). Comparing “phylogenetic turnover” to species turnover allows us to distinguish deep-time processes that may restrict the ranges of clades from contemporary processes that may constrain the range limits of individual species (2). For example, evolutionary conservation of traits may exclude entire clades from certain habitats, leading to strong phylogenetic turnover over ecological gradients (3). Alternatively, if traits that underpin environmental associations are evolutionarily labile, species turnover will be higher than phylogenetic turnover and better predicted by ecological variation.The tropical Andes provide an ideal natural laboratory for investigating community turnover in response to biotic and abiotic changes in the environment. Habitable elevational gradients spanning more than 5,000 vertical meters encompass rapid changes in vegetation structure, temperature, atmospheric pressure, ultraviolet (UV) exposure, and precipitation (23, 24). The Andean cordillera generates broad orographic precipitation, but its complex topography also creates a patchwork of rain shadows. Rain-shadowed slopes and valleys fragment the ranges of humid and dry-adapted species, particularly those occurring at higher elevations (25–29). Environmental change across elevational gradients of the Andes is exceptionally rapid compared to change along axes parallel to the cordillera. As a result, spatial distance and environmental difference are decoupled. Pairs of communities separated by the same geographic distance may have similar or contrasting environments. In this way, this landscape provides the opportunity to pinpoint environmental effects on community turnover and distinguish them from the effects of dispersal limitation.The Andes are a global hot spot for species richness and turnover, evolutionary distinctness, and small-ranged species (30–33). Species interactions are thought to be particularly important in shaping Andean community turnover: For example, Andean birds are often highly specialized on particular habitats and resources (13, 34), and competitive exclusion is thought to further limit and reinforce range boundaries (7, 35–37). However, parasitism has received less attention as a driver of turnover compared to competition (35, 37) and bird–plant mutualisms (36, 38, 39). One important group that could affect bird turnover is the hemosporidians (Apicomplexa: Haemosporida), a diverse clade of vector-borne parasites in the genera Haemoproteus, Parahaemoproteus, Plasmodium, and Leucocytozoon (40, 41). These parasites can reduce the fitness of their hosts, even in low-level chronic infections (42), and are thought to have the potential to shape avian biogeographic patterns (40, 43). Hemosporidian communities in turn are thought to be influenced to varying degrees by host community, climate, and barriers to dispersal (44–51), but improved modeling frameworks with new data are needed to reciprocally test the causes of host and parasite turnover across biodiverse, tropical landscapes.In this study, we identified and compared the drivers of diversity in interacting bird and hemosporidian communities of the Peruvian Andes. First, we tested whether similar or different drivers affect host and parasite turnover; second, we tested how drivers of turnover vary with spatial scale; and third, we tested how drivers of turnover have changed over evolutionary time. Then, we used a complementary modeling approach to identify sources of variation in species richness among host and parasite communities, respectively. We used these models to map host and parasite turnover and richness to identify hot spots for faunal overlap and transition, critical zones for biodiversity study and protection.     

Novel Method for Real Time Co‐Registration of IVUS and Coronary Angiography

Objectives

We present our experience with a novel method for real time co‐registration of intravascular ultrasound (IVUS) and coronary angiography.

Background

A major limitation of the current practice of concomitant use of coronary angiography and IVUS is that the locations of the acquired IVUS images are not correlated with their exact locations on the vessel roadmap obtained by coronary angiography.

Methods

Phantoms simulating the coronary tree were used to test the accuracy and potential of co‐registration. Subsequently we examined patients who underwent IVUS during cardiac catheterization. Analysis and feasibility were performed in 42 arteries of 36 patients.

Results

The statistical validation in phantoms resulted in a co‐registration accuracy of 1.12 mm. The length measurement on an angiogram resulted in an accuracy of 0.38 mm. Co‐registration in patients was successful in all cases and four categories were assisted by 1(bad) to 5 (good) grading. Accuracy (the co‐registration precision in pointing at the exact corresponding location): 4.8±0.41; Ease of use and workflow: 4.74±0.44; Stent landing zone detection and evaluation: 4.58±0.5; Stent landing zone length and diameter measurement: 4.94±0.23. The co‐registration error was estimated as no more than 1 mm.

Conclusion

In this pilot study, we found that the novel IVUS and coronary angiography co‐registration method is accurate, easy to use, fast and user‐friendly. This method precludes the need to use motorized automated pull back device. (J Interven Cardiol 2016;29:225–231)

     

Current status and future opportunities for controlling acromegaly

Growth-hormone (GH) secreting adenomas, including acromegaly, account for approximately one-sixth of all pituitary adenomas and are associated with mortality rates at least twice that of the general population. The ultimate goal of therapy for acromegaly is normalization of morbidity and mortality rates achieved through removal or reduction of the tumor mass and normalization of insulin-like growth factor I (IGF-I) levels. Previously published efficacy results of current treatment modalities (surgery, conventional radiation, and medical therapy with dopamine agonists and somatostatin analogs) are often difficult to compare because of the different criteria used to define cure (some of which are now considered inadequate). For each of these modalities, pooled data from a series of acromegaly studies were reviewed for rates of IGF-I normalization, a currently accepted definition of cure. The results showed overall cure rates of approximately 10% for bromocriptine, 34% for cabergoline, 36% for conventional radiation, 50–90% for surgery for microadenomas and less than 50% for macroadenomas, and 54–66% for octreotide. These cure rates based on IGF-I normalization are generally less than those reported for cure based solely on GH levels. Novel new therapies for acromegaly include the somatostatin analog, lanreotide, Gamma Knife radiosurgery, and pegvisomant, the first in its class of new GH receptor antagonists. Although it does not appear that Gamma Knife radiosurgery results in significantly higher cure rates or fewer complications, it does provide a notable improvement in delivery compared with conventional radiation. Early studies have reported IGF-I normalization in 48% of lanreotide-treated patients and up to 97% of pegvisomant-treated.     

Comorbid Profile Rather than Age Determines Hip Fracture Mortality in a Nonagenarian Population

Background

In light of poor outcomes with nonoperative management of hip fractures, orthopedic surgeons are faced with difficult decisions about which patients are too ill or too old for surgical treatment.

Questions/Purposes

This study sought to investigate if patients over 90 years had different preoperative laboratory, clinical, and injury characteristics than younger patients with the same injury. We compared our cohort with previously published data. We wished to identify if there were pre-injury risk factors associated with 30-day mortality, which could be modified to enhance postoperative outcomes.

Methods

This is a retrospective review of 198 operatively managed hip fractures in patients 75 years or older. We collected data on demographics, select preoperative laboratory values, injury type, comorbidities, and 30-day mortality.

Results

Eleven (5.6%) of the cohort died within 30 days of surgery, 6.3% in the younger group, and 3.7% in the older group; the difference was not statistically significant. For baseline characteristics, there was no difference between the age groups for pre-injury comorbidities, hemoglobin, serum albumin, BUN, prevalence of UTI, or fracture type. A total of 67 (35.8%) patients had evidence of UTI on admission.

Conclusions

These findings reveal that in our dichotomized cohort, pre-injury characteristics were similar and age alone was not an independent predictor of mortality. These data may inform decision-making for orthopedic surgeons and the medical providers who consult to optimize these patients for surgery. We identified high rates of UTI in both age groups, a potentially remediable factor to optimize outcomes in hip fracture surgery in elderly patients.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-015-9435-y) contains supplementary material, which is available to authorized users.