bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coronary Flow Reserve Impairment in Apical vs Asymmetrical Septal Hypertrophic Cardiomyopathy
Authors: Ahn Hyo‐Suk , Kim Hyung‐Kwan , Park Eun‐Ah , Lee Whal , Kim Yong‐Jin , Cho Goo‐Yeong , Park Jae‐Hyung , Sohn Dae‐Won 
Published: February 2013

AbstractBackgroundMechanisms underlying a reduction in coronary flow reserve (CFR) in hypertrophic cardiomyopathy (HCM), especially apical HCM (ApHCM), are elusive. This study set out to evaluate mechanisms underlying a reduction in CFR in 2 HCM subtypes.HypothesisMechanisms for CFR reduction in HCM are different between the 2 subtypes of HCM.MethodsThirty‐one patients with asymmetrical septal hypertrophy (ASH), 43 with ApHCM, and 27 healthy volunteers were recruited. Mean diastolic coronary flow velocity (CFmv) was monitored before and after adenosine infusion by transthoracic echocardiography in the mid‐to‐distal left anterior descending coronary artery. Coronary flow reserve was defined as the ratio between CFmv before and after adenosine infusion. Left ventricular mass index and stress myocardial perfusion were assessed by cardiac magnetic resonance imaging.ResultsAlthough basal CFmv was higher in ASH patients than in healthy controls (P < 0.05), it was similar in ApHCM patients and controls (P = 0.85). Poststress CFmv was significantly lower in both HCM subtypes than in controls (P < 0.05). Consequently, CFR was higher in controls than in ASH or ApHCM patients (P < 0.05). When HCM patients were stratified into 2 groups based on the presence of CFR impairment, no difference was observed between these 2 groups in terms of left ventricular mass index by cardiac magnetic resonance imaging. Multivariate logistic regression analysis identified basal CFmv as the only independent variable associated with CFR reduction in HCM (r2 = 0.49, P < 0.001).ConclusionsWhereas the inability to augment coronary flow to its maximal level during stress was found to underlie CFR impairment in both HCM subtypes, the recruitment of vasodilatory capacity at baseline was more prominent in ASH than in ApHCM patients.This study was presented in the Annual Scientific Meeting of the American Society of Echocardiography, June 30–July 3, 2012, National Harbor, Maryland.This research was supported by Handok Research Fund 2012 and by the Leading Foreign Research Institute Recruitment Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (0640‐20100001).The authors have no other funding, financial relationships, or conflicts of interest to disclose.
Left Ventricular Assist Devices and Gastrointestinal Bleeding: A Narrative Review of Case Reports and Case Series
Authors: Islam Sameer , Cevik Cihan , Madonna Rosalinda , Frandah Wesam , Islam Ebtesam , Islam Sherazad , Nugent Kenneth 
Published: February 2013

AbstractBackgroundThe use of left ventricular assist devices (LVADs) has become a state‐of‐the‐art therapy for advanced cardiac heart failure; however, multiple reports in the literature describe an increased risk for gastrointestinal (GI) bleeding in these patients. We characterized this association by reviewing recent studies on this topic.HypothesisGI bleeding occurs frequently in patients with LVADs, especially with devices with nonpulsatile flow patterns.MethodsWe performed a comprehensive literature review to identify articles that reported GI bleeding in patients with LVADs. Databases used included PubMed, EMBASE, Scopus, Web of Knowledge, and Ovid. Baseline and outcome data were then ed from these reports.ResultsWe identified 10 case reports and 22 case series with 1543 patients. The mean age was 54.2 years. Most patients had nonpulsatile LVADs (1316, 85.3%). Three hundred and seventeen patients (20.5%) developed GI bleeding; this occurred more frequently in patients with nonpulsatile LVADs. Multiple procedures were performed without complications but often did not identify a definite bleeding site. Suspect lesions occurred throughout the GI tract but were more frequent in the upper GI tract. Many patients had arteriovenous malformations. All patients received medical therapy. None of the patients had their LVAD replaced. The use of anticoagulation did not appear to predispose these patients to more GI bleeding episodes.Conclusions:Patients with LVADs have frequent GI bleeds, especially from arteriovenous malformations, which can occur throughout the GI tract. Most diagnostic and therapeutic interventions can be used safely in these patients. The pathogenesis of the GI bleeding in these patients may involve the use of anticoagulant medications, the formation of arteriovenous malformations, loss of von Willebrand factor activity, and mucosal ischemia.The authors have no funding, financial relationships, or conflicts of interest to disclose.
The Hidden Risks of Advancing Age and Concomitant Ischemic Heart Disease After Aortic Valve Replacement
Authors: Mitchell Annelies E. , Mitchell Ian M. 
Published: February 2013

AbstractBackground:Despite an increasing patient risk profile, in‐hospital mortality after aortic valve replacement (AVR) has declined.Hypothesis:Advanced age, concomitant coronary artery bypass grafting (CABG), and increasing comorbidity negatively affect outcomes after AVR and do so particularly in the early months after hospital discharge, where results compare much less favorably with mortality during the first 30 days.Methods:The study population consisted of all patients undergoing elective AVR by a single surgeon, with and without CABG, in the decade of 2000–2009. Age, logistic EuroSCORE, diabetes, type of operation, and 30‐day and 1‐year mortality were recorded.Results:One hundred ninety‐one patients underwent isolated AVR; 133 underwent AVR + CABG. The average age increased by 5.7 years, octogenarians by 50%, logistic EuroSCORE by 18%, and the proportion of diabetics from 4% to 25.5%. Concomitant CABG surgery increased from 36% to 49%. Overall mortality for isolated AVR was zero in the first 30 days and 1.6% in the next 11 months. For AVR and CABG, mortality was 3.75% and 9%, respectively. For octogenarians, mortality was zero and 5.9% for AVR and 4.76% and 14.29% for AVR and CABG at 30 days and in the next 11 months, respectively.Conclusions:Thirty‐day mortality in all age groups remained low but was much higher in the short term after discharge from hospital, particularly in octogenarians and those with concomitant ischemic heart disease. This should inform the consent process (which traditionally concentrates on in‐hospital mortality) and there should be greater awareness of the frailty and particular requirements of the elderly after discharge.This work was presented at the meeting of the Scandinavian Society for Research in Cardiothoracic Surgery, Geilo, Norway, February 10, 2012.The authors have no funding, financial relationships, or conflicts of interest to disclose.
Intestinal Absorption and Pancreatic Function are Preserved in Anorexia Nervosa Patients in Both a Severely Malnourished State and After Recovery
Authors: Martínez‐Olmos Miguel Angel , Peinó Roberto , Prieto‐Tenreiro Alma , Lage Mary , Nieto Laura , Lord Teresa , Molina‐Pérez Esther , Domínguez‐Muñoz Juan Enrique , Casanueva Felipe F. 
Published: February 2013

AbstractIntroductionAnorexia nervosa (AN) is characterised by a refusal to normal body weight accompanied by a marked restriction of food intake, frequently leading to severe malnutrition. In severe malnutrition and wasting syndromes, mucosal atrophy, altered gastrointestinal motility and pancreatic atrophy, which alter digestive function and can exacerbate malnutrition, have been described. The objective of this work was to determine intestinal absorption and pancreatic function in severely malnourished AN patients before and after recovery.MethodsTen severely malnourished AN women were studied at hospital admittance (body mass index = 11.44–16.16 kg/m2) and after weight recovery with artificial nutrition (body mass index ≥ 20 kg/m2). A 13C‐labelled triglycerides digestion test, faecal elastase test and d‐xylose absorption test were performed.ResultsIn nine patients, 13C‐labelled triglycerides digestion tests and the faecal elastase and d‐xylose tests were normal both before and after weight recovery. In one patient, the results were abnormal, and they led to the detection of a previously undiagnosed celiac disease in addition to her AN.ConclusionIn this series, there was neither intestinal absorption nor pancreatic function disturbances in severely malnourished AN patients either before or after weight recovery. The usefulness of these tests in the differentiation of functional versus structural changes needs further studies. Copyright © 2013 John Wiley & Sons, Ltd and Eating Disorders Association.
Purification, characterization and comparison of Penicillium purpurogenum β‐glucuronidases expressed in Escherichia coli and Pichia pastoris
Authors: Zou Shuping , Guo Shuyuan , Kaleem Imdad , Li Chun 
Published: February 2013

AbstractBackgroundTo investigate the effects of post‐translational modifications in different recombinant expression systems on the catalytic properties of recombinant β‐glucuronidase. The β‐glucuronidase (GUS) gene from Penicillium purpurogenum Li‐3 was cloned and successfully expressed in Escherichia coli BL21 and Pichia pastoris G115.ResultsThe recombinant E. coli produced a 15‐fold increased level of β‐glucuronidase while the recombinant P. pastoris strain produced a 6.9‐fold increased level of β‐glucuronidase compared with their parent strains. The β‐glucuronidases from recombinant E. coli (PGUS‐E) and P. pastors (PGUS‐P) were purified to 35.9‐ and 47.4‐fold, respectively, through affinity, ion exchange and gel filtration chromatography. PGUS‐E from E. coli was a non‐glycosylated protein with an apparent molecular mass of 72.43 kDa, while PGUS‐P from P. pastors was appropriately glycosylated with a molecular mass of 78.83 kDa measured by MALDI/TOF‐MS. Although both recombinant β‐glucuronidases exhibited similar pH optima, the glycosylated PGUS‐P showed a significantly higher thermal stability and less sensitivity to metal ions compared with the non‐glycosylated PGUS‐E. The glycosylated PGUS‐P also displayed lower Km values, and higher kcat/Km ratios than the non‐glycosylated enzyme towards glycyrrhizin.ConclusionThese results revealed the key role of post‐translational modifications in the P. pastors expression system on the catalytic properties of β‐glucuronidase and its potential stability over the prokaryotic expression system which could be applied as an important tool for the functional enhancement of industrial enzymes. © 2013 Society of Chemical Industry
Development of naphthalene and quinoxaline‐based donor–acceptor conjugated copolymers for delivering high open‐circuit voltage in photovoltaic devices
Authors: Baek Myung‐Jin , Park Hanok , Dutta Pranabesh , Lee Woo‐Hyung , Kang In‐Nam , Lee Soo‐Hyoung 
Published: February 2013

AbstractTwo new quinoxaline‐based polymers, poly[1,5‐didecyloxynaphthalene‐alt‐5,5′‐(5,8‐dithiophen‐2‐yl)‐2,3‐bis(4‐octyloxyphenyl)quinoxaline (PNQx‐p) and poly[1,5‐didecyloxynaphthalene‐alt‐5,5′‐(5,8‐dithiophen‐2‐yl)‐2,3‐bis(3‐octyloxyphenyl)quinoxaline (PNQx‐m), were synthesized by Suzuki coupling reaction and characterized. Thermogravimetric analysis revealed that these polymers are thermally stable with degradation temperature up to 320 °C. As evident from the electrochemical and optical studies, the copolymers have comparable optical band gap (∼2 eV) and nearly similar deep highest occupied molecular orbital (HOMO) energy levels of −5.59 (PNQx‐p) and −5.61 eV (PNQx‐p). The resulting copolymers possessed relatively low HOMO energy levels promising good air stability and high open circuit voltage (Voc) for photovoltaic applications. The optimized photovoltaic device with a structure of ITO/PEDOT:PSS/PNQx‐m:PC71BM (1:2, w/w)/LiF/Al shows a power conversion efficiency up to 2.29% with a short circuit current density of 5.61 mA/cm2, an Voc of 0.93 V and a fill factor of 43.73% under an illumination of AM 1.5, 100 mW/cm2. The efficiency of the PNQx‐m polymer improved from 2.29 to 2.95% using 1,8‐diiodoocane as an additive (0.25%). © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Poly(methyl methacrylate‐co‐pentaerythritol tetraacrylate‐co‐butyl methacrylate)‐g‐polystyrene: Synthesis and high oil‐absorption property
Authors: Liang Ying , Liu Delong , Chen Hou 
Published: February 2013

AbstractWell‐defined high oil‐absorption resin was successfully prepared via living radical polymerization on surface of polystyrene resin‐supported N‐chlorosulfonamide group utilizing methyl methacrylate and butyl methacrylate as monomers, ferric trichloride/iminodiacetic acid (FeCl3/IDA) as catalyst system, pentaerythritol tetraacrylate as crosslinker, and L‐ascorbic acid as reducing agent. The polymerization proceeded in a “living” polymerization manner as indicated by linearity kinetic plot of the polymerization. Effects of crosslinker, catalyst, macroinitiator, reducing agent on polymerization and absorption property were discussed in detail. The chemical structure of sorbent was determined by FTIR spectrometry. The oil‐absorption resin shows a toluene absorption capacity of 21 g g−1. The adsorption of oil behaves as pseudo‐first‐order kinetic model rather than pseudo‐second‐order kinetic model. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Improving ethanol and xylitol fermentation at elevated temperature through substitution of xylose reductase inKluyveromyces marxianus
Authors: Zhang Biao , Li Lulu , Zhang Jia , Gao Xiaolian , Wang Dongmei , Hong Jiong 
Published: February 2013

AbstractThermo-tolerant yeast Kluyveromyces marxianus is able to utilize a wide range of substrates, including xylose; however, the xylose fermentation ability is weak because of the redox imbalance under oxygen-limited conditions. Alleviating the intracellular redox imbalance through engineering the coenzyme specificity of NADPH-preferring xylose reductase (XR) and improving the expression of XR should promote xylose consumption and fermentation. In this study, the native xylose reductase gene (Kmxyl1) of the K. marxianus strain was substituted with XR or its mutant genes from Pichia stipitis (Scheffersomyces stipitis). The ability of the resultant recombinant strains to assimilate xylose to produce xylitol and ethanol at elevated temperature was greatly improved. The strain YZB014 expressing mutant PsXR N272D, which has a higher activity with both NADPH and NADH as the coenzyme, achieved the best results, and produced 3.55 g l−1 ethanol and 11.32 g l−1 xylitol—an increase of 12.24- and 2.70-fold in product at 42 °C, respectively. A 3.94-fold increase of xylose consumption was observed compared with the K. marxianus YHJ010 harboring KmXyl1. However, the strain YZB015 expressing a mutant PsXR K21A/N272D, with which co-enzyme preference was completely reversed from NADPH to NADH, failed to ferment due to the low expression. So in order to improve xylose consumption and fermentation in K. marxianus, both higher activity and co-enzyme specificity change are necessary.
Nahrungsmittelallergien im Vorschulalter - aktueller Stand der Diagnostik und Therapie
Authors: Ferrari G. , Eng A. 
Published: February 2013

In den letzten Jahrzehnten hat die Prävalenz der Nahrungsmittelallergien im Vorschulalter zugenommen. Je nach auslösendem Antigen wachsen sich viele dieser Allergien aber bis ins Alter von 3 - 5 Jahren aus. Trotz verbesserter Allergie-Diagnostik und Kenntnisse des Verlaufes schränken Nahrungsmittelallergien die Lebensqualität der betroffenen Patienten und ihrer Familie ein. Die klinische Manifestation der Nahrungsmittelallergien reicht von milden kutanen Symptomen bis zu lebensgefährlichen Reaktionen mit anaphylaktischem Schock. Im Kindes- und Jugendalter sind Nahrungsmittel häufigste Ursache von Anaphylaxien. Aufgabe der Grundversorger bzw. Kinderärzte sind Erkennung von Risikopatienten, frühzeitige Diagnose und Beratung der Angehörigen betreffend präventiven Maßnahmen und Notfalltherapie (z. B. Adrenalin) bei akzidenteller Einnahme der Allergie-auslösenden Nahrungsmittel. Da es bis heute noch keine kausale Therapie gibt, bleibt die Allergenkarenz wichtigste Maßnahme bei Nahrungsmittelallergien.
Bewegung und Adipositas
Authors: Kriemler  , Puder  
Published: February 2013

Bewegung und Adipositas sind zwei der am häufigsten gebrauchten Schlagwörter der Gesundheit der letzten Jahre, gebraucht von der Laienpresse bis zu den renommierten medizinischen Fachzeitschriften. Beide erreichen ihr Publikum, da jeder Leser entweder selbst betroffen ist, Betroffene kennt und diese beraten muss - oder als Autor ein brisantes Wissenschaftsthema aufnimmt, um die Problematik zu beleuchten und Lösungsansätze für das weltweite Problem der fehlenden Bewegung und der Adipositas zu finden. Dabei ist es allen klar, dass es keine Patentlösung gibt und es vermutlich noch viele Jahrzehnte dauern wird, bis der motorisierte, energieüberladene Mensch wieder zu einem gesunden Bewegungs- und Essverhalten zurückfindet - wenn denn diese Normalisierung überhaupt noch möglich ist. Wichtig ist jedoch die Erkenntnis, dass leichtes Übergewicht nicht sehr schadet, dass aber der fehlende Gebrauch unserer Muskeln zu mehr Krankheit und einer reduzierten Lebenserwartung führt. Zumindest gilt dies für den Erwachsenen und es ist plausibel, dass dieser Ansatz nicht gänzlich falsch sein kann für das Kind. Wir werden im nachfolgenden Artikel auf Bewegung und Adipositas eingehen und beschreiben, wie man das "zu viel" und "zu wenig" definiert und misst, was man weiß über den Zusammenhang von Bewegung, Adipositas und Gesundheit im Schulalter, und was für praktische Ansätze bestehen, um aus möglichst jedem Schulkind einen "normalgewichtigen" aktiven Erdenbürger zu machen.
Das Mammakarzinom - Therapiestandards und neue Therapiemöglichkeiten 2012, ein onkologisches Review
Authors: Vetter  , Rochlitz  
Published: February 2013

Das Mammakarzinom ist das häufigste Tumorleiden der Frau mit einer Inzidenzrate von 110/100.000 für alle Altersgruppen in Europa. Die Inzidenz nimmt mit zunehmendem Alter zu. Die Behandlung ist multimodal und umfasst Chirurgie, Radiotherapie, Chemotherapie mit und ohne Antikörpertherapie und endokrinologische Therapien. In den letzten 40 Jahren haben sich die Überlebensraten deutlich verbessert. So stieg die Fünf-Jahres-Überlebensrate für lokalisierte Mammakarzinome von 85% im Jahre 1970 auf 98% im Jahre 2010. Auch in der metastasierten Situation kam es zu einer Verbesserung des 5-Jahres-Gesamtüberlebens von < 10% im Jahre 1970 auf 26% im Jahre 2010. Möglich wurde dies durch verbesserte und modernere Therapien, aber auch durch verbessertes Screening und damit eine Diagnose in früheren Stadien. Diese Übersichtsarbeit beschreibt die Therapiestandards gemäß internationalen Guidelines und neue Therapiemöglichkeiten bei lokalisiertem und metastasiertem Mammakarzinom.
Rationale Synkopenabklärung
Authors: Kühne Michael , Conen David 
Published: February 2013

Synkopen sind ein häufiges klinisches Problem, gekennzeichnet durch einen plötzlich auftretenden, kurzen Bewusstseinsverlust mit vollständiger Erholung innert Sekunden. Bei jungen Menschen stehen hauptsächlich die vasovagalen Synkopen ohne prognostische Relevanz im Vordergrund, in der zweiten Lebenshälfte kommt es immer häufiger zu kardialen Synkopen mit ernster Prognose. Die primäre Abklärung besteht in erster Linie aus einer detaillierten Anamnese (Fremdanamnese wann immer möglich), der klinischen Untersuchung (inklusive Blutdruckmessung liegend und stehend) sowie einem 12-Kanal-EKG. Finden sich hier keine Auffälligkeiten, darf bei einem Erstereignis zugewartet werden. Bei positiven Befunden sollte aber eine weiterführende kardiologische Abklärung mittels Echokardiografie zur Erfassung einer strukturellen Herzerkrankung oder Belastungs-EKG bei belastungsbedingten Synkopen erfolgen. Das 24-Stunden-Holter-EKG hat eine schlechte diagnostische Ausbeute und sollte vor allem bei Patienten < 60 Jahren ohne Hinweise auf strukturelle Herzkrankheit in aller Regel nicht zur Anwendung kommen. Eine unauffällige 24-Stunden-Holter-Untersuchung schließt rhythmogene Synkopen nicht aus. Deshalb stellen Holter-EKG's mit längerer Aufzeichnungszeit oder implantierbare loop recorder mit Aufzeichnungszeiten bis zu 2 Jahren in ausgewählten Fällen mögliche Alternativen dar.
Schwindel als Begleitsymptom bei älteren Patienten
Authors: Ilsemann-Karakoumis Julia , Nickel Christian H. , Bingisser Roland 
Published: February 2013

Schwindel tritt häufig im Rahmen von „poly-syndromalen Zuständen“ als eines von mehreren unzusammenhängenden Symptomen auf. Schwindel kann als „unspezifisches“ Symptom bezeichnet werden, wenn er nicht als eindeutig abgrenzbare Hauptbeschwerde, sondern im Rahmen von anderen unspezifischen Symptomen, wie Gangunsicherheit und allgemeiner Schwäche, identifiziert wird. Davon abzugrenzen sind zum einen der erklärbare „Begleitschwindel“, welcher klar im Rahmen einer definierten Grunderkrankung (schwere Anämie) auftritt und zum anderen der Schwindel als spezifisches und abklärungsbedürftiges Hauptsymptom, welches in Zusammenschau mit einer pathologischen neurologischen bzw. otologischen Untersuchung Hinweise auf ein begrenztes Spektrum von Differentialdiagnosen gibt und daher als „systematischer Schwindel“ bezeichnet werden kann. Der vorliegende Artikel hat zum Ziel, die Ursachen von „Schwindel als Begleitsymptom“ bei fast ausnahmslos älteren Patienten, die sich mit weiteren unspezifischen Symptomen auf Notfallstationen vorstellen, zu beleuchten. Die Verteilung dieser den unspezifischen Symptomen – hier im Speziellen „Schwindel als Begleitsymptom“ – zugrunde liegenden Diagnosen erwies sich als sehr breit und erstreckte sich über 16 verschiedene ICD-10 Kapitel. Entscheidend ist für den Praktiker die Tatsache, dass „Schwindel als Begleitsymptom“ bei den unterschiedlichsten Diagnosen vorkommt, keine Hinweise auf die Grunderkrankung erlaubt und in mehr als der Hälfte der Patienten mit akuten, behandlungsbedürftigen Krankheiten einhergeht. Weil diese Grunderkrankung oft nur nach einer aufwändigen Abklärung diagnostiziert werden kann, ist eine Risiko-Stratifizierung schon bei Präsentation anzustreben.
Protein Requirements in the Elderly
Authors: Volkert Dorothee , Sieber Cornel Christian 
Published: February 2013

Adequate protein intake and the maintenance of nitrogen equilibrium are of particular importance in the elderly because this age group is at increased risk of illness and malnutrition. The current recommendation for protein intake of healthy elderly subjects is 0.8 g/kg body weight/day, the same as for younger adults. Nitrogen balance studies in the elderly, however, revealed conflicting results; some studies suggest that not all elderly can achieve a nitrogen balance with a protein intake of 0.8 g/kg body weight/day, particularly if energy supply is not adequate. Beyond the amount of protein needed for nitrogen balance, the optimal protein intake for preservation of lean body mass, body functions, and health is of paramount interest. At present, there is insufficient longer-term research with defined health outcomes to derive recommendations in this regard. Very little is also known about the protein needs of frail and unhealthy elderly. Until more evidence is available, it seems reasonable to ensure a protein intake of at least 0.8 g/kg body weight/day in all elderly persons, particularly in those at risk of malnutrition (e.g., frail and multimorbid elderly). In addition to ascertaining adequate protein and energy intake, physical activity should be encouraged in order to increase energy expenditure and food intake and to facilitate muscle protein anabolism.