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PubMed2003

Assessment of lung particle accumulation in factory workers by magnetic field measurement.

OBJECTIVES: In industrial settings, minute particles of industrial substances lodge in the lungs and accumulate over decades, often leading to pneumoconiosis. Although these particles have been almost impossible to detect with x-rays, especially initially, we still rely upon them for detection of such deposits. As a result, particle accumulation is not detected early enough, and eventually diagnosed pneumoconiosis is typically irreversible. Accordingly, we investigated an alternative detection method that utilizes the magnetic characteristics of the particles after they are excited by an external magnetic field. Using accumulation of magnetic particles as a surrogate marker for total particle accumulation, our goal was to develop a method that can determine particle quantity and distribution in the lungs of individuals in different types of industrial situations. This method would allow us to identify factors that affect particle accumulation and to detect early such accumulations, before the pneumoconiosis stage. The pilot study reported herein represents proof of principle that such a method is feasible. MATERIALS AND METHODS: After a magnetic field generated by a strong direct current is applied to particles, they continue to generate a weak magnetic field even after the external field is removed (relaxation). We measured relaxation using an external detector (scanning a flux-gate magnetometer, Helmholtz coil). To field test this method. we studied 150 subjects in various industrial settings. We studied a variety of factory workers, including those involved in welding and cutting for different employment durations. A static magnetic field of 50mT to the chest, and the residual magnetic field distribution were measured by scanning a flux-gate magnetometer in a 2-dimensional region covering the whole chest. RESULTS: The strength of the magnetic field from the lungs of our subjects generally increased with the length of employment, particularly after 11-20 years. Welders showed higher particle accumulation than the others. Across all types of jobs, and work durations, smokers had lung particle accumulations substantially higher than non-smokers. CONCLUSIONS: 1. In the study reported herein, we describe application of a novel, portable device for measuring the accumulation of magnetizable particles in the lungs of factory workers. These particles are viewed as a surrogate for determining the extent and distribution of total particles in the lung. This is based on the detection of signal emanating from para- and ferromagnetic particles when they relax after an external magnetic field is switched off. 2. Particle accumulation increases proportionally to employment duration in welders, but may be less severe in other types of workers within the same company. 3. Smoking greatly increases the extent of particle accumulation. 4. Additional studies are now necessary to correlate signal with: (a) particle density at various sites, (b) total particle accumulation in the lungs, (c) lung function, and (d) the severity of lung fibrosis and pneumoconiosis. If correlated, the method may be useful in the early detection of particle accumulation and may allow for the assessment of outcomes following interventions for the treatment and prevention of pneumoconiosis.

Diagnostic Imaging↗
PubMed2002

[Effects of power-frequency magnetic fields exposure on phosphorylation and enzymatic activity of stress-activated protein kinase and its upstream kinase].

OBJECTIVE: To study the effects of 50 Hz power-frequency magnetic fields on signal transduction pathway of stress-activated protein kinase(SAPK), and explore the cellular signal transduction mechanism of the biological effects induced by power-frequency magnetic fields. METHODS: Chinese hamster lung(CHL) cell line was exposed to power-frequency magnetic fields with two intensities for different exposure durations. The cytoplasmic protein was extracted and the phosphorylated portion of SAPK and SEK1/MKK4 was measured with Western blotting analysis. The SAPK enzymatic activity was measured by the solid-phase kinase assay in cells exposed to power-frequency magnetic fields for 15 min. RESULTS: Both 0.4 mT and 0.8 mT power-frequency magnetic fields could enhance the phosphorylation of SAPK in a time-relative course manner, and reached the maximum extent at 15 min, with an increase of 20% and 17% respectively. The solid-phase kinase assay showed that the enzymatic activities of SAPK were also increased, which were 2.9 +/- 0.4 and 2.1 +/- 0.9 times of control respectively. However, the duration of SAPK phosphorylation induced by 0.8 mT was longer than that of 0.4 mT, while the duration and extent of SAPK dephosphorylation was remarkably shorter than that of 0.4 mT. The power-frequency magnetic fields under equal conditions could not phosphorylate(activate) the SEK1/MKK4. CONCLUSION: Power-frequency magnetic fields could activate the SAPK, but not SEK1/MKK4. It is suggested that power-frequency magnetic fields may activate SAPK signal transduction pathway through a kinase other than SEK1/MKK4. The activation mechanism of SAPK of power-frequency magnetic fields needs to be identified in more detail.

Animals↗
PubMedDate not supplied

Double-blind placebo-controlled trial of static magnets for the treatment of osteoarthritis of the knee: results of a pilot study.

CONTEXT: Outpatient clinical studies of magnet therapy, a complementary therapy commonly used to treat osteoarthritis (OA), have been limited by the absence of a credible placebo control. OBJECTIVE: Our objective was to assess the feasibility and promise of studying static magnetic therapy for knee OA and determine the ability of a new placebo-magnet device to provide concealment of group assignment. DESIGN: Randomized, double-blind, placebo-controlled clinical trial. SETTING: Academic teaching hospital in Boston. PARTICIPANTS: We enrolled 29 subjects with idiopathic or post-traumatic OA of the knee. INTERVENTIONS: Subjects received either high-strength magnetic (active) or placebo-magnetic (placebo) knee sleeve treatment for 4 hours in a monitored setting and self-treatment 6 hours daily for 6 weeks. MAIN OUTCOME MEASURES: Primary outcomes were change in knee pain as measured by the WOMAC Osteoarthritis Index Pain Subscale at 6 weeks and extent of group concealment at study end. RESULTS: At 4 hours, VAS pain scores (+/- SE) on a 5-item scale (0-500, 500 worst) decreased 79 +/- 18 mm in the active group and 10 +/- 21 mm in the placebo group (P < 0.05). There were no significant differences in any primary or secondary measure of efficacy between the treatment groups at 6 weeks. Despite widespread testing for magnetic properties, at study end, 69% of the active group and 77% of the placebo group (P > 0.2) believed that they had been assigned to the active treatment group. CONCLUSION: Despite our small sample size, magnets showed statistically significant efficacy compared to placebo after 4 hours under rigorously controlled conditions. The sustained efficacy of magnetic therapy for knee osteoarthritis could be assessed in an adequately powered trial utilizing an appropriate control such our new placebo-magnet device.

Aged↗
PubMed2004

Intraspinal anomalies associated with isolated congenital hemivertebra: the role of routine magnetic resonance imaging.

BACKGROUND: Previous studies have demonstrated high rates of intraspinal anomalies in patients with congenital scoliosis; however, various authors have not considered the presence of an isolated hemivertebra to be sufficient reason for further evaluation with magnetic resonance imaging. Consequently, the rate of magnetic resonance imaging-detected intraspinal anomalies and subsequent neurosurgical intervention in patients with a single hemivertebra is unknown. Therefore, we studied all patients with a hemivertebra, after eliminating patients with a myelomeningocele, to compare those who had a single hemivertebra with those who had a complex hemivertebral pattern. METHODS: A retrospective review of the history, physical examination findings, and magnetic resonance imaging findings for patients who had presented with at least one hemivertebra, excluding those who had a myelomeningocele, was conducted to identify the prevalence of intraspinal anomalies as seen on magnetic resonance imaging and the rate of subsequent neurosurgical intervention. Additionally, the diagnostic value of the history and the physical examination in predicting the presence of intraspinal anomalies was determined. RESULTS: One hundred and sixteen patients with congenital scoliosis and a curve that included at least one hemivertebra were identified. Seventy-six of these patients had had magnetic resonance imaging and were included in the present study. The mean age of these patients at the time of presentation was 4.9 years, and the mean duration of follow-up was 7.7 years. Twenty-nine patients had an isolated hemivertebra, and forty-seven patients had a complex hemivertebral pattern. Eight (28%) of the twenty-nine patients with an isolated hemivertebra and ten (21%) of the forty-seven patients with a complex hemivertebral pattern had an intraspinal anomaly that was detected with magnetic resonance imaging. Overall, an abnormal finding on the history or physical examination demonstrated an accuracy of 71%, a sensitivity of 56%, a specificity of 76%, a positive predictive value of 42%, and a negative predictive value of 85% for the diagnosis of an intraspinal anomaly. Three patients with an isolated hemivertebra and five patients with a complex hemivertebral pattern underwent neurosurgical intervention. All eight patients who underwent neurosurgical intervention had had detection of an intraspinal anomaly with magnetic resonance imaging, whereas only four of these patients (two of whom had an isolated hemivertebra and two of whom had a complex hemivertebral pattern) had had an abnormal finding on either the history or the physical examination. CONCLUSIONS: Patients who have an isolated hemivertebra and those who have a complex hemivertebral pattern have similar rates of intraspinal anomalies that are detected with magnetic resonance imaging and similar rates of subsequent neurosurgical intervention. The history and physical examination findings are not predictive of intraspinal anomalies. Therefore, a magnetic resonance imaging evaluation of the entire spine should be considered for all patients with congenital scoliosis, including those with an isolated hemivertebra.

Abnormalities, Multiple↗
PubMed2001

[Bone healing and biochemical blood parameters after arteficial osteotomy of rabbits' femur treated by low-frequency magnetic field].

Aim of the study was to investigate the effect of magnetic fields on bone fracture healing and biochemical indices of bone turnover. Young male "White Newzealand Rabbits" were exposed after osteotomy of the femur of the hind-paw in narcosis for 31 days in a low-frequency magnetic field (field parameters: frequency 15.3 Hz, signal form: sine, magnetic field strength: 50 microT peak value). Eight animals each were assigned randomly for a single blind study to 3 groups. Controls were kept in a sham-exposition cage without magnetic field influence and were compared with a group in (Pseudo-) Helmholtz-coil arrangement with a horizontal magnetic field and a further group in a cylinder coil (vertical magnetic field). The daily duration of stay in the (sham-) exposition arrangements amounted to 30 minutes respectively. The activities of the alkaline phosphatase (AP) and creatinkinase (CK) were evaluated preoperatively, after the 19th and 31st experimental day, the callus density by means of computertomography after the 31st experimental day (two-tailed t-test). The densitometrically assessed callus densities of the magnetically treated groups were highly significant (p < 0.0001) compared with the controls. In spite of accelerated fracture healing the activities of the ALP were lower at both postoperative examinations than preoperatively, in the cylinder-coil the activity proved to be significantly lower (p < 0.05) compared with the controls after 31 days. Significant differences in CK were detected at no time. In conclusion, we confirm the positive magnetic field effects on fracture healing. The mechanisms of interaction of magnetic field and bone fracture healing remain to be clarified.

Alkaline Phosphatase↗
PubMed2004

The Nobel Prize in Physiology or Medicine in 2003 to Paul C. Lauterbur, Peter Mansfield for magnetic resonance imaging.

Imaging of human internal organs by exact and non-invasive methods is very important for medical diagnosis, treatment and follow-up. 2003 Nobel Laureates in Physiology or Medicine have made original discoveries in the use of magnetic resonance to visualize different structures. Their discoveries have led to the development of modern magnetic resonance imaging, MRI, which represents a breakthrough in medical diagnostics and research. Atomic nuclei within a strong magnetic field rotate with a frequency depending on the strength of the magnetic field. Their energy can increase if they absorb radio waves with the same frequency (resonance). When atomic nuclei return to their previous energy status, radio waves are emitted. These discoveries were awarded the Nobel Prize in Physics in 1952. During the following decades, magnetic resonance was used mainly for studies of the chemical structure of substances. In the beginning of the 1970s, 2003 Nobel Laureates made pioneering contributions, which later led to the applications of magnetic resonance in medical imaging. Paul Lauterbur (born 1929), Urbana, Illinois, USA, discovered the possibility to create a two-dimensional picture by introducing gradients to a magnetic field. Analysing the characteristics of the emitted radio waves he could determine their origin. This fact made it possible to build up a two-dimensional picture of structures that could not be visualized by other methods. Peter Mansfield (born 1933), Nottingham, England, further developed the utilization of gradients in the magnetic field. He showed, that the signals could be mathematically analysed, which made it possible to develop a useful imaging technique. Mansfield also showed how extremely fast imaging could be. It became technically possible within a decade. Magnetic resonance imaging, MRI, is now a routine method in medical diagnostics. Worldwide, more than 60 million investigations are performed each year, and the method is still rapidly evolving. MRI is often superior to other imaging techniques and significantly improves diagnostics in many diseases. MRI has replaced several invasive methods of examination and in this way has reduced the risk and discomfort of many patients. (Fig. 3, Ref. 3.).

England↗
PubMedDate not supplied

[Experimental modeling of the blood vessels magnetic embolization].

The embolization of blood vessels is used on a large scale: the method is applied in different diseases, in the ablation of organs, but especially in tumor necrosis. The embolization can be also magnetic, if the embolus is obtained through the deposit in the vessel of magnetic nano or microparticles in the presence of an external magnetic field. The objective of our study was the modeling of the magnetic embolization using amorphous magnetic microspheres that have strong magnetic properties and are biocompatible. Experimental tests were made in order to observe the building of the magnetic embolus inside a thin spiral tube and to determine the influence of some parameters on the efficiency of occlusions: the dimensions of magnetic microspheres (1-300 mm), the debit of the liquid (4.66 - 16.5 ml/min), the viscosity of the carrier liquid (1.007 - 7.34 cSt), the direction and the intensity of the external magnetic field (340 - 600 Gs), the shape of the tube and the linear length of the deposit (5 - 50 mm). Under pre-established experimental conditions the efficiencies of occlusions were between 67% and 100%.

Blood Vessels↗
PubMed1991

Awake discography. A comparison study with magnetic resonance imaging.

This study was undertaken to determine the correlation between awake discography findings and magnetic resonance imaging in the evaluation of symptomatic lumbar disc disease. The study included 164 consecutive patients who underwent evaluation with discography and magnetic resonance imaging for lumbar disc disease from August 1987 to September 1989. Chronic low-back pain, with or without radicular symptoms, was the presenting complaint in each case. Each patient had previously failed conservative treatment. The average age was 36 (range, 19-66 years). Magnetic resonance images were performed before discography in each case. Discography was performed with patients minimally sedated and under local anesthesia. A lateral approach was used. Magnetic resonance imaging and discography correlated in 90 cases (55%) and differed in 74 (45%). Considering disc levels, discography and magnetic resonance imaging correlated in 371 discs (80%). There were 172 normal discs and 199 abnormal discs. Of the abnormal discs, 151 (76%) reproduced symptoms. In 60 discs (13%), magnetic resonance images showed abnormal findings and the discogram normal findings. Discs levels classified as abnormal on magnetic resonance imaging demonstrated that 108 discs (37%) were asymptomatic. Magnetic resonance imaging showed normal findings and the discogram abnormal findings in 34 discs (7%), of which 21 (5%) recreated exact symptoms and 13 (2%) caused no pain. Magnetic resonance imaging is a static test and discography the only available dynamic test for disc evaluation. Awake discography is a diagnostic study that can determine which abnormal discs are symptomatic via the pain response.

Adult↗
PubMed1989

[The new magnets for dental prostheses].

With the introduction of metallic alloys based on rare earth, the dental prothesis disposes of new magnets as a method of denture retention whose retentive force is 20 to 50 time superior to the conventional magnets. There are two main types of magnets: the open field magnets as the Dyna and the closed field magnets as the Gillings and the Jackson. The latters have been devised to avoid propagation of the magnetic field in the living tissues, the harmlessness of this propagation being argued by the researchers. The magnets present several advantages tied to the conservation of the roots as the maintenance of the proprioception, the conservation of the socket bone, the strengthening of the remaining teeth and the psychological comfort for the patient, others tied to the technique itself as the simplicity of realization, the easiness of insertion and removal of the prothesis and the absence of wear. As far as terminology is concerned, we consider a magnet as a magnetic axial attachment.

Denture Design↗
PubMed1996

[Magnetic resonance of the spinal cord: a densitometric analysis].

BACKGROUND: Images obtained by magnetic resonance can present changes in a variety of haematologic disorders. The vertebral magnetic resonance signal depends chiefly on the relationship between fatty and cellular components of the haemopoietic bone marrow. A quantitative analysis of signal can be performed either during the magnetic resonance examination or on the computer-stored images. In this work, a densitometric grey-scale method is presented allowing to analyze the signal intensity on printed magnetic resonance images for those cases in which the computer-stored information is lacking. PATIENTS AND METHODS: A comparative study between magnetic resonance signal and the result of the densitometric analysis was carried out in 29 patients with different haematologic disorders. In order to achieve a suitable standardization, an internal control in both measures was used, i.e., the magnetic resonance signal intensity and the grey intensity of an area of spinal cord, respectively, yielding two ratios: magnetic resonance ratio and grey ratio. RESULTS: The precision analysis of the densitometric method gave the following results: within-batch coefficient of variation was 1.78%, between-batch coefficient of variation was 1.94% and overall reproducibility 6.4%. The correlation between magnetic resonance ratio and grey ratio was very high, i.e., 0.98 (p < 0.001). Moreover, the regression line displayed on ideal location since it originated in the point 0 and showed a slope of 45 degrees. CONCLUSION: The densitometric method presented in this paper can be useful for the quantitative analysis of the magnetic resonance signal intensity generated by the haemopoietic bone marrow, for those cases in which the computer-stored information is lacking.

Data Interpretation, Statistical↗
PubMed1996

Estimation of the gastric residence time of magnetic dosage forms using the Heidelberg capsule.

A new method for determining the gastrointestinal transit of magnetic dosage forms under the influence of an extracorporal magnet has been developed. A magnetic model dosage form was constructed consisting of small magnets attached to a pH-telemetering capsule (Heidelberg capsule). The transmission of the pH measurements was not affected by the magnetic field. The force of attraction of the magnetic model dosage form by the external magnet was characterised. In an in vivo study in five subjects the transmitted pH values showed indirectly that the gastric residence time of the magnetic model dosage form was prolonged significantly in the presence of an extracorporal magnet (t-Test, paired data, p < 0.05).

Adult↗
PubMedDate not supplied

Measure of magnetization transfer in multiple sclerosis demyelinating plaques, white matter ischemic lesions, and edema.

PURPOSE: To define the percentage of magnetization transfer of multiple sclerosis (MS) plaques, ischemic white matter lesions, and vasogenic edema to determine whether this measurement can help differentiate these entities. METHODS: Findings were compared in 25 patients with proved MS, 20 patients with white matter ischemic lesions, and 72 patients with white matter edema (caused by tumors, infections, or acute/subacute infarctions) in the periventricular system, centrum semiovale, and subcortical white matter. Magnetization transfer was performed using an on-resonance binomial pulse. The percentage of magnetization transfer of the normal white matter was also calculated. RESULTS: Magnetization transfer was significantly higher in white matter ischemic lesions (range, 31% to 38%; mean, 34% +/- 0.6%) than in demyelinating plaques of MS (range, 19% to 28%; mean, 22.5% +/- 1%) and in edema (range, 29% to 37%; mean, 30.2% +/- 0.4%). No statistical difference in percentage of magnetization transfer was found among lesions in the periventricular system (34% +/- 0.6%), centrum semiovale (35% +/- 0.5%), or subcortical white matter (33% +/- 0.6%), or in vasogenic edema associated with tumors, infections, or infarction. CONCLUSION: Differences in magnetization transfer suggest less change of demyelination in white matter ischemic lesions than in MS plaques and are significantly different in this respect from similar MS plaques. Magnetization transfer of edema was less than that of normal white matter or fell between ischemic abnormalities and MS plaques. Percentages of magnetization transfer below the mid-20% range is highly suggestive of demyelination. Vasogenic edema, our surrogate for increased water content of white matter, caused a decrease in the percentage of magnetization transfer.

Adult↗
PubMed2003

Three-dimensional forward solver and its performance analysis for magnetic resonance electrical impedance tomography (MREIT) using recessed electrodes.

In magnetic resonance electrical impedance tomography (MREIT), we try to reconstruct a cross-sectional resistivity (or conductivity) image of a subject. When we inject a current through surface electrodes, it generates a magnetic field. Using a magnetic resonance imaging (MRI) scanner, we can obtain the induced magnetic flux density from MR phase images of the subject. We use recessed electrodes to avoid undesirable artefacts near electrodes in measuring magnetic flux densities. An MREIT image reconstruction algorithm produces cross-sectional resistivity images utilizing the measured internal magnetic flux density in addition to boundary voltage data. In order to develop such an image reconstruction algorithm, we need a three-dimensional forward solver. Given injection currents as boundary conditions, the forward solver described in this paper computes voltage and current density distributions using the finite element method (FEM). Then, it calculates the magnetic flux density within the subject using the Biot-Savart law and FEM. The performance of the forward solver is analysed and found to be enough for use in MREIT for resistivity image reconstructions and also experimental designs and validations. The forward solver may find other applications where one needs to compute voltage, current density and magnetic flux density distributions all within a volume conductor.

Algorithms↗
PubMed2005

Magnetic resonance markers for early diagnosis and progression of Alzheimer's disease.

With increasing life expectancy, the early diagnosis and treatment of Alzheimer's disease has become critical in sustaining a healthy society. Noninvasive markers of disease progression starting from the earliest stages of pathologic involvement are required for determining the effectiveness of putative disease-modifying therapies that are under development. Cross-sectional and longitudinal studies indicate that magnetic resonance-based volume measurements of atrophy are potential markers of the progression of Alzheimer's disease, starting from the preclinical stages. Other magnetic resonance techniques that are sensitive to the different aspects of Alzheimer's disease pathology, such as biochemical ((proton) magnetic resonance spectroscopy), microstructural (diffusion magnetic resonance imaging), functional (functional magnetic resonance imaging) and blood flow (perfusion magnetic resonance imaging) changes, have not been as extensively studied longitudinally. Recent efforts of imaging amyloid plaques with magnetic resonance imaging generate the prospect for in vivo imaging of the pathologic substrate of Alzheimer's disease in the future. In order for magnetic resonance modalities to qualify as surrogate markers for early diagnosis and progression of Alzheimer's disease, multicenter longitudinal studies are needed.

Alzheimer Disease↗
PubMed2001

Do studies of wire code and childhood leukemia point towards or away from magnetic fields as the causal agent?

A long-standing point of controversy in the epidemiologic literature concerns the meaning of a wire code-childhood leukemia association for assessing the role of magnetic field exposure. Six studies of wire codes and childhood leukemia in North America were examined, three of which reported positive associations and all of which found some relation between wire codes and measured magnetic fields. Supporting magnetic fields as the basis for the wire code associations are the correspondence between those wire code levels which predict distinct magnetic fields and those which predict leukemia risk in the positive studies. Geographic locations and methods that refine wire codes as magnetic fields predictors also tend to strengthen the association with leukemia. Opposing arguments are based on the failure of the wire code-magnetic field association to predict the strength of association across studies, including the unexplained lack of association between wire codes and leukemia in the Midwest and in Canada. Alternatives to magnetic fields are less supported; residential mobility, social class, and neighborhood characteristics are unlikely to explain a wire code effect. Ambiguity persists because of the modest strength of the wire code-leukemia association, the complexity of the relation between wire codes and magnetic fields, lack of knowledge of risk factors for childhood leukemia, and the limited evaluation of wire code correlates other than magnetic fields.

Canada↗
PubMed2004

Apparent biological effect of strong magnetic field on mosquito egg hatching.

Apparent biological effects of strong magnetic fields were observed in the hatching behavior of fresh mosquito eggs in the center of 9.4 and 14.1 T magnets. In the first experiment performed at 20 +/- 1 degrees C, the hatching was delayed 32 h by a 9.4 T magnetic field and 71 h by a 14.1 T magnetic field. In the second experiment performed at 22 +/- 1 degrees C, the hatching was delayed 14 h by a 9.4 T magnetic field and 27 h by a 14.1 T magnetic field. In the magnetic field range of this study, the hatching delay increases nonlinearly with the intensity of the magnetic field. The experimental results also suggest that the biological effects of magnetic fields could be reversible or partially reversible to some extent.

Animals↗
PubMed2006

Effects of pulsed magnetic stimulation on tumor development and immune functions in mice.

We investigated the effects of pulsed magnetic stimulation on tumor development processes and immune functions in mice. A circular coil (inner diameter = 15 mm, outer diameter = 75 mm) was used in the experiments. Stimulus conditions were pulse width = 238 micros, peak magnetic field = 0.25 T (at the center of the coil), frequency = 25 pulses/s, 1,000 pulses/sample/day and magnetically induced eddy currents in mice = 0.79-1.54 A/m(2). In an animal study, B16-BL6 melanoma model mice were exposed to the pulsed magnetic stimulation for 16 days from the day of injection of cancer cells. A tumor growth study revealed a significant tumor weight decrease in the stimulated group (54% of the sham group). In a cellular study, B16-BL6 cells were also exposed to the magnetic field (1,000 pulses/sample, and eddy currents at the bottom of the dish = 2.36-2.90 A/m(2)); however, the magnetically induced eddy currents had no effect on cell viabilities. Cytokine production in mouse spleens was measured to analyze the immunomodulatory effect after the pulsed magnetic stimulation. tumor necrosis factor (TNF-alpha) production in mouse spleens was significantly activated after the exposure of the stimulus condition described above. These results showed the first evidence of the anti-tumor effect and immunomodulatory effects brought about by the application of repetitive magnetic stimulation and also suggested the possible relationship between anti-tumor effects and the increase of TNF-alpha levels caused by pulsed magnetic stimulation.

Animals↗
PubMed1999

Magnetic Effect on Ion-Exchange Kinetics.

Effects of magnetic exposure on an ion-exchange process are investigated, employing ion-exchange resins. The electrolyte solution, resin suspension, and water are mixed in a container, and the mass transfer coefficient is determined by measuring the change of the ionic concentration in the bulk. Two methods of magnetic exposure are performed: case (1) in which only the electrolyte solution is exposed to the magnetic field and case (2) in which only the resin suspension is exposed to the magnetic field. The following features are found in both cases: (i) the film mass transfer rate reduces by about 5% when the exposure time is greater than 25 min, (ii) the magnetic effect is reduced by adding the alcohol, (iii) the magnetic effect remains for about 3 days but disappears after 6 days, and (iv) the magnetic effect is observable in the solutions of structure-disordering ions, but not in the solutions of structure-ordering ions. As for the temperature dependence, the magnetic effect decreases with temperature in case (1) but it stays constant in case (2). It is postulated that the magnetic effects are attributable to the stabilization of water molecules around the structure-ordering ion and those on the resin surface. Copyright 1999 Academic Press.

Journal Article↗