Alceu Gaspar Raiser

Total intravenous anesthesia with propofol and S(+)‐ketamine in rabbits

OBJECTIVE To evaluate total intravenous anesthesia with propofol alone or in combination with S(+)-ketamine in rabbits undergoing surgery. STUDY DESIGN Prospective, randomized, blinded trial. ANIMALS Nine 6-month-old New Zealand white rabbits, weighing 2.5-3 kg. METHODS Animals received acepromazine (0.1 mg kg(-1)) and buprenorphine (20 microg kg(-1)) IM, and anesthesia was induced with propofol (2 mg kg(-1)) and S(+)-ketamine (1 mg kg(-1)) IV. Rabbits received two of three treatments: propofol (0.8 mg kg(-1) minute(-1)) (control treatment, P), propofol (0.8 mg kg(-1) minute(-1)) + S(+)-ketamine (100 microg kg(-1) minute(-1)) (PK100) or propofol (0.8 mg kg(-1) minute(-1)) + S(+)-ketamine (200 microg kg(-1) minute(-1)) (PK200). All animals received 100% O(2) during anesthesia. Heart rate, mean arterial pressure, hemoglobin oxygen saturation and respiratory rate were measured every 5 minutes for 60 minutes. Blood-gas parameters were measured at zero time and 60 minutes. Additional propofol injections, if necessary, and recovery time were recorded. RESULTS An increase in heart rate was observed in P and PK200 up to 10 minutes after induction of anesthesia. Blood pressure decreased from baseline values during the first 10 minutes in P and PK200, and during the first 15 minutes and between 45 and 55 minutes in PK100. A reduction in respiratory rate was observed after 5 minutes in all treatments. Respiratory acidosis was observed in all treatments. Six (2.8) [median (interquartile range)] further propofol injections were necessary in P, which differed statistically from PK100 [1 (0.2)] and PK200 [2 (0.6)]. Recovery time was shorter in P compared with PK100 and PK200, being [7.5 minutes (4.11)], [17.5 minutes (10.30)], and [12 minutes (10.30)], respectively. CONCLUSIONS AND CLINICAL RELEVANCE S(+)-ketamine potentiates propofol-induced anesthesia in rabbits, providing better maintenance of heart rate. All of these techniques were accompanied by clinically significant respiratory depression.

Transplante autólogo de células mononucleares da medula óssea em úlcera de córnea experimental em cães

Bone marrow (BM) mononuclear cells (MC) are a great subject in tissual regeneration. The main stem cell source to the eye is the limbus. Theses cells replace injured corneal cells, however, if the limbal stem cells are not functional, a limbal deficiency with concomitant conjunctivalization takes place. This pathological condition can be caused for several reasons, in which alkali burns are the most common. To conduct a research about transplanted BM MC presence, the cells homing and to histopathologically compare the treated and sham group, an experimental corneal ulcer model associated with MC autotransplant was used. Sixteen, male or female, stray dogs suffered experimental corneal ulceration with sodium hydroxide soaked filter discs. After the lesions, animals were submitted to subconjunctival autotransplant of previously marked BM MC. The evaluation was made by immunofluorescence on the sixth day after lesions creation and histopathology was conducted 15 days after the same procedure, when it was possible to observe that the MC grafted in the injured area, the cells did not execute the homing process and, despite the inflammatory decrease, they did not help the corneal epithelial healing process in a short term evaluation. Thus, future studies about MC transplantations in corneal ulcers are indicated.

Teste de biocompatibilidade e resistência de membranas de látex em cães

The natural latex extracted of the Rubber Tree, has properties to induce characteristics of tissue vascularization and regeneration that had been comproved in different species and tissues. This study tested the biocompatibility of three latex membranes in six dogs. Two of these membranes have not been used yet, while one of them has been tested in previous studies. Membranes were implanted between the cutaneous and the rectum of the abdomen muscles by a surgical procedure. In a forty five days period, the animals were evaluated for pain, clinical and macroscopic alterations of the membranes and, after the membranes were removed in order to submit them to histological exams. Mechanical traction tests were realized in control membranes to measure deformation and resistance. The results indicated that membranes are compatible, and able to substitute the muscular sheath in dogs, excepting membrane 2, because of it rejecting characteristics.

Homoimplante ortotópico conservado, associado à terapia "soft laser" na reparação tenopatelar em cão

The aim of the present research was to develop an alternative method of treatment for tenopatellar lesions. The tenopatellar implant, preserved in glycerin 98%, was applied in 24 dogs, associated (group I - twelve dogs) or not (group II - twelve dogs) to laser therapy with gallium arsenide during the first ten post-operative days. The animals in each group were divided again in subgroups according to body weight (between 10 and 20kg or between 21 and 30kg) and according to post-operative period (60, 120 and 180 days) of evaluation. The stifle joint was immobilized through percutaneous external skeletal fixation type II for 30 post-operative days. Temporary articular immobilization provided adequate joint stability. At radiographic exams, different stages of bone resorption from the implant were verified, being more evident at 180 days post-operativelly. Microscopically, fragments of osteal trabecules of the graft, in reabsorption phase, surrounded by osteoclasts and filled with fibrovascular tissue were verified in all the groups. Newbone formation at the graft from endochondral ossification, more evident at the 180th day group, was noted. Despite the need for more studies, with a longer period of post-operatory evaluation, the implant of an orthotopic homologous tenopatellar segment preserved in glycerin 98% is suitable for replacement of tenopatellar segments in dogs weighting up to 30 kg.

Analgesia epidural com clonidina ou romifidina em cães submetidos à cirurgia coxofemoral

Cardiovascular alterations and analgesia in 14 dogs submitted to epidural administration of clonidine or romifidine to enable coxofemoral surgery were evaluated. Dogs were separated in two groups: Cloni group received 150µg of clonidine and Romi group, 20µg/kg of romifidine. Anesthetic induction was performed using propofol (8mg/kg) and maintenance using halothane and O2 in spontaneous breathing. The puncture of epidural space was performed just after anesthetic induction. Heart rate and respiratory rate, systolic arterial rate, hemoglobin oxygen saturation and halothane concentration were assessed before anesthetic induction, and at each 10 minutes until the end of the surgery. Samples of arterial blood were collected after anesthesic induction and at the end of the surgical procedure in order to assess pH, PaCO2, PaO2, SaO2, BE and HCO3- levels. The analgesia degree (intense, middle or inadequated) was evaluated for two postoperative hours. Numerical data were analysed with ANOVA and Bonferronis test (P< 0.05). Dogs of Romi group had bradycardia, bradyarrhrytmia, and hypertension. The heart rate and systolic arterial pressure in the Cloni group were within the physiologic variation parameter to dogs. In conclusion epidural administration of clonidine or romifidine produce intense intraoperative analgesia, with no respiratory depression, and middle analgesia for two postoperative hours. Bradycardia and hypotension were not observed with epidural clonidine, however, bradyarrhytmia and hypertension ocurred with epidural romifidine.

Células-tronco mononucleares autólogas e proteína óssea morfogenética na cicatrização de defeitos tibiais experimentalmente induzidos em cães

Avaliou-se a utilizacao de celulas-tronco mononucleares (CTM) na cicatrizacao de defeito osseo experimental como alternativa aos metodos convencionais, analisando-se o tempo de evolucao cicatricial e a presenca dessas celulas no tecido neoformado. Foram utilizados 18 caes, separados em tres grupos (G) de seis, e de cada animal foram colhidas celulas da medula ossea (MO), contadas e analisadas para morfometria, por meio da contagem manual e mielograma. Um defeito osseo tibial foi entao criado cirurgicamente, e a lesao tratada com esponja de gelatina embebida em solucao fisiologica (G1), esponja de gelatina embebida com aspirado de MO processado (G2) e esponja de gelatina embebida com aspirado de MO processado e proteina ossea morfogenetica (rhBMP-2) (G3). A cicatrizacao foi entao avaliada por estudos radiograficos, e a presenca de CTM foi identificada por meio de marcadores nanocristais Qtracker, em microscopia com luz fluorescente, uma semana apos a intervencao cirurgica. Entre as celulas identificadas pelo marcador, foram encontradas celulas da linhagem ossea. As avaliacoes radiograficas demonstram crescimento osseo acelerado nos animais de G2 e G3. Houve diferencas significativas entre o G1 e G3 em todos os tempos estudados, e entre G1 e G2 nos tempos de 30 e 45 dias. A utilizacao de CTM adultas suplementadas ou nao com rhBMP-2 e alternativa favoravel ao crescimento osseo em defeitos experimentais agudos de tibia de caes.

Biometria ultra-sonográfica bidimensional em tempo real do globo ocular de cães

Sixty ocular globes of 30 health dogs were utilized to perform a real-time ultrasonic biometry, with the objective of getting distance measurement of intra-ocular structures. The measurements were taken from cross-sectional sagital image with the dogs in esternal recumbence, and manual containment, with the use of topical ocular anesthetic vehicle applied in the cornea. A 7.5 MHz transducer of a mechanical sector scanner without flotation pad was used. The measure averages were 3.9 ± 0.7mm (D1) distance between the midcornea to anterior capsule; 6.1 ± 1.2mm (D2) lens thickness; 10.5 ± 1.0mm (D3) lens diameter; 9.1 ± 0.4mm (D4) vitreous chamber depth; and 18.8 ± 0.9mm (D5) midcornea to retinal distance. Significant difference was observed among the right and left eyes only in D1.

A radiação laser arseneto de gálio (AsGa) na regeneração do nervo radial submetido a reparação cirúrgica secundária

Twenty-four cross bred adult dogs were separated into four groups and submitted to bilateral neurotomy of the radial nerve, at the level of the distal third of the humerus. In each dog the epineural anastomosis was made 21 days after neurotomy. The surgical region of the left forearm received daily irradiation with GaAs laser for a ten day period in order to evaluate its influence on the repair process. The right forearm was the control. Functional recovery of the forearms was evaluated through ambulation, test of sensibility and motion evaluation. Nerve regeneration was confirmed by histological studies of the anastomosed nervous stumps, collected by biopsy in the 10th day (group A), in the 30th day (group B), in the 60th day (group C) and in the 90th day (group D) after neuroanastomosis. The histological studies showed that the proliferation of the connective tissue on the anastomosis region was the factor that proved to be the greatest impeachment for the nervous regeneration. The GaAs laser radiation decreases the local inflammatory response but may contribute to neuroma formation.

Secnidazole for the treatment of giardiasis in naturally infected cats.

Giardia duodenalis causes enteric infections in humans and animals worldwide. Inefficiency of metronidazole is commonly reported in the veterinary clinic routine in the treatment of giardiasis in dogs and cats. The aim of this study was to evaluate the efficacy of secnidazole in the control of infection caused by G. duodenalis in naturally infected cats. For this purpose two experiments were carried out. In the first experiment seven cats were infected with G. duodenalis and treated orally with a single dose of secnidazole (30 mg kg(-1)). In the second experiment a total of 16 cats were used, 11 naturally infected with G. duodenalis and five negative for the parasite. Animals were divided into three groups: group A (n=5) was composed by non-infected animals (negative control), group B (n=5) consisted of infected but untreated animals and group C (n=6) was composed by cats treated orally with a single dose of secnidazole (30 mg kg(-1)). Hematological and biochemical parameters were evaluated before and after treatment. The first experiment reached 100% of efficacy because no cysts were found in the feces after treatment. However, doubts about intoxication and interference with hematological and biochemical parameters came to light. No side effects were observed, and the biochemical and hematological parameters of treated animals remained within physiological range, except for one feline which had elevation of liver enzymes. Based on these results, the utilization of secnidazole could be suggested for the treatment of giardiasis in cats. The main advantage of this treatment is that only a single dose is required, which is interesting in animals hard to handle like cats.

Estimulação elétrica neuromuscular de média freqüência (russa) em cães com atrofia muscular induzida

The medium frequency neuromuscular electrical stimulation (NMES) (Russa) or Kotz is designed for recuperation of muscle mass in dogs with muscular atrophy in disuse. This study aims to utilize medium frequency NMES on the femoral quadriceps of dogs with induced muscular atrophy and evaluate the occurrence of gain in mass. Eight dogs in two groups denominated GI, or control, and GII, or treated were used. For the induction of muscular atrophy, the left femoral-tibial-patellar joint was immobilized for 30 days. NMES treatment began 48 hours after the removal of the immobilization device on dogs from group II and was carried out three times per week, with an interval of 48 hours between each session, during 60 days. The following parameters were measured: thigh perimeter, goniometry of the knee, creatine kinase (CK) enzymes and morphometry of the muscular fibers in transversal cuts of the vastus lateralis muscle, collected through a muscular biopsy. EENM was utilized on the femoral quadriceps at a frequency of 2500 Hz, with pulse duration of 50%, and the time on/off was at a proportion of 1:2. There was no significant difference between the thigh perimeter and the activity of enzyme CK between groups I and II. As for the goniometry a significant increase (P<0,05) was observed among 0 and 30 days after the immobilization in group II. As for the morphometry of the fibers of the vastus lateralis, a significant increase (P<0,05) was observed in the transversal area of the treated group on the 90th day when compared with that observed at the time of immobilization and among the groups, group II presented a greater transversal area (P<0.05) on the 90th day. The medium frequency NMES brings about a hypertrophy of the vastus lateralis muscle in dogs after induced muscular atrophy.A estimulacao eletrica neuromuscular (EENM) de media frequencia (Russa) ou de Kotz pode ser empregada para a recuperacao de massa muscular em animais apresentando atrofia muscular por desuso. Assim, o objetivo deste trabalho foi empregar a EENM de media frequencia no quadriceps femoral de caes com atrofia muscular induzida, avaliando-se a ocorrencia de ganho de massa. Foram utilizados oito caes em dois grupos denominados de GI ou controle e de GII ou tratado. Para a inducao da atrofia muscular, a articulacao femoro-tibio-patelar esquerda foi imobilizada por 30 dias. Apos 48 horas da remocao, foi realizada a EENM nos caes do grupo II, tres vezes por semana, com intervalo de 48 horas cada sessao, pelo periodo de 60 dias. Foram avaliadas a mensuracao da perimetria da coxa, da goniometria do joelho, as enzimas creatina-quinase (CK) e morfometria das fibras musculares em cortes transversais do musculo vasto lateral, colhido mediante a biopsia muscular. A EENM foi empregada no musculo quadriceps femoral numa frequencia de 2.500Hz, largura de pulso de 50% e relacao de tempo on/off de 1:2. Nao houve diferenca significativa quanto aos valores de perimetria da coxa e a atividade da enzima CK entre os grupos I e II. Na goniometria, houve diminuicao significativa (P<0,05) da amplitude articular apos a remocao do aparelho de fixacao externa somente nos animais do grupo II, em comparacao a com tempo zero. Quanto a morfometria das fibras do musculo vasto lateral, foram notados valores maiores de area das fibras no grupo Tratado, em relacao ao Controle (P<0,05), no dia 90, e, no grupo Tratado, entre os dias zero e 90. A EENM de media frequencia ocasiona hipertrofia do musculo vasto lateral em caes apos a atrofia muscular induzida.