30 research outputs found
Physiological basis for longitudinal motion of the arterial wall
As opposed to arterial distension in the radial plane, longitudinal wall motion (LWM) is a multiphasic and bidirectional displacement of the arterial wall in the anterograde (i.e., in the direction of blood flow) and retrograde (i.e., opposing direction of blood flow) directions. While initially disregarded as imaging artifact, LWM has been consistently reported in ultrasound investigations in the last decade and is reproducible beat-to-beat, albeit with large inter-individual variability across healthy and diseased populations. Emerging literature has sought to examine the mechanistic control of LWM to explain the shape and variability of the motion pattern but lacks considerations for key foundational vascular principles at the level of the arterial wall ultrastructure. The purpose of this review is to summarize the potential factors that underpin the causes and control of arterial LWM, spanning considerations from the arterial extracellular matrix to systems-level integrative theories. First, an overview of LWM and relevant aspects wall composition will be discussed, including major features of the multiphasic pattern, arterial wall extracellular components, tunica fiber orientations, and arterial longitudinal pre-stretch. Second, current theories on the systems-level physiological mechanisms driving LWM will be discussed in the context of available evidence including experimental human research, porcine studies, and mathematical models. Throughout, we discuss implications of these observations with suggestions for future priority research areas
Prophylactic anticoagulation to prevent venous thromboembolism in traumatic intracranial hemorrhage: a decision analysis
Abstract
Introduction
Patients with intracranial hemorrhage due to traumatic brain injury are at high risk of developing venous thromboembolism including deep vein thrombosis (DVT) and pulmonary embolism (PE). Thus, there is a trade-off between the risks of progression of intracranial hemorrhage (ICH) versus reduction of DVT/PE with the use of prophylactic anticoagulation. Using decision analysis modeling techniques, we developed a model for examining this trade-off for trauma patients with documented ICH.
Methods
The decision node involved the choice to administer or to withhold low molecular weight heparin (LMWH) anticoagulation prophylaxis at 24 hours. Advantages of withholding therapy were decreased risk of ICH progression (death, disabling neurologic deficit, non-disabling neurologic deficit), and decreased risk of systemic bleeding complications (death, massive bleed). The associated disadvantage was greater risk of developing DVT/PE or death. Probabilities for each outcome were derived from natural history studies and randomized controlled trials when available. Utilities were obtained from accepted databases and previous studies.
Results
The expected value associated with withholding anticoagulation prophylaxis was similar (0.90) to that associated with the LMWH strategy (0.89). Only two threshold values were encountered in one-way sensitivity analyses. If the effectiveness of LMWH at preventing DVT exceeded 80% (range from literature 33% to 82%) our model favoured this therapy. Similarly, our model favoured use of LMWH if this therapy increased the risk of ICH progression by no more than 5% above the baseline risk.
Conclusions
Our model showed no clear advantage to providing or withholding anticoagulant prophylaxis for DVT/PE prevention at 24 hours after traumatic brain injury associated with ICH. Therefore randomized controlled trials are justifiable and needed to guide clinicians
Desenvolvimento e modernidade versus trabalho: quais os impactos para a classe trabalhadora?
Objetivou-se analisar as implicações dos aspectos inerentes à modernidade e quais os impactos gerados para as classes trabalhadoras. O estudo necessitou de um aprofundamento teórico e bibliográfico, visando um maior entendimento das questões ligadas a esses impactos e de que forma as classes trabalhadoras seguem expostas a trabalhos precários, terceirização dos trabalhos, desemprego, subemprego e trabalho informal. Os impactos desta modernidade para as classes trabalhadores e para as relações de trabalho impostas pelo capital, só aumentam as discussões sobre as questões precárias de trabalho, ou seja, sobre as formas (modernas ou não) de dominação de uma classe articulada e poderosa, sobre outra, frágil e totalmente desarticulada. Para tanto, os procedimentos metodológicos utilizados são: pesquisa bibliográfica, documental com abordagem qualitativa e análise de conteúd
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Propositive follow-up: Long-term immune responses to the 4CMenB and MenACWY vaccines in people living with HIV.
BACKGROUND: People living with HIV have an increased risk of meningococcal disease. The Propositive trial evaluated co-administration of two doses of a four-component recombinant protein-based MenB vaccine (4CMenB) and a quadrivalent conjugate polysaccharide MenACWY vaccine (MenACWY-CRM197) given 1 month apart in people with HIV. The follow-up trial assessed the immunogenicity of these vaccines at 1.5 and 2.5 years after primary vaccination. METHODS: Participants who completed the parent Propositive trial were invited to the follow-up study. Immunogenicity analysis was performed at 18 and 30 months after primary vaccination. Primary outcome measures were serum bactericidal antibody (SBA) geometric mean titres (GMTs) against three MenB reference strains and the proportion of participants maintaining a protective SBA titre of ≥4 at 18 and 30 months. Secondary outcome measures were SBA GMTs against MenA, C, W, and Y serogroups and the proportion of participants maintaining a protective SBA titre of ≥8 at 18 and 30 months. The trial is registered with Clinicaltrials.gov (NCT042394300). RESULTS: A total of 40 participants aged 22-47 years were enrolled. Geometric mean titres waned by 18 and 30 months but remained higher than pre-vaccination for all MenB strains and MenA, C, W, and Y. In total, 75%-85% of participants retained protective SBA titres by 30 months against individual MenB strains, whereas 68.8% of patients retained protective antibody titres against all three MenB strains. Antibodies against MenC waned more rapidly than did those against MenA, W, and Y. The proportion of participants with protective titres against MenC at 30 months was also lower (46.9%) than that with protective titres against MenA (87.5%), W (78.1%), and Y (87.5%). CONCLUSIONS: Immune responses against MenB in our cohort of people living with HIV at 2.5 years of follow-up were reassuring, with 68.8% of participants retaining protection against all three reference strains. However, responses against MenC were lower than those against MenA, W, and Y serogroups
South Asian Stories: Elements of Culture and Faith
Children of the South Asian diaspora come from a vast variety of social, cultural, and religious backgrounds. Join author and New York Times\u27 Wirecutter journalist Kaitlyn Wells as she chats with three picture book authors of South Asian heritage about their experiences sharing aspects of culture and faith in the midst of storytelling. This session features members of KidLit in Color
Desenvolvimento e modernidade versus trabalho: quais os impactos para a classe trabalhadora?
This study aimed to analyze the implications of the aspects inherent to modernity and what the
impacts for the working classes . The
study required a theoretical and bibliographical deepening
, designed to further understanding of the issues associated with these impacts and how the
working classes follow exposed to precarious work , outsourcing of jobs, unemployment ,
underemployment
and informal work. The impacts of this modernity to the working classes and
working relations imposed by capital, only increase the discussions about the precarious issues of
work, that is , on ways ( modern or not) domination of an articulate and powerful
class , on another
, fragile and totally disjointed . To do so, the methodological procedures used are: bibliographical
, documentary research with a qualitative approach and content analysisObjetivou
-
se analisar as implicações dos aspectos inerentes Ã
modernidade e quais os impactos
gerados para as classes trabalhadoras. O estudo necessitou de um aprofundamento teórico e
bibliográfico, visando um maior entendimento das questões ligadas a esses impactos e de que
forma as classes trabalhadoras seguem exp
ostas a trabalhos precários, terceirização dos trabalhos,
desemprego, subemprego e trabalho informal. Os impactos desta modernidade para as classes
trabalhadores e para as relações de trabalho impostas pelo capital, só aumentam as discussões
sobre as quest
ões precárias de trabalho, ou seja, sobre as formas (modernas ou não) de dominação
de uma classe articulada e poderosa, sobre outra, frágil e totalmente desarticulada. Para tanto, os
procedimentos metodológicos utilizados são: pesquisa bibliográfica, docum
ental com abordagem
qualitativa e análise de conteúd
Leptospirosis in sugarcane plantation and fishing communities in Kagera northwestern Tanzania.
BackgroundLeptospirosis is a bacterial zoonotic disease of worldwide importance, though relatively neglected in many African countries including sub Saharan Africa that is among areas with high burden of this disease. The disease is often mistaken for other febrile illnesses such as dengue, malaria, rickettsioses and enteric fever. Leptospirosis is an occupational disease likely to affect people working in environments prone to infestation with rodents which are the primary reservoir hosts of this disease. Some of the populations at risk include: sugarcane plantation workers, wetland farmers, fishermen and abattoir workers. In this study we investigated the prevalence of antibodies against Leptospira among sugarcane plantation and factory workers, fishing communities as well as among rodents and shrews in domestic and peridomestic environments within the study areas.MethodsThe study was conducted in Kagera region, northwestern Tanzania and it involved sugarcane plantation workers (cutters and weeders), sugar factory workers and the fishing community at Kagera Sugar Company in Missenyi district and Musira island in Lake Victoria, Kagera, respectively. Blood was collected from consenting human adults, and from rodents and shrews (insectivores) captured live using Sherman traps. Serological detection of leptospiral antibodies in blood serum was carried out by the microscopic agglutination test (MAT).ResultsA total of 455 participants were recruited from the sugarcane plantation (n = 401) and fishing community (n = 54) while 31 rodents and shrews were captured. The overall prevalence of antibodies against Leptospira in human was 15.8%. Sugarcane cutters had higher seroprevalence than other sugar factory workers. Prevalent antibodies against Leptospira serovars in humans were against serovars Lora (6.8%), Sokoine (5.3%), Pomona (2.4%), Hebdomadis (1.1%) and Kenya (0.2%). Detected leptospiral serovars in reservoir hosts were Sokoine (12.5%) and Grippotyphosa (4.2%). Serovar Sokoine was detected both in humans and small mammals.ConclusionLeptospirosis is a public health threat affecting populations at risk, such as sugarcane plantation workers and fishing communities. Public awareness targeting risk occupational groups is much needed for mitigation of leptospirosis in the study areas and other vulnerable populations in Tanzania and elsewhere
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The propositive study: Immunogenicity and safety of a four-component recombinant protein-based vaccine against MenB and a quadrivalent conjugate MenACWY vaccine in people living with HIV.
BACKGROUND: People living with HIV have been shown to have an increased risk of invasive meningococcal disease. In some countries, meningococcal vaccines are now routinely recommended to all people living with HIV, but no study has yet assessed the immunogenicity and safety of a meningococcal serogroup B vaccine or the co-administration of a MenB and MenACWY vaccine in people living with HIV. METHODS: This phase IV open-label clinical trial investigated the immunogenicity and safety of two doses of a four-component recombinant protein-based MenB vaccine (4CMenB) and a quadrivalent conjugate polysaccharide MenACWY vaccine (MenACWY-CRM197) given 1 month apart in a population of people living with HIV. Immunogenicity analysis was performed before vaccination and 1 month after the second doses of 4CMenB and MenACWY. Primary outcome measures were serum bactericidal assay geometric mean titres against three MenB reference strains at baseline and 1 month post vaccination, the proportion of participants achieving a putative protective titre of ≥4, and the proportion of participants with a ≥4-fold rise in titre from baseline. Secondary outcome measures were serum bactericidal assay geometric mean titres against MenA, C, W, and Y reference strains at baseline and 1 month post vaccination, the proportion achieving a putative protective titre of ≥8, and the proportion with a ≥4-fold rise in titre from baseline. Safety outcomes were solicited and unsolicited adverse events in the 7 days following vaccination. The trial was registered with clinicaltrials.gov (NCT03682939). FINDINGS: In total, 55 participants aged 20-45 years were enrolled. All participants (100%; 95% confidence interval [CI] 93-100) achieved putative protective titres for two of the three MenB strains and for MenA, W, and Y. A total of 98% (95% CI 89-100) achieved a protective titre for the third MenB strain and 94% (95% CI 83-99) for MenC. No serious adverse events were reported. INTERPRETATION: 4CMenB and MenACWY were immunogenic and well-tolerated in a population of people living with HIV 1 month after two doses
AGDISTIS - agnostic disambiguation of named entities using linked open data
Over the last decades, several billion Web pages have been made available on the Web. The ongoing transition from the current Web of unstructured data to the Data Web yet requires scalable and accurate approaches for the extraction of structured data in RDF (Resource Description Framework) from these websites. One of the key steps towards extracting RDF from text is the disambiguation of named entities. We address this issue by presenting AGDISTIS, a novel knowledge-base-agnostic approach for named entity disambiguation. Our approach combines the Hypertext-Induced Topic Search (HITS) algorithm with label expansion strategies and string similarity measures. Based on this combination, AGDISTIS can efficiently detect the correct URIs for a given set of named entities within an input text
Group B Streptococcus (GBS) colonisation is dynamic over time, whilst GBS capsular polysaccharides-specific antibody remains stable.
Group B Streptococcus (GBS) is a leading cause of adverse pregnancy outcomes due to invasive infection. This study investigated longitudinal variation in GBS rectovaginal colonisation, serum and vaginal GBS capsular polysaccharide (CPS)-specific antibody levels. Non-pregnant women were recruited in the UK, and were sampled every two weeks over a 12-week period. GBS isolates were taken from recto-vaginal swabs and serotyped by polymerase chain reaction. Serum and vaginal immunoglobulin G (IgG) and nasal immunoglobulin A (IgA) specific to CPS were measured by Luminex, and total IgG/A by ELISA. 70 women were enrolled, of median age 26. Out of the 66 participants who completed at least three visits: 14/47 (29.8%) women that were GBS negative at screening became positive in follow up visits and 16/19 (84.2%) women who were GBS positive at screening became negative. There was 50% probability of becoming negative 36 days after the first positive swab. The rate of detectable GBS carriage fluctuated over time, although serum, vaginal and nasal CPS-specific antibody levels remained constant. Levels of CPS-specific antibodies were higher in the serum of individuals colonised with GBS than in non-colonised, but similar in the vaginal and nasal mucosa. We found correlations between antibody levels in serum and the vaginal and nasal mucosa. Our study demonstrates the feasibility of elution methods to retrieve vaginal and nasal antibodies, and the optimisation of immunoassays to measure GBS-CPS specific antibodies. The difference between the dynamics of colonisation and antibody response is interesting and further investigation is required for vaccine development