176 research outputs found
Characterization of a Feline Model of Factor XII Deficiency: The In Vivo Role of FXII in Vascular Injury and Inflammatory Responses
For nearly 6 decades scientists have been identifying and defining the many roles of the blood serine protease Factor XII (FXII) in vitro and in vivo. Each year we gain new information about this elusive protein, however conflicts still exist over the importance of FXII in human disease states. Factor XII participates in coagulation, fibrinolysis, renin angiotensin, and immune system responses making it an integral part of mammalian life. Animal models offer the best way to study the importance of a factor in vivo, however only two readily available FXII deficient models exist, i.e. the gene-manipulated mouse and our cats. This work characterizes the origin of the genetic defect causing FXII deficiency in a colony of domestic cats, and investigates in vivo acute responses to intravascular and intradermal (extravascular) injury. Ultimately we aim to provide a well defined animal model for therapeutic targeting strategies, and gain new insights into the importance of FXII in cellular and extracellular interactions. Chapter 1 provides a comprehensive overview of the biological features of FXII: its importance as a central player in coagulation, fibrinolysis, complement activation, the innate immune system, and vascular repair; its molecular and genetic structure and cellular interactions; and the attributed pathophysiology derived from human and mouse studies. Chapter 2 details the feline FXII gene and the mutation discovered in our colony along with protein studies to confirm our findings. Vascular injury and associated fibrinolytic and inflammatory response studies comprise Chapter 3. We found that FXII procoagulant activity is not necessary to initiate clotting and to form stable thrombi upon an initial venous or arterial injury. However, FXII appears to aid in clot stability following a second intravascular injury 48 hours later on the contralateral veins. Inflammatory mediators are also significantly reduced in FXII deficient animals. Chapter 4 addresses the role of FXII in recruiting inflammatory cells to a site of heme-induced skin injury. Our studies explore a new method of nitric-oxide driven innate immune response, finding significantly fewer inflammatory cell infiltrates in FXII deficient cats. Chapter 5 offers future studies to pursue with this model based on results of these dissertation findings
Resgate etnobotânico de plantas medicinais e validação da sua atividade antibacteriana
The use of plant is a common practice, especially for rural communities. One way to
get this data on medicinal plants is through ethnobotanical surveys. It is through
ethnobotany that seeks knowledge and the rescue of traditional knowledge
particularly related to the use of flora resources. The study aims to rescue the
ethnobotanical knowledge of informants on medicinal plants of Pelotas and Capão do
Leão and validate the in vitro antibacterial activity of the plants that hold this end,
against the major bacteria isolated from bovine udder with mastitis. An
ethnobotanical rescue with three informants was conducted. We identified 83 plant
species belonging to 40 botanical families, with the Asteraceae and Lamiaceae
families the most representative in number of species and the sheet of the most used
plant. Of the 83 plants identified, 26 were cited as antimicrobial and validated through
the microdilution technique in broth. There were 16 plants that have some
antibacterial action in the face of bacteria tested. We can conclude that the
informants use a wide variety of medicinal plants both in healing and in disease
prevention and the pariparoba species (Piper reginelli (Miq.) C. DC.) And bitch theta
(Zanthoxylum astrigerum (RSCowan) PG Waterman ) are the most promising among
the different and may be performed later in vivo studies with the purpose of
determining its effect on the prevention of bovine mastitis.Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superior - CAPESA utilização dos vegetais é uma prática usual, principalmente para as comunidades
rurais. Uma das formas de se obter esses dados sobre as plantas medicinais é
através de levantamentos etnobotânicos. É através da etnobotânica que se busca o
conhecimento e o resgate do saber tradicional particularmente relacionado ao uso
dos recursos da flora. O trabalho tem como objetivo resgatar o conhecimento
etnobotânico de informantes sobre plantas medicinais do municÃpio de Pelotas e
Capão do Leão e validar in vitro a ação antibacteriana das plantas que possuem
este fim, frente às principais bactérias isoladas do úbere bovino com mastite. Foi
realizado um resgate etnobotânico com três informantes. Foram identificadas 83
espécies vegetais distribuÃdas em 40 famÃlias botânicas, sendo as famÃlias
Asteraceae e Lamiaceae as de maior número de espécie sendo a folha a parte da
planta mais utilizada. Das 83 plantas identificadas, 26 foram citadas como
antimicrobianos e validadas através da Técnica de Microdiluição em Caldo. Foram
16 as espécies que apresentam alguma ação antibacteriana frente às bactérias
testadas. Podemos concluir que as informantes utilizam uma grande diversidade de
plantas medicinais tanto na cura como na prevenção das doenças e que as espécies
pariparoba (Piper regnellii (Miq.) C. DC.) e teta de cadela (Zanthoxylum astrigerum
(R.S.Cowan) P.G. Waterman) são as mais promissoras dentre as testadas, podendo
ser posteriormente realizados estudos in vivo com a finalidade de determinar sua
ação na prevenção da mastite bovina
Neurogenic factor-induced Langerhans cell activation in diabetic mice with mechanical allodynia
Abstract
Background
Langerhans cells (LCs) are antigen-presenting dendritic cells located in the skin. It has been reported that LC activation is associated with painful diabetic neuropathy (PDN); however, the mechanism of LC activation is still unclear.
Methods
The db/db mouse, a rodent model of PDN, was used to study the roles of LCs in the development of PDN in type 2 diabetes. Hind foot pads from db/db and control db/+ mice from 5 to 24 weeks of age (encompassing the period of mechanical allodynia development and its abatement) were collected and processed for immunohistochemistry studies. LCs were identified with immunohistochemistry using an antibody against CD207 (Langerin). The intraepidermal nerve fibers and subepidermal nerve plexus were identified by immunohistochemistry of protein gene product 9.5 (PGP 9.5) and tropomyosin-receptor kinase (Trk) A, the high affinity nerve growth factor receptor.
Results
CD207-positive LCs increased in the db/db mouse during the period of mechanical allodynia, from 8 to 10 weeks of age, in both the epidermis and subepidermal plexus. At 16 weeks of age, when mechanical allodynia diminishes, LC populations were reduced in the epidermis and subepidermal plexus. Epidermal LCs (ELCs) were positive for Trk A. Subepidermal LCs (SLCs) were positive for CD68, suggesting that they are immature LCs. Additionally, these SLCs were positive for the receptor of advanced glycation end products (RAGE) and were in direct contact with TNF-α-positive nerve fibers in the subepidermal nerve plexus during the period of mechanical allodynia. Intrathecal administration of SB203580, a p38 kinase inhibitor, significantly reduced mechanical allodynia, TNF-α expression in the subepidermal plexus, and increased both ELC and SLC populations during the period of mechanical allodynia.
Conclusions
Our data support the hypothesis that increased LC populations in PDN are activated by p38-dependent neurogenic factors and may be involved in the pathogenesis of PDN.http://deepblue.lib.umich.edu/bitstream/2027.42/135942/1/12974_2013_Article_838.pd
Neurogenic factor-induced Langerhans cell activation in diabetic mice with mechanical allodynia
Abstract
Background
Langerhans cells (LCs) are antigen-presenting dendritic cells located in the skin. It has been reported that LC activation is associated with painful diabetic neuropathy (PDN); however, the mechanism of LC activation is still unclear.
Methods
The db/db mouse, a rodent model of PDN, was used to study the roles of LCs in the development of PDN in type 2 diabetes. Hind foot pads from db/db and control db/+ mice from 5 to 24 weeks of age (encompassing the period of mechanical allodynia development and its abatement) were collected and processed for immunohistochemistry studies. LCs were identified with immunohistochemistry using an antibody against CD207 (Langerin). The intraepidermal nerve fibers and subepidermal nerve plexus were identified by immunohistochemistry of protein gene product 9.5 (PGP 9.5) and tropomyosin-receptor kinase (Trk) A, the high affinity nerve growth factor receptor.
Results
CD207-positive LCs increased in the db/db mouse during the period of mechanical allodynia, from 8 to 10 weeks of age, in both the epidermis and subepidermal plexus. At 16 weeks of age, when mechanical allodynia diminishes, LC populations were reduced in the epidermis and subepidermal plexus. Epidermal LCs (ELCs) were positive for Trk A. Subepidermal LCs (SLCs) were positive for CD68, suggesting that they are immature LCs. Additionally, these SLCs were positive for the receptor of advanced glycation end products (RAGE) and were in direct contact with TNF-α-positive nerve fibers in the subepidermal nerve plexus during the period of mechanical allodynia. Intrathecal administration of SB203580, a p38 kinase inhibitor, significantly reduced mechanical allodynia, TNF-α expression in the subepidermal plexus, and increased both ELC and SLC populations during the period of mechanical allodynia.
Conclusions
Our data support the hypothesis that increased LC populations in PDN are activated by p38-dependent neurogenic factors and may be involved in the pathogenesis of PDN.http://deepblue.lib.umich.edu/bitstream/2027.42/112392/1/12974_2013_Article_838.pd
Spatial mapping of hematopoietic clones in human bone marrow
UNLABELLED: Clonal hematopoiesis (CH) is the expansion of somatically mutated cells in the hematopoietic compartment of individuals without hematopoietic dysfunction. Large CH clones (i.e., \u3e2% variant allele fraction) predispose to hematologic malignancy, but CH is detected at lower levels in nearly all middle-aged individuals. Prior work has extensively characterized CH in peripheral blood, but the spatial distribution of hematopoietic clones in human bone marrow is largely undescribed. To understand CH at this level, we developed a method for spatially aware somatic mutation profiling and characterized the bone marrow of a patient with polycythemia vera. We identified the complex clonal distribution of somatic mutations in the hematopoietic compartment, the restriction of somatic mutations to specific subpopulations of hematopoietic cells, and spatial constraints of these clones in the bone marrow. This proof of principle paves the way to answering fundamental questions regarding CH spatial organization and factors driving CH expansion and malignant transformation in the bone marrow.
SIGNIFICANCE: CH occurs commonly in humans and can predispose to hematologic malignancy. Although well characterized in blood, it is poorly understood how clones are spatially distributed in the bone marrow. To answer this, we developed methods for spatially aware somatic mutation profiling to describe clonal heterogeneity in human bone marrow. See related commentary by Austin and Aifantis, p. 139
Adapting adaptive design methods to accelerate adoption of a digital asthma management intervention
Investigators conducting translational research in real-world settings may experience changes that create challenges to the successful completion of the trial as well as post-trial adoption and implementation. Adaptive designs support translational research by systematically adapting
content and methods to meet the needs of target populations, settings and contexts. This manuscript describes an adaptive implementation
research model that provides strategies for changing content, delivery processes, and research methods to correct course when anticipated and
unanticipated circumstances occur during a pragmatic trial. The Breathewell Program included two large pragmatic trials of the effectiveness
of a digital communication technology intervention to improve symptom management and medication adherence in asthma care. The first trial
targeted parents of children with asthma; the second targeted adults with asthma. Adaptations were made iteratively to adjust to dynamic conditions within the healthcare setting, informed by prospectively collected stakeholder input, and were categorized retrospectively by the authors
as proactive or reactive. Study outcomes demonstrated improved treatment adherence and clinical efficiency. Kaiser Permanente Colorado, the
setting for both studies, adopted the speech recognition intervention into routine care, however, both interventions required numerous adaptations, including changes to target population, intervention content, and internal workflows. Proactive and reactive adaptations assured that
both trials were successfully completed. Adaptive research designs will continue to provide an important pathway to move healthcare delivery
research into practice while conducting ongoing effectiveness evaluation.Ye
Transition to Virtual Asthma Care During the COVID-19 Pandemic: An Observational Study
BACKGROUND: The COVID-19 pandemic increased reliance
on virtual care for patients with persistent asthma.
OBJECTIVE: This retrospective cohort study assessed changes
from in-person to virtual care during the pandemic. In patients
with persistent asthma, compared with the same period before
the pandemic.
METHODS: Kaiser Permanente Colorado members aged 18 to
99 years with persistent asthma were evaluated during two
periods (March to October 2019 and March to October 2020).
Comparison of asthma exacerbations (hospitalizations,
emergency department visits, and courses of oral prednisone)
and asthma medication metrics were evaluated between the two
periods and by type of care received during the pandemic (no
care, virtual care only, in-person care only, or a mix of virtual
and in-person care). Population characteristics by type of care
received during the pandemic were also evaluated.
RESULTS: Among 7,805 adults with persistent asthma, those
who used more virtual care or sought no care during the
pandemic were younger and had fewer comorbidities, mental
health diagnoses, or financial barriers. Exacerbations decreased
(0.264 to 0.214; P <.001) as did courses of prednisone (0.213 to
0.169). Asthma medication adherence (0.53 to 0.54; P <.001)
and the asthma medication ratio, a quality-of-care metric (0.755
to 0.762; P [ .019), increased slightly. Patients receiving a mix
of in-person and virtual care had the highest rate of exacerbations (0.83) and a lower asthma medication ratio (0.74) despite
having the highest adherence (.57).
CONCLUSIONS: Despite an increase in virtual care, asthma
exacerbations decreased except among individuals who received
both in-person and virtual care, likely because they had more severe disease.Ye
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