In vitro efficacy of glutaraldehyde-crosslinked chitosan microspheres against the fish-pathogenic ciliate Philasterides dicentrarchi.

Philasterides dicentrarchi is a protozoan ciliate which causes significant economic losses in fish aquaculture. This study investigated the effects of chitosan microspheres cross linked with glutaraldehyde and containing beta-cyclodextrin (betaCD) on the survival of this parasite in 7 d cultures. When used alone in assays, neither chitosan nor betaCD showed any activity, whereas free glutaraldehyde was strongly toxic to the parasite. Microspheres were likewise strongly toxic, at total glutaraldehyde concentrations much lower than with free glutaraldehyde: near-100% ciliate death was obtained (1) with 50 microg ml(-1) of microspheres prepared with 5% glutaraldehyde and no betaCD, or (2) with 10 microg ml(-1) of microspheres prepared with 0.15% glutaraldehyde and 0.1% betaCD. This suggests that the main active component is glutaraldehyde, but that the presence of small amounts of betaCD enhances efficacy. This high efficacy, together with the low toxicity to fish and rapid biodegradability of the individual components, suggest that these microspheres may be an attractive alternative to the formaldehyde baths traditionally used for the control of this parasite.

Indocyanine green mediated photothrombosis for the management of predominantly classic choroidal neovascularisation caused by age related macular degeneration.

AIMS: To study the effectiveness of indocyanine green mediated photothrombosis in the management of predominantly classic subfoveal choroidal neovascularisation associated with age related macular degeneration. METHODS: Prospective, non-comparative, interventional case series of nine patients with predominantly classic subfoveal choroidal neovascularisation secondary to age related macular degeneration who declined photocoagulation or verteporfin photodynamic therapy. Patients were submitted to one or more treatments with an intravenous injection of a small volume of high concentration indocyanine green solution followed by low irradiance, large spot 810 nm continuous laser application via a transpupillary approach. Main outcome measures were change in best corrected visual acuity and macular exudative manifestations. RESULTS: After 12 months of follow up, the final best corrected visual acuity was the same (plus or minus two ETDRS lines) in five eyes (55%), improved more than two ETDRS lines in three eyes (33%), and worsened by more than two lines in the remaining eye. The improved vision was probably related to partial or complete restoration of the macular architecture as a result of fluid resolution, whereas the worsened vision was primarily the result of treatment failure in achieving substantial choroidal neovascular occlusion. There were no complications related to the procedure. CONCLUSION: Indocyanine green mediated photothrombosis may be an effective alternative treatment for predominantly classic subfoveal choroidal neovascularisation caused by age related macular degeneration.

[Photocontrol of the synthesis of chlorophyll a and phycocyanin in the cyanobacterium Calothrix crustacea Schousboe]. / Fotocontrol de la síntesis de clorofila a y de ficocianina en la cianobacteria Calothrix crustacea Schousboe.

Chlorophyll a and phycocyanin synthesis in the cyanobacterium Calothrix crustacea Schousboe (ecophene Rivularia bullata) have been studied in white light after the application of red and green light pulses. The light quality produces a complementary pattern in the pigment synthesis. Chlorophyll synthesis is stimulated by red light pulses whereas phycocyanin synthesis is by green light pulses. Because the effect of red light on chlorophyll synthesis shows some far-red photoreversibility, the action of phytochrome is proposed. The green light effect on phycocyanin synthesis is only partially reversed by far-red light. This reversion is lost after incubation in white light for two hours. The effect of green light on phycocyanin synthesis could not only be due to phytochrome since theoretically in green light the level of the active form of phytochrome is lower than in red light. Thus, the action of a specific green light photoreceptor is proposed.

Efecto del cigarrillo en la agregacion plaquetaria de personas jovenes. / Effect of cigarettes in platelet aggregation in young people

Se estudia la agregacion plaquetaria en 18 personas jovenes fumadoras habituales y se compara con la de 15 personas no fumadoras de la misma edad. En las personas fumadoras se observa un aumento significativo en la velocidad inicial de agregacion, cuando esta se estimula con ADP. Al separar los individuos de acuerdo al sexo, se pudo establecer que la mayor agregacion entre los fumadoras se les hizo el estudio antes e inmediatamente despues de fumar un cigarrillo y se encontro un aumento de la velocidad inicial de la agregacion con ADP y un aumento aun mas considerable de la velocidad inicial, cuando se agregaba con epinofrenia. Los hallazgos permiten pensar, que las plaquetas de las mujeres son mas sensibles a los efectos del cigarrillo que las de los hombres, y que la reactividad plaquetaria a la epinefrina exogena, aumenta inmediatamente despues de fumar