Use of a modified hair strand test to assess the antifungal activity kinetics of dog hair after a 2% climbazole shampoo application.

BACKGROUND: The "hair strand test" was first developed as a model to evaluate the antifungal activity of antidandruff shampoos. OBJECTIVE: To assess the residual activity of an antifungal shampoo on the hair shafts of dogs after a single application, followed by bathing with a physiological shampoo one month later. ANIMALS: Six beagles (two males and four females) from a research colony. METHODS: Dogs were bathed with a 2% climbazole shampoo. Hairs were collected before application of the shampoo and at scheduled intervals for 30 days after treatment. A physiological shampoo was then applied to all dogs and hairs were collected following the same schedule. The inhibition zone around the hair shafts was measured after incubation on Sabouraud's dextrose agar plates streaked with three Malassezia pachydermatis strains. RESULTS: Inhibition zones around hairs collected from dogs bathed with 2% climbazole shampoo were significantly larger than those around hairs collected before shampooing at all time points (P = 0.003). An increase in the width of the inhibition zones around climbazole treated hairs was observed following physiological shampoo on Day 30 (P = 0.005). No significant differences were observed between Malassezia pachydermatis isolates (P = 0.571). No inhibition zones were seen around the hairs of dogs bathed with physiological shampoo only. CONCLUSIONS: The modified hair strand test is useful for the assessment of residual antifungal activity on animal hairs. Use of a physiological shampoo following antifungal shampoo therapy may increase the efficacy of the antifungal product for the control of Malassezia overgrowth.

A pilot study of the efficacy of wipes containing chlorhexidine 0.3%, climbazole 0.5% and Tris-EDTA to reduce Malassezia pachydermatis populations on canine skin.

BACKGROUND: Wipes containing chlorhexidine and azole derivates have been recommended for veterinary use. No study has been published about their activity against Malassezia pachydermatis. HYPOTHESIS/OBJECTIVES: To evaluate the in vivo and in vitro activity of wipes soaked in a chlorhexidine, climbazole and Tris-EDTA solution against Malassezia pachydermatis. ANIMALS: Five research colony shar-pei dogs. METHODS: Wipes were applied once daily onto the left axilla, left groin and perianal area (protocol A), and twice daily on the right axilla, right groin and umbilical region (protocol B) for 3 days. In vivo activity was evaluated by quantifying Malassezia colonies through contact plates on the selected body areas before and after wipe application. The activity of the solution in which the wipes were soaked was assessed in vitro by contact tests following the European Standard UNI EN 1275 guidelines. RESULTS: Samples collected after wipe application showed a significant and rapid reduction of Malassezia yeast CFU. No significant difference in the Malassezia reduction was found between protocols A and B. In vitro assay showed 100% activity against Malassezia yeasts after a 15 min contact time with the wipe solution. CONCLUSIONS AND CLINICAL IMPORTANCE: Wipes containing chlorhexidine, climbazole and Tris-EDTA substantially reduced the M. pachydermatis population on the skin of dogs. The results, although this was an uncontrolled study performed on a small number of dogs, suggest that these wipes may be useful for topical therapy of Malassezia dermatitis involving the lips, paws, perianal area and skin folds.

Canine atopic dermatitis diagnostic criteria: evaluation of four sets of published criteria among veterinary students.

Canine atopic dermatitis (cAD) is a major teaching point as its diagnosis and treatment are difficult. During 11 weeks, 140 dogs and students (third, fourth, and fifth years) were recruited and paired. One of the four lists of diagnostic criteria was randomly attributed to each student. Concordance results, calculated with Cohen's kappa, ranged from slight (κ=0.07) to moderate (κ=0.53). Favrot's diagnostic criteria received the best results. It has been observed that results are improved with clinical experience. We observed that students often forgot that Favrot's criteria apply only to pruritic dogs and that the fulfillment of the criteria allows only a suspicion, not a diagnosis, of cAD. Primary pruritus and corticosteroid-responsive pruritus were often misunderstood.

Effects of 5 weeks of training at the same time of day on the diurnal variations of maximal muscle power performance.

The purpose of this study was to investigate whether maximal muscle power production in humans is influenced by the habitual time of training to provide recommendations for adapting training hours in the month preceding a competition. Sixteen participants performed maximal brief squat and countermovement jumps and short-term cycle sprints tests before and after 5 weeks of training. Subjects were randomly assigned to either a Morning-Trained Group (MTG, 7:00-9:00 hr) or an Evening-Trained Group (ETG, 17:00-19:00 hr). They trained and performed the evaluation tests in both the morning and evening in their naturally warm and moderately humid environment. The results indicated a significant increase in performance (approximately 5-6% for both tests) after training for both groups but failed to show any time-of-day effect on either performance or training benefit. These findings could be linked to the stabilization of performances throughout the day because of the passive warm-up effect of the environment. In summary, our data showed that anaerobic muscle power production could be performed at any time of day with the same benefit.

Evaluation of immunogenicity and protection of the Mic1-3 knockout Toxoplasma gondii live attenuated strain in the feline host.

Toxoplasmosis is a zoonotic disease caused by the parasite Toxoplasma gondii. Up to a third of the global human population is estimated to carry a T. gondii infection, which can result in severe complications in immunocompromised individuals and pregnant women. Humans and animals can become infected by ingesting either tissue cysts containing T. gondii bradyzoites, from raw or undercooked meat, or sporulated oocysts from environmental sources. T. gondii oocysts are released in the faeces of cats and other felids, which are the parasite's definitive hosts, leading to environmental contamination. Therefore, vaccination of the feline host against T. gondii is an interesting strategy to interrupt the parasitic life cycle and subsequently limit contamination of intermediate hosts. With this goal in mind, we tested in cats, an attenuated live strain of T. gondii deleted for the Mic1 and Mic3 genes (Mic1-3KO) that was previously shown to be an efficient vaccine candidate in mouse and sheep models. Subcutaneous or oral vaccination routes induced a high specific antibody titer in the cat sera, indicating that the Mic1-3KO strain is immunogenic for cats. To assess protection induced by the vaccine candidate strain, we followed oocysts shedding by vaccinated cats, after oral challenge with a T. gondii wild-type strain. Surprisingly, a high antibody titer did not prevent cats from shedding oocysts from the challenge strain, regardless of the vaccination route. Our results show that the Mic1-3KO vaccine candidate is immunogenic in the feline host, is well tolerated and safe, but does not confer protection against oocysts shedding after natural infection with wild type T. gondii. This result highlights the particular relationship between T. gondii and its unique definitive host, which indicates the need for further investigations to improve vaccination strategies to limit environmental and livestock contaminations.

Assessment of ocular discomfort caused by 5 shampoos using the Slug Mucosal Irritation test.

Assessment of ocular discomfort caused by veterinary care products is less legitimately regulated than that caused by human care products. The Slug Mucosal Irritation (SMI) assay was adapted to evaluate canine hygiene shampoos to predict ocular discomfort. Experiments were performed using four commercial canine shampoos, a baby care product, and two controls (ArtTear® and BAC1%). Groups of 3 slugs were tested with 5% dilution of the 7 test substances. The negative control (ArtTear®) was the best tolerated. The baby care product Mixa bébé as well as Douxo Entretien Démêlant and Phlox Shampooing Entretien were classified to cause mild ocular discomfort. Together with the positive control (BAC 1%), Shampooing Physiologique Virbac and Physiovet Shampooing were considered to cause severe ocular discomfort. Different intensities of ocular discomfort were measured for veterinary care products. The SMI model was considered as a reproducible and adaptable evaluation method for screening veterinary care products causing ocular discomfort.

Efficacy of guar gum-based ronidazole capsules as a treatment for Tritrichomonas foetus infection in cats.

Objectives The aims of the study were to determine the in vitro drug release of guar gum-coated capsules of ronidazole, and to evaluate the pharmacokinetics and efficacy of this formulation for the treatment of cats naturally infected with Tritrichomonas foetus. Methods The pharmacokinetics of ronidazole were evaluated in five healthy cats and five cats infected with T foetus. In a second step, the clinical efficacy of these capsules was evaluated by a controlled, randomised, double-blind clinical trial performed in 47 infected cats from French catteries. In this study, cats were randomly allocated to either the ronidazole treatment group (n = 25) or a placebo group (n = 22). Ronidazole (30 mg/kg) q24h for 14 days was administered to the treated cats. After 14 days of treatment, the presence of T foetus was tested by conventional PCR assay. Results In the pharmacokinetic study, a delayed peak plasma concentration was observed in healthy and infected cats, with no significant difference between these two groups (mean geometric mean of 9 h for time to maximum plasma concentration [Tmax], 21.6 µg/ml for time to maximum plasma concentration [Cmax] and 467.4 µg/h/ml for the area under the curve [AUC] in healthy cats; and 9.4 h for Tmax, 17.1 µg/ml for Cmax and 481 µg/h/ml for AUC in infected cats). In the clinical trial, T foetus was detected in 16% of cats from the treated group and 82% of cats from the placebo group at the end of the study ( P <0.001). No clinical signs of adverse drug reactions were observed. Conclusions and relevance Oral administration of guar gum-coated capsules of ronidazole at a dose of 30 mg/kg once daily for 14 days delays the peak plasma concentration and eradicates infection in most cases.

Ex-Vivo percutaneous absorption of enrofloxacin: Comparison of LMOG organogel vs. pentravan cream.

The objective of this study was to investigate the percutaneous absorption of enrofloxacin from two base formulations, Pentravan cream and LMOG organogel. Ex-vivo experiments were carried out on pig ear skin. The percutaneous permeation through pig skin of two formulations containing 5 wt% of enrofloxacin was measured and compared using Franz diffusion cells. At appropriate intervals up to 120 h, diffusion samples were taken and analyzed using HPLC assays. Permeation profiles were established and the parameters Tlag and flux values were calculated. In this ex-vivo study, the flux values were 0.35 µgcm(-2)h(-1) for Pentravan and 1.22 µgcm(-2)h(-1) for LMOG organogel, corresponding respectively to 7.9 % and 29.3 % of enrofloxacin absorbed after 120 h by these formulations. The lag time (T lag) of Pentravan and organogel were 6.32 and 0.015 h respectively. The absorption time to reach the antibiotic concentration of enrofloxacin (2 µgmL(-1)) in the receptor was 60 h with Pentravan and 30 h with the organogel, suggesting more effective treatment by the latter. Enrofloxacin contained in organogel could be absorbed through pig ear skin 3.7 times greater than that in Pentravan (commercial formulation). This study demonstrates the perspective of organogel formulations as potential drug delivery systems.

PrP(c) deficiency and dasatinib protect mouse intestines against radiation injury by inhibiting of c-Src.

BACKGROUND & AIM: Despite extensive study of the contribution of cell death and apoptosis to radiation-induced acute intestinal injury, our knowledge of the signaling mechanisms involved in epithelial barrier dysfunction remains inadequate. Because PrP(c) plays a key role in intestinal homeostasis by renewing epithelia, we sought to study its role in epithelial barrier function after irradiation. DESIGN: Histology, morphometry and plasma FD-4 levels were used to examine ileal architecture, wound healing, and intestinal leakage in PrP(c)-deficient (KO) and wild-type (WT) mice after total-body irradiation. Impairment of the PrP(c) Src pathway after irradiation was explored by immunofluorescence and confocal microscopy, with Caco-2/Tc7 cells. Lastly, dasatinib treatment was used to switch off the Src pathway in vitro and in vivo. RESULTS: The decrease in radiation-induced lethality, improved intestinal wound healing, and reduced intestinal leakage promoted by PrP(c) deficiency demonstrate its involvement in acute intestinal damage. Irradiation of Cacao2/Tc7 cells induced PrP(c) to target the nuclei associated with Src activation. Finally, the protective effect triggered by dasatinib confirmed Src involvement in radiation-induced acute intestinal toxicity. CONCLUSION: Our data are the first to show a role for the PrP(c)-Src pathway in acute intestinal response to radiation injury and offer a novel therapeutic opportunity.

Resazurin metabolism assay is a new sensitive alternative test in isolated pig cornea.

The main object of our study was to investigate whether the resazurin metabolism assay is a sensitive surfactant and alcohol toxicity test in isolated pig cornea and to compare this recently developed fluorometric assay with the data collected in the eye irritation reference chemical data bank. Resazurin is a substrate that changes color in response to metabolic activity. Isolated pig corneas were immersed for 10 min in surfactants and alcohol irritant solutions. After incubation, resorufin fluorescence was read and corneal viability was assessed. This corneal viability was compared with the maximal modified average score published in the report of ECETOC. This assay highlighted different concentration-dependent irritation potentials of the three surfactants tested, and the same results were obtained with corneas treated with the alcohols. We observed that the degree of surfactant- and alcohol-induced decrease in corneal viability, using the resazurin reduction test, was correlated with the in vivo irritancy measurements as determined by the Draize test and scored with the Modified Maximum Average Score (MMAS). This assay allowed us to classify the ocular irritancy of the tested surfactants and alcohols in the same ranking order as the Draize classification. Corneal viability measurement can be used as a potential alternative for the toxicological assessment of surfactants and alcohols. The nontoxic, nonradioactive resazurin metabolism assay allows rapid assessment of many samples with simple equipment and at reduced cost for continuous monitoring of corneal viability. This assay seems to be suitable as a toxicological screening test for eye irritation determination.

Null alleles of ABCG2 encoding the breast cancer resistance protein define the new blood group system Junior.

The breast cancer resistance protein, also known as ABCG2, is one of the most highly studied ATP-binding cassette (ABC) transporters because of its ability to confer multidrug resistance. The lack of information on the physiological role of ABCG2 in humans severely limits cancer chemotherapeutic approaches targeting this transporter. We report here that ABCG2 comprises the molecular basis of a new blood group system (Junior, Jr) and that individuals of the Jr(a-) blood type have inherited two null alleles of ABCG2. We identified five frameshift and three nonsense mutations in ABCG2. We also show that the prevalence of the Jr(a-) blood type in the Japanese and European Gypsy populations is related to the p.Gln126* and p.Arg236* protein alterations, respectively. The identification of ABCG2(-/-) (Jr(a-)) individuals who appear phenotypically normal is an essential step toward targeting ABCG2 in cancer and also in understanding the physiological and pharmacological roles of this promiscuous transporter in humans.

Amlodipine: One of the main anti-hypertensive drugs in veterinary therapeutics.

Amlodipine is a dihydropyridine compound and belongs to the pharmacological family of calcium channel blockers. It is one of the main treatments of systemic arterial hypertension in cats and its validity has been confirmed in several reports. Its beneficial effect on the peripheral and coronary vascular bed is due to immediate vasodilation and to a delayed anti-hypertrophic action. The aim of the present review is to highlight the clinically-relevant characteristics of amlodipine, especially regarding its mechanism of action, and to present the main clinical reports supporting its interest in veterinary cardiology.

A new nondestructive cytometric assay based on resazurin metabolism and an organ culture model for the assessment of corneal viability.

BACKGROUND: Three-dimensional culture or human corneal equivalents for safety testing are difficult to investigate with classic cytometric or biochemical methods. So a fluorometric method is proposed using resazurin probe. METHODS: Absorbance and fluorescence spectra of the oxidized and reduced forms of resazurin were performed to determine optimal measurement conditions. More than 100 enucleated porcine eyes were used for this experiment. Twelve corneas were immersed in resazurin solution and fluorescence was measured hourly from 1 to 10 h. Ninety benzalkonium chloride-treated corneas and control corneas were used as toxicity controls, and corneal viability was compared with in vivo rabbit eye irritation. RESULTS: After analysis of spectra, the optimal measurement condition of resazurin metabolism proved to be a fluorescence measurement using 570 nm excitation wavelength and 590 nm emission wavelength. The reduction of resazurin was optimal after 6 h of incubation. Resazurin metabolism by isolated pig corneas varied proportionately with the benzalkonium chloride concentration employed, clearly showing significant differences (P < 0.001) in agreement with the in vivo data. CONCLUSION: The resazurin metabolism test can be used to evaluate corneal viability and can thus be a potential alternative for toxicological assessments. This assay allows rapid assessment of non destructed samples, with simple equipment and at a reduced cost for continuous monitoring of corneal viability and possibly other three-dimensional cellular models.