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  1. Article: Assessment of Two Rapid Assays for Diagnostic Capability to Accurately Identify Infection by Treponema pallidum.

    Constantine, Niel T / Sill, Anne M / Gudesblat, Elizabeth / Paulus, Samantha / Saleh, Ahmed

    The journal of applied laboratory medicine

    2021  Volume 1, Issue 4, Page(s) 346–356

    Abstract: Background: Rapid, point-of-care tests that accurately identify syphilis are gaining popularity and offer several advantages over classic tests.: Methods: The SD Bioline Syphilis 3.0 and the Chembio DPP Syphilis Screen and Confirm Assay (CB) were ... ...

    Abstract Background: Rapid, point-of-care tests that accurately identify syphilis are gaining popularity and offer several advantages over classic tests.
    Methods: The SD Bioline Syphilis 3.0 and the Chembio DPP Syphilis Screen and Confirm Assay (CB) were assessed using 1283 samples that had been characterized by reference tests. The challenge samples included 5 commercial panels (seroconversion, mixed-titer), archived samples, fresh samples, and a dilution series. Both tests detect specific anti-treponemal antibodies, and the CB additionally detects antibodies to a non-treponemal (NT) component. The evaluation was used to determine performance indices and compare with those cited by the manufacturers.
    Results: When assessing reactivity to treponemal, the sensitivities for the 2 tests were 98.3% and 93.2%, with specificities of 100% and 99.4%, respectively. For both tests, precision, whole blood testing, and high-temperature testing produced perfect results, and there were no invalid results. Comparisons of 2 different lots of each test indicated excellent concordance (100% and 99.5%), and reproducibility was 100% and 98.0%, respectively. For the CB, the sensitivity for the NT component was between 65.3% and 80.9%, but increased to 98.5% with samples having a rapid plasma regain (RPR) titer of ≥8. The specificity for NT was found to be 100%, and the reading of results visually and when using a battery-operated reader indicated a concordance for all challenges of 95%-100%.
    Conclusions: Both rapid tests produced impressive results for the detection of antibodies to treponemal for all challenges and exceeded, met, or closely approached the performance characteristics as cited by the manufacturers.
    Language English
    Publishing date 2021-01-26
    Publishing country England
    Document type Journal Article
    ISSN 2576-9456
    ISSN 2576-9456
    DOI 10.1373/jalm.2016.021402
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Book ; Thesis: THE USE OF MONOCLONAL-HYBRIDOMA ANTIBODIES FOR VISUALIZING AND STUDYING THE ANTIGENS OF LEISHMANIA BRAZILIENSIS

    Constantine, Niel T.

    1981  

    Title variant USE OF MONOCLONAL-HYBRIDOMA ANTIBODIES FOR VISUALIZING AND STUDYING THE ANTIGENS OF LEISHMANIA BRAZILIENSIS
    Author's details BY NIEL THEODORE CONSTANTINE
    Size VIII, 198 P.
    Document type Book ; Thesis
    Thesis / German Habilitation thesis BALTIMORE, UNIV. OF MARYLAND, DISS., 1981
    HBZ-ID HT002708774
    Database Catalogue ZB MED Medicine, Health

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  3. Book: Retroviral testing

    Constantine, Niel T. / Callahan, Johnny D. / Watts, Douglas M.

    essentials for quality control and laboratory diagnosis

    1992  

    Author's details Niel T. Constantine ; Johnny D. Callahan ; Douglas M. Watts
    Keywords AIDS Serodiagnosis / methods ; HIV Infections / diagnosis ; Quality Control ; Retroviridae Infections / diagnosis ; Aids ; Serodiagnostik ; Retroviren
    Subject Acquired immune deficiency syndrome ; Erworbenes Immundefektsyndrom ; Serologische Diagnostik ; Serologische Untersuchung ; Serumdiagnostik ; Immundiagnostik ; Immunodiagnostik ; Leukoviren ; Retroviridae
    Size 228 S. : Ill., graph. Darst.
    Publisher CRC Pr
    Publishing place Boca Raton u.a.
    Publishing country United States
    Document type Book
    Old title Frühere Ausg. u.d.T. HIV testing & quality control
    HBZ-ID HT004371420
    ISBN 0-8493-4429-8 ; 978-0-8493-4429-9
    Database Catalogue ZB MED Medicine, Health

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  4. Article ; Online: Decreasing Tryptophan and Increasing Neopterin Plasma Levels During Pregnancy are Associated with High First Trimester

    Postolache, Teodor T / Upadhyaya, Sanjaya K / Spector, Anna M / Mohyuddin, Iqra / Constantine, Niel / Ernst, Robert K / Wadhawan, Abhishek / Dutra, Samia Valeria Ozorio / Dagdag, Aline / Makkar, Hina / Lowry, Christopher A / Akram, Faisal / Fuchs, Dietmar / Brenner, Lisa A / Groer, Maureen W / Reynolds, Mark A

    Current topics in medicinal chemistry

    2022  Volume 22, Issue 25, Page(s) 2126–2144

    Abstract: Background: Immune activation or high levels of stress may lead to increased metabolism of tryptophan during pregnancy. Porphyromonas gingivalis (Pg), the "keystone" periodontal pathogen, induces immune and indoleamine 2,3-dioxygenase (IDO) activation. ... ...

    Abstract Background: Immune activation or high levels of stress may lead to increased metabolism of tryptophan during pregnancy. Porphyromonas gingivalis (Pg), the "keystone" periodontal pathogen, induces immune and indoleamine 2,3-dioxygenase (IDO) activation. Thus, we hypothesized that larger gestational decreases in tryptophan and elevations in neopterin and kynurenine would occur in pregnant women with elevated IgG antibodies to Pg capsular (K) serotypes.
    Methods: Venous blood of 52 Hispanic pregnant women with a mean age (SD) of 31.8 (5.9) years was sampled once per trimester of pregnancy (V1, V2, V3), and plasma was obtained and stored. ELISAs were used to measure Pg capsular (K) serotype IgG serointensity (V1 only) and neopterin levels (V1-V3). Tryptophan and kynurenine (V1-V3) were measured with high-performance liquid chromatography. The participants having IgG serointensity for any of the seven Pg K serotypes in the highest quartile were defined as the "High PgK_IgG" group and those having IgG serointensity for all K serotypes in the lowest three quartiles were defined as the "Low PgK_IgG" group. Statistics included multivariable linear and nonparametric methods.
    Results: Significant decreases in plasma tryptophan levels and increases in neopterin during gestation were found in "High PgK_IgG" women but not in "Low PgK_IgG" women. Kynurenine changes were not significantly different between the two groups.
    Conclusion: If replicated in larger studies and further characterized clinically, radiologically, and microbiologically, our results may potentially lead to novel interventional targets, as well as the development of more complete prognostic and predictive interactive biomarkers for adverse obstetrical outcomes and peripartum depression, and their prevention.
    MeSH term(s) Pregnancy ; Female ; Humans ; Adult ; Neopterin ; Tryptophan ; Pregnancy Trimester, First ; Porphyromonas gingivalis ; Immunoglobulin G
    Chemical Substances Neopterin (670-65-5) ; Tryptophan (8DUH1N11BX) ; Immunoglobulin G
    Language English
    Publishing date 2022-04-13
    Publishing country United Arab Emirates
    Document type Journal Article
    ZDB-ID 2064823-6
    ISSN 1873-4294 ; 1568-0266
    ISSN (online) 1873-4294
    ISSN 1568-0266
    DOI 10.2174/1568026622666220404115543
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Toxoplasma gondii IgG Serointensity Is Positively Associated With Frailty.

    Mohyuddin, Hira / Laffon, Blanca / Teixeira, João P / Costa, Solange / Teixeira-Gomes, Armanda / Pásaro, Eduardo / Constantine, Niel / Dagdag, Aline / Ortmeyer, Heidi K / Tizenberg, Boris / Afram, Liubov / Yen, Poyu / Marano, Christopher / Lowry, Christopher A / Hoisington, Andrew J / RachBeisel, Jill A / Valdiglesias, Vanessa / Lema-Arranz, Carlota / Fernández-Bertólez, Natalia /
    Maseda, Ana / Millán-Calenti, José C / Kovacs, Elizabeth J / Gostner, Johanna M / Fuchs, Dietmar / Brenner, Lisa A / Lorenzo-López, Laura / Postolache, Teodor T

    The journals of gerontology. Series A, Biological sciences and medical sciences

    2023  Volume 79, Issue 3

    Abstract: ... T. gondii), a common parasite causing an oligosymptomatic unremitting infection, and frailty, and ... secondarily between T. gondii and previously reported markers of immune activation in frailty.: Methods ... age: mean (SD) 77.3 (8.0); 61% women]. Plasma T. gondii immunoglobulin G (IgG) serointensity was ...

    Abstract Background: Persistent inflammation related to aging ("inflammaging") is exacerbated by chronic infections and contributes to frailty in older adults. We hypothesized associations between Toxoplasma gondii (T. gondii), a common parasite causing an oligosymptomatic unremitting infection, and frailty, and secondarily between T. gondii and previously reported markers of immune activation in frailty.
    Methods: We analyzed available demographic, social, and clinical data in Spanish and Portuguese older adults [N = 601; age: mean (SD) 77.3 (8.0); 61% women]. Plasma T. gondii immunoglobulin G (IgG) serointensity was measured with an enzyme-linked immunosorbent assay. The Fried criteria were used to define frailty status. Validated translations of Mini-Mental State Examination, Geriatric Depression Scale, and the Charlson Comorbidity Index were used to evaluate confounders. Previously analyzed biomarkers that were significantly associated with frailty in both prior reports and the current study, and also related to T. gondii serointensity, were further accounted for in multivariable logistic models with frailty as outcome.
    Results: In T. gondii-seropositives, there was a significant positive association between T. gondii IgG serointensity and frailty, accounting for age (p = .0002), and resisting adjustment for multiple successive confounders. Among biomarkers linked with frailty, kynurenine/tryptophan and soluble tumor necrosis factor receptor II were positively associated with T. gondii serointensity in seropositives (p < .05). Associations with other biomarkers were not significant.
    Conclusions: This first reported association between T. gondii and frailty is limited by a cross-sectional design and warrants replication. While certain biomarkers of inflammaging were associated with both T. gondii IgG serointensity and frailty, they did not fully mediate the T. gondii-frailty association.
    MeSH term(s) Humans ; Female ; Aged ; Male ; Toxoplasma ; Toxoplasmosis ; Frailty ; Cross-Sectional Studies ; Immunoglobulin G ; Antibodies, Protozoan ; Biomarkers ; Immunoglobulin M ; Risk Factors
    Chemical Substances Immunoglobulin G ; Antibodies, Protozoan ; Biomarkers ; Immunoglobulin M
    Language English
    Publishing date 2023-11-15
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1223643-3
    ISSN 1758-535X ; 1079-5006
    ISSN (online) 1758-535X
    ISSN 1079-5006
    DOI 10.1093/gerona/glad228
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: HIV testing technologies after two decades of evolution.

    Constantine, Niel T / Zink, Holly

    The Indian journal of medical research

    2005  Volume 121, Issue 4, Page(s) 519–538

    Abstract: Over the past two decades, HIV diagnostics have been essential in detecting and monitoring infection, and continue to play a major role in saving lives throughout the world. As technology evolved, screening, confirmatory, and HIV monitoring assays have ... ...

    Abstract Over the past two decades, HIV diagnostics have been essential in detecting and monitoring infection, and continue to play a major role in saving lives throughout the world. As technology evolved, screening, confirmatory, and HIV monitoring assays have been improved and offer better alternatives to address blood screening, surveillance, diagnosis, and patient management. Molecular methods are critical in detecting early infection and for managing patients on anti retroviral therapy whose viral infection may become resistant to therapy. In addition, modifications to conventional methods have introduced new assays, such as sensitive/less sensitive (detuned) assays that can estimate when someone was infected, thereby providing a useful tool for epidemiologic incidence estimates and enrollment into specific intervention programmes for recently infected persons. Many of the newly evolving technologies are essential for use in resource-limited countries because they can address cost issues, limited infrastructure, and a lack of formally trained personnel. Newer rapid HIV kits can be stored in a wide range of temperatures (2-30 degrees C) to address cold-chain issues, can use easily-collected fingerstick blood and oral fluids, and have one-step procedures that are relatively foolproof. Manual CD4 lymphocyte count assays that require only a light microscope and haemacytometer and more simple assays to estimate viral load are appropriate for developing countries where sophisticated instrumentation cannot be supported. Technologic advances with HIV diagnostics continue to address outstanding and new issues associated with diagnosis and the monitoring of infection by providing more simplified, cost-effective, and accurate testing throughout the world.
    MeSH term(s) AIDS Serodiagnosis/methods ; Blotting, Western ; Branched DNA Signal Amplification Assay ; Enzyme-Linked Immunosorbent Assay ; HIV Infections/diagnosis ; Humans ; Polymerase Chain Reaction ; RNA, Viral/blood
    Chemical Substances RNA, Viral
    Language English
    Publishing date 2005-04
    Publishing country India
    Document type Journal Article ; Review
    ZDB-ID 390883-5
    ISSN 0971-5916 ; 0019-5340
    ISSN 0971-5916 ; 0019-5340
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Immunomagnetic quantitative immuno-PCR for detection of less than one HIV-1 virion.

    Barletta, Janet / Bartolome, Amelita / Constantine, Niel T

    Journal of virological methods

    2009  Volume 157, Issue 2, Page(s) 122–132

    Abstract: Methods that allow the accurate and reliable detection of ultra-low molecular levels of proteins using techniques such as quantitative immuno-PCR (qIPCR) have demonstrated numerous technical difficulties. Protein detection methods lose specificity when ... ...

    Abstract Methods that allow the accurate and reliable detection of ultra-low molecular levels of proteins using techniques such as quantitative immuno-PCR (qIPCR) have demonstrated numerous technical difficulties. Protein detection methods lose specificity when the protein target is immersed within a matrix of thousands of molecules having wide ranges of concentrations. In addition, sensitivities are limited because of high background signals. To validate the performance of an immunomagnetic bead qIPCR method designed to remove the 'matrix' effect for HIV-1 p24 antigen detection, regression analyses were performed using samples from patients infected with HIV-1 diluted to approximately 100-1000, 10-100, 1-10, and 0.1-1.0 HIV-1 p24 Ag molecules/reaction. The number of HIV-1 p24 Ag molecules was derived from quantified HIV-1 RNA determinations. The modified immunomagnetic qIPCR bead assay demonstrated a limit of quantification of 10-100 HIV-1 p24 molecules per reaction, with an average correlation coefficient of 0.948+/-0.028 over a 4-log dynamic range. This method detects less than one HIV-1 virion (a limit of detection unreported previously for HIV-1), and thus, has the potential to identify HIV-1 infection and monitor the dynamics of the disease course earlier than nucleic acid methods. The immunomagnetic qIPCR bead assay is a simple and inexpensive method for ultra-low protein detection of infectious agents, toxins, and cancer markers at a level unrecognized previously using any enzymatic or molecular method.
    MeSH term(s) HIV Core Protein p24/immunology ; HIV Core Protein p24/isolation & purification ; HIV-1/immunology ; HIV-1/isolation & purification ; Humans ; Immunomagnetic Separation/methods ; Polymerase Chain Reaction/methods ; Sensitivity and Specificity ; Virion/immunology ; Virion/isolation & purification
    Chemical Substances HIV Core Protein p24 ; p24 protein, Human Immunodeficiency Virus Type 1
    Language English
    Publishing date 2009-05
    Publishing country Netherlands
    Document type Journal Article ; Validation Studies
    ZDB-ID 8013-5
    ISSN 1879-0984 ; 0166-0934
    ISSN (online) 1879-0984
    ISSN 0166-0934
    DOI 10.1016/j.jviromet.2008.12.013
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article: Rapid confirmation of HIV infection.

    Constantine, Niel T / Ketema, Fassil

    International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases

    2003  Volume 6, Issue 3, Page(s) 170–177

    Abstract: Objective: To investigate the utility of a prototype rapid confirmatory HIV assay which offers specific results in 5 min and has applications in a variety of important testing situations.: Methods: The performance of the rapid confirmatory assay was ... ...

    Abstract Objective: To investigate the utility of a prototype rapid confirmatory HIV assay which offers specific results in 5 min and has applications in a variety of important testing situations.
    Methods: The performance of the rapid confirmatory assay was assessed with 849 blood samples, including serum, plasma, venipuncture whole blood, and peripheral blood collected via fingerstick. Included were over 700 HIV Western blot (WB)-confirmed antibody positive sera, and others which were classified as negative or indeterminate by WB. The analytic sensitivity of the rapid confirmatory assay was assessed using 13 HIV-1 seroconversion panels, and all results were compared to those of an FDA-licensed WB reference test.
    Results: The rapid test exhibited 100% concordance with the reference test when testing HIV-1 WB-confirmed positive samples, and 92.3% concordance with samples having WB-inconclusive results. The sensitivity for confirming recent seroconversion was as good, or better than, the FDA-licensed HIV-1 WB in 10/13 panels. The rapid assay performed accurately with whole blood collected from fingerstick, and exhibited excellent precision and reproducibility.
    Conclusion: We conclude that this rapid HIV confirmatory assay, the first of its kind, demonstrates proof of principle for the accurate confirmation of HIV-1 infection and offers important advantages in public health and clinical testing venues.
    MeSH term(s) AIDS Serodiagnosis ; Blotting, Western ; HIV Antibodies/blood ; HIV Antigens/immunology ; HIV Infections/diagnosis ; HIV Infections/virology ; HIV-1/immunology ; Humans ; Reagent Kits, Diagnostic ; Reference Standards ; Sensitivity and Specificity ; Time Factors
    Chemical Substances HIV Antibodies ; HIV Antigens ; Reagent Kits, Diagnostic
    Language English
    Publishing date 2003-04-08
    Publishing country Canada
    Document type Comparative Study ; Evaluation Studies ; Journal Article
    ZDB-ID 1331197-9
    ISSN 1878-3511 ; 1201-9712
    ISSN (online) 1878-3511
    ISSN 1201-9712
    DOI 10.1016/s1201-9712(02)90106-2
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Demographic profiles of newly acquired HIV infections among adolescents and young adults in the U.S.

    Sill, Anne M / Constantine, Niel T / Wilson, Craig M / Peralta, Ligia

    The Journal of adolescent health : official publication of the Society for Adolescent Medicine

    2009  Volume 46, Issue 1, Page(s) 93–96

    Abstract: Understanding the demographic and risk profiles of youth with recent HIV infection offers insight for imputing the dynamics of the epidemic and targeting prevention efforts. Three hundred forty-two HIV-positive youth were tested using a Sensitive/Less ... ...

    Abstract Understanding the demographic and risk profiles of youth with recent HIV infection offers insight for imputing the dynamics of the epidemic and targeting prevention efforts. Three hundred forty-two HIV-positive youth were tested using a Sensitive/Less Sensitive strategy; 33% were classified as recently infected; with the majority (51%) occurring within African Americans.
    MeSH term(s) Adolescent ; Demography ; Female ; HIV Seropositivity/epidemiology ; HIV Seropositivity/ethnology ; HIV Seroprevalence/trends ; HIV-1/immunology ; HIV-1/isolation & purification ; Humans ; Incidence ; Male ; United States/epidemiology ; Young Adult
    Language English
    Publishing date 2009-07-08
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 1063374-1
    ISSN 1879-1972 ; 1054-139X
    ISSN (online) 1879-1972
    ISSN 1054-139X
    DOI 10.1016/j.jadohealth.2009.05.003
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: Update on the laboratory diagnosis and monitoring of HIV infection.

    Constantine, Niel T / Kabat, William / Zhao, Richard Y

    Cell research

    2005  Volume 15, Issue 11-12, Page(s) 870–876

    Abstract: In China, the estimated number of HIV infected cases is approaching one million. Although public education has been initiated for awareness and behavioral modification for this devastating infection, better diagnostic methods are needed to identify ... ...

    Abstract In China, the estimated number of HIV infected cases is approaching one million. Although public education has been initiated for awareness and behavioral modification for this devastating infection, better diagnostic methods are needed to identify infected persons and manage infection. Simple and more accurate diagnostic tools have become available, particularly for early detection and to monitor treatment in those who receive anti-retroviral treatment. In this short review, we summarize some of the common and new methodologies that can be used in clinical laboratories, in the field, or in private laboratories. These range from simple antibody tests to more sophistical methods that are used to monitor disease progression and identify drug resistance. These tools can assist physicians, medical practitioners, and laboratory personnel to select suitable diagnostic tools for the diagnosis, blood screening, monitoring of disease progression, and for detection of drug resistance to anti-retroviral therapies.
    MeSH term(s) HIV ; HIV Infections/blood ; HIV Infections/diagnosis ; Humans
    Language English
    Publishing date 2005-11
    Publishing country England
    Document type Journal Article ; Review
    ZDB-ID 1319303-x
    ISSN 1748-7838 ; 1001-0602
    ISSN (online) 1748-7838
    ISSN 1001-0602
    DOI 10.1038/sj.cr.7290361
    Database MEDical Literature Analysis and Retrieval System OnLINE

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