bluuebunny/crossref_metadata_2025 huggingface dataset:
Chronic ethanol treatment reduces the magnitude of hippocampal LTD in the adult rat
Authors: Thinschmidt J.S. , Walker D.W. , King M.A.
Published: April 2003

Human alcoholics and animals that have received chronic ethanol treatment (CET) display memory deficits. Previous work in our laboratory has shown that CET produces damage to the hippocampus and a reduction in the magnitude of hippocampal long‐term synaptic potentiation. In the present report we examined the effects of CET on hippocampal long‐term depression (LTD). We used in vitro hippocampal slices to examine LTD after rats received 38–41 weeks of paired feeding on liquid diets containing ethanol or isocaloric sucrose. Stimulation delivered through electrodes in the CA3‐CA1 Schaffer collateral pathway activated synaptic population responses in CA1. LTD of CA1 stratum radiatum evoked field potential slope was not induced by 900 single pulses at 1 Hz, but was elicited by 900 pulse pairs separated by 50 or 200 msec delivered at 1 Hz (pLFS50, pLFS200). LTD evoked by pLFS200, but not by pLFS50, was significantly reduced in slices from ethanol‐treated rats. The N‐methyl D‐aspartate (NMDA) receptor antagonist 2‐amino‐5‐phosphonopentanoic acid (AP5) (50 μM) blocked LTD induced by pLFS50 and pLFS200 equally, but the L‐type calcium channel blocker nimodipine (10 μM) had no effect on either type of LTD. Thus, direct effects on these channels cannot explain how CET selectively reduces the magnitude of pLFS200 LTD. Finally, we describe a novel and robust LTD of the presynaptic afferent volley that is resistant to CET, NMDAR antagonists, GABA‐A receptor blockade, and blockade of L‐type calcium channels. Synapse 48:189–197, 2003. © 2003 Wiley‐Liss, Inc.
Detection of a concerted conformational change in the ATPase domain of DnaK triggered by peptide binding
Authors: Slepenkov Sergey V. , Witt Stephan N.
Published: April 2003

The molecular chaperone DnaK is composed of two functional domains, the ATPase domain and the substrate‐binding domain. In this report, we show that peptide binding to DnaK can be sensed in real time through a labeled nucleotide bound in the ATPase domain. Specifically, when N8‐(4‐N′‐methylanthraniloylaminobutyl)‐8‐aminoadenosine 5′‐triphosphate (MABA)–ATP·DnaK complexes are rapidly mixed with excess peptide, MABA fluorescence rapidly increases and the rate of increase is proportional to peptide concentration. Analysis of the formation traces yield on and off rate constants that are exactly equal to the rate constants obtained from experiments that directly probe peptide binding to DnaK. These results are the first to show that peptide binding to ATP·DnaK triggers a concerted conformational change in the ATPase domain.
The trichothecene biosynthesis gene cluster of Fusarium graminearum F15 contains a limited number of essential pathway genes and expressed non‐essential genes
Authors: Kimura Makoto , Tokai Takeshi , O’Donnell Kerry , Ward Todd J , Fujimura Makoto , Hamamoto Hiroshi , Shibata Takehiko , Yamaguchi Isamu
Published: April 2003

We report for the first time the complete structure and sequence of the trichothecene biosynthesis gene cluster (i.e. Tri5‐cluster) from Fusarium graminearum F15, a strain that produces 3‐acetyldeoxynivalenol (3‐ADON). A putative tyrosinase and polysaccharide deacetylase gene flank the Tri5‐cluster: the number of pathway genes between them is less than half the total number of steps necessary for 3‐ADON biosynthesis. In comparison with partial Tri5‐cluster sequences of strains with 15‐acetyldeoxynivalenol and 4‐acetylnivalenol chemotypes, the Tri5‐cluster from strain F15 contains three genes that are apparently unnecessary for the biosynthesis of 3‐ADON (i.e. Tri8 and Tri3, which are expressed, and pseudo‐Tri13, which is not expressed). In addition, the Tri7 gene was missing from the cluster. Recombinant TRI3 protein showed limited trichothecene C‐15 acetylase activity. In contrast, recombinant TRI8 protein displayed no C‐3 deacetylase activity, suggesting that the loss or alteration of function contribute directly to the chemotype difference.
Identification of a 1‐epi‐valienol 7‐kinase activity in the producer of acarbose, Actinoplanes sp. SE50/110
Authors: Zhang Chang-Sheng , Podeschwa Michael , Block Oliver , Altenbach Hans-Josef , Piepersberg Wolfgang , Wehmeier Udo F
Published: April 2003

In the biosynthesis of the C7‐cyclitol moiety, valienol, of the α‐glucosidase inhibitor acarbose in Actinoplanes sp. SE50/110 various cyclitol phosphates, such as 1‐epi‐valienol‐7‐phosphate, are postulated precursors. In the cell extracts of Actinoplanes SE50/110 we found a new kinase activity which specifically phosphorylates 1‐epi‐valienol; other C7‐cyclitol analogs were only weakly or not phosphorylated. The purified product of the kinase reaction turned out to be 1‐epi‐valienol‐7‐phosphate in analyses by nuclear magnetic resonance spectroscopy. The enzyme seems not to be encoded by an acb gene and, therefore, plays a role in a salvage pathway rather than directly in the de novo biosynthesis of acarbose.
Protein transport via the cpTat pathway displays cooperativity and is stimulated by transport‐incompetent substrate
Authors: Alder Natahan N , Theg Steven M
Published: April 2003

Kinetic analyses of cpTat‐mediated protein transport across the thylakoid membrane were conducted, revealing three important characteristics of this translocation pathway. First, transport via the cpTAT system displays a non‐Michaelis–Menten, sigmoidal rate–substrate relationship with an apparent Hill coefficient of 1.80, indicative of positive homotropic cooperativity. Second, the presence of transport‐incompetent substrates was found not to competitively inhibit the translocation of transport‐competent substrates. However, the presence of low concentrations of transport‐incompetent protein enhances the transport of wild type substrate. Together, these findings suggest that interaction between Tat machinery components and both transport‐competent and transport‐incompetent protein may elicit a cooperative effect on the translocation rate.
Oxidative stress in cell culture: an under‐appreciated problem?
Authors: Halliwell Barry
Published: April 2003

Cell culture studies have given much valuable information about mechanisms of metabolism and signal transduction and of regulation of gene expression, proliferation, senescence, and death. However, cells in culture may behave differently from cells in vivo in many ways. One of these is that cell culture imposes a state of oxidative stress on cells. I argue that cells that survive and grow in culture might use ROS‐dependent signal transduction pathways that rarely or never operate in vivo. A further problem is that cell culture media can catalyse the oxidation of compounds added to them, resulting in apparent cellular effects that are in fact due to oxidation products such as ROS. Such artefacts may have affected many studies on the effects of ascorbate, thiols, flavonoids and other polyphenolic compounds on cells in culture.
The products of the mitochondrial orf25 and orfB genes are FO components in the plant F1FO ATP synthase
Authors: Heazlewood J.L. , Whelan J. , Millar A.H.
Published: April 2003

The FO portion of the mitochondrial ATP synthase contains a range of different subunits in bacteria, yeast and mammals. A search of the Arabidopsis genome identified sequence orthologs for only some of these subunits. Blue native polyacrylamide gel electrophoresis separation of Arabidopsis mitochondrial respiratory chain complexes revealed intact F1FO, and separated F1 and FO components. The subunits of each complex were analysed by mass spectrometry and matched to Arabidopsis genes. In the F1FO complex a series of nine known subunits were identified along with two additional proteins matching the predicted products of the mitochondrial encoded orfB and orf25 genes. The F1 complex contained the five well‐characterised F1 subunits, while four subunits in the FO complex were identified: subunit 9, d subunit, and the orfB and orf25 products. Previously, orfB has been suggested as the plant equivalent of subunit 8 based on structural and sequence similarity. We propose that orf25 is the plant b subunit based on structural similarity and its presence in the FO complex. Chimerics of orf25, orfB, subunit 9 and subunit 6 have been associated with cytoplasmic male sterility in a variety of plant species, our additional findings now place all these proteins in the same protein complex.
Firefly luciferase is a bifunctional enzyme: ATP‐dependent monooxygenase and a long chain fatty acyl‐CoA synthetase
Authors: Oba Yuichi , Ojika Makoto , Inouye Satoshi
Published: April 2003

Firefly luciferase can catalyze the formation of fatty acyl‐CoA via fatty acyl‐adenylate from fatty acid in the presence of ATP, Mg2+ and coenzyme A (CoA). A long chain fatty acyl‐CoA (C16–C20), produced by luciferase from a North American firefly (Photinus pyralis) and a Japanese firefly (Luciola cruciata), was isolated and identified by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry analysis. Of a number of substrates tested, linolenic acid (C18:3) and arachidonic acid (C20:4) appear to be suitable for acyl‐CoA synthesis. This evidence suggests that firefly luciferase within peroxisomes of the cells in the photogenic organ may be a bifunctional enzyme, catalyzing not only the bioluminescence reaction but also the fatty acyl‐CoA synthetic reaction.
Modulation of lymphatic distribution of subcutaneously injected poloxamer 407‐coated nanospheres: the effect of the ethylene oxide chain configuration
Authors: Moghimi S.M
Published: April 2003

Lymphatic distribution of interstitially injected poloxamer 407‐coated nanospheres (45 nm in diameter) is controlled by surface configuration of the ethylene oxide (EO) segments of the adsorbed copolymer. At low poloxamer surface coverage, EO tails spread laterally on a nanosphere surface and assume a ‘flat or mushroom‐like’ configuration. Such entities drain rapidly from the subcutaneous site of injection into the initial lymphatic, when compared to uncoated nanospheres, and subsequently are captured by scavengers of the regional lymph nodes. In vitro experiments have also confirmed that such entities are prone to phagocytosis. When the equilibrium poloxamer concentration is at 75 μg/ml or greater the EO chains become more closely packed and project outward from the nanosphere surface. These surface‐engineered nanospheres drain faster than those with EO chains in mushroom configurations into the initial lymphatic, escape clearance by lymph node macrophages, reach the systemic circulation, and remain in the blood for prolonged periods. These experiments provide a rational approach for the design and engineering of nano‐vehicles for optimal lymphatic targeting and are discussed.
Molecular identification of wheat endoxylanase inhibitor TAXI‐I1, member of a new class of plant proteins
Authors: Fierens Katleen , Brijs Kristof , Courtin Christophe M , Gebruers Kurt , Goesaert Hans , Raedschelders Gert , Robben Johan , Van Campenhout Steven , Volckaert Guido , Delcour Jan A
Published: April 2003

riticum
estivum endoylanase nhibitors (TAXIs) are wheat proteins that inhibit family 11 endoxylanases commonly used in different (bio)technological processes. Here, we report on the identification of the TAXI‐I gene which encodes a mature protein of 381 amino acids with a calculated molecular mass of 38.8 kDa. When expressed in Escherichia coli, the recombinant protein had the specificity and inhibitory activity of natural TAXI‐I, providing conclusive evidence that the isolated gene encodes an endoxylanase inhibitor. Bioinformatical analysis indicated that no conserved domains nor motifs common to other known proteins are present. Sequence analysis revealed similarity with a glycoprotein of carrot and with gene families in Arabidopsis thaliana and rice, all with unknown functions. Our data indicate that TAXI‐I belongs to a newly identified class of plant proteins for which a molecular function as glycoside hydrolase inhibitor can now be suggested.
Social characteristics of seasonal affective disorder patients: comparison with suicide attempters with non-seasonal major depression and other mood disorder patients
Authors: Pendse B.P.G. , Öjehagen A.. , Engström G. , Träskman-Bendz L.
Published: April 2003

Although it is evident from numerous studies that patients with mood disorders generally have a deficient social functioning and a weak social network, little is known about these aspects of seasonal affective disorder (SAD) patients. We studied the social situation, the social network and the social functioning of SAD (n = 20) patients in comparison with matched suicide attempters (SA) with non-seasonal major depression, and with findings from other major depressive disorder (MDD) studies and community samples. The social situation and the clinical background of both the SAD and the SA groups were almost similar and the social networks were equally disadvantageous and weaker than those observed in some community/healthy populations. Furthermore, the data on global functioning and social adjustment of the SAD group were well comparable to those of other MDD patients and significantly worse than that of a community sample. Thus, the results indicate a considerable social impairment in SAD.
Targeting apoptotic signalling pathway and pro‐inflammatory cytokine expression as therapeutic intervention in TPE induced lung damage
Authors: Narayanan Kishore , Krishnamoorthy Bhavani , Ezhilarasan Ravesanker , Miyamoto Shigeki , Balakrishnan Arun
Published: April 2003

Tropical pulmonary eosinophilia (TPE) is an occult manifestation of filariasis, brought about by helminth parasites Wuchereria bancrofti and Brugia malayi. Treatment of patients suffering from TPE involves the administration of diethyl carbamazine and Ivermectin. Although the drugs are able to block acute inflammation, they are not able to alleviate chronic basal inflammation. We have attempted to examine the disease by targeting two important components; namely filarial parasitic sheath proteins (FPP) induced apoptosis and pro‐inflammatory cytokine response in human laryngeal carcinoma cells of epithelial origin (HEp‐2) cells an epithelial cell line. Earlier studies by us have shown that FPP exposure induced apoptosis in these cells. In this study with hydrocortisone, calpain inhibitor (ALLN) and phorbol myristate acetate (PMA) treatments we demonstrate that apoptosis is inhibited as shown by [3H] thymidine incorporation studies, propidium iodide staining and Annexin V staining. Hydrocortisone at a dose, which inhibits cell death also down regulated, the expression of pro‐inflammatory cytokines IL‐6 and IL‐8. These findings give us insights into the multifaceted approach one may adopt to target critical signalling molecules using appropriate inhibitors, which could eventually be used to reduce lung damage in TPE.
Buffon's Needle on Caustics and Torus Quantization
Authors: Lavenda B. H.
Published: April 2003

The probability of n + 1 intersections of a long needle in the Buffon problem is the eikonal of a Hankel function which is the principal term in the uniform asymptotic expansion in powers of the small distance between the parallel lines. Evaluating this probability using the torus quantization conditions shows that in the physically meaningful region, where a closed convergence of rays covers the caustic circle, the probability is greater than unity. In addition, the method of steepest descent shows that the caustic and reflection indices are more general than the ones given by torus quantization. The distance from the light source to the center of caustic circle corresponds to the length of the needle, and n times the distance between the parallel lines is the radius of the caustic. Unlike diffraction problems, the solution cannot be extended to the shadow zone since the angles become imaginary. In the continuum limit where the distance between the parallels tends to zero, the number of intersections is governed by an arc sine law in which maximum number of intersections, or the maximum chord length in a circle of a given radius, is most probable.
Emancipatory Responses to Oppression: The Template of Land‐Use Planning and the Old Order Amish of Ontario
Authors: Bennett Edward M.
Published: April 2003

In this paper I discuss the clash of values between the Old Order Amish community of Ontario and the dominant social paradigm in agriculture. Land‐use and agricultural regulations, designed for an industrial style of agriculture, are experienced as a threat to the survival of the Old Order Amish agricultural social economy and community. The paper describes how I have worked with the Old Order Amish to respond to these challenges and to create public policies that will allow them to maintain their human and agricultural diversity and small‐scale sustainable farm practices. Four case studies illuminating the oppressive land‐use regulations along with the emancipatory responses to the oppression are examined. The social transformation themes include principles and processes for community psychologists, land‐use planners, and community economic development practitioners to consider. The article has heuristic value for a practice‐based approach to social change.
Rapid Diagnosis of Spontaneous Bacterial Peritonitis by Use of Reagent Strips
Authors: Castellote José , López Carmen , Gornals Joan , Tremosa Gemma , Fariña Eva Rodríguez , Baliellas Carmen , Domingo Alicia , Xiol Xavier
Published: April 2003

We studied the use of reagent strips for diagnosis of spontaneous bacterial peritonitis (SBP) in cirrhotic patients with ascites. A reagent strip for leukocyte esterase designed for the testing of urine with a colorimetric 5–grade scale (0 to 4) was used to evaluate ascitic fluid in 228 nonselected paracentesis performed in 128 cirrhotic patients. We diagnosed 52 SBP and 5 secondary bacterial peritonitis by means of polymorphonuclear cell count and classical criteria. When we considered positive a reagent strip result of 3 or 4, sensitivity was 89% (51 of 57), specificity was 99% (170 of 171), and positive predictive value was 98%. When we considered positive a reagent strip result of 2 or more, sensitivity was 96% (55 of 57), specificity was 89% (152 of 171), and negative predictive value was 99%. In conclusion, the use of reagent strips is a rapid, easy to use, and inexpensive tool for diagnosis of ascitic fluid infection. A positive result should be an indication for empirical antibiotic therapy, and a negative result may be useful as a screening test to exclude SBP. (Hepatology 2003;37:893–896.)
Nonalcoholic Fatty Liver, Steatohepatitis, and the Metabolic Syndrome
Authors: Marchesini Giulio , Bugianesi Elisabetta , Forlani Gabriele , Cerrelli Fernanda , Lenzi Marco , Manini Rita , Natale Stefania , Vanni Ester , Villanova Nicola , Melchionda Nazario , Rizzetto Mario
Published: April 2003

Nonalcoholic fatty liver disease (NAFLD) has been associated with the insulin–resistance syndrome, at present defined as the metabolic syndrome, whose limits were recently set. We assessed the prevalence of the metabolic syndrome in 304 consecutive NAFLD patients without overt diabetes, on the basis of 3 or more criteria out of 5 defined by the U.S. National Institutes of Health (waist circumference, glucose, high–density lipoprotein [HDL]–cholesterol, triglycerides, and arterial pressure). The prevalence of the metabolic syndrome increased with increasing body mass index, from 18% in normal–weight subjects to 67% in obesity. Insulin resistance (Homeostasis Model Assessment method) was significantly associated with the metabolic syndrome (odds ratio [OR], 2.5; 95% CI, 1.5–4.2; P < .001). Liver biopsy was available in 163 cases (54%). A total of 120 patients (73.6%) were classified as having nonalcoholic steatohepatitis (NASH); 88% of them had a metabolic syndrome (vs. 53% of patients with pure fatty liver; P < .0001). Logistic regression analysis confirmed that the presence of metabolic syndrome carried a high risk of NASH among NAFLD subjects (OR, 3.2; 95% CI, 1.2–8.9; P = .026) after correction for sex, age, and body mass. In particular, the syndrome was associated with a high risk of severe fibrosis (OR, 3.5; 95% CI, 1.1–11.2; P = .032). In conclusion, the presence of multiple metabolic disorders is associated with a potentially progressive, severe liver disease. The increasing prevalence of obesity, coupled with diabetes, dyslipidemia, hypertension, and ultimately the metabolic syndrome puts a very large population at risk of forthcoming liver failure in the next decades. (Hepatology 2003;37:917–923.)
Factors affecting food choice in relation to fruit and vegetable intake: a review
Authors: Pollard J , Kirk S. F. L , Cade J. E
Published: April 2003

The present review provides an investigation into the food choice decisions made by individuals in relation to fruit and vegetable consumption. A comprehensive body of evidence now exists concerning the protective effect of fruit and vegetables against a number of diseases, particularly cardiovascular disease and certain forms of cancer. Current UK recommendations are to increase intakes of fruit and vegetables to 400 g/person per d. In the main body of the review the factors that affect food choice decisions of adults in relation to fruit and vegetable consumption are studied, following a suggested framework of food choice. Factors covered include sensory appeal, familiarity and habit, social interactions, cost, availability, time constraints, personal ideology, media and advertising and health. The content of the review shows just how complex the food choice process can be. Health promotion techniques can be better targeted towards certain groups of individuals, all holding similar sets of values, when making food choice decisions. Food choice, in relation to fruit and vegetable intake, needs to be studied in more depth, in order to provide effective nutrition education programmes, in particular the sets of priorities that different sub-groups of the population consider when making food choice decisions.
Interaction of early diet and the development of the immune system
Authors: Gil Angel , Rueda Ricardo
Published: April 2003

The present review focuses on the specific effects of nutrients on the development of the immune system in early life. There is a big gap regarding the specific mechanisms that regulate immunity at the intestinal level and their impact in the systemic immune function. For this reason, during the last few years there has been great interest in ascertaining the mechanisms that regulate the intestinal immune function, as well as to understand how specific nutrients interact with the gut-associated lymphoid tissue. We have reviewed this topic with special emphasis on how human milk, and its components, influence the early development of intestinal immunity in breast-fed infants compared with formula-fed infants. Interactions between nutrients and intestinal microbiota have also been reviewed. Some micronutrients such as nucleotides and gangliosides, which are present in human milk and also in most foods, are able to influence immune functionality at very low concentrations. The specific action of these micronutrients on some parameters of immunity, as well as their potential mechanisms of action, have been considered in detail. However, there are limited data on how other specific nutrients, namely protein and non-protein N-containing compounds, lipids, carbohydrates, and others, such as minerals, vitamins, fibre, non-nutritional dietary compounds (flavonoids, carotenoids, phyto-oestrogens, etc), influence immunity. In the present review we have provided data regarding the potential effects of these compounds on the immune response in early life. The increasing use of functional foods by the public to improve their general health and prevent the incidence of chronic diseases has become a major area of interest within the nutrition community. Of the many functional foods available, probiotics have been most studied in infancy and childhood, particularly with regard to the prevention of allergic diseases. Infant formulae and fermented milks containing large quantities of probiotics are produced and consumed by Europeans and in other industrialized countries. In the present review we cover the clinical effects of probiotics in preventing disease during early life, as well as the potential mechanisms of interaction between probiotics and the gastrointestinal tract.
The Transcriptional Repressor Gfi1 Affects Development of Early, Uncommitted c-Kit+ T Cell Progenitors and CD4/CD8 Lineage Decision in the Thymus
Authors: Yücel Raif , Karsunky Holger , Klein-Hitpass Ludger , Möröy Tarik
Published: April 2003

In the thymus, several steps of proliferative expansion and selection coordinate the maturation of precursors into antigen-specific T cells. Here we identify the transcriptional repressor Gfi1 as an important regulator of this maturation process. Mice lacking Gfi1 show reduced thymic cellularity due to an increased cell death rate, lack of proliferation, and a differentiation block in the very early uncommitted CD4−/CD8−/c-Kit+ cytokine-dependent T cell progenitors that have not yet initiated VDJ recombination. In addition, Gfi1-deficient mice show increased major histocompatibility complex class I–restricted positive selection and develop significantly more CD8+ cells suggesting a requirement of Gfi1 for a correct CD4/CD8 lineage decision. Absence of Gfi1 correlates with high level expression of the genes for lung Krüppel-like factor (LKLF), inhibitor of DNA binding (Id)1 and Id2, suggesting the existence of new regulatory pathways in pre-T cell development and thymic selection in which Gfi1 acts upstream of LKLF as well as the E-proteins, which are negatively regulated by Id1 and Id2.
Quantitation of CD8+ T Cell Responses to Newly Identified HLA-A*0201–restricted T Cell Epitopes Conserved Among Vaccinia and Variola (Smallpox) Viruses
Authors: Terajima Masanori , Cruz John , Raines Gregory , Kilpatrick Elizabeth D. , Kennedy Jeffrey S. , Rothman Alan L. , Ennis Francis A.
Published: April 2003

Immunization with vaccinia virus resulted in long-lasting protection against smallpox and was the approach used to eliminate natural smallpox infections worldwide. Due to the concern about the potential use of smallpox virus as a bioweapon, smallpox vaccination is currently being reintroduced. Severe complications from vaccination were associated with congenital or acquired T cell deficiencies, but not with congenital agammaglobulinemia, suggesting the importance of T cell immunity in recovery from infection. In this report, we identified two CD8+ T cell epitopes restricted by the most common human major histocompatibility complex (MHC) class I allele, HLA-A*0201. Both epitopes are highly conserved in vaccinia and variola viruses. The frequency of vaccinia-specific CD8+ T cell responses to these epitopes measured by interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) assay and HLA/peptide tetramer staining peaked 2 wk after primary immunization and then declined, but were still detectable 1 to 3 yr after primary immunization. 2 wk after immunization, IFN-γ–producing cells specific to these two epitopes were 14% of total vaccinia virus-specific IFN-γ–producing cells in one donor, 35% in the second donor, and 6% in the third donor. This information will be useful for studies of human T cell memory and for the design and analyses of the immunogenicity of experimental vaccinia vaccines.
Serotypes, Virulence Genes, and Intimin Types of Shiga Toxin (Verotoxin)-Producing
Escherichia coli
Isolates from Healthy Sheep in Spain
Authors: Blanco M. , Blanco J. E. , Mora A. , Rey J. , Alonso J. M. , Hermoso M. , Hermoso J. , Alonso M. P. , Dahbi G. , González E. A. , Bernárdez M. I. , Blanco J.
Published: April 2003

Fecal swabs obtained from 1,300 healthy lambs in 93 flocks in Spain in 1997 were examined for Shiga toxin-producing
Escherichia coli
(STEC). STEC O157:H7 strains were isolated from 5 (0.4%) animals in 4 flocks, and non-O157 STEC strains were isolated from 462 (36%) lambs in 63 flocks. A total of 384 ovine STEC strains were characterized in this study. PCR showed that 213 (55%) strains carried the
stx
1
gene, 10 (3%) possessed the
stx
2
gene, and 161 (42%) carried both the
stx
1
and the
stx
2
genes. Enterohemolysin (
ehxA
) and intimin (
eae
) virulence genes were detected in 106 (28%) and 23 (6%) of the STEC strains, respectively. The STEC strains belonged to 35 O serogroups and 64 O:H serotypes (including 18 new serotypes). However, 72% were of 1 of the following 12 serotypes: O5:H−, O6:H10, O91:H−, O117:H−, O128:H−, O128:H2, O136:H20, O146:H8, O146:H21, O156:H−, O166:H28, and ONT:H21 (where NT is nontypeable). Although the 384 STEC strains belonged to 95 different seropathotypes (associations between serotypes and virulence genes), 49% of strains belonged to only 11. O91:H−
stx
1
stx
2
(54 strains) was the most common seropathotype, followed by O128:H−
stx
1
stx
2
(33 strains) and O6:H10
stx
1
(25 strains). Three strains of serotypes O26:H11, O156:H11, and OX177:H11 had intimin type β1; 5 strains of serotype O157:H7 possessed intimin type γ1; and 15 strains of serotypes O49:H−, O52:H12, O156:H− (12 strains), and O156:H25 had the new intimin, intimin type ζ. The majority (82%) of ovine STEC strains belonged to serotypes previously found to be associated with human STEC strains, and 51% belonged to serotypes associated with STEC strains isolated from patients with hemolytic-uremic syndrome. Thus, this study confirms that healthy sheep are a major reservoir of STEC strains pathogenic for humans.
Quantitative Detection of
Moraxella catarrhalis
in Nasopharyngeal Secretions by Real-Time PCR
Authors: Greiner Oliver , Day Philip J. R. , Altwegg Martin , Nadal David
Published: April 2003

The recognition of
Moraxella catarrhalis
as an important cause of respiratory tract infections has been protracted, mainly because it is a frequent commensal organism of the upper respiratory tract and the diagnostic sensitivity of blood or pleural fluid culture is low. Given that the amount of
M. catarrhalis
bacteria in the upper respiratory tract may change during infection, quantification of these bacteria in nasopharyngeal secretions (NPSs) by real-time PCR may offer a suitable diagnostic approach. Using primers and a fluorescent probe specific for the
copB
outer membrane protein gene, we detected DNA from serial dilutions of
M. catarrhalis
cells corresponding to 1 to 10
6
cells. Importantly, there was no difference in the amplification efficiency when the same DNA was mixed with DNA from NPSs devoid of
M. catarrhalis
. The specificity of the reaction was further confirmed by the lack of amplification of DNAs from other
Moraxella
species, nontypeable
Haemophilus influenzae
,
H. influenzae
type b,
Streptococcus pneumoniae
,
Streptococcus oralis
,
Streptococcus pyogenes
,
Bordetella pertussis
,
Corynebacterium diphtheriae
, and various
Neisseria
species. The assay applied to NPSs from 184 patients with respiratory tract infections performed with a sensitivity of 100% and a specificity of up to 98% compared to the culture results. The numbers of
M. catarrhalis
organisms detected by real-time PCR correlated with the numbers detected by semiquantitative culture. This real-time PCR assay targeting the
copB
outer membrane protein gene provided a sensitive and reliable means for the rapid detection and quantification of
M. catarrhalis
in NPSs; may serve as a tool to study changes in the amounts of
M. catarrhalis
during lower respiratory tract infections or following vaccination against
S. pneumoniae
,
H. influenzae
, or
N. meningitidis
; and may be applied to other clinical samples.
Characterization of Finnish
Mycobacterium tuberculosis
Isolates by Spoligotyping
Authors: Puustinen Kirsi , Marjamäki Merja , Rastogi Nalin , Sola Christophe , Filliol Ingrid , Ruutu Petri , Holmström Pekka , Viljanen Matti K. , Soini Hanna
Published: April 2003

The molecular epidemiology of tuberculosis (TB) in Finland was studied by spoligotyping 380
Mycobacterium tuberculosis
isolates. The isolates were obtained during a 1-year study period from July 2000 to June 2001 and represented 90% of new
M. tuberculosis
findings by culture in the whole country during the study period. The spoligotyping results were compared to the World Spoligotyping Database of the Institut Pasteur de Guadeloupe, which contains data from >14,000
M. tuberculosis
isolates obtained worldwide. A total of 138 different spoligotypes were identified among the 380
M. tuberculosis
isolates. Thirty-eight (10%) isolates had unique spoligotypes, while 342 (90%) isolates belonged to 100 shared types. The four most common spoligotypes caused approximately one-third of the Finnish TB cases. Forty-seven of the 138 (34.1%) spoligotypes and 61 (16.1%) of the 380
M. tuberculosis
isolates had spoligotypes that had not been previously reported. Only four (1.1%) patients were infected with an isolate belonging to the Beijing genotype. The characterization of Finnish
M. tuberculosis
isolates by spoligotyping shows that ubiquitous spoligotypes were common, but many spoligotypes specific to Finland were also found. However, Beijing family isolates were rarely encountered, although this spoligotype is predominant in our eastern and southern neighbors.
Detection of
Ehrlichia
spp.,
Anaplasma
spp.,
Rickettsia
spp., and Other Eubacteria in Ticks from the Thai-Myanmar Border and Vietnam
Authors: Parola Philippe , Cornet Jean-Paul , Sanogo Yibayiri Osée , Miller R. Scott , Thien Huynh Van , Gonzalez Jean-Paul , Raoult Didier , Telford Sam R. , Wongsrichanalai Chansuda
Published: April 2003

A total of 650 ticks, including 13 species from five genera, were collected from animals, from people, or by flagging of the vegetation at sites on the Thai-Myanmar border and in Vietnam. They were tested by PCR to detect DNA of bacteria of the order
Rickettsiales
. Three
Anaplasma
spp. were detected in ticks collected in Thailand, including (i)
Anaplasma
sp. strain AnDa465, which was considered a genotype of
Anaplasma platys
(formerly
Ehrlichia platys
) and which was obtained from
Dermacentor auratus
ticks collected from dogs; (ii)
Anaplasma
sp. strain AnAj360, which was obtained from
Amblyomma javanense
ticks collected on a pangolin; and (iii)
Anaplasma
sp. strain AnHl446, which was closely related to
Anaplasma bovis
and which was detected in
Haemaphysalis lagrangei
ticks collected from a bear. Three
Ehrlichia
spp. were identified, including (i)
Ehrlichia
sp. strain EBm52, which was obtained from
Boophilus microplus
ticks collected from cattle from Thailand; (ii)
Ehrlichia
sp. strain EHh324, which was closely related to
Ehrlichia chaffeensis
and which was detected in
Haemaphysalis hystricis
ticks collected from wild pigs in Vietnam; and (iii)
Ehrlichia
sp. strain EHh317, which was closely related to
Ehrlichia
sp. strain EBm52 and which was also detected in
H. hystricis
ticks collected from wild pigs in Vietnam. Two
Rickettsia
spp. were detected in Thailand, including (i)
Rickettsia
sp. strain RDla420, which was detected in
Dermacentor auratus
ticks collected from a bear, and (ii)
Rickettsia
sp. strain RDla440, which was identified from two pools of
Dermacentor
larvae collected from a wild pig nest. Finally, two bacteria named
Eubacterium
sp. strain Hw124 and
Eubacterium
sp. strain Hw191 were identified in
Haemaphysalis wellingtoni
ticks collected from chicken in Thailand; these strains could belong to a new group of bacteria.
Characterization of Encapsulated and Noncapsulated
Haemophilus influenzae
and Determination of Phylogenetic Relationships by Multilocus Sequence Typing
Authors: Meats Emma , Feil Edward J. , Stringer Suzanna , Cody Alison J. , Goldstein Richard , Kroll J. Simon , Popovic Tanja , Spratt Brian G.
Published: April 2003

A multilocus sequence typing (MLST) scheme has been developed for the unambiguous characterization of encapsulated and noncapsulated
Haemophilus influenzae
isolates. The sequences of internal fragments of seven housekeeping genes were determined for 131 isolates, comprising a diverse set of 104 serotype a, b, c, d, e, and f isolates and 27 noncapsulated isolates. Many of the encapsulated isolates had previously been characterized by multilocus enzyme electrophoresis (MLEE), and the validity of the MLST scheme was established by the very similar clustering of isolates obtained by these methods. Isolates of serotypes c, d, e, and f formed monophyletic groups on a dendrogram constructed from the differences in the allelic profiles of the isolates, whereas there were highly divergent lineages of both serotype a and b isolates. Noncapsulated isolates were distinct from encapsulated isolates and, with one exception, were within two highly divergent clusters. The relationships between the major lineages of encapsulated
H. influenzae
inferred from MLEE data could not be discerned on a dendrogram constructed from differences in the allelic profiles, but were apparent on a tree reconstructed from the concatenated nucleotide sequences. Recombination has not therefore completely eliminated phylogenetic signal, and in support of this, for encapsulated isolates, there was significant congruence between many of the trees reconstructed from the sequences of the seven individual loci. Congruence was less apparent for noncapsulated isolates, suggesting that the impact of recombination is greater among noncapsulated than encapsulated isolates. The
H. influenzae
MLST scheme is available at
www.mlst.net
, it allows any isolate to be compared with those in the MLST database, and (for encapsulated isolates) it assigns isolates to their phylogenetic lineage, via the Internet.
Haemophilus influenzae
Carriage in Children Attending French Day Care Centers: a Molecular Epidemiological Study
Authors: Dabernat Henri , Plisson-Sauné Marie-Anne , Delmas Catherine , Séguy Martine , Faucon Gèneviéve , Pélissier Roselyne , Carsenti Hélène , Pradier Christian , Roussel-Delvallez Micheline , Leroy Joël , Dupont Marie-Jeanne , De Bels Frédéric , Dellamonica Pierre
Published: April 2003

The nasopharyngeal
Haemophilus influenzae
flora of healthy children under the age of 3 years attending day care centers in three distinct French geographic areas was analyzed by sampling during two periods, spring 1999 (May and June) and fall 1999 (November and December). The average carrier rate among 1,683 children was 40.9%. The prevalence of capsulated
H. influenzae
carriers was 0.4% for type f and 0.6% for type e. No type b strains were found among these children, of whom 98.5% had received one or more doses of anti-
Haemophilus
b vaccine. Among the strains, 44.5% were TEM-type beta-lactamase producers and nine (1.3%) were beta-lactamase-negative ampicillin-resistant strains. Pulsed-field gel electrophoresis restriction patterns showed a large diversity with 366
Sma
I patterns from 663 strains. Among the strains isolated during a given period, 33% were isolated simultaneously in more than one area. In each area, depending on the sampling period, 68 to 72% of the strains had new pulsotypes and persistence of 28 to 32% of the strains was noted. For the 297 beta-lactamase-producing strains, 194 patterns were found. The genomic diversity of these strains was comparable to that of the whole set of strains and does not suggest a clonal diffusion. Among the beta-lactamase-producing strains isolated in November and December, depending on the area, 66 to 73% had new pulsotypes with persistence of only 27 to 33% of the strains. In any given geographic area, colonization by
H. influenzae
appears to be a dynamic process involving a high degree of genomic heterogeneity among the noncapsulated colonizing strains.
Evaluation of the BDProbeTec ET System for Direct Detection of
Mycobacterium tuberculosis
in Pulmonary and Extrapulmonary Samples: a Multicenter Study
Authors: Mazzarelli Gianna , Rindi Laura , Piccoli Paola , Scarparo Claudio , Garzelli Carlo , Tortoli Enrico
Published: April 2003

We evaluated the BDProbeTec ET system (Becton Dickinson, Sparks, Md.), a strand displacement amplification-based technique, for direct detection of
Mycobacterium tuberculosis
in 867 clinical samples. Of 294 extrapulmonary specimens, 52 had positive results by both BDProbeTec ET and culture and 209 had negative results by both methods; sensitivity and specificity were 76.5 and 95.9%, respectively. After resolution of discrepancies, the sensitivity rose to 77.8%.
drs
(Distantly Related
sic
) Gene Polymorphisms among
emm12
-Type
Streptococcus pyogenes
Isolates
Authors: Brandt Claudia M. , Haase Gerhard , Spellerberg Barbara , Holland Regina , Lütticken Rudolf
Published: April 2003

Twenty-eight
emm12
-type
Streptococcus pyogenes
isolates from patients with invasive and noninvasive infections or from asymptomatic carriers were genetically typed. Sequencing of
drs
(distantly related
sic
[streptococcal inhibitor of complement]) genes identified two novel alleles and revealed a polymorphism for
drs
similar to that of
sic
. No association was observed between the five different
drs
alleles and the five restriction patterns of the
vir
regulon for the isolates studied. These data suggest that
drs
sequencing may be useful for further differentiation of
S. pyogenes
isolates with
emm12
and identical
vir
regulon restriction patterns.
Differentiation between Isolates of
Aspergillus fumigatus
from Breeding Turkeys and Their Environment by Genotyping with Microsatellite Markers
Authors: Lair-Fulleringer Sybille , Guillot Jacques , Desterke Christophe , Seguin Dominique , Warin Stephan , Bezille Arnaud , Chermette René , Bretagne Stéphane
Published: April 2003

To elucidate the epidemiology of the different forms of avian aspergillosis, 114
Aspergillus fumigatus
isolates from sacrificed turkeys and 134
A. fumigatus
isolates from air samples were collected and genotyped by microsatellite polymorphism marker analysis. Air sampling confirmed the huge diversity of
A. fumigatus
populations. Whereas older animals harbored several combinations of genotypes, 1-day-old chicks carried a unique genotype, suggesting a unique source of contamination.
Reaction of Thianthrene Cation Radical with Diarylmercurials. Search for Single Electron Transfer Is Elusive
Authors: Hoque A. K. M. M. , Shine Henry J. , Venkatachalam T. Krishnan
Published: April 2003

Diarylmercurials (Ar2Hg) with Ar = p-tolyl Ib, o-tolyl Ic, p-anisyl Id and 2-allyloxy-4,5-dimethylphenyl Ie, reacted with thianthrene cation radical perchlorate (Th.+ClO4-) in two stoichiometric ratios: 2 : 1 and 4 : 1 (Th.+ClO4-/Ar2Hg). In the 2 : 1 ratio the products were the 5-arylthianthreniumyl perchlorates IIb - IIe, thianthrene (Th) and ArHg+ClO4- (assayed as ArHgCl, III) in quantitative yields. In the 4 : 1 ratio reaction with ArHg+ occurred, too, and the products were IIb - IIe, Th, the complex Th3Hg(ClO4)2 and HgO (after workup). In contrast, Ph2Hg (Ia) did not react beyond the 2 : 1 stoichiometry. In the reactions with Ie, no evidence for formation and cyclization of free 2-allyloxy-4,5-dimethylphenyl radical was found. Reaction of and product formation from these arylmercurials, therefore, does not occur in single electron transfer steps that lead to free aryl radicals. Instead electron transfer appears to occur within a complex of Ar2Hg with Th.+ from which II and other products are subsequently formed.
Temperature Dependences in the O + OH → O2 + H Reaction. Quasiclassical Trajectory Calculation
Authors: Klimo Viliam , Bittererová Martina , Biskupič Stanislav , Urban Ján , Micov Miroslav
Published: April 2003

The reaction O + OH → O2 + H in conditions of combustion of hydrocarbons and polymers was modelled by using the method of quasiclassical trajectories. The potential energy surface was determined by the multiconfiguration interaction method and fitted with the analytical form of the extended LEPS function. Attention was paid to the mean values of the vibrational and rotational quantum numbers of O2 molecules and their temperature dependence. The temperature dependence of the mean lifetime of the OOH collision complex was also examined. The calculated rate constants were analyzed and compared with the experimental data over the temperature region of the combustion processes.
The Effect of Chemical and Thermal Treatment on Permselectivity and Resistance Values of Cellophane Membranes
Authors: Benavente Juana
Published: April 2003

Membrane potentials through a chemically treated cellophane membrane have been measured at different temperatures. The results have been analysed on the bases of the Kobatake equation for the membrane potential, which permits the evaluation of some parameters related to the membrane structure. The influence of temperature on these parameters has been considered. The comparison among the permselectivity and electrical resistance values obtained at 25 °C with an untreated and two treated cellophane membranes, one chemically treated and another annealed, show a more significant loss of selectivity for the chemically treated membrane than for the annealed one, which can be attributed to a higher influence of the chemical treatment on the cellophane membrane structure than that due to the heating.
Absolute Chronoamperometric Determination with Cylindrical Semimicroelectrode
Authors: Mesároš Štefan , Rievaj Miroslav , Bustin Dušan
Published: April 2003

An analytical application of chronoamperometry for determination of electroactive species not requiring standardization is described in this paper. It is based upon the separation of current component limited by linear diffusion from that limited by cylindrical contribution to the total flux of determined substance to the cylindrical (wire) Pt-semimicroelectrode (radius 0.02 mm and length 15 mm). The absolute method of determination was verified with o-dianizidine, ferrocyanide, ascorbic acid and dopamine. The optimalization of radius of the cylindrical electrode to minimize the determination error is also presented.
Dependence of log k Obtained by HPLC on log P'exp in the Series Piperidino and Morpholinoethyl Esters of o-, m- and p-Alkoxy Substituted Phenylcarbamic Acids
Authors: Sedlárová Eva , Čižmárik Jozef , Novosedlíková Dana , Podhorová Katarína , Šranková Lucia , Šrank Andrej
Published: April 2003

Dependence of log k obtained by the HPLC method on log P'exp obtained by the classical method was investigated in two series of basic ethyl phenylcarbamic acids. The linear dependence was found with o-substituted series and p-substituted morpholino derivatives. The relation with p-derivatives of the piperidino series is close to linearity, while that of m-derivatives of both series is not linear.
A Simulated Experiment for Examining the Effect of Errors in the Composition of the Equilibrium Liquid-Vapour Phases on the Calculated Number of Theoretical Stages of a Rectification Column
Authors: Dojčanský Ján , Bafrncová Soňa , Surový Július
Published: April 2003

Five model binary systems differing in the relative volatilities and their changes were used to simulate the effect of random errors and bias in the L-G equilibrium phase composition on the calculation of the number of theoretical stages of a continuously working rectification column in various operating conditions.
Vibrational Transition Probabilities and Dissociation Energy of the PF Molecule
Authors: Rajamanickam Narayanan , Fernandez Gomez Manuel , Lopez Gonzalez Juan Jesus
Published: April 2003

The Franck-Condon factors (vibrational transition probabilities) and r-centroids have been evaluated by a more reliable numerical interogation procedure for the bands of b1Σ+ - X3Σ- system of the PF molecule, using a suitable potential. The dissociation energy, De = 318 kJ mol-1 for the electronic ground state of this molecule has been estimated by fitting the electronegativity function to the experimental potential energy curve.