179 resultados para ELISA Kits
Resumo:
Pregnancy is proposed to be a Th2 phenomenon, where Th2 cytokines inhibit Th1 responses to improve fetal survival. The importance of interleukin-10 (IL-10), an immunomodulatory cytokine produced by Th2 cells, in the maintenance of normal pregnancy is becoming increasingly apparent. In a longitudinal case-control study, the physiological effect of pregnancy on plasma IL-10 was investigated. The plasma concentration of IL-10 was determined using an ELISA technique in 99 pregnant women sampled at 12, 20 and 35 weeks of gestation, 38 non-pregnant control subjects sampled in parallel and in a subgroup of women sampled at 3 days post-partum (n, pregnant 21, non-pregnant 21). Plasma IL-10 was significantly higher in pregnant women at 12, 20 and 35 weeks of gestation (p
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Studies on the immunoglobulin (Ig)E immune responses to the gastric nematode, Teladorsagia circumcincta, have demonstrated a major high molecular weight allergen (HMWTc). Cross reactive allergens of similar MW were demonstrated for Trichostrongylus colubriformis and Cooperia curticei, but not for Haemonchus contortus. Purification of HMWTc was achieved by gel-filtration chromatography, and nonreducing SDS-PAGE and Western blot analysis revealed two closely associated bands with a molecular weight of approximately 140-150?kDa. Reduction showed four IgE reactive bands of 120, 50, 45 and 30?kDa, and deglycosylation abrogated the immunoreactivity of the 120 and 30?kDa bands. Ultrastructural immunolocalization by electron microscopy revealed that the IgE reactivity was confined to the cuticular surface of the infective (L3) larvae. ELISA studies to determine the IgE anti-HMWTc responses in lambs during their first grazing season, demonstrated significantly higher IgE antibody in lambs with low accumulative faecal egg count (FEC) compared to animals with high accumulative FEC. These studies provide evidence for a protective function of IgE antibody in Teladorsagia infections in lambs.
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Light microscopic studies comparing sperm parameters show little association between diabetes and male fertility. However, with the introduction of new analytical techniques, evidence is now emerging of previously undetectable effects of diabetes on sperm function. Specifically, a recent study has found a significantly higher sperm nuclear DNA fragmentation in diabetic men. As advanced glycation end products (AGEs) are important instigators of oxidative stress and cell dysfunction in numerous diabetic complications, we hypothesized that these compounds could also be present in the male reproductive tract. The presence and localization of the most prominent AGE, carboxymethyl-lysine (CML), in the human testis, epididymis and sperm was determined by immunohistochemistry. Parallel ELISA and Western blot analyses were performed to ascertain the amount of CML in seminal plasma and sperm from 13 diabetic and nine non-diabetic subjects. CML immunoreactivity was found throughout the seminiferous epithelium, the nuclei of spermatogonia and spermatocytes, in the basal and principle cells cytoplasm and nuclei of the caput epididymis and on most sperm tails, mid pieces and all cytoplasmic droplets. The acrosomal cap, especially the equatorial band, was prominently stained in diabetic samples only. The amount of CML was significantly higher (p = 0.004) in sperm from non-diabetic men. Considering the known detrimental actions of AGEs in other organs, the presence, location and quantity of CML, particularly the increased expression found in diabetic men, suggest that these compounds may play a hitherto unrecognized role in male infertility.
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Anticoccidials are compounds that are widely used as feed additives to prevent and treat coccidiosis. They are licensed for use in a prescribed concentration and during a certain time interval for broilers and pullets but not for laying hens. It was shown in the past that carry-over at the feeding mill is found to be the main reason for the presence of residues in eggs. An animal experiment was set up to investigate the effect of carry-over at the feeding mill on the presence of residues of anticoccidials in eggs. For the compounds diclazuril, robenidine, halofuginone and nicarbazin in combination with narasin, two concentration levels were tested: the maximum allowed concentration for broilers (100%) and a concentration corresponding to 5% carry-over during feed preparation. Also dimetridazole was included in the experiment but only at one concentration level. Eggs were sampled during treatment (14 days) and for a period of 30 days after withdrawal of the anticoccidial-containing feed. Residues were determined, and deposition and depletion curves were generated. Analyses were performed by ELISA and LC-MS/MS. For all compounds, substantial residues could be found in the 5% groups, which points out the risk of carry-over at the feeding mill. The distribution of the residues between egg yolk and white was determined by analyzing both fractions.
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Six polyclonal antisera to chloramphenicol (CAP) were successfully raised in camels, donkeys and goats. As a comparison of sensitivity, IC50 values ranged from 0.3 ng mL(-1) to 5.5 ng mL(-1) by enzyme-linked immunosorbent assay (ELISA) and from 0.7 ng mL(-1) to 1.7 ng mL(-1) by biosensor assay. The introduction of bovine milk extract improved the sensitivity of four of the antisera by ELISA and two by biosensor assay; a reduction in sensitivity of the remaining antisera ranged by a factor of 1.1-2.6. Porcine kidney extract reduced the sensitivity of all the antisera by a factor ranging from 1.1 to 7 by ELISA and a factor of 1.5 to 4 by biosensor. A low cross-reactivity with thiamphenicol (TAP) and florfenicol (FF) was displayed by antiserurn G2 (1.2% and 18%, respectively) when a homologous ELISA assay format was employed. No cross-reactivity was displayed by any of the antisera when a homologous biosensor assay format was employed. Switching to a heterologous ELISA format prompted three of the antisera to display more significant cross-reactivity with TAP and FF (53% and 82%, respectively, using Dl). The heterologous biosensor assay also increased the cross-reactivity of D1 for TAP and FF (56% and 129%, respectively) and of one other antiserum (Gl) to a lesser degree. However, unlike the ELISA, the heterologous biosensor assay produced a substantial reduction in sensitivity (by a factor of 6 for D1). (C) 2007 Elsevier B.V. All rights reserved.
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Tuberculosis (TB) pleural disease is complicated by extensive tissue destruction. Matrix metalloproteinase (MMP)-1 and -9 are implicated in immunopathology of pulmonary and central nervous system TB. There are few data on MMP activity in TB pleurisy. The present study investigated MMP-1, -2 and -9 and their specific inhibitors (tissue inhibitor of metalloproteinase (TIMP)-1 and -2) in tuberculous effusions, and correlated these with clinical and histopathological features. Clinical data, routine blood tests, and pleural fluid/biopsy material were obtained from 89 patients presenting with pleural effusions in a TB-endemic area. MMP-1, -2 and -9 were measured by zymography or western blot, and TIMP-1 and -2 by ELISA. Pleural biopsies were examined microscopically, cultured for acid–alcohol fast bacilli and immunostained for MMP-9. Tuberculous pleural effusions contained the highest concentrations of MMP-9 compared with malignant effusions or heart failure transudates. MMP-9 concentrations were highest in effusions from patients with granulomatous biopsies: median (interquartile range) 108 (61–218) pg·mL-1 versus 43 (12–83) pg·mL-1 in those with nongranulomatous pleural biopsies. MMP-1 and -2 were not upregulated in tuberculous pleural fluid. The ratio of MMP-9:TIMP-1 was significantly higher in TB effusions. Tuberculous pleurisy is characterised by a specific pattern of matrix metalloproteinase-9 upregulation, correlating with the presence of granulomas and suggesting a specific role for matrix metalloproteinase-9 in inflammatory responses in tuberculous pleural disease.
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We present Ca it K and Ti it optical spectra of early-type stars taken mainly from the ultraviolet and visual echelle spectrograph (LIVES) Paranal Observatory Project, plus H 1 21-cm spectra, from the Vila-Elisa and Leiden-Dwingeloo Surveys, which are employed to obtain distances to intermediate- and high-velocity clouds (IHVCs). H I emission at a velocity of -117 km s(-1) towards the sightline HD 30677 (l, b = 190 degrees.2, -22 degrees.2) with column density -1.7 x 10(19) cm(-2) has no corresponding Ca Pi K absorption in the LIVES spectrum, which has a signal-to-noise ratio (S/N) of 610 per resolution element. The star has a spectroscopically determined distance of 2.7 kpc, and hence sets this as a firm lower distance limit towards Anti-Centre cloud ACII. Towards another sightline (HD 46185 with 1, b = 222 0, -10 degrees.1), H1 at a velocity of +122 km s(-1) and column density of 1.2 x 10(19) cm(-2) is seen. The corresponding Ca Pi K spectrum has a S/N of 780, although no absorption is observed at the cloud velocity. This similarly places a firm lower distance limit of 2.9 kpc towards this parcel of gas that may be an intermediate-velocity (IV) cloud. The lack of IV Ca it absorption towards HD 196426 (1, b = 45 degrees.8, -23 degrees.3) at a S/N of 500 reinforces a lower distance limit of -700 pc towards this part of complex gp, where the H I column density is 1.1 x 1019 cm(-2) and velocity is +78 km s(-1). Additionally, no IV Cart is seen in absorption in the spectrum of HD 19445, which is strong in H I with a column density of 8 x 10(19) cm(-2) at a velocity of - -42 km s(-1), placing a firm although uninteresting lower distance limit of 39 pc to this part of IV South. Finally, no high-velocity Call K absorption is seen towards HD 115363 (l, b = 306.0,-1.0) at a S/N of 410, placing a lower distance of -3.2 kpc towards the HVC gas at velocity of - +224 km s(-1) and WE column density of 5.2 x 10(19) cm(-2). This gas is in the same region of the sky as complex WE (Wakker 2001), but at higher velocities. The non-detection of Ca it K absorption sets a lower distance of -3.2 kpc towards the HVC, which is unsurprising if this feature is indeed related to the Magellanic System.
Resumo:
AIMS/HYPOTHESIS: Recent studies suggest that oxidative stress should be monitored alongside HbA(1c) to identify subgroups of diabetic patients at high risk of initiation or progression of retinopathy. The acrolein-derived advanced lipoxidation end-product (ALE), [Formula: see text]-(3-formyl-3,4-dehydropiperidino)lysine (FDP-lysine), is a useful biomarker that reflects the cumulative burden of oxidative stress over long periods of time. The purpose of the present study was to investigate whether serum and haemoglobin levels of FDP-lysine are associated with the severity of diabetic retinopathy in type 1 and type 2 diabetic patients.
METHODS: Serum and haemoglobin levels of FDP-lysine were measured by competitive ELISA in 59 type 1 and 76 type 2 diabetic patients with no retinopathy, non-proliferative retinopathy or proliferative retinopathy (mean age [+/-SEM] 54.3 +/- 1.3 years), and in 47 non-diabetic control individuals (mean age 51.9 +/- 2.1 years).
RESULTS: Serum and haemoglobin levels of FDP-lysine were significantly increased in diabetic patients compared with control individuals (p = 0.04 and p = 0.002, respectively). However, no significant association was found between levels of serum FDP-lysine and the severity of diabetic retinopathy (p = 0.97). In contrast, increased haemoglobin FDP-lysine levels were observed in patients with proliferative retinopathy compared with patients without retinopathy and with non-proliferative retinopathy (p = 0.04). The relationship of FDP-lysine with proliferative retinopathy was unaltered after adjustment for HbA(1c), or other clinical parameters.
CONCLUSIONS/INTERPRETATION: Our data suggest that haemoglobin FDP-lysine may provide a useful risk marker for the development of proliferative diabetic retinopathy independently of HbA(1c), and that elevated intracellular ALE formation may be involved in the pathogenesis of this sight-threatening complication of diabetes.
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Okadaic acid (OA) and structurally related toxins dinophysistoxin-1 (DTX-1), and DTX-2, are lipophilic marine biotoxins. The current reference method for the analysis of these toxins is the mouse bioassay (MBA). This method is under increasing criticism both from an ethical point of view and because of its limited sensitivity and specificity. Alternative replacement methods must be rapid, robust, cost effective, specific and sensitive. Although published immuno-based detection techniques have good sensitivities, they are restricted in their use because of their inability to: (i) detect all of the OA toxins that contribute to contamination; and (ii) factor in the relative toxicities of each contaminant. Monoclonal antibodies (MAbs) were produced to OA and an automated biosensor screening assay developed and compared with ELISA techniques. The screening assay was designed to increase the probability of identifying a MAb capable of detecting all OA toxins. The result was the generation of a unique MAb which not only cross-reacted with both DTX-1 and DTX-2 but had a cross-reactivity profile in buffer that reflected exactly the intrinsic toxic potency of the OA group of toxins. Preliminary matrix studies reflected these results. This antibody is an excellent candidate for the development of a range of functional immunochemical-based detection assays for this group of toxins.
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Rheologically structured vehicle (RSV) gels were developed as delivery systems for vaginal mucosal vaccination with an HIV-1 envelope glycoprotein (CN54gp140). RSVs comprised a mucoadhesive matrix forming and vaginal fluid absorbing polymer. The mucoadhesive and rheological properties of the RSVs were evaluated in vitro, and the distribution, antigenicity and release of CN54gp140 were analysed by ELISA. CN54gp140 was uniformly distributed within the RSVs and continuously released in vitro in an antigenically intact form over 24 h. Vaginal administration to rabbits induced specific serum IgG, and IgG and IgA in genital tract secretions. The RSVs are a viable delivery modality for vaginal immunization.
Increased cerebral output of free radicals during hypoxia: implications for acute mountain sickness?
Resumo:
Bailey DM, Taudorf S, Berg RMG, Lundby C, McEneny J, Young IS, Evans KA, James PE, Shore A, Hullin DA, McCord JM, Pedersen BK, Moller K. Increased cerebral output of free radicals during hypoxia: implications for acute mountain sickness? Am J Physiol Regul Integr Comp Physiol 297: R1283-R1292, 2009. First published September 2, 2009; doi: 10.1152/ajpregu.00366.2009.-This study examined whether hypoxia causes free radical-mediated disruption of the blood-brain barrier (BBB) and impaired cerebral oxidative metabolism and whether this has any bearing on neurological symptoms ascribed to acute mountain sickness (AMS). Ten men provided internal jugular vein and radial artery blood samples during normoxia and 9-h passive exposure to hypoxia (12.9% O-2). Cerebral blood flow was determined by the Kety-Schmidt technique with net exchange calculated by the Fick principle. AMS and headache were determined with clinically validated questionnaires. Electron paramagnetic resonance spectroscopy and ozone-based chemiluminescence were employed for direct detection of spin-trapped free radicals and nitric oxide metabolites. Neuron-specific enolase (NSE), S100 beta, and 3-nitrotyrosine (3-NT) were determined by ELISA. Hypoxia increased the arterio-jugular venous concentration difference (a-v(D)) and net cerebral output of lipid-derived alkoxyl-alkyl free radicals and lipid hydroperoxides (P
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Breakdown of the inner blood-retinal barrier (iBRB) occurs early in diabetes and is central to the development of sight-threatening diabetic macular edema (DME) as retinopathy progresses. In the current study, we examined how advanced glycation end products (AGEs) forming early in diabetes could modulate vasopermeability factor expression in the diabetic retina and alter inter-endothelial cell tight junction (TJ) integrity leading to iBRB dysfunction. We also investigated the potential for an AGE inhibitor to prevent this acute pathology and examined a role of the AGE-binding protein galectin-3 (Gal-3) in AGE-mediated cell retinal pathophysiology. Diabetes was induced in C57/BL6 wild-type (WT) mice and in Gal-3(-/-) transgenic mice. Blood glucose was monitored and AGE levels were quantified by ELISA and immunohistochemistry. The diabetic groups were subdivided, and one group was treated with the AGE-inhibitor pyridoxamine (PM) while separate groups of WT and Gal-3(-/-) mice were maintained as nondiabetic controls. iBRB integrity was assessed by Evans blue assay alongside visualisation of TJ protein complexes via occludin-1 immunolocalization in retinal flat mounts. Retinal expression levels of the vasopermeability factor VEGF were quantified using real-time RT-PCR and ELISA. WT diabetic mice showed significant AGE -immunoreactivity in the retinal microvasculature and also showed significant iBRB breakdown (P < .005). These diabetics had higher VEGF mRNA and protein expression in comparison to controls (P < .01). PM-treated diabetics had normal iBRB function and significantly reduced diabetes-mediated VEGF expression. Diabetic retinal vessels showed disrupted TJ integrity when compared to controls, while PM-treated diabetics demonstrated near-normal configuration. Gal-3(-/-) mice showed significantly less diabetes-mediated iBRB dysfunction, junctional disruption, and VEGF expression changes than their WT counterparts. The data suggests an AGE-mediated disruption of iBRB via upregulation of VEGF in the diabetic retina, possibly modulating disruption of TJ integrity, even after acute diabetes. Prevention of AGE formation or genetic deletion of Gal-3 can effectively prevent these acute diabetic retinopathy changes.
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Alpha-1-antitrypsin (A1AT) deficiency is characterized by increased neutrophil elastase (NE) activity and oxidative stress in the lung. We hypothesized that NE exposure generates reactive oxygen species by increasing lung nonheme iron. To test this hypothesis, we measured bronchoalveolar lavage (BAL) iron and ferritin levels, using inductively coupled plasma (ICP) optical emission spectroscopy and an ELISA, respectively, in A1AT-deficient patients and healthy subjects. To confirm the role of NE in regulating lung iron homeostasis, we administered intratracheally NE or control buffer to rats and measured BAL and lung iron and ferritin. Our results demonstrated that A1AT-deficient patients and rats postelastase exposure have elevated levels of iron and ferritin in the BAL. To investigate the mechanism of NE-induced increased iron levels, we exposed normal human airway epithelial cells to either NE or control vehicle in the presence or absence of ferritin, and quantified intracellular iron uptake using calcein fluorescence and ICP mass spectroscopy. We also tested whether NE degraded ferritin in vitro using ELISA and western analysis. We demonstrated in vitro that NE increased intracellular nonheme iron levels and degraded ferritin. Our results suggest that NE digests ferritin increasing the extracellular iron pool available for cellular uptake.
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Since 1994, Irish cattle have been exposed to greater risks of acquiring Mycobacterium avium subspecies paratuberculosis (MAP) infection as a consequence of the importation of over 70,000 animals from continental Europe. In recent years, there has been an increase in the number of reported clinical cases of paratuberculosis in Ireland. This study examines the prevalence of factors that promote the introduction and within-herd transmission of Mycobacterium avium subspecies paratuberculosis (MAP) on selected Irish dairy farms in the Cork region, and the association between these factors and the results of MAP screening tests on milk sock filter residue (MFR). A total of 59 dairy farms, selected using non-random methods but apparently free of endemic paratuberculosis, were enrolled into the study. A questionnaire was used to collect data about risk factors for MAP introduction and transmission. The MFR was assessed on six occasions over 24 months for the presence of MAP, using culture and immunomagnetic separation prior to polymerase chain reaction (IMS-PCR). Furthermore, blood samples from all entire male and female animals over one year of age in 20 herds were tested by ELISA. Eighteen (31%) farms had operated as closed herds since 1994, 28 (47%) had purchased from multiple sources and 14 (24%) had either direct or indirect (progeny) contact with imported animals. Milk and colostrum were mixed on 51% of farms, while 88% of farms fed pooled milk. Thirty (51%) herds tested negative to MFR culture and IMS-PCR, 12 (20%) were MFR culture positive, 26 (44%) were IMS-PCR positive and seven (12%) were both culture and IMS-PCR positive. The probability of a positive MFR culture was significantly associated with reduced attendance at calving, and with increased use of individual calf pens and increased (but not significantly) if multiple suckling was practised. There was poor agreement between MFR culture and MFR IMS-PCR results, but moderate agreement between MFR culture and ELISA test results. This study highlights a lack of awareness among Irish dairy farmers about the effect of inadequate biosecurity on MAP introduction. Furthermore, within-herd transmission will be facilitated by traditional calf rearing and waste management practices. The findings of viable MAP in the presence of known transmission factors in non-clinically affected herds could be a prelude to long-term problems for the Irish cattle and agri-business generally.
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Amphibian skin secretions are renowned as complex mixtures of bioactive peptides many of which are analogues of endogenous regulatory peptides. While skin secretions can be obtained non-invasively for peptidome analysis, parallel studies on the granular gland transcriptome required specimen sacrifice. The aim of the present study was to analyse archived skin secretions to determine the robustness of bioactive peptide precursor-encoding polyadenylated mRNAs in an attempt to extract maximum molecular information from rare samples. A range of solvated skin secretion samples were examined after lyophilisation for their potential to generate viable and comprehensive cDNA libraries based upon polyadenylated mRNA capture and amplification/cloning using appropriate commercial kits. Here we present unequivocal data that the granular gland transcriptome persists in a PCR amenable format even after storage for as long as 12 years in 0.1%(v/v) aqueous trifluoroacetic acid (TFA). We used a pooled skin secretion sample (2 ml) from the yellow-bellied toad, Bombina variegata (n = 14), containing the equivalent of 5 mg/ml of lyophilised skin secretion, that had been used in part for peptide isolation purposes in 1998 and had been stored at - 20 °C since that time. In the first cloning experiment, 12 different bombinin-like peptide precursor cDNAs were cloned encoding 17 different bombinins, the majority of which were novel. Subsequently, bombesin and bradykinin-related peptide precursor transcripts have been cloned successfully. These data illustrate the unexpected stability/longevity of the transcriptome in these secretions — a finding with implications for both this field of research and for the wider field of molecular biology.