Longitudinal variation in O6-alkylguanine DNA-alkyltransferase activity in the human colon and rectum

In a systematic study of O6-alkylguanine DNA-alkyltransferase activity in the human colon and rectum, tumours were found to occur in regions of low activity. These results are consistent with the hypothesis that O6-alkylguanine DNA-alkyltransferase levels and alkylating agent exposure may be important determinants of large bowel tumorigenesis

Computer-Aided Chemistry at Surrey — the way ahead

This article describes the objectives and rationale of the degree course in Computer-Aided Chemistry at the University of Surrey. The course, which is the first of its kind, represents a sharp break with the past in that industry was intimately involved in the early stages of the planning as well as providing subsequent support; furthermore, much of the teaching is done via a workshop approach. The course aims to produce high-calibre chemists, particularly of the analytical kind, with a firm foundation in computing and having benefited from the close collaboration and cooperation of industry

Bone density and depression in premenopausal South African women: a pilot study

Objective: It is posited that the effect of depression on BMD is dependent on the severity of depression. Conflicting evidence exists regarding this possible association. This study investigated the association between depression and low bone mineral density (BMD). Methods: The hypothesis was investigated in a random sample of volunteers (n=40) and in premenopausal female psychiatric patients (n=5) diagnosed with recurrent severe major depression. The outcome measures were BMD (DEXA); depression (Beck Depression Inventory and Psychological General Well-being Scale) and 24-hour saliva cortisol levels (ELISA). In a comparison of women (4 of the 40 i.e. “control” subjects) with negligible symptoms of depression and the five patients with severe recurrent major depression- BMD, depression, saliva cortisol and bone turnover markers were measured and compared. Pro-inflammatory status (IL-1 and TNF-alpha) was investigated in the psychiatric patients only. Results: In the random – non clinical - sample of women (n=40), 26 exhibited normal BMD and 14 exhibited low BMD. Depressive symptoms and cortisol levelswere not significantly different between these two groups. Women with severe recurrent major depression(n=5) exhibited lower median BMD T-scores, higher overall bone turnover and higher 24-hour cortisol levels compared to “control” subjects (n=4). The psychiatric patients also exhibited elevated IL-1 levels. Conclusion: The effect of depression on BMD may be dependent on the depression severity. IL-1 and cortisol are possible mediators in depression-induced BMD loss.Key words: Bone mineral density; Cortisol; Depression; Pro-inflammatory cytokine

Fern spore extracts can damage DNA

The carcinogenicity of the vegetative tissues of bracken fern (Pteridium) has long been established. More recently, the carcinogenic effects of the spores of bracken have also been recognized. Both vegetative tissues and spores of bracken can induce adducts in DNA in animal tissues, but the possible genotoxic or carcinogenic effects of spores from fern species other than bracken are unknown. The single-cell gel electrophoresis (‘comet’) assay was used to investigate whether fern spores can cause DNA damage in vitro. Extracts of spores from six fern species were administered to cultured human premyeloid leukaemia (K562) cells. Spore extracts of five fern species: Anemia phyllitidis, Dicksonia antarctica, Pteridium aquilinum, Pteris vittata and Sadleria pallida, induced significantly more DNA strand breaks than those in the control groups. Only in one species, Osmunda regalis, was the effect no different from that in the control groups. Using extracts from A. phyllitidis and P. vittata, the extent of DNA damage was increased by increasing the original dose 10 times, whereas an experiment in which exposure times were varied suggested that the highest levels of strand breaks appear after 2 h exposure. Simultaneous incubation with human S9 liver enzyme mix ablated the damaging effect of the extracts. Our data show that fern spore extracts can cause DNA damage in human cells in vitro. Considering the strong correlation between DNA damage and carcinogenic events, the observations made in this report may well have some implications for human health. © 2000 Cancer Research Campaig