Ketamine-dexmedetomidine combined with local anesthesia, with or without different doses of atipamezole in the postoperative period, for orchiectomy in cats.

OBJECTIVE: To evaluate the anesthetic and cardiopulmonary effects of ketamine-dexmedetomidine combined with local anesthesia, associated or not in the postoperative period with different doses of atipamezole, for orchiectomy in cats. ANIMALS: 24 healthy cats. PROCEDURES: Cats received ketamine (7 mg/kg) combined with dexmedetomidine (10 µg/kg) IM, and 1 mL of saline (group KDSAL), 25 µg/kg (group KDAT25), or 50 µg/kg (group KDAT50) of atipamezole IV, postoperatively. All cats received local anesthesia (2 mg/kg of lidocaine) intratesticular and SC. Physiologic variables were recorded at baseline and at time points during anesthesia. Ketamine rescue dose (1 mg/kg) was recorded. The quality of recovery, the degree of sedation, and side effects were evaluated postoperatively. RESULTS: 2 cats received a single additional bolus of ketamine to perform local anesthesia. Heart rate was lower in KDSAL, KDAT25, and KDAT50 during anesthesia, compared with baseline. Hypertension was observed intraoperatively in all groups. The time to head up, pedal reflex regained time, time to sternal recumbency, and time to standing were shorter in KDAT25 and KDAT50 compared to KDSAL. Lower sedation scores were assigned sooner to KDAT25 and KDAT50 than KDSAL. All groups resulted in low recovery quality scores and no side effects. CLINICAL RELEVANCE: At the doses used, ketamine-dexmedetomidine combined with local anesthesia allowed the performance of orchiectomy. Rescue dose of ketamine for performing local anesthesia may be required. This combination can result in hypertension. Both atipamezole doses shortened the anesthetic recovery, without differences among them, and side effects.

VTR: A Web Tool for Identifying Analogous Contacts on Protein Structures and Their Complexes.

Evolutionarily related proteins can present similar structures but very dissimilar sequences. Hence, understanding the role of the inter-residues contacts for the protein structure has been the target of many studies. Contacts comprise non-covalent interactions, which are essential to stabilize macromolecular structures such as proteins. Here we show VTR, a new method for the detection of analogous contacts in protein pairs. The VTR web tool performs structural alignment between proteins and detects interactions that occur in similar regions. To evaluate our tool, we proposed three case studies: we 1) compared vertebrate myoglobin and truncated invertebrate hemoglobin; 2) analyzed interactions between the spike protein RBD of SARS-CoV-2 and the cell receptor ACE2; and 3) compared a glucose-tolerant and a non-tolerant ß-glucosidase enzyme used for biofuel production. The case studies demonstrate the potential of VTR for the understanding of functional similarities between distantly sequence-related proteins, as well as the exploration of important drug targets and rational design of enzymes for industrial applications. We envision VTR as a promising tool for understanding differences and similarities between homologous proteins with similar 3D structures but different sequences. VTR is available at http://bioinfo.dcc.ufmg.br/vtr.

Reduced tissue parasitic load and infectivity to sand flies in dogs naturally infected by Leishmania (Leishmania) chagasi following treatment with a liposome formulation of meglumine antimoniate.

The toxicity and antileishmanial effectiveness of a novel liposome formulation of meglumine antimoniate in mongrel dogs with visceral leishmaniasis (VL) obtained from a region where VL is endemic in Brazil have been investigated. Groups of 12 animals received by the intravenous route four doses (with 4-day intervals) of either liposomal meglumine antimoniate (group I [GI], 6.5 mg Sb/kg of body weight/dose), empty liposomes (GII), or isotonic saline (GIII). Evaluation of markers of hematopoietic, hepatic, and renal functions before and just after treatment showed no significant change. On the other hand, transitory adverse reactions, including prostration, defecation, tachypnea, and sialorrhea, were observed during the first 15 min after injections in GI and GII. Parasitological evaluation of sternal bone marrow 4 days after the last dose showed a significant reduction of parasite burden in GI, compared to the other groups. Immunocytochemical evaluations of the skin, bone marrow, cervical lymph nodes, livers, and spleens of dogs for parasites, 150 days after treatment, indicated significant parasite suppression (higher than 95.7%) in the lymph nodes, livers, and spleens of GI, compared to control groups. Feeding of Lutzomyia longipalpis phlebotomines on dogs from GI, 150 days after treatment, resulted in a significant reduction of sand fly infection efficiency, compared to feeding on animals from GII and GIII. This is the first report of both long-term parasite suppression and reduction of infectivity to sand flies in naturally infected dogs following treatment with a liposome-encapsulated drug. Importantly, this was achieved using a 20-fold-lower cumulative dose of Sb than is used for conventional antimonial treatment.