Molecular battles between plant and pathogenic bacteria in the phyllosphere

The phyllosphere, i.e., the aerial parts of the plant, provides one of the most important niches for microbial colonization. This niche supports the survival and, often, proliferation of microbes such as fungi and bacteria with diverse lifestyles including epiphytes, saprophytes, and pathogens. Although most microbes may complete the life cycle on the leaf surface, pathogens must enter the leaf and multiply aggressively in the leaf interior. Natural surface openings, such as stomata, are important entry sites for bacteria. Stomata are known for their vital role in water transpiration and gas exchange between the plant and the environment that is essential for plant growth. Recent studies have shown that stomata can also play an active role in limiting bacterial invasion of both human and plant pathogenic bacteria as part of the plant innate immune system. As counter-defense, plant pathogens such as Pseudomonas syringae pv tomato (Pst) DC3000 use the virulence factor coronatine to suppress stomate-based defense. A novel and crucial early battleground in host-pathogen interaction in the phyllosphere has been discovered with broad implications in the study of bacterial pathogenesis, host immunity, and molecular ecology of bacterial diseases.

Molecular battles between plant and pathogenic bacteria in the phyllosphere.

The phyllosphere, i.e., the aerial parts of the plant, provides one of the most important niches for microbial colonization. This niche supports the survival and, often, proliferation of microbes such as fungi and bacteria with diverse lifestyles including epiphytes, saprophytes, and pathogens. Although most microbes may complete the life cycle on the leaf surface, pathogens must enter the leaf and multiply aggressively in the leaf interior. Natural surface openings, such as stomata, are important entry sites for bacteria. Stomata are known for their vital role in water transpiration and gas exchange between the plant and the environment that is essential for plant growth. Recent studies have shown that stomata can also play an active role in limiting bacterial invasion of both human and plant pathogenic bacteria as part of the plant innate immune system. As counter-defense, plant pathogens such as Pseudomonas syringae pv tomato (Pst) DC3000 use the virulence factor coronatine to suppress stomate-based defense. A novel and crucial early battleground in host-pathogen interaction in the phyllosphere has been discovered with broad implications in the study of bacterial pathogenesis, host immunity, and molecular ecology of bacterial diseases.

Distance measurements in the borderline region of applicability of CW EPR and DEER: a model study on a homologous series of spin-labelled peptides.

Inter-spin distances between 1 nm and 4.5 nm are measured by continuous wave (CW) and pulsed electron paramagnetic resonance (EPR) methods for a series of nitroxide-spin-labelled peptides. The upper distance limit for measuring dipolar coupling by the broadening of the CW spectrum and the lower distance limit for the present optimally-adjusted double electron electron resonance (DEER) set-up are determined and found to be both around 1.6-1.9 nm. The methods for determining distances and corresponding distributions from CW spectral line broadening are reviewed and further developed. Also, the work shows that a correction factor is required for the analysis of inter-spin distances below approximately 2 nm for DEER measurements and this is calculated using the density matrix formalism.

Empowerment among Latina nurses in Mexico, New York and Indiana.

BACKGROUND: Increasing empowerment among nurses may help retain nurses and increase the international workforce. There are very few cross-national studies of nurse empowerment reported in the professional literature. AIM: To conduct a cross-national exploratory study testing a theoretical model of nurse empowerment. DESIGN: Descriptive survey of three convenience samples of graduate Latina nurses in Monterrey, Mexico, New York City and Indiana. METHODS: Data were collected using self-administered questionnaires. The Klakovich Reciprocal Empowerment Scale (RES) was translated into Mexican-Spanish using a translation back-translation technique. Variables for the study included empowerment, years of experience, job satisfaction and intent to stay. Frequency distributions and descriptive statistics were used to analyse the data. FINDINGS: Empowerment involves reciprocity between the leader and follower, a common vision and synergy about the work, and a sense of ownership in the work site. Mexican nurses scored significantly higher on synergy than Latina nurses in New York and Indiana. Empowerment is related to job satisfaction, age and years of employment. CONCLUSIONS: Results indicate the usefulness of the RES instrument for Latina nurses and the need for further research with larger samples. Cross-national research provides culturally sensitive information. Such research partnerships facilitate modelling the importance of nursing research to graduate nurses and students.

Evidence of a functional alpha7-neuronal nicotinic receptor subtype located on motoneurons of the dorsal motor nucleus of the vagus.

In vitro autoradiography using 125I-alpha-bungarotoxin (alpha-BGTx) and anti-alpha7 immunohistochemistry were performed on the dorsal motor nucleus of the vagus (DMV) of sham and chronically vagotomized rats to determine whether the alpha7-nicotinic acetylcholine receptor (nAChR) is located postsynaptically on DMV neurons whose axons contribute to the vagus nerve. Intense bilateral 125I-alpha-BGTx binding and anti-alpha7 immunostaining were observed in coronal brain sections containing the DMV of sham-vagotomized animals. Unilateral cervical vagotomy resulted in ipsilateral losses of 125I-alpha-BGTx binding and anti-alpha7 immunostaining from the DMV. Simultaneous staining of rat brainstem sections with anti-alpha7 and anti-choline acetyltransferase (ChAT) antibodies (to identify cholinergic DMV neurons that project into the vagus nerve) revealed that every DMV neuron that was stained for ChAT showed alpha7-staining as well. In vagotomized animals, no ChAT-positive neurons expressing alpha7-nAChRs remained in the ipsilateral DMV. We conclude that the alpha7-nAChR subtype is located postsynaptically on DMV neurons. To test whether the alpha7-nAChR is similar to the alpha7-homomeric nAChR, experiments were performed in anesthetized rats, and compounds were microinjected into the DMV while monitoring intragastric pressure (IGP). alpha-BGTx and strychnine antagonized nicotine-induced increases in IGP; no antagonism was observed with methyllycaconitine, a compound known to block the homomeric alpha7-nAChR subtype. Recovery from alpha-BGTx-induced antagonism of the nicotine response was observed. We conclude that there is a nAChR containing the alpha7-subunit in the DMV that is different from the homomeric alpha7-nAChR subtype.

Hospital conversion foundations. Issues in creation, operation, and evaluation.

A major healthcare transformation in the United States is the conversion of nonprofit hospitals to for-profit entities, and the creation of hospital conversion foundations for the nonprofit charitable assets, which now exceeds $9 billion. Because less than 21% of the 525 hospitals converting from nonprofit to for-profit ownership have established a hospital conversion foundation, the public's monetary losses are considerable. This article examines some of the key legal and organizational issues related to hospital conversion foundations including factors related to establishing fair value of the converting hospital, foundation mission, use of conversion revenue, governance, and evaluation.

Pulmonary artery trauma due to balloon dilation: recognition, avoidance and management.

OBJECTIVES: We reviewed the management and outcome of patients experiencing pulmonary artery (PA) trauma during balloon dilation (BD). BACKGROUND: Balloon dilation of the PA is important in the management of peripheral pulmonary stenosis. Successful BD requires a controlled tear of the PA; excessive tearing can produce complications ranging from pseudoaneurysms to rupture and death. The incidence and optimum management for such complications are unreported. METHODS: All records of patients who underwent branch PA dilation between June 1984 and October 1997 were reviewed; those with a significant complication were analyzed. RESULTS: Of 1,286 catheterizations in 782 patients, PA trauma (excluding isolated pulmonary edema and PA aneurysms) was identified in 29 catheterizations in 26 patients. Tears occurred distal to the area of stenosis in most cases (62%). Intensive medical management, with and without catheter directed therapy, was employed. The damaged PA was successfully coil embolized in five patients, four of whom survived; temporary balloon occlusion did not prevent death in two patients. There were six deaths from pulmonary hemorrhage. A case control analysis demonstrated that PA trauma was significantly associated with pulmonary hypertension. CONCLUSIONS: Pulmonary artery trauma associated with BD occurs mostly distal to the site of narrowing, is associated with underlying pulmonary hypertension and is frequently (5/12 or 42%) fatal in those with unconfined tears. Intensive management strategies as well as attention to distal balloon position may reduce incidence and mortality. Coil occlusion of the damaged PA appears to be a valuable strategy to prevent fatal hemorrhage.

Problem-based learning for nursing: integrating lessons from other disciplines with nursing experiences.

Problem-based learning (PBL) is a philosophy and teaching method that structures knowledge in clinical contexts, strengthens motivation to learn, develops clinical reasoning skills, and enhances self-directed and life-long learning. During the past 30 years, PBL has been implemented in schools of medicine worldwide, including 100 of the 126 schools in the United States. This article reviews the international PBL literature and focuses on the key aspects of this paradigm in educating health professionals: recent history and worldwide diffusion, basic characteristics and rationale, typical case presentation, student and tutor roles, and data-based outcomes. Conclusions from selected meta-analytic studies of assessment are described and discussed. The potential of PBL for nursing education is examined. Key implementation issues are identified, including the challenge to persuade faculty to move from efficient teaching to effective learning.

Hospital ownership, performance, and outcomes: assessing the state-of-the-science.

OBJECTIVE: This study 1) identified the research evidence; 2) assessed the state-of-the-science surrounding hospital ownership, performance, and outcomes in acute care hospitals in the United States; and 3) identified measurable components of hospital performance and outcomes for the organization, patient, and community. BACKGROUND: As the size of the nonprofit sector decreases and the size of the for-profit sector increases, hospital ownership warrants examination. Most research has focused on either ownership and performance or ownership and outcomes, rather than the potential interaction of all three variables. METHODS: A comprehensive, computerized search of the healthcare research literature yielded 69 data-based references published between 1985 and 1999. Coding sheets were developed to abstract the articles. Analysis involved synthesizing the research evidence for each of the three major variables and their components. RESULTS: Hospital ownership has an impact on hospital performance in relation to system operations; costs, prices, and financial management practices; and personnel issues. Organizational outcomes are similar among hospital ownership types in relation to increasing administrative costs and overall mediocre efficiency. Organizational outcomes differ among hospital ownership types in relation to nursing staff mix and professional satisfaction. The association of hospital ownership with patient outcomes varies depending on the dimension measured. The evidence is mixed or inconclusive regarding hospital ownership and access to care, morbidity, and mortality. The association of hospital ownership and adverse events is consistently supported. Hospital ownership status has an impact on the type and magnitude of community benefits. Differences among the three hospital ownership types are minimized in a competitive market. CONCLUSIONS: This study reinforces the position that nurse researchers need to include hospital ownership as an important structural variable in their studies of hospital-based nursing. Examining the conceptual links between ownership, performance, and outcomes requires the integration of macro-level and micro-level theory.

Chemokines and chemokine receptors in the pathogenesis of multiple sclerosis.

In recent years we have seen growing evidence for the role of chemokines in the pathogenesis of several infectious and non-infectious inflammatory CNS disease states, including Multiple Sclerosis (MS) and its animal model, experimental allergic encephalomyelitis (EAE). An increase in proinflammatory chemokines has been associated with demyelinating lesions and clinical neurological dysfunction in patients with MS; these chemokines could be potential targets for MS therapy. Besides a clearly defined role in mediating leukocyte migration, these and other chemokines may act as immunoregulatory molecules in the driving to Th1/Th2 responses, switch of cytokine profiles, and the induction of tolerance. Since chemokine receptors have now been identified on macrophages, microglia, astrocytes, and endothelial cells as well as neurons in the CNS, chemokine/receptor interactions may mediate functional responses in a variety of CNS cell types during the course of inflammatory disease states. Therefore, clarification of the roles of chemokines and their receptors in the pathogenesis of EAE and MS will be useful in establishing immunotherapeutic strategies for these neurological autoimmune disorders.

Using problem-based learning to redesign nursing administration masters programs.

Problem-based learning (PBL) is offered as an appropriate pedagogy to prepare nurse managers for the uncertainties of future administrative practice. It is a student-centered, experiential learning strategy aimed at developing clinical reasoning, structuring knowledge in real-life contexts, motivating learning, and developing self-learning skills. Health professions and business schools report positive feedback from their stakeholders after adopting this new learning paradigm.

Left superior vena cava connection to unroofed coronary sinus associated with positional cyanosis: successful transcatheter treatment using Gianturco-Grifka vascular occlusion device.

A persistent left superior vena cava connection to an unroofed coronary sinus is a rare cardiac anomaly that is associated with a variable degree of cyanosis. We report an infant with this condition and the unusual feature of cyanosis dependent on head position. When the patient's head was rotated to the left, he developed severe stenosis of the left internal jugular vein, enlarged cervical collateral veins that connected to the right superior vena cava and had an oxygen saturation 95%. When the patient's head was rotated to the right, the left internal jugular vein was widely patent and systemic oxygen saturation decreased to 87%. There was no right ventricular volume overload. Temporary occlusion of the left superior vena cava documented tolerable proximal venous pressure. Cyanosis was relieved by transcatheter closure of the left superior vena cava with a Gianturco-Grifka vascular occlusion device. Cathet. Cardiovasc. Intervent. 48:369-373, 1999.

Hospital consolidation. Applying stakeholder analysis to merger life-cycle.

Nearly three of every five hospitals in the United States have been involved in some form of consolidation during the past 5 years. Within this turbulent hospital merger environment, nurse executives are confronted with organizational, professional, and personal decisions. Stakeholder analysis is offered as one strategy to facilitate effectiveness throughout the hospitals' merger life-cycle.

Acute stroke patients comparing outcomes with and without case management.

Stroke represents a major human and economic challenge to society. The literature suggests that interdisciplinary clinical pathways maximize stroke patient outcomes, whether care is delivered in a designated stroke unit or in a general medical service. In this article, the authors describe the case management model implemented at Columbus Regional Hospital, a 325-bed rural referral hospital in southeastern Indiana. A retrospective chart review compared 23 patients with non-hemorrhagic strokes using two different models of care delivery: unit-based nursing case management and standard nursing care. Differences in outcomes are reported in relation to interdisciplinary utilization, timeliness of referrals, patient education, discharge dispositions, home safety assessments, next-site-of-care communications, length of hospital stay, and patient satisfaction.

Leaflet development, induction time, and medium influence somatic embryogenesis in peanut (Arachis hypogaea L.).

Factors affecting somatic embryogenesis in peanut (Arachis hypogaea L.) using leaflet explants of seedlings obtained from aseptically germinated embryo axes were evaluated. Somatic embryogenesis was influenced by developmental stage, leaflet size, induction medium, and time on induction medium. Leaflets that were 5-7 mm long had a greater embryogenic response than smaller or larger leaflets. Percent embryogenesis and mean number of embryos were related to the developmental stage of germinating seedlings. A greater response was obtained if leaflets were folded and closely appressed. Preselection of leaflets increased percent embryogenesis from 21% up to 67%. As leaflets unfolded, embryogenesis decreased; open leaflets lost the potential for embryogenesis. The optimal induction conditions were a 7-day incubation period on Murashige and Skoog medium with 136 µM 2,4-dichlorophenoxyacetic acid and 0.93 µM kinetin. Somatic embryos germinated to form plants that exhibited a normal morphology.

Differentiated nursing practice: assessing the state-of-the-science.

The authors present their findings following an exhaustive literature review of research on differentiated nursing practice (DNP) that used a number of tools to measure various aspects of DNP that are applicable across the health care delivery continuum. Issues related to DNP include: optimal nursing care, matching patient needs with nurse competencies, effective use of nursing resources, equitable compensation, career satisfaction, loyalty to employers, and enhanced prestige of the nursing profession. One 1992 Massachusetts study of a three-role oncology unit project (including patient care manager, clinical nurse, and patient care technician), showed positive change in five criteria including: standards of nursing care, actual care hours, average labor costs, job satisfaction and patient satisfaction. A 1990 Arizona study that included unit assistants concluded that DNP supported a decline in the use of supplemental staff and staff overtime which led to cost savings, and increases in the actual hours of care and nurse satisfaction.

Organizational effectiveness: toward an integrated model for schools of nursing.

Assessing the quality of academic institutions involves much more than the opinions of peers or experts. Examination of the organizational effectiveness of schools of nursing has been neglected. Current emphasis on assessing educational outcomes has diverted attention from the construct, organizational effectiveness, and more comprehensive theory-driven approaches to evaluation. This review of the organizational effectiveness literature focuses on the major assessment models: goal attainment, human relations, open systems, internal processes, culture, and life cycle. Attention is given to the influence of organizational maturation on an integrated model of organizational effectiveness. Selected macrolevel studies of schools of nursing are examined, and an agenda for nursing research is proposed.