A novel, multichannel, comb-frequency Doppler backscatter system

Doppler backscattering has emerged in recent years as a powerful diagnostic tool in high temperature fusion plasmas. The technique is sensitive to plasma turbulence flow and has been utilized to determine radial electric field and to study geodesic acoustic modes, zonal flows, and intermediate scale density turbulence. The current manuscript describes a novel technique for creating a stable, multichannel system covering the V-band frequency range (50-75 GHz) which enables simultaneous monitoring of turbulent flows and fluctuation levels at eight distinct spatial locations. The system is based on a high-frequency, low phase noise comb-frequency generator combined with a filter bank and quadrature detection system. The system is now in operation on DIII-D and has allowed monitoring of the flow and turbulence levels across the plasma radius during events such as the L-H transition.

Cloning and expression of Aspergillus tamarii FS132 lipase gene in Pichia pastoris

A lipase gene (atl) was cloned from Aspergillus tamarii FS132 for the first time. The gene was found to have an open reading frame of 1024 base pairs (bp), and the coding region of the gene contained two introns (51 bp and 52 bp). Multi-alignment analysis of the deduced amino acid sequence indicated high homology between the enzyme and mono-and diacylglycerol lipases from fungi Aspergillus. The recombinant lipase was expressed in Pichia pastoris GS115 cells. The recombinant lipase was found to have a molecular mass of 36.7 kDa, and it exhibited lipase activity of 20 U/mL in culture supernatant when tributyrin was used as the substrate.

Hyperglycaemia confers resistance to chemotherapy on breast cancer cells: the role of fatty acid synthase

The prognosis for women with breast cancer is adversely affected by the comorbidities of obesity and diabetes mellitus (DM), which are conditions associated with elevated levels of circulating fatty acids, hyperglycaemia and hyperinsulinaemia. We investigated the effects of exposure of non-malignant and malignant human breast epithelial cells to elevated levels of fatty acids and glucose on their growth, survival and response to chemotherapeutic agents. We found that palmitate induced cell death in the non-malignant cells but not in the malignant cells, which was abrogated through the inhibition of ceramide production and by oleate but not by IGF1. Fatty acid synthase (FAS) is responsible for the de novo synthesis of fatty acids from sugars, and is over-expressed in many epithelial cancers. Abundance of FAS was higher in malignant cells than in non-malignant cells, and was up-regulated by IGF1 in both cell types. IGF-induced growth of non-malignant cells was unaffected by suppression of FAS expression, whereas that of malignant cells was blocked as was their resistance to palmitate-induced cell death. Palmitate did not affect cell proliferation, whereas oleate promoted the growth of non-malignant cells but had the opposite effect, that is, inhibition of IGF1-induced growth of malignant cells. However, when the phosphatidylinositol 3-kinase pathway was inhibited, oleate enhanced IGF1-induced growth in both cell types. Hyperglycaemia conferred resistance on malignant cells, but not on non-malignant cells, to chemotherapy-induced cell death. This resistance was overcome by inhibiting FAS or ceramide production. Understanding the mechanisms involved in the associations between obesity, DM and breast cancer may lead to more effective treatment regimens and new therapeutic targets.

Invasion of human coronary artery endothelial cells by Streptococcus mutans OMZ175

INTRODUCTION

Dissemination of oral bacteria into the bloodstream has been associated with eating, oral hygiene, and dental procedures; including tooth extraction, endodontic treatment, and periodontal surgery. Recently, studies identified Streptococcus mutans, the primary etiological agent of dental caries, as the most prevalent bacterial species found in clinical samples from patients who underwent heart valve and atheromatous plaque surgery.

METHODS

By using antibiotic protection assays, we tested the capacity of 14 strains of S. mutans to invade primary human coronary artery endothelial cells (HCAEC).

RESULTS

Serotype e strain B14 and serotype f strain OMZ175 of S. mutans were able to efficiently invade HCAEC. Among the tested strains, serotype f S. mutans OMZ175 was the most invasive, whereas strains of serotype c S. mutans, the most prevalent serotype in dental plaque, were not invasive. Based on its high invasion rate, we further investigated the invasive properties of serotype f OMZ175. Using transmission electron microscopy and antibiotic protection assays we demonstrate that S. mutans OMZ175 is capable of attaching to the HCAEC surface, entering the cells and surviving in HCAEC for at least 29 h.

DISCUSSION

Our findings highlight a potential role for S. mutans in the pathogenesis of certain cardiovascular diseases.

Amygdala protein kinase C epsilon controls alcohol consumption

Alcoholism is a progressive disorder that involves the amygdala. Mice lacking protein kinase C epsilon (PKCepsilon) show reduced ethanol consumption, sensitivity and reward. We therefore investigated whether PKCepsilon signaling in the amygdala is involved in ethanol consumption. Local knockdown of PKCepsilon in the amygdala reduced ethanol consumption and preference in a limited-access paradigm. Further, mice that are heterozygous for the PKCepsilon allele consume less ethanol compared with wild-type mice in this paradigm. These mice have a >50% reduction in the abundance of PKCepsilon in the amygdala compared with wild-type mice. We conclude that amygdala PKCepsilon is important for ethanol consumption in mice.

Expression and hormonal regulation of IL-11Ralpha in canine uterus during early pregnancy

Embryo implantation is critical for the successful establishment of pregnancy. Interleukin-11 (IL-11) is essential for adequate decidualization in the mouse and human via binding to the specific IL-11 receptor alpha (IL-11Ralpha). But the expression and regulation of IL-11 and IL-11Ralpha in the canine endometrium remain unknown. The aim of this study was to investigate the differential expression of IL-11Ralpha in canine uterus during early pregnancy and its regulation under different conditions by in situ hybridization. Interleukin-11Ralpha mRNA was mainly localized in glandular epithelium in canine uterus. There was a low level of IL-11Ralpha expression in the glandular epithelium on days 6, 12 and 17 of pregnancy. On day 20 of pregnancy when embryo implanted, IL-11Ralpha mRNA was highly expressed in the glandular epithelium surrounding the embryo, but not in the luminal epithelium and stroma. On day 23 of pregnancy, the expression of IL-11Ralpha mRNA maintained a constant level compared with the expression of day 20 and increased on day 28 of pregnancy. During the oestrous cycle, a high level of IL-11Ralpha mRNA expression was seen in the oestrous uterus. Progesterone slightly induced the expression of IL-11Ralpha mRNA in the ovariectomized canine uterus. These results suggest that IL-11Ralpha expression is closely related to canine implantation and up-regulated by progesterone.

Detection of zonal flow spectra in DIII-D by a dual-channel Doppler backscattering system

Doppler backscattering (DBS) has been successfully used to measure the E x B flow velocity and local intermediate wavenumber density fluctuation levels in the DIII-D tokamak. Depending on the launch angle and the frequency of the probing beam, the signal backscattered from the plasma cut-off layer is sensitive to density fluctuations at a specific perpendicular wavenumber (1 < or = k(perpendicular rho(s)) < or = 4). Due to the localization and high time resolution for poloidal flow measurements, DBS is well suited to detect stationary and time-dependent shear flows [zonal flows (ZFs)]. We present a novel scheme to measure ZF spectra using a dual-channel DBS system capable of simultaneously probing two minor radii separated by a distance of 0.2 cm < Delta r < 3 cm. Frequency spectra of geodesic acoustic modes and low frequency ZFs (f or = 10 kHz) have been obtained for 0.6 < r/a < 0.95.