1,255 research outputs found
The Ethical Review of Health Care Quality Improvement Initiatives: Findings From the Field
Based on surveys, examines the review mechanisms of quality improvement initiatives, including frequency; type, such as use of independent review boards; and consideration for ethical issues such as minimal risk and patient privacy and confidentiality
Spontaneous Iliopsoas Hematoma following Microvascular Free Tissue Transfer.
Spontaneous hematoma within the iliopsoas muscle (SIH) is a rare complication most commonly seen in coagulopathic patients. Often, patients undergoing microvascular free tissue transfer are anticoagulated for anastomotic patency. Here we describe two cases of postoperative SIH following contralateral anterolateral thigh (ALT) free tissue transfer for reconstruction of oncologic head and neck defects. Both patients described hip pain after mobilization and had a corresponding acute blood loss anemia. Diagnosis of SIH was confirmed by CT and both patients were managed conservatively. Given that anticoagulation is a common practice following head and neck free tissue transfer, surgeons should be aware of this potential complication
{beta}3GnT2 Maintains Adenylyl Cyclase-3 Signaling and Axon Guidance Molecule Expression in the Olfactory Epithelium
In the olfactory epithelium (OE), odorant receptor stimulation generates cAMP signals that function in both odor detection and the regulation of axon guidance molecule expression. The enzyme that synthesizes cAMP, adenylyl cyclase 3 (AC3), is coexpressed in olfactory sensory neurons (OSNs) with poly-N-acetyllactosamine (PLN) oligosaccharides determined by the glycosyltransferase beta3GnT2. The loss of either enzyme results in similar defects in olfactory bulb (OB) innervation and OSN survival, suggesting that glycosylation may be important for AC3 function. We show here that AC3 is extensively modified with N-linked PLN, which is essential for AC3 activity and localization. On Western blots, AC3 from the wild-type OE migrates diffusely as a heavily glycosylated 200 kDa band that interacts with the PLN-binding lectin LEA. AC3 from the beta3GnT2(-/-) OE loses these PLN modifications, migrating instead as a 140 kDa glycoprotein. Furthermore, basal and forskolin-stimulated cAMP production is reduced 80-90% in the beta3GnT2(-/-) OE. Although AC3 traffics normally to null OSN cilia, it is absent from axon projections that aberrantly target the OB. The cAMP-dependent guidance receptor neuropilin-1 is also lost from beta3GnT2(-/-) OSNs and axons, while semaphorin-3A ligand expression is upregulated. In addition, kirrel2, a mosaically expressed adhesion molecule that functions in axon sorting, is absent from beta3GnT2(-/-) OB projections. These results demonstrate that PLN glycans are essential in OSNs for proper AC3 localization and function. We propose that the loss of cAMP-dependent guidance cues is also a critical factor in the severe axon guidance defects observed in beta3GnT2(-/-) mice
Risk factors for otitis media in children with special emphasis on the role of colonization with bacterial airway pathogens: the Generation R study
Acute otitis media is the most frequent diagnosis in children visiting physicians’ offices. Risk factors for otitis media have been widely studied. Yet, the correlation between bacterial carriage and the development of otitis media is not entirely clear. Our aim was to study in a population-based prospective cohort the risk factors for otitis media in the second year of life with special emphasis on the role of colonization with Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. The study was embedded in the Generation R Study. Data on risk factors and doctor-diagnosed otitis media were obtained by midwives, hospital registries and postal questionnaires in the whole cohort (n = 7,295). Nasopharyngeal swabs were obtained at the age of 1.5, 6 and 14 months in the focus cohort (n = 1,079). Of these children, 2,515 (47.2%) suffered at least one period of otitis media in their second year of life. The occurrence of otitis media during the follow-up period in the first 6 months of life and between 6 and 12 months of age was associated with the risk of otitis media in the second year of life (aOR, 1.83 95% CI 1.24–2.71 and aOR 2.72, 95% CI 2.18–3.38, respectively). Having siblings was associated with an increased risk for otitis media in the second year of life (aOR 1.42, 95% CI 1.13–1.79). No associations were found between bacterial carriage in the first year of life and otitis media in the second year of life. In our study, otitis media in the first year of life is an independent risk factor for otitis media in the second year of life. Surprisingly, bacterial carriage in the first year of life did not add to this risk. Moreover, no association was observed between bacterial carriage in the first year of life and otitis in the second year of life
A categorical foundation for Bayesian probability
Given two measurable spaces and with countably generated
-algebras, a perfect prior probability measure on and a
sampling distribution , there is a corresponding inference
map which is unique up to a set of measure zero. Thus,
given a data measurement , a posterior probability
can be computed. This procedure is iterative: with
each updated probability , we obtain a new joint distribution which in
turn yields a new inference map and the process repeats with each
additional measurement. The main result uses an existence theorem for regular
conditional probabilities by Faden, which holds in more generality than the
setting of Polish spaces. This less stringent setting then allows for
non-trivial decision rules (Eilenberg--Moore algebras) on finite (as well as
non finite) spaces, and also provides for a common framework for decision
theory and Bayesian probability.Comment: 15 pages; revised setting to more clearly explain how to incorporate
perfect measures and the Giry monad; to appear in Applied Categorical
Structure
Olfactory discrimination largely persists in mice with defects in odorant receptor expression and axon guidance
<p>Abstract</p> <p>Background</p> <p>The defining feature of the main olfactory system in mice is that each olfactory sensory neuron expresses only one of more than a thousand different odorant receptor genes. Axons expressing the same odorant receptor converge onto a small number of targets in the olfactory bulb such that each glomerulus is made up of axon terminals expressing just one odorant receptor. It is thought that this precision in axon targeting is required to maintain highly refined odor discrimination. We previously showed that β3GnT2<sup>−/−</sup> mice have severe developmental and axon guidance defects. The phenotype of these mice is similar to adenylyl cyclase 3 (AC3) knockout mice largely due to the significant down-regulation of AC3 activity in β3GnT2<sup>−/−</sup> neurons.</p> <p>Results</p> <p>Microarray analysis reveals that nearly one quarter of all odorant receptor genes are down regulated in β3GnT2<sup>−/−</sup> mice compared to controls. Analysis of OR expression by quantitative PCR and <it>in situ</it> hybridization demonstrates that the number of neurons expressing some odorant receptors, such as mOR256-17, is increased by nearly 60% whereas for others such as mOR28 the number of neurons is decreased by more than 75% in β3GnT2<sup>−/−</sup> olfactory epithelia. Analysis of axon trajectories confirms that many axons track to inappropriate targets in β3GnT2<sup>−/−</sup> mice, and some glomeruli are populated by axons expressing more than one odorant receptor. Results show that mutant mice perform nearly as well as control mice in an odor discrimination task. In addition, <it>in situ</it> hybridization studies indicate that the expression of several activity dependent genes is unaffected in β3GnT2<sup>−/−</sup> olfactory neurons.</p> <p>Conclusions</p> <p>Results presented here show that many odorant receptors are under-expressed in β3GnT2<sup>−/−</sup> mice and further demonstrate that additional axon subsets grow into inappropriate targets or minimally innervate glomeruli in the olfactory bulb. Odor evoked gene expression is unchanged and β3GnT2<sup>−/−</sup> mice exhibit a relatively small deficit in their ability to discriminate divergent odors. Results suggest that despite the fact that β3GnT2<sup>−/−</sup> mice have decreased AC3 activity, decreased expression of many ORs, and display many axon growth and guidance errors, odor-evoked activity in cilia of mutant olfactory neurons remains largely intact.</p
Delayed expression of cell cycle proteins contributes to astroglial scar formation and chronic inflammation after rat spinal cord contusion
Background
Traumatic spinal cord injury (SCI) induces secondary tissue damage that is associated with astrogliosis and inflammation. We previously reported that acute upregulation of a cluster of cell-cycle-related genes contributes to post-mitotic cell death and secondary damage after SCI. However, it remains unclear whether cell cycle activation continues more chronically and contributes to more delayed glial change. Here we examined expression of cell cycle-related proteins up to 4 months following SCI, as well as the effects of the selective cyclin-dependent kinase (CDKs) inhibitor CR8, on astrogliosis and microglial activation in a rat SCI contusion model. Methods
Adult male rats were subjected to moderate spinal cord contusion injury at T8 using a well-characterized weight-drop model. Tissue from the lesion epicenter was obtained 4 weeks or 4 months post-injury, and processed for protein expression and lesion volume. Functional recovery was assessed over the 4 months after injury. Results
Immunoblot analysis demonstrated a marked continued upregulation of cell cycle-related proteins − including cyclin D1 and E, CDK4, E2F5 and PCNA − for 4 months post-injury that were highly expressed by GFAP+ astrocytes and microglia, and co-localized with inflammatory-related proteins. CR8 administrated systemically 3 h post-injury and continued for 7 days limited the sustained elevation of cell cycle proteins and immunoreactivity of GFAP, Iba-1 and p22PHOX − a key component of NADPH oxidase − up to 4 months after SCI. CR8 treatment significantly reduced lesion volume, which typically progressed in untreated animals between 1 and 4 months after trauma. Functional recovery was also significantly improved by CR8 treatment after SCI from week 2 through week 16. Conclusions
These data demonstrate that cell cycle-related proteins are chronically upregulated after SCI and may contribute to astroglial scar formation, chronic inflammation and further tissue loss
Outcomes of deep hypothermic circulatory arrest in pediatric cardiac surgery: A single center experience
AbstractBackgroundDeep hypothermic circulatory arrest (DHCA) is a technique used in the repair of complex congenital cardiac lesions that require aortic arch or pulmonary vein repair. DHCA has been linked to adverse outcomes and neurologic complications. Selective cerebral perfusion (SCP) may be added to DHCA to prevent neurological complication. Air embolism and hyperperfusion injury may be encountered. The aim of this study was to evaluate the safety and efficacy of simple DHCA and to outline the early outcomes especially the neurological ones.MethodsTwenty nine patients underwent surgical repair of congenital cardiac lesion with DHCA at a single institution from January 2010 to November 2015. DHCA was conducted with a target esophageal temperature of 18° and placement of an ice pack on the head. No selective perfusion was done. Demographic, operative and postoperative data were reviewed. Mortality, any neurological complications including seizers, coma, and stroke were recorded.ResultsThe mean age was 20.6 ± 8.2 months (range: 9 days to 154 months). The majority were males (20, 69%). The mean weight was 5.57 ± 4.2 kg (range: 2.3–17.5 kg). DHCA time was 20.03 min (range 3–52 min). There were three (10.3%) deaths. Two deaths occurred after Norwood operation, and one after interrupted aortic arch repair. None of the deaths were related to neurological injury. None of the patients developed seizers, coma, abnormal movement or neurological deficits.ConclusionsSimple DHCA without SCP is a safe, expeditious and reliable method for brain protection during repair of complex cardiac lesions, with acceptable outcomes
Perivascular Expression and Potent Vasoconstrictor Effect of Dynorphin A in Cerebral Arteries
BACKGROUND: Numerous literary data indicate that dynorphin A (DYN-A) has a significant impact on cerebral circulation, especially under pathophysiological conditions, but its potential direct influence on the tone of cerebral vessels is obscure. The aim of the present study was threefold: 1) to clarify if DYN-A is present in cerebral vessels, 2) to determine if it exerts any direct effect on cerebrovascular tone, and if so, 3) to analyze the role of κ-opiate receptors in mediating the effect. METHODOLOGY/PRINCIPAL FINDINGS: Immunohistochemical analysis revealed the expression of DYN-A in perivascular nerves of rat pial arteries as well as in both rat and human intraparenchymal vessels of the cerebral cortex. In isolated rat basilar and middle cerebral arteries (BAs and MCAs) DYN-A (1-13) and DYN-A (1-17) but not DYN-A (1-8) or dynorphin B (DYN-B) induced strong vasoconstriction in micromolar concentrations. The maximal effects, compared to a reference contraction induced by 124 mM K(+), were 115±6% and 104±10% in BAs and 113±3% and 125±9% in MCAs for 10 µM of DYN-A (1-13) and DYN-A (1-17), respectively. The vasoconstrictor effects of DYN-A (1-13) could be inhibited but not abolished by both the κ-opiate receptor antagonist nor-Binaltorphimine dihydrochloride (NORBI) and blockade of G(i/o)-protein mediated signaling by pertussis toxin. Finally, des-Tyr(1) DYN-A (2-13), which reportedly fails to activate κ-opiate receptors, induced vasoconstriction of 45±11% in BAs and 50±5% in MCAs at 10 µM, which effects were resistant to NORBI. CONCLUSION/SIGNIFICANCE: DYN-A is present in rat and human cerebral perivascular nerves and induces sustained contraction of rat cerebral arteries. This vasoconstrictor effect is only partly mediated by κ-opiate receptors and heterotrimeric G(i/o)-proteins. To our knowledge our present findings are the first to indicate that DYN-A has a direct cerebral vasoconstrictor effect and that a dynorphin-induced vascular action may be, at least in part, independent of κ-opiate receptors
A Developmental Perspective on Underage Alcohol Use
Underage alcohol use can be viewed as a developmental phenomenon because many kinds of developmental changes and expectations appear to influence this behavior and also because it has consequences for development. Data on alcohol use, abuse, and dependence show clear age-related patterns. Moreover, many of the effects that alcohol use has on the drinker, in both the short and long term, depend on the developmental timing of alcohol use or exposure. Finally, many developmental connections have been observed in the risk and protective factors that predict the likelihood of problem alcohol use in young people. Therefore, efforts to understand and address underage drinking would benefit from a developmental perspective, and the general principles of developmental psychopathology offer a useful conceptual framework for research and prevention concerned with underage drinking. KEY WORDS: Underage drinking; child; adolescent; alcohol and other drug (AOD) use, abuse, and dependence; AOD use initiation; age of AOD use onset; growth and development; biological development; psychological development; developmental psychopathology; risk and protective factors; genetic factors; environmental factors; AOD effects and consequencesPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65129/1/UM 51, Masten 2009, A developmental perspective on underage alcohol use, Alcohol Research and Health.pd
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