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Patrick Augustijns - One of the best experts on this subject based on the ideXlab platform.
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Stable ciliary activity in human nasal epithelial cells grown in a perfusion system
International Journal of Pharmaceutics, 2005Co-Authors: Silvia Dimova, V Vlaeminck, M Noppe, Marcus E. Brewster, Mark Jorissen, Patrick AugustijnsAbstract:Purpose: Explore the usefulness of a perfusion system in order to establish human nasal epithelial cell cultures suitable for long-term in vitro ciliary beat frequency (CBF) and cilio-toxicity studies. Methods: The cells were obtained by protease digestion of nasal biopsy material. The cells were plated at a density of 0.8–1 × 10 6 /cm 2 on Vitrogen-coated polyethylene terephthalate membranes, and cultured under submerged conditions in a CO2 incubator or in a perfusion system (initiated on days 8–9 after plating). The CBF was determined at 24.1 ± 0.8 ◦ Cb y a computerized microscope photometry system. The morphology of the cultured cells was characterized by transmission electron microscopy (TEM). Results: Under CO2 incubator culture conditions, stable ciliary activity was expressed and maintained from day 2 to day 24. Under perfusion system culture conditions, the CBF (mean ± S.D., n = 4) amounted to 8.4 ± 0.9 and 8.8 ± 0.4 Hz on days 7 and 14, respectively. These values were lower as compared to the corresponding CBF obtained in the CO2 incubator cultures (9.5 ± 0.6 and 9.9 ± 1.0 Hz, respectively). Reference cilio-stimulatory (glycocholate) and cilio-inhibitory (Chlorocresol) compounds were used to assess CBF reactivity. In the CO2 incubator and 7- and 14-days perfusion system cultures, glycocholate (0.5%) showed a reversible cilio-stimulatory effect of 23, 26 and 21%, respectively, while Chlorocresol (0.005%) exerted a reversible cilioinhibitory effect of 36, 40 and 36%, respectively. TEM revealed polarized cuboidal to columnar epithelial morphology, with well-differentiated ciliated cells under CO 2 and perfusion system conditions (up to day 23). Conclusion: Culturing human nasal epithelial cells on Vitrogen-coated polyethylene terephthalate membranes in submerged conditions in a CO2 incubator and in a perfusion system offers the possibility for long-term preservation (up to 22–24 days) of stable and reactive CBF in vitro. © 2004 Elsevier B.V. All rights reserved.
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Stable ciliary activity in human nasal epithelial cells grown in a perfusion system.
International journal of pharmaceutics, 2005Co-Authors: Silvia Dimova, V Vlaeminck, M Noppe, Marcus E. Brewster, Mark Jorissen, Patrick AugustijnsAbstract:Explore the usefulness of a perfusion system in order to establish human nasal epithelial cell cultures suitable for long-term in vitro ciliary beat frequency (CBF) and cilio-toxicity studies. The cells were obtained by protease digestion of nasal biopsy material. The cells were plated at a density of 0.8-1 x 10(6)/cm2 on Vitrogen-coated polyethylene terephthalate membranes, and cultured under submerged conditions in a CO2 incubator or in a perfusion system (initiated on days 8-9 after plating). The CBF was determined at 24.1 +/- 0.8 degrees C by a computerized microscope photometry system. The morphology of the cultured cells was characterized by transmission electron microscopy (TEM). Under CO2 incubator culture conditions, stable ciliary activity was expressed and maintained from day 2 to day 24. Under perfusion system culture conditions, the CBF (mean+/-S.D., n = 4) amounted to 8.4 +/- 0.9 and 8.8 +/- 0.4 Hz on days 7 and 14, respectively. These values were lower as compared to the corresponding CBF obtained in the CO2 incubator cultures (9.5 +/- 0.6 and 9.9 +/- 1.0 Hz, respectively). Reference cilio-stimulatory (glycocholate) and cilio-inhibitory (Chlorocresol) compounds were used to assess CBF reactivity. In the CO2 incubator and 7- and 14-days perfusion system cultures, glycocholate (0.5%) showed a reversible cilio-stimulatory effect of 23, 26 and 21%, respectively, while Chlorocresol (0.005%) exerted a reversible cilio-inhibitory effect of 36, 40 and 36%, respectively. TEM revealed polarized cuboidal to columnar epithelial morphology, with well-differentiated ciliated cells under CO2 and perfusion system conditions (up to day 23). Culturing human nasal epithelial cells on Vitrogen-coated polyethylene terephthalate membranes in submerged conditions in a CO2 incubator and in a perfusion system offers the possibility for long-term preservation (up to 22-24 days) of stable and reactive CBF in vitro.
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High‐speed digital imaging method for ciliary beat frequency measurement
The Journal of pharmacy and pharmacology, 2005Co-Authors: Svetlana Dimova, M Noppe, Marcus E. Brewster, Mark Jorissen, Frederik Maes, Patrick AugustijnsAbstract:The aim of this study was to develop a high-speed digital imaging system and related software for ciliary beat frequency (CFB) analysis in order to establish an automated and reliable method that is observer independent and faster compared to the conventional computerized microscope photometry method. Using primary human nasal epithelial cell cultures, the CBF was recorded with a computerized microscope photometry system and a high-speed digital imaging system. To obtain a wide range of frequencies, glycocholate (0.5%) and Chlorocresol (0.005%) were used as ciliostimulatory and cilio-inhibitory reference compounds, respectively. The mean values in hertz (± s.d.) obtained with the photometry and high-speed digital imaging systems were: controls 8.2 ± 0.9 and 7.9 ± 1.1; Chlorocresol 5.0 ± 0.9 and 5.1 ± 1.1; glycocholate 9.8 ± 1.0 and 9.7 ± 0.8. A similar increase (by 20 and 24%) and decrease (by 38 and 35%) in CBF was determined by the two methods after glycocholate and Chlorocresol treatment, respectively. The mean difference between the photometry and high-speed digital imaging methods was 0.2 ± 0.6 Hz, and the Bland-Altman limits of agreement were from −1.0 to + 1.4 Hz, suggesting that the results obtained by these two methods could be used interchangeably. These results show the reliability of the high-speed digital imaging system and the software developed for in-vitro CBF measurements. The advantages of the system include: (i) fast data acquisition and calculation, (ii) whole field automated CBF analysis and (iii) reduction in selection bias.
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Effects of Pharmaceutical Compounds on Ciliary Beating in Human Nasal Epithelial Cells: A Comparative Study of Cell Culture Models
Pharmaceutical Research, 1999Co-Authors: Remigius Uchenna Agu, Mark Jorissen, Tom Willems, Guy Van Den Mooter, Renaat Kinget, Patrick AugustijnsAbstract:Purpose . To test two in vitro human nasal epithelial cell culture systems for their ability to screen the effects of pharmaceutical compounds on ciliary beating. Methods . Human nasal epithelial cells were cultured as monolayer and in a sequential monolayer-suspension culture with in vitro ciliogenesis. The influence of reference cilio-stimulatory compounds (glycocholate, isoprenaline), reference cilio-inhibitory compounds (Chlorocresol, diphenhydramine) and pH on ciliary beating was investigated using computerized microscope photometry. Results . Sodium glycocholate (0.5% w/v) maximally and reversibly increased CBF of the cells in both culture systems by 26 ± 4% (monolayer) and 18 ± 6% (suspension). Similarly, isoprenaline (10^-3 M) maximally, but irreversibly increased CBF of the cells by 14 ± 3% (monolayer) and 17 ± 4% (suspension). Chlorocresol (0.005% w/ v) reversibly reduced the CBF of the cells by 50 ± 6% (monolayer) and 34 ± 4% (suspension); at a higher concentration (0.1% w/v) it resulted in instantaneous and irreversible ciliostasis. Diphenhydramine (0.1% w/v) reversibly reduced CBF in both culture systems by 45 ± 13% (monolayer) and 69 ± 5% (suspension); irreversible cilio-stasis occurred in less than 2 minutes in both culture systems upon cell exposure to diphenhydramine (1.0% w/v). In the monolayer culture system, CBF was stable only within the physiological pH range of 6.5−8.0; ciliary beating in the suspension culture remained stable within a pH range of 4.0−10.0. Conclusions . Both cell culture systems are suitable for screening the effects of pharmaceutical compounds on ciliary beating. Especially the sequential monolayer-suspension culture appears to be very promising as ciliary activity can be preserved for as long as 6 months.
Guangyou Yang - One of the best experts on this subject based on the ideXlab platform.
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Efficacy of a Chlorocresol-based disinfectant product on Toxocara canis eggs
Parasitology research, 2020Co-Authors: Senzhao Zhang, Christiana Angel, Yunjian Liu, Lu Wang, Xuan Zhou, Xuerong Peng, Guangyou YangAbstract:Toxocara canis is a common parasite of dogs and can cause zoonotic toxocariasis in humans. As a part of control programs for this agent, optimized hygiene including chemical disinfection is considered essential in the prevention and control of zoonotic toxocariasis in humans. However, commonly used disinfectants at present mostly fail to inhibit the embryogenesis and viability of T. canis eggs. To this effect, the present study was designed to evaluate the effect of a Chlorocresol-based disinfectant product Neopredisan®135-1 (NP) on embryonic development of T. canis eggs in vitro and to investigate the infectivity of exposed eggs by assessing larval establishment in a mouse model. Under in vitro conditions, NP at a final concentration of 0.25, 0.50, 1, 2, or 4% all exhibited significant killing effect on T. canis embryogenesis compared with the control eggs (P
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efficacy of a Chlorocresol based disinfectant product on toxocara canis eggs
Parasitology Research, 2020Co-Authors: Senzhao Zhang, Christiana Angel, Yunjian Liu, Lu Wang, Xuan Zhou, Xuerong Peng, Guangyou Yang, Yue XieAbstract:Toxocara canis is a common parasite of dogs and can cause zoonotic toxocariasis in humans. As a part of control programs for this agent, optimized hygiene including chemical disinfection is considered essential in the prevention and control of zoonotic toxocariasis in humans. However, commonly used disinfectants at present mostly fail to inhibit the embryogenesis and viability of T. canis eggs. To this effect, the present study was designed to evaluate the effect of a Chlorocresol-based disinfectant product Neopredisan®135-1 (NP) on embryonic development of T. canis eggs in vitro and to investigate the infectivity of exposed eggs by assessing larval establishment in a mouse model. Under in vitro conditions, NP at a final concentration of 0.25, 0.50, 1, 2, or 4% all exhibited significant killing effect on T. canis embryogenesis compared with the control eggs (P < 0.05), regardless of contact times (30, 60, 90, or 120 min). Such killing activity increased in a concentration- and time-dependent manner, with a maximum killing efficacy of 95.81% at 4% concentration and 120 min exposure time. Comparisons between low and high concentrations and between short and long contact times concluded that a protocol using the 1% concentration of NP with a 90-min contact could be the most suitable for practical application. Additionally, the lower larval recovery in mice inoculated with eggs treated by either 0.25 or 0.5% NP than that from their corresponding controls (P < 0.05) verified once again that NP had an adverse impact on the larval development of T. canis eggs even at a low concentration. To the best of our knowledge, this is the first study to report the effect of the Chlorocresol-based disinfectant NP on the embryonation and larval development of T. canis eggs, and the results presented here would contribute to environmental clearance and control of toxocariasis by providing an alternative disinfectant resource. However, it is highlighted that the clearance of the novel and existing sources of infection including larvated eggs in places treated with NP is not guaranteed and therefore continuous monitoring and additional disinfection are still required.
Christiana Angel - One of the best experts on this subject based on the ideXlab platform.
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Efficacy of a Chlorocresol-based disinfectant product on Toxocara canis eggs
Parasitology research, 2020Co-Authors: Senzhao Zhang, Christiana Angel, Yunjian Liu, Lu Wang, Xuan Zhou, Xuerong Peng, Guangyou YangAbstract:Toxocara canis is a common parasite of dogs and can cause zoonotic toxocariasis in humans. As a part of control programs for this agent, optimized hygiene including chemical disinfection is considered essential in the prevention and control of zoonotic toxocariasis in humans. However, commonly used disinfectants at present mostly fail to inhibit the embryogenesis and viability of T. canis eggs. To this effect, the present study was designed to evaluate the effect of a Chlorocresol-based disinfectant product Neopredisan®135-1 (NP) on embryonic development of T. canis eggs in vitro and to investigate the infectivity of exposed eggs by assessing larval establishment in a mouse model. Under in vitro conditions, NP at a final concentration of 0.25, 0.50, 1, 2, or 4% all exhibited significant killing effect on T. canis embryogenesis compared with the control eggs (P
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efficacy of a Chlorocresol based disinfectant product on toxocara canis eggs
Parasitology Research, 2020Co-Authors: Senzhao Zhang, Christiana Angel, Yunjian Liu, Lu Wang, Xuan Zhou, Xuerong Peng, Guangyou Yang, Yue XieAbstract:Toxocara canis is a common parasite of dogs and can cause zoonotic toxocariasis in humans. As a part of control programs for this agent, optimized hygiene including chemical disinfection is considered essential in the prevention and control of zoonotic toxocariasis in humans. However, commonly used disinfectants at present mostly fail to inhibit the embryogenesis and viability of T. canis eggs. To this effect, the present study was designed to evaluate the effect of a Chlorocresol-based disinfectant product Neopredisan®135-1 (NP) on embryonic development of T. canis eggs in vitro and to investigate the infectivity of exposed eggs by assessing larval establishment in a mouse model. Under in vitro conditions, NP at a final concentration of 0.25, 0.50, 1, 2, or 4% all exhibited significant killing effect on T. canis embryogenesis compared with the control eggs (P < 0.05), regardless of contact times (30, 60, 90, or 120 min). Such killing activity increased in a concentration- and time-dependent manner, with a maximum killing efficacy of 95.81% at 4% concentration and 120 min exposure time. Comparisons between low and high concentrations and between short and long contact times concluded that a protocol using the 1% concentration of NP with a 90-min contact could be the most suitable for practical application. Additionally, the lower larval recovery in mice inoculated with eggs treated by either 0.25 or 0.5% NP than that from their corresponding controls (P < 0.05) verified once again that NP had an adverse impact on the larval development of T. canis eggs even at a low concentration. To the best of our knowledge, this is the first study to report the effect of the Chlorocresol-based disinfectant NP on the embryonation and larval development of T. canis eggs, and the results presented here would contribute to environmental clearance and control of toxocariasis by providing an alternative disinfectant resource. However, it is highlighted that the clearance of the novel and existing sources of infection including larvated eggs in places treated with NP is not guaranteed and therefore continuous monitoring and additional disinfection are still required.
Senzhao Zhang - One of the best experts on this subject based on the ideXlab platform.
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Efficacy of a Chlorocresol-based disinfectant product on Toxocara canis eggs
Parasitology research, 2020Co-Authors: Senzhao Zhang, Christiana Angel, Yunjian Liu, Lu Wang, Xuan Zhou, Xuerong Peng, Guangyou YangAbstract:Toxocara canis is a common parasite of dogs and can cause zoonotic toxocariasis in humans. As a part of control programs for this agent, optimized hygiene including chemical disinfection is considered essential in the prevention and control of zoonotic toxocariasis in humans. However, commonly used disinfectants at present mostly fail to inhibit the embryogenesis and viability of T. canis eggs. To this effect, the present study was designed to evaluate the effect of a Chlorocresol-based disinfectant product Neopredisan®135-1 (NP) on embryonic development of T. canis eggs in vitro and to investigate the infectivity of exposed eggs by assessing larval establishment in a mouse model. Under in vitro conditions, NP at a final concentration of 0.25, 0.50, 1, 2, or 4% all exhibited significant killing effect on T. canis embryogenesis compared with the control eggs (P
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efficacy of a Chlorocresol based disinfectant product on toxocara canis eggs
Parasitology Research, 2020Co-Authors: Senzhao Zhang, Christiana Angel, Yunjian Liu, Lu Wang, Xuan Zhou, Xuerong Peng, Guangyou Yang, Yue XieAbstract:Toxocara canis is a common parasite of dogs and can cause zoonotic toxocariasis in humans. As a part of control programs for this agent, optimized hygiene including chemical disinfection is considered essential in the prevention and control of zoonotic toxocariasis in humans. However, commonly used disinfectants at present mostly fail to inhibit the embryogenesis and viability of T. canis eggs. To this effect, the present study was designed to evaluate the effect of a Chlorocresol-based disinfectant product Neopredisan®135-1 (NP) on embryonic development of T. canis eggs in vitro and to investigate the infectivity of exposed eggs by assessing larval establishment in a mouse model. Under in vitro conditions, NP at a final concentration of 0.25, 0.50, 1, 2, or 4% all exhibited significant killing effect on T. canis embryogenesis compared with the control eggs (P < 0.05), regardless of contact times (30, 60, 90, or 120 min). Such killing activity increased in a concentration- and time-dependent manner, with a maximum killing efficacy of 95.81% at 4% concentration and 120 min exposure time. Comparisons between low and high concentrations and between short and long contact times concluded that a protocol using the 1% concentration of NP with a 90-min contact could be the most suitable for practical application. Additionally, the lower larval recovery in mice inoculated with eggs treated by either 0.25 or 0.5% NP than that from their corresponding controls (P < 0.05) verified once again that NP had an adverse impact on the larval development of T. canis eggs even at a low concentration. To the best of our knowledge, this is the first study to report the effect of the Chlorocresol-based disinfectant NP on the embryonation and larval development of T. canis eggs, and the results presented here would contribute to environmental clearance and control of toxocariasis by providing an alternative disinfectant resource. However, it is highlighted that the clearance of the novel and existing sources of infection including larvated eggs in places treated with NP is not guaranteed and therefore continuous monitoring and additional disinfection are still required.
Francesco Zorzato - One of the best experts on this subject based on the ideXlab platform.
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Chlorocresol an additive to commercial succinylcholine induces contracture of human malignant hyperthermia susceptible muscles via activation of the ryanodine receptor calcium sup 2 channel
Anesthesiology, 1996Co-Authors: Vincenzo Tegazzin, Erica Scutari, Susan Treves, Francesco ZorzatoAbstract:Background : A defect in the ryanodine (Ry,) receptor Ca 2+ channel has been implicated as one of the possible underlying causes of malignant hyperthermia (MH), a pharmacogenetic disorder characterized by sustained muscle contracture. The disease is triggered by common halogenated anesthetics and skeletal muscle relaxants, such as succinylcholine. This study tested whether the functional properties of the Ry 1 receptor Ca 2+ channel are affected by Chlorocresol, preservative added to a commercial preparation of succinylcholine (Midarine) and other parenteral compounds. Methods : In vitro contracture testing was carried out on muscle biopsies from malignant hyperthermia-susceptible (MHS) and -negative (MHN) individual according to the protocol of the European MH group. Ca 2+ flux studies on isolated rabbit sarcoplasmic reticulum fractions were measured spectrophotometrically by following the A 710-790 of the Ca 2+ indicator antipyrylazo III. Results : Chlorocresol causes muscle contracture in MHS muscles at a concentration of 25-50 μM and potentiates the caffeine contracture response in human MHS muscles. Sub-threshold (20 μM) concentrations of Chlorocresol increase both the Kd and the V max of caffeine-induced Ca 2+ release from isolated rabbit terminal cisternae. Conclusions : These data suggest that, in muscle from MHS individuals, the enhanced Ca 2+ released from the sarcoplasmic reticulum may not be due to the effect of succinylcholine alone but rather to the action of the preservative Chlorocresol added to the drug.
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Chlorocresol: an activator of ryanodine receptor-mediated Ca2+ release.
Molecular Pharmacology, 1993Co-Authors: Francesco Zorzato, Erica Scutari, Vincenzo Tegazzin, E Clementi, Susan TrevesAbstract:: In the present study we investigated the effect of the compound Chlorocresol on intracellular Ca2+ homeostasis. Three different systems that have been shown to express the ryanodine receptor Ca2+ channel were chosen, i.e., skeletal muscle sarcoplasmic reticulum, cerebellar microsomes, and PC12 cells. In skeletal muscle sarcoplasmic reticulum, 4-chloro-m-cresol was found to be a potent activator of Ca2+ release mediated by a ruthenium red/caffeine-sensitive Ca2+ release channel. In cerebellar microsomes, this compound released Ca2+ from an inositol-1,4,5-trisphosphate-insensitive store, suggesting that there too it was acting at the ryanodine receptor level. When tested on PC12 cells, Chlorocresol released Ca2+ from a caffeine- and thapsigargin-sensitive intracellular store. In addition, the compound was capable of releasing Ca2+ after pretreatment of PC12 cells with bradykinin, suggesting that it acts on a channel contained within an intracellular Ca2+ store that is distinct from that sensitive to inositol-1,4,5-trisphosphate. Structure-activity relationship analyses suggest that the chloro and methyl groups in Chlorocresols are important for the activation of the ryanodine receptor Ca2+ release channel.