Structural analysis of chloroplast tail-anchored membrane protein recognition by ArsA1.

In mammals and yeast, tail-anchored (TA) membrane proteins destined for the post-translational pathway are safely delivered to the endoplasmic reticulum (ER) membrane by a well-known targeting factor, TRC40/Get3. In contrast, the underlying mechanism for translocation of TA proteins in plants remains obscure. How this unique eukaryotic membrane-trafficking system correctly distinguishes different subsets of TA proteins destined for various organelles, including mitochondria, chloroplasts and the ER, is a key question of long standing. Here, we present crystal structures of algal ArsA1 (the Get3 homolog) in a distinct nucleotide-free open state and bound to adenylyl-imidodiphosphate. This approximately 80-kDa protein possesses a monomeric architecture, with two ATPase domains in a single polypeptide chain. It is capable of binding chloroplast (TOC34 and TOC159) and mitochondrial (TOM7) TA proteins based on features of its transmembrane domain as well as the regions immediately before and after the transmembrane domain. Several helices located above the TA-binding groove comprise the interlocking hook-like motif implicated by mutational analyses in TA substrate recognition. Our data provide insights into the molecular basis of the highly specific selectivity of interactions of algal ArsA1 with the correct sets of TA substrates before membrane targeting in plant cells.

[Application of Team-Based Games in the Classroom: Teaching Medical Terminology as an Example].

Healthcare providers use distinct medical terminology to communicate in professional healthcare settings in Taiwan. Moreover, nursing students understand the importance of acquiring a good command of this medical terminology to the development of their professional careers. Thus, using proper teaching strategies to boost student participation and interest in their studies is an important responsibility and task. Social Learning Theory has been widely used in education. According to this theory, learners learn about new models of behavior and modify old models through observation and imitation. Moreover, they gain opportunities for observation and imitation through social interaction. Team-based games that are based on this theory are designed to enhance interest in study and interpersonal interaction among learners through peer observation and study and help promote active learning and group study. This article describes the use of a team-based game to teach the strategies involved in selecting medical terminologies commonly used in clinical settings. This game has earned positive responses and evaluations from students. Nursing teachers may design diversified team-based games and use this teaching strategy to teach medical terminology as well as other subjects.

[Applying Game-Based Learning in Nursing Education: Empathy Board Game Learning].

Attending lectures and reading are two common approaches to acquiring knowledge, while repetitive practice is a common approach to acquiring skills. Nurturing proper attitudes in students is one of the greatest challenges for educators. Health professionals must incorporate empathy into their practice. Creative teaching strategies may offer a feasible approach to enhancing empathy-related competence. The present article focuses on analyzing current, empathy-related curriculums in nursing education in Taiwan, exploring the concepts of empathy and game-based learning, presenting the development of an empathy board game as a teaching aid, and, finally, evaluating the developed education application. Based on the learner-centered principle, this aid was designed with peer learning, allowing learners to influence the learning process, to simulate the various roles of clients, and to develop diverse interpersonal dialogues. The continuous learning loops were formed using the gamification mechanism and transformation, enabling students to connect and practice the three elements of empathy ability: emotion, cognition and expression. Via the game elements of competition, interaction, storytelling, real-time responses, concretizing feedback, integrated peer learning, and equality between teachers and students, students who play patient roles are able to perceive different levels of comfort, which encourages the development of insight into the meaning of empathy. Thereby, the goals of the empathy lesson is achievable within a creative game-based learning environment.

Enzymatic characterization and crystal structure analysis of Chlamydomonas reinhardtii dehydroascorbate reductase and their implications for oxidative stress.

Dehydroascorbate reductase (DHAR) is a key enzyme for glutathione (GSH)-dependent reduction of dehydroascorbate (DHA) to recycled ascorbate (AsA) in plants, and plays a major role against the toxicity of reactive oxygen species (ROS). Previously, we proposed that the increase of AsA regeneration via enhanced DHAR activity modulates the ascorbate-glutathione cycle activity against photooxidative stress in Chlamydomonas reinhardtii. In the present work, we use site-directed mutagenesis and crystal structure analysis to elucidate the molecular basis of how C. reinhardtii DHAR (CrDHAR1) is involved in the detoxification mechanisms. Mutagenesis data show that the D21A, D21N and C22A mutations result in severe loss of the enzyme's function, suggesting crucial roles of Asp-21 and Cys-22 in substrate binding and catalysis. The mutant K11A also exhibits reduced redox activity (∼50%). The crystal structure of apo CrDHAR1 further provides insights into the proposed mechanism centering on the strictly conserved Cys-22, which is suggested to initiate the redox reactions of DHA and GSH. Furthermore, in vitro oxidation of the recombinant CrDHAR1 in the presence of 1 mM H2O2 has minor effects on the Km for the substrates but significantly reduces the kcat. The enzyme's activity and its mRNA abundance in the C. reinhardtii cells are increased by treatment with 0.2-1 mM H2O2 but decreased when H2O2 is ≥ 1.5 mM. The latter decrease is accompanied by oxidative damage and lower AsA concentrations. These biochemical and physiological data provide new insights into the catalytic mechanism of CrDHAR1, which protects the C. reinhardtii cells from oxidative stress-induced toxicity.

In search of tail-anchored protein machinery in plants: reevaluating the role of arsenite transporters.

Although the mechanisms underlying selective targeting of tail-anchored (TA) membrane proteins are well established in mammalian and yeast cells, little is known about their role in mediating intracellular membrane trafficking in plant cells. However, a recent study suggested that, in green algae, arsenite transporters located in the cytosol (ArsA1 and ArsA2) control the insertion of TA proteins into the membrane-bound organelles. In the present work, we overproduced and purified these hydrophilic proteins to near homogeneity. The analysis of their catalytic properties clearly demonstrates that C. reinhardtii ArsA proteins exhibit oxyanion-independent ATPase activity, as neither arsenite nor antimonite showed strong effects. Co-expression of ArsA proteins with TA-transmembrane regions showed not only that the former interact with the latter, but that ArsA1 does not share the same ligand specificity as ArsA2. Together with a structural model and molecular dynamics simulations, we propose that C. reinhadtii ArsA proteins are not arsenite transporters, but a TA-protein targeting factor. Further, we propose that ArsA targeting specificity is achieved at the ligand level, with ArsA1 mainly carrying TA-proteins to the chloroplast, while ArsA2 to the endoplasmic reticulum.

Concealing emotions: nurses' experiences with induced abortion care.

AIMS AND OBJECTIVES: To explore the experiences of nurses involved with induced abortion care in the delivery room in Taiwan. BACKGROUND: Induced abortion has emotional, ethical and legal facets. In Taiwan, several studies have addressed the ethical issues, abortion methods and women's experiences with abortion care. Although abortion rates have increased, there has been insufficient attention on the views and experiences of nurses working in the delivery room who are involved with induced abortion care. DESIGN: Qualitative, semistructured interviews. METHODS: This study used a purposive sampling method. In total, 22 nurses involved with induced abortion care were selected. Semistructured interviews with guidelines were conducted, and the content analysis method was used to analyse the data. RESULTS: Our study identified one main theme and five associated subthemes: concealing emotions, which included the inability to refuse, contradictory emotions, mental unease, respect for life and self-protection. CONCLUSION: This is the first specific qualitative study performed in Taiwan to explore nurses' experiences, and this study also sought to address the concealing of emotions by nurses when they perform induced abortion care, which causes moral distress and creates ethical dilemmas. The findings of this study showed that social-cultural beliefs profoundly influence nurses' values and that the rights of nurses are neglected. RELEVANCE TO CLINICAL PRACTICE: The profession should promote small-group and case-study discussions, the clarification of values and reflective thinking among nurses. Continued professional education that provides stress relief will allow nurses to develop self-healing and self-care behaviours, which will enable them to overcome the fear of death while strengthening pregnancy termination counselling, leading to better quality professional care.

Taiwanese nurses' experiences of difficulties in providing patient education in hospital settings.

Taiwanese nurses face increasingly demanding working conditions along with a distinctive culture where family members participate in medical decisionmaking. This research explores Taiwanese nurses' perceptions of patient education, with a focus on the difficulties. Data were collected by in-depth focus group discussions with nursing staff (n=53) from the medical and surgical wards of two teaching hospitals. Transcripts were analyzed and revealed six themes: source of fulfillment and pressure; excessive workload; alternating between patients; not knowing who to teach; difficulty in communication; and disrupted confidence and work rhythm. Research findings could help managers understand the difficulties faced by nurses in providing health education. Nurses should broaden the scope of patient education activities to include family members. Additionally, nurses should discuss patients' desires and expectations from family members in medical treatment and decisionmaking.

Reasons for middle-aged women in Taiwan to choose hysterectomy: a qualitative study using the bounded rationality perspective.

AIMS AND OBJECTIVES: To explore women's perspectives on deciding to undergo hysterectomy for benign conditions based on physicians' recommendations and the women's own judgement. BACKGROUND: Hysterectomy is the second most common surgical procedure worldwide. Although most hysterectomies are elective, physicians may recommend treatment that involves a loss of sexuality or ovary removal, creating a difficult choice for women. DESIGN: Qualitative, in-depth interview METHODS: A purposive sample of 17 women was recruited. The women had decided to undergo hysterectomy after the diagnosis of uterine fibroids. All these women had already decided not to have more children. Data were collected by in-depth interviewing, and content analysis was used to analyse the data. RESULTS: Our study revealed five themes: release from stress, inescapable fate, positive support, hoping for peace of mind and sense of trust. CONCLUSIONS: The participants felt that mental and physical health were the most important considerations, noting that when women no longer want children, a uterus is useless. The women believed that they retained their womanhood, even without a uterus, and were satisfied with the outcomes of their hysterectomy decisions. RELEVANCE TO CLINICAL PRACTICE: Our findings might serve as educational and counselling reference materials for healthcare providers, ensuring that women receive appropriate care quality and have their needs met. Healthcare providers can then maximise women's empowerment, deepen their awareness of body image and their concept of self-care and help them to clearly perceive their own concerns and needs so that they can make suitable decisions.

Rifaximin versus Nonabsorbable Disaccharides for the Treatment of Hepatic Encephalopathy: A Meta-Analysis.

Background. Many studies have found that the antibiotic rifaximin is effective for the treatment of hepatic encephalopathy. However, there is no uniform view on the efficacy and safety of rifaximin. Methods. We performed a meta-analysis through electronic searches to evaluate the efficacy and safety of rifaximin in comparison with nonabsorbable disaccharides. Results. A total of 8 randomized controlled trials including 407 patients were included. The efficacy of rifaximin was equivalent to nonabsorbable disaccharides according to the statistical data (risk ratio (RR): 1.06, 95% CI: 0.94-1.19; P = 0.34). Analysis showed that patients treated with rifaximin had better results in serum ammonia levels (weighted mean difference (WMD): -10.63, 95% CI: -30.63-9.38; P = 0.30), mental status (WMD: -0.32, 95% CI: -0.67-0.03; P = 0.07), asterixis (WMD: -0.12, 95% CI: -0.31-0.08; P = 0.23), electroencephalogram response (WMD: -0.21, 95% CI: -0.34--0.09; P = 0.0007), and grades of portosystemic encephalopathy (WMD: -2.30, 95% CI: -2.78--1.82; P < 0.00001), but only the last ones had statistical significance. The safety of rifaximin was better than nonabsorbable disaccharides (RR: 0.19, 95% CI: 0.10-0.34; P < 0.00001). Conclusion. Rifaximin is at least as effective as nonabsorbable disaccharides, maybe better for the treatment of hepatic encephalopathy. And the safety of rifaximin is better.

Cultural implications of managing chronic illness: treating elderly Chinese patients with heart failure.

Dietary patterns are associated with morbidity and mortality of heart failure. Volume overload was the most common cause for re-hospitalization for heart failure patients. However, recommended preventive strategies of restricting excessive dietary sodium and fluid intake were found to be in vain. This study looks at the preventive dietary instructions from a cultural context, and examined the effects of sodium and fluid restriction on twelve elderly Chinese patients hospitalized with heart failure through a qualitative design. Four themes emerged from the data: medicine-food homology, salt and sodium as synonymous, activity intolerance but still wanting social connections, and barriers to asking questions. Results suggested that living with heart failure is a complex and changeable process for both patients and caregivers. Many patients reported low levels of understanding concerning their symptoms and heart function deterioration. The findings found that good communication requires cultural sensitivity, objective listening to the patient's narrative, and helping patients find meaning between their experiences and symptom control.

Mechanism of action of salinomycin on growth and migration in pancreatic cancer cell lines.

OBJECTIVES: Pancreatic cancer is one of the most aggressive and lethal cancers worldwide and there are few effective treatments. Recently, salinomycin (Sal) was reported to alter proliferation and apoptosis in various tumors. This prompted us to investigate the effect of Sal on pancreatic cancer cells and to explore the possible molecular mechanism in vitro. METHODS: After treatment with Sal, pancreatic cancer cell viability and apoptosis were analyzed by Hoechst 33342 staining and flow cytometry, respectively. Invasion and metastasis of pancreatic cancer cells were assayed by a Transwell migration assay. Flow cytometry was also used to assessed the fraction of CD133(+) cell subpopulations. The expression of proliferating cell nuclear antigen (PCNA), Bcl-2, E-cadherin, and Wnt/ß-catenin signaling-related proteins were detected by RT-PCR and western blot. RESULTS: Sal inhibited the growth and migration of pancreatic cancer cells in vitro in a dose- and time-dependent manner. We found that the proportion of CD133(+) cell subpopulations decreased after treatment with Sal in pancreatic cancer cell lines at the same time. The percentage of apoptotic cells was increased after Sal treatment. Compared with control groups, Bax and E-cadherin were significantly upregulated, and Bcl-2 and PCNA were significantly downregulated in Sal-treated cells. The expression of Wnt/ß-catenin signaling-related proteins (ß-catenin and p-GSK-3ß) was inhibited. CONCLUSIONS: These results indicate that Sal could influence the cell growth and migration in pancreatic cancer cells in vitro, which may occur by inhibition of Wnt/ß-catenin signaling.

Salinomycin inhibits proliferation and induces apoptosis of human hepatocellular carcinoma cells in vitro and in vivo.

The anti-tumor antibiotic salinomycin (Sal) was recently identified as a selective inhibitor of breast cancer stem cells; however, the effect of Sal on hepatocellular carcinoma (HCC) is not clear. This study aimed to determine the anti-tumor efficacy and mechanism of Sal on HCC. HCC cell lines (HepG2, SMMC-7721, and BEL-7402) were treated with Sal. Cell doubling time was determinated by drawing growth curve, cell viability was evaluated using the Cell Counting Kit 8. The fraction of CD133(+) cell subpopulations was assessed by flow cytometry. We found that Sal inhibits proliferation and decreases PCNA levels as well as the proportion of HCC CD133(+)cell subpopulations in HCC cells. Cell cycle was analyzed using flow cytometry and showed that Sal caused cell cycle arrest of the various HCC cell lines in different phases. Cell apoptosis was evaluated using flow cytometry and Hoechst 33342 staining. Sal induced apoptosis as characterized by an increase in the Bax/Bcl-2 ratio. Several signaling pathways were selected for further mechanistic analyses using real time-PCR and Western blot assays. Compared to control, ß-catenin expression is significantly down-regulated upon Sal addition. The Ca(2+) concentration in HCC cells was examined by flow cytometry and higher Ca(2+) concentrations were observed in Sal treatment groups. The anti-tumor effect of Sal was further verified in vivo using the hepatoma orthotopic tumor model and the data obtained showed that the size of liver tumors in Sal-treated groups decreased compared to controls. Immunohistochemistry and TUNEL staining also demonstrated that Sal inhibits proliferation and induces apoptosis in vivo. Finally, the role of Sal on in vivo Wnt/ß-catenin signaling was evaluated by Western blot and immunohistochemistry. This study demonstrates Sal inhibits proliferation and induces apoptosis of HCC cells in vitro and in vivo and one potential mechanism is inhibition of Wnt/ß-catenin signaling via increased intracellular Ca(2+) levels.

Cultural and hierarchical influences: ethical issues faced by Taiwanese nursing students.

OBJECTIVES Improving nurses' competence in resolving clinical ethical issues must start with ethics education in training and clinical practice. However, many students complain that they cannot apply classroom learning to actual clinical scenarios. This study explored ethical issues and dilemmas, and their impact experienced by student nurses in clinical practice. METHODS Focus groups were conducted with 44 first-year student nurses from a 2-year college course in northern Taiwan. Interviews were tape-recorded and verbatim transcripts were analysed using content analysis. RESULTS Students expressed and discussed their views in eight focus groups. Analysis of interviews revealed five themes: frustration at inability to help some patients; oppression caused by lower status; lack of honesty and ethical courage; powerlessness, and self-encouragement in adversity. CONCLUSIONS Taiwanese nurse ethics training was only recently introduced and the curriculum has not addressed the clinical reality in Taiwan. This reality includes limitations arising from the medical hierarchy and the socio-cultural role of families in medical decision making, which may inhibit ethical judgements and decision making. In clinical dilemmas, the most common problems faced by Taiwanese nursing students involved not knowing how to handle some situations, inability to abide by principles, and a lack of appropriate role models. Hence, we suggest that nursing ethics education should: (i) integrate scenarios involving ethical dilemmas into daily routines; (ii) give students opportunities to discuss their feelings about their experiences; (iii) allow teachers and students to talk about scenarios with ethical implications, and (iv) provide students with opportunities to reflect on clinical scenarios in order to clarify their values and learn how to respect the value of life.

An ongoing process: a qualitative study of how the alcohol-dependent free themselves of addiction through progressive abstinence.

BACKGROUND: Most people being treated for alcoholism are unable to successfully quit drinking within their treatment programs. In few cases do we know the full picture of how abstinence is achieved in Taiwan. We tracked processes of abstinence in alcohol-dependency disorders, based on study evidence and results. This research explores the process of recovery from the viewpoint of the alcohol-dependent. METHODS: Semi-structured interviews were conducted in two different settings, using purpose sampling, during 2003-2004. The data were analyzed using content analysis. Participants were 32 adults, purposefully selected from an Alcoholics Anonymous group and a psychiatric hospital in North Taiwan. RESULTS: We found that the abstinence process is an ongoing process, in which the alcohol-dependent free themselves of addiction progressively. This process never ends or resolves in complete recovery. We have identified three stages in the struggle against alcoholism: the Indulgence, Ambivalence and Attempt (IAA) cycle, in which the sufferer is trapped in a cycle of attempting to give up and failing; the Turning Point, in which a Personal Nadir is reached, and the Ongoing Process of abstinence, in which a constant effort is made to remain sober through willpower and with the help of support groups. We also discuss Influencing Factors that can derail abstinence attempts, pushing the sufferer back into the IAA cycle. CONCLUSION: This study provides important points of reference for alcohol and drug service workers and community healthcare professionals in Taiwan, casting light on the abstinence process and providing a basis for intervention or rehabilitation services.

[Comparison of immune responses induced by recombinant attenuated Salmonella typhi carrying eukaryotic expression plasmid or prokaryotic expression plasmid of HCV core protein].

Hepatitis C virus (HCV) core protein is considered to be an attractive candidate for development of protective HCV vaccines. However, this protein may attenuate the induction of systemic immune responses due to its immunomodulatory properties. In this study, we constructed a HCV core gene-containing eukaryotic expression plamid pCI-C, and an in vivo-inducible prokaryotic expression plasmid pZW-C, and transformed the recombinant plasmids into an attenuated Salmonella typhimurium aroA strain SL7207. The resulting bacterial strains SL7207/pCI-C and SL7207/pZW-C were used to orally immunize BALB/c mice, and the immune responses specific to HCV core protein were assessed. Immunization with the recombinant bacteria SL7207/pCI-C led to a persistent drop in percentage of CD3 CD4 T cells, and induced a weak anti-core IgG production. Splenocytes from SL7207/pCI-C immunized mice developed a relatively weak proliferation response and inferior cytotoxic activity compared to those from the mice immunized with bacteria SL7207/pZW-C. Boost immunization with SL7207/ pCI-C yielded limited improvement in immune strength, while the boost with bacteria SL7207/pZW-C significantly enhanced the immune response. These results suggest that de novo synthesis of native HCV core protein may blunt the induction of immune responses. Attenuated S. typhimurium carrying HCV core protein could efficiently activate systemic cellular and humoral responses, and may be a promising strategy for the development of core-based HCV vaccines.

The self-empowerment process of primary caregivers: A study of caring for elderly with dementia.

The purpose of this qualitative research was to explore and develop the process of self-empowerment for primary caregivers responsible for caring for elderly with dementia. Nine primary caregivers who lived in northern Taiwan were interviewed through a theoretical sampling procedure. In-depth, face-to-face interviews were tape-recorded and transcribed verbatim. The grounded theory method was applied for analyzing data. The six main components that emerged in this model: "filial piety", "feeling of out of control", "inner awareness", "care ability", "emotion reconstruction", and "life management". This model starts from "filial piety" and "feeling of out of control," then evokes caregivers' "inner awareness". The inner awareness powerfully influences caregivers' "care ability", "emotion reconstruction" and "life management," which account for the three inner mechanism parts in their caregiving experience. Each part comprises three stages that are influenced by "inner awareness". The lower stage of each part supports the next higher stage. The same stages in all parts parallel one another, and influence each other by providing support or creating barriers. On the other side, competition between support and barriers from the outside environment determines the completion of this self-empowerment process. Results of this research extend the knowledge in understanding the psychological processes related to caring for elderly with dementia. The findings also provide readers a positive viewpoint on the caring experiences of primary caregivers of elderly with dementia.

Decision-making tree for women considering hysterectomy.

AIMS: This paper reports on a study carried out to establish a decision tree model to describe how women in Taiwan make the decision whether or not to have a hysterectomy. In addition, we examined the predictability of the decision-tree model. BACKGROUND: Hysterectomy is the second most common surgical procedure performed worldwide. Medical professionals believe that the operation can relieve pain and prevent cervical cancer, thus improving a woman's quality of life. While most physicians advise hysterectomy even for benign uterine conditions, feminists decry the belief that the uterus has no purpose, believing that it is an important symbol of womanhood. METHODS: The study was conducted in two phases. Phase I, the model development phase, was carried out to generalize data from a qualitative study of 14 women and to establish a tree model outlining their decision to proceed with hysterectomy. The second phase was the model prediction phase that applied inductive and deductive methods to data analysis and development of the decision-tree model. The model tree was then tested with 18 women who were deciding whether or not to undergo hysterectomy. Using the decision-making tree, we studied the women's thought processes and analysed their primary concerns. The study was carried out in 1999-2001. RESULTS: The study determined 13 criteria that Taiwanese women use when deciding about having a hysterectomy. Developed in accordance with Gladwin's methodology, the model tree successfully predicted 90% of decisions whether or not to have a hysterectomy. CONCLUSIONS: Nurses working in gynaecological services should understand how women decide to undergo hysterectomy so that the proper counselling and follow-up can be provided. With further testing, our decision tree may help in this process.