bluuebunny/crossref_metadata_2025_split huggingface dataset:
Emergence and Control of Fluoroquinolone-Resistant, Toxin A–Negative, Toxin B–PositiveClostridium difficile
Authors: Drudy Denise , Harnedy Norma , Fanning Séamus , Hannan Margaret , Kyne Lorraine 
Published: July 2007

Background.Clostridium difficileis a major cause of infectious diarrhea in hospitalized patients. Between August 2003 and January 2004, we experienced an increase in the incidence ofC. difficile–associated disease. We describe the investigation into and management of the outbreak in this article.Methods.A total of 73 consecutive patients with nosocomialC. difficile–associated diarrhea were identified.C. difficileisolates were characterized using toxin-specific enzyme immunoassays, a tissue-culture fibroblast cytotoxicity assay, polymerase chain reaction (PCR), and antimicrobial susceptibility tests. Rates of recurrence and ofC. difficilecolitis were recorded. Changes in antibiotic use and infection control policies were documented.Results.The incidence ofC. difficile–associated diarrhea peaked at 21 cases per 1,000 patient admissions. Of theC. difficileisolates recovered, 85 (95%) were identical toxin A–negative and toxin B-positive strains, corresponding to toxinotype VIII and PCR ribotype 017. All clonal isolates were resistant to multiple antibiotics, including ofloxacin, ciprofloxacin, levofloxacin, moxifloxacin, and gatifloxacin (minimum inhibitory concentrations [MICs] of greater than 32μg/mL) and erythromycin, clarithromycin, and clindamycin (MICs of greater than 256μg/mL). RecurrentC. difficile–associated disease occurred in 26 (36%) of the patients. At least 10 (14%) of the patients developedC. difficilecolitis. Additional infection control measures introduced included the use of ward memos, a hand-hygiene awareness campaign, increased environmental cleaning, attention to prescribing practices for antibiotics, increased awareness of diarrheal illness, and early isolation of affected patients. Total use of fluoroquinolones did not change throughout the study period. Despite persistence of this toxin-variant strain, the incidence ofC. difficile–associated disease in our institution decreased to fewer than 5 cases per 1,000 admissions.Conclusions.We report on the emergence of a fluoroquinolone- and clindamycin-resistant, toxin A–negative, and toxin B–positive strain ofC. difficileassociated with an outbreak ofC. difficile–associated disease in our institution during a 6-month period. We found that careful attention to improvement of infection control interventions was the most important means of controlling this nosocomial pathogen.
The long‐range transport of birch (Betula) pollen from Poland and Germany causes significant pre‐season concentrations in Denmark
Authors: Skjøth C. A. , Sommer J. , Stach A. , Smith M. , Brandt J. 
Published: July 2007

SummaryBackground
Birch pollen is highly allergic and has the potential for episodically long‐range transport. Such episodes will in general occur out of the main pollen season. During this time, allergy patients are unprotected and high pollen concentrations will therefore have a full allergenic impact.Objective
To show that Denmark obtains significant quantities of birch pollen from Poland or Germany before the local trees start to flower.Methods
Simultaneous observations of pollen concentrations and phenology in the potential source area in Poland as well as in Denmark were performed in 2006. The Danish pollen records from 2000 to 2006 were analysed for possible long‐range transport episodes and analysed with trajectories in combination with a birch tree source map.Results
In 2006, high pollen concentrations were observed in Denmark with bi‐hourly concentrations above 500 grains/m3 before the local trees began to flower. Poland was identified as a source region. The analysis of the historical pollen record from Copenhagen shows significant pre‐seasonal pollen episodes almost every year from 2000 to 2006. In all episodes, trajectory analysis identified Germany or Poland as source regions.Conclusion
Denmark obtains significant pre‐seasonal quantities of birch pollen from either Poland or Germany almost every year. Forecasting of birch pollen quantities relevant to allergy patients must therefore, take into account long‐range transport. This cannot be based on measured concentrations in Denmark. The most effective way to improve the current Danish pollen forecasts is to extend the current forecasts with atmospheric transport models that take into account pollen emission and transport from countries such as Germany and Poland. Unless long‐range transport is taken into account, pre‐seasonal pollen episodes will have a full allergic impact, as the allergy patients in general will be unprotected during that time.
Clinical features and genetic analysis of four Brazilian kindreds with resistance to thyroid hormone
Authors: Magalhães Patricia Künzle Ribeiro , Rodrigues Dare Gustavo Leopoldo , Rodrigues dos Santos Sandra , Nogueira Celia Regina , De Castro Margaret , Zanini Maciel Lea Maria 
Published: July 2007

SummaryObjective  Resistance to thyroid hormone (RTH) is a dominantly inherited syndrome of reduced tissue responsiveness to thyroid hormone usually due to mutations located in the ligand‐binding domain and adjacent hinge region of the thyroid hormone receptor β (TRβ). In the present report we describe the clinical and laboratory characteristics and the genetic analysis of patients with this rare disorder from a Brazilian population.Patients  Four unrelated Brazilian families with diagnosis of RTH were studied. Age at diagnosis varied from 14 months to 29 years.Results  All affected individuals were clinically euthyroid, except for one patient who presented immediately after birth with hyperthyroidism. All individuals had tachycardia and goitre, elevated concentrations of free thyroid hormones and reduced sensitivity to thyroid hormone. Direct sequencing analysis of the TRβ gene revealed four previously reported mutations: c.949G→A, c.1313G→A, c.1357C→A and c.1358dupC in families A, B, C and D, respectively.Conclusion  The present report shows that the frequent mutations described in the thyroid hormone receptor worldwide are also present in the Brazilian population, which is characterized by a variable ethnic background.
Economic burden of a gluten‐free diet
Authors: Lee A. R. , Ng D. L. , Zivin J. , Green P. H. R. 
Published: July 2007

AbstractBackground  Coeliac disease is a common, autoimmune disorder, for which the only treatment is lifelong adherence to a gluten‐free diet. This study evaluates the economic burden of adhering to a gluten‐free diet.Methods  A market basket of products identified by name brand, weight or package size for both regular wheat‐based products and gluten‐free counterparts was developed. The differences in price between purchase venues, both type of store (general grocery store, an upscale grocery store and a health food store and four internet‐based grocery sites) and region was also analysed.Results  Availability of gluten‐free products varied between the different venues, regular grocery stores carried 36%, while upscale markets carried 41%, and health food stores 94%, compared with 100% availability on the internet. Overall, every gluten‐free product was more expensive than their wheat‐based counterpart (P ≤ 0.05). Bread and pasta was twice as expensive as their wheat‐based counterparts. Cost was affected more by shopping venue than geographic location.Conclusions  This study demonstrated that gluten‐free foods have poor availability and are more expensive than their gluten‐containing counterparts. The impact of these findings on dietary compliance and the quality of life needs to be addressed.
Fitting photosynthetic carbon dioxide response curves for C3 leaves
Authors: SHARKEY THOMAS D. , BERNACCHI CARL J. , FARQUHAR GRAHAM D. , SINGSAAS ERIC L. 
Published: July 2007

ABSTRACTPhotosynthetic responses to carbon dioxide concentration can provide data on a number of important parameters related to leaf physiology. Methods for fitting a model to such data are briefly described. The method will fit the following parameters: Vcmax, J, TPU, Rd and gm[maximum carboxylation rate allowed by ribulose 1·5‐bisphosphate carboxylase/oxygenase (Rubisco), rate of photosynthetic electron transport (based on NADPH requirement), triose phosphate use, day respiration and mesophyll conductance, respectively]. The method requires at least five data pairs of net CO2 assimilation (A) and [CO2] in the intercellular airspaces of the leaf (Ci) and requires users to indicate the presumed limiting factor. The output is (1) calculated CO2 partial pressure at the sites of carboxylation, Cc, (2) values for the five parameters at the measurement temperature and (3) values adjusted to 25 °C to facilitate comparisons. Fitting this model is a way of exploring leaf level photosynthesis. However, interpreting leaf level photosynthesis in terms of underlying biochemistry and biophysics is subject to assumptions that hold to a greater or lesser degree, a major assumption being that all parts of the leaf are behaving in the same way at each instant.
Assessment of live kidney donors by magnetic resonance angiography: reliability and impact on outcomes
Authors: Monroy‐Cuadros Mauricio , McLaughlin Kevin , Salazar Anastasio , Yilmaz Serdar 
Published: July 2007

Abstract: Background:  Kidney allograft retrieval from live donors requires accurate determination of kidney anatomy prior to surgery, particularly the arterial supply. Traditionally, conventional angiography has been used to obtain this information. Magnetic resonance angiography (MRA) offers a non‐invasive, cost‐effective alternative, but has been considered to be less accurate. Despite this criticism, many centers have moved to MRA screening of potential kidney donors. The objective of this study is to evaluate our experience of the reliability of MRA in determining the arterial anatomy of living kidney donors as compared to the intra‐operative findings.Methods:  We performed a retrospective review of gadolinium‐enhanced, ultra‐fast, three‐dimensional, spoiled gradient‐echo MRA in live kidney donors in the Southern Alberta Transplant Program and compared these results with the intra‐operative findings during nephrectomy, as the gold standard.Results:  Of the 66 patients, an accessory renal artery was found intra‐operatively in eight cases; two of which were erroneously diagnosed as normal by MRA. The negative predictive value for MRA was 0.97, false‐negative rate was 0.25, and sensitivity was 0.75. No patient experienced side‐effects from the MRA procedure. No donor needed conversion to open nephrectomy because of an undetected accessory renal artery. One allograft with an accessory renal artery developed thrombosis of the lower pole of the kidney despite arterial reconstruction. Kidney function in the recipient of this allograft was excellent and there was no urinary leak.Conclusion:  In our hands, MRA determined the vascular anatomy of potential kidney donors with an acceptable negative predictive value of 97%.
Acute rheumatic fever: Adherence to secondary prophylaxis and follow up of Indigenous patients in the Katherine region of the Northern Territory
Authors: Stewart Tanya , McDonald Robert , Currie Bart 
Published: July 2007

AbstractObjective:  This paper evaluates adherence with secondary preventative treatment and follow up of acute rheumatic fever (ARF) within the Katherine region of the Northern Territory after the introduction of an ARF register. We aimed to assess the rate of adherence with penicillin prophylaxis and follow‐up guidelines in patients with previous ARF and the effect of factors such as age, sex, disease severity and clinic attendance. Design:  Retrospective study. Setting:  Five Indigenous Community Health Centres located in the Katherine region of the Northern Territory, Australia. Participants:  Fifty‐nine people resident in five communities who were prescribed monthly prophylactic penicillin for ARF during the 24 months between September 2002 and September 2004. All subjects were Indigenous. Main outcome measure:  Main outcome measures were the number of penicillin injections received over the 24‐month period and frequency of echocardiogram and specialist follow up in comparison to Rheumatic Fever Registry Guidelines. Results:  Mean adherence with prophylaxis was 56% of prescribed doses. A non‐significant trend towards improved adherence was seen in children, patients with less severe disease and those who attended the clinic more frequently. Rheumatic Fever Registry Guidelines for echocardiogram and specialist review were met by 63% and 59% of subjects, respectively. Conclusion:  Within this population adherence with penicillin prophylaxis is inadequate to protect against recurrence of ARF and consequent worsening of rheumatic heart disease. In addition, the Rheumatic Fever Registry Guidelines for specialist follow up and echocardiogram are not being adhered to for many patients.
Evidence‐based use of medications in patients with coronary artery disease in a rural Australian community
Authors: Granmyr Jenny , Ball Patrick , Curran Shane , Wang Lexin 
Published: July 2007

AbstractObjective:  To evaluate the evidence‐based use of major drug groups for coronary artery disease (CAD) in patients with chronic heart failure and to identify potential interactions. Design:  A retrospective study. Setting:  A major non‐metropolitan teaching hospital in rural New South Wales. Participants:  Includes 24 men and 25 women, with an age average of 77.2 ± 7.5 years, range 60–96 years. All patients were over 18 years old with CAD and heart failure.Main outcome measures:  The evidence‐based use of medications and potential drug interactions. Results:  On admission, 71% were treated with aspirin/clopidogrel, 71% with angiotensin‐converting enzyme inhibitors or angiotensin receptor blocker, 39% with beta‐blockers, 29% with short‐acting nitrates and 59% with statins. The use of these medications remained unchanged at time of discharge (P > 0.05). Of the 23 patients with hypertension at admission, blood pressure was controlled in seven (30%) before discharge. Potential drug interactions were identified in 37% of the patients. Non‐steroidal anti‐inflammatory drugs were used in seven (14%) patients.Conclusions:  The use of aspirin, angiotensin‐converting enzyme inhibitors/angiotensin receptor blocker, beta‐blockers, short‐acting nitrate and statins in patients with CAD compares favourably with international literatures. However, there is room for improvement in the use of beta‐blockers and statins. A greater effort needs to be made to prevent clinically significant drug interactions.
Reciprocal relationships and potential feedbacks between biodiversity and disturbance
Authors: Randall Hughes A. , Byrnes Jarrett E. , Kimbro David L. , Stachowicz John J. 
Published: July 2007

AbstractTwo major foci of ecological research involve reciprocal views of the relationship between biodiversity and disturbance: disturbance determines community diversity or diversity determines realized disturbance severity. Here, we present an initial attempt to synthesize these two approaches in order to understand whether feedbacks occur, and what their effects on patterns of diversity might be. Our review of published experiments shows that (i) disturbance severity can be both a cause and a consequence of local diversity in a wide range of ecosystems and (ii) shapes of the unidirectional relationships between diversity and disturbance can be quite variable. To explore how feedbacks between diversity and disturbance might operate to alter expected patterns of diversity in nature, we develop and then evaluate a conceptual model that decomposes the relationships into component parts, considering sequentially the effect of diversity on disturbance severity, and the effect of realized disturbance on diversity loss, subsequent recruitment, and competitive exclusion. Our model suggests that feedbacks can increase mean values of richness, decrease variability, and alter the patterns of correlation between diversity and disturbance in nature. We close by offering ideas for future research to help fill gaps in our understanding of reciprocal relationships among ecological variables like diversity and disturbance.
Subcellular targeting is a key condition for high‐level accumulation of cellulase protein in transgenic maize seed
Authors: Hood Elizabeth E. , Love Robert , Lane Jeff , Bray Jeff , Clough Richard , Pappu Kamesh , Drees Carol , Hood Kendall R. , Yoon Sangwoong , Ahmad Atta , Howard John A. 
Published: July 2007

SummaryEthanol from lignocellulosic biomass is being pursued as an alternative to petroleum‐based transportation fuels. To succeed in this endeavour, efficient digestion of cellulose into monomeric sugar streams is a key step. Current production systems for cellulase enzymes, i.e. fungi and bacteria, cannot meet the cost and huge volume requirements of this commodity‐based industry. Transgenic maize (Zea mays L.) seed containing cellulase protein in embryo tissue, with protein localized to the endoplasmic reticulum, cell wall or vacuole, allows the recovery of commercial amounts of enzyme. E1 cellulase, an endo‐β‐1,4‐glucanase from Acidothermus cellulolyticus, was recovered at levels greater than 16% total soluble protein (TSP) in single seed. More significantly, cellobiohydrolase I (CBH I), an exocellulase from Trichoderma reesei, also accumulated to levels greater than 16% TSP in single seed, nearly 1000‐fold higher than the expression in any other plant reported in the literature. The catalytic domain was the dominant form of E1 that was detected in the endoplasmic reticulum and vacuole, whereas CBH I holoenzyme was present in the cell wall. With one exception, individual transgenic events contained single inserts. Recovery of high levels of enzyme in T2 ears demonstrated that expression is likely to be stable over multiple generations. The enzymes were active in cleaving soluble substrate.
Association of P‐Wave Duration, Dispersion, and Terminal Force in Relation to P‐Wave Axis among Outpatients
Authors: Prajapat Laxman , Ariyarajah Vignendra , Frisella Mary E. , Apiyasawat Sirin , Spodick David H. 
Published: July 2007

Background: While P‐wave duration (P‐dur) and dispersion (P‐disp) could both reflect fractionated and inhomogeneous propagation of sinus cardiac impulses, and may therefore be associated with each other, a clear relationship has not been extensively studied. We studied these markers as well as the significance of P‐wave terminal force in lead V1 (PTFV1) in relation to the P‐wave axis (P‐axis). Methods: We appraised our previously studied sample of 500 consecutively numbered, otherwise unselected, electrocardiograms (ECGs) of outpatients from the University of Massachusetts, Worcester, Massachusetts, for the foregoing P‐wave characteristics. P‐disp, defined as the difference of the duration between the widest and narrowest P wave, and the greatest P‐dur after a 12‐lead ECG search, was measured manually to the nearest 10 ms. PTFV1 was considered positive when ≥40 mm2 terminal deflection was present on biphasic P waves on lead V1. Normal P‐axis was considered 0° to +75° by manually constructing the mean frontal plane electrical P‐axis from standard limb leads. Results: After excluding those with atrial arrhythmias, paced rhythms, errors in lead placement, P waves with low amplitude or overall technically poor tracing, 428 ECGs formed our final sample. P‐dur was strongly associated with P‐disp (P < 0.0001), but the correlation remained weak (r = 0.42). Overall, P‐dur was not significantly associated with P‐axis but when divided into tertiles and quintiles, the significance was evident within the range of the normal P‐axis, particularly 0° to +60° (P < 0.0001). In a subanalysis of 380 ECGs that had appreciable biphasic P waves on lead V1, PTFV1 was noted on 178 (47%) ECGs and was significantly associated with P‐dur (P < 0.0001), P‐disp (P < 0.0001), and P‐axis (P = 002). When considering P‐axis in tertiles and quintiles, P‐dur was greater in patients with a positive PTFV1 and significant within the normal range of the P‐axis, especially from 0° to +60°. Conclusion: P‐dur, P‐disp, and PTFV1 appear to share a significant tripartite association in relation to the normal P‐axis, particularly when P‐axis ranges 0° to +60°. Therefore, for optimal clinical assessment, these markers should be evaluated in relation to the normal P‐axis.
C‐Reactive Protein Is Associated with Heart Rate Variability
Authors: Madsen Trine , Christensen Jeppe Hagstrup , Toft Egon , Schmidt Erik Berg 
Published: July 2007

Background: The aim of this study was to investigate the relation between low‐grade inflammation and autonomic dysfunction, both of which may be risk markers for sudden cardiac death. Methods: A total of 269 subjects referred for elective coronary angiography because of clinically suspected coronary heart disease were included in the study. Of these 27% had a previous myocardial infarction and 70% had significant coronary stenoses. A 24‐hour Holter‐recording was obtained from all subjects, and time‐domain heart rate variability indices were analyzed. C‐reactive protein was measured using a high‐sensitivity assay. Results: Mean SDNN was significantly higher in the lower compared to the upper hs‐CRP quartile (140 ± 34 ms vs 113 ± 29 ms; P < 0.001). Similar results were found for SDNNindex (54 ± 16 ms vs 46 ± 12 ms; P = 0.002) and SDANN (125 ± 33 ms vs 101 ± 31 ms; P < 0.001). The association was strongest for subjects with a previous myocardial infarction, subjects with significant coronary stenoses, and males. In a linear regression analysis, hs‐CRP remained an independent determinant of each of these three heart rate variability indices (all P < 0.001). Conclusion: C‐reactive protein and heart rate variability are independently associated. This may support a link between low‐grade inflammation and autonomic dysfunction.
Dynamic Changes in T‐Wave Amplitude during Tilt Table Testing: Correlation with Outcomes
Authors: Mayuga Kenneth A. , Fouad‐Tarazi Fetnat 
Published: July 2007

Background: Changes in autonomic tone may play a role in syncope. Autonomic tone has been shown to affect cardiac repolarization in the ECG. Changes in the T wave can be seen during head‐up tilt table (HUT) testing with unknown significance or relationship to outcomes. Methods: Twelve‐lead ECGs during HUT testing from 150 patients were reviewed from a prospectively collected registry database. ECGs during supine‐rest, 30‐45‐70° tilt, and 5‐minute supine recovery were reviewed. Changes in the T wave, that is, decreased amplitude with or without becoming negative or flipping from negative to positive, were recorded for each stage. Outcomes of the HUT test include nondiagnostic, postural orthostatic hypotension (POH), postural orthostatic tachycardia syndrome (POTS), and vasovagal response (VVR). Age (Younger: <50 year old; Older: ≥50 year old) and gender were analyzed. Results: Of 150 patients (108 women; 80 Younger), 135 had T‐wave changes during HUT; changes resolved in 114 patients during supine recovery. Changes mostly occurred in inferior and anterolateral leads. POH occurred in 114 patients, POTS in 67, and VVR in 30. T‐wave changes in V1 inversely correlated with POH (P = 0.005). T‐wave changes in inferior leads II, III, aVF and in anterolateral leads V3–V6 positively correlated with POTS (P < 0.05). Female gender and younger age correlated with POTS independent of the leads (P < 0.05). Concomitant T‐wave changes in V5 and V6 correlated with VVR; changes in aVF also correlated with VVR (P < 0.05). Conclusions: Dynamic T‐wave changes during HUT testing in inferior and anterolateral leads are associated with POTS and VVR independent of age and gender. Changes in autonomic tone may play a role and need further study.