Long-term effects of 900 MHz radiofrequency radiation emitted from mobile phone on testicular tissue and epididymal semen quality

The purpose of this study is to bridge this gap by investigating effects of long term 900?MHz mobile phone exposure on reproductive organs of male rats. The study was carried out on 14 adult Wistar Albino rats by dividing them randomly into two groups (n: 7) as sham group and exposure group. Rats were exposed to 900?MHz radiofrequency (RF) radiation emitted from a GSM signal generator. Point, 1?g and 10?g specific absorption rate (SAR) levels of testis and prostate were found as 0.0623?W/kg, 0.0445?W/kg and 0.0373?W/kg, respectively. The rats in the exposure group were subject to RF radiation 3?h per day (7?d a week) for one year. For the sham group, the same procedure was applied, except the generator was turned off. At the end of the study, epididymal sperm concentration, progressive sperm motility, abnormal sperm rate, all-genital organs weights and testis histopathology were evaluated. Any differences were not observed in sperm motility and concentration (p?>?0.05). However, the morphologically normal spermatozoa rates were found higher in the exposure group (p?p?p?相似文献   

Effect of long-term 50 Hz magnetic field exposure on the micronucleated polychromatic erythrocytes of mice

In recent years extremely low-frequency magnetic fields (ELF-EMF) have become widely used in human activities, leading to an increased chance of exposure to ELF-EMF. There are few reports on in vivo mammalian genotoxic effects using micronucleus (MN) assays, which generally have been used as a short-term screening system. We analyzed the possible genotoxic effect induced by long-term exposure (7, 14, 21, 28?d) of a 50?Hz ELM-MF to mice by measuring the increase in frequency of micronucleated polychromatic erythrocyte in their bone marrow (MNPCEs) and we compared it with that induced by 50?cGy of X-rays. Subsequently, we tried to reduce this chromosomal damage by administering four antioxidants substances with radioprotective capacities: dimethyl sulfoxide (DMSO), 6-n-propyl-2-thiouracil (PTU), grape-procyanidins (P) and citrus flavonoids extract (CE). The increase in micronucleated cells was higher in both physical treatments (Control?p?p?>?0.001)); however, the antioxidant substances only showed a genoprotective capacity against the damage induced by ionizing radiation (Ci?>?PTU?=?DMSO (p?P?=?CE (p?相似文献   

Effects of 837 and 1950 MHz radiofrequency radiation exposure alone or combined on oxidative stress in MCF10A cells

The aim of this study was to determine whether the exposure to either single or multiple radio‐frequency (RF) radiation frequencies could induce oxidative stress in cell cultures. Exposures of human MCF10A mammary epithelial cells to either a single frequency (837 MHz alone or 1950 MHz alone) or multiple frequencies (837 and 1950 MHz) were conducted at specific absorption rate (SAR) values of 4 W/kg for 2 h. During the exposure period, the temperature in the exposure chamber was maintained isothermally. Intracellular levels of reactive oxygen species (ROS), the antioxidant enzyme activity of superoxide dismutase (SOD), and the ratio of reduced/oxidized glutathione (GSH/GSSG) showed no statistically significant alterations as the result of either single or multiple RF radiation exposures. In contrast, ionizing radiation‐exposed cells, used as a positive control, showed evident changes in all measured biological endpoints. These results indicate that single or multiple RF radiation exposure did not elicit oxidative stress in MCF10A cells under our exposure conditions. Bioelectromagnetics 33:604–611, 2012. © 2012 Wiley Periodicals, Inc.     

Effect of γ radiation on physiological parameters of the ethanolic fermentation

This work examines the efficacy of radiation in reducing the viability of certain contaminating bacteria of sugar-cane must and the consequential beneficial effect of lethal doses of radiation on some physiological parameters of the yeast-based ethanolic fermentation. The must from sugar-cane juice was inoculated with different bacteria that usually contaminate the must in the production facilities: Bacillus and Lactobacillus. The contaminated must was irradiated at 2.0, 4.0, 6.0, 8.0 and 10.0 kGy of gamma radiation. The population density of the bacteria in the irradiated must was recorded. Ethanolic fermentation by yeast (Saccharomyces cerevisiae) was carried out and the total acidity, the volatile acidity and the organic acids (lactic and acetic) produced during the fermentation were determined. The ethanol yield was also recorded. The treatment with radiation reduced the population of the contaminating microorganisms of the sugar-cane must. The acidity and the organic acids (lactic and acetic) produced during the fermentation decreased as the dose of radiation applied to the must increased. It is concluded that irradiation was efficient in decontaminating the sugar-cane must and improved the biochemical parameters of the ethanolic fermentation, including the ethanol yield by 2%.     

Effect of peptidyltransferase inhibitors on ribonuclease P activity from Dictyostelium discoideum – Effect of antibiotics on RNase P

The effect of several peptidyltransferase inhibitors on ribonuclease P activity from Dictyostelium discoideum was investigated. Among the inhibitors tested puromycin, amicetin and blasticidin S revealed a dose-dependent inhibition of tRNA maturation. Blasticidin S and amicetin do not compete with puromycin for the same site on the enzyme, suggesting the existence of distinct antibiotic binding sites on D. discoideum RNase P. Inhibition experiments further indicate that binding sites for blasticidin S and amicetin overlap.     

Effect of volatiles emitted from wilted Populus nigra L. leaves on the mating and oviposition of Helicoverpa armigera (Hübner)

Wilted black poplar, Populus nigra ‘Italica’ L., leaves are very attractive to a vast number of noctuid moth species. This provides an opportunity for the development of effective trapping methods for the integrated management of pest species, such as Helicoverpa armigera, a major global and economically important insect pest.In the present study, we investigated the (1) nocturnal attraction patterns of H. armigera males and females to wilted P. nigra leaves; (2) effects of P. nigra volatiles on the mate-searching behavior of males through laboratory serial-chamber bioassays and field trapping; and (3) effects of P. nigra volatiles on the ovipositional choice and reproductive performance of females. Females and males, when tested alone, could be attracted by wilted P. nigra leaves, and the time periods of the first two attraction peaks were largely overlapped between sexes. Streams consisting of wilted P. nigra leaves and virgin females were not more attractive than virgin females alone, regardless of the stream sequence in a serial chamber. However, a stream of virgin females passed through wilted P. nigra leaves was more attractive than wilted P. nigra leaves alone. The addition of P. nigra extracts and its major aromatic components to the sex lure of H. armigera did not attract more moths than the sex lure alone. The volatiles from wilted P. nigra leaves were significantly more attractive to ovipositing females than those from cotton, tomato, and corn leaves, but equally attractive to tobacco leaves. Females exposed to volatiles from different leaves (P. nigra, cotton, and tobacco) showed similar fecundities. In summary, the attraction of moths to wilted P. nigra leaves may be attributable to multiple mechanisms, including the adsorption of sex pheromones, ovipostional attraction, and possible feeding attraction.     

Effect of TNFα on osteoblastogenesis from mesenchymal stem cells

Background

Bone destruction and osteoporosis are accelerated in chronic inflammatory diseases, such as rheumatoid arthritis (RA) and periodontitis, in which many studies have shown the proinflammatory cytokines, especially TNFα, play an important role; TNFα causes osteoclast-induced bone destruction as well as the inhibition of osteoblastogenesis.

Scope of review

Here we review our current understanding of the mechanism of the effect of TNFα on osteoblastogenesis from mesenchymal stem cells (MSCs). We also highlight the function of MSC in the pathogenesis of autoimmune diseases.

Major conclusions

Many studies have revealed that TNFα inhibits osteoblastogenesis through several mechanisms. On the other hand, it has been also reported that TNFα promotes osteoblastogenesis. These discrepancies may depend on the cellular types, the model animals, and the timing and duration of TNFα administration.

General significance

A full understanding of the role and function of TNFα on osteoblastogenesis from MSC may lead to targeted new therapies for chronic inflammation diseases, such as RA and periodontitis.     

The Lack of Toxic Effect of High-Power Short-Pulse 101 GHz Millimeter Waves on Healthy Mice

Irradiation of cancer cells by non-ionizing millimeter waves (MMW) causes increased cell mortality. We examined if MMW have toxic effects on healthy mice. To that end, the skin of healthy C57BL/6 mice was irradiated locally at the right flank with 101 GHz MMW in a pulsed (5–10 µs) regime using a free electron laser. Irradiation was performed in a dose-dependent manner, with 20–50 pulses and a power range of 0.5–1.5 kW. Physical, physiological, and pathological parameters as well as behavior were examined before and after irradiation. Our results showed that all parameters were within normal range for all experimental mice groups and for the control group. No significant changes were noted in the physical, physiological, or behavioral status of the mice following irradiation as compared with the control group. In addition, no significant changes were found in locomotor, exploratory behavior, or anxiety of the irradiated mice and no pathological changes were noted following the hematological and biochemical blood analysis. Our results indicate that irradiation of healthy mice with MMW does not cause any general toxic effects. Bioelectromagnetics. © 2020 Bioelectromagnetics Society.     

Effect of cobalt-60 (γ radiation) on multidrug-resistant multiple myeloma cell lines

Emergence of resistance to chemotherapy and radiotherapy is a major obstacle for the successful treatment of MM (multiple myeloma). Prednisone, vincristine and melphalan are commonly used chemotherapeutic agents for the treatment of MM. In the current study, we examined the presence of possible cross-resistance between these drugs and gamma (γ) radiation. Prednisone, vincristine and melphalan resistant RPMI-8226 and U-266 MM cells were generated by stepwise increasing concentrations of the drugs. The sensitive and resistant cells were exposed to 200- and 800 cGy γ radiation, and proliferation was examined by XTT {2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide} assay. The results showed that Prednisone- and melphalan-resistant RPMI-8226 cells were also cross-resistant to 200 and 800 cGy γ radiation application, while vincristine-resistant cells did not show resistance. On the other hand, Prednisone-, vincristine- and melphalan-resistant U-266 cells showed cross-resistance to 200- and 800 cGy γ radiation application. These results demonstrated that MM cells resistant to anticancer agents respond to radiation in different levels. These findings may be important in the clinical applications of radiation therapy in the treatment of vincristine resistant MM.     

Effect of immobilization on stability and properties of N-acetyl-β-d-hexosaminidase from Turbo cornutus

A mixture of glycosidases from the liver of the gastropod Turbo cornutus was co-immobilized with bovine serum albumin and glutaraldehyde, and then cast as membranes. The properties of immobilized N-acetyl-β-d-hexosaminidase were studied. The recovery of N-acetyl-β-d-hexosaminidase after immobilization was unaffected by increasing the concentration of glutaraldehyde, but was decreased by increasing the bovine serum albumin concentration. The immobilized enzyme showed enhanced resistance towards proteolytic and thermal inactivation. While the pH optimum for the soluble enzyme was 4.0, a bimodal pH curve with optima at 3.4 and 5.0 was observed after insolubilization. This bimodality was abolished when the immobilized enzyme was assayed in the presence of M NaCl. The K_m values, for p-nitrophenyl 2-acetamido-2-deoxy-β-d-glucopyranoside, of the immobilized isoenzymes of N-acetyl-β-d-hexosaminidase were larger than those of their soluble counterparts. No loss of activity could be detected in the membrane after using it for 24 consecutive assays or after storage for at least 50 days at 4°.     

Effect of temperature on some characteristics of the thermostable α-amylase from Bacillus licheniformis

The V _max of an extracellular, thermostable -amylase from Bacillus licheniformis 44MB82 were 5.70×10^-3 and 9.70×10^-3 mM s^-1 at 30 and 90°C, respectively, whereas the K _m values were similar (0.9 mg ml^-1) at both temperatures. Excluding dextrins, the dominant products from soluble starch and amylopectin hydrolysis contained less than six glucose residues. The enzyme hydrolysed amylopectin better than soluble starch. Increasing the temperature from 30 to 90°C was accompanied by an increase in the production of malto-oligosaccharides, especially maltotetrose, and this was related to the secondary hydrolysis of maltopentose and maltohexose.The authors are with the Institute of Microbiology, Bulgarian Academy of Sciences, Sofia 1113. 26 Academician G. Bonchev, Bulgaria     

Effect of zinc salts on the structure–function of actomyosin from pelagic fish

The effect of zinc salts, zinc chloride and zinc sulfate on the structure and ATPase enzyme activity of actomyosin from pelagic fish (Sardinella longiceps) has been investigated. ATPase enzyme activity decreased in the presence of both the zinc salts. The inhibitory effect is present in both pH of 7.0 and 9.0. At concentration of 1 × 10^?3 M of zinc salts, complete inhibition of ATPase enzyme activity is observed. With the increase in temperature from 25 °C to 45 °C the ATPase activity decreased by nearly 80%. The solubility profile of actomyosin in the presence of zinc salts shows a sigmoid pattern as the concentration of both the zinc salts increases. Free SH content of actomyosin decreased with the increase in concentration of zinc salts. Intrinsic fluorescence indicated significant decrease in relative fluorescence intensity of actomyosin. This indicates significant alterations in the structure of actomyosin. Analysis of secondary structure also indicates significant alteration in the α-helical content upon binding of both zinc salts.     

Effect of glutaraldehyde on oligosaccharide production by β-galactosidase from Bacillus circulans

Summary The oligosaccharide-producing activity of -galactosidase-1, one of the isomers of -galactosidase (-d-galactoside galactohydrolase, EC 3.2.1.23) from Bacillus circulans was changed after immobilization onto porous silica gel (Merckogel) by crosslinkage with glutaraldehyde. The reason for this modification was studied by treating the free enzyme with glutaraldehyde. Glutaraldehyde of 0.025% to 3% modified 40% to 90% of the free amino groups with or without intermolecular crosslinking. The maximum yield of oligosaccharides increased from 12% to 40% depending upon degree of modification, while native enzyme gave only 6% trisaccharides during hydrolysis of 127 mM lactose. The K _m value for the enzyme treated with glutaraldehyde was also increased.     

Design and Dosimetric Analysis of an Exposure Facility for Investigating Possible Effects of 2.45 GHz Wi-Fi Signals on Human Sleep

A new head exposure system for double-blind provocation studies investigating possible effects of 2.45 GHz Wi-Fi exposure on human sleep was developed and dosimetrically analyzed. The exposure system includes six simultaneously radiating directional antennas arranged along a circle (radius 0.6 m) around the test subject's head, and enables a virtually uniform head exposure, i.e. without any preferred direction of incidence, during sleep. The system is fully computer-controlled and applies a real wireless local area network (WLAN) signal representing different transmission patterns as expected in real WLAN scenarios, i.e. phases of “beacon only” as well as phases of different data transmission rates. Sham and verum are applied in a double-blind crossover study design and all relevant exposure data, i.e. forward and reverse power at all six antenna inputs, are continuously recorded for quality control. For a total antenna input power (sum of all antennas) of 220 mW, typical specific absorption rate (SAR) in cortical brain regions is approximately 1–2 mW/kg (mass average SAR over respective brain region), which can be seen as a realistic worst-case exposure level in real WLAN scenarios. Taking into account variations of head positions during the experiments, the resulting exposure of different brain regions may deviate from the given average SAR levels up to 10 dB. Peak spatial 10 g average SAR in all brain and all head tissues is between 1.5–3.5 and 10.4–25 mW/kg, respectively. Bioelectromagnetics. © 2020 Bioelectromagnetics Society.     

Effect of pH on transfructosylation and hydrolysis by β-fructofuranosidase from Aspergillus oryzae

 β-Fructofuranosidase was purified from commercial alkaline protease (Aspergillus oryzae origin). The optimal pH of its transfructosylating activity was more alkaline (pH 8) than that of its hydrolyzing activity (pH 5). In the case of a 24-h reaction with sucrose, the hydrolysis and transfructosylation reaction were optimal at pH 4–5 and pH 8, respectively. In the reaction at pH 8 1-kestose and nystose were the main fructooligosaccharides produced. The transfer ratio was hardly different between pH 5 and pH 8 early in the reaction, but the transfer products (1-kestose and nystose) were decreased at pH 5 as the reaction proceeded because of their hydrolysis. Received: 18 January 1995/Received last revision: 23 August 1995/Accepted: 13 September 1995     

Effect of peripheral nerve on the neurite growth from retinal explants in culture

The effect of peripheral nerve (PN) on neurite outgrowth from retinal explants of adult hamsters was examined.Cultures of retinal explants,and co-cultures of retinal explants and PN were performed using chick retinal basement memebrane (BM) as substrate.The presence of PN increases the number and length of neurite outgrowth.In addition,a high proportion of neurites situated close to PN tend to grow towards it.Since there was no contact between retinal explants and PN,we suggest that PN might secete diffusible substances to attract the neurites to grow towards it.