379 research outputs found
Case Report Subclavian Artery Pseudoaneurysm Formation 3 Months after a Game of Rugby Union
Pseudoaneurysms of the subclavian artery remain a rare complication after fracture of the clavicle. We report a case of delayed diagnosis of a subclavian artery pseudoaneurysm after a closed fracture of the clavicle in a 15-year-old patient, 3 months after the original injury while playing rugby union. Despite several attendances to the Emergency Department with vague symptoms, the final diagnosis was confirmed by duplex ultrasound and Computed Tomography of the thorax. Surgical repair was indicated due to acute limb ischaemia from distal embolisation from a large pseudoaneurysm, with the patient making a full recovery. This case highlights the need for clinical vigilance when assessing patients, particularly on repeated occasions when their recovery appears to be impaired. A thorough history and clinical examination can raise suspicion of even rare occurrences and aid prompt management. Case Report A 15-year-old boy attended the Emergency Department (ED) with a short history of a pale left arm. He denied pain but complained of some altered sensation throughout his left hand. He had a significant recent medical history, having suffered a fractured midshaft of his left clavicle (see Physical examination on his final visit revealed a warm but pale arm with no radial, ulnar, or brachial pulses palpable, but a normal capillary refill time of 2 seconds, and a reduced power in his intrinsic muscles of his left hand, but normal peripheral neurovascular examinations in remaining limbs and an electrocardiograph showing sinus rhythm. Chest Xray confirmed no cervical ribs. A duplex ultrasound scan showed a loss of flow in the brachial artery below the left elbow, with thrombus partially occluding the artery. Also noted was a 3 cm abnormality in the left subclavian artery that was thought to be a subclavian aneurysm that contained thrombus. Subsequent Computed Tomography (CT) of the thorax Transfer was arranged that day to the local acute vascular surgeon on call, where he underwent a subclavian-axillary bypass and brachial embolectomy. After 4 days of recovery as an inpatient including a heparin infusion he was discharged, symptom-free. Discussion The annual incidence rate of clavicular fractures is estimated to be between 30 and 60 cases per 100,000 peopl
Cooperative virulence can emerge via horizontal gene transfer but is stabilized by transmission
Intestinal inflammation fuels Salmonella Typhimurium ( S .Tm) transmission despite a fitness cost associated with the expression of virulence. Cheater mutants can emerge that profit from inflammation without enduring this cost. Intestinal virulence in S .Tm is therefore a cooperative trait, and its evolution a conundrum. Horizontal gene transfer (HGT) of cooperative alleles may facilitate the emergence of cooperative virulence, despite its instability. To test this hypothesis, we cloned hilD , coding for a master regulator of virulence, into a conjugative plasmid that is highly transferrable during intestinal colonization. We demonstrate that virulence can emerge by hilD transfer between avirulent strains in vivo . However, this was indeed unstable and hilD mutant cheaters arose within a few days. The timing of cheater emergence depended on the cost. We further show that stabilization of cooperative virulence in S .Tm is dependent on transmission dynamics, strengthened by population bottlenecks, leading cheaters to extinction and allowing cooperators to thrive
Software Transactional Memory, OpenMP and Pthread implementations of the Conjugate Gradients Method - a Preliminary Evaluation
This paper shows the runtime and cache-efficiency of parallel implementations of the Conjugate Gradients Method based on the three paradigms Software Transactional Memory (STM), OpenMP and Pthreads. While the two last named concepts are used to manage parallelization as well as synchronization, STM was designed to handle only the latter. In our work we disclose that an improved cache efficiency does not necessarily lead to a better execution time because the execution time is dominated by the thread wait time at the barriers
In situ measurement of bovine serum albumin interaction with gold nanospheres
Here we present in situ observations of adsorption of bovine serum albumin (BSA) on citratestabilized
gold nanospheres. We implemented scattering correlation spectroscopy as a tool to
quantify changes in the nanoparticle Brownian motion resulting from BSA adsorption onto the
nanoparticle surface. Protein binding was observed as an increase in the nanoparticle
hydrodynamic radius. Our results indicate the formation of a protein monolayer at similar albumin
concentrations as those found in human blood. Additionally, by monitoring the frequency and
intensity of individual scattering events caused by single gold nanoparticles passing the
observation volume, we found that BSA did not induce colloidal aggregation, a relevant result
from the toxicological viewpoint. Moreover, to elucidate the thermodynamics of the gold
nanoparticle-BSA association, we measured an adsorption isotherm which was best described by
an anti-cooperative binding model. The number of binding sites based on this model was
consistent with a BSA monolayer in its native state. In contrast, experiments using poly-ethylene
glycol capped gold nanoparticles revealed no evidence for adsorption of BSA
Results from the national sepsis practice survey: predictions about mortality and morbidity and recommendations for limitation of care orders
Introduction:
Critically ill patients and families rely upon physicians to provide estimates of prognosis and recommendations for care. Little is known about patient and clinician factors which influence these predictions. The association between these predictions and recommendations for continued aggressive care is also understudied.
Methods:
We administered a mail-based survey with simulated clinical vignettes to a random sample of the Critical Care Assembly of the American Thoracic Society. Vignettes represented a patient with septic shock with multi-organ failure with identical APACHE II scores and sepsis-associated organ failures. Vignettes varied by age (50 or 70 years old), body mass index (BMI) (normal or obese) and co-morbidities (none or recently diagnosed stage IIA lung cancer). All subjects received the vignettes with the highest and lowest mortality predictions from pilot testing and two additional, randomly selected vignettes. Respondents estimated outcomes and selected care for each hypothetical patient.
Results:
Despite identical severity of illness, the range of estimates for hospital mortality (5th to 95th percentile range, 17% to 78%) and for problems with self-care (5th to 95th percentile range, 2% to 74%) was wide. Similar variation was observed when clinical factors (age, BMI, and co-morbidities) were identical. Estimates of hospital mortality and problems with self-care among survivors were significantly higher in vignettes with obese BMIs (4.3% and 5.3% higher, respectively), older age (8.2% and 11.6% higher, respectively), and cancer diagnosis (5.9% and 6.9% higher, respectively). Higher estimates of mortality (adjusted odds ratio 1.29 per 10% increase in predicted mortality), perceived problems with self-care (adjusted odds ratio 1.26 per 10% increase in predicted problems with self-care), and early-stage lung cancer (adjusted odds ratio 5.82) were independently associated with recommendations to limit care.
Conclusions:
The studied clinical factors were consistently associated with poorer outcome predictions but did not explain the variation in prognoses offered by experienced physicians. These observations raise concern that provided information and the resulting decisions about continued aggressive care may be influenced by individual physician perception. To provide more reliable and accurate estimates of outcomes, tools are needed which incorporate patient characteristics and preferences with physician predictions and practices
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