bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of class I histone deacetylases with transcriptional corepressor CtBP
Authors: Subramanian T , Chinnadurai G
Published: April 2003

The C‐terminal binding protein (CtBP) family proteins are transcriptional regulators that are conserved from worm to human. They function as corepressors of a wide array of DNA‐binding transcriptional repressors. The mammalian CtBPs appear to mediate transcriptional repression in a histone deacetylase (HDAC)‐dependent or ‐independent manner, depending on the context of the promoter. To identify the components of the CtBP corepressor complex, we isolated CtBP‐containing protein complexes from the nuclear extracts prepared from HeLa cells infected with adenovirus vectors that expresses hCtBP1. Western blot analysis of these complexes suggests that hCtBP1 associates with class I HDACs, HDAC‐1, HDAC‐2 and HDAC‐3. Some of these HDACs also interact with the Drosophila CtBP homolog, dCtBP. The CtBP protein complex exhibits significant HDAC activity in vitro suggesting that association of CtBP with HDACs may be functionally relevant.
Acceptability of a new modular protein substitute for the dietary treatment of phenylketonuria
Authors: Rohr F. J. , Munier A. W. , Levy H. L.
Published: April 2003

The major source of protein in the dietary treatment of phenylketonuria (PKU) is a phenylalanine‐free amino acid mixture. Traditionally, these medical products have also contained other nutrients and have been in powder form. However, their disagreeable taste and odour, the large volume required to provide sufficient protein and the inconvenience of their preparation and storage have hindered compliance with consumption among adolescents and adults. We studied the acceptability of a new medical product for the treatment of PKU. This product, Phlexy‐10 (SHS North America, Gaithersburg, MD, USA), is available in three forms: sachets of premeasured powder to be constituted as a drink, fruit‐flavoured bars and prefilled capsules. A vitamin–mineral mixture is separately provided. The forms are interchangeable because each component (one sachet, one bar or 20 capsules) provides 10 g of amino acids. Since the product is primarily a source of amino acids, protein requirements can be met using a smaller volume than with traditional medical products. Eleven subjects enrolled in a 24‐week trial that included clinical and laboratory evaluations. Nine subjects completed the study and 8 remained on the Phlexy‐10 after the study. The powder drink was the favourite module used. One‐third of the subjects included the bars and another third included the capsules in their regimens. The vitamin–mineral mixture was the least acceptable component. Mean weekly blood phenylalanine decreased by 40% from mean baseline levels. Blood concentrations of vitamins and minerals were normal except for a low zinc concentration in two subjects and a low vitamin B12 concentration in another. The lower caloric content and the separate vitamin–mineral mixture require careful monitoring of these nutrients. Phlexy‐10 appears to be an adequate medical product for the treatment of PKU. Its convenience, flexibility of form and improved taste are appealing to many individuals on diet for PKU.
Genetic Counseling: Clinical Geneticists' Views
Authors: Michie Susan , Smith Jonathan A. , Heaversedge Jonty , Read Simon
Published: April 2003

Evaluation of genetic counseling requires a clear consensus about its objectives, which is not evident in published definitions and guidelines. This study aims to investigate clinical geneticists' beliefs and thoughts about their practice.

Structured interviews with eight clinical geneticists addressed the aims, skills, and expectations of genetic counseling. Analysis of transcribed interviews revealed four key themes, with contradictory aspects:

1. Providing information that is objective, full, and accurate versus information that is contingent on circumstances and tailored to individual needs.

2. Eliciting emotion and dealing with it directly versus dampening down and containing emotion.

3. Communicating nondirectively versus directively.

4. Expecting to perform a range of sophisticated tasks while having minimal training in the necessary skills to achieve these.

These results have implications for the nature of the professional role, the development of training required for it, and the evaluation of genetic counseling.
Case Report: Object Relations Family Therapy as a Model for Genetic Counseling
Authors: Diekmann‐Tapon Dagmar
Published: April 2003

Object relations family therapy (ORFT) is a psychoanalytically based approach for the treatment of couples and families which stresses the importance of past relationships. The therapist assumes a parentlike role and provides a holding environment in which clients can explore unconscious motivations. This paper will discuss the applicability of this method to genetic counseling. The case of a couple seen for recurrent trisomies will be presented and used as an example to discuss how ORFT might serve as a framework in a genetic counseling session.
Neighborhood Structure, Parenting Processes, and the Development of Youths' Externalizing Behaviors: A Multilevel Analysis
Authors: Beyers Jennifer M. , Bates John E. , Pettit Gregory S. , Dodge Kenneth A.
Published: April 2003

Associations among neighborhood structure, parenting processes, and the development of externalizing behavior problems were investigated in a longitudinal sample of early adolescents (from age 11 to 13). Mothers' reports of parental monitoring (at age 11), mothers' and youths' reports of the amount of youths' unsupervised time (at age 11), and youths' reports of positive parental involvement (at age 12) were used to predict initial levels (at age 11) and growth rates in youths' externalizing behavior as reported by teachers. Census‐based measures of neighborhood structural disadvantage, residential instability, and concentrated affluence were expected to moderate the effects of parenting processes (e.g., parental monitoring) on externalizing behavior. Hierarchical linear modeling results revealed that less parental monitoring was associated with more externalizing behavior problems at age 11, and more unsupervised time spent out in the community (vs. unsupervised time in any context) and less positive parental involvement were associated with increases in externalizing behavior across time. Furthermore, the decrease in externalizing levels associated with more parental monitoring was significantly more pronounced when youths lived in neighborhoods with more residential instability.
Identity and Oppression: Differential Responses to an In‐Between Status
Authors: Sonn Christopher C. , Fisher Adrian T.
Published: April 2003

Oppression operates at various levels, with varying degrees of negativity, and groups respond in markedly different ways. In this paper, the in‐between status of the colored South African group is used to illustrate issues of identity and oppression under the Apartheid system—and differing ways in which oppression was experienced and used. The colored group had many social advantages over Blacks, but were also used to oppress that group. Habituation, accommodation, and relative advantage were identified as dynamics within the broader context of power and privilege that contributed to cultural and psychological marginality and status ambivalence of the coloreds. These processes must be understood within the historical, social, and political context of the community. What is evident from the data is that groups and individuals can take up various positions along a continuum of oppressor—oppressed, depending upon the contexts, time, and social and legal relationships involved in their interactions.
Prevention Science and Neighborhood Influences on Low‐Income Children's Development: Theoretical and Methodological Issues
Authors: Roosa Mark W. , Jones Sarah , Tein Jenn-Yun , Cree Willa
Published: April 2003

Despite the rapid growth of research on neighborhood influences on children, little of this research may be useful to prevention scientists. Most studies have ignored processes by which neighborhood conditions influence individual outcomes. To encourage neighborhood research that can better guide the development of preventive interventions, we propose a model that focuses attention on mediating and moderating processes, is appropriate for studies interested in individual differences in outcomes, acknowledges the transactions between residents and neighborhoods, and is sensitive to how neighborhood influences may differ for children at different developmental stages. Furthermore, we argue that greater attention to several methodological issues also can make neighborhood research more useful for the next generation of prevention programs to help low‐income urban families and children cope successfully with the challenges posed by their neighborhoods.
The Challenge of a Positive Self‐Image in a Colonial Context: A Psychology of Liberation for the Puerto Rican Experience
Authors: Varas-Díaz Nelson , Serrano-García Irma
Published: April 2003

Community psychology and the psychology of liberation provide a framework to analyze colonization. Puerto Rico has always been a colony. This experience has direct negative effects on Puerto Ricans' national identities and their emotions. The purpose of this study was to explore emotions associated with Puerto Rican national identities in a sample of 35 high school students. While participating in 4 focus groups, the youths discussed negative and positive emotions associated to their national identities. The most frequent ones were shame and pride. They also identified situations which promoted negative and positive emotions. The role of a community psychology of liberation in understanding these phenomena as well as in embracing resistance to colonization is discussed.
Sociopolitical Development
Authors: Watts Roderick J. , Williams Nat Chioke , Jagers Robert J.
Published: April 2003

This paper examines theories and concepts relevant to sociopolitical development (SPD). As an emerging theory, SPD expands on empowerment and similar ideas related to social change and activism in community psychology—oppression, liberation, critical consciousness, and culture among them. SPD is the process by which individuals acquire the knowledge, analytical skills, emotional faculties, and the capacity for action in political and social systems necessary to interpret and resist oppression. Equally as important is a vision of liberation that is an alternative to oppressive conditions. All of these concepts have been underemphasized in the social change literature of U.S. community psychology. In our view, sociopolitical development is vital to human development and the creation of a just society. As part of identifying and illustrating concepts and processes relevant to SPD theory, we will draw from the words of young African American activists who were interviewed as part of a research study.
Microdissection–Based Allelotyping Discriminates De Novo Tumor From Intrahepatic Spread in Hepatocellular Carcinoma
Authors: Finkelstein Sydney D. , Marsh Wallis , Demetris Anthony J. , Swalsky Patricia A. , Sasatomi Eizaburo , Bonham Andrew , Subotin Michael , Dvorchik Igor
Published: April 2003

A total of 103 cases of hepatocellular carcinoma (HCC) arising in native livers discovered at the time of transplantation underwent allelic loss analysis. HCC mutational allelotyping targeted 10 genomic loci (1p, 3p, 5q, 7q, 8q, 9p, 10q, 17p, 17q, 18q) using 18 polymorphic microsatellite markers situated in proximity to known tumor suppressor genes associated with human carcinogenesis. Gene analysis was performed on microdissected tissue samples removed from 4–μm thick histologic sections at specific topographic sites selected on the basis of representative cellular characteristics. Microdissection targets included largest tumor nodule at 2 locations as well as up to 3 additional tumor nodules in each case. HCC genotyping characteristics including mutational profile and cumulative fractional allelic loss (FAL) were correlated with clinical and pathologic features. Individual nodules of HCC showed 2 patterns of mutational change: (1) essentially concordant mutational profiles consistent with intrahepatic spread of tumor, or (2) discordant mutational profiles consistent with independent primary cancer formation. In 15 of 56 cases (27%) in which the HCC was in a multinodular, bilobar form (T4), sufficient discordance in the allelic loss profile enabled a more accurate T–stage classification with better prediction of recurrence–free survival. In conclusion, microdissection genotyping of HCC is an effective and objective means to (1) distinguish between de novo HCC tumor formation versus intrahepatic spread of cancer and to (2) improve on current methods for prediction of tumor aggressiveness and recurrence–free survival after liver transplantation. (Hepatology 2003;37:871–879.)
P18(Ink4c) Collaborates With Other Cdk–Inhibitory Proteins in the Regenerating Liver
Authors: Luedde Tom , Rodriguez Maria E. , Tacke Frank , Xiong Yue , Brenner David A. , Trautwein Christian
Published: April 2003

p18(INK4c) belongs to the family of cyclin–dependent kinase inhibitory proteins that target the cyclin–dependent kinases and inhibit their catalytic activity. The role of p18(INK4c) for cell cycle progression in vivo is characterized poorly. Therefore, we studied the expression and physiologic relevance of p18 in quiescent and proliferating hepatocytes during liver regeneration. For our analysis we used single– (p18[INK4c], p27[KIP1], p21[CIP1/WAF1]), and double–mutant (p18/p21, p18/p27) mice. p18 expression was found in quiescent hepatocytes and a slight up–regulation was evident after partial hepatectomy (PH). p18 knockout animals showed normal cell cycle progression after PH. However, when p18/p21 and p18/p27 double–mutant mice were used, differences in cell cycle progression were evident compared with wild–type (wt) and single knockout animals. In p18/p21 knockout animals, the G1 phase was shortened as evidenced by an earlier onset of cyclin D and proliferating cell nuclear antigen (PCNA) expression and cyclin–dependent kinase (CDK) activation after PH. In contrast, in p18/p27 knockout animals, the G1 phase was unchanged, but the amount of proliferating hepatocytes (5–bromo–2′–deoxyuridine [BrdU] and PCNA positive) 48 hours after PH was elevated. In conclusion, our results suggest that p18 is involved in cell cycle progression after PH. Additionally we provide evidence that timing and strength of DNA synthesis in hepatocytes after PH is regulated tightly through the collaboration of different cell cycle inhibitors. (Hepatology 2003;37:833–841.)
The Relationship Of In Vivo 31P Mr Spectroscopy to Histology in Chronic Hepatitis C
Authors: Lim Adrian K.P. , Patel Nayna , Hamilton Gavin , Hajnal Joseph V. , Goldin Robert D. , Taylor-Robinson Simon D.
Published: April 2003

Liver biopsy remains the gold standard for characterizing diffuse liver disease and is associated with significant morbidity and, rarely, mortality. Our aim was to investigate whether a noninvasive technique, in vivo phosphorus 31 (31P)–magnetic resonance spectroscopy (MRS), could be used to assess the severity of hepatitis C virus (HCV)–related liver disease. Fifteen healthy controls and 48 patients with biopsy–proven HCV–related liver disease were studied prospectively. Based on their histologic fibrosis (F) and necroinflammatory (NI) scores, patients were divided into mild hepatitis (F ≤ 2/6, NI ≤ 3/18), moderate/severe hepatitis (3 ≤ F < 6 or NI ≥ 4/18), and cirrhosis (F = 6/6). Hepatic 31P MR spectra were obtained using a 1.5–T spectroscopy system. Quantitation of the 31P signals was performed in the time domain using the Advanced MAgnetic RESonance algorithm. There was a monotonic increase in the mean ± 1 standard error phosphomonoester (PME) to phosphodiester (PDE) ratios for the control, mild disease, moderate disease, and cirrhosis groups: 0.15 ± 0.01, 0.18 ± 0.02, 0.25 ± 0.02, 0.38 ± 0.04, respectively (ANOVA, P < .001). An 80% sensitivity and specificity was achieved when using a PME/PDE ratio less than or equal to 0.2 to denote mild hepatitis and a corresponding ratio greater than or equal to 0.3 to denote cirrhosis. No other significant spectral changes were observed. In conclusion, 31P MRS can separate mild from moderate disease and these 2 groups from cirrhosis. The ability to differentiate these populations of patients has therapeutic implications and 31P MRS, in some situations, would not only complement a liver biopsy but could replace it and be of particular value in assessing disease progression. (Hepatology 2003;37:788–794.)
Interferon-producing Cells Fail to Induce Proliferation of Naive T Cells but Can Promote Expansion and T Helper 1 Differentiation of Antigen-experienced Unpolarized T Cells
Authors: Krug Anne , Veeraswamy Ravi , Pekosz Andrew , Kanagawa Osami , Unanue Emil R. , Colonna Marco , Cella Marina
Published: April 2003

Interferon-producing cells (IPCs) secrete high levels of type I interferon in response to certain viruses. The lack of lineage markers, the expression of major histocompatibility complex (MHC) class II and the capacity to stimulate allogeneic T cells have led these cells to be classified as a subset of dendritic cells (DCs), called plasmacytoid DCs (PDCs). However, the role of IPCs/PDCs in initiating primary immune responses remains elusive. Here we examined the antigen presenting capacity of murine IPCs in antigen specific systems. While CD8α+ and CD11b+ DCs induced logarithmic expansion of naive CD4 and CD8 T cells, without conferring T helper commitment at a first encounter, primary IPCs lacked the ability to stimulate naive T cells. However, when antigen-experienced, nonpolarized T cells expanded by classical DC subsets, were restimulated by IPCs, they proliferated and produced high amounts of IFN-γ. These data indicate that IPCs can effectively stimulate preactivated or memory-type T cells and exert an immune-regulatory role. They also suggest that expansion of naive T cells and acquisition of effector function during antigen-specific T cell responses may involve different antigen-presenting cell (APC) types. Independent and coordinated control of T cell proliferation and differentiation would provide the immune system with greater flexibility in regulating immune responses.
Human Immunoglobulin M Memory B Cells Controlling Streptococcus pneumoniae Infections Are Generated in the Spleen
Authors: Kruetzmann Stephanie , Rosado M. Manuela , Weber Holger , Germing Ulrich , Tournilhac Olivier , Peter Hans-Hartmut , Berner Reinhard , Peters Anke , Boehm Thomas , Plebani Alessandro , Quinti Isabella , Carsetti Rita
Published: April 2003

Splenectomized and asplenic patients have a high incidence of infections by encapsulated bacteria and do not respond to polysaccharide vaccines. To understand whether the absence of the spleen is associated with a defined B cell defect, we analyzed B cell subsets in the peripheral blood. We found that a population of B cells known as immunoglobulin (Ig)M memory is lacking in patients without spleen. The absence of IgM memory B cells correlates with an impaired immune response to encapsulated bacteria not only in splenectomized patients, but also in individuals with an intact spleen. We show that the physiological and transient predisposition to pneumococcal infections of young children (0–2 yr) is associated with the lack of circulating IgM memory B cells and of serum antipolysaccharide IgM. We also demonstrate that IgM memory B cells are undetectable in a fraction of patients with common variable immunodeficiency, who have recurrent and invasive infections by encapsulated bacteria. IgM memory B cells, therefore, require the spleen for their generation and/or survival and are responsible for the protection against encapsulated bacteria.
B Cell Receptor–independent Stimuli Trigger Immunoglobulin (Ig) Class Switch Recombination and Production of IgG Autoantibodies by Anergic Self-Reactive B Cells
Authors: Phan Tri Giang , Amesbury Michelle , Gardam Sandra , Crosbie Jeffrey , Hasbold Jhagvaral , Hodgkin Philip D. , Basten Antony , Brink Robert
Published: April 2003

In both humans and animals, immunoglobulin (Ig)G autoantibodies are less frequent but more pathogenic than IgM autoantibodies, suggesting that controls over Ig isotype switching are required to reinforce B cell self-tolerance. We have used gene targeting to produce mice in which hen egg lysozyme (HEL)-specific B cells can switch to all Ig isotypes (SWHEL mice). When crossed with soluble HEL transgenic (Tg) mice, self-reactive SWHEL B cells became anergic. However, in contrast to anergic B cells from the original nonswitching anti-HEL × soluble HEL double Tg model, self-reactive SWHEL B cells also displayed an immature phenotype, reduced lifespan, and exclusion from the splenic follicle. These differences were not related to their ability to Ig class switch, but instead to competition with non-HEL–binding B cells generated by VH gene replacement in SWHEL mice. When activated in vitro with B cell receptor (BCR)-independent stimuli such as anti-CD40 monoclonal antibody plus interleukin 4 or lipopolysaccharide (LPS), anergic SWHEL double Tg B cells proliferated and produced IgG anti-HEL antibodies as efficiently as naive HEL-binding B cells from SWHEL Ig Tg mice. These results demonstrate that no intrinsic constraints to isotype switching exist in anergic self-reactive B cells. Instead, production of IgG autoantibodies is prevented by separate controls that reduce the likelihood of anergic B cells encountering BCR-independent stimuli. That bacteria-derived LPS could circumvent these controls may explain the well-known association between autoantibody-mediated diseases and episodes of systemic infection.
16S Ribosomal DNA Sequence-Based Analysis of Clinically Significant Gram-Positive Anaerobic Cocci
Authors: Song Yuli , Liu Chengxu , McTeague Maureen , Finegold Sydney M.
Published: April 2003

Sequence analysis of the 16S rRNA gene represents a highly accurate and versatile method for bacterial classification and identification, even when the species in question is notoriously difficult to identify by phenotypic means. However, its use for identification based on public sequence databases is not without limitation due to the presence of ambiguous data in the databases. In this study, we evaluated the utility of 16S ribosomal DNA sequencing as a means of identifying clinically important gram-positive anaerobic cocci (GPAC) by sequencing 13 type strains of established GPAC species and 156 clinical isolates that had been studied only by phenotypic tests. Among the 13 type strains of GPAC species we tested, only 4 gave a “perfect” match with their corresponding sequences in GenBank, whereas the other 9 had lower sequence similarities (<98%). This indicates that data in the public database may be inaccurate at times. Based on the sequences of the 13 type strains obtained in this study, 84% (131 of 156) of the clinical isolates were accurately identified to species level, with the remaining 25 clinical strains revealing nine unique sequences that may represent eight novel species. This finding is in contrast to the phenotypic identification results, by which only 56% of isolates were correctly identified to species level.
Diagnosis of
Plasmodium falciparum
Malaria at Delivery: Comparison of Blood Film Preparation Methods and of Blood Films with Histology
Authors: Rogerson Stephen J. , Mkundika Patrick , Kanjala Maxwell K.
Published: April 2003

We compared peripheral and placental blood films (made by different techniques) with placental histology for diagnosis of
Plasmodium falciparum
malaria in pregnancy. Samples from 464 women were examined, of whom 124 (26.7%) had active
P. falciparum
infection and 148 (31.9%) had past infection. Placental histology was more sensitive (91%) than peripheral blood film (47%) or placental blood film (63%) examination and also detected past infection. Few women had microscopically detectable infection without a positive histology. Infection detected by histology only and past infection were both associated with significantly lower infant birth weight and with lower hemoglobin concentrations compared to the results for uninfected women. Thick blood films were prepared with blood obtained by placental incision or scraping of the incision margin (263 samples) or by washing of placental tissue (235 samples). Each gave similar sensitivities (76 to 78%), specificities (98 to 99%), positive predictive values (92 to 98%), and negative predictive values (93 to 94%); but the median levels of parasitemia were lower for incision samples (840 parasites/μl) than scrapings (2,295 parasites/μl) (
P
= 0.02). Placental histology is the most sensitive method for the diagnosis of malaria in pregnancy. Methods for preparation of placental films may affect the density, but not the prevalence, of
P. falciparum
infection detected.
Evaluation of the MicroSeq System for Identification of Mycobacteria by 16S Ribosomal DNA Sequencing and Its Integration into a Routine Clinical Mycobacteriology Laboratory
Authors: Hall Leslie , Doerr Kelly A. , Wohlfiel Sherri L. , Roberts Glenn D.
Published: April 2003

An evaluation of the MicroSeq 500 microbial identification system by nucleic acid sequencing and the Mayo Clinic experience with its integration into a routine clinical laboratory setting are described. Evaluation of the MicroSeq 500 microbial identification system was accomplished with 59 American Type Culture Collection (ATCC) strains and 328 clinical isolates of mycobacteria identified by conventional and 16S ribosomal DNA sequencing by using the MicroSeq 500 microbial identification system. Nucleic acid sequencing identified 58 of 59 (98.3%) ATCC strains to the species level or to the correct group or complex level. The identification results for 219 of 243 clinical isolates (90.1%) with a distance score of <1% were concordant with the identifications made by phenotypic methods. The remaining 85 isolates had distance scores of >1%; 35 (41.1%) were identified to the appropriate species level or group or complex level; 13 (15.3%) were identified to the species level. All 85 isolates were determined to be mycobacterial species, either novel species or species that exhibited significant genotypic divergence from an organism in the database with the closest match. Integration of nucleic acid sequencing into the routine mycobacteriology laboratory and use of the MicroSeq 500 microbial identification system and Mayo Clinic databases containing additional genotypes of common species and added species significantly reduced the number of organisms that could not be identified by phenotypic methods. The turnaround time was shortened to 24 h, and results were reported much earlier. A limited number of species could not be differentiated from one another by 16S ribosomal DNA sequencing; however, the method provides for the identification of unusual species and more accurate identifications and offers the promise of being the most accurate method available.
Combined Use of
Paracoccidioides brasiliensis
Recombinant 27-Kilodalton and Purified 87-Kilodalton Antigens in an Enzyme-Linked Immunosorbent Assay for Serodiagnosis of Paracoccidioidomycosis
Authors: Díez Soraya , Gómez Beatriz L. , McEwen Juan G. , Restrepo Angela , Hay Rod J. , Hamilton Andrew J.
Published: April 2003

The diagnosis of paracoccidioidomycosis (PCM) has relied on the identification of the host's humoral response by using a variety of immunological methods, such as complement fixation and immunodiffusion. Although these approaches are useful, historically their sensitivity and specificity have often been compromised by the use of complex mixtures of undefined antigens. The use of combinations of purified, well-characterized antigens appears preferable and may yield optimum results. Accordingly an indirect enzyme-linked immunosorbent assay (ELISA) using combinations of the previously described 27-kDa recombinant antigen and the 87-kDa heat shock protein were used for diagnosis and follow-up of patients with PCM. A total of 37 patients classified according to their clinical presentations (7 with the acute or subacute form of the disease, 22 with the chronic form of the disease, and 8 with the chronic unifocal form) were studied. Eighteen of these patients were also evaluated at every follow-up appointment. Forty serum samples from patients with other diseases and 50 serum samples from healthy individuals were also studied. Detection of anti-27-kDa and anti-87-kDa antibodies in sera of patients with PCM by ELISA using a combination of the two purified proteins showed a sensitivity of 92% with a specificity of 88% in comparison with normal human sera and 90% in comparison with the heterologous sera. These results demonstrated a significant increase in sensitivity and specificity compared to results when the antigens were used separately. Thus, the use of combinations of well-defined antigens appears to offer clear advantages over the use of single antigens when diagnosing PCM.
Molecular Characterization of
Anaplasma phagocytophilum
and
Borrelia burgdorferi
in
Ixodes scapularis
Ticks from Pennsylvania
Authors: Courtney Joshua W. , Dryden Richard L. , Montgomery Jill , Schneider Bradley S. , Smith Gary , Massung Robert F.
Published: April 2003

Ixodes scapularis
ticks were collected in 2000 and 2001 from two areas in Pennsylvania and tested for the presence of
Anaplasma phagocytophilum
and
Borrelia burgdorferi
by PCR and DNA sequencing. Of the ticks collected from northwestern and southeastern Pennsylvania, 162 of 263 (61.6%) and 25 of 191 (13.1%), respectively, were found to be positive for
B. burgdorferi
. DNA sequencing showed >99% identity with
B. burgdorferi
strains B31 and JD1. PCR testing for
A. phagocytophilum
revealed that 5 of 263 (1.9%) from northwestern Pennsylvania and 76 of 191 (39.8%) from southeastern Pennsylvania were positive. DNA sequencing revealed two genotypes of
A. phagocytophilum
, the human granulocytic ehrlichiosis (HGE) agent and a variant (AP-Variant 1) that has not been associated with human infection. Although only the HGE agent was present in northwestern Pennsylvania, both genotypes were found in southeastern Pennsylvania. These data add to a growing body of evidence showing that AP-Variant 1 is the predominant agent in areas where both genotypes coexist.
Anaplasma marginale msp1
α Genotypes Evolved under Positive Selection Pressure but Are Not Markers for Geographic Isolates
Authors: de la Fuente José , Van Den Bussche Ronald A. , Prado Tulio M. , Kocan Katherine M.
Published: April 2003

Anaplasma marginale
(order
Rickettsiales
, family
Anaplasmataceae
), a tick-borne pathogen of cattle, is endemic in tropical and subtropical regions of the world. Many geographic isolates of
A. marginale
occur in the United States and have been identified by major surface protein 1a (MSP1a), which varies in sequence and molecular weight due to different numbers of tandem 28- to 29-amino-acid repeats. The present study was undertaken to examine the genetic variations among isolates of
A. marginale
obtained during 2001 from infected cattle from east-central Oklahoma, where
A. marginale
is endemic. The gene and protein sequences of MSP1a and
msp4
nucleotide sequences were used to infer the phylogenetic relationships among Oklahoma and New World isolates from Argentina, Brazil, Mexico, and the United States. All 11
A. marginale
isolates collected from Oklahoma had different MSP1a sequences but identical MSP4 sequences. The phylogenies of the
msp4
sequences of 13 isolates from Oklahoma in comparison with those of 7 Latin American isolates and 12 U.S. isolates by maximum-parsimony (MP) and maximum-likelihood (ML) analyses, with
A. centrale
and
A. ovis
sequences used as outgroups, provided strong bootstrap analysis support for a Latin American clade. Isolates of
A. marginale
from the southern United States (Florida, Mississippi, and Virginia) and the west-central United States (California, Idaho, Illinois, Oregon, Missouri, and Texas) also grouped into two clades. Both clades contained isolates from Oklahoma, suggesting extensive cattle movement. ML analysis of the
msp4
sequences of isolates from Oklahoma provided bootstrap analysis support for east-central and north-central clades in Oklahoma, and both clades included isolates from Stillwater, Okla. Analysis of the codon and amino acid changes among the
msp4
sequences of isolates with different phylogenies provided evidence that
msp4
is not under positive selection pressure. In contrast, the phylogenies of the MSP1a DNA and protein sequences of 13 isolates from Oklahoma in comparison with those of 7 Latin American and 13 isolates from the United States by MP and ML analyses demonstrated no geographic clustering and provided evidence that this gene is under positive selection pressure. The results indicate that
msp1α
is not a marker for the characterization of
A. marginale
geographic isolates and suggest that the genetic heterogeneity observed among isolates of
A. marginale
within Oklahoma could be explained by cattle movement and the maintenance of different genotypes by independent transmission events.
Clinical Value of Specific Immunoglobulin E Detection by Enzyme-Linked Immunosorbent Assay in Cases of Acquired and Congenital Toxoplasmosis
Authors: Foudrinier F. , Villena I. , Jaussaud R. , Aubert D. , Chemla C. , Martinot F. , Pinon J. M.
Published: April 2003

The clinical value of immunoenzymatic (enzyme-linked immunosorbent assay) detection of anti-
Toxoplasma
immunoglobulin E (IgE) was assessed by studying 2,036 sera from 792 subjects, comprising seronegative controls and subjects with acute, active, reactivated, or congenital toxoplasmosis. Included were nonimmunized adults; pregnant women with recently acquired infection (acute toxoplasmosis); immunocompetent subjects with recently acquired severe infection (active toxoplasmosis) expressed as fever, adenopathies, splenomegaly, pneumonia, meningitis, or disseminated infection; subjects—some of them immunocompromised—whose previously moderate IgG antibody levels rose, suggesting a reactivation of quiescent toxoplasmosis; and infants born to seroconverted mothers and evaluated for diagnosis of congenital infection and therapeutic management. Specific IgE antibodies were never detected in seronegative subjects. They were present in 85.7% of asymptomatic seroconverters and in 100% of seroconverters with overt toxoplasmosis, following two different kinetics: in the former, the specific IgE titer generally presented a brief peak 2 to 3 months postinfection and then fell rapidly, whereas specific IgE persisted at a very high titer for several months in the latter. IgE emerged concomitantly with the increase in IgG during toxoplasmic reactivation. For neonatal diagnosis of congenital toxoplasmosis, IgE was less informative than IgM and IgA (sensitivities, 59.5, 64.3, and 76.2%, respectively) and had a specificity of 91.9%. Nevertheless, simultaneous measurement of the three isotypes at birth improved the diagnostic yield to 81% relative to the combination of IgA and IgM. Emergence of specific IgE during postnatal treatment for congenital toxoplasmosis is a sign of poor adherence or inadequate dosing.
Nocardia veterana
, a New Emerging Pathogen
Authors: Pottumarthy Sudha , Limaye Ajit P. , Prentice Jennifer L. , Houze Yolanda B. , Swanzy Susan R. , Cookson Brad T.
Published: April 2003

Nocardia veterana
is a newly described species named after the veteran's hospital where it was first isolated. This initial type strain was not thought to be clinically significant. We describe three cases of pulmonary disease attributable to
N
.
veterana
: two cases in patients presenting with multiple pulmonary nodules in a setting of immunocompromise and one case of exacerbation of chronic pulmonary disease. The isolates were susceptible to ampicillin, imipenem, gentamicin, amikacin, and trimethoprim-sulfamethoxazole and had reduced susceptibilities to ceftriaxone, cefotaxime, minocycline, and ciprofloxacin. The MICs of amoxicillin-clavulanate were higher than that of ampicillin alone, and the bacteria produced a β-lactamase detectable only after induction with clavulanic acid. Phenotypically, the isolates could not be characterized beyond the
Nocardia
genus level. All three isolates were definitively identified as
N
.
veterana
by PCR and sequencing of the 16S rRNA gene. On the basis of their susceptibility and restriction enzyme analysis profiles, our findings indicate that they could potentially be misidentified as
N
.
nova
. These cases illustrate the pathogenic potential of this newly described species and emphasize the importance of accurate identification of
Nocardia
isolates to the species level by integrated use of phenotypic and genotypic methods.
Nucleotide and Predicted Amino Acid Sequence-Based Analysis of the Avian Metapneumovirus Type C Cell Attachment Glycoprotein Gene: Phylogenetic Analysis and Molecular Epidemiology of U.S. Pneumoviruses
Authors: Alvarez Rene , Lwamba Humphrey M. , Kapczynski Darrell R. , Njenga M. Kariuki , Seal Bruce S.
Published: April 2003

A serologically distinct avian metapneumovirus (aMPV) was isolated in the United States after an outbreak of turkey rhinotracheitis (TRT) in February 1997. The newly recognized U.S. virus was subsequently demonstrated to be genetically distinct from European subtypes and was designated aMPV serotype C (aMPV/C). We have determined the nucleotide sequence of the gene encoding the cell attachment glycoprotein (G) of aMPV/C (Colorado strain and three Minnesota isolates) and predicted amino acid sequence by sequencing cloned cDNAs synthesized from intracellular RNA of aMPV/C-infected cells. The nucleotide sequence comprised 1,321 nucleotides with only one predicted open reading frame encoding a protein of 435 amino acids, with a predicted
M
r
of 48,840. The structural characteristics of the predicted G protein of aMPV/C were similar to those of the human respiratory syncytial virus (hRSV) attachment G protein, including two mucin-like regions (heparin-binding domains) flanking both sides of a CX3C chemokine motif present in a conserved hydrophobic pocket. Comparison of the deduced G-protein amino acid sequence of aMPV/C with those of aMPV serotypes A, B, and D, as well as hRSV revealed overall predicted amino acid sequence identities ranging from 4 to 16.5%, suggesting a distant relationship. However, G-protein sequence identities ranged from 72 to 97% when aMPV/C was compared to other members within the aMPV/C subtype or 21% for the recently identified human MPV (hMPV) G protein. Ratios of nonsynonymous to synonymous nucleotide changes were greater than one in the G gene when comparing the more recent Minnesota isolates to the original Colorado isolate. Epidemiologically, this indicates positive selection among U.S. isolates since the first outbreak of TRT in the United States.
Molecular Detection of
Histoplasma capsulatum
var.
capsulatum
in Human Clinical Samples
Authors: Bracca Andrea , Tosello María Elena , Girardini Javier E. , Amigot Susana L. , Gomez Carlos , Serra Esteban
Published: April 2003

We developed a seminested PCR for the diagnosis of histoplasmosis that amplifies a portion of the
Histoplasma capsulatum
H antigen gene. This assay is highly sensitive and specific, being able to detect genomic material corresponding to less than 10 yeast cells without cross-reaction against other bacterial or fungal pathogens.
Properties and Reactivity of First and Second Row Hydrides. IV. Interactions Between Hydrides and Their Radical Ions
Authors: Zahradník Rudolf
Published: April 2003

The energies and heats of ion-molecule reactions have been calculated (MP4/6-31G**//6-31G** or better level) and compared with the experimental values obtained from the heats of formation. Two main types of reactions have been studied: (i) AHn + AHn+• ↔ AHn+1+ + AHn-1• (A = C to F and Si to Cl), (ii) AHn + BHm+• ↔ AHn+1+ + BHm-1• or AHn-1+• + BHm+1+ (A and B = C to F). In contrast to (i), processes of type (ii) permit easy differentiation between the proton transfer and hydrogen atom abstraction mechanisms. A third type of interaction involves reactions with radical anions (A = Li to F); comparison was made with analogous processes with radical cations. A brief comment is made about the influence of the level of computational sophistication on the energies and heats of reaction, as well as on the stabilization energy of a hydrogen bonded intermediate, a structure which is similar to that of the reaction products.
Similarity Approach to Chemical Reactivity. Substituent Effect in Pericyclic Reactions
Authors: Ponec Robert
Published: April 2003

The recently introduced similarity approach to chemical reactivity was applied to the systematic investigation of the substituent effect on pericyclic reactivity. The agreement of the resulting predictions with available experimental or theoretical data confirms that the basic features of the substituent effect are correctly reproduced by the model.
Ab initio Calculations of the Rotation-Vibration Spectrum of Na3+
Authors: Češpiva Ladislav , Bonačič-Koutecký Vlasta , Koutecký Jaroslav , Jensen Per , Hrouda Vojtěch , Čársky Petr , Špirko Vladimír , Hobza Pavel
Published: April 2003

SCF, 6C-SCF, MP4 and valence-electron full CI calculations were performed in order to determine the potential surface of Na3+. A power series in the variables yi = 1 - exp (-a∆ri), where ∆ri are bond length displacements from equilibrium, has been fitted through the surface obtained and used in a variational rotation-vibration calculations with a basis set of products of Morse-oscillator eigenfunctions and symmetric top rotational wave functions. In contrast to H3+, Na3+ behaves as a very rigid molecule and does not exhibit any anomalous anharmonicity. With our best potential surface, MP4, the predicted E' and A1' fundamental frequencies are 105.1 and 146.7 cm-1, and the harmonic E' and A1' frequencies are 106.5 and 148.3 cm-1.
Metal-Ligand Electronic Interactions in Mononuclear and Dinuclear Triethylenetetraminecobalt(III) Complexes Containing the Anion of Quinizarin (1,4-Dihydroxy-9,10-anthraquinone)
Authors: Robinson Edward A. , Earley Joseph E.
Published: April 2003

1,4-Dihydroxy-9,10-anthraquinonatotriethylenetetraminecobalt(III) cation and its conjugate acid and the tetrapositive dinuclear μ-1,4-dihydroxy-9,10-anthraquinonatotriethylenetetraminecobalt(III) cation have been prepared in aqueous solution and characterized by spectroscopy and cyclical voltammetry. Both spectra and electrochemistry indicate that there is significant interaction between ligand-centered orbitals and metal-centered orbitals in all three species.
The Effect of Ethyl Xanthogenate on the Electrokinetic Properties and Surface Free Energy of Galena
Authors: Espinosa-Jiménez M. , Hayas-Barrú A. , González-Caballero F.
Published: April 2003

An experimental investigation is described on the zeta potential and surface free energy of the system galena/potassium ethyl xanthogenate. The behavior of the zeta potential of galena with different electrolytes and with pH is also showed. The potential of zero charge of galena was found to be at pH 4.8. The negative zeta potential, obtained from electrophoretic measurements of the galena/ethyl xanthogenate system, increased with the increasing concentration of this compound in solution. This shows that the adsorption of the ethyl xanthogenate onto galena is the responsible of the above mentioned increase of the zeta potential of the system. The uptake of -S- group of ethyl xathogenate by the oxidized products existing on the galena surface could be the cause of the increase in the negative electric charge of the interface. The surface free energy of galena and their dispersion and nondispersion components have been obtained from the contact angle measurements of both water and diiodomethane liquid drops, onto galena previously treated with different concentrations of xanthogenate in solution. While the dispersion component of the surface free energy of galena increases weakly with the concentration of the ethyl xanthogenate in solution, the nondispersion component has a significant decrease with it. therefore, the increasing hydrophobicity of the galena can be correlated with the increase in the zeta potential of this mineral, which is due to the adsorption of the collector.
The Polarographic and Voltammetric Determination of N,N-Dimethyl-4-amino-3'-nitroazobenzene
Authors: Barek Jiří , Dřevínková Dana , Mejstřík Viktor , Zima Jiří
Published: April 2003

The polarographic reduction of N,N-dimethyl-4-amino-3'-nitroazobenzene was studied by tast polarography and differential pulse polarography, constant potential coulometry and cyclic voltammetry and mechanism was proposed for the reduction. Optimal conditions were found for the determination of the test substance using tast polarography in concentration range 1 . 10-4 - 2 . 10-6 mol l-1, differential pulse polarography at classical dropping mercury electrode and fast scan differential pulse voltammetry at a hanging mercury drop electrode in range 1 . 10-4 - 2 . 10-7 mol l-1 and linear scan voltammetry at a hanging mercury drop electrode in range 1 . 10-5 - 2 . 10-8 mol l-1. A further increase in the sensitivity was achieved through adsorptive accumulation of the test substance on the surface of the working electrode, permitting the determination to be carried out in the concentration range 1 . 10-7 - 2 . 10-9 mol l-1.
Deformation of the Adamantane Skeleton by Substitution: Crystal Structure of 1-Methylsulfonyladamantane
Authors: Tinant Bernard , Declercq Jean-Paul , Exner Otto
Published: April 2003

The crystals of 1-methylsulfonyladamantane are monoclinic, space group P21/a, with a = 11.094(3), b = 7.668(2), c = 13.161(3) Å, β = 101.74(2)0, V = 1 096.1(5) Å3, Z = 4, Dx = 1.29 g cm -3, MoKα, λ = 0.71069 Å, μ = 2.65 cm-1, F(000) = 456, T = 291 K, the final R value is 0.036 for 1 834 observed reflections. For this compound and from literature data, the bond angles of adamantane derivatives are briefly discussed: the angle on the substituted C(1) atom depends clearly on the substituent but the available figures are still rather imprecise.
Electrochemical Study of cis-Dicyanobisethylenediaminechromium(III) Ion and Its Adducts with Hg(II) and Ag(I)
Authors: Rievaj Miroslav , Korgová Elena , Bustin Dušan
Published: April 2003

Electrochemical properties of [Cr(CN2)(en)2]+ are described. Reactions of this complex with Hg(II) and Ag(I) were studied. Their stoichiometry (1 : 1) was determined using potentiometric and amperometric titration. Different pulse voltammetry (DPV) was applied to identify their products - dinuclear adducts. It was concluded on the bases of DPV experiments that linkage isomerization of bridding cyano ligand occurs in the process of adducts formation. The decomposition (aquation) of these adducts was followed and the influence of H+ and Hg2+ concentration on its rate was measured and discussed. The paper also deals with a spontaneous isomerization of unstable CN linkage isomers Cr(NC)2 and Cr(CN)(CN) to the stable isomer Cr(NC)2.