RESUMO
Nowadays, the term "Molecular Biology" (MB) is generally a pplied to the biochemical processes that involve genes and the expression of proteins for which specific genes code. In recent years, astonishing advances have occurred in this field. Currently, there are many important powerful techniques allowing scientists to study the molecular mechanisms involved in many human genetic diseases. Furthermore, it is important to underline that the possibilities are not limited to the diagnosis and study of these genetic diseases. Indeed, by studying gene expression, MB also allows the molecular study of many acquired diseases such as viral hepatitis and cancer.Therefore, these major advances in the knowledge of gene biology are facilitating the arrival of a new era of gene therapy. This article will describe the most important techniques currently used in MB. Firstly, techniques involved in recombinant DNA technology will be discussed and these will include the study of DNA and the possibility of identifying the expression of abnormal genes, e.g. to identify individuals for paternity. Secondly, a description of techniques designed to study the expression of genes and their regulation will follow and they involve the study of RNA. Thirdly, the impact of genetic molecular studies as tools for medical diagnosis will be discussed and analysed. Finally, a discussion concerning the rational basis for gene therapy and its future perspectives is included. In this article, we have focused on technical or diagnostic aspects ofMolecular Biology. Although Ethics are also an interesting issue to deal with, theseissues are far beyond the scope of this review.
Assuntos
Nefropatias/genética , Biologia Molecular , Impressões Digitais de DNA , Regulação da Expressão Gênica/genética , Terapia Genética , Humanos , Nefropatias/diagnóstico , Nefropatias/terapia , PaternidadeRESUMO
La hormona paratiroidea (PTH) y la proteína relacionada con la PTH (PTHrP) producen efectos biológicos similares a través del receptor PTH/PTHrP. Poco se sabe del papel fisiológico de la PTHrP, que inicialmente se identificó como el agente responsable de la hipercalcemia asociada a enfermedades malignas. Aunque esta proteína se produce ampliamente en diferentes tejidos, su concentración se encuentra debajo de los límites de detección, hecho que sugiere que en circunstancias fisiológicas actúa en forma autocrina o paracrina. Se han descrito algunas diferencias en los efectos de ambas proteínas posiblemente relacionados con la existencia de diferentes receptores. En este sentido, recientemente se ha descrito un receptor específico para la PTH, el receptor PTH-2. Estudios recientes han demostrado la expresión del receptor PTH/PTHrP y de la PTHrP en el glomérulo renal. Además, existen datos que muestran un efecto directo de PTH y PTHrP sobre el flujo plasmático renal y la filtración glomerular. La PTHrP posee las características de una proteína multifuncional, incluyendo efectos proliferativos sobre las células mesangiales, y se especula que tenga un papel importante en la fisiología y fisiopatología renales (AU)
