Métodos de inactivación de patógenos en Plasma Fresco y Concentrados de Plaquetas / Pathogen Inactivation technology in fresh plasma and platelets concentrates

Las Tecnologías de Inactivación de Patógenos (TIPS) proveen un camino adicional para proteger el abastecimiento de sangre de agentes conocidos, emergentes y aún desconocidos. El principio precautorio refrendado por la FDA luego de la crisis del VIH/SIDA, establece que para situaciones de incertidumbre científica debiera tenerse en cuenta la posibilidad de riesgo aún en ausencia de pruebas de lo contrario. Pudiera argumentarse entonces que las TIPS representan la quintaesencia del principio precautorio. Si bien se ha acortado el intervalo entre el reconocimiento de un agente a la implementación de medidas para prevenirlo, hay a menudo un periodo de retardo temprano, durante el que una enfermedad no parece representar un riesgo para el receptor o la salud humana en general. El daño causado por ellos se ha mencionado como "una propiedad fija e inevitable de la práctica transfusional". Las TIPS para plasma fresco incluyen las siguientes: MBLT (Tratamiento con Luz y Azul de Metileno). PLT (Tratamiento con Psoralenos y Luz). RFLT (tratamiento con Riboflavina y Luz) además existe un método de Solvente Detergente para pools de plasma. Mientras que para los concentrados de plaquetas se pueden usar el Tratamiento con Luz Ultravioleta y Amotosaleno-UVA. Existe un riesgo potencial en retrasar la implementación de las TIPS mientras se aguarda la evidencia y el sistema absolutamente perfecto de ponerlas en práctica. Llegó el momento de actuar.

Pathogen Inactivation Technology (PIT) provides an additional way to protect the blood supply from agents known, emerging and yet unidentified. The precautionary principie which was first endorsed by FDA after the crisis of HIV / AIDS, states that for situations of scientific uncertainty should be taken into account the possibility of risk even in the absence of proof to the contrary. It could be argued then, that PITs represent the quintessence of the precautionary principie. Almost all of the potential for TTD is eradicated, often before the responsible agent is even recognized. Although the interval between the recognition of an agent to implement measures to prevent it has been shortened, there is often an earlier period of delay, during which a disease does not appear to represent a risk to the recipient or to human health in general. The damage caused bythem has been called a "fixed and inevitable property of transfusion practice." Techniques for pathogen inactivation of plasma include the following. MBLT (Methylene Blue and Light Treatment). PLT (Psoralens and Light Treatment). RFLT (Riboflavin and Light Treatment) in addition, there is a method of Solvent Detergent (SD) for pools of plasma. Techniques for pathogen inactivation of platelets include the following Ultra Violet Light Treatment and Amotosalen- UVA.There is great potential risk in delaying the implementation of Pathogen Inactivation Technologies (PITs) while awaiting the evidence and the absolute pedect system to put it into operation. It is time to act.

Coumarins from the aerial parts of Prangos uloptera (Apiaceae) / Cumarinas das partes aéreas de Prangos uloptera (Apiaceae)

Phytochemical studies on the aerial parts of Prangos uloptera, an endemic Iranian species of the genus Prangos, yielded five coumarins, xanthotoxin (1), prangenin (2), scopoletin (3), deltoin (4) and prangolarin (5). The structures of these coumarins were elucidated by spectroscopic means, and the antioxidant potential of 1-5 was evaluated by the DPPH assay. The chemotaxonomic significance of 1-5 is also discussed.

Os estudos fitoquímicos das partes aéreas de Prangos uloptera, uma espécie do gênero Prangos endêmica do Irã, forneceram cinco cumarinas, xantotoxina (1), prangenina (2), escopoletina (3), deltoína (4) e prangolarina (5). As estruturas destas cumarinas foram elucidas através de métodos espectroscópicos e o potencial antioxidante de 1-5 foi avaliado pelo ensaio de DPPH. O significado quimiotaxonômico de 1-5 também é discutido.

Photophysical and photobiological properties of 3-carbethoxypsoralen.

3-Carbethoxypsoralen (3-CP), a linear tricyclic psoralen, known for its photoreaction with DNA to form monofunctional cyclobutane adducts with pyrimidine bases, was found to produce a highly reactive cytotoxic species, singlet oxygen (1O2) to a greater extent than several other linear psoralens such as psoralen, 8-MOP, 5-MOP or angular psoralens (angelicin). 3-CP also produced superoxide radicals (O2-.) at a rate slower than psoralens in the following order:psoralen > angelicin > 3-CP > 8-MOP > 5-MOP. 1O2 produced by photoactivated 3-CP was found to oxidize tyrosine and Dopa to Dopachrome, and subsequently their conversion to melanin. It also induced photooxidation of 2'-deoxyguanosine. Reactive oxygen species produced by 3-CP also induced lipid peroxidation. The rate of dopachrome formation to promote its conversion to melanin and lipid peroxidation by 3-CP and other linear and angular psoralens and hematoporphyrin derivatives may be related to their skin photosensitizing ability and the rate of 1O2 production. Topically applied 3-CP on hairless mice exposed to UVA radiation was found to be a nonphotocarcinogenic agent in contrast to 8-MOP, which under similar conditions produced a 70% tumour yield (squamous cell carcinoma) in 65 weeks. 3-CP was observed to be a photolabile compound and was converted to a dihydro-form as previously reported by other investigators. The photoconversion of 3-CP to 4',5'-dihydro-3-CP was enhanced under N2, whereas, under O2 atmosphere, lesser degree of photoconversion was observed, thus, indicating that reduction takes place via an anoxic or Type I mechanism. The significance of these observations are discussed in relation to the skin photosensitizing, nonphotocarcinogenic, and photochemotherapeutic potential of 3-CP.

Psoralenos y UVA (PUVA), 20 años de experiencia clínica / Psoralens and UVA (PUVA), 20 years of clinical experience

Los psoralenos son derivados de las furocumarinas, inicialmente obtenidos de los vegetales y posteriormente se han desarrollado sintéticamente. El PUVA es útil en vitiligo, psoriasis, micosis fungoide, liquen plano, urticaria pigmentosa y otras enfermedades. Los psoralenos sintéticos con los que contamos son 8-metoxipsoraleno (8-MOP), el trimetoxipsoralen, el 5-metroxipsoralen (5-MOP). Se ha observado que a pesar de ser tratamientos prolongados, el PUVA es un buen tratamiento para psoriasis y vitiligo, aunque influye mucho la selección del paciente