Browsing by Issue Date, starting with "2010-09-23"
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- The Use of Annexin-V labeled with 99mTc in the evaluation of cardiotoxicity induced by anthracyclinesPublication . Miranda, Cecília; Cunha, Lídia; Metello, Luís F.The antineoplastic Anthracyclines are effective agents for various tumors, there is a dose-response relationship for these drugs, however, cardiotoxicity limits their therapeutic potential and threaten the cardiac function of patients. The mechanism of the onset of cardiotoxicity is still not clarified, the most common hypothesis is related to the triggering mechanisms of programmed death - apoptosis - that promote various morphological and biochemical changes in cells. A very early stage, there is the exposure of phosphatidylserine, a phospholipid that in healthy cells remains in the inner leaflet of the plasma membrane. This exhibition may be marked through radioactive molecules, as is the case of 99mTcAnnexin V, the Annexin V is an endogenous human protein, distributed intracellularly, with high affinity for phosphatidylserine.
- Cyclotech - contribution to solve the Technetium shortage by using low energy medical cyclotronsPublication . Metello, Luís F.; Gelbart, W.; Benedict, Malcom; Cunha, Lídia; Alves, Francisco; Johnson, Richard R.This paper presents work in progress, to develop an efficient and economic way to directly produce Technetium 99metastable (99mTc) using low-energy cyclotrons. Its importance is well established and relates with the increased global trouble in delivering 99mTc to Nuclear Medicine Departments relying on this radioisotope. Since the present delivery strategy has clearly demonstrated its intrinsic limits, our group decided to follow a distinct approach that uses the broad distribution of the low energy cyclotrons and the accessibility of Molybdenum 100 (100Mo) as the Target material. This is indeed an important issue to consider, since the system here presented, named CYCLOTECH, it is not based on the use of Highly Enriched (or even Low Enriched) Uranium 235 (235U), so entirely complying with the actual international trends and directives concerning the use of this potential highly critical material. The production technique is based on the nuclear reaction 100Mo (p,2n) 99mTc whose production yields have already been documented. Until this moment two Patent requests have already been submitted (the first at the INPI, in Portugal, and the second at the USPTO, in the USA); others are being prepared for submission on a near future. The object of the CYCLOTECH system is to present 99mTc to Nuclear Medicine radiopharmacists in a routine, reliable and efficient manner that, remaining always flexible, entirely blends with established protocols. To facilitate workflow and Radiation Protection measures, it has been developed a Target Station that can be installed on most of the existing PET cyclotrons and that will tolerate up to 400 μA of beam by allowing the beam to strike the Target material at an adequately oblique angle. The Target Station permits the remote and automatic loading and discharge of the Targets from a carriage of 10 Target bodies. On other hand, several methods of Target material deposition and Target substrates are presented. The object was to create a cost effective means of depositing and intermediate the target material thickness (25 - 100μm) with a minimum of loss on a substrate that is able to easily transport the heat associated with high beam currents. Finally, the separation techniques presented are a combination of both physical and column chemistry. The object was to extract and deliver 99mTc in the identical form now in use in radiopharmacies worldwide. In addition, the Target material is recovered and can be recycled.