DYNAMICS OF TEAR FLOW USING THE PHENOL RED THREAD TEST

1994 ◽  
Vol 71 (Supplement) ◽  
pp. 142
Author(s):  
Kenneth J. Blades ◽  
Sudhir Patel
Keyword(s):  
Phenol Red ◽  
Tear Flow

scholarly journals Effect of Intramuscular Medetomidine Administration on Tear Flow in Rats

2020 ◽  
Vol 7 (2) ◽  
pp. 42 ◽  
Author(s):  
Teppei Kanda ◽  
Yuka Mizoguchi ◽  
Kayo Furumoto ◽  
Yuki Shimizu ◽  
Noritaka Maeta ◽  
...  
Keyword(s):  
Linear Regression ◽  
Linear Regression Analysis ◽  
Area Under The Curve ◽  
Calculated Data ◽  
Physiological Saline ◽  
Control Group ◽  
Phenol Red ◽  
Dependent Manner ◽  
Tear Flow ◽  
Physiological Saline Solution

Medetomidine has been reported to decrease tear flow significantly in dogs, cats, and pigs when used as a sedative or analgesic; however, there are no such reports when it comes to rats. The present study aimed to investigate the effect of medetomidine on tear flow in rats. Medetomidine in doses of 50, 100, or 200 µg/kg or a physiological saline solution as the control, were administered intramuscularly to male Slc:Wistar/ST rats. After the administration of medetomidine, tear flow in both eyes was measured using a phenol red thread tear test. The area under the curve (AUC) of phenol red thread test values from baseline to 8 h was calculated. Data were plotted against the dose of medetomidine and simple linear regression analysis was performed. The effect of the drug on phenol red thread test values was considered dose-related when linear analysis yielded a significant relationship. In all medetomidine-treated groups, tear flow decreased significantly in both eyes after administration, while no significant changes were observed in either eye in the control group. The AUC values from baseline to 8 h after administration in groups treated with 100 and 200 µg/kg of medetomidine were significantly lower in both the left and right eyes compared to the control group. The linear regression of the AUC values was significant for both eyes. Our results indicated that the intramuscular administration of medetomidine in rats decreased tear flow significantly in a dose-dependent manner.

The dynamics of tear flow within a phenol red impregnated thread

1996 ◽  
Vol 16 (5) ◽  
pp. 409-415 ◽  
Author(s):  
Kenneth J. Blades ◽  
Sudi Patel
Keyword(s):  
Phenol Red ◽  
Tear Flow

scholarly journals Effect of Different Doses of Atipamezole on Reversal of Medetomidine-Induced Tear-Flow Decrease in Rats

2020 ◽  
Vol 7 (4) ◽  
pp. 197
Author(s):  
Teppei Kanda ◽  
Manami Gotoh ◽  
Ayumi Makino ◽  
Kayo Furumoto ◽  
Yuki Shimizu ◽  
...  
Keyword(s):  
Baseline Level ◽  
Optimal Dose ◽  
Intramuscular Administration ◽  
Phenol Red ◽  
Α2 Adrenoceptor ◽  
Tear Flow ◽  
Adrenoceptor Agonists ◽  
Different Doses

It has been reported that α2-adrenoceptor agonists such as medetomidine decrease tear flow in many species, including rats. Few studies have investigated the involvement of α2-adrenoceptor in decreased tear flow; the issue has not been illustrated sufficiently. Therefore, we aimed to investigate the effect of different doses of atipamezole on the reversal of medetomidine-induced tear-flow decrease to reveal the specific involvement of α2-adrenoceptor. Treatment with 400, 800, or 1600 µg/kg atipamezole (or saline as the control) was intramuscularly administered to rats 15 min following intramuscular administration of 200 µg/kg medetomidine. After medetomidine administration, tear flow was measured using a phenol red thread test (PRTT). PRTT values decreased significantly after 200 µg/kg medetomidine administration. The PRTT values after 800 (optimal dose to reverse) and 1600 µg/kg atipamezole administration reached baseline, but never exceeded it significantly. Treatment with 400 µg/kg atipamezole also reversed the decrease in PRTT value but the PRTT remained lower than baseline. The optimal dose and the higher dose of atipamezole fully reversed the medetomidine-induced decrease in tear flow to the baseline level in rats, while the lower dose of atipamezole partially recovered tear flow.

Effect of fumarprotocetraric acid isolated the Lichen Cladonia verticillaris on tracheobronchial phenol red excretion in mice

Planta Medica ◽  
2011 ◽  
Vol 77 (12) ◽  
Author(s):  
GP Duarte ◽  
GD Alves ◽  
ED Franco ◽  
RG Melo ◽  
DP Cordeiro ◽  
...  
Keyword(s):  
Phenol Red

An easy and low-cost biomagnetic methodology to study regional gastrointestinal transit in rats

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Leonardo Pinto ◽  
Guilherme Soares ◽  
André Próspero ◽  
Erick Stoppa ◽  
Gabriel Biasotti ◽  
...  
Keyword(s):  
Low Cost ◽  
Gastrointestinal Transit ◽  
Alternate Current ◽  
Phenol Red ◽  
Distal Small Intestine ◽  
Reliable Assessment ◽  
Imaging Approach ◽  
Magnetic Tracer ◽  
Tracer Distribution ◽  
Gi Transit

Abstract The identification of gastrointestinal (GI) motility disorders requires the evaluation of regional GI transit, and the development of alternative methodologies in animals has a significant impact on translational approaches. Therefore, the purpose of this study was to validate an easy and low-cost methodology (alternate current biosusceptometry – ACB) for the assessment of regional GI transit in rats through images. Rats were fed a test meal containing magnetic tracer and phenol red, and GI segments (stomach, proximal, medial and distal small intestine, and cecum) were collected to assess tracer’s retention at distinct times after ingestion (0, 60, 120, 240, and 360 min). Images were obtained by scanning the segments, and phenol red concentration was determined by the sample’s absorbance. The temporal retention profile, geometric center, gastric emptying, and cecum arrival were evaluated. The correlation coefficient between methods was 0.802, and the temporal retention of each segment was successfully assessed. GI parameters yielded comparable results between methods, and ACB images presented advantages as the possibility to visualize intrasegmental tracer distribution and the automated scan of the segments. The imaging approach provided a reliable assessment of several parameters simultaneously and may serve as an accurate and sensitive approach for regional GI research in rats.

scholarly journals Ce-MOF with Intrinsic Haloperoxidase-Like Activity for Ratiometric Colorimetric Detection of Hydrogen Peroxide

Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 204
Author(s):  
Yanyan Cheng ◽  
Ling Liang ◽  
Fanggui Ye ◽  
Shulin Zhao
Keyword(s):  
Structural Characteristics ◽  
Metal Organic Framework ◽  
Colorimetric Detection ◽  
Mixed Valence ◽  
Bromophenol Blue ◽  
Phenol Red ◽  
Chromogenic Substrate ◽  
Colorimetric Sensing ◽  
Sensing Platform ◽  
Metal Organic

Metal–organic framework (MOF) nanozymes, as emerging members of the nanozymes, have received more and more attention due to their composition and structural characteristics. In this work, we report that mixed-valence state Ce-MOF (MVCM) has intrinsic haloperoxidase-mimicking activity. MVCM was synthesized by partial oxidation method using Ce-MOF as a precursor. In the presence of H2O2 and Br−, MVCM can catalyze oxidative bromination of chromogenic substrate phenol red (PR) to produce the blue product bromophenol blue (Br4PR), showing good haloperoxidase-like activity. Because of the special chromogenic substrate, we constructed a ratiometric colorimetric-sensing platform by detecting the absorbance of the MVCM-(PR, Br−) system at wavelengths of 590 and 430, for quantifying H2O2, where the detection limit of the H2O2 is 3.25 μM. In addition, the haloperoxidase-mimicking mechanism of the MVCM is proposed. Moreover, through enzyme kinetics monitoring, the Km (H2O2 and NH4Br) of the MVCM is lower than that of cerium oxide nanomaterials, indicating that the MVCM has a stronger binding affinity for H2O2 and NH4Br than other materials. This work provides more application prospects for the development of nanozymes in the field of biosensors in the future.

scholarly journals Magnetic Field-Assisted Photocatalytic Degradation of Organic Pollutants over Bi1−xRxFeO3 (R = Ce, Tb; x = 0.00, 0.05, 0.10 and 0.15) Nanostructures

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4079
Author(s):  
Radhalayam Dhanalakshmi ◽  
Nambi Venkatesan Giridharan ◽  
Juliano C. Denardin
Keyword(s):  
Magnetic Field ◽  
Rare Earth ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Organic Pollutants ◽  
Visible Light Irradiation ◽  
Organic Pollutant ◽  
Hydrothermal Process ◽  
Phenol Red ◽  
Magnetic Features

Magnetic-field-accelerated photocatalytic degradation of the phenol red (PR) as a model organic pollutant was studied using rare-earth elements modified BiFeO3 (Bi1−xRxFeO3 (R = Ce, Tb; x = 0.0, 0.05, 0.10 and 0.15); BFO: RE) nanostructures. The nanostructures were prepared via the hydrothermal process and their morphological, structural, functional, optical and magnetic features were investigated in detail. The effect of magnetic fields (MFs) on photocatalysis were examined by applying the different MFs under visible light irradiation. The enhanced photodegradation efficiencies were achieved by increasing the MF up to 0.5T and reduced at 0.7T for the compositions x = 0.10 in both Ce and Tb substituted BFO. Further, mineralization efficiencies of PR, reproducibility of MF-assisted photocatalysis, stability and recyclability of BFO: RE nanostructures were also tested.

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