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Gregory B Penner - One of the best experts on this subject based on the ideXlab platform.
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technical note evaluation of a continuous ruminal pH Measurement system for use in noncannulated small ruminants
Journal of Animal Science, 2009Co-Authors: Gregory B Penner, J R Aschenbach, Gotthold Gabel, M ObaAbstract:The objective of this study was to evaluate the precision and accuracy of an indwelling ruminal pH Measurement system that could be used in small ruminants (small ruminant ruminal pH Measurement system; SRS) without requiring ruminal cannulation. The outer diameter, length, and weight of the SRS were 20.6 mm, 138 mm, and 245 g, respectively. This device was capable of logging pH, temperature, and battery voltage. In Exp. 1, a ruminally cannulated sheep (94 kg) was infused with a 40% (wt/vol) glucose solution to supply 5 g of glucose/kg of BW into the rumen. Ruminal pH was recorded every 30 s simultaneously using a portable pH meter and the SRS. In Exp. 2, 30 noncannulated sheep (72 +/- 10 kg of BW) were orally administered with a 40% glucose solution as described above (5 g of glucose/kg of BW; n = 22) or an equivalent volume of water (12.5 mL/kg of BW; n = 8). Sheep were slaughtered 3 h after the oral drench, and immediately after slaughter ruminal pH readings were measured manually using a portable pH meter and were compared with Measurements recorded by the SRS. In Exp. 1, the relationship between manual pH Measurement using a portable pH meter and the SRS (226 data pairs) had a Pearson correlation coefficient and concordance correlation coefficient of 0.97 and 0.96, respectively. Furthermore, the scale shift and location shift observed in Exp. 1 were 1.28 and 0.00, respectively. The relationship between Measurements conducted manually using a portable pH meter and the SRS in Exp. 2 had Pearson and concordance correlation coefficients of 0.96 and 0.95, respectively. The respective scale and location shifts for Exp. 2 were 1.16 and 0.04. These results indicate that the Measurements obtained from SRS were in agreement with simultaneous Measurements manually conducted using a portable pH meter, suggesting that the SRS can be used to measure ruminal pH in noncannulated small ruminants.
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an evaluation of the accuracy and precision of a stand alone submersible continuous ruminal pH Measurement system
Journal of Dairy Science, 2006Co-Authors: Gregory B Penner, K A Beauchemin, T MutsvangwaAbstract:The objectives of this study were 1) to develop and evaluate the accuracy and precision of a new stand-alone submersible continuous ruminal pH Measurement system called the Lethbridge Research Centre ruminal pH Measurement system (LRCpH; Experiment 1); 2) to establish the accuracy and precision of a well-documented, previously used continuous indwelling ruminal pH system (CIpH) to ensure that the new system (LRCpH) was as accurate and precise as the previous system (CIpH; Experiment 2); and 3) to determine the required frequency for pH electrode standardization by comparing baseline millivolt readings of pH electrodes in pH buffers 4 and 7 after 0, 24, 48, and 72 h of ruminal incubation (Experiment 3). In Experiment 1, 6 pregnant Holstein heifers, 3 lactating, primiparous Holstein cows, and 2 Black Angus heifers were used. All experimental animals were fitted with permanent ruminal cannulas. In Experiment 2, the 3 cannulated, lactating, primiparous Holstein cows were used. In both experiments, ruminal pH was determined continuously using indwelling pH electrodes. Subsequently, mean pH values were then compared with ruminal pH values obtained using spot samples of ruminal fluid (MANpH) obtained at the same time. A correlation coefficient accounting for repeated measures was calculated and results were used to calculate the concordance correlation to examine the relationships between the LRCpH-derived values and MANpH, and the CIpH-derived values and MANpH. In Experiment 3, the 6 pregnant Holstein heifers were used along with 6 new submersible pH electrodes. In Experiments 1 and 2, the comparison of the LRCpH output (1- and 5-min averages) to MANpH had higher correlation coefficients after accounting for repeated measures (0.98 and 0.97 for 1- and 5-min averages, respectively) and concordance correlation coefficients (0.96 and 0.97 for 1- and 5-min averages, respectively) than the comparison of CIpH to MANpH (0.88 and 0.87, correlation coefficient and concordance correlation coefficient, respectively). The concordance correlation analysis indicated that the ruminal pH data for LRCpH (1- and 5-min averages) vs. MANpH had location shifts that were smaller than those of the CIpH vs. MANpH. However, the scale shift was similar between the LRCpH and the CIpH. The plotted data from both systems closely resembled the line y = x, indicating that both systems were accurate and precise. In Experiment 3, changes in baseline millivolt readings for pH readings after 24, 48, or 72 h of ruminal incubation were not significantly different than zero, indicating that daily standardization of new electrodes was not essential. Results from this study indicate that the LRCpH system can accurately and precisely measure ruminal pH; thus, it provides increased opportunity for researchers to measure ruminal pH and the occurrence of ruminal acidosis in unrestrained cattle.
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an evaluation of the accuracy and precision of a stand alone submersible continuous ruminal pH Measurement system
Journal of Dairy Science, 2006Co-Authors: Gregory B Penner, K A Beauchemin, T MutsvangwaAbstract:The objectives of this study were 1) to develop and evaluate the accuracy and precision of a new standalone submersible continuous ruminal pH Measurement system called the Lethbridge Research Centre ruminalpHMeasurementsystem(LRCpH;Experiment 1); 2) to establish the accuracy and precision of a welldocumented, previously used continuous indwelling ruminal pH system (CIpH) to ensure that the new system (LRCpH) was as accurate and precise as the previous system (CIpH; Experiment 2); and 3) to determine the required frequency for pH electrode standardization by comparing baseline millivolt readings of pH electrodes in pH buffers 4 and 7 after 0, 24, 48, and 72 h of ruminal incubation(Experiment3).InExperiment1,6pregnant Holstein heifers, 3 lactating, primiparous Holstein cows, and 2 Black Angus heifers were used. All experimental animals were fitted with permanent ruminal cannulas. In Experiment 2, the 3 cannulated, lactating, primiparous Holstein cows were used. In both experiments, ruminal pH was determined continuously using indwelling pH electrodes. Subsequently, mean pH values were then compared with ruminal pH values obtained using spot samples of ruminal fluid (MANpH) obtained at the same time. A correlation coefficient accounting for repeated measures was calculated and results were used to calculate the concordance correlation to examine the relationships between the LRCpH-derived values and MANpH, and the CIpH-derived values and MANpH. In Experiment 3, the 6 pregnant Holstein heifers were used along with 6 new submersible pH electrodes. In Experiments 1 and 2, the comparison of the LRCpH output (1- and 5-min averages) to MANpH had higher correlation coefficients after accounting for repeated measures (0.98 and 0.97for 1- and 5-min averages, respectively) and concordance correlation coefficients (0.96 and 0.97 for 1- and 5-min averages, respectively) than the comparison of CIpH to MANpH (0.88
T Mutsvangwa - One of the best experts on this subject based on the ideXlab platform.
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an evaluation of the accuracy and precision of a stand alone submersible continuous ruminal pH Measurement system
Journal of Dairy Science, 2006Co-Authors: Gregory B Penner, K A Beauchemin, T MutsvangwaAbstract:The objectives of this study were 1) to develop and evaluate the accuracy and precision of a new stand-alone submersible continuous ruminal pH Measurement system called the Lethbridge Research Centre ruminal pH Measurement system (LRCpH; Experiment 1); 2) to establish the accuracy and precision of a well-documented, previously used continuous indwelling ruminal pH system (CIpH) to ensure that the new system (LRCpH) was as accurate and precise as the previous system (CIpH; Experiment 2); and 3) to determine the required frequency for pH electrode standardization by comparing baseline millivolt readings of pH electrodes in pH buffers 4 and 7 after 0, 24, 48, and 72 h of ruminal incubation (Experiment 3). In Experiment 1, 6 pregnant Holstein heifers, 3 lactating, primiparous Holstein cows, and 2 Black Angus heifers were used. All experimental animals were fitted with permanent ruminal cannulas. In Experiment 2, the 3 cannulated, lactating, primiparous Holstein cows were used. In both experiments, ruminal pH was determined continuously using indwelling pH electrodes. Subsequently, mean pH values were then compared with ruminal pH values obtained using spot samples of ruminal fluid (MANpH) obtained at the same time. A correlation coefficient accounting for repeated measures was calculated and results were used to calculate the concordance correlation to examine the relationships between the LRCpH-derived values and MANpH, and the CIpH-derived values and MANpH. In Experiment 3, the 6 pregnant Holstein heifers were used along with 6 new submersible pH electrodes. In Experiments 1 and 2, the comparison of the LRCpH output (1- and 5-min averages) to MANpH had higher correlation coefficients after accounting for repeated measures (0.98 and 0.97 for 1- and 5-min averages, respectively) and concordance correlation coefficients (0.96 and 0.97 for 1- and 5-min averages, respectively) than the comparison of CIpH to MANpH (0.88 and 0.87, correlation coefficient and concordance correlation coefficient, respectively). The concordance correlation analysis indicated that the ruminal pH data for LRCpH (1- and 5-min averages) vs. MANpH had location shifts that were smaller than those of the CIpH vs. MANpH. However, the scale shift was similar between the LRCpH and the CIpH. The plotted data from both systems closely resembled the line y = x, indicating that both systems were accurate and precise. In Experiment 3, changes in baseline millivolt readings for pH readings after 24, 48, or 72 h of ruminal incubation were not significantly different than zero, indicating that daily standardization of new electrodes was not essential. Results from this study indicate that the LRCpH system can accurately and precisely measure ruminal pH; thus, it provides increased opportunity for researchers to measure ruminal pH and the occurrence of ruminal acidosis in unrestrained cattle.
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an evaluation of the accuracy and precision of a stand alone submersible continuous ruminal pH Measurement system
Journal of Dairy Science, 2006Co-Authors: Gregory B Penner, K A Beauchemin, T MutsvangwaAbstract:The objectives of this study were 1) to develop and evaluate the accuracy and precision of a new standalone submersible continuous ruminal pH Measurement system called the Lethbridge Research Centre ruminalpHMeasurementsystem(LRCpH;Experiment 1); 2) to establish the accuracy and precision of a welldocumented, previously used continuous indwelling ruminal pH system (CIpH) to ensure that the new system (LRCpH) was as accurate and precise as the previous system (CIpH; Experiment 2); and 3) to determine the required frequency for pH electrode standardization by comparing baseline millivolt readings of pH electrodes in pH buffers 4 and 7 after 0, 24, 48, and 72 h of ruminal incubation(Experiment3).InExperiment1,6pregnant Holstein heifers, 3 lactating, primiparous Holstein cows, and 2 Black Angus heifers were used. All experimental animals were fitted with permanent ruminal cannulas. In Experiment 2, the 3 cannulated, lactating, primiparous Holstein cows were used. In both experiments, ruminal pH was determined continuously using indwelling pH electrodes. Subsequently, mean pH values were then compared with ruminal pH values obtained using spot samples of ruminal fluid (MANpH) obtained at the same time. A correlation coefficient accounting for repeated measures was calculated and results were used to calculate the concordance correlation to examine the relationships between the LRCpH-derived values and MANpH, and the CIpH-derived values and MANpH. In Experiment 3, the 6 pregnant Holstein heifers were used along with 6 new submersible pH electrodes. In Experiments 1 and 2, the comparison of the LRCpH output (1- and 5-min averages) to MANpH had higher correlation coefficients after accounting for repeated measures (0.98 and 0.97for 1- and 5-min averages, respectively) and concordance correlation coefficients (0.96 and 0.97 for 1- and 5-min averages, respectively) than the comparison of CIpH to MANpH (0.88
Keiji Okada - One of the best experts on this subject based on the ideXlab platform.
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simultaneous estimation of the pH of rumen and reticulum fluids of cows using a radio transmission pH Measurement system
Journal of Veterinary Medical Science, 2012Co-Authors: Atsushi Kimura, Hitoshi Mizuguchi, Keiji Okada, Shigeru Sato, Hiroko Goto, Norio Yamagishi, Kazunori ItoAbstract:Circadian pH changes in the fluid of the rumen (bottom and middle) and reticulum were assessed simultaneously using wireless and wired radio-transmission pH-Measurement systems in cows fed a control diet (C diet) or rumen-acidosis-inducing diet (RAI diet). The pH in the three sites decreased following the morning and evening feedings. In cows fed the C diet, the bottom-rumen and reticular pH reverted to the basal level by the next morning, while the middle-rumen pH did not recover completely, suggesting that active fermentation occurred in the middle of the rumen. The mean pH at 1 hr intervals was higher in the reticulum than at the bottom and in the middle of the rumen. The relatively stable reticular pH may result from dilution due to salivation. In cows fed the RAI diet, the bottom-rumen pH fell to approximately 5.2 after the evening feeding, but returned to the basal level by the next morning. In contrast, the middle-rumen pH did not return to the basal level (6.5) within 24 hr, presumably owing to continuous, vigorous fermentation. There were positive correlations between the pH at the bottom and in the middle of the rumen and at the bottom of the rumen and in the reticulum. These findings indicate that our radio-transmission pH-Measurement system may be suitable tool for simultaneous Measurement of pH in the rumen and reticulum fluid.
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Technical note: development and testing of a radio transmission pH Measurement system for continuous monitoring of ruminal pH in cows.
Preventive Veterinary Medicine, 2011Co-Authors: Shigeru Sato, Hitoshi Mizuguchi, Kentaro Ikuta, Atushi Kimura, Keiji OkadaAbstract:An indwelling ruminal pH system has been used for the continuous recording of ruminal pH to evaluate subacute ruminal acidosis (SARA) in dairy cows. However this system does not allow the field application. The objective of this study was to develop a new radio transmission pH Measurement system, and to assess its performance and usefulness in a continuous evaluation of ruminal pH for use on commercial dairy farms. The radio transmission pH Measurement system consists of a wireless pH sensor, a data Measurement receiver, a relay unit, and a personal computer installed special software. The pH sensor is housed in a bullet shaped bolus, which also encloses a pH amplifier circuit, a central processing unit (CPU) circuit, a radio frequency (RF) circuit, and a battery. The mean variations of the Measurements by the glass pH electrode were +0.20 (n = 10) after 2 months of continuous recording, compared to the values confirmed by standard pH solutions for pH 4 and pH 7 at the start of the recording. The mean lifetime of the internal battery was 2.5 months (n = 10) when Measurements were continuously transmitted every 10 min. Ruminal pH recorded by our new system was compared to that of the spot sampling of ruminal fluid. The mean pH for spot sampling was 6.36 ± 0.55 (n = 96), and the mean pH of continuous recording was 6.22 ± 0.54 (n = 96). There was a good correlation between continuous recording and spot sampling (r = 0.986, P < 0.01). We also examined whether our new pH system was able to detect experimentally induced ruminal acidosis in cows and to record long-term changes in ruminal pH. In the cows fed acidosis-inducing diets, the ruminal pH dropped markedly during the first 2 h following the morning feeding, and decreased moreover following the evening feeding, with many pulse-like pH changes. The pH of the cows showed the lowest values of 5.3–5.2 in the midnight time period and it recovered to the normal value by the next morning feeding. In one healthy periparturient cow, the circadian changes in ruminal pH were observed as a constant pattern in the pre-parturient period, however that pattern became variable in the post-partum period. The frequency of the ruminal pH lower than 5.5 increased markedly 3 and 4 days after parturition. We demonstrated the possible application of a radio transmission pH Measurement system for the assessment and monitoring of the ruminal pH of cows. Our new system might contribute to accurate assessment and prevention of SARA.
V Maunoury - One of the best experts on this subject based on the ideXlab platform.
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in vivo pH Measurement and imaging of tumor tissue using a pH sensitive fluorescent probe 5 6 carboxyfluorescein instrumental and experimental studies
Photochemistry and Photobiology, 1994Co-Authors: Serge Mordon, J M Devoisselle, V MaunouryAbstract:This study evaluated the effectiveness of dual-wavelength ratio fluorescence imaging using a pH-dependent indicator (5,6-carboxyfluorescein, 5,6-CF) for in vivo pH mapping of tissue. A prototype version of a highly sensitive fluorescence imaging device consisting of a modified xenon lamp, an image-intensified camera and a digital image-processing system has been developed. 5,6-Carboxyfluorescein was used because its fluorescence emission increases as a function of pH in the pHysiological (6.0-7.4) pH range. The ratio of fluorescence intensities obtained with the imaging system has been calibrated using aqueous 5,6-CF standards at various pH values. Because the pH of interstitial fluid of malignant tumors tends to be lower than that of normal tissue and can be depressed by glucose administration, experiments were performed on 10 CDF mice bearing lympHoid leukemia P388 grafted subcutaneously. The range of linearity of the calibration curve was obtained between 5.3 and 6.7 with a measured pKa value of 5.93. Consequently the maximum sensitivity was observed in this range. The calculated pH from ratio images was 6.21 +/- 0.12 in tumorous tissue. This value was equivalent to those obtained at the same time using microelectrodes (6.2 +/- 0.3). These experiments showed that a dose of 5 mg/kg 5,6-CF and an excitation power density of 2.5 mW/cm2 are sufficient to give a fluorescent pH image of tumors. The limitation of 5,6-CF for the in vivo mapping of tissue results from its low pKa and consequent range of sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)
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in vivo pH Measurement and imaging of tumor tissue using a pH sensitive fluorescent probe 5 6 carboxyfluorescein instrumental and experimental studies
Photochemistry and Photobiology, 1994Co-Authors: Serge Mordon, J M Devoisselle, V MaunouryAbstract:Abstract This study evaluated the effectiveness of dual-wavelength ratio fluorescence imaging using a pH-dependent indicator (5,6–carboxyfluorescein, 5,6–CF) for in vivo pH mapping of tissue. A prototype version of a highly sensitive fluorescence imaging device consisting of a modified xenon lamp, an image-intensified camera and a digital imageprocessing system has been developed. 5,6–Carboxyfluorescein was used because its fluorescence emission increases as a function of pH in the pHysiological (6.0–7.4) pH range. The ratio of fluorescence intensities obtained with the imaging system has been calibrated using aqueous 5,6–CF standards at various pH values. Because the pH of interstitial fluid of malignant tumors tends to be lower than that of normal tissue and can be depressed by glucose administration, experiments were performed on 10 CDF mice bearing lympHoid leukemia P388 grafted subcutaneously. The range of linearity of the calibration curve was obtained between 5.3 and 6.7 with a measured pK, value of 5.93. Consequently the maximum sensitivity was observed in this range. The calculated pH from ratio images was 6.21 ± 0.12 in tumorous tissue. This value was equivalent to those obtained at the same time using microelectrodes (6.2 ± 0.3). These experiments showed that a dose of 5 mg/kg 5,6–CF and an excitation power density of 2.5 mW/cm2 are sufficient to give a fluorescent pH image of tumors. The limitation of 5,6–CF for the in vivo mapping of tissue results from its low pKa and consequent range of sensitivity. The advantages of this imaging technique compared to microelectrodes are that it (1) is noninvasive, (2) displays a two-dimensional pH image with high resolution (profile distribution of pH in tissue) and (3) can be used to monitor pH over a few hours.
Serge Mordon - One of the best experts on this subject based on the ideXlab platform.
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in vivo application of intestinal pH Measurement using 2 7 bis carboxyethyl 5 6 carboxyfluorescein bcecf fluorescence imaging
Photochemistry and Photobiology, 1999Co-Authors: Xavier Marechal, Serge Mordon, J M Devoisselle, Sylvie Begu, Benoit Guery, Remi Neviere, Bruno Buys, Guy Dhelin, Jean Claude Lesage, D MathieuAbstract:Measurement of gastrointestinal intramucosal pH (pHim) has been recognized as an important factor in the detection of hypoxia-induced dysfunctions. However, current pH Measurement techniques are limited in terms of time and spatial resolutions. A major advance in accurate pH Measurement was the development of the ratiometric fluorescent indicator dye, 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF). This study aimed to set up and validate a fluorescence imaging technique to measure in vivo the intramucosal pH (pHim) of the intestine. The intestine was inserted into an optical chamber placed under a microscope. Animals were injected intravenously with the pH-sensitive fluorescent dye BCECF. Fluorescence was visualized by illuminating the intestine alternately at 490 and 470 nm. The emitted fluorescence was directed to an intensified camera. The ratio of emitted fluorescence at excitation wavelengths of 490 and 470 nm was measured, corrected and converted to pHim by constructing a calibration curve. The pHim controls were performed with a pH microelectrode and were correlated with venous blood gas sampling. Results show that pHim is determined with an accuracy of +/- 0.07 pH units and a response time of 1 min. In conclusion pHim mapping of rat intestine can be obtained by fluorescence imaging using BCECF. This technology could be easily adapted for endoscopic pH Measurements.
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in vivo pH Measurement and imaging of tumor tissue using a pH sensitive fluorescent probe 5 6 carboxyfluorescein instrumental and experimental studies
Photochemistry and Photobiology, 1994Co-Authors: Serge Mordon, J M Devoisselle, V MaunouryAbstract:This study evaluated the effectiveness of dual-wavelength ratio fluorescence imaging using a pH-dependent indicator (5,6-carboxyfluorescein, 5,6-CF) for in vivo pH mapping of tissue. A prototype version of a highly sensitive fluorescence imaging device consisting of a modified xenon lamp, an image-intensified camera and a digital image-processing system has been developed. 5,6-Carboxyfluorescein was used because its fluorescence emission increases as a function of pH in the pHysiological (6.0-7.4) pH range. The ratio of fluorescence intensities obtained with the imaging system has been calibrated using aqueous 5,6-CF standards at various pH values. Because the pH of interstitial fluid of malignant tumors tends to be lower than that of normal tissue and can be depressed by glucose administration, experiments were performed on 10 CDF mice bearing lympHoid leukemia P388 grafted subcutaneously. The range of linearity of the calibration curve was obtained between 5.3 and 6.7 with a measured pKa value of 5.93. Consequently the maximum sensitivity was observed in this range. The calculated pH from ratio images was 6.21 +/- 0.12 in tumorous tissue. This value was equivalent to those obtained at the same time using microelectrodes (6.2 +/- 0.3). These experiments showed that a dose of 5 mg/kg 5,6-CF and an excitation power density of 2.5 mW/cm2 are sufficient to give a fluorescent pH image of tumors. The limitation of 5,6-CF for the in vivo mapping of tissue results from its low pKa and consequent range of sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)
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in vivo pH Measurement and imaging of tumor tissue using a pH sensitive fluorescent probe 5 6 carboxyfluorescein instrumental and experimental studies
Photochemistry and Photobiology, 1994Co-Authors: Serge Mordon, J M Devoisselle, V MaunouryAbstract:Abstract This study evaluated the effectiveness of dual-wavelength ratio fluorescence imaging using a pH-dependent indicator (5,6–carboxyfluorescein, 5,6–CF) for in vivo pH mapping of tissue. A prototype version of a highly sensitive fluorescence imaging device consisting of a modified xenon lamp, an image-intensified camera and a digital imageprocessing system has been developed. 5,6–Carboxyfluorescein was used because its fluorescence emission increases as a function of pH in the pHysiological (6.0–7.4) pH range. The ratio of fluorescence intensities obtained with the imaging system has been calibrated using aqueous 5,6–CF standards at various pH values. Because the pH of interstitial fluid of malignant tumors tends to be lower than that of normal tissue and can be depressed by glucose administration, experiments were performed on 10 CDF mice bearing lympHoid leukemia P388 grafted subcutaneously. The range of linearity of the calibration curve was obtained between 5.3 and 6.7 with a measured pK, value of 5.93. Consequently the maximum sensitivity was observed in this range. The calculated pH from ratio images was 6.21 ± 0.12 in tumorous tissue. This value was equivalent to those obtained at the same time using microelectrodes (6.2 ± 0.3). These experiments showed that a dose of 5 mg/kg 5,6–CF and an excitation power density of 2.5 mW/cm2 are sufficient to give a fluorescent pH image of tumors. The limitation of 5,6–CF for the in vivo mapping of tissue results from its low pKa and consequent range of sensitivity. The advantages of this imaging technique compared to microelectrodes are that it (1) is noninvasive, (2) displays a two-dimensional pH image with high resolution (profile distribution of pH in tissue) and (3) can be used to monitor pH over a few hours.