Efficacy of horse chestnut leaf extract ALH-L1005 as a matrix metalloproteinase inhibitor in ligature-induced periodontitis in canine model.

Matrix metalloproteinases (MMPs) are the main proteinases associated with periodontal tissue destruction and remodeling. Therefore, inhibition of host-derived MMPs has a key role in the prevention and reduction of periodontitis progression. Horse chestnut (Aesculus hippocastanum L.) extracts have been used as treatments for inflammatory disease, traditionally. This study assessed the clinical effect as a MMP inhibitor of horse chestnut leaf extract ALH-L1005 on periodontitis. ALH-L1005 was obtained from horse chestnut leaf and its MMP inhibitory activities estimated. Periodontitis was induced in beagles assigned to 4 groups and medicated for 6 weeks: low dose test (LT; ALH-L1005, 100 mg/kg/day), high dose test (HT; ALH-L1005, 200 mg/kg/day), positive control (PC; doxycycline, 10 mg/kg/day), or negative control (NC; placebo). Before and after administration, clinical indices of the teeth and MMP quantity in gingival tissues using zymography were measured. Clinical conditions of the LT, HT, and PC groups were significantly improved after 6 weeks. In zymographic evaluations, gelatinolytic and caseinolytic activities were suppressed in LT, HT, and PC groups but not in the NC group. The results suggest that ALH-L1005 could be an effective agent for clinical prevention and treatment of periodontitis by inhibiting the gelatinase and collagenase activities, which can detach periodontal ligaments from alveolar bone.

Acute changes in central corneal thickness according to experimental adjustment of intraocular pressure in normal canine eyes.

Central corneal thickness (CCT) can be a promising source of glaucoma monitoring and diagnosis. This study evaluated changes in CCT according to experimental adjustment of intraocular pressure (IOP) in canine eyes. To adjust and measure IOP, each eye was cannulated with two 26-gauge needles under inhalant anesthesia. One needle was connected to a pressure transducer, and the other was connected to an adjustable bag of physiologic saline. IOP was stepwise increased from 10 mmHg to 70 mmHg in 10 mmHg increments (Group T). IOP was maintained at 15 mmHg (Group C15), 30 mmHg (Group C30), 45 mmHg (Group C45), 60 mmHg (Group C60) and 75 mmHg (Group C75) during the experiment. CCT was measured with an ultrasonic pachymeter every 10 min after cannulation. There was a significant difference in the effect of time on CCT (P<0.001) and difference in CCT (dCCT; P<0.001) between groups. The CCT of group C15 remained constant during the experiment. However, group T showed an initial decrease and then an increase after passing the lowest point. Group C30 showed decreasing values for 30 min, after which the values remained constant. The values in Group C45 showed no changes for 40 min and then increased. The values in group C60 showed no change for 20 min and then increased. Group C75 showed a steady increase. In conclusion, the CCT showed two core changes according to increased IOP. This study provides essential basic data to enable further investigation into the association of IOP and CCT in dogs.

Effects of conditioned media from human amniotic epithelial cells on corneal alkali injuries in rabbits.

This study was performed to evaluate the effects of conditioned media (CM) from human amniotic epithelial cells (HAECs) on the corneal wound healing process. Eighteen rabbits (36 eyes) were used and randomly assigned to three groups according treatment: CM from HAECs (group 1), vehicle alone (group 2), and saline (group 3). Corneal alkali injuries were induced with 1 N sodium hydroxide. Each reagent used for treatment evaluation was injected into the dorsal bulbar subconjunctiva and the area of the corneal epithelial defect was measured every other day. Two animals from each group were euthanized at a time on days 3, 7, and 15, and the cornea was removed for histological examination. The sum of the epithelial defect areas measured on day 0 to day 6 as well as day 0 to day 14 in group 1 was significantly smaller than those of other groups. Histological examination revealed that the group 1 corneas had less inflammatory cell infiltration and showed more intact epithelial features compared to the other groups. These results suggest that CM from HAECs promote corneal wound healing in rabbits.

Experimental determination of a subantimicrobial dosage of doxycycline hyclate for treatment of periodontitis in Beagles.

OBJECTIVE: To identify a subantimicrobial dose of doxycycline hyclate (SDD) and for the treatment of periodontitis in dogs. ANIMALS: 20 healthy Beagles for measurement of serum doxycycline concentration and 15 Beagles with periodontitis for evaluation of the efficacy of the SDD. PROCEDURES: 5 dogs each received doxycycline hyclate PO at a dose of 1, 2, 3, or 5 mg/kg. Blood samples were collected before and after administration, and serum concentrations of doxycycline were measured via high-performance liquid chromatography. Mean serum doxycycline concentrations were calculated, and SDDs were identified. In a separate trial, the identified SDDs (1 or 2 mg/kg) were administered PO once a day for 1 month to dogs with periodontitis (n = 5/group) and a control group (5) was fed vehicle only during the same period. Degree of gingival attachment and bleeding on probing (present or absent) were recorded. Gingival samples were collected before and after the 1-month period from the same anatomic sites. Degree of matrix metalloproteinase inhibition in gingival samples was determined via gelatin zymography and compared among treatment groups. RESULTS: Mean serum doxycycline concentrations in healthy dogs that received 1 or 2 mg of doxycycline/kg were consistently significantly lower than the minimal inhibitory doxycycline concentration for treatment of periodontitis throughout the 24-hour posttreatment period. Zymographic intensities were lower in dogs given 1 and 2 mg/kg than in the control dogs, and the degree of gingival attachment and bleeding significantly improved in dogs given 2 mg/kg, compared with in the control dogs and dogs given 1 mg of doxycycline/kg. CONCLUSIONS AND CLINICAL RELEVANCE: A doxycycline dosage of 2 mg/kg daily appeared to be an appropriate subantimicrobial regimen for dogs with periodontitis. Furthermore, this dosage may be suitable for long-term treatment of gelatinolytic inflammatory diseases such as periodontitis in this species.

A modified method for inducing periodontitis in dogs using a silk-wire twisted ligature.

This study was designed to assess the effectiveness of a modified silk ligature twisted with wire for inducing advanced periodontitis. Periodontitis was induced in five premolars and one molar of 20 healthy dogs over a 60-day period. The dogs were divided into four groups according to the ligature-inducing materials used: soft moistened food only, wire ligature (WL), silk ligature (SL) and twisted ligature with silk and wire (SWL). Periodontal indices were recorded, and dental radiographs were taken before and after 60 days of ligation. The ligatures were checked daily and the day the ligature fell out was noted. The period during which the ligatures were maintained was significantly shorter for the SL group compared to the SWL group (p < 0.05). Results of the clinical examination showed that almost all periodontal status parameters including the plaque index, gingival index, clinical attachment level, and bleeding on probing were significantly exacerbated in the SWL group compared to the other groups (p < 0.05). Radiographic evaluation demonstrated that alveolar bone levels were significantly lower in the SWL group than the other groups on day 60 (p < 0.05). These results suggested that experimental periodontitis induced by SWL could be an effective method for investigating periodontitis in canine models.

Accuracy of intraocular pressure measurements in dogs using two different tonometers and plano therapeutic soft contact lenses.

OBJECTIVE: To compare and evaluate the accuracy of intraocular pressure (IOP) measured through a therapeutic contact lens, using applanation (TonoPen XL(®)) and rebound (TonoVet(®)) tonometers in enucleated dog eyes. ANIMALS STUDIED: A total of 30 enucleated eyes from 15 beagle dogs. PROCEDURES: To measure accurate IOP, the anterior chamber of each enucleated eye was cannulated with two 26-gauge needles and two polyethylene tubes were connected vertically to an adjustable reservoir bag of normal saline and a pressure transducer. IOP was measured by the TonoPen XL(®) followed by the TonoVet(®) without a contact lens. After a contact lens was applied to the cornea, IOP was re-measured in the same order. Three consecutive IOP measurements were performed using both tonometers. RESULTS: Without the contact lens, the IOP values obtained by both tonometers correlated well according to the regression analysis (TonoVet(®): γ(2) = 0.98, TonoPen XL(®): γ(2) = 0.97, P < 0.001). The TonoPen XL(®) consistently underestimated values as transducer IOP increased; however, IOP values measured with the TonoPen XL(®) were in close agreement and were less variable than those determined with the TonoVet(®) when a contact lens was applied to the cornea. Bland-Altman analysis was used to determine the lower and upper limits of agreement (TonoVet(®): -29.7 and +21.1 mmHg, TonoPen XL(®): -3.9 and +3.6 mmHg) between the two devices. CONCLUSIONS: This study suggests that the TonoPen XL(®) is a useful tonometer for dogs wearing therapeutic contact lenses, and importantly, contact lenses would not need to be removed prior to IOP measurement.

Effect of central corneal thickness on intraocular pressure with the rebound tonometer and the applanation tonometer in normal dogs.

OBJECTIVE: To evaluate the effect of central corneal thickness (CCT) on the measurement of intraocular pressure (IOP) with the rebound (TonoVet(®)) and applanation (TonoPen XL(®)) tonometers in beagle dogs. ANIMAL STUDIED: Both eyes of 60 clinically normal dogs were used. PROCEDURES: The IOP was measured by the TonoVet(®), followed by the TonoPen XL(®) in half of the dogs, while the other half was measured in the reverse order. All CCT measurements were performed 10 min after the use of the second tonometer. RESULTS: The mean IOP value measured by the TonoVet(®) (16.9 ± 3.7 mmHg) was significantly higher than the TonoPen XL(®) (11.6 ± 2.7 mmHg; P < 0.001). The IOP values obtained by both tonometers were correlated in the regression analysis (γ(2) = 0.4393, P < 0.001). Bland-Altman analysis showed that the lower and upper limits of agreement between the two devices were -0.1 and +10.8 mmHg, respectively. The mean CCT was 549.7 ± 51.0 µm. There was a correlation between the IOP values obtained by the two tonometers and CCT readings in the regression analysis (TonoVet(®) : P = 0.002, TonoPen XL(®) : P = 0.035). The regression equation demonstrated that for every 100 µm increase in CCT, there was an elevation of 1 and 2 mmHg in IOP measured by the TonoPen XL(®) and TonoVet(®), respectively. CONCLUSIONS: The IOP obtained by the TonoVet(®) and TonoPen XL(®) would be affected by variations in the CCT. Therefore, the CCT should be considered when interpreting IOP values measured by tonometers in dogs.

C-arm fluoroscopy for the removal of an intraorbital foreign body in a cat.

This report describes the clinical manifestations, diagnosis and minimally surgical intervention of a cat with an intraorbital foreign body. A spayed female cat of unknown age was presented with a recurrent cutaneous sinus tract of the left suborbital region. The cat had not vocalized at all since the adoption. A sharp-edged radiopaque foreign body was visualized on dental radiography. Computed tomography outlined the length of the foreign body from the intraorbital soft tissue to the pharynx. The foreign body was removed under the guide of C-arm fluoroscope with minimal skin incision. The surgical site healed completely on the 11th postoperative day, and the cat vocalized normally after healing.

Evaluation of the analgesic effect of intracameral lidocaine hydrochloride injection on intraoperative and postoperative pain in healthy dogs undergoing phacoemulsification.

OBJECTIVE: To evaluate the intraoperative and postoperative analgesic effects of intracameral lidocaine hydrochloride injection in dogs undergoing phacoemulsification. ANIMALS: 12 healthy Beagles with healthy eyes. PROCEDURES: Dogs were randomly assigned to receive 1 of 2 intracameral injections: 2% lidocaine hydrochloride solution (0.3 mL) or an equivalent amount of balanced salt solution (BSS). All dogs were treated with acepromazine (0.05 mg/kg, i.v.) and cefazolin (30 mg/kg, i.v.), and tropicamide drops were topically applied to the eyes. Anesthesia was induced with propofol and maintained with isoflurane. The initial end-tidal isoflurane concentration was maintained at 1.2%. Heart rate, respiratory rate, arterial blood pressure, esophageal temperature, inspired and end-tidal isoflurane concentrations, and oxygen saturation were recorded every 5 minutes. The allocated agent was injected intracamerally after aspiration of the same volume of aqueous humor. Ten minutes after injection, phacoemulsification was performed. After surgery began, the isoflurane concentration was adjusted according to heart rate and mean arterial blood pressure. Pain scores were recorded before surgery and at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 6, 8, 16, and 24 hours after extubation. RESULTS: Isoflurane requirements were significantly higher in the BSS group than in the lidocaine group. Mean +/- SD time to administration of supplementary analgesia was significantly shorter in the BSS group (1.4 +/- 1.2 hours) than in the lidocaine group (4.9 +/- 1.2 hours). CONCLUSIONS AND CLINICAL RELEVANCE: Intracameral lidocaine injection had significant analgesic effects in dogs undergoing cataract surgery. Results of this study suggest the value of intracameral lidocaine injection as an analgesic for intraocular surgery in dogs.