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Amini P, Okeme JO. Tear Fluid as a Matrix for Biomonitoring Environmental and Chemical Exposures. Curr Environ Health Rep 2024:10.1007/s40572-024-00454-7. [PMID: 38967858 DOI: 10.1007/s40572-024-00454-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2024] [Indexed: 07/06/2024]
Abstract
PURPOSE Exposures to hazardous chemicals have been linked to many detrimental health effects and it is therefore critical to have effective biomonitoring methods to better evaluate key environmental exposures that increase the risk of chronic disease and death. Traditional biomonitoring utilizing blood and urine is limited due to the specialized skills and invasiveness of collecting these fluid samples. This systematic review focuses on tear fluid, which is largely under-researched, as a promising complementary matrix to the traditional fluids used for biomonitoring. The objective is to evaluate the practicability of using human tear fluid for biomonitoring environmental exposures, highlighting potential pitfalls and opportunities. RECENT FINDING Tear fluid biomonitoring represents a promising method for assessing exposures because it can be collected with minimal invasiveness and tears contain exposure markers from both the external and internal environments. Tear fluid uniquely interfaces with the external environment at the air-tear interface, providing a surface for airborne chemicals to diffuse into the ocular environment and interact with biomolecules. Tear fluid also contains molecules from the internal environment that have travelled from the blood to tears by crossing the blood-tear barrier. This review demonstrates that tear fluid can be used to identify hazardous chemicals from the external environment and differentiate exposure groups.
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Affiliation(s)
- Parshawn Amini
- Department of Chemistry & Chemical Biology, McMaster University, Hamilton, ON, Ontario, L8S 4L8, Canada
| | - Joseph O Okeme
- Department of Chemistry & Chemical Biology, McMaster University, Hamilton, ON, Ontario, L8S 4L8, Canada.
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2
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Achten R, Thijs J, van der Wal M, van Luijk C, van Luin M, el Amrani M, Knol E, Delemarre E, Jager CDH, de Graaf M, Bakker D, de Boer J, van Wijk F, de Bruin‐Weller M. High dupilumab levels in tear fluid of atopic dermatitis patients with moderate-to-severe ocular surface disease. Clin Transl Allergy 2023; 13:e12221. [PMID: 36705509 PMCID: PMC9842774 DOI: 10.1002/clt2.12221] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 12/19/2022] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND The patho-mechanism of ocular surface disease (OSD) in dupilumab-treated atopic dermatitis (AD) patients remains unclear. The aim of this study is to measure dupilumab levels in tear fluid and serum, and relate these findings to the severity of OSD during dupilumab treatment in AD patients. METHODS This prospective study included dupilumab-treated moderate-to-severe AD patients who were seen by a dermatologist and an ophthalmologist before the start of dupilumab (baseline), and after 4 and 28 weeks of dupilumab treatment. Dupilumab levels in tear fluid and serum were measured by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Additionally, a pilot study was conducted to measure dupilumab on conjunctival epithelial cells using flow cytometry and LC-MS/MS. RESULTS At baseline, 89.6% (n = 43/48) of the patients had OSD, with 50.0% having moderate-to-severe OSD. After 28 weeks of dupilumab treatment, the median dupilumab tear fluid levels were 0.55 mg/L (IQR 0.35-1.31) and 0.29 mg/L (IQR 0.16-0.60) in patients with moderate-to-severe OSD and patients with no or mild OSD, respectively (p = 0.02). Dupilumab levels could be detected on conjunctival epithelial cells of 5 AD patients treated with dupilumab for 4 weeks. CONCLUSION Patients with moderate-to-severe OSD had higher dupilumab tear fluid levels compared to patients with no or mild OSD, indicating that dupilumab reaches the ocular surface. Dupilumab was also detected in conjunctival cell suspensions and was found to directly bind CD45-conjunctival epithelial cells. This suggests that AD-induced changes of the conjunctival epithelium may play a role in the development of OSD as well as increased local drug availability.
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Affiliation(s)
- Roselie Achten
- Department of Dermatology and AllergologyNational Expertise Center for Atopic Dermatitis, University Medical Center UtrechtUtrechtThe Netherlands
| | - Judith Thijs
- Department of Dermatology and AllergologyNational Expertise Center for Atopic Dermatitis, University Medical Center UtrechtUtrechtThe Netherlands
| | - Marlot van der Wal
- Center for Translational ImmunologyUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Chantal van Luijk
- Department of OphthalmologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Matthijs van Luin
- Department of Clinical PharmacyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Mohsin el Amrani
- Department of Clinical PharmacyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Edward Knol
- Department of Dermatology and AllergologyNational Expertise Center for Atopic Dermatitis, University Medical Center UtrechtUtrechtThe Netherlands,Center for Translational ImmunologyUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Eveline Delemarre
- Center for Translational ImmunologyUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Constance den Hartog Jager
- Center for Translational ImmunologyUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Marlies de Graaf
- Department of Dermatology and AllergologyNational Expertise Center for Atopic Dermatitis, University Medical Center UtrechtUtrechtThe Netherlands
| | - Daphne Bakker
- Department of Dermatology and AllergologyNational Expertise Center for Atopic Dermatitis, University Medical Center UtrechtUtrechtThe Netherlands
| | - Joke de Boer
- Department of OphthalmologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Femke van Wijk
- Center for Translational ImmunologyUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Marjolein de Bruin‐Weller
- Department of Dermatology and AllergologyNational Expertise Center for Atopic Dermatitis, University Medical Center UtrechtUtrechtThe Netherlands
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Ritchoo S, Havanapan PO, Phungthanom N, Rucksaken R, Muikaew R, Sussadee M. Analysis and comparison of tear protein profiles in dogs using different tear collection methods. BMC Vet Res 2022; 18:442. [PMID: 36539822 PMCID: PMC9768899 DOI: 10.1186/s12917-022-03543-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 12/07/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Tear proteomic analysis has become an important tool in medical and veterinary research. The tear collection method could influence the tear protein profile. This study aims to evaluate the protein profiles of dog tears collected using microcapillary tubes (MT), Schirmer tear strips (ST), and ophthalmic sponges (OS). METHODS The tear samples were collected using MT, ST, and OS. Tear protein profiles were analyzed using two-dimensional electrophoresis (2-DE) and the different protein spots' expression was compared. Fourteen protein spots were identified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS Tear protein concentrations ranged from 2.80 to 4.03 μg/μL, with no statistically significant differences among collection methods. Protein expression in each collection method differed in terms of both the number and intensity of the spots. There were 249, 327, and 330 protein spots found from tears collected with MT, ST, and OS, respectively. The proteins albumin, haptoglobin, and lactoferrin identified from OS were found to have higher spot intensities than other methods of collection. The use of MT demonstrated the downregulation of nine proteins. CONCLUSIONS The recent study supported that tear protein analysis is affected by different tear collection methods. Although ST is commonly used for tear collection, it provides insufficient information to study particular tear proteins.
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Affiliation(s)
- Sudpatchara Ritchoo
- grid.9723.f0000 0001 0944 049XDepartment of Veterinary Technology, Faculty of Veterinary Technology, Kasetsart University, Bangkok, Thailand
| | - Phattara-orn Havanapan
- grid.10223.320000 0004 1937 0490Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakhonpathom, Thailand
| | - Nuanwan Phungthanom
- grid.10223.320000 0004 1937 0490Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakhonpathom, Thailand
| | - Rucksak Rucksaken
- grid.9723.f0000 0001 0944 049XDepartment of Veterinary Technology, Faculty of Veterinary Technology, Kasetsart University, Bangkok, Thailand
| | - Rattana Muikaew
- grid.9723.f0000 0001 0944 049XDepartment of Veterinary Technology, Faculty of Veterinary Technology, Kasetsart University, Bangkok, Thailand
| | - Metita Sussadee
- grid.9723.f0000 0001 0944 049XDepartment of Veterinary Technology, Faculty of Veterinary Technology, Kasetsart University, Bangkok, Thailand
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Bowden AC, Allbaugh RA, Smith JS, Mochel JP, Sebbag L. Kinetics and minimal inhibitory concentrations of ceftiofur in tear film following extended-release parenteral administration (Excede®) in dogs. Front Vet Sci 2022; 9:975113. [PMID: 36213401 PMCID: PMC9535610 DOI: 10.3389/fvets.2022.975113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 08/22/2022] [Indexed: 12/05/2022] Open
Abstract
Purpose Describe the pharmacokinetics of extended-release parenteral ceftiofur (Excede®) in canine tear film and compare these concentrations to minimal inhibitory concentrations (MICs) of ceftiofur against common ocular pathogens in dogs. Method Six dogs of various breeds were enrolled. Disruption of blood-tear barrier was achieved with histamine-induced conjunctivitis to ensure clinical relevance of the results. Each dog received a single subcutaneous injection of 5 mg/kg Excede®, followed by tear collection with Schirmer strips at times 0, 0.25, 0.5, 1, 2, 4, 8, 12, 24, 36, 48, 72, 96, 120, 144, 168, 192, 216 and 240 h. Drug quantification was performed with liquid chromatography-mass spectrometry. MICs were determined for Staphylococcus pseudintermedius, Streptococcus canis and Pseudomonas aeruginosa by assessing bacterial growth (n = 10 per bacterial species) in the presence of ceftiofur at increasing concentrations. Results Blood-tear barrier breakdown provided tear film concentrations of ceftiofur 3.2–28.9-fold higher than in the contralateral healthy eye (n = 1 dog, pilot experiment). In all six dogs, ceftiofur concentrations in tears varied from 2.3 to 637.5 ng/mL and were detectable up to 10 days (240 h) after subcutaneous injection. However, tear levels always remained below MICs for common ocular isolates (≥640 ng/mL). Conclusions Ceftiofur reached the tear compartment (for up to 10 days) after a single parenteral injection, however tear concentrations were extremely variable and too low to be effective against common bacterial pathogens in dogs. Further studies with different ceftiofur dosage or other long-acting injectable antibiotics are warranted.
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Affiliation(s)
- Anna Catherine Bowden
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Rachel A. Allbaugh
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Joe S. Smith
- Department of Biomedical Sciences, SMART Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Jonathan P. Mochel
- Department of Biomedical Sciences, SMART Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Lionel Sebbag
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
- Department of Biomedical Sciences, SMART Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel
- *Correspondence: Lionel Sebbag
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Videla R, Sommardahl C, Smith J, Schaefer DMW, Cox S. Pharmacokinetics of Orally Administered Prednisolone in Alpacas. Front Vet Sci 2021; 8:745890. [PMID: 34746285 PMCID: PMC8569471 DOI: 10.3389/fvets.2021.745890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 09/06/2021] [Indexed: 11/15/2022] Open
Abstract
This study aimed to determine the pharmacokinetics of prednisolone following intravenous and oral administration in healthy adult alpacas. Healthy adult alpacas were given prednisolone (IV, n = 4), as well as orally (PO, n = 6). Prednisolone was administered IV once (1 mg/kg). Oral administration was once daily for 5 days (2 mg/kg). Each treatment was separated by a minimum 4 month washout period. Samples were collected at 0 (pre-administration), 0.083, 0.167, 0.25, 0.5, 0.75, 1, 2, 4, 8, 12, and 24 h after IV administration, and at 0 (pre-administration), 0.25, 0.5, 0.75, 1, 2, 4, 8, 12, 24 after the first and 5th PO administration. Samples were also taken for serial complete blood count and biochemistry analysis. Prednisolone concentration was determined by high pressure liquid chromatography. Non-compartmental pharmacokinetic parameters were then determined. After IV administration clearance was 347 mL/kg/hr, elimination half-life was 2.98 h, and area under the curve was 2,940 h*ng/mL. After initial and fifth oral administration elimination half-life was 5.27 and 5.39 h; maximum concentration was 74 and 68 ng/mL; time to maximum concentration was 2.67 and 2.33 h; and area under the curve was 713 and 660 hr*ng/mL. Oral bioavailability was determined to be 13.7%. Packed cell volume, hemoglobin, and red blood cell counts were significantly decreased 5 days after the first PO administration, and serum glucose was significantly elevated 5 days after the first PO administration. In conclusion, serum concentrations of prednisolone after IV and PO administration appear to be similar to other veterinary species. Future research will be needed to determine the pharmacodynamics of prednisolone in alpacas.
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Affiliation(s)
- Ricardo Videla
- Department of Large Animal Clinical Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Carla Sommardahl
- Department of Large Animal Clinical Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Joe Smith
- Department of Large Animal Clinical Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States.,Department of Biomedical Sciences, Iowa State University, Ames, IA, United States
| | - Deanna M W Schaefer
- Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Sherry Cox
- Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States
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Lucyshyn DR, Good KL, Knickelbein KE, Chang MW, Strøm AR, Hollingsworth SR, Thomasy SM, Leonard BC, Sebbag L, Wiggans KT, Maggs DJ. Subcutaneous administration of triamcinolone as part of the management of feline eosinophilic keratoconjunctivitis. J Feline Med Surg 2021; 23:575-583. [PMID: 33140999 PMCID: PMC10741297 DOI: 10.1177/1098612x20968660] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES The aim of this retrospective case-control study was to report the efficacy of subcutaneous triamcinolone as part of a regimen for feline eosinophilic keratoconjunctivitis (FEK). METHODS Records and clinical photographs were reviewed and lesions semiquantitatively graded for cats with cytologically confirmed FEK. Clinical data were compared between a study population of nine cats (11 eyes) treated with, and a reference population of seven cats (eight eyes) treated without, a median of 0.11 mg/kg (range 0.10-0.20 mg/kg) of triamcinolone acetonide subcutaneously. RESULTS Breed, sex, age and prevalence of corneal ulceration at presentation; corneal disease severity before and at the initiation of immunomodulation; and duration of antiviral treatment before immunomodulation did not differ significantly between populations (P ⩾0.059). Corneal plaques resolved in five cats each from the study and reference populations (P = 0.366). Median (range) time from immunomodulation to corneal plaque resolution did not significantly differ (P = 0.246) between the study (median 14 days; range 8-38 days) and reference (median 28 days, range 14-46 days) populations. No adverse reactions were attributed to triamcinolone administration, and all corneal ulcers in the study population re-epithelialized within 14 days (range 8-38 days) following triamcinolone injection. Time to corneal ulcer re-epithelialization following triamcinolone injection varied minimally in those receiving antivirals prior to (8 or 30 days until re-epithelialization), simultaneously with (38 days) or after (14 or 24 days) triamcinolone. CONCLUSIONS AND RELEVANCE In otherwise healthy cats with FEK, subcutaneous administration of triamcinolone appears to be well tolerated and as efficacious as conventional topical immunomodulatory therapies. It may be especially useful in ulcerated eyes where topical immunomodulation is contraindicated.
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Affiliation(s)
- Danica R Lucyshyn
- Department of Surgical and Radiological Sciences, University of California-Davis, Davis, CA, USA
| | - Kathryn L Good
- Department of Surgical and Radiological Sciences, University of California-Davis, Davis, CA, USA
| | - Kelly E Knickelbein
- Veterinary Medical Teaching Hospital, University of California-Davis, Davis, CA, USA
| | - Maggie W Chang
- School of Veterinary Medicine, University of California-Davis, Davis, CA, USA
| | - Ann R Strøm
- Veterinary Medical Teaching Hospital, University of California-Davis, Davis, CA, USA
| | - Steven R Hollingsworth
- Department of Surgical and Radiological Sciences, University of California-Davis, Davis, CA, USA
| | - Sara M Thomasy
- Department of Surgical and Radiological Sciences, University of California-Davis, Davis, CA, USA
- Department of Ophthalmology and Vision Science, School of Medicine, University of California-Davis, Davis, CA, USA
| | - Brian C Leonard
- Department of Surgical and Radiological Sciences, University of California-Davis, Davis, CA, USA
| | - Lionel Sebbag
- Veterinary Medical Teaching Hospital, University of California-Davis, Davis, CA, USA
| | - K Tomo Wiggans
- Veterinary Medical Teaching Hospital, University of California-Davis, Davis, CA, USA
| | - David J Maggs
- Department of Surgical and Radiological Sciences, University of California-Davis, Davis, CA, USA
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Romaneck AK, Sebbag L. Case Report: Clinical Remission in a Cat With Severe Bilateral Eosinophilic Keratitis Receiving Combined Immunosuppressive Therapy (Triamcinolone Acetonide and Tacrolimus). Front Vet Sci 2021; 8:580396. [PMID: 33996955 PMCID: PMC8121169 DOI: 10.3389/fvets.2021.580396] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 03/31/2021] [Indexed: 11/13/2022] Open
Abstract
A 2-year-old domestic shorthair cat was examined for severe keratitis of 10 months duration, non-responsive to 0.1% dexamethasone q8-12h. Patient and owner compliance were poor given ocular discomfort and hiding behavior. On presentation, both eyes (OU) had severe ulcerative keratitis that masked examination of deeper structures and resulted in absent menace response OU. Corneal cytology was consistent with eosinophilic keratitis (EK) OU. Initial therapy included subcutaneous triamcinolone acetonide injection (0.2 mg/kg), 0.3% ciprofloxacin OU q12h, and two compounded drugs started 5 days later upon receipt: 0.5% tacrolimus OU q6h, 0.5% cidofovir OU q12h. Visual behavior and ocular comfort were reportedly much improved within 24 h. At the first recheck (Day 11), patient and owner compliance were reported to be excellent, menace response was positive OU, and keratitis was dramatically reduced OU with absent fluorescein uptake. Subcutaneous triamcinolone acetonide was repeated (0.2 mg/kg), ciprofloxacin was discontinued, cidofovir was continued q12h, and tacrolimus was slowly tapered (q8h × 3 weeks then q12h). Keratitis was nearly 100% resolved at the second recheck (Day 38); cidofovir was discontinued and tacrolimus was slowly tapered (q12h × 1 week, q24h × 4 weeks, q48h × 4 weeks) then discontinued. A third recheck (Day 101) confirmed clinical remission OU, and disease did not reoccur within a 1 year follow up period (photographic documentation by owner). In sum, adjunct use of triamcinolone acetonide greatly improved therapeutic compliance and helped control severe EK in a rapid and effective manner.
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Affiliation(s)
- Amanda K Romaneck
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Lionel Sebbag
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States.,Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
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Sebbag L, Kirner NS, Wulf LW, Mochel JP. Tear Film Pharmacokinetics and Systemic Absorption Following Topical Administration of 1% Prednisolone Acetate Ophthalmic Suspension in Dogs. Front Vet Sci 2020; 7:571350. [PMID: 33195562 PMCID: PMC7652929 DOI: 10.3389/fvets.2020.571350] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/08/2020] [Indexed: 01/21/2023] Open
Abstract
The study aimed to determine the tear film pharmacokinetics following topical administration of 1% prednisolone acetate—assessing whether two drops would provide a superior kinetic profile compared to one drop—and to determine the fraction of an eye drop that reaches the systemic circulation in dogs. Two separate experiments were conducted in eight healthy Beagle dogs: (i) Instillation of 1 drop (35 μL) or 2 drops (70 μL) of 1% prednisolone acetate ophthalmic suspension in each eye, followed by tear collections with Schirmer strips from 0 to 720 min; (ii) Instillation of 1 or 2 drops of 1% prednisolone acetate in both eyes 4 times daily for 3 days, followed by blood collection 10–15 min after each topical administration on Day 3. Tear and blood samples were analyzed with high performance liquid chromatography to determine the levels of prodrug (prednisolone acetate), active metabolite (prednisolone) and total prednisolone (prednisolonetotal = prodrug + active metabolite). Prednisolone levels represented 10 and 72% of prednisolonetotal concentrations in tears and plasma, respectively, indicating a greater hydrolysis of prodrug in the blood vs. tear compartment. For eyes receiving one or two drops, tear film prednisolonetotal concentrations were high (~3.1 mg/mL) immediately following topical administration but rapidly decreased by ~45% at 1 min and ~95% at 15 min. No differences were noted between 1 vs. 2 drops in tear film prednisolonetotal concentrations (including maximal concentration, Cmax) or residual drug levels in tears at any time point (P ≥ 0.097); however, instillation of 2 drops provided a higher average tear concentration (Cavg) and overall drug exposure to the ocular surface (AUClast) over the 12-h sampling period (P = 0.009). Average plasma prednisolonetotal concentration represented ≤ 2% of the dose applied to the ocular surface, and did not differ significantly for dogs receiving 1 drop (17 ng/mL) or 2 drops (20 ng/mL) 4 times daily for 3 days (P = 0.438). In sum, topical corticotherapy is beneficial for inflammatory conditions of the canine anterior segment given the relatively high concentrations achieved in tears, although caution is warranted to prevent unwanted local or systemic adverse effects.
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Affiliation(s)
- Lionel Sebbag
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States.,Department of Biomedical Sciences, SMART Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Nicolette S Kirner
- Lloyd Veterinary Medical Center, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Larry W Wulf
- PhAST Laboratory, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Jonathan P Mochel
- Department of Biomedical Sciences, SMART Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
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Sebbag L, Mochel JP. Pharmacokinetics of Oral Prednisone at Various Doses in Dogs: Preliminary Findings Using a Naïve Pooled-Data Approach. Front Vet Sci 2020; 7:571457. [PMID: 33195563 PMCID: PMC7604266 DOI: 10.3389/fvets.2020.571457] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 09/09/2020] [Indexed: 12/17/2022] Open
Abstract
This pilot study aimed to determine the plasma pharmacokinetics of prednisone and its active metabolite prednisolone following oral prednisone administration in dogs-using dosing regimens that cover anti-inflammatory to immuno-suppressive biological effects. Six healthy Beagle dogs were given 0.5, 1, 2, and 4 mg/kg prednisone orally once daily for 5 days, each successive course separated by a washout period of 9 days. At steady-state (Day 4), a sparse sampling design allowed for collection of blood from 2/6 individuals for each of the following time points: 0, 15, 30, 60, 90, 120, 240, 480, and 720 min. Prednisone and prednisolone were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Oral prednisone was rapidly converted to prednisolone in dogs (≤ 30 min), with plasma prednisolone reaching ~6-fold greater levels (0-656.1 ng/mL) than prednisone (0-98.8 ng/mL) overall. The ratio of plasma prednisolone/prednisone was constant across the dosing regimens, indicating a non-saturation of the hepatic 11-β-hydroxysteroid dehydrogenase that converts the prodrug to the active metabolite in dogs. The level of both corticosteroids increased with increasing dosing regimens, albeit in a non-linear manner. Non-compartmental pharmacokinetic parameters are described, including peak concentration (Cmax), time of peak concentration (Tmax), area under the concentration-time curve (AUClast), and the elimination half-life (t 1/2) for both corticosteroids, as well as clearance and volume of distribution during the terminal phase (Vz) for the administered drug (prednisone). In sum, the present study utilizes a sparse sampling and naïve pooled-data approach to estimate pharmacokinetic parameters for prednisone and prednisolone, providing supporting preliminary knowledge that can be used to optimize corticosteroid efficacy and minimize toxicity in canine patients.
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Affiliation(s)
- Lionel Sebbag
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States.,Department of Biomedical Sciences, SMART Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Jonathan P Mochel
- Department of Biomedical Sciences, SMART Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
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10
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Sebbag L, Mochel JP. An eye on the dog as the scientist's best friend for translational research in ophthalmology: Focus on the ocular surface. Med Res Rev 2020; 40:2566-2604. [PMID: 32735080 DOI: 10.1002/med.21716] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/01/2020] [Accepted: 07/15/2020] [Indexed: 12/15/2022]
Abstract
Preclinical animal studies provide valuable opportunities to better understand human diseases and contribute to major advances in medicine. This review provides a comprehensive overview of ocular parameters in humans and selected animals, with a focus on the ocular surface, detailing species differences in ocular surface anatomy, physiology, tear film dynamics and tear film composition. We describe major pitfalls that tremendously limit the translational potential of traditional laboratory animals (i.e., rabbits, mice, and rats) in ophthalmic research, and highlight the benefits of integrating companion dogs with clinical analogues to human diseases into preclinical pharmacology studies. This One Health approach can help accelerate and improve the framework in which ophthalmic research is translated to the human clinic. Studies can be conducted in canine subjects with naturally occurring or noninvasively induced ocular surface disorders (e.g., dry eye disease, conjunctivitis), reviewed herein, and tear fluid can be easily retrieved from canine eyes for various bioanalytical purposes. In this review, we discuss common tear collection methods, including capillary tubes and Schirmer tear strips, and provide guidelines for tear sampling and extraction to improve the reliability of analyte quantification (drugs, proteins, others).
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Affiliation(s)
- Lionel Sebbag
- Department of Biomedical Sciences, SMART Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.,Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Jonathan P Mochel
- Department of Biomedical Sciences, SMART Pharmacology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
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Sebbag L, Soler EA, Allbaugh RA, Mochel JP. Impact of acute conjunctivitis on ocular surface homeostasis in dogs. Vet Ophthalmol 2020; 23:828-833. [PMID: 32666689 DOI: 10.1111/vop.12804] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 06/15/2020] [Accepted: 06/20/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To investigate the effects of acute conjunctivitis on tear film characteristics and corneal sensitivity in dogs. ANIMALS STUDIED Eight female spayed Beagle dogs (1.5-2 years old, 7.5-10 kg). PROCEDURES On two consecutive days, one randomly selected eye in each dog received 1 or 375 mg/mL histamine solution to induce mild or severe conjunctivitis, while the contralateral eye served as control. Diagnostic tests were performed in the following order: fluorescein instillation and repeated tear collection over 20 minutes (to determine tear volume [TV] and turnover rate [TTR] by fluorophotometry), Schirmer tear test-1 (STT-1), tear ferning, corneal esthesiometry, and tear film breakup time (TFBUT). RESULTS Results are presented as median values for severe conjunctivitis, mild conjunctivitis, and control eyes. Eyes with severe conjunctivitis had significantly higher STT-1 (24, 19.5, 17.5 mm/min; P = .002) and significantly lower TFBUT (10.5, 13.5, 15.5 s; P = .002), but no changes were noted in corneal tactile sensation (2, 2.5, 2.5 cm) or tear ferning (grades 2, 2, 2.5). Severe conjunctivitis significantly increased TV by nearly 10-fold (631, 97, 65 µL) initially (reflex tearing), although basal TV returned rapidly (<5 minutes) in all eyes (46, 58, 48 µL). Finally, there was a nonsignificant trend for higher reflex TTR in the conjunctivitis vs control eyes (68, 58, 43%/min). CONCLUSIONS Experimentally induced conjunctivitis increases tear quantity and decreases tear quality in dogs, but has no impact on corneal sensitivity. Changes in tear film dynamics could affect ocular pharmacology (eg, precorneal retention time), although homeostasis of lacrimal volume and drainage is rapidly restored.
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Affiliation(s)
- Lionel Sebbag
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.,SMART Pharmacology, Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Elizabeth A Soler
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Rachel A Allbaugh
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Jonathan P Mochel
- SMART Pharmacology, Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
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Tinklenberg RL, Murphy SD, Mochel JP, Seo YJ, Mahaffey AL, Yan Y, Ward JL. Evaluation of dose-response effects of short-term oral prednisone administration on clinicopathologic and hemodynamic variables in healthy dogs. Am J Vet Res 2020; 81:317-325. [PMID: 32228253 DOI: 10.2460/ajvr.81.4.317] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine whether a dose-response relationship exists between short-term oral prednisone administration and common clinicopathologic variables, cardiovascular biomarkers, and systolic arterial blood pressure (SAP) in healthy dogs. ANIMALS 8 healthy Beagles. PROCEDURES Dogs underwent five 5-day experiments (no prednisone treatment [control condition] and prednisone administration at 0.5, 1, 2, and 4 mg/kg, PO, q 24 h), with a 9-day washout period between protocols. Analyses performed before and after treatments included a CBC, serum biochemical analysis, and determination of SAP, fractional excretion of electrolytes, urine protein-to-creatinine ratio, glomerular filtration rate (GFR), serum N-terminal pro B-type natriuretic peptide (NT-proBNP) and plasma cortisol concentrations, and plasma renin activity. Linear mixed-effects modeling was used to compare changes in variables from baseline (day 1 for the same experiment) among treatment conditions. RESULTS Changes in serum glucose concentration and GFR were significantly greater after administration of prednisone at 4 mg/kg than for the control condition. Fractional excretion of sodium was decreased from baseline when dogs received 0.5, 1, or 4 mg of prednisone/kg, compared with results for the control condition. Several expected changes in clinicopathologic values were observed after prednisone administration at any dose. Changes in serum NT-proBNP concentration, plasma renin activity, and SAP did not differ from changes for the control condition at any prednisone dose. CONCLUSIONS AND CLINICAL RELEVANCE Oral prednisone administration did not affect SAP, NT-proBNP concentration, or measures of renin-angiotensin-aldosterone system activation in healthy laboratory-housed dogs but was associated with relative increases in GFR and serum glucose concentration.
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