Great Difference (great + difference)

Distribution by Scientific Domains


Selected Abstracts


Antimicrobial resistance in the subgingival microflora in patients with adult periodontitis

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2000
A comparison between The Netherlands, Spain
Abstract Background: The widespread use of antibiotics for prophylaxis and treatment of bacterial infections has lead to the emergence of resistant human pathogens. Great differences have been documented between European countries in the use of systemic antibiotics. In parallel, significant differences in levels of resistant pathogens have been documented. Aim: To investigate whether differences in antibiotic use influence the level of antimicrobial resistance of the subgingival microflora of untreated patients with adult periodontitis in The Netherlands and Spain. Method: Blood agar plates containing breakpoint concentrations of penicillin, amoxicillin, amoxicillin and clavunalate, metronidazole, erythromycin, azithromycin, clindamycin and tetracycline were used to determine the proportion of bacteria from the subgingival plaque that was resistant to these antibiotics. In the Spanish patients, statistically significant higher mean levels of resistance were found for penicillin, amoxicillin, metronidazole, clindamycin and tetracycline. The mean number of different bacterial species growing on the selective plates was higher in the Spanish patients, as was the % of resistant strains of most periodontal pathogens. A striking difference was observed in the frequency of occurrence of tetracycline-resistant periodontal pathogens. In Spain, 5 patients had 3 tetracycline resistant periodontal pathogens, whereas this was not observed in any of the Dutch patients. Conclusions: The widespread use of antibiotics in Spain is reflected in the level of resistance of the subgingival microflora of adult patients with periodontitis. [source]


Mediators of rat ischemic hepatic preconditioning after cold preservation identified by microarray analysis

LIVER TRANSPLANTATION, Issue 11 2006
Ŕurea Navarro-Sabaté
Hepatic ischemia-reperfusion injury associated with liver transplantation is an as yet unresolved problem in clinical practice. Preconditioning protects the liver against the deleterious effects of ischemia, although the mechanism underlying this preconditioning is still unclear. To profile gene expression patterns involved in hepatic ischemic preconditioning, we analyzed the changes in gene expression in rat livers by DNA microarray analysis. Approximately 116 genes were found to have altered gene expression after 8 hours of cold ischemia. Moreover, the expression of 218 genes was modified by classic preconditioning followed by the same ischemia process. Given the importance of the effects of ischemic preconditioning (IP) in minimizing the liver damage induced by sustained ischemia before reperfusion, this study analyzed the putative genes involved in the beneficial role of IP in liver grafts undergoing cold ischemia before its implantation in the recipient (IP+I). Great differences were found in the gene expression pattern of ischemic preconditioning + long cold ischemia (IP+I) group when compared with the long cold ischemia alone condition (I), which could explain the protective regulatory mechanisms that take place after preconditioning. Twenty-six genes that were downregulated in cold ischemia were found upregulated after preconditioning preceding a long cold ischemia period. These would be genes activated or maintained by preconditioning. Heat shock protein genes and 3-hydroxy-3-methylglutaryl-coenzyme A reductase are among the most markedly induced transcripts. Liver Transpl. 12:1615,1625, 2006. © 2006 AASLD. [source]


Transcriptome analysis of barley anthers: effect of mannitol treatment on microspore embryogenesis

PHYSIOLOGIA PLANTARUM, Issue 4 2006
María Muńoz-Amatriaín
Carbohydrate starvation is an efficient stress treatment for induction of microspore embryogenesis. Transcriptome analysis of the response of anthers to mannitol treatment using the 22k Barley1 GeneChip revealed large changes in gene expression. Statistical analysis and filtering for four-fold or greater changes resulted in 2673 genes, of which 887 were upregulated and 1786 downregulated. Great differences in some metabolic pathways, accompanied by a multidimensional stress response, were found. Analysis of transcription factors showed that most of the downregulated transcription factors were related to growth and development, and the upregulated factors with abiotic and biotic stress responses and changes in developmental programs. Interestingly, the expression of most cell cycle-related genes did not change significantly. Transcriptome analysis provided a successful approach for the identification of genes involved in mannitol treatment, essential for triggering microspore embryogenesis. [source]


Who owns the universities?

ECONOMIC AFFAIRS, Issue 3 2001
The battle for university independence, against the dependency culture
Universities have lapsed into an ,abject state of financial dependence on central government' from which they should be reclaimed. Moreover, they are no longer intellectually independent. A ,single, simple financial reform' would make a great difference: universities need to determine the costs of their activities, charging accordingly, and government should once again offer students scholarships which would cover the greater part of the ,basic costs' of their courses. [source]


Essential fatty acids supplementation in different-stage atopic dogs fed on a controlled diet

JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3-6 2005
C. Abba
Summary The aim of this trial was to evaluate the effects of polyunsaturated fatty acid (PUFA) supplementation in different-stages atopic dogs fed on a controlled diet. Twenty-two non-seasonal atopic dogs of different breeds and ages were included in the 2-month trial. All the patients were given an essential fatty acid (EFA) supplementation [17 mg/kg eicosapentaenoic acid (EPA) + 5 mg/kg docosahexaenoic acid (DHA) + 35 mg/kg gammalinolenic acid (GLA)], the global (diet + supplementation) , -6 to , -3 ratio was 5.5,1. Two groups of dogs were considered: group A ,pre-immunotherapy' (15 cases) included dogs with early stages atopy, which had not been submitted to any treatment yet; group B ,post-immunotherapy' (seven cases) included dogs with chronic atopy immunotherapy non-responsive. Clinical evaluations were performed at the beginning, on day 30 and at the end of the trial. Blood serum fatty acids profile was determined at the beginning and at the end of the study. Better clinical results were obtained in group A, a great difference was found between the two groups on pruritus score. Serum arachidonic acid (AA) was significantly lower at the end of the trial in group A while GLA was significantly higher in group B. We hypothesized that different-stages atopic dogs could have different response to EFA supplementation, maybe because of a different fatty acids metabolism. Early stages cases seem to be more responsive to EFA supplementation. [source]


Impact of curing temperature on microstructures and properties of isobutylene,isoprene rubber/clay nanocomposites

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2008
Yong-Lai Lu
Abstract In this work, the influence of curing temperature on microstructures of isobutylene,isoprene rubber/clay nanocomposites (IIRCNs) prepared by melt compounding was characterized using wide-angle X-ray diffraction and TEM. The gas barrier and tensile properties of IIRCN cured under different temperature were examined. The results reveal that high pressure, curing reactions, and reactions of amine intercalants with curing agents together play important roles on determining the final microstructures of cured IIRCNs. Changing curing temperature would dramatically alter intercalated structure, dispersion homogeneity, filler,rubber interaction strength, and crosslinking density of obtained IIRCN, resulting in great difference in final properties. Finally, some suggestions for the preparation of successful RCNs were proposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]


Structure, texture and surface acidity studies of a series of mixed zinc,aluminum (60,90 molar % Al) phosphate catalysts

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2 2001
Karim Mtalsi
Abstract A series of mixed zinc,aluminum phosphate (ZnAlP) catalysts containing 40,90 aluminum molar % were synthesized by a coprecipitation method and characterized by nitrogen adsorption,desorption, X-ray diffraction, FTIR spectroscopy, thermogravimetric analysis (TGA), differential thermal analysis (DTA), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature programmed desorption (TPD) of ammonia. The presence of aluminum greatly affected the surface properties of Zn3(PO4)2 by delaying the crystallization process of Zn3(PO4)2. All amorphous samples were shown to be mesoporous and they contained two types of aluminum surface hydroxyl groups and one type of phosphorus hydroxyl group, as shown by DRIFT spectra. The specific surface area and the acidity of ZnAlP increased on increasing the aluminum content. On the other hand, a great difference in the texture and the concentration of surface acid sites was found by changing the precipitating agent and calcination temperature. Thus these factors also play an important role in the final properties of these catalysts. © 2001 Society of Chemical Industry [source]


Prevalence of Actinobacillus actinomycetemcomitans and clinical conditions in children and adolescents from rural and urban areas of central Italy

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 8 2000
Michele Paolantonio
Abstract Background: The aim of this study was to report on the prevalence of Actinobacillus actinomycetemcomitans (Aa) and the periodontal clinical conditions in children and adolescents from a rural area of central Italy compared with the ones from an urban area of the same region. Method: The study population consisted of 780 systemically healthy children, aged 6,14 years inhabiting the county of Chieti. 505 children attended 3 primary and 2 secondary schools from a rural area whereas 275 individuals attended 1 primary and 1 secondary school from the city of Chieti. The 2 provincial areas present a great difference in socioeconomic level and cultural background. Clinical examination consisted of recording the % of gingival sites positive for the presence of plaque (Pl+), bleeding on probing (BOP+), mean probing depth (PD) from each primary or permanent tooth fully erupted in the oral cavity. Loss of periodontal attachment (AL+) was evaluated only in interproximal sites. AL+ subjects were distinguished in juvenile periodontitis (JP) prepubertal periodontis and early periodontitis (EP) patients. 8 gingival sites were microbiologically sampled in each subject and cultured, after pooling, for the presence of Aa. Results: 30.3% of rural subjects, were positive for the presence of Aa, the difference from urban children (16%) being statistically significant (p=0.01) irrespective of gender and age. Aa showed a significantly (p=0.006) higher mean proportion in subgingival plaque samples from rural children (0.13% versus 0.02%). Loss of periodontal attachment in at least one site was found in 18 rural children (3.56%) (3 JP; 15 EP) and 2 urban girls (0.72%) (1 JP; 1 EP). No significant differences for AL were observed within the rural group according to the gender and age differentiation. In the urban group, both AL+ subjects were Aa+, while among children from rural areas all 3 JP and 13 EP subjects were Aa+. Rural subjects evidenced significantly worse clinical parameters with respect to urban children (% Pl+ sites: p=0.000; % BOP+ sites: p=0.010; mean PD: p=0.000.) The relative risk for AL+ sites was significantly greater (2.42) in rural subjects harboring Aa in subgingival plaque. Similarly, the presence of Aa in subgingival plaque was related to a greater risk of more than 50% of BOP+ gingival sites in both rural and urban subjects (1.45 and 8.40, respectively). Conclusions: Results of this study suggest that Aa colonization in children and adolescents from central Italy is affected by socioeconomic and cultural factors; these factors also affect the periodontal condition of the subjects. [source]


EVALUATION OF OLFACTORY INTENSITY: COMPARATIVE STUDY OF TWO METHODS

JOURNAL OF SENSORY STUDIES, Issue 4 2004
BORIANA ATANASOVA
ABSTRACT Two experimental procedures recommended for the evaluation of the psychophysical characteristics of odorous compounds, olfactory matching with the 1-butanol scale and cross-modality matching with the finger span are compared. The intensity of ethyl butyrate and guaiacol solutions presented at four different concentration levels was evaluated by a panel of sixteen subjects over five repetitions using the two methods. Each stimulus was delivered to the subject from a Teflon bag through a nose-shaped glass sniffing port. The discrimination ability, repeatability, panel homogeneity and within-subject variability of the methods were assessed. Results indicate that with both methods, subjects were able to highly discriminate the presented concentration levels of the odorants. There were no great difference in repeatability and the same individual variability was observed between both methods. However, the smaller within-subject variability highlighted for the 1-butanol scale method suggested that this method is potentially more powerful than finger-span method. [source]


Effects of diapause duration on future reproduction in the cabbage beetle, Colaphellus bowringi: positive or negative?

PHYSIOLOGICAL ENTOMOLOGY, Issue 2 2006
Xiao-Ping Wang
Abstract., Cabbage beetles, Colaphellus bowringi, undergoing an imaginal summer and winter diapause in the soil, show a great difference in diapause duration (from several months to more than 3 years) under natural conditions. The effects of diapause duration on future reproduction in the beetle are investigated at 25 °C with an LD 14 : 10 h photoperiod and under natural conditions. The fecundity of postdiapause adults with a short diapause of 5 months and nondiapause adults is similar, showing that a short diapause has no affect on reproduction, whereas the longevity of postdiapause adults with a short diapause of 5 months is significantly shorter than nondiapause adults, showing that a short diapause has a negative affect on longevity. The mean total egg production per female and longevities of postdiapause adults with long diapause periods of 16, 22, 29 and 34 months are similar to nondiapause adults, but the mean daily egg production per female is significantly higher than nondiapause adults, showing that extended diapause has a positive effect on postdiapause reproduction. The offspring of postdiapause parents require a relatively shorter time for egg development compared with the offspring of nondiapause parents, showing that diapause has a positive effect on their offspring's performance. However, there are no significant differences among offspring performance in terms of survival, adult longevity, mean egg production per female and mean daily egg production per female. [source]


Photoinitiated alternating copolymerization of vinyl ethers with chlorotrifluoroethylene

POLYMER INTERNATIONAL, Issue 7 2002
Manuel Gaboyard
Abstract The photoinitiated copolymerization of chlorotrifluoroethylene (CTFE) with several vinyl ethers [ethyl vinyl ether (EVE), 2-chloroethyl vinyl ether (CEVE), cyclohexyl vinyl ether (CHVE), 4-hydroxybutyl vinyl ether (HBVE)] was studied. CTFE is an acceptor monomer (e,,,1.5) whereas vinyl ethers are donor monomers (e,,,,1.5), and therefore their copolymerization led to alternating copolymers, as indicated by elementary analysis. The equilibrium constant (KF) of the charge-transfer complex formation (CTC) was determined by 19F NMR spectroscopy. Under our experimental conditions, KF was low for CHVE/CTFE and HBVE/CTFE systems, 0.058 and 0.013,l mol,1 respectively. It can be assumed that the copolymerization involves the free monomers rather than propagation via the donor,acceptor complex. The alternating structure arises from the great difference in polarity between the two types of monomers. Several functional copolymers were prepared in good yield and with molecular weight close to 15,000,g,mol,1. © 2002 Society of Chemical Industry [source]


Phytoecdysteroid C2-hydroxylase is microsomal in spinach, Spinacia oleracea L.,

ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 4 2009
Ahmed Bakrim
Abstract An enzyme involved in the biosynthesis of phytoecdysteroids, the C2-hydroxylase, has been investigated in spinach, Spinacia oleracea. This enzyme is microsomal and its Km has been determined using 2-deoxy-20-hydroxyecdysone as substrate (Km=3.72,µM). It is much more efficient with 2-deoxy-20-hydroxyecdysone than with 2-deoxyecdysone and, conversely, the C20-hydroxylase is more active on 2-deoxyecdysone than on ecdysone. These data support the conclusion that C20-hydroxylation precedes C2-hydroxylation. The C2-hydroxylase is inhibited by high concentrations of 20E. Substrate specificity and subcellular localization of C2-hydroxylase differ between plants and insects, and these data, as well as those previously reported on other biosynthetic steps, show the great difference between plant and insect ecdysteroid biosynthetic pathways and suggest an independent origin for the pathways in both kingdoms. © 2009 Wiley Periodicals, Inc. [source]


Legibility evaluation with oculomotor analysis.

ELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 9 2010
The relationship between contrast, legibility
Abstract Web page legibility is important because of the widespread use of the World Wide Web, and color combinations between the foreground and background are crucial to assuring sufficient legibility. In our previous studies, the visibilities of several web-safe color combinations were examined using a psychological method. In those studies, simple stimuli were used because of experimental restrictions. In this study, the legibility of sentences on Web sites was examined using an oculomotor-based psychophysiological method, and the effect of achromatic color combinations, that is, the contrast, was examined in terms of the calculated reading time. The presentation stimuli were positive colorations, whose font color luminance was lower than the background color, and negative colorations, whose font color luminance was higher than the background color. The number of characters per line was arranged to be the same on each page, and four levels of achromatic contrast (the contrast between the background color and the font color), namely, 92.5%, 75.0%, 50.0%, and 25.0%, were examined. It was shown that the reading time increased when the contrast decreased. However, with negative coloration, there were great differences between individuals. Therefore, considering web accessibility, legibility is found to be improved when using a positive coloration. © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(9): 27,33, 2010; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10243 [source]


An evidence-based approach to equine parasite control: It ain't the 60s anymore

EQUINE VETERINARY EDUCATION, Issue 6 2010
R. M. Kaplan
Summary Most veterinarians continue to recommend anthelmintic treatment programmes for horses that derive from knowledge and concepts more than 40 years old. However, much has changed since these recommendations were first introduced and current approaches routinely fail to provide optimal or even adequate levels of parasite control. There are many reasons for this. Recent studies demonstrate that anthelmintic resistance in equine parasites is highly prevalent and multiple-drug resistance is common in some countries, but few veterinarians take this into account when making treatment decisions or when recommending rotation of anthelmintics. Furthermore, the current approach of treating all horses at frequent intervals was designed specifically to control the highly pathogenic large strongyle, Strongylus vulgaris. But this parasite is now quite uncommon in managed horses in most of the world. Presently, the cyathostomins (small strongyles) are the principal parasitic pathogens of mature horses. The biology and pathogenesis of cyathostomins and S. vulgaris are very different and therefore require an entirely different approach. Furthermore, it is known that parasites are highly over-dispersed in hosts, such that a small percentage of hosts harbour most of the parasites. The common practices of recommending the same treatment programme for all horses despite great differences in parasite burdens, recommending prophylactic treatment of all horses without indication of parasitic disease or knowing what species of parasites are infecting the horses, recommending use of drugs without knowledge of their efficacy and failing to perform diagnostic (faecal egg count) surveillance for estimating parasite burdens and determining treatment efficacy, are all incompatible with current standards of veterinary practice. Consequently, it is necessary that attitudes and approaches to parasite control in horses undergo a complete overhaul. This is best achieved by following an evidence-based approach that takes into account all of these issues and is based on science, not tradition. [source]


The effects of different input data and their spatial resolution on the results obtained from a conceptual nutrient emissions model: the River Stör case study

HYDROLOGICAL PROCESSES, Issue 18 2005
Markus Venohr
Abstract This paper focuses on the influences of different data sources, and the variation in spatial resolution of input data and analysis, on the calculated nutrient emissions using the conceptual model MONERIS. MONERIS calculates both nitrogen and phosphorus emissions from point and diffuse sources and the riverine nutrient retention. By subtracting the retention from the emissions, a riverine nutrient load was estimated and compared with the observed nutrient river load. All calculations were conducted for the period from 1991 to 1993. The River Stör, with a catchment area of 1135 km2, located in a postglacial lowland landscape in northern Germany, was chosen as a case study area. Two different data sets (e.g. land use, soil type or wastewater treatment plant inventory) were used: a commonly available standard data set (German or European maps) and a more detailed set with a higher spatial resolution derived from several studies at the Ecosystem Research Centre in Kiel. Initially, both data sets were used to apply MONERIS to the total catchment. The results were compared to adapt some of the free model-parameters to the conditions in the relatively small lowland river catchment. Using the standard data set, total nutrient emissions of 2320 tons year,1 of nitrogen and 96 tons year,1 phosphorus were calculated. The detailed data set yielded slightly higher emissions for nitrogen (2420 tons year,1) and for phosphorus (102 tons year,1). According to the spatial resolution, the proportion of the area of tile drainages and sandy soils derived from the different data sets varies considerably. This causes great differences in the total nutrient emissions estimated by the two approaches. Comparing the observed and the calculated nutrient loads, reliable results for catchments larger than 50 km2, or third-order streams, could be shown. Copyright © 2005 John Wiley & Sons, Ltd. [source]


In situ rumen degradation and in vitro gas production of some selected grains from Turkey

JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 9-10 2002
H. D. Umucalilar
Summary An investigation of the dry matter degradability (DMD) and effective dry matter degradability (EDDM) was performed for barley, wheat, rye, corn, triticale and oat samples, using the Nylon-bag technique. Gas production (GP), metabolizable energy (ME) and in vitro organic matter digestibility (IVOMD) were also studied by using Hohenheim gas test. The DM from barley, wheat, rye and triticale was digested rapidly in the rumen, and, at the 48 h of incubation, degradability was found to be approximately about 80%. The higher degradability observed for these grains than for oats and corn was attributable to the structure of these grains. In contrast, DM of corn and oats was degraded very slowly and reached 66.7 and 66.5 at 48 h, respectively. Effective degradability values of barley, wheat, rye, corn, triticale and oats were determined to be 61.4, 69.0, 64.0, 41.7, 66.7 and 58.6% in 5% rumen outflow rate, respectively. At the end of the 48 h incubation, total gas productions in barley, wheat, rye, corn, triticale and oats were estimated to be 83.6, 87.2, 87.5, 83.5, 85.8 and 63.9 ml/200 mg DM, respectively. The mean ME values of these grains calculated from cumulative gas amount at 24 h incubation were 11.8, 12.1, 12.3, 10.9, 12.4 and 10.2 MJ/kg DM, respectively. In vitro digestible organic matter of barley, wheat, rye, corn, triticale and oats were estimated to be 85.0, 87.3, 88.2, 79.5, 89.0 and 72.6%. Percentage overall EDDM (k=5%) of barley, wheat, rye, triticale and oats was positively correlated with in vitro GP at 6 h, cumulative GP at 24 h and total GP at 48 h (p<0.05). As a result, in situ dry matter degradation of grains showed great differences depending on the chemical compositions. In situ EDDM of grains may be predicted from in vitro gas production parameters. [source]


The MAGi RNA extraction method: a highly efficient and simple procedure for fresh and dry plant tissues

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2009
e Gül Ince
Abstract BACKGROUND: Samples from different plant species, different organs or tissues at different times of the year, usually show great differences in their cell compositions, pH, and the endogenous RNase activities, decreasing the RNA yield and quality. RESULTS: In this study we describe a reagent and a simple total RNA isolation method for plant organs, tissues and dry seeds. The RNA extraction reagent (MAGi) is non-toxic and can be stored at room temperature for several months to years. The principle of the total RNA extraction is that tissues are lysed in extraction solution with the aid of mortar homogenization,maceration, and cellular proteins, polysaccharides and DNA are removed from the RNA. We tested the reported method on more than 16 different types of plant seed and 15 different tissues and organs of pepper. CONCLUSION: The RNA extraction procedure reported in the present study greatly reduces the time required to isolate dry seed total RNA and other tissues by more than half as compared with the previously reported methods. The range of typical RNA yield and quality represents a significant improvement over existing protocols. The quality is high enough to be considered as suitable method for RT-PCR, cDNA library construction and microarray gene expression studies. Copyright © 2008 Society of Chemical Industry [source]


Variations in cadmium accumulation among rice cultivars and types and the selection of cultivars for reducing cadmium in the diet

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2005
Jianguo Liu
Abstract A pot trial was conducted with 52 rice cultivars of different types collected from different origins. The results showed that there were great differences in Cd concentrations in straw, brown rice and grain chaff among the rice cultivars grown in a soil containing a Cd concentration of 100 mg kg,1; the Cd concentrations in brown rice ranged from 0.22 to 2.86 mg kg,1. The great genotypic differences in Cd concentrations indicated that it is possible to lower the Cd content of rice through cultivar selection and breeding. Significant differences were found in the Cd concentrations of the rice types of Indica consanguinity and those of Japonica consanguinity, but not between their origins. There were significant correlations between straw and brown rice in Cd concentration and in the total amount of Cd accumulated. The distribution ratios of the Cd accumulated in brown rice to the total Cd accumulation in the above-ground rice plant varied greatly from 12.9 to 137.8 g kg,1, and there was significant correlation between the distribution ratios and Cd concentrations in brown rice. These indicated that Cd concentration in rice grain is governed by the transport of Cd from root to shoot and also from shoot to grain. Cd concentrations in brown rice also correlated significantly with some important agronomic traits, as well as with nitrogen concentrations, one of the most important criteria for rice quality. Copyright © 2004 Society of Chemical Industry [source]


Bacterial community profiles of endodontic abscesses from Brazilian and USA subjects as compared by denaturing gradient gel electrophoresis analysis

MOLECULAR ORAL MICROBIOLOGY, Issue 1 2007
J. C. Machado de Oliveira
This study compared the bacterial community profiles of the microbiota associated with acute apical abscesses from Brazilian and USA patients using denaturing gradient gel electrophoresis (DGGE). DNA was extracted from purulent exudate aspirates and part of the 16S rRNA gene was amplified by polymerase chain reaction and separated by DGGE. The resulting banding patterns, which were representative of the bacterial community structures in samples from the two locations, were then compared. Distinct DGGE banding patterns were observed from different samples. Ninety-nine bands with distinct positions in the gels were detected, of which 27 were found only in the USA samples and 13 were exclusive to Brazilian samples. Four of the 59 shared bands showed very discrepant findings with regard to prevalence in the two locations. Cluster analysis of DGGE banding profiles showed a great variability in the bacterial populations associated with teeth with abscesses regardless of the geographical location. Two big clusters, one for each location, were observed. Other clusters contained a mixture of samples from the two locations. The results of the present study demonstrated a great variability in the bacterial community profiles among samples. This indicates that the bacterial communities of abscesses are unique for each individual in terms of diversity. The composition of the microbiota in some samples showed a geography-related pattern. Furthermore, several bands were exclusive for each location and others were shared by the two locations and showed great differences in prevalence. [source]


Prediction of agrochemical residue data on fruit using an informatic system (PARDIS model)

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 10 2008
Maura Calliera
Abstract A ,step-by-step' method was used to develop a simplified procedure for calculating pesticide residue levels on fruit at harvest by considering the application of the compound and the relevant routes of loss. The model is applicable to cases where the most important exposure route is by direct spray to the canopy of the crop and where uptake into the plant by the roots can be disregarded. The exposure dose is calculated by considering the proportion of total crop cover represented by the fruits. The loss processes considered are photodegradation, uptake, volatilization and washoff. The outputs of the model were compared with measured residues of pesticides on pear. Analysis of the model fit demonstrates that the model predicted the measured data with a good level of accuracy for four of seven investigated pesticides. The predicted/observed quotients are close to 1, as is the modelling efficiency, and there are no great differences between the predicted and observed values. Taking into account the extreme simplicity of the model and the complexity of the environmental processes considered, these results encourage further research into the modelling of residue behaviour in food commodities. The objectives of this work were to produce a tool to predict pesticide residues in products of plant origin, to complement monitoring of pesticide levels and to be useful in evaluating the effect of government policies on food safety. All predicted values were below the maximum levels fixed for pesticide residues in pear, as amended in Council Directives 86/362/EEC and 90/642/EEC. Copyright © 2008 Society of Chemical Industry [source]


What are the prevalence and incidence of tooth loss in the adult and elderly population in Europe?

CLINICAL ORAL IMPLANTS RESEARCH, Issue 2007
Frauke Müller
Abstract Objective: The purpose of this review was to study the prevalence and incidence of edentulism and tooth loss in European countries. Material and method: A literature search was performed by means of Medline/PubMed using various combinations of keywords concerning prevalence and incidence of tooth loss and edentulism, complemented by a hand search. Inclusion criteria were cross-sectional and longitudinal clinical and questionnaire studies of representative or random samples of ,100 subjects at the initial examination. Sixty articles were identified; the hand search gave 13 more references. Results: This literature review demonstrated that there is a lack of epidemiological studies on edentulism and tooth loss in many countries in Europe. The quality of available data varied considerably. There is a documented decline of edentulism with still great differences in prevalence between countries, between geographical regions within countries and between groups with various backgrounds. The mean number of lost teeth increases with age. In several countries many dentate subjects aged 60 years and over still have reduced dentitions possibly needing prosthodontic treatment. The incidence of tooth loss is low but with geographical variation between age groups, and there is a trend for decreasing incidence over the last decades. A great number of variables are associated with tooth loss, and there is no consensus whether dental disease related or socio-behavioural factors are the most important risk factors. Institutionalised elderly people have, in general, more compromised oral health, including fewer teeth, than those at the same age living freely. Conclusion: Tooth loss and edentulism are declining at least in those European countries where reliable data are available. However, the WHO goal of retaining at least 20 teeth at the age of 80 years has not yet been met but is being approached in some countries. [source]