Nonthermal control of Escherichia coli growth using extremely low frequency electromagnetic (ELF-EM) waves.

BACKGROUND: Escherichia coli (E. coli) bacteria normally live in the intestines of people and animals. Most E. coli are harmless and the treatment of the infection could be achieved by using antibiotics, however the effectiveness is still debatable and needs more investigation. OBJECTIVE: Researching the inhibition resonance frequency of square amplitude modulating waves (QAMW) that can inhibit the growth activity of E. coli and its ability to make division. METHODS: A range of different extremely low frequencies of square amplitude modulated waves (QAMW) from 0.1 to 1.0 Hz from two generators with a constant carrier frequency of 10 MHz, amplitude of 10 Vpp, modulating depth ± 2 Vpp and constant field strength 200 V/m were used to treat E. coli cells at 37 °C. RESULTS: The exposure of E. coli to 0.3 Hz QAMW for 90 min was the most inhibited frequency where the bacterial growth inhibited by 42.3%. Furthermore, a significant increase in antibiotic susceptibility to protein and cell wall inhibitors was investigated. Also, results of the chromosomal DNA sequences, dielectric relaxation and TEM indicated highly significant molecular and morphological changes after the exposure. CONCLUSIONS: We concluded that the exposure of E. coli to QAMW at the inhibiting frequency interfered with the bioelectric signals generated from the bacteria during the cell division and changed the cellular activity and DNA sequences, and these changes lead to a significant inhibition of the bacterial growth. This is a new promising technique that aids to avoid the repetitive use of antibiotics against the bacterial pathogens.

Combination of bacteriolytic therapy with magnetic field for Ehrlich tumour treatment.

Referable to the limited response of the current available cancer treatment modalities, new effective cancer fighting treatments are needed. This work investigates the efficiency of intratumoural injection of Pseudomonas aeruginosa bacteria combined with a local tumour exposure to extremely low frequency square pulsed magnetic field (ELF SPMF) in the mouse Ehrlich tumour. 64 Ehrlich ascites tumour-implanted female albino BALB/C mice were equally split up into 4 groups. Group 1 (GP1) was the positive control group. Group 2 (GP2) received a single intratumoural injection of P. aeruginosa bacteria. Group 3 (GP3) was exposed to ELF SPMF for tumour local exposure. Group 4 (GP4) was treated with P. aeruginosa intratumoural injection followed by local exposure of the tumour to ELF SPMF. Treatment monitoring was evaluated using ultrastructural examination, flow cytometry analysis in addition to the measurement of tumour dielectric properties. Tumour cell apoptosis was obvious in GP2 and GP4, but, with higher severity and percentages in GP2. Tumour biophysical properties revealed a significant increase in static conductivity σS of GP2, and decreases in dielectric increment Δɛ´of both GP2 and GP4 compared to the GP1. Unfortunately, GP2 mice showed severe signs of toxicity. We advocate the utilization of the combination of P. aeruginosa and SPMF to yield the most effective antitumour agent with less bacteria-related toxicity.

Role of duty cycle on Pseudomonas aeruginosa growth inhibition mechanisms by positive electric pulses.

BACKGROUND: P. aeruginosa considered as a notoriously difficult organism to be controlled by antibiotics or disinfectants. The potential use of alternative means as an aid to avoid the wide use of antibiotics against bacteria pathogen has been recently arisen remarkably. OBJECTIVE: Effect of extremely low frequency positive electric pulse with different duty cycles on Pseudomonas aeruginosa (ATCC: 27853) growth by constructed and implemented exposure device was investigated in this study. METHODS: The exposure device was applied to give extremely low frequency in the range of 0.1 up to 20 Hz with the capability to control the duty cycle of each pulse with variation from 10% up to 100%. Growth curves of Pseudomonas aeruginosa were investigated before and after exposure to different frequencies (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 Hz) through measuring the optical density and cell count. Exposures to selected frequencies in the whole ranges of duty cycles were done. These studies were followed by DNA fragmentation, transmission electron microscope (TEM), antibiotic susceptibility tests, and dielectric measurements. RESULTS: Findings revealed inhibition effect by 48.56% and 47.4% together with change in the DNA structural properties for samples exposed to 0.5 Hz and 0.7 Hz respectively. Moreover the data indicated important role of duty cycle on the inhibition mechanism. CONCLUSION: It is concluded that there are two different mechanisms of interaction between positive electric pulse and microorganism occurred; 0.5 Hz caused rupture in cell wall while 0.7 Hz caused denaturation of the inner consistent of the cell.

Solid Ehrlich tumor growth treatment by magnetic waves.

In this work the retardation of Ehrlich tumor growth implanted in mice was studied by employing 4.5 Hz magnetic field. Eighty female Balb/c mice were used, twenty as normal group; the other sixty mice were inoculated with Ehrlich tumor, then they were divided equally into three groups namely A, B and C. Group A (control group) animals were not exposed to the magnetic field. The tumors in the thigh of the animals of group B were exposed to 4.5 Hz, 2 Gauss square wave magnetic field by using a small solenoid connected to a power square wave generator. Group C animals were whole body exposed inside a large solenoid to 4.5 Hz, 2 Gauss square wave magnetic field. Both groups B and C were exposed for a period of 2 weeks at a rate 2 hours per day. Tumor volume, survival period, histological examination and dielectric relaxation of the tumor were measured to investigate the activity of the tumor of the exposed and the unexposed animals. The results indicated that exposing the tumor tissue to 4.5 Hz square wave magnetic field for 2 weeks at a rate 2 hours/day inhibited tumor growth and increased the survival period of the animals. However, group B showed more improvements than did group C. This was attributed to some distortions in the square waveform in the large solenoid (group C). By comparing data from current and previous work, it was concluded that the use of magnetic waves showed better results over previously published work using amplitude modulated electromagnetic waves with the same frequency.

Effect of 50 Hz, 0.2 mT magnetic fields on RBC properties and heart functions of albino rats.

In this work the effect of sinusoidal 50 Hz, 0.2 mT magnetic fields on the red blood cells (RBCs) and heart functions of Albino rats were investigated. Twenty-four male Albino rats were equally divided into four groups, A, B, C, and D. Animals from groups B were continuously exposed to the magnetic field for 15 days; and groups C and D, for 30 days. Group A was used as control. Animals from group D were kept after exposure to the magnetic field for a period of 45 days for delayed effect studies. The osmotic fragility and shape of RBCs' membrane and hemoglobin (Hb) structure tests were carried out for all groups. The dielectric relaxation of Hb molecules was measured in the frequency range of 0.1-10 MHz and the dielectric increment (Deltaepsilon), relaxation time (tau), molecular radius (r), and Cole-Cole parameter (alpha) were calculated for all groups. The ECG was measured for all animals before and after exposure to the magnetic field. The results indicated that exposure of the animals to 50 Hz, 0.2 mT magnetic fields resulted in the decrease of RBCs membrane elasticity and permeability and changes in the molecular structure of Hb. The ECG of the exposed animals was considerably altered. The data also indicated that there was no sign of repair in the newly generated RBCs structure and the ECG after removing the animals from the magnetic field, which indicates that the blood generating system was severely injured. The injuries in the heart of the animals were attributed to the loss of some physiological functions of the RBCs as a result of exposures of the rats to the magnetic field.

Effect of dialysis on erythrocyte membrane of chronically hemodialyzed patients.

The present work examines the role of uremia and the effect of dialysis treatment on red blood cells (RBCs) membrane properties of hemodialysis patients. The results showed that, the uremic patients had a lower values of erythrocyte deformability than that of healthy control subject. The median osmotic fragility (MOF) showed a significant increase in hemodialyzed patients than that for control group. The osmotic resistance to hemolysis was improved after dialysis. The solubilization process of the RBCs membrane showed that the detergent concentration needed to solubilize the RBCs membrane for uremic patient was much higher than that for control group. The abnormalities of the present results for RBCs membrane properties are mostly related to membrane fluidity, which are slightly improved after dialysis. Biochemical analysis showed a decreasing trend in RBCs count, urea nitrogen, creatinine, potassium,