Size Control of 99mTc-tin Colloid Using PVP and Buffer Solution for Sentinel Lymph Node Detection

Colloidal particle size is an important characteristic that allows mapping sentinel nodes in lymphoscintigraphy. This investigation aimed to introduce different ways of making a 99mTc-tin colloid with a size of tens of nanometers. All agents, tin fluoride, sodium fluoride, poloxamer-188, and polyvinylpyrrolidone (PVP), were mixed and labeled with 99mTc. Either phosphate or sodium bicarbonate buffers were used to adjust the pH levels. When the buffers were added, the size of the colloids increased. However, as the PVP continued to increase, the size of the colloids was controlled to within tens of nanometers. In all samples, phosphate buffer added PVP (30 mg) stabilized tin colloid (99mTc-PPTC-30) and sodium bicarbonate solution added PVP (50 mg) stabilized tin colloid (99mTc-BPTC-50) were chosen for in vitro and in vivo studies. 99mTc-BPTC-50 (100 nm) mainly accumulated in the liver. When a rabbit was given a toe injection, the node uptake of 99mTc-PPTC-30 decreased over time, while 99mTc-BPTC-50 increased. Therefore, 99mTc-BPTC-50 could be a good candidate radiopharmaceutical for sentinel node detection. The significance of this study is that nano-sized tin colloid can be made very easily and quickly by PVP.

Synthesis and characterization of Tin [IV] complexes with multidentate Schiff Bases and their biological activity uses

A series of tin [IV] chloride complexes with multidentate Schiff bases were prepared. The complexes were characterized by elemental analysis, conductance and spectral data. TGA and DTA have also been carried out to confirm the composition of the complexes. Based on these measurements coordination numbers 6 and 8 are proposed for the complexes. The biological activity of some Schiff bases and their tin [IV] complexes are also discussed. The mass spectral fragmentation mode of o-naphphen and its complex are also considered

Influência do tipo de reconstruçäo na retençäo de coroas totais fundidas / Influence of reconstruction type in the casting full crowns

A finalidade deste estudo foi verificar a resistência à remoçäo por traçäo de coroas totais fundidas cimentadas em dentes reconstruídos com núcleo fundido, amálgama e resina composta, associados a pinos retidos em dentina ou no conduto radicular, comparando sua retentividade com a de coroas metálicas fundidas cimentadas em dentes com preparos feitos totalmente em estrutura dentária sadia. Foram selecionados 60 molares superiores recém-extraídos, 10 dentes para cada condiçäo experimental, os quais foram incluídos por suas raízes até 1 mm da junçäo cemento-esmalte em bases plásticas, com resina acrílica ativada quimicamente, para receber preparo tipo coroa total. Com exceçäo da condiçäo controle (dente sem reconstruçäo), as demais tiveram, após preparo cavitário, o corte da porçäo coronária a 1,5 mm do ângulo cavosuperficial, bem como a remoçäo do teto da câmara pulpar...