bluuebunny/crossref_metadata_2025 huggingface dataset:
A cell shrinkage‐induced non‐selective cation conductance with a novel pharmacology in Ehrlich–Lettre‐ascites tumour cells
Authors: Lawonn Peter , Hoffmann Else K , Hougaard Charlotte , Wehner Frank
Published: April 2003

In whole‐cell recordings on Ehrlich–Lettre‐ascites tumour (ELA) cells, the shrinkage‐induced activation of a cation conductance with a selectivity ratio P
Na:P
Li:P
K:P
choline:P
NMDG of 1.00:0.97:0.88:0.03:0.01 was observed. In order of potency, this conductance was blocked by Gd3+=benzamil>amiloride>ethyl‐isopropyl‐amiloride (EIPA). In patch‐clamp studies using the cell‐attached configuration, a 14 pS channel became detectable that was reversibly activated upon hypertonic cell shrinkage. It is concluded that ELA cells express a shrinkage‐induced cation channel that may reflect a molecular link between amiloride‐sensitive and ‐insensitive channels. In addition, because of its pharmacological profile, it may possibly be related to epithelial Na+ channels (ENaCs).
Modeling and mutational analysis of the GAF domain of the cGMP‐binding, cGMP‐specific phosphodiesterase, PDE5
Authors: Sopory Shailaja , Balaji S , Srinivasan N , Visweswariah Sandhya S
Published: April 2003

The GAFa domain of the cGMP‐binding, cGMP‐specific phosphodiesterase (PDE5A) was modeled on the crystal structure of PDE2A GAF domain and residues involved in cGMP binding identified. Tandem GAFa and GAFb domains of PDE5A, expressed in Escherichia coli, bound cGMP (K
d 27 nM). Mutation of aspartate‐299 in GAFa, suggested earlier to be critical for cGMP binding, did not abrogate cGMP binding, but mutation of F205, which formed a stacking interaction with the guanine ring of cGMP, led to complete loss of cGMP binding. Therefore, the GAFa domain of PDE5A adopts a structure similar to the GAFb domain of PDE2A, and provides the sole site for cGMP binding in PDE5A.
Differential inhibition of fracture healing by non‐selective and cyclooxygenase‐2 selective non‐steroidal anti‐inflammatory drugs
Authors: Gerstenfeld Louis C. , Thiede Mark , Seibert Karen , Mielke Cindy , Phippard Deborah , Svagr Bohus , Cullinane Dennis , Einhorn Thomas A.
Published: April 2003

Non‐steroidal anti‐inflammatory drugs (NSAIDs) specifically inhibit cyclooxygenase (COX) activity and are widely used as anti‐arthritics, post‐surgical analgesics, and for the relief of acute musculoskeletal pain. Recent studies suggest that non‐specific NSAIDs, which inhibit both COX‐1 and COX‐2 isoforms, delay bone healing. The objectives of this study were 2‐fold; first, to measure the relative changes in the normal expression of COX‐1 and COX‐2 mRNAs over a 42 day period of fracture healing and second, to compare the effects of a commonly used non‐specific NSAID, ketorolac, with a COX‐2 specific NSAID, Parecoxib (a pro‐drug of valdecoxib), on this process. Simple, closed, transverse fractures were generated in femora of male Sprague‐Dawley rats weighing approximately 450 g each. Total RNA was prepared from the calluses obtained prior to fracture and at 1, 3, 5, 7, 10, 14, 21, 35 and 42 days post‐fracture and levels of COX‐1 and COX‐2 mRNA were measured using real time PCR. While the relative levels of COX‐1 mRNA remained constant over a 21‐day period, COX‐2 mRNA levels showed peak expression during the first 14 days of healing and returned to basal levels by day 21. Mechanical properties of the calluses were then assessed at 21 and 35 days post‐fracture in untreated animals and animals treated with either ketorolac or high or low dose parecoxib. At both 21 and 35 days after fracture, calluses in the group treated with the ketorolac showed a significant reduction in mechanical strength and stiffness when compared with controls (p < 0.05). At the 21‐day time point, calluses of the parecoxib treated animals showed a lower mean mechanical strength than controls, but the inhibition was not statistically significant. Based on physical analysis of the bones, 3 of 12 (25%) of the ketorolac‐treated and 1 of 12 (8%) of the high dose parecoxib‐treated animals showed failure to unite their fractures by 21 days, while all fractures in both groups showed union by 35 days. Histological analysis at 21 days showed that the calluses in the ketorolac‐treated group contained substantial amounts of residual cartilage while neither the control nor the parecoxib‐treated animals showed comparable amounts of cartilage at this stage. These results demonstrate that ketorolac and parecoxib delay fracture healing in this model, but in this study daily administration of ketorolac, a non‐selective COX inhibitor had a greater affect on this process. They further demonstrate that a COX‐2 selective NSAID, such as parecoxib (valdecoxib), has only a small effect on delaying fracture healing even at doses that are known to fully inhibit prostaglandin production. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Introducing a new recruitment approach to sample collection for genetic association studies in opioid dependence
Authors: Franke Petra , Wendel Birgit , Knapp Michael , Schwab Sibylle G. , Neef Daniela , Maier Wolfgang , Wildenauer Dieter B. , Hoehe Margret R.
Published: April 2003

Objective. –

In a modified case–control association study we tested the assumption that two polymorphisms (A118G in exon 1 and IVS2+31 in intron 2) of the human μ-opioid receptor gene (OPRM1) confer susceptibility to opioid dependence.

Methods. –

In contrast to classical case–control studies both groups, opioid dependent cases and non-opioid dependent controls were recruited from individuals who have had access to drugs including opioids and who had been sentenced for violation of the “Dangerous Drugs Act” in Germany.

Results. –

For the two allelic variants of OPRM1 under study we did not find evidence for association with opioid dependence.

Conclusions. –

Despite absence of association we think that this recruitment approach introduced here, is useful since it putatively offers a more adequate matching for case–control association studies of opioid dependent individuals.
Is multidisciplinary care of heart failure cost‐beneficial when combined with optimal medical care?
Authors: Ledwidge Mark , Barry Michael , Cahill John , Ryan Enda , Maurer Brian , Ryder Mary , Travers Bronagh , Timmons Lorna , McDonald Ken
Published: April 2003

Background:

Multidisciplinary care (MDC) of heart failure (HF) can significantly reduce rates of unplanned hospitalisation, the major cost component of HF care.

Aims:

This prospective, randomised, controlled study examines the cost‐benefits of MDC of HF in the setting of optimal medical care.

Methods:

98 NYHA class IV HF patients (mean age 70.8±10.5 years) were randomised to MDC (n=51) or routine care (RC; n=47) of HF. A direct intervention cost was calculated from contact time (scheduled and unscheduled) spent by the MDC team. Unplanned hospitalisation costs for HF were calculated at a daily rate of €242. Outcomes were determined in monetary terms, i.e. the cost of the service per hospitalisation prevented and net costs/savings at 3 months.

Results:

The direct intervention cost of the MDC team was €5860, with an average cost per patient of €113 (95% Cl: 97–128). At 3 months, there were a total of 12 unplanned HF readmissions in the RC group (25.5% rate, 195 days) compared to 2 in the MDC group (3.9% rate, 17 days). The number needed to treat to prevent one hospitalisation for HF was 6 over 3 months. The cost of the service per hospitalisation prevented was €586. The intervention produced a net cost saving of €37,216 for 51 patients treated over 3 months. Sensitivity analyses using 50% variation in costs and lower relative risk reductions confirmed the cost‐benefits of the intervention.

Conclusion:

MDC of HF remains cost‐beneficial when combined with optimal, medical care. The significant clinical and cost‐benefits suggest that this intensive approach to MDC and medical management should become the standard of care for HF.
Gender Differences in Patients with Heart Failure
Authors: Strömberg Anna , Mårtensson Jan
Published: April 2003

Aim: The aim of this literature review was to review and discuss the differences between men and women with heart failure with regard to epidemiology, aetiology, diagnostics, prognosis, pharmacological and non-pharmacological treatment, and the impact of heart failure on psychosocial factors and healthcare utilisation. Method: Two primary health care resources, MEDLINE and CINAHL, were selected to review the current literature. In MEDLINE, 234 abstracts dealing with heart failure and gender/sex were found and in CINAHL, 20 abstracts. Conclusion: Men have a higher incidence of heart failure, but the overall prevalence rate is similar in both sexes, since women survive longer after the onset of heart failure. Women tend to be older when diagnosed with heart failure and more often have diastolic dysfunction than men. The extent of sex differences in treatment, hospital cost and quality of care can partly be explained by age differences. The life situations for men and women with heart failure are different. Physical and social restrictions affecting daily life activities are experienced as most bothersome for men, whereas restrictions affecting the possibility to support family and friends are most difficult to accept for women. Women with heart failure ascribe more positive meanings to their illness. Despite this, women seem to experience a lower overall quality of life than men. The known gender differences in patients with heart failure need to be highlighted in guidelines as well as implemented in standard care.
Are General Practitioners Willing and Able to Provide Genetic Services for Common Diseases?
Authors: Suchard Marc A. , Yudkin Patricia , Sinsheimer Janet S.
Published: April 2003

Primary care in the United Kingdom has been advocated as an optimal location for the provision of genetic services for common diseases. Little, however, is known about general practitioners' own views toward this suggestion or the possible demand for such services from patients. To assess general practitioners' attitudes to providing genetic services for common diseases, and to estimate the demand from patients for these services, we used a single‐page postal questionnaire survey of all 359 general practitioners registered with the Oxfordshire Health Authority; 339 (94%) responded. These physicians reported that a mean 4.1 patients (95% CI, 3.3–4.9) out of every 1,000 consulting them were concerned about their own risk of a common disease associated with a diagnosis in a family member. Half of the general practitioners (95% CI, 45–56%) counseled about genetics in the last year.

A majority of general practitioners accept the need to provide genetic services, but far fewer are competent to do so. Although 60% (95% CI, 55–65%) believed they should be involved with genetic screening for common diseases, only 29% (95% CI, 24–34%) felt sufficiently prepared to take family histories and draw pedigrees, and only 15% (95% CI, 11–19%) felt sufficiently prepared to counsel patients about their genetic test results. Given the necessary training and information, 63% (95% CI, 58–68%) and 64% (95% CI, 59–69%) were willing to provide these services. Even with training and information, not all would be willing to provide these services, and lack of time may be a major deterrent. “Practice‐enabling” strategies, such as computerized aids in genetics, may be useful.
Social Contexts: Transcending Their Power and Their Fragility
Authors: Moos Rudolf H.
Published: April 2003

For more than four decades, my colleagues and I have examined how social contexts and individuals influence each other. To provide a perspective on this work, I describe some lessons we have learned: situational influence exemplifies both the power and fragility of social contexts; common aspects of settings underlie their power, for better and for worse; individuals' health and well‐being is affected by powerful forces in eight domains; and intervention programs are powerful settings that encompass risks as well as rewards. I then note some unresolved questions, such as how to balance the risks and rewards of powerful environments, how to better understand the interplay between individuals and the social contexts they select and create, how to learn from the fact that many people overcome the power of traumatic social contexts, and how to apply our knowledge to balance the risks and rewards of individual and community contexts.
Cytochrome P450 2E1 Genotype and the Susceptibility to Antituberculosis Drug–Induced Hepatitis
Authors: Huang Yi-Shin , Chern Herng-Der , Su Wei-Juin , Wu Jaw-Ching , Chang Shi-Chuan , Chiang Chi-Huei , Chang Full-Young , Lee Shou-Dong
Published: April 2003

Most cases with antituberculosis drug–induced hepatitis have been attributed to isoniazid. Isoniazid is metabolized by hepatic N–acetyltransferase (NAT) and cytochrome P450 2E1 (CYP2E1) to form hepatotoxins. However, the role of CYP2E1 in this hepatotoxicity has not yet been reported. The aim of this study was to evaluate whether the polymorphism of the CYP2E1 gene is associated with antituberculosis drug–induced hepatitis. A total of 318 tuberculosis patients who received antituberculosis treatment were followed prospectively. Their CYP2E1 and NAT2 genotypes were determined using a polymerase chain reaction with restriction fragment length polymorphism method. Twenty–one healthy volunteers were recruited for CYP2E1 phenotype study using a chlorzoxazone test. Forty–nine (15.4%) patients were diagnosed to have drug–induced hepatotoxicity. Patients with homozygous wild genotype CYP2E1 c1/c1 had a higher risk of hepatotoxicity (20.0%; odds ratio [OR], 2.52) than those with mutant allele c2 (CYP2E1 c1/c2 or c2/c2, 9.0%, P = .009). If CYP2E1 c1/c2 or c2/c2 genotype combined with rapid acetylator status was regarded as the reference group, the risk of hepatotoxicity increased from 3.94 for CYP2E1 c1/c1 with rapid acetylator status to 7.43 for CYP2E1 c1/c1 with slow acetylator status. After adjustment for acetylator status and age, the CYP2E1 c1/c1 genotype remained an independent risk factor for hepatotoxicity (OR, 2.38; P = .017). Furthermore, under the administration of isoniazid, the volunteers with CYP2E1 c1/c1 genotype had higher CYP2E1 activity than those with other genotypes had and, hence, might produce more hepatotoxins. In conclusion, CYP 2E1 genetic polymorphism may be associated with susceptibility to antituberculosis drug–induced hepatitis. (Hepatology 2003;37:924–930.)
Hepatitis C Virus Infection in the General Population: A Community–Based Study in West Bengal, India
Authors: Chowdhury Abhijit , Santra Amal , Chaudhuri Susmita , Dhali Gopal Krishna , Chaudhuri Sujit , Maity Satya Gopal , Naik Trailokya Nath , Bhattacharya Sujit Kumar , Mazumder Debendra Nath Guha
Published: April 2003

Limited information is available about the prevalence and genotype distribution of hepatitis C virus (HCV) in the general population of India. A community–based epidemiologic study was carried out in a district in West Bengal, India. By a 1:3 sampling method, 3,579 individuals were preselected from 10,737 inhabitants of 9 villages of the district, of whom 2,973 (83.1%) agreed to participate. Twenty–six subjects (0.87%) were HCV antibody positive. The prevalence increased from 0.31% in subjects <10 years of age to 1.85% in those ≥60 years. No difference in prevalence between men and women was observed. Serum alanine aminotransferase (ALT) levels were elevated in 30.8% (8 of 26) of anti–HCV–positive subjects compared with 3.2% (94 of 2,947) anti–HCV–negative subjects (P < .001). HCV RNA was detectable in 80.8% (95% CI, 65.6%–95.91%) of the anti–HCV–positive subjects by reverse transcription–primed polymerase chain reaction (RT–PCR). The participants were HCV types 1b in 2 (9.5%), 3a in 8 (38.1%), 3b in 6 (28.6%), and unclassified in 5 (23.8%). Nucleotide sequencing and phylogenetic analysis assigned the unclassified type to genotype 3e. In conclusion, this study provides general population–based estimates of HCV prevalence, including genotypes, from a South Asian country. Although the prevalence of HCV infection in this population was lower than that reported from industrialized countries of the west, the total reservoir of infection is significant and calls for public health measures, including health education to limit the magnitude of the problem.(Hepatology 2003;37:802–809.)
Influence of Ursodeoxycholate–Enriched Diet on Liver Tumor Growth in Hbv Transgenic Mice
Authors: Barone Michele , Maiorano Eugenio , Ladisa Roberta , Cuomo Rosario , Pece Antonia , Berloco Pasquale , Caruso Maria Lucia , Valentini Anna Maria , Iolascon Achille , Francavilla Antonio , Di Leo Alfredo , Ierardi Enzo
Published: April 2003

Hepatitis B virus (HBV) transgenic mice (official designation, Tg [Alb–1 HBV] Bri 44) invariably develop macroscopically evident tumors within the 20th month of life. Sustained proliferative activity seems to play an important role in the development of these lesions. We previously showed that ursodeoxycholate (UDC) stimulates hepatocyte proliferation in various experimental settings. Herein, we tested the assumption that biological factors able to further increase liver cell proliferation, such as UDC, could accelerate tumor development in this animal model. For this study, 22 eight–week–old male transgenic mice were divided into 2 groups; 11 animals received a standard diet, and 11 received a UDC–enriched diet. The 2 groups were further divided into 2 subgroups of 5 and 6 animals each and were sacrificed at 3 and 15 months of age, respectively. These different times were chosen to exclude diet–related toxicity (in 3–month–old mice) and evaluate tumor growth (in 15–month–old mice). In addition, hepatocyte proliferation was assessed in all animals. In 3–month–old mice receiving UDC, cholestatic and cytolytic indices as well as liver histology were comparable to those in controls. At 15 months, all UDC–treated mice showed large multinodular tumors whereas only 33% of controls developed smaller uninodular neoplasms. Hepatocyte proliferation was increased in all animals receiving UDC compared with controls. In conclusion, the increase in serum UDC (undetectable in mice fed a standard diet), in the absence of any toxic effect on the liver, suggests the involvement of this bile salt in the stimulation of hepatocyte proliferation and tumor growth. (Hepatology 2003;37:880–886.)
Costimulation via OX40L Expressed by B Cells Is Sufficient to Determine the Extent of Primary CD4 Cell Expansion and Th2 Cytokine Secretion In Vivo
Authors: Linton Phyllis-Jean , Bautista Beverly , Biederman Elana , Bradley Evan S. , Harbertson Judith , Kondrack Robyn M. , Padrick Ryan C. , Bradley Linda M.
Published: April 2003

The development of effector and memory CD4 cell populations depends upon both T cell receptor (TCR) engagement of peptide/major histocompatibility complex (MHC) class II complexes and ligation of costimulatory molecules with counter receptors on antigen-presenting cells (APCs). We showed previously that sustained interactions with APCs could be crucial for optimal expansion of CD4 cells and for development of effectors that secrete cytokines associated with Th2 cells. Using an adoptive transfer model with TCR transgenic CD4 cells, we now show that responses of CD4 cells primed in B cell–deficient mice become aborted, but are fully restored upon the transfer of activated B cells. Although B cells have the capacity to secrete multiple cytokines that could affect CD4 priming, including IL-4, we were unable to distinguish a role for cytokines that are secreted by B cells. However, B cell costimulation via the OX40L/OX40 pathway that has been implicated in CD4 cell expansion, survival, and Th2 development was required. Th2 but not Th1 responses were impaired in OX40L-deficient recipients and normal responses were restored with OX40L sufficient B cells. The results suggest that without engagement of OX40L on B cells, CD4 cell responses to many protein Ag would be dominated by Th1 cytokines. These data have important implications for strategies to achieve optimal priming of CD4 subsets.
CD1d-expressing Dendritic Cells but Not Thymic Epithelial Cells Can Mediate Negative Selection of NKT Cells
Authors: Chun Taehoon , Page Michael J. , Gapin Laurent , Matsuda Jennifer L. , Xu Honglin , Nguyen Hanh , Kang Hyung-Sik , Stanic Aleksandar K. , Joyce Sebastian , Koltun Walter A. , Chorney Michael J. , Kronenberg Mitchell , Wang Chyung-Ru
Published: April 2003

Natural killer T (NKT) cells are a unique immunoregulatory T cell population that is positively selected by CD1d-expressing thymocytes. Previous studies have shown that NKT cells exhibit autoreactivity, which raises the question of whether they are subject to negative selection. Here, we report that the addition of agonist glycolipid α-galactosylceramide (α-GalCer) to a fetal thymic organ culture (FTOC) induces a dose-dependent disappearance of NKT cells, suggesting that NKT cells are susceptible to negative selection. Overexpression of CD1d in transgenic (Tg) mice results in reduced numbers of NKT cells, and the residual NKT cells in CD1d-Tg mice exhibit both an altered Vβ usage and a reduced sensitivity to antigen. Furthermore, bone marrow (BM) chimeras between Tg and WT mice reveal that CD1d-expressing BM-derived dendritic cells, but not thymic epithelial cells, mediate the efficient negative selection of NKT cells. Thus, our data suggest that NKT cells developmentally undergo negative selection when engaged by high-avidity antigen or abundant self-antigen.
Dendritic Cell Responses to Early Murine Cytomegalovirus Infection
Authors: Dalod Marc , Hamilton Tanya , Salomon Rachelle , Salazar-Mather Thais P. , Henry Stanley C. , Hamilton John D. , Biron Christine A.
Published: April 2003

Differentiation of dendritic cells (DCs) into particular subsets may act to shape innate and adaptive immune responses, but little is known about how this occurs during infections. Plasmacytoid dendritic cells (PDCs) are major producers of interferon (IFN)-α/β in response to many viruses. Here, the functions of these and other splenic DC subsets are further analyzed after in vivo infection with murine cytomegalovirus (MCMV). Viral challenge induced PDC maturation, their production of high levels of innate cytokines, and their ability to activate natural killer (NK) cells. The conditions also licensed PDCs to efficiently activate CD8 T cells in vitro. Non-plasmacytoid DCs induced T lymphocyte activation in vitro. As MCMV preferentially infected CD8α+ DCs, however, restricted access to antigens may limit plasmacytoid and CD11b+ DC contribution to CD8 T cell activation. IFN-α/β regulated multiple DC responses, limiting viral replication in all DC and IL-12 production especially in the CD11b+ subset but promoting PDC accumulation and CD8α+ DC maturation. Thus, during defense against a viral infection, PDCs appear specialized for initiation of innate, and as a result of their production of IFN-α/β, regulate other DCs for induction of adaptive immunity. Therefore, they may orchestrate the DC subsets to shape endogenous immune responses to viruses.
Combined Deficiency of p50 and cRel in CD4+ T Cells Reveals an Essential Requirement for Nuclear Factor κB in Regulating Mature T Cell Survival and In Vivo Function
Authors: Zheng Ye , Vig Monika , Lyons Jesse , Van Parijs Luk , Beg Amer A.
Published: April 2003

Signaling pathways involved in regulating T cell proliferation and survival are not well understood. Here we have investigated a possible role of the nuclear factor (NF)-κB pathway in regulating mature T cell function by using CD4+ T cells from p50−/− cRel−/− mice, which exhibit virtually no inducible κB site binding activity. Studies with these mice indicate an essential role of T cell receptor (TCR)-induced NF-κB in regulating interleukin (IL)-2 expression, cell cycle entry, and survival of T cells. Our results further indicate that NF-κB regulates TCR-induced expression of antiapoptotic Bcl-2 family members. Strikingly, retroviral transduction of CD4+ T cells with the NF-κB–inducing IκB kinase β showed that NF-κB activation is not only necessary but also sufficient for T cell survival. In contrast, our results indicate a lack of involvement of NF-κB in both IL-2 and Akt-induced survival pathways. In vivo, p50−/− cRel−/− mice showed impaired superantigen-induced T cell responses as well as decreased numbers of effector/memory and regulatory CD4+ T cells. These findings provide the first demonstration of a role for NF-κB proteins in regulating T cell function in vivo and establish a critically important function of NF-κB in TCR-induced regulation of survival.
Use of Amplified Fragment Length Polymorphism Analysis To Identify Medically Important
Candida
spp., Including
C
.
dubliniensis
Authors: Borst A. , Theelen B. , Reinders E. , Boekhout T. , Fluit A. C. , Savelkoul P. H. M.
Published: April 2003

Non-
C
andida albicans Candida
species are increasingly being isolated. These species show differences in levels of resistance to antimycotic agents and mortality. Therefore, it is important to be able to correctly identify the causative organism to the species level. Identification of
C
.
dubliniensis
in particular remains problematic due to the high degree of phenotypic similarity between this species and
C. albicans
. The use of amplified fragment length polymorphism (AFLP) analysis as an identification method for medically important
Candida
species was investigated. Our results show very clear differences among medically important
Candida
species. Furthermore, when screening a large collection of clinical isolates previously identified on CHROMagar as
C
.
albicans
, we found a misidentification rate of 6%. AFLP analysis is universally applicable, and the patterns can easily be stored in a general, accessible database. Therefore, AFLP might prove to be a reliable method for the identification of medically important
Candida
species.
Presence and Characterization of Extraintestinal Pathogenic
Escherichia coli
Virulence Genes in F165-Positive
E. coli
Strains Isolated from Diseased Calves and Pigs
Authors: Dezfulian Hojabr , Batisson Isabelle , Fairbrother John M. , Lau Peter C. K. , Nassar Atef , Szatmari George , Harel Josée
Published: April 2003

The virulence genotype profile and presence of a pathogenicity island(s) (PAI) were studied in 18 strains of F165-positive
Escherichia coli
originally isolated from diseased calves or piglets. On the basis of their adhesion phenotypes and genotypes, these extraintestinal pathogenic strains were classified into three groups. The F165 fimbrial complex consists of at least two serologically and genetically distinct fimbriae: F165
1
and F165
2
. F165
1
is encoded by the
foo
operon (
pap
-like), and F165
2
is encoded by
fot
(
sfa
related). Strains in group 1 were
foo
and
fot
positive, strains in group 2 were
foo
and
afa
positive, and strains in group 3 were
foo
positive only. The strains were tested for the presence of virulence genes found mainly in extraintestinal pathogenic
E. coli
(ExPEC) strains. Although all the strains were positive for the
papA
variant encoding F11 fimbriae
incD
,
traT
, and
papC
, the prevalence of virulence genes commonly found in PAIs associated with ExPEC strains was highly variable, with strains of group 2 harboring most of the virulence genes tested.
papG
allele III was detected in all strains in group 1 and in one strain in group 3. All other strains were negative for the known alleles encoding PapG adhesins. The association of virulence genes with tRNA genes was characterized in these strains by using pulsed-field gel electrophoresis and DNA hybridization. The insertion site of the
foo
operon was found at the
pheU
tRNA locus in 16 of the 18 strains and at the
selC
tRNA locus in the other 2 strains. Furthermore, 8 of the 18 strains harbored a high-pathogenicity island which was inserted in either the
asnT
or the
asnV
/
U
tRNA locus. These results suggest the presence of one or more PAIs in septicemic strains from animals and the association of the
foo
operon with at least one of these islands. F165-positive strains share certain virulence traits with ExPEC, and most of them are pathogenic in piglets, as tested in experimental infections.
Characterization of Clinical Isolates of
Enterobacteriaceae
from Italy by the BD Phoenix Extended-Spectrum β-Lactamase Detection Method
Authors: Sanguinetti Maurizio , Posteraro Brunella , Spanu Teresa , Ciccaglione Daniela , Romano Lucio , Fiori Barbara , Nicoletti Giuseppe , Zanetti Stefania , Fadda Giovanni
Published: April 2003

Production of extended-spectrum β-lactamases (ESBLs) is an important mechanism of β-lactam resistance in
Enterobacteriaceae
. Identification of ESBLs based on phenotypic tests is the strategy most commonly used in clinical microbiology laboratories. The Phoenix ESBL test (BD Diagnostic Systems, Sparks, Md.) is a recently developed automated system for detection of ESBL-producing gram-negative bacteria. An algorithm based on phenotypic responses to a panel of cephalosporins (ceftazidime plus clavulanic acid, ceftazidime, cefotaxime plus clavulanic acid, cefpodoxime, and ceftriaxone plus clavulanic acid) was used to test 510 clinical isolates of
Escherichia coli
,
Klebsiella pneumoniae
,
Klebsiella oxytoca
,
Proteus mirabilis
,
Providencia stuartii
,
Morganella morganii
,
Enterobacter aerogenes
,
Enterobacter cloacae
,
Serratia marcescens
,
Citrobacter freundii
, and
Citrobacter koseri
. Of these isolates, 319 were identified as ESBL producers, and the remaining 191 were identified as non-ESBL producers based on the results of current phenotypic tests. Combined use of isoelectric focusing, PCR, and/or DNA sequencing demonstrated that 288 isolates possessed

bla
TEM-1

- and/or

bla
SHV-1

-derived genes, and 28 had a

bla
CTX-M

gene. Among the 191 non-ESBL-producing isolates, 77 isolates produced an AmpC-type enzyme, 110 isolates possessed TEM-1, TEM-2, or SHV-1 β-lactamases, and the remaining four isolates (all
K. oxytoca
strains) hyperproduced K1 chromosomal β-lactamase. The Phoenix ESBL test system gave positive results for all the 319 ESBL-producing isolates and also for two of the four K1-hyperproducing isolates of
K. oxytoca
. Compared with the phenotypic tests and molecular analyses, the Phoenix system displayed 100% sensitivity and 98.9% specificity. These findings suggest that the Phoenix ESBL test can be a rapid and reliable method for laboratory detection of ESBL resistance in gram-negative bacteria.
Accuracy of the TRUGENEHIV-1Genotyping Kit
Authors: Grant Robert M. , Kuritzkes Daniel R. , Johnson Victoria A. , Mellors John W. , Sullivan John L. , Swanstrom Ronald , D'Aquila Richard T. , Van Gorder Mark , Holodniy Mark , Lloyd, Robert M. , Reid Caroline , Morgan Gillian F. , Winslow Dean L.
Published: April 2003

Drug resistance and poor virological responses are associated with well-characterized mutations in the viral reading frames that encode the proteins that are targeted by currently available antiretroviral drugs. An integrated system was developed that includes target gene amplification, DNA sequencing chemistry (TRUGENEHIV-1Genotyping Kit), and hardware and interpretative software (the OpenGene DNA Sequencing System) for detection of mutations in the human immunodeficiency virus type 1 (HIV-1) protease and reverse transcriptase sequences. The integrated system incorporates reverse transcription-PCR from extracted HIV-1 RNA, a coupled amplification and sequencing step (CLIP), polyacrylamide gel electrophoresis, semiautomated analysis of data, and generation of an interpretative report. To assess the accuracy and robustness of the assay system, 270 coded plasma specimens derived from nine patients were sent to six laboratories for blinded analysis. All specimens contained HIV-1 subtype B viruses. Results of 270 independent assays were compared to “gold standard” consensus sequences of the virus populations determined by sequence analysis of 16 to 20 clones of viral DNA amplicons derived from two independent PCRs using primers not used in the kit. The accuracy of the integrated system for nucleotide base identification was 98.7%, and the accuracy for codon identification at 54 sites associated with drug resistance was 97.6%. In a separate analysis of plasma spiked with infectious molecular clones, the assay reproducibly detected all 72 different drug resistance mutations that were evaluated. There were no significant differences in accuracy between laboratories, between technologists, between kit lots, or between days. This integrated assay system for the detection of HIV-1 drug resistance mutations has a high degree of accuracy and reproducibility in several laboratories.
Analysis of Molecular Epidemiology of Chilean
Salmonella enterica
Serotype Enteritidis Isolates by Pulsed-Field Gel Electrophoresis and Bacteriophage Typing
Authors: Fernandez Jorge , Fica Alberto , Ebensperger German , Calfullan Hector , Prat Soledad , Fernandez Alda , Alexandre Marcela , Heitmann Ingrid
Published: April 2003

Human
Salmonella enterica
serotype Enteritidis infections emerged in Chile in 1994.
S. enterica
serotype Enteritidis phage type 1 isolates predominated in the north, and phage type 4 isolates predominated in the central and southern regions. A study was planned to characterize this epidemic using the best discriminatory typing technique. Research involved 441
S. enterica
serotype Enteritidis isolates, including clinical preepidemic samples (
n
= 74; 1975 to 1993) and epidemic (
n
= 199), food (
n
= 72), poultry (
n
= 57), and some Latin American (
n
= 39) isolates. The best method was selected based on a sample of preepidemic isolates, analyzing the discriminatory power (DP) obtained by phage typing and randomly amplified polymorphic DNA and pulsed-field gel electophoresis (PFGE) analysis. The highest DP was associated with
Bln
I PFGE-bacteriophage typing analysis (0.993). A total of 38
Bln
I patterns (B patterns) were identified before the epidemic period, 19 since 1994, and only 4 in both periods. Two major clusters were identified by phylogenetic analysis, and the predominant B patterns clustered in the same branch. Combined analysis revealed that specific B pattern-phage type combinations (subtypes) disappeared before 1994, that different genotypes associated with
S. enterica
serotype Enteritidis phage type 4 had been observed since 1988, and that strain diversity increased before the expansion of
S. enterica
serotype Enteritidis in 1994. Predominant subtype B3-phage type 4 was associated with the central and southern regions, and subtype B38-phage type 1 was associated with the north (
P
< 0.0001). Food and poultry isolates matched the predominant
S. enterica
serotype Enteritidis subtypes, but isolates identified in neighboring countries (Peru and Bolivia) did not match
S. enterica
serotype Enteritidis subtypes identified in the north of Chile. The results of this work demonstrate that genetic diversity, replacement, and expansion of specific
S. enterica
serotype Enteritidis subtypes were associated with epidemic changes.
New Filamentous Fungus
Sagenomella chlamydospora
Responsible for a Disseminated Infection in a Dog
Authors: Gené Josepa , Blanco José L. , Cano Josep , García Marta E. , Guarro Josep
Published: April 2003

A filamentous fungus that caused a fatal systemic infection in a dog has been identified as the new species
Sagenomella chlamydospora
. When the case was initially reported, the fungus was identified as
Paecilomyces
sp. This study emphasizes how difficult can be the identification of the causative agent of an infection when an uncommon microorganism is involved. This is the first time that this genus has been involved in animal infections, including humans.
Quantitative Detection of
Chlamydia psittaci
and
C. pecorum
by High-Sensitivity Real-Time PCR Reveals High Prevalence of Vaginal Infection in Cattle
Authors: DeGraves Fred J. , Gao Dongya , Hehnen Hans-Robert , Schlapp Tobias , Kaltenboeck Bernhard
Published: April 2003

Bovine vaginal cytobrush specimens were analyzed for the presence of
Chlamydia
spp. by a high-sensitivity, high-specificity quantitative PCR. The 53% prevalence of low-level
Chlamydia psittaci
and
C. pecorum
genital infection detected in virgin heifers suggests predominantely extragenital transmission of
Chlamydia
in cattle and conforms to the high seroprevalence of anti-
Chlamydia
antibodies.
Detection of Single Cells of
Cryptococcus neoformans
in Clinical Samples by Solid-Phase Cytometry
Authors: Bauters T. G. M. , Swinne D. , Stove V. , Nelis H. J.
Published: April 2003

A method based on solid-phase cytometry for the detection and enumeration of single cells of
Cryptococcus neoformans
in serum and cerebrospinal fluid is described. Both viable and nonviable cells are detected by using fluorescence viability labeling and immunofluorescence. This 30-min procedure has a detection limit of 3 to 6 cells per ml.
Prevalence of Norwalk-Like Virus Infections in Cases of Viral Gastroenteritis among Children in Osaka City, Japan
Authors: Iritani Nobuhiro , Seto Yoshiyuki , Kubo Hideyuki , Murakami Tsukasa , Haruki Kosuke , Ayata Minoru , Ogura Hisashi
Published: April 2003

Surveillance of Norwalk-like virus (NLV) infections in cases of pediatric gastroenteritis between April 1996 and March 2000 showed that NLVs were an important causative agent in viral gastroenteritis cases among children between November and January in those years. The predominant type of NLV was closely related to Lordsdale virus in genogroup 2. During the 1999-2000 season, Arg320-like strains, which may be genetic recombinants, suddenly appeared and spread.
DNase Pretreatment of Master Mix Reagents Improves the Validity of Universal 16S rRNA Gene PCR Results
Authors: Heininger Alexandra , Binder Marlies , Ellinger Andreas , Botzenhart Konrad , Unertl Klaus , Döring Gerd
Published: April 2003

DNase I pretreatment of 16S rRNA gene PCR reagents was tested. The DNase I requirement for the elimination of false-positive results varied between 0.1 and 70 IU per master mix depending on the applied
Taq
polymerase. PCR sensitivity was mostly maintained when 0.1 IU of DNase I was used.
Clonal Dissemination of
Yersinia enterocolitica
Strains with Various Susceptibilities to Nalidixic Acid
Authors: Sánchez-Céspedes Javier , Navia Margarita M. , Martínez Rocío , Orden Beatriz , Millán Rosario , Ruiz Joaquín , Vila Jordi
Published: April 2003

Ten epidemiologically related
Yersinia enterocolitica
clinical isolates were studied. Six isolates were nalidixic acid resistant (MIC > 512 μg/ml), with mutations in the quinolone resistance-determining region (QRDR) of the
gyrA
gene, suggesting clonal dissemination of a nalidixic acid-susceptible
Y. enterocolitica
strain which has acquired different mutations generating resistance to nalidixic acid.
Distribution of the
saa
Gene in Strains of Shiga Toxin-Producing
Escherichia coli
of Human and Bovine Origins
Authors: Jenkins Claire , Perry Neil T. , Cheasty Tom , Shaw Darren J. , Frankel Gad , Dougan Gordon , Gunn George J. , Smith Henry R. , Paton Adrienne W. , Paton James C.
Published: April 2003

Certain strains of Shiga toxin-producing
Escherichia coli
(STEC) which do not have the locus of enterocyte effacement pathogenicity island carry the STEC autoagglutinating adhesin (
saa
) gene. The distribution of the
saa
gene in STEC isolates from patients with hemolytic-uremic syndrome (HUS), patients with less severe diarrheal disease, asymptomatic individuals, and healthy cattle was examined.
saa
-positive strains were detected more frequently (
P
< 0.001) in STEC strains from bovines (32 of 56 strains) than in those from humans (8 of 91 strains). No significant association (
P
= 0.135) was found between the
saa
gene and STEC isolated from patients with HUS (6 of 46 strains) or diarrhea (2 of 29 strains) and from healthy controls (0 of 16 strains).
Dehydrochlorination of Poly(vinyl chloride) in Isotactic Systems
Authors: Burda Jaroslav , Lukáš Rudolf
Published: April 2003

The dehydrochlorination of isotactic, low-molecular-weight models of PVC, dimers to pentamers, was studied using the semiempirical MNDO method. The results obtained lead to the conclusion that the thermal dehydrochlorination of PVC can occur through either a radical or an ionic mechanism, depending on the reaction conditions. The arising conjugated polyene structures do not grow by the generally accepted "zip" mechanism, but rather through the "alternating growth" mechanism. A comparison was also made to the reactivity of isotactic and syndiotactic sequences from the point of view of kinetic and thermodynamic factors. It follows from the computations that the splitting off of the first HCl molecule is easier in the isotactic sequence, but that subsequent growth of the polyene chain occurs more readily in syndiotactic systems.
Preparation of vic-Mercaptoisopentanols
Authors: Végh Daniel , Uher Michal , Rajniaková Oľga , Dandárová Miloslava , Kováč Milan
Published: April 2003

This paper describes the preparation of some mercaptoisopentanols: 2-mercapto-3-methyl-1-butanol (I), 1-mercapto-3-methyl-2-butanol (II), 3-mercapto-3-methyl-2-butanol (III) and the unsaturated analogue of compound I - 2-mercapto-3-methyl-2-buten-1-ol (IV). These compounds belong to the flavonoid group present in food responsible for deterioration of their gustatory properties.
New Synthesis of N-Acylurea Derivatives
Authors: Kutschy Peter , Dzurilla Milan , Ficeri Vlastimír , Koščík Dušan
Published: April 2003

S-Allyl N-acylmonothiocarbamates react in boiling benzene with primary and secondary amines in the presence of catalytic amounts of triethylamine. In this reaction, the S-allyl group is replaced with the amino group under formation of N-acylurea derivatives in 45 - 90% yields. The wide applicability of the reaction is demonstrated by the synthesis of eighty four N-acyl-N'-substituted and N-acyl-N',N'-disubstituted ureas with various aliphatic, aromatic and heterocyclo substituents.
Analysis of Asymmetric Sigmoid Kinetic Curves of Autocatalytic Reactions
Authors: Fazekaš Tomáš , Nagy Arpád , Treindl Ľudovít
Published: April 2003

A new procedure for the analysis of sigmoid autocatalytic curves was developed based on the simulated annealing method. The procedure is particularly well suited to the treatment of asymmetric sigmoid shapes. The method was applied to the autocatalytic oxidation of citric acid with potassium permanganate.
Equilibrium Studies of Binary and Ternary Complexes of Palladium(II) Involving Amino Acids
Authors: Shoukry Mohamed M. , Shoukry Eman M.
Published: April 2003

The formation constants of the binary and ternary complexes of palladium(II) with diethylenetriamine and amino acids as ligands have been determined potentiometrically at 25 °C in 0.1 M NaNO3 solution. The relative stability of each ternary complex was compared with that of the corresponding binary complexes in terms of ∆logK values. The mode of chelation was ascertained by conductivity measurements.
Contribution to the Semiempirical Interpretation of the Anisotropy of the 29Si NMR Shielding Tensor in Silicates. II. Influence of Changes in the O-Si-O Bond Angle in SiO44- Ion
Authors: Vogel Christine , Wolff Renate , Radeglia Reiner
Published: April 2003

The influence of variations in the OSiO bond angle α on the anisotropy of the 29Si shielding tensor of the monosilicate anion SiO44- in C3ν symmetry has been investigated by semiempirical CNDO/2 calculations. In the valence basis set of the silicon atom, no d-orbitals were employed. It could be shown that the terms characterizing the four Si-O bond contributions to ∆σ are of greatest importance for reproducing the experimentally observed trend of anisotropy signs in silicates. Both the increasing O(1)-Si-O(B) bond angle α, and the decreasing Si-O(1) bond length r(Si-O(1)) (and vice versa) exhibit an amplifying geometrical influence on ∆σ.
Copper(II) Dihydroxybenzoates; Synthesis and Properties
Authors: Sokolík Jozef , Lučanská Brigita , Plesch Gustáv , Tumová Ingrid , Valent Aladár , Švec Pavel , Krätsmár-Šmogrovič Juraj
Published: April 2003

Compounds of composition Cu(2,5-DHB)2 . 4 H2O (DHB, dihydroxybenoate anion) and Cu(2,Y-DHB)2 . 8 H2O (Y = 4 or 6) were prepared as potential antiinflamatory gents with a view of pharmacological screening. The room-temperature magnetic moments allow to classify all compounds into the group of magnetically diluted copper(II) complexes. According the EPR and electronic spectra, the degree of tetragonal distortion increases passing from Cu(2,6-DHB)2 . 8 H2O (III) through Cu(2,4-DHB)2 . 8 H2O (I) to Cu(2,5-DHB)2 . 4 H2O (II. The complexes differ also in the cooperative ordering in their structures. All tested compounds exhibit higher antiinflamatory activities (on dextran edema) than free carboxylic acids. However, their effects were accompanied with relatively high toxicity. Remarkable results were also achieved on evaluating the antipyretic activity.
Synthesis of Dimethyl Carbonate from Carbon Dioxide and Methanol in the Presence of Organotin Compounds
Authors: Kizlink Juraj
Published: April 2003

The effect of a series of organotin(II) compounds of the formulae Bu2SnX2 (X = OMe, OEt, OBu, Cl Br, OPh, OOCMe, OOC(CH2)10Me, SSNEt2; X2 = O, (OH, Cl) and Bu2XSnOSnXBu2 (X = Cl, Br, OOCMe, OBu, n-Bu) in the synthesis of dimethyl carbonate by the title reaction was studied. It was found that the most efficient compounds of the series were the tin alkoxides Bu2Sn(OR)2 (R = Me, Et, Bu) which afforded the carbonate in up to 160 mole % yields (with respect to the tin compound) under convenient reaction conditions (low CO2 pressure, 130 - 190 °C, 6 h).
Synthesis of 1-(2,3-Dideoxy-4-C-methyl-β-D-glycero-pent-2-enofuranosyl)thymine, 1-(2,3-Dideoxy-4-C-methyl-β-D-glycero-pentofuranosyl)thymine and 1-(4-C-Azidomethyl-2-deoxy-β-D-threo-pentofuranosyl)thymine
Authors: Hřebabecký Hubert , Holý Antonín
Published: April 2003

Reaction of isopropylidene derivative I with thionyl chloride in hexamethylphosphoric triamide afforded chloro derivative II. Removal of the isopropylidene group in II by treatment with a cation-exchanging resin (H+ form) gave the free chloro nucleoside III. reduction of the chloro derivative II with tributylstannane and subsequent removal of the isopropylidene group yielded deoxy derivative V. This was protected with tert-butyldiphenylsilyl group and converted into the mesylate VII. Elimination of the mesyl group followed by desilylation gave 1-(2,3-dideoxy-4-C-methyl-β-D-glycero-pent-2-enofuranosyl)thymine (IX) which was hydrogenated to afford 1-(2,3-dideoxy-4-C-methyl-β-D-glycero-pentofuranosyl)thymine (X). 1-(1-C-Azidomethyl-2-deoxy-β-D-threo-pentofuranosyl)thymine (XIII) was prepared by mesylation of the isopropylidene derivative I, nucleophilic substitution of the mesyl group with azide and removal of the isopropylidene group.
The Oxides and Oxyacids of Tellurium
Authors: Loub Josef
Published: April 2003

A critical review of the oxides and oxyacids of tellurium is presented. The crystal chemistry of the compounds is discussed in detail. The average bond distances and angles of the Te(IV)O4, Te(VI)O6, Te(VI)-O-H...O-Te(VI) and Te-O-Te groups have been calculated by statistical evaluation of the geometry of the structures. The deviation of Te(VI)O6 from the average geometry were quantitatively characterized by distortion indices. The Te(IV)O4 and Te(VI)O6 groups were evaluated also by the bond valences s(Te-O). The compounds whose distortion indices or Σs(Te-O) values were outside the interval x ± 3σ should be checked.
The Isolation of Carnosic Acid 12-Methyl Ether from Salvia officinalis L. and NMR Study of Its Methyl Ester
Authors: Djarmati Zoltan , Jankov Ratko M. , Csanádi János , Djordjevic Aleksandar
Published: April 2003

In continuation of our studies on the chemical compositions of the aerial parts of cultivated Salvia officinalis L., we have isolated the title substance for the first time in this type of Sage. The structure of this isolated compound was established by spectroscopic data and some chemical reactions. Investigation of 1H and 13C NMR, homonuclear (COSY) (1H-1H), heteronuclear (HETCOR) (1H-13C), and selective INEPT spectra, permitted the unambiguous assignment of the 1H and 13C NMR spectra, what gave the possibility to resolve signals of similar natural products.