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D L Rudolph

Publications and source records attributed to D L Rudolph.

50 records · Page 3Linked to original sources
PubMed1992

Serologic confirmation of simian T-lymphotropic virus type I infection by using immunoassays developed for human T-lymphotropic virus antibody detection.

Serum specimens from diverse species of Old World monkeys, categorized as seropositive (n = 97) or seronegative (n = 23) for human T-lymphotropic virus (HTLV) infection, were tested by using recombinant env-spiked Western immunoblot assays and synthetic peptide assays for simultaneous detection and discrimination of simian T-lymphotropic virus (STLV) infection. Of the 97 seropositive specimens, 93 reacted with the recombinant transmembrane (r21env) protein and 90 reacted with a recombinant, MTA-1, derived from the central region of the external glycoprotein of HTLV-I (rgp46env), thus yielding test sensitivities of 96 and 93%, respectively. While 1 of the 23 negative monkey specimens reacted with r21env, none reacted with rgp46env, for overall specificities of 96 and 100%, respectively. Analysis of synthetic peptide-based immunoassays demonstrated that while 85 of 97 (88%) seropositive specimens reacted with HTLV-I-specific epitope (p19gag), none of the specimens reacted with HTLV-II-specific epitope (gp52env). These results show that recombinant envelope-spiked Western blots provide a simple means for serologic confirmation of STLV-I infection and that type-specific synthetic peptides can be used to confirm the virus type in seropositive monkey specimens.

Animals↗
PubMed1991

Constitutive expression of c-jun and jun-B in cell lines infected with human T-lymphotropic virus types I and II.

To better understand the transcriptional regulation of human T-lymphotropic viruses, expression of the nuclear proto-oncogenes, jun-B and c-jun were examined in cell lines infected with HTLV-I/II. Constitutive high levels of jun-B and c-jun expression were observed in HTLV-I (MT-2, Hut-102, IR, FS, SP) and HTLV-II infected cell lines (Mo-T, PAN). In contrast, the uninfected cell lines (Jurkat, Hut-78) expressed only basal levels of jun. This expression of jun was not dependent upon IL-2, as both IL-2 dependent (IR, FS, SP, and Pan) and IL-2 independent (MT-2, Hut-102, Mo-T) cell lines constitutively expressed transcripts for jun-B and c-jun. These data demonstrate that deregulated expression of nuclear protooncogenes such as jun may lead to cellular proliferation and the protein products of these nuclear oncogenes may potentially serve as transcriptional activators of HTLV-LTR by complexing with other nuclear proteins.

Blotting, Northern↗
PubMed1991

Constitutive production of interleukin-6 and tumor necrosis factor-alpha from spontaneously proliferating T cells in patients with human T-cell lymphotropic virus type-I/II.

The human T-cell lymphotropic viruses (HTLV) type I and type II are capable of inducing a variety of cellular genes, including many of the cytokines that regulate cell proliferation. To determine if the spontaneous proliferation of peripheral blood mononuclear cells from patients infected with HTLV-I and HTLV-II was related to coordinate expression of cytokines, we analyzed the levels of interleukin-1 beta (IL-1 beta), IL-2, IL-3, IL-4, IL-6, tumor necrosis factor-alpha (TNF-alpha) and interferon-tau (IFN-tau) in culture supernatants derived from spontaneously proliferating cells. Significantly elevated levels of IL-6 and TNF-alpha were present in culture supernatants from HTLV-I/II-infected individuals when compared with normal controls (P less than .01). Kinetic experiments showed that both IL-6 and TNF-alpha were elevated by day 5. None of the other cytokines (IL-1 beta, IL-2, IL-3, IL-4, and IFN-tau) were detectable in any of the culture. These data suggest that release of IL-6 and TNF-alpha may regulate lymphocyte proliferation in HTLV-I/II-infected individuals.

Adult↗
PubMed1991

Serologic discrimination of human T cell lymphotropic virus infection by using a synthetic peptide-based enzyme immunoassay.

Synthetic peptides corresponding with unique regions of the envelope glycoproteins (gp46) of human T cell lymphotropic viruses (HTLVs) were used in an enzyme immunoassay to determine if HTLV-I and -II infections could be discriminated. Two synthetic HTLV-I sequence-derived peptides, Env-1 (amino acids 191-215) and Env-5 (amino acids 242-257), reacted with 92% and 100% of the serum specimens (n = 52) from HTLV-I-infected persons, respectively. Although a small percentage (8.6%) of serum specimens from persons infected with HTLV-II cross-reacted with Env-1, none of these specimens reacted with Env-5. Peptide Env-2 encoded by the envelope region of HTLV-II (amino acids 187-210) reacted with serum specimens from both HTLV-I (94%)- and HTLV-II (74%)-infected patients, whereas Env-6, another HTLV-II peptide (amino acids 238-254), reacted with less than 6% of the specimens. Therefore, the Env-5 peptide with amino acid sequence SerProAsnValSerValProSerSerSerSerThrProLeuLeuTyr represents an immunodominant domain of HTLV-I that is recognized by serum antibodies from all HTLV-I-infected persons. Moreover, the Env-5-based ELISA allows a categorical distinction between the closely related HTLV-I and -II infections.

Amino Acid Sequence↗
PubMed1991

A synthetic peptide elicits antibodies reactive with the external glycoprotein of human T cell lymphotropic virus type I.

A synthetic peptide derived from the external glycoprotein of human T cell lymphotropic virus type I (HTLV-I) (Env-5; amino acids 242 to 256) reacted with IgG antibodies in serum specimens from HTLV-I-infected individuals. C-terminal residues of Env-5 were crucial for the antibody reactivity. Polyclonal rabbit antibodies to Env-5 did not inhibit syncytium formation but such antibodies reacted specifically with gp68env and gp46env glycoproteins of HTLV-I in an immunoblot analysis. Immunoprecipitation of the surface-labelled MT-2 (HTLV-I-infected) cell line with anti-Env-5 precipitated the gp68env precursor protein. It was concluded that peptide Env-5 mimics a surface-exposed epitope on the HTLV-I external glycoprotein.

Amino Acid Sequence↗
PubMed1991

Synthetic peptide-based immunoassays for distinguishing between human T-cell lymphotropic virus type I and type II infections in seropositive individuals.

Until now, serologic tests that distinguish the closely related human T-cell lymphotropic virus types I (HTLV-I) and II (HTLV-II) infections have not been available. Synthetic peptide assays, employing peptides derived from the core and envelope proteins of HTLV-I and HTLV-II (SynthEIA and Select-HTLV tests), were evaluated for the ability to serologically discriminate HTLV-I and HTLV-II infections. Of 32 HTLV-I- and 57 HTLV-II-positive serum specimens from individuals whose infections were confirmed by polymerase chain reaction, the SynthEIA test categorized 29 (91%) as HTLV-I and 50 (88%) as HTLV-II, and 10 (11%) were nontypeable. In contrast, the Select-HTLV test categorized 32 (100%) as HTLV-I and 55 (96%) as HTLV-II, and 2 (2%) were nontypeable. The specificity of both the assays in seropositive serum specimens was 100% in that none of the specimens were incorrectly classified. Additional serum specimens obtained from clinically diseased patients from the United States (n = 8) and asymptomatic carriers and patients from Japan (an endemic population for HTLV-I; n = 40) were categorized as HTLV-I by at least one of the assays, while serum specimens from Guaymi Indians from Panama (an endemic population for HTLV-II; n = 13) were categorized as HTLV-II. Thus, peptide enzyme immunoassays appear to represent a simple technique employing chemically synthesized antigens for discrimination between antibodies of HTLV-I and HTLV-II.

Antibodies, Viral↗
PubMed1991

Characterization of immunodominant epitopes of gag and pol gene-encoded proteins of human T-cell lymphotropic virus type I.

A series of synthetic peptides derived from the corresponding regions of the gag, pol, and env proteins of human T-cell lymphotropic virus types I (HTLV-I) and II (HTLV-II) were used in an enzyme immunoassay to map the immunodominant epitopes of HTLV. Serum specimens from 79 of 87 (91%) HTLV-I-infected patients reacted with the synthetic peptide Gag-1a (amino acids [a.a.] 102 to 117) derived from the C terminus of the p19gag protein of HTLV-I. Minimal cross-reactivity (11%) was observed with serum specimens from HTLV-II-infected patients. Peptide Pol-3, encoded by the pol region of HTLV-I (a.a. 487 to 502), reacted with serum specimens from both HTLV-I- and HTLV-II-infected patients (94 and 86%, respectively). The antibody levels to Pol-3 were significantly higher (P less than 0.01) in patients with HTLV-I-associated myelopathy/tropical spastic paraparesis than in either adult T-cell leukemia patients or HTLV-I-positive asymptomatic carriers. None of the other peptides studied demonstrated significant binding to serum specimens obtained from HTLV-I- or HTLV-II-infected individuals. While Gag-1a did not react with serum specimens from normal controls, Pol-3 demonstrated some reaction with specimens from seronegative individuals (11.4%). The antibodies to Gag-1a and Pol-3 in serum specimens from HTLV-I-infected patients could be specifically inhibited by the corresponding synthetic peptides and by a crude HTLV-I antigen preparation, indicating that these peptides mimic native epitopes present in HTLV-I proteins that are recognized by serum antibodies from HTLV-I- and -II-infected individuals.

Amino Acid Sequence↗
PubMedDate not supplied

Antibody responses to the env epitopes of human T-lymphotropic virus type I in rhesus macaques' naturally infected with simian T-lymphotropic virus type I.

Synthetic peptides derived from the env protein of human T-lymphotropic virus type I (HTLV-I) were used to identify the immunodominant motifs in rhesus macaques naturally infected with simian T-lymphotropic virus type I (STLV-I). Of the 13 peptides derived from the env protein of HTLV-I, Env-1(191-214) and Env-5(242-257) reacted with 81% (44/54) and 54% (29/54) of specimens from infected monkeys, respectively. A recombinant protein (MTA-I162-209) reacted with 53 of 54 (98%) STLV-I-infected serum specimens. While similar immune reactivities to Env-1 and MTA-1 were observed in both HTLV-I-infected human sera and STLV-I-infected monkey sera, the reactivity to Env-5 was significantly higher in HTLV-I-infected human sera. Differential reactivities may be attributed to the differences in the secondary structures of the STLV-I and HTLV-I envelope protein in the Env-5 region, since homologous peptide with STLV-I sequence did not result in enhanced sensitivity of anti-Env-5 antibody detection.

Amino Acid Sequence↗
PubMedDate not supplied

Numerical investigation of road salt impact on an urban wellfield.

The impact of road salt on a wellfield in a complex glacial moraine aquifer system is studied by numerical simulation. The moraine underlies an extensive urban and industrial landscape, which draws its water supply from >20 wellfields, several of which are approaching or have exceeded the drinking water limit for chloride. The study investigates the mechanisms of road salt infiltration, storage, and transport in the subsurface and assesses the effectiveness of mitigation measures designed to reduce the impact. The three-dimensional transport model accounts for increases in salt loading, as well as growth of the urbanized area and road network over the past 50 years. The simulations, which focus on one impacted wellfield, show chloride plumes originating mainly at arterial roads and migrating through aquitard windows into the water supply aquifers. The results suggest that the aquifer system contains a large and heterogeneously distributed mass of chloride and that concentrations in the aquifer can be substantially higher than the concentrations in the well water. Future impact scenarios indicate that although the system responds rapidly to reductions in salt loading, the residual chloride mass may take decades to flush out, even if road salting were discontinued. The implications with respect to urban wellfields in typical snow-belt areas are discussed.

Chlorides↗
PubMedDate not supplied

Well vulnerability: a quantitative approach for source water protection.

The concept of vulnerability of drinking water sources is reviewed, and a quantitative approach for assessing well vulnerability for complex three-dimensional ground water systems is developed. The approach focuses on the relative expected impact of potential contaminant sources at unknown locations within a well capture zone, providing relative measures of intrinsic well vulnerability, including the expected times of arrival of a contaminant, the dispersion-related reduction in concentration, the time taken to breach a certain quality objective, and the corresponding exposure times. Thus, the result of the analysis includes the usual advective travel time information used in conventional wellhead protection analysis, plus a set of selected quantitative measures expressing the expected impact. The technique is based on adjoint theory and combines forward- and backward-in-time transport modeling using a standard numerical flow and transport code. The methodology is demonstrated using the case study of a complex glacial multiaquifer system in Ontario. The new approach will be useful in helping water managers develop more physically based and quantitative wellhead protection strategies.

Computer Simulation↗
PubMedDate not supplied

Contrasting nitrate adsorption in Andisols of two coffee plantations in Costa Rica.

Fertilizer use in coffee plantations is a suspected cause of rising ground water nitrate concentrations in the ground water-dependent Central Valley of Costa Rica. Nitrate adsorption was evaluated beneath two coffee (Coffea arabica L.) plantations in the Central Valley. Previous work at one site had identified unsaturated zone nitrate retardation relative to a tritium tracer. Differences in nitrate adsorption were assessed in cores to 4 m depth in Andisols at this and one other plantation using differences in KCl- and water-extractable nitrate as an index. Significant adsorption was confirmed at the site of the previous tracer test, but not at the second site. Anion exchange capacity, X-ray diffraction data, extractable Al and Si, and soil pH in NaF corroborated that differences in adsorption characteristics were related to subtle differences in clay mineralogy. Soils at the site with significant nitrate adsorption showed an Al-rich allophane clay content compared with a more weathered, Si-rich allophane and halloysite clay mineral content at the site with negligible adsorption. At the site with significant nitrate adsorption, nitrate occupied less than 10% of the total anion adsorption capacity, suggesting that adsorption may provide long-term potential for mitigation or delay of nitrate leaching. Evaluation of nitrate sorption potential of soil at local and landscape scales would be useful in development of nitrogen management practices to reduce nitrate leaching to ground water.

Adsorption↗