bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of arachidonic acid on the spatial cognition of aged rats
Authors: OKAICHI YOKO , OKAICHI HIROSHIGE , AKIMOTO KENGO , KAWASHIMA HIROSHI , TOYODA‐ONO YOSHIKO , KISO YOSHINOBU , TOKIMOTO NAOKO 
Published: June 2006

Abstract:  To examine the effects of arachidonic acid (AA) on age‐related cognitive deficits, Fischer 344 rats were given an AA‐supplemented powder diet for 12 weeks from 18.6 months old as part of the old AA (OA) group. Other age‐matched rats were fed a non‐AA‐supplemented powder diet as part of the old control (OC) group, and young rats were fed lab pellets as part of the young control (YC) group. When the aged rats reached 20.0 months old, all animals were tested for spontaneous activity in an open field, followed by the Morris water maze place and cue tasks. Escape latencies for the place task showed that the YC rats were fastest, and there was no difference between the OA and OC groups. However, the probe test and the first block of the cue task indicated that the OA rats remembered the location of an invisible platform better than the OC rats. Although the amount of hippocampal AA was larger in the OA rats than in the OC rats, the difference was not significant. The results showed that AA administration to aged animals may alleviate age‐related deficits in spatial cognition.
Decreased IH in Hippocampal Area CA1 Pyramidal Neurons after Perinatal Seizure‐inducing Hypoxia
Authors: Zhang Kun , Peng Bi‐wen , Sanchez Russell M. 
Published: June 2006

Summary:  Purpose: The hyperpolarization‐activated cation current (IH) has been proposed to play a role in some forms of epileptogenesis, as it critically regulates synaptic integration and intrinsic excitability of principal limbic neurons and can be pathologically altered after experimentally induced seizures. In hippocampal CA1 pyramidal neurons, IH is functionally decreased after kainate‐induced status epilepticus in adult rats but is increased after hyperthermia‐induced seizures in immature rat pups. This study aimed to determine whether and how IH may be altered in CA1 pyramidal neurons after seizure‐inducing global hypoxia in the neonatal brain. Methods: Seizures were induced in rat pups on postnatal day 10 by 14‐ to 16‐min exposure to 5–7% O2. Whole‐cell patch‐clamp recordings were obtained from hippocampal CA1 pyramidal neurons in slices 30 min to 3 days after hypoxia treatment, and from control age‐matched littermates. IH was isolated under voltage‐clamp by subtracting current responses to hyperpolarizing voltage steps before and during application of the IH blocker ZD 7288 (100 μM). Results: IH was significantly decreased in pyramidal neurons from the hypoxia‐treated group compared with controls (p < 0.001; 19 controls; 15 hypoxia). Analyses of tail currents and activation kinetics indicated no statistically significant differences between groups in the voltage dependence or time constants of activation. Conclusions: These data indicate that a single episode of neonatal hypoxia that induces seizures can persistently decrease IH in CA1 pyramidal neurons, raising this as a potential contributing mechanism to epileptogenesis in this setting. Our findings further indicate that the consequences of seizures for IH may depend more on seizure etiology than on maturational stage.
Risk factors for oral hairy leukoplakia in HIV‐infected adults of Brazil
Authors: Moura Mariela Dutra Gontijo , Grossmann Soraya de Mattos Camargo , Fonseca Linaena Méricy da Silva , Senna Maria Inês Barreiros , Mesquita Ricardo Alves 
Published: June 2006

Background:  Oral hairy leukoplakia (OHL) may be an indicator of the progression of Human Immunodeficiency Virus (HIV)‐induced immuno‐depression, and the evaluation of risk factors leading to OHL is important in the management of these HIV‐infected patients. However, there are few studies that analyze risk factors leading to OHL in the Brazilian population. The aim of this case–control study is to present data about prevalence rates and risk factors leading to OHL in a sample of HIV‐infected adults in Brazil.Methods:  This case–control study included 111 HIV‐infected patients treated at a clinic for sexually transmitted diseases and HIV. In the initial examinations with dentists, variables were collected from all patients. Diagnosis of OHL was performed in accordance with the International Classification System and cytological features. The Fisher and the chi‐squared tests were used for statistical analysis. The proportional prevalence and odds ratio were estimated.Results:  Outcome presented a positive, statistically significant association among the presence of OHL and viral load of 3000 copies/μl or greater (P = 0.0001; odds ratio (OR) = 5.8), presence of oral candidiasis (P = 0.0000; OR = 11.1), previous use of fluconazole (P = 0.0000; OR = 24.6), and use of systemic acyclovir (P = 0.032; OR = 4.3). Antiretroviral medication presented a negative, statistically significant association with the presence of OHL (P = 0.002; OR = 8.4).Conclusions:  Prevalence of OHL was 28.8%. Viral load, oral candidiasis, previous use of fluconazole, and systemic acyclovir were determined to be risk factors for OHL. Antiretroviral medication proved to be protective against the development of OHL.
Isolation of the Atlantic salmon tyrosinase gene family reveals heterogenous transcripts in a leukocyte cell line
Authors: Thorsen Jim , Høyheim Bjørn , Koppang Erling O. 
Published: June 2006

SummaryIn ectothermic vertebrates, visceral organs harbor melanin‐containing cells. Their ability as pigment producers is nevertheless disputed. To address expression of the key genes for melanogenesis in Atlantic salmon (Salmo salar), a tyrosinase‐positive leukocyte cell line (SHK‐1) and skin were used to obtain full‐length tyrosinase (Tyr), tyrosinase‐like protein‐1 (Tyrp1), and dopachrome tautomerase (Dct) mRNA transcripts. In the SHK‐1 cells, two different Tyrp1 transcripts were identified, one lacking exon 1. However, only the full‐length version of Tyrp1 was identified in the skin. Sequencing of Tyrp1 genomic region revealed that the two Tyrp1 transcripts might originate from two different loci, possibly a result of pseudo‐tetraploidity of the Atlantic salmon genome. Expression of Tyr, Tyrp1 and Dct was investigated by quantitative real‐time reverse transcriptase polymerase cain reaction showing highest expression in the SHK‐1 cell line and skin, intermediate in pronephros, and negligible or absent in liver and muscle. Histological approaches were used to demonstrate melanin and revealed presence of melanized cells in skin, kidney and liver, and absence of such cells in muscle. In addition to verify melanin synthesis abilities of visceral‐located cells, our results indicate loci‐specific transcription differences between populations of melanin‐producing cells in Atlantic salmon.
A New Farnesyl Diphosphate Synthase Gene fromTaxus mediaRehder: Cloning, Characterization and Functional Complementation
Authors: Liao Zhi‐Hua , Chen Min , Gong Yi‐Fu , Li Zhu‐Gang , Zuo Kai‐Jing , Wang Peng , Tan Feng , Sun Xiao‐Fen , Tang Ke‐Xuan 
Published: June 2006

AbstractFarnesyl diphosphate synthase (FPS; EC 2.5.1.10) catalyzes the production of 15‐carbon farnesyl diphosphate which is a branch‐point intermediate for many terpenoids. This reaction is considered to be a rate‐limiting step in terpenoid biosynthesis. Here we report for the first time the cloning of a new full‐length cDNA encoding farnesyl diphosphate synthase from a gymnosperm plant species,Taxus mediaRehder, designated asTmFPS1.The full‐length cDNA ofTmFPS1(GenBank accession number: AY461811) was 1 464 bp with a 1 056‐bp open reading frame encoding a 351‐amino acid polypeptide with a calculated molecular weight of 40.3 kDa and a theoretical pI of 5.07. Bioinformatic analysis revealed that TmFPS1 contained all five conserved domains of prenyltransferases, and showed homology to other FPSs of plant origin. Phylogenetic analysis showed that farnesyl diphosphate synthases can be divided into two groups: one of prokaryotic origin and the other of eukaryotic origin. TmFPS1 was grouped with FPSs of plant origin. Homology‐based structural modeling showed that TmFPS1 had the typical spatial structure of FPS, whose most prominent structural feature is the arrangement of 13 core helices around a large central cavity in which the catalytic reaction takes place. Our bioinformatic analysis strongly suggests thatTmFPS1is a functional gene. Southern blot analysis revealed thatTmFPS1belongs to a smallFPSgene family inT. media.Northern blot analysis indicated thatTmFPS1is expressed in all tested tissues, including the needles, stems and roots ofT. media.Subsequently, functional complementation withTmFPS1in a FPS‐deficient mutant yeast demonstrated thatTmFPS1did encode farnesyl diphosphate synthase, which rescued the yeast mutant. This study will be helpful in future investigations aiming at understanding the detailed role of FPS in terpenoid biosynthesis flux control at the molecular genetic level.(Managing editor: Wei Wang)
Type-Specific Antibodies to Pneumococcal Capsular Polysaccharide Acquired either Naturally or after Vaccination with Prevenar in Children with Underlying Chronic or Recurrent Lung Diseases
Authors: Navarro David , Escribano Amparo , Cebrián Laura , Gimeno Concepción , García-Maset Leonor , García-de-Lomas Juan ,   the Spanish Pneumococcal Infection Study Network
Published: June 2006

ABSTRACT

The antibody response to capsular polysaccharides of pneumococcal serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F elicited either naturally or after vaccination with Prevenar was investigated in a cohort of children (
n
= 163) with underlying chronic or recurrent lung diseases at risk of developing pneumococcal pneumonia and ultimately invasive disease. Serum concentrations of serotype-specific antibodies, as measured by enzyme-linked immunosorbent assay, in unvaccinated children (
n
= 88) were higher in nasopharyngeal carriers (
n
= 10) than in noncarriers (
n
= 78) both at baseline and during follow-up. However, the antibody levels depended on the serotype and age of the children. During the study period, 35% of unvaccinated noncarriers and 60% of unvaccinated carriers displayed serum antibodies to all serotypes above the reported WHO working group putative protective serum concentration against invasive disease (0.2 μg/ml). Overall, children vaccinated with Prevenar before enrollment (
n
= 61), irrespective of their carrier status, displayed significantly higher serum levels of antibodies to all serotypes than unvaccinated children. More than 85% of the vaccinated children had protective serum antibody concentrations at baseline; although antibody titers tended to decrease over time, the above-mentioned figure remained without change at the end of follow-up. The vaccine Prevenar elicited a significant rise in serum antibody concentrations against all serotypes in 14 children vaccinated at entry. All of these children acquired and maintained serum antibody levels of >0.2 μg/ml throughout the study (a mean of 13 months of follow-up). These data support the systematic use of the vaccine Prevenar in children with underlying chronic or recurrent lung diseases and stress the fact that a percentage of vaccinated children may need to be revaccinated in order to achieve protection against pneumococcal disease.
Evaluation of the Interlaboratory Concordance in Quantification of Human Immunodeficiency Virus-Specific T Cells with a Gamma Interferon Enzyme-Linked Immunospot Assay
Authors: Samri A. , Durier C. , Urrutia A. , Sanchez I. , Gahery-Segard H. , Imbart S. , Sinet M. , Tartour E. , Aboulker J.-P. , Autran B. , Venet A. ,   the ANRS ELISpot Standardization Group
Published: June 2006

ABSTRACTThe gamma interferon (IFN-γ) enzyme-linked immunospot (ELISPOT) assay is a reference method for the ex vivo monitoring of antigen-specific T cells and a primary tool for assessing clinical trials of human immunodeficiency virus (HIV) or cancer vaccines. Four experienced laboratories in Paris compared their results with this method by exchanging frozen blood samples from eight HIV-seronegative and eight HIV-seropositive subjects. Each laboratory measured the IFN-γ-producing cells specific for HIV, Epstein-Barr virus, cytomegalovirus, and influenza using the same set of peptides and the same ELISPOT reader but its own ELISPOT technique. The cutoff values for positive responses (50 or 100 spot-forming cells/106peripheral blood mononuclear cells over background) were consistent with the binomial statistic criterion. The global qualitative concordance, as assessed by the kappa index, ranged from 0.38 to 0.92, that is, moderate to excellent, and was better for non-HIV 9-mer peptide pools than for HIV 15-mer peptide pools. The interlaboratory coefficient of variation for the frequency of virus-specific T cells was 18.7% (data are expressed on a log scale). Clustering analysis of HIV-positive subjects showed qualitative agreement for ELISPOT results from all four laboratories. Overall, the good interlaboratory qualitative concordance of IFN-γ ELISPOT assays with only the peptide source and ELISPOT reader in common suggests that a qualitative comparison of interlaboratory findings is feasible. Nonetheless, a single set of standard operating procedures should be used in multicenter trials to improve standardization.
Candidemia in Norway (1991 to 2003): Results from a Nationwide Study
Authors: Sandven Per , Bevanger Lars , Digranes Asbjørn , Haukland Hanne H. , Mannsåker Turid , Gaustad Peter ,   the Norwegian Yeast Study Group
Published: June 2006

ABSTRACT

A long-term, nationwide prospective candidemia study has been ongoing in Norway since 1991. All medical microbiological laboratories in the country have participated. During the period 1991 to 2003 a total of 1,393 episodes of candidemia occurred in 1,348 patients. The incidence of candidemia episodes per 100,000 inhabitants increased from approximately 2 episodes in the early 1990s to 3 episodes in 2001 to 2003. The average annual incidences varied markedly between the age groups. The incidence was high in patients aged <1 year and in patients aged ≥70 years. In patients ≥80 years of age, the incidence has increased during the last 3 years from an annual average of 6.5 to 15.6 cases/100,000 inhabitants in 2003. Four
Candida
species (
C. albicans
[70%],
C. glabrata
[13%],
C. tropicalis
[7%], and
C. parapsilosis
[6%]) accounted for 95.5% of the isolates. The species distribution has been constant during the 13-year study period. The distribution of the most important species varied with the age of the patient. In patients <1 year of age, the majority of episodes were caused by
C. albicans
(91%). The occurrence of
C. glabrata
increased with age. In patients ≥80 years of age, approximately 1/3 of all episodes were due to this species. All
C. albicans
strains were susceptible to fluconazole. The percentage of yeast isolates with decreased susceptibility to fluconazole (MICs ≥ 16 μg/ml) was 10.7% during the first period of this study (1991 to 1996) and 11.7% during the second period (1997 to 2003).
Unusual Naturally Occurring Humoral and Cellular Mutated Epitopes of Hepatitis B Virus in a Chronically Infected Argentine Patient with Anti-HBs Antibodies
Authors: Cuestas María L. , Mathet Verónica L. , Ruiz Vanesa , Minassian María L. , Rivero Cintia , Sala Andrea , Corach Daniel , Alessio Analía , Pozzati Marcia , Frider Bernardo , Oubiña José R. 
Published: June 2006

ABSTRACT

Serum hepatitis B virus (HBV) DNA was extracted from a chronically infected patient with cocirculation of hepatitis B surface antigen (HBsAg) and anti-HBs antibodies. Direct PCR and clone-derived sequences of the S and overlapped P genes were obtained. DNA sequences and phylogenetic analysis ascribed this isolate to genotype A (serotype
adw2
). Five of six HBV DNA clones exhibited point mutations inside and outside the major hydrophilic region, while the sixth clone exhibited a genotype A “wild-type” amino acid sequence. Observed replacements included both humoral and/or cellular (major histocompatibility complex class I [MHC-I] and MHC-II) HBV mutated epitopes, such as S45A, P46H, L49H, C107R, T125A, M133K, I152F, P153T, T161S, G185E, A194T, G202R, and I213L. None of these mutants were individually present within a given clone. The I213L replacement was the only one observed in the five clones carrying nonsynonymous mutations in the S gene. Some of the amino acid substitutions are reportedly known to be responsible for the emergence of immune escape mutants. C107R replacement prevents disulfide bonding, thus disrupting the first loop of the HBsAg. Circulation of some of these mutants may represent a potential risk for the community, since neither current hepatitis B vaccines nor hyperimmune hepatitis B immune globulin are effectively prevent the liver disease thereto associated. Moreover, some of the recorded HBsAg variants may influence the accuracy of the results obtained with currently used diagnostic tests.
Phaeoacremonium parasiticum
Infections Confirmed by β-Tubulin Sequence Analysis of Case Isolates
Authors: Baddley John W. , Mostert Lizel , Summerbell Richard C. , Moser Stephen A. 
Published: June 2006

ABSTRACT

Phaeoacremonium parasiticum
is an agent of opportunistic phaeohyphomycosis belonging to a genus encompassing numerous recently described and soon-to-be-described, difficult-to-identify human pathogens. It appears in the literature to be an uncommon etiologic agent, yet we encountered several cases in a single year. Each presented problems in laboratory identification and case management. We present two cases of invasive disease with definite identification and susceptibility results. These cases are analyzed in relation to a brief review of previous cases known to have been caused by this species. Our first case involved a 40-year-old male cardiac transplant recipient with multiple localized skin lesions. The second featured a 31-year-old female with aplastic anemia and prolonged neutropenia who developed disseminated disease, with multiple positive blood cultures and skin lesions. Both patients died despite aggressive surgical and antifungal therapy. Fungal susceptibility testing showed that our isolates appeared to be susceptible to amphotericin B, itraconazole, voriconazole, ravuconazole, and posaconazole. Because phenotypic identification of
Phaeoacremonium
is notably problematic, sequence-based confirmation was performed using a recently proposed standard based on use of a segment of the 5′ end of the β-tubulin gene. Sequences from both isolates involved in the cases were over 99% similar to the corresponding sequence of the ex-type isolate of
P. parasiticum.
The close DNA similarity, corroborated by relevant morphological similarities (e.g., long, thin phialides and tuberculate hyphae bearing warts up to 3 μm high), confirms these two isolates as
P. parasiticum
.
Immune Suppression as the Etiology of Failure To Detect Anti-HBc Antibodies in Patients with Chronic Hepatitis B Virus Infection
Authors: Avettand-Fenoel V. , Thabut D. , Katlama C. , Poynard T. , Thibault V. 
Published: June 2006

ABSTRACT
A lack of anti-HBc antibodies during chronic hepatitis B virus infection is a serological pattern that is rarely observed. In our series of 39 patients with such a confirmed profile, mutations within the precore/core gene were rarely found and the lack of antibody detection was mostly explained by concurrent immunosuppression and the low sensitivities of the serological assays.
Distribution and Invasiveness of
Streptococcus pneumoniae
Serotypes in Switzerland, a Country with Low Antibiotic Selection Pressure, from 2001 to 2004
Authors: Kronenberg Andreas , Zucs Phillip , Droz Sara , Mühlemann Kathrin 
Published: June 2006

ABSTRACT

To describe the serotype-specific epidemiology of colonizing and invasive
Streptococcus pneumoniae
isolates, which is important for vaccination strategies, we analyzed a total of 2,388 invasive and 1,540 colonizing
S. pneumoniae
isolates collected between January 2001 and December 2004 within two nationwide surveillance programs. We found that the relative rank orders of the most frequent serotypes (serotypes 1, 3, 4, 6B, 7F, 14, 19F, and 23F) differed among invasive and colonizing isolates. Serotypes 1, 4, 5, 7F, 8, 9V, and 14 had increased invasive potential, and serotypes/serogroups 3, 6A, 7, 10, 11, 19F, and 23F were associated with colonization. The proportion of pediatric serotypes was higher among children <5 years old (48.5%) and persons >64 years old (34.1%) than among other age groups (29.1%); it was also higher in West Switzerland (40.2%) than in other geographic regions (34.7%). Likewise, serotype-specific proportions of penicillin-resistant isolates for types 6B, 9V, 14, and 19F were significantly higher in West Switzerland. The relative frequency of pediatric serotypes corresponded with antibiotic consumption patterns. We conclude that the epidemiology of invasive and colonizing
S. pneumoniae
isolates is influenced by the serotype-specific potential for invasiveness, and therefore, surveillance programs should include colonizing and invasive
S. pneumoniae
isolates. Antibiotic selection pressure determines the serotype distribution in different age groups and geographic regions and therefore the expected direct and indirect effects of the 7-valent conjugate vaccine.
Multilocus Sequence Typing for Analyses of Clonality of
Candida albicans
Strains in Taiwan
Authors: Chen Kuo-Wei , Chen Yee-Chun , Lo Hsiu-Jung , Odds Frank C. , Wang Tzu-Hui , Lin Chi-Yang , Li Shu-Ying 
Published: June 2006

ABSTRACT

Multilocus sequence typing (MLST) was used to characterize the genetic profiles of 51
Candida albicans
isolates collected from 12 hospitals in Taiwan. Among the 51 isolates, 16 were epidemiologically unrelated, 28 were isolates from 11 critically ill, human immunodeficiency virus (HIV)-negative patients, and 7 were long-term serial isolates from 3 HIV-positive patients. Internal regions of seven housekeeping genes were sequenced. A total of 83 polymorphic nucleotide sites were identified. Ten to 20 different genotypes were observed at the different loci, resulting, when combined, in 45 unique genotype combinations or diploid sequence types (DSTs). Thirty (36.1%) of the 83 individual changes were synonymous and 53 (63.9%) were nonsynonymous. Due to the diploid nature of
C. albicans
, MLST was more discriminatory than the pulsed-field gel electrophoresis-BssHII-restricted fragment method in discriminating epidemiologically related strains. MLST is able to trace the microevolution over time of
C. albicans
isolates in the same patient. All but one of the DSTs of our Taiwanese strain collections were novel to the internet
C. albicans
DST database (
http://test1.mlst.net/
). The DSTs of
C. albicans
in Taiwan were analyzed together with those of the reference strains and of the strains from the United Kingdom and United States by unweighted-pair group method using average linkages and minimum spanning tree. Our result showed that the DNA type of each isolate was patient specific and associated with ABC type and decade of isolation but not associated with mating type, anatomical source of isolation, hospital origin, or fluconazole resistance patterns.