Effect of meloxicam and its combination with levofloxacin, pazufloxacin, and enrofloxacin on the plasma antioxidative activity and the body weight of rabbits

First study on the immunohistochemical expression of cyclooxygenase-2 and clinicopathological association in canine hepatoid gland neoplasms

Background and Aim: Hepatoid gland neoplasms (HGNs) constitute one of the most common cutaneous tumors that arise from perianal glands in dogs and are clinically characterized by rapid growth. Cyclooxygenase-2 (COX-2), the inducible form of the enzyme, is associated with several hallmarks of tumorigenesis. Its expression has been confirmed in several human and animal neoplastic tissues, but there are no reports in hepatoid gland tissues. Therefore, this study aimed to investigate COX-2 immunoexpression in canine HGNs, compare the expression among groups of normal hepatoid glands, hepatoid gland adenomas (HGAs), hepatoid gland epitheliomas (HGEs), and hepatoid gland carcinomas (HGCs), and assess the association of the COX-2 expression with clinicopathological features. Materials and Methods: Sixty-one formalin-fixed paraffin-embedded canine hepatoid gland tissues (20 samples of HGAs, 16 of HGEs, 15 of HGCs, and 10 of normal hepatoid glands) were analyzed for COX-2 expression using immunohistochemistry with scoring for percentage positivity and intensity. Multiple comparisons of COX-2 expression among normal and neoplastic hepatoid glands and the associations between COX-2 expression and clinicopathological features were analyzed. Results: Cyclooxygenase-2 expression was not detected in 60% of normal hepatoid glands and 25% of HGAs. Seventy-five percent of HGAs had a weak expression, while 43.7% and 56.3% of HGEs showed weak and moderate expression, respectively. The expression of HGCs ranged from weak (13.3%) to moderate (33.3%) and strong (53.3%). The immunoreactivity score of COX-2 labeling was significantly different among the normal and neoplastic hepatoid glands (p < 0.0001). The highest score was observed in the HGCs. Only in HGCs, the strong COX-2 expression was significantly associated with some clinicopathological features, including tissue invasion (p = 0.007) and necrosis (p = 0.029). Conclusion: These results suggest that COX-2 may play a role in the modulation of neoplastic cell growth. These preliminary data lead to further investigation on the potential of COX-2 expression as a prognostic indicator and COX-2 inhibitors for canine HGCs treatment.

Levofloxacin in veterinary medicine: a literature review

A potent third-generation antimicrobial fluoroquinolone drug, levofloxacin was introduced into human clinical practice in 1993. Levofloxacin is also used in veterinary medicine, however its use is limited: it is completely banned for veterinary use in the EU, and used extralabel in only companion animals in the USA. Since its introduction to clinical practice, many studies have been published on levofloxacin in animal species, including pharmacokinetic studies, tissue drug depletion, efficacy, and animal microbial isolate susceptibility to levofloxacin. This literature overview highlights the most clinically relevant and scientifically important levofloxacin studies linked to the field of veterinary medicine.

Effect of levofloxacin, pazufloxacin, enrofloxacin, and meloxicam on the immunolocalization of ABCG-2 transporter protein in rabbit retina

Adenosine triphosphate-binding cassette (ABC) sub-family G member-2 (ABCG-2) is a transporter protein, implicated for multi-drug efflux from tissues. This study evaluated the effect of fluoroquinolones; levofloxacin, pazufloxacin and enrofloxacin, and non-steroidal anti-inflammatory drug, meloxicam; on the immunolocalization of ABCG-2 transporter protein of rabbit retinas. Thirty-two male rabbits were randomly divided in to eight groups. Control group was gavaged, 2% benzyl alcohol in 5% dextrose since these chemicals are excipients of the drug preparations used in the treatment groups of this study. Four groups were exclusively gavaged, levofloxacin hemihydrate (10 mg/kg body weight b.i.d 12 h), pazufloxacin mesylate (10 mg/kg body weight b.i.d 12 h), enrofloxacin (20 mg/kg body weight o.d.), and meloxicam (0.2 mg/kg body weight o.d.), respectively. Three other groups were co-gavaged meloxicam with above fluoroquinolones, respectively. These drugs were administered for 21 days. ABCG-2 immunolocalization was mild in the retinas of control and levofloxacin-alone-treated groups. The immunolocalization intensity was significantly higher in meloxicam-alone-treated group when compared to control and levofloxacin-alone-treated groups. Immunolocalization of this transporter increased in the levofloxacin-meloxicam co-treated group when compared to the levofloxacin-alone-treated group. Highest immunolocalization was observed in the enrofloxacin-meloxicam co-treated group although the immunolocalization of all treatment groups, except the levofloxacin-alone-treated group, was significantly higher than the control and levofloxacin-alone-treated groups.