20 research outputs found

    Targeting Cattle-Borne Zoonoses and Cattle Pathogens Using a Novel Trypanosomatid-Based Delivery System

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    Trypanosomatid parasites are notorious for the human diseases they cause throughout Africa and South America. However, non-pathogenic trypanosomatids are also found worldwide, infecting a wide range of hosts. One example is Trypanosoma (Megatrypanum) theileri, a ubiquitous protozoan commensal of bovids, which is distributed globally. Exploiting knowledge of pathogenic trypanosomatids, we have developed Trypanosoma theileri as a novel vehicle to deliver vaccine antigens and other proteins to cattle. Conditions for the growth and transfection of T. theileri have been optimised and expressed heterologous proteins targeted for secretion or specific localisation at the cell interior or surface using trafficking signals from Trypanosoma brucei. In cattle, the engineered vehicle could establish in the context of a pre-existing natural T. theileri population, was maintained long-term and generated specific immune responses to an expressed Babesia antigen at protective levels. Building on several decades of basic research into trypanosomatid pathogens, Trypanosoma theileri offers significant potential to target multiple infections, including major cattle-borne zoonoses such as Escherichia coli, Salmonella spp., Brucella abortus and Mycobacterium spp. It also has the potential to deliver therapeutics to cattle, including the lytic factor that protects humans from cattle trypanosomiasis. This could alleviate poverty by protecting indigenous African cattle from African trypanosomiasis

    Purinergic signalling and immune cells

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    This review article provides a historical perspective on the role of purinergic signalling in the regulation of various subsets of immune cells from early discoveries to current understanding. It is now recognised that adenosine 5'-triphosphate (ATP) and other nucleotides are released from cells following stress or injury. They can act on virtually all subsets of immune cells through a spectrum of P2X ligand-gated ion channels and G protein-coupled P2Y receptors. Furthermore, ATP is rapidly degraded into adenosine by ectonucleotidases such as CD39 and CD73, and adenosine exerts additional regulatory effects through its own receptors. The resulting effect ranges from stimulation to tolerance depending on the amount and time courses of nucleotides released, and the balance between ATP and adenosine. This review identifies the various receptors involved in the different subsets of immune cells and their effects on the function of these cells

    Oxygen Saturation in the Dental Pulp of Maxillary and Mandibular Molars - Part 2

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    <div><p>Abstract This study determined the oxygen saturation (SaO2) in dental pulp of healthy maxillary and mandibular molars. Mean of SaO2 was evaluated in 112 maxillary and mandibular molars using pulse oximetry. Quantitative variables were described by mean and standard deviation. Variables with symmetric distribution were compared by Student t test and Mann-Whitney test. Pearson’s correlation coefficient was used to correlate quantitative variables. Analysis of variance was used to assess differences in SaO2 levels between the molar groups, followed by post-hoc Tukey. The significance level established at p<0.05. Mean of oxygen saturation for the 112 molar dental pulps was 85.09%. There was no significant correlation (r=-0.007; p=0.977) between the mean of SaO2 of molar pulps with patient´s indicator finger (92.89%). There was a significant difference (p=0.037) between the mean of SaO2 of the first (85.76%) and second maxillary molars (81.87%), and it was not significant (p=0.1775) between the first and second mandibular molars. Maxillary molars had lower pulpal SaO2 (83.59%) than mandibular molars (86.89%) (p=0.018). The mean of the patient’s response time to the cold stimulus was 1.12 s (maxillary molars 1.25 s and mandibular molars 0.99 s)(p=0.052). There was no significant correlation between the time response of the patient to the cold stimulus and the SaO2 for molars. The mean oxygen saturation level was 85.09%. The mandibular molars presented higher SaO2 level than maxillary molars.</p></div

    Oxygen Saturation in the Dental Pulp of Maxillary Premolars in Different Age Groups - Part 1

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    <div><p>Abstract The aim of this study was to determine oxygen saturation levels in the dental pulp of maxillary premolars in different age groups. A total of 120 human maxillary premolars with normal dental pulps were selected covering the following age groups: 20-24, 25-29, 30-34, 35-39 and 40-44 years (n=24 each group). Oxygen saturation was assessed using pulse oximetry. Analysis of variance was used to assess differences in oxygen saturation levels and Tukey’s test was used to identify the age groups that differed from each other. Significance was set at 0.05. Mean oxygen saturation of 120 premolars was 86.20% considering all age groups. Significantly reduced levels were found in the oldest group compared to the other groups: 40 to 44 years - 80.00% vs. 89.71, 87.67, 88.71, and 84.80% for age groups 20-24, 25-29, 30-34, 35-39 years, respectively. The mean oxygen saturation levels were similar between 20 and 39 years of age (86.20%) in the whole sample, but reduced significantly in the 40-44-year age group, suggesting that older patients present lower oxygen saturation results even in the absence of pulp tissue injury.</p></div
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