Intermolecular Interactions between Cysteine and Aromatic Amino Acids with a Phenyl Moiety in the DNA-Binding Domain of Heat Shock Factor 1 Regulate Thermal Stress-Induced Trimerization.

In this study, we investigated the trimerization mechanism and structure of heat shock factor 1 (HSF1) using western blotting, tryptophan (Trp) fluorescence spectroscopy, and molecular modeling. First, we examined the DNA-binding domains of human (Homo sapiens), goldfish (Carassius auratus), and walleye pollock (Gadus chalcogrammus) HSF1s by mutating key residues (36 and 103) that are thought to directly affect trimer formation. Human, goldfish, and walleye pollock HSF1s contain cysteine at residue 36 but cysteine (C), tyrosine (Y), and phenylalanine (F), respectively, at residue 103. The optimal trimerization temperatures for the wild-type HSF1s of each species were found to be 42, 37, and 20 °C, respectively. Interestingly, a mutation experiment revealed that trimerization occurred at 42 °C when residue 103 was cysteine, at 37 °C when it was tyrosine, and at 20 °C when it was phenylalanine, regardless of the species. In addition, it was confirmed that when residue 103 of the three species was mutated to alanine, trimerization did not occur. This suggests that in addition to trimerization via disulfide bond formation between the cysteine residues in human HSF1, trimerization can also occur via the formation of a different type of bond between cysteine and aromatic ring residues such as tyrosine and phenylalanine. We also confirmed that at least one cysteine is required for the trimerization of HSF1s, regardless of its position (residue 36 or 103). Additionally, it was shown that the trimer formation temperature is related to growth and survival in fish.

Differential virulence of infectious hematopoietic necrosis virus (IHNV) isolated from salmonid fish in Gangwon Province, Korea.

The present study investigated the virulence and expression of innate immunity genes in isolates of infectious hematopoietic necrosis virus (IHNV) in Gangwon province, South Korea, by challenging rainbow trout, Atlantic salmon, and coho salmon. Eight IHNV isolates were used to infect RTG-2 cells for viral replication using plaque assays. Three isolates with the highest replication rates, the RtPc0314g and RtPc0314c isolates of the JRt-Shizuoka type and the RtPc0816g isolate of the JRt-Nagano type, were experimentally infected into the fish. In rainbow trout, both RtPc0314c and RtPc0314g isolates showed 100% cumulative mortality while the RtPc0816g isolate showed 60% cumulative mortality for 14 days. In contrast, all three isolates showed <60% cumulative mortality in Atlantic salmon and coho salmon. The expression of G genes in the kidney was higher than that in the spleen-infected fish, with the highest expression observed in the kidneys of rainbow trout. The relative expression levels of innate immunity genes were higher in rainbow trout than in Atlantic salmon and coho salmon. The expression level of immunoglobulin M increased until day 7, and the expression of type I interferon was higher in the spleen than in other tissues. The expression of Mx-1 was higher in the kidney and liver than other tissues. These results indicate that IHNV isolates from Gangwon province show host-specific virulence in rainbow trout and that their virulence and replication were higher in JRt-Shizuoka type than in JRt-Nagano type isolates.

Potential role of HSP90 in mediating the interactions between estrogen receptor (ER) and aryl hydrocarbon receptor (AhR) signaling pathways.

The estrogen receptor (ER) and aryl hydrocarbon receptor (AhR) are ligand-activated transcription factors involved in estrogen or xenobiotic exposure, whereas the 90-kDa heat shock protein (HSP90), which is a ubiquitously expressed molecular chaperone, is involved in the signal transduction process. Although the interactions between these pathways have been under investigation, the mechanisms are unclear and the potential role of HSP90 in these interactions has not been reported. The results of goldfish primary hepatocytes showed that exposure to PCB77 and 17ß-estradiol (E2) alone induced significant protein expression of cytochrome P450 1A (CYP1A) and vitellogenin (VTG), respectively. On the other hand, the combined exposure to PCB77 and E2 led to the reduction of CYP1A and VTG compared to the single treatments. Although the AhRs and ERs were naturally induced during the co-treatment, the total amount of HSP90 binding to the receptors was not changed. Furthermore, while the HSP90 chaperon activity was blocked by the specific inhibitor (geldanamycin), reciprocal inhibition between AhR and ER pathways was not observed. These findings indicate a potential role of HSP90 where competition between AhR and ER for binding to HSP90 can occur and cause reciprocal inhibition.

Evidence-based practice for pain management for cancer patients in an acute care setting.

The purpose of this study is to implement an evidence utilization project using an audit and feedback approach to improve cancer pain management. A three-phased audit and feedback approach was used. A 46-bed oncology nursing unit in the university's cancer centre was selected as a research site. Nursing records extracted from 137 patients (65 for the baseline assessment and 72 for the follow-up audit) were used to examine nurse compliance with four audit criteria derived from best practice guidelines related to the assessment and management of pain. We observed a significant improvement in compliance from baseline to follow-up for the following criteria: documenting the side effects of opioids (2-83%), use of a formalized pain assessment tool (22-75%), and providing education for pain assessment and management to patients and caregivers (0-47%). The audit and feedback method was applicable to the implementation of clinical practice guidelines for cancer pain management. Leadership from both administrative personnel and staff nurses working together contributes to the spread of an evidence-based practice culture in clinical settings. As it was conducted in a single oncology nursing unit and was implemented over a short period of time, the results should be carefully interpreted.

Nurses' knowledge about end-of-life care: where are we?

BACKGROUND: During the end-of-life stage, patients suffer from multiple symptoms or impairments of altered body systems. This study examined nurses' knowledge of end-of-life care and also the relationship between the nurses' knowledge and their characteristics. METHODS: This was a descriptive, correlational study using a convenience sample of 368 Korean registered nurses working in cancer units, general wards, and intensive care units of a university health system. Twenty questions of the Palliative Care Quiz for Nursing (PCQN) were used to examine nurses' knowledge of end-of-life care. RESULTS: The mean score on the PCQN was 8.95 of a possible 20. Participants who had the end-of-life care education (M = 9.57, SD = 2.19) tended to score higher than those without this education (M = 8.47, SD = 2.34), and the difference was statistically significant. CONCLUSION: Comprehensive continuing education programs on end-of-life care should be provided to fill the gap in knowledge and skill of staff nurses.

Implementation of best practice for chemotherapy-induced nausea and vomiting in an acute care setting.

BACKGROUND: Chemotherapy-induced nausea and vomiting is the commonest side-effect for patients undergoing cancer treatment with chemotherapy. These symptoms can lead to nutritional deficiencies, dehydration and electrolyte imbalance, and negative impacts on quality of life. However, wide gaps exist between clinician and patient perceptions of nausea and vomiting. Effective communication about these symptoms is essential for proper treatment. We conducted a recent chart review to identify gaps in practice regarding chemotherapy-induced nausea and vomiting assessment and documentation. AIM: The goal of this project was to improve local practice in the management of chemotherapy-induced nausea and vomiting in patients with cancer. METHODS: This study used one pre- and two post-implementation audit strategies utilising the Joanna Briggs Institute Practical Application of Clinical Evidence System (JBI-PACES) and Getting Research into Practice (GRiP) module. The study was conducted in the 33-bed oncology ward of a large acute care hospital in Korea from February 2010 to June 2010. To facilitate evidence-based nursing practice, audit-feedback-re-audit cycles strategies were used. The audits included four criteria recommended by the Joanna Briggs Institute. RESULTS: There were statistically significant improvements in all four criteria. The first post-implementation audit showed that all four audit criteria rated >50% in compliance. At the second follow-up audit, all four audit criteria rated 100% compliance, indicating excellent compliance with best practice. The differences between the pre- and post-data were statistically significant (P < 0.001) for all four audit criteria. CONCLUSIONS: The results indicate that the pre- and post-implementation audits are an effective method in improvement of assessment, documentation and evidence-based nursing implementation for cancer symptom management.

Environmental estrogenic effects and gonadal development in wild goldfish (Carassius auratus).

Serum vitellogenin (VTG) contents of wild goldfish (Carassius auratus) were investigated as a sensitive biomarker for artificial estrogenic compounds in aquatic environments. Goldfish was sampled from a pristine area, a river situated 5 km downstream from a sewage treatment works (STW), and also from the Young-San River in Korea. The female yolk precursor protein VTG was not detected when gonadosomatic index (GSI) was less than 0.85%, while VTG levels of >10 microg/ml were found in males whose GSI was less than 1.53%. In male goldfish sampled from STW and the Young-San River, the higher VTG corresponded to lower GSI. This study suggested a trend that gonad development was connected to VTG levels in both sexes, and the application of GSI and histological analysis provide an attractive possibility that it could be included in the panel of markers used for estrogenic activity investigation of aquatic environments.

Two distinct disulfide bonds formed in human heat shock transcription factor 1 act in opposition to regulate its DNA binding activity.

Under circumstances of heat stress, heat shock transcription factor 1 (HSF1) plays important roles in heat shock protein expression. In this study, an increasing concentration of dithiothreitol (DTT) was found to either enhance or inhibit the heat-induced trimerization of HSF1, suggesting the involvement of dual redox-dependent HSF1 activation mechanisms. Our in vitro experiments show that the heat-induced bonding between the cysteine C36 and C103 residues of HSF1 forms an intermolecular disulfide covalent bond (SS-I bond) and that it directly causes HSF1 to trimerize and bond to DNA. Gel filtration assays show that HSF1 can form intermolecular hydrophobic interaction-mediated (iHI-m) noncovalent oligomers. However, the lack of a trimerization domain prevents HSF1 activation, which suggests that iHI-m noncovalent trimerization is a precondition of SS-I bond formation. On the other hand, intramolecular SS-II bond (in which the C153, C373, and C378 residues of HSF1 participate) formation inhibits this iHI-m trimerization, thereby preventing SS-I bond formation and DNA binding. Thus, HSF1 activation is regulated positively by intermolecular SS-I bond formation and negatively by intramolecular SS-II bond formation. Importantly, these two SS bonds confer different DTT sensitivities (the SS-II bond is more sensitive). Therefore, a low concentration of DTT cleaves the SS-II bond but not the SS-I bond and thus improves DNA binding of HSF1, whereas a high concentration DTT cuts both SS bonds and inhibits HSF1 activation. We propose that these interesting effects further explain cellular HSF1 trimerization, DNA binding, and transcription when cells are under stress.