Publications by authors named "John V Stokes"

The guinea pig was the original animal model developed for investigating spotted fever rickettsiosis (SFR). This model system has persisted on account of the guinea pig's conduciveness to tick transmission of SFR agents and ability to recapitulate SFR in humans through clinical signs that include fever, unthriftiness, and in some cases the development of an eschar. The guinea pig is the smallest animal model for SFR that allows the collection of multiple blood and skin samples antemortem for longitudinal studies.

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Macrophages are scavenger cells and a fundamental part of innate and adaptive immune responses, and they are important in wound repair and tissue remodeling. The functions of macrophages include engulfing and killing invading pathogens, processing and presenting antigens, initiation of inflammation, secreting cytokines and other inflammatory mediators, and participating in the maintenance and repair of tissues. Based on functional differences and surface and intracellular marker expression, macrophages can be generally divided into either M1 (inflammatory) or M2 (wound healing); the M2 type can be further divided into M2a, M2b, M2c, and M2d.

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Spotted Fever Rickettsiosis (SFR) is caused by spotted fever group spp. (SFGR), and is associated with symptoms common to other illnesses, making it challenging to diagnose before detecting SFGR-specific antibodies. The guinea pig is a valuable biomedical model for studying Spotted Fever Rickettsiosis (SFR); its immune system is more like the human immune system than that of the murine model, and guinea pigs develop characteristic clinical signs.

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Intact, the skin typically serves as an effective barrier to the external world; however, once pathogens have breached this barrier via a wound, such as a tick bite, the surrounding tissues must recruit immune cells from the blood to neutralize the pathogen. With innate and adaptive immune systems being similar between the guinea pig and human systems, the ability of guinea pigs to show clinical signs of many infectious diseases, and the large size of guinea pigs relative to a murine model, the guinea pig is a valuable model for studying tick-borne and other pathogens that invade the skin. Here, we report a novel assay for assessing guinea pig leukocyte infiltration in the skin.

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Assessing cells, proteins, and total RNA in the spinal cord is vital for advancing our understanding of neuroinflammation and neurodegenerative diseases. For instance, immune cells infiltrate the spinal cord in the experimental autoimmune encephalomyelitis (EAE) model, commonly used to study multiple sclerosis. Thus, it is valuable to assess total RNA to determine the neuronal and inflammatory profiles in the spinal cord.

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Based on limited serological studies, at least 10% of the US population has been exposed to spotted fever group (SFGR) species. The immunofluorescence antibody assay (IFA) has been the gold standard for the serodiagnosis of rickettsial infections such as spotted fever rickettsiosis (SFR). However, the IFA is semi-quantitative and subjective, requiring a high level of expertise to interpret it correctly.

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The guinea pig (Cavia porcellus) has an established track record as an animal model, with its utility in rickettsial research documented as early as the turn of the 20 century. From identifying Rickettsia rickettsii as the agent of Rocky Mountain spotted fever and ticks as the natural transmission route to evaluating protective immunity and treatment for tick-borne rickettsiae, guinea pigs have been essential for advances in our understanding of spotted fever rickettsioses (SFR). Tick feeding on guinea pigs is feasible and results in transmission of tick-borne rickettsiae.

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American canine hepatozoonosis (ACH) is a debilitating tick-borne disease characterized by pyrexia, body wasting, myopathy, mucopurulent ocular discharge, and periosteal proliferation. The causative agent, Hepatozoon americanum, is an apicomplexan that utilizes the Gulf Coast tick, Amblyomma maculatum, as its definitive host and vector. Unlike most tick-borne disease agents, H.

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Guinea pigs are an ideal animal model for the study of several infectious diseases, including tuberculosis, legionellosis, brucellosis, and spotted fever rickettsiosis. In comparison to the murine model, clinical signs in guinea pigs are more representative of disease in humans, the guinea pig immune system is more similar to that of the human, and their large size offers logistic advantages for sample collection while following disease progression. Unfortunately, the advantage of using guinea pigs in biomedical research, particularly in understanding the immune response to infectious agents, is limited in large part by the paucity of available reagents and lack of genetically manipulated strains.

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The reniform nematode () is a sedentary semi-endoparasitic species that is pathogenic on many row crops, fruits, and vegetables. Here, the authors present a draft genome assembly of . using small- and large-insert libraries sequenced on the Illumina GAIIx and MiSeq platforms.

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Rickettsia parkeri, a causative agent of spotted fever rickettsiosis, is transmitted by Amblyomma maculatum (Gulf Coast tick), a tick that may also carry a non-pathogenic spotted fever group Rickettsia, "Candidatus Rickettsia andeanae". Here, we evaluated R. parkeri and "Candidatus R.

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Amblyomma maculatum is the primary vector for the spotted fever group rickettsiae, Rickettsia parkeri, a known pathogen, and "Candidatus Rickettsia andeanae," currently considered nonpathogenic. Spotted fever group rickettsiae are typically endothelial cell associated and rarely circulate in the blood. Horizontal transmission to naïve ticks through blood feeding from an infected host is likely rare.

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Many effects of the non-psychoactive cannabinoid, cannabidiol (CBD), have been described in immune responses induced by strong immunological stimuli. It has also been shown that CBD enhances IL-2 production in response to low-level T cell stimulation. Since IL-2, in combination with TGF-β1, are critical for Treg induction, we hypothesized that CBD would induce CD4CD25FOXP3 Tregs in response to low-level stimulation.

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Unlabelled: Tick-borne borreliae include Lyme disease and relapsing fever agents, and they are transmitted primarily by ixodid (hard) and argasid (soft) tick vectors, respectively. Tick-host interactions during feeding are complex, with host immune responses influenced by biological differences in tick feeding and individual differences within and between host species. One of the first encounters for spirochetes entering vertebrate host skin is with local antigen-presenting cells, regardless of whether the tick-associated Borrelia sp.

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Hepatic steatosis is recognized as an independent risk factor for the development of cardiovascular disease. While obesity and type 2 diabetes are well-established risk factors in the development of hepatic steatosis, recent studies have revealed exposure to mixtures of persistent organic pollutants (POPs), which are environmental contaminants in various fatty foods, can promote steatosis. Thus, the present study was designed to determine if exposure to a defined mixture of prevalent polychlorinated biphenyls (PCBs) and organochlorine (OC) pesticides or their metabolites promote hepatic steatosis in a genetically induced model of type 2 diabetes, the leptin-deficient ob/ob mouse.

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Multiple sclerosis (MS) is an autoimmune neurodegenerative disorder, characterized by demyelination of neurons in the central nervous system. To investigate the pathogenicity of various T cell types in MS, especially IFN-γ- or IL-17-producing CD4(+ )cells (TH1 or TH17 cells, respectively), the mouse model, experimental autoimmune encephalomyelitis (EAE), is commonly used. One method by which EAE is induced is immunization with myelin oligodendrocyte glycoprotein (MOG) peptide (MOG35-55) followed by subsequent injections of pertussis toxin (PTX) as an adjuvant.

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Exposure to p,p'-DDE (DDE), the main bioaccumulative metabolite of the organochlorine insecticide p,p'-DDT, is associated with a higher prevalence of obesity, dyslipidemia, insulin resistance, metabolic syndrome, and immunomodulation. The present study was carried out to determine whether DDE perturbs adipose tissue homeostasis through modulation of macrophage function. Treatment with DDE or a cyclooxygenase-2 inhibitor prior to lipopolysaccharide exposure significantly decreased production of prostaglandins (PG) from J774a.

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Background: Relaxin levels in seminal plasma have been associated with positive effects on sperm motility and quality, and thus having potential roles in male fertility. However, the origin of seminal relaxin, within the male reproductive tract, and the moment of its release in the vicinity of spermatozoa remain unclear. Here, we assessed the longitudinal distribution of relaxin and its receptors RXFP1 and RXFP2 in the reproductive tract, sex accessory glands, and spermatozoa of adult boars.

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Regulatory T cells (Tregs) are known to control autoreactivity during and subsequent to the development of the peripheral immune system. Professional antigen presenting cells (APCs), dendritic cells (DCs) and monocytes, have an important role in inducing Tregs. For the first time, this study evaluated proportions and phenotypes of Tregs in canine peripheral blood depleted of professional APCs, utilizing liposomal clodronate (LC) and multicolor flow cytometry analysis.

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Recent studies have shown that monocytes and macrophages not only present antigens to effector T cells and stimulate and shape T cell-mediated immune responses, but they also prime naïve T cells, thus initiating adaptive immune responses. Phosphatidylinositol 3-kinase functions at an early phase of toll-like receptor signaling pathways, modulates the magnitude of the primary immune responses, and is involved in the reorganization of the actin cytoskeleton during macropinocytic and phagocytic antigen uptakes, important early steps in triggering adaptive immune responses. We assessed by flow cytometry the endocytic capacities of bovine monocytes by using endocytic tracers and transformed with a green fluorescence plasmid GFP to evaluate macropinocytosis, mannose receptor-mediated endocytosis, and phagocytosis in bovine professional antigen presenting cells, respectively.

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Bioaccumulative organohalogen chemicals, such as organochlorine (OC) insecticides, have been increasingly associated with disease etiology; however, the mechanistic link between chemical exposure and diseases, such as atherosclerosis, cancer, and diabetes, is complex and poorly defined. Systemic oxidative stress stemming from OC exposure might play a vital role in the development of these pathologies. Monocytes are important surveillance cells of the innate immune system that respond to extracellular signals possessing danger-associated molecular patterns by synthesizing oxyradicals, such as superoxide, for the purpose of combating infectious pathogens.

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Background: L-arginine is considered to be one of the most versatile amino acids due to the fact that it serves as a precursor for many important molecules in cellular physiology. When supplemented in the diet, L-arginine can increase the number of implantation sites in mice and rats, suggesting an effect at the level of the endometrium. To this end, this study determined the effect that L-arginine has on apoptosis and cell proliferation in human endometrial RL95-2 cells.

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We evaluated an intervention that combined task analysis and differential reinforcement for teaching tackling skills to 2 high school football athletes. As a result of intervention, both players tackled more proficiently in practice drills and maintained proficient tackling during games.

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We evaluated several behavioral coaching procedures for improving offensive line pass-blocking skills with 5 high school varsity football players. Pass blocking was measured during practice drills and games, and our intervention included descriptive feedback with and without video feedback and teaching with acoustical guidance (TAG). Intervention components and pass blocking were evaluated in a multiple baseline design, which showed that video feedback and TAG were the most effective procedures.

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