bluuebunny/crossref_metadata_2025_split huggingface dataset:
Attached and Unattached Bacterial Communities in a 120-Meter Corehole in an Acidic, Crystalline Rock Aquifer
Authors: Lehman R. Michael , Roberto Francisco F. , Earley Drummond , Bruhn Debby F. , Brink Susan E. , O'Connell Sean P. , Delwiche Mark E. , Colwell Frederick S. 
Published: July 2002

ABSTRACT

The bacteria colonizing geologic core sections (attached) were contrasted with those found suspended in the groundwater (unattached) by examining the microbiology of 16 depth-paired core and groundwater samples using a suite of culture-independent and culture-dependent analyses. One hundred twenty-two meters was continuously cored from a buried chalcopyrite ore hosted in a biotite-quartz-monzonite porphyry at the Mineral Park Mine near Kingman, Ariz. Every fourth 1.5-m core was acquired using microbiologically defensible methods, and these core sections were aseptically processed for characterization of the attached bacteria. Groundwater samples containing unattached bacteria were collected from the uncased corehole at depth intervals corresponding to the individual cores using an inflatable straddle packer sampler. The groundwater was acidic (pH 2.8 to 5.0), with low levels of dissolved oxygen and high concentrations of sulfate and metals, including ferrous iron. Total numbers of attached cells were less than 10
5
cells g of core material
−1
while unattached cells numbered about 10
5
cells ml of groundwater
−1
. Attached and unattached acidophilic heterotrophs were observed throughout the depth profile. In contrast, acidophilic chemolithotrophs were not found attached to the rock but were commonly observed in the groundwater. Attached communities were composed of low numbers (<40 CFU g
−1
) of neutrophilic heterotrophs that exhibited a high degree of morphologic diversity, while unattached communities contained higher numbers (ca. 10
3
CFU ml
−1
) of neutrophilic heterotrophs of limited diversity. Sulfate-reducing bacteria were restricted to the deepest samples of both core and groundwater. 16S ribosomal DNA sequence analysis of attached, acidophilic isolates indicated that organisms closely related to heterotrophic, acidophilic mesophiles such as
Acidiphilium organovorum
and, surprisingly, to the moderately thermophilic
Alicyclobacillus acidocaldarius
were present. The results indicate that viable (but possibly inactive) microorganisms were present in the buried ore and that there was substantial distinction in biomass and physiological capabilities between attached and unattached populations.
Efficacy of Common Laboratory Disinfectants on the Infectivity of
Cryptosporidium parvum
Oocysts in Cell Culture
Authors: Weir Susan C. , Pokorny Nicholas J. , Carreno Ramon A. , Trevors Jack T. , Lee Hung 
Published: July 2002

ABSTRACT

Nine liquid disinfectants were tested for their ability to reduce infectivity of
Cryptosporidium parvum
oocysts in cell culture. A 4-min exposure to 6% hydrogen peroxide and a 13-min exposure to ammonium hydroxide-amended windshield washer fluid reduced infectivity 1,000-fold. Other disinfectants tested (70% ethanol, 37% methanol, 6% sodium hypochlorite, 70% isopropanol, and three commercial disinfectants) did not reduce the infectivity after a 33-min exposure. The results indicate that hydrogen peroxide and windshield washer fluid or ammonium hydroxide disinfectant may be suitable laboratory disinfectants against
C. parvum
oocysts.
Impact of Irradiation and Polycyclic Aromatic Hydrocarbon Spiking on Microbial Populations in Marine Sediment for Future Aging and Biodegradability Studies
Authors: Melcher Rebecca J. , Apitz Sabine E. , Hemmingsen Barbara B. 
Published: July 2002

ABSTRACT

Experiments were carried out to develop methods to generate well-characterized, polycyclic aromatic hydrocarbon (PAH)-spiked, aged but minimally altered sediments for fate, biodegradation, and bioavailability experiments. Changes in indigenous bacterial populations were monitored in mesocosms constructed of relatively clean San Diego Bay sediments, with and without exposure to gamma radiation, and then spiked with five different PAHs and hexadecane. While phenanthrene and chrysene degraders were present in the unspiked sediments and increased during handling, PAH spiking of nonirradiated sediments led to dramatic increases in their numbers. Phenotypic characterization of isolates able to grow on phenanthrene or chrysene placed them in several genera of marine bacteria:
Vibrio
,
Marinobacter
or
Cycloclasticus
,
Pseudoalteromonas
,
Marinomonas
, and
Halomonas
. This is the first time that marine PAH degraders have been identified as the latter two genera, expanding the diversity of marine bacteria with this ability. Even at the highest irradiation dose (10 megarads), heterotrophs and endospore formers reappeared within weeks. However, while bacteria from the unirradiated sediments had the capacity to both grow on and mineralize
14
C-labeled phenanthrene and chrysene, irradiation prevented the reappearance of PAH degraders for up to 4 months, allowing spikes to age onto the sediments, which can be used to model biodegradation in marine sediments.
Production of Sepiapterin in
Escherichia coli
by Coexpression of Cyanobacterial GTP Cyclohydrolase I and Human 6-Pyruvoyltetrahydropterin Synthase
Authors: Woo Hyun Joo , Kang Jee Yun , Choi Yong Kee , Park Young Shik 
Published: July 2002

ABSTRACT

Synechocystis
sp. strain PCC 6803 GTP cyclohydrolase I and human 6-pyruvoyltetrahydropterin synthase were coexpressed in
Escherichia coli
. The
E. coli
transformant produced sepiapterin, which was identified by high-performance liquid chromatography and enzymatically converted to dihydrobiopterin by sepiapterin reductase. Aldose reductase, another indispensable enzyme for sepiapterin production, may be endogenous in
E. coli
.
Evaluation of TruCount Absolute-Count Tubes for Determining CD4 and CD8 Cell Numbers in Human Immunodeficiency Virus-Positive Adults
Authors: Schnizlein-Bick Carol T. , Spritzler John , Wilkening Cynthia L. , Nicholson Janet K. A. , O'Gorman Maurice R. G. ,   Site InvestigatorsThe NIAID DAIDS New Technologies Evaluation Group
Published: July 2002

ABSTRACT
A single-platform technology that uses an internal bead standard and three-color flow cytometry to determine CD4 and CD8 absolute counts was evaluated for reproducibility and agreement. Values obtained using TruCount absolute-count tubes were compared to those obtained using a two-color predicate methodology. Sixty specimens from human immunodeficiency virus type 1-infected donors were shipped to five laboratories. Each site also analyzed replicates of 14 human immunodeficiency virus type 1-infected local specimens at 6 h and again at 24 h. The interlaboratory variability was significantly less with TruCount (median difference in percent coefficient of variation [%CV] between the two methods was −8% and −3% for CD4 and CD8, respectively) than with the predicate method. Intralaboratory variability was smaller, with a median difference in %CV of −1% for both CD4 and CD8 with 6-h samples and −2% and −3% for CD4 and CD8, respectively, with 24-h samples. Use of TruCount for shipped samples resulted in a median CD4 count change of 7 cells (50th estimated percentile) when all laboratories and CD4 strata were combined. For on-site samples, the median CD4 count change was 10 CD4 cells for 6-h samples and 2 CD4 cells for 24-h samples. Individual site biases occurred in both directions and cancelled each other when the data were combined for all laboratories. Thus, the combined data showed a smaller change in median CD4 count than what may have occurred at an individual site. In summary, the use of TruCount decreased both the inter- and intralaboratory variability in determining absolute CD4 and CD8 counts.
Cytopathic Changes in Rat Microglial Cells Induced by PathogenicAcanthamoeba culbertsoni: Morphology and Cytokine Release
Authors: Shin Ho-Joon , Cho Myung-Soo , Jung Suk-Yul , Kim Hyung-Il , Park Sun , Seo Jang-Hoon , Yoo Jung-Chil , Im Kyung-Il 
Published: July 2002

ABSTRACTTo determine whether pathogenicAcanthamoeba culbertsonitrophozoites and lysate can induce cytopathic changes in primary-culture microglial cells, morphological changes were observed by transmission electron microscopy (TEM). In addition, the secretion of two kinds of cytokines, tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β), from microglial cells was observed. Trophozoites of pathogenicA. culbertsonimade contact with microglial cells and produced digipodia. TEM revealed that microglial cells cocultured with amoebic trophozoites underwent a necrotic process, accompanied by lysis of the cell membrane. TEM of microglial cells cocultured with amoebic lysate showed that the membranes of the small cytoplasmic vacuoles as well as the cell membrane were lysed. The amounts of TNF-α secreted from microglial cells cocultured withA. culbertsonitrophozoites or lysate increased at 6 h of incubation. The amounts of IL-1β secreted from microglial cells cocultured withA. culbertsonitrophozoites at 6 h of incubation was similar to those secreted from the control group, but the amounts decreased during cultivation withA. culbertsonilysate. These results suggest that pathogenicA. culbertsoniinduces the cytopathic effects in primary-culture rat microglial cells, with the effects characterized by necrosis of microglial cells and changes in levels of secretion of TNF-α and IL-1β from microglial cells.
Heartwater (
Cowdria ruminantium
Infection) as a Cause of Postrestocking Mortality of Goats in Mozambique
Authors: Bekker Cornelis P. J. , Vink Daan , Lopes Pereira Carlos M. , Wapenaar Wendela , Langa Afonso , Jongejan Frans 
Published: July 2002

ABSTRACT

A serological survey in Mozambique to detect antibodies to
Cowdria ruminantium
, the etiologic agent of heartwater, revealed a seroprevalence of 8.1% (
n
= 332) for goats in the northern province of Tete and of 65.6% (
n
= 326) for goats in the southern provinces. Translocation of 10 serologically negative goats from Tete to farms in the south resulted in two clinical cases of heartwater that were fatal. In addition, four goats seroconverted within the study period of 5 weeks. One goat showed no symptoms. Two goats died of other causes, whereas the remaining goat went missing after 1 week. Experimental needle infections of goats and sheep were conducted to confirm results and to isolate different strains of
C. ruminantium
. These data indicate that translocation of goats from the north to the south of Mozambique bears a high risk of
C. ruminantium
infection, which can cause fatal disease.
Modulation ofMycobacterium bovis-Specific Responses of Bovine Peripheral Blood Mononuclear Cells by 1,25-Dihydroxyvitamin D3
Authors: Waters W. R. , Nonnecke B. J. , Rahner T. E. , Palmer M. V. , Whipple D. L. , Horst R. L. 
Published: July 2002

ABSTRACTHistorically, administration of vitamin D has been considered beneficial in the treatment of tuberculosis. The interaction of this vitamin {i.e., 1,25-dihdroxyvitamin D3[1,25(OH)2D3]} with the antitubercular immune response, however, is not clear. In the present study, in vitro recall responses of peripheral blood mononuclear cells (PBMC) from cattle infected withMycobacterium boviswere used to study the immune-modulatory effects of 1,25(OH)2D3onM. bovis-specific responses in vitro. Addition of 1 or 10 nM 1,25(OH)2D3inhibitedM. bovis-specific proliferative responses of PBMC fromM. bovis-infected cattle, affecting predominately the CD4+cell subset. In addition, 1,25(OH)2D3inhibitedM. bovis-specific gamma interferon (IFN-γ) production yet enhancedM. bovis-specific nitric oxide (NO) production. Lymphocyte apoptosis, measured by flow cytometry using annexin-V staining, was diminished by addition of 1,25(OH)2D3to PBMC cultures. These findings support the current hypothesis that 1,25(OH)2D3enhances mycobacterial killing by increasing NO production, a potent antimicrobial mechanism of activated macrophages, and suggest that 1,25(OH)2D3limits host damage by decreasingM. bovis-induced IFN-γ production.
Depletion of Human NK and CD8 Cells prior to In Vitro H1N1 Flu Vaccine Stimulation Increases the Number of Gamma Interferon-Secreting Cells Compared to the Initial Undepleted Population in an ELISPOT Assay
Authors: Dercamp Christophe , Sanchez Violette , Barrier Julie , Trannoy Emanuelle , Guy Bruno 
Published: July 2002

ABSTRACTIn order to study the respective roles of CD4, CD8, and CD56 (NK) cells in gamma interferon (IFN-γ) production after in vitro stimulation with flu vaccine in a healthy adult human population, we depleted these cellular subtypes before stimulation with antigen (inactivated split vaccine, A/Texas H1N1, or A/Sydney H3N2). We observed that while CD4 cells were required for IFN-γ secretion in both conditions in vitro, CD56 (NK) cells and, to a lesser extent, CD8 cells had a negative effect on such synthesis upon H1N1 stimulation, as judged by an increased number of spots compared to the initial undepleted population. This regulation of IFN-γ secretion was associated with an increase in ICAM-1 expression, in particular on T and B cells. This study points out the importance of evaluating in vitro immune responses on a whole-cell population in addition to isolated subtypes if one needs to address potential cellular interactions occurring in vivo in some situations (H1N1 stimulation in the present case). Such cross-regulations occur even in vitro during the antigenic stimulation step.
Differential Modulation of Surface and Intracellular Protein Expression by T Cells after Stimulation in the Presence of Monensin or Brefeldin A
Authors: O'Neil-Andersen Nancy J. , Lawrence David A. 
Published: July 2002

ABSTRACTIntracellular cytokine staining is an increasingly popular analytical tool that can be used to define the profile of cytokines in various disease states. One important requirement for this assay is the inclusion of a protein transport inhibitor in stimulated cell cultures to trap the cytokine, thus allowing a brighter signal. Two compounds commonly used for this purpose are brefeldin A (BFA) and monensin (MN). Flow cytometry was used to assess the differential effects of BFA and MN on surface CD3, -4, -8, and -69 expression and the intracellular expression of gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) following stimulation with phorbol myristate acetate and ionomycin. We found that BFA blocked the majority of CD3+cells from expressing surface CD69, but BFA did not inhibit intracellular CD69 expression. MN did not significantly inhibit surface CD69 expression. With regard to lymphocyte marker expression following activation, surface CD4 expression was significantly downregulated; however, less downregulation was observed with BFA treatment than with MN treatment. Analyzing intracellular cytokine expression, BFA trapped a greater percentage of TNF-α inside activated cells than MN. An analysis of the cytokine concentration in culture supernatants indicated that cells treated with MN released TNF-α and IFN-γ from the cells, while the BFA-treated cells released IFN-γ only. With prolonged (18-h) stimulation, the cells treated with MN were less viable than those treated with BFA. We conclude that the choice of a protein transport inhibitor is an important variable in this assay. When developing this method as a tool for clinical immunology laboratory analysis, investigators should consider the differential effects of BFA and MN on results.
Heterologous Expression, Purification, and Immunological Reactivity of a Recombinant HSP60 from
Paracoccidioides brasiliensis
Authors: Cunha Daniela A. , Zancopé-Oliveira Roseli M. , Sueli M. , Felipe S. , Salem-Izacc Silvia M. , Deepe George S. , Soares Célia M. A. 
Published: July 2002

ABSTRACT

The complete coding cDNA of HSP60 from
Paracoccidioides brasiliensis
was overexpressed in an
Escherichia coli
host to produce high levels of recombinant protein. The protein was purified by affinity chromatography. A total of 169 human serum samples were tested for reactivity by Western blot analysis with the purified HSP60 recombinant protein. Immunoblots indicated that the recombinant
P. brasiliensis
HSP60 was recognized by antibodies in 72 of 75 sera from paracoccidioidomycosis patients. No cross-reactivity was detected with individual sera from patients with aspergillosis, sporotrichosis, cryptococcosis, and tuberculosis. Reactivity to HSP60 was observed in sera from 9.52% of control healthy individuals and 11.5% of patients with histoplasmosis. The high sensitivity and specificity (97.3 and 92.5%, respectively) for HSP60 suggested that the recombinant protein can be used singly or in association with other recombinant antigens to detect antibody responses in
P. brasiliensis
-infected patients.
YKL-40 Is Elevated in Cerebrospinal Fluid from Patients with Purulent Meningitis
Authors: Østergaard Christian , Johansen Julia S. , Benfield Thomas , Price Paul A. , Lundgren Jens D. 
Published: July 2002

ABSTRACTYKL-40, a member of the family 18 glycosyl hydrolases, is secreted by activated neutrophils and macrophages. It is a growth factor for connective tissue cells and a potent migration factor for endothelial cells and may function in inflammation and tissue remodeling. YKL-40 was determined in 134 cerebrospinal fluid (CSF) samples taken on admission from patients suspected of having meningitis (48 with purulent meningitis, 49 with lymphocytic meningitis, 5 with encephalitis, and 32 without evidence of meningitis). YKL-40 levels in CSF were significantly higher in patients with purulent meningitis (median, 663 μg/liter [range, 20 to 8,960]) and encephalitis (5,430 μg/liter [620 to 11,600]) than in patients with lymphocytic meningitis (137 μg/liter [41 to 1,865]) or patients without meningitis (167 μg/liter [24 to 630]) (Kruskal-Wallis and Dunn multiple comparison tests,P< 0.001). CSF YKL-40 levels were also determined for 26 patients with purulent meningitis having a repuncture, and patients who died (n= 5) had significantly higher YKL-40 levels than patients who survived (n= 21) (2,100 μg/liter [1,160 to 7,050] versus 885 μg/liter [192 to 15,400], respectively; Mann-Whitney test,P= 0.018). YKL-40 was most likely locally produced, since patients with infections of the central nervous system had CSF YKL-40 levels that were at least 10-fold higher than the corresponding levels in serum (2,033 μg/liter [470 to 11,600] versus 80 μg/liter [19 to 195]). The CSF neopterin level was the biochemical parameter in CSF and blood that correlated best with CSF YKL-40 levels, indicating that YKL-40 may be produced by activated macrophages within the central nervous system. In conclusion, high levels of YKL-40 in CSF are found in patients with purulent meningitis.
Cloning and Expression of aHelicobacter bilisImmunoreactive Protein
Authors: Feng Sunlian , Hodzic Emir , Kendall Lon V. , Smith Amy , Freet Kimberly , Barthold Stephen W. 
Published: July 2002

ABSTRACTIn an effort to identify immunoreactiveHelicobacter bilisantigens with potential for serodiagnosis, sera from mice experimentally infected withH. biliswere used to screen anH. bilisgenomic DNA expression library. Among 17 immunoreactive clones, several contained sequences that encoded a predicted 167-kDa protein (P167). Five overlapping P167 peptides (P167A to P167E) of approximately 40 kDa each were generated and tested. Immune sera reacted with fragments P167C and P167D at dilutions of 1:1,600 and 1:6,400, respectively, and reacted with anH. bilismembrane extract at a dilution of 1:800 in an enzyme-linked immunosorbent assay. Sera from mice experimentally infected withH. hepaticusdid not react with P167C and P167D. Sera from mice naturally infected withH. bilisbut not sera from mice naturally infected withH. hepaticusreacted with P167C and P167D. Hyperimmune sera against P167C peptide reacted with recombinant P167C and with a 120-kDa band inH. bilislysates but did not react with a protein of the same size on immunoblots prepared fromH. hepaticus,H. muridarum, or unrelatedBorrelia burgdorferiandCampylobacter jejuniwhole-cell lysates. Nevertheless, the P167A, P167B, P167C, and P167D primers, but not the P167E primers, amplified DNA fromH. hepaticus, and all five primer sets amplified DNA fromH. muridarum. These results suggest that P167 is an immunodominant,H. bilis-specific antigen that may have potential for use in serodiagnosis.
Angiogenic Effects of Extracellular Human Immunodeficiency Virus Type 1 Tat Protein and Its Role in the Pathogenesis of AIDS-Associated Kaposi's Sarcoma
Authors: Barillari Giovanni , Ensoli Barbara 
Published: July 2002

SUMMARYThe Tat protein of human immunodeficiency virus (HIV) type 1 is a transactivator of viral gene expression that is required for virus replication and spread. Moreover, Tat is released by acutely HIV-infected cells via a leaderless secretory pathway and in a biologically active form that exerts effects on both HIV-infected and uninfected cells from different organs and systems. This review focuses on the activities of extracellular Tat protein on endothelial cells, on angiogenesis, and on the pathogenesis of AIDS-associated angioproliferative diseases such as Kaposi's sarcoma. In particular, we discuss results from different groups indicating that Tat mimics the proangiogenic activities of extracellular matrix molecules and that it enhances the effects of angiogenic factors.
Characterization of the Cell Adhesion Site ofTrypanosoma cruziMetacyclic Stage Surface Glycoprotein gp82
Authors: Manque Patricio M. , Eichinger Daniel , Juliano Maria A. , Juliano Luiz , Araya Jorge E. , Yoshida Nobuko 
Published: July 2002

ABSTRACTThe surface glycoprotein gp82, expressed in the insect-stage metacyclic trypomastigotes ofTrypanosoma cruzi, has been implicated in mammalian cell invasion. Here we have characterized the cell adhesion site of gp82 by using recombinant proteins and synthetic peptides based on gp82. The recombinant protein Del-4/8, lacking 65 amino acids of gp82 central domain (at positions 257 to 321), was virtually devoid of cell-binding activity and lacked the ability to inhibit parasite invasion, in contrast to J18, the construct containing the full-length gp82 sequence (amino acids 1 to 516). Constructs with shorter deletions, i.e., Del-4 (deleted from 257 to 271) and Del-8 (deleted from 293 to 321), bound to target cells to a significantly lesser degree than did J18. The sites deleted in recombinant proteins Del-4 and Del-8 contained acidic amino acids critical for cell adhesion. Thus, the cell-binding capacity of protein Del-E/D, lacking the glutamic acid (259/260) and aspartic acid (303/304) pairs, was negligible, as was its capacity to inhibit parasite internalization. Of a set of synthetic peptides spanning the gp82 central domain, a 22-mer hybrid peptide, p4/8, formed by two noncontiguous sequences (at positions 257 to 273 and 302 to 306) and containing the four acidic residues, competed with the binding of J18 protein to target cells and significantly inhibited (∼60%) the penetration of parasites. This peptide, generated by the juxtaposition of sequences that are separated by a hydrophobic stretch in the linear molecule, appears to be mimicking a conformation-dependent cell-binding site of gp82. Experiments of antibody competition with a set of 20-mer overlapping peptides mapped the epitope for 3F6, a monoclonal antibody directed to gp82 that inhibits parasite invasion, to the sequence represented by peptide p3 (244 to 263), which has a partial overlap with the cell adhesion site.