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41.
Training makes an important contribution to maintaining a safe working environment, but trainees may have problems achieving maximum information retention if they are not motivated and interested. The authors describe an innovative safety training program that has been well received by employees and associated with a 62% drop in workplace injuries over a two-year period.  相似文献   
42.
Despite the high prevalence of obstructive sleep apnea (OSA) in type 2 diabetes mellitus (DM), the attributable vascular risk from each condition is unknown. We hypothesize that OSA may have a similar effect on vascular function as type 2 diabetes does. Healthy normal‐weight subjects, healthy obese subjects, subjects with type 2 diabetes, and obese subjects with OSA were enrolled. Vascular function was assessed with brachial artery ultrasound for flow‐mediated dilatation (FMD) and in skin microcirculation by laser Doppler flowmetry. One hundred fifty‐three subjects were studied: healthy normal‐weight controls (NCs) (n = 14), healthy obese controls (OCs) (n = 33), subjects with DM (n = 68), and obese subjects with OSA (n = 38). The DM group did not undergo sleep study and thus may have had subclinical OSA. The OSA and type 2 diabetes groups had impaired FMD as compared to both the normal‐weight and OC groups (5.8 ± 3.8%, 5.4 ± 1.6% vs. 9.1 ± 2.5%, 8.3 ± 5.1%, respectively, P < 0.001, post hoc Fischer test). When referenced to the NC group, a multiple linear regression model adjusting for covariates found that baseline brachial artery diameter (β = ?3.75, P < 0.001), OSA (β = ?2.45, P = 0.02) and type 2 diabetes status (β = ?2.31, P = 0.02), negatively predicted % FMD. OSA status did not seem to affect nitroglycerin‐induced vasodilation (endothelium‐independent) of the brachial artery or vascular function in the skin microcirculation. OSA impairs endothelial function in the brachial artery to a similar degree as type 2 diabetes does. OSA, however, does not appear to affect brachial endothelium‐independent vasodilation or skin microcirculatory function. Treatment of OSA in patients with concomitant type 2 diabetes, therefore, may be a potential therapeutic option to improve macro‐, but not microvascular outcomes.  相似文献   
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The involvement of P2Y receptors, which are activated by extracellular nucleotides, in proliferative regulation of human lung epithelial cells is unclear. Here we show that extracellular ATP and UTP stimulate bromodeoxyuridine (BrdU) incorporation into epithelial cell lines. The nucleotide efficacy profile [ATP = ADP > UDP >or= UTP > adenosine >or= 2-methylthioadenosine-5'-diphosphate, with alpha,beta-methylene adenosine 5'-triphosphate, 2',3'-O-(4-benzoylbenzoyl)adenosine 5'-triphosphate, AMP, UMP, and ATPalphaS inactive] and PCR analysis indicate involvement of P2Y2 and P2Y6 receptors. The signal transduction pathway, which, via the P2Y2 receptor, transmits the proliferative activity of ATP or UTP in A549 cells downstream of phospholipase C, depends on Ca2+/calmodulin-dependent protein kinase II and nuclear factor-kappaB, but not on protein kinase C. Signaling does not involve the mitogen-activated protein kinases extracellular signal-regulated kinases-1 and -2, the phosphatidylinositol 3-kinase pathway, or Src kinases. Thus nucleotides regulate proliferation of human lung epithelial cells by a novel pathway. The stimulatory effect of UTP, but not ATP, in A549 cells is attenuated by preincubation with interleukin-1beta and interleukin-6, but not tumor necrosis factor-alpha. This indicates an important role for the pyrimidine-activated P2Y receptor in the inflammatory response of lung epithelia. ATP antagonizes the antiproliferative effect of the anticancer drugs paclitaxel and etoposide, whereas it enhances the activity of cisplatin about fourfold. Thus pathways activated by extracellular nucleotides differentially control proliferation of lung epithelial tumor cells.  相似文献   
45.
We studied the effect of ectomycorrhizal fungi on bacterial communities colonizing roots of Douglas fir (Pseudotsuga menziesii). Mycorrhizal tips were cleaned of soil and separated based on gross morphological characteristics. Sequencing of the internal transcribed spacers of the nuclear rRNA gene cluster indicated that the majority of the tips were colonized by fungi in the Russulaceae, with the genera Russula and Lactarius comprising 70% of the tips. Because coamplification of organellar 16S rRNA genes can interfere with bacterial community analysis of root tips, we developed and tested a new primer pair that permits amplification of bacterial 16S rRNA genes but discriminates more effectively against organellar sequences than commonly used bacterial primer sets. We then used terminal restriction fragment length polymorphism (T-RFLP) and sequence analysis of the 16S rRNA gene to examine differences in bacterial communities associated with the mycorrhizal tips. Cluster analysis of T-RFLP profiles indicated that there were different bacterial communities among the root tips; however, the communities did not seem to be affected by the taxonomic identity of the ectomycorrhizal fungi. Terminal restriction fragment profiling and sequencing of cloned partial 16S rRNA genes indicated that most bacteria on the ectomycorrhizal tips were related to the Alphaproteobacteria and the Bacteroidetes group.  相似文献   
46.
This study investigates the responses of white sturgeon larvae (Acipenser transmontanus) to starvation and thermal stress, through the measurement of nutritional status (i.e. growth performances) and cellular biomarkers: heat shock proteins (Hsp) 70 and 90. White sturgeon larvae (25 day post hatch; initial weight 179.0 ± 5.1 mg) were fed (20% body weight per day) or starved for 24, 48 or 72 hrs. Every 24 hrs, five larvae from each of the starved or fed treatment replicates were exposed to heat shock resulting from an increase in water temperature from 19°C to 26°C, at a rate of 1°C per 15 min, and maintained at 26°C for 4 hrs. No mortality was observed in this study. Starvation significantly (p < 0.05) decreased the body weight and body contents of energy, protein, and lipid of the experimental larvae, compared to the fed larvae. Heat shock induced the expressions of Hsp70 and Hsp90 in both the fed and starved group; however, starvation reduced the induction at all sampling points. The current study demonstrates that poor larval nutritional status, assessed by the aforementioned parameters, reduced heat shock responses to thermal stress, as measured by heat shock protein levels. Furthermore, Hsp70 and 90 are more sensitive to heat shock and starvation, respectively. This may be, in part, a result of the different functioning of the heat shock proteins in cellular stress response and warrants further study.  相似文献   
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Although the sequence specificity, biostability, and low toxicity of PMO (phosphorodiamidate morpholino oligomers) make them good antisense agents to study gene function, their limited ability to cross cell membranes limits their use in cell culture. In this paper we show that conjugation to arginine-rich peptides significantly enhanced the cellular uptake of PMO. The factors that affect the conjugate's cellular uptake and its antisense activity toward a targeted mRNA were investigated. Factors studied include the number of arginines in the peptide, the choice of cross-linker, the peptide conjugation position, the length of the PMO, and the cell culture conditions. Delivery of PMO to the cell nucleus and cytosol required conjugation rather than complexation of peptides to PMO. R(9)F(2)C was best suited to deliver a PMO to its target RNA resulting in the strongest antisense effect. By simply adding the R(9)F(2)C-PMO conjugate into the cell culture medium at low microM concentration, missplicing of pre-mRNA was corrected. This particular peptide-conjugated PMO was more effective than the PMO conjugated to the transmembrane transport peptides of HIV-1 Tat protein, Drosophila antennapedia protein, or to peptides with fewer arginines. Length of PMO did not affect a peptide's delivery efficacy, but all other factors were important. R(9)F(2)C peptide provided a simple and efficient delivery of PMO to a RNA target. Conjugation of peptide to PMO enhances the opportunities to evaluate gene functions in cell cultures.  相似文献   
49.
Preparation of 14C-Labeled Sterigmatocystin in Liquid Media   总被引:1,自引:2,他引:1       下载免费PDF全文
14C-labeled sterigmatocystin was prepared from surface cultures of Aspergillus versicolor A-18074 maintained in liquid media by multiple additions of [1-14C]acetate to the cultures. The highest yield of 7.75 mg/10 ml was found with a sucrose-asparagine-ammonium medium in which more than 3% of the radioactivity of the added [1-14C]acetate was recovered in the purified [ring-14C] sterigmatocystin. The method offers an easy way to prepare 14C-labeled sterigmatocystin for studies of this mycotoxin.  相似文献   
50.
There is no doubt that Gulf service has affected the well-being of some of the members of the UK armed forces who served in that conflict, yet the reason for this remain unclear. At present, the debate surrounding Gulf War Syndrome (GWS) has become stagnant and highly polarized. This paper argues that a new perspective is needed to further improve our understanding of the problem and suggests that the methods and theories of anthropology, with its focus on nuances and subtleties, can provide new insights. Data were generated from 14 months of ethnographic fieldwork in the UK including participant observation, semi-structured interviews and document analysis. Anthropology provides a unique way of approaching and understanding somatic symptoms and suggests that GWS symptom reporting can be seen as a form of communication. The work focuses on the sufferers' accounts, the symptoms themselves and the context within which we find them in order to better understand what was being expressed and commented upon. Although necessary to contextualize GWS through situating it among other emergent illnesses and widespread health beliefs, this paper shows there is a need to bring back the particular. This work seeks to make sense of the cultural circumstances, specific and general, which gave rise to the illness.  相似文献   
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