Mobile Phone Radiation : Physiological & Pathophysiologcal Considerations.

It is documented that electromagnetic emissions from mobile phones can interfere with brain’s signal processing activity due to their oscillatory similitude to the inherent rhythms of the brain, akin to “electromagnetic interference” observed while using mobile phones in aeroplanes. At high power density levels, thermal effects occur, some of which can be attributed to heat induced stress mechanisms. The less understood non-thermal effects occur at low radio frequency/microwave power density levels and are not accompanied by any body temperature rise. The safety standards set by international agencies are based on thermal effects. For the mobile phones, ICNIRP 1998 guidelines restrict spatial peak of microwave exposure to 2 W/Kg SAR values averaged over 10 g of tissue for 6 minutes. Some of the reported electromagnetic radiation (EMR) induced adverse effects are brain tumours, male infertility and immune dysfunction with increased susceptibility to infections. Pathophysiological mechanisms of interaction of EMR at plasma membrane are calcium efflux from cell membranes, increased expression of stress proteins, influence on channels/gap junctions in cell membrane, overproduction of reactive oxygen species, ornithine decarboxylase activation, reduction in melatonin levels, decrease in protein kinase C activity, damage to DNA and change in gene expression in brain cells and altered blood- brain barrier. There are equal number of conflicting reports in literature regarding EMR exposure and brain tumours. A comprehensive review concludes “overall the studies published to date do not demonstrate an increased risk within approximately 10 years of use for any tumour of the brain or any other head tumour.” Another review summarises that there is “enough data to convince that long-term exposure to low intensity EMR below the ICNIRP guidelines can promote cancer development”. However the time limit for exposure has been suggested as more than 10 years. For conducting epidemiological studies, some of the difficulties experienced are obtaining unexposed controls or cohorts, follow up of the cohorts, actual dose measurement for exposure assessment in case-control studies, inaccuracy ,recall bias and selective non response in recall of phone use by mobile phone users, long induction times, long latencies (the effects we observe now are of analogue phones that are no longer used ) and the rarity of observed malignancies, variable ways of using the phone by the user i.e. left or right ear, head sets/speaker/blue tooth etc. Large-scale epidemiological studies should employ personal MW dosimeters for strict dose measurement and for interpreting actual tissue exposure.

Association of anticardiolipin antibodies levels with instent restenosis in patients with coronary artery disease.

Present study was conducted to evaluate the association of IgG anticardiolipin antibodies with instent restenosis in patients having undergone percutaneous intervention with bare metal or drug eluting stents. Coronary artery disease patients with stent placement at least 6 months prior were screened for eligibility. 26 satisfied the inclusion/exclusion criteria. 10 patients with symptoms of restenosis, confirmed on check angiography served as cases and 16 without symptoms of restenosis served as control. Unpaired t- test was applied to ascertain the significance of any difference between control and study groups. Antibody levels were estimated on ELISA reader. The mean (±SD) anticardiolipin antibodies levels in cases and controls were 11.8±5.1 GPL/U/ml and 14.3±10.2 GPL/U/ml, respectively. The difference was not statistically significant (P>0.05). In conclusion, we did not observe any significant correlation between the level of IgG aCL and instent restenosis.

Simulation of physiology experiments--an alternative to animal use.

Amphibian experiments on nerve-muscle preparation and heart are essential as per first year MBBS practical syllabus, for learning basic concepts in Physiology. Need was felt to design and develop computer based simulation software as an alternative to animal use, due to growing concern and stringent laws imposed by animal ethical bodies. Computer algorithms were developed for 13 amphibian experiments, by manually tracing the graphs obtained through mechanical experimentation and storing the X, Y coordinates for the end points of each line segment as data base tables. By retrieving the data base tables, one for each experiment, the computer simulated graphs were drawn using Visual Basic 6 with timer control and Macromedia Flash for animation effects. A CD-ROM consisting of the software for computer simulation of all the amphibian experiments, as an alternative to the conventional animal experiments, has been developed for the benefit of medical students across the country, as a useful active learning tool.

Assessment of respiratory and sympathetic cardiovascular parameters in obese school children.

The study was undertaken to assess the respiratory and sympathetic cardiovascular functions in obese and non obese school children of 12-16 years age group, randomly selected from two schools of Rajpura (Punjab), representing mixed socioeconomic group of Punjabi ethnicity and categorized as obese or controls as per standard criteria for Body Mass Index (BMI). Dynamic lung function tests and pressor response to cold (Cold pressor test) and isometric exercise (Handgrip dynamometer test) were carried out. Statistical analysis comprised students' t-test, at 95% confidence level and simple linear regression analysis. The results indicated significantly higher baseline diastolic blood pressure (DBP) (P < 0.004) in obese children correlating positively with BMI (r = 0.57). Significantly increased DBP response to applied cold stimulus (response/range, P < 0.02 and maximal value, P < 0.001) and borderline response to isometric exercise (P < 0.002) in obese children indicated autonomic instability. The dynamic lung functions were significantly decreased (P < 0.04) in obese subjects and correlated negatively with BMI. Personal data forms of obese children revealed less physical activity and excessive intake of junk foods. Thus it is concluded that obese children have derangement of sympathetic cardiovascular functions and reduced pulmonary functions.

Assessment of olfactory status in allergic and non-allergic rhinitis patients.

A study undertaken to assess the olfactory acuity in allergic (group I) and non-allergic rhinitis (group II) patients in comparison with age and sex matched controls (group III). Patients presenting with atleast three of the five cardinal symptoms of rhinitis i.e. rhinorrhoea, sneezing, itching, headache and nasal obstruction were grouped as non-infective rhinitis and further divided into allergic rhinitis (group I, n = 20) and non-allergic rhinitis (group II, n = 20) based on nasal smear cytology positivity or negativity for eosinophils respectively. Detailed Ear, Nose and Throat examination was carried out in both the groups and peripheral blood samples were analysed for total, differential leukocyte and absolute eosinophil counts using standard techniques. In all the three groups the olfactory thresholds for 5 odorants i.e. musk (M), formalin (F), camphor (C), asafoetida (A, 10% aqueous solution) and oil of peppermint (P, 20%) were evaluated for testing musky, pungent, camphorous, putrid and minty odours respectively by the method described by Elsberg and Levy for quantitative olfactometry. The results indicated elevation of olfactory thresholds (delta %, calculated taking control values as 100%) for 4 or 5 odorants in group I and group II patients respectively as compared with controls (group I: delta % for P--89.6%; M--116.4%; A--55.8%; P < 0.001; C--73.1%; P < 0.02; F--26.6% N.S.; group II: P--96.9%; M--99.3%, P < 0.01 for both; A--66.8%; C--102.7%, P < 0.001; F--42%, P < 0.05). In the non allergic rhinitis group the magnitude of the olfactory loss was more severe except for the odorant musk. Further interpretations as per gender based specificities revealed more severe olfactory loss in males of both the groups for the odorants peppermint and musk and moderately severe olfactory loss for formalin and camphor as compared to females. However, for the odorant asafoetida females showed greater olfactory loss than males in both the groups (delta % 73.38% versus 52% in group I and 81.29% versus 69.7% in group II).