The effects of low-energy 60-Hz environmental electromagnetic fields upon the growth-related enzyme ornithine decarboxylase

People living in the industrial society of today are unavoidablyexposed to low-energy electromagnetic (EM) radiation. The potentialrisk to human health of such exposure has received much study.In this regard, numerous epidemiological studies have linkedexposure to low-energy EM fields to increased cancer risk. Weinvestigated the ability of low-energy 60-Hz EM fields to alterthe activity of ornithine decarboxylase (ODC) in a number ofestablished cell lines. The activity of ODC, the controllingenzyme in polyamine biosynthesis, has been shown to be elevatedin growing cells or tissues and during the process of tumorpromotion. A 1-h exposure to a 60-Hz EM field of an intensityof 10 mV/cm produced a 5-fold increase in ODC activity in humanlymphoma CEM cells and a 2- to 3-fold increase in mouse myelomacells (P3) relative to the unexposed cultures. Depending uponthe cell type, ODC activity increased during the 1-h exposureperiod and remain ed elevated for several hours after the fieldexposure ended. In another series of experiments, fields ofan intensity as low as 0.1 mV/cm for a 1-h period produced a30% increase in the activity of ODC in Reuber H35 hepatoma cellsgrown in monolayer culture. In the H35 cells, continuous exposureto the 60-Hz EM field (10 mV/cm) for periods of 2 and 3 h resultedin either no increase in ODC activity (2 h) or a decrease inenzyme activity (3 h) compared to the unexposed control cultures.The data is discussed in relation to possible molecular mechanismsof field-cell interaction, the importance of the exposure intervalsaltering cellular ODC activity and the potential ability of60-Hz EM fields to serve as a tumor promoting stimulus.     

Does ageing have an effect on midbrain premotor nuclei for vertical eye movements?

Currently, there is debate in the clinical literature as to whether defects in vertical gaze are a consequence of normal ageing or a component of an underlying neurodegenerative disorder. Although pathological changes have been demonstrated in diseased subjects, no study to date has addressed the question of normal ageing effects. In this retrospective study, we examined 23 neurologically and pathologically normal subjects (age 18-91). Using an unbiased, frame-based sampling method, we quantified neuronal and glial cell densities in 10 young (<50) and 13 aged (>65) subjects in the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF), the key premotor substrate in the vertical gaze pathway. We found no statistically significant difference in neuronal density, glial cell density, or neuron-to-glial cell ratios between the young and the aged. We conclude, therefore, that neuronal loss, neuronal atrophy, or gliosis in the riMLF are not consequences of normal ageing.     

Extracellular adenosine,formed during low level NMDA receptor activation,provides an inhibitory threshold against further NMDA receptor-midiated neurotransmission in the cortex

In the cortex only a few of the available NMDA receptors must be activated to evoke maximal release of adenosine. In fact, maximal adenosine release occurs at 30 μM NMDA, a concentration at which noradrenaline release is only 20% maximal. NMDA-evoked noradrenaline release appears to require the generation of propagated action potentials, while adenosine release does not. Noncompetitive block of NMDA-evoked release of adenosine, but not noradrenaline, can be overcome by increasing NMDA concentrations. The above findings are consistent with the possibility that there are spare receptors for NMDA-evoked adenosine release, but not for nor-adrenaline release. These spare receptors are not due to elevated levels of glycine in the vicinity of those NMDA receptors mediating adenosine release. Functionally, it appears that low level NMDA receptor activation provides a purinergic inhibitory threshold against higher level NMDA receptor mediated processes. This could provide inhibitory tone and selectivity for critical functions, such as learning, memory, and synaptic plasticity in the cortex. © 1993 Wiley-Liss, Inc.     

Postoperative radiotherapy for locally advanced colon cancer

Background: The role of adjuvant postoperative radiotherapy for locally advanced colon cancer is not well documented. Methods: Seventy-eight patients who underwent a complete resection of B2-C colon cancer received postoperative radiotherapy. Twenty-eight patients received ⩽45 Gy; 50 patients received 50–55 Gy. Twenty-seven patients received adjuvant fluorouracil-based chemotherapy. All patients were followed for a minimum of 3 years; no patients were lost to follow-up. Results: The overall local control rate was 88%. The 5-year actuarial rate of local control was 96% after 50–55 Gy postoperative radiotherapy compared with 76% after <50 Gy (p=0.0095). Multivariate analysis of local control showed that only radiotherapy dose significantly influenced this end point. Cause-specific survival rates at 5 years were B2, 67%; B3, 90%; C1, 100%; C2, 61%; C3, 36%; and overall, 63%. Multivariate analysis of cause-specific survival showed that only stage significantly influenced this end point. Bowel obstruction caused by adhesions developed in three patients and required a laparotomy; radiation-induced sarcoma developed in one additional patient. Conclusions: Postoperative radiotherapy appears to reduce the risk of local recurrence in patients with locally advanced colon cancer. The optimal dose is probably 50–55 Gy at 1.8 Gy per fraction. Postoperative radiotherapy may improve cause-specific survival for patients with stages B3 and C2 cancers.     

POLICE INVOLVEMENT WITH CLIENTS HAVING INTELLECTUAL DISABILITIES: A PILOT STUDY IN SOUTH LONDON

Following the increasing trend for de-institutionalisation of people with learning disabilities, community services are increasingly being utilised to support those who also display challenging behaviours. Where severely challenging behaviours are involved community service providers may require additional support from die police service. The authors undertook a retrospective pilot study among two major community care providers in South London, and looked at the reasons for calling the police, the frequency with which die police were called; staff expectations in calling the police and the outcomes for die clients in terms of further involvement with the criminal justice system. The authors note that the police were generally used as additional support when clients became too difficult for the immediate service providers to manage. It is also noted that police action on behalf of victims was generally low and that the police were never called in response to clients with learning disabilities reporting having witnessed crime. The authors note that further research is required.