Cleuza Maria de Faria Rezende

Hidroxiapatita sintética como substituto ósseo em defeito experimental provocado no terço proximal da tíbia em cão: aspectos à microscopia eletrônica de transmissão

With the objective of studying the synthetic hydroxyapatite (HAP-91) as a bone substitute, eight healthy mongrel adult dogs were used. Following the habitual anesthetic and surgical protocol, a bone defect was provoked in the proximal diafisis of the left and right tibias, being implanted the graft of HAP-91 just in the right tibia. The animals, two at each time, were sacrificed at the 8th, 30th, 60th and 120th days after the surgery, when lesion samples were obtained for histopathology, submitted to the double coloration in 1% uranil acetate solution and in lead citrate solution. These sections were examined and photographed in an electronic transmission microscope. The bone tissue components were identified both in the control and treated tibia. The absorption of HAP-91 was characterized by the presence of multinuclear cells in the interface between the hydroxyapatite and the bone, morphologically considered as osteoclasts. In addition, the concomitant presence of HAP-91, with the adjacent formation of new bone was found, which suggests that the osteointegration of HAP-91 is similar to the bone reabsorption apposition normal process.

Site of Intrauterine Artificial Insemination in the Bitch does not Affect Sperm Distribution within the Uterus

The aim of this study was to evaluate the distribution of frozen-thawed spermatozoa within the uterine lumen and oviducts following intrauterine laparoscopic deposition at two sites. Twelve bitches of unknown reproductive history were randomly distributed into two groups. Semen (3 ml containing 300 × 10(6) frozen-thawed spermatozoa) was infused at the uterine body (UB group) or at the cranial tip of the left uterine horn. A 22-G catheter was used to access the uterine lumen. Sperm cell distribution was evaluated after ovariohysterectomy performed 3 h after artificial insemination (AI). There was no difference between groups in mean time to perform AI. Spermatozoa were detected in all uterine segments, including the tip of both horns, but none was detected in the oviduct. The 22-G catheter facilitated deposition of semen in the uterine lumen, particularly at the UB site. Sperm cell distribution occurred evenly along both horns, independent of the site of semen deposition.

Estudo experimental do poliuretano de óleo de mamona (Ricinus communis) como substituto parcial do tendão calcâneo comum em coelhos (Oryctolagus cuniculus)

With the goal of evaluating the efficiency of a prosthesis of castor-oil plant (Ricinus communis) polyurethane as a partial substitute for common calcaneous tendon, 30 New Zealand female rabbits, aging between two to three months, weighting about 2kg were used. After general anesthesia, the surgical procedure in both members consisted of rear lateral longitudinal incision, in the medium third of the distal of tibia and exposition of the common calcaneous tendon. After the tenectomies of the gastrocnemius muscle tendon, the polyurethane prosthesis of about 0,5cm in length by 0,5 in diameter was seized to the proximal and distal of the tendon stumps, using polypropylene 4-0 suture just like the Keessler modified technique. The prosthesis of polyurethane in the form of elastomers revealed qualities like the texture and flexibility similar to the tendon tissue, and it can be made in the form and size desired. In addition, it can be shaped, cut and sterilized in wet heat. All animals could stand on the surgically treated members immediately after the end of anesthetic effect. No clinical signs of infection and no dehiscence of the cut were observed. An increase of local volume, due to the edema, evident in the first week after the surgery could be noted, which gradually disappeared. It was possible to detect easily upon touch the prosthesis which remained fixed in place. Clinically, the polyurethane of castor-oil plant did not induce any unfavorable reaction which could compromise the tendon healing and can be indicated as a temporary substitute of a tendon.

Technetium-99m-labeled ceftizoxime loaded long-circulating and pH-sensitive liposomes used to identify osteomyelitis

Osteomyelitis is an infectious disease located in the bone or bone marrow. Long-circulating and pH-sensitive liposomes containing a technetium-99m-labeled antibiotic, ceftizoxime, (SpHL-(99m)Tc-CF) were developed to identify osteomyelitis foci. Biodistribution studies and scintigraphic images of bone infection or non infection-bearing rats that had been treated with these liposomes were performed. A high accumulation in infectious foci and high values in the target-non target ratio could be observed. These results indicate the potential of SpHL-(99m)Tc-CF as a potential agent for the diagnosis of bone infections.

Scintigraphic imaging using technetium-99m-labeled ceftizoxime in an experimental model of acute osteomyelitis in rats.

Purpose To investigate inflammatory (zymosan) and infectious (Staphylococcus aureus) processes in experimental models in rats using technetium-99m-labeled ceftizoxime (CFT). Methods Male Wistar rats were used for the development of the inflammatory (zymosan) and infectious (S. aureus) processes in the medullary cavity of the left tibia. Sterile saline was used for the control group. At 48 h after induction of the processes, the animals were anesthetized and scintigraphic images were acquired at 1, 2, 4, and 6 h after intravenous injection of 0.1 ml of 99mTc–CFT (55 MBq). Quantitative analysis of the scintigraphic images was performed by counting the radioactivity in the regions of interest. Samples of tibia were taken for histopathological examination. Results The images showed that 99mTc–CFT presented higher tropism to infectious foci than with the inflammatory site. The average value of the target/nontarget ratio of the 99mTc–CFT was significantly higher in the infected (2.40±0.22) than in the inflamed tibia (1.50±0.05) and the control group (1.05±0.04) for all of the investigated times. The histological data showed a similar inflammatory response for both the S. aureus and zymosan groups. Conclusion The 99mTc–CFT presented a high tropism and retention for an infected region in this model of osteomyelitis, thereby constituting an interesting strategy to distinguish aseptic from septic sites.

Orthopedic implant of a polyhydroxybutyrate (PHB) and hydroxyapatite composite in cats

The purpose of this study was to evaluate the tissue response to a 70% polyhydroxybutyrate and 30% hydroxyapatite composite in the form of a bone implant, placed intracortically in the distal metaphyseal of the right femur, and subcutaneous implants in cats. Samples of the composite were implanted subcutaneously in the dorsolumbar region and the distal metaphyseal region of the right femur of the animals. The study used 12 neutered adult mixed breed cats, weighing an average of 3.5 kg. The cats were randomly divided into three groups: GI, GII and GIII, according to the length of the assessment period. The assessments of their subcutaneous and bone tissues were performed at 15, 30 and 45 days and at 30, 60 and 90 days, respectively. The subcutaneous and bone reactions to the composites were characterized by granulomatous inflammation with a predominance of macrophages and giant cells. The results showed that the composites triggered a chronic local inflammatory response, despite their clinical acceptance.

Propriedades biomecânicas da fáscia lata e do ligamento cruzado cranial de cães

Bilateral preparations of fascia lata and cranial cruciate ligament from 15 dogs were tested in Instron machine, model 4482. Dogs were from both sexes, between one and four years of age and weighing in average about 11.80 ± 1.99kg. Fascia lata strips were tested straight and twisted and the cranial cruciate ligaments were tested with an angle of 135° between the femur and tibia and 0°, 15° of external tibial rotation and 15° of internal tibial rotation in relation to femur. The traction test velocity was 8.47mm per second. The maximum force of fascia lata strips was of approximately 290 Newtons and the maximum stress, 28 Megapascal. Similar results of strength and stress properties were found for the strips of fascia lata straight and twisted, although twisted strips presented a higher deformation than straight ones. External and internal tibial rotation did not influence the maximum force and maximum stress of the cranial cruciate ligament, that were of about 660 Newtons and 75 Megapascal, respectively. Fascia lata strips reached 44% of ligaments maximum force and 37% of maximum strain, and twisted strips reached 70% of ligaments maximum deformation, deserving straight strips to be recommended for cranial cruciate ligament substitution in dogs.

Contração de feridas após cobertura com substitutos temporários de pele

Experimentals wounds have covered with temporary skin substitutes, made of poliurethane, hidrocolloid, hemicellulose and vaseline and gauze in order to avaliate the area and contraction percentual at the 7th, 14th and 28th days. The hidrocolloidal dressing provided reduction of the initial area at the 7th day and no significant difference was observed on the other periods.

Composição do líquido sinovial de cães com ruptura do ligamento cruzado cranial

The characteristics of the synovial fluid of both stifle joints from dogs with unilateral cranial cruciate ligament rupture were studied in six adult dogs. The macroscopic parameters observed were color, volume, viscosity, turbidity, and coagulation. In addition, mucin tests were performed. The microscopic parameters were global cell counting and differential cell counting. Two animals presented normal viscosity and in the others the viscosity was reduced. The result of the mucin test was normal in all animals and there was no coagulation of the fluid when in contact with the air. The differential cell counting was maintained within regular standards cited in the literature. Therefore, in the cases of cranial cruciate ligament rupture, the synovial fluid of the stifle joint can stay without any macroscopic change. Although the global and relative cell composition of the affected joint synovial fluid were kept within regular standards according to the literature, they were consistently higher than that of the normal joint.

Imobilização interna da coluna vertebral lombar com placas de cloreto de polivinila, em cães - parte I: resultados clínico-cirúrgicos

The tissue reaction and toxicity ofpolyvinylchloride (PVC) orthopedic plates, jixed by screws Io lhe vertebral bodies and by cerdage vires to lhe spinous processes, were tested in twenty dogs with lhe lumbar spine destabitized ai L2-L3. During the 45 days of the study, the technique was considered effective based on clinical results. Microscopio studiesjromfragments of the tiver, kidney and popliteat lymph node, did not suggest PVC plates toxicity, bui it were observed: l) granulomatous inflammatory reaction and vascular alterations in ihefibrous lissues adjacent to theplate; 2) splenic hematopoiesis and 3) vertebral osteonecrosis, osteoporosis, osteopetrosis, osteopenia and myelofibrosis. Although these alterations were found subclinics, more research should be done in order to found harmiess PVC, before introducing this material in spinal traumatology.The tissue reaction and toxicity ofpolyvinylchloride (PVC) orthopedic plates, jixed by screws Io lhe vertebral bodies and by cerdage vires to lhe spinous processes, were tested in twenty dogs with lhe lumbar spine destabitized ai L2-L3. During the 45 days of the study, the technique was considered effective based on clinical results. Microscopio studiesjromfragments of the tiver, kidney and popliteat lymph node, did not suggest PVC plates toxicity, bui it were observed: l) granulomatous inflammatory reaction and vascular alterations in ihefibrous lissues adjacent to theplate; 2) splenic hematopoiesis and 3) vertebral osteonecrosis, osteoporosis, osteopetrosis, osteopenia and myelofibrosis. Although these alterations were found subclinics, more research should be done in order to found harmiess PVC, before introducing this material in spinal traumatology.