Rogério Ribeiro Robes

Detection of Bartonella spp. in neotropical felids and evaluation of risk factors and hematological abnormalities associated with infection.

Although antibodies to Bartonella henselae have been described in all neotropical felid species, DNA has been detected in only one species, Leopardus wiedii. The aim of this study was to determine whether DNA of Bartonella spp. could be detected in blood of other captive neotropical felids and evaluate risk factors and hematological findings associated with infection. Blood samples were collected from 57 small felids, including 1 Leopardus geoffroyi, 17 L. wiedii, 22 Leopardus tigrinus, 14 Leopardus pardalis, and 3 Puma yagouaroundi; 10 blood samples from Panthera onca were retrieved from blood banks. Complete blood counts were performed on blood samples from small felids, while all samples were evaluated by PCR. DNA extraction was confirmed by amplification of the cat GAPDH gene. Bartonella spp. were assessed by amplifying a fragment of their 16S-23S rRNA intergenic spacer region; PCR products were purified and sequenced. For the small neotropical felids, risk factors [origin (wild-caught or zoo-born), gender, felid species, and flea exposure] were evaluated using exact multiple logistic regression. Hematological findings (anemia, polycythemia/hyperproteinemia, leukocytosis and leukopenia) were tested for association with infection using Fishers exact test. The 635bp product amplified from 10 samples (10/67=14.92%) was identified as B. henselae by sequencing. Small neotropical felid males were more likely to be positive than females (95% CI=0.00-0.451, p=0.0028), however other analyzed variables were not considered risk factors (p>0.05). Hematological abnormalities were not associated with infection (p>0.05). This is the first report documenting B. henselae detection by PCR in several species of neotropical felids.

Survey of Feline Leukemia Virus and Feline Coronaviruses in Captive Neotropical Wild Felids from Southern Brazil

Abstract A total of 57 captive neotropical felids (one Leopardus geoffroyi, 14 Leopardus pardalis, 17 Leopardus wiedii, 22 Leopardus tigrinus, and three Puma yagouaroundi) from the Itaipu Binacional Wildlife Research Center (Refúgio Bela Vista, Southern Brazil) were anesthetized for blood collection. Feces samples were available for 44 animals, including one L. geoffroyi, eight L. pardalis, 14 L. wiedii, 20 L. tigrinus, and one P. yagouaroundi. Total DNA and RNA were extracted from blood and feces, respectively, using commercial kits. Blood DNA samples were evaluated by polymerase chain reaction (PCR) for feline leukemia virus (FeLV) proviral DNA, whereas reverse transcriptase–PCR was run on fecal samples for detection of coronavirus RNA. None of the samples were positive for coronaviruses. A male L. pardalis and a female L. tigrinus were positive for FeLV proviral DNA, and identities of PCR products were confirmed by sequencing. This is the first evidence of FeLV proviral DNA in these species in Southern Brazil.

Inflammatory reaction and tensile strength of the abdominal wall after an implant of polypropylene mesh and polypropylene/poliglecaprone mesh for abdominal wall defect treatment in rats

PURPOSE To compare the inflammatory reaction and the growing resistance of the abdominal wall with the use of poliglecaprone meshes and polypropylene meshes associated with poliglecaprone in the correction of abdominal defects. METHODS Seventy-seven Wistar rats were divided into three groups: CG (non-operated animals: EG (polypropylene mesh) and UG (polypropylene and poliglecaprone mesh). A muscular and aponeurotic defect was formed and treated according to the group. Evaluations were made after 4, 7, 14, 28 and 56 days. The resistance and inflammatory pattern were studied. RESULTS There was a gradual and significant gain in resistance, regularly in the EG and irregularly in the UG, which was lower on the 14th day (p=0.008). The inflammatory reaction was acute and more intense in the UG on the fourth day. At all other times, the inflammatory pattern was acute to chronic, similar in both groups, with minimum intensity on the 56th day. CONCLUSION The greater resistance offered by the polypropylene mesh was regular and ascending, stabilizing on the 28th day, while that of the polypropylene/poliglecaprone was not even. In the end, the resistances were similar. The inflammatory response was greater in the UG on the fourth day and similar at all other times.

Characteristics of the fibroplasia and collagen expression in the abdominal wall after implant of the polypropylene mesh and polypropylene/polyglecaprone mesh in rats.

PURPOSE To compare fibroplasia and the resistance of the abdominal wall when polypropylene meshes and polypropylene/poliglecaprone are used. METHODS Seventy-seven male Wistar rats were divided into three groups: Control Group (for resistance); Group E (polypropylene mesh); and Group U (polypropylene/poliglecaprone mesh). The animals in Groups E and U had a standard muscular and aponeurotic defect, with integral peritoneum, and correction with the mesh. Measurements were taken 4, 7, 14, 28 and 56 days after surgery. The resistance, and collagen density were studied. RESULTS Resistance on the 56th day was similar in both meshes. The gain in resistance described an ascending curve for the polypropylene mesh and was irregular in the case of the polypropylene/poliglecaprone. Fibroplasia showed a gain in type I and type III collagen in both groups (p<0.001). Collagen III stabilized in the 14th day and collagen I continued to ascend. CONCLUSIONS The gain in resistance of the polypropylene mesh is regular and ascending, whereas the polypropylene/poliglecaprone is not regular. The final resistance of both meshes is similar; the collagen density increases over time, and show the same inflammatory potential.

Impact of hypertension in liver regeneration in rats

PURPOSE To determine the impact of hypertension in liver regeneration, in rats by examining gain in liver mass and the replication of hepatocytes and stellate cells. METHODS Forty Wistar rats were allocated into two groups of twenty, the control and experiment group. The experiment group animals were submitted to induction of renovascular hypertension. A week later, all the animals underwent a partial hepatectomy. Measurements were taken after 24 hours and seven days, when ten animals in each group were euthanized. Thus, four subgroups were obtained. The livers were excised and sent for histopathological analysis. RESULTS The control group had a greater gain in liver mass than the experiment group seven days after partial hepatectomy (p=0.0051). The difference in the activate stellate cell count was not statistically significant following analysis after both 24 hours and seven days (p=1.0). A higher number of dividing hepatocytes was observed in the control group seven days after partial hepatectomy (p=0.0014). CONCLUSION In rats, hypertension had no direct influence on stellate cell replication, but led to a delay in liver mass gain and were shown to be a reduction factor on hepatocyte replication seven days after partial hepatectomy.

Comparative study of fibrosis induced by Marlex®, Parietex Composite®, Vicryl® and Ultrapro® meshes1

PURPOSE To evaluate the fibrosis induced by four different meshes: Marlex®, Parietex Composite®, Vicryl® and Ultrapro®. METHODS Histological cutouts of abdominal wall were analyzed with polarized light 28 days after the meshes implants and colorized by picrosirius to identify the intensity of collagen types I and III, and their maturation index. RESULTS When the four groups were compared, the total collagen area analyzed was bigger in groups A and D, with no difference between them. The collagen type I density was bigger in group A, with an average of 9.62 ± 1.0, and smaller in group C, with an average of 3.86 ± 0.59. The collagen type III density was similar in groups A, B and C, and bigger in group D. The collagen maturation index was different in each of the four groups, bigger in group A with 0.87, group B with 0.66, group D with 0.57 and group C with 0.33 (p = 0.0000). CONCLUSION The most prominent fibrosis promotion in the given meshes was found on Marlex® (polypropylene mesh) and the Parietex Composite® (non-biodegradable polyester); the collagen maturation index was higher in the Marlex® mesh, followed by Ultrapro®, Parietex Composite® and Vicryl® meshes.

Comparative study of polyglactin 910 and simple catgut in the formation of intraperitoneal adhesions

PURPOSE To compare polyglactin 910 and simple catgut sutures for the incidence of intraperitoneal adhesions. METHODS Twenty female Wistar rats were placed into two groups. Group 1 received ischemic sutures and Group 2 received polyglactin 910. Five sutures inductive of adhesions in each rat were made. After 14 days, the rats were euthanized with an assessment of the presence of adhesions, the number of sutures involved and classification according to the Granat et al. scale described by Ozel et al17. RESULTS In total, 19 of the 20 rats presented adhesions, with nine from Group 1 and ten from Group 2. There was a smaller number of affected sutures in Group 1, while in Group 2 the majority of the sutures formed adhesions (p=0.0197). According to the Granat et al. scale, Group 1 predominately developed fine, filamentous adhesions or thickening in a restricted area. Group 2 mainly presented extensive, thick adhesions with the involvement of the viscera (p=0.0055). CONCLUSION Polyglactin 910 sutures formed more adhesions that were more extensive and thicker than the simple catgut sutures.

Comparison between polypropylene and polypropylene with poliglecaprone meshes on intraperitoneal adhesion formation

OBJECTIVE to compare intraperitoneal adhesion formation in rats when using polypropylene and polypropylene with poliglecaprone meshes. METHODS we used twenty male, Wistar rats, divided in two groups. In group 1, the rats received the polypropylene mesh on their right side and the polypropylene with poliglecaprone mesh on their left side. In group 2 the position of the meshes was inverted. After 30 days, we analyzed the presence or not of adhesion formation, including only those over the meshes. The findings undergone an analysis through the Mann-Whitney test, at a level of significance of p≤0.05. RESULTS all meshes presented adhesions. We verified that, for the polypropylene meshes, the percentage of their surface covered by adhesions varied from 10.5 to 100%, with an average of 34.07±24.21%, while for the polypropylene with poliglecaprone mesh, the percentage covered by adhesions varied between 8.5% and 100%, with an average of 44.7±32.85% (p=0.12). CONCLUSION both meshes lead to adhesion formation, none being superior to the other.