Cooperative Response of Escherichia Coli Cells to the Resonance Effect of Millimeter Waves at Super Low Intensity

Cells of Escherichia coli K12 AB1157 were irradiated with millimeter waves (MMW) within the power density (PD) range of 10^?20 to 10 ⁴ W/cm². MMW were applied for 0.5–70 min at 51.76 GHz or 41.32 GHz at which, as had been shown earlier, MMW resonantly changes the genome conformational state (GCS) of E. coli K12 AB1157 cells. The changes in the GCS were tested with the method of anomalous viscosity time dependence (AVTD). It was demonstrated that the resonance effect of MMW manifests itself at PD up to 10^?19 W/cm². Dependences of MMW effect on power density and time of exposure proved to have distinct characteristics when cells are irradiated during the logarithmic or stationary phases of the culture's growth. It was found that the resonance effect of MMW on the GCS of E. coli cells at the early stationary phase changes the developmental dynamics of the irradiated culture. It was established for the first time that the magnitude of the resonance MMW effect depends on the concentration of irradiated cells. An analysis of the results indicates an electromagnetic rather than diffusion nature of the cells' cooperative responses to millimeter waves.     

Millimeter wave effects on electrical responses of the sural nerve in vivo

Millimeter wave (MMW, 42.25 GHz)‐induced changes in electrical activity of the murine sural nerve were studied in vivo using external electrode recordings. MMW were applied to the receptive field of the sural nerve in the hind paw. We found two types of responses of the sural nerve to MMW exposure. First, MMW exposure at the incident power density ≥45 mW/cm² inhibited the spontaneous electrical activity. Exposure with lower intensities (10–30 mW/cm²) produced no detectable changes in the firing rate. Second, the nerve responded to the cessation of MMW exposure with a transient increase in the firing rate. The effect lasted 20–40 s. The threshold intensity for this effect was 160 mW/cm². Radiant heat exposure reproduced only the inhibitory effect of MMW but not the transient excitatory response. Depletion of mast cells by compound 48/80 eliminated the transient response of the nerve. It was suggested that the cold sensitive fibers were responsible for the inhibitory effect of MMW and radiant heat exposures. However, the receptors and mechanisms involved in inducing the transient response to MMW exposure are not clear. The hypothesis of mast cell involvement was discussed. Bioelectromagnetics 31:180–190, 2010. © 2009 Wiley‐Liss, Inc.     

Resonance effect of millimeter waves in the power range from 10-19 to 3 × 10-3 W/cm2 on Escherichia coli cells at different concentrations

The effect of millimeter waves (MMWs) on the genome conformational state (GCS) of E. coli AB1157 cells was studied by the method of anomalous viscosity time dependencies (AVTD) in the frequency range of 51.64-51.85 GHz. The 51.755 GHz resonance frequency of the cell reaction to MMWs did not depend on power density (PD) in the range from 10^-19 to 3 × 10^-3 W/cm². The half-width of the resonant reaction of cells showed a sigmoid dependence on PD, changing from 3 MHz to 100 MHz. The PD dependence of the half-width had the same shape for different concentrations of exposed cells (4 × 10⁷ and 4 × 10⁸ cells/ml), whereas the magnitude of the 51.755 GHz resonance effect differed significantly and depended on the PD of MMW exposure. Sharp narrowing of the 51.755 GHz resonance in the PD range from 10^-4 to 10^-7 W/cm² was followed by an emergence of new resonance frequencies. The PD dependence of the MMW effect at one of these resonance frequencies (51.674 GHz) differed markedly from the corresponding dependence at the 51.755 GHz resonance, the power window occurring in the range from 10^-16 to 10^-8 W/cm². The results obtained were explained in the framework of a model of electron-conformational interactions. The frequency-time parameters of this model appeared to be in good agreement with experimental data. © 1996 Wiley-Liss, Inc.     

Distinct gene expression profiles of human type 1 and type 2 T helper cells

Background

The development and activation of CD4⁺ helper T cell (Th) subsets with distinct patterns of unbalanced production of cytokines play an important part in infectious, allergic and autoimmune diseases. Human neonatal cord blood CD4⁺ Th cells can be polarized into type 1 or type 2-like effector cells in vitro by culturing them in the presence of interleukin (IL)-12 or IL-4, respectively. We have exploited this experimental system to identify marker genes that are differentially expressed by polarized Th1 and Th2 cells. An oligonucleotide microarray specifically designed to screen for inflammation-related candidate genes was used and the differential expression was further validated with a quantitative real-time RT-PCR method.

Results

In addition to the previously described marker genes of Th cells, we report subtle changes in the expression of several other genes that represent growth factors, receptors and other signaling molecules in polarized Th1 and Th2 cell subsets. Additionally, we describe a novel set of genes as Th1/Th2 differentiation markers for cells activated by anti-CD3 and anti-CD28 antibodies.

Conclusions

This study demonstrates the power of the targeted use of microarrays in combination with quantitative real-time RT-PCR in identifying and validating new marker genes for gene expression studies.     

Microarray-Based Approach Identifies Differentially Expressed MicroRNAs in Porcine Sexually Immature and Mature Testes

Background

MicroRNAs (miRNAs) are short non-coding RNA molecules which are proved to be involved in mammalian spermatogenesis. Their expression and function in the porcine germ cells are not fully understood.

Methodology

We employed a miRNA microarray containing 1260 unique miRNA probes to evaluate the miRNA expression patterns between sexually immature (60-day) and mature (180-day) pig testes. One hundred and twenty nine miRNAs representing 164 reporter miRNAs were expressed differently (p<0.1). Fifty one miRNAs were significantly up-regulated and 78 miRNAs were down-regulated in mature testes. Nine of these differentially expressed miRNAs were validated using quantitative RT-PCR assay. Totally 15919 putative miRNA-target sites were detected by using RNA22 method to align 445 NCBI pig cDNA sequences with these 129 differentially expressed miRNAs, and seven putative target genes involved in spermatogenesis including DAZL, RNF4 gene were simply confirmed by quantitative RT-PCR.

Conclusions

Overall, the results of this study indicated specific miRNAs expression in porcine testes and suggested that miRNAs had a role in regulating spermatogenesis.     

Differentially expressed genes in the ovary of the sixth day of pupal “Ming” lethal egg mutant of silkworm, Bombyx mori

The “Ming” lethal egg mutant (l-e^m) is a vitelline membrane mutant in silkworm, Bombyx mori. The eggs laid by the l-e^m mutant lose water, ultimately causing death within an hour. Previous studies have shown that the deletion of BmEP80 is responsible for the l-e^m mutation in silkworm, B. mori. In the current study, digital gene expression (DGE) was performed to investigate the difference of gene expression in ovaries between wild type and l-e^m mutant on the sixth day of the pupal stage to obtain a global view of gene expression profiles using the ovaries of three l-e^m mutants and three wild types. The results showed a total of 3,463,495 and 3,607,936 clean tags in the wild type and the l-e^m mutant libraries, respectively. Compared with those of wild type, 239 differentially expressed genes were detected in the l-e^m mutant, wherein 181 genes are up-regulated and 58 genes are down-regulated in the mutant strain. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis results showed that no pathway was significantly enriched and three pathways are tightly related to protein synthesis among the five leading pathways. Moreover, the expression profiles of eight important differentially expressed genes related to oogenesis changed. These results provide a comprehensive gene expression analysis of oogenesis and vitellogenesis in B. mori which facilitates understanding of both the specific molecular mechanism of the 1-e^m mutant and Lepidopteran oogenesis in general.     

Differential gene expression profile in Pseudomonas putida NBRIC19-treated wheat (Triticum aestivum) plants subjected to biotic stress of Parthenium hysterophorus

The inoculation of Pseudomonas putida NBRIC19 protected wheat plant from phytotoxic effect of Parthenium hysterophorus (Parthenium) and enhanced root length, shoot length, dry weight, spike length and chlorophyll content. With the aim to screen for genes differentially expressed in P. putida NBRIC19-inoculated wheat grown along with Parthenium (WPT), the suppression subtractive hybridization (SSH) methodology was employed. The SSH analysis was performed with WPC (uninoculated wheat grown along with Parthenium) as driver and WPT as tester. The cDNA library, enriched with differentially expressed ESTs (expressed sequence tags), were constructed from WPT. Following an initial screen of 165 ESTs in our library, 32 ESTs were identified, annotated and further validated by semiquantitative RT-PCR. The differentially expressed ESTs were associated with general stress response, defense response, growth and development, metabolic process, photosynthesis, signal transduction, and some other with unknown function. Five ESTs showing downregulation in expression level in response to Parthenium got upregulated due to P. putida NBRIC19 inoculation and further validated by quantitative real time PCR analysis at different time intervals viz. 15, 30, 45 and 90 days. SSH has been implemented for the first time to gain insights into molecular events underlying successful role of P. putida NBRIC19 in providing protection to wheat against Parthenium. The information generated in this study provides new clues to aid the understanding of genes corresponding to differentially expressed ESTs putatively involved in allelopathic interactions. Further characterization and functional analysis of these genes may provide valuable information for future studies of the molecular mechanism by which plants adapt to allelopathic effect of Parthenium.     

The effect of low-intensity coherent extremely high frequency electromagnetic radiation on growth parameters for <Emphasis Type="Italic">Enterococcus hirae</Emphasis> bacteria

It is found that for Enterococcus hirae ATCC9790 bacteria grown in anaerobic conditions, one-hour exposure to low-intensity (radiant power of 0.06 mW/cm²) coherent extremely high frequency electromagnetic radiation (from 45 to 53 GHz), or millimeter electromagnetic radiation, leads to an appreciable increase in latent growth time and to a decrease in specific growth rate; herein, the effects intensify as the frequency increases from 49 to 53 GHz. The result is enhanced at an increase in the radiation duration from 30 min to 1 h; however, a further increase in the exposure time up to 2 h does not lead to intensification of the effect. It is shown that the effect of extremely high frequency electromagnetic radiation on Enterococcus hirae does not depend on pH of the medium (pH 6.0 or 8.0). It may be expected that these bacteria have protective or reparation mechanisms that compensate long-term action of this radiation; it is not improbable that various mechanisms of pH regulation are present as well.     

Microarray Analysis of Gene-Expression Profile in Hepatocellular Carcinoma Cell, BEL-7402, with Stable Suppression of hLRH-1 via a DNA Vector-based RNA Interference

To establish a cell line with a permanent suppression of hLRH-1 in this study, a stable RNAi vector (pSineohLRH-1) targeting hLRH-1 was constructed and introduced into hepatocellular carcinoma cell, BEL-7402. By semiquantitative RT-PCR analysis, the expression of hLRH-1 in BEL-7402 cells carrying pSineohLRH-1 was shown to be significantly suppressed by up to ∼60%. In addition, microarray analysis was carried out to assess the extent of altered gene expression in BEL-7402 cells with stable knockdown of hLRH-1. Direct comparison of gene-expression profiles of more than 18 000 genes showed that 405 of the expressed genes in hLRH-1-knockdown cells differed dramatically in expression levels from those in controls, which suggested the even extensive biological functions of hLRH-1. Interestingly, among those differentially expressed genes, some are cancer-associated such as Gadd45β and PTEN, and their expressions were further validated. Although the identification of the exact relationship between these genes and hLRH-1 awaits intensive investigation, the findings of this study provide new insights into the mechanism by which hLRH-1 is involved in tumorigenesis.