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Jean Riou

Publications and source records attributed to Jean Riou.

8 recordsLinked to original sources
PubMed2005

Evaluation of the Bio-Rad VARIANT II HbA2/HbA1C Dual Program for measurement of hemoglobin concentrations and detection of variants.

In this work data obtained on the VARIANT II hemoglobin analyzer using the Dual Kit elution system were compared to those obtained with the beta-Thalassemia Short Program. Since many laboratories still use an earlier model of the hemoglobin analyzer, the Variant 1, these data were also compared to those obtained with the latter instrument. Our study is divided into two parts. The first is an evaluation of the precision of the VARIANT II for determining the levels of hemoglobin (Hb)A2 and Hb F. This was carried out for normal subjects, thalassemic patients and patients with HbS. The second part concerns the potential of this instrument in the presumptive identification of Hb variants.

Fetal Hemoglobin↗
PubMed2002

Hb O-Tibesti [beta121(GH4)Glu-->Lys; beta11(A8)Val-->Ile], a hemoglobin variant carrying in the same beta chain the substitutions of Hb O-Arab and Hb Hamilton, found in combination with Hb S [beta6(A3)Glu-->Val].

Hb O-Tibesti, carries in the same chain the substitution of Hb O-Arab [beta121(GH4)Glu-->Lys] and that of Hb Hamilton [beta11(A8)Val-->Ile]. Hb O-Tibesti may be distinguished from Hb O-Arab by polyacrylamide gel electrophoresis in the presence of urea and Triton-X100, and by reversed phase high performance liquid chromatography. It was found in a compound heterozygous condition with Hb S [beta6(A3)Glu-->Val] in a child of Chad-Sudanese descent, suffering from a sickle cell syndrome. Compared to the classical description of the Hb S/Hb O-Arab association, the additional Hb Hamilton mutation does not seem to modify the clinical presentation.

Amino Acid Substitution↗
PubMed2002

Globin chain analysis by reversed phase high performance liquid chromatography: recent developments.

Reversed phase high performance liquid chromatography of globin chains is an important additional tool in the study of hemoglobin abnormalities. Using a technique modified from that of Leone et al.,[1] we report here the relative chromatographic behavior of about 200 different hemoglobin variants. This method provides an additional dimension in the presumptive characterization of hemoglobin variants. It was also found to be of special value for measuring the expression of neutral variants, such as thalassemic or unstable hemoglobins, and to identify neutral mutations associated with another variant, resulting in unusual hematological presentations.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Hb Montfermeil [beta 130(H8) Tyr-->Cys]: suggests a key role for the interaction between helix A and H in oxygen affinity of the hemoglobin molecule.

Hb Montfermeil [beta130(H8) Tyr-->Cys] is a high oxygen affinity variant causing erythrocytosis. The cysteine replacement is buried in the inside of the beta chain where it alters the interactions between helix A and H, with a further effect on helix E. This position has already been proposed to contribute to the difference in oxygen affinity between human and bovine hemoglobins. Three dimensional structural considerations and comparison of the functional behavior of other variants suggest that this region is an important determinant of the intrinsic oxygen affinity of the hemoglobin molecule.

Amino Acid Sequence↗