Biomedical subjects
Publications and source records attributed to J Cheek.
This study describes preliminary results of an investigation of RMSF in Arizona associated with the brown dog tick, Rhipicephalus sanguineus. High numbers of dogs and heavy infestations of ticks created a situation leading to human disease.
Iron-sulfur clusters are widespread in biological systems and participate in a broad range of functions. These functions include electron transport, mediation of redox as well as non-redox catalysis, and regulation of gene expression. A new role for iron-sulfur clusters has emerged in recent years as a number of enzymes have been identified that utilize Fe-S clusters and S-adenosylmethionine (AdoMet) to initiate radical catalysis. This Fe-S cluster-mediated radical catalysis includes the generation of stable protein-centered radicals as well as generation of substrate radical intermediates, with evidence suggesting a common mechanism involving an intermediate adenosyl radical. Although the mechanism of generation of the adenosyl radical intermediate is currently not well understood, it likely represents novel chemistry for iron-sulfur clusters. The purpose of this review is to present the current state of knowledge of this newly emerging group of Fe-S/AdoMet enzymes.
This exploratory, descriptive study examined the search and selection process for an aged care facility following discharge of a family member from an acute setting. Few studies have examined this process and its effects on families. Individuals from 25 families where a family member had been recently admitted to an aged care facility following discharge from an acute setting were interviewed. This article reports participants' perceptions of the search and selection process and its effect on the family. Five major themes emerged from the data: good fortune, wear and tear on the sponsor, dealing with the system, urgency, and adjusting. The results can be used to inform and assist families and health professionals working with families in this situation.
Searching for, and selecting, an aged care facility for a family member upon his or her discharge from an acute setting is known, anecdotally, to be a challenge; but the process itself, and its effects on families, has seldom been examined. In this exploratory/descriptive study, face-to-face in-depth interviews were conducted with sponsors (often family members) of residents who had been admitted to an aged care facility within the past 90 days, following their discharge from an acute care setting. Where possible, both sponsor and resident were interviewed. This paper reports on the participants' perceptions of the search and selection process. Specific areas of interest were probed: Why and how the decision was made to seek residential placement; when and how the search for an aged care facility began; factors that were important in the family's final selection process; what happened when families, either initially or in the long term, were unable to find a place in an aged care facility; and the family's perspective about the efficacy of the search and selection process and its effect on the well being of the family. Residents are often passive in the search and selection process, while sponsors are often actively involved. Very few residents or sponsors consider planning for an aged care facility prior to hospitalisation, and there is often the perception by families of having very little support at this stressful and emotional time. The decision to relocate a family member in these circumstances is a stressful experience and should be viewed as a family crisis, particularly if unexpected such as upon discharge from an acute setting. These findings provide valuable insights that can be used to guide and assist families experiencing this process, as well as health care professionals working with families in this situation.
To better understand the spectral properties of high valent and oxyferrous states in naturally occurring iron chlorin-containing proteins, we have prepared the oxoferryl compound I derivative of iron methylchlorin-reconstituted horseradish peroxidase (MeChl-HRP) and the compound II and oxyferrous compound III states of iron MeChl-reconstituted myoglobin. Initial spectral characterization has been carried out with UV-visible absorption and magnetic circular dichroism. In addition, the peroxidase activity of iron MeChl-HRP in pyrogallol oxidation has been found to be 40% of the rate for native HRP. Previous studies of oxoferryl chlorins have employed tetraphenylchlorins in organic solvents at low temperatures; stable oxyferrous chlorins have not been previously examined. The present study describes the compound I, II, and III states of histidine-ligated iron chlorins in a protein environment for the first time.
The Escherichia coli lipA gene product has been genetically linked to carbon-sulfur bond formation in lipoic acid biosynthesis [Vanden Boom, T. J., Reed, K. E., and Cronan, J. E., Jr. (1991) J. Bacteriol. 173, 6411-6420], although in vitro lipoate biosynthesis with LipA has never been observed. In this study, the lipA gene and a hexahistidine tagged lipA construct (LipA-His) were overexpressed in E. coli as soluble proteins. The proteins were purified as a mixture of monomeric and dimeric species that contain approximately four iron atoms per LipA polypeptide and a similar amount of acid-labile sulfide. Electron paramagnetic resonance and electronic absorbance spectroscopy indicate that the proteins contain a mixture of [3Fe-4S] and [4Fe-4S] cluster states. Reduction with sodium dithionite results in small quantities of an S = 1/2 [4Fe-4S](1+) cluster with the majority of the protein containing a species consistent with an S = 0 [4Fe-4S](2+) cluster. LipA was assayed for lipoate or lipoyl-ACP formation using E. coli lipoate-protein ligase A (LplA) or lipoyl-[acyl-carrier-protein]-protein-N-lipoyltransferase (LipB), respectively, to lipoylate apo-pyruvate dehydrogenase complex (apo-PDC) [Jordan, S. W., and Cronan, J. E. (1997) Methods Enzymol. 279, 176-183]. When sodium dithionite-reduced LipA was incubated with octanoyl-ACP, LipB, apo-PDC, and S-adenosyl methionine (AdoMet), lipoylated PDC was formed. As shown by this assay, octanoic acid is not a substrate for LipA. Confirmation that LipA catalyzes formation of lipoyl groups from octanoyl-ACP was obtained by MALDI mass spectrometry of a recombinant PDC lipoyl-binding domain that had been lipoylated in a LipA reaction. These results provide information about the mechanism of LipA catalysis and place LipA within the family of iron-sulfur proteins that utilize AdoMet for radical-based chemistry.
Pyruvate formate-lyase-activating enzyme (PFL-AE) from Escherichia coli (E. coli) catalyzes the stereospecific abstraction of a hydrogen atom from Gly734 of pyruvate formate-lyase (PFL) in a reaction that is strictly dependent on the cosubstrate S-adenosyl-l-methionine (AdoMet). Although PFL-AE is an iron-dependent enzyme, isolation of the enzyme with its metal center intact has proven difficult due to the oxygen sensitivity and lability of the metal center. We report here the first isolation of PFL-AE under nondenaturing, strictly anaerobic conditions. Iron and sulfide analysis as well as UV-visible, EPR, and resonance Raman data support the presence of a [3Fe-4S](+) cluster in the purified enzyme. The isolated native enzyme, but not apo-enzyme, exhibits a high specific activity (31 U/mg) in the absence of added iron, indicating that the native cluster is necessary and sufficient for enzymatic activity.
A series of ferric and ferrous derivatives of wild-type ascorbate peroxidase (APX) and of an engineered K(+)-site mutant of APX that has had its potassium cation binding site removed have been examined by electronic absorption and magnetic circular dichroism (MCD) spectroscopy at 4 degrees C. Wild-type ferric APX has spectroscopic properties that are very similar to those of ferric cytochrome c peroxidase (CCP) and likely exists primarily as a five-coordinate high-spin heme ligated on the proximal side by a histidine at pH 7. There is also evidence for minority contributions from six-coordinate high- and low-spin species (histidine-water, histidine-hydroxide, and bis-histidine). The K(+)-site mutant of APX varies considerably in the electronic absorption and MCD spectra in both the ferric and ferrous states when compared with spectra of the wild-type APX. The electronic absorption and MCD spectra of the engineered K(+)-site APX mutant are essentially identical to those of cytochrome b5, a known bis-imidazole (histidine) ligated heme system. It therefore appears that the K(+)-site mutant of APX has undergone a conformational change to yield a bis-histidine coordination structure in both the ferric and ferrous oxidation states at neutral pH. This conformational change is the result of mutagenesis of the protein to remove the K(+)-binding site which is located approximately 8 A from the peroxide binding pocket. Thus, mutations of protein residues on the proximal side of the heme cause changes in iron ligation on the distal side.
OBJECTIVE: Australian data indicate that Vietnamese-born women in Australia have a significantly higher incidence of cervical cancer than other Australian women. This study explored self-reported factors associated with Vietnamese-born women's participation in cervical screening. METHOD: A structured 60-item questionnaire was used to conduct an interview survey with 199 Vietnamese-born women over the age of 18 years and resident in Adelaide. RESULTS: Eighty-seven per cent (87%) of the women had heard of a Pap smear and 75% had had a test at some time. Reported participation increased with age, education level, marriage and length of stay in Australia. The family doctor was the most important source of information about Pap smears and the majority of the women reported they would have a smear if recommended by their doctor. Friends and family were the second information source about cervix screening. CONCLUSIONS AND IMPLICATIONS: These findings have clear implications for practice. Strategies to promote preventive health messages to this group of women should involve general practitioners and peer networks.
The electronic absorption and magnetic circular dichroism (MCD) spectra of ferric histidine-tailed microperoxidase-10 (His-MP10) change dramatically as the pH is raised from 1.8 to 11.8. Two distinct species are observed (pKa = 4.4). The spectra of acidic ferric His-MP10 nearly match those of ferric mesoporphyrin-reconstituted myoglobin and so the axial ligands are assigned to be histidine and water. The retention of histidine ligation below pH 4 contrasts to the behavior of myoglobin and horseradish peroxidase which convert to five-coordinate water ligated and then lose the heme prosthetic group at even lower pH. Neutral and alkaline ferric His-MP10 have spectra that are very similar to those of the imidazole complex of ferric mesoporphyrin-reconstituted myoglobin. Thus, we conclude that it is bis-histidine ligated with the C-terminal histidine bound as the sixth ligand. Thus, ferric His-MP10 exhibits a pH-dependent ligand switch with a change in axial ligation from water and histidine at low pH to bis-histidine at neutral and alkaline pH.
This paper provides an initial report of an educational innovation in nursing that promotes exchange of information and close cooperation between hospitals and a university. Data from a computerized nursing care planning system are used as the basis for the design of the acute care clinical component of the nursing curriculum. The project has been developed with the aim of minimizing the theory-practice gap and making the transition from university to hospital an easier process for students and new graduates. From the very early stages of the project, it was recognized that the introduction of new computer-based innovations or educational technology, in itself, would not necessarily improve teaching and learning. Therefore, strong emphasis was placed on how the database would be used as the basis for sound curriculum development while maintaining the clinical and practical focus required by students. Difficulties associated with the project, ranging from lengthy legal negotiations to the challenge of integrating a curriculum strongly based on critical reflection and problem-solving with a highly prescriptive hospital database are reported. The project not only provides an example of the efficient exchange and use of hospital-based data for teaching purposes but also provides the groundwork for many potential and exciting developments in national and international nursing data exchange.
The use of information technologies throughout the world continues to increase rapidly and inexorably. Information exchange is rapidly becoming a major economic commodity. The short half-life of professional and technical knowledge necessitates nursing graduates having generic qualities that will enable them to adapt to technical change and cope with an 'information overabundant environment'. Today's nurses must have the capacity to access information, both physically and intellectually; that is, they must be information-literate. Nurses need to be discerning information consumers in order to acquire knowledge and skills in relation to their jobs and social roles and as participants of a democratic society. This paper examines information literacy as a critical resource for nurses as lifelong learners, and explores how information literacy is situated in the nursing literature. The authors pose two questions. Firstly, just how information-literate and aware of information literacy is the nursing profession? Secondly, how can the attitudes, skills and knowledge associated with information literacy be fostered, cultivated and attained in nursing education?
Funding constraints, demands for improved efficiency, low staff to student ratios and improved computer software (D. Wright, The use of multimedia computers and software in nurse education, Health Inf. 1 (3) (1995) 101-107.) all combine to produce a situation where a dramatic increase in the use of CBE for tertiary nurse education appears inevitable. In particular there is a very strong movement towards the development of nurse education materials able to be delivered via the World Wide Web (WWW). Given the speed and the extent of these developments it is essential that CBE developments are subject to adequate review and critique. In particular it is important that the pedagogical concepts under pinning the CBE are congruent with the technological innovation being implemented. This paper provides such a review and critique through the discussion of a project concerned with the integration of a computerised hospital nursing care planning database into the undergraduate nursing curriculum. The evaluation of the project not only raises many issues and concerns relevant to CBE in general, but also provides examples of the ways in which CBE can be used to link theory to practice. It also highlights the need for congruency between pedagogy, technology and student learning. Implications arising from the project are discussed at length, including the possibility for clinicians and academics to work collaboratively on database development.
Competencies have been formulated for entry level nurses. Specialist and generic advanced nursing competencies are also being developed. This paper describes exploratory groundwork on aged and extended care nursing competencies derived from interviews with nurses, allied health staff, residents and their families from one setting. Critical Incident Technique1 was used to guide semistructured interviews with 29 participants. A thematic analysis of the data suggests that the Australian Nursing Council Inc.2 competencies make a useful but incomplete contribution to understanding the perceived role of nursing in aged and extended care. A conceptual framework developed from the data illustrates the interdependence of competencies with the context in which they are observed. The framework proposes a number of elements which have the potential to offer a means to better interpret nursing competence (critical aspects) in aged and extended care contexts.
Policy is an integral part of nursing. At the organisational level, policies are constantly developed in a seemingly endless quest to provide more effective and efficient nursing services and outcomes. Such an increasing generation of policy appears to rest on the taken-for-granted assumption by nurses that policy is essential for good nursing practice. However, is it necessarily the case that the generation of policy documents advances the practice of nursing? Rather, does the apparent uncritical adoption of the role of policy by nurses actually serve to further regulate, control, and even limit the practice of nursing? This paper uses a critical perspective to explore nursing policy. In so doing it exposes the effect of policy on the construction and maintenance of everyday understandings of nursing practice.
This paper addresses Foucauldian theory and its usefulness to nursing research. It is written in the form of a discussion between the authors on the merits and liabilities of Foucauldian theory as applied to analyses of nursing. As such, it focuses upon some of the more pertinent critiques of both Foucauldian and postmodern theory. By addressing Foucault from two different positions, the discussion seeks to demonstrate the complexity of Foucauldian theory and warns against over-simplification in its application to nursing research. The authors also argue for an awareness of the strengths and weaknesses of any given theoretical stance.
Flanagan's critical incident technique was used to explore the beliefs of a cross-section of careers (both nursing and others) and consumers about the value of nursing and the nature of nursing's contribution in aged and extended care. The exploratory study found that nurses' being there, with and for residents, their families, and other health professionals, was influenced by two major themes that emerged from the data: personal and structural considerations. In this article, the potential of critical incident technique as a research method in nursing and for generating information about critical aspects of nursing work in aged and extended care is demonstrated.
Nurses administer medications every day as part of their practice. Consequently, many studies have explored nurses and the part they play in medication administration. The focus of these studies has often been limited, concentrating on nurses and drug errors, rather than on incorporating a broader view of nurses and the medication administration process in general. In an attempt to broaden the focus of the discussion about nurses and medication administration, this study used Critical Incident Technique (C.I.T.) to identify registered nurses' perceptions of factors affecting the quality administration of medications in their practice setting. Five categories of themes emerged as having an impact on nurses and the administration of medications: the context, the procedures, the groups of professionals involved, the personal attributes of individual staff, and the client. Implications of the research for nursing education and practice are discussed.