The impact of ingested potato type II inhibitors on the production of the major serine proteases in the gut of Helicoverpa armigera

The flowers of the ornamental tobacco produce high levels of a series of 6 kDa serine protease inhibitors (NaPIs) that are effective inhibitors of trypsins and chymotrypsins from lepidopteran species. These inhibitors have a negative impact on the growth and development of lepidopteran larvae and have a potential role in plant protection. Here we investigate the effect of NaPIs on the activity and levels of serine proteases in the gut of Helicoverpa armigera larvae and explore the adaptive mechanisms larvae employ to overcome the negative effects of NaPIs in the diet. Polyclonal antibodies were raised against a Helicoverpa punctigera trypsin that is a target for NaPIs and two H. punctigera chymotrypsins; one that is resistant and one that is susceptible to inhibition by NaPIs. The antibodies were used to optimize procedures for extraction of proteases for immunoblot analysis and to assess the effect of NaPIs on the relative levels of the proteases in the gut and frass. We discovered that consumption of NaPIs did not lead to over-production of trypsins or chymotrypsins but did result in excessive loss of proteases to the frass.

What level of knowledge do elementary school teachers possess concerning the care of children with asthma? A pilot study

A self-report questionnaire was used to assess the level of knowledge among a convenience sample of 34 elementary school teachers in a rural school district in Illinois. The questionnaire addressed general asthma knowledge and management, including signs and symptoms, triggers, and treatment. The results suggest a knowledge deficit among this sample of elementary school teachers; the average score was 75%. Teachers with an increased exposure/experience with asthma scored significantly higher than did those with limited exposure. Implications of these findings for schools in rural areas are discussed.

Comparison of pulse oximetry measures in a healthy population

In this study finger and ear oximetry readings of 89 healthy persons were compared. The findings do not support the common nursing practice of using a finger sensor to obtain a pulse oximetry reading from an individual's ear if the finger is not usable.

Comparison of nurse workload approaches

BACKGROUND

For hospitals in the United States, the number of patients who lie in beds at midnight is considered to be the standard indicator of nursing workload; relatively little attention is given to the total number of patients cared for in a 24-hour day. Staffing decisions are related to cost of care. Such decisions are made on a per-shift basis, calculating hours per patient day (HPPD) based upon midnight census provides little decision-making support about variable staffing needs over a 24-hour period. The discrepancy between nurse managers' staffing based on real-time patient needs and financial analysts looking only at units of service captured at midnight clearly speaks to the need for a new metric of measurement.

OBJECTIVE

To describe the variations in nursing workload across two medical units using a comparison of intra-day census recommendations for staffing and those projected based on the midnight census alone.

METHODS

Data were retrieved from a primary data set that included: (1) the number of patients lying in beds at four different times during a 24-hour period: 06.00, 14.00, 22.00 hours and at midnight; (2) projected nursing hours needed based on the numbers of patients lying in beds at different times during the 24-hour period; and (3) the number of projected nursing hours needed for the numbers of patients lying in bed and those who were admitted and discharged in an 8-hour period of time.

RESULTS

Statistically significant increases in 06.00 hour patient counts were found with statistically lower patient counts at both 14.00 and 22.00 hours compared with the midnight census alone. Nursing hour projections per day did not show any significance when projected based on intra day vs. midnight census alone. Statistically significant increases in nursing hour projections were seen on all three shifts when admissions and discharges and the nursing workload associated with those procedures were calculated.

CONCLUSIONS

Findings suggest that the midnight census alone may well not be the most precise measure to predict nursing workload or to cost out nursing care. To accurately capture the realities of a 24-hour nursing workload, the nursing work associated with patient admissions and discharges has to be a part of the equation.

IMPLICATIONS FOR NURSING MANAGEMENT

The tradition of using the midnight census to budget 24 hours of nursing services in the hospital setting does not capture the totality of nursing workload. A model that costs out direct nursing care in the hospital and ultimately bills separately for that care is needed to reflect the realities of hospital nursing workload.

Persistent complement-dependent anti-AnWj in a lymphoproliferative disorder: a case study and review

AnWj is a high-incidence antigen present on the red blood cells (RBCs) of greater than 99 percent of the general population. A 58-year-old man underwent autologous hematopoietic stem cell transplantation (HSCT) for stage IVa mantle cell lymphoma. This procedure was complicated by failure to engraft, necessitating ongoing support with blood components. After a 2-month period of uneventful transfusion support, the patient experienced increasingly severe reactions with fever and evidence of intravascular hemolysis, including hemoglobinuria. Testing revealed a complement-dependent anti-AnWj. Phenotyping confirmed the AnWj- phenotype. Anti-AnWj was persistent despite immunosuppression, including treatment with allogeneic HSCT. Of interest, the pathogenesis of the downregulation of the graft AnWj in this patient is unclear.

Nurses' knowledge and attitudes regarding pain assessment and intervention

Registered nurses were queried about their knowledge and attitudes regarding pain management. Results suggest knowledge of pain management principles and interventions is insufficient.

Location of blood pressure measurement

Health care workers in a rural community hospital were queried about factors associated with blood pressure (BP) accuracy. Results suggest remedial education regarding cuff size, patient position, arm position, and location for accurate BP measurement is needed.

Seawater Mg/Ca controls polymorph mineralogy of microbial CaCO3: a potential proxy for calcite-aragonite seas in Precambrian time

A previously published hydrothermal brine-river water mixing model driven by ocean crust production suggests that the molar Mg/Ca ratio of seawater (mMg/Ca(sw)) has varied significantly (approximately 1.0-5.2) over Precambrian time, resulting in six intervals of aragonite-favouring seas (mMg/Ca(sw) > 2) and five intervals of calcite-favouring seas (mMg/Ca(sw) < 2) since the Late Archaean. To evaluate the viability of microbial carbonates as mineralogical proxy for Precambrian calcite-aragonite seas, calcifying microbial marine biofilms were cultured in experimental seawaters formulated over the range of Mg/Ca ratios believed to have characterized Precambrian seawater. Biofilms cultured in experimental aragonite seawater (mMg/Ca(sw) = 5.2) precipitated primarily aragonite with lesser amounts of high-Mg calcite (mMg/Ca(calcite) = 0.16), while biofilms cultured in experimental calcite seawater (mMg/Ca(sw) = 1.5) precipitated exclusively lower magnesian calcite (mMg/Ca(calcite) = 0.06). Furthermore, Mg/Ca(calcite )varied proportionally with Mg/Ca(sw). This nearly abiotic mineralogical response of the biofilm CaCO3 to altered Mg/Ca(sw) is consistent with the assertion that biofilm calcification proceeds more through the elevation of , via metabolic removal of CO2 and/or H+, than through the elevation of Ca2+, which would alter the Mg/Ca ratio of the biofilm's calcifying fluid causing its pattern of CaCO3 polymorph precipitation (aragonite vs. calcite; Mg-incorporation in calcite) to deviate from that of abiotic calcification. If previous assertions are correct that the physicochemical properties of Precambrian seawater were such that Mg/Ca(sw) was the primary variable influencing CaCO3 polymorph mineralogy, then the observed response of the biofilms' CaCO3 polymorph mineralogy to variations in Mg/Ca(sw), combined with the ubiquity of such microbial carbonates in Precambrian strata, suggests that the original polymorph mineralogy and Mg/Ca(calcite )of well-preserved microbial carbonates may be an archive of calcite-aragonite seas throughout Precambrian time. These results invite a systematic evaluation of microbial carbonate primary mineralogy to empirically constrain Precambrian seawater Mg/Ca.

Risk of malignancy in resected cystic tumors of the pancreas < or =3 cm in size: is it safe to observe asymptomatic patients? A multi-institutional report

Recent international consensus guidelines propose that cystic pancreatic tumors less than 3 cm in size in asymptomatic patients with no radiographic features concerning for malignancy are safe to observe; however, there is little published data to support this recommendation. The purpose of this study was to determine the prevalence of malignancy in this group of patients using pancreatic resection databases from five high-volume pancreatic centers to assess the appropriateness of these guidelines. All pancreatic resections performed for cystic neoplasms < or =3 cm in size were evaluated over the time period of 1998-2006. One hundred sixty-six cases were identified, and the clinical, radiographic, and pathological data were reviewed. The correlation with age, gender, and symptoms (abdominal pain, nausea and vomiting, jaundice, presence of pancreatitis, unexplained weight loss, and anorexia), radiographic features suggestive of malignancy by either computed tomography, magnetic resonance imaging, or endoscopic ultrasound (presence of solid component, lymphadenopathy, or dilated main pancreatic duct or common bile duct), and the presence of malignancy was assessed using univariate and multivariate analysis. Among the 166 pancreatic resections for cystic pancreatic tumors < or =3 cm, 135 cases were benign [38 serous cystadenomas, 35 mucinous cystic neoplasms, 60 intraductal papillary mucinous neoplasms (IPMN), 1 cystic papillary tumor, and 1 cystic islet cell tumor], whereas 31 cases were malignant (14 mucinous cystic adenocarcinomas and 13 invasive carcinomas and 4 in situ carcinomas arising in the setting of IPMN). A greater incidence of cystic neoplasms was seen in female patients (99/166, 60%). Gender was a predictor of malignant pathology, with male patients having a higher incidence of malignancy (19/67, 28%) compared to female patients (12/99, 12%; p < 0.02). Older age was associated with malignancy (mean age 67 years in patients with malignant disease vs 62 years in patients with benign lesions (p < 0.05). A majority of the patients with malignancy were symptomatic (28/31, 90%). Symptoms that correlated with malignancy included jaundice (p < 0.001), weight loss (p < 0.003), and anorexia (p < 0.05). Radiographic features that correlated with malignancy were presence of a solid component (p < 0.0001), main pancreatic duct dilation (p = 0.002), common bile duct dilation (p < 0.001), and lymphadenopathy (p < 0.002). Twenty-seven of 31(87%) patients with malignant lesions had at least one radiographic feature concerning for malignancy. Forty-five patients (27%) were identified as having asymptomatic cystic neoplasms. All but three (6.6%) of the patients in this group had benign disease. Of the patients that had no symptoms and no radiographic features, 1 out of 30 (3.3%) had malignancy (carcinoma in situ arising in a side branch IPMN). Malignancy in cystic neoplasms < or =3 cm in size was associated with older age, male gender, presence of symptoms (jaundice, weight loss, and anorexia), and presence of concerning radiographic features (solid component, main pancreatic duct dilation, common bile duct dilation, and lymphadenopathy). Among asymptomatic patients that displayed no discernable radiographic features suggestive of malignancy who underwent resection, the incidence of occult malignancy was 3.3%. This study suggests that a group of patients with small cystic pancreatic neoplasms who have low risk of malignancy can be identified, and selective resection of these lesions may be appropriate.

Development of a solar-powered microbial fuel cell

AIMS

To understand factors that impact solar-powered electricity generation by Rhodobacter sphaeroides in a single-chamber microbial fuel cell (MFC).

METHODS AND RESULTS

The MFC used submerged platinum-coated carbon paper anodes and cathodes of the same material, in contact with atmospheric oxygen. Power was measured by monitoring voltage drop across an external resistance. Biohydrogen production and in situ hydrogen oxidation were identified as the main mechanisms for electron transfer to the MFC circuit. The nitrogen source affected MFC performance, with glutamate and nitrate-enhancing power production over ammonium.

CONCLUSIONS

Power generation depended on the nature of the nitrogen source and on the availability of light. With light, the maximum point power density was 790 mW m(-2) (2.9 W m(-3)). In the dark, power output was less than 0.5 mW m(-2) (0.008 W m(-3)). Also, sustainable electrochemical activity was possible in cultures that did not receive a nitrogen source.

SIGNIFICANCE AND IMPACT OF THE STUDY

We show conditions at which solar energy can serve as an alternative energy source for MFC operation. Power densities obtained with these one-chamber solar-driven MFC were comparable with densities reported in nonphotosynthetic MFC and sustainable for longer times than with previous work on two-chamber systems using photosynthetic bacteria.

Medication errors in a rural hospital

The purpose of this investigation was to compare and contrast three nursing shifts in a small rural Midwestern hospital with regard to the number of reported medication errors, the units on which they occurred, and the types and severity of errors. Results can be beneficial in planning and implementing a quality improvement program in the area of medication administration with the nursing staff.

Disability Law and Nursing Education: An Update

Over the past decade, the courts have been called upon to apply the provisions of the Americans With Disabilities Act and Section 504 of the Rehabilitation Act in several cases with implications for programs of nursing education. Courts have restricted who may be considered a qualified individual with disabilities. They have clarified the relative obligations of both students and educators in determining accommodations. Courts have been especially deferential to educational programs preparing health care professionals when program standards and pedagogical requirements are clearly articulated. However, accessibility and compliance with recommendations for accommodations are required at all sites where students are educated. Less clear are judicial interpretations related to making technology accessible and to the disclosure by programs of information about students' disabilities during licensing. These findings lead to several conclusions. First is the need for development of profession-wide standards of competencies and skills for nurses. Second is the need for dialogue about the potential for disability discrimination between nursing educators and state licensing bodies. Last is that faculty and administrators can proceed with some degree of confidence in protecting program practices that are based on sound pedagogical reasoning.

Evidenced-based Factors in Readmission of Patients with Heart Failure

The purpose of this project was to organize the variables associated with the hospital readmission of patients with heart failure (HF) into a usable framework to inform clinical practice and facilitate administrative decision making. An integrated, systematic review of the literature was used as the research approach. A content analysis of the sample (31 research reports from the years 1986-2004) yielded multiple factors associated with the hospital readmission of HF patients. Factors and their definitions were extracted, grouped into like categories, and eventually classified into 5 domains-demographic, physiologic, psychosocial, patient functioning, and resource utilization. The resulting framework has clinical, research, and administrative implications in the delivery of care to HF patients.

Quality of Life After Participation in a Rural Phase II Cardiac Rehabilitation Program

The purpose of this study was to explore the effectiveness of a cardiac rehabilitation program (phase II) in improving participants' quality of life (QOL). Existing data collected previously by a not-for-profit rural community hospital using the SF-36 tool were analyzed. The secondary data consisted of precardiac and post-cardiac rehabilitation SF-36 scores for 121 phase II participants. All the 8 subscale post scores of the SF-36 were higher when compared to the pre-rehabilitation scores. In this non-controlled trial, results suggest that participation in rural cardiac rehabilitation programs may improve patients' perceptions of QOL and health.

Development of the Nursing Outcome (NOC) label: hyperactivity level

TOPIC

Hyperactivity, a persistent, severe pattern of inattention or impulsivity, places children at risk for impaired functioning in many developmental areas. This behavior is characterized by short attention span, low frustration tolerance, impulsivity, distractibility, and increased physical activity. Responses from multiple sources in the child's environment must be monitored to manage childhood hyperactivity.

PURPOSE

Success at school, in peer relationships, and parent-child interactions is frequently affected by hyperactivity. Using a focus group approach, a Nursing Outcomes Classification (NOC) label, definition, and indicators were developed for Hyperactivity Level.

SOURCES

Review of the literature allowed for a content analysis approach and conceptualization of hyperactivity at several levels.

CONCLUSION

Twenty three (23) measurable indicators were formulated and refined into conceptually and clinically coherent outcomes. Clinical relevance and utility were presented through a case study approach.

Reducing sediment and phosphorus in tributary waters with alum and polyacrylamide

The Salton Sea is the largest inland water body in California, covering an area of 980 km(2). Inflow to the Salton Sea (1.6 km(3) yr(-1)) is predominately nutrient-rich agricultural wastewater, which has led to eutrophication. Because internal phosphorus release from the bottom sediments is comparatively low and external phosphorus loading to the Salton Sea is high, reduction of tributary phosphorus is expected to reduce algal blooms, increase dissolved oxygen, and reduce odors. Removing both dissolved phosphorus and phosphorus-laden sediment from agricultural drainage water (ADW) should decrease eutrophication. Both alum and polyacrylamide (PAM) are commonly used in wastewater treatment to remove phosphorus and sediment and were tested for use in tributary waters. Laboratory jar tests determined PAM effectiveness (2 mg L(-1)) for turbidity reduction as cationic > anionic = nonionic. Although cationic PAM was the most effective at reducing turbidity at higher speeds, there was no observed difference between the neutral and anionic PAMs at velocity gradients of 18 to 45 s(-1). Alum (4 mg L(-1) Al) reduced turbidity in low energy systems (velocity gradients < 10 s(-1)) by 95% and was necessary to reduce soluble phosphorus, which comprises 47 to 100% of the total P concentration in the tributaries. When PAM was added with alum, the anionic PAM became ineffective in aiding flocculation. The nonionic PAM (2 mg L(-1)) + alum (4 mg L(-1) Al) is recommended to reduce suspended solids in higher energy systems and reduce soluble P by 93%.

Defining quality of nursing work life

As the largest single employee component of hospitals, nurses are critical to the functioning of the organization, and improving employee productivity continues to be a common theme in the health care literature. However, any increased productivity will be transitory if achieved at the expense of the quality of nurses' work life (QNWL), since improvement in the QNWL is prerequisite to improved productivity. The conceptual components of the concept of QNWL that differentiate QNWL from the concept job satisfaction are explored.

Defensins--components of the innate immune system in plants

Plant defensins are small (c.a. 5 kDa), basic, cysteine-rich proteins with antimicrobial activities. They are ubiquitous in plants and form part of the innate immunity arsenal. Plant defensins are encoded by small multigene families and are expressed in various plant tissues, but are best characterized in seeds. They are typically produced as preproteins, however, a small subset are produced as larger precursors with C-terminal prodomains. To date, the three-dimensional solution structures of seven seed- and two floral-derived defensins have been elucidated by (1)H-NMR spectroscopy. Despite limited amino acid sequence identities, these defensins have comparable global folds with features that are characteristic of the cysteine-stabilized alphabeta (CSalphabeta) motif. Interestingly, their structures are remarkably similar to those of insect defensins and scorpion toxins. Functionally, these proteins exhibit a diverse array of biological activities, although they all serve a common function as defenders of their hosts. This review describes the distribution, biosynthesis, structure, function and mode of action of plant defensins and reflects on their potential in agribiotechnological applications.

Hospital Readmission From Home Health Care Before and After Prospective Payment

PURPOSE

To describe and compare clients who were readmitted to the hospital during an episode of home health care, before and after the inception of the prospective payment system (PPS).

DESIGN

A longitudinal mixed design was used to replicate a study conducted 9 years previously (pre-PPS) in the same home care agency in the central part of the United States.

METHODS

Seventy-six closed-case medical records from a not-for-profit hospital-affiliated home care agency were retrospectively reviewed and compared to pre-PPS data. The same data collection tool, the Hospital Readmission Inventory, was used for both pre- and post-PPS studies. Nurse administrators at the data collection agency were interviewed concerning comparative results.

FINDINGS

Currently readmitted clients were sicker than were those in the previous research report, they were readmitted sooner for a different diagnosis, and they had less continuity of services.

CONCLUSIONS

The home health care industry has undergone a dramatic change in payment for services, from fee-for-service to PPS. Of particular concern is the adverse patient outcome of an unplanned hospital readmission. Prior studies have characterized such patients in home health care, but no comparative reports were found in a literature search since the inception of PPS. Findings from this study indicated that an increased emphasis on cost containment and higher-risk clients appear to have changed patterns of care delivery.

Hospital Readmission From a Transitional Care Unit

The purpose of this project was to characterize patients readmitted to the hospital during a stay in a transitional care unit (TCUT). Typically, readmitted patients were females, widowed, with 8 medical diagnoses, and taking 12 different medications. Readmission from the TCU occurred within 7 days as a result of a newly developed problem. Most patients did not return home after readmission from the TCU. Understanding high-risk patients' characteristics that lead to costly hospital readmission during a stay in the TCU can assist clinicians and healthcare providers to plan and implement timely and effective interventions, and help facility personnel in fiscal and resource management issues.

Getting inside depression and suicide ideation

As part of this Magnet hospital's safety initiatives, nurses conduct age-specific screening for depression, and, when appropriate, for suicide ideation.

Nursing Work Life in Acute Care

The purpose of this project was to explore how acute care nurses in a midwestern state rate the quality of their work life. A simple random sample of 1500 registered nurses was surveyed. Data were collected using Brooks' Quality of Nursing Worklife Survey (Brooks BA. Development of an Instrument to Measure Quality of Nursing Work Life [unpublished doctoral dissertation]. Chicago: University of Illinois at Chicago; 2001). Findings suggested that nursing workload was too heavy, and there was not enough time todo the job well. This study revealed that there remain ongoing and fundamental work life concerns for staff nurses that the profession has neither addressed nor resolved in any meaningful, long-term way.

Realigning the Communication Paradigm in Nursing Case Management

Communication underlies all of case management (CM), and better comprehension of the processes of communication within the context of the CM role may facilitate positive patient and organizational outcomes, and assist providers and policy makers in designing effective CM systems. Thus, the purpose of this qualitative, pilot project was to explore dimensions of communication of the nurse case manager role within a hospital setting. The results describe a “hub and spoke” model of communications and suggest the utility of this familiar model for understanding the communication dynamics for those who work as nursing case managers in hospital settings. Findings suggest that nurse case managers are at various times both advocates and mediators—communications roles that may encompass somewhat contradictory demands and perspectives.

The Effectiveness of Feminist Pedagogy in Empowering a Community of Learners

The purpose of this study was to determine whether a pedagogy grounded in feminist ideals has the potential to empower students to make changes consistent with those ideals in their personal and professional lives. In Phase I, qualitative data were collected through e-mail questionnaires from students in two nursing schools, one in Canada and one in the United States. Findings were used to identify an appropriate tool to measure the empowering influence of feminist pedagogy. In Phase 2, a pretest-posttest design used Barrett's Power as Knowing Participation in Change Tool (PKPCT) to measure student empowerment. A clinical setting was added in a third baccalaureate nursing program. A total of 218 students participated in seven course offerings-four classroom and three clinical. One hundred one matched pairs were obtained, for an overall response rate of 46%. Repeated measures ANOVA revealed that overall empowerment scores, as measured by the PKPCT, and classroom empowerment (CE), as measured by the addition of a variable (i.e., the ability to contribute in class), increased significantly from pretest to posttest. Interaction between Sites 1 and 2 was also significant. Regression analysis indicated posttest CE scores added to pretest PKPCT and CE scores provided a strong model to predict overall empowerment scores, measured by the PKPCT at Time 2 (R2 = .703). Despite limitations related to loss of follow up and low response rates at one site, the results of this study supported both hypotheses: that empowerment would increase over the course of the class in which feminist pedagogical principles were used, and that classroom empowerment is likely to extend beyond the classroom to personal and work environments.

Removal of nano and microparticles by granular filter media coated with nanoporous aluminium oxide

Conventional filtration was designed to achieve high levels of particle and pathogen removal. Previous studies have examined the possibility of modifying filtration media to improve their ability to remove microorganisms and viruses. Although these studies have evaluated filter media coatings for this purpose, none have evaluated nanoscale particle suspensions as coating materials. The overall goal of this paper is to describe the preliminary test results of nanoporous aluminium oxide coated media that can be used to enhance filtration of nano and microparticles. Filtration tests were carried out using columns packed with uncoated and coated forms of granular anthracite or granular activated carbon. A positive correlation between isoelectric pH of filter media and particle removal was observed. The modified filter media with a higher isoelectric pH facilitated better removal of bacteriophage MS2 and 3 microm latex microspheres, possibly due to increased favorable electrostatic interactions.

An innovative photocatalytic technology in the treatment of river water containing humic substances

This study addresses the application of a photoelectrocatalytic (PEC) system with separated hole and electron reactions to treat humic acid (HA) from river water. A TiO2 electrode, coated by the sol-gel method, is used for that purpose. The degradation of humic acid in the river water was followed with respect to time using parameters of UV254, color and total organic carbon (TOC). For comparison purposes the photocatalytic (PC) removal of HA was also studied on the same photoanode. The obtained results showed that the PEC system was much more effective than the PC method. The effect of other important reaction variables, such as external potential, oxygen and UV intensity on HA degradation were also investigated. For all the external applied potential conditions and UV intensity range over 90% removal of UV254 and color were obtained with the PEC system while TOC removal was between 58-80%.

Evaluation of Kd underestimation using solid phase microextraction

Many important environmental pollutants are strongly adsorbing hydrophobic compounds. Because of their potential to adsorb to dissolved organic matter (DOM), their partition coefficient Kd may be underestimated by the conventional approach due to incomplete phase separation. In this study, solid-phase microextraction (SPME) was compared with liquid-liquid partition (LLP) for measuring Kd of bifenthrin and permethrin isomers on sediments. Due to its selective detection of the freely dissolved concentration, SPME gave Kd values 0.6-4.4-fold greater than those obtained by LLP in creek and field sediments and 3.6-21.7-fold greater in nursery runoff sediments. Underestimation by the conventional method was attributed to adsorption to DOM that was not excluded from the aqueous phase by centrifugation. The degree of underestimation was dependent on the source and amount of DOM and may be generally significant for compounds that have DOM adsorption coefficient (KDOM) > 10(4). This study provides evidence that the existing Kd values for many hydrophobic pollutants may be underestimated, and SPME may be a viable, efficacious tool for evaluating the underestimation.

Client characteristics and the cost of home care in the prospective payment system

There has been much speculation in the literature about the effect of the prospective payment system (PPS) on the home care industry but few reports of systematic investigation. Clearly, comprehension of client characteristics is essential for categorizing home care clients into the correct Home Health Resource Groups, for allocating resources appropriately, and for implementing necessary organizational changes to accommodate clients who require variations in the amount of resources predicted by the PPS. The purposes of this study were to compare the characteristics of home health clients that resulted in a financial gain or a financial loss for one agency under the PPS with those of the interim payment system. A secondary data analysis of 140 cases compiled by one not-for-profit hospital-affiliated home care organization was completed. Results suggested that client characteristics of the projected loss group had more recertifications on admission and at the end of the 60-day episode, a longer stay (3 weeks), and more visits, particularly from skilled nursing. Comprehension of client characteristics and the subsequent ability to adjust for the proper case mix will be crucial if home care agencies are to remain financially viable under the PPS. Replication of this project needs to be done using more variables and multiple sites.

Nursing research in home health care: endangered species?

An information revolution is occurring in home health care documentation processes and systems. The federally mandated Outcomes and Assessment Information Set (OASIS) for patient assessment and the use of electronic patient medical records will significantly affect the conduct of nursing research in home health care. The purposes of this article are to inform potential home care nurse researchers about the standardization of patient information as exemplified by OASIS and electronic patient medical records and recommend strategies to accommodate these changes. The potential for meaningful, scholarly studies in home care has never been greater, but researchers must address new challenges and adapt investigations accordingly.

Combined endoscopic mucosal resection and photodynamic therapy for esophageal neoplasia within Barrett's esophagus

BACKGROUND

Endoscopic mucosal resection (EMR) and photodynamic therapy have been proposed as treatments for early stage cancers. EMR is limited by its focal nature whereas photodynamic therapy is dependent on precise staging. The combination of EMR and photodynamic therapy were studied in the treatment of superficial cancer in patients with Barrett's esophagus.

METHODS

Seventeen consecutive nonsurgical patients with superficial cancers underwent EMR followed by photodynamic therapy with a porphyrin photosensitizer. Photoradiation was performed at 630 nm for a total dose of 200 J/cm of diffuser.

RESULTS

Seventeen patients (15 men; mean age 69 +/- 13 years) underwent EMR. The mean diameter of mucosal resection was 1 cm. The margins were involved by cancer in 3 cases. EMR improved staging in 8 patients (47%). Sixteen (94%) patients remained in remission (median follow-up 13 months). Complications included minor bleeding after EMR in 1 patient (6%), stricture in 5 (30%), cutaneous phototoxicity in 2 (12%), and supraventricular tachycardia in 1 patient (6%).

CONCLUSIONS

Combined EMR and photodynamic therapy appears to be an effective and safe therapy for superficial esophageal cancer within Barrett's esophagus. This combination improves cancer staging, removes the superficial cancer, and eliminates remaining mucosa at risk for cancer development.

Hydrolysis of phosphotriesters: determination of transition states in parallel reactions by heavy-atom isotope effects

The remote label method was used to measure primary and secondary (18)O isotope effects in the alkaline hydrolysis of O,O-diethylphosphorylcholine iodide (DEPC) and the primary (18)O effect in the alkaline hydrolysis of O,O-diethyl-m-nitrobenzyl phosphate (DEmNBP). Both the leaving group of interest (choline or m-nitrobenzyl alcohol) and ethanol can be ejected during hydrolysis due to the similarity of their pK values. The heavy-atom isotope effects were measured by isotope ratio mass spectrometry. Parallel reaction and incomplete labeling corrections were made for both systems. DEPC has a primary (18)O isotope effect of 1.041 +/- 0.003 and a secondary (18)O isotope effect of 1.033 +/- 0.002. The primary (18)O isotope effect for DEmNBP was 1.052 +/- 0.003. These large effects suggest a highly associative transition state in which the nucleophile approaches very close to the phosphorus atom to eject the leaving group. The large values are also indicative of a large compression, or general movement, on the reaction coordinate.

Solution structures by 1H NMR of the novel cyclic trypsin inhibitor SFTI-1 from sunflower seeds and an acyclic permutant

SFTI-1 is a recently discovered cyclic peptide trypsin inhibitor from sunflower seeds comprising 14 amino acid residues. It is the most potent known Bowman-Birk inhibitor and the only naturally occurring cyclic one. The solution structure of SFTI-1 has been determined by 1H-NMR spectroscopy and compared with a synthetic acyclic permutant. The solution structures of both are remarkably similar. The lowest energy structures from each family of 20 structures of cyclic and acyclic SFTI-1 have an rmsd over the backbone and heavy atoms of 0.29 A and 0.66 A, respectively. The structures consist of two short antiparallel beta-strands joined by an extended loop containing the active site at one end. Cyclic SFTI-1 also has a hairpin turn completing the cycle. Both molecules contain particularly stable arrangements of cross-linking hydrogen bonds between the beta-strands and a single disulfide bridge, making them rigid and well defined in solution. These stable arrangements allow both the cyclic and acyclic variants of SFTI-1 to inhibit trypsin with very high potencies (0.5 nM and 12.1 nM, respectively). The cyclic nature of SFTI-1 appears to have evolved to provide higher trypsin inhibition as well as higher stability. The solution structures are similar to the crystal structure of the cyclic inhibitor in complex with trypsin. The lack of a major conformational change upon binding suggests that the structure of SFTI-1 is rigid and already pre-organized for maximal binding due to minimization of entropic losses compared to a more flexible ligand. These properties make SFTI-1 an ideal platform for the design of small peptidic pharmaceuticals or pesticides.

Biochemical characterization of cartilage affected by osteochondritis dissecans in the humeral head of dogs

OBJECTIVE

To determine glycosaminoglycan (GAG) concentration and immunohistochemical staining characteristics of type-I, -II, and -X collagen from cartilage affected by osteochondritis dissecans (OCD) in dogs.

ANIMALS

31 dogs with OCD and 11 clinically normal purpose-bred dogs.

PROCEDURE

Cartilage samples were evaluated microscopically, and GAG content was determined. Immunohistochemical staining was performed for type-I, -II, and -X collagen. Sections were subjectively evaluated for location and intensity of staining.

RESULTS

Cartilage affected by OCD had a variety of pathologic changes and significantly lower GAG concentrations than did normal cartilage. Normal cartilage had no detectable type-I collagen. For dogs < 9 months of age, cartilage affected by OCD had significantly more type-I collagen but significantly less type-X collagen than did control cartilage. For dogs > 12 months of age, cartilage affected by OCD contained significantly more type-I collagen than did control cartilage. There was a significant negative correlation between immunoreactivity of type-I collagen and that of type-II and -X collagen. A significant positive correlation was found between immunoreactivity of type-II and -X collagen.

CONCLUSIONS AND CLINICAL RELEVANCE

Cartilage affected by OCD contains less GAG, more type-I collagen, and less type-X collagen, compared with normal cartilage. A direct correlation between these changes and the etiopathogenesis of OCD was not established.

Extent of high-grade dysplasia in Barrett's esophagus correlates with risk of adenocarcinoma

BACKGROUND & AIMS

The identification of any high-grade dysplasia (HGD) in Barrett's esophagus has been considered to be an indication for esophagectomy because of the increased risk of cancer. The aim of this study was to determine if a limited extent of HGD has the same potential for cancer as diffuse HGD.

METHODS

A retrospective cohort study was performed to assess the risk of developing adenocarcinoma in relationship to the extent of HGD found on endoscopic surveillance. The extent of HGD was defined as focal if cytologic and/or architectural changes of HGD were limited to a single focus of 5 or fewer crypts and diffuse if more than 5 crypts were involved in a single biopsy specimen or if HGD involved more than one biopsy fragment. The relative risk of cancer was assessed using a Cox proportional hazard model, and cancer-free survival was determined using survival curves.

RESULTS

Sixty-seven patients with diffuse HGD and 33 with focal HGD satisfied selection criteria. Cancer-free survival rates at 1 and 3 years were 93% and 86% for focal HGD compared with 62% and 44% for diffuse HGD (P < 0.001). On univariate analysis, extent of HGD (relative risk, 5.36; 95% confidence interval, 1.84-15.56), nodularity on endoscopy (relative risk, 3.98; 95% confidence interval, 1.97-8.04), and lack of acid suppression (relative risk, 2.48; 95% confidence interval, 1.16-5.28) were associated with an increased risk of esophageal adenocarcinoma. Diffuse HGD had a 3.7-fold increase in the risk of esophageal cancer compared with focal HGD (P = 0.02) on multivariate analysis.

CONCLUSIONS

Patients with focal HGD are less likely to have cancer during the first year after diagnosis or on subsequent follow-up compared with diffuse HGD.

Contribution of intraoperative enteroscopy in the management of obscure gastrointestinal bleeding

Obscure gastrointestinal bleeding remains a significant diagnostic challenge. Our aims were (1) to determine the efficacy of intraoperative enteroscopy (IOE) in identifying lesions responsible for obscure gastrointestinal bleeding and (2) to determine the outcome of patients after treatment of these lesions. We retrospectively reviewed all patients who underwent IOE for obscure gastrointestinal bleeding from 1992 to 1998. Patients were divided into those with overt and those with occult gastrointestinal bleeding. Follow-up was complete in 67 patients (96%), with a median of 32 months (range 1 to 91 months). Seventy patients (52 overt and 18 occult) underwent IOE after extensive preoperative evaluation. Median duration of bleeding was 12 months, requiring a median of 14 blood transfusions. Risk factors for bleeding were identified in 46 patients (61%). A lesion was identified and treated in 52 patients (74%)-39 in the overt group and 13 in the occult group. Lesions identified were vascular (54%), ulcerations (31%), tumors (11%), and small bowel diverticula (4%). Overall, 35 patients (52%) were found to have one or more lesions at IOE that were treated surgically and had no further bleeding. IOE, through a mid-small bowel enterotomy, has low morbidity and is effective in that it identified a treatable lesion in 74% of patients, which led to cure of bleeding in 52%.

Doing more with less and less with more

The "devil is in the details" of any policy response. What forms such changes may take, and what research informs them, are critical to the profession as a whole and to practitioners on a daily basis. Research partnerships between home care agencies and university professors may provide rigorous, systematic, and validated findings necessary for meaningful solutions (Plotkin & Roche, 2000). The evidence of a dialogue between nursing researchers, home healthcare practitioners, and policymakers anticipating impacts on practice of changing fiscal and information-gathering requirements is scant. Such issues are in need a priority discussion by agencies, and collaborative investigative efforts between all involved.

Recent advances in external skeletal fixation

While the use of external skeletal fixation was once associated with substantial postoperative morbidity, clinical and experimental studies have led to technological advances and modifications in application techniques that have greatly improved the results obtained with this treatment modality. The past decade saw numerous advances in external skeletal fixator implants, components and instrumentation, including improvements in fixation pin design, and the development of new linear external skeletal fixation systems and economical circular external skeletal fixation systems specifically engineered for use in dogs and cats. In addition, a greater understanding of fixator biomechanics and the pathobiology of the bone-fixation pin interface have improved fixator application practices. This article reviews many of the more significant recent advances in external skeletal fixation.

The solution structure of C1-T1, a two-domain proteinase inhibitor derived from a circular precursor protein from Nicotiana alata

A two-domain portion of the proteinase inhibitor precursor from Nicotiana alata (NaProPI) has been expressed and its structure determined by NMR spectroscopy. NaProPI contains six almost identical 53 amino acid repeats that fold into six highly similar domains; however, the sequence repeats do not coincide with the structural domains. Five of the structural domains comprise the C-terminal portion of one repeat and the N-terminal portion of the next. The sixth domain contains the C-terminal portion of the sixth repeat and the N-terminal portion of the first repeat. Disulphide bonds link these C and N-terminal fragments to generate the clasped-bracelet fold of NaProPI. The three-dimensional structure of NaProPI is not known, but it is conceivable that adjacent domains in NaProPI interact to generate the circular "bracelet" with the N and C termini in close enough proximity to facilitate formation of the disulphide bonds that form the "clasp". The expressed protein, examined in the current study, comprises residues 25-135 of NaProPI and encompasses the first two contiguous structural domains, namely the chymotrypsin inhibitor C1 and the trypsin inhibitor T1, joined by a five-residue linker, and is referred to as C1-T1. The tertiary structure of each domain in C1-T1 is identical to that found in the isolated inhibitors. However, no nuclear Overhauser effect contacts are observed between the two domains and the five-residue linker adopts an extended conformation. The absence of interactions between the domains indicates that adjacent domains do not specifically interact to drive the circularisation of NaProPI. These results are in agreement with recent data which describe similar PI precursors from other members of the Solanaceae having two, three, or four repeats. The lack of strong interdomain association is likely to be important for the function of individual inhibitors by ensuring that there is no masking of reactive sites upon release from the precursor.

Theory and laboratory study of a tall passive chamber for measuring gas fluxes at soil surface

A tall passive flux chamber with a height significantly greater than its horizontal dimensions is proposed for measuring fluxes of volatile organic compounds (VOCs) at the soil surface. The main feature of this tall chamber is the presence of a vertical concentration gradient of the target gas in the chamber. The emission and transport behavior of the target gas in the soil-chamber system are analyzed using the diffusion theory. A mathematical model is developed to estimate the flux from the soil into the tall chamber, providing the target gas establishes a detectable vertical concentration gradient in the chamber. To obtain the data required for calculating flux, only two gas concentrations (C1 and C2) at two heights (h1 and h2) within the chamber need to be measured at the end of a short chamber placement time (tp). To evaluate the applicability of the tall chamber for measuring flux, several laboratory tests have been conducted, using CH2Cl2 and CH3Br as the target gases. The results indicate that the proposed tall chamber has promising potential as a method for measuring fluxes of VOCs at the soil surface.