RESUMO
The present objective was to increase the number of biomechanical cycles performed using non-chondrodystrophic dog specimens, based on the study by Araújo (2017), comparing partial lateral corpectomy (PLC) alone, corpectomy and pediculectomy, and PLC associated with pediculectomy and hemilaminectomy to determine if there are significant differences between them regarding deformation versus applied force. Groups were divided as: control (G1), corpectomy (G2), corpectomy +pediculectomy (G3), and corpectomy + pediculectomy + hemilaminectomy (G4). The level of displacement versus force was observed during axial compression, flexion, extension, right and left lateral bending, and right and left axial rotation. Significant differences were observed between groups for flexion, extension, right and left axial rotation, and left lateral bending, whereas there was no difference for axial compression and right lateral bending. PLC and PLC with pediculectomy had significant differences in flexion and in extension, similar to PLC associated with pediculectomy and with hemilaminectomy in right and left axial rotation, flexion, extension, and right lateral bending.
O presente objetivo foi, a partir de grupos de espécimes caninas não condrodistróficas, aumentar o número de ciclos biomecânicos realizados, com base no estudo de Araújo (2017), comparando-se corpectomia parcial lateral (CPL) isolada, corpectomia e pediculectomia, à CPL associada à pediculectomia e à hemilaminectomia, no intuito de determinar se há diferenças significativas entre eles quanto à deformação versus à força aplicada. Os grupos foram divididos em: controle (G1), corpectomia (G2), corpectomia + pediculectomia (G3) e corpectomia + pediculectomia + hemilaminectomia (G4). O nível de deslocamento versus a força foi observado durante a compressão axial, a flexão, a extensão, a flexão lateral direita e esquerda e a rotação axial direita e esquerda. Observaram-se diferenças significativas entre os grupos para flexão, extensão, rotação axial direita e esquerda e flexão lateral esquerda, ao passo que, na compressão axial e na flexão lateral direita, não houve diferença. CPL e CPL com pediculectomia tiveram diferenças significativas na flexão e na extensão, semelhantemente à CPL associada à pediculectomia e à hemilaminectomia nos movimentos de rotação axial direita e esquerda, flexão, extensão e flexão lateral direita.
Assuntos
Animais , Cães , Compressão da Medula Espinal/cirurgia , Discotomia/métodos , Discotomia/veterinária , Degeneração do Disco Intervertebral/veterináriaRESUMO
Objetivou-se com este trabalho analisar a resistência de placas ósseas de acrílico, confeccionadas com cortadora a laser CO2, quando submetidas às forças que agem sobre o foco de fratura. Foram utilizados 40 fêmures de ovinos (Ovis aries) e confeccionadas 40 placas de acrílico, os quais foram avaliados em grupos: grupo OP - foram avaliados 20 ossos fraturados reduzidos com 20 placas de acrílico; grupo PS - foram avaliadas 20 placas de acrílico; e grupo OS - foram avaliados 20 ossos íntegros e frescos. Todos foram submetidos a ensaios mecânicos de compressão, flexão, torção e tração, em máquina de ensaios universal EMIC® 10000. Os testes eram interrompidos quando havia fratura do corpo de prova. O grupo PS suportou carga de compressão significativamente superior aos demais grupos OP e OS (13.255±290N, 4.932±827N e 8.681±303N, respectivamente). Já em relação à prova de flexão, o grupo OS foi significativamente mais resistente, com média de 2.698±305N, em relação aos grupos OP e PS, que obtiveram 1.315±92N e 1.537±37N, respectivamente. Conclui-se que as placas de acrílico usinadas a laser apresentam resistência mecânica inferior ao fêmur de ovinos, entretanto, devido à resistência exibida nos testes, demonstraram potencial para serem implantadas em ossos com menor demanda de carga.(AU)
The objective of this work was to analyze the resistance of acrylic bone plates, made with CO 2 laser cutter, when subjected to the forces acting on the fracture focus. Forty ovine femurs (Ovis aries) were used and 40 acrylic plates were prepared and evaluated in groups: In the OP Group, 20 fractured bones reduced with 20 acrylic plates were evaluated; in the PS Group, 20 acrylic plates were evaluated; and in the OS Group 20 intact and fresh bones were evaluated. All were submitted to mechanical tests of compression, bending, twisting and traction in an EMIC® 10000 universal testing machine. The tests were interrupted when the body of proof was fractured. The PS group supported a significantly higher compression load than the other OP and OS groups (13,255±290 N, 4,932±827 N and 8,681±303 N, respectively). Regarding the flexural test, the OS group was significantly more resistant, with a mean of 2,698±305 N, compared to the groups OP and PS that obtained 1,315±92 N and 1,537±37 N respectively. It is concluded that the laser-machined acrylic plates have inferior mechanical resistance to the femur of the ovine, however, due to the presented resistance, it shows potential to be implanted in bones with lower load demand.(AU)
Assuntos
Resistência à Tração , Materiais Biocompatíveis/análise , Fenômenos Biomecânicos , Placas Ósseas , /análise , OvinosRESUMO
Objetivou-se com este trabalho analisar a resistência de placas ósseas de acrílico, confeccionadas com cortadora a laser CO2, quando submetidas às forças que agem sobre o foco de fratura. Foram utilizados 40 fêmures de ovinos (Ovis aries) e confeccionadas 40 placas de acrílico, os quais foram avaliados em grupos: grupo OP - foram avaliados 20 ossos fraturados reduzidos com 20 placas de acrílico; grupo PS - foram avaliadas 20 placas de acrílico; e grupo OS - foram avaliados 20 ossos íntegros e frescos. Todos foram submetidos a ensaios mecânicos de compressão, flexão, torção e tração, em máquina de ensaios universal EMIC® 10000. Os testes eram interrompidos quando havia fratura do corpo de prova. O grupo PS suportou carga de compressão significativamente superior aos demais grupos OP e OS (13.255±290N, 4.932±827N e 8.681±303N, respectivamente). Já em relação à prova de flexão, o grupo OS foi significativamente mais resistente, com média de 2.698±305N, em relação aos grupos OP e PS, que obtiveram 1.315±92N e 1.537±37N, respectivamente. Conclui-se que as placas de acrílico usinadas a laser apresentam resistência mecânica inferior ao fêmur de ovinos, entretanto, devido à resistência exibida nos testes, demonstraram potencial para serem implantadas em ossos com menor demanda de carga.(AU)
The objective of this work was to analyze the resistance of acrylic bone plates, made with CO 2 laser cutter, when subjected to the forces acting on the fracture focus. Forty ovine femurs (Ovis aries) were used and 40 acrylic plates were prepared and evaluated in groups: In the OP Group, 20 fractured bones reduced with 20 acrylic plates were evaluated; in the PS Group, 20 acrylic plates were evaluated; and in the OS Group 20 intact and fresh bones were evaluated. All were submitted to mechanical tests of compression, bending, twisting and traction in an EMIC® 10000 universal testing machine. The tests were interrupted when the body of proof was fractured. The PS group supported a significantly higher compression load than the other OP and OS groups (13,255±290 N, 4,932±827 N and 8,681±303 N, respectively). Regarding the flexural test, the OS group was significantly more resistant, with a mean of 2,698±305 N, compared to the groups OP and PS that obtained 1,315±92 N and 1,537±37 N respectively. It is concluded that the laser-machined acrylic plates have inferior mechanical resistance to the femur of the ovine, however, due to the presented resistance, it shows potential to be implanted in bones with lower load demand.(AU)
Assuntos
Resistência à Tração , Materiais Biocompatíveis/análise , Fenômenos Biomecânicos , Placas Ósseas , Ciência dos Materiais/análise , OvinosRESUMO
Objetivou-se com este trabalho comparar biomecanicamente os posicionamentos dorsal e medial da placa bloqueada na artrodese do carpo em cães. Para isso, foram utilizados sete pares de membros torácicos de cães eutanasiados por razões não relacionadas ao estudo, em que sete membros foram estabilizados com placa dorsal, e seus respectivos pares com placa em posicionamento medial. Os membros com as articulações radiocarpometacarpianas estabilizadas cirurgicamente foram submetidos a ensaio de compressão axial em máquina universal de ensaios de materiais, e os dados de limite de elasticidade, rigidez estrutural, carga máxima e carga no momento da fratura dos posicionamentos foram comparados por meio do teste de Student-Newman-Keuls, a um nível de significância de 5%. Todos os membros foram fraturados no terço distal do terceiro metacarpo; nos membros com placa dorsal, a fratura ocorreu distal ao orifício distal e, nos membros com placa medial, a fratura ocorreu no último orifício dos metacarpos dois e três. Não houve dobra ou quebra de placas e parafusos e não houve diferença significativa entre os posicionamentos dorsal e medial dos implantes quanto aos parâmetros avaliados.(AU)
The aim of this study was to compare biomechanically the dorsal and medial positions of the locking plates on carpal arthrodesis in dogs. For this, seven pairs of thoracic limbs of dogs were used, in which seven limbs were stabilized with dorsal plate and seven limbs with plate in medial positioning. The members with the surgically stabilized radiocarpal-metacarpal joints were submitted to axial compression testing in a universal testing machine and the yield load, structural rigidity, maximum load and ultimate load of the positioning were compared by Student-Newman-Keuls test at a significance level of 5%. All members fractured in the distal third of the third metacarpal, in the limbs with dorsal plate the fracture occurred distal to the distal hole and in the members with medial plate the fracture occurred in the last hole of the metacarpals two and three. There was no bending or broken implants. There was no significant biomechanical differencebetween the dorsal and medial positions of the implants.(AU)
Assuntos
Animais , Cães , Artrodese/veterinária , Fenômenos Biomecânicos , Cães/anormalidadesRESUMO
Objetivou-se com este trabalho comparar biomecanicamente os posicionamentos dorsal e medial da placa bloqueada na artrodese do carpo em cães. Para isso, foram utilizados sete pares de membros torácicos de cães eutanasiados por razões não relacionadas ao estudo, em que sete membros foram estabilizados com placa dorsal, e seus respectivos pares com placa em posicionamento medial. Os membros com as articulações radiocarpometacarpianas estabilizadas cirurgicamente foram submetidos a ensaio de compressão axial em máquina universal de ensaios de materiais, e os dados de limite de elasticidade, rigidez estrutural, carga máxima e carga no momento da fratura dos posicionamentos foram comparados por meio do teste de Student-Newman-Keuls, a um nível de significância de 5%. Todos os membros foram fraturados no terço distal do terceiro metacarpo; nos membros com placa dorsal, a fratura ocorreu distal ao orifício distal e, nos membros com placa medial, a fratura ocorreu no último orifício dos metacarpos dois e três. Não houve dobra ou quebra de placas e parafusos e não houve diferença significativa entre os posicionamentos dorsal e medial dos implantes quanto aos parâmetros avaliados.(AU)
The aim of this study was to compare biomechanically the dorsal and medial positions of the locking plates on carpal arthrodesis in dogs. For this, seven pairs of thoracic limbs of dogs were used, in which seven limbs were stabilized with dorsal plate and seven limbs with plate in medial positioning. The members with the surgically stabilized radiocarpal-metacarpal joints were submitted to axial compression testing in a universal testing machine and the yield load, structural rigidity, maximum load and ultimate load of the positioning were compared by Student-Newman-Keuls test at a significance level of 5%. All members fractured in the distal third of the third metacarpal, in the limbs with dorsal plate the fracture occurred distal to the distal hole and in the members with medial plate the fracture occurred in the last hole of the metacarpals two and three. There was no bending or broken implants. There was no significant biomechanical differencebetween the dorsal and medial positions of the implants.(AU)
Assuntos
Animais , Cães , Artrodese/veterinária , Fenômenos Biomecânicos , Cães/anormalidadesRESUMO
PURPOSE: We sought to determine the mechanisms of downregulation of the airway transcription factor Foxa2 in lung cancer and the expression status of Foxa2 in non-small-cell lung cancer (NSCLC). METHODS: A series of 25 lung cancer cell lines were evaluated for Foxa2 protein expression, FOXA2 mRNA levels, FOXA2 mutations, FOXA2 copy number changes and for evidence of FOXA2 promoter hypermethylation. In addition, 32 NSCLCs were sequenced for FOXA2 mutations and 173 primary NSCLC tumors evaluated for Foxa2 expression using an immunohistochemical assay. RESULTS: Out of the 25 cell lines, 13 (52%) had undetectable FOXA2 mRNA. The expression of FOXA2 mRNA and Foxa2 protein were congruent in 19/22 cells (p = 0.001). FOXA2 mutations were not identified in primary NSCLCs and were infrequent in cell lines. Focal or broad chromosomal deletions involving FOXA2 were not present. The promoter region of FOXA2 had evidence of hypermethylation, with an inverse correlation between FOXA2 mRNA expression and presence of CpG dinucleotide methylation (p < 0.0001). In primary NSCLC tumor specimens, there was a high frequency of either absence (42/173, 24.2%) or no/low expression (96/173, 55.4%) of Foxa2. In 130 patients with stage I NSCLC there was a trend towards decreased survival in tumors with no/low expression of Foxa2 (HR of 1.6, 95%CI 0.9-3.1; p = 0.122). CONCLUSIONS: Loss of expression of Foxa2 is frequent in lung cancer cell lines and NSCLCs. The main mechanism of downregulation of Foxa2 is epigenetic silencing through promoter hypermethylation. Further elucidation of the involvement of Foxa2 and other airway transcription factors in the pathogenesis of lung cancer may identify novel therapeutic targets.
Assuntos
Adenocarcinoma/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Regulação para Baixo , Epigênese Genética , Fator 3-beta Nuclear de Hepatócito/genética , Neoplasias Pulmonares/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Metilação de DNA , Análise Mutacional de DNA , Feminino , Dosagem de Genes , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Fator 3-beta Nuclear de Hepatócito/metabolismo , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Regiões Promotoras GenéticasRESUMO
Frozen-thawed sexed semen from six bulls (Holstein) was used for studying their efficiency in an in vitro fertilization (IVF)-programme and to compare their ultrastructure with in vitro produced bovine blastocysts produced with non-sorted sperm. Progressive motility of sorted spermatozoa, their IVF rate, development of produced blastocysts and the ultrastructure of the blastocysts were analysed. The cleavage rates of sexed sperm of bulls (groups S1, S2 and S4) were significantly lower than that of unsorted control sperm (P < 0.01). Blastocyst development at day 7 of the sexed semen groups varied between 3.5% and 28.8% versus 33.6% for non-sexed semen. The individual blastocyst yield with sexed semen of group S5 (28.8%) was similar to the mean blastocyst production of the non-sexed control spermatozoa (C, 33.6%; P > 0.05). The remaining five sexed sperm groups resulted in significantly lower developmental rates of blastocysts on day 7 (S1, 4.9%; S2, 0%; S3, 0%, S4, 3.5%; S6, 25.8%, P < 0.01). Group S2 showed microbiological contamination in 50% (four of eight) and S3 in 100% of the experiments (eight of eight). Progressive motility of sexed sperm was significantly lower than that of unsorted sperm (S1, 48 +/- 12.0%; S2, 41 +/- 11.9%; S3, 39.0 +/- 9.9%; S4, 42 +/- 4.6%; P < 0.01; S5, 72 +/- 7.1% and S6, 64 +/- 9.3; P < 0.05 versus C 82 +/- 4.6%). The percentage of progressive motile spermatozoa showed a good correlation with the developmental capacity of blastocysts (r(2): >0.70), the regression parameter was significant (P < 0.01). Furthermore, with a straw containing 10 x 10(6) sexed spermatozoa significantly lower number oocytes was fertilized than with the same concentration of non-sexed sperm (P < 0.01). Our results demonstrate that the suitability of sperm sorting for in vitro fertilization (IVF) is lower than no sexed sperm. Our ultrastructural studies showed that blastocysts produced with flow-cytometrically sex-sorted spermatozoa possessed deviations in the number and structure of organelles like mitochondria, rough endoplasmic reticulum (ER) and nuclear envelope. These morphological alterations may be responsible for compromised development that observed in embryos produced with sex-sorted spermatozoa. Thus, we conclude that sperm sex sorting can markedly affect the efficiency of an IVF-programme.
Assuntos
Blastocisto/ultraestrutura , Bovinos/fisiologia , Fertilização in vitro/veterinária , Pré-Seleção do Sexo , Espermatozoides/fisiologia , Animais , Fase de Clivagem do Zigoto , Feminino , Fertilização in vitro/métodos , Citometria de Fluxo/veterinária , Masculino , Microscopia Eletrônica de Transmissão , Gravidez , Taxa de Gravidez , Motilidade dos EspermatozoidesRESUMO
Microsomes isolated from complete hydatidiform moles (CHM) were able to convert [3H]pregnenolone to [3H]progesterone which indicates the presence of 3 beta-hydroxysteroid dehydrogenase/isomerase (3 beta-HSD) activity. The kinetic parameters found (Km = 0.63 microM and Vmax = 1-3.05 nmol/min/mg of protein) were like those observed in microsomes from normal early placenta (NEP) of similar gestational age (herein) and term placenta suggesting that the enzymes from the three sources are kinetically similar. Testosterone, progesterone and estradiol in a dose range of 0.05-5 mumol/l inhibited differently the in vitro conversion of [3H]pregnenolone to [3H]progesterone in a dose-dependent manner. The steroid concentrations necessary to inhibit the conversion of pregnenolone to progesterone by 50% (ID50) in CHM were 0.1 microM for testosterone, 0.6 microM for progesterone and 3 microM for estradiol, whereas in NEP they were 2.5, 1 and 5 microM respectively. The Ki values calculated from these ID50 in CHM together with the reported levels of endogenous steroids indicate that the accumulation of testosterone and progesterone inside the molar vesicle could physiologically regulate the rate of further conversion of pregnenolone to progesterone. The present findings could provide an explanation for the low level of progesterone in patients with CHM in the second trimester of pregnancy which in turn may directly or indirectly affect the spontaneous expulsion of this aberrant tissue.
Assuntos
Mola Hidatiforme/metabolismo , Hidroxiesteroide Desidrogenases/metabolismo , Microssomos/enzimologia , Ligação Competitiva , Relação Dose-Resposta a Droga , Estradiol/administração & dosagem , Estradiol/farmacologia , Feminino , Humanos , Hiperplasia/patologia , Cinética , Microssomos/efeitos dos fármacos , Placenta/efeitos dos fármacos , Placenta/enzimologia , Gravidez , Progesterona/administração & dosagem , Progesterona/metabolismo , Progesterona/farmacologia , Testosterona/administração & dosagem , Testosterona/metabolismo , Testosterona/farmacologiaRESUMO
The effects of 50 microM of progesterone (P4), estradiol (E2), estrone (E1), estriol (E3), dehydroepiandrosterone (DHIA), androstenedione (delta 4) and testosterone (T) on the bioconversion of [3H]pregnenolone (6 nM) to [3H]P4 were investigated by incubating 200 mg of tissue fragments as well as equivalent aliquots of microsomes from human term placenta during 30 min. All the steroids assayed, except E3, significantly inhibited the [3H]P4 formation in a microsome incubation system with respect to the control assay (P less than 0.001). Conversely in a tissue incubation system. P4, E1 as well as E3 had no effect on [3H]pregnenolone bioconversion while E2 slightly decreased the [3H]P4 formation (P less than 0.05) compared with the control. A significant inhibition was observed in this system with the other steroids (P less than 0.001). To investigate these apparent different results of inhibition-noninhibition of the same steroids irrespective of the system of incubation used, the effects of P4, E2 and T on 3 beta-hydroxysteroid dehydrogenase/isomerase (3 beta-HSD) activity were studied in tissue fragments and microsomes in kinetic terms. The results found indicate that these steroids inhibited in a competitive fashion the 3 beta-HSD activity in both systems. The different Ki values found in tissue fragments and microsomes respectively for P4 (1.8 microM vs 0.5 microM), E2 (2.3 microM vs 0.6 microM) and T (0.25 microM vs 0.3 microM) explain the bioconversion results obtained in presence of 50 microM of the same steroids. These results include inhibition of [3H]P4 formation by T in tissue fragments as well as in microsomes whereas P4 and E2 inhibited the [3H]P4 formation only in microsomes. Furthermore, the comparison of these Ki values with the available data of intraplacental and circulating concentrations of the same steroids in human term pregnancy suggest that only P4 would be expected to cause marked 3 beta-HSD inhibition in physiological conditions.
Assuntos
3-Hidroxiesteroide Desidrogenases/metabolismo , Hormônios Esteroides Gonadais/farmacologia , Microssomos/enzimologia , Placenta/enzimologia , Progesterona/farmacologia , 3-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Androstenodiona/farmacologia , Ligação Competitiva , Desidroepiandrosterona/farmacologia , Estradiol/farmacologia , Estriol/farmacologia , Estrona/farmacologia , Feminino , Humanos , Cinética , Placenta/ultraestrutura , Gravidez , Pregnenolona/metabolismo , Progesterona/biossíntese , Testosterona/farmacologiaRESUMO
Se realiza un estudio prospectivo entre diciembre de 1988 y junio de 1989, que comprende una serie de treinta y ocho mujeres embarazadas después de una procreación médicamente asistida. Se analizan los eventos del principio de la gestación con la ayuda de la ecografía transvaginal y los valores de gonadotropina coriónica humana (HCG). En vista de los pocos resultados hasta ahora publicados, este estudio preliminar podría ser de gran interés para definir lo más precozmente posible el diagnóstico, el pronóstico y la conducta a seguir en caso de embarazo