Integrating Web-based technology into distance education for nurses in China: computer and Internet access and attitudes

To increase continuing education accessibility, nurses around the world are turning to Web-based instruction. However, for Internet education to be successful, particularly in developing countries, nurses must have access to computers and the Internet as well as positive attitudes toward this form of learning. As part of a distance education project for nurses of the Tianjin Municipality in China, a survey of nurses was conducted to examine their sources of professional knowledge as well as their computer and Internet access and attitudes. The attitudes of the nurses were generally positive, and there was evidence of rapidly increasing use of and access to computers and the Internet. This article reports the results of that survey and their implications for Web-based teaching of Chinese nurses.     

A role for CD4 in peripheral T cell differentiation

A rapid method for the simultaneous determination of cholesterol and its oxidation products as well as alpha-to-copherol and tocopherolquinone in brain subcellular fractions is described. The samples are saponified and extracted with hexane. It is not necessary to remove cholesterol in the sample before analyzing for oxysterols. The hexane extract can be used for the assay of cholesterol compounds by capillary gas chromatography and tocopherol compounds by liquid chromatography using a procedure reported previously. Oxidation of synaptosomes by a mixture of Fe2+ plus ascorbate resulted in the production of 7-keto-, 7 alpha-hydroxy-, 7 beta-hydroxy-, and 5 alpha, 6 alpha-epoxycholesterols. The identities of these products were confirmed with gas chromatography/mass spectrometry. Cholesterol oxidase treatment did not result in the formation of any of the above compounds. Thus the types and amounts of the products of oxidation of cholesterol were dependent upon the oxidizing agent. Extraction of the oxysterols under milder conditions without saponification using sodium dodecyl sulfate cannot be used since such treatment results in low recovery of oxysterols. Oxidation of synaptosomes by low concentrations of ferrous iron and ascorbate resulted in (i) low levels of oxidation of cholesterol which could be followed by estimating the production of oxysterols and (ii) oxidation of a substantial percentage of alpha-tocopherol. The proposed procedure will be useful in monitoring the oxidation of small quantities of membrane cholesterol in vitro.     

Regulation of monocyte IL-10 synthesis by endogenous IL-1 and TNF-alpha: role of the p38 and p42/44 mitogen-activated protein kinases

IL-10 is an anti-inflammatory cytokine with potent immunomodulatory effects, including inhibition of cytokine production. However, regulation of monocyte IL-10 production is poorly understood. In this report we have investigated the mechanisms of LPS-induced IL-10 production by human peripheral blood monocytes and demonstrate that IL-10 synthesis is uniquely dependent on the endogenous proinflammatory cytokines IL-1 and/or TNF-alpha. LPS signal transduction in monocytes has been shown to involve activation of the p38 and p42 mitogen-activated protein kinase (MAPK) cascades. The results in this paper indicate that inhibition of p38 MAPK potently inhibited the production of IL-10, IL-1beta, and TNF-alpha, whereas blockade of the p42/44 MAPK pathway, while partially inhibiting TNF-alpha and IL-1beta production, had no effect on monocyte secretion of IL-10. Furthermore, neither the inhibition of monocyte TNF-alpha induced by IL-10 nor the stimulation of soluble TNF receptor production was affected by inhibition of the p42/44 MAPK pathway, suggesting that this signaling event is not involved in either monocyte production of or anti-inflammatory responses to IL-10. These data raise the interesting possibility that proinflammatory TNF-alpha-mediated effects may be selectively blocked without modulating the induction or the response to IL-10, whereas the signaling events associated with the anti-inflammatory events induced by IL-10 remain to be elucidated.     

Identification of conserved amino acids in the human granulocyte-macrophage colony-stimulating factor receptor alpha subunit critical for function. Evidence for formation of a heterodimeric receptor complex prior to ligand binding

A superfamily of growth factor and cytokine receptors has recently been identified, which is characterized by four spatially conserved cysteine residues, a tryptophan-serine motif (WSXWS) in the extracellular domain, and a proline-rich cytoplasmic domain. The high affinity human granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor (hGM-CSFR) consists of two subunits, alpha (hGM-CSFR alpha) and beta (hGM-CSFR beta), both of which are members of the receptor superfamily. In this study, we prepared mutations in conserved amino acids of the receptor subunit necessary for GM-CSF binding (hGM-CSFR alpha) and analyzed mutant receptors for low affinity binding, internalization, and high affinity binding when complexed with the beta subunit. Mutations in the cytoplasmic domain did not affect GM-CSF binding or receptor internalization. Mutation of a single conserved serine residue within the WSXWS motif diminishes cell surface receptor expression but not ligand binding. Mutation of either the second or third conserved cysteine residue of hGM-CSFR alpha resulted in complete loss of low affinity binding; however, co-expression of the cysteine 2 mutant with hGM-CSFR beta yielded a high affinity receptor complex. Since neither the cysteine 2 mutant nor the beta subunit can bind ligand alone, this result suggests that hGM-CSFR alpha and hGM-CSFR beta exist in a preformed heterodimeric protein complex on the plasma membrane.