bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in left ventricular diastolic function in coronary artery disease with and without angina pectoris assessed from exercise ventriculography
Authors: Tebbe U. , Hoffmeister N. , Sauer G. , Neuhaus K. L. , Kreuzer H.
Published: October 2013

In 11 normals and 43 patients with coronary artery disease left ventricular (LV) diastolic pressure–volume (P–V) curves were obtained from biplane ventriculograms and simultaneous high fidelity pressure measurements.

During exercise ventriculography 20 patients had angina pectoris (group B), and 16 patients were asymptomatic (group A). At rest there were no akinetic segments in 28 patients (group C), and an akinetic segment was found in 15 (group D). With different total work loads (951 ± 134 and 2100 ± 245 kpm in groups B and A), LV minimal and end‐diastolic pressures and corresponding ventricular volumes increased to a similar extent in patients with and without angina during exercise ventriculography. With comparable work loads (1,296±221 and 1,494±195 kpm in groups C and D) the mean increase in diastolic pressure and volume was larger in group D, which corresponded to the more depressed LV resting function.

Shifts in the diastolic P–V relationship with exercise were quantitated from the constants a and b of the linear log P–V relationship. In the control group, a and b did not change significantly, but in all CAD groups a significant decrease in a and a significant increase in b were observed during exercise. These changes were more pronounced in groups B and D, but were statistically significant in group A, too.

While no patient with angina had an unchanged diastolic P–V relationship, as many as 12 patients had significant P–V shifts in the absence of angina. Eight of these were expected to develop myocardial ischemia with exercise as judged from their coronary artery stenosis and ventriculograms. A similar correlation was found for the diastolic P–V alterations and the exercise ECG. Fourteen patients without any ST‐segment change during exercise showed significant P–V shifts, while no patient with signs of ischemia in the ECG had an unchanged P–V curve.

We conclude that LV diastolic function is more sensitive to myocardial ischemia than both angina pectoris and the exercise ECG. An inappropriate increase in LV filling pressure with exercise probably reflects myocardial ischemia even in the absence of angina pectoris and ST‐segment depression in the ECG.
Measurement of heterogeneous myocardial blood flow
Authors: Schanzenbächer P. , Klocke F. J.
Published: October 2013

Inert gas measurements of myocardial blood flow have been compared to simultaneous radioactive microsphere flow measurements. Average flow per unit weight agreed within 20% in 20 of 24 comparisons. With the inert gas technique flows up to 580 ml/min/100 g could be measured. Semilogarithmically plotted desaturation curves were distinctively curvilinear. It is concluded that the shape of the washout curve is a function of the underlying flow pattern.
Global and regional left ventricular contractility and coronary collaterals in stable ischemic heart disease
Authors: Nieminen M. S. , Valle M. , Lassila E. , Heikkilä J. , Hekali P. , Frick M. H.
Published: October 2013

Global and regional left ventricular contractility were determined in 43 patients with stable ischemic heart disease utilizing echocardiography. Indices of contractility from multiple left ventricular segments were related to both the coronary obstructions and the presence of collateral supply. The impact of past myocardial infarction was taken into account. Global left ventricular contractility decreased with increasing degree of coronary obstructions (r = 0.69; p<0.001). In patients with collateral supply global contractility decreased with increasing degree of collateral supply (r = 0.59; p<0.001).

Analysis of myocardial regions corresponding to the three major coronary arteries disclosed that past myocardial infarction resulted in decreased contraction indices (p<0.01‐0.001). This effect was related neither to the degree of obstruction once it exceeded 50% nor to the presence of collateral supply. A comparison of patients with single‐vessel disease, no prior infarction, and similar coronary obstructions revealed no differences in regional contractility whether collaterals were present or not. Regional contractility decreased in linear fashion in relation to increasing coronary obstructions (p<0.001). Collaterals became angiographically visible when the obstructions exceeded 75% but their appearance did not prevent the deterioration of contractility.

It is concluded that collaterals are visualized by angiography when the coronary artery obstructions exceed 75%. Their presence does not, however, affect the global or regional decline in contractility associated with increasing severity of coronary artery obstructions. Moreover, they do not attenuate the decline in regional contractility associated with prior myocardial infarctions.
Decrease in cardiotoxicity of contrast media in coronary angiography by addition of calcium ions: A combined experimental and clinical study
Authors: Zipfel J. , Baller D. , Blanke H. , Karsch K. R. , Rentrop P. , Hellige G.
Published: October 2013

The cardiotoxicity of commonly used contrast media such as sodium methylglucamine diatrizoate is related to nonphysiologic concentrations of ions and high osmolality. Following injection there is an excessive decrease in ambient calcium which disturbs the extracellular Na+/Ca2+ ratio and results in myocardial depression. In animal studies (anesthetized, intact mongrel dogs) this cardiodepressive effect could be fully compensated by adding 22.5 mEq/1 of ionic calcium to the contrast medium.

In 16 patients studied for coronary artery disease (CAD) 72 injections of sodium methylglucamine diatrizoate, mainly in the left coronary artery, were thoroughly investigated. There was marked depression of left ventricular pressure (‐22%) and (dP/dt)max (‐27%), and marked heart rate slowing (‐29%). Added calcium in the concentration cited reduced significantly (p<0.001) the myocardial depression to −15% and −13%, respectively, but did not completely compensate it. The heart rate slowing was not altered significantly. It was concluded that the addition of calcium may be helpful when studying high‐risk patients and using high injection volumes.
Comparison of myocardial potassium and thallium flux as studied by tracer methods
Authors: Nitsch J. , Steinbeck G. , Lüderitz B.
Published: October 2013

Although myocardial scintigraphy with 201thallium is widely applied in humans, the behavior of thallium at the cellular level is still under discussion. We compared the transmembrane fluxes of potassium and thallium in the isolated papillary muscle of guinea pigs. A qualitative conformity exists between potassium and thallium fluxes with respect to heart rate and temperature. Quantative comparison revealed a decreased flux rate of thallium for efflux when compared with potassium. The time dependence of thallium influx indicates that thallium scintigraphy of the myocardium reflects mainly an extracellular distribution.
Enzyme activities of human myocardium: Creatine kinase and hexose phosphate isomerase
Authors: Haralambie G. , Uy J.
Published: October 2013

Creatine kinase (CK) and hexose phosphate isomerase (PHI) activities were determined in 36 samples of human heart muscle obtained from patients during cardiovascular surgery. With one exception, CK activities were higher than any reported so far in the literature (papillary muscle, left ventricle: 2,521 ±776 IU/g wet weight at 37°C). PHI Activities, the first time measured, are comparable to those in skeletal muscle (200‐400 U/g, higher in papillary muscle than in the right auricle). The activities of both enzymes determined correlate significantly (all samples considered together: r = 0.773; p<0.001). Results are discussed with respect to their possible clinical interest as well as their significance for myocardial metabolism.
Hemophilus influenzae pericarditis
Authors: Sink J. D. , Spray T. L. , Rankin J. S.
Published: October 2013

Although Hemophilus influenzae infections have long been considered to be a disease of childhood, recent reports have demonstrated an increasing frequency of serious Hemophilus influenzae infections in adults. A case of purulent H. influenzae pericarditis in a previously healthy adult without evidence of concurrent H. influenzae infection is reported.
Digital subtraction angiography: Present and future uses in cardiovascular diagnosis
Authors: Myerowitz P. D.
Published: October 2013

Digital subtraction angiography (DSA) has been proved to be an effective means of visualizing the cardiovascular system following intravenous injection of contrast material. Excellent quality images have been obtained of the left ventricle, the thoracic aorta and its major branches, the carotid arteries, the abdominal aorta and its major branches, lower extremity vessels, and intracerebral vessels. Avoiding the risks and discomforts of direct arterial puncture and the need for hospitalization, DSA is safer and more economical than standard arteriography. It is, therefore, useful both as a screening tool and, in many patients, as a diagnostic tool for the evaluation of vascular disease. Left ventricular studies provide excellent qualitative and quantitative evaluation of left ventricular function. Arterial injections of contrast have provided excellent quality images of the vascular tree with low volume dilute contrast material. Lower extremity vessels not visualized by standard arteriography have been seen following intra‐arterial contrast injections using DSA. Aortic root injections have been used to demonstrate coronary arteries and coronary artery bypass grafts. Although intravenous injections of contrast have shown coronary artery bypass graft patency with reasonable success, they have not proved useful at this point in defining the exact anatomy. Other video techniques following arterial injections of contrast have been used to calculate vessel flows. Although coronary artery images in animal studies following intravenous contrast injection are improving, they are still not of diagnostic quality. Digital subtraction angiography, therefore, has proved itself a useful adjunct to standard arteriographic techniques. Its future potential has not yet been defined.
Echocardiography in patients with acute cerebral events
Authors: Bergeron G. A. , Shah P. M.
Published: October 2013

The question of the clinical and economic feasibility of echocardiographic screening for cardiac disease in patients with symptoms of acute cerebral events was assessed by recording M‐mode and two‐dimensional (2D) echocardiograms in 170 patients. Patients with transient ischemic attacks or cerebral infarctions were included. Of the patients with satisfactory echocardiograms, 96 (56%) had normal diagnostic findings; 74 (43%) had cardiac disorders possibly related to the acute cerebral event. There were 4 patients who fulfilled the standard criteria for mitral valve prolapse and 7 patients who were identified as having probable cardiac thrombosis or vegetation, or both. Thus, M‐mode and two‐dimensional echocardiography was of limited value in patients referred for these studies for screening to exclude mitral valve prolapse and cardiac thrombosis or vegetation. Although a diverse range of cardiac disorders was demonstrated that may be associated with cerebral ischemia, the overall low yield does not support such screening and should be reserved for selected patients.
Controversies in hypertension: Mild hypertension, isolated systolic hypertension, and the choice of a step one drug
Authors: Cressman M. D. , Gifford R. W.
Published: October 2013

The realization that cardiovascular morbidity and mortality increases in patients with mild elevation of either systolic or diastolic blood pressure has led to a consideration to treat millions of patients with mild diastolic or isolated systolic hypertension. The cost of administering a successful antihypertensive treatment program and the potential adverse effects of pharmacologic agents is of great concern. It has been emphasized that the risk of premature mortality differs in individual patients according to the number of associated cardiovascular risk factors at any level of blood pressure. This has led to a suggestion that only high risk patients be treated. However, a significant number of low risk patients with mild hypertension develop a more severe or complicated form of their disease even over a follow‐up period of five to ten years. There is no good way to identify these patients. Trials of antihypertensive therapy suggest a beneficial effect of blood pressure lowering in mild hypertension. No trials of antihypertensive therapy in elderly patients with isolated systolic hypertension have been reported, but the elevation in systolic blood pressure appears to be an independent risk factor for cardiovascular mortality. Even the choice of the first step agent in treatment is debatable. Diuretics or beta blockers effectively lower blood pressure in the majority of hypertensive patients, particularly if modest dietary sodium restriction is achieved. The incidence of side effects, either symptomatic or biochemical, is similar but diuretics are unquestionably cheaper and probably more effective. Successful application of an antihypertensive treatment program may continue to reduce our unacceptably great incidence of cardiovascular disease.
Coronary hemodynamic data in ischemic heart disease according to ischemic behavior during pacing
Authors: Cribier A. , Berland J. , Cazor J. L. , Letac B.
Published: October 2013

In order to study the circulatory changes induced by maximal atrial pacing in coronary patients, coronary sinus blood flow (CBF) measured by continuous thermodilution, lactate extraction coefficient (K), arteriovenous difference in oxygen (AVO2 diff), and aortic blood pressure (BP) were measured at basal state and at maximal heart rate (HRmax) in 11 patients without coronary disease (group I) and in 28 patients with severe coronary lesions, divided into two groups according to the absence (group IIa) or the presence (group IIb) of chest pain and ST‐segment depression at HRmax. K was inverted in group IIb (24±17% vs −23±39%, p < 0.001), but remained unchanged in group I and group IIa. Despite similar HRmax, percent increase in CBF was significantly lower in group IIb (54±34%), than in group I (113±54%, p < 0.01). This contrasts with the higher values of the product of heart rate times systolic blood pressure (HR × SBP) as well as of diastolic blood pressure (DBP) in group IIb. The decrease in coronary resistances was lower in group IIb than in group I (p < 0.001), and also lower than in group IIa (p < 0.05). The ratio MO2 × CBF/systolic BP × HRmax was significantly lowered only in group IIb (p < 0.001) confirming the imbalance between myocardial oxygen supply and oxygen demand. In coronary patients, myocardial ischemia induced by atrial pacing is related to an insufficient increase in CBF, well evidenced by continuous thermodilution.
Cholinium‐based Supported Ionic Liquid Membranes: A Sustainable Route for Carbon Dioxide Separation
Authors: Tomé Liliana C. , Patinha David J. S. , Ferreira Rui , Garcia Helga , Silva Pereira Cristina , Freire Carmen S. R. , Rebelo Luís Paulo N. , Marrucho Isabel M.
Published: October 2013

Aiming at full sustainability of CO2 separation processes, a series of supported ionic liquid membranes based on environmentally friendly cholinium carboxylate ionic liquids were successfully prepared. Their gas permeation properties were measured and high permselectivities were obtained for both CO2/CH4 and CO2/N2.
Clinical Considerations on Anticoagulation Management in Cardiovascular Diseases During Pregnancy
Authors: Goland Sorel , Zilberman Liaz , Elkayam Uri
Published: October 2013

Clinical Development Phases I‐III Regulatory, Quality, Manufacturing

Pregnancy‐associated thrombosis is an important cause of morbidity and mortality during pregnancy. All anticoagulation options are associated with risks and benefits. Thus, although anticoagulation therapy is an important component of the management of thrombotic complications in pregnancy, it is associated with fetal and maternal complications. Therefore, pregnancy poses a serious therapeutic dilemma for both physicians and their patients. This review summarizes the available data on anticoagulation therapy for thromboembolic prophylaxis in pregnant women focusing on cardiovascular disorders, especially on treatment strategy in pregnant women with mechanical heart valves.
Platelet Fragmentation: A Novel Opinion for Thrombosis Therapy
Authors: Zhang Wei
Published: October 2013

Preclinical Research

Ischemic cardio‐cerebrovascular events represent a leading cause of morbidity and death worldwide. Given the central role of platelets in thrombus formation, antiplatelet therapy has great clinical value for the treatment of thrombotic diseases. Currently, most antiplatelet therapies aim at preventing thrombus formation by inhibiting platelet function, but not at direct thrombolysis; the latter is highly desirable clinically. In this article, the discovery of a cellular and molecular mechanism inducing platelet fragmentation is reviewed, which has led to the development of a novel, potential therapeutic approach to improve current thrombosis therapy.
The Remarkable Hyperchromicity of Ketohydrazone Dyes and Pigment Lakes Derived from 4‐Morpholino‐2‐naphthol
Authors: Aiken Stuart , Gabbutt Christopher D. , Gillie Lisa J. , Heywood Jonathan D. , Jacquemin Denis , Rice Craig R. , Heron B. Mark
Published: October 2013

The syntheses of a series of new ketohydrazone dyes and pigment lakes with a unique structural motif derived from 4‐morpholino‐2‐naphthol are described. The morpholine substituent is responsible for the hypsochromically shifted absorption maxima with significantly enhanced molar extinction coefficients of the new dyes; this conclusion is supported by time‐dependent DFT (TD‐DFT) simulations. The location of the morpholine substituent at a sterically demanding site in the pigment lake obstructs further coordination of the bridging sulfonate groups in the solid state and prevents the formation of a 1‐dimensional polymeric system, which is common for other pigment lakes.
Evaluating fire blocking performance of barrier fabrics
Authors: Nazaré Shonali , Pitts William , Flynn Shaun , Shields John. R. , Davis Rick D.
Published: October 2013

A series of evaluations were performed on different types of barrier fabrics (BFs) used in soft furnishings. Fundamental properties that influence the heat transfer characteristics of barrier material as it relates to thermal protection of cushioning components in upholstered products are discussed. This is important to enable a priori selection of BFs such that a final upholstered product complies with flammability regulations.

Heat transfer measurements are used to determine effectiveness of materials to be used as barrier materials. A new bench‐scale composite test method is also described to assess qualitative fire blocking performance of BFs. When tested for heat transfer characteristics, the area density and thickness of BFs show strong influence. However, when tested as a composite in a mock‐up assembly, the BFs considered in this study showed a clear distinction between active and passive BFs. In the case of chemically active BFs, the construction parameters and material properties such as thickness, air permeability, and heat transfer were of little significance. In the case of passive BFs, however, these parameters became decisive. Results from this study suggest that if the BF is not an active fire barrier, then the amount of heat transferred through BF is critical. Copyright © 2013 John Wiley & Sons, Ltd.
Mechanics Behavior Induced by Chemical Expansion for Oxide Anode of Solid Oxide Fuel Cells
Authors: Wang Y. , Zhu S. , Zhan Z. , Xia C.
Published: October 2013

Oxide anodes of solid oxide fuel cells are usually stable in the redox cycling process. However, they may be subjected to mechanical stresses associated with chemical expansion due to the stoichiometrical variation. A novel method is presented to detect the mechanical stresses by combining the Fick's second law, oxygen surface exchange, and oxygen‐ion diffusion properties. The surface tensile stress is weak for the small structural dimensions due to the short diffusion length. When the surface exchange kinetics is increased by means such as surface modification, the improved surface exchange rate may result in large mechanical stress and the stress‐loading rate, and consequently, reduce the redox stability. A new modulus (ω) is introduced to predict the mechanical behavior, and larger ω means higher mechanical stress. Finally, the prediction is experimentally confirmed with (La0.75Sr0.25)0.95Cr0.5Mn0.5O3–δ (LSCM) samples, where the fracture is related to its conductivity. It is found that porous LSCM has excellent stability in the atmosphere change process. However, fractures are observed with Ni impregnated porous LSCM due to the increased surface exchanged coefficient, which means larger ω.
Long‐term experience with reduced planning target volume margins and intensity‐modulated radiotherapy with daily image‐guidance for head and neck cancer
Authors: Chen Allen M. , Yu Yao , Daly Megan E. , Farwell D. Gregory , H. Benedict Stanley , Purdy James A.
Published: October 2013

Background

The purpose of this study was to compare outcomes among patients treated by intensity‐modulated radiotherapy (IMRT) with daily image‐guided radiotherapy (IGRT) for head and neck cancer according to the margins used to expand the clinical target volume (CTV) to create a planning target volume (PTV).

Methods

Three hundred sixty‐seven consecutive patients were treated with IMRT for squamous cell carcinoma of the head and neck. The first 103 patients were treated with 5‐mm CTV‐to‐PTV margins. The subsequent 264 patients were treated using reduced (3 mm) margins.

Results

The 3‐year locoregional control for patients treated using 5‐mm and 3‐mm CTV‐to‐PTV margins, respectively, was 78% and 80% (p = .75). The incidence of gastrostomy‐tube dependence at 1 year was 10% and 3%, respectively (p = .001). The incidence of posttreatment esophageal stricture was 14% and 7%, respectively (p = .01).

Conclusion

The use of reduced (3 mm) CTV‐to‐PTV margins was associated with reduced late toxicity while maintaining locoregional control. © 2014 Wiley Periodicals, Inc. Head Neck 36: 1766–1772, 2014
Gold‐Catalyzed Alkynylation: Acetylene‐Transfer instead of Functionalization
Authors: Brand Jonathan P. , Li Yifan , Waser Jérôme
Published: October 2013

Over the last fifteen years, gold has been raised from the status of an inert noble metal to one of the most‐often‐used catalysts in synthetic chemistry. The functionalization of the triple bond of alkynes has been especially successful in this respect. In contrast, gold‐catalyzed alkynylation reactions only began to emerge in 2007. Since then, three different approaches have been successfully used for this transformation. 1) Gold nanoparticles have been shown to promote catalytic cycles based on the oxidative arylation of aryl halides to give a “palladium‐free Sonogashira reaction”. 2) The use of benziodoxol(on)e hypervalent iodine compounds as oxidative alkynylation reagents has allowed the CH functionalization of electron‐rich heterocycles under mild conditions with a very broad functional‐group tolerance. 3) The use of iodobenzene acetate or Selectfluor as an external oxidant has led to the first alkynylation methods based on direct CH/CH coupling reactions. In only six years, gold‐catalyzed alkynylation methods have grown from non‐existent to useful synthetic procedures for the synthesis of structurally diverse alkynes. Considering that acetylenes are among the most‐important building blocks for applications in synthetic chemistry, chemical biology, and materials science, there is tremendous potential for the further development of gold‐catalyzed alkynylation reactions in the future.
Pulsed radiofrequency inhibited activation of spinal mitogen‐activated protein kinases and ameliorated early neuropathic pain in rats
Authors: Lin M.‐L. , Lin W.‐T. , Huang R.‐Y. , Chen T.‐C. , Huang S.‐H. , Chang C.‐H. , Tsai S.‐Y. , Chiu H.‐W. , Yeh G.‐C. , Lin C.‐W. , Wen Y.‐R.
Published: October 2013

Background

Pulsed radiofrequency (PRF) has been widely used to treat chronic pain, but the effectiveness and mechanisms in preventing early neuropathic pain have not been well explored. Even fewer knowledge is available in its impact on glia‐mediated nociceptive sensitization. This study aims to elucidate the modulation of PRF on nerve injury‐induced pain development and activation of spinal mitogen‐activated protein kinases (MAPKs).

Methods

In a rat spinal nerve ligation (SNL) model, a low‐volt PRF treatment was applied to the L5 dorsal root ganglion after nerve injury. Nociceptive behaviours were measured by von Frey and heat withdrawal tests at multiple time points. MAPK activations, including p‐ERK and p‐p38, as well as TNF‐α level in the spinal dorsal horn were assessed and the cell types that expressed MAPK activation were identified by double immunofluorescence staining.

Results

We found that SNL promptly induced neuropathic pain in the affected hind limb for over 1 week as well as increased p‐ERK and p‐p38 in the spinal dorsal horn. PRF significantly attenuated SNL‐induced mechanical allodynia and thermal hyperalgesia for 5–7 days. PRF also inhibited ERK and p38 activations, which were found majorly located within neurons and microglia, respectively. Besides, PRF significantly suppressed expression of TNF‐α in the spinal dorsal horn throughout the course.

Conclusions

Low‐volt PRF significantly ameliorated SNL‐induced acute pain. Inferentially, PRF may inhibit spinal sensitization by down‐regulating spinal MAPK activations and activation‐mediated cytokine release. We demonstrated that early PRF treatment in acute nerve injury helps to ameliorate neuropathic pain development.
A fibrous bed bioreactor to improve the productivity of succinic acid by Actinobacillus succinogenes
Authors: Yan Qiang , Zheng Pu , Dong Jin‐Jun , Sun Zhi‐Hao
Published: October 2013

BACKGROUND

Succinic acid is one of the most important biorefinery platform chemicals. The fibrous‐bed bioreactor (FBB), comprising spiral cotton fiber packed in a modified bioreactor, is effective for anaerobic cell‐immobilized fermentation. In this study, fermentation production of succinic acid by Actinobacillus succinogenes using a FBB was investigated.

RESULTS

The effect of different initial glucose concentrations on succinic acid production in batch fermentation in a FBB was examined, which indicated that the optimal initial glucose concentration was 55 g L‐1. In 10 batches of repeated‐batch fermentation, the average succinic acid productivity, concentration, and yield were 3.61 g L‐1 h‐1, 39.0 g L‐1, and 0.85 g g‐1, respectively. A maximum succinic acid concentration of 98.7 g L‐1 was reached in fed‐batch fermentation comprising four batches of fermentation, with a succinic acid yield of 0.89 g g‐1 and productivity of 2.77 g L‐1 h‐1.

CONCLUSION

Succinic acid fermentation by A. succinogenes in a FBB was successfully performed to enhance succinic acid productivity. And also, high succinic acid concentration with high reactor productivity and yield were simultaneously achieved in the FBB with fed‐batch fermentation. © 2013 Society of Chemical Industry
Aqueous two‐phase systems for the extraction of phenolic compounds from eucalyptus (Eucalyptus globulus) wood industrial wastes
Authors: Xavier Lucía , Freire M. Sonia , Vidal‐Tato Isabel , González‐Álvarez Julia
Published: October 2013

BACKGROUND

Aqueous two‐phase extraction is recognized as an effective, versatile and important emerging green‐technique for the downstream processing of biomolecules. Extraction of phenolic compounds from trimmings of Eucalyptus globulus wood veneers was studied using aqueous two‐phase systems (ATPS) (water + polymer + salt) based on PEG 2000 and ammonium sulphate. The aim was the recovery of phenolic compounds to be used as natural antioxidants. Experiments were planned to optimize the extraction process. The influence of several operational conditions (time, temperature, ATPS composition, solid–liquid ratio and settlement time) on phenolics recovery was studied.

RESULTS

It was found that phenolic compounds have preference for the top PEG‐rich phase. Settlement time had no significant impact on phase composition. Total phenols yield increased with temperature, extraction time and amount of solvent used. However, ATPS composition did not significantly influence total phenol yield. Extract analysis by RP‐HPLC‐ESI‐TOF confirmed the presence of phenolic compounds with potential antioxidant activity, namely, mono and digalloyl glucose, (−)‐gallic acid, ellagic acid and quercetin 3‐O‐rhamnoside.

CONCLUSION

Results demonstrated that extraction with ATPS (PEG 2000 and ammonium sulphate) is an efficient way for recovering phenolics from eucalyptus wastes without requiring previous purification (total phenols yield of up to 1.88 ± 0.04 mg GAE/100 o.d. wood). © 2013 Society of Chemical Industry
Upper aerodigestive magnetic foreign bodies in children
Authors: Brown Julie C. , Baik Fred M. , Ou Henry C. , Otjen Jeffrey P. , Parish Hannah G. , Chan Dylan K.
Published: October 2013

Objectives/Hypothesis

Small, powerful magnets are increasingly available in toys and other products, and are responsible for increasing numbers of foreign body injuries in children. Small, spherical, neodymium magnets available since 2008 are of particular concern. We aimed to identify all cases of upper aerodigestive foreign bodies at our institution over 15.5 years of study.

Study Design

Case series including all patients treated at an urban, tertiary care children's hospital who had upper aerodigestive magnetic foreign bodies, from January 1, 1998 through April 30, 2013.

Methods

We manually reviewed 7,049 patient records abstracted from billing data to identify all patients 0 to 20 years of age who had upper aerodigestive magnetic foreign bodies.

Results

We identified four cases of upper aerodigestive magnetic foreign bodies, one involving the hypopharynx, and three involving the upper esophagus. Three occurred in 2010 or later. Two cases involve the ingestion of multiple, spherical, neodymium magnets recently marketed as desktop toys. In both of these cases, there was a rapid development of mucosal injury at the site of attraction between two magnets.

Conclusions

As small, powerful magnets become more ubiquitous, pediatric magnet foreign body injuries are increasing. Although most are gastrointestinal, we identified four recent cases involving the upper aerodigestive tract. Multiple magnets lodged in the hypopharynx or esophagus can rapidly cause pressure necrosis of mucosal tissues, and merit prompt management. Education regarding magnet safety and improved magnet safety standards are needed to reduce the risk of these injuries.

Level of Evidence

4. Laryngoscope, 124:1481–1485, 2014
What is the role of the larynx in adult obstructive sleep apnea?
Authors: Dedhia Raj C. , Rosen Clark A. , Soose Ryan J.
Published: October 2013

Objectives/Hypothesis

To examine the current body of literature supporting the role of the larynx in adult obstructive sleep apnea (OSA).

Data Sources

PubMed.

Methods

PubMed search using medical subject headings “larynx” and “obstructive sleep apnea.” Original articles in English related to adult patients were initially included, and the bibliographies of pertinent articles were hand‐searched for additional articles.

Results

A total of 17 articles were included in the review in the following subgroups: neuromuscular role of larynx (n = 3), anatomic contribution of larynx to OSA (n = 7), and special populations (n = 7). The sensory component of the superior laryngeal nerve plays a critical role in airway patency during sleep, and patients with OSA have increased endolaryngeal sensory thresholds compared to controls. Primary epiglottic obstruction in the hypopharynx represents 15% of patients with OSA unable to tolerate continuous positive airway pressure. Head and neck cancer and multiple system atrophy are two entities with high rates of OSA due in part to laryngeal abnormalities.

Conclusions

The endolarynx warrants consideration in the pathophysiology of OSA, particularly as it relates to sensory dysfunction and epiglottic obstruction. Patients with head and neck cancer of the laryngopharynx are at significant risk of OSA. Further research is needed to better understand and heighten awareness of the intimate role that the larynx may play in OSA. Laryngoscope, 124:1029–1034, 2014
Does buccal cancer have worse prognosis than other oral cavity cancers?
Authors: Camilon P. Ryan , Stokes William A. , Fuller Colin W. , Nguyen Shaun A. , Lentsch Eric J.
Published: October 2013

Objectives/Hypothesis

To determine whether buccal squamous cell carcinoma has worse overall survival (OS) and disease‐specific survival (DSS) than cancers in the rest of the oral cavity.

Study Design

Retrospective analysis of a large population database.

Methods

We began with a Kaplan‐Meier analysis of OS and DSS for buccal versus nonbuccal tumors with unmatched data, followed by an analysis of cases matched for race, age at diagnosis, stage at diagnosis, and treatment modality. This was supported by a univariate Cox regression comparing buccal cancer to nonbuccal cancer, followed by a multivariate Cox regression that included all significant variables studied.

Results

With unmatched data, buccal cancer had significantly lesser OS and DSS values than cancers in the rest of the oral cavity (P < .001). After case matching, the differences between OS and DSS for buccal cancer versus nonbuccal oral cancer were no longer significant. Univariate Cox regression models with respect to OS and DSS showed a significant difference between buccal cancer and nonbuccal cancer. However, with multivariate analysis, buccal hazard ratios for OS and DSS were not significant.

Conclusions

With the largest series of buccal carcinoma to date, our study concludes that the OS and DSS of buccal cancer are similar to those of cancers in other oral cavity sites once age at diagnosis, tumor stage, treatment, and race are taken into consideration. The previously perceived poor prognosis of buccal carcinoma may be due to variations in tumor presentation, such as later stage and older patient age.

Level of Evidence

2b Laryngoscope, 124:1386–1391, 2014
Poly(styrene‐r‐butadiene)‐b‐poly(poly(ethylene glycol) methyl ether methacrylate) as a silica dispersant in rubber compounds
Authors: Lee Jong‐yeop , Lee Taeheon , Kim Kihyun , Kim Byunghee , Kwag Gwanghoon , Kim Jae‐yun , Ji Sangchul , Kim Wonho , Paik Hyun‐jong
Published: October 2013

To improve the dispersion of silica in silica‐filled styrene–butadiene rubber tire tread compounds, we synthesized poly(styrene‐r‐butadiene)‐b‐poly(poly(ethylene glycol) methyl ether methacrylate) (p(SB‐b‐PEGMA)) as a silica dispersant. p(SB‐b‐PEGMA) was synthesized by combining living anionic polymerization (LAP) and atom transfer radical polymerization (ATRP). Initially, α‐bromoisobutyryl‐terminated poly(styrene‐r‐butadiene) (pSB‐Br) was prepared by LAP of styrene and butadiene and sequential additions of ethylene oxide and α‐bromoisobutyryl bromide. pSB‐Br was then used as the macroinitiator in the ATRP of PEGMA (Mn = 300 g mol−1). The structure of p(SB‐b‐PEGMA) was characterized using gel permeation chromatography and 1H NMR spectroscopy. The application of p(SB‐b‐PEGMA) as a silica dispersant in styrene–butadiene rubber/silica decreased the optimal vulcanization time and improved the mechanical properties, which included 100% and 300% moduli, crosslinking density and silica dispersion. © 2013 Society of Chemical Industry
A comparative study of phosphoric acid‐doped m‐PBI membranes
Authors: A. Perry Kelly , L. More Karren , Andrew Payzant E. , Meisner Roberta A. , Sumpter Bobby G. , Benicewicz Brian C.
Published: October 2013

Phosphoric acid (PA)‐doped m‐polybenzimidazole (PBI) membranes used in high temperature fuel cells and hydrogen pumps were prepared by a conventional imbibing process and a sol–gel fabrication process. A comparative study was conducted to investigate the critical properties of PA doping levels, ionic conductivities, mechanical properties, and molecular ordering. This systematic study found that sol–gel PA‐doped m‐PBI membranes were able to absorb higher acid doping levels and to achieve higher ionic conductivities than conventionally imbibed membranes when treated in an equivalent manner. Even at similar acid loadings, the sol–gel membranes exhibited higher ionic conductivities. Heat treatment of conventionally imbibed membranes with ≤29 wt % solids caused a significant reduction in mechanical properties; conversely, sol–gel membranes exhibited an enhancement in mechanical properties. From X‐ray structural studies and atomistic simulations, both conventionally imbibed and sol–gel membranes exhibited d‐spacings of 3.5 and 4.6 Å, which were tentatively attributed to parallel ring stacking and staggered side‐to‐side packing, respectively, of the imidazole rings in these aromatic heterocyclic polymers. An anisotropic staggered side‐to‐side chain packing present in the conventional membranes may be related to the reduction in mechanical properties. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Polym. Phys. 2014, 52, 26–35
Plasma protein analysis of patients with different B‐cell lymphomas using high‐content antibody microarrays
Authors: Schröder Christoph , Srinivasan Harish , Sill Martin , Linseisen Jakob , Fellenberg Kurt , Becker Nikolaus , Nieters Alexandra , Hoheisel Jörg D.
Published: October 2013

Purpose

In this study, plasma samples from a multicentric case‐control study on lymphoma were analyzed for the identification of proteins useful for diagnosis.

Experimental design

The protein content in the plasma of 100 patients suffering from the three most common B‐cell lymphomas and 100 control samples was studied with antibody microarrays composed of 810 antibodies that target cancer‐associated proteins. Sample pools were screened for an identification of marker proteins. Then, the samples were analyzed individually to validate the usability of these markers.

Results

More than 200 proteins with disease‐associated abundance changes were found. The evaluation on individual patients confirmed some molecules as robust informative markers while others were inadequate for this purpose. In addition, the analysis revealed distinct subgroups for each of the three investigated B‐cell lymphoma subtypes. With this information, we delineated a classifier that discriminates the different lymphoma entities.

Conclusions and clinical relevance

Variations in plasma protein abundance permit discrimination between different patient groups. After validation on a larger study cohort, the findings could have diagnostic as well as differential diagnostic potential. Beside this, methodological aspects were critically evaluated, such as the value of sample pooling for the identification of biomarkers that are useful for a diagnosis on individual patients.
X‐Band Microwave Properties and Ignition Predictions of Neat Explosives
Authors: Daily Megan E. , Glover Brian B. , Son Steven F. , Groven Lori J.
Published: October 2013

Microwave frequency electromagnetic properties are critical for understanding and predicting the heating and ignition behavior of explosives subjected to microwave irradiation. In this work we report relative complex permittivity measurements in the X‐band (8–12 GHz) for 13 neat explosives measured by the circular cavity technique. This data set was then used in conjunction with COMSOL 4.3 Multiphysics® finite element analysis software to design and simulate a low power (100 W), high electric field X‐band microwave applicator. The role of the sample holder on our ability to directly study the response of explosives to electromagnetic energy is examined and shown to be critical. Times to ignition were predicted for PETN, TATB, and HMX and indicate that for the proposed applicator and considered properties ignition may occur in less than one second exposure. These predictions show that explosives can be effectively heated in short time scales through direct microwave heating without absorptive binders or inclusions.
Improving the accuracy of protein stability predictions with multistate design using a variety of backbone ensembles
Authors: Davey James A. , Chica Roberto A.
Published: October 2013

Multistate computational protein design (MSD) with backbone ensembles approximating conformational flexibility can predict higher quality sequences than single‐state design with a single fixed backbone. However, it is currently unclear what characteristics of backbone ensembles are required for the accurate prediction of protein sequence stability. In this study, we aimed to improve the accuracy of protein stability predictions made with MSD by using a variety of backbone ensembles to recapitulate the experimentally measured stability of 85 Streptococcal protein G domain β1 sequences. Ensembles tested here include an NMR ensemble as well as those generated by molecular dynamics (MD) simulations, by Backrub motions, and by PertMin, a new method that we developed involving the perturbation of atomic coordinates followed by energy minimization. MSD with the PertMin ensembles resulted in the most accurate predictions by providing the highest number of stable sequences in the top 25, and by correctly binning sequences as stable or unstable with the highest success rate (≈90%) and the lowest number of false positives. The performance of PertMin ensembles is due to the fact that their members closely resemble the input crystal structure and have low potential energy. Conversely, the NMR ensemble as well as those generated by MD simulations at 500 or 1000 K reduced prediction accuracy due to their low structural similarity to the crystal structure. The ensembles tested herein thus represent on‐ or off‐target models of the native protein fold and could be used in future studies to design for desired properties other than stability. Proteins 2014; 82:771–784. © 2013 Wiley Periodicals, Inc.
Molecular dynamics study of HIV‐1 RT‐DNA‐nevirapine complexes explains NNRTI inhibition and resistance by connection mutations
Authors: Vijayan R. S. K. , Arnold Eddy , Das Kalyan
Published: October 2013

HIV‐1 reverse transcriptase (RT) is a multifunctional enzyme that is targeted by nucleoside analogs (NRTIs) and non‐nucleoside RT inhibitors (NNRTIs). NNRTIs are allosteric inhibitors of RT, and constitute an integral part of several highly active antiretroviral therapy regimens. Under selective pressure, HIV‐1 acquires resistance against NNRTIs primarily by selecting mutations around the NNRTI pocket. Complete RT sequencing of clinical isolates revealed that spatially distal mutations arising in connection and the RNase H domain also confer NNRTI resistance and contribute to NRTI resistance. However, the precise structural mechanism by which the connection domain mutations confer NNRTI resistance is poorly understood. We performed 50‐ns molecular dynamics (MD) simulations, followed by essential dynamics, free‐energy landscape analyses, and network analyses of RT‐DNA, RT‐DNA‐nevirapine (NVP), and N348I/T369I mutant RT‐DNA‐NVP complexes. MD simulation studies revealed altered global motions and restricted conformational landscape of RT upon NVP binding. Analysis of protein structure network parameters demonstrated a dissortative hub pattern in the RT‐DNA complex and an assortative hub pattern in the RT‐DNA‐NVP complex suggesting enhanced rigidity of RT upon NVP binding. The connection subdomain mutations N348I/T369I did not induce any significant structural change; rather, these mutations modulate the conformational dynamics and alter the long‐range allosteric communication network between the connection subdomain and NNRTI pocket. Insights from the present study provide a structural basis for the biochemical and clinical findings on drug resistance caused by the connection and RNase H mutations. Proteins 2014; 82:815–829. © 2013 Wiley Periodicals, Inc.
Conformational changes in DNA‐binding proteins: Relationships with precomplex features and contributions to specificity and stability
Authors: Mizuguchi Kenji , Ahmad Shandar
Published: October 2013

Both Proteins and DNA undergo conformational changes in order to form functional complexes and also to facilitate interactions with other molecules. These changes have direct implications for the stability and specificity of the complex, as well as the cooperativity of interactions between multiple entities. In this work, we have extensively analyzed conformational changes in DNA‐binding proteins by superimposing DNA‐bound and unbound pairs of protein structures in a curated database of 90 proteins. We manually examined each of these pairs, unified the authors' annotations, and summarized our observations by classifying conformational changes into six structural categories. We explored a relationship between conformational changes and functional classes, binding motifs, target specificity, biophysical features of unbound proteins, and stability of the complex. In addition, we have also investigated the degree to which the intrinsic flexibility can explain conformational changes in a subset of 52 proteins with high quality coordinate data. Our results indicate that conformational changes in DNA‐binding proteins contribute significantly to both the stability of the complex and the specificity of targets recognized by them. We also conclude that most conformational changes occur in proteins interacting with specific DNA targets, even though unbound protein structures may have sufficient information to interact with DNA in a nonspecific manner. Proteins 2014; 82:841–857. © 2013 Wiley Periodicals, Inc.
Infantile spinale Muskelatrophie: mehr als eine Motoneuronerkrankung?
Authors: Rudnik-Schöneborn S. , Lorson C.L. , Shababi M.
Published: October 2013

Die infantile spinale Muskelatrophie (SMA) – bedingt durch homozygote Mutationen im Survival-motor-neuron-1(SMN1)-Gen – ist durch eine Degeneration von motorischen Neuronen im Vorderhorn des Rückenmarks und im Hirnstamm charakterisiert. Die Folge eines SMN-Proteinmangels ist eine progrediente Muskelatrophie mit proximal betonten Lähmungen der Willkürmuskulatur und motorischen Hirnnervenausfällen. In den letzten Jahren mehren sich klinische Beobachtungen und Berichte von Tiermodellen, dass eine SMN-Proteinreduktion zusätzlich zu unterschiedlichen Funktionsstörungen anderer Organsysteme führt. Diese betreffen insbesondere das periphere, zentrale und autonome Nervensystem, die Entwicklung des Herzes, die Funktion des Verdauungstrakts und metabolische Veränderungen. Um sinnvolle und effiziente Therapiestrategien zu entwickeln und um weiteren Komplikationen begegnen zu können, die sich z. B. bei einer längeren Überlebensdauer v. a. von schwer betroffenen Patienten ergeben können, ist es erforderlich, dass jede mögliche Organpathologie systematisch untersucht wird. Der Vergleich mit SMA-Mausmodellen ist hierfür außerordentlich hilfreich, wenn auch die phänotypischen Auswirkungen nicht vollständig auf den Menschen übertragbar sind.
Genetische Diagnostik und Beratung bei Arthrogryposis
Authors: Heller R. , Hoffmann K.
Published: October 2013

Es werden wichtige Probleme in der Diagnostik bei Patienten mit Arthrogryposis dargestellt und Definitionen eingeführt. Danach werden praktische Ansätze für die Diagnostik und humangenetische Betreuung vorgeschlagen.