Rat thyroid graft transplantation after cryopreservation with scintigraphic standardization for an experimental study

Abstract Purpose: Budget cuts among other factors undermine the use of state-of-the-art equipment by many research groups. This doesn't mean that their scientific data are not reliable or top-notch. Resort to adaptations is a recurrent need in their reality. The aim of this study was to assess whether scintigraphy with 99mTcO4 is effective in evaluating the functionality of thyroid grafts after cryopreservation in rats. Material and methods: 24 rats were randomly distributed into 3 groups: Control Group (CG), without surgical procedure, Hypothyroidism Group (HTG), submitted to total thyroidectomy, and Transplanted Group (TG), with total thyroidectomy and cryopreservation of the thyroid gland for 7 days followed by grafting of a thyroid lobe. A protocol using a gamma camera imaging was conducted fourteen weeks after transplantation, and the whole body 99mTc, focusing on the topic of heterotopic thyroid uptake was evaluated. Results: The images acquired had good quality with no noise and artifacts that could jeopardize its analysis. On the 14th day, HTG displayed no thyroid uptake, and the TG had a clear uptake of the thyroid graft in the topography of the biceps femoris muscle. Presented data also showed that both equipment spatial resolution and alignment (4.375 mm) did not interfere with the physiological uptake of 99mTc by the thyroid graft. Conclusion: The viability and functionality of cryopreserved thyroid autotransplantation in rats who underwent total thyroidectomy were successfully accessed by the scintigraphy protocol developed. HIGHLIGHTS Adaptations in validated methods are a recurrent trend due to limited budgets which does not diminish their functionality. Scintigraphy with 99mTcO4 is effective in evaluating the functionality of thyroid grafts after cryopreservation in rats. It is possible to adapt human SPECT for other animals for clinical and research purposes.

Exploring cortical bone density through the ultrasound integrated reflection coefficient / Densidade óssea cortical analisada pelo coeficiente de reflexão ultrassônica

ABSTRACT Objective: This work evaluates the relationship between ultrasonic reflection and bone density from fourteen cylindrical bovine cortical bone samples (3.0-cm thick). Methods: Twenty US reflection signals per sample were acquired along the bone surface (2.0-mm step). The Integrated Reflection Coefficient (IRC) from each signal was compared to Quantitative Computed Tomography (QCT). Results: Seven IRC and QCT curves presented Pearson's Correlation R-values above 0.5. For weak correlation curves, QCT and IRC showed similar trends in several segments. Conclusion: IRC was sensitive to bone density variation. Level of Evidence: Experimental Study, Investigating a Diagnostic Test.

RESUMO Objetivo: Este estudo avalia a relação entre a reflexão ultrassônica e a densidade óssea de 14 amostras cilíndricas de osso cortical bovino (3,0 cm de espessura). Métodos: Foi realizada a aquisição de 20 sinais de reflexão ultrassônica por amostra (passo de 2,0 mm), ao longo da superfície óssea. O Coeficiente de Reflexão Integrado (IRC) de cada sinal foi comparado por Tomografia Computadorizada Quantitativa (QCT). Resultados: Sete curvas de IRC e QCT apresentaram valor de Correlação R de Pearson acima de 0,5. Para curvas de correlação fraca, QCT e IRC apresentaram tendências semelhantes em vários segmentos. Conclusão: O IRC foi sensível à variação da densidade óssea. Nível de evidência: Estudo Experimental, Investigação de Exame Diagnóstico.

Antimicrobial activity of Anonna mucosa (Jacq.) grown in vivo and obtained by in vitroculture

Brazilian flora includes numerous species of medicinal importance that can be used to develop new drugs. Plant tissue culture offers strategies for conservation and use of these species allowing continuous production of plants and bioactive substances. Annona mucosa has produced substances such as acetogenins and alkaloids that exhibit antimicrobial activities. The widespread use of antibiotics has led to an increase in multidrug-resistant bacteria, which represents a serious risk of infection. In view of this problem, the aim of this work was to evaluate the antibacterial potential of extracts of A. mucosa obtained by in vitro techniques and also cultured under in vivo conditions. Segments from seedlings were inoculated onto different culture media containing the auxin picloram and the cytokinin kinetin at different concentrations. The calluses obtained were used to produce cell suspension cultures. The materials were subjected to methanol extraction and subsequent fractionation in hexane and dichloromethane. The antimicrobial activity against 20 strains of clinical relevance was evaluated by the macrodilution method at minimum inhibitory and minimum bactericidal concentrations. The extracts showed selective antimicrobial activity, inhibiting the growth of Streptococcus pyogenes and Bacillus thuringiensis at different concentrations. The plant tissue culture methods produced plant materials with antibacterial properties, as well as in vivo grown plants. The antibacterial activity of material obtained through biotechnological procedures of A. mucosa is reported here for the first time.