Autologous transplantation of adult adipose derived stem cells into rabbit urethral wall

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reproductive responses of rabbit does to a supplemental lighting program

The objective was to investigate whether the productivity of rabbit does can be improved, when natural photoperiod is decreasing, by adopting a supplemental lighting program. Three experiments were conducted involving two groups: control, submitted to the natural decreasing photoperiod, and supplemented with a lighting program which provided 14 h light/24 h beginning at 10 weeks of age. In the first experiment, 20 nulliparous does, 10 from each group, were euthanized 8 h after being presented to a buck; the overall number of follicles, whose diameter exceeded I mm, was determined macroscopically. The right ovaries were collected, histologically analyzed, and electronically measured. In the second experiment, 30 nulliparous does, 15 from each group, were presented to a buck (day 1). Receptive does were euthanized on day 8 to evaluate embryonic survival (number of normal embryos/ovulation rate). In the third experiment, 48 nulliparous does, 24 from each group, were followed from the first presentation to the buck until the weaning of the first litter. The effect of treatment on reproductive and body weight traits of does, and litter performance traits, at birth and weaning, was evaluated. The average number of follicles whose diameter exceeded 1 mm was higher in the treatment group (12.05 +/- 1.07 vs. 8.63 +/- 1.00, P=0.03 7). Receptive does of the treatment group had heavier ovaries relative to those of the control group (790 +/- 59 vs. 470 +/- 64 mg, P=0.004), whereas no treatment difference regarding this trait was found for non-receptive ones. Treatment had a favorable effect on pregnancy rate of total exposed and of receptive does (80.0% vs. 33.3%, P=0.01, and 92.3% vs. 50.0%, P=0.02, respectively). The number of underdeveloped embryos was lower (0.067 +/- 0.380 vs. 2.500 +/- 0.455, P=0.004), embryonic survival up to day 8, and uterus weight was higher in the treatment group (0.839 +/- 0.075 vs. 0.534 +/- 0.087, P=0.033 and 13.83 +/- 0.72 vs. 10.99 +/- 0.84, P=0.037, respectively). Number of presentations tended to be lower (1.32 +/- 0.17 vs. 1.75 +/- 0.16, P=0.077) and adjusted litter size in the first reproductive cycle tended to be higher (7.09 +/- 0.89 vs. 5.22 +/- 0.68, P=0.091) in the treatment group relative to the control.

Real-time ultrasound to predict rabbit carcass composition and volume of longissimus dorsi muscle

Real-time ultrasonography (RTU) was used to measure the longissimus dorsi muscle (LM) volume in vivo and to predict the carcass composition of rabbits. For this, 63 New Zealand White × Californian rabbits with 2093±63 g live weight were used. Animals were scanned between the 6th and 7th lumbar vertebrae using an RTU equipment with a 7.5 MHz probe. Measurements of LM volume were obtianed both in vivo and on carcass. Regression equations were used for the prediction of carcass composition and LM volume using the LM volume measured obtained with RTU (LMVU) as independent variable. Carcass meat, bone and total dissectible fat weights represented 780, 164 and 56 g/kg of the reference carcass weight, respectively. Regression equations showed a strong relationship between LMVU and the correspondent volume in carcass. Furthermore, LMVU was also useful in predicting the amounts of carcass tissues. It is possible to predict LM volume in the carcass using the LM volume measured in vivo by RTU. The amount of carcass tissues can be predicted by the LM volume measured in vivo by RTU.

Evaluation of Centrifuged Bone Marrow on Bone Regeneration Around Implants in Rabbit Tibia

Objective: To evaluate the bone regeneration of cervical defects produced around titanium implants filled with blood clot and filled with centrifuged bone marrow (CBM) by means of histomorphometric analysis.Materials and Methods: Twelve rabbits received 2 titanium implants in each right tibia, with the upper cortical prepared with a 5-mm drill and the lower cortex with a 3-mm-diameter drill. Euthanasia was performed to allow analysis at 7, 21, and 60 days after operation. The samples were embedded in light curing resin, cut and stained with alizarin red and Stevenel blue for a histomorphometric analysis of the bone-to-implant contact (BIC) and the bone area around implant (BA). The values obtained were statistically analyzed using the nonparametric Kruskal-Wallis test (P = 0.05).Results: At 60 days postoperation, the groups had their cervical defects completely filled by neo-formed bone tissue. There was no statistically significant difference between the groups regarding BIC and BA during the analyzed periods.Conclusion: There was no difference in the bone repair of periimplant cervical defects with or without the use of CBM. (Implant Dent 2012;21:481-485)

Histometric Analysis of Bone Repair in Bone-Implant Interface Using a Polylactic/Polyglycolic Acid Copolymer Associated With Implants in Rabbit Tibia

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Postsurgical stability of counterclockwise maxillomandibular advancement surgery: Affect of articular disc repositioning

Purpose: This study evaluated the affect of disc displacement and articular disc repositioning on stability after surgical counterclockwise rotation and advancement of the maxillomandibular complex.Patients and Methods: A total of 72 patients (59 females, 13 males), with an average age of 30 years (range, 15 to 60 years) were evaluated. The patients were divided into 3 groups. Group 1 (G1; n = 21), with healthy temporomandibular joints (TMJs), underwent double jaw surgery only. Group 2 (G2; n = 35), with articular disc dislocation, underwent articular disc repositioning using the Mitek anchor (Mitek Surgical Products, Westwood, MA) technique concomitantly with orthognathic surgery. Group 3 (G3; n = 16), with articular disc dislocation, underwent orthognathic surgery only. Average postsurgical follow-up was 31 months. Each patient's lateral cephalograms were traced, digitized twice, and averaged to estimate surgical changes and postsurgical stability.Results: After surgery, the occlusal plane angle was decreased significantly in all 3 groups: by -6.3 +/- -15.0 degrees in G1, by -9.6 +/- 4.8 degrees in G2, and by -7.1 +/- 4.8 degrees in G3. The maxillomandibular complex was advanced and rotated counterclockwise similarly in all 3 groups, with advancement at the menton of 12.4 +/- 5.5 mm in G1, 13.5 +/- 4.3 mm in G2, and 13.6 +/- 5.0 mm in G3; advancement at the B point of 9.5 +/- 4.9 mm in G1, 10.2 +/- 3.7 mm in G2, and 10.8 +/- 3.7 mm in G3; and advancement at the lower incisor edge of 7.1 +/- 4.6 mm in G1, 6.6 +/- 3.2 mm in G2, and 7.9 +/- 3.0 mm in G3. Postsurgery, the occlusal plane angle increased in G3 (2.6 +/- 3.8 degrees; 37% relapse rate) but remained stable in G1 and G2. Postsurgical mandibular changes in the horizontal direction demonstrated a significant relapse in G3 at the menton (-3.8 +/- 4.1 mm; 28%), the B point (-3.0 +/- 3.4 mm; 28%), and the lower incisor edge (-2.3 +/- 2.1 mm; 34%) but remained stable in G1 and G2.Conclusions: Maxillomandibular advancement with counterclockwise rotation of the occlusal plane is a stable procedure for patients with healthy TMJs and for patients undergoing simultaneous TMJ disc repositioning using the Mitek anchor technique. Those patients with preoperative TMJ articular disc displacement who underwent double-jaw surgery and no TMJ intervention experienced significant relapse. (C) 2008 American Association of Oral and Maxillofacial Surgeons.

Bioglass Associated With Leukocyte-Poor Platelet-Rich Plasma in the Rabbit Maxillary Sinus: Histomorphometric, Densitometric, and Fractal Analysis

The objective of the present study was to evaluate the outcomes of autogenous bone graft (AB) and bioglass (BG) associated or not with leukocyte-poor platelet-rich plasma (LP-PRP) in the rabbit maxillary sinus (MS) by histomorphometric and radiographic analysis. Twenty rabbits divided into 2 groups (G1, G2) were submitted to sinus lift surgery. In G1, 10 MS were grafted with AB and 10 MS were grafted with BG. In G2, 10 MS were grafted with AB + LP-PRP and 10 MS were grafted with BG + LP-PRP. After 90 days, the animals were killed and specimens were obtained, x-rayed, and submitted to histomorphometric, radiographic bone density (RD) and fractal dimension analysis. Radiographic bone density mean values (SD), expressed as aluminum equivalent in mm, of AB, BG, AB + LP-PRP, and BG + LP-PRP groups were 1.79 (0.31), 2.04 (0.39), 1.61 (0.28), and 1.53 (0.30), respectively. Significant differences (P < 0.05) were observed between BG and AB, and BG + PRP and BG. Fractal dimension mean values were 1.48 (0.04), 1.35 (0.08), 1.44 (0.04), and 1.44 (0.06), respectively. Significant differences were observed between BG and AB, and AB + LP-PRP and BG. Mean values for the percentage of bone inside MS were 63.30 (8.60), 52.65 (10.41), 55.25 (7.01), and 51.07 (10.25), respectively. No differences were found. No correlations were observed among percentage of bone, RD and FD. Histological analysis showed that MS treated with AB presented mature and new bone formation. The other groups showed minor bone formation. Within the limitations of this study, the results indicated that at a 90-day time end point, AB yielded better results than AB + LP-PRP, BG, and BG + LP-PRP and should be considered the primary material for MS augmentation.

Biological Performance of Chemical Hydroxyapatite Coating Associated With Implant Surface Modification by Laser Beam: Biomechanical Study in Rabbit Tibias

Purpose: Considering the potential of the association between laser ablation and smaller scale hydroxyapatite (HA) coatings to create a stable and bioactive surface on titanium dental implants, the aim of the present study was to determine, by the removal torque test, the effects of a surface treatment created by laser-ablation (Nd:YAG) and, later, thin deposition of HA particles by a chemical process, compared to implants with only laser-ablation and implants with machined surfaces.Materials and Methods: Forty-eight rabbits received I implant by tibia of the following surfaces: machined surface (MS), laser-modified surface (LMS), and biomimetic hydroxiapatite coated surface (HA). After 4, 8, and 12 weeks of healing, the removal torque was measured by a torque gauge. The surfaces studied were analyzed according to their topography, chemical composition, and roughness.Results: Average removal torque in each period was 23.28, 24.0, and 33.85 Ncm to MS, 33.0, 39.87, and 54.57 Ncm to LMS, and 55.42, 63.71 and 64.0 Ncm to HA. The difference was statistically significant (P < .05) between the LMS-MS and HA-MS surfaces in all periods of evaluation, and between LMS-HA to 4 and 8 weeks of healing. The surface characterization showed a deep, rough, and regular topography provided by the laser conditioning, that was followed by the HA coating.Conclusions: Based on these results, it was possible to conclude that the implants with laser surface modification associated with HA biomimetic coating can shorten the implant healing period by the increase of bone implant interaction during the first 2 months after implant placement. (C) 2009 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 67:1706-1715, 2009

Effect of GaAlAs Laser Irradiation on the Epiphyseal Cartilage of Rats

Objective: To study the effect of an 830-nm gallium-aluminum-arsenic (GaAlAs) diode laser at two different energy densities (5 and 15 J/cm(2)) on the epiphyseal cartilage of rats by evaluating bone length and the number of chondrocytes and thickness of each zone of the epiphyseal cartilage. Background Data: Few studies have been conducted on the effects of low-level laser therapy on the epiphyseal cartilage at different irradiation doses. Materials and Methods: A total of 30 male Wistar rats with 23 days of age and weighing 90 g on average were randomly divided into 3 groups: control group (CG, no stimulation), G5 group (energy density, 5 J/cm(2)), and G15 group (energy density, 15 J/cm(2)). Laser treatment sessions were administered every other day for a total of 10 sessions. The animals were killed 24 h after the last treatment session. Histological slides of the epiphyseal cartilage were stained with hematoxylin-eosin (HE), photographed with a Zeiss photomicroscope, and subjected to histometric and histological analyses. Statistical analysis was performed using one-way analysis of variance followed by Tukey's post hoc test. All statistical tests were performed at a significance level of 0.05. Results: Histological analysis and x-ray radiographs revealed an increase in thickness of the epiphyseal cartilage and in the number of chondrocytes in the G5 and G15 groups. Conclusion: The 830-nm GaAlAs diode laser, within the parameters used in this study, induced changes in the thickness of the epiphyseal cartilage and increased the number of chondrocytes, but this was not sufficient to induce changes in bone length.

Cardioplegia using low volumic cardioplegic agents: morphological study in isolated rabbit hearts

INTRODUÇÃO: A solução cardioplégica farmacológica busca eliminar as conseqüências do dano isquêmico, que é o resultado do desbalanço entre a oferta e o consumo de energia durante a parada dos batimentos cardíacos, nas cirurgias cardíacas com circulação extracorpórea. OBJETIVO: Este trabalho avalia experimentalmente as alterações estruturais e ultra-estruturais em coração isolado de coelhos submetidos à parada protegida pela Solução para Cardioplegia de Baixo Volume (SCBV). MÉTODO: O estudo compreendeu um grupo controle e dois grupos experimentais. No grupo I, a parada cardíaca foi obtida pela infusão da SCBV por 2 horas. No grupo II, o experimento foi conduzido da mesma forma até a parada protegida pela SCBV por duas horas, imediatamente procedeu-se à reperfusão com solução oxigenada de Ringer Locke (RL) por uma hora. No grupo controle os corações foram perfundidos com solução oxigenada de RL por duas horas. Após os experimentos, oito amostras de parede lateral do ventrículo esquerdo foram fixadas em formaldeído 10% e glutaraldeído 2,5% para análises histológica e ultra-estrutural. RESULTADOS: As células do miocárdio, fibroblastos e células endoteliais, observadas nos grupos experimentais I e II, apresentaram marginalização da heterocromatina, compactação do nucléolo, alteração na forma das mitocôndrias, compactação das cristas e aumento da densidade da matriz mitocondrial, indicando que tanto a estrutura nuclear quanto a das organelas citoplasmáticas foram alteradas em relação às células do grupo controle. CONCLUSÃO: As modificações estruturais foram decorrentes de uma adaptação fisiológica da célula, não sendo indicativas de oncose ou apoptose, sugerindo, portanto, que a solução cardioplégica utilizada foi eficiente para a preservação das células.

The effect of L-arginine on guinea-pig and rabbit airway smooth muscle function in vitro

We have investigated the effects of L-arginine, D-arginine and L-lysine on airway smooth muscle responsiveness to spasmogens in vitro. Both L-arginine and D-arginine (100 mM) significantly reduced the contractile potency and maximal contractile response to histamine but not to methacholine or potassium chloride in guinea-pig epithelium-denuded isolated trachea. Similarly, the contractile response to histamine was significantly reduced by L-arginine (100 mM) in rabbit epithelium-denuded isolated bronchus. The amino acid L-lysine (100 mM) failed to significantly alter the contractile potency of histamine in guinea-pig isolated trachea (P>0.05). In guinea-pig isolated trachea precontracted with histamine, both L-arginine and D-arginine produced a concentration-dependent relaxation which was not significantly altered by epithelium removal or by the presence of the nitric oxide synthase inhibitor, NG-nitro L-arginine methyl ester (L-NAME; 50 µM). Thus, at very high concentrations, arginine exhibit a non-competitive antagonism of histamine-induced contraction of isolated airway preparations that was independent of the generation of nitric oxide and was not dependent on charge. These observations confirm previous studies of cutaneous permeability responses and of contractile responses of guinea-pig isolated ileal smooth muscle. Taken together, the data suggest that high concentrations of arginine can exert an anti-histamine effect.

Estabilização extra-articular do joelho com fáscia lata autógena em cães de raças de grande porte

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Assessment of bovine biomaterials containing bone morphogenetic proteins bound to absorbable hydroxyapatite in rabbit segmental bone defects

OBJETIVO: Avaliar a capacidade osteo-regenerativa de dois biomateriais utilizando um modelo de defeito segmentar efetuado nas diáfises do rádio de coelhos. MÉTODOS: O defeito direito foi preenchido com pool de proteínas morfogenéticas ósseas (pBMPs) e hidroxiapatita em pó ultrafina absorvível (HA) combinada com matriz óssea inorgânica desmineralizada e colágeno, derivados do osso bovino (Grupo A). O defeito esquerdo foi preenchido com matriz óssea desmineralizada bovina com pBMPs e hidroxiapatita em pó ultrafina absorvível (Grupo B). em ambos os defeitos utilizou-se membrana reabsorvível de cortical bovina desmineralizada para reter os biomateriais no defeito ósseo e guiar a regeneração tecidual. Os coelhos foram submetidos à eutanásia aos 30, 90 e 150 dias após a cirurgia. Foram efetuados exames radiográficos, tomográficos e histológicos em todos os espécimes. RESULTADOS: Aos 30 dias de pós-cirúrgico, o osso cortical desmineralizado foi totalmente reabsorvido em ambos os grupos. A HA tinha reabsorvido nos defeitos do Grupo A, mas persistiu nos do Grupo B. Uma reação de corpo estranho foi evidente com ambos os produtos, porém mais pronunciada no Grupo B. Aos 90 dias os defeitos do grupo B tinham mais formação óssea que os do Grupo A. Entretanto, aos 150 dias após a cirurgia, nenhum tratamento havia promovido o completo reparo do defeito. CONCLUSÃO: Os biomateriais testados contribuíram pouco ou quase nada para a reconstituição do defeito segmentar.

O centro instantâneo de movimento e vetor velocidade em joelhos submetidos a incisuroplastia troclear e estabilização articular após transecção do ligamento cruzado cranial em cães

Avaliou-se o centro instantâneo de movimento e vetor velocidade após a transecção do ligamento cruzado cranial (LCCr), seguida da substituição ligamentar por retalho de fáscia lata, associada ou não a incisuroplastia troclear (ITR) em nove cães adultos. O joelho direito (GI) foi submetido a ITR e posterior estabilização articular, e o joelho esquerdo submetido somente a substituição ligamentar (GC). Os animais foram avaliados nos períodos pré-operatório, pós-operatório imediato e aos 30, 90 e 180 de pós-operatório, correspondente ao momento de eutanásia de subgrupos de três animais. O centro instantâneo de movimento (CIM) e o vetor velocidade (Vv) resultante foram determinados por meio do deslocamento de pontos a partir da análise radiográfica dos joelhos. Todas as articulações apresentavam CIM e Vv normais antes da transecção do ligamento cruzado cranial. Após a estabilização articular, acompanhada ou não de ITR, observou-se o posicionamento normal do CIM e Vv resultante, em todos os períodos de avaliação, apesar da presença de movimento de gaveta em três animais de GC e dois de GI no pós-operatório imediato, em dois animais de cada grupo, aos 30 dias de avaliação, e em um animal em cada grupo nas avaliações subseqüentes. Conclui-se que a estabilização articular com retalho de fáscia lata, associada ou não a ITR, mantém a integridade biomecânica do joelho, quando considerados o CIM e o Vv.