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Because of a heightened public awareness of issues pertaining to the use of electromagnetic energy, concurrent with a rapid growth of the cellular telephone industry, a study was initiated to characterize the electromagnetic environment associated with typical cell-site antennas. In particular, the radio-frequency electromagnetic (RF) fields in the vicinity of several antenna towers, ranging in height from 46-82 m, were characterized by measurement. In all cases, the antennas were omnidirectional co-linear arrays. The maximal power densities considered representative of public exposure were found to be less than 100 microW/m2 (10 nW/cm2) per radio channel. Comparison of measured values with the corresponding values that were calculated from the free-space transmission formula indicated that the analytical technique is conservative (i.e., overestimates field levels). The measured and corresponding analytical values were found to be well below accepted exposure limits even when extrapolated to simultaneous and continuous operation of the maximal number of transmitters that would be expected to be installed at a cell-site. Additional measurements were made in the near field of the same antenna type in a roof-mounted configuration. At a distance of 0.7 m from the antenna, the maximal power density in the main beam was found to be less than 30 W/m2 (3 mW/cm2) when normalized to sixteen radio channels (the maximal number used on a single antenna) and less than 30 mW/m2 (3 microW/m2) at 70 m. In all cases, the effective radiated power (ERP) by each radio channel was 100 W referenced to a half-wave dipole. This paper describes the instrumentation and measurement techniques used for this study and provides a summary of the results.
Fifty-three patients with colorectal cancer Dukes' B2 and C were randomized after surgery. One group was treated by radio-and/or chemotherapy and the second by radio-and/or chemotherapy and MER. After 24 and 36 months a significant longer disease free interval, lower recurrence rate and better survival was found in the group treated by radio-chemo- and immunotherapy. Treatment was well tolerated and there were few local side effects from the MER injections. The long time efficacy of this adjuvant treatment whether it increases the cure rate or only delays recurrence does require longer follow-up.
Following high dose radio-iodine therapy, some radiation damage to the salivary glands is to be expected since iodine is taken up by these glands. The great individual variation in the uptake makes it impossible to predict the severity of the damage. T max and maximal excretion capacity after stimulation were therefore estimated by a camera functional scintigram with digital read out in patients following radioiodine therapy (0.1-3.2 Ci); the excretion index was used as an indirect measure of salivary flow. After a dose up to 0.3 Ci there is a change of T max and maximal excretion capacity in 30% of patients; after a dose of 0.5 to 1 Ci it is found in 60 and 80% and after very high doses of 1.1 to 3.2 Ci an abnormal Tmax was found in two-thirds of all patients and reduced or absent excretion capacity in all nine patients in this group. The excretion index also depended significantly on the cumulative dose. All patients who had received very high doses showed marked hyposialia or asialia. The early results of interim examinations suggest, similar to radio-iodine induced hypothyroidism, a cumulative risk of reduced function. In view of the long survival period of patients with differentiated thyroid carcinomas attention should be drawn to this side effect.
The evidence presented in this paper suggests that coumarin is a RES stimulator. An enhanced removal of both RPP and radio RPVP was observed beginning at or before 30 minutes and lasting up to 6 hours. Over this time, RPP removal was enhanced by an average of 40%, while RPVP removal was enhanced by 60%. Since RPVP is non-metbabolizable, its levels may be a more accurate estimate of the stimulatory effect of coumarin. This evidence fits in well previous results which have suggested that coumarin may increase the number of phagocytic cells. Other results have shown enhancement of protein lysis by 74% over similar periods, while enhanced protease activity levels of 50% have been observed to accompany this.
After oral administration iodine 131 is demonstrable within hours and days in thyroid cyst fluid. This iodine concentration may be caused by active metabolism in the cyst, depending on thyroid function. Highest levels of iodine 131 are found in autonomous nodules.
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Platelet adhesion under static and flow conditions from a washed platelet suspension containing albumin to a polymer deposited by radio-frequency glow discharge of allylamine vapour on a poly(ethylene terephthalate) substrate was measured. Electron spectroscopy for chemical analysis was used to characterize the surface. Fibrinogen adsorption from a series of dilute plasma solutions to radio-frequency glow discharge/allylamine, measured using 125I radiolabelled baboon fibrinogen, increased with decreasing plasma dilution to a level much higher than that previously observed on polyurethanes. Elutability by sodium dodecyl sulphate of fibrinogen adsorbed from dilute plasma also increased with increasing plasma concentration, but fibrinogen preadsorbed from plasma became non-elutable when surfaces were stored in buffer for 5 d before contact with sodium dodecyl sulphate. Platelet adhesion to substrates which had been pre-adsorbed with dilute plasma was measured using baboon platelets radiolabelled with 111In. Adhesion greatly decreased as the plasma concentration used for preadsorption increased, suggesting that non-specific platelet binding to the bare surface occurs when protein coverage is incomplete. Non-specific platelet binding was inhibited to varying degrees by preadsorption of different proteins to the surface. Platelet adhesion to surfaces preadsorbed with dilute (1.0%) baboon and human plasmas lacking fibrinogen (i.e. serum, heat-defibrinogenated plasma and congenitally afibrinogenemic plasma) was diminished compared with normal plasma. Addition of exogenous fibrinogen to the deficient plasma partially restored platelet adhesion to normal levels. Adhesion to surfaces preadsorbed with human plasma deficient in von Willebrand factor was comparable to that observed with normal plasma. The plasma preadsorption studies with fibrinogen deficient media suggested that adsorbed fibrinogen is necessary for platelet adhesion to the radio-frequency glow discharge/allylamine substrate at high protein coverage. However, since adhesion was greatly reduced when the plasma preadsorbed substrate was stored in buffer before platelet contact, the conformation of adsorbed fibrinogen is also important in mediating platelet adhesion to radio-frequency glow discharge.
The apical and basal-lateral plasma membranes of toad bladder epithelium were radio-iodinated with the glucose-glucose oxidase-lactoperoxidase system. The covalently bound radio iodine was used as a marker during subcellular fractionation and membrane isolation. Homogenization conditions that ensured rupture of more than 80% of the cells without substantial nuclear damage were defined by Normarski optics. The nuclei were separated by differential centrifugation and the apical and basal-lateral components were resolved by differential and sucrose density gradient centrifugation. The apical components yielded two radioactive bands that were identified as glycocalyx and plasma membrane labeled with 125I. The basal-lateral components yielded a hetero-disperse pattern made up of at least 3 radioactive bands, but the bulk of the activity of ouabain-sensitive ATPase comigrated with only one of these bands. The mitochondia, identified by assays for cytochrome oxidase and NADH cytochrome c reductase activities, were separated from the radio-iodine labeled by centrifugation in sucrose density gradients under isokinetic conditions. The labeled glycocalyx and the slowly migrating components of basal-lateral labeling were separated from the radio-iodinated membranes by centrifugation at 100,000 x g x 1 hr after removal of the mitochrondria by the isokinetic method. The labeled membranes were then subjected to ultracentrifugation in sucrose density gradients under isopycnic conditions; the basal-lateral membranes containing ouabain-sensitive ATP-ase were well resolved from the apical membranes by this method. These results provide a relatively rapid method of attaining partial purification of the apical and basal-lateral plasma membranes of toad bladder epithelium.
The Sauvé-Kapandji procedure has been performed in 15 non-rheumatoid patients with chronic distal radio-ulnar joint dislocation accompanied by joint damage or deformity. The clinical results were favourable; wrist pain improved in all patients, wrist flexion-extension was increased by more than 10 degrees in nine patients, grip strength of at least 80% of the contralateral wrist was achieved in 11 patients, and forearm rotation was more than 150 degrees in 12 patients. However, X-ray examination revealed an unstable proximal ulnar stump and radio-ulnar convergence in all patients similar to that associated with the Darrach procedure. Although the Sauvé-Kapandji procedure can preserve ulnar support of the wrist and is believed to yield more satisfactory results than the Darrach procedure, its extensive use is not recommended for non-rheumatoid distal radio-ulnar joint disorders, but it is recommended for chronic distal radio-ulnar joint dislocation with articular injury or deformity.
Gas-liquid chromatography with radioactivity detection (Radio-GLC) was investigated as an analytical means of determining the fractional turnover rates of plasma free fatty acids. For this purpose normal dogs were infused with 1.838 muCi/min of [1-14C]oleic acid complexed with albumin and plasma samples were taken at 0 to 110 minutes. The plasma free fatty acids were isolated by a modified Dole extraction and the methyl esters, prepared by diazomethylation, were identified and quantitated by GLC and radio-GLC using radioactive methyl heptadecanoate as internal standard. The study demonstrates that physiologically feasible infusion rates and loads of radioactive acids can be found which permit accurate analyses of plasma free fatty acids by radio-GLC. During a 2-hour infusion no labeled acid other than oleic appeared in plasma indicating that the method could be used to study the turnover of a mixture of fatty acids simultaneously. These results also indicate that conventional methods of determination of radioactivity in purified extracts can be employed without concern for recycling of label among the fatty acids, at least over short periods of time. The radio-GLC technique described yields approximately 20% higher fractional turnover times for oleic acid than do standard methods.
The distal radio-ulnar joint participates in the biomechanics of the wrist both by transmission of carpal stresses and by its role in the mobility of the wrist. Fractures of the distal radio-ulnar joint are often missed as they are frequently only a radiation of fractures of the radius to the distal radio-ulnar joint. Computed tomography is the most useful examination to assess the severity of these lesions. Distal radio-ulnar dislocations may also be associated with fractures of the radius, but usually occur in isolation. The diagnosis is difficult, as the slightest rotation on plain X-rays interferes with the evaluation criteria. A CT scan in the neutral position and in pronation and supination is the examination of choice for dislocations and subluxations, but must be interpreted according to strict criteria. In contrast, a tea of the triangular ligament can only be assessed on arthrography and the distinction between traumatic and degenerative rupture is difficult. The patient's age, the site of the perforation and the length of the ulna are important elements in the diagnostic decision. MRI appears to be a promising examination for investigation of this joint, but the quality of the images is not yet perfectly reproducible.
Vibration-induced changes in the distal radio-ulnar joint were analysed by comparing workers using motorised saws (978 cases) and a control group. The following are the essential findings: 1. Exposure to vibration causes characteristic changes in the distal radio-ulnar joint, particularly on the left, consisting of osteophytosis, deformity and cystic rarefaction. 2. The frequency of the arthrosis is related in a statistically significant manner to a) length of exposure, b) age. 3. The subjective complaints of numbness, weakness and pain can, to some extent, be related to the radio-ulnar arthrosis. 4. Vibration is not the only factor in the genesis of the degenerative process of the distal radio-ulnar joint; ordinary use and stress can cause similar changes, although to a much less marked extent. The aetiological role of local vibration as a factor in causing the arthrosis has been confirmed.
The effect of radio and microwave radiation on dietary atherosclerosis of rabbits was tested. 16 New Zealand white rabbits were exposed to microwave (2.45 GHz) radiation at a power density of 20--30 mW/cm2 for 4 h a day, 5 days a week for 8 to 10 weeks. Irradiated animals had serum cholesterol concentrations, aortic wall cholesterol concentrations and percentage of intimal surface involved in atherosclerotic lesions which were not different from age and weight matched controls. Continuous radio frequency irradiation (1 MHz) for 8 to 11 weeks with a field strength of 30 V/cm also failed to change these indices of atherogenesis. We conclude that under the conditions of these experiments radio and microwave irradiation do not affect the course of diet induced atherogenesis.
A fully implantable radio-telemetric differential intracranial pressure sensor is described with a zero-point calibration that can be confirmed repeatedly. Intracranial pressure (ICP) is measured with the device by the principle of applying a known external pressure to the scalp above the sensor and simultaneously detecting by radio-telemetry the zero-point of the sensor corresponding to a balance of pressures across it. The radio-telemetry is implemented by a resonant circuit in the sensor of which the resonant radiofrequency is detected outside the body. The sensor is passive, has built-in barametric compensation, negligible permeability of temperature drift, no calibration ambiguities, and fast dynamic response. The implanted sensor has been used successfully for short-term as well as long-term ICP monitoring. It has been implemented primarily for intermittent ICP measurements, but also adapted to continuous recording. Preliminary clinical experience with the system indicates that it is effective, safe, and simple to operate.
This report is a description of the development and organisation of an area radio paging service in Cambridge and its application to doctors and para-medical staff working in various hospitals and in the community. It reviews the first five years of operation.Personal selective radio paging has some fundamental advantages over the car radio-telephone as a means of communication. Currently, the service operates only in the Cambridge area, but it is planned to extend this to cover the new county of Cambridgeshire by February 1975, and, at the same time, to introduce speech.