bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Short‐term Isometric Muscle Contraction and the Valsalva Maneuver on Systemic and Pulmonary Hemodynamics in Patients with Severe Heart Failure
Authors: Soucek Miroslav , Frana Petr , Kara Tomas , Sitar Jan , Halamek Josef , Jurak Pavel , Rihacek Ivan , Spinarova Lenka , Oral Ivo
Published: April 2009

Background

Chronic heart failure is characterized by high mortality, frequent hospitalization, and reduced quality of life. Patients with severe heart failure are often in very poor physical condition, they are unable to take part in the usual exercise programs, and therefore need an individual approach.

Hypothesis

To assess the systemic and pulmonary hemodynamic responses to maximum voluntary contraction of the lower extremity muscles (MVC‐LEM) with persistent physiologic breathing, the Valsalva maneuver, and the combination of Valsalva with MVC‐LEM.

Methods

Seventeen patients with severe heart failure (ejection fraction 20%) were exposed to 3 types of load for a period of 10 seconds: 1) MVC‐LEM with persistent physiologic breathing, 2) the Valsalva maneuver, and 3) a combination of MVC‐LEM with the Valsalva maneuver. During each measurement, a continuous, time‐synchronized record was taken of the electrocardiogram, and the pulmonary and systemic blood pressures.

Results

There were slight changes in the heart rate and systemic blood pressure when comparing resting versus MVC‐LEM values. There were much greater and significant changes (P < .01) in the systemic and pulmonary blood pressures when comparing resting versus the Valsalva maneuver or the combination of the MVC‐LEM plus the Valsalva maneuver values.

Conclusions

A short maximum voluntary contraction of the muscles of the lower extremities with persistent physiologic breathing did not have an abnormal effect on the systemic and pulmonary hemodynamics in patients with severe chronic heart failure. The Valsalva maneuver caused significantly higher hemodynamic changes in the systemic and pulmonary system with possible negative effects. Copyright © 2009 Wiley Periodicals, Inc.
Clinical Practice Guides
Authors: Richard Conti C.
Published: April 2009

In this editorial, I would like to share some thoughts about clinical studies, including value and limitations using as an example a recently published randomized clinical trial. Randomized and non‐randomized clinical trials, epidemiologic studies, and registries guide our clinical practice. They are good but not perfect. Why is this the case? One of the answers is that they provide mean values for outcomes, and mean values do not explain the clinical outcomes of the outliers. A good illustrative example is survival after myocardial infarction. The data that are provided are usually average data, but these data may not reflect the same outcome in patients with little myocardial ischemia and good ventricular function compared to those with poor ventricular function and a large amount of myocardium in jeopardy due to myocardial ischemia. Copyright © 2009 Wiley Periodicals, Inc.
Carbohydrate antigen 19‐9 change during chemotherapy for advanced pancreatic adenocarcinoma
Authors: Reni Michele , Cereda Stefano , Balzano Gianpaolo , Passoni Paolo , Rognone Alessia , Fugazza Clara , Mazza Elena , Zerbi Alessandro , Di Carlo Valerio , Villa Eugenio
Published: April 2009

BACKGROUND:

Radiologic assessment of tumor response in pancreatic cancer is complicated by desmoplastic reactions within or around the tumor. The objective of this study was to evaluate the correlation between a decline in carbohydrate antigen 19‐9 (CA 19‐9) and survival in patients with advanced pancreatic cancer who received upfront chemotherapy.

METHODS:

CA 19‐9 serum basal values were measured in 247 patients with advanced pancreatic cancer who were enrolled in 5 consecutive trials between 1997 and 2007. Survival curves were compared among patients who had a predefined CA 19‐9 nadir variation (<50%. Group 1; 50% to 89%, Group 2; or >89%, Group 3). To eliminate guarantee‐time bias, survival analysis was repeated using the landmark method.

RESULTS:

In both univariate and multivariate analysis, the basal CA 19‐9 value significantly predicted survival. The median survival was 15.5 months for 34 patients who had normal basal CA 19‐9 values, 11.9 months for 108 patients who had basal values between 38 U/mL and 1167 U/mL, and 8 months for 105 patients who had basal values >1167 U/mL. At least 1 CA 19‐9 follow‐up value was available for 204 patients who had baseline values greater than normal. A significant difference in overall survival was observed in univariate and multivariate analyses between Groups 1 and 2, between Groups 1 and 3, and between Groups 2 and 3. The results were confirmed using the landmark method.

CONCLUSIONS:

In this study, baseline CA 19‐9 was confirmed as an independent prognostic factor for survival, and it may be considered as a stratification factor in trials in patients with advanced pancreatic cancer. Biochemical response may be used as a complementary measure to radiologic response to provide a better assessment of chemotherapy activity and to drive treatment decisions in clinical practice. Cancer 2009. © 2009 American Cancer Society.
Adsorption of Insulin Peptide on Charged Single‐Walled Carbon Nanotubes: Significant Role of Ordered Water Molecules
Authors: Shen Jia‐Wei , Wu Tao , Wang Qi , Kang Yu , Chen Xin
Published: April 2009

Ordered hydration shells: The more ordered hydration shells outside the charged CNT surfaces prevent more compact adsorption of the peptide in the charged CNT systems (see picture), but peptide binding strengths on the charged CNT surfaces are stronger due to the electrostatic interaction.

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Studies of adsorption dynamics and stability for peptides/proteins on single‐walled carbon nanotubes (SWNTs) are of great importance for a better understanding of the properties and nature of nanotube‐based biosystems. Herein, the dynamics and mechanism of the adsorption of the insulin chain B peptide on different charged SWNTs are investigated by explicit solvent molecular dynamics simulations. The results show that all types of surfaces effectively attract the model peptide. Water molecules play a significant role in peptide adsorption on the surfaces of charged carbon nanotubes (CNTs). Compared to peptide adsorption on neutral CNT surfaces, the more ordered hydration shells outside the tube prevent more compact adsorption of the peptide in charged CNT systems. This shield effect leads to a smaller conformational change and van der Waals interaction between the peptide and surfaces, but peptide binding strengths on charged CNT surfaces are stronger than those on the neutral CNT surface due to the strong electrostatic interaction. The result of these simulations implies the possibility of improving the binding strength of peptides/proteins on CNT surfaces, as well as keeping the integrity of the peptide/protein conformation in peptide/protein–CNT complexes by charging the CNTs.
Circular Dichroism in Ion Yields of Femtosecond‐Laser Mass Spectrometry
Authors: Breunig H. Georg , Urbasch Gunter , Horsch Philipp , Cordes Jens , Koert Ulrich , Weitzel Karl‐Michael
Published: April 2009

Telling the difference quickly: Femtosecond laser pulses are not only suitable to distinguish structural isomers. They also provide access to the distinction of enantiomers by combination of circular dichroism and mass spectrometry (see picture).

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Characterization of a 2.8 kJ Small Plasma Focus Using a Five Phase Radiative Model
Authors: Al‐Hawat Sh. , Saloum S.
Published: April 2009

A radiative five‐phase plasma focus model (axial phase, inward radial phase, reflected shock phase, radiative phase and expanded phase) was applied to a 2.8 kJ plasma focus device to find the structure of the plasma focus formation and to calculate the plasma parameters and emitted radiation from the plasma pinch.

To verify the model, the radiation probability of such device in neon plasma has been studied; a linear approximation method was applied by a FORTRAN program which has been written for this purpose.

The theoretical and experimental results of the temporal development of current and voltage at 0.9 mbar of neon and spike voltages at different filling gas pressures were obtained and compared.

In addition to that our plasma focus (PF) device was compared with different PF devices in relation to the plasma energy density and the drive parameter (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Predicted Properties of Cylindrical Microhollow Cathode Discharges in Helium Using a Two‐Dimensional, Self‐Consistent Fluid Model
Authors: Gu X.W. , Meng L. , Yan Y. , Sun Y.Q.
Published: April 2009

In this paper, a numerical simulation model was developed to simulate the helium plasma in a cylindrical Microhollow cathode based on a two‐dimensional, time‐dependent and self‐consistent fluid model. The aim of our work is to provide estimates of the main discharge and plasma parameters and to help understand the basic mechanisms governing the MHCD devices. Accurate solutions of the continuity equations, electron energy balance equation and possion's equation with realistic boundary conditions are obtained. Realistic discharge characteristics are simulated, which are very important to understand the phenomena of microhollow cathode discharge (MHCD). The results show that there exists a hollow cathode effect in the discharge process. He electric field is mainly a radial field close to the cathode in the discharge area. The influences of gas pressure and cathode dimension on discharge characteristics were also investigated (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Regeneration in Rheum emodi Wall.: A step towards conservation of an endangered medicinal plant species
Authors: Malik Sonia , Kumar Ravi , Vats Surender K. , Bhushan Shashi , Sharma Madhu , Ahuja Paramvir Singh
Published: April 2009

Shoot buds emerged from intact leaves while still attached to plants after 60 days, without subculturing, on Murashige and Skoog (MS) medium containing 10.0 μM 6‐benzylaminopurine and 5.0 μM indole‐3‐butyric acid. Histological studies revealed the emergence of shoot buds directly from the leaf surface without an intervening callus phase. Regenerated plantlets were successfully transferred to the greenhouse after rooting in plant growth regulator‐free MS medium. The survival percentage of transferred plants was very low. However, pretreatment of the plants at low temperature (15±2°C) for 10 days before transfer to greenhouse conditions increased the survival percentage. The increased survival was supported by an increased number of vascular bundles, leaf thickness, net rate of photosynthesis (PN), stomatal conductance (gs) and density (SD). The direct regeneration method from intact leaves of R. emodi will reduce the cost, time and labor required and hence can be successfully employed for faster in vitro multiplication and conservation of this endangered and medicinally important plant species.
Effect of protease treatment on dyeing properties of wool fabrics for single bath
Authors: Cui Li , Yu Yuanyuan , Fan Xuerong , Wang Ping , Wang Qiang
Published: April 2009

During the conventional process of dyeing for wool fabric, the most important problem is the damage to wool fiber and energy waste because of high temperature. In this paper, the effect of a commercial protease, Savinase 16L from Novozymes, on low temperature dyeing properties of wool fabric was studied. The results showed that after treatment with protease for 30 min at 50°C and pH 8.0, the exhaustion of the Acid Yellow 116 on wool fabric increased 11.11% and 8.58% by comparing with that on the control samples without protease treatment when dyeing at 80°C and 90°C, respectively. And the dye absorption at 90oC on protease pretreated wool fabric was almost the same as that with the conventional boiling dyeing procedure. A single bath process containing protease treatment at 50°C and pH 8 and dyeing at 90°C and pH 4 was investigated. The dyeing effect of wool fabric dyed with one‐bath process was nearly the same as that with the two‐bath method and conventional boiling dyeing process. The results suggest that protease treatment offers an option of a one‐bath dyeing process, replacing the water‐ and energy‐consuming two‐bath method and conventional dyeing process.
Seismic strengthening of RC columns using external steel cage
Authors: Nagaprasad Pasala , Sahoo Dipti Ranjan , Rai Durgesh C.
Published: April 2009

Steel caging technique is commonly used for the seismic strengthening of reinforced concrete (RC) columns of rectangular cross‐section. The steel cage consists of angle sections placed at corners and held together by battens at intervals along the height. In the present study, a rational design method is developed to proportion the steel cage considering its confinement effect on the column concrete. An experimental study was carried out to verify the effectiveness of the proposed design method and detailing of steel cage battens within potential plastic hinge regions. One ordinary RC column and two strengthened columns were investigated experimentally under constant axial compressive load and gradually increasing reversed cyclic lateral displacements. Both strengthened columns showed excellent behavior in terms of flexural strength, lateral stiffness, energy dissipation and ductility due to the external confinement of the column concrete. The proposed model for confinement effect due to steel cage reasonably predicted moment capacities of the strengthened sections, which matched with the observed experimental values. Copyright © 2009 John Wiley & Sons, Ltd.
Cross‐adaptation of a model human stress‐related odour with fragrance chemicals and ethyl esters of axillary odorants: gender‐specific effects
Authors: Wysocki Charles J. , Louie Jennifer , Leyden James J. , Blank David , Gill Manjindar , Smith Les , McDermott Keith , Preti George
Published: April 2009

The human axillae have a characteristic odour that is comprised of or generated from a mixture of C6–C11 normal, branched, hydroxy‐ and unsaturated acids (and other compounds). We used ethyl esters of one of these acids and a palette of fragrance compounds (tested individually) to evaluate the effectiveness of these chemicals to reduce the overall olfactory impact of a model of human stress‐related odour (SRO) by cross‐adaptation (adaptation to one odorant can reduce sensitivity to other odorants). Sensory volunteers provided hedonic and intensity ratings of the SRO and of each of the potential cross‐adapting agents prior to 2.5 min of induced olfactory adaptation to each agent. Across adaptation, possible cross‐adaptation was evaluated by intermittent evaluations of the perceived intensity of the SRO. We determined that some potential cross‐adapting agents did reduce the impact of the SRO; however, the same chemicals were not necessarily effective for male and female SRO. Indeed, the list of effective chemicals depended upon the gender of the donor of the SRO and the gender of the sensory volunteer, suggesting a gender‐specific response to both the SRO‐stimuli used and the fragrance chemicals used to cross‐adapt it. Copyright © 2009 John Wiley & Sons, Ltd.
A propensity score approach to correction for bias due to population stratification using genetic and non‐genetic factors
Authors: Zhao Huaqing , Rebbeck Timothy R. , Mitra Nandita
Published: April 2009

Confounding due to population stratification (PS) arises when differences in both allele and disease frequencies exist in a population of mixed racial/ethnic subpopulations. Genomic control, structured association, principal components analysis (PCA), and multidimensional scaling (MDS) approaches have been proposed to address this bias using genetic markers. However, confounding due to PS can also be due to non‐genetic factors. Propensity scores are widely used to address confounding in observational studies but have not been adapted to deal with PS in genetic association studies. We propose a genomic propensity score (GPS) approach to correct for bias due to PS that considers both genetic and non‐genetic factors. We compare the GPS method with PCA and MDS using simulation studies. Our results show that GPS can adequately adjust and consistently correct for bias due to PS. Under no/mild, moderate, and severe PS, GPS yielded estimated with bias close to 0 (mean=−0.0044, standard error=0.0087). Under moderate or severe PS, the GPS method consistently outperforms the PCA method in terms of bias, coverage probability (CP), and type I error. Under moderate PS, the GPS method consistently outperforms the MDS method in terms of CP. PCA maintains relatively high power compared to both MDS and GPS methods under the simulated situations. GPS and MDS are comparable in terms of statistical properties such as bias, type I error, and power. The GPS method provides a novel and robust tool for obtaining less‐biased estimates of genetic associations that can consider both genetic and non‐genetic factors. Genet. Epidemiol. 33:679–690, 2009. © 2009 Wiley‐Liss, Inc.
Unrecognised psychological problems impair quality of life and increase consultation rates in Chinese elderly patients
Authors: Lam Cindy L. K. , Chin Weng Yee , Lee Peter W. H. , Lo Yvonne Y. C. , Fong Daniel Y. T. , Lam Tai Pong
Published: April 2009

Objective

Studies have shown that psychological problems in elderly patients are often unrecognised in primary care. The aim of this study was to investigate the quality of life and consultation rates of Chinese elderly patients with unrecognised psychological problems in primary care. The prevalence and risk factors of unrecognised psychological problems were also determined.

Methods

A cross‐sectional study on consecutive patients aged ≥60 with no known psychological diseases were screened by the Hospital Anxiety and Depression Scale (HADS) when they consulted at two primary care clinics in Hong Kong. Data on socio‐demographic characteristics, chronic morbidity, consultation rates, and health‐related quality of life (HROQL) were collected. Multivariable regressions were used to determine the effect of a positive HADS score on HRQOL scores and consultation rates, and the risk factors of unrecognised psychological problems.

Results

One thousand eight hundred and fifty‐four subjects (mean age 72.6 years and 52% male) were screened and the estimated prevalence of unrecognised psychological diseases was 23% (95% CI = 13.1–33.8%). A positive screening result was associated with poorer SF‐36 HROQL scores and higher episodic consultation rates. An increased risk of unrecognised psychological problems was associated with the presence of more than two chronic diseases. Other risk factors included female gender, no formal education and having chronic pulmonary disease or heart disease. Living with a spouse increased the risk in elderly women.

Conclusions

Unrecognised psychological problems are common in Chinese elderly patients in primary care. They are clinically important because they impair quality of life and increase the utilization of consultations. Copyright © 2009 John Wiley & Sons, Ltd.
Do current levels of air pollution kill? The impact of air pollution on population mortality in England
Authors: Janke Katharina , Propper Carol , Henderson John
Published: April 2009

The current air quality limit values for airborne pollutants in the UK are low by historical standards and are at levels that are believed not to harm health. We assess whether this view is correct. We examine the relationship between common sources of airborne pollution and population mortality for England. We use data at local authority level for 1998–2005 to examine whether current levels of airborne pollution, as measured by annual mean concentrations of carbon monoxide, nitrogen dioxide, particulate matter less than 10 µm in diameter (PM10) and ozone, are associated with excess deaths. We examine all‐cause mortality and deaths from specific cardiovascular and respiratory causes that are known to be exacerbated by air pollution. The panel nature of our data allows us to control for any unobserved time‐invariant associations at local authority level between high levels of air pollution and poor population health and for common time trends. We estimate multi‐pollutant models to allow for the fact that three of the pollutants are closely correlated. We find that higher levels of PM10 and ozone are associated with higher mortality rates, and the effect sizes are considerably larger than previously estimated from the primarily time series studies for England. Copyright © 2009 John Wiley & Sons, Ltd.
Suboptimal provision of preventive healthcare due to expected enrollee turnover among private insurers
Authors: Herring Bradley
Published: April 2009

Many preventive healthcare procedures are widely recognized as cost‐effective but have relatively low utilization rates in the US. Because preventive care is a present‐period investment with a future‐period expected financial return, enrollee turnover among private insurers lowers the expected return of this investment. In this paper, I present a simple theoretical model to illustrate the suboptimal provision of preventive healthcare that results from insurers ‘free riding’ off of the provision from others. I also provide an empirical test of this hypothesis using data from the Community Tracking Study's Household Survey. I use lagged market‐level measures of employment‐induced insurer turnover to identify variation in insurers' expectations and test for the effect of turnover on several different measures of medical utilization. As expected, I find that turnover has a significantly negative effect on the utilization of preventive services and has no effect on the utilization of acute services used as a control. Copyright © 2009 John Wiley & Sons, Ltd.
Triterpenoids and Saponins from the Leaves of Uncaria hirsuta
Authors: Xin Wen‐Bo , Chou Gui‐Xin , Wang Zheng‐Tao
Published: April 2009

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Three new triterpenoids, (3β)‐3‐hydroxy‐27‐noroleano‐13(28)‐lactone (1), (22α)‐22‐hydroxy‐3‐oxo‐urs‐12‐ene‐27,28‐dioic acid (4), and (3β)‐3‐(β‐D‐glucopyranosyloxy)‐12‐oxopyroquinovic acid β‐D‐glucopyranosyl ester (7), together with four known compounds, pyrocincholic acid ethyl ester (2), pyrocincholic acid (3), quinovic acid (5), and (3β)‐3‐(β‐D‐quinovopyranosyloxy)pyrocincholic acid β‐D‐glucopyranosyl ester (6), were isolated from the EtOH extract of the leaves of Uncaria hirsuta Haviland. Their structures were determined by means of spectroscopic analyses, including HR‐ESI‐MS and 2D‐NMR techniques. The configuration of 1 was confirmed by X‐ray analysis; 2 is an artefact, as verified by the HPLC and LC/MS analysis.
‘N‐Stereogenic Quaternary Ammonium Salts’ from L‐Amino Acids: Synthesis, Separation, and Absolute Configuration
Authors: Wu Hua‐Fang , Lin Wen‐Bin , Xia Li‐Zi , Luo Ying‐Gang , Chen Xiao‐Zhen , Li Guo‐You , Zhang Guo‐Lin , Pan Xin‐Fu
Published: April 2009

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Diastereoisomeric linear and cyclic ‘N‐chiral quaternary ammonium salts’ (QASs) were efficiently synthesized from corresponding L‐amino acids in high yields. The diastereoisomers of each pair of ‘N‐chiral QASs’ were successfully separated. The absolute configurations of these QASs were determined predominately by X‐ray single‐crystal analysis. The 1H‐NMR data of ‘N‐chiral QASs’ provided characteristic information on the configuration of the N‐chiral center. ‘N‐Chiral QASs’ exemplified by [N(R)]‐2a and [N(S)]‐2a are stable in protic and aprotic solvents within a broad pH and temperature range.
A Triterpenoid and Sesquiterpenoids from the Resinous Exudates of Commiphora myrrha
Authors: Shen Tao , Wan Wen‐Zhu , Wang Xiao‐Ning , Yuan Hui‐Qing , Ji Mei , Lou Hong‐Xiang
Published: April 2009

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A new 30(14→13)abeo‐dammarane triterpenoid, myrrhasin (1), a new 14(10→1)abeo‐eudesmane sesquiterpenoid, myrrhanolide A (2), and two new cadinane sesquiterpenoids, myrrhanolides B and C (3 and 4, resp.), as well as nine known sesquiterpenoids, 5–13, were isolated from the resinous exudates of Commiphora myrrha. Their structures were determined on the basis of extensive MS and NMR spectroscopic analyses. The isolated compounds 1–6 were evaluated for their cytotoxicity against the PC3 and DU145 human prostate tumor cell lines.
Two New Acylated Flavonol Glycosides from the Roots of Otostegia limbata
Authors: Khan Afsar , Ahmad Viqar U. , Farooq Umar
Published: April 2009

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Two new acylated flavonol glycosides, 5‐hydroxy‐2‐(4‐hydroxyphenyl)‐4‐oxo‐7‐[(α‐L‐rhamnopyranosyl)oxy]‐4H‐chromen‐3‐yl β‐D‐glucopyranosyl‐(1→2)‐[β‐D‐glucopyranosyl‐(1→4)]‐[6‐O‐[(2E)‐3‐(4‐hydroxyphenyl)prop‐2‐enoyl]‐β‐D‐glucopyranosyl‐(1→3)]‐α‐L‐rhamnopyranoside (1) and 5‐hydroxy‐2‐(4‐hydroxyphenyl)‐4‐oxo‐7‐[(α‐L‐rhamnopyranosyl)oxy]‐4H‐chromen‐3‐yl [6‐O‐[(2E)‐3‐(4‐hydroxyphenyl)prop‐2‐enoyl]‐β‐D‐glucopyranosyl‐(1→2)]‐[β‐D‐glucopyranosyl‐(1→4)]‐[6‐O‐[(2E)‐3‐(4‐hydroxyphenyl)prop‐2‐enoyl]‐β‐D‐glucopyranosyl‐(1→3)]‐α‐L‐rhamnopyranoside (2), were isolated from the roots of Otostegia limbata, along with two known flavones, cirsimaritin and 3′‐O‐methyleupatorin. Their structures were elucidated on the basis of spectroscopic evidences and chemical methods.
Alkaloids from the Leaves of Daphniphyllum longeracemosumRosenth.
Authors: Li Chun‐Shun , Di Ying‐Tong , Zhang Qiang , Zhang Yu , Tan Chen‐Jian , Hao Xiao‐Jiang
Published: April 2009

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Four new Daphniphyllum alkaloids, daphlongamines E–H (1–4, resp.), along with 19 known alkaloids, were isolated from the leaves of Daphniphyllum longeracemosum. Their structures were characterized by spectroscopic methods, especially 2D‐NMR techniques. It is noteworthy that aconitine‐ and veatchine‐type diterpenoid alkaloids were also isolated from this species.
Two New Triterpenes from the Surface Layer of Poria cocos
Authors: Yang Chun‐Hua , Zhang Shi‐Fang , Liu Wen‐Ying , Zhang Zun‐Jian , Liu Jing‐Han
Published: April 2009

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Two new triterpenes, poricoic acid AE (1) and poricoic acid CE (2), were isolated from the surface layer of the mushroom Poria cocos (Schw.) Wolf, together with four known triterpenes, 3‐O‐acetyldehydroeburicoic acid, 3‐oxolanosta‐7,9(11),24(31)‐trien‐21‐oic acid, dehydrotrametenolic acid, and poricoic acid A. The structures of the two new triterpenes were elucidated as 16α‐hydroxy‐3,4‐seco‐lanosta‐4(28),7,9(11),24(31)‐tetraene‐3,21‐dioic acid‐3‐ethyl ester (1) and 3,4‐secolanosta‐4(28),7,9(11),24(31)‐tetraene‐3,21‐dioic acid‐3‐ethyl ester (2) mainly on the basis of HR‐ESI‐MS, EI‐MS, and 2D‐NMR analyses.
Lignans and Triterpenoids from the Stems of Kadsura induta
Authors: Ma Wenhui , Ma Xiaolin , Lu Yan , Chen Daofeng
Published: April 2009

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Two new lignans, kadsurindutins C and H (1 and 2, resp.), and a new 18(13→12)‐abeo‐lanostane triterpenoid acid, kadindutic acid (3), were isolated from the stems of Kadsura induta, together with known lignans and triterpenoids. Their structures and configurations were elucidated by spectroscopic methods, including 2D‐NMR techniques.
New Diterpenoids from Tinospora capillipes
Authors: Zhan Zha‐Jun , Zhang Xiao‐Yong , Hou Xiao‐Rong , Li Cheng‐Ping , Shan Wei‐Guang
Published: April 2009

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A phytochemical study of the roots of Tinospora capillipes resulted in the characterization of two new highly unsaturated diterpenoids, tinocapilactones A and B (1 and 2), as well as of six known ones. The structures of 1 and 2 were assigned on the basis of extensive 1D‐ and 2D‐NMR experiments, combined with mass‐spectrometric methods.
New Bisbibenzyls from Dendrobium falconeri
Authors: Sritularak Boonchoo , Likhitwitayawuid Kittisak
Published: April 2009

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Two new bis(bibenzyls) named dendrofalconerols A and B (1 and 2, resp.) were isolated from the stems of Dendrobium falconeri (Orchidaceae), along with six known phenolic compounds which included docosanoyl (E)‐ferulate, tetracosyl (Z)‐p‐coumarate, tetracosyl (E)‐p‐coumarate, 2‐(p‐hydroxyphenyl)ethyl p‐coumarate, p‐hydroxybenzoic acid, and p‐hydroxybenzaldehyde. 2‐(p‐Hydroxyphenyl)ethyl p‐coumarate displayed a marginal inhibitory effect against Herpes simplex virus type 1, whereas the remaining compounds were devoid of antiherpetic activity.
Three New Compounds from Incarvillea delavayi
Authors: Lu Tao , Shen Yun‐Heng , Lu Min , Tang Jian , Shan Lei , Liu Run‐Hui , Li Hui‐Liang , Zhang Wei‐Dong
Published: April 2009

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Phytochemical studies on the whole plant of Incarvillea delavayi resulted in the isolation of three new compounds, incarvilleaol (1), incarvillaldehyde (2) and 2‐(1,4‐dihydroxycyclohexyl)ethyl caffeate (3). Their structures were defined on the basis of UV, IR, 1D‐ and 2D‐NMR (1H,1H‐COSY, DEPT, HSQC, HMBC), as well as HR‐ESI‐MS analyses.
Global and gene‐specific promoter methylation changes are related to anti‐B[a]PDE‐DNA adduct levels and influence micronuclei levels in polycyclic aromatic hydrocarbon‐exposed individuals
Authors: Pavanello Sofia , Bollati Valentina , Pesatori Angela Cecilia , Kapka Lucyna , Bolognesi Claudia , Bertazzi Pier Alberto , Baccarelli Andrea
Published: April 2009

We investigated the effect of chronic exposure to polycyclic aromatic hydrocarbons (PAHs) on DNA methylation states (percentage of methylated cytosines (%mC)) in Polish male nonsmoking coke‐oven workers and matched controls. Methylation states of gene‐specific promoters (p53, p16, HIC1 and IL‐6) and of Alu and LINE‐1 repetitive elements, as surrogate measures of global methylation, were quantified by pyrosequencing in peripheral blood lymphocytes (PBLs). DNA methylation was evaluated in relation to PAH exposure, assessed by urinary 1‐pyrenol and anti‐benzo[a]pyrene diolepoxide (anti‐B[a]PDE)‐DNA adduct levels, a critical genetic damage from B[a]P. We also evaluated whether PAH‐induced DNA methylation states were in turn associated with micronuclei in PBLs, an indicator of chromosomal instability. © 2009 UICC
Distribution of human papillomavirus types in cervical cancers in Hong Kong: Current situation and changes over the last decades
Authors: Chan Paul K.S. , Ho Wendy C.S. , Yu Mei‐Yung , Pong Wai‐Mei , Chan Alexander C.L. , Chan Amanda K.C. , Cheung Tak‐Hong , Wong Martin C.S. , To Ka‐Fai , Ng Ho‐Keung
Published: April 2009

Human papillomavirus (HPV) type distribution among cervical cancers and its possible changes over time are key issues that determine the cost‐effectiveness of HPV vaccines. Cervical cancers diagnosed during 3 periods (1997–2007, N = 280; 1984–1986, N = 74; 1972–1973, N = 81) in Hong Kong were examined for HPV type distribution using sensitive broad‐catching methods. The results showed a variation in HPV distribution between histological groups. Among cervical squamous cell carcinoma (SCC) cases diagnosed over the past 10 years, HPV16 was most commonly found (61.2%), followed by HPV18 (17.7%), HPV52 (14.7%) and HPV58 (9.9%), whereas adeno/adenosquamous cell carcinoma was dominated by HPV18 (56.3%) and HPV16 (50.0%). The proportion of HPV16‐positive SCC showed a significant linear trend of increase with time (45.2% for 1972–1973, 58.8% for 1984–1986, 61.2% for 1997–2007; pTrend = 0.023), whereas HPV52‐positive SCC decreased with time (30.1% for 1972–1973; 29.4% for 1984–1986, 14.7% for 1997–2007; pTrend = 0.001). Vaccines comprising HPV16/18 cover 62.6% of SCC and 93.8% of adeno/adenosquamous carcinoma in Hong Kong, and inclusion of HPV52 and HPV58 can increase the coverage by 18.4% for SCC and 4.1% for adeno/adenosquamous cell carcinoma. HPV type distribution may change over time. Further investigations to reveal the determinants for such changes and continuous monitoring for possible type replacement as a result of widespread long‐term use of HPV vaccines are warranted. Multiple infections are commonly revealed by sensitive broad‐catching methods such as those used in this study. However, their implication on vaccine efficacy and cost‐effective analyses should be taken cautiously. © 2009 UICC
Profiles of carbohydrate ligands associated with adsorbed proteins on self‐assembled monolayers of defined chemistries
Authors: Shankar Sucharita P. , Chen Inn Inn , Keselowsky Benjamin G. , García Andrés J. , Babensee Julia E.
Published: April 2009

Conserved protein–carbohydrate–lipid pathogen‐associated molecular patterns (PAMPs) interact with cells of the innate immune system to mediate antigen recognition and internalization and activation of immune cells. We examined if analogous “biomaterial‐associated molecular patterns” composed of proteins, specifically their carbohydrate modifications, existed on biomaterials, which can play a role in mediating the innate immune response to biomaterials. To probe for these carbohydrates in the adsorbed protein layer, as directed by the underlying biomaterial chemistry, self‐assembled monolayers (SAMs) presenting CH3, OH, COOH, or NH2 were preincubated with serum/plasma, and the presence of carbohydrate ligands of C‐type lectin receptors (CLRs) was investigated using lectin probes in an enzyme‐linked lectin assay (ELLA). Presentation of CLR ligands was detected on control tissue culture polystyrene (TCPS). Absorbances of mannose or N‐acetylglucosamine increased with decreasing incubating serum concentration, whereas absorbances of sialylated epitopes or fucose remained unchanged. Absorbances of α‐galactose or N‐acetylgalactosamine decreased with decreasing incubating serum concentration; β‐galactose was undetectable. Among SAM endgroups, preincubation with 10% serum resulted in differential presentation of CLR ligands: higher α‐galactose on COOH SAMs than NH2 or CH3 SAMs, highest complex mannose on NH2 SAMs, and higher complex mannose on OH SAMs than CH3 SAMs. Least sialylated groups were detected on CH3 SAMs. In summary, biomaterial chemistry may regulate protein adsorption and hence unique presentation of associated carbohydrates. The ultimate goal is to identify the effects of protein glycosylations associated with biomaterials in stimulating innate immune responses. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Enhanced polarization of embryonic hippocampal neurons on micron scale electrospun fibers
Authors: Lee Jae Young , Bashur Chris A. , Gomez Natalia , Goldstein Aaron S. , Schmidt Christine E.
Published: April 2009

Electrospun fibers have been fabricated for wide use as artificial tissue engineering scaffolds. In particular, fibers smaller than a cell body have been extensively employed to mimic natural extracellular matrix (ECM) and to explore specific responses by various cell types. We investigated the effects of various poly(lactic acid‐co‐glycolic acid) (PLGA) fiber features on embryonic hippocampal neurons in the early developmental stages in terms of initial axon formation (i.e., polarization) and axon orientation. We produced PLGA fibers that have average diameters ranging from 0.44 μm to 2.2 μm and different degrees of fiber alignment (16–58° in angular standard deviation). After 22 h in culture, embryonic hippocampal neurons grown on PLGA fibers exhibited more axon formation with a 30–50% increase over those on spin‐coated smooth PLGA films. This improvement was independent of fiber diameter and alignment; however, slightly more polarization was observed on the smaller fibers and the more aligned fibers. In addition, average axon length of the polarized embryonic hippocampal neurons was not significantly different among the PLGA fibers when compared with cells grown on spin‐coated PLGA films. These findings suggest that fibers of subcellular diameters stimulate initial axon establishment and guide the direction of axonal extension; however, these fibers do not appear to affect the overall axon length. This information will be valuable in understanding the roles of subcellular features on neuron development and for the design of biomaterials for neural tissue interfacing. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Design and characterization of a biodegradable composite scaffold for ligament tissue engineering
Authors: Hayami James W. S. , Surrao Denver C. , Waldman Stephen D. , Amsden Brian G.
Published: April 2009

Herein we report on the development and characterization of a biodegradable composite scaffold for ligament tissue engineering based on the fundamental morphological features of the native ligament. An aligned fibrous component was used to mimic the fibrous collagen network and a hydrogel component to mimic the proteoglycan‐water matrix of the ligament. The composite scaffold was constructed from cell‐adherent, base‐etched, electrospun poly(ϵ‐caprolactone‐co‐D,L‐lactide) (PCLDLLA) fibers embedded in a noncell‐adherent photocrosslinked N‐methacrylated glycol chitosan (MGC) hydrogel seeded with primary ligament fibroblasts. Base etching improved cellular adhesion to the PCLDLLA material. Cells within the MGC hydrogel remained viable (72 ± 4%) during the 4‐week culture period. Immunohistochemistry staining revealed ligament ECM markers collagen type I, collagen type III, and decorin organizing and accumulating along the PCLDLLA fibers within the composite scaffolds. On the basis of these results, it was determined that the composite scaffold design was a viable alternative to the current approaches used for ligament tissue engineering and merits further study. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2010
Temperature evaluation during PMMA screw augmentation in osteoporotic bone—An in vitro study about the risk of thermal necrosis in human femoral heads
Authors: Boner Vanessa , Kuhn Philipp , Mendel Thomas , Gisep Armando
Published: April 2009

The use of polymethylmethacrylate (PMMA) bone cement to augment hip screws reduces cut‐out risk but is associated with an exothermic reaction. This in vitro investigation evaluated the risk of thermal necrosis when augmenting the implant purchase with PMMA. A pilot study analyzed the effects of different PMMA layer thicknesses on temperatures around an implant. The main study used either 3.0 or 6.0 cc PMMA for hip screw augmentation in human femoral heads. The risk of thermal necrosis was estimated according to critical values reported in literature. Highest temperatures were measured inside the PMMA with a significant drop of average maximum temperatures from the center of the PMMA to the PMMA/bone interface. Risk of thermal necrosis exists with PMMA layer thicknesses greater than 5.0 mm. In the main study, we found no risk of thermal necrosis at the PMMA/bone interface or in the surrounding bone, neither with 3.0 nor 6.0 cc PMMA. The results of the two studies were consistent regarding average peak temperatures related to associated cement layer thicknesses. The results of this in vitro study reduce objections concerning the risk of thermal necrosis when augmenting cancellous bone around hip screws with up to 6.0 cc PMMA. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2009
Preparation of surface‐modified poly(butylene terephthalate) nonwovens and their application as leukocyte removal filters
Authors: Kim Eun Jin , Yeo Gwu‐Dong , Pai Chaul‐Min , Kang Inn‐Kyu
Published: April 2009

Blood transfusion‐related adverse reactions have been reported to be caused by leukocytes in blood products. It is now generally accepted that it would be highly desirable to reduce leukocytes level as low as possible. In this study, melt‐blown poly(butylene terephthalate) nonwoven (PBT‐NW) was treated with a hydroxyapatite (HA) surface‐modification method for removal of leukocytes from blood components. Acrylic acid was graft‐polymerized onto the surface of the PBT‐NW after oxygen plasma glow discharge treatment. The PBT‐NW surface was covered with a thin layer of HA produced by immersing the polymer surface in an aqueous solution containing high concentrations of PO43− and Ca2+ after graft‐polymerization of acrylic acid, which provided the nucleus for HA crystallization. The surface was characterized using water contact angles, attenuated total reflection‐Fourier transform infrared (ATR‐FT‐IR), and electron spectroscopy for chemical analysis. When filtration was performed with a unit of red blood cell concentrates, HA‐deposited PBT‐NW (PBT‐HA) removed 98.5% of the leukocytes and recovered 99.5% of the erythrocytes, suggesting that HA‐deposited PBT‐NW is a very promising blood filter for selective removal of leukocytes. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Bacterial adhesion to diamond‐like carbon as compared to stainless steel
Authors: Soininen Antti , Tiainen Veli‐Matti , Konttinen Yrjö T. , van der Mei Henny C. , Busscher Henk J. , Sharma Prashant K.
Published: April 2009

Recent studies suggest that diamond‐like carbon (DLC) coatings are suitable candidates for application on biomedical devices and implants, due to their high hardness, low friction, high wear and corrosion resistance, chemical inertness, smoothness, and tissue and blood compatibility. However, most studies have neglected the potential susceptibility of DLC coatings to bacterial adhesion, which is the first step in the development of implant‐related infections. This study compares adhesion of seven bacterial strains, commonly implicated in implant‐related infections, to tetrahedral amorphous carbon, with their adhesion to AISI 316L surgical steel. The results show that bacterial adhesion to DLC was similar to the adhesion to commonly used stainless steel. This suggests that DLC coating can be advantageously used on implants made of AISI 316L or other materials without increasing the risk to implant‐related infections. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Development, characterization, and validation of porous carbonated hydroxyapatite bone cement
Authors: Tang Pei‐Fu , Li Gang , Wang Ji‐Fang , Zheng Qiu‐Jian , Wang Yan
Published: April 2009

Carbonated hydroxyapatite (CHA) bone cement is capable of self‐setting and forming structures similar to mineralized bone. Conventional CHA leaves little room for new bone formation and delays remodeling. The purposes of this study were to develop porous CHA (PCHA) bone cement and to investigate its physicochemical properties, biocompatibility, biodegradation, and in vivo bone repair potential. Vesicants were added to modify CHA, and the solidification time, porosity, and pore size of the PCHA cements were examined. The cytotoxicity and bone repair potential of PCHA were tested in a rabbit bone defect model and assessed by x‐ray, histological examination, and mechanical testing. The porosity of the modified PCHA was 36%; 90.23% of the pores were greater than 70 μm, with a calcium/phosphate ratio of 1.64 and a solidification time of 15 minutes. The PCHA did not affect bone cell growth in vitro, and the degrading time of the PCHA was two and four times faster in vitro and in vivo when compared to CHA. In the bone defect model, the amount of new bone formation in the PCHA‐treated group was eight times greater than that of the CHA group; the compressive strength of the PCHA setting was relatively weak in the first weeks but increased significantly at 8 to 16 weeks compared to the CHA group. The PCHA has stable physicochemical properties and excellent biocompatibility; it degrades faster than CHA, provides more porous spaces for new bone ingrowths, and may be a new form of bone cement for the management of bone defects. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2009
Cytotoxic effects of different concentrations of a carbamide peroxide bleaching gel on odontoblast‐like cells MDPC‐23
Authors: de Lima Adriano Fonseca , Lessa Fernanda Campos Rosetti , Gasparoto Mancini Maria Nadir , Hebling Josimeri , de Souza Costa Carlos Alberto , Marchi Giselle Maria
Published: April 2009

This study evaluated the cytotoxic effects of a carbamide peroxide (CP) bleaching gel at different concentrations on odontoblast‐like cells. Immortalized cells of the MDPC‐23 cell line (30,000 cells/cm2) were incubated for 48 h. The bleaching gel was diluted in DMEM culture medium originating extracts with different CP concentrations. The amount (μg/mL) of hydrogen peroxide (H2O2) released from each extract was measured by the leukocrystal violet/horseradish peroxidase enzyme assay. Five groups (n = 10) were formed according to the CP concentration in the extracts: G1‐DMEM (control); G2‐0.0001% CP (0.025 μg/mL H2O2); G3‐0.001% CP (0.43 μg/mL H2O2); G4‐0.01% CP (2.21 μg/mL H2O2); and G5‐0.1% CP (29.74 μg/mL H2O2). MDPC‐23 cells were exposed to the bleaching gel extracts for 60 min and cell metabolism was evaluated by the MTT assay. Data were analyzed statistically by one‐way ANOVA and Tukey's test (α = 0.05). Cell morphology was examined by scanning electron microscopy. The percentages of viable cells were as follows: G1, 100%; G2, 89.41%; G3, 82.4%; G4, 61.5%; and G5, 23.0%. G2 and G3 did not differ significantly (p > 0.05) from G1. The most severe cytotoxic effects were observed in G3 and G4. In conclusion, even at low concentrations, the CP gel extracts presented cytotoxic effects. This cytotoxicity was dose‐dependent, and the 0.1% CP concentration caused the most intense cytopathic effects to the MDPC‐23 cells. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2009
Complex molecular assemblies at hand via interactive simulations
Authors: Delalande Olivier , Férey Nicolas , Grasseau Gilles , Baaden Marc
Published: April 2009

Studying complex molecular assemblies interactively is becoming an increasingly appealing approach to molecular modeling. Here we focus on interactive molecular dynamics (IMD) as a textbook example for interactive simulation methods. Such simulations can be useful in exploring and generating hypotheses about the structural and mechanical aspects of biomolecular interactions. For the first time, we carry out low‐resolution coarse‐grain IMD simulations. Such simplified modeling methods currently appear to be more suitable for interactive experiments and represent a well‐balanced compromise between an important gain in computational speed versus a moderate loss in modeling accuracy compared to higher resolution all‐atom simulations. This is particularly useful for initial exploration and hypothesis development for rare molecular interaction events. We evaluate which applications are currently feasible using molecular assemblies from 1900 to over 300,000 particles. Three biochemical systems are discussed: the guanylate kinase (GK) enzyme, the outer membrane protease T and the soluble N‐ethylmaleimide‐sensitive factor attachment protein receptors complex involved in membrane fusion. We induce large conformational changes, carry out interactive docking experiments, probe lipid–protein interactions and are able to sense the mechanical properties of a molecular model. Furthermore, such interactive simulations facilitate exploration of modeling parameters for method improvement. For the purpose of these simulations, we have developed a freely available software library called MDDriver. It uses the IMD protocol from NAMD and facilitates the implementation and application of interactive simulations. With MDDriver it becomes very easy to render any particle‐based molecular simulation engine interactive. Here we use its implementation in the Gromacs software as an example. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2009