4,374 research outputs found
Aerobic fitness impacts sympathoadrenal axis responses to concurrent challenges
The combination of mental and physical challenges can elicit exacerbated cardiorespiratory (CR) and catecholamine responses above that of a single challenge alone.
Purpose
This study examined the effects of a combination of acute mental challenges and physical stress on cardiorespiratory and catecholamine responses.
Method
Eight below-average fitness (LF VO2max = 36.58 +/- 3.36 ml(-1) kg(-1) min(-1)) and eight above-average fitness (HF VO2max = 51.18 +/- 2.09 ml(-1) kg(-1) min(-1)) participants completed an exercise-alone condition (EAC) session consisting of moderate-intensity cycling at 60% VO2max for 37 min, and a dual-challenge condition (DCC) that included concurrent participation in mental challenges while cycling.
Result
The DCC resulted in increases in perceived workload, CR, epinephrine, and norepinephrine responses overall. HF participants had greater absolute CR and catecholamine responses compared to LF participants and quicker HR recovery after the dual challenge.
Conclusion
These findings demonstrate that cardiorespiratory fitness does impact the effect of concurrent stressors on CR and catecholamine responses
Bacterial Cholangitis, Cholecystitis, or both in Dogs
BACKGROUND: Bacterial cholangitis and cholecystitis are rarely reported, poorly characterized diseases in the dog. OBJECTIVES: To characterize the clinical features of these conditions. ANIMALS: Twentyâseven clientâowned dogs with bacterial cholangitis, cholecystitis, or both. METHODS: Multicenter, retrospective cases series of dogs with bacterial cholangitis, cholecystitis, or both, presenting January 2000 to June 2011 to 4 Veterinary Schools in Ireland/United Kingdom. Interrogation of hospital databases identified all cases with the inclusion criteria; histopathologically confirmed cholangitis or cholecystitis and bile culture/cytology results supporting a bacterial etiology. RESULTS: Twentyâseven dogs met the inclusion criteria with approximately 460 hepatitis cases documented over the same study period. Typical clinical pathology findings were increases in liver enzyme activities (25/26), hyperbilirubinemia (20/26), and an inflammatory leukogram (21/24). Ultrasound findings, although nonspecific, aided decisionâmaking in 25/26 cases. The most frequent hepatobiliary bacterial isolates were Escherichia coli (n = 17; 16 cases), Enterococcus spp. (n = 8; 6 cases), and Clostridium spp. (n = 5; 5 cases). Antimicrobial resistance was an important feature of aerobic isolates; 10/16 E. coli isolates resistant to 3 or more antimicrobial classes. Biliary tract rupture complicated nearly one third of cases, associated with significant mortality (4/8). Discharged dogs had a guarded to fair prognosis; 17/18 alive at 2 months, although 5/10 reâevaluated had persistent liver enzyme elevation 2â12 months later. CONCLUSION AND CLINICAL SIGNIFICANCE: Bacterial cholangitis and cholecystitis occur more frequently than suggested by current literature and should be considered in dogs presenting with jaundice and fever, abdominal pain, or an inflammatory leukogram or with ultrasonographic evidence of gallbladder abnormalities
The Ticks (Arachnida: Acari: Ixodida) of Arkansas
Although ticks are a nuisance to humans and other animals, they are an important part of the biota of North America. In addition, they are vectors of many tick-borne disease agents that can negatively affect higher vertebrates. In Arkansas, there have been no recent comprehensive summaries of the ticks (Acari: Ixodida) in the last 40+ yrs. Here, we provide a summary of the ticks of the state and note the disease agents they can transmit
Maternal immune activation causes age- and region-specific changes in brain cytokines in offspring throughout development
Maternal infection is a risk factor for autism spectrum disorder (ASD) and schizophrenia (SZ). Indeed, modeling this risk factor in mice through maternal immune activation (MIA) causes ASD- and SZ-like neuropathologies and behaviors in the offspring. Although MIA upregulates pro-inflammatory cytokines in the fetal brain, whether MIA leads to long-lasting changes in brain cytokines during postnatal development remains unknown. Here, we tested this possibility by measuring protein levels of 23 cytokines in the blood and three brain regions from offspring of poly(I:C)- and saline-injected mice at five postnatal ages using multiplex arrays. Most cytokines examined are present in sera and brains throughout development. MIA induces changes in the levels of many cytokines in the brains and sera of offspring in a region- and age-specific manner. These MIA-induced changes follow a few, unexpected and distinct patterns. In frontal and cingulate cortices, several, mostly pro-inflammatory, cytokines are elevated at birth, followed by decreases during periods of synaptogenesis and plasticity, and increases again in the adult. Cytokines are also altered in postnatal hippocampus, but in a pattern distinct from the other regions. The MIA-induced changes in brain cytokines do not correlate with changes in serum cytokines from the same animals. Finally, these MIA-induced cytokine changes are not accompanied by breaches in the bloodâbrain barrier, immune cell infiltration or increases in microglial density. Together, these data indicate that MIA leads to long-lasting, region-specific changes in brain cytokines in offspringâsimilar to those reported for ASD and SZâthat may alter CNS development and behavior
Introduction to special issue on neuroimmunology in brain development and disease
Although neural-immune cross-talk during disease
and/or trauma has been studied for many years, the
dogma has been that there is little interaction between
the immune and nervous systems in healthy individuals.
This belief was historically based on indications
that the blood-brain barrier (BBB) blocks immune
cell infiltration into the central nervous system
(CNS), leading to limited immune responses in the
CNS, and by a lack of classical immune proteins in
the brain (Murphy and Sturm, 1923; Joly et al.,
1991). However, recent observations from both clinical
and basic science research have caused a paradigm
shift in our understanding of neural-immune
interactions, indicating clearly that there is extensive
communication between these systems (McAllister
and van de Water, 2009). There is now clear evidence
that environmental insults that alter the immune
response can affect brain development as well as
behavior (Patterson, 2009; Meyer et al., 2011). Moreover,
mouse models of neurodevelopmental disorders
have provided strong support for immune involvement
in CNS development and disease (Patterson,
2009; Patterson, 2011). Finally, several different
kinds of immune molecules, including cytokines,
major histocompatibility complex (MHC) proteins,
and complement, are expressed in the developing and
adult brain and have critical functions in brain development
and plasticity (Garay and McAllister, 2009;
Shatz, 2009; Elmer and McAllister, 2012; Stephan et
al., 2012). In this Special Issue, we include reviews
covering a range of topics from epidemiology indicating
a role for immune dysregulation in neurodevelopmental
disorders to basic mechanisms underlying the
effects of immune molecules in brain development
and disease
Risk of severe COVID-19 in patients with inflammatory rheumatic diseases treated with immunosuppressive therapy in Scotland
Objective: To investigate the association of severe coronavirus disease 2019 (COVID-19) in patients with inflammatory
rheumatic diseases (IRDs) treated with immunosuppressive drugs.
Method: A list of 4633 patients on targeted â biological or targeted synthetic â DMARDs in March 2020 was linked to a caseâ
control study that includes all cases of COVID-19 in Scotland.
Results: By 22 November 2021, 433 of the 4633 patients treated with targeted DMARDS had been diagnosed with COVID-19,
of whom 58 had been hospitalized. With all those in the population not on DMARDs as the reference category, the rate ratio for
hospitalized COVID-19 associated with DMARD treatment was 2.14 [95% confidence interval (CI) 2.02â2.26] in those on
conventional synthetic (cs) DMARDs, 2.01 (95% CI 1.38â2.91) in those on tumour necrosis factor (TNF) inhibitors as the only
targeted agent, and 3.83 (95% CI 2.65â5.56) in those on other targeted DMARDs. Among those on csDMARDs, rate ratios for
hospitalized COVID-19 were lowest at 1.66 (95% CI 1.51â1.82) in those on methotrexate and highest at 5.4 (95% CI 4.4â6.7) in
those on glucocorticoids at an average dose > 10 mg/day prednisolone equivalent.
Conclusion: The risk of hospitalized COVID-19 is elevated in IRD patients treated with immunosuppressive drugs compared
with the general population. Of these drugs, methotrexate, hydroxychloroquine, and TNF inhibitors carry the lowest risk. The
highest risk is associated with prednisolone. A larger study is needed to estimate reliably the risks associated with each class of
targeted DMAR
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