RESUMO
The objective of the present work is to study the biodistribution and tumor retention properties of etoposide (anticancer agent) and etoposide loaded tripalmitin nanoparticles (ETPL) after intratumoral administration in Dalton's lymphoma tumor bearing mice. ETPL nanoparticles were prepared by melt-emulsification and high pressure homogenization followed by spray drying technique. The nanoparticles were uniform and possessed 387 nm mean diameter and negative charge with excellent redispersibility in aqueous media. Radiolabeling of etoposide and ETPL nanoparticles with Technetium-99m (99mTc) resulted in complexes with high labeling efficiency and low radiocolloid formation. The labeled complexes showed good in vitro stability as indicated by low transchelation in presence of DTPA and cysteine and stability in human serum. Biodistribution and tumor retention studies were performed for etoposide and ETPL nanoparticles after intratumoral injection in mice bearing Dalton's lymphoma tumor. Etoposide experienced rapid clearance from the tumor, while the disposition of ETPL nanoparticles was slower. The tissue concentrations of ETPL nanoparticles increased with time (i.e. at 6h and 24h post injection) indicating its retention in tumor site for a longer time. Tumor retention of both etoposide and ETPL nanoparticles was studied upto 48h post injection. The tumor concentration of both etoposide and ETPL nanoparticles was high initially (8.57 percent and 41.8 percent injected dose at 0.5h post injection) and decreased with time (0.12 percent and 1.68 percent injected dose at 48h post injection). The concentration of etoposide rapidly declined from the tumor site while the tumor retention of ETPL nanoparticles was significantly higher than free etoposide (P < 0.001) at all the time points studied. The over all many fold higher tumor retention of ETPL nanoparticles (14 folds even at 48h post injection) compared to etoposide, coupled with lower tissue distribution signifies...
Assuntos
Camundongos , Animais , Antineoplásicos Fitogênicos/farmacocinética , Etoposídeo/farmacocinética , Linfoma , Linfoma/metabolismo , Tecnécio/farmacocinética , Tomografia Computadorizada de Emissão de Fóton Único , Antineoplásicos Fitogênicos/administração & dosagem , Distribuição Tecidual , Estabilidade de Medicamentos , Injeções Intralesionais , Portadores de Fármacos , Camundongos Endogâmicos BALB CRESUMO
To study the utility of sterically stabilized liposomes (stealth liposomes) in tumor scintigraphy by studying its biodistribution and accumulation in target tissue after radiolabeling with Technetium-99m (99mTC). Conventional and Stealth liposomes were prepared by lipid film hydration method using methotrexate as model anticancer drug. Radiolabeling of the liposomes was carried out by direct labeling using reduced 99mTc. Experimental conditions for maximum labeling yield were optimized. The stability studies were carried out to check binding strength of the radiolabeled complexes. The blood kinetic study was carried out in rabbits after giving the labeled complex by intravenous administration through ear vein. The biodistribution studies were carried out in the Ehrlich ascites tumor (EAT) bearing mice after intravenous administration through tail vein, showed prolonged circulation in blood and significant increase in the accumulation in tumor for the sterically stabilized liposomes compared to the conventional liposomes. The gamma scintigraphic image shows the distribution of the stealth liposomes in liver, spleen, kidney and tumor. The study gives precise idea about the use of stealth liposomes in tumor scintigraphy and organ distribution studies.
Assuntos
Camundongos , Lipossomos , Neoplasias Experimentais , Carcinoma de Ehrlich , MetotrexatoRESUMO
As part of the WHO Collaborative Study on Strategies for Extending Mental Health Care 259 families in four developing countries (Colombia, India, Sudan and the Philippines) were screened with regard to the social burden caused by mental illness of one of its members. Levels of subsistence, previous illness, financial burden, personal relations and social acceptance were studied. The social burden was greatest in the urban areas.
Assuntos
Família , Transtornos Mentais , Adulto , Colômbia , Comparação Transcultural , Países em Desenvolvimento , Feminino , Humanos , Índia , Masculino , Transtornos Mentais/economia , Serviços de Saúde Mental , Pessoa de Meia-Idade , Filipinas , Sudão , Organização Mundial da SaúdeRESUMO
To ascertain the frequency of mental disorders in Sudan, Philippines, India, and Columbia, 925 children attending primary health care facilities were studied. Rates of between 12% and 29% were found in the four study areas. The range of mental disorders diagnosed was similar to the encountered in industrialized countries. The research procedure involved a two-stage screening in which a ten-item "reporting questionnaire" constituted the first stage. The study has shown that mental disorders are common among children attending primary health care facilities in four developing countries and that accompanying adults (usually the mothers) readily recognize and report common psychologic and behavioral symptoms when these are solicited by means of a simple set of questions. Despite this, the primary health workers themselves recognized only between 10% and 22% of the cases of mental disorder. The result have been used to design appropriate brief training courses in childhood mental disorders for primary health workers in the countries participating in the study.