427 research outputs found
The pulmonary surfactant system matures upon pipping in the freshwater turtle Chelydra serpentina
© The Company of BiologistsPulmonary surfactant (PS), a mixture of phospholipids (PL), neutral lipids and surfactant proteins (SP), lowers surface tension within the lung, which increases lung compliance and improves the removal of fluid at birth. Here, we have examined the expression of thyroid transcription factor-1 (TTF-1) and the surfactant protein SP-B, and also the composition of pulmonary surfactant lipids in the developing lung of the turtle Chelydra serpentina. Lavage and lung tissue were collected from late embryonic, pipped and hatchling turtles. TTF-1, a regulator of gene expression of surfactant proteins and cell differentiation in mammals, was detected using immunohistochemistry in epithelia of the gas-exchange area and conducting airways during late development. Expression declined in hatchlings. SP-B was detected in subsets of cells within the respiratory epithelium at all stages sampled. The same cell types also stained for TTF-1. Turtle surfactant lipids matured toward the end of incubation. Maximal secretion of both total phospholipids and disaturated phospholipid (DSP) occurred at the time of pipping, coincident with the onset of breathing. The DSP/PL ratio increased after pipping, whereas cholesterol levels (Chol) increased prior to pipping. This resulted in a decrease in the Chol/PL and Chol/DSP ratios after pipping. Thus, TTF-1 and SP-B appear to be highly conserved within the vertebrates. Maturation of surfactant phospholipid content occurred with the commencement of pulmonary ventilation.Sonya D. Johnston, Christopher B. Daniels, David Cenzato, Jeffrey A. Whitsett and Sandra Orgei
Feasibility of using Grindr™ to distribute HIV self-test kits to men who have sex with men in Los Angeles, California
Background: Our study aimed to determine if Grindr™ is an effective means of reaching high-risk men who have sex with men (MSM) for HIV testing. In Los Angeles (LA), Black and Latino MSM have the highest rate of HIV infection, and Black MSM in LA are four-fold more likely than white MSM to not know they are infected with HIV. Those MSM are also major users of social networking apps. Grindr™ was used to provide access to free HIV self-testing. Methods: Free HIV self-test kits were advertised on Grindr™ from 13 October to 11 November 2014, consisting of 300 000 banner ads and three broadcast messages targeting a high-risk HIV population in LA. Eligible participants, Black or Latino, MSM and who were aged ≥18 years of age, were invited to take a survey 2 weeks after test delivery. Results: The website received 4389 unique visitors and 333 test requests, of which 247 (74%) were requests for mailed tests, 58 (17%) were for vouchers and 28 (8%) were for vending machines. Of the 125 participants, 74% reported at least one episode of condomless anal intercourse in the past 3 months, 29% last tested for HIV over 1 year ago and 9% had never been tested. Conclusions: It was feasible to use Grindr™ to distribute HIV self-test kits. Users are willing to provide personal information in exchange for a free self-test and found self-tests acceptable and easy to use. HIV self-testing promotion through apps has a high potential to reach untested high-risk populations
Amelioration of Binge Eating by Nucleus Accumbens Shell Deep Brain Stimulation in Mice Involves D2 Receptor Modulation
Hedonic overconsumption contributing to obesity involves altered activation within the mesolimbic dopamine system. Dysregulation of dopamine signaling in the nucleus accumbens shell (NAS) has been implicated in reward-seeking behaviors, such as binge eating, which contributes to treatment resistance in obesity (Wise, 2012). Direct modulation of the NAS with deep brain stimulation (DBS), a surgical procedure currently under investigation in humans for the treatment of major depression, obsessive–compulsive disorder, and addiction, may also be effective in ameliorating binge eating. Therefore, we examined the ability of DBS of the NAS to block this behavior in mice. c-Fos immunoreactivity was assessed as a marker of DBS-mediated neuronal activation. NAS DBS was found to reduce binge eating and increased c-Fos levels in this region. DBS of the dorsal striatum had no influence on this behavior, demonstrating anatomical specificity for this effect. The dopamine D2 receptor antagonist, raclopride, attenuated the action of DBS, whereas the D1 receptor antagonist, SCH-23390, was ineffective, suggesting that dopamine signaling involving D2 receptors underlies the effect of NAS DBS. To determine the potential translational relevance to the obese state, chronic NAS DBS was also examined in diet-induced obese mice and was found to acutely reduce caloric intake and induce weight loss. Together, these findings support the involvement of the mesolimbic dopamine pathways in the hedonic mechanisms contributing to obesity, and the efficacy of NAS DBS to modulate this system
Combining Citizen Science and Genomics to Investigate Tick, Pathogen, and Commensal Microbiome at Single-Tick Resolution
The prevalence of tickborne diseases worldwide is increasing virtually unchecked due to the lack of effective control strategies. The transmission dynamics of tickborne pathogens are influenced by the tick microbiome, tick co-infection with other pathogens, and environmental features. Understanding this complex system could lead to new strategies for pathogen control, but will require large-scale, high-resolution data. Here, we introduce Project Acari, a citizen science-based project to assay, at single-tick resolution, species, pathogen infection status, microbiome profile, and environmental conditions of tens of thousands of ticks collected from numerous sites across the United States. In the first phase of the project, we collected more than 2,400 ticks wild-caught by citizen scientists and developed high-throughput methods to process and sequence them individually. Applying these methods to 192 Ixodes scapularis ticks collected in a region with a high incidence of Lyme disease, we found that 62% were colonized by Borrelia burgdorferi, the Lyme disease pathogen. In contrast to previous reports, we did not find an association between the microbiome diversity of a tick and its probability of carrying B. burgdorferi. However, we did find undescribed associations between B. burgdorferi carriage and the presence of specific microbial taxa within individual ticks. Our findings underscore the power of coupling citizen science with high-throughput processing to reveal pathogen dynamics. Our approach can be extended for massively parallel screening of individual ticks, offering a powerful tool to elucidate the ecology of tickborne disease and to guide pathogen-control initiatives
Iatrogenic Spinal Cord Injury Resulting From Cervical Spine Surgery.
STUDY DESIGN: Retrospective cohort study of prospectively collected data.
OBJECTIVE: To examine the incidence of iatrogenic spinal cord injury following elective cervical spine surgery.
METHODS: A retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network was conducted. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, were reviewed to identify occurrence of iatrogenic spinal cord injury.
RESULTS: In total, 3 cases of iatrogenic spinal cord injury following cervical spine surgery were identified. Institutional incidence rates ranged from 0.0% to 0.24%. Of the 3 patients with quadriplegia, one underwent anterior-only surgery with 2-level cervical corpectomy, one underwent anterior surgery with corpectomy in addition to posterior surgery, and one underwent posterior decompression and fusion surgery alone. One patient had complete neurologic recovery, one partially recovered, and one did not recover motor function.
CONCLUSION: Iatrogenic spinal cord injury following cervical spine surgery is a rare and devastating adverse event. No standard protocol exists that can guarantee prevention of this complication, and there is a lack of consensus regarding evaluation and treatment when it does occur. Emergent imaging with magnetic resonance imaging or computed tomography myelography to evaluate for compressive etiology or malpositioned instrumentation and avoidance of hypotension should be performed in cases of intraoperative and postoperative spinal cord injury
Prolonged Drying Trend Coincident with the Demise of Norse Settlement in Southern Greenland
Declining temperature has been thought to explain the abandonment of Norse settlements, southern Greenland, in the early 15th century, although limited paleoclimate evidence is available from the inner settlement region itself. Here, we reconstruct the temperature and hydroclimate history from lake sediments at a site adjacent to a former Norse farm. We find no substantial temperature changes during the settlement period but rather that the region experienced a persistent drying trend, which peaked in the 16th century. Drier climate would have notably reduced grass production, which was essential for livestock overwintering, and this drying trend is concurrent with a Norse diet shift. We conclude that increasingly dry conditions played a more important role in undermining the viability of the Eastern Settlement than minor temperature changes
Optimizing patient care and outcomes through the congenital heart center of the 21st century
Pediatric cardiovascular services are responding to the dynamic changes in the medical environment, including the business of medicine. The opportunity to advance our pediatric cardiology field through collaboration is now realized, permitting us to define meaningful quality metrics and establish national benchmarks through multicenter efforts. In March 2016, the American College of Cardiology hosted the first Adult Congenital/Pediatric Cardiology Section Congenital Heart Community Day. This was an open participation meeting for clinicians, administrators, patients/parents to propose metrics that optimize patient care and outcomes for a stateâ ofâ theâ art congenital heart center of the 21st century. Care center collaboration helps overcome the barrier of relative small volumes at any given program. Patients and families have become active collaborative partners with care centers in the definition of acute and longitudinal outcomes and our quality metrics. Understanding programmatic metrics that create an environment to provide outstanding congenital heart care will allow centers to improve their structure, processes and ultimately outcomes, leading to an increasing number of centers that provide excellent care. This manuscript provides background, as well listing of proposed specialty domain quality metrics for centers, and thus serves as an updated baseline for the ongoing dynamic process of optimizing care and realizing patient value.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143653/1/chd12575_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143653/2/chd12575.pd
Interpretation of positive troponin results among patients with and without myocardial infarction.
Measuring cardiac troponins is integral to diagnosing acute myocardial infarction (AMI); however, troponins may be elevated without AMI, and the use of multiple different assays confounds comparisons. We considered characteristics and serial troponin values in emergency department chest pain patients with and without AMI to interpret troponin excursions. We compared serial troponin in 124 AMI and non-AMI patients from the observational Performance of Triage Cardiac Markers in the Clinical Setting (PEARL) study who presented with chest pain and had at least one troponin value exceeding the 99th percentile of normal. Because 8 assays were used during data collection, we employed a method of scaling the troponin value to the corresponding assay\u27s 99th percentile upper reference limit to standardize the results. In 81 AMI patients, 96% had elevated troponin at the first test following initial elevation, compared to 73% of the 43 non-AMI patients
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