Blood donors' attitudes towards voluntary non-remunerated donation in Trinidad and Tobago.

OBJECTIVES: To assess the attitude towards voluntary non-remunerated blood donation among blood donors in Trinidad and Tobago (TRT). BACKGROUND: Blood donors in TRT are either family replacement (F/R, 87%) or remunerated (13%). There is chronic blood shortage and high seroreactivity for transfusion-transmissible infections (TTI) in donors. Converting existing to voluntary non-remunerated donors (VNRD) reduces the need to recruit news donors in achieving 100% VNRD. METHODS: A questionnaire-based, cross-sectional survey was conducted at two blood collection centres at an interval of 8 years. Donors were surveyed for sociodemographic characteristics, awareness of the blood shortage, previous donation behaviour, donor-beneficiary linkage if F/R, willingness to become VNRD and choice of motivators for converting to VNRD. RESULTS: A total of 400 and 595 donors respectively participated in Surveys 1 and 2, of whom 92·8 and 86·3% were F/R (P < 0·001), respectively. In both surveys, 52% of participants were unaware of an existing blood shortage (P = 0·983). Only 9·8 and 9·1% of participants expressed unwillingness to become VNRD (P = 0·720). The main motivators to convert to VNRD were reminders from the centre (84%) and extended opening hours (78%) in Survey 1 as compared to confidence that donated blood was used properly (73%) and shortened waiting times to donate (73%) in Survey 2. CONCLUSION: Despite low awareness of blood shortage, willingness to become VNRD was high among existing donors. Accountability and donor convenience underpinned the main motivators for converting to VNRD.

Sensitivity to genotoxic effects of bleomycin in humans: possible relationship to environmental carcinogenesis.

Responses to the genotoxic effect of bleomycin in lymphocytes of blood cultures, expressed as the average number of chromatid breaks per cell (b/c), varied from less than 0.20 to more than 2.00 in 335 normal individuals. More than 11% of the subjects tested showed a b/c rate above 1.00 and more than 22% showed a b/c rate above 0.80. These individuals are considered sensitive to this radiomimetic drug. The distributional profile of bleomycin responses of the control individuals appears to be representative of the normal human population. In patients with cancers of the colon (83), upper aerodigestive tract (head/neck) (77), and lung (71), the frequencies of subjects in the hypersensitive class were found to be between 40 and 50%, and the response profiles were distinctly different from those of the control population. On the other hand, in a group of elderly cigarette smokers, who exhibited no symptoms of lung cancer, the bleomycin sensitivity profile was significantly skewed toward the more resistant stratum, with only one hypersensitive case among 56 individuals tested (1.78%). The sensitivity profile of patients with breast cancer (82) was similar to that of the control population. Our data suggest that: (1) mutagen sensitivity may play an important role in carcinogenesis of organs and tissues that have direct contact with the external environment (respiratory, digestive, and integumentary systems); (2) it appears to have no significant influence on carcinogenesis of tissues that are not directly exposed to the environment (e.g., breast, brain); and (3) it also has little impact on carcinogenesis in individuals with a hereditary predisposition to cancer (e.g., retinoblastoma, Gardner's syndrome). Development of more effective and precise test systems for carcinogen sensitivity is highly desirable for identification of persons at risk.

Differential susceptibility to a mutagen among human individuals: synergistic effect on chromosome damage between bleomycin and aphidicolin.

Lymphocytes of standard human blood cultures were treated with bleomycin, aphidicolin and a combination of these two agents. A synergistic effect on chromosome damage was obvious when the two agents were used simultaneously. Various experiments showed that Aphidicolin induces chromosome breakage only in cells in the S-phase; Despite the quantitative differences in response to bleomycin among individuals, the frequency of chromatid breakages becomes high when the two agents are used together. The data suggest a differential DNA repair capacity among human subjects, since aphidicolin is known to inhibit DNA polymerase alpha, which is necessary for DNA replication and DNA repair.