Combined RAF1 protein expression and p53 mutational status provides a strong predictor of cellular radiosensitivity

The tumour suppressor gene, p53, and genes coding for positive signal transduction factors can influence transit through cell-cycle checkpoints and modulate radiosensitivity. Here we examine the effects of RAF1 protein on the rate of exit from a G2/M block induced by γ-irradiation in relation to intrinsic cellular radiosensitivity in human cell lines expressing wild-type p53 (wtp53) protein as compared to mutant p53 (mutp53) protein. Cell lines which expressed mutp53 protein were all relatively radioresistant and exhibited no relationship between RAF1 protein and cellular radiosensitivity. Cell lines expressing wtp53 protein, however, showed a strong relationship between RAF1 protein levels and the radiosensitivity parameter SF2. In addition, when post-irradiation perturbation of G2/M transit was compared using the parameter T50 (time after the peak of G2/M delay at which 50% of the cells had exited from a block induced by 2 Gy of irradiation), RAF1 was related to T50 in wtp53, but not mutp53, cell lines. Cell lines which expressed wtp53 protein and high levels of RAF1 had shorter T50s and were also more radiosensitive. These results suggest a cooperative role for wtp53 and RAF1 protein in determining cellular radiosensitivity in human cells, which involves control of the G2/M checkpoint. © 2000 Cancer Research Campaig

Relative biological effectiveness of fast neutrons for apoptosis in mouse hair follicles

This study compared the effects of high linear energy transfer (LET) fast neutrons on the induction of apoptosis in the hair follicles of ICR mice with those of low LET 60Co γ-rays. The changes that occurred from 0 to 24 h after exposing the mice to either 2 Gy of γ-rays (2 Gy/min) or 0.8 Gy of neutrons (94 mGy/min, 35 MeV) were examined. The maximum frequency was found at 12 h (γ-rays) or 8 h (neutrons) after irradiation. The mice that received 0-8 Gy of γ-rays or 0-1.6 Gy of neutrons were examined 8 h after irradiation. The dose-response curves were analyzed using the best-fit curve model. The dose-response curves were linear-quadratic, and a significant relationship was found between the frequency of apoptotic cells and the dose. The morphological findings in the irradiated groups were typical apoptotic fragments in the matrix region of the hair follicle, but the spontaneous existence of apoptotic fragments was rarely observed in the control group. In the presence of an apoptosis frequency between 2 and 14 per follicle, the relative biological effectiveness values of neutrons in small and large follicles were 2.09 ± 0.30 and 2.15 ± 0.18, respectively

Healthcare workers’ beliefs, motivations and behaviours affecting adequate provision of sexual and reproductive healthcare services to adolescents in Cape Town, South Africa: a qualitative study

BACKGROUND: Adolescents’ sexual and reproductive healthcare (SRH) needs have been prioritized globally, and they have the rights to access and utilize SRH services for their needs. However, adolescents under-utilize SRH services, especially in sub-Saharan Africa. Many factors play a role in the under-utilization of SRH services by adolescents, such as the attitude and behaviour of healthcare workers. The aim of this study therefore, was to explore and gain an in-depth understanding of healthcare workers’ beliefs, motivations and behaviours affecting adequate provision of these services to adolescents in South Africa. METHODS: Twenty-four healthcare workers in public SRH services in Cape Town, South Africa participated in this qualitative study through focus group discussions. To fulfill the aims of this study, nine focus group discussions were conducted among the SRH nurses. RESULTS: SRH nurses indicated that they are experiencing challenges with the concept and practice of termination of pregnancy. They explained that this practice contradicted their opposing beliefs and values. Some nurses felt that they had insufficient SRH skills, which hinder their provision of adequate SRH services to adolescents, while others described constraints within the health system such as not enough time to provide the necessary care. They also explained having limited access to schools where they can provide SRH education and pregnancy prevention services in the surrounding area. CONCLUSIONS: Nurses are faced with numerous challenges when providing SRH services to adolescents. Providing the nurses with training programmes that emphasize value clarification may help them to separate their personal beliefs and norms from the workplace practice. This may help them to focus on the needs of the adolescent in a way that is beneficial to them. At the health systems level, issues such as clinic operating hours need to be structured such that the time pressure and constraints upon the nurse is relieved

Predictors of nurses’ and midwives’ intentions to provide maternal and child healthcare services to adolescents in South Africa

BACKGROUND: Adolescent mothers are at a much higher risk for maternal mortality compared to mothers aged 20 years and above. Newborns born to adolescent mothers are also more likely to have low birth weight, with the risk of long-term effects such as early onset of adult diabetes than newborns of older mothers. Few studies have investigated the determinants of adequate quality maternal and child healthcare services to pregnant adolescents. This study was conducted to gain an understanding of nurses’ and midwives’ intentions to provide maternal and child healthcare and family planning services to adolescents in South Africa. METHODS: A total of 190 nurses and midwives completed a cross-sectional survey. The survey included components on demographics, knowledge of maternal and child healthcare (MCH) and family planning (FP) services, attitude towards family planning services, subjective norms regarding maternal and child healthcare and family planning services, self-efficacy with maternal and child healthcare and family planning services, and intentions to provide maternal and child healthcare and family planning services to adolescents. Pearson’s correlation analysis was conducted to determine the association between knowledge, attitude, subjective norms, self-efficacy, and intention variables for FP and MCH services. A 2-step linear regression analysis was then conducted for both FP and MCH services to predict the intentions to provide FP and MCH services to adolescents. RESULTS: Self-efficacy to conduct MCH services (β = 0.55, p < 0.01) and years of experience as a nurse- midwife (β = 0.14, p < 0.05) were associated with stronger intentions to provide the services. Self-efficacy to provide FP services (β = 0.30, p < 0.01) was associated with stronger intentions to provide FP services. CONCLUSIONS: Self-efficacy has a strong and positive association with the intentions to provide both MCH and FP services, while there is a moderate association with attitude and norms. There is a need to improve and strengthen nurses’ and midwives’ self-efficacy in conducting both MCH and FP services in order to improve the quality and utilization of the services by adolescents in South Africa.IS