The effect of external deoxyribonucleosides on deoxyribonucleoside triphosphate concentrations in human lymphocytes.

The effects of deoxyribonucleosides on the intracellular levels of deoxyribonucleoside triphosphates (dNTP) and on the rate of labelled thymidine incorporated into DNA of human phytohaemag-glutinin-stimulated lymphocytes have been studied. Thymidine (10^?2–10^?6M) expanded the dTTP and reduced dATP and dCTP levels. Deoxycytidine (10^?3M) expanded the dCTP level and caused inhibition of [³H] thymidine incorporation into DNA but had no detectable effect on the other dNTP concentrations. Deoxyadenosine (10^?3 M) expanded the dATP level, and reduced the other dNTP levels and deoxyguanosine (10^?4M) expanded the dGTP level and reduced the dCTP level; both inhibited [³H] thymidine incorporation into DNA. The sensitivity of these cells to the addition of deoxynucleosides to their culture medium indicates that the plasma and tissue levels of nucleosides may profoundly influence DNA synthesis by human cells in vivo.     

How to recognize and manage psychological distress in cancer patients

Psychological distress is common in cancer patients, however, it is often unrecognized and untreated. We aimed to identify barriers to cancer patients expressing their psychological concerns, and to recommend strategies to assist oncologists to elicit, recognize, and manage psychological distress in their patients. Medline, Psychlit, and the Cochrane databases were searched for articles relating to the detection of emotional distress in patients. Patients can provide verbal and non-verbal information about their emotional state. However, many patients may not reveal emotional issues as they believe it is not a doctor's role to help with their emotional concerns. Moreover, patients may normalize or somatize their feelings. Anxiety and depression can mimic physical symptoms of cancer or treatments, and consequently emotional distress may not be detected. Techniques such as active listening, using open questions and emotional words, responding appropriately to patients' emotional cues, and a patient-centred consulting style can assist in detection. Screening tools for psychological distress and patient question prompt sheets administered prior to the consultation can also be useful. In conclusion, the application of basic communication techniques enhances detection of patients' emotional concerns. Training oncologists in these techniques should improve the psychosocial care of cancer patients.     

Developments in drug delivery: implications for cancer care

Changes in drug delivery as well as new drug development have impacted on cancer care in the past twenty years. Several modified release chemicals now have a role in cancer care, and new routes of drug delivery have been established as part of standard care. A range of strategies has been investigated to enhance anti-tumor selectivity of drugs including antibodies, liposomes and carrier molecules homing or activated in the environment of tumors. Fixed drug combinations are also used in cancer supportive care, and may find use in a range of settings.     

An improved brain slice model of nerve agent-induced seizure activity

A brain slice model was developed to investigate the mechanisms of seizure activity induced by soman and the effectiveness of potential anticonvulsant drugs. Unlike previously reported slice studies with nerve agents, this model contains the entorhinal cortex as well as the hippocampus. This allows the study of the spread of seizure discharges within the limbic system and the development of prolonged, sustained discharges that are rarely seen in the simple hippocampal slice preparation. Soman (1 microM) induced a second population spike in the evoked field potential in the CA1 or CA3 region within 15-20 min. In almost all the slices tested, this developed into spontaneous seizure activity within 30-40 min. As well as interictal bursts, many slices also showed longer periods of high-frequency bursting analogous to ictal seizure activity that originated in the entorhinal cortex. This activity appeared similar to that induced by the muscarinic agonist pilocarpine. Both the second population spike and the spontaneous discharges could be blocked by diazepam and by AMPA/kainate antagonists, but not by the NMDA antagonists AP5 and MK-801. This study confirms that the combined hippocampal-entorhinal cortex slice preparation is a suitable model for investigating the origin and propagation of nerve-agent-induced seizures within the limbic system.     

Sharing decisions in cancer care

Previous studies have demonstrated that the majority of cancer patients fail to achieve their desired level of participation during treatment decision making. However, it is unclear whether this failure affects patient well-being and satisfaction. Furthermore, whilst shared decision making is currently espoused as the preferred model for doctor patient relations, little empirical evidence exists showing it has beneficial effects for patients. We aimed to evaluate the impact of shared decision making and the achievement of preferred role on patient anxiety, recall of information, and satisfaction. Patients with cancer indicated their preferred level of participation in decision making and preferences for information and emotional support prior to their initial consultation with an oncologist. Anxiety was assessed prior to and immediately after the consultation and recall seven days after the consultation. Anxiety was reassessed at two-weeks post-consultation at which time patients also reported their satisfaction with the consultation and perceived role of participation in treatment decision making. Satisfaction with the information and emotional support received was also evaluated. Of the 233 patients available for analysis, a match between preferred and perceived roles was found for over one-third of patients (34%), with 29% more active and 37% less involved in decision making than preferred. Multivariate analyses demonstrated that role mismatch significantly predicted changes in anxiety levels from pre to immediate postconsultation (p = 0.03). However, irrespective of preferred role in decision making, perceived role, but not role mismatch, significantly and independently predicted satisfaction with both the consultation (p = 0.0005) and the amount of information and emotional support received from the doctor (p = 0.004). Patients who reported a shared role in decision making were most satisfied with the consultation and with the information about treatment and emotional support received. Those who reported that either themselves or the doctor exclusively made the decision were least satisfied. These findings underscore the pre-eminence of the shared decision making model and suggest that encouraging participation may be the safest standard approach. Doctor - as well as patient - based interventions are required to promote patient participation.