Search results for "RATS"

Quantification of GABA(A) receptor subunit mRNAs by non-radioisotopic competitive RT-PCR utilizing plate-based EIA methodology.

2000

We developed a non-radioisotopic quantitative competitive RT-PCR method for the measurement of gamma-aminobutyric acid (GABA) type A receptor subunit mRNA levels. The specificity of the method was optimized by the use of four subunit-specific oligonucleotides in the sequential steps: reverse transcription, polymerase chain reaction (PCR), and detection. The biotinylated PCR products were bound on streptavidin-coated microtiter plates allowing detection of the products using dinitrophenyl (DNP)-labeled probes and anti-DNP alkaline phosphatase conjugate. The method was set up for the six major cerebellar GABA(A) receptor subunits: alpha1; alpha6; beta2; beta3; gamma2 and delta. The method is …

Microcirculation after cerebral venous occlusions as assessed by laser Doppler scanning.

1997

✓ Research on cerebral venous circulation disturbances (CVCDs) has been limited partly by the paucity of animal models that produce consistent venous infarction. Occlusion of two adjacent cortical veins in rats by means of a photochemical thrombotic technique provides a minimally invasive, clinically relevant, and reproducible model suited to study the pathophysiology of CVCDs. In this study, the effects of venous occlusion on regional cortical blood flow and the brain damage that ensues were evaluated. Cortical vein occlusion was induced by photoactivation of rose bengal via 100-µm fiberoptic illumination. The cerebral venous flow pattern was examined using fluorescence angiography until 9…

Alterations of regional cerebral blood flow and oxygen saturation in a rat sinus-vein thrombosis model.

1996

Background and Purpose The pathophysiology of sinus-vein thrombosis (SVT) in patients and experimental animals is still poorly understood. This study was designed to examine and further elucidate the pathophysiological sequence of events, especially the relationship between local and regional blood flow and hemoglobin oxygen saturation (HbSO 2 ) detected at identical locations. The use of both parameters as outcome indicators should be compared. Methods SVT was induced by ligation of the superior sagittal sinus (SSS) and slow injection of kaolin-cephalin suspension into the SSS in rats. Regional cerebral blood flow (rCBF) was assessed by laser-Doppler flowmetry together with regional HbSO …

Evaluation of the anti-inflammatory and analgesic activity of Me-UCH9, a dual cyclooxygenase-2/5-lipoxygenase inhibitor

2007

Abstract Recently, we reported the dual inhibition of cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LO) activity by some phenylsulphonyl urenyl chalcone derivatives. 2,4-dichloro-4′ N [ N ′(4″methylphenylsulphonyl)urenyl] chalcone (Me-UCH9), was selected in the present study to determine its potential anti-inflammatory and analgesic effect after oral administration in several animal models related to the activation of COX-2 and 5-LO pathways. In the zymosan stimulated mouse air pouch model, Me-UCH9, reduced in a dose-dependent manner leukotriene B 4 (LTB 4 ) levels in pouch exudates obtained at 4 h, as well as prostaglandin E 2 (PGE 2 ) generated through COX-2 activation at 24 h. Tumor nec…

Biochemical analysis of class II antigens. Identification of a two- and a three-polypeptide chain complex of I-A locus equivalent molecules in the ra…

1983

The polypeptide chain composition of class II antigens from LEW rat spleen cells was studied utilizing cross-reactive mouse alloantiserum A. TH anti-A.TL (specificity anti-Iak) and the monoclonal antibodies MRC-OX6 and MRC-OX3 for immunoprecipitation. Two-dimensional gel mapping of A. TH anti-A. TL immunoprecipitates revealed that, as in the mouse, two groups of class II antigens exist corresponding to I-A and I-E locus equivalent structures. In the absence of reducing agents three monomeric chains α, 36 kDa (p36); γ, 33 kDa (p33); and β, 23 kDa (p23), were detected for I-A equivalent antigens, whereas I-E equivalent molecules separated into five monomeric chains: α, 37 kDa (p37); γ, 33 kDa…

Activity–Bioavailability balance in Oral Drug Development for a Selected Group of 6‐Fluoroquinolones

2002

Abstract A nomogram is proposed to select the best candidate in drug development studies with quinolones and is intended to substitute other possible models. The nomogram is referred to as an activity–bioavailability balance (ABB) because it includes the following two criteria: ABB= 1 / gm MIC ( drug candidate ) 1 /gm MIC ( ciprofloxacin ) · F calc \( drug candidate \) F calc ( ciproflaxacin ) . The in vitro activity of a group of 4′ N ‐alkyl‐ciprofloxacin derivatives was determined together with that of ciprofloxacin, initially against some reference strains and subsequently against 159 clinical isolates of eight selected species. The inverse of the geometric mean of the lowest concentrati…

Prediction of acute toxicity of organophosphorus pesticides using topological indices

2007

Topological indices were used in the prediction of the acute toxicity (intraperitoneal and oral LD(50)) of organophosphorus pesticides on rats. Models with six variables for the prediction of LD(50)-i.p. (r = 0.849, Q(2) = 0.613) and eight variables for LD(50)-oral (r = 0.906, Q(2) = 0.701) were selected. External group and cross-validation by use of leave-n-out tests were also performed in order to assess the stability and the prediction performance of the selected topological models.

A current source density analysis of field potentials evoked in slices of visual cortex

1987

The method of one-dimensional current source density (CSD) analysis was applied to field potentials recorded from 350 microns thick slices of the primary visual cortex of rats and cats. Field potentials were elicited by stimulation of the white matter and recorded along trajectories perpendicular to the cortical layers at spatial intervals of 25 to 50 microns. The resulting CSD distributions resembled closely those recorded from the cat visual cortex "in vivo". The responses with the shortest latency were distinct sinks in layers IV and VI probably reflecting monosynaptic EPSP's from specific thalamic afferents. From layer IV activity was relayed along three major routes: 1. to the supragra…

Acute and short-term toxicity of 2,3,4,6-tetrachlorophenol in rats

1981

Ras-related GTPase Rhob represses NF-kappaB signaling.

2000

rhoB encoding a Ras-related GTPase is immediate-early inducible by genotoxic treatments, indicating that it is part of the cellular stress response. Here, we investigated the influence of RhoB on signal pathways that are rapidly evoked by genotoxic compounds. The data obtained show that wild-type RhoB neither affects activation of mitogen-activated protein kinases nor AP-1-dependent gene expression. However, RhoB inhibited both basal and genotoxic agent-stimulated activity of the transcription factor nuclear factor kappaB (NF-kappaB). Thus, RhoB attenuated alkylation-induced increase in the DNA binding activity of NF-kappaB and abrogated NF-kappaB-driven gene expression. Furthermore, RhoB i…