26 resultados para Short chain fatty acid


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Phytochemical investigation of a dichloromethane-methanol (1:1) extract of the fruit pericarp of Omphalocarpum procerum which exhibited antiplasmodial activity during preliminary screening led to the isolation of the new fatty ester triterpenoid 3β-hexadecanoyloxy-28-hydroxyolean-12-en-11-one (1), together with five known compounds 2-6. The structure of the new compound as well as those of the known compounds was established by means of spectroscopic methods and by comparison with previously reported data. Compounds 1- 4 were evaluated in-vitro for their cytotoxicity against L6 cell lines and antiprotozoal activities against Plasmodium falciparum, Leishmania donovani, Trypanosoma brucei rhodesiense and Trypanosoma cruzi (species responsible for human malaria, visceral leishmaniasis, African trypanosomiasis and Chagas disease, respectively). The tested compounds showed weak to moderate antiprotozoal activity and, no significant effect was detected regarding their cytotoxic potency.

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OBJECTIVES The number of heart transplantations is limited by donor organ availability. Donation after circulatory determination of death (DCDD) could significantly improve graft availability; however, organs undergo warm ischaemia followed by reperfusion, leading to tissue damage. Laboratory studies suggest that mechanical postconditioning [(MPC); brief, intermittent periods of ischaemia at the onset of reperfusion] can limit reperfusion injury; however, clinical translation has been disappointing. We hypothesized that MPC-induced cardioprotection depends on fatty acid levels at reperfusion. METHODS Experiments were performed with an isolated rat heart model of DCDD. Hearts of male Wistar rats (n = 42) underwent working-mode perfusion for 20 min (baseline), 27 min of global ischaemia and 60 min reperfusion with or without MPC (two cycles of 30 s reperfusion/30 s ischaemia) in the presence or absence of high fat [(HF); 1.2 mM palmitate]. Haemodynamic parameters, necrosis factors and oxygen consumption (O2C) were assessed. Recovery rate was calculated as the value at 60 min reperfusion expressed as a percentage of the mean baseline value. The Kruskal-Wallis test was used to provide an overview of differences between experimental groups, and pairwise comparisons were performed to compare specific time points of interest for parameters with significant overall results. RESULTS Percent recovery of left ventricular (LV) work [developed pressure (DP)-heart rate product] at 60 min reperfusion was higher in hearts reperfused without fat versus with fat (58 ± 8 vs 23 ± 26%, P < 0.01) in the absence of MPC. In the absence of fat, MPC did not affect post-ischaemic haemodynamic recovery. Among the hearts reperfused with HF, two significantly different subgroups emerged according to recovery of LV work: low recovery (LoR) and high recovery (HiR) subgroups. At 60 min reperfusion, recovery was increased with MPC versus no MPC for LV work (79 ± 6 vs 55 ± 7, respectively; P < 0.05) in HiR subgroups and for DP (40 ± 27 vs 4 ± 2%), dP/dtmax (37 ± 24 vs 5 ± 3%) and dP/dtmin (33 ± 21 vs 5 ± 4%; P < 0.01 for all) in LoR subgroups. CONCLUSIONS Effects of MPC depend on energy substrate availability; MPC increased recovery of LV work in the presence, but not in the absence, of HF. Controlled reperfusion may be useful for therapeutic strategies aimed at improving post-ischaemic recovery of cardiac DCDD grafts, and ultimately in increasing donor heart availability.

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Gebiet: Chirurgie Abstract: OBJECTIVES: – The number of heart transplantations is limited by donor organ availability. Donation after circulatory determination of death (DCDD) could significantly improve graft availability, however, organs undergo warm ischaemia followed by reperfusion, leading to tissue damage. Laboratory studies suggest that mechanical postconditioning [(MPC), brief, intermittent periods of ischaemia at the onset of reperfusion] can limit reperfusion injury, however, clinical translation has been disappointing. We hypothesized that MPC-induced cardioprotection depends on fatty acid levels at reperfusion. – – METHODS: – Experiments were performed with an isolated rat heart model of DCDD. Hearts of male Wistar rats (n = 42) underwent working-mode perfusion for 20 min (baseline), 27 min of global ischaemia and 60 min reperfusion with or without MPC (two cycles of 30 s reperfusion/30 s ischaemia) in the presence or absence of high fat [(HF), 1.2 mM palmitate]. Haemodynamic parameters, necrosis factors and oxygen consumption (O2C) were assessed. Recovery rate was calculated as the value at 60 min reperfusion expressed as a percentage of the mean baseline value. The Kruskal-Wallis test was used to provide an overview of differences between experimental groups, and pairwise comparisons were performed to compare specific time points of interest for parameters with significant overall results. – – RESULTS: – Percent recovery of left ventricular (LV) work [developed pressure (DP)-heart rate product] at 60 min reperfusion was higher in hearts reperfused without fat versus with fat (58 ± 8 vs 23 ± 26%, P < 0.01) in the absence of MPC. In the absence of fat, MPC did not affect post-ischaemic haemodynamic recovery. Among the hearts reperfused with HF, two significantly different subgroups emerged according to recovery of LV work: low recovery (LoR) and high recovery (HiR) subgroups. At 60 min reperfusion, recovery was increased with MPC versus no MPC for LV work (79 ± 6 vs 55 ± 7, respectively, P < 0.05) in HiR subgroups and for DP (40 ± 27 vs 4 ± 2%), dP/dtmax (37 ± 24 vs 5 ± 3%) and dP/dtmin (33 ± 21 vs 5 ± 4%, P < 0.01 for all) in LoR subgroups. – – CONCLUSIONS: – Effects of MPC depend on energy substrate availability, MPC increased recovery of LV work in the presence, but not in the absence, of HF. Controlled reperfusion may be useful for therapeutic strategies aimed at improving post-ischaemic recovery of cardiac DCDD grafts, and ultimately in increasing donor heart availability.

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BACKGROUND The early diagnosis of acute myocardial infarction (AMI) very soon after symptom onset remains a major clinical challenge, even when using high-sensitivity cardiac troponin (hs-cTnT). METHODS AND RESULTS We investigated the incremental value of heart-type fatty acid-binding protein (hFABP) in a pre-specified subgroup analysis of patients presenting with suspected AMI within 1 h of symptom onset to the emergency department (ED) in a multicentre study. HFABP was measured in a blinded fashion. Two independent cardiologists using all available clinical information, including hs-cTnT, adjudicated the final diagnosis. Overall, 1411 patients were enrolled, of whom 105 patients presented within 1 h of symptom onset. Of these, 34 patients (32.4%) had AMI. The diagnostic accuracy as quantified by the area under the receiver-operating characteristics curve (AUC) of hFABP was high (0.84 (95% CI 0.74-0.94)). However, the additional use of hFABP only marginally increased the diagnostic accuracy of hs-cTnT (AUC 0.88 (95% CI 0.81-0.94) for hs-cTnT alone to 0.90 (95% CI 0.83-0.98) for the combination; p=ns). After the exclusion of 18 AMI patients with ST-segment elevation, similar results were obtained. Among the 16 AMI patients without ST-segment elevation, six had normal hs-cTnT at presentation. Of these, hFABP was elevated in two (33.3%) patients. CONCLUSIONS hFABP does not seem to significantly improve the early diagnostic accuracy of hs-cTnT in the important subgroup of patients with suspected AMI presenting to the ED very early after symptom onset.

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The fatty acid synthesis type II pathway has received considerable interest as a candidate therapeutic target in Plasmodium falciparum asexual blood-stage infections. This apicoplast-resident pathway, distinct from the mammalian type I process, includes FabI. Here, we report synthetic chemistry and transfection studies concluding that Plasmodium FabI is not the target of the antimalarial activity of triclosan, an inhibitor of bacterial FabI. Disruption of fabI in P. falciparum or the rodent parasite P. berghei does not impede blood-stage growth. In contrast, mosquito-derived, FabI-deficient P. berghei sporozoites are markedly less infective for mice and typically fail to complete liver-stage development in vitro. This defect is characterized by an inability to form intrahepatic merosomes that normally initiate blood-stage infections. These data illuminate key differences between liver- and blood-stage parasites in their requirements for host versus de novo synthesized fatty acids, and create new prospects for stage-specific antimalarial interventions.

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Feather pecking in laying hens is a serious behavioral problem that is often associated with feather eating. The intake of feathers may influence the gut microbiota and its metabolism. The aim of this study was to determine the effect of 2 different diets, with or without 5% ground feathers, on the gut microbiota and the resulting microbial fermentation products and to identify keratin-degrading bacteria in chicken digesta. One-day-old Lohmann-Selected Leghorn chicks were divided into 3 feeding groups: group A (control), B (5% ground feathers in the diet), and C, in which the control diet was fed until wk 12 and then switched to the 5% feather diet to study the effect of time of first feather ingestion. The gut microbiota was analyzed by cultivation and denaturing gradient gel electrophoresis of ileum and cecum digesta. Short-chain fatty acids, ammonia, and lactate concentrations were measured as microbial metabolites. The concentration of keratinolytic bacteria increased after feather ingestion in the ileum (P < 0.001) and cecum (P = 0.033). Bacterial species that hydrolyzed keratin were identified as Enterococcus faecium, Lactobacillus crispatus, Lactobacillus reuteri-like species (97% sequence homology), and Lactobacillus salivarius-like species (97% sequence homology). Molecular analysis of cecal DNA extracts showed that the feather diet lowered the bacterial diversity indicated by a reduced richness (P < 0.001) and shannon (P = 0.012) index. The pattern of microbial metabolites indicated some changes, especially in the cecum. This study showed that feather intake induced an adaptation of the intestinal microbiota in chickens. It remains unclear to what extent the changed metabolism of the microbiota reflects the feather intake and could have an effect on the behavior of the hens.

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An extensive array of compounds has been studied for the treatment of ulcerative colitis (UC). The most frequently used nonbiologic drugs for the oral and intravenous treatment of ulcerative colitis include 5-aminosalicylate (5-ASA) drugs (mesalamine and derivatives), sulfasalazine, and other azo-bonded molecules of 5-ASA, steroids, calcineurin inhibitors (cyclosporine, tacrolimus, and sirolimus), thiopurines (azathioprine, 6-mercaptopurine), and methotrexate, which are already presented in other sections of this book and are thus not considered in this chapter. The therapies presented in this section should be considered as potential alternatives, mostly for mild-to-moderate ulcerative colitis (UC). They are substances mostly used without FDA indications, such as heparin, nicotine, rosiglitazone, and N-acetylcysteine as well as “natural” compounds suggested to have anti-inflammatory or reparative properties, such as aloe vera, curcumin, short-chain fatty acids, and Bowman-Birk inhibitor

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OBJECTIVE Short-chain enoyl-CoA hydratase (ECHS1) is a multifunctional mitochondrial matrix enzyme that is involved in the oxidation of fatty acids and essential amino acids such as valine. Here, we describe the broad phenotypic spectrum and pathobiochemistry of individuals with autosomal-recessive ECHS1 deficiency. METHODS Using exome sequencing, we identified ten unrelated individuals carrying compound heterozygous or homozygous mutations in ECHS1. Functional investigations in patient-derived fibroblast cell lines included immunoblotting, enzyme activity measurement, and a palmitate loading assay. RESULTS Patients showed a heterogeneous phenotype with disease onset in the first year of life and course ranging from neonatal death to survival into adulthood. The most prominent clinical features were encephalopathy (10/10), deafness (9/9), epilepsy (6/9), optic atrophy (6/10), and cardiomyopathy (4/10). Serum lactate was elevated and brain magnetic resonance imaging showed white matter changes or a Leigh-like pattern resembling disorders of mitochondrial energy metabolism. Analysis of patients' fibroblast cell lines (6/10) provided further evidence for the pathogenicity of the respective mutations by showing reduced ECHS1 protein levels and reduced 2-enoyl-CoA hydratase activity. While serum acylcarnitine profiles were largely normal, in vitro palmitate loading of patient fibroblasts revealed increased butyrylcarnitine, unmasking the functional defect in mitochondrial β-oxidation of short-chain fatty acids. Urinary excretion of 2-methyl-2,3-dihydroxybutyrate - a potential derivative of acryloyl-CoA in the valine catabolic pathway - was significantly increased, indicating impaired valine oxidation. INTERPRETATION In conclusion, we define the phenotypic spectrum of a new syndrome caused by ECHS1 deficiency. We speculate that both the β-oxidation defect and the block in l-valine metabolism, with accumulation of toxic methacrylyl-CoA and acryloyl-CoA, contribute to the disorder that may be amenable to metabolic treatment approaches.