Impact of successive freezing-thawing cycles on 3-T magnetic resonance images of the digits of isolated equine limbs

The purpose of this study was to assess the impact of freezing and thawing on MR images of equine feet examined ex vivo. Nine equine cadaver digits were first imaged at room temperature (T0). Among the 9 digits, 3 (group 1) were imaged in a 3 Tesla MR system after one and after 2 freezing-thawing cycles. Digits of group 1 were thawed in a cold room at 4°C for 36h. Three other digits (group 2) were imaged after one freezing-thawing cycle. Digits of group 2 were thawed in a cold room at 4°C and then rescanned after 24h at room temperature. The last 3 digits (group 3) were scanned after one freezing-thawing cycle. Digits of group 3 were thawed at room temperature for 24h. Sequences used were Spin Echo (SE) T1, Turbo Spin Echo (TSE) T2 and proton density (PD), Short Tau Inversion Recovery (STIR), Double Echo Steady State (DESS), 3D Gradient Echo (GE) T1 and 2D GE T2*. Images obtained on the fresh limbs at room temperature were subjectively compared side by side to images obtained at the different freezing-thawing cycles. A quantitative analysis to assess signal change between examinations was realized by measuring signal to noise ratio (SNR). Visibility and margination of the anatomical structures of the foot and overall image quality were subjectively considered unchanged except for the hoof where the lamina was considered less visible distally after freezing and thawing in the GE T2* and in TSE T2 and PD sequences. Quantitative analysis demonstrated SNR changes in the bone marrow only in the distal phalanx in the SE T1 sequence when the feet were thawed at room temperature. When the feet were thawed in a cold room at 4°C, bone marrow SNR changes were present in the SE T1, GE T1 and TSE PD sequences. Signal changes were significant in the synovial recess when the thawing process was made at 4°C and not when the thawing process was at ambient temperature. The soft tissue structures and the hoof capsule showed significant changes with an increase of SNR, except in STIR, after freezing and thawing at 4°C and at room temperature. SNR changes in the soft tissues were mainly present in GE sequences

Hysteroscopy and the butyl-cyanoacrylate on experimental sterilization of rabbit uterine tubes

Purpose: To assess the sterilization effectiveness on uterine tube of rabbit by the cyanoacrylate adhesive. Methods: Hysteroscopy tubal catheterization was performed randomly in 12 animals (24 uterine tubes) assigned to the sham group (GS) and 15 animals (30 uterine tubes) to the n-butyl-cyanoacrylate (GB). The female rabbits were observed during 30, 90 and 180 days and mated to fertile males. The no pregnant rabbits were submitted to in vitro burst pressure test for patency by air insufflation (40 mmHg). The microscopic assessment was performed to parameters of damages in epithelium caused by the adhesive, the degree of inflammatory process, morphometry data values of tube diameter (UT) (cm), mucosa thickness (MT) and the myosalpinx thickness (MyT) (mm). The mucosa cells densitometry (total optical density) was expressed by the amount of DNA. The significance of the differences in histological scores and in thickness measurements were made by ANOVA test (P value < 0.05). Results: In all animals of GB: the adhesive was attached to the mucosa; there was no pregnancy; no records of significant degree on inflammatory process; the patency test was negative and densitometry of DNA showed similar values to the both groups independently of observation periods. The layers thickness of GB-UT(1.118±0.117), GB-MT(0.447±0.247) and GB-MyT(0.853±0.097) were larger than the GS-UT(0.666±0.409), GS-MT(0.211±0.070) and GS-MyT(0.442±0.143). Conclusion: This approach offers a safe and feasible method of uterine tube obstruction. Key words: Sterilization, Reproductive. Tissue Adhesives. Fallopian Tubes. Rabbits.Objetivo: Verificar a eficácia do adesivo de cianoacrilato na esterilização de tubas uterinas de coelhas. Métodos: A cateterização tubária por histeroscopia foi realizada randomicamente em 12 animais (24 tubas uterinas) formando o Grupo Sham (GS) e 15 animais (30 tubas uterinas) para o grupo do n-butil-cianoacrilato (GB). As coelhas foram observadas por 30, 90 e 180 dias e acasaladas com machos férteis. As tubas uterinas das fêmeas que não ficaram grávidas foram submetidas ao teste de pressão de rompimento in vitro, com insuflação de ar (40mmHg). A microscopia óptica estudou os danos causados ao epitélio pelo adesivo, o grau de processo inflamatório, a morfometria do diâmetro tubário (UT) (cm), da mucosa (MT) e do miosalpinge (MyT) (mm). A densitometria das células da mucosa (Densidade Óptica Total) foi expressa pela contagem do DNA. As significâncias dos diferentes escores histológicos e das medidas das camadas foram avaliadas pelo Teste de ANOVA (P<0,005). Resultados: Em todos os animais do GB: o adesivo estava aderido na mucosa tubária, não ocorreu prenhez, não houve significância nos graus do processo inflamatório, o teste de perviedade foi negativo e a densitometria do DNA apresentou valores similares em todos os grupos, independente do período de observação. A medida das camadas do GB-UT(1.118±0.117), GB-MT(0.447±0.247) e GB-MyT (0.853±0.097) foi maior que as dos GS-UT(0.666±0.409), GS-MT(0.211±0.070) e GS-MyT(0.442±0.143). Conclusão: O procedimento proposto foi de fácil execução e eficaz para obstrução da tuba uterina de coelhas

Esterilização tubária com adesivo cirúrgico sintético: estudo experimental

Objetivo: Estudar a perviedade da tuba uterina de coelhas submetidas a aplicação endotubária pela via transvaginal de n-butil-2-cianoacrilato. Método: Vinte coelhas (Orictolagus cuniculus) da linhagem Nova Zelândia foram distribuídas em dois grupos, 1 (controle) e 2 (experimento). O grupo controle foi submetido a técnica operatória para esterilização pelo método proposto por Pomeroy e o grupo experimento teve a aplicação de 0,25mL do adesivo cirúrgico n-butil-2-cianoacrilato no lúmen tubário por via transvaginal. Após quatro semanas e quatro acasalamentos e o diagnóstico clínico da presença de gestação, foram submetidos a três testes de perviedade: histerossalpingografia (in vivo), teste de perviedade com corante azul de metileno (in vitro) e teste de pressão de rompimento (in vitro). Foi realizada a morfometria computadorizada digitalizada para medir o diâmetro tubário, a mucosa e o miossalpinge. Resultados: Houve vazamento em somente uma tuba uterina do grupo 2, embora o adesivo estivesse presente no lúmen tubário, o que foi não significante estatisticamente. Apresentou significância estatística a morfometria, que mostrou aumento nas medidas do diâmetro tubário, da mucosa e do miossalpinge, que consideramos ser pela presença do polímero formado pelo adesivo, não havendo danos celulares. Conclusões: Concluímos que a aplicação transvaginal de nbutil- 2-cianoacrilato no lúmen tubário de coelhas é tão eficaz para esterilização quanto o método de Pomeroy.Background: Study of the patency of the uterine tube of rabbits submitted to the transvaginal approach application of n-butyl-2-cyanoacrylate. Methods: Twenty rabbits were used (Orictolagus cuniculus) of the lineage New Zealand, distributed in two groups, 1 (control) and 2 (try). Control group was submitted to the technique for sterilization through the method proposed by Pomeroy and the group experiment had the application of 0,25mL of the surgical adhesive n-butyl-2-cyanoacrylate in the isthmus of uterine tube, via transvaginal. After four weeks and four time mated and the clinical diagnosis of gestation appearance, they were submitted to three patency tests: histerosalpingography (in vivo), patency test with color metilen blue (in vitro) and test of breaking pressure (in vitro). Digital computerized morfometry was accomplished to measure the diameter of tubes, mucous membrane and miosalpinx. Results: The results showed leak in only one uterine tube of the group 2, although the sticker was present in the isthmus of uterine tube. Statistical significancy was shown by the morfometry that showed increase in the measures of the diameter tube, of mucous membrane and of miosalpinx, that we considered to be for the presence of the polymeric formed by the adhesive, not cellular damages. Conclusions: We concluded that the application n-butyl-2-cyanoacrylate of transvaginal route in the uterine tubes of rabbits is so effective for sterilization as the method of Pomeroy