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1.
Clinics ; 66(7): 1237-1245, 2011. ilus
Artigo em Inglês | LILACS | ID: lil-596915

RESUMO

INTRODUCTION: Environmental exposure to man-made electromagnetic fields has been steadily increasing with the growing demand for electronic items that are operational at various frequencies. Testicular function is particularly susceptible to radiation emitted by electromagnetic fields. OBJECTIVES: This study aimed to examine the therapeutic effects of a pulsed electromagnetic field (100 Hz) on the reproductive systems of male Wistar rats (70 days old). METHODS: The experiments were divided into five groups: microwave sham, microwave exposure (2.45 GHz), pulsed electromagnetic field sham, pulsed electromagnetic field (100 Hz) exposure, and microwave/pulsed electromagnetic field exposure. The animals were exposed for 2 hours/day for 60 days. After exposure, the animals were sacrificed, their sperm was used for creatine and caspase assays, and their serum was used for melatonin and testosterone assays. RESULTS: The results showed significant increases in caspase and creatine kinase and significant decreases in testosterone and melatonin in the exposed groups. This finding emphasizes that reactive oxygen species (a potential inducer of cancer) are the primary cause of DNA damage. However, pulsed electromagnetic field exposure relieves the effect of microwave exposure by inducing Faraday currents. CONCLUSIONS: Electromagnetic fields are recognized as hazards that affect testicular function by generating reactive oxygen species and reduce the bioavailability of androgen to maturing spermatozoa. Thus, microwave exposure adversely affects male fertility, whereas pulsed electromagnetic field therapy is a non-invasive, simple technique that can be used as a scavenger agent to combat oxidative stress.


Assuntos
Animais , Masculino , Ratos , Magnetoterapia/efeitos adversos , Micro-Ondas/efeitos adversos , Testículo/efeitos da radiação , Apoptose/efeitos da radiação , Biomarcadores/análise , /análise , Creatina Quinase/análise , Infertilidade Masculina/etiologia , Melatonina/análise , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Espécies Reativas de Oxigênio/efeitos da radiação , Fatores de Tempo , Testosterona/análise
2.
Indian J Exp Biol ; 2010 Oct; 48(10): 1008-1019
Artigo em Inglês | IMSEAR | ID: sea-145059

RESUMO

The scientific basis of nanotechnology as envisaged from the first principles is compared to bulk behavior. Development of nanoparticles having controllable physical and electronic properties has opened up possibility of designing artificial solids. Top down and bottom up approaches are emphasized. The role of nanoparticle (quantum dots) application in nanophotonics (photovoltaic cell), and drug delivery vehicle is discussed. Fundamentals of DNA structure as the prime site in bionanotechnological manipulations is also discussed. A summary of presently available devices and applications are presented.

3.
Indian J Exp Biol ; 2010 Oct; 48(10): 987-992
Artigo em Inglês | IMSEAR | ID: sea-145056

RESUMO

A significant decrease in protein kinase C and total sperm count along with increased apoptosis were observed in male Wistar rats exposed to mobile phone frequencies (2 h/day × 35 days at 0.9 W/kg specific absorption rate). The results suggest that a reduction in protein kinase activity may be related to overproduction of reactive oxygen species (ROS) under microwave field exposure. Decrease in sperm count and an increase in apoptosis may be causative factor due to mobile radiation exposure leading to infertility.

4.
Indian J Exp Biol ; 2010 Oct; 48(10): 982-986
Artigo em Inglês | IMSEAR | ID: sea-145055

RESUMO

Chronic (2h/d × 8 weeks) exposure to magnetic field (MF; 50 Hz, 17.9 T) in complete spinal cord (T13) transected rats restored food intake (FI), water intake (WI) and body weight (BW) which were decreased in the spinal cord injured rats. The results suggest a significant beneficial effect of chronic exposure to magnetic field of paraplegic rats.

5.
Indian J Exp Biol ; 2010 Oct; 48(10): 959-981
Artigo em Inglês | IMSEAR | ID: sea-145054

RESUMO

Existence of low level electromagnetic fields in the environment has been known since antiquity and their biological implications are noted for several decades. As such dosimetry of such field parameters and their emissions from various sources of mass utilization has been a subject of constant concern. Recent advancement in mobile communications has also drawn attention to their biological effects. Hand held children and adults alike generally use mobile sources as cordless phones in various positions with respect to the body. Further, an increasing number of mobile communication base stations have led to wide ranging concern about possible health effects of radiofrequency emissions. There are two distinct possibilities by which health could be affected as a result of radio frequency field exposure. These are thermal effects caused by holding mobile phones close to the body and extended conversations over a long period of time. Secondly, there could be possibly non thermal effects from both phones and base stations whereby the affects could also be cumulative. Some people may be adversely affected by the environmental impact of mobile phone base stations situated near their homes, schools or any other place. In addition to mobile phones, appliances like microwave oven etc are also in increasing use. Apart from the controversy over the possible health effects due to the non-thermal effect of electromagnetic fields the electromagnetic interaction of portable radio waves with human head needs to be quantitatively evaluated. Relating to this is the criteria of safe exposure to the population at large. While a lot of efforts have gone into resolving the issue, a clear picture has yet to emerge. Recent advances and the problems relating to the safety criteria are discussed.

6.
Indian J Exp Biol ; 2010 June; 48(6): 586-592
Artigo em Inglês | IMSEAR | ID: sea-145011

RESUMO

Wistar rats (70 days old) were exposed for 2 h a day for 45 days continuously at 10 GHz [power density 0.214 mW/cm2, specific absorption rate (SAR) 0.014 W/kg] and 50 GHz (power density 0.86 μW/cm2, SAR 8.0 ×10-4 W/kg). Micronuclei (MN), reactive oxygen species (ROS), and antioxidant enzymes activity were estimated in the blood cells and serum. These radiations induce micronuclei formation and significant increase in ROS production. Significant changes in the level of serum glutathione peroxidase, superoxide dismutase and catalase were observed in exposed group as compared with control group. It is concluded that microwave exposure can be affective at genetic level. This may be an indication of tumor promotion, which comes through the overproduction of reactive oxygen species.

7.
Artigo em Inglês | IMSEAR | ID: sea-135943

RESUMO

Background & objectives: Postmenopausal osteoporosis leads to a significant decline in bone mass. That complicates the treatment outcome. The objective of the present study was to find out the effects of pulsed modulated low level electric field capacitively coupled on bone histology of induced osteoporotic rats, for screening the potential therapy for osteoporosis. Methods: Osteopororosis was induced by performed by bilateral ovariectomy of female Wistar rats. After one month of surgery electric field stimulation was delivered to one leg of experimatal rats while the other was sham exposed. After 60 days of exposure treated rats were sacrificed and femur and tibia bones were segregated into (i) control (CON), (ii) ovariectomized (OVX) and (iii) ovariectomized + electrical stimulation (OVX+ES). Results: Histopathological analyses showed that capacitively coupled pulsed electric field exposure treatment augmented and restored the bone marrow cell population. Immunohistological localization of alkaline phosphatase (ALP) showed the increased activity of this enzyme after electrostimulation, which showed an enhanced osteoblast differentiation. Collagen histochemistry showed high amount of collagen fiber in exposed rats bones than that of osteoporotic bones. Electron microscopic study revealed the enhancement of microstructural composition and compactness in cortical and trabecular part of treated bones. Interpretation & conclusions: Our results suggest that capacitively coupled pulsed electric field exposure treatment of specified parameters is efficacious in attenuating the effects of ovariectomy induced osteoporosis and restore the bone loss.


Assuntos
Fosfatase Alcalina/metabolismo , Animais , Células da Medula Óssea/patologia , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Colágeno/metabolismo , Modelos Animais de Doenças , Terapia por Estimulação Elétrica/métodos , Feminino , Humanos , Osteoporose/metabolismo , Osteoporose/patologia , Osteoporose/terapia , Ovariectomia , Ratos , Ratos Wistar
8.
Indian J Exp Biol ; 2003 Jun; 41(6): 581-6
Artigo em Inglês | IMSEAR | ID: sea-59382

RESUMO

Effect of modulated pulsed electromagnetic fields (PEMFs; carrier frequency, 14 MHz. modulated at 16 Hz of amplitude 10 V peak to peak) on sciatic neurectomy induced osteoporosis in rat femur and tibia resulted in statistically significant increase in bone mineral density, and deceleration in bone resorption process and consequently further osteoporosis in rat bone. These results suggest that such an effective window of pulsed radio frequency fields may be used therapeutically for the treatment of osteoporosis.


Assuntos
Absorciometria de Fóton , Animais , Osso e Ossos/efeitos da radiação , Masculino , Osteoporose/etiologia , Ondas de Rádio , Ratos , Ratos Wistar
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