Josephine Chow

Phototoxicity of benzoporphyrin derivative (BPD) has been tested in vitro and compared with that of hematoporphyrin (HP). After 1-hour activation with visible light, BPD was 10 times more cytotoxic than HP toward human adherent cell lines: A549 lung cancer, Calu-1 lung carcinoma, and CCD-19Lu normal lung, killing 100% of cells at the concentration of 70 ng/ml. Under the same conditions, BPD was 10-70 times more cytotoxic than HP toward nonadherent cells and cell lines. Tested were human leukemia cell lines HL60, K562, and KG1, normal human lymphocytes, and mouse mastocytoma cell line P815. The concentrations required to kill 100% of cells varied between 10 and 500 ng BPD/ml and between 0.2 and 10 micrograms HP/ml. The difference between the nonadherent cell lines in respect to their sensitivity to phototoxicity of both BPD and HP seemed to be related to the cell sizes, with the smallest cells being the most vulnerable. The most attractive characteristic of BPD in addition to its powerful phototoxicity is its maximum absorption around 700 nm, which is in the range of wavelengths penetrating tissues the best. This characteristic alone could make BPD a drug of choice in cancer photodynamic therapy when the safety of its use is ensured. Preliminary tests in vivo have shown that DBA/2J mice can tolerate a single ip injection of 20-60 micrograms BPD as well as the same dose of HP. The biodistribution and toxicity studies of BPD are under way in our laboratory.

SUMMARY Objectives : This multicentre, prospective, open label, randomised controlled trial was to determine whether buttonhole cannulation technique in new and established haemodialysis fistula reduced complications and prolonged the access life compared to usual practice. Method : Seventy subjects were recruited for this study. Subjects randomised to the buttonhole group had their fistula cannulated by the same staff member for two to four weeks at the same angle and direction with sharp needles. Once the tunnel was developed, blunt needles were used. The control group continued with usual practice (rope ladder rotation technique). Results : Infection at the cannulation site occurred in four patients in the buttonhole group and one in the rope ladder rotation group (p = 0.11). Haematomas at the cannulation site and site pain experienced during the dialysis session were more often recorded for the buttonhole group (p < 0.05). Conclusions : This study showed that buttonhole cannulation resulted more infections, haematoma formation and site pain during dialysis than with the rope ladder rotation group. A further larger scale longitudinal study is recommended.

The following case reports are of two patients who have developed hypersensitivity reactions to the red cell growth hormones, darbepoietin and erythropoietin. The subsequent skin testing and clinical course suggested that the cause of these reactions was due to the excipient polysorbate 80. This finding might have implications in the recent increase in the incidence of pure red cell aplasia.