455,349 research outputs found
Calcitonin receptor-like receptor is expressed on gastrointestinal immune cells
Background/Aims: Pharmacological and morphological studies suggest that the gut mucosal immune system and local neuropeptide-containing neurones interact. We aimed to determine whether gut immune cells are targets for calcitonin gene-related peptide (CGRP), which has potent immune regulatory properties. Methods: Using density gradient centrifugation, rat lamina propria mononuclear cells (LP-MNCs) and intra-epithelial lymphocytes (IELs) were isolated. RT-PCR was employed for the detection of mRNA of rat calcitonin receptor-like receptor (CRLR), which is considered to represent the pharmacologically defined CGRP receptor-1 subtype, as well as mRNA of the receptor activity-modifying proteins, which are essential for CRLR function and determine ligand specificity. A radioreceptor assay was employed for the detection of specific CGRP binding sites. Results: RT-PCR and DNA sequencing showed that LP-MNCs and IELs express CRLR. Incubation of isolated LP-MNCs with radiolabelled alphaCGRP revealed the existence of specific binding sites for CGRP. Conclusion: These novel data indicate that mucosal immune cells of the rat gut are a target for CGRP and provide significant evidence that CGRP functions as an immune regulator in the gut mucosa. Copyright (C) 2002 S. Karger AG, Basel
Audio-visual detection benefits in the rat
Human psychophysical studies have described multisensory perceptual benefits such as enhanced detection rates and faster reaction times in great detail. However, the neural circuits and mechanism underlying multisensory integration remain difficult to study in the primate brain. While rodents offer the advantage of a range of experimental methodologies to study the neural basis of multisensory processing, rodent studies are still limited due to the small number of available multisensory protocols. We here demonstrate the feasibility of an audio-visual stimulus detection task for rats, in which the animals detect lateralized uni- and multi-sensory stimuli in a two-response forced choice paradigm. We show that animals reliably learn and perform this task. Reaction times were significantly faster and behavioral performance levels higher in multisensory compared to unisensory conditions. This benefit was strongest for dim visual targets, in agreement with classical patterns of multisensory integration, and was specific to task-informative sounds, while uninformative sounds speeded reaction times with little costs for detection performance. Importantly, multisensory benefits for stimulus detection and reaction times appeared at different levels of task proficiency and training experience, suggesting distinct mechanisms inducing these two multisensory benefits. Our results demonstrate behavioral multisensory enhancement in rats in analogy to behavioral patterns known from other species, such as humans. In addition, our paradigm enriches the set of behavioral tasks on which future studies can rely, for example to combine behavioral measurements with imaging or pharmacological studies in the behaving animal or to study changes of integration properties in disease models
Species- and organ-specificity of secretory proteins derived from human prostate and seminal vesicles
Polyclonal antibodies against semenogelin (SG) isolated from human seminal vesicle secretion and acid phosphatase (PAP), β‐microseminoprotein (β‐MSP), and Prostate‐Specific Antigen (PSA) derived from human prostatic fluid, as well as a monoclonal antibody against β‐MSP were used for immunocytochemical detection of the respective antigens in different organs from different species. SG immunoreactivity was detected in the epithelium of the pubertal and adult human and in monkey seminal vesicle, ampulla of the vas deferens, and ejaculatory duct. PAP, β‐MSP, and PSA immunoreactivities were detected in the pubertal and adult human prostate and the cranial and caudal monkey prostate. With the exception of a weak PSA immunoreactivity in the proximal portions of the ejaculatory duct, none of the latter antisera reacted with seminal vesicle, ampullary, and ejaculatory duct epithelium. Among the non‐primate species studied (dog, bull, rat, guinea pig) only the canine prostatic epithelium displayed a definite immunoreactivity with the PAP antibody and a moderate reaction with the PSA antibody. No immunoreaction was seen in bull and rat seminal vesicle and canine ampulla of the vas deferens with the SG antibody. The same was true for the (ventral) prostate of rat, bull, and dog for β‐MSP. The epithelium of the rat dorsal prostate showed a slight cross‐reactivity with the monoclonal antibody against β‐MSP and one polyclonal antibody against PSA. The findings indicate a rather strict species‐dependent expression of human seminal proteins which show some similarities in primates, but only marginal relationship to species with different physiology of seminal fluid
Acoustical structured illumination for super-resolution ultrasound imaging.
Structured illumination microscopy is an optical method to increase the spatial resolution of wide-field fluorescence imaging beyond the diffraction limit by applying a spatially structured illumination light. Here, we extend this concept to facilitate super-resolution ultrasound imaging by manipulating the transmitted sound field to encode the high spatial frequencies into the observed image through aliasing. Post processing is applied to precisely shift the spectral components to their proper positions in k-space and effectively double the spatial resolution of the reconstructed image compared to one-way focusing. The method has broad application, including the detection of small lesions for early cancer diagnosis, improving the detection of the borders of organs and tumors, and enhancing visualization of vascular features. The method can be implemented with conventional ultrasound systems, without the need for additional components. The resulting image enhancement is demonstrated with both test objects and ex vivo rat metacarpals and phalanges
New high-performance liquid chromatography-dad method for analytical determination of arbutin and hydroquinone in rat plasma
Natural substances present in herbal preparations should be carefully used because they can give toxic or therapeutic effects despite of their amount or the way of administration. The safety of products of vegetable origin must be assessed before commercialisation by monitoring the active ingredients and their metabolites. This study was therefore designed to identify and quantify arbutin and its metabolite hydroquinone, naturally present in Arctostaphylos uva-ursi (L.) Spreng plant in rat plasma, after an acute and subacute administration of aqueous arbutin solution in Wistar rats. For this purpose a reversed-phase high-performance liquid chromatography coupled with photodiode array detection was developed to assess the pharmacokinetic of arbutin and hydroquinone in plasma of female rats treated with aqueous arbutin solutions. The detection (arbutin: 0.0617 µg/ml and hydroquinone 0.0120 µg/ml) and quantification (arbutin: 0.2060 µg/ml and hydroquinone: 0.0400 µg/ml) limits were determined. At the arbutin concentration level of 10.7 µg/ml repeatability was 13.33% and its recovery 93.4±6.93%, while at the hydroquinone concentration level of 10.6 µg/ml repeatability was 11.66% and its recovery 92.9±7.75%. Furthermore the method was fully validated and the obtained data indicate that the new method provides good performances
Detecting extreme mass ratio inspiral events in LISA data using the Hierarchical Algorithm for Clusters and Ridges (HACR)
One of the most exciting prospects for the Laser Interferometer Space Antenna
(LISA) is the detection of gravitational waves from the inspirals of
stellar-mass compact objects into supermassive black holes. Detection of these
sources is an extremely challenging computational problem due to the large
parameter space and low amplitude of the signals. However, recent work has
suggested that the nearest extreme mass ratio inspiral (EMRI) events will be
sufficiently loud that they might be detected using computationally cheap,
template-free techniques, such as a time-frequency analysis. In this paper, we
examine a particular time-frequency algorithm, the Hierarchical Algorithm for
Clusters and Ridges (HACR). This algorithm searches for clusters in a power map
and uses the properties of those clusters to identify signals in the data. We
find that HACR applied to the raw spectrogram performs poorly, but when the
data is binned during the construction of the spectrogram, the algorithm can
detect typical EMRI events at distances of up to Gpc. This is a little
further than the simple Excess Power method that has been considered
previously. We discuss the HACR algorithm, including tuning for single and
multiple sources, and illustrate its performance for detection of typical EMRI
events, and other likely LISA sources, such as white dwarf binaries and
supermassive black hole mergers. We also discuss how HACR cluster properties
could be used for parameter extraction.Comment: 21 pages, 11 figures, submitted to Class. Quantum Gravity. Modified
and shortened in light of referee's comments. Updated results consider tuning
over all three HACR thresholds, and show 10-15% improvement in detection rat
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Active Transport of Peptides Across the Intact Human Tympanic Membrane.
We previously identified peptides that are actively transported across the intact tympanic membrane (TM) of rats with infected middle ears. To assess the possibility that this transport would also occur across the human TM, we first developed and validated an assay to evaluate transport in vitro using fragments of the TM. Using this assay, we demonstrated the ability of phage bearing a TM-transiting peptide to cross freshly dissected TM fragments from infected rats or from uninfected rats, guinea pigs and rabbits. We then evaluated transport across fragments of the human TM that were discarded during otologic surgery. Human trans-TM transport was similar to that seen in the animal species. Finally, we found that free peptide, unconnected to phage, was transported across the TM at a rate comparable to that seen for peptide-bearing phage. These studies provide evidence supporting the concept of peptide-mediated drug delivery across the intact TM and into the middle ears of patients
Rat Monoclonal Antibodies Specific for LST1 Proteins
The LST1 gene is located in the human MHC class III region and encodes transmembrane and soluble isoforms that have been suggested to play a role in the regulation of the immune response and are associated with inflammatory diseases such as rheumatoid arthritis. Here we describe the generation and characterization of the first monoclonal antibodies against LST1. Two hybridoma lines secreting monoclonal antibodies designated 7E2 and 8D12 were established. The 7E2 antibody detects recombinant and endogenous LST1 by Western blot analysis while 8D12 reacts with recombinant and endogenous LST1 in immunoprecipitation and flow cytometry procedures. The newly established antibodies were used to survey LST1 protein expression in human cell lines, which was found to be tightly regulated, allowing the expression of transmembrane isoforms but suppressing soluble isoforms
Aldehyde Dehidrogenase Level and Fatty Acid Ethyl Ester as Biochemical Markers Persist Longer Than Ethanol in Wistar Rats After Chronic Alcohol Consumption
Alcohol consumption in human has increased from year to year in Indonesia and more recently, anincreasing number of cases of alcohol intoxication, alcoholic liver disease, and death were observed.The purpose of this experimental study was to examine the significance of two known biochemicalmarkers of alcohol given by mouth in the Wistar rats. The study design used was the “Truerandomized experimental post test only control group design". The rats were randomly distributedaccording to the experimental design and were treated daily for six weeks (chronic intake) with 5%and 20% alcohol. This study used 15 rats with 5 rats for treatment group treated with 5% alcohol, 5rats for treatment group treated with 20% alcohol, and 5 rats as control group treated with distilledwater. The biochemical markers were aldehyde dehydrogenase (ALDH) and Fatty Acid Ethyl Esters(FAEE). ALDH and FAEE were two biochemical markers of ethanol which are sensitive and specificfor alcohol consumption. The study was conducted in two phases. Initially, rats were treated orallyeveryday for six weeks with 5% and 20% alcohol, and then the blood level of ethanol, ALDH andFAEE were measured. Blood samples were collected at 6 and 24 hours after the last oral intake ofchronic alcohol administration. Qualitative analysis was carried out to detect the presence of ethanol,ALDH, and FAEE in the treatment groups and quantitative analysis to determine their levels in theblood of Wistar rats. Statistical analysis of ALDH was done by using parametric test and the presenceof FAEE persisting longer than ethanol by non-parametric test. The results showed that ALDHpersisted and increased significantly following chronic consumption of alcohol in the rats. Similarly,FAEEs persisted longer than ethanol after alcohol intake. After six hours, the ALDH level increasedby 108.14% in the rat treated chronically with 5% alcohol and by 85.07% in rat treated with 20%alcohol. After 24 hours, FAEE also persisted longer in the blood than ethanol following treatmentwith alcohol 5%. ALDH levels increased by 83.11% after chronic treatment with 5% alcohol and by112.05% in the rats treated with 20% alcohol. In the blood collected 24 hours after the last treatmentwith 5% alcohol, ALDH increased by 95.11% and by 86.79% in the rats treated with 20% alcohol.FAEE persisted longer than ethanol in the blood following administration of 5 % and 20% alcoholboth at 24 hours following chronic treatment. The longer persisting ALDH and FAEE were new andgood biochemical blood markers for chronic alcohol consumption in the Wistar rats
Study of protein expresion [sic] in peri-infarct tissue after cerebral ischemia
In this work, we report our study of protein expression in rat peri-infarct tissue, 48 h after the induction of permanent focal cerebral ischemia. Two proteomic approaches, gel electrophoresis with mass spectrometry and combined fractional diagonal chromatography (COFRADIC), were performed using tissue samples from the periphery of the induced cerebral ischemic lesions, using tissue from the contra-lateral hemisphere as a control. Several protein spots (3408) were identified by gel electrophoresis, and 11 showed significant differences in expression between peri-infarct and contralateral tissues (at least 3-fold, p < 0.05). Using COFRADIC, 5412 proteins were identified, with 72 showing a difference in expression. Apart from blood-related proteins (such as serum albumin), both techniques showed that the 70 kDa family of heat shock proteins were highly expressed in the peri-infarct tissue. Further studies by 1D and 2D western blotting and immunohistochemistry revealed that only one member of this family (the inducible form, HSP72 or HSP70i) is specifically expressed by the peri-infarct tissue, while the majority of this family (the constitutive form, HSC70 or HSP70c) is expressed in the whole brain. Our data support that HSP72 is a suitable biomarker of peri-infarct tissue in the ischemic brain
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