bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultra‐performance liquid chromatography/time‐of‐flight mass spectrometry as a chemotaxonomic tool for the analysis of Gentianaceae species
Authors: Urbain Aurélie , Marston Andrew , Marsden‐Edwards Emma , Hostettmann Kurt
Published: January 2009

Introduction

The segregation between the genera Gentiana and Gentianella among the Gentianaceae family is poorly defined. In order to clarify the classification of these genera, some researchers have tried to incorporate data about the chemical constitution, but this has not yet been achieved in a comprehensive way.

Objective

To develop a fast and reproducible analytical method for the observation of characteristic fingerprints of secondary metabolites of each genus.

Methodology

Seven species were investigated, three Gentianella and four Gentiana selected for their close taxonomic links within each genus. Ten xanthones previously isolated from one of these species were used as chemotaxonomic markers. A UPLC/ESI‐TOF‐MS method was developed to analyse the methanolic extracts.

Results

The UPLC/TOF‐MS provided clear metabolic fingerprints and elemental composition of the compounds. The profiles of the three Gentianella species were strikingly similar. On the contrary, metabolic profiles of Gentiana species were very different from the Gentianella chromatograms and also from each other. Several compounds were unique to each genus and therefore could be used as biomarkers.

Conclusion

UPLC/TOF‐MS can be applied as a chemotaxonomic tool for the rapid screening of Gentianaceae species and for the distinction between closely related taxa from the Gentianaceae family. Copyright © 2009 John Wiley & Sons, Ltd.
An optimised, small‐scale preparation of high‐quality RNA from dry seeds of Davidia involucrata
Authors: Qi G. , Li J. T. , Ruan Q. P. , Yang J. , Su Z. X.
Published: January 2009

Introduction

The dormancy of Davidia involucrata seeds normally lasts for an extended period of time and because of this unique property the species is an excellent model for studying the molecular mechanisms of plant dormancy. The use of minimal plant material is desirable for RNA extraction since D. involucrata is a rare plant and it is relatively difficult to collect large amounts of seeds in order to perform molecular biology studies.

Objective

To improve the quality of RNA obtained from seeds of D. involucrata by eliminating the oxidation of polyphenols during extraction and by preventing polysaccharides and other impurities from being extracted.

Methods

A previously described method was modified by the addition of 4% (w/v) poly(N‐vinyl‐2‐pyrrolidone) to the dry seeds during grinding and by adding 5% (v/v) β‐mercaptoethanol and 28% (v/v) ethanol to the extraction buffer. Two further centrifugation steps (5000 and 8000 rpm) were utilised and one‐seventh volume of ethanol was incubated with the supernatant at 4°C for 2–3 h prior to the precipitation of RNA.

Results

Following these modifications, an effective method was established for total RNA extraction from a small amount of dry seeds of D. involucrata. The isolated RNA was shown to have high purity and integrity by gel electrophoresis and spectrophotometry, and was confirmed to be suitable for RT‐PCR and the construction of cDNA libraries.

Conclusion

The modified method reduced the amount of seeds required for extraction of total DNA and was beneficial for preserving the endangered species. Copyright © 2008 John Wiley & Sons, Ltd.
Isolation and purification of acid‐labile carotenoid 5,6‐epoxides on modified silica gels
Authors: Nagy Veronika , Agócs Attila , Turcsi Erika , Deli József
Published: January 2009

Introduction

The acid‐labile carotenoid 5,6‐epoxides occur in all green plants and in most fruits, but their isolation or purifica‐tion is complicated and expensive because they decompose on normal silica gels. Alkaline stationary phases in open column chromatography (OCC) have low capacities, which makes them unsuitable for preparative scale.

Objective

To find a simple high‐capacity stationary phase for OCC that does not induce transformations of acid‐labile compounds.

Methodology

Commercially available silica gel was treated with aqueous sodium bicarbonate solution to neutralise its slightly acidic character, and was then washed and dried. The effect of the treated gel (named silica‐9) on violaxanthin was studied. The modified gel was also applied to the OCC of different complex natural extracts (maple leaves and fruits of yellow paprika). Carotenoids were examined by HPLC‐PAD both before and after chromatography on the modified gel.

Results

Violaxanthin decomposed rapidly on normal silica gels but not on the modified gel. Chromatography of plant extracts showed that the modified gel had a similar capacity to the untreated gel but did not effect epoxy‐carotenoids, which could be separated or enriched readily on a large scale.

Conclusion

The modified gel does not induce any transformation or decomposition of epoxy‐carotenoids but still exhibits a high capacity, suggesting that it can be used in preparative organic chemistry as an additional and convenient tool in the OCC for the separation of other acid‐labile compounds. Copyright © 2009 John Wiley & Sons, Ltd.
Gas chromatographic analysis of dimethyltryptamine and β‐carboline alkaloids in ayahuasca, an amazonian psychoactive plant beverage
Authors: Pires Ana Paula Salum , De Oliveira Carolina Dizioli Rodrigues , Moura Sidnei , Dörr Felipe Augusto , Silva Wagner Abreu E. , Yonamine Mauricio
Published: January 2009

Introduction

Ayahuasca is obtained by infusing the pounded stems of Banisteriopsis caapi in combination with the leaves of Psychotria viridis. P. viridis is rich in the psychedelic indole N,N‐dimethyltryptamine, whereas B. caapi contains substantial amounts of β‐carboline alkaloids, mainly harmine, harmaline and tetrahydroharmine, which are monoamine‐oxidase inhibitors. Because of differences in composition in ayahuasca preparations, a method to measure their main active constituents is needed.

Objective

To develop a gas chromatographic method for the simultaneous determination of dimethyltryptamine and the main β‐carbolines found in ayahuasca preparations.

Methodology

The alkaloids were extracted by means of solid phase extraction (C18) and detected by gas chromatography with nitrogen/phosphorous detector.

Results

The lower limit of quantification (LLOQ) was 0.02 mg/mL for all analytes. The calibration curves were linear over a concentration range of 0.02–4.0 mg/mL (r2 > 0.99). The method was also precise (RSD < 10%).

Conclusion

A simple gas chromatographic method to determine the main alkaloids found in ayahuasca was developed and validated. The method can be useful to estimate administered doses in animals and humans for further pharmacological and toxicological investigations of ayahuasca. Copyright © 2009 John Wiley & Sons, Ltd.
Social adjustment among Chinese women following breast cancer surgery
Authors: Lam Wendy WT , Chan Miranda , Hung Wai Ka , Or Amy , Fielding Richard
Published: January 2009

Background: How breast cancer surgery affects social adjustment among Chinese women is unknown, as are factors predicting such adjustment.

Methods: 405 Chinese women receiving surgery for localized breast cancer completed Social Adjustment Scales (Ch‐SAS) at 1‐, 4‐ and 8‐months post‐operatively. Subscale scores were regressed on baseline (days 3–12 post‐operatively) measures of treatment decision‐making difficulty (TDMD), self‐efficacy (GSeS), consultation satisfaction (C‐MISS‐R), psychological (CHQ‐12) and physical distress (PD), and 1‐month follow‐up optimism (C‐LOT‐R), and disappointment (E‐OI), fully adjusted for demographic and clinical factors.

Results: All Ch‐SAS subscales except appearance & sexuality changed significantly over 8‐months follow‐up: Enjoyment of social activities (F=27.38, df 2, p<0.001) and self‐image (F=3.63, df 2, p=0.027) improved slightly. Family interaction (F=26.63, df 2, p<0.001) and interaction with friends (F=3.37, df 2, p=0.035) declined slightly. Family and friends interaction subscales were predominantly predicted by high self‐efficacy and optimism, whereas self‐image and appearance & sexuality subscales were predominantly predicted by low treatment outcome disappointment, TDM difficulties, baseline psychological morbidity and high self‐efficacy. Enjoyment of social activities was predicted by low baseline psychological distress and concurrent physical symptom distress.

Conclusion: High self‐efficacy and optimism predicted women who have better social relationships with friends and family. Higher self‐efficacy, low TDM difficulties, less disappointment with treatment outcome and low psychological and physical distress predicted better adjustment to self‐image and body image. Copyright © 2009 John Wiley & Sons, Ltd.
Distress in couples approached for genetic counseling and BRCA1/2 testing during adjuvant radiotherapy
Authors: Schlich‐Bakker Kathryn J. , ten Kroode Herman F. J. , Wárlám Rodenhuis Carla C. , Ausems Margreet G. E. M. , van den Bout Jan
Published: January 2009

Objective: Breast cancer patients mostly rely on their partners for support in dealing with their cancer diagnosis and treatment. Genetic counseling and BRCA1/2 testing during primary treatment may add to demands made on their partners. This study aimed to gain insight into the extent of psychological distress in partners of recently diagnosed patients and to find factors to help identify couples vulnerable to high psychological distress after an active approach for genetic counseling.

Methods: Breast cancer patients and their partners (n=110) completed psychological distress measures (HADS and IES) prior to the approach for counseling (T0), after the approach (T1), and after leaving the genetic counseling protocol (T2). Couples not approached for counseling (n=85) completed similar questionnaires.

Results: Partners reported an equal or lower level of distress than patients, with a positive correlation between the two, although partners and patients differed in the course of their distress. Couples approached for genetic counseling did not differ in the level or course of either distress measure from not approached couples. A high baseline distress best predicts long‐term high distress in patients and their partners. Younger patients were found to be particularly vulnerable.

Conclusions: The approach for genetic counseling during adjuvant radiotherapy was not associated with extra psychological distress in partners or patients in the first year following the breast cancer diagnosis. A partner's long‐term level of distress was significantly associated with that of the patient. Highly distressed patients with highly distressed partners were most likely to experience high distress in the long term. Copyright © 2009 John Wiley & Sons, Ltd.
Intrusive cognitions and their appraisal in anxious cancer patients
Authors: Whitaker Katriina L. , Watson Maggie , Brewin Chris R.
Published: January 2009

Objective: Previous research found that anxious cancer patients experience uncontrollable negative intrusive cognitions that have an impact on coping and are associated with significant psychological distress. This is the first study to examine the appraisal of intrusive cognitions in an anxious group of cancer patients.

Methods: A sample of 139 anxious cancer patients was assessed for evidence of intrusive phenomena, including memories, images and thoughts. Patients completed the Response to Intrusions Questionnaire and the Impact of Event Scale in relation to intrusive cognitions.

Results: Forty‐eight percent (67/139) reported frequent, uncontrollable intrusive cognitions. Intrusive thoughts and images were equally as common and images were associated with increased distress and uncontrollability. A significant positive linear relationship was found between the number of intrusions and anxiety severity (P<0.05). Negative appraisal of intrusive cognitions was associated with anxiety (P<0.01) and depression severity (P<0.01), intrusion‐specific distress (P<0.01), rumination (P<0.01) and cognitive avoidance (P<0.01), after controlling for intrusion frequency.

Conclusion: Negative appraisal of intrusive cognitions plays a significant role in psychological distress and intrusion‐specific distress in anxious cancer patients. Finding similarities in the types of intrusive cognitions reported by cancer patients and other anxious populations highlights the potential applicability of psychological therapies developed to reduce the frequency and impact of intrusive cognitions. Copyright © 2009 John Wiley & Sons, Ltd.
Ammonia solutions explosivity
Authors: Dupont Laurent
Published: January 2009

Explosion risks resulting from the industrial handling of aqueous ammonia solutions are often not taken into account in risk assessments, especially for dilute solutions, although accidental explosions implying ammonia vapors are reported in the literature. In fact, ammonia solutions do not show any flash point, but are able to form an explosive atmosphere. In this study, explosivity characteristics of several ammonia solutions, more or less diluted, were determined in a 20‐L sphere device.

It appears that the explosion range of ammonia solutions depends on the temperature and on the ammonia concentration. The explosion severity is smaller than for pure ammonia because of the presence of water and it tends to decrease slightly with dilution. However, the maximal explosion pressure is still above 3 bar with the 10% solution. Hence, such aqueous solutions, even diluted, handled in enclosed spaces can generate great disasters. © 2009 American Institute of Chemical Engineers Process Saf Prog, 2009
Contraceptive method switch and discontinuation among women migrants in indonesia
Authors: Liew Hui‐Peng
Published: January 2009

Using the 2000 wave of the Indonesian Family Life Survey (IFLS3), this study attempts to examine the relationship between migration and contraceptive method switch and discontinuation in Indonesia. The major conclusion from the multinomial logistic regression is that repeated migrants are more likely than one‐time migrants to discontinue use of the same method. However, the differentials in the likelihood of discontinuing use of the same method among women migrants is eliminated after controlling for the quality of health centre/family planning programme and the degree of infrastructure development in a community. The results of this study will contribute important foundational knowledge about the extent of contraceptive use dynamics by women of different migration experiences in Indonesia. This knowledge will provide guidance to policymakers to employ effective means to incorporate migration and issues that are sensitive to women migrants in their family planning and reproductive health programmes. Copyright © 2009 John Wiley & Sons, Ltd.
The use of neem for controlling gastric hyperacidity and ulcer
Authors: Maity Pallab , Biswas Kaushik , Chattopadhyay Ishita , Banerjee Ranajit K. , Bandyopadhyay Uday
Published: January 2009

H2‐receptor blockers and proton pump inhibitors are now used extensively to control gastric and duodenal ulcer, inflammation and pain, but these drugs have limitations and are not always affordable. The development of novel nontoxic antiulcer drugs, including from medicinal plants, is therefore desirable, and Azadirachta indica A. Juss, commonly known as Neem, is known to have potent gastroprotective and antiulcer effects. This review deals with the pharmacological and biochemical studies carried out regarding the antiulcer activities of Neem extracts and their mechanism of action, including the inhibition of acid secretion. A comparison with ranitidine and omeprazole in some animal models has been included and clinical studies, where available, have also been incorporated, along with a safety evaluation. Neem bark extract has the potential for the development of novel medicines for the therapeutic control of gastric hyperacidity and ulcer. Copyright © 2009 John Wiley & Sons, Ltd.
Aucubin prevents loss of hippocampal neurons and regulates antioxidative activity in diabetic encephalopathy rats
Authors: Xue Hong‐Yu , Jin Lei , Jin Li‐Ji , Li Xiao‐Yu , Zhang Peng , Ma Yong‐Sheng , Lu Ya‐Nan , Xia Yan‐Qiu , Xu Yong‐Ping
Published: January 2009

In this study, the neuroprotection of aucubin and its mechanism were evaluated in the rat model of diabetic encephalopathy. Diabetes mellitus (DM) rats were stratified by cognitive capability (CC), and assigned to four treatment groups for aucubin treatment (doses of 0, 1, 5 or 10 mg/kg aucubin), with a further two groups of non‐DM rats ranked by CC as controls for aucubin (doses of 0 or 5 mg/kg aucubin). Neuroprotection was estimated by the indexes of behavior and histology. Behavioral testing was performed in a Y‐maze. The surviving neurons in CA1–CA4 and subiculum (SC) of the hippocampus were counted under a microscope. In addition, the apoptotic neurons in the CA1 of the hippocampus were also examined by using TUNEL staining. In order to clarify the mechanism of aucubin's neuroprotection, the activities of endogenous antioxidants and nitric oxide synthase (NOS) together with the content of lipid peroxide in the hippocampus were assayed. The results proved that aucubin significantly reduced the content of lipid peroxide, regulated the activities of antioxidant enzymatic and decreased the activity of NOS. All these effects indicated that aucubin was a potential neuroprotective agent and its neuroprotective effects were achieved, at least in part, by promoting endogenous antioxidant enzymatic activities. Copyright © 2009 John Wiley & Sons, Ltd.
Assessment of systemic interaction between Swertia chirata extract and its Bioactive constituents in rabbits
Authors: Suryawanshi Satyendra , Asthana R. K. , Gupta R. C.
Published: January 2009

The plant Swertia chirata (Gentianaceae) is known for its multifarious medicinal value in the Indian system of medicine (Ayurveda). Its methanol extracts having antidiabetic activity contains mangiferin, amarogentin, amaroswerin, sweroside and swertiamarin as active constituents. The pharmacokinetics of mangiferin and amarogentin have been carried out after intravenous administration of pure standards and extract from S. chirata (CT) in rabbits to assess systemic interaction. The remaining three components were also monitored in plasma for pharmacokinetic estimation based on the ratio analysis method. Mangiferin was characterized by a relative low clearance (∼0.14 L/h/kg) and a lesser volume of distribution (∼0.15 L/kg), while amarogentin exhibited a rapid clearance (∼2.62 L/h/kg) and wide distribution (∼1.08 L/kg) from the systemic circulation. No significant difference was observed in pharmacokinetic parameters of mangiferin and amarogentin either administered alone or as CT formulation in rabbits. Copyright © 2009 John Wiley & Sons, Ltd.
Extract of Prunus persica flesh (PPFE) improves chemotherapeutic efficacy and protects against nephrotoxicity in cisplatin‐treated mice
Authors: Lee Chang Ki , Park Kwang‐Kyun , Hwang Jae‐Kwan , Lee Sang Kook , Chung Won‐Yoon
Published: January 2009

Cisplatin (cis‐diamminedichloroplatinum II) is one of the most effective chemotherapeutic agents used in the treatment of a variety of human solid tumors. However, its clinical use is rather limited as a result of severe nephrotoxicity. The principal objective of this study was to evaluate the protective effect of Prunus persica flesh extract (PPFE) against cisplatin‐induced nephrotoxicity in animal models, and whether its use influences the therapeutic efficacy of cisplatin. The administration of PPFE alone significantly inhibited the growth of CT‐26 colon carcinoma xenografted onto mice without adverse effects. The combination of PPFE and cisplatin enhanced the inhibitory effect of cisplatin against tumor growth. In a xenograft model involving the repeated administration of low‐dose cisplatin for 15 days, and in an acute toxicity model involving a single administration of high‐dose cisplatin over a 16 h period, the administration of PPFE in combination with and prior to the cisplatin injection reversed the cisplatin‐induced reduction in the kidney weight. PPFE blocked the increases in the serum blood urea nitrogen and creatinine levels associated with the kidney damage. Moreover, the administration of PPFE induced a significant reduction in cisplatin‐induced oxidative stress. These results indicate that PPFE may promote the therapeutic efficacy of cisplatin therapy, while attenuating its inherent nephrotoxicity. Copyright © 2009 John Wiley & Sons, Ltd.
Antioxidant capacity of Melampyrum barbatum – weed and medicinal plant
Authors: Štajner D. , Popović B. M. , Boža P. , Kapor A.
Published: January 2009

This study was designed to examine antioxidant and free radical scavenging activities of red and yellow forms of Melampyrum barbatum L. In this study, we report the results concerning flower and leaf antioxidant enzyme activities (superoxide dismutase, catalase, guaiacol peroxidase and glutathione peroxidase), reduced glutathione quantity, flavonoids, photosynthetic pigments and soluble protein contents and quantities of malonyldialdehyde, •OH and O2•− radicals; total antioxidant capacity was determined by FRAP (Ferric Reducing Antioxidant Power) method and scavenger activity by DPPH (1,1‐diphenyl‐2‐pycril‐hydrasil radical) method. Lipofuscin ‘plant age pigments’ were also determined. According to our results, flowers of the red form of M. barbatum exhibited the highest antioxidant capacity. Copyright © 2009 John Wiley & Sons, Ltd.
Attitudes and knowledge toward natural products safety in the pharmacy setting: an Italian study
Authors: Cuzzolin Laura , Benoni Giuseppina
Published: January 2009

The lack of a professional supervision may expose consumers of natural products to risks; pharmacists play an important role in giving information about these substances. A survey was designed to investigate the attitudes and knowledge of consumers and pharmacists toward the safety of natural products.

Twenty‐three pharmacies participated in the project. On the basis of a pre‐structured 17‐item questionnaire, face‐to‐face interviews were conducted with consumers buying a natural product over a 6‐month period. A further 8 items had to be compiled by pharmacists about the purchased product.

During the study period, 1420 interviews were carried out. The most frequently purchased products were echinacea, propolis, garlic, guggul, ginkgo, liquorice, ginseng, glucomannan, guarana, valerian, and passionflower; 71.8% of consumers reported to have been taking conventional medicines along with natural products. Some (3.9%) referred to adverse effects in the last year: allergic reactions after cartilage of shark, propolis and thyme; anxiety after hypericum; hypotension and tachycardia after a mix containing chamomile, valerian and melissa; pyrosis and stomach‐ache after laxative‐depurative herbs. Pharmacists referred to some adverse effects observed in the past in relation to the products bought by consumers involved in this study.

Findings from this study demonstrate that in general consumers need information on herbal safety and pharmacists are more likely to answer correctly about the use of herbs rather than about cautions, adverse effects and interactions. Copyright © 2009 John Wiley & Sons, Ltd.
Inhibitory effect of magnolol on Trp‐P‐2‐induced DNA damage in various organs in mice
Authors: Saito Junichiro , Fukushima Hiroko , Nagase Hisamitsu
Published: January 2009

Magnolol has been reported to strongly inhibit the mutagenicity induced by indirect mutagens in the Ames test as well as the clastogenicity induced by benzo(a)pyrene (B(a)P) in the mice micronucleus test. Here, we evaluated the inhibitory effect of magnolol on the DNA damage induced by 3‐amino‐1‐methyl‐5H‐pyrido[4,3‐b]indole (Trp‐P‐2) in various organs using the mice alkaline single cell gel electrophoresis (SCG) assay. Animals were treated with a single oral administration of magnolol (0.01, 0.1, 1, 10, and 100 mg/kg), followed by a single intraperitoneal injection of Trp‐P‐2 (10 mg/kg). The liver, lung, and kidney were removed at 3 h after treatment and used in SCG assay. The results indicated that magnolol inhibited Trp‐P‐2‐induced DNA damage in various organs. To elucidate the mechanism of this inhibitory effect against Trp‐P‐2, we investigated the inhibitory effect of magnolol onin vivoCYP1A2 activity using the zoxazolamine paralysis test. Magnolol significantly prolonged zoxazolamine paralysis time and showed an inhibitory effect onin vivoCYP1A2 activity. These results indicate that magnolol has an inhibitory effect on the DNA damage induced by Trp‐P‐2 in various organsin vivo. This inhibitory mechanism is considered due toin vivoCYP1A2 inhibition. Copyright © 2009 John Wiley & Sons, Ltd.
Review of the pharmacological effects of Vitis vinifera (Grape) and its bioactive compounds
Authors: Nassiri‐Asl Marjan , Hosseinzadeh Hossein
Published: January 2009

Vitis vinifera, known as the grapevine, is native to southern Europe and Western Asia. Grape seed and skin contain several active components including flavonoids, polyphenols, anthocyanins, proanthocyanidins, procyanidines, and the stilbene derivative resveratrol. Grape seed extract in particular has been reported to possess a broad spectrum of pharmacological and therapeutic effects such as antioxidative, anti‐inflammatory, and antimicrobial activities, as well as having cardioprotective, hepatoprotective, and neuroprotective effects. Thus, the present review attempts to give a short overview on the pharmacological, toxicological, and clinical studies of grape and its active components. Copyright © 2009 John Wiley & Sons, Ltd.
Nettle extract (Urtica dioica) affects key receptors and enzymes associated with allergic rhinitis
Authors: Roschek Bill , Fink Ryan C. , McMichael Matthew , Alberte Randall S.
Published: January 2009

A nettle (Urtica dioica) extract shows in vitro inhibition of several key inflammatory events that cause the symptoms of seasonal allergies. These include the antagonist and negative agonist activity against the Histamine‐1 (H1) receptor and the inhibition of mast cell tryptase preventing degranulation and release of a host of pro‐inflammatory mediators that cause the symptoms of hay fevers. The nettle extract also inhibits prostaglandin formation through inhibition of Cyclooxygenase‐1 (COX‐1), Cyclooxygenase‐2 (COX‐2), and Hematopoietic Prostaglandin D2 synthase (HPGDS), central enzymes in pro‐inflammatory pathways. The IC50 value for histamine receptor antagonist activity was 251 (±13) µg mL−1 and for the histamine receptor negative agonist activity was 193 (±71) µg mL−1. The IC50 values for inhibition of mast cell tryptase was 172 (±28) µg mL−1, for COX‐1 was 160 (±47) µg mL−1, for COX‐2 was 275 (±9) µg mL−1, and for HPGDS was 295 (±51) µg mL−1. Through the use of DART TOF‐MS, which yields exact masses and relative abundances of compounds present in complex mixtures, bioactives have been identified in nettle that contribute to the inhibition of pro‐inflammatory pathways related to allergic rhinitis. These results provide for the first time, a mechanistic understanding of the role of nettle extracts in reducing allergic and other inflammatory responses in vitro. Copyright © 2009 John Wiley & Sons, Ltd.
On‐chip solid‐phase extraction pre‐concentration/focusing substrates coupled to atmospheric pressure matrix‐assisted laser desorption/ionization ion trap mass spectrometry for high sensitivity biomolecule analysis
Authors: Navare Arti , Nouzova Marcela , Noriega Fernando G. , Hernández‐Martínez Salvador , Menzel Christoph , Fernández Facundo M.
Published: January 2009

Atmospheric pressure matrix‐assisted laser desorption/ionization (AP‐MALDI) has proven a convenient and rapid method for ion production in the mass spectrometric (MS) analysis of biomolecules. AP‐MALDI and electrospray ionization (ESI) sources are easily interchangeable in most mass spectrometers. However, AP‐MALDI suffers from less‐than‐optimal sensitivity due to ion losses during transport from the atmosphere into the vacuum of the mass spectrometer. Here, we study the signal‐to‐noise ratio (S/N) gains observed when an on‐chip dynamic pre‐concentration/focusing approach is coupled to AP‐MALDI for the MS analysis of neuropeptides and protein digests. It was found that, in comparison with conventional AP‐MALDI targets, focusing targets showed (1) a sensitivity enhancement of approximately two orders of magnitude with S/N gains of 200–900 for hydrophobic substrates, and 150–400 for weak cation‐exchange (WCX) substrates; (2) improved detection limits as low as 5 fmol/µL for standard peptides; (3) significantly reduced matrix background; and (4) higher inter‐day reproducibility. The improved sensitivity allowed successful tandem mass spectrometric (MS/MS) sequencing of dilute solutions of a derivatized tryptic digest of a protein standard, and enabled the first reported AP‐MALDI MS detection of neuropeptides from Aedes aegypti mosquito heads. Copyright © 2009 John Wiley & Sons, Ltd.
Development and validation of a gas chromatography/mass spectrometry method for the metabolic profiling of human colon tissue
Authors: Mal Mainak , Koh Poh Koon , Cheah Peh Yean , Chan Eric Chun Yong
Published: January 2009

In this study, a gas chromatography/mass spectrometry (GC/MS) method was developed and validated for the metabolic profiling of human colon tissue. Each colon tissue sample (20 mg) was ultra‐sonicated with 1 mL of a mixture of chloroform/methanol/water in the ratio of 20:50:20 (v/v/v), followed by centrifugation, collection of supernatant, drying, removal of moisture using anhydrous toluene and finally derivatization using N‐methyl‐N‐trifluoroacetamide (MSTFA) with 1% trimethylchlorosilane (TMCS). A volume of 1 µL of the derivatized mixture was injected into the GC/MS system. A total of 53 endogenous metabolites were separated and identified in the GC/MS chromatogram, all of which were selected to evaluate the sample stability and precision of the method. Of the identified endogenous metabolites 19 belonging to diverse chemical classes and covering a wide range of the GC retention times (Rt) were selected to investigate the quantitative linearity of the method. The developed GC/MS method demonstrated good reproducibility with intra‐ and inter‐day precision within relative standard deviation (RSD) of ±15%. The metabolic profiles of the intact tissue were determined to be stable (100 ± 15%) for up to 90 days at −80°C. Satisfactory results were also obtained in the case of other stability‐indicating studies such as freeze/thaw cycle stability, bench‐top stability and autosampler stability. The developed method showed a good linear response for each of the 19 analytes tested (r2 > 0.99). Our GC/MS metabolic profiling method was successfully applied to discriminate biopsied colorectal cancer (CRC) tissue from their matched normal tissue obtained from six CRC patients using orthogonal partial least‐squares discriminant analysis [two latent variables, R2Y = 0.977 and Q2 (cumulative) = 0.877]. Copyright © 2009 John Wiley & Sons, Ltd.
Path planning in image space for autonomous robot navigation in unstructured environments
Authors: Otte Michael W. , Richardson Scott G. , Mulligan Jane , Grudic Gregory
Published: January 2009

Path planning systems using graph‐search algorithms such as A* usually operate in uniform plan‐view occupancy grids. However, the sensors used to construct these grids observe the environment in their own sample space based on sensor type and viewpoint. In this paper we present animage spacetechnique for path planning in unknown unstructured outdoor environments. Our method differs from previous techniques in that we perform path search directly in image space—the native sensor space of the imaging sensor. After an image space path has been found, it is used for navigation in the real world. By operating at the resolution of the image sensor, image space planning facilitates accurate robot vs. obstacle localization and enables a high degree of movement precision. Our image space planning techniques can potentially be used with many different kinds of sensor data, and we experimentally evaluate the use of stereo disparity and color information. We present an extension to the basic image space planning system called thecylindrical plannerthat simulates a 2π field of view with a cylindrically shaped occupancy grid. We believe that image space planning is well suited for use in the local subsystem of a hierarchical planner and implement ahybrid hierarchical plannerthat utilizes the cylindrical planner as a local planning subsystem and a two‐dimensional Cartesian planner as the global planning subsystem. All three systems are implemented and experimentally tested on a real robot. We evaluate the failure modes of image space planning and discuss how to avoid them. We find that image space enables precise real‐time, near‐field planning. © 2009 Wiley Periodicals, Inc.
Learning outdoor mobile robot behaviors by example
Authors: Roberts Richard , Pippin Charles , Balch Tucker
Published: January 2009

We present an implementation and analysis of a real‐time, online, supervised learning system for nonparametrically learning behaviors from a human trainer on a mobile robot in outdoor environments. This approach enables a human operator to train and tune robot behaviors simply by driving the robot with a remote control. Hand‐designed behaviors for outdoor environments often require many parameters, and complicated behaviors can be difficult or impossible to specify with a manageable number of parameters. Furthermore, their design requires knowledge of the robot's internal models and knowledge of the environment in which the behaviors will be used. In real‐world scenarios, we can design new behaviors using our learning system much more quickly than we can write hand‐crafted behaviors. We present the results of training the robot to execute several specialized and general‐purpose behaviors, including traversing a slalom, staying near “cover,” navigating on paths, navigating in an obstacle field, and general‐purpose navigation. Our system learns and executes most of these behaviors well after 1–4 h of operator training time. In quantitative tests, the learned behavior is not as robust as a hand‐crafted behavior but often completes obstacle courses more quickly. Additionally, we identify the factors that influence the effectiveness of this approach and investigate the properties of the training data provided by the human trainer. On the basis of our analyses, we suggest future work to ensure sufficient training, handle conflicting training examples, model robot dynamics, and further investigate dimensionality reduction of perception features. © 2009 Wiley Periodicals, Inc.
Cholinergic direct inhibition of N‐methyl‐D aspartate receptor‐mediated currents in the rat neocortex
Authors: Flores‐Hernandez Jorge , Salgado Humberto , De La Rosa Victor , Avila‐Ruiz Tania , Torres‐Ramirez Oswaldo , Lopez‐Lopez Gustavo , Atzori Marco
Published: January 2009

Acetylcholine (ACh) and N‐methyl‐D aspartate receptors (NMDARs) interact in the regulation of multiple important brain functions. NMDAR activation is indirectly modulated by ACh through the activation of muscarinic or nicotinic receptors. Scant information is available on whether ACh directly interacts with the NMDAR. By using a cortical brain slice preparation we found that the application of ACh and of other drugs acting on muscarinic or nicotinic receptors induces an acute and reversible reduction of NMDAR‐mediated currents (INMDA), ranging from 20 to 90% of the control amplitude. The reduction displayed similar features in synaptic INMDA in brain slices, as well as in currents evoked by NMDA application in brain slices or from acutely dissociated cortical cells, demonstrating its postsynaptic nature. The cholinergic inhibition of INMDA displayed an onset–offset rate in the order of a second, and was resistant to the presence of the muscarinic antagonist atropine (10 μM) in the extracellular solution, and of G‐protein blocker GDPβS (500 μM) and activator GTPγS (400 μM) in the intracellular solution, indicating that it was not G‐protein dependent. Recording at depolarized or hyperpolarized holding voltages reduced NMDAR‐mediated currents to similar extents, suggesting that the inhibition was voltage‐independent, whereas the reduction was markedly more pronounced in the presence of glycine (20 μM). A detailed analysis of the effects of tubocurarine suggested that at least this drug interfered with glycine‐dependent NMDAR‐activity. We conclude that NMDAR‐mediated current scan be inhibited directly by cholinergic drugs, possibly by direct interaction within one or more subunits of the NMDAR. Our results could supply a new interpretation to previous studies on the role of ACh at the glutamatergic synapse. Synapse 63:308–318, 2009. © 2009 Wiley‐Liss, Inc.
SV2 frustrating exocytosis at the semi‐diffusor synapse
Authors: Vautrin Jean
Published: January 2009

Presynaptic exocytosis is the mechanism commonly believed to release transmitters by diffusion through a pore opening during vesicular membrane fusion with the plasmalemma, but evidence suggesting that exocytosis and transmitter release are two separate steps of synaptic transmission is accumulating. Vesicular glycoconjugates such as Synaptic Vesicle Protein 2 (SV2) proteoglycans and gangliosides retain transmitters in a nondiffusible form and are transported to the synaptic cleft where they contribute forming a dense synaptomatrix. Transmitters are permanently present in synaptic clefts and readily releasable transmitter is easily accessible from the outer side of the presynaptic membrane suggesting that synaptomatrix glycoconjugates prevent immediate release after PKC‐dependent exocytosis. The calcium sensor synaptotagmin is also present at the presynaptic plasma membrane and binds SV2 suggesting a direct coupling between the calcium transient and transmitter release from the synaptomatrix. A quantitative coupling of the cytosolic calcic transient to transmitter release from the synaptomatrix explains better complexity and plasticity of miniature postsynaptic signals hitherto difficult to account for in exocytic terms. This alternative representation of synaptic transmission in which the same components of the synaptomatrix support adhesion and signaling functions may cast new lights on synaptic diseases such as Alzheimer's disease. Synapse 63:319–338, 2009. © 2009 Wiley‐Liss, Inc.
Fluoxetine administration modulates the cytoskeletal microtubular system in the rat hippocampus
Authors: Bianchi Massimiliano , Shah Ajit J. , Fone Kevin C.F. , Atkins Alan R. , Dawson Lee A. , Heidbreder Christian A. , Hows Mark E. , Hagan Jim J. , Marsden Charles A.
Published: January 2009

A number of studies suggest that stressful conditions can induce structural alterations in the hippocampus and that antidepressant drugs may prevent such deficits. In particular, the selective serotonin reuptake inhibitor (SSRI) fluoxetine was more effective in modulating different neuronal plasticity phenomena and related molecules in rat hippocampus. Cytoskeletal microtubule dynamics are fundamental to dendrites and axons remodeling, leading to the hypothesis that fluoxetine may affect the microtubular system. However, despite reports of stress‐induced alterations in microtubule dynamics by different stressors, only few studies investigated the in vivo effects of antidepressants on microtubules in specific rat brain regions. The present study investigated the dose‐related (1, 5, or 10 mg/kg i.p.) effects of acute and chronic (21 days) treatments with fluoxetine on the ratio of hippocampal α‐tubulin isoforms which is thought to reflect microtubule dynamics. Western Blot analysis was used to quantify α‐tubulin isoforms, high‐performance liquid chromatography and fluorescence detection was used to measure ex vivo monoamine metabolism. The results showed that acute fluoxetine increased the stable forms acetylated and detyrosinated α‐tubulin. Conversely, chronic fluoxetine decreased acetylated α‐tubulin, indicative of increased microtubule dynamics. The neuron‐specific Δ2‐Tubulin was increased by chronic fluoxetine indicating neuronal involvement in the observed cytoskeletal changes. Although acute and chronic fluoxetine similarly altered serotonin metabolism by inhibition of serotonin reuptake, this showed no apparent correlation to the cytoskeletal perturbations. Our findings demonstrate that fluoxetine administration modulates microtubule dynamics in rat hippocampus. The cytoskeletal effect exerted by fluoxetine may eventually culminate in promoting events of structural neuronal remodeling. Synapse 63:359–364, 2009. © 2009 Wiley‐Liss, Inc.
Magnetic quantum dots for multimodal imaging
Authors: Koole Rolf , Mulder Willem J. M. , van Schooneveld Matti M. , Strijkers Gustav J. , Meijerink Andries , Nicolay Klaas
Published: January 2009

Multimodal contrast agents based on highly luminescent quantum dots (QDs) combined with magnetic nanoparticles (MNPs) or ions form an exciting class of new materials for bioimaging. With two functionalities integrated in a single nanoparticle, a sensitive contrast agent for two very powerful and highly complementary imaging techniques [fluorescence imaging and magnetic resonance imaging (MRI)] is obtained. In this review, the state of the art in this rapidly developing field is given. This is done by describing the developments for four different approaches to integrate the fluorescence and magnetic properties in a single nanoparticle. The first type of particles is created by the growth of heterostructures in which a QD is either overgrown with a layer of a magnetic material or linked to a (superpara, or ferro) MNP. The second approach involves doping of paramagnetic ions into QDs. A third option is to use silica or polymer nanoparticles as a matrix for the incorporation of both QDs and MNPs. Finally, it is possible to introduce chelating molecules with paramagnetic ions (e.g., Gd‐DTPA) into the coordination shell of the QDs. All different approaches have resulted in recent breakthroughs and the demonstration of the capability of bioimaging using both functionalities. In addition to giving an overview of the most exciting recent developments, the pros and cons of the four different classes of bimodal contrast agents are discussed, ending with an outlook on the future of this emerging new field Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging
Nanostructured polymer scaffolds for tissue engineering and regenerative medicine
Authors: Smith I. O. , Liu X. H. , Smith L. A. , Ma P. X.
Published: January 2009

The structural features of tissue engineering scaffolds affect cell response and must be engineered to support cell adhesion, proliferation and differentiation. The scaffold acts as an interim synthetic extracellular matrix (ECM) that cells interact with prior to forming a new tissue. In this review, bone tissue engineering is used as the primary example for the sake of brevity. We focus on nanofibrous scaffolds and the incorporation of other components including other nanofeatures into the scaffold structure. Since the ECM is comprised in large part of collagen fibers, between 50 and 500 nm in diameter, well‐designed nanofibrous scaffolds mimic this structure. Our group has developed a novel thermally induced phase separation (TIPS) process in which a solution of biodegradable polymer is cast into a porous scaffold, resulting in a nanofibrous pore‐wall structure. These nanoscale fibers have a diameter (50–500 nm) comparable to those collagen fibers found in the ECM. This process can then be combined with a porogen leaching technique, also developed by our group, to engineer an interconnected pore structure that promotes cell migration and tissue ingrowth in three dimensions. To improve upon efforts to incorporate a ceramic component into polymer scaffolds by mixing, our group has also developed a technique where apatite crystals are grown onto biodegradable polymer scaffolds by soaking them in simulated body fluid (SBF). By changing the polymer used, the concentration of ions in the SBF and by varying the treatment time, the size and distribution of these crystals are varied. Work is currently being done to improve the distribution of these crystals throughout three‐dimensional scaffolds and to create nanoscale apatite deposits that better mimic those found in the ECM. In both nanofibrous and composite scaffolds, cell adhesion, proliferation and differentiation improved when compared to control scaffolds. Additionally, composite scaffolds showed a decrease in incidence of apoptosis when compared to polymer control in bone tissue engineering. Nanoparticles have been integrated into the nanostructured scaffolds to deliver biologically active molecules such as growth and differentiation factors to regulate cell behavior for optimal tissue regeneration Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Implantable Materials and Surgical Technologies > Nanomaterials and Implants
Archaeological analysis of Roman glass excavated from Zadar, Croatia, by a newly developed portable XRF spectrometer for glass
Authors: Tantrakarn K. , Kato N. , Hokura A. , Nakai I. , Fujii Y. , Gluščević S.
Published: January 2009

A newly developed portable x‐ray fluorescence spectrometer has been evaluated through the onsite and nondestructive analyses of 109 Roman glass artifacts excavated at a Roman cemetery found in Zadar, Croatia. The spectrometer has been designed for on‐site analysis of archaeological glass objects. The instrument consists of an x‐ray tube with a Pd target operated at up to 40 kV, silicon drift detector (SDD) with a polymer window, and an enlargeable vacuum sampling chamber. With this system, quantitative analysis of the light elements such as Na and Mg that are important components of glass, as well as heavy trace elements, was successfully carried out. The obtained results evidenced the use of Natron as fluxing agent with alkali contents of 14–22 wt% Na2O, 0.5 wt% MgO and 1.2 wt% Al2O3. In addition, it was found that the differences in the use of Mn and/or Sb as decolorizing agent in colorless bell‐shaped flasks collected from 10 different localities along the coast of Croatia comparing with the same type flasks excavated from Zadar. Copyright © 2009 John Wiley & Sons, Ltd.
The Vita Apostolica: Diversity or Dissent
Authors: McDonnell Ernest W.
Published: January 2009

The concept vita apostolica embraced three basic principles: imitation of the primitive church, poor, simple, and penitential, with interests and activities restricted to the spiritual domain; a passionate love for souls at home and far afield; and evangelical poverty in common, either predicated on mendicancy or mitigated by the work of one's own hands. It became, during the age of Gregorian reform and after, a compelling program instinct with the fervor, spontaneity, and humanity of the first community at Jerusalem (Acts, iv, 32; cf. Luke, x, 1–12). It postulated reform and criticism in a restless age of expanding economic and geographical horizons, a more rational political system, an increasingly complex social organization, a multiplicity of divergent intellectual currents, and corresponding new spiritual needs. Such a momentous evolution of society, challenging the status quo in all its parts, demanded a reappraisal of the resources and ends of the church, the most powerful and tenacious defender of tradition.