Parasitic dodder expresses an arsenal of secreted cellulases with multi-substrate specificity during host invasion

Cuscuta campestris is a common and problematic parasitic plant which relies on haustoria to connect to and siphon nutrients from host plants. Glycoside hydrolase family 9 (GH9) cellulases (EC 3.2.1.4) play critical roles in plant cell wall biosynthesis and disassembly, but their roles during Cuscuta host invasion remains underexplored. In this study, we identified 22 full-length GH9 cellulase genes in C. campestris genome, which encoded fifteen secreted and seven membrane-anchored cellulases that showed distinct phylogenetic relationships. Expression profiles suggested that some of the genes are involved in biosynthesis and remodeling of the parasite's cell wall during haustoriogenesis, while other genes encoding secreted B- and C-type cellulases are tentatively associated with degrading host cell walls during invasion. Transcriptomic data in a host-free system and in the presence of susceptible or partially resistant tomato hosts, showed for especially GH9B7, GH9B11 and GH9B12 a shift in expression profiles in the presence of hosts, being more highly expressed during host attachment, indicating that Cuscuta can tune cellulase expression in response to a host. Functional analyses of recombinant B- and C-type cellulases showed endoglucanase activities over wide pH and temperature conditions, and activities towards multiple cellulose and hemicellulose substrates. These findings improve our understanding of host cell wall disassembly by Cuscuta, and cellulase activity towards broad substrate range potentially explain its wide host range. This is the first study to provide a broad biochemical insight into Cuscuta GH9 cellulases, which based on our study may have potential applications in industrial bioprocessing.

Cuscuta campestris fine-tunes gene expression during haustoriogenesis as an adaptation to different hosts

The Cuscuta genus comprises obligate parasitic plants that have an unusually wide host range. Whether Cuscuta uses different infection strategies for different hosts or whether the infection strategy is mechanistically and enzymatically conserved remains unknown. To address this, we investigated molecular events during the interaction between field dodder (Cuscuta campestris) and two host species of the Solanum genus that are known to react differently to parasitic infection. We found that host gene induction, particularly of cell wall fortifying genes, coincided with a differential induction of genes for cell wall degradation in the parasite in the cultivated tomato (Solanum lycopersicum) but not in a wild relative (Solanum pennellii). This indicates that the parasite can adjust its gene expression in response to its host. This idea was supported by the increased expression of C. campestris genes encoding an endo-β-1,4-mannanase in response to exposure of the parasite to purified mono- and polysaccharides in a host-independent infection system. Our results suggest multiple key roles of the host cell wall in determining the outcome of an infection attempt.

Changes in health-related quality of life following percutaneous coronary intervention – a nationwide prospective cohort study

Background

In addition to mortality and morbidity, improved health-related quality of life (HRQOL) is a goal of treatment in patients suffering of cardiovascular heart disease. There is a limited knowledge of changes in HRQOL following percutaneous coronary intervention (PCI).

Aims

The aims of this study were to determine total and gender specific changes in HRQOL at baseline and four-years following PCI.

Methods

This study use data from the Norwegian Coronary Stent Trial which included 9013 patients undergoing first time percutaneous coronary intervention in Norway during September 2008–February 2011. HRQOL was assessed using the Short-Form-12 (SF-12) at baseline and at four years of follow up in a representative subgroup (n=775).

Results

The mean age was 64 years (SD 9.2) and 75% were male. Eighty percent were living with a partner and 67% had a higher level of education. The majority of the patients had stable angina as indication for PCI (40%). There was a significant improvement in all domains of SF-12 from baseline to four years of follow up (p<0.001). The highest changes were in Role Physical (43.6 vs. 48.2), Bodily Pain (44.8 vs. 50.1) and Vitality (44.1 vs. 49.3). Analysing gender differences at four years follow-up, men had a higher improvement in the physical component summary score than women (4.8 vs 2.8, p=0.04), but not in the mental component summary score (2.8 vs 4.4, p=0.11).

Conclusion

In patients undergoing first time PCI, HRQOL improved significant from baseline to four years of follow up. Both at baseline and at five years of follow up males report a higher HRQOL compared to females.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Northern Norway Regional Health Authority

A host-free transcriptome for haustoriogenesis in Cuscuta campestris: Signature gene expression identifies markers of successive development stages

The development of the infection organ of the parasitic angiosperm genus Cuscuta is a dynamic process that is normally obscured from view as it happens endophytically in its host. We artificially induced haustoriogenesis in Cuscuta campestris by far-red light to define specific morphologically different stages and analyze their transcriptional patterns. This information enabled us to extract sets of high-confidence housekeeping and marker genes for the different stages, validated in a natural infection setting on a compatible host. This study provides a framework for more reproducible investigations of haustoriogenesis and the processes governing host-parasite interactions in shoot parasites, with C. campestris as a model species.

The Enigma of Interspecific Plasmodesmata: Insight From Parasitic Plants

Parasitic plants live in intimate physical connection with other plants serving as their hosts. These host plants provide the inorganic and organic compounds that the parasites need for their propagation. The uptake of the macromolecular compounds happens through symplasmic connections in the form of plasmodesmata. In contrast to regular plasmodesmata, which connect genetically identical cells of an individual plant, the plasmodesmata that connect the cells of host and parasite join separate individuals belonging to different species and are therefore termed "interspecific". The existence of such interspecific plasmodesmata was deduced either indirectly using molecular approaches or observed directly by ultrastructural analyses. Most of this evidence concerns shoot parasitic Cuscuta species and root parasitic Orobanchaceae, which can both infect a large range of phylogenetically distant hosts. The existence of an interspecific chimeric symplast is both striking and unique and, with exceptions being observed in closely related grafted plants, exist only in these parasitic relationships. Considering the recent technical advances and upcoming tools for analyzing parasitic plants, interspecific plasmodesmata in parasite/host connections are a promising system for studying secondary plasmodesmata. For open questions like how their formation is induced, how their positioning is controlled and if they are initiated by one or both bordering cells simultaneously, the parasite/host interface with two adjacent distinguishable genetic systems provides valuable advantages. We summarize here what is known about interspecific plasmodesmata between parasitic plants and their hosts and discuss the potential of the intriguing parasite/host system for deepening our insight into plasmodesmatal structure, function, and development.

De novo assembly and annotation of the North American bison (Bison bison) reference genome and subsequent variant identification

Genomic tools have improved the ability to manage bison populations and enhanced efforts to conserve this iconic species. These tools have been particularly useful for detecting introgression of cattle genome within bison herds but are limited by the need to use the cattle genome as a surrogate for mapping reads. This complicates efforts to distinguish the species of origin of chromosomal segments in individual bison at the genomic level. An assembly (Bison_UMD1.0) based on 75X genome coverage by Illumina and 454 reads was generated using the MaSuRCA assembler, generating a 2.81 Gigbases de novo reference genome from American bison. Comparison of bison and domestic cattle references identified 28 443 364 single nucleotide variants and 2 627 645 insertions/deletions distinguishing the species. Sequence alignment of an additional 12 modern bison samples and two historic bison samples to domestic cattle and bison references provides a dataset of genomic variants defining the different species and within-species variation. This first annotated draft assembly represents a resource for the management and conservation of bison, as well as a means to study the effects on the genome of interspecies hybridization. The comparisons of historical bison sequences with the new bison reference identified genomic differences between modern and pre-population bottleneck bison. The results support the application of genomics to enhance future research on disease, the establishment of satellite conservation herds and insight into bison and cattle speciation. The first genome assembly for bison and dataset provides a foundation that can be built upon as genetic technologies improve over the years.

Mind-Craft: Exploring the Effect of Digital Visual Experience on Changes to Orientation Sensitivity in Visual Contour Perception

Visual perception depends fundamentally on statistical regularities in the environment to make sense of the world. One such regularity is the orientation anisotropy typical of natural scenes; most natural scenes contain slightly more canonical (horizontal and vertical) information than oblique information. This property is likely a primary cause of the oblique effect in which subjects experience greater perceptual fluency with horizontally and vertically oriented content than oblique. Recent changes in the visual environment, including the "carpentered" content in urban scenes and the framed, caricatured content in digital screen media presentations, may have altered the typical (natural) level of orientation anisotropy. The current work evaluated whether digital visual experience, or visual experience with framed digital content, has the potential to alter the magnitude of the oblique effect in visual perception. Experiment 1 successfully established a novel eye-tracking method capable of indexing the visual oblique effect quickly and reliably and demonstrated the oblique effect. Experiment 2 used this method and found that one session of exposure to a specific video game altered visual orientation perception. Taken together, these results indicate that exposure to the realistic, but caricatured scene statistics of digital screen media, can alter visual contour perception in one session.

0944 Shhh! Initiative: Sleep Health Practices In Pediatric Hospitals

Introduction

Hospitalizations often result in significant sleep disruption, despite the importance of sleep in healing (Cmiel, et al., 2004). Research-to-date has focused primarily on adult intensive care (ICU) with minimal focus on pediatric patients. The aim of this study was to assess pediatric inpatient healthcare providers’ understanding of and attitudes towards sleep in the hospital environment with the goal of developing a sleep health educational intervention as well as modifications to standards of care that unnecessarily interrupt sleep of pediatric inpatients.

Methods

An online survey was administered to pediatric inpatient staff (nurses, physicians, residents) at a Mid-Atlantic children’s hospital focused on assessing their understanding of sleep in the context of inpatient care (N = 316). Respondents were 30-50 years old (54%), primarily identified as female (88%), and most (60%) reported being in a nursing position.

Results

Quantitative findings (N = 316) revealed that 65% reported patients were sometimes, rarely, or never allowed to sleep without being awakened from administration of non-critical medications. A majority (63.8%) reported that sometimes, rarely, or never do they consider interruption of sleep in decisions on when to give medications, while 54.9% reported the quantity and quality of sleep is rarely/never considered in a patient’s treatment. Qualitative responses (N = 248) confirmed these findings with 34.3% reporting that they considered re-scheduling medications to minimize sleep interruptions. Despite this finding, only 15.7% reported they would assess or give attention to sleep in the context of patient recovery and treatment.

Conclusion

Pediatric healthcare providers are aware of the importance of sleep for their patients; however, they are not prioritizing sleep as a part of treatment in their behaviors and decisions. Next steps include developing and implementing an intervention for pediatric healthcare providers to follow through on limiting sleep interruptions as well as focusing on sleep in the treatment process.

Support

N/A

A rapid preparation procedure for laser microdissection-mediated harvest of plant tissues for gene expression analysis

BACKGROUND

Gene expression changes that govern essential biological processes can occur at the cell-specific level. To gain insight into such events, laser microdissection is applied to cut out specific cells or tissues from which RNA for gene expression analysis is isolated. However, the preparation of plant tissue sections for laser microdissection and subsequent RNA isolation usually involves fixation and embedding, processes that are often time-consuming and can lower the yield and quality of isolated RNA.

RESULTS

Infection sites of the parasitic plant Cuscuta reflexa growing on its compatible host plant Pelargonium zonale were sectioned using a vibratome and dried on glass slides at 4 °C before laser microdissection. High quality RNA (RQI > 7) was isolated from 1 mm2, 3 mm2 and 6 mm2 total surface areas of laser microdissection-harvested C. reflexa tissue, with the yield of RNA correlating to the amount of collected material (on average 7 ng total RNA/mm2). The expression levels of two parasite genes previously found to be highly expressed during host plant infection were shown to differ individually between specific regions of the infection site. By drying plant sections under low pressure to reduce the dehydration time, the induced expression of two wound-related genes during preparation was avoided.

CONCLUSIONS

Plants can be prepared quickly and easily for laser microdissection by direct sectioning of fresh tissue followed by dehydration on glass slides. We show that RNA isolated from material treated in this manner maintains high quality and enables the investigation of differential gene expression at a high morphological resolution.

Determining the IgG concentrations in bovine colostrum and calf sera with a novel enzymatic assay

Background

Immune protection in newborn calves relies on a combination of the timing, volume and quality of colostrum consumed by the calf after birth. Poor quality colostrum with inadequate immunoglobulin concentration contributes to failed transfer of passive immunity in calves, leading to higher calf morbidity and mortality. Therefore, estimating colostrum quality and ensuring the transfer of passive immunity on farm is of critical importance. Currently, there are no on-farm tools that directly measure immunoglobulin content in colostrum or serum. The aim of this study was to apply a novel molecular assay, split trehalase immunoglobulin G assay (STIGA), to directly estimate immunoglobulin content in dairy and beef colostrum and calf sera, and to examine its potential to be developed as on-farm test. The STIGA is based on a split version of trehalase TreA, an enzyme that converts trehalose into glucose, enabling the use of a common glucometer for signal detection. In a first study, 60 dairy and 64 beef colostrum and 83 dairy and 84 beef calf sera samples were tested with STIGA, and the resulting glucose production was measured and compared with radial immunodiffusion, the standard method for measuring immunoglobulin concentrations.

Results

Pearson correlation coefficients between the methods were determined and the sensitivity, specificity, and accuracy of the test were calculated for different colostrum quality and failed transfer of passive immunity cut-off points. The correlations of the STIGA measured by colorimetric enzymatic reaction compared to radial immunodiffusion for dairy and beef colostrum were 0.72 and 0.73, respectively, whereas the correlations for dairy and beef sera were 0.9 and 0.85, respectively. Next, STIGA was tested in a blinded study with fresh colostrum and serum samples where the correlation coefficient was 0.93 and 0.94, respectively. Furthermore, the performance of STIGA followed by glucometer readings resulted in correlations with radial immunodiffusion of 0.7 and 0.85 for dairy and beef colostrum and 0.94 and 0.83 for dairy and beef calf serum.

Conclusions

A split TreA assay was validated for measurement of the immunoglobulin content of colostrum and calf sera using both a lab-based format and in a more user-friendly format compatible with on-farm testing.

Activity of xyloglucan endotransglucosylases/hydrolases suggests a role during host invasion by the parasitic plant Cuscuta reflexa

The parasitic vines of the genus Cuscuta form haustoria that grow into other plants and connect with their vascular system, thus allowing the parasite to feed on its host. A major obstacle that meets the infection organ as it penetrates the host tissue is the rigid plant cell wall. In the present study, we examined the activity of xyloglucan endotransglucosylases/hydrolases (XTHs) during the host-invasive growth of the haustorium. The level of xyloglucan endotransglucosylation (XET) activity was found to peak at the penetrating stage of Cuscuta reflexa on its host Pelargonium zonale. In vivo colocalization of XET activity and donor substrate demonstrated XET activity at the border between host and parasite. A test for secretion of XET-active enzymes from haustoria of C. reflexa corroborated this and further indicated that the xyloglucan-modifying enzymes originated from the parasite. A known inhibitor of XET, Coomassie Brilliant Blue R250, was shown to reduce the level of XET in penetrating haustoria of C. reflexa. Moreover, the coating of P. zonale petioles with the inhibitor compound lowered the number of successful haustorial invasions of this otherwise compatible host plant. The presented data indicate that the activity of Cuscuta XTHs at the host-parasite interface is essential to penetration of host plant tissue.

Identification of Brucella spp. in feral swine (Sus scrofa) at abattoirs in Texas, USA

Various tissues, nasal swabs, urine and blood samples were collected from 376 feral swine at two federally inspected abattoirs in Texas during six separate sampling periods in 2015. Samples were tested for Brucella spp. by culture and serology. Brucella spp. were cultured from 13.0% of feral swine, and antibodies were detected in 9.8%. Only 32.7% of culture-positive feral swine were also antibody positive, and 43.2% of antibody-positive feral swine were culture positive. Approximately, the same number of males (14.0%) and females (12.1%) were culture positive, and slightly more males (10.5%) than females (8.7%) were antibody positive. Our results indicate that serology likely underestimates the prevalence of feral swine infected, and that those who come in contact with feral swine should be aware of the symptoms of infection with Brucella spp. to ensure prompt treatment.

Healthful dietary patterns and long-term weight change among women with a history of gestational diabetes mellitus

BACKGROUND/OBJECTIVE

Diet represents a key strategy for the prevention of obesity and type 2 diabetes among women with a history of gestational diabetes mellitus (GDM), although effective dietary patterns to prevent weight gain in the long term are largely unknown. We sought to evaluate whether improvement in overall diet quality is associated with less long-term weight gain among high-risk women with prior GDM.

SUBJECTS/METHODS

Women with a history of GDM (N=3397) were followed from 1991 to 2011, or until diagnosis of type 2 diabetes or other chronic disease. Usual diet was assessed via food frequency questionnaire every 4 years from which we calculated the Alternative Healthy Eating Index (aHEI-2010), Alternate Mediterranean Diet (AMED) and Dietary Approaches to Stop Hypertension (DASH) dietary pattern scores. Weight, lifestyle and health-related outcomes were self-reported every 2 years. We estimated the change in dietary score with change in body weight using linear regression models adjusting for age, baseline body mass index (BMI), baseline and simultaneous change in physical activity and smoking status and other risk factors.

RESULTS

Women were followed up to 20 years, gaining an average 1.9 kg (s.d.=7.0) per 4-year period. Women in the highest quintile (Q5) of diet change (most improvement in quality) gained significantly less weight per 4-year period than the lowest quintile (Q1; decrease in quality), independent of other risk factors (4-year weight change, aHEI-2010: Q5=1.30 kg vs Q1=3.27 kg; AMED: Q5=0.94 kg vs Q1=2.56 kg, DASH: Q5=0.64 kg vs Q1=2.75 kg). Significant effect modification by BMI (p-interactions <0.001) indicated a greater magnitude of weight change among women with a higher baseline BMI for all three patterns.

CONCLUSIONS

Increased diet quality was associated with less weight gain, independent of other lifestyle factors. Post-partum recommendations on diet quality may provide one strategy to prevent long-term weight gain in this high-risk group.

Getting ready for host invasion: elevated expression and action of xyloglucan endotransglucosylases/hydrolases in developing haustoria of the holoparasitic angiosperm Cuscuta

Changes in cell walls have been previously observed in the mature infection organ, or haustorium, of the parasitic angiosperm Cuscuta, but are not equally well charted in young haustoria. In this study, we focused on the molecular processes in the early stages of developing haustoria; that is, before the parasite engages in a physiological contact with its host. We describe first the identification of differentially expressed genes in young haustoria whose development was induced by far-red light and tactile stimuli in the absence of a host plant by suppression subtractive hybridization. To improve sequence information and to aid in the identification of the obtained candidates, reference transcriptomes derived from two species of Cuscuta, C. gronovii and C. reflexa, were generated. Subsequent quantitative gene expression analysis with different tissues of C. reflexa revealed that among the genes that were up-regulated in young haustoria, two xyloglucan endotransglucosylase/hydrolase (XTH) genes were highly expressed almost exclusively at the onset of haustorium development. The same expression pattern was also found for the closest XTH homologues from C. gronovii. In situ assays for XTH-specific action suggested that xyloglucan endotransglucosylation was most pronounced in the cell walls of the swelling area of the haustorium facing the host plant, but was also detectable in later stages of haustoriogenesis. We propose that xyloglucan remodelling by Cuscuta XTHs prepares the parasite for host infection and possibly aids the invasive growth of the haustorium.

Two sides of the same coin: Xyloglucan endotransglucosylases/hydrolases in host infection by the parasitic plant Cuscuta

The holoparasitic angiosperm Cuscuta develops haustoria that enable it to feed on other plants. Recent findings corroborate the long-standing theory that cell wall modifications are required in order for the parasite to successfully infect a host, and further suggest that changes to xyloglucan through the activity of xyloglucan endotransglucosylases/hydrolases (XTHs) are essential. On the other hand, XTH expression was also detected in resistant tomato upon an attack by Cuscuta, which suggests that both host and parasite use these enzymes in their "arms race." Here, we summarize existing data on the cell wall-modifying activities of XTHs during parasitization and present a model suggesting how XTHs might function to make the host's resources accessible to Cuscuta.

Cell wall composition profiling of parasitic giant dodder (Cuscuta reflexa) and its hosts: a priori differences and induced changes

Host plant penetration is the gateway to survival for holoparasitic Cuscuta and requires host cell wall degradation. Compositional differences of cell walls may explain why some hosts are amenable to such degradation while others can resist infection. Antibody-based techniques for comprehensive profiling of cell wall epitopes and cell wall-modifying enzymes were applied to several susceptible hosts and a resistant host of Cuscuta reflexa and to the parasite itself. Infected tissue of Pelargonium zonale contained high concentrations of de-esterified homogalacturonans in the cell walls, particularly adjacent to the parasite's haustoria. High pectinolytic activity in haustorial extracts and high expression levels of pectate lyase genes suggest that the parasite contributes directly to wall remodeling. Mannan and xylan concentrations were low in P. zonale and in five susceptible tomato introgression lines, but high in the resistant Solanum lycopersicum cv M82, and in C. reflexa itself. Knowledge of the composition of resistant host cell walls and the parasite's own cell walls is useful in developing strategies to prevent infection by parasitic plants.

Youth with disabilities' perspectives of the environment and participation: a qualitative meta-synthesis

Meta-syntheses can enhance our knowledge regarding the impact of the environment on the participation of youth with disabilities and generate theoretical frameworks to inform policy and best practices. The purpose of this study was to describe school-aged youth with disabilities' perspectives regarding the impact of the environment and modifications on their participation. A meta-synthesis systematically integrates qualitative evidence from multiple studies. Six databases were searched and 1287 citations reviewed for inclusion by two independent raters; 15 qualitative articles were selected for inclusion. Two independent reviewers evaluated the quality of each study and coded the results section. Patterns between codes within and across articles were examined using a constant comparative approach. Environments may be more or less inclusive for youth with disabilities depending upon others' understanding of individual abilities and needs, youth involvement in decisions about accommodations, and quality of services and policies. Youth implemented strategies to negotiate environmental barriers and appraised the quality of their participation based on the extent to which they engaged alongside peers. This meta-synthesis generated a framework illustrating the relationship between the environment, modifications and participation, and provided a conceptualization of participation grounded in the lived experiences of youth with disabilities. Findings reveal gaps in current knowledge and highlight the importance of involving youth with disabilities in decision making.

Patient safety in developing countries: retrospective estimation of scale and nature of harm to patients in hospital

OBJECTIVE

To assess the frequency and nature of adverse events to patients in selected hospitals in developing or transitional economies.

DESIGN

Retrospective medical record review of hospital admissions during 2005 in eight countries.

SETTING

Ministries of Health of Egypt, Jordan, Kenya, Morocco, Tunisia, Sudan, South Africa and Yemen; the World Health Organisation (WHO) Eastern Mediterranean and African Regions (EMRO and AFRO), and WHO Patient Safety.

PARTICIPANTS

Convenience sample of 26 hospitals from which 15,548 patient records were randomly sampled.

MAIN OUTCOME MEASURES

Two stage screening. Initial screening based on 18 explicit criteria. Records that screened positive were then reviewed by a senior physician for determination of adverse event, its preventability, and the resulting disability.

RESULTS

Of the 15,548 records reviewed, 8.2% showed at least one adverse event, with a range of 2.5% to 18.4% per country. Of these events, 83% were judged to be preventable, while about 30% were associated with death of the patient. About 34% adverse events were from therapeutic errors in relatively non-complex clinical situations. Inadequate training and supervision of clinical staff or the failure to follow policies or protocols contributed to most events.

CONCLUSIONS

Unsafe patient care represents a serious and considerable danger to patients in the hospitals that were studied, and hence should be a high priority public health problem. Many other developing and transitional economies will probably share similar rates of harm and similar contributory factors. The convenience sampling of hospitals might limit the interpretation of results, but the identified adverse event rates show an estimate that should stimulate and facilitate the urgent institution of appropriate remedial action and also to trigger more research. Prevention of these adverse events will be complex and involves improving basic clinical processes and does not simply depend on the provision of more resources.

A Relativistic Four- and Two-component Generalized-active-space Coupled Cluster Method

We present an overview of our recent developments of relativistic generalized-active-space coupled cluster and its initial applications to heavy-element systems. The new genuinely string-based method may treat coupled cluster expansions of general order and simulate multi-reference expansions by including higher excitations in properly constructed active spinor spaces. The four-component Dirac-Coulomb Hamiltonian or any approximation to it may be employed, and the underlying spinors are assumed and required to be time-reversal partners. The capability of the new approach is demonstrated and discussed in sample applications to HBr and BiH.

Brain metastases in breast cancer: Different survival by biological subtype and Ki67 expression

1069

Background: Ten to 15% of patients (pts) with breast cancer will be diagnosed with central nervous system (CNS) metastases, and autopsy series suggest that up to 30% of pts have evidence of CNS disease at the time of death. The idenfication of factors that may predispose to CNS metastasis may help lead to earlier detection and possibly to improvement in disease management. Methods: Breast cancer pts with CNS metastases were identified within a database of 1300 breast cancer diganoses from 1995 to 2007 at the Department of Oncology, Azienda ULSS 13 VE. Pathologic features of tumor samples were examined using standard immunohistochemical assays. Results: Fifty-one pts with CNS metastases were identified. Median age at primary breast cancer diagnosis was 49 years (range, 28–78); median time to CNS metastases was 45 months (range, 3–244). HER2 overexpression was found in tumors from 25 pts (49.0%); 23 pts had tumors lacking overexpression of HER2, estrogen receptors (ER), and progesterone receptors (PgR) (ie, “triple negative” disease). Overexpression of p53 (at least 20% tumor cells positive), Ki67 (at least 20%), and BCL2 (at least 30%) were detected in tumors from 16 pts (31.4%), 32 pts (62.7%), and 14 pts (27.5%), respectively. Median survival from CNS involvement was 3.67 months (95% CI 2.05–5.28), with 24.4% and 15.3% of patients estimated to be alive at 12 and 24 months, respectively (Kaplan-Meier product limit method). A Cox proportional hazards analysis found that Ki67 overexpression was the only factor independently associated with a significantly increased risk of death (2.7-fold increase, p=0.028), while triple negative status was associated with a 1.8-fold increase in the risk of death (P=0.08) (Table). Conclusions: In our series of breast cancer pts with CNS metastases, nearly all had either HER2 overexpression or triple-negative disease. Pts whose tumors had higher proliferative indices, assessed by Ki67, had the poorest prognosis.

[Table: see text]

[Table: see text]

Interstitial nephritis with acute renal failure following cardiac surgery and treatment with methicillin

Six patients developed acute renal failure 13-19 days after cardiac surgery with extracorporeal circulation. None of the patients had suffered from postoperative hypotension; slight hemolysis was present for only 1-2 days post-operatively. Acute renal failure lasted for 11-80 days in four patients. In two patients creatinine clearance stabilized at reduced values. Seven renal biopsies from the six patients showed severe acute interstitial nephritis with mononuclear cellular infiltration and distal tubular damage. No immune deposits were detected in glomeruli or tubular basement membrane. All six patients had been treated prophylactically with methicillin and the acute renal disease was probably elicited by this drug.

Detection of adverse events in a Scottish hospital using a consensus-based methodology

OBJECTIVE

To determine, using a consensus based methodology, the rate and nature of adverse events (AEs) among patients admitted to acute medicine, acute surgery and obstetrics in a large teaching hospital in Scotland.

METHODS

Retrospective case-note review of 450 medical, nursing and medication records to identify and classify adverse events. For 354 patients whose length of stay was greater than 24 hours, the overall adverse event rate was 7.9% which ranged from 0% in obstetrics, 7.2% in acute medicine to 13% in acute surgery. Among all AEs, 43% were deemed preventable by a consensus group and 59% of the AEs contributed to a proportion of the patients' hospital stay or led to hospital readmission. Whilst nurse identification of adverse events was highly specific (94%), its sensitivity was poor (43%). Only 10% of the identified AEs were identified by the hospital's voluntary reporting system for adverse events. The estimated additional cost of adverse events in terms of bed days was ł69,189 which if extrapolated Scotland-wide could cost ł297 million per annum.

CONCLUSIONS

This study supports the need to continue the traditional retrospective record review to identify adverse events. The current hospital-based reporting of adverse events does not provide a complete measure of adverse events and needs to be complemented by other measures.

K+ as a vasodilator in resting human muscle: implications for exercise hyperaemia

AIM

Potassium (K(+)) released from contracting skeletal muscle is considered a vasodilatory agent. This concept is mainly based on experiments infusing non-physiological doses of K(+). The aim of the present study was to investigate the role of K(+) in blood flow regulation.

METHODS

We measured leg blood flow (LBF) and arterio-venous (A-V) O(2) difference in 13 subjects while infusing K(+) into the femoral artery at a rate of 0.2, 0.4, 0.6 and 0.8 mmol min(-1).

RESULTS

The lowest dose increased the calculated femoral artery plasma K(+) concentration by approx.1 mmol L(-1). Graded K(+) infusions increased LBF from 0.39 +/- 0.06 to 0.56 +/- 0.13, 0.58 +/- 0.17, 0.61 +/- 0.11 and 0.71 +/- 0.17 L min(-1), respectively, whereas the leg A-V O(2) difference decreased from 74 +/- 9 to 60 +/- 12, 52 +/- 11, 53 +/- 9 and 45 +/- 7 mL L(-1), respectively (P < 0.05). Mean arterial pressure was unchanged, indicating that the increase in LBF was associated with vasodilatation. The effect of K(+) was totally inhibited by infusion (27 micromol min(-1)) of Ba(2+), an inhibitor of Kir2.1 channels. Simultaneous infusion of ATP and K(+) evoked an increase in LBF equalled to the sum of their effects.

CONCLUSIONS

Physiological infusions of K(+) induce significant increases in resting LBF, which are completely blunted by inhibition of the Kir2.1 channels. The present findings in resting skeletal muscle suggest that K(+) released from contracting muscle might be involved in exercise hyperaemia. However, the magnitude of increase in LBF observed with K(+) infusion suggests that K(+) only accounts for a limited fraction of the hyperaemic response to exercise.