Expression and activation of RAS and mitogen-activated protein kinases in macrophages treated in vitro with cisplatin: regulation by kinases, phosphatases and Ca2+/calmodulin

Predictors of patients' experiences of nursing care in medical-surgical wards

The purposes of this study were to explore patients' opinions of nursing care and to identify predictors of patients' experiences of nursing care in medical-surgical wards. The sample of the study was 225 adult patients in medical-surgical wards in a major teaching hospital in Jordan. The experiences of nursing care total score in this study was relatively high. The findings showed that the majority of the participants had positive experiences regarding the time nurses spent with them as well as the respect nurses provided to patients' relatives and friends. Although the amount of information nurses provided to patients was found to be a significant predictor of patients' experiences, the provided information was perceived by the majority of the patients as inadequate. Identifying factors that enhance patients' experiences of nursing care is crucial as it assists nurses to provide better care.

In vitro activation of murine peritoneal macrophages by ultraviolet B radiation: upregulation of CD18, production of NO, proinflammatory cytokines and a signal transduction pathway

In the present study, we report the activation of murine peritoneal macrophages in vitro on irradiation with sublethal dose of UVB (50 mJ/cm(2)). The activation involves enhanced expression of CD18 molecule and production of nitric oxide (NO), tumor necrosis factor (TNF-alpha) and interleukin-1 (IL-1). Production of NO, TNF-alpha and IL-1 by the macrophages on UVB irradiation was found to peak at 24 h of incubation post UVB irradiation. Increased iNOS, TNF-alpha and IL-1beta mRNAs expression was also observed by reverse transcription and polymerase chain reaction (RT-PCR). The RT-PCR results also showed the increased transcription of IL-6, IL-12, TLR2 and TLR4 genes in UVB-irradiated macrophages. Increased expression of phospho-IkappaB was also observed by immunoblotting in UVB-irradiated macrophages. Investigating the signal transduction pathway responsible for the NO, TNF-alpha and IL-1 production by the UVB-irradiated macrophages, it was observed that the pharmacological inhibitors pertussis toxin, wortmannin, PD98059, SB202190 and genistein blocked NO, TNF-alpha and IL-1 production suggesting the probable involvement of G-proteins, phosphoinositol-3-kinase, p42/44, p38 mitogen activated protein kinases and tyrosine kinases in the above process.

Activation of c-Jun N-terminal kinase is required for ultraviolet B-induced apoptosis of murine peritoneal macrophages in vitro

The mechanisms of ultraviolet B (UVB)-induced apoptosis and the role of c-Jun N-terminal kinase (JNK) mitogen activated protein kinase (MAPK) in murine peritoneal macrophages, the terminally differentiated non-dividing cells were investigated. Exposure of macrophages to UVB 100 mJ/cm2 induced rapid apoptosis concurrent with activation of JNK and mitochondrial cytochrome c release leading to procaspase-3 activation. Late into the UVB-induced apoptosis, a caspase-mediated cleavage of Bid was observed. Caspase inhibitors N-Benzylocarbonyl-Val-Asp-fluoromethyl ketone and N-Acetyl-Asp-Glu-Val-Asp-aldehyde inhibited the UVB-induced apoptosis without preventing the release of cytochrome c and JNK activation. The inhibition of JNK MAPK prevented UVB-induced apoptosis, concomitant with inhibition in cytochrome c release and procaspase-3 activation. However, it had no effect on procaspase-8 activation. These results indicate that activation of JNK MAPK upstream of caspases might play an important role in the apoptotic process of macrophages exposed to UVB irradiation.

Monocyte chemoattractant protein-1-induced activation of p42/44 MAPK and c-Jun in murine peritoneal macrophages: a potential pathway for macrophage activation

The role of monocyte chemoattractant protein-1 (MCP-1) in mediating the infiltration and activation of monocytes/macrophages into the sites of inflammation or tumor growth is well documented, but the molecular mechanism(s) involved in the process is poorly understood. In the current investigation, we demonstrate activation of the p42/44 MAPK-mediated signal transduction in murine peritoneal macrophages on stimulation with MCP-1 (10-100 ng/ml) in vitro. The p42/44 MAPK activation was determined by studying the expression of the phosphorylated p42/44 MAPK (Thr202/Tyr204) in the MCP-1-treated macrophages. This response was found to be rapid and time dependent, detectable within 5 min of MCP-1 stimulation. PD98058 (5-50 microM), a specific inhibitor of MAPK kinase (MEK) inhibited the p42/44 MAPK phosphorylation, indicating the specificity of the response. Furthermore, the MCP-1-induced phosphorylation of p42/44 MAPK was found to be blocked by pertussis toxin (100 ng/ml), tyrosine kinase inhibitor-genestein (10 ng/ml), PI3K inhibitor-wortmannin (20-200 microM), and anti-CCR2 antibody (2.5 microg/ml). Additionally, phosphorylation of JNK and activation of the transcription factor, c-Jun, were also noted in response to MCP-1 treatment. Lastly, the MCP1-induced p42/44 MAPK activity was correlated with the functional activation of macrophages by demonstrating the dose-specific inhibition of actin polymerization, macrophage-mediated tumor cell cytotoxicity, and tumor necrosis factor-alpha (TNF-alpha) transcription/production afforded by PD98059 in the MCP-1-treated macrophages. Taken together, these data suggest the involvement of the p42/44 MAPK/c-Jun pathway in the signal transduction process, leading to activation of murine peritoneal macrophages.