A novel microcurrent dressing for wound healing in a rat skin defect model.

BACKGROUND: The exogenous application of low-intensity electric stimulation (ES) may mimic a natural endogenous bioelectric current and accelerate the repair process of skin wounds. This study designed a novel microcurrent dressing (MCD) and evaluated its potential effects on wound healing in a rat skin defect model. METHODS: First, wireless ES was integrated into a medical cotton cushion to fabricate the MCD, and its electrical property was examined by using a universal power meter. Then, animal experiments were conducted to evaluate the MCD's effect. Forty-five rats were randomized into control (Con) group, Vaseline gauze (VG) group and MCD group. A full-thickness round skin incision 1.5 cm in diameter was made on the back of each animal. Apart from routine disinfection, the Con rats were untreated, whereas the other two groups were treated with VG or MCD. On days 3, 7 and 14 post injury, the wound areas were observed and measured using image analysis software following photography, and the skin samples were harvested from wound tissue. Then, histopathological morphology was observed routinely by hematoxylin and eosin (HE) staining; tumor necrosis factor α (TNF-α) and interleukin (IL)-1ß expression were detected by Western blotting. Vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) expression were detected with immunohistochemistry. RESULTS: The MCD generated a sf electric potential greater than 0.95 V. Animal experiments showed that the wound-healing rate in the MCD group was significantly increased compared with the Con and VG groups (P < 0.05 or P < 0.01). Histopathological observation revealed an alleviated inflammatory response, induced vascular proliferation and accelerated epithelization in the MCD group. Moreover, samples from the MCD group expressed reduced TNF-α and IL-1ß levels and increased VEGF and EGF levels compared with those of the other two groups (P < 0.05 or P < 0.01). However, no significant difference was noted between the Con and VG groups at each time point. CONCLUSIONS: The MCD generates a stable and lasting ES and significantly promotes wound healing by reducing inflammation duration and increasing growth factors expression. Thus, MCD may act as a promising biomaterial device for skin wound healing.

Behavioral Abnormality along with NMDAR-related CREB Suppression in Rat Hippocampus after Shortwave Exposure.

OBJECTIVE: To estimate the detrimental effects of shortwave exposure on rat hippocampal structure and function and explore the underlying mechanisms. METHODS: One hundred Wistar rats were randomly divided into four groups (25 rats per group) and exposed to 27 MHz continuous shortwave at a power density of 5, 10, or 30 mW/cm2 for 6 min once only or underwent sham exposure for the control. The spatial learning and memory, electroencephalogram (EEG), hippocampal structure and Nissl bodies were analysed. Furthermore, the expressions of N-methyl-D-aspartate receptor (NMDAR) subunits (NR1, NR2A, and NR2B), cAMP responsive element-binding protein (CREB) and phosphorylated CREB (p-CREB) in hippocampal tissue were analysed on 1, 7, and 14 days after exposure. RESULTS: The rats in the 10 and 30 mW/cm2 groups had poor learning and memory, disrupted EEG oscillations, and injured hippocampal structures, including hippocampal neurons degeneration, mitochondria cavitation and blood capillaries swelling. The Nissl body content was also reduced in the exposure groups. Moreover, the hippocampal tissue in the 30 mW/cm2 group had increased expressions of NR2A and NR2B and decreased levels of CREB and p-CREB. CONCLUSION: Shortwave exposure (27 MHz, with an average power density of 10 and 30 mW/cm2) impaired rats' spatial learning and memory and caused a series of dose-dependent pathophysiological changes. Moreover, NMDAR-related CREB pathway suppression might be involved in shortwave-induced structural and functional impairments in the rat hippocampus.

Microwave-induced Apoptosis and Cytotoxicity of NK Cells through ERK1/2 Signaling.

OBJECTIVE: To investigate microwave-induced morphological and functional injury of natural killer (NK) cells and uncover their mechanisms. METHODS: NK-92 cells were exposed to 10, 30, and 50 mW/cm2 microwaves for 5 min. Ultrastructural changes, cellular apoptosis and cell cycle regulation were detected at 1 h and 24 h after exposure. Cytotoxic activity was assayed at 1 h after exposure, while perforin and NKG2D expression were detected at 1 h, 6 h, and 12 h after exposure. To clarify the mechanisms, phosphorylated ERK (p-ERK) was detected at 1 h after exposure. Moreover, microwave-induced cellular apoptosis and cell cycle regulation were analyzed after blockade of ERK signaling by using U0126. RESULTS: Microwave-induced morphological and ultrastructural injury, dose-dependent apoptosis (P < 0.001) and cell cycle arrest (P < 0.001) were detected at 1 h after microwave exposure. Moreover, significant apoptosis was still detected at 24 h after 50 mW/cm2 microwave exposure (P < 0.01). In the 30 mW/cm2 microwave exposure model, microwaves impaired the cytotoxic activity of NK-92 cells at 1 h and down regulated perforin protein both at 1 h and 6 h after exposure (P < 0.05). Furthermore, p-ERK was down regulated at 1 h after exposure (P < 0.05), while ERK blockade significantly promoted microwave-induced apoptosis (P < 0.05) and downregulation of perforin (P < 0.01). CONCLUSION: Microwave dose-dependently induced morphological and functional injury in NK-92 cells, possibly through ERK-mediated regulation of apoptosis and perforin expression.

Real-time Assessment of Cytosolic, Mitochondrial, and Nuclear Calcium Levels Change in Rat Pheochromocytoma Cells during Pulsed Microwave Exposure Using a Genetically Encoded Calcium Indicator.

Little information is available about the effects of exposure to pulsed microwaves on neuronal Ca2+ signaling under non-thermal conditions. In this study, rat pheochromocytoma (PC12) cells were exposed to pulsed microwaves for 6 min at a specific absorption rate (SAR) of 4 W/kg to assess possible real-time effects. During microwave exposure, free calcium dynamics in the cytosol, mitochondria, and nucleus of cells were monitored by time-lapse microfluorimetry using a genetically encoded calcium indicator (ratiometric-pericam, ratiometric-pericam-mt, and ratiometric-pericam-nu). We established a waveguide-based real-time microwave exposure system under accurately controlled environmental and dosimetric conditions and found no significant changes in the cytosolic, mitochondrial, or nuclear calcium levels in PC12 cells. These findings suggest that no dynamic changes occurred in [Ca2+]c, [Ca2+]m, or [Ca2+]n of PC12 cells at the non-thermal level.

Identification of a Novel Rat NR2B Subunit Gene Promoter Region Variant and Its Association with Microwave-Induced Neuron Impairment.

Microwave radiation has been implicated in cognitive dysfunction and neuronal injury in animal models and in human investigations; however, the mechanism of these effects is unclear. In this study, single nucleotide polymorphism (SNP) sites in the rat GRIN2B promoter region were screened. The associations of these SNPs with microwave-induced rat brain dysfunction and with rat pheochromocytoma-12 (PC12) cell function were investigated. Wistar rats (n = 160) were exposed to microwave radiation (30 mW/cm(2) for 5 min/day, 5 days/week, over a period of 2 months). Screening of the GRIN2B promoter region revealed a stable C-to-T variant at nucleotide position -217 that was not induced by microwave exposure. The learning and memory ability, amino acid contents in the hippocampus and cerebrospinal fluid, and NR2B expression were then investigated in the different genotypes. Following microwave exposure, NR2B protein expression decreased, while the Glu contents in the hippocampus and CSF increased, and memory impairment was observed in the TT genotype but not the CC and CT genotypes. In PC12 cells, the effects of the T allele were more pronounced than those of the C allele on transcription factor binding ability, transcriptional activity, NR2B mRNA, and protein expression. These effects may be related to the detrimental role of the T allele and the protective role of the C allele in rat brain function and PC12 cells exposed to microwave radiation.

Heijiangdan ointment relieves oxidative stress from radiation dermatitis induced by (60)Co γ-ray in mice.

OBJECTIVE: To investigate the effects of Heijiangdan Ointment ( HJD) on oxidative stress in (60)Co γ-ray radiation-induced dermatitis in mice. METHODS: Female Wistar mice with grade 4 radiation dermatitis induced by (60)Co γ-rays were randomly divided into four groups (n=12 per group); the HJD-treated, recombinant human epidermal growth factor (rhEGF)-treated, Trolox-treated, and untreated groups, along with a negative control group. On the 11th and 21st days after treatment, 6 mice in each group were chosen for evaluation. The levels of superoxide dismutase (SOD), malondialdehyde (MDA), and lactate dehydrogenase (LDH) were detected using spectrophotometric methods. The fibroblast mitochondria were observed by transmission electron microscopy (TEM). The expressions of fibroblast growth factor 2 (FGF-2) and transforming growth factor ß1 (TGF-ß1) were analyzed by western blot. RESULTS: Compared with the untreated group, the levels of SOD, MDA and LDH, on the 11th and 21st days after treatment showed significant difference (P<0.05). TEM analysis indicated that fibroblast mitochondria in the untreated group exhibited swelling and the cristae appeared fractured, while in the HJD group, the swelling of mitochondria was limited and the rough endoplasmic reticulum appeared more relaxed. The expressions of FGF-2 and TGF-ß1 increased in the untreated group compared with the negative control group (P<0.05). After treatment, the expression of FGF-2, rhEGF and Trolox in the HJD group were significantly increased compared with the untreated group (P<0.05), or compared with the negative control group (P<0.05). The expression of TGF-ß1 showed significant difference between untreated and negative control groups (P<0.05). HJD and Trolox increased the level of TGF-ß1 and the difference was marked as compared with the untreated and negative control groups (P<0.05). CONCLUSION: HJD relieves oxidative stress-induced injury, increases the antioxidant activity, mitigates the fibroblast mitochondrial damage, up-regulates the expression of growth factor, and promotes mitochondrial repair in mice.

Microwave-Induced Structural and Functional Injury of Hippocampal and PC12 Cells Is Accompanied by Abnormal Changes in the NMDAR-PSD95-CaMKII Pathway.

Recent studies have highlighted the important role of the postsynaptic NMDAR-PSD95-CaMKII pathway for synaptic transmission and related neuronal injury. Here, we tested changes in the components of this pathway upon microwave-induced neuronal structure and function impairments. Ultrastructural and functional changes were induced in hippocampal neurons of rats and in PC12 cells exposed to microwave radiation. We detected abnormal protein and mRNA expression, as well as posttranslational modifications in the NMDAR-PSD95-CaMKII pathway and its associated components, such as synapsin I, following microwave radiation exposure of rats and PC12 cells. Thus, microwave radiation may induce neuronal injury via changes in the molecular organization of postsynaptic density and modulation of the biochemical cascade that potentiates synaptic transmission.

Protecting intestinal epithelial cell number 6 against fission neutron irradiation through NF-κB signaling pathway.

The purpose of this paper is to explore the change of NF-κB signaling pathway in intestinal epithelial cell induced by fission neutron irradiation and the influence of the PI3K/Akt pathway inhibitor LY294002. Three groups of IEC-6 cell lines were given: control group, neutron irradiation of 4 Gy group, and neutron irradiation of 4 Gy with LY294002 treatment group. Except the control group, the other groups were irradiated by neutron of 4 Gy. LY294002 was given before 24 hours of neutron irradiation. At 6 h and 24 h after neutron irradiation, the morphologic changes, proliferation ability, apoptosis, and necrosis rates of the IEC-6 cell lines were assayed and the changes of NF-κB and PI3K/Akt pathway were detected. At 6 h and 24 h after neutron irradiation of 4 Gy, the proliferation ability of the IEC-6 cells decreased and lots of apoptotic and necrotic cells were found. The injuries in LY294002 treatment and neutron irradiation group were more serious than those in control and neutron irradiation groups. The results suggest that IEC-6 cells were obviously damaged and induced serious apoptosis and necrosis by neutron irradiation of 4Gy; the NF-κB signaling pathway in IEC-6 was activated by neutron irradiation which could protect IEC-6 against injury by neutron irradiation; LY294002 could inhibit the activity of IEC-6 cells.

Microwave exposure impairs synaptic plasticity in the rat hippocampus and PC12 cells through over-activation of the NMDA receptor signaling pathway.

OBJECTIVE: The aim of this study is to investigate whether microwave exposure would affect the N-methyl-D-aspartate receptor (NMDAR) signaling pathway to establish whether this plays a role in synaptic plasticity impairment. METHODS: 48 male Wistar rats were exposed to 30 mW/cm2 microwave for 10 min every other day for three times. Hippocampal structure was observed through H&E staining and transmission electron microscope. PC12 cells were exposed to 30 mW/cm2 microwave for 5 min and the synapse morphology was visualized with scanning electron microscope and atomic force microscope. The release of amino acid neurotransmitters and calcium influx were detected. The expressions of several key NMDAR signaling molecules were evaluated. RESULTS: Microwave exposure caused injury in rat hippocampal structure and PC12 cells, especially the structure and quantity of synapses. The ratio of glutamic acid and gamma-aminobutyric acid neurotransmitters was increased and the intracellular calcium level was elevated in PC12 cells. A significant change in NMDAR subunits (NR1, NR2A, and NR2B) and related signaling molecules (Ca2+/calmodulin-dependent kinase II gamma and phosphorylated cAMP-response element binding protein) were examined. CONCLUSION: 30 mW/cm2 microwave exposure resulted in alterations of synaptic structure, amino acid neurotransmitter release and calcium influx. NMDAR signaling molecules were closely associated with impaired synaptic plasticity.

Pathological changes in the sinoatrial node tissues of rats caused by pulsed microwave exposure.

To observe microwave induced dynamic pathological changes in the sinus nodes, wistar rats were exposed to 0, 5, 10, 50 mW/cm2 microwave. In 10 and 50 mW/cm2 groups, disorganized sinoatrial node cells, cell swelling, cytoplasmic condensation, nuclear pyknosis, and anachromasis, swollen, and empty mitochondria, and blurred and focally dissolved myofibrils could be detected from 1 to 28 d, while reduced parenchymal cells, increased collagen fibers, and extracellular matrix remodeling of interstitial cells were observed from 6 to 12 months. In conclusion, 10 and 50 mW/cm2 microwave could cause structural damages in the sinoatrial node and extracellular matrix remodeling in rats.

Activation of VEGF/Flk-1-ERK Pathway Induced Blood-Brain Barrier Injury After Microwave Exposure.

Microwaves have been suggested to induce neuronal injury and increase permeability of the blood-brain barrier (BBB), but the mechanism remains unknown. The role of the vascular endothelial growth factor (VEGF)/Flk-1-Raf/MAPK kinase (MEK)/extracellular-regulated protein kinase (ERK) pathway in structural and functional injury of the blood-brain barrier (BBB) following microwave exposure was examined. An in vitro BBB model composed of the ECV304 cell line and primary rat cerebral astrocytes was exposed to microwave radiation (50 mW/cm(2), 5 min). The structure was observed by scanning electron microscopy (SEM) and the permeability was assessed by measuring transendothelial electrical resistance (TEER) and horseradish peroxidase (HRP) transmission. Activity and expression of VEGF/Flk-1-ERK pathway components and occludin also were examined. Our results showed that microwave radiation caused intercellular tight junctions to broaden and fracture with decreased TEER values and increased HRP permeability. After microwave exposure, activation of the VEGF/Flk-1-ERK pathway and Tyr phosphorylation of occludin were observed, along with down-regulated expression and interaction of occludin with zonula occludens-1 (ZO-1). After Flk-1 (SU5416) and MEK1/2 (U0126) inhibitors were used, the structure and function of the BBB were recovered. The increase in expression of ERK signal transduction molecules was muted, while the expression and the activity of occludin were accelerated, as well as the interactions of occludin with p-ERK and ZO-1 following microwave radiation. Thus, microwave radiation may induce BBB damage by activating the VEGF/Flk-1-ERK pathway, enhancing Tyr phosphorylation of occludin, while partially inhibiting expression and interaction of occludin with ZO-1.

Alterations of cognitive function and 5-HT system in rats after long term microwave exposure.

The increased use of microwaves raises concerns about its impact on health including cognitive function in which neurotransmitter system plays an important role. In this study, we focused on the serotonin system and evaluated the long term effects of chronic microwave radiation on cognition and correlated items. Wistar rats were exposed or sham exposed to 2.856GHz microwaves with the average power density of 5, 10, 20 or 30mW/cm(2) respectively for 6min three times a week up to 6weeks. At different time points after the last exposure, spatial learning and memory function, morphology structure of the hippocampus, electroencephalogram (EEG) and neurotransmitter content (amino acid and monoamine) of rats were tested. Above results raised our interest in serotonin system. Tryptophan hydroxylase 1 (TPH1) and monoamine oxidase (MAO), two important rate-limiting enzymes in serotonin synthesis and metabolic process respectively, were detected. Expressions of serotonin receptors including 5-HT1A, 2A, 2C receptors were measured. We demonstrated that chronic exposure to microwave (2.856GHz, with the average power density of 5, 10, 20 and 30mW/cm(2)) could induce dose-dependent deficit of spatial learning and memory in rats accompanied with inhibition of brain electrical activity, the degeneration of hippocampus neurons, and the disturbance of neurotransmitters, among which the increase of 5-HT occurred as the main long-term change that the decrease of its metabolism partly contributed to. Besides, the variations of 5-HT1AR and 5-HT2CR expressions were also indicated. The results suggested that in the long-term way, chronic microwave exposure could induce cognitive deficit and 5-HT system may be involved in it.

AduoLa Fuzhenglin down-regulates microwave-induced expression of ß1-adrenergic receptor and muscarinic type 2 acetylcholine receptor in myocardial cells of rats.

This paper is aimed to study the effect of ADL on expression of ß1-AR and M2-AchR in myocardial cells of rats exposed to microwave radiation. Immunohistochemistry, Western blot and image analysis were used to detect the expression of ß1-AR and M2-AchR in myocardial cells at 7 and 14 d after microwave exposure. The results show that the expression level was higher in microwave exposure group and 0.75 g/(kg•d) ADL group than in sham operation group and significantly lower in 1.5 and 3.0 g/(kg•d) ADL groups than in microwave group. So we have a conclusion that the expression of ß1-AR and M2-AchR is down-regulated in myocardial cells of rats exposed to microwave radiation. ADL can protect rats against microwave-induced heart tissue injury.

Upregulation of HIF-1α via activation of ERK and PI3K pathway mediated protective response to microwave-induced mitochondrial injury in neuron-like cells.

Microwave-induced learning and memory deficits in animal models have been gaining attention in recent years, largely because of increasing public concerns on growing environmental influences. The data from our group and others have showed that the injury of mitochondria, the major source of cellular adenosine triphosphate (ATP) in primary neurons, could be detected in the neuron cells of microwave-exposed rats. In this study, we provided some insights into the cellular and molecular mechanisms behind mitochondrial injury in PC12 cell-derived neuron-like cells. PC12 cell-derived neuron-like cells were exposed to 30 mW/cm(2) microwave for 5 min, and damages of mitochondrial ultrastructure could be observed by using transmission electron microscopy. Impairments of mitochondrial function, indicated by decrease of ATP content, reduction of succinate dehydrogenase (SDH) and cytochrome c oxidase (COX) activities, decrease of mitochondrial membrane potential (MMP), and increase of reactive oxygen species (ROS) production, could be detected. We also found that hypoxia-inducible factor-1 (HIF-1α), a key regulator responsible for hypoxic response of the mammalian cells, was upregulated in microwave-exposed neuron-like cells. Furthermore, HIF-1α overexpression protected mitochondria from injury by increasing the ATP contents and MMP, while HIF-1α silence promoted microwave-induced mitochondrial damage. Finally, we demonstrated that both ERK and PI3K signaling activation are required in microwave-induced HIF-1α activation and protective response. In conclusion, we elucidated a regulatory connection between impairments of mitochondrial function and HIF-1α activation in microwave-exposed neuron-like cells. By modulating mitochondrial function and protecting neuron-like cells against microwave-induced mitochondrial injury, HIF-1α represents a promising therapeutic target for microwave radiation injury.

Relationship between cognition function and hippocampus structure after long-term microwave exposure.

OBJECTIVE: To analyze the effects of long-term microwave exposure on hippocampal structure and function in the rat. METHODS: Experiments were performed on 184 male Wistar rats (three exposure groups and a sham group). Microwaves were applied daily for 6 min over 1 month at average power densities of 2.5, 5, and 10 mW/cm2. Learning and memory abilities were assessed by Morris water maze. High performance liquid chromatography was used to detect neurotransmitter concentrations in the hippocampus. Hippocampal structures were observed by histopathological analysis. RESULTS: Following long-term microwave exposure there was a significant decrease in learning and memory activity in the 7 d, 14 d, and 1 m in all three microwave exposure groups. Neurotransmitter concentrations of four amino acids (glutamate, aspartic acid, glycine, and gamma-aminobutyric acid) in hippocampus were increased in the 2.5 and 5 mW/cm2 groups and decreased in the 10 mW/cm2 group. There was evidence of neuronal degeneration and enlarged perivascular spaces in the hippocampus in the microwave exposure groups. Further, mitochondria became swollen and cristae were disordered. The rough endoplasmic reticulum exhibited sacculated distension and there was a decrease in the quantity of synaptic vesicles. CONCLUSION: These data suggest that the hippocampus can be injured by long-term microwave exposure, which might result in impairment of cognitive function due to neurotransmitter disruption.

Application of 1H-NMR-based metabolomics for detecting injury induced by long-term microwave exposure in Wistar rats' urine.

There has been growing public concern regarding exposure to microwave fields as a potential human health hazard. This study aimed to identify sensitive biochemical indexes for the detection of injury induced by microwave exposure. Male Wistar rats were exposed to microwaves for 6 min per day, 5 days per week over a period of 1 month at an average power density of 5 mW/cm(2) (specific absorption rate of 2.1 W/kg). Urine specimens were collected over 24 h in metabolic cages at 7 days, 21 days, 2 months, and 6 months after exposure. (1)H NMR spectroscopy data were analyzed using multivariate statistical techniques. Urine metabolic profiles of rats after long-term microwave exposure were significantly differentiated from those of sham-treated controls using principal component analysis or partial least squares discriminant analysis. Significant differences in low molecular weight metabolites (acetate, succinate, citrate, ketoglutarate, glucose, taurine, phenylalanine, tyrosine, and hippurate) were identified in the 5 mW/cm(2) microwave exposure group compared with the sham-treated controls at 7 days, 21 days, and 2 months. Metabolites returned to normal levels by 6 months after exposure. These data indicated that these metabolites were related to the perturbations of energy metabolism particularly in the tricarboxylic acid cycle, and the metabolism of amino acids, monoamines, and choline in urine represent potential indexes for the detection of injury induced by long-term microwave exposure.

[The protective effects of Aduola Fuzhenglin on the heart injury induced by microwave exposure in rats].

OBJECTIVE: To study the protective effects of AduoLa Fuzhenglin(ADL) on the heart injury induced by microwave exposure in rats. METHODS: One hundred forty male Wistar rats were divided randomly into 5 groups: control, microwave radiation, 0.75 g x kg(-1) d(-1) ADL, 1.50 g x kg(-1) d(-1) ADL and 3.00 g x kg(-1) d(-1) ADL pretreatment groups. Rats in three ADL pretreatment groups were administrated by ADL per day for 2w then exposed to 30 mW/cm2 microwaves for 15 min. The left ventricle blood of rats was obtained at 7 d and 14 d after exposure to microwaves, and the blood Ca2+, AST and CK were detected with Coulter automatic biochemical analyzer, then the histological changes and ultrastructure of heart were observed under light and electron microscopes. RESULTS: At 7 d and 14 d after exposure to microwaves, the blood Ca2+, AST and CK concentrations significantly increased (P<0.05 or P<0.01) as compared with controls; Heart muscle fibers showed wavilness, endotheliocyte karyopyknosis, anachromasis; The mitochondria swelling and cavitation, intercalary dies blurred in radiation groups. The changes in 0.75 g x kg(-1) d(-1) ADL pretreatment group were similar to the radiation group, but in 1.50 g x kg(-1)d(-1) and 3.00 g x kg(-1) d(-1) ADL pretreatment groups, above indexes of rats significantly reduced as compared with microwaves group (P<0.05); also the blood Ca2+, AST, CK contents were significantly lower than those in microwave group (P<0.05); The heart showed a tendency to improve. CONCLUSION: Microwave radiation (30 mW/cm2) can cause the blood Ca2+, AST and CK turbulence, and heart injury in the histology and ultrastructure; ADL at the dosages of 1.50 g x kg(-1) d(-1) and 3.00 g x kg(-1) d(-1) has a protective effects on the heart injury induced by microwave in rats.

[Construction of the recombinant plasmid of pcDNA3.0-RKIP and expression in PC12 cells].

AIM: To construct the eukaryotic expression vectors of RKIP plasmid and detect its expression in PC12 cells. METHODS: The coding sequence of RKIP was generated by nested-PCR using total RNA extracted from the root ganglion neurons of rats. RKIP gene was cloned into the eukaryotic expression vector pcDNA3.0. After restriction enzyme analysis and sequence identification, the recombinant plasmid was transfected into PC12 cells with non-liposome mediated method by Vigofect. The expression of RKIP was detected by Western blot. RESULTS: The results of enzyme analysis and sequencing both identified DNA sequence of recombinant plasmid pcDNA3.0-RKIP correctly. The expression of RKIP increased obviously after transfection into PC12 cells. CONCLUSION: The eukaryotic expression plasmid of pcDNA3.0-RKIP was constructed successfully and it can be sustainly expressed in PC12 cells. This provides experimental basis for further study on the neurological function of RKIP.

[Long-term microwave radiation affects male reproduction in rats].

OBJECTIVE: To investigate the effect of long-term microwave radiation on male reproduction in rats. METHODS: A total of 100 male Wistar rats were exposed to microwave radiation with average power density of 0, 2.5, 5 and 10 mW/cm2 for 4 weeks, 5 times a week and 6 minutes per time. Changes in serum testosterone, testicular index, histology and ultrastructure, and the percentage of teratospermia in the epididymis were observed dynamically at 6 h, 7 d, 14 d, 28 d and 60 d after the exposure. RESULTS: There was a significant decrease in serum testosterone concentration at 28 d after microwave radiation at 2.5, 5 and 10 mW/cm2 ([10.20 +/- 4.31] ng/ml, [5.56 +/- 3.47] ng/ml and [7.53 +/- 4.54] ng/ml) and at 60 d at 10 mW/cm2 ( [15.95 +/- 9.54] ng/ml), as compared with the control group ([23.35 +/- 8.06] ng/ml and [31.40 +/- 9.56] ng/ml) (P < 0.05 or P < 0.01). No significant changes were found in the testis index at 6 h -60 d after microwave radiation at the three doses, but different degrees of degeneration, necrosis and shedding of spermatogenic cells, thinning of spermatogenic epithelia, and decrease or deletion of spermatozoa were observed, and more obvious at 28 d and 60 d. Swelling and cavitation of mitochondria in all spermatogenic cells, agglutination and margin translocation of nuclear chromatin in the spermatogonial and Leydig cells were seen at 7 d and 60 d after 5 mW/cm2 microwave radiation. The rate of teratospermia of the epididymis was increased, more obviously at 7 d after 2.5, 5 mW/cm2, 60 d after 5 mW/cm2, and 7 d, 28 d and 60 d after 10 mW/cm2 microwave radiation (P < 0.05 or P < 0.01). CONCLUSION: Long-term microwave radiation may cause injury to male reproduction, which is positively correlated with the radiation dose, and has an obvious late effect.