Preliminary investigations on the utility of an erbium, chromium YSGG laser

A variety of laser systems are under investigation as potential tools in dentistry. Most of these systems have been shown to be efficacious for soft tissue surgery of the mucous membranes; however, cutting bone and dental hard tissues has only recently been possible. In this report from the University of California at Los Angeles School of Dentistry, a review of laser applications in dentistry is discussed. The utility of a new laser system using an erbium YSGG medium with air water spray to cut soft tissues, bone, enamel and dentin is under investigation and preliminary research findings are presented.     

Relationship between phosphorylation and activity of heme-regulated eukaryotic initiation factor 2 alpha kinase

In heme-deficient reticulocytes and their lysates, a heme-regulated inhibitor of protein synthesis is activated; this inhibitor is a cyclic AMP-independent protein kinase that specifically phosphorylates the alpha subunit of the eukaryotic initiation factor 2 (eIF-2 alpha). Heme regulates this kinase by inhibiting its activation and activity. The purified heme-regulated kinase (HRI) undergoes autophosphorylation; at least 3 mol of phosphate can be incorporated per HRI subunit (Mr 80,000). The phosphorylation of HRI, its eIF-2 alpha kinase activity, and its ability to inhibit protein synthesis are diminished by hemin (5 microM) and increased by N-ethylmaleimide (MalNEt). Treatment of MalNEt-activated HRI with hemin reduces its autophosphorylation and its ability to inhibit protein synthesis . These findings demonstrate a correlation of the phosphorylation of HRI, its eIF-2 alpha kinase activity, and its inhibition of protein synthesis. The mechanism of hemin regulation of HRI activity was studied by examining the binding of hemin to purified HRI. Significant binding was demonstrable by difference spectroscopy which revealed a pronounced shift in the absorption spectrum of hemin with the appearance of a peak at 418 nm, a shift similar to that observed with proteins known to bind hemin. These findings are consistent with a direct effect of hemin on HRI.     

Kinase-negative mutants of JAK1 can sustain interferon-gamma-inducible gene expression but not an antiviral state

The receptor-associated protein tyrosine kinases JAK1 and JAK2 are both required for the interferon (IFN)-gamma response. The effects of expressing kinase-negative JAK mutant proteins on signal transduction in response to IFN-gamma in wild-type cells and in mutant cells lacking either JAK1 or JAK2 have been analysed. In cells lacking endogenous JAK1 the expression of a transfected kinase-negative JAK1 can sustain substantial IFN-gamma-inducible gene expression, consistent with a structural as well as an enzymic role for JAK1. Kinase-negative JAK2, expressed in cells lacking endogenous JAK2, cannot sustain IFN-gamma-inducible gene expression, despite low level activation of STAT1 DNA binding activity. When expressed in wild-type cells, kinase-negative JAK2 acts as a dominant-negative inhibitor of the IFN-gamma response. Further analysis of the JAK/STAT pathway suggests a model for the IFN-gamma response in which the initial phosphorylation of JAK1 and JAK2 is mediated by JAK2, whereas phosphorylation of the IFN-gamma receptor is normally carried out by JAK1. The efficient phosphorylation of STAT 1 in the receptor-JAK complex may again depend on JAK2. Interestingly, a JAK1-dependent signal, in addition to STAT1 activation, appears to be required for the expression of the antiviral state.     

Lithium ion modulation of the neuronal responses evoked by monoaminergic receptor agonists

The authors studied the action of lithium ions on the responses of rat dorsal root ganglion neurons and frog spinal motoneurons evoked by monoamine agonists using the microelectrode technique. Lithium ions reversibly inhibit the depolarizing responses of spinal sensory neurons and motoneurons evoked by activation of muscarinic choline-, alpha 1-adreno-, and 5-hydroxytryptamine2 receptors, but enhance the hyperpolarizing neuronal responses evoked by activation of 5-hidroxytryptamine1A receptors.     

Release of PAHs Through Runoff from the Gwangan Bridge to the Coast in Busan,Korea

This study was carried out from the Gwangan Bridge in Busan, Korea in order to examine the characteristics and the amount of PAHs in runoff from Gwangan Bridge, and the consequential PAH burdens in the ocean. The runoff samples were collected in particulate and dissolved phase, and the ambient air samples were collected in particulate and gaseous phase. In this study, 20 samples were collected from 10 different sites. The concentrations of 16 PAHs, in particulate road surface samples, ranged from 76.71 to 170.98 ng/g, and the dissolved road surface runoff samples ranged from 23.31 to 72.9 ng/L. In ambient air, the PAHs concentration in gaseous phase was higher than the samples in particulate phase. From these results, the amount of annual release of PAHs through runoff into the coast was calculated, and the Toxic Potency Equivalency Factors and Dioxin Toxic Equivalency Factors were applied. The annual release of total PAHs and the carcinogenic PAHs via runoff from Gwangan Bridge to the coast were 14.1 g/yr and 3.13 g/yr, respectively. The PAHs-_TPEQ was 0.85 g/yr and the PAH-_{dioxin TEQ} was 0.69 mg/yr.     

Crude extracts of asteraceous weeds

Petrol and ethanolic extracts of six asteraceous weeds were added to artificial diets to screen for growth inhibition and mortality of the variegated cutworm,Peridroma saucia (Hbn). Petrol and ethanolic extracts ofArtemisia tridentata andChamomilla suaveolens and ethanolic extracts ofChrysothamnus nauseosus andCentaurea diffusa severely inhibited larval growth at five times the natural concentrations. The twoC. suaveolens extracts and the ethanol extract ofA. tridentata were active at the natural concentration (100%) and were further examined at 20, 40, 60, and 80% of this level. Inhibition of larval growth was directly related to concentration for each of the three extracts tested. EC₅₀s (effective concentration to inhibit growth by 50% relative to controls) for the three extracts were 36–42% of the naturally occurring level in the plants. Nutritional indices were calculated for secondinstarP. saucia feeding on the activeA. tridentata EtOH extract and the petrol extract fromC. suaveolens. Addition of the activeA. tridentata EtOH or theC. suaveolens petrol extract to the diet resulted in significant reduction in the relative growth rate of larvae, although theA. tridentata extract was much more inhibitory. Dietary utilization was significantly lower for larvae fed theA. tridentata EtOH extract.     

Pro- and Anti-Inflammatory Cytokines in the Context of NK Cell–Trophoblast Interactions

During pregnancy, uterine NK cells interact with trophoblast cells. In addition to contact interactions, uterine NK cells are influenced by cytokines, which are secreted by the cells of the decidua microenvironment. Cytokines can affect the phenotypic characteristics of NK cells and change their functional activity. An imbalance of pro- and anti-inflammatory signals can lead to the development of reproductive pathology. The aim of this study was to assess the effects of cytokines on NK cells in the presence of trophoblast cells in an in vitro model. We used TNFα, IFNγ, TGFβ and IL-10; the NK-92 cell line; and peripheral blood NK cells (pNKs) from healthy, non-pregnant women. For trophoblast cells, the JEG-3 cell line was used. In the monoculture of NK-92 cells, TNFα caused a decrease in CD56 expression. In the coculture of NK cells with JEG-3 cells, TNFα increased the expression of NKG2C and NKG2A by NK-92 cells. Under the influence of TGFβ, the expression of CD56 increased and the expression of NKp30 decreased in the monoculture. After the preliminary cultivation of NK-92 cells in the presence of TGFβ, their cytotoxicity increased. In the case of adding TGFβ to the PBMC culture, as well as coculturing PBMCs and JEG-3 cells, the expression of CD56 and NKp44 by pNK cells was reduced. The differences in the effects of TGFβ in the model using NK-92 cells and pNK cells may be associated with the possible influence of monocytes or other lymphoid cells from the mononuclear fraction.