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PubMed1995

Cell fission and formation of mini cell bodies by high frequency alternating electric field.

We report the use of high frequency alternating electric fields (AC) to induce deformation of sea urchin eggs, leading to budding of membrane vesicles or fission of cells. Several mini cell bodies can be prepared from a single egg by carefully manipulating the frequency and amplitude of the AC field and the ratio between the interelectrode spacing and the cell diameter, alpha. alpha values between 2.2 and 3.5 have been found to be optimal for inducing fission of sea urchin eggs. In a typical experiment, a sea urchin egg (diameter = 75 microns), suspended in a low ionic medium (conductance < 2 mS/m), was located under the microscope between two platinum wire electrodes, separated by a distance of approximately 200 microns. A medium strength AC field (< 100 V/cm at 2 MHz) was applied to attract the egg to one of the two electrodes via dielectrophoresis. This process took place in a few seconds. The voltage was then slowly increased to approximately 1000 V/cm over approximately 30 s. The cell elongated and separated into two fragments, the larger one containing the nucleus. When the field was turned off, the mother cell and the daughter vesicle retracted to form spherical mini cell bodies that appear to be stable as assessed by the absence of swelling for the duration of the experiment (approximately 15 min). This indicates that membranes of these mini cell bodies were not leaky to ions and small molecules. This procedure could be repeated a few times to make several mini cell bodies from a single egg. With practice, several minicell bodies could also be prepared in a single fission experiment by adjusting the field parameters and the a value. Cell fission is a result of the mechanical stress produced by the AC field. These procedures may be used to prepare mini membrane vesicles for voltage clamp experiments or to perform microsurgical manipulation of cells, embryos, or chromosomes.

Animals↗
PubMed1994

Chick embryo development can be irreversibly altered by early exposure to weak extremely-low-frequency magnetic fields.

Several reports have shown that weak, extremely-low-frequency (ELF), pulsed magnetic fields (PMFs) can adversely affect the early embryonic development of the chick. In this study, freshly fertilized chicken eggs were exposed during the first 48 h of postlaying incubation to PMFs with 100 Hz repetition rate, 1.0 microT peak-to-peak amplitude, and 500 microseconds pulse duration. Two different pulse waveforms were used, having rise and fall times of 85 microseconds (PMF-A) or 2.1 microseconds (PMF-B). It has been reported that, with 2 day exposure, these fields significantly increase the proportion of developmental abnormalities. In the present study, following exposure, the eggs were allowed to incubate for an additional 9 days in the absence of the PMFs. The embryos were taken out of the eggs and studied blind. Each of the two PMF-exposed groups showed an excess in the percentage of developmental anomalies compared with the respective sham-exposed samples. This excess of anomalies was not significant for the PMF-A-treated embryos (P = 0.173), whereas it was significant for the PMF-B-exposed group (P = 0.007), which showed a particularly high rate of early embryonic death. These results reveal that PMFs can induce irreversible developmental alterations and confirm that the pulse waveform can be a determinant factor in the embryonic response to ELF magnetic fields. The data also validate previous work based on the study of PMFs' effects at day 2 of embryonic development under field exposure.

Abnormalities, Radiation-Induced↗
PubMed1985

Treatment of recalcitrant non-union with a capacitively coupled electrical field. A preliminary report.

Twenty-two well established non-unions in twenty patients were treated with a capacitively coupled electrical signal (sine wave, sixty kilohertz, five volts peak to peak) that was applied non-invasively through stainless-steel capacitor plates placed on the skin surface overlying the approximate site of the non-union. The average age of the eleven female and nine male patients in this series was 38.4 years, and the average duration of the twenty-two non-unions was 3.3 years. Seventeen of the non-unions were labeled recalcitrant, meaning that they had failed to heal after either previous bone-grafting or another type of electrical stimulation, or both. Five of the non-unions had not been previously treated. Seventeen (77.3 per cent) of the non-unions achieved solid osseous union after an average of 22.5 weeks of treatment with capacitive coupling. The results in this small series were not affected by the non-union being recalcitrant, by the fact that one patient bore full weight on the extremity in a cast, by the presence of osteomyelitis, or by the presence of remaining metallic internal-fixation devices in the bone. Since capacitive coupling is non-invasive, involves portable equipment, allows full weight-bearing on the lower extremity in a cast, is easy to apply, and does not require precise localization of the capacitor plates, it has distinct advantages over other methods of treating non-union with electricity.

Adolescent↗
PubMed2000

Small-group format for continuing medical education: a report from the field.

BACKGROUND: For continuing medical education (CME) to be effective, several key features must be realized. These include a learner-directed agenda of topics, presentation of information by trusted peers or local experts, and opportunity for practice and feedback. If the information comes from several sources--printed materials, peer discussion, patient questions, and presentation from the specialist community--the perception of need for and the durability of change are enhanced. Finally, motivation for change must be high enough for change to occur, yet not overwhelming. METHOD: Facilitated small-group discussion among general practitioner colleagues with an expert specialist around clinic-based problems meets many of these requirements. When followed up by relevant literature, key concepts and practice changes are reinforced. RESULTS: We discuss our 3-year experience with the small-group format, comprising more than 25 sessions as either learners or facilitators. We describe the maturation of our group. We highlight the benefits to learners, including the relevance to clinical practice and the opportunity to ascertain the standard of care of peers. The benefits to the specialist are also discussed, including opportunities to learn which suggestions are difficult to implement. IMPLICATIONS: Our experience demonstrates that this format is sustainable over the long term. The success of the small-group format at improving CME and patient outcomes deserves further evaluation.

Canada↗
PubMed2006

Evidence-based treatments in the field: a brief report on provider knowledge, implementation, and practice.

This study examined familiarity, perceived effectiveness, and implementation of evidence-based treatments for children in community settings. A sample of service providers in agencies affiliated with federal programs to improve children's mental health services was identified using a snowball sampling procedure. Forty-four percent of the sample (n = 616) responded to a Web-based survey designed to collect data on evidence-based treatments. High familiarity with, relatively high-perceived effectiveness, and generally high use of evidence-based treatments were reported. Partial implementation of treatment protocols within the context of few agency mandates and widely ranging supports for the implementation of evidence-based treatments was found. Results support the inclusion of more complex models of diffusion, dissemination and implementation in research, and development efforts for evidence-based treatments.

Adult↗
PubMed2000

Encouraging inherently safer production in European firms: a report from the field.

It is now generally recognized that in order to make significant advances in accident prevention, the focus of industrial firms must shift from assessing the risks of existing production and manufacturing systems to discovering technological alternatives, i.e. from the identification of problems to the identification of solutions. Encouraging the industrial firm to perform (1) an inherent safety opportunity audit (ISOA) to identify where inherently safer technology (IST) is needed, and (2) a technology options analysis (TOA) and to identify specific inherently safer options that will advance the adoption of primary prevention strategies that will alter production systems so that there are less inherent safety risks. Experience gained from a methodology to encourage inherently safer production (ISP) in industrial firms in the Netherlands and Greece is discussed. Successful approaches require both technological and managerial changes. Firms must have the willingness, opportunity, and the capability to change. Implications for the EU Seveso, IPPC, and EMAS Directives are also discussed.

Accidents, Occupational↗
PubMed2003

Physiological responses to repeated bouts of high-intensity ultraendurance cycling--a field study case report.

The present study aimed to 1) examine the relationship between laboratory-based measures and high-intensity ultraendurance (HIU) performance during an intermittent 24-h relay ultraendurance mountain bike race (approximately 20 min cycling, approximately 60 min recovery), and 2) examine physiological and performance based changes throughout the HIU event. Prior to the HIU event, four highly-trained male cyclists (age = 24.0 +/- 2.1 yr; mass = 75.0 +/- 2.7 kg; VO2peak = 70 +/- 3 ml x kg(-1) x min(-1)) performed 1) a progressive exercise test to determine peak volume of oxygen uptake (VO2peak), peak power output (PPO), and ventilatory threshold (T(vent)), 2) time-to-fatigue tests at 100% (TF100) and 150% of PPO (TF150), and 3) a laboratory simulated 40-km time trial (TT40). Blood lactate (Lac(-)), haematocrit and haemoglobin were measured at 6-h intervals throughout the HIU event, while heart rate (HR) was recorded continuously. Intermittent HIU performance, performance HR, recovery HR, and Lac(-) declined (P < 0.05), while plasma volume expanded (P < 0.05) during the HIU event. TF100 was related to the decline in lap time (r = -0.96; P < 0.05), and a trend (P = 0.081) was found between TF150 and average intermittent HIU speed (r = 0.92). However, other measures (VO2peak, PPO, T(vent), and TT40) were not related to HIU performance. Measures of high-intensity endurance performance (TF100, TF150) were better predictors of intermittent HIU performance than traditional laboratory-based measures of aerobic capacity.

Adult↗
PubMed2006

Primer: assessing the efficacy and safety of nonpharmacologic treatments for chronic rheumatic diseases.

Nonpharmacologic treatments (including surgery, technical operation, rehabilitation, physiotherapy, education or the use of external technical devices) represent a wide range of treatments for chronic rheumatic disease. Randomized, controlled trials (RCTs) are recognized as the best method for avoiding bias in assessing nonpharmacologic treatments. Designs such as nonrandomized studies, cluster-randomized trials, patient-preference trials, modified Zelen-design trials, tracker trials and expertise-based RCTs could, however, be used to assess such treatments. Assessing nonpharmacologic treatments involves methodologic issues linked to difficulties associated with blinding, duration of the study, main outcomes of the study, difficulties associated with standardizing the intervention and the influence of health-care providers. Hence, these treatments cannot be assessed according to the standards used for pharmacologic treatments. As well, specific instruments such as A CheckList to Evaluate A Report of a NonPharmacological Trial (CLEAR NPT) should be used to assess the quality of reports in this field. Important reporting guidelines that take an evidence-based approach to improve the quality of reports from RCTs, such as the Consolidated Standards of Reporting Trials (CONSORT) statement, should be extended to take these issues into account.

Chronic Disease↗
PubMed2001

Epilepsy--doctor's dilemma, lawyer's delight? Medico-legal consequences of practising in the field of epilepsy report of an International League Against Epilepsy British Branch meeting--Edinburgh, April 2000.

Six cases are described where the medical management of a person's epilepsy was brought under legal scrutiny. Lessons learnt from this educational exercise include improving doctor patient communication, the function of a Coroner's Court, when is misdiagnosis negligent, the vagaries of expert witnesses, should failure to diagnose a tumour be blamed on the physician or the service when facilities are inadequate, is failure to recognise a rare drug interaction, failure to warn against an interaction, or failure to take a proper history, negligent? The conference also examined the legal ramifications of the nurse/doctor relationship in epilepsy care, the place of epilepsy guidelines and, due to its interactive nature, reflected on the audience's epilepsy knowledge, which, in places seemed significantly deficient. It was a gripping educational exercise.

Adolescent↗
PubMed1986

Humoral antibody responses to biannual multiantigen vaccination: report of a field trial on children in Sudan.

One hundred and sixty-six children aged 3-30/12 were enrolled in this study. Initially all children were given a single injection containing live measles vaccine, diphtheria and tetanus toxoids, inactivated polio vaccine and meningococcal, A & C polysaccharide, plus an intradermal injection of BCG. In a second visit 6 months later each child was tuberculin tested and given a second dose of all the above vaccines with the exception of BCG. Blood samples were obtained before and 1 month after each vaccination. Following the second dose there was satisfactory seroconversion for all the vaccines. Tuberculin positivity rose from 5.4% before BCG vaccination to 94.4% 6 months after its administration. It is concluded that it is safe and effective to give these antigens simultaneously and that this particular schedule lends itself for use with nomadic and other unaccessible groups of population.

Antibodies, Bacterial↗