Changes in cell death of peripheral blood lymphocytes isolated from children with acute lymphoblastic leukemia upon stimulation with 7 Hz, 30 mT pulsed electromagnetic field.

Pulsed electromagnetic field (PEMF) influenced the viability of proliferating in vitro peripheral blood mononuclear cells (PBMCs) isolated from Crohn's disease patients as well as acute myeloblastic leukemia (AML) patients by induction of cell death, but did not cause any vital changes in cells from healthy donors. Experiments with lymphoid U937 and monocytic MonoMac6 cell lines have shown a protective effect of PEMF on the death process in cells treated with death inducers. The aim of the current study was to investigate the influence of PEMF on native proliferating leukocytes originating from newly diagnosed acute lymphoblastic leukemia (ALL) patients. The effects of exposure to PEMF were studied in PBMCs from 20 children with ALL. PBMCs were stimulated with three doses of PEMF (7 Hz, 30 mT) for 4 h each with 24 h intervals. After the last stimulation, the cells were double stained with annexin V and propidium iodide dye to estimate viability by flow cytometric analysis. The results indicated an increase of annexin V positive as well as double stained annexin V and propidium iodide positive cells after exposure to threefold PEMF stimulation. A low-frequency pulsed electromagnetic field induces cell death in native proliferating cells isolated from ALL patients. The increased vulnerability of proliferating PBMCs to PEMF-induced interactions may be potentially applied in the therapy of ALL. The analysis of expression of apoptosis-related genes revealed changes in mRNA of some genes engaged in the intrinsic apoptotic pathway belonging to the Bcl-2 family and the pathway with apoptosis-inducing factor (AIF) abundance upon PEMF stimulation of PBMCs.

[Electric activity of vagus nerve in rats according to satiety]. / Aktywnosc elektryczna nerwu blednego u szczurów w zaleznosci od stopnia sytosci.

Vagus nerve as a part of brain-gut axis transmits peripheral information to the brain via vagovagal reflexes. Electric properties of the vagus are not exactly known. Analysis of electric changes in vagal nerves evoked by physiologic impulse such as stomach distention by food would facilitate applying better documented and therefore safer vagal neuromodulation. The aim of our study was analysis and interpretation of electric properties of the left vagus in vivo in fasted and satiated Wistar rats. Silver measuring electrodes connected to analog amplifier (A-M Systems 3000) were attached to the nerve in the neck region. The signal was filtered and probing by computer recording system (ADInstruments Power Lab) and additional analyses were performed using GNU Octave programme. Our resuts have shown that the higher amplitude the smaller number of counted impulses in the vagus was detected. This relationship was true only till the maximum level typical for each recording (about 15-20 dB). We note that observed inter spike interval can be approximated with log-normal distribution, and that its mu parameter is enough to characterize a particular recording. Satiated rats were characterized by higher number of spikes per second in the nerve than fasted ones (0.9 vs 0.26) indicating that food intake increased nervous activity 3-4 times comparing to fasted state. The outcomes encourage us to state that good quality characteristic of the left vagus nerve activity provides an effective tool for detection of peripheral signals which are transmitting via vagal afferents to the higher centres. Target vagal neuromodulation to obtain certain terapeutic effects may be possible.

Magnetically induced vagal nerve stimulation and food intake and body mass in growing rats.

Electrostimulation of vagal nerve (VNS) by microchip (MC) with magnetic field energy supply may "mimic" the physiological output associated with gastric mechanoreceptors activation by food and lead to decrease in food intake and subsequently decrease in weight gain. Vago-vagal reflexes in growing animals seems to be mainly responsible for meal size regulation and other compensatory (hormonal or neural) mechanisms prevent from decrease in body mass.

Pulsating electromagnetic field induces apoptosis of rat's bowel Cajal's cells.

UNLABELLED: We previously have shown that pulsating electromagnetic field (PEMF) reduce expression of interstitial cells of Cajal (ICCs) in the rat gastrointestinal tract. Aim of present study was to determine whether diminished expression of ICCs in the rat's bowel after PEMF exposure was related to apoptosis and to PEMF dose. METHODS: rats were divided into two groups (n= 32). First group (n = 16) was exposed to four rising doses of PEMF from one dose 12.5 x 10(3) A(2) x h/m(2) to four doses 50 x 10(3) A(2) x h/m(2). Second group (n = 16) served as a control. Tissue samples of the rat duodenum and colon from exposed to PEMF and control animals were fixed and paraffin embedded and cryostat frozen. The tangential paraffin bowel sections were stained with anti c-Kit antibody. C-Kit positive cells were assessed by image analysis. Apoptosis detection in rat's tissues was performed with rabbit polyclonal anti-Bax antibody. RESULTS: the surface of c-Kit immunopositive cells decreased in the duodenum and colon of rats stimulated with PEMF in a dose dependent manner with increase in expression of pro-apoptotic Bax protein in c-Kit immunopositive myenteric cells. The apoptosis - inducing action of PEMF on the c-Kit immunoreactivity of Cajal's cells suggests a possible therapeutical implications in diseases associated with overactive smooth muscles dysfunction. Pulsating electromagnetic field (PEMF) induced changed immunoreactivity in rat's myenteric Cajal cells. C-Kit diminished reactivity of ICCs was proved to be caused by triggering of apoptotic pathwa in ICCs upon PEMF stimulation. PEMF generated apoptosis was dependant on applied dose of PEMF and detected by immunostaining with antibody against proapoptic protein Bax.

[Microchip neuromodulation of the autonomic system with magnetic field energy supply]. / Neuromodulacja czynnosci wegetatywnych z uzyciem neurowszczepów zasilanych polem magnetycznym.

We describe technical solution of the problem MC magnetic field energy supply showing that system is effective in the neuromodulation of the vagal activity associated with food intake. Effect of MC on decrease of food intake were related to strength of the magnetic field (19-350).

Effects of vagal pacing on food intake and body mass in pigs.

UNLABELLED: In obesity patients inexpensive, non-invasive, low risk treatment remains a holy grail. The purpose of this study was to evaluate effect of long term and low frequency vagal pacing on feeding behavior in pigs. METHODS: Two groups of animals were investigated, first control with sham operation and second group with microchip (MC) on both vagal nerves placed laparoscopically. In both groups EGG was performed before and after MC implantation. Parameters of stimulation were stable (amplitude 170 mV, frequency 1 Hz, impulse duration 170 ms). RESULTS: MC group demonstrated continuous decrease in body weight gain during 8 weeks of experiment at average of 3.73 +/- 0.5 vs. 4.83 +/- 1.1 (p < 0.05). Food intake also decreased in MC group and was 16.38 +/- 1.3 vs. control 17.5 +/- 1.7 kg/w (ns). EGG recording showed decreased percent normogastria in MC group 26.66 +/- 10 vs. 76.2 +/- 16 (p < 0.05) mostly at cost of tachygastria 62.3 +/- 15 vs. 35.4 +/- 16% of the recording time. CONCLUSION: MC vagal pacing mostly decreased body weight being without significant influence on food intake causing gastric dysrhythmia.