bluuebunny/crossref_metadata_2025 huggingface dataset:
An unusual case of peripartum pulmonary oedema
Authors: Reddy Yogesh N V , Sundaram Varun , Stamler Jonathan S
Published: September 2013

A previously healthy woman in her early 20s presented in week 38 of pregnancy with a 2-week history of haemoptysis, positional dyspnoea and an examination suggestive of pulmonary oedema. A chest CT showed a left lower lobe lung mass invading through the inferior pulmonary vein into the left atrium and abutting the posterior mitral leaflet. Pulmonary oedema consequent on left inferior pulmonary vein occlusion was initially restricted to the left lower lobe, but progressed to involve the contralateral lung following extension of the mass to the mitral orifice, resulting in functional mitral stenosis. A biopsy was positive for poorly differentiated spindle cell neoplasm. This is the first reported case of a pregnant patient with spindle cell neoplasm of lung and of a spindle neoplasm causing mitral stenosis, as well as the youngest known case of this disease.
Peliosis hepatis: a complicating finding in a case of biliary colic
Authors: Grønlykke Lars , Tarp Britta , Hamilton Dutoit Stephen , Wilkens Rune
Published: September 2013

A 33-year-old woman was referred for an ultrasound of the abdomen because of biliary colic. The symptoms had started 2 months after giving birth to her first child. The ultrasound showed gallstones, but it also revealed multiple focal liver lesions that were initially thought to be malignant. The examination was supplemented with a CT scan, contrast-enhanced ultrasound (CEUS) and MRI. The lesions were suspected to be peliosis hepatis—a rare morphological entity characterised by multiple blood-filled cavities in the liver. Because of uncertainty as to the aetiology of the lesions demonstrated at CEUS and MRI, the diagnosis was definitively confirmed by large-size needle biopsies. Regular size biopsies were initially insufficient for diagnosis. The use of oral contraceptives for several years or the recent pregnancy may have been the cause of peliosis hepatis in this patient.
Ataxia: a diagnostic perplexity and management dilemma
Authors: Chaubey Vinod K , Chhabra Lovely , Kapila Aaysha
Published: September 2013

A 79-year-old woman presented with lower extremity weakness and unsteadiness for 2 weeks. She was recently diagnosed with refractory atrial flutter and was prescribed amiodarone. Physical examination revealed signs of cerebellar dysfunction. Neuroimaging including CT and MRI were unremarkable. Her hospital course included the development of ventricular tachycardia necessitating increment in amiodarone dose. Laboratory studies were unremarkable except mild transaminitis. Other workup including the one for paraneoplastic neurological involvement was negative. The patient experienced worsening of ataxia requiring assistance with ambulation. In view of comprehensive routine negative work-up for ataxia, recent use of amiodarone and worsening of symptomatology with increase in its dosing, drug-induced neurotoxicity from amiodarone was suspected. Amiodarone dose was subsequently reduced and mexilitine was introduced as an additive antiarrhythmic therapy for ventricular tachycardia. In follow-up, the patient experienced significant improvement in her symptoms and was able to ambulate independently. She was subsequently discharged to short-term rehabilitation.
Is this an exacerbation of asthma? A cautionary tale
Authors: Sidhu Bharat , Nanda Uttam , Abbas Shahab
Published: September 2013

Asthma exacerbations are a fairly common presentation to emergency departments. However, a careful history, clinical examination and interpretation of investigations may uncover a more serious pathology. We present an interesting case of a 44-year-old man with symptoms suggestive of an asthma exacerbation, who was found to have Churg-Strauss vasculitis/eosinophilic granulomatosis with polyangitis. He had clinical features of a vasculitis, ECG changes and a troponin T level of 7562 ng/L. Renal biopsy confirmed Churg-Strauss vasculitis. Cardiac involvement in Churg-Strauss Syndrome (CSS) is one of the leading causes of mortality. We describe the successful diagnosis and management of a patient with CSS.
Paradoxical air embolism following central venous catheter removal
Authors: Khan Hiba , Zaidi Afzal
Published: September 2013

Central venous catheters are commonly used in the management of critically ill patients. This case report described a rare but potentially fatal complication of central venous catheter use. A 52-year-old man underwent mechanical aortic valve replacement for infective endocarditis. On day 8 postoperatively he accidentally removed his catheter and collapsed with symptoms and signs suggestive of a cerebral air embolism. A transthoracic echocardiogram showed air bubbles in both the right and left ventricles of the heart confirming the presence of a paradoxical air embolism.
Rare causes of persistent wheeze that mimic poorly controlled asthma
Authors: Mokoka Matshediso Constantia , Ullah Khalil , Curran David R , O'Connor Terence M
Published: September 2013

Upper airway obstruction can present with stridor or expiratory or inspiratory wheeze and is commonly misdiagnosed as asthma. As asthma is common, such cases can remain hidden among patients with lower airway obstruction who attend primary care or respiratory clinics. We describe four causes of upper airway obstruction (paradoxical vocal cord movement, subglottic stenosis, retrosternal goitre and double aortic arch) which were misdiagnosed as ‘poorly controlled asthma’.
Visual analogue scales in stroke: what can they tell us about health-related quality of life?
Authors: Hilari Katerina , Boreham Lois-Danielle
Published: September 2013

Objectives

 Contrasting accounts exist on whether people with stroke are able to self-report on outcomes using visual analogue scales (VASs). We explored correlations between multi-item scale-rated health-related quality of life (HRQL) and VAS-rated HRQL after stroke, and compared those with versus without aphasia.

Design

Cross-sectional survey.

Setting

Community dwelling stroke patients living in London.

Participants

People with first stroke were recruited during their hospital stay and were assessed 3 months later.

Measures

The Frenchay Aphasia Screening Test, the Stroke and Aphasia Quality of Life Scale (SAQOL-39g) and a single vertical VAS.

Results

73 people took part, 14 with aphasia. VAS scores were significantly correlated with the overall SAQOL-39g (r=0.69, p<0.01). SAQOL-39g subdomain scores were also correlated with VAS scores, with the psychosocial domain most highly correlated (r=0.67, p<0.01) and the communication least correlated (ρ=0.30, p<0.05). SAQOL-39g—VAS difference scores were higher for people with aphasia and the difference was significant (t (71)=2.02, p<0.05).

Conclusions

Despite the significant correlation of the overall SAQOL-39g and the VAS-rated HRQL, subdomain results suggested that people considered mostly psychosocial aspects when rating their HRQL on a single VAS. Agreement was poorer for people with aphasia, raising issues for the use of VASs with people with aphasia.
The association between patients’ beliefs about medicines and adherence to drug treatment after stroke: a cross-sectional questionnaire survey
Authors: Sjölander Maria , Eriksson Marie , Glader Eva-Lotta
Published: September 2013

Objectives

Adherence to preventive drug treatment is a clinical problem and we hypothesised that patients’ beliefs about medicines and stroke are associated with adherence. The objective was to examine associations between beliefs of patients with stroke about stroke and drug treatment and their adherence to drug treatment.

Design

Cross-sectional questionnaire survey.

Setting

Patients with stroke from 25 Swedish hospitals were included.

Measurements

Questionnaires were sent to 989 patients to assess their perceptions about stroke (Brief Illness Perception Questionnaire, Brief IPQ), beliefs about medicines (Beliefs about Medicines Questionnaires, BMQ) and adherence to treatment (Medication Adherence Report Scale, MARS) 3 months after stroke onset. Only patients living at home were included in the analysis. The primary outcome was self-reported adherence as measured on MARS. MARS scores were dichotomised into adherent/non-adherent. Background and clinical data from the Swedish Stroke register were included.

Results

811 patients were still living at home and 595 answered the questionnaire. Complete MARS data were available for 578 patients and 72 (12.5%) of these were classified as non-adherent. Non-adherent patients scored lower on positive beliefs as measured on BMQ-necessity (OR = 0.90, 95% CI 0.83 to 0.98) and BMQ-benefit (OR=0.77, 95% CI 0.68 to 0.87), and higher on negative beliefs as measured on BMQ-concern (OR=1.12, 95% CI 1.05 to 1.21), BMQ-overuse (OR=1.29, 95% CI 1.14 to 1.45), and BMQ-harm (OR=1.12, 95% CI 1.01 to 1.24). The Brief IPQ showed that non-adherent patients believed their current treatment to be less useful (p=0.001).

Conclusions

This study showed associations between beliefs of Swedish patients with stroke about medicines and adherence. Positive beliefs were less common and negative more common among non-adherent. To improve adherence, patients’ beliefs about medicines should be considered.
SUDDEN CHANGE OF QUANTUM DISCORD UNDER SINGLE QUBIT NOISE
Authors: JIA LI-XING , LI BO , YUE R.-H. , FAN HENG
Published: September 2013

We show that the sudden change of quantum correlation can occur even when only one part of the composite entangled state is exposed to a noisy environment. Our results are illustrated through the action of different noisy environments individually on a single qubit of quantum system. Composite noise on the whole of the quantum system is thus not the necessarily condition for the occurrence of sudden transition for quantum correlation.
REDUCED SHAKEDOWN FORMULATION IN PLANE STRESS PROBLEMS
Authors: PHAM DUC CHINH
Published: September 2013

Shakedown theory determines the load limits for structures under variable loads. Our recently-constructed reduced shakedown kinematic formulations are re-examined, with particular expressions constructed for plane stress problems in both cases of Mises and Tresca materials. While the possibilities for numerical implementations of the reduced forms are to be explored, we illustrate the applications of the forms to estimate the nonshakedown loads for a circular hollow disk under variable pressure and temperature fields.
NEUTRALIZATION OF STEEL FIBER REINFORCED CONCRETE UNDER MULTIPLE INFLUENTIAL FACTORS
Authors: NIU DITAO , WANG YAN
Published: September 2013

In this paper, the durability of steel fiber reinforced concrete/SFRC is tested under the combined effects of carbonization and acid rain erosion. Mass loss rate, splitting tensile strength loss rate, eroded thickness and neutralization depth were taken as evaluation index. Test results indicated that the concrete mass loss rate, splitting tensile strength loss rate, and eroded thickness of SFRC under the multi-combined effects of acid rain and carbonization are greater than that of SFRC affected by the acid rain; the neutralization depth of SFRC are larger under the multi-factor effects of acid rain and carbonization compared to the superposition of them. According to the analysis of combined effects, the carbonization and acid rain has almost equal contribution to the neutralization of concrete. Proper mixture of steel fiber can effectively inhibit the erosion of original concrete under the effect of acid rain and reduce the neutralization depth. According to the varied mixing proportions in the test, the SFRC with the steel fiber mixing proportions of 1.5% has the best durability.
EXTENDING THE APPLICABILITY OF NEWTON'S METHOD ON RIEMANNIAN MANIFOLDS WITH VALUES IN A CONE
Authors: Argyros Ioannis K. , George Santhosh
Published: September 2013

We present a new semilocal convergence analysis of Newton's method on Riemannian manifolds with values in a cone in order to solve the inclusion problem. Using more precise majorizing sequences than in earlier studies such as [J. H. Wang, S. Huang and C. Li, Extended Newton's method for mappings on Riemannian manifolds with values in a cone, Taiwanese J. Math.13(2B) (2009) 633–656] and the concept of L-average Lipschitz condition we provide: weaker sufficient convergence conditions; tighter error analysis on the distances involved and an at least as precise information on the solutions. These advantages are obtained using the same parameters and functions. Applications include the celebrated Newton–Kantorovich theorem.
Dielectric behavior of alumina thin film under high DC electric field prepared by sol–gel method
Authors: Yao Manwen , Shan Wei
Published: September 2013

Dielectric behavior of aluminum oxide (Al2O3) thin film under high DC electric field is presented and discussed. Aluminum oxide thin films were prepared starting from aluminum isopropoxide as a precursor via a wet chemistry route. Silicon substrates and silica glass substrates were used to deposit the films via spin-coating technique. The deposited films were then annealed under 450°C–700°C for 2–3 h. Dense, crack-free and uniform films were obtained. The thickness of the films is in the range of 200–800 nm. The films obtained are in amorphous state as revealed by the X-ray diffraction patterns. Voltage–Current (V–I) characteristics of the films were used to study the dielectric behavior of the films. Very low leakage current density J under high DC electric field E can be obtained. The breakdown electric field of the films is around 1.2 MV/cm. The V–I characteristics of the films are slightly nonlinear. With platinum as bottom electrode and gold as top electrode, successive breakdown phenomena of the films under high DC electric field were observed. Each breakdown event of the film corresponds to a sharp spike at the V–I plot of the sample. The shape of the breakdown spots of the films are in crater-like with a breakdown channel of diameter around a few micrometers as revealed by SEM images. The top gold electrode at the breakdown spots either splashed out or ripped off from the breakdown spots, which isolated the breakdown spots from rest of the electrode, and made the successive breakdown of the sample possible. The breakdown spots of the sample are concentrated at the edge of the electrode with proportional spacing, which can be easily understood as the edge effect of the parallel capacitor configuration, while the uniform distribution of the breakdown spots signifies that the uniformity of the films thus prepared are satisfied. Breakdown spots apart from the electrode edge can also be observed. Most of such spots associated with ripped-off gold film electrode in large area. We suppose such breakdown took place at higher electric field after the successive breakdown at the electrode edge and the isolation of the edge part from rest of the sample. Higher energy is needed to tear off larger section of the electrode. The breakdown characteristics of the films reported in this work are useful for the further study to enhance the breakdown strength of the film.
Helping scientists, engineers to work up to 100 times faster
Authors: Guo Philip
Published: September 2013

The
Communications
Web site, http://cacm.acm.org, features more than a dozen bloggers in the BLOG@CACM community. In each issue of
Communications
, we'll publish selected posts or excerpts.

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Philip Guo explains how programming skills can make scientists and engineers more efficient and creative.
Tuning in to graphene
Authors: Wright Alex
Published: September 2013

New ultra-fast wireless antennas may be on the way, but don't throw away your old wireless router just yet.
Making the internet safe for gadgets
Authors: Geller Tom
Published: September 2013

Initiatives favor direct connections, named resources, and cryptography.
The Alan Turing Year leaves a rich legacy
Authors: Underwood Sarah
Published: September 2013

A year-long celebration of the life and work of a man whom many call the founding father of computer science.
Personal, Pseudonymous, and Anonymous Data: The problem of identification
Authors: Bourne Iain
Published: September 2013

Why defining what counts as personal data is important for data protection and information sharing.
Understanding the Data Environment
Authors: Mackey Elaine , Elliot Mark
Published: September 2013

Protecting data privacy and anonymity requires a better understanding of the conditions and mechanisms under which they may be threatened.
An Illustrated Primer in Differential Privacy
Authors: Task Christine
Published: September 2013

The vast amounts of data that are now available provide new opportunities to social science researchers, but also raise huge privacy concerns for data subjects. Differential privacy offers a way to balance the needs of both parties. But how?
Cynthia Dwork on Differential Privacy
Authors: Zuba Michael
Published: September 2013

Distinguished Scientist at Microsoft Research, Dr. Cynthia Dwork, provides a first-hand look at the basics of differential privacy.
WLAN Security
Authors: Kuusisto Finn
Published: September 2013

A look back at wireless technology through the years.
Talking 'Bout Your Reputation
Authors: Birch David
Published: September 2013

People think they want anonymity, but actually desire privacy. But how do we reframe the debate surrounding privacy and security? Perhaps technology is the answer.
The New Firefox Cookie Policy
Authors: Mayer Jonathan
Published: September 2013

Stanford grad student Jonathan Mayer discusses cookies, Web tracking, and changes to Mozilla's cookie policy.
Type-1 pericytes participate in fibrous tissue deposition in aged skeletal muscle
Authors: Birbrair Alexander , Zhang Tan , Wang Zhong-Min , Messi Maria Laura , Mintz Akiva , Delbono Osvaldo
Published: September 2013

In older adults, changes in skeletal muscle composition are associated with increased fibrosis, loss of mass, and decreased force, which can lead to dependency, morbidity, and mortality. Understanding the biological mechanisms responsible is essential to sustaining and improving their quality of life. Compared with young mice, aged mice take longer to recover from muscle injury; their tissue fibrosis is more extensive, and regenerated myofibers are smaller. Strong evidence indicates that cells called pericytes, embedded in the basement membrane of capillaries, contribute to the satellite-cell pool and muscle growth. In addition to their role in skeletal muscle repair, after tissue damage, they detach from capillaries and migrate to the interstitial space to participate in fibrosis formation. Here we distinguish two bona fide pericyte subtypes in the skeletal muscle interstitium, type-1 (Nestin-GFP−/NG2-DsRed+) and type-2 (Nestin-GFP+/NG2-DsRed+), and characterize their heretofore unknown specific roles in the aging environment. Our in vitro results show that type-1 and type-2 pericytes are either fibrogenic or myogenic, respectively. Transplantation studies in young animals indicate that type-2 pericytes are myogenic, while type-1 pericytes remain in the interstitial space. In older mice, however, the muscular regenerative capacity of type-2 pericytes is limited, and type-1 pericytes produce collagen, contributing to fibrous tissue deposition. We conclude that in injured muscles from aging mice, the pericytes involved in skeletal muscle repair differ from those associated with scar formation.
Time-dependent modulation of GABAA-ergic synaptic transmission by allopregnanolone in locus coeruleus neurons of Mecp2-null mice
Authors: Jin Xin , Zhong Weiwei , Jiang Chun
Published: September 2013

Rett syndrome (RTT) is a neurodevelopmental disorder with symptoms starting 6–18 mo after birth, while what underlies the delayed onset is unclear. Allopregnanolone (Allop) is a metabolite of progesterone and a potent modulator of GABAA-ergic currents whose defects are seen in RTT. Allop changes its concentration during the perinatal period, which may affect central neurons via the GABAA-ergic synaptic transmission, contributing to the onset of the disease. To determine whether Mecp2 disruption affects Allop modulation, we performed studies in brain slices obtained from wild-type (WT) and Mecp2 −/Y mice. Allop dose dependently suppressed locus coeruleus (LC) neuronal excitability in WT mice, while Mecp2-null neurons showed significant defects. Using optogenetic approaches, channelrhodopsin was specifically expressed in GABA-ergic neurons in which optical stimulation evoked action potentials. In LC neurons of WT mice, Allop exposure increased the amplitude of GABAA-ergic inhibitory postsynaptic currents (IPSCs) evoked by optical stimulation and prolonged the IPSC decay time. Consistently, Allop augmented both frequency and amplitude of GABAA-ergic spontaneous IPSCs (sIPSCs) and extended the decay time of sIPSCs. The Allop-induced potentiation of sIPSCs was deficient in Mecp2 −/Y mice. Surprisingly, the impairment occurred at 3 wk postnatal age, while no significant difference in Allop modulation was observed in 1–2 wk between WT and Mecp2 −/Y mice. These results indicate that the modulation of GABAA-ergic synaptic transmission by Allop is impaired in LC neurons of Mecp2-null mice at a time when RTT-like symptoms manifest, suggesting a potential mechanism for the delayed onset of the disease.
Cell surface F1/Fo ATP synthase contributes to interstitial flow-mediated development of the acidic microenvironment in tumor tissues
Authors: Kawai Yoshiko , Kaidoh Maki , Yokoyama Yumiko , Ohhashi Toshio
Published: September 2013

To address pivotal roles of cell surface F1/FO ATP synthase in the development of acidic microenvironment in tumor tissues, we investigated effects of shear stress stimulation on the cultured human breast cancer cells, MDA-MB-231 and MDA-MB-157, or human melanoma cells, SK-Mel-1. Shear stress stimulation (0.5–5.0 dyn/cm2), the levels of which are similar to those produced by the interstitial flow, induced strength-dependent corelease of ATP and H+ from the cells, which triggered CO2 gas excretion. In contrast, the same level of shear stress stimulation did not induce significant ATP release and CO2 gas excretion from the control human mammary epithelial cells (HMEC). Marked immunocytochemical and mRNA expression of cell surface F1/FO ATP synthase, vacuolar-ATPase (V-ATPase), carbonic anhydrase type IX, and ectonucleoside triphosphate diphosphohydrolase (ENTPDase) 3 were detected in MDA-MB-231 cells, but little or no expression on the HMEC. Pretreatment with cell surface F1/FO ATP synthase inhibitors, but not cell surface V-ATPase inhibitors, caused a significant reduction of the shear stress stimulation-mediated ATP release and CO2 gas excretion from MDA-MB-231 cells. The ENTPDase activity in the shear stress-loaded MDA-MB-231 cell culture medium supernatant increased significantly in a time-dependent manner. In addition, MDA-MB-231 cells displayed strong staining for purinergic 2Y1 (P2Y1) receptors on their surfaces, and the receptors partially colocalized with ENTPDase 3. These findings suggest that cell surface F1/FO ATP synthase, but not V-ATPase, may play key roles in the development of interstitial flow-mediated acidic microenvironment in tumor tissues through the shear stress stimulation-induced ATP and H+ corelease and CO2 gas production.
Evolution and Cell Physiology. 3. Using Dictyostelium discoideum to investigate mechanisms of epithelial polarity
Authors: Weis William I. , Nelson W. James , Dickinson Daniel J.
Published: September 2013

In Metazoa, a polarized epithelium forms a single-cell-layered barrier that separates the outside from the inside of the organism. In tubular epithelia, the apical side of the cell is constricted relative to the basal side, forming a wedge-shaped cell that can pack into a tube. Apical constriction is mediated by actomyosin activity. In higher animals, apical actomyosin is connected between cells by specialized cell-cell junctions that contain a classical cadherin, the Wnt signaling protein β-catenin, and the actin-binding protein α-catenin. The molecular mechanisms that lead to selective accumulation of myosin at the apical surface of cells are poorly understood. We found that the nonmetazoan Dictyostelium discoideum forms a polarized epithelium that surrounds the stalk tube at the tip of the multicellular fruiting body. Although D. discoideum lacks a cadherin homolog, it expresses homologs of β- and α-catenin. Both catenins are essential for formation of the tip epithelium, polarized protein secretion, and proper multicellular morphogenesis. Myosin localizes apically in tip epithelial cells, and it appears that constriction of this epithelial tube is required for proper morphogenesis. Localization of myosin II is controlled by the protein IQGAP1 and its binding partners cortexillins I and II, which function downstream of α- and β-catenin to exclude myosin from the basolateral cortex and promote apical accumulation of myosin. These studies show that the function of catenins in cell polarity predates the evolution of Wnt signaling and classical cadherins, and that apical localization of myosin is a morphogenetic mechanism conserved from nonmetazoans to vertebrates.
Chronic vasodilation increases renal medullary PDE5A and α-ENaC through independent renin-angiotensin-aldosterone system pathways
Authors: West Crystal A. , Shaw Stefan , Sasser Jennifer M. , Fekete Andrea , Alexander Tyler , Cunningham Mark W. , Masilamani Shyama M. E. , Baylis Chris
Published: September 2013

We have previously observed that many of the renal and hemodynamic adaptations seen in normal pregnancy can be induced in virgin female rats by chronic systemic vasodilation. Fourteen-day vasodilation with sodium nitrite or nifedipine (NIF) produced plasma volume expansion (PVE), hemodilution, and increased renal medullary phosphodiesterase 5A (PDE5A) protein. The present study examined the role of the renin-angiotensin-aldosterone system (RAAS) in this mechanism. Virgin females were treated for 14 days with NIF (10 mg·kg−1·day−1via diet), NIF with spironolactone [SPR; mineralocorticoid receptor (MR) blocker, 200–300 mg·kg−1·day−1via diet], NIF with losartan [LOS; angiotensin type 1 (AT1) receptor blocker, 20 mg·kg−1·day−1via diet], enalapril (ENAL; angiotensin-converting enzyme inhibitor, 62.5 mg/l via water), or vehicle (CON). Mean arterial pressure (MAP) was reduced 7.4 ± 0.5% with NIF, 6.33 ± 0.5% with NIF + SPR, 13.3 ± 0.9% with NIF + LOS, and 12.0 ± 0.4% with ENAL vs. baseline MAP. Compared with CON (3.6 ± 0.3%), plasma volume factored for body weight was increased by NIF (5.2 ± 0.4%) treatment but not by NIF + SPR (4.3 ± 0.3%), NIF + LOS (3.6 ± 0.1%), or ENAL (4.0 ± 0.3%). NIF increased PDE5A protein abundance in the renal inner medulla, and SPR did not prevent this increase (188 ± 16 and 204 ± 22% of CON, respectively). NIF increased the α-subunit of the epithelial sodium channel (α-ENaC) protein in renal outer (365 ± 44%) and inner (526 ± 83%) medulla, and SPR prevented these changes. There was no change in either PDE5A or α-ENaC abundance vs. CON in rats treated with NIF + LOS or ENAL. These data indicate that the PVE and renal medullary adaptations in response to chronic vasodilation result from RAAS signaling, with increases in PDE5A mediated through AT1receptor and α-ENaC through the MR.
Protection of signal processing at low temperature in baroreceptive neurons in the nucleus tractus solitarius of Syrian hamsters, a hibernating species
Authors: Sekizawa Shin-Ichi , Horwitz Barbara A. , Horowitz John M. , Chen Chao-Yin
Published: September 2013

We previously described synaptic currents between baroreceptor fibers and second-order neurons in the nucleus tractus solitarius (NTS) that were larger in Syrian hamsters than in rats. This suggested that although electrical activity throughout the hamster brain decreased as brain temperature declined, the greater synaptic input to its NTS would support continued operation of cardiorespiratory reflexes at low body temperatures. Here, we focused on properties that would protect these neurons against potential damage from the larger synaptic inputs, testing the hypotheses that hamster NTS neurons exhibit: 1) intrinsic N-methyl-d-aspartate receptor (NMDAR) properties that limit Ca2+influx to a greater degree than do rat NTS neurons and 2) properties that reduce gating signals to NMDARs to a greater degree than in rat NTS neurons. Whole cell patch-clamp recordings on anatomically identified second-order NTS baroreceptive neurons showed that NMDAR-mediated synaptic currents between sensory fibers and second-order NTS neurons were larger in hamsters than in rats at 33°C and 15°C, with no difference in their permeability to Ca2+. However, at 15°C, but not at 33°C, non-NMDAR currents evoked by glutamate released from baroreceptor fibers had significantly shorter durations in hamsters than in rats. Thus, hamster NMDARs did not exhibit lower Ca2+influx than did rats (negating hypothesis 1), but they did exhibit significant differences in non-NMDAR neuronal properties at low temperature (consistent with hypothesis 2). The latter (shorter duration of non-NMDAR currents) would likely limit NMDAR coincidence gating and may help protect hamster NTS neurons, enabling them to contribute to signal processing at low body temperatures.
Muscle metabolic responses during high-intensity intermittent exercise measured by31P-MRS: relationship to the critical power concept
Authors: Chidnok Weerapong , DiMenna Fred J. , Fulford Jonathan , Bailey Stephen J. , Skiba Philip F. , Vanhatalo Anni , Jones Andrew M.
Published: September 2013

We investigated the responses of intramuscular phosphate-linked metabolites and pH (as assessed by31P-MRS) during intermittent high-intensity exercise protocols performed with different recovery-interval durations. Following estimation of the parameters of the power-duration relationship, i.e., the critical power ( CP) and curvature constant ( W′), for severe-intensity constant-power exercise, nine male subjects completed three intermittent exercise protocols to exhaustion where periods of high-intensity constant-power exercise (60 s) were separated by different durations of passive recovery (18 s, 30 s and 48 s). The tolerable duration of exercise was 304 ± 68 s, 516 ± 142 s, and 847 ± 240 s for the 18-s, 30-s, and 48-s recovery protocols, respectively ( P < 0.05). The work done > CP ( W> CP) was significantly greater for all intermittent protocols compared with the subjects' W′, and this difference became progressively greater as recovery-interval duration was increased. The restoration of intramuscular phosphocreatine concentration during recovery was greatest, intermediate, and least for 48 s, 30 s, and 18 s of recovery, respectively ( P < 0.05). The W> CPin excess of W′ increased with greater durations of recovery, and this was correlated with the mean magnitude of muscle phosphocreatine reconstitution between work intervals ( r = 0.61; P < 0.01). The results of this study show that during intermittent high-intensity exercise, recovery intervals allow intramuscular homeostasis to be restored, with the degree of restoration being related to the duration of the recovery interval. Consequently, and consistent with the intermittent CP model, the ability to perform W> CPduring intermittent high-intensity exercise and, therefore, exercise tolerance, increases when recovery-interval duration is extended.
Evidence of cell damages caused by circulating bubbles: high level of free mitochondrial DNA in plasma of rats
Authors: Vallée Nicolas , Gaillard Sandrine , Peinnequin André , Risso Jean-Jacques , Blatteau Jean-Eric
Published: September 2013

Bubble formation can occur in the vascular system after diving, leading to decompression sickness (DCS). DCS signs and symptoms range from minor to death. Too often, patients are admitted to a hyperbaric center with atypical symptoms, as bubbles cannot be detected anymore. In the absence of a relevant biomarker for humans, the therapeutic management remains difficult. As circulating DNA was found in the blood of healthy humans and animals, our study was made to correlate the extracellular mitochondrial DNA (mDNA) concentration with the occurrence of clinical DCS symptoms resulting from initial bubble-induced damages. Therefore, 109 rats were subjected to decompression from a simulated 90-m sea water dive, after which, 78 rats survived (71.6%). Among the survivors, 15.6% exhibited typical DCS symptoms (DCS group), whereas the remaining 56% showed no detectable symptoms (noDCS group). Here, we report that the symptomatic rats displayed both a circulating mDNA level (DNADCS → 2.99 ± 2.62) and a bubble grade (median Spencer score = 3) higher than rats from the noDCS group (DNAnoDCS → 1.49 ± 1.27; Spencer score = 1). These higher levels could be correlated with the platelet and leukocyte consumption induced by the pathogenic decompression. Rats with no detectable bubble had lower circulating mDNA than those with higher bubble scores. We determined that in rats, a level of circulating mDNA >1.91 was highly predictive of DCS with a positive-predictive value of 87.3% and an odds ratio of 4.57. Thus circulating mDNA could become a relevant biomarker to diagnose DCS and should be investigated further to confirm its potential application in humans.
Activation properties of trigeminal motoneurons in participants with and without bruxism
Authors: D'Amico Jessica M. , Yavuz Ş. Utku , Saraçoğlu Ahmet , Atiş Elif Sibel , Gorassini Monica A. , Türker Kemal S.
Published: September 2013

In animals, sodium- and calcium-mediated persistent inward currents (PICs), which produce long-lasting periods of depolarization under conditions of low synaptic drive, can be activated in trigeminal motoneurons following the application of the monoamine serotonin. Here we examined if PICs are activated in human trigeminal motoneurons during voluntary contractions and under physiological levels of monoaminergic drive (e.g., serotonin and norepinephrine) using a paired motor unit analysis technique. We also examined if PICs activated during voluntary contractions are larger in participants who demonstrate involuntary chewing during sleep (bruxism), which is accompanied by periods of high monoaminergic drive. In control participants, during a slowly increasing and then decreasing isometric contraction, the firing rate of an earlier-recruited masseter motor unit, which served as a measure of synaptic input to a later-recruited test unit, was consistently lower during derecruitment of the test unit compared with at recruitment (ΔF = 4.6 ± 1.5 imp/s). The ΔF, therefore, is a measure of the reduction in synaptic input needed to counteract the depolarization from the PIC to provide an indirect estimate of PIC amplitude. The range of ΔF values measured in the bruxer participants during similar voluntary contractions was the same as in controls, suggesting that abnormally high levels of monoaminergic drive are not continually present in the absence of involuntary motor activity. We also observed a consistent “onion skin effect” during the moderately sized contractions (<20% of maximal), whereby the firing rate of higher threshold motor units discharged at slower rates (by 4–7 imp/s) compared with motor units with relatively lower thresholds. The presence of lower firing rates in the more fatigue-prone, higher threshold trigeminal motoneurons, in addition to the activation of PICs, likely facilitates the activation of the masseter muscle during motor activities such as eating, nonnutritive chewing, clenching, and yawning.
The In Vitro Antibiotic Susceptibility of Malaysian Isolates ofBurkholderia pseudomallei
Authors: Ahmad Norazah , Hashim Rohaidah , Mohd Noor Azura
Published: September 2013

Acute melioidosis may present as localised or septicaemic infections and can be fatal if left untreated.Burkholderia pseudomalleiresistant to antibiotics used for the treatment of melioidosis had been reported. The aim of this study was to determine the in vitro antibiotic susceptibility patterns ofBurkholderia pseudomalleiisolated in Malaysia to a panel of antibiotics used for the treatment of melioidosis and also to potential alternative antibiotics such as tigecycline, ampicillin/sulbactam, and piperacillin/tazobactam. A total of 170Burkholderia pseudomalleiisolates were subjected to minimum inhibitory concentration determination usingE-test method to eleven antibiotics. All isolates were sensitive to meropenem and piperacillin/tazobactam. For ceftazidime, imipenem, amoxicillin/clavulanic acid, and doxycycline resistance was observed in 1 isolate (0.6%) for each of the antibiotics. Trimethoprim/sulfamethoxazole resistance was observed in 17 (10%) isolates. For other antibiotics, ampicillin/sulbactam, chloramphenicol, tigecycline, and ciprofloxacin resistance were observed in 1 (0.6%), 6 (3.5%), 60 (35.3%) and 98 (57.7%) isolates respectively. One isolate B170/06 exhibited resistance to 4 antibiotics, namely, ciprofloxacin, chloramphenicol, trimethoprim/sulfamethoxazole, and tigecycline. In conclusion, the Malaysian isolates were highly susceptible to the current antibiotics used in the treatment of melioidosis in Malaysia. Multiple resistances to the antibiotics used in the maintenance therapy are the cause for a concern.
Preparation, Characterization, and Cytotoxicity of Various Chitosan Nanoparticles
Authors: Yao Qian , Liu Wei , Gou Xiao-Jun , Guo Xiao-Qiang , Yan Jun , Song Qin , Chen Feng-Zheng , Zhao Qi , Chen Chao , Chen Tian
Published: September 2013

Chitosan nanoparticles (CS‐NPs) without drug loading have diverse biological activity. In this study, we prepared CS‐NPs, CS‐NPs solidified by different amount of glutaraldehyde, and CS‐NPs modified with either biotin (B‐CS‐NPs) or biotin and avidin (A‐B‐CS‐NPs) and examined their cytotoxicity on HepG2 cells. The morphology and size were measured by transmission electron microscopy and photon correction spectroscopy, respectively. The extent of solidification was validated by the approach of sonication. Biotin connect density on the surface of B‐CS‐NPs and A‐B‐CS‐NPs was determined by biotin assay kit. The results showed that most of the NPs were round and their mean sizes were all below 300 nm. Biotin connect density of B‐CS‐NPs and A‐B‐CS‐NPs was 2.18 ± 0.36 and 1.26 ± 0.11 mol biotin/mol CS, respectively. At relatively low concentration, CS‐NPs with higher extent of solidification exhibited more vigorous inhibitory effect against HepG2 cells than those without solidification. When NPs were incubated with cancer cells for 48 h, compared with CS‐NPs, the anticancer activity of B‐CS‐NPs and A‐B‐CS‐NPs was enhanced significantly (P < 0.05). In addition, A‐B‐CS‐NPs showed superior cytotoxicity over B‐CS‐NPs. This study demonstrates that modification with biotin and avidin may be an efficient way in improving antitumor activity of CS‐NPs against hepatic carcinoma.
An Inverse Method to Reconstruct Complete Stiffness Information of Rubber Bushing
Authors: Lei Gang , Chen Qian , Liu Ying , Jiang Jingjing
Published: September 2013

A specific rubber bushing, with only radial and axial stiffness data having been acquired, is studied. In terms of the hyperelastic material of this bushing, three-term Ogden law is utilized as the material constitutive model which requires to be characterized. Without the material mechanical tests provided, a parameter identification method is proposed for searching a group of acceptable parameters which are able to model rubber-like material of this rubber bushing. In this case, based on the nonlinear finite element analysis method and optimization technique, the parameters of material law are determined, and the rotational stiffness of this bushing is also evaluated. The complete stiffness information has been established.
Antioxidant Delivery Pathways in the Anterior Eye
Authors: Umapathy Ankita , Donaldson Paul , Lim Julie
Published: September 2013

Tissues in the anterior segment of the eye are particular vulnerable to oxidative stress. To minimise oxidative stress, ocular tissues utilise a range of antioxidant defence systems which include nonenzymatic and enzymatic antioxidants in combination with repair and chaperone systems. However, as we age our antioxidant defence systems are overwhelmed resulting in increased oxidative stress and damage to tissues of the eye and the onset of various ocular pathologies such as corneal opacities, lens cataracts, and glaucoma. While it is well established that nonenzymatic antioxidants such as ascorbic acid and glutathione are important in protecting ocular tissues from oxidative stress, less is known about the delivery mechanisms used to accumulate these endogenous antioxidants in the different tissues of the eye. This review aims to summarise what is currently known about the antioxidant transport pathways in the anterior eye and how a deeper understanding of these transport systems with respect to ocular physiology could be used to increase antioxidant levels and delay the onset of eye diseases.
Nearly Complete Response of Brain Metastases from HER2 Overexpressing Breast Cancer with Lapatinib and Capecitabine after Whole Brain Irradiation
Authors: Oktay Esin , Yersal Özlem , Meydan Nezih , Sağıroğlu Mehmet , Uyanık Ömer , Barutca Sabri
Published: September 2013

Trastuzumab treatment does not prevent intracranial seeding and is largely ineffective for established central nervous system metastasis in HER2 overexpressing breast cancer patients. Combination therapy of lapatinib and capecitabine may be an effective treatment option for brain metastasis of HER2-positive breast cancer. We report a patient with breast cancer overexpressing HER-2 where brain metastases were successfully treated with radiation and a combination of lapatinib and capecitabine.
Comparison of a Clinic-Based ELISA Test Kit with the Immunofluorescence Antibody Test for AssayingLeishmania infantumAntibodies in Dogs
Authors: Proverbio Daniela , Spada Eva , Baggiani Luciana , Bagnagatti De Giorgi Giada , Perego Roberta
Published: September 2013

This study compares a rapid Immunospecific Kalazar Canine Rapid Spot IF with the gold standard test (indirect fluorescent antibody test (IFAT)) for detection ofLeishmania infantumspecific IgG serum antibodies in naturally exposed dogs. Serum samples were obtained from 89 healthy dogs and dogs affected by canine leishmaniosis (CanL). IgG-IFAT titers ≥80 were considered positive. Anti-L. infantumIgG antibodies were found in 54 samples with titers ranging from 1 : 80 to 1 : 5120. The performance of the rapid Immunospecific Kalazar was evaluated using a ROC curve. The area under the ROC curve of 0.957 was significantly different from 0.5 (), and therefore it can be concluded that the rapid Immunospecific Kalazar has the ability to distinguish canine sera with and withoutL. infantumIgG. The best performance of the test was at a cutoff >0 (sensitivity 92.6%, specificity 97%). The test can be used for disease screening if the cutoff is >0 (highest sensitivity, 92.6%) and is recommended as confirmatory test for the presence ofL. infantumIgG antibodies if the cutoff is set >2 (highest specificity, 100%).
Spontaneous Neck Hematoma in a Patient with Fibromuscular Dysplasia: A Case Report and a Review of the Literature
Authors: Cohen Oded , Yehuda Moshe , Adi Meital , Lahav Yonatan , Halperin Doron
Published: September 2013

Background. Fibromuscular dysplasia (FMD) is a vascular disease that may present as aneurysms in the cervical arteries. Spontaneous neck hematoma is a rare life threatening medical condition. This is the first report of neck hematoma in a patient with FMD.Methods and Results. We present a case of a 69-year-old woman, with diagnosed cervical FMD and a 3-day history of sore throat and neck pain, who presented with enlarging neck hematoma. No active bleeding was noticed on CT angiography, airway was not compromised, and patient was managed conservatively. Next day, invasive angiography was performed, and no bleeding vessel was demonstrated. Patient has improved and was discharged after 5 days of hospitalization. We have discussed the different etiology of this condition, focusing on systemic vascular diseases.Conclusion. Complaint of neck pain in a patient with a FMD should raise suspicion for possible neck hematoma. Conversely, spontaneous neck hematoma without clear etiology should raise suspicion for a systemic vascular disease.
MHD Slip Flow of Newtonian Fluid past a Stretching Sheet with Thermal Convective Boundary Condition, Radiation, and Chemical Reaction
Authors: Abdel-Rahman Reda G.
Published: September 2013

An analysis is carried out to study the problem of heat and mass transfer flow over a moving permeable flat stretching sheet in the presence of convective boundary condition, slip, radiation, heat generation/absorption, and first-order chemical reaction. The viscosity of fluid is assumed to vary linearly with temperature. Also the diffusivity is assumed to vary linearly with concentration. The governing partial differential equations have been reduced to the coupled nonlinear ordinary differential equations by using Lie group point of transformations. The system of transformed nonlinear ordinary differential equations is solved numerically using shooting techniques with fourth-order Runge-Kutta integration scheme. Comparison between the existing literature and the present study was carried out and found to be in excellent agreement. The effects of the various interesting parameters on the flow, heat, and mass transfer are analyzed and discussed through graphs in detail. The values of the local Nusselt number, the local skin friction, and the local Sherwood number for different physical parameters are also tabulated.
Primary Acinic Cell Carcinoma of the Breast: A Clinicopathological and Immunohistochemical Study
Authors: Shingu Kiyoshi , Ito Tokiko , Kaneko Gengo , Itoh Nobuo
Published: September 2013

Acinic cell carcinoma of the breast is an extremely rare, malignant neoplasm characterized by widespread acinar cell-like differentiation and clinically low-grade malignancy. Herein, we report a case of acinic cell carcinoma of the breast in a 41-year-old woman. The tumor was poorly demarcated but had a firm consistency. It was removed with lumpectomy, and sentinel lymph node biopsy was performed to check for metastasis. Microscopically, the tumor showed an infiltrative growth pattern with a combination of solid, trabecular, and microglandular areas. Many of the tumor cells had abundant clear vacuolated cytoplasm containing zymogen-typed granules which resemble acinar cells of the salivary glands. The immunohistochemical profile of the tumor was also similar to that of salivary gland acinic cell carcinoma: the tumor cells were positive for amylase, lysozyme,α-1-antichymotrypsin, S-100 protein, and epithelial membrane antigen and negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. She received postoperative chemoradiation therapy and has been well for 3 years since surgery. As studies on large series are lacking, further studies are needed to elucidate the biological characteristics of acinic cell carcinoma of the breast.
Elastic Stability of Annular Thin Plates with One Free Edge
Authors: Jillella Nagarjuna , Peddieson John
Published: September 2013

The elastic stability of annular thin plates having one free edge and subjected to axisymmetric radial edge loads at the other edge is investigated. The supported edge is allowed to be either simply supported or clamped against axial (transverse) deflection. Both compression buckling and tension buckling (wrinkling) are investigated. To insure accuracy, two methods of solving the appropriate eigenvalue problems are used and found to yield essentially identical results. A selection of these results for both compression and tension buckling is presented graphically and used to illustrate interesting aspects of the solutions.