bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Vitro Activities of Position 2 Substitution-Bearing 6-Nitro- and 6-Amino-Benzothiazoles and Their Corresponding Anthranilic Acid Derivatives againstLeishmania infantumandTrichomonas vaginalis
Authors: Delmas Florence , Di Giorgio Carole , Robin Maxime , Azas Nadine , Gasquet Monique , Detang Claire , Costa Muriel , Timon-David Pierre , Galy Jean-Pierre 
Published: July 2002

ABSTRACT6-Nitro- and 6-amino-benzothiazoles bearing different chains in position 2 and their corresponding anthranilic acid derivatives were investigated for their in vitro antiparasitic properties against parasites of the speciesLeishmania infantumandTrichomonas vaginaliscompared to their toxicity towards human monocytes. Biological investigations established that the antiprotozoal properties depended greatly on the chemical structure of the position 2 substitution-bearing group. Compound C1, 2-[(2-chloro-benzothiazol-6-yl) amino] benzoic acid, demonstrated an interesting antiproliferative activity towards parasites of the speciesT. vaginalis, while compound C11, 2-({2-[(2-hydroxyethyl) amino]-benzothiazol-6-yl} amino) benzoic acid, exhibited a promising activity against parasites of the speciesL. infantumin their intracellular amastigote form. Additional experiments established that compound C11, which was poorly toxic against the promastigote and the extracellular amastigote forms of the parasite, could improve host-protective mechanisms againstLeishmaniaby preventing parasite internalization by macrophages and stimulating NO production, by means of a mechanism synergistically enhanced by the presence of gamma interferon.
Activities of Six Different Quinolones against Clinical Respiratory Isolates of
Streptococcus pneumoniae
with Reduced Susceptibility to Ciprofloxacin in Spain
Authors: Pérez-Trallero E. , García-Rey C. , Martín-Sánchez A. M. , Aguilar L. , García-de-Lomas J. , Ruiz J. 
Published: July 2002

ABSTRACT
Six quinolones were tested on 817 consecutive pneumococcal isolates for which ciprofloxacin MICs were high (≥2 μg/ml); the isolates had been collected during two recent Spanish surveillance studies. For strains for which the ciprofloxacin MIC was ≥4 μg/ml, the MICs at which 90% of the isolates tested against gemifloxacin, moxifloxacin, gatifloxacin, sparfloxacin, levofloxacin, and ofloxacin were inhibited were 0.25, 1, 1, 1, 4 and 16 μg/ml, respectively, and the corresponding prevalences of resistance were 0, 1, 4.5, 9.5, 8.4 and 23%. The proportion of isolates for which the ciprofloxacin MIC is high has increased over time.
Rapid Detection of a Molecular Marker for Chloroquine-Resistant Falciparum Malaria
Authors: Durand Rémy , Huart Virginie , Jafari Sayeh , Le Bras Jacques 
Published: July 2002

ABSTRACT

A PCR-based technique using molecular beacons was developed to detect the chloroquine resistance-associated
pfcrt
K76T point mutation in
Plasmodium falciparum
. One hundred thirty African clinical isolates were tested by the new method in comparison with the PCR-restriction fragment length polymorphism method. This rapid and inexpensive genomic assay could expand the possibilities for monitoring chloroquine resistance.
Seasonal Fluctuations and Long-Term Persistence of Pathogenic Populations of
Agrobacterium
spp. in Soils
Authors: Krimi Z. , Petit A. , Mougel C. , Dessaux Y. , Nesme X. 
Published: July 2002

ABSTRACT

Short- and long-term persistence of pathogenic (i.e., tumor forming) agrobacteria in soil was investigated in six nursery plots with a history of high crown gall incidence. No pathogenic
Agrobacterium
strains were isolated in soil samples taken in fall and winter in any plots, but such strains were isolated from both bulk soils and weed rhizospheres (over 0.5 × 10
5
pathogenic CFU/g of bulk soil or rhizosphere) in three out of six plots in spring and summer. PCR amplifications of a
vir
sequence from DNA extracted from soil confirmed the presence of Ti plasmids in summer and their absence in fall and winter. The results indicate that strains that harbor a Ti plasmid had an unforeseen positive fitness versus Ti plasmid-free strains in soil and rhizosphere in spring and summer in spite of the apparent absence of tumor, and hence of opines. The gain of fitness occurred during a bloom of all cultivable agrobacteria observed only in conducive soils. An evolution of the pathogenic population was recorded during a 4-year period in one particularly conducive soil. In 1990, the pathogenic population in this soil consisted of only biovar 1 strains harboring both octopine- and nopaline-type Ti plasmids. In 1994, it consisted of only nopaline-type Ti plasmids equally distributed among biovar 1 and 2 strains. These results suggest that nopaline-type Ti plasmids conferred a better survival ability than octopine-type Ti plasmids to biovar 2 agrobacteria under the present field conditions.
Modeling the Interactions of
Lactobacillus curvatus
Colonies in Solid Medium: Consequences for Food Quality and Safety
Authors: Malakar P. K. , Martens D. E. , van Breukelen W. , Boom R. M. , Zwietering M. H. , van 't Riet K. 
Published: July 2002

ABSTRACT

The growth process of
Lactobacillus curvatus
colonies was quantified by a coupled growth and diffusion equation incorporating a volumetric rate of lactic acid production. Analytical solutions were compared to numerical ones, and both were able to predict the onset of interaction well. The derived analytical solution modeled the lactic acid concentration profile as a function of the diffusion coefficient, colony radius, and volumetric production rate. Interaction was assumed to occur when the volume-averaged specific growth rate of the cells in a colony was 90% of the initial maximum rate. Growth of
L. curvatus
in solid medium is dependent on the number of cells in a colony. In colonies with populations of fewer than 10
5
cells, mass transfer limitation is not significant for the growth process. When the initial inoculation density is relatively high, colonies are not able to grow to these sizes and growth approaches that of broth cultures (negligible mass transfer limitation). In foods, which resemble the model solid system and in which the initial inoculation density is high, it will be appropriate to use predictive models of broth cultures to estimate growth. For a very low initial inoculation density, large colonies can develop that will start to deviate from growth in broth cultures, but only after large outgrowth.
Cardiovascular Effects of Fermented Milk Containing Angiotensin-Converting Enzyme Inhibitors Evaluated in Permanently Catheterized, Spontaneously Hypertensive Rats
Authors: Fuglsang Anders , Nilsson Dan , Nyborg Niels C. B. 
Published: July 2002

ABSTRACT

In this study, two strains of
Lactobacillus helveticus
were used to produce fermented milk rich in angiotensin-converting enzyme (ACE) inhibitors. In vitro tests revealed that the two milks contained competitive inhibitors of ACE in amounts comparable to what has been obtained in previously reported studies. The two milks were administered by gavage to spontaneously hypertensive rats that had had a permanent aortic catheter inserted through the left arteria carotis, and mean arterial blood pressure and heart rate were monitored from 4 to 8 h after administration. Unfermented milk and milk fermented with a lactococcal strain that does not produce inhibitors were used as controls. Highly significant blood pressure effects were observed; i.e., milk fermented with the two strains of
L. helveticus
gave a more pronounced drop in blood pressure than the controls. Significant differences in heart rate effects were detected with one of the strains.
Changes in Bacterioplankton Community Structure and Activity with Depth in a Eutrophic Lake as Revealed by 5S rRNA Analysis
Authors: Dominik Katja , Höfle Manfred G. 
Published: July 2002

ABSTRACT

The community structure of bacterioplankton was studied at different depths (0 to 25 m) of a temperate eutrophic lake (Lake Plußsee in northern Germany) by using comparative 5S rRNA analysis. The relative amounts of taxonomic groups were estimated from 5S rRNA bands separated by high-resolution electrophoresis. Comparison of partial 5S rRNA sequences enabled detection of changes in single taxa over space and during seasons. Overall, the bacterioplankton community was dominated by 3 to 14 abundant (>4% of the total 5S rRNA) taxa. In general, the number of 5S rRNA bands (i.e., the number of bacterial taxa) decreased with depth. In the fall, when thermal stratification and chemical stratification were much more pronounced than they were in the spring, the correlation between the depth layers and the community structure was more pronounced. Therefore, in the fall each layer had its own community structure; i.e., there were different community structures in the epilimnion, the metalimnion, and the hypolimnion. Only three 5S rRNA bands were detected in the hypolimnion during the fall, and one band accounted for about 70% of the total 5S rRNA. The sequences of individual 5S rRNA bands from the spring and fall were different for all size classes analyzed except two bands, one of which was identified as
Comamonas acidivorans.
In the overall analysis of the depth profiles, the diversity in the epilimnion contrasted with the reduced diversity of the bacterioplankton communities in the hypolimnion, and large differences occurred in the composition of the epilimnion at different seasons except for generalists like
C. acidivorans.
Use of 16S Ribosomal DNA for Delineation of Marine Bacterioplankton Species
Authors: Hagström Åke , Pommier Thomas , Rohwer Forest , Simu Karin , Stolte Willem , Svensson Dominika , Zweifel Ulla Li 
Published: July 2002

ABSTRACT
All of the marine bacterioplankton-derived 16S ribosomal DNA sequences previously deposited in GenBank were reanalyzed to determine the number of bacterial species in the oceanic surface waters. These sequences have been entered into the database since 1990. The rate of new additions reached a peak in 1999 and subsequently leveled off, suggesting that much of the marine microbial species richness has been sampled. When the GenBank sequences were dereplicated by using 97% similarity as a cutoff, 1,117 unique ribotypes were found. Of the unique sequences, 609 came from uncultured environmental clones and 508 came from cultured bacteria. We conclude that the apparent bacterioplankton species richness is relatively low.
An Aspartyl Protease Inhibitor Orthologue Expressed byParelaphostrongylus tenuisIs Immunogenic in an Atypical Host
Authors: Duffy Michael S. , MacAfee Nancy , Burt Michael D. B. , Appleton Judith A. 
Published: July 2002

ABSTRACTParelaphostrongylus tenuisis a neurotropic nematode common in white-tailed deer (Odocoileus virginianus) of eastern North America. This parasite is the causative agent of a debilitating neurologic disease in atypical hosts, including domestic livestock. In order to identify proteins of potential significance in the host-parasite relationship, a cDNA library was produced from adultP. tenuismRNA. Screening the library with antisera from infected red deer (Cervus elaphus elaphus) and immunized AO strain rats, we identified clones with sequence similarities to aspartyl protease inhibitors from several parasitic nematodes. Antibody that was generated against this recombinant protein ofP. tenuis(Pt-API-1) detected the native protein in E/S products, in muscle and gonad, and on the surface of the cuticle of adult male and femaleP. tenuis. The native protein was detected in internal structures of first-stage (L1) and third-stage (L3) larvae. Reverse transcription-PCR confirmed expression ofPt-api-1in L1, L3, and adult male and female worms. Expression ofPt-API-1 throughout the life cycle ofP. tenuissuggests an essential function. Antibodies specific for recombinantPt-API-1 were detected by enzyme-linked immunosorbent assay in sera from 12 red deer experimentally infected withP. tenuis. Antibodies were detected within 28 to 56 days postinfection. Responses were sustained or biphasic in animals with patent infections, consistent with expression ofPt-API-1 by L1. Our results are compatible with findings in other parasitic nematodes showing that aspartyl protease inhibitors are highly immunogenic.
Sputum Cytokine Levels in Patients with Pulmonary Tuberculosis as Early Markers of Mycobacterial Clearance
Authors: Ribeiro-Rodrigues Rodrigo , Resende Co Tatiana , Johnson John L. , Ribeiro Fabiola , Palaci Moises , Sá Ricardo T. , Maciel Ethel L. , Pereira Lima Fausto E. , Dettoni Valderio , Toossi Zahra , Boom W. Henry , Dietze Reynaldo , Ellner Jerrold J. , Hirsch Christina S. 
Published: July 2002

ABSTRACTSputum and serum from patients with active pulmonary tuberculosis (TB), healthy purified protein derivative-positive adults, and patients with bacterial pneumonia were collected to simultaneously assess local immunity in the lungs and peripheral blood. To determine whether cytokine profiles in sputum from TB patients and control subjects were a reflection of its cellular composition, cytospin slides were prepared in parallel and assessed for the presence of relative proportions of epithelial cells, neutrophils, macrophages, and T cells. Gamma interferon (IFN-γ) in sputum from TB patients was markedly elevated over levels for both control groups. With anti-TB therapy, IFN-γ levels in sputum from TB patients decreased rapidly and by week 4 of treatment were comparable to those in sputum from controls. Further, IFN-γ levels in sputum closely followed mycobacterial clearance. Although detected at fourfold-lower levels, IFN-γ immunoreactivities in serum followed kinetics in sputum. TNF-α, interleukin 8 (IL-8) and IL-6 also were readily detected in sputum from TB patients at baseline and responded to anti-TB therapy. In contrast to IFN-γ, however, TNF-α and IL-8 levels also were elevated in sputum from pneumonia controls. These data indicate that sputum cytokines correlate with disease activity during active TB of the lung and may serve as potential early markers for sputum conversion and response to anti-TB therapy.
Validation of an In-House Assay for Cytomegalovirus Immunoglobulin G (CMV IgG) Avidity and Relationship of Avidity to CMV IgM Levels
Authors: Prince Harry E. , Leber Amy L. 
Published: July 2002

ABSTRACT

Measurement of cytomegalovirus (CMV)-specific immunoglobulin G (IgG) avidity has proven to be a powerful tool for distinguishing primary from nonprimary CMV infection. An in-house enzyme-linked immunosorbent assay (ELISA) for measuring CMV IgG avidity was validated using 84 sera from pregnant women who had recently seroconverted following primary CMV infection and 74 sera from individuals with past CMV infection (IgG-positive and IgM-negative profile). Of the 84 sera from pregnant women, 73 sera were collected within 120 days of the last IgG-negative sample, and 72 of these 73 sera (99%) exhibited an avidity index (AI) of <50%. In contrast, 71 of 74 (96%) sera from individuals with past CMV infection exhibited CMV AI values of >60%. Thus, low avidity in the in-house ELISA was defined as an AI of ⩽50%, whereas high avidity was defined as an AI of ⩾60%. In additional studies, the relationship between CMV IgG avidity and CMV IgM levels was examined using 64 CMV IgG-positive sera (time since seroconversion unknown) exhibiting equivocal or positive results in a CMV IgM capture ELISA (Diamedix). Of these 64 sera, 29 exhibited IgM index values of ⩾3.0, and 27 of these 29 (93%) exhibited low IgG avidity. A similar trend was observed when a subset of these 64 sera (
n
= 48) was tested in another CMV IgM capture ELISA (Trinity); of 18 sera with IgM index values of ⩾3.0, 17 (94%) exhibited low IgG avidity. These findings demonstrate the validity of an in-house ELISA for CMV IgG avidity and further show that strong reactivity of CMV IgG-positive sera in either of two CMV IgM capture assays is a reliable indicator of low CMV IgG avidity, and thus, recent CMV infection.
Evaluation of Urine as a Clinical Specimen for Diagnosis of Hepatitis A
Authors: Joshi Madhuri S. , Chitambar Shobha D. , Arankalle Vidya A. , Chadha Mandeep S. 
Published: July 2002

ABSTRACT

The present study pertains to the evaluation of urine as a specimen for detection of anti-hepatitis A virus (anti-HAV) antibodies. Immunoglobulin M (IgM), IgG, and IgA capture enzyme-linked immunosorbent assays for hepatitis A were performed on paired serum and urine specimens collected from hepatitis A patients (
n
= 92), healthy individuals (
n
= 100), non-A hepatitis patients (
n
= 70), and patients with nonhepatic diseases (
n
= 64, including 37 renal disease patients). Hepatitis A patients seropositive for anti-HAV IgM showed 95.65% uropositivity. No false-positive reactions were observed in control groups. The uropositivity of anti-HAV IgM persisted during the convalescent phase of the disease. Anti-HAV IgG uropositivity correlated well with corresponding seropositivity in all groups (
P
> 0.05 for each). No significant difference between the proportions of serum and urine positivity for anti-HAV IgA was noted (
P
> 0.05 for each). Using seroreactivity as a “gold standard,” the sensitivity and specificity for anti-HAV IgM, anti-HAV IgG, and anti-HAV IgA tests with urine as a specimen were found to be 95.65 and 100%, 97.76 and 76.47%, and 92.23 and 88.18%, respectively. Urine appears to be comparable to serum for diagnosis of recent and past infection with hepatitis A.
Preadult Stage Parasites and Multiple Timed Exposure to Infective Larvae Are Involved in Development of Limb Edema in
Brugia malayi
-Infected Indian Leaf Monkeys (
Presbytis entellus
)
Authors: Murthy P. K. , Khan M. A. , Rajani H. B. , Srivastava V. M. L. 
Published: July 2002

ABSTRACT

The pathogenesis of filarial limb edema is not known. The role of parasitological variables and parasite-mediated phenomena in the development of limb edema was investigated in the
Presbytis entellus
-
Brugia malayi
model. Infection was initiated with subcutaneous inoculation of infective third-stage larvae (L
3
), and the animals were reexposed to different doses of L
3
at the prepatent, patent, and diminishing microfilaremia (0 to 5% of peak microfilaremia count) stages of infection. A large L
3
inoculum size and repeated inoculation in the ankle region during the prepatent, patent, and diminishing microfilaremia stages of infection were found to be necessary for reproducible induction of limb edema. The preadult stage of the parasite was found to be the most potent inducer of limb edema, followed by L
5
and L
4
. The presence of the proinflammatory cytokines tumor necrosis factor alpha, interleukin-1β, and interleukin-6 in edema fluid in the leg receiving the parasite challenge indicated that the limb edema development was due to parasite-mediated cytokine responses. The absence of bacterial infection or anti-streptolysin O titer in the edema fluid and blood indicated that bacterial infection is not necessary for the development of limb edema.
Cultivation ofBabesiaandBabesia-Like Blood Parasites: Agents of an Emerging Zoonotic Disease
Authors: Schuster Frederick L. 
Published: July 2002

SUMMARYBabesiaand its close relatives are members of a group of organisms called piroplasms, a name which comes from their pear-shaped outlines. Long associated with blood diseases of cattle and other mammals, members of the genusBabesiahave been recognized since the 1950s as infectious agents in humans. Species of this protozoan blood parasite that have routinely been isolated from mice (B. microti) or cattle (B. divergens) have also been isolated from humans. In addition to these familiar species, new isolates that resist being placed in existing taxonomic categories are the basis for rethinking their phylogenetic relationships based on sequencing data. The parasite represents a threat to the safety of the blood supply in that blood from asymptomatic humans can transmitBabesiato blood recipients. Such transmissions have occurred. The development of methods for cultivation of these organisms represents a significant opportunity to study their biology and disease potential. In addition, in vitro cultivation has provided a basis for studying immune responses of mammals to these infectious agents, with the hope of ultimately producing attenuated strains that could be used for immunizing of cattle and, perhaps, humans who live in areas of endemicity. The microaerophilous stationary phase culture technique, which uses a tissue culture medium base supplemented with appropriate serum and erythrocytes, has made it possible to obtain large numbers of parasitized erythrocytes for studying the biology of this parasite.
Microarray-Based Identification of
htrA
, a
Streptococcus pneumoniae
Gene That Is Regulated by the CiaRH Two-Component System and Contributes to Nasopharyngeal Colonization
Authors: Sebert M. E. , Palmer L. M. , Rosenberg M. , Weiser J. N. 
Published: July 2002

ABSTRACT

Nasopharyngeal carriage is the reservoir from which most disease with
Streptococcus pneumoniae
arises. Survival as a commensal in this environment is likely to require a set of adaptations distinct from those needed to cause disease, some of which may be mediated by two-component signal transduction systems (TCSTS). We examined the contributions of nine pneumococcal TCSTS to the process of nasopharyngeal colonization by using an infant rat model. Whereas deletions in all but one of these systems have been associated previously with a high degree of attenuation in a murine model of pneumonia, only the CiaRH system was necessary for efficient carriage. Transcriptional analysis by using microarray hybridization identified a locus consisting of two adjacent genes,
htrA
and
spoJ
, that was specifically and strongly downregulated in a Δ
ciaRH
-null mutant. A
S. pneumoniae
strain lacking the
htrA
gene encoding a putative serine protease, but not one lacking
spoJ
, showed decreased fitness in a competitive model of colonization, a finding consistent with this gene mediating a portion of the carriage deficit observed with the Δ
ciaRH
strain.
Phenotypes of a Naturally Defective
recB
Allele in
Neisseria meningitidis
Clinical Isolates
Authors: Salvatore Paola , Bucci Cecilia , Pagliarulo Caterina , Tredici Maurizio , Colicchio Roberta , Cantalupo Giuseppina , Bardaro Marcellino , Del Giudice Luigi , Massardo Domenica R. , Lavitola Alfredo , Bruni Carmelo B. , Alifano Pietro 
Published: July 2002

ABSTRACT

Neisseria meningitidis
strains belonging to the hypervirulent lineage ET-37 and several unrelated strains are extremely UV sensitive. The phenotype is consequent to the presence of a nonfunctional
recB
ET-37
allele carrying multiple missense mutations. Phenotypic analysis has been performed with congenic meningococcal strains harboring either the wild-type
recB
allele or the
recB
ET-37
allele. Congenic
recB
ET-37
meningococci, in addition to being sensitive to UV, were defective both in repair of DNA lesions induced by UV treatment and, partially, in recombination-mediated transformation. Consistently, the wild-type, but not the
recB
ET-37
, allele was able to complement the
Escherichia coli recB21
mutation to UV resistance and proficiency in recombination.
recB
ET-37
meningococci did not exhibit higher frequencies of spontaneous mutation to rifampin resistance than
recB
-proficient strains. However, mutation rates were enhanced following UV treatment, a phenomenon not observed in the
recB
-proficient counterpart. Interestingly, the results of PCR-based assays demonstrated that the presence of the
recB
ET-37
allele considerably increased the frequency of recombination at the pilin loci. The main conclusion that can be drawn is that the presence of the defective
recB
ET-37
allele in
N. meningitidis
isolates causes an increase in genetic diversity, due to an ineffective RecBCD-dependent DNA repair and recombination pathway, and an increase in pilin antigenic variation.