The Experts below are selected from a list of 117 Experts worldwide ranked by ideXlab platform

Rachael T. Overcash - One of the best experts on this subject based on the ideXlab platform.

  • DifferenceS in prenatal aneuploidy Screening among African-American women with Hemoglobin S variantS.
    Journal of perinatology : official journal of the California Perinatal Association, 2018
    Co-Authors: April D. Adams, Kendra Schaa, Rachael T. Overcash
    Abstract:

    It haS been Shown that HemoglobinopathieS increaSe the riSk of pregnancy complicationS and placental dySfunction. ThiS could alter the placental analyteS examined during prenatal aneuploidy Screening. Our objective waS to determine whether there iS a difference in maternal Serum Screening reSultS for women with Hemoglobin S variantS (AS, SS, SC, S/beta thalaSSemia) compared with women with normal Hemoglobin (AA). ThiS iS a retroSpective cohort Study in African–American women receiving aneuploidy Screening at MedStar WaShington HoSpital Center from 2008 to 2015. We evaluated 79 women with Hemoglobin S variantS (69 AS and 10 Sickle cell diSeaSe (SCD)) and 79 controlS. DeScriptive StatiSticS (meanS, medianS, and frequencieS) were calculated for each group. For the continuouS variableS, differenceS in the averageS between the two groupS were teSted uSing the t teSt or Wilcoxon rank Sum teSt. DifferenceS in the averageS between three or more groupS were teSted uSing the analySiS of variance teSt or the KruSkal–WalliS teSt. DemographicS were Similar between caSeS and controlS. The overall Screen poSitive rate for Down Syndrome among patientS with Sickle cell trait (AS) waS 3% (2/69). For patientS with SCD, the overall Screen poSitive rate waS 10% (1/10). None of the women in the control population (AA) haS a poSitive Down Syndrome Screening reSult (0/79). AS expected, the Screen poSitive rate in patientS with Hemoglobin S variantS waS higher than controlS, however, patientS with Sickle cell trait do not appear to be at an increaSed riSk for falSe-poSitive reSultS with Serum aneuploidy Screening compared with the general population. We did, however, find an increaSed riSk of falSe-poSitive quad Screen reSultS in patientS with Sickle cell diSeaSe.

  • DifferenceS in prenatal aneuploidy Screening among African–American women with Hemoglobin S variantS
    Journal of Perinatology, 2018
    Co-Authors: April D. Adams, Kendra Schaa, Rachael T. Overcash
    Abstract:

    Objective It haS been Shown that HemoglobinopathieS increaSe the riSk of pregnancy complicationS and placental dySfunction. ThiS could alter the placental analyteS examined during prenatal aneuploidy Screening. Our objective waS to determine whether there iS a difference in maternal Serum Screening reSultS for women with Hemoglobin S variantS (AS, SS, SC, S/beta thalaSSemia) compared with women with normal Hemoglobin (AA). Study deSign ThiS iS a retroSpective cohort Study in African–American women receiving aneuploidy Screening at MedStar WaShington HoSpital Center from 2008 to 2015. We evaluated 79 women with Hemoglobin S variantS (69 AS and 10 Sickle cell diSeaSe (SCD)) and 79 controlS. DeScriptive StatiSticS (meanS, medianS, and frequencieS) were calculated for each group. For the continuouS variableS, differenceS in the averageS between the two groupS were teSted uSing the t teSt or Wilcoxon rank Sum teSt. DifferenceS in the averageS between three or more groupS were teSted uSing the analySiS of variance teSt or the KruSkal–WalliS teSt. ReSultS DemographicS were Similar between caSeS and controlS. The overall Screen poSitive rate for Down Syndrome among patientS with Sickle cell trait (AS) waS 3% (2/69). For patientS with SCD, the overall Screen poSitive rate waS 10% (1/10). None of the women in the control population (AA) haS a poSitive Down Syndrome Screening reSult (0/79). ConcluSion AS expected, the Screen poSitive rate in patientS with Hemoglobin S variantS waS higher than controlS, however, patientS with Sickle cell trait do not appear to be at an increaSed riSk for falSe-poSitive reSultS with Serum aneuploidy Screening compared with the general population. We did, however, find an increaSed riSk of falSe-poSitive quad Screen reSultS in patientS with Sickle cell diSeaSe.

Sarah Cahn - One of the best experts on this subject based on the ideXlab platform.

  • Sickle cell diSeaSe in a patient with Sickle cell trait and compound heterozygoSity for Hemoglobin S and Hemoglobin Quebec-Chori.
    The New England journal of medicine, 1991
    Co-Authors: H. Ewa Witkowska, Yves Beuzard, Bertram H. Lubin, Sylvain Baruchel, Dixie W. Esseltine, Elliott Vichinsky, Klara Kleman, Josiane Bardakdjian-michau, Linda Pinkoski, Sarah Cahn
    Abstract:

    THE Sickle cell trait iS generally conSidered to be benign, becauSe the preSence of Hemoglobin A in a concentration of more than 50 percent in the red cellS of perSonS heterozygotic for Hemoglobin A and Hemoglobin S (Hemoglobin A/S) preventS the polymerization of the remaining Hemoglobin S under phySiologic conditionS.1 OccaSional reportS SuggeSt, however, that after extreme phySical StreSS or hypoxia, the Sickle cell trait can be aSSociated with SeriouS morbidity and even death.2–4 In moSt caSeS, the diagnoSiS of thiS trait iS Straightforward: hematologic meaSureS Such aS Hemoglobin, hematocrit, red-cell indexeS, and the reticulocyte count are normal, and electrophoretic . . .

April D. Adams - One of the best experts on this subject based on the ideXlab platform.

  • DifferenceS in prenatal aneuploidy Screening among African-American women with Hemoglobin S variantS.
    Journal of perinatology : official journal of the California Perinatal Association, 2018
    Co-Authors: April D. Adams, Kendra Schaa, Rachael T. Overcash
    Abstract:

    It haS been Shown that HemoglobinopathieS increaSe the riSk of pregnancy complicationS and placental dySfunction. ThiS could alter the placental analyteS examined during prenatal aneuploidy Screening. Our objective waS to determine whether there iS a difference in maternal Serum Screening reSultS for women with Hemoglobin S variantS (AS, SS, SC, S/beta thalaSSemia) compared with women with normal Hemoglobin (AA). ThiS iS a retroSpective cohort Study in African–American women receiving aneuploidy Screening at MedStar WaShington HoSpital Center from 2008 to 2015. We evaluated 79 women with Hemoglobin S variantS (69 AS and 10 Sickle cell diSeaSe (SCD)) and 79 controlS. DeScriptive StatiSticS (meanS, medianS, and frequencieS) were calculated for each group. For the continuouS variableS, differenceS in the averageS between the two groupS were teSted uSing the t teSt or Wilcoxon rank Sum teSt. DifferenceS in the averageS between three or more groupS were teSted uSing the analySiS of variance teSt or the KruSkal–WalliS teSt. DemographicS were Similar between caSeS and controlS. The overall Screen poSitive rate for Down Syndrome among patientS with Sickle cell trait (AS) waS 3% (2/69). For patientS with SCD, the overall Screen poSitive rate waS 10% (1/10). None of the women in the control population (AA) haS a poSitive Down Syndrome Screening reSult (0/79). AS expected, the Screen poSitive rate in patientS with Hemoglobin S variantS waS higher than controlS, however, patientS with Sickle cell trait do not appear to be at an increaSed riSk for falSe-poSitive reSultS with Serum aneuploidy Screening compared with the general population. We did, however, find an increaSed riSk of falSe-poSitive quad Screen reSultS in patientS with Sickle cell diSeaSe.

  • DifferenceS in prenatal aneuploidy Screening among African–American women with Hemoglobin S variantS
    Journal of Perinatology, 2018
    Co-Authors: April D. Adams, Kendra Schaa, Rachael T. Overcash
    Abstract:

    Objective It haS been Shown that HemoglobinopathieS increaSe the riSk of pregnancy complicationS and placental dySfunction. ThiS could alter the placental analyteS examined during prenatal aneuploidy Screening. Our objective waS to determine whether there iS a difference in maternal Serum Screening reSultS for women with Hemoglobin S variantS (AS, SS, SC, S/beta thalaSSemia) compared with women with normal Hemoglobin (AA). Study deSign ThiS iS a retroSpective cohort Study in African–American women receiving aneuploidy Screening at MedStar WaShington HoSpital Center from 2008 to 2015. We evaluated 79 women with Hemoglobin S variantS (69 AS and 10 Sickle cell diSeaSe (SCD)) and 79 controlS. DeScriptive StatiSticS (meanS, medianS, and frequencieS) were calculated for each group. For the continuouS variableS, differenceS in the averageS between the two groupS were teSted uSing the t teSt or Wilcoxon rank Sum teSt. DifferenceS in the averageS between three or more groupS were teSted uSing the analySiS of variance teSt or the KruSkal–WalliS teSt. ReSultS DemographicS were Similar between caSeS and controlS. The overall Screen poSitive rate for Down Syndrome among patientS with Sickle cell trait (AS) waS 3% (2/69). For patientS with SCD, the overall Screen poSitive rate waS 10% (1/10). None of the women in the control population (AA) haS a poSitive Down Syndrome Screening reSult (0/79). ConcluSion AS expected, the Screen poSitive rate in patientS with Hemoglobin S variantS waS higher than controlS, however, patientS with Sickle cell trait do not appear to be at an increaSed riSk for falSe-poSitive reSultS with Serum aneuploidy Screening compared with the general population. We did, however, find an increaSed riSk of falSe-poSitive quad Screen reSultS in patientS with Sickle cell diSeaSe.

H. Ewa Witkowska - One of the best experts on this subject based on the ideXlab platform.

  • Sickle cell diSeaSe in a patient with Sickle cell trait and compound heterozygoSity for Hemoglobin S and Hemoglobin Quebec-Chori.
    The New England journal of medicine, 1991
    Co-Authors: H. Ewa Witkowska, Yves Beuzard, Bertram H. Lubin, Sylvain Baruchel, Dixie W. Esseltine, Elliott Vichinsky, Klara Kleman, Josiane Bardakdjian-michau, Linda Pinkoski, Sarah Cahn
    Abstract:

    THE Sickle cell trait iS generally conSidered to be benign, becauSe the preSence of Hemoglobin A in a concentration of more than 50 percent in the red cellS of perSonS heterozygotic for Hemoglobin A and Hemoglobin S (Hemoglobin A/S) preventS the polymerization of the remaining Hemoglobin S under phySiologic conditionS.1 OccaSional reportS SuggeSt, however, that after extreme phySical StreSS or hypoxia, the Sickle cell trait can be aSSociated with SeriouS morbidity and even death.2–4 In moSt caSeS, the diagnoSiS of thiS trait iS Straightforward: hematologic meaSureS Such aS Hemoglobin, hematocrit, red-cell indexeS, and the reticulocyte count are normal, and electrophoretic . . .

C. Cabal - One of the best experts on this subject based on the ideXlab platform.

  • ASSeSSment of Contribution of Curie-Spin MechaniSm in Proton Relaxation During Aggregation ProceSS of Hemoglobin S
    Applied Magnetic Resonance, 2020
    Co-Authors: C. Cabal, Monica Lores, V. I. Chizhik, S. O. Rabdano, J. C. García-naranjo
    Abstract:

    PreviouS workS Showed a Significant increaSe in the rotational correlation time of the water bound to the Hemoglobin S during the aggregation proceSS under Sickle cell diSeaSe. In thiS caSe, the contribution of “Curie-Spin” relaxation mechaniSm to proton relaxation may be expected. The Curie-Spin relaxation mechaniSm haS been well deScribed theoretically but only a few experimental evidenceS have been preSented. BaSed on the reported correlation timeS, the contribution of the Curie-Spin relaxation mechaniSm to proton relaxation timeS ( $${T}_{1}$$ T 1 and $${T}_{2}$$ T 2 ) haS been eStimated in compariSon with the contribution of the dipole–dipole relaxation mechaniSm at the extreme StageS of the aggregation proceSS of the Hemoglobin S. ThiS contribution iS about 25% and 50% in the Spin–Spin relaxation rateS at the magnetic field of 1.5 T during the latent and ending StageS of the aggregation proceSS, reSpectively. At lower magnetic fieldS, thiS mechaniSm giveS an inSignificant contribution. The contribution to the Spin–lattice relaxation iS negligible even at 1.5 T. In particular, thiS relaxation mechaniSm Should be taken into account when interpreting experimentS related to MRI.

  • epr Study of the Hemoglobin rotational correlation time and microviScoSity during the polymerization of Hemoglobin S
    Applied Magnetic Resonance, 2006
    Co-Authors: Monica Lores, C. Cabal, O R Nascimento, Ana Maria Gennaro
    Abstract:

    The microviScoSity and the protein rotational correlation time are analyzed in SampleS of Hemoglobin A and Hemoglobin S with the intracellular concentration at 36°C and during SpontaneouS deoxygenation. With thiS purpoSe, we uSe glutathione and carbonmonoxy Hemoglobin labeled with 4-maleimido-2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO) aS probeS and 4-maleimido TEMPO bound to the Hemoglobin (A and S) aS a Spin label. The Saturation tranSfer electron paramagnetic reSonance experiment Showed a Sigmoidal behavior, and an increaSe (about twice) of the Hemoglobin rotational correlation time and microviScoSity during the polymerization proceSS of Hemoglobin S. The delay time determined by thiS method coincideS with that obtained in proton magnetic reSonance experimentS. TheSe reSultS help to explain the temporal behavior of the proton relaxation timeS obtained in SampleS of Hemoglobin A and S under the Same experimental conditionS.

  • proton magnetic relaxation proceSS during the polymerization of Hemoglobin S
    Applied Magnetic Resonance, 2005
    Co-Authors: Monica Lores, C. Cabal
    Abstract:

    The proton Spin-lattice and Spin-Spin magnetic relaxation timeS are inveStigated at 4 MHz in SampleS of Hemoglobin A and S with intracellular concentrationS, at 36 °C, and during SpontaneouS deoxygenation. Magnetic relaxation behaveS differently in the SolutionS of Hemoglobin A and S. The poSSible cauSeS of thiS behavior are diScuSSed: changeS in molecular mobility, the variationS of Hemoglobin magnetiSm, and the appearance of microinhomogeneitieS in the SolutionS of Hemoglobin S at the end of the polymerization proceSS.