bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leonardo da Vinci's “A Skull Sectioned”: Skull and dental formula revisited
Authors: Gerrits Peter O. , Veening Jan G. 
Published: March 2012

AbstractWhat can be learned from historical anatomical drawings and how to incorporate these drawings into anatomical teaching? The drawing “A skull sectioned” (RL 19058v) by Leonardo da Vinci (1452–1519), hides more detailed information than reported earlier. A well‐chosen section cut explores sectioned paranasal sinuses and ductus nasolacrimalis. A dissected lateral wall of the maxilla is also present. Furthermore, at the level of the foramen mentale, the drawing displays compact and spongious bony components, together with a cross‐section through the foramen mentale and its connection with the canalis mandibulae. Leonardo was the first to describe a correct dental formula (6424) and made efforts to place this formula above the related dental elements. However, taking into account, the morphological features of the individual elements of the maxilla, it can be suggested that Leonardo sketched a “peculiar dental element” on the position of the right maxillary premolar in the dental sketch. The fact that the author did not make any comment on that special element is remarkable. Leonardo could have had sufficient knowledge of the precise morphology of maxillary and mandibular premolars, since the author depicted these elements in the dissected skull. The fact that the author also had access to premolars in situ corroborates our suggestion that “something went wrong” in this part of the drawing. The present study shows that historical anatomical drawings are very useful for interactive learning of detailed anatomy for students in medicine and dentistry. Clin. Anat., 2013. © 2012 Wiley Periodicals, Inc.
Musculotendinous architecture of pathological supraspinatus: A pilot in vivo ultrasonography study
Authors: Kim Soo Y. , Bleakney Robert R. , Rindlisbacher Tim , Ravichandiran Kajeandra , Rosser Benjamin W.C. , Boynton Erin 
Published: March 2012

AbstractArchitectural changes associated with tendon tears of the supraspinatus muscle (SP) have not been thoroughly investigated in vivo with the muscle in relaxed and contracted states. The purpose of this study was to quantify the geometric properties within the distinct regions of SP in subjects with full‐thickness tendon tears using an ultrasound protocol previously developed in our laboratory, and to compare findings with age/gender matched normal controls. Twelve SP from eight participants (6 male/2 female), mean age 57 ± 6.0 years, were investigated. Muscle geometric properties of the anterior region (middle and deep parts) and posterior region (deep part) were measured using image analysis software. Along with whole muscle thickness, fiber bundle length (FBL) and pennation angle (PA) were computed for architecturally distinct regions and/or parts. Pathologic SP was categorized according to the extent of the tear in the tendon (with or without retraction). In the anterior region, mean FBL of the pathologic SP was similar with normal controls; however, mean PA was significantly smaller in pathologic SP with retraction compared with normal controls, in the contracted state (P < 0.05). Mean FBL in the posterior region in both relaxed and contracted states was significantly shorter in the pathologic SP with retraction compared with normal controls (P < 0.05). Findings suggest FBL changes associated with tendon pathology vary between the distinct regions, and PA changes are related to whether there is retraction of the tendon. The ultrasound protocol may provide important information on architectural changes that may assist in decision making and surgical planning. Clin. Anat., 2013. © 2012 Wiley Periodicals, Inc.
Endovascular stent provides more effective early relief of SVC obstruction compared to balloon angioplasty
Authors: Aldoss Osamah , Arain Nofil , Menk Jeremiah , Kochilas Lazaros , Gruenstein Daniel 
Published: March 2012

ObjectiveTo determine whether superior vena cava (SVC) stent implantation is superior to balloon angioplasty for relieving SVC stenosis.BackgroundSVC stent and balloon dilation have been used as treatment for SVC stenosis. Although safe and effective, outcome data comparing the two methods are limited.MethodsA Pediatric Cardiac Care Consortium review identified SVC stenosis. Patients who required SVC intervention were divided into two subgroups—balloon dilation (Group A) and stent implantation (Group B). Logistic regression and the log‐rank test were used to test the need for re‐intervention within 6 months after the initial procedure.ResultsSVC intervention was performed on 210/637 patients with SVC stenosis (33%). There were 108/210 (51%) patients with balloon dilation (Group A) and 102/210 (49%) with stent implantation (Group B). Re‐intervention within 6 months of the initial intervention was more common in Group A compared to Group B [Group A = 31/40 (77.5%); Group B = 5/22 (22.7%)]. The odds‐ratio for re‐intervention within 6 months of the initial procedure for balloon vs. stent, is 7.3 [95% CI: (2.91, 22.3), P < 0.0001]. In addition, during the first 6 months after an intervention for SVC stenosis the proportion of patients with stent implantation that remained free of re‐intervention was significantly higher than after balloon angioplasty (log‐rank test, P < 0.0001). Neither age nor weight was significantly associated with the need for re‐intervention.ConclusionsSVC stent implantation is more effective than angioplasty in relief of SVC obstruction. Weight and age are not risk factors for early re‐intervention. © 2012 Wiley Periodicals, Inc.
Acute severe mitral regurgitation following balloon mitral valvotomy: Echocardiographic features, operative findings, and outcome in 50 surgical cases
Authors: Nanjappa Manjunath C. , Ananthakrishna Rajiv , Setty Srinivasa K. Hemanna , Bhat Prabhavathi , Shankarappa Ravindranath K. , Panneerselvam Arunkumar , Kamalapurkar Giridhar , Bhat Seetharama P.S. , Rao Venugopal Ram 
Published: March 2012

ObjectiveTo analyze the echocardiographic and operative findings with respect to mitral valve anatomy in individuals undergoing emergency surgery for acute severe mitral regurgitation (MR) following balloon mitral valvotomy (BMV). In addition, the clinical profile and outcomes are highlighted.BackgroundAcute severe MR is a major complication of BMV. There are only a few reports which have studied the echocardiographic and operative findings in this setting. In addition, optimal timing of surgery is uncertain.MethodsProspective study of 50 consecutive patients undergoing emergency mitral valve replacement (MVR) for acute severe MR following BMV.ResultsIn 3855 patients who underwent BMV, acute severe MR developed in 50 cases (1.3%) and was referred for emergency MVR. Hypotension (72%), hypoxia (64%), orthopnea (14%), and pulmonary edema (12%) were the clinical manifestations. Severe MR was secondary to anterior mitral leaflet tear in 36 cases (72%), paracommisural tear with annular involvement in seven cases (14%), posterior mitral leaflet tear in five cases (10%) and chordal tear in two cases (4%). The correlation between two‐dimensional transthoracic echocardiography (2D‐TTE) and operative finding for mitral valve calcification was found to be strong (r = 0.862), in contrast to submitral fusion, where it was found to be moderate (r = 0.536). In‐hospital mortality was 12%. Mortality was higher in patients whose time to surgery was ≥24 hr when compared to those who underwent MVR within 24 hr (P < 0.001).ConclusionsHypotension and hypoxia are the predominant manifestations of acute severe MR following BMV. Anterior mitral leaflet tear is the most common etiology for severe MR. 2D‐TTE underestimated the severity of submitral disease. Early MVR (<24 hr) is recommended for optimal outcome. © 2012 Wiley Periodicals, Inc.
Embozene™ microspheres induced nonreperfused myocardial infarction in an experimental swine model
Authors: Varga‐Szemes Akos , Kiss Pal , Brott Brigitta C. , Wang Dezhi , Simor Tamas , Elgavish Gabriel A. 
Published: March 2012

ObjectivesTo develop a magnetic resonance imaging (MRI) compatible, percutaneous technique for the generation of nonreperfused myocardial infarct (MI).BackgroundModeling nontreated MI has major importance in the development and preclinical testing of new therapeutic strategies for patients missing the time window suitable for revascularization following MI.MethodsIn 31 male swine, nonreperfused MI was generated by permanent occlusion of either the LAD or LCX coronary artery using 900 μm Embozene™ microspheres. Animals were monitored for 90 min postocclusion. Surviving animals were followed up for 2 (n = 6), 4 (n = 6), 14 (n = 6), or 56 (n = 6) days. At the end of the planned study session, contrast enhanced MRI, triphenyl‐tetrazolium‐chloride staining, and microscopic histopathology were carried out.ResultsThe mortality rate in this study was 22.6%. Intraoperative arrhythmias occurred in 14 cases: premature ventricular complexes with (5) or without (3) ventricular tachycardia, 2nd degree atrio‐ventricular block (1), and ventricular fibrillation (6). MRI, TTC, and histology confirmed the existence of MI in every case. Macroscopic pathology showed that the microspheres caused a practically total occlusion at the epicardial level of the coronary artery. Multiple infarcts were detected in one case, probably due to unintentional reflux of the microspheres. Microspheres retained in the coronary arteries did not cause any MRI artifact.ConclusionsThe generation of nonreperfused MI is feasible by percutaneous injection of Embozene into the coronary artery system. The MI model thus obtained is suitable for the purposes of MRI experiments. © 2012 Wiley Periodicals, Inc.
Asymmetric Nucleophilic Monofluorobenzylation of Carbonyl Compounds: Synthesis of Enantiopure vic‐Fluorohydrins and α‐Fluorobenzylketones
Authors: Arroyo Yolanda , Sanz‐Tejedor M. Ascensión , Parra Alejandro , García Ruano José Luis 
Published: March 2012

AbstractAsymmetric nucleophilic monofluoroalkylation of a broad range of aldehydes with an α‐fluoro‐γ‐sulfinylbenzyl carbanion takes place with complete control of the facial selectivity at the carbanion and good to high anti‐diastereoselectivity to give easily separable mixtures of two optically pure 1,2‐fluorohydrin derivatives (up to 24:1 anti/syn). Separation and removal of the p‐tolylsulfinyl group with tBuLi provides enantiomerically pure anti‐1,2‐disubstituted‐1,2‐fluorohydrins, whereas α‐fluorobenzylketones can be obtained by desulfinylation of the mixture followed by pyridinium chlorochromate oxidation (one‐pot process).
Oxygen Transport by Hemoglobin
Authors: Mairbäurl Heimo , Weber Roy E. 
Published: March 2012

AbstractHemoglobin (Hb) constitutes a vital link between ambient O2availability and aerobic metabolism by transporting oxygen (O2) from the respiratory surfaces of the lungs or gills to the O2‐consuming tissues. The amount of O2available to tissues depends on the blood‐perfusion rate, as well as the arterio‐venous difference in blood O2contents, which is determined by the respective loading and unloading O2tensions and Hb‐O2‐affinity. Short‐termadjustments in tissue oxygen delivery in response to decreased O2supply or increased O2demand (under exercise, hypoxia at high altitude, cardiovascular disease, and ischemia) are mediated by metabolically induced changes in the red cell levels of allosteric effectors such as protons (H+), carbon dioxide (CO2), organic phosphates, and chloride (Cl−) that modulate Hb‐O2affinity. Thelong‐term, genetically coded adaptations in oxygen transport encountered in animals that permanently are subjected to low environmental O2tensions commonly result from changes in the molecular structure of Hb, notably amino acid exchanges that alter Hb's intrinsic O2affinity or its sensitivity to allosteric effectors. Structure‐function studies of animal Hbs and human Hb mutants illustrate the different strategies for adjusting Hb‐O2affinity and optimizing tissue oxygen supply. © 2012 American Physiological Society.Compr Physiol2:1463‐1489, 2012.
Oxygen Uptake Kinetics
Authors: Poole David C. , Jones Andrew M. 
Published: March 2012

AbstractMuscular exercise requires transitions to and from metabolic rates often exceeding an order of magnitude above resting and places prodigious demands on the oxidative machinery and O2‐transport pathway. The science of kinetics seeks to characterize the dynamic profiles of the respiratory, cardiovascular, and muscular systems and their integration to resolve the essential control mechanisms of muscle energetics and oxidative function: a goal not feasible using the steady‐state response. Essential features of the O2uptake (o2) kinetics response are highly conserved across the animal kingdom. For a given metabolic demand, fasto2kinetics mandates a smaller O2deficit, less substrate‐level phosphorylation and high exercise tolerance. By the same token, slowo2kinetics incurs a high O2deficit, presents a greater challenge to homeostasis and presages poor exercise tolerance. Compelling evidence supports that, in healthy individuals walking, running, or cycling upright,o2kinetics control resides within the exercising muscle(s) and is therefore not dependent upon, or limited by, upstream O2‐transport systems. However, disease, aging, and other imposed constraints may redistributeo2kinetics control more proximally within the O2‐transport system. Greater understanding ofo2kinetics control and, in particular, its relation to the plasticity of the O2‐transport/utilization system is considered important for improving the human condition, not just in athletic populations, but crucially for patients suffering from pathologically slowedo2kinetics as well as the burgeoning elderly population. © 2012 American Physiological Society.Compr Physiol2:933‐996, 2012.
Integration of Biological Clocks and Rhythms
Authors: Refinetti Roberto 
Published: March 2012

AbstractAnimals, plants, and microorganisms exhibit numerous biological rhythms that are generated by numerous biological clocks. This article summarizes experimental data pertinent to the often‐ignored issue of integration of multiple rhythms. Five contexts of integration are discussed: (i) integration of circadian rhythms of multiple processes within an individual organism, (ii) integration of biological rhythms operating in different time scales (such as tidal, daily, and seasonal), (iii) integration of rhythms across multiple species, (iv) integration of rhythms of different members of a species, and (v) integration of rhythmicity and physiological homeostasis. Understanding of these multiple rhythmic interactions is an important first step in the eventual thorough understanding of how organisms arrange their vital functions temporally within and without their bodies. © 2012 American Physiological Society.Compr Physiol2:1213‐1239, 2012.
Coordination of Breathing with Nonrespiratory Activities
Authors: Bartlett Donald , Leiter James C. 
Published: March 2012

AbstractMany articles in this section ofComprehensive Physiologyare concerned with the development and function of a central pattern generator (CPG) for the control of breathing in vertebrate animals. The action of the respiratory CPG is extensively modified by cortical and other descending influences as well as by feedback from peripheral sensory systems. The central nervous system also incorporates other CPGs, which orchestrate a wide variety of discrete and repetitive, voluntary and involuntary movements. The coordination of breathing with these other activities requires interaction and coordination between the respiratory CPG and those governing the nonrespiratory activities. Most of these interactions are complex and poorly understood. They seem to involve both conventional synaptic crosstalk between groups of neurons and fluid identity of neurons as belonging to one CPG or another: neurons that normally participate in breathing may be temporarily borrowed or hijacked by a competing or interrupting activity. This review explores the control of breathing as it is influenced by many activities that are generally considered to be nonrespiratory. The mechanistic detail varies greatly among topics, reflecting the wide variety of pertinent experiments. © 2012 American Physiological Society.Compr Physiol2:1387‐1415, 2012.
The impact and outcomes of establishing an integrated interdisciplinary surgical team to care for the diabetic foot
Authors: Armstrong David G. , Bharara Manish , White Matthew , Lepow Brian , Bhatnagar Sugam , Fisher Timothy , Kimbriel Heather R. , Walters Jodi , Goshima Kaoru R. , Hughes John , Mills Joseph L. 
Published: March 2012

AbstractObjectiveThis study aimed to quantify the impact of an integrated diabetic foot surgical service on outcomes and changes in surgical volume and focus.MethodsWe abstracted registry data from 48 consecutive months at a single institution, evaluating all patients with diabetic foot complications requiring surgery or vascular intervention, and compared outcomes in the 24 months before and after integrating podiatric surgery with vascular surgical limb‐salvage service.ResultsThe service performed 2923 operations; 790 (27.0%) were related to treatment of diabetic foot complications in 374 patients. Of these, 502 were classified as non‐vascular diabetic foot surgery and 288 were vascular interventions. Urgent surgery was significantly reduced after team implementation (77.7% vs 48.5%,p < 0.0001; OR = 3.7, 95% CI: 2.4–5.5). The high/low amputation ratio decreased from 0.35 to 0.27 due to an increase in low‐level (midfoot) amputations (8.2% vs 26.1%,p < 0.0001; OR = 4.0, 95% CI: 2.0–83.3). A 45.7% reduction in below‐knee amputations was realized with a stable above‐knee/below‐knee amputation ratio (0.73–0.81). One‐third of patients required vascular intervention. Vascular reconstructions increased 44.1% following institution of the team. Initial revascularization was endovascular in 70.6% of patients. Repeat endovascular intervention or conversion to open bypass was required in 37.1% of these patients, almost double the reintervention rate of those receiving open bypass first (18.9%).ConclusionsInterdisciplinary diabetic foot surgery teams may significantly impact surgery type, with greater focus on proactive and preventive, rather than reactive and ablative, procedures. Although endovascular limb‐sparing procedures have become increasingly applicable, open bypass remains critical to success. Copyright © 2012 John Wiley & Sons, Ltd.
Folate deficiency is associated with the formation of complex nuclear anomalies in the cytokinesis‐block micronucleus cytome assay
Authors: Bull Caroline F. , Mayrhofer Graham , Zeegers Dimphy , Mun Grace Low Kah , Hande M. Prakash , Fenech Michael F. 
Published: March 2012

AbstractChromosomal instability (CIN) is an important hallmark to oncogenesis and can be diagnosed morphologically by the presence of nuclear anomalies such as micronuclei (MN), nucleoplasmic bridges (NPBs), and nuclear buds (NBuds). We have identified additional nuclear anomalies formed under folate‐deficient conditions, defined as “fused” nuclei (FUS), “circular” nuclei (CIR), and “horse‐shoe” nuclei (HS) and investigated their suitability for inclusion as additional CIN biomarkers in the lymphocyte cytokinesis‐block micronucleus cytome (CBMN‐Cyt) assay. Although the morphological appearance of FUS, CIR, and HS suggested an origin from multiple NPB in the fusion region between the two nuclei, the very low frequency of dicentric chromosomes in metaphase spreads from these cultures did not support this model. Fluorescence in situ hybridization (FISH) analysis of cytokinesis‐blocked binucleated (BN) cells with peptide nucleic acid probes for telomeres and centromeres (PNA–FISH) revealed a high proportion of fusion regions contained both centromeric and telomeric DNA. This suggests that folate deficiency may disrupt the process of sister chromatid separation and chromosome segregation during mitosis. It was concluded that the FUS, CIR, and HS morphologies represent promising biomarkers of CIN that are sensitive to folate deficiency, and further validation and investigation of the mechanisms responsible for their formation is warranted. Mol. Mutagen. 2012. © 2012 Wiley Periodicals, Inc.
A computational method for geometric optimization of enhanced heat transfer devices based upon entropy generation minimization
Authors: Betchen Lee J. , Straatman Anthony G. 
Published: March 2012

SUMMARYA computational fluid dynamics‐based optimization methodology is developed, appropriate for the geometric optimization of enhanced heat transfer devices based upon the principle of entropy generation minimization, in which the objective function is evaluated from a flow field obtained by computational simulation. A quasi‐Newton optimization procedure is employed, with computation of the objective function gradients based upon a finite difference approach. The optimization procedure is developed to be general with regard to the choice of objective function, the details of the problem under consideration, and the computational methodology employed in solving the fluid flow and heat transfer problems. A novel implementation of a Taylor series‐based procedure for the fast solution of nearby problems is presented, which is found to greatly benefit the efficiency of the present methodology. Finally, a numerical experiment is presented, illustrating the use of the present method in the geometric optimization of a practical enhanced heat transfer device on the basis of the criterion of entropy generation minimization. The optimization of the fin spacing of a simple plate fin heat sink is considered, and a comparison of the computational results with results obtained by analytical optimization based upon empirical friction factor and Nusselt number correlations is given. Copyright © 2012 John Wiley & Sons, Ltd.
Galectin‐4, a novel neuronal regulator of myelination
Authors: Stancic Mirjana , Slijepcevic Davor , Nomden Anita , Vos Michel J. , de Jonge Jenny C. , Sikkema Arend H. , Gabius Hans‐J. , Hoekstra Dick , Baron Wia 
Published: March 2012

AbstractMyelination of axons by oligodendrocytes (OLGs) is essential for proper saltatory nerve conduction, i.e., rapid transmission of nerve impulses. Among others, extracellular matrix (ECM) molecules, neuronal signaling, and axonal adhesion regulate the biogenesis and maintenance of myelin membranes, driven by polarized transport of myelin‐specific proteins and lipids. Galectin‐4, a tandem‐repeat‐type lectin with affinity to sulfatide and nonsialylated termini of N‐glycans, has the ability to regulate adhesion of cells to ECM components and is also involved in polarized membrane trafficking. We, therefore, anticipated that galectin‐4 might play a role in myelination. Here, we show that in developing postnatal rat brains galectin‐4 expression is downregulated just before the onset of myelination. Intriguingly, when immature OLGs were treated with galectin‐4, OLG maturation was retarded, while a subset of the immature OLGs reverted to a morphologically less complex progenitor stage, displaying concomitantly an increase in proliferation. Similarly, myelination was inhibited when galectin‐4 or anti‐galectin‐4 antibodies were added to co‐cultures of dorsal root ganglion neurons and OLGs. Neurons and OLGs were identified as a possible source of galectin‐4, both in vitro and in vivo. In culture, neurons but not OLGs released galectin‐4. Interestingly, in co‐cultures, a reduced release of endogenous galectin‐4 correlated with the onset of myelination. Moreover, galectin‐4‐reactive sites are transiently expressed on processes of premyelinating primary OLGs, but not on neurons. Taken together, these results identify neuronal galectin‐4 as a candidate for a soluble regulator of OLG differentiation and, hence, myelination. © 2012 Wiley Periodicals, Inc.