Specific Combinations (specific + combination)

Distribution by Scientific Domains


Selected Abstracts


Prevalence and correlates of comorbidity 8 years after a first psychotic episode

ACTA PSYCHIATRICA SCANDINAVICA, Issue 1 2007
S. Farrelly
Objective:, While rates and correlates of comorbidity have been investigated in the early course of psychosis, little is known about comorbidity in the medium-to-longer term or its relationship with outcome. Method:, A total of 182 first-episode psychosis (FEP) patients who met DSM-IV criteria for a current psychotic disorder 8 years after index presentation were grouped according to concurrent comorbidity [no concurrent axis I disorder; concurrent substance use disorder (SUD); other concurrent axis I disorder; concurrent SUD and other axis I disorder]. Outcomes were compared between groups controlling for relevant covariates. Results:, As much as 39% met criteria for one or more concurrent axis 1 diagnoses. Comorbidity was associated with greater severity of general psychopathology, but not with measures of functioning, treatment or negative symptoms. Conclusion:, Specific combinations of comorbid disorders may influence patterns of psychotic symptomatology. Routine examination of axis I disorders is warranted in the ongoing management of psychosis. [source]


HBV core sequence: definition of genotype-specific variability and correlation with geographical origin

JOURNAL OF VIRAL HEPATITIS, Issue 6 2004
M. Jazayeri
Summary., There are eight genotypes and nine subtypes of HBV. Small differences in geographical origin are associated with sequence changes in the surface gene. Here, we compared core gene sequences from different genotypes and geographical regions. Specific combinations of 24 amino acid substitutions at nine residues allowed allocation of a sequence to a subtype. Six of these nine residues were located in different T cell epitopes depending on HBV geographical area and/or genotype. Thirty-seven nucleotide changes were associated uniquely with specific genotypes and subtypes. Unique amino acid and nucleotide variants were found in a majority of sequences from specific countries as well as within subtype ayw2 and adr. Specific nucleotide motifs were defined for Korean, Indian, Chinese, Italian and Pacific region isolates. Finally, we observed amino acid motifs that were common to either South-east Asian or Western populations, irrespective of subtype. We believe that HBV strains spread within constrained ethnic groups, result in selection pressures that define sequence variability within each subtype. It suggests that particular T cell epitopes are specific for geographical regions, and thus ethnic groups; this may affect the design of immunomodulatory therapies. [source]


Novel design of multicapillary arrays for high-throughput DNA sequencing

ELECTROPHORESIS, Issue 14 2006
Andriy Tsupryk Dr.
Abstract A novel approach to design and optimize linear multicapillary arrays,(LMCAs) for high-throughput DNA sequencing is proposed. A significant increase in the number of capillary lanes is obtained due to the use of composite insertions alternately placed between working capillaries of the array and a specific combination of refractive indices of the DNA separation matrix, capillary glass, the insertions and a medium which surrounds the capillary array. Theoretical and experimental studies showed that in conjunction with a dual-side laser illumination scheme, the proposed LMCA design allows a simultaneous uniform irradiation of as many as 550,working capillaries. [source]


Toxicity of total dissolved solids associated with two mine effluents to chironomid larvae and early life stages of rainbow trout

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2000
Peter M. Chapman
Abstract Asessment of total dissolved solids (TDS) represents anintegrated measure of the concentrations of common ions (e.g., sodium, potassium, calcium, magnesium, chloride, sulfate, and bicarbonate) in freshwaters. Toxicity related to these ions is due to the specific combination and concentration of ions and is not predictable from TDS concentrations. Short-term chronic toxicity tests were conducted with larval chironomids and trout (eggs and swim-up fry) to assess their TDS tolerance relative to effluents from two Alaskan mines. Both effluents are characterized by high TDS content but differ with respect to concentrations of specific ions and alkalinity. The toxicity tests were conducted with synthetic effluents formulated to match the ionic composition of each mine discharge. No toxicity was observed at >2,000 mg of TDS/L with embryos or developing fry, but chironomids exhibited effects above 1,100 mg of TDS/L. These tests, together with information on the health of field populations (fish and benthic invertebrates), are appropriate and relevant for determining site-specific whole effluent TDS concentrations. [source]


Combination of Clk family kinase and SRp75 modulates alternative splicing of Adenovirus E1A

GENES TO CELLS, Issue 3 2008
Jun-ichiro Yomoda
SR proteins are non-snRNP splicing factors harbouring a domain rich in Arg-Ser repeats, which are extensively phosphorylated by several kinases. We performed a comparative study of different SR kinases, including SRPK, Clk, PRP4 and DYRK, and found that only Clks efficiently altered 5, splice site selection of Adenovirus E1A. The phosphorylation state of SR proteins was examined using a phospho-SR specific antibody mAb1H4 and a 75 kDa protein was most evidently hyperphosphorylated by Clks. Administration of TG003, a specific inhibitor for the Clk family members, specifically and rapidly induced dephosphorylation of 75 kDa SR protein. Imaging with mRFP-SRp75 in living cells revealed that its nuclear distribution was rapidly altered upon inhibition of the Clk activity by TG003. Co-transfection experiments demonstrated that HA-tagged SRp75 was hyperphosphorylated by Clk family members, but not by other SR kinases. These results indicate that Clks specifically hyperphosphorylate SRp75. Furthermore, SRp75 over-expression promoted the selection of 12S 5, splice site in E1A pre-mRNA, which is stimulated by co-expression of Clks. These results suggest that the specific combination of SR protein and SR kinase plays a distinct role in alternative splicing through dynamic balance of phosphorylation. [source]


A plate assay for simultaneous screening of polysaccharide- and protein-degrading micro-organisms

LETTERS IN APPLIED MICROBIOLOGY, Issue 2 2005
L.N. Ten
Abstract Aims:, To develop a plate assay for simultaneous screening of polysaccharide-degrading and protein-degrading micro-organisms. Methods and Results:, A plate assay, based on the visible solubilization of small substrate particles and the formation of haloes on Petri dishes, containing a mixture of diversely coloured insoluble polysaccharides and dye-labelled collagen as chromogenic substrates, was developed. This method was successfully applied for isolating the diverse polysaccharide- and/or protein-degrading bacteria from soil and sludge samples. Selected strains were identified using 16S rDNA partial sequencing; most of them belong to the genera Bacillus, Cellulomonas and Cellulosimicrobium. Conclusions:, This novel approach provides unique and valuable information for direct primary screening when the target of selection is micro-organisms exhibiting protein-degrading activity, polysaccharide-degrading activity or a specific combination of them. Significance and Impact of the Study:, This plate assay is convenient and easy to perform, rapid, and more adaptable for screening of a large number of samples, compared with other existing methods in the literature. [source]


The spatial scale of adaptive population differentiation in a wide-spread, well-dispersed plant species

OIKOS, Issue 12 2008
Ute Becker
Adaptation to the specific conditions at different sites may contribute strongly to the wide distribution of a plant species. However, little is known about the scale at which such adaptation occurs in common species. We studied population differentiation, plasticity and local adaptation of the short-lived perennial Hypochoeris radicata, a widespread and common plant whose seeds are well-dispersed. We reciprocally transplanted seedlings among several populations of different size within and among three European regions (in the northwest Czech Republic, central Germany and the central Netherlands) and studied several fitness-related traits over two growing seasons. The region in which the reciprocal transplant experiment was carried out had no influence on the performance of seedlings, indicating that there were no differences in overall habitat quality. In contrast, the site within region, and the plot within site strongly influenced mean plant performance. Plants from different populations of origin differed in their performance, indicating genetic variation among populations, but performance strongly depended on the specific combination of population of origin and transplant site. Plants that grew at their home site produced on average almost twice the number of seeds per transplant (a multiplicative fitness measure) than foreign plants originating from other sites. Survival, rosette size and multiplicative fitness all decreased with increasing distance from the home site to the transplant site. The size of the population of origin did not influence overall plant performance or the strength of local adaptation. In conclusion, our results indicate that the common and widespread H. radicata consists of locally adapted genotypes within its European range at a relatively small scale. Thus a large potential for gene flow by seeds and a high density of populations do not appear to be sufficient to prevent population differentiation by selection. [source]


Effect of a novel botanical agent Drynol Cibotin on human osteoblast cells and implications for osteoporosis: promotion of cell growth, calcium uptake and collagen production

PHYTOTHERAPY RESEARCH, Issue S2 2010
Barbara Wegiel
Abstract Osteoporosis is a widespread problem afflicting millions of people. Drynol Cibotinis is a newly developed proprietary botanical combination of eight botanicals including Angelica sinensis, Glycine max, Wild yam, Ligustrum lucidum, Astragalus membranaceus, Cuscuta chinensis, Psoraleae corylifoliae, and Drynaria fortune. Each of the botanicals has been used in traditional Chinese medicine to treat osteoporosis. The effect of Drynol Cibotinis, with the specific combination of these anti-osteoporosis botanicals for promoting bone growth, was examined in this study. The effects of Drynol Cibotin on cell growth, apoptosis, cell spreading, calcium uptake and production of bone matrix proteins Collagen I and Laminin B2 on human osteoblast cells were assessed by BrdU incorporation, TUNEL assay, cell staining, intracellular Ca2+ measurement and Western blot analysis. The results showed that Drynol Cibotin significantly increased cell proliferation and inhibited apoptosis in osteoblasts (P < 0.01). In addition, Drynol Cibotin was found to promote cell spreading and greatly increase calcium uptake both instantaneously and in the long term (P < 0.01). Furthermore, Drynol Cibotin significantly increased production of two key extracellular matrix proteins in bone cells: Collagen I and Laminin B2. These results indicate that Drynol Cibotin alone or in combination with amino acids and vitamins may have prophylactic potentials in osteoporosis. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Fibroblast Growth Factor 2 Promotes Endothelial Differentiation of Adipose Tissue-Derived Stem Cells

THE JOURNAL OF SEXUAL MEDICINE, Issue 4 2009
Hongxiu Ning PhD
ABSTRACT Introduction., Adipose tissue-derived stem cells (ADSC) could potentially restore endothelial function in vasculogenic erectile dysfunction (ED). The mechanism for ADSC endothelial differentiation remained unidentified. Aim., To test whether ADSC could differentiate into endothelial cells in the penis and to identify the underlying mechanism of ADSC endothelial differentiation. Methods., For in vivo endothelial differentiation, ADSC were labeled with bromodeoxyuridine (BrdU), injected into rat corpora cavernosa, and localized by immunofluorescence and phase-contrast microscopy. For in vitro endothelial differentiation, ADSC were grown in endothelial growth medium 2 (EGM2), stained for endothelial markers CD31, von Willebrand Factor (vWF), and endothelial nitric oxide synthase (eNOS), and assessed for the ability to form tube-like structures in Matrigel and to endocytose acetylated low-density lipoprotein (Ac-LDL). To identify factors that promote ADSC endothelial differentiation, ADSC were grown in various media, each of which contained a specific combination of supplemental factors and assessed for LDL-uptake. PD173074, a selective inhibitor of fibroblast growth factor 2 (FGF2) receptor, was used to confirm the importance of FGF2 signaling for ADSC endothelial differentiation. Main Outcome Measures., In vivo endothelial differentiation was assessed by immunofluorescence microscopy. In vitro endothelial differentiation was assessed by immunofluorescence, Matrigel tube formation, and Ac-LDL uptake. Results., Injected ADSC were localized to the sinusoid endothelium, some of which stained positive for both BrdU and endothelial antigen rat endothelial cell antigen. ADSC proliferated at a faster rate in EGM2 than in standard DMEM, expressed endothelial markers CD31, vWF, and eNOS, formed tube-like structures in Matrigel, and endocytosed Ac-LDL. These properties were greatly diminished when ADSC were grown in the absence of FGF2 but were unaffected when grown in the absence of vascular endothelial growth factor, insulin-like growth factor, or epidermal growth factor. Furthermore, ADSC displayed similar endothelial properties when grown in FGF2-supplemented basic medium as in EGM2. Finally, blockade of FGF2 signaling with PD173074 abrogated ADSC endothelial differentiation. Conclusions., ADSC could differentiate into endothelial cells in the penis. FGF2 signaling mediates ADSC endothelial differentiation. Ning H, Liu G, Lin G, Yang R, Lue TF, and Lin CS. FGF2 promotes endothelial differentiation of adipose tissue-derived stem cells. J Sex Med **;**:**,**. [source]


Invisible Fences: Egalitarianism, Nationalism and Racism

THE JOURNAL OF THE ROYAL ANTHROPOLOGICAL INSTITUTE, Issue 1 2002
Marianne Gullestad
With its specific combination of a bureaucratic welfare state and an open, globalized capitalist economy, Norway, along with the other Nordic countries, provides a particularly interesting context for the examination of the relationship between egalitarianism, nationalism, and racism in Europe. A racialization of difference takes place, as immigration emerges as a site for racial and racist discourse, and as a site of conjuncture between the welfare state and its citizens. By presenting an analysis of the contemporary debate on immigration in Norway, this article demonstrates how equality conceived as sameness (,imagined sameness') underpins a growing ethnification of national identity. Widely different utterances and points of view refer to metaphors of home and family life, a close link between territory and generalized kinship, and the renewed importance of Lutheran Christianity in contrast to Islam. A model of group identity and relationship is therefore suggested, in which organizational boundaries and cultural substance inflect one another, rather than being the bases of different or even opposed approaches. It is also argued that anthropologists need to take a more serious interest in the European majority populations. [source]


Professional Basketball's Unsportsmanlike Fouls in the Eyes of the Beholders

APPLIED PSYCHOLOGY, Issue 3 2010
Michael Bar-Eli
A series of three experiments, based on the method of Functional Measurement, has explored the importance assigned by professional basketball players to relevant dispositions of defense and offense players, as determinants of unsportsmanlike fouls. The 106 participants were leading male players in the premier basketball league in Israel. Experiment 1 was based on a 16 (24)-cell model. In an individual meeting, each participant estimated the likelihood that a defense player would commit an unsportsmanlike foul on an offense player. In each of the 16 to-be-judged incidents, specific information on a specific combination of aggressiveness and susceptibility to victimisation of two imaginary protagonists in an offense,defense on-the-court incident was given to the participant. Experiment 2 was a replication of Experiment 1. There, however, names of 16 well-known players were mentioned, the aggressiveness and susceptibility to victimisation of each fitting the model requirements. In Experiment 3, a partial replication of Experiment 2, likelihood estimations were made from two perspectives,potential perpetrator and potential victim. Overall, meaningful importance was assigned especially to the dispositions of the perpetrator, not the victim. The findings are conceived as reflections of players' cognitive schemata of on-the-court violence. Basée sur la méthode de la mesure fonctionnelle, une série de 3 expérimentations a exploré l'importance que des joueurs de basket professionnels attribuent aux dispositions de joueurs attaquant ou défenseur à commettre des fautes anti sportives. Les 106 sujets sont des joueurs de sexe masculin de la ligue 1 de basket israélienne. L'expérience 1 est basée sur un modèle à 16 (24) cases. Lors de passation individuelle, chaque participant estime la probabilité qu'un joueur arrière commette une faute anti sportive sur un joueur avant. Pour chacun des 16 incidents à juger, une information spécifique a été donnée aux participants. Il s'agissait d'une combinaison particulière de l'agressivité et de la propension à la victimisation des deux protagonistes imaginaires dans une situation d'incident soit offensif soit défensif sur le terrain. L'expérimentation 2 est une réplique de la première. Cependant, les noms de 16 joueurs connus sont mentionnés, l'agressivité et la propension à la victimisation étaient appropriées aux exigences du modèle. Dans l'expérience 3, réplique partielle de la deuxième, la probabilité des estimations a été faite selon deux perspectives: auteur potentiel et victime potentielle. Globalement, une importance significative a été assignée aux dispositions de l'auteur et non de la victime. Les résultats sont conçus comme reflétant le schéma cognitif des joueurs lors de violence sur le terrain. [source]


5-Alpha- and 5-beta-2-deoxyintegristerone A, a 5-alpha and 5-beta isomer pair of ecdysteroids isolated from the Silene genus

BIOMEDICAL CHROMATOGRAPHY, Issue 6 2002
M. Báthori
5-Alpha-2-deoxyintegristerone A and 5-beta-2-deoxyintegristerone A were isolated from the aerial parts of Silene italica ssp. nemoralis (Waldst. and Kit.) Nyman using a specific combination of absorption column chromatography, preparative thin-layer chromatography and preparative HPLC. Both normal-phase and reversed-phase modes of HPLC were employed for isolation. Structural elucidation of 5-alpha-2-deoxyintegristerone A was completed by X-ray diffraction. Both 5-alpha-2-deoxyintegristerone A and 5-beta-2-deoxyintegristerone A were firstly isolated from this plant. We propose that 5-alpha-2-deoxyintegristerone A is not an artifact but an integral part of the ecdysteroid spectrum of Silene italica ssp. nemoralis (Waldst. and Kit.) Nyman. Copyright © 2002 John Wiley & Sons, Ltd. [source]


On the Use of the Moving Average Trading Rule to Test for Weak Form Efficiency in Capital Markets

ECONOMIC NOTES, Issue 2 2008
Alexandros E. Milionis
The examination for the possible existence of predictive power in the moving average trading rule has been used extensively to test the hypothesis of weak form market efficiency in capital markets. This work focuses mainly on the study of the variation of the moving average (MA) trading rule performance as a function of the length of the longer MA. Empirical analysis of daily data from NYSE and the Athens Stock Exchange reveal high variability of the performance of the MA trading rule as a function of the MA length and on some occasions the series of successive trading rule total returns is non-stationary. These findings have direct implications in weak form market efficiency testing. Indeed, given this high variability of the performance of the MA trading rule, by just finding out that trading rules with some specific combinations of MA lengths can or cannot beat the market, as is the case in most of the published work thus far, is not enough evidence for or against the existence of weak form market efficiency. Results also show that on average in about three out of four cases trading rule signals are false, a fact that leaves a lot of space for improved trading rule performance if trading rule signals are combined with other information (e.g. filters, or volume of trade). Finally, some evidence of enhanced trading rule performance for the shorter MA lengths was found. This enhanced performance is partly attributed to the higher probability that a trading rule signal is not a whipsaw, as well as to the larger number of days out-of-the-market which are associated with shorter MA lengths. [source]


Compositionally Graded Steels: A Strategy for Materials Development,

ADVANCED ENGINEERING MATERIALS, Issue 12 2009
Béchir Chéhab
A topic of increasing importance in Materials Science is the optimization of microstructures to attain specific combinations of properties. Especially interesting are the design requirements where conflicting properties have to be simultaneously fulfilled. Compositionally graded and architectured materials, in which the properties change over space provide a means of meeting these challenging design requirements. [source]


Designed Fabrication of Silica-Based Nanostructured Particle Systems for Nanomedicine Applications,

ADVANCED FUNCTIONAL MATERIALS, Issue 23 2008
Yuanzhe Piao
Abstract Suitably integrating multiple nanomaterials into nanostructured particle systems with specific combinations of properties has recently attracted significant attention in the research community. In particular, numerous particle systems have been designed and fabricated by integrating diverse materials with monodispersed silica nanoparticles. One or more distinct nanomaterials can be assembled on, encapsulated within, or integrated both inside and on the surface of silica nanoparticles using different chemistries and techniques to create multifunctional nanosystems. Research on these particle systems for biomedical applications has progressed rapidly during recent years due to the synergistic advantages of these complexes compared to the use of single components. This feature article surveys recent research progress on the fabrication strategies of these nanoparticle systems and their applications to medical diagnostics and therapy, thereby paving the way for the emerging field of nanomedicine. [source]


Soil frost effects on soil water and runoff dynamics along a boreal transect: 2.

HYDROLOGICAL PROCESSES, Issue 6 2001
Simulations
Abstract A physically based SVAT-model was tested with soil and snow physical measurements, as well as runoff data from an 8600 m2 catchment in northern Sweden in order to quantify the influence of soil frost on spring snowmelt runoff in a moderately sloped, boreal forest. The model was run as an array of connected profiles cascading to the brook. For three winter seasons (1995,98) it was able to predict the onset and total accumulation of the runoff with satisfactory accuracy. Surface runoff was identified as only a minor fraction of the total runoff occurring during short periods in connection with ice blocking of the water-conducting pores. Little surface runoff, though, does not mean that soil frost is unimportant for spring runoff. Simulations without frost routines systematically underestimated the total accumulated runoff. The possibility of major frost effects appearing in response to specific combinations of weather conditions were also tested. Different scenarios of critical initial conditions for the winter, e.g. high water saturation and delayed snow accumulation leading to an increased frost penetration, were tested. These showed that under special circumstances there is potential for increased spring runoff due to soil frost. Copyright © 2001 John Wiley & Sons, Ltd. [source]


A High-Throughput Assay of Cell-Surface Interactions using Topographical and Chemical Gradients,

ADVANCED MATERIALS, Issue 3 2009
Jing Yang
Orthogonal wettability and topographical gradients in a combinatorial sample format are fabricated using plasma-polymer-coated microgrooved surfaces. Preferred cell proliferation is found on specific combinations of topography and chemistry. This proof-of-concept study demonstrates the potential applications of this sample format for investigating the relationship between multiple surface properties on cellular response in a high-throughput manner. [source]


Property enhancement of epoxy resins by using a combination of polyamide and montmorillonite

ADVANCES IN POLYMER TECHNOLOGY, Issue 4 2007
M. Bakar
Abstract A bisphenol-A epoxy resin cured with triethylenetetramine was modified with the addition of a polyamide oligomer and a small amount of montmorillonite. Compositions with different amounts of modifiers were obtained and tested for their impact strength, flexural strength, and resistance to crack propagation. The latter was assessed by measuring the critical stress intensity factor in a three-point bending mode. Scanning electron microscopy was used to examine the sample fracture surfaces. It was found that the addition of 2% montmorillonite or 5% polyamide resulted in the best improvement of the impact strength and the critical stress intensity factor relative to the unmodified epoxy resin. However, the flexural strength and toughness measured under three-point bending mode was found to increase to a lesser extent. Hybrid compositions containing specific combinations of both modifier and nanofiller not only exhibited a higher impact strength and resistance to crack propagation but also displayed a synergistic effect in relation to the fracture energy. The results indicate that the improvement in mechanical properties of the epoxy resin was due to the formation of a heterogeneous morphology resulting from phase separation of the polymeric modifier. From the scanning electron microscopy and thermal analysis, it appears that the toughening may arise from chemical reactions that have taken place between the epoxy resin and the polymeric modifier, which was partially solubilized in the resin matrix. © 2008 Wiley Periodicals, Inc. Adv Polym Techn 26:223,231, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20103 [source]


Benzodiazepines and injury: a risk adjusted model,,

PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 1 2005
Dustin D. French MA
Abstract Background Benzodiazepines (BZD) are one class of medications that are generally acknowledged to be a risk factor for injuries. Objective Our objective was to link outpatient prescription data with clinical data in order to develop a risk adjusted binary model that associates BZD usage with the risk for a healthcare encounter for an injury. Methods In total, 3 years of outpatient BZD prescription data, totaling 133,872 outpatient BZD prescriptions for 13,745 patients for a VA medical center, were combined with data from inpatient and outpatient administrative databases. The model incorporated Elixhauser comorbidity measures with 1-year look back period, along with hospital discharges, marital status, age, mean arterial pressure and body mass index. The model also included the dose of the drug, converted to valium equivalents and its duration. The model was analyzed using generalized estimation equations (GEE). Results Dose, duration, discharges and various comorbidities were associated with an increased risk for injury, while being married reduced the risk. Increased body mass was associated with increased injury risk. Increased mean arterial pressure was associated with decreased risk. Conclusions These findings offer guidance on how specific combinations of risk factors and potential protective effects may impact accidental injury risk. Clinicians prescribing or adjusting BZDs can use these results to more accurately tailor medication regimens for a patient. Our findings suggest that clinicians should also consider the nature of the social support system available to the patient in assessing total injury risk. Copyright © 2004 John Wiley & Sons, Ltd. [source]


Genetic variation of chloroplast DNA in Zingiberaceae taxa from Myanmar assessed by PCR,restriction fragment length polymorphism analysis

ANNALS OF APPLIED BIOLOGY, Issue 1 2009
D. Ahmad
Abstract We examined genetic variation in 22 accessions belonging to 11 species in four genera of the Zingiberaceae, mainly from Myanmar, by PCR,restriction fragment length polymorphism analysis to investigate their relationships within this family. Two of 10 chloroplast gene regions (trnS-trnfM and trnK2,trnQr) showed differential PCR amplification across the taxa. Restriction enzyme digestion of the PCR products revealed interspecific variability. The restriction patterns were used to classify the regions as either highly conserved or variable across the taxa. None of the regions was highly conserved across the four genera, and the level of conservation varied. The gene region trnS-trnfM appeared to display interspecific variability among most of the species. However, the relative efficiency of different restriction enzymes depended on the gene regions and genera investigated. Cluster analysis revealed interspecific discrimination among the taxa. The two Curcuma species (Curcuma zedoaria and Curcuma xanthorrhiza) appeared to be identical, thus supporting their recent classification as synonyms. The results provide the basis for selecting specific combinations of restriction enzymes and gene regions of chloroplast DNA (cpDNA) to identify interspecific variation in the Zingiberaceae and to identify both highly conserved and variable regions. Overall, cpDNA depicted comparatively diverse genetic profile of the studied germplasm. The genetic information revealed here can be applied to the conservation and future breeding of Zingiber and Curcuma species. [source]


Mitochondrial DNA variability in Poles and Russians

ANNALS OF HUMAN GENETICS, Issue 4 2002
B. A. MALYARCHUK
Mitochondrial DNA (mtDNA) sequence variation was examined in Poles (from the Pomerania-Kujawy region; n = 436) and Russians (from three different regions of the European part of Russia; n = 201), for which the two hypervariable segments (HVS I and HVS II) and haplogroup-specific coding region sites were analyzed. The use of mtDNA coding region RFLP analysis made it possible to distinguish parallel mutations that occurred at particular sites in the HVS I and II regions during mtDNA evolution. In total, parallel mutations were identified at 73 nucleotide sites in HVS I (17.8%) and 31 sites in HVS II (7.73%). The classification of mitochondrial haplotypes revealed the presence of all major European haplogroups, which were characterized by similar patterns of distribution in Poles and Russians. An analysis of the distribution of the control region haplotypes did not reveal any specific combinations of unique mtDNA haplotypes and their subclusters that clearly distinguish both Poles and Russians from the neighbouring European populations. The only exception is a novel subcluster U4a within subhaplogroup U4, defined by a diagnostic mutation at nucleotide position 310 in HVS II. This subcluster was found in common predominantly between Poles and Russians (at a frequency of 2.3% and 2.0%, respectively) and may therefore have a central-eastern European origin. [source]


Region-specific effects of N,N,-dodecane-1,12-diyl-bis-3-picolinium dibromide on nicotine-induced increase in extracellular dopamine in vivo

BRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2008
S Rahman
Background and purpose: Systemic administration of N,N,-dodecane-1,12-diyl-bis-3-picolinium dibromide (bPiDDB), an antagonist of nicotinic acetylcholine receptors (nAChRs) attenuated the nicotine-induced increase in dopamine levels in nucleus accumbens (NAcc). Experimental approach: Using in vivo microdialysis, we investigated the effects of local perfusion of the novel nAChR antagonist bPiDDB into the NAcc or ventral tegmental area (VTA) on increased extracellular dopamine in NAcc, induced by systemic nicotine. We also examined the concentration-dependent effects of bPiDDB on the acetylcholine (ACh)-evoked response of specific recombinant neuronal nAChR subtypes expressed in Xenopus oocytes, using electrophysiological methods. Key results: Nicotine (0.4 mg kg,1, s.c.) increased extracellular dopamine in NAcc, which was attenuated by intra-VTA perfusion of mecamylamine (100 ,M). Intra-VTA perfusion of bPiDDB (1 and 10 ,M) reduced nicotine-induced increases in extracellular dopamine in NAcc. In contrast, intra-NAcc perfusion of bPiDDB (1 or 10 ,M) failed to alter the nicotine-induced increase in dopamine in NAcc. Intra-VTA perfusion of bPiDDB alone did not alter basal dopamine levels, compared to control, nor the increased dopamine in NAcc following amphetamine (0.5 mg kg,1, s.c.). Using Xenopus oocytes, bPiDDB (0.01,100 ,M) inhibited the response to ACh on specific combinations of rat neuronal nAChR subunits, with highest potency at ,3,4,3 and lowest potency at ,6/3,2,3. Conclusions and implications: bPiDDB-Sensitive nAChRs involved in regulating nicotine-induced dopamine release are located in the VTA, rather than in the NAcc. As bPiDDB has properties different from the prototypical nAChR antagonist mecamylamine, further development may lead to novel nAChR antagonists for the treatment of tobacco dependence. British Journal of Pharmacology (2008) 153, 792,804; doi:10.1038/sj.bjp.0707612; published online 3 December 2007 [source]


Evaluation of the conformational propensities of peptide isosteres as a basis for selecting bioactive pseudopeptides

CHEMICAL BIOLOGY & DRUG DESIGN, Issue 6 2001
S. Gupta
Abstract: Our aim was to compare the repertoires of conformers formed by the model zwitterionic peptides AA and AAA in aqueous solution with the conformational profiles of a range of their peptide isosteres, so as to facilitate selection of isosteres for synthesis and testing as biologically stable surrogates of bioactive di- and tripeptides. Comparisons were based upon the results of conformational analysis using a random search approach implemented within the SYBYL molecular modelling package, using zwitterionic molecules, simulated aqueous solvation using a dielectric constant of 80 and allowing all torsions to vary. For each compound, individual conformers were grouped on the basis of specific combinations of psi, phi and omega torsions and, using their energies, the aggregated percentage for each group was calculated using a Boltzmann distribution and displayed using a 3D pseudo Ramachandran plot relating percentage conformer to psi and phi torsions. Retroamide, N -methylamide and thioamide isosteres showed the best match to natural peptides and to the molecular recognition parameters defined for substrates of peptide transporters. The results should aid rational design of therapeutic agents in various areas, e.g. oral delivery of drugs by peptide transporters and of peptidase inhibitors. This approach may usefully be applied to various biochemical and pharmaceutical topics. [source]


Modeling Growth Rate Dispersion in Industrial Crystallizers

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 3 2003
G.M. Westhoff
Abstract The phenomenon of healing appears to be a plausible explanation for the growth rate dispersion observed in many industrial crystallizers. In this paper a growth model is postulated, which describes the healing of plastically deformed attrition fragments. The rate of healing is assumed to be inversely proportional to the initial strain and to the rate of change of either the length, the area, or the volume of the crystal. The validity of the proposed model is verified by the simulation of growth of the smallest crystals (L0) in time in a growth experiment for specific combinations of the model parameters. In addition, the applicability of the proposed model is evaluated through simulations of steady state experimental data obtained in a 75-liter Draft Tube (DT) crystallizer. It is concluded that the proposed model is able to fit reasonably well the experimental crystal size distribution. The model predicts the existence of a ,dead time' during which attrition fragments with large initial strain do not grow and which may last several residence times. [source]