Energy restriction effects on splanchnic and peripherial tissue metabolite fluxes with or without the addition of Lasalocid

Concentration and net fluxes of glucose (GLU), nonesterifled fatty acids (NEFA), acetoacetate (ACAC), β-hydroxybutyrate (BOHB) and volatile fatty acids (VFA) were studied in mature, non-pregnant, non-lactating ewes with or without the addition of the ionophore Lasalocid. Chronic indwelling catheters were placed in portal, hepatic and mesenteric veins, and the caudal vena cava and aorta at least 14 days prior to experiments. Ewes were fed alfalfa pellets at 100% or 50% of the NRC metabolizable energy requirement during the first study. During the second study, the feeding regimen was identical except for the addition of Lasalocid (44 mg/kg) to the fed. On experiment days, paraaminohippurate (PAH, 1.5% @ .764 ml/min.) was infused via the mesenteric catheter in order to measure blood flow across down stream tissues. After a one hour equilibration period, a series of 6 samples (12 ml) were drawn simultaneously at 30 min. intervals from the portal and hepatic veins and the caudal vena cava and aorta. Flux rates were calculated by multiplying venoarterial (V-A) differences by blood flow rates across the respective tissue. Rump V-A differences were calculated instead of flux rates because a simultaneous blood flow could not be measured. Whole blood was analyzed for PAH, GLU, ACAC and BOHB. Plasma was analyzed for NEFA and VFA’s. During the first study, energy restriction (ER) reduced splanchnic blood flow specifically at the expense of the portal vein contribution to the liver (HEP) indicating that a larger percentage of peripherally released metabolites reached the liver. Energy restriction also decreased (P \u3c .05) arterial glucose from 2.68 to 2.41 mM due to increased (P \u3c .05) glucose uptake by portal- drained viscera (PDV). Liver GLU release (30 mmol/h) was unchanged. NEFA arterial concentrations increased (P \u3c .01) 2 fold due to a 3 fold increase (P \u3c .01) in rump release and despite a 2.5 fold increase (P \u3c .01) in hepatic uptake. Hepatic extraction of NEFA also increased (P \u3c .01) by 50%. Because HEP NEFA uptake increased during ER, HEP release of ACAC decreased (P \u3c .01), while release of BOHB increased (P \u3c .05) 2 fold. However, PDV release of both ketones decreased ~60% (P \u3c .05, ACAC; P \u3c .05, BOHB) due to the energy restriction. Arterial acetate concentration decreased (P \u3c .01) during ER by 36% due to a decrease (P \u3c .01) in PDV release of ~50% (927 to 439 μmol/min). There was no significant HEP flux of acetate, but rump uptake decreased (P \u3c .01) 43%, dependent upon concentration. Arterial propionate concentration was unaffected by ER despite a decrease (P \u3c .01) of 60% in PDV release due to a concomitant decrease (P \u3c .01) of 60% in HEP uptake. Rump uptake of propionate was not affected by ER, remaining constant at ~25-35% of circulating concentrations. Arterial butyrate concentrations statistically decreased (P \u3c .01) from 8 to 5 μM with ER, with ER, however, this may not be physiologically significant because both PDV release and HEP uptake decreased (P \u3c .01) resulting in no change in total splanchnic output. This work demonstrates that decreasing ME intake by 50% increases the animals reliance on endogenous fuels (i.e. hepatic ketogenesis and peripheral lypolysis) because potential ME from VFA PDV release decreased probably due to decreased organic matter fermentation. During the second study, energy restriction did not change splanchnic blood flow. Arterial glucose concentration actually increased (P \u3c .01) from 2.36 to 2.56mM despite a decease (P \u3c .05) in total splanchnic release of 40%. Liver release of GLU was not statistically different, however, it was approx. 33% lower than what was expected (20 vs. 30 mmol/h). NEFA arterial concentrations increased (P \u3c .01) 2 fold despite a 2 fold increase (P \u3c .01) in hepatic uptake and a switch from rump release to utilization (P \u3c .01). Arterial ACAC concentrations did not change despite a decrease (P \u3c .01) of 60% in portal vein viscera (PDV) release. BOHB arterial concentrations increased (P \u3c .01) due to an increase (P \u3c .01) in HEP production of 45%. Acetate arterial concentrations decreased (P \u3c .01), as did portal concentrations. PDV acetate release decreased (P \u3c .01) almost 65%, resulting in decreased (P \u3c .01) TSP release. Propionate arterial concentrations decreased (P \u3c .01) almost 50%, while portal concentrations decreased (P \u3c .01) almost 65%. PDV release of propionate decreased almost 75%. HEP propionate uptake decreased nearly 70%. However, TSP release still saw a decrease (P \u3c .01) from 31 to 2 μmol/min. Butyrate arterial concentrations decreased (P \u3c .01), as did portal concentrations. There was no change in TSP butyrate release, despite a decrease (P \u3c .01) of 65% in PDV release. HEP butyrate uptake also decreased (P \u3c .01) 66%. Valerate portal concentrations decreased (P\u3c.05) 40%. PDV release of valerate decreased (P \u3c .05) 40%, as did HEP uptake. There were no significant net flux changes with either of the branched chain volatile fatty acids, isobutyrate and isovalerate

Non-Thyroidal Illness in Chronic Renal Failure: Triiodothyronine Levels and Modulation of Extra-Cellular Superoxide Dismutase (ec-SOD)

Oxidative stress (OS) is implicated in several chronic diseases. Extra-cellular superoxide dismutase (ec-SOD) catalyses the dismutation of superoxide anions with a protective role in endothelial cells. In chronic kidney disease (CKD), OS and thyroid dysfunction (low fT3 syndrome) are frequently present, but their relationship has not yet been investigated. This cohort study evaluated ec-SOD activity in CKD patients during haemodialysis, divided into "acute haemodialytic patients" (AH, 1-3 months of treatment) and "chronic haemodialytic patients" (CH, treated for a longer period). We also evaluated plasmatic total antioxidant capacity (TAC) and its relationships with thyroid hormones. Two basal samples ("basal 1", obtained 3 days after the last dialysis; and "basal 2", obtained 2 days after the last dialysis) were collected. On the same day of basal 2, a sample was collected 5 and 10 min after the standard heparin dose and at the end of the procedure. The ec-SOD values were significantly higher in CH vs. AH in all determinations. Moreover, the same patients had lower TAC values. When the CH patients were divided into two subgroups according to fT3 levels (normal or low), we found significantly lower ec-SOD values in the group with low fT3 in the basal, 5, and 10 min samples. A significant correlation was also observed between fT3 and ec-SOD in the basal 1 samples. These data, confirming OS and low fT3 syndrome in patients with CKD, suggest that low fT3 concentrations can influence ec-SOD activity and could therefore potentially contribute to endothelial oxidative damage in these patients

Direct detection and characterization of foot-and-mouth disease virus in East Africa using a field-ready real-time PCR platform

Effective control and monitoring of foot-and-mouth disease (FMD) relies upon rapid and accurate disease confirmation. Currently, clinical samples are usually tested in reference laboratories using standardized assays recommended by The World Organisation for Animal Health (OIE). However, the requirements for prompt and serotype-specific diagnosis during FMD outbreaks, and the need to establish robust laboratory testing capacity in FMD-endemic countries have motivated the development of simple diagnostic platforms to support local decision-making. Using a portable thermocycler, the T-COR™ 8, this study describes the laboratory and field evaluation of a commercially available, lyophilized pan-serotype-specific real-time RT-PCR (rRT-PCR) assay and a newly available FMD virus (FMDV) typing assay (East Africa-specific for serotypes: O, A, Southern African Territories [SAT] 1 and 2). Analytical sensitivity, diagnostic sensitivity and specificity of the pan-serotype-specific lyophilized assay were comparable to that of an OIE-recommended laboratory-based rRT-PCR (determined using a panel of 57 FMDV-positive samples and six non-FMDV vesicular disease samples for differential diagnosis). The FMDV-typing assay was able to correctly identify the serotype of 33/36 FMDV-positive samples (no cross-reactivity between serotypes was evident). Furthermore, the assays were able to accurately detect and type FMDV RNA in multiple sample types, including epithelial tissue suspensions, serum, oesophageal–pharyngeal (OP) fluid and oral swabs, both with and without the use of nucleic acid extraction. When deployed in laboratory and field settings in Tanzania, Kenya and Ethiopia, both assays reliably detected and serotyped FMDV RNA in samples (n = 144) collected from pre-clinical, clinical and clinically recovered cattle. These data support the use of field-ready rRT-PCR platforms in endemic settings for simple, highly sensitive and rapid detection and/or characterization of FMDV

Feed and nutrition in organic aquaculture

publishedVersio

One health research in Northern Tanzania – challenges and progress

East Africa has one of the world’s fastest growing human populations—many of whom are dependent on livestock—as well as some of the world’s largest wildlife populations. Humans, livestock, and wildlife often interact closely, intimately linking human, animal, and environmental health. The concept of One Health captures this interconnectedness, including the social structures and beliefs driving interactions between species and their environments. East African policymakers and researchers are recognising and encouraging One Health research, with both groups increasingly playing a leading role in this subject area. One Health research requires interaction between scientists from different disciplines, such as the biological and social sciences and human and veterinary medicine. Different disciplines draw on norms, methodologies, and terminologies that have evolved within their respective institutions and that may be distinct from or in conflict with one another. These differences impact interdisciplinary research, both around theoretical and methodological approaches and during project operationalisation. We present experiential knowledge gained from numerous ongoing projects in northern Tanzania, including those dealing with bacterial zoonoses associated with febrile illness, foodborne disease, and anthrax. We use the examples to illustrate differences between and within social and biological sciences and between industrialised and traditional societies, for example, with regard to consenting procedures or the ethical treatment of animals. We describe challenges encountered in ethical approval processes, consenting procedures, and field and laboratory logistics and offer suggestions for improvement. While considerable investment of time in sensitisation, communication, and collaboration is needed to overcome interdisciplinary challenges inherent in One Health research, this can yield great rewards in paving the way for successful implementation of One Health projects. Furthermore, continued investment in African institutions and scientists will strengthen the role of East Africa as a world leader in One Health research

Crosstalk between skin inflammation and adipose tissue-derived products: pathogenic evidence linking psoriasis to increased adiposity.

INTRODUCTION: Psoriasis is a chronic skin disorder associated with several comorbid conditions. In psoriasis pathogenesis, the role of some cytokines, including TNF-α and IL-17, has been elucidated. Beside their pro-inflammatory activity, they may also affect glucose and lipid metabolism, possibly promoting insulin resistance and obesity. On the other hand, adipose tissue, secreting adipokines such as chemerin, visfatin, leptin, and adiponectin, not only regulates glucose and lipid metabolism, and endothelial cell function regulation, but it may contribute to inflammation. AREAS COVERED: This review provides an updated 'state-of-the-art' about the reciprocal contribution of a small subset of conventional cytokines and adipokines involved in chronic inflammatory pathways, upregulated in both psoriasis and increased adiposity. A systematic search was conducted using the PubMed Medline database for primary articles. Expert commentary: Because psoriasis is associated with increased adiposity, it would be important to define the contribution of chronic skin inflammation to the onset of obesity and vice versa. Clarifying the pathogenic mechanism underlying this association, a therapeutic strategy having favorable effects on both psoriasis and increased adiposity could be identified

Mas-related G-protein–coupled receptors inhibit pathological pain in mice

An important objective of pain research is to identify novel drug targets for the treatment of pathological persistent pain states, such as inflammatory and neuropathic pain. Mas-related G-protein–coupled receptors (Mrgprs) represent a large family of orphan receptors specifically expressed in small-diameter nociceptive primary sensory neurons. To determine the roles of Mrgprs in persistent pathological pain states, we exploited a mouse line in which a chromosomal locus spanning 12 Mrgpr genes was deleted (KO). Initial studies indicated that these KO mice show prolonged mechanical- and thermal-pain hypersensitivity after hind-paw inflammation compared with wild-type littermates. Here, we show that this mutation also enhances the windup response of dorsal-horn wide dynamic-range neurons, an electrophysiological model for the triggering of central pain sensitization. Deletion of the Mrgpr cluster also blocked the analgesic effect of intrathecally applied bovine adrenal medulla peptide 8–22 (BAM 8–22), an MrgprC11 agonist, on both inflammatory heat hyperalgesia and neuropathic mechanical allodynia. Spinal application of bovine adrenal medulla peptide 8–22 also significantly attenuated windup in wild-type mice, an effect eliminated in KO mice. These data suggest that members of the Mrgpr family, in particular MrgprC11, may constitute an endogenous inhibitory mechanism for regulating persistent pain in mice. Agonists for these receptors may, therefore, represent a class of antihyperalgesics for treating persistent pain with minimal side effects because of the highly specific expression of their targets

Block of death-receptor apoptosis protects mouse cytomegalovirus from macrophages and is a determinant of virulence in immunodeficient hosts.

The inhibition of death-receptor apoptosis is a conserved viral function. The murine cytomegalovirus (MCMV) gene M36 is a sequence and functional homologue of the human cytomegalovirus gene UL36, and it encodes an inhibitor of apoptosis that binds to caspase-8, blocks downstream signaling and thus contributes to viral fitness in macrophages and in vivo. Here we show a direct link between the inability of mutants lacking the M36 gene (ΔM36) to inhibit apoptosis, poor viral growth in macrophage cell cultures and viral in vivo fitness and virulence. ΔM36 grew poorly in RAG1 knockout mice and in RAG/IL-2-receptor common gamma chain double knockout mice (RAGγC(-/-)), but the depletion of macrophages in either mouse strain rescued the growth of ΔM36 to almost wild-type levels. This was consistent with the observation that activated macrophages were sufficient to impair ΔM36 growth in vitro. Namely, spiking fibroblast cell cultures with activated macrophages had a suppressive effect on ΔM36 growth, which could be reverted by z-VAD-fmk, a chemical apoptosis inhibitor. TNFα from activated macrophages synergized with IFNγ in target cells to inhibit ΔM36 growth. Hence, our data show that poor ΔM36 growth in macrophages does not reflect a defect in tropism, but rather a defect in the suppression of antiviral mediators secreted by macrophages. To the best of our knowledge, this shows for the first time an immune evasion mechanism that protects MCMV selectively from the antiviral activity of macrophages, and thus critically contributes to viral pathogenicity in the immunocompromised host devoid of the adaptive immune system

Blocking spinal CCR2 with AZ889 reversed hyperalgesia in a model of neuropathic pain

<p>Abstract</p> <p>Background</p> <p>The CCR2/CCL2 system has been identified as a regulator in the pathogenesis of neuropathy-induced pain. However, CCR2 target validation in analgesia and the mechanism underlying antinociception produced by CCR2 antagonists remains poorly understood. In this study, <it>in vitro </it>and <it>in vivo </it>pharmacological approaches using a novel CCR2 antagonist, AZ889, strengthened the hypothesis of a CCR2 contribution to neuropathic pain and provided confidence over the possibilities to treat neuropathic pain with CCR2 antagonists.</p> <p>Results</p> <p>We provided evidence that dorsal root ganglia (DRG) cells harvested from CCI animals responded to stimulation by CCL2 with a concentration-dependent calcium rise involving PLC-dependent internal stores. This response was associated with an increase in evoked neuronal action potentials suggesting these cells were sensitive to CCR2 signalling. Importantly, treatment with AZ889 abolished CCL2-evoked excitation confirming that this activity is CCR2-mediated. Neuronal and non-neuronal cells in the spinal cord were also excited by CCL2 applications indicating an important role of spinal CCR2 in neuropathic pain. We next showed that in vivo spinal intrathecal injection of AZ889 produced dose-dependent analgesia in CCI rats. Additionally, application of AZ889 to the exposed spinal cord inhibited evoked neuronal activity and confirmed that CCR2-mediated analgesia involved predominantly the spinal cord. Furthermore, AZ889 abolished NMDA-dependent wind-up of spinal withdrawal reflex pathway in neuropathic animals giving insight into the spinal mechanism underlying the analgesic properties of AZ889.</p> <p>Conclusions</p> <p>Overall, this study strengthens the important role of CCR2 in neuropathic pain and highlights feasibility that interfering on this mechanism at the spinal level with a selective antagonist can provide new analgesia opportunities.</p