Subject: night blindness/polycythemia

   
   Acta Ophthalmol Scand 2000 Feb;78(1):53-7
   
Impaired dark adaptation in polycythemia. Improvement after treatment.

    Havelius U, Berglund S, Falke P, Hindfelt B, Krakau T
    
   Department of Ophthalmology, Internal Medicine, University Hospital
   MAS, University of Lund, Malmo, Sweden. Ulf.Havelius@oftal.mas.lu.se
   
   PURPOSE: To determine if dark adaptation is reduced in individuals
   with polycythemia and if so whether there is any improvement in dark
   adaptation after treatment. METHODS: Dark adaptation was recorded
   monocularly by automatic dark adaptometry in ten consecutive patients
   with polycythemia before and after treatment. Analogue investigations
   were performed in 31 healthy control subjects. RESULTS: Dark
   adaptation was markedly impaired in the patients as compared with the
   control subjects. After reduction of the red cell count and
   normalization of the hematocrit and hemoglobin the dark adaptation was
   markedly improved. There was no significant change in dark vision in
   the control subjects negating a confounding learning effect.
   CONCLUSION: The findings indicate a sustained but reversible neuronal
   hypofunction secondary to polycythemia. As the rheological abnormality
   was normalized, dark adaptation was improved, probably secondary to
   normalized microcirculation within the retina or the brain, or both,
   possibly with reactivation of formerly inactive neuronal cells.
   
   PMID: 10726790, UI: 20189324
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Subject: IRON/GLUCOSE-6-PHOSPHATE DEHYDROGENASE

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   Biochim Biophys Acta 1245: 359-365 (1995)[96125732]

Oxidative damage of bovine serum albumin and other enzyme proteins by
iron-chelate complexes.



    T. Ogino & S. Okada



   Department of Pathology, Okayama University Medical School, Japan.

   Direct oxidative protein damage by iron-nitrilotriacetate (NTA), as
   well as physiological iron complexes, iron-citrate and iron-ADP was
   studied in the presence or absence of H2O2, using bovine serum albumin
   (BSA), glucose-6-phosphate dehydrogenase (G-6-PD), glutathione
   reductase (GSSGRase) and catalase as the target proteins. Both
   Fe(III)NTA+H2O2 and Fe(II)NTA+H2O2 caused marked BSA fragmentation
   which accompanied the decrease in the intrinsic tryptophan
   fluorescence and appearance of bityrosine fluorescence. However,
   Fe(III)citrate+H2O2 showed only slight BSA fragmentation. In the
   absence of H2O2, Fe(II) NTA but not Fe(III)NTA caused similar but
   slight BSA fragmentation, which depended on the molecular oxygen.
   Fe(II)citrate also showed O2-dependent BSA fragmentation to a
   comparable degree, however, Fe(II)ADP showed no detectable BSA damage.
   BSA fragmentation by Fe(II)NTA+O2 and by Fe(III)NTA+H2O2 resulted in
   the appearance of the new alpha-amino groups. Electron spin resonance
   study using 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trapping
   reagent showed DMPO-OH spin adduct, which suggests the presence of
   hydroxyl radical, in Fe(III)NTA+H2O2, but not in Fe(II)NTA+O2 system.
   Fe(II)NTA inactivated G-6-PD and GSSGRase in a O2-dependent manner,
   however, G-6-PD was more susceptible to the damage. This enzyme
   inactivation also accompanied the protein fragmentation and was not
   due to simple sulfhydryl oxidation. Catalase was not significantly
   inactivated nor fragmented by Fe(II)NTA+O2. These findings suggest
   that the interaction between proteins and iron-chelate complexes is
   important in iron catalyzed oxidative damage, and that the structure
   of the chelating agent may determine the target molecules.

   MeSH Terms:
     * Animal
     * Catalase/metabolism
     * Cattle
     * Cyclic N-Oxides
     * Electron Spin Resonance Spectroscopy
     * Free Radicals
     * Glucosephosphate Dehydrogenase/metabolism
     * Glutathione Reductase/metabolism
     * Iron Chelates/metabolism
     * Oxidative Stress
     * Serum Albumin, Bovine/metabolism
     * Spin Trapping



   Substances:
     * Catalase
     * Glucosephosphate Dehydrogenase
     * Glutathione Reductase
     * Serum Albumin, Bovine
     * Iron Chelates
     * Cyclic N-Oxides
     * Free Radicals
     * 5,5-dimethyl-1-pyrroline-1-oxide


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   JAMA 233: 1184-8 (1975)[76007893]
   
Genetic disorders of human red blood cells.

   
   
    E. Beutler
    
   
   
   Human red blood cells (RBCs) are subject to an enormous degree of
   genetic diversity. The variability that occurs may result in anemia,
   cyanosis, polycythemia, or may cause no hematologic alterations.
   Genetic abnormalities affecting hemoglobin include the sickling
   disorders, the unstable hemoglobinopathies, hemoglobinopathies
   associated with polycythemia or with methemoglobinemia, and the alpha-
   and beta-thalassemias. The most common enzymatic abnormality of RBCs
   is glucose-6-phosphate dehydrogenase deficiency, but defects of many
   other enzymes leading to hemolytic anemia have been identified.
   Deficiences of RBC enzymes may also be important in the diagnosis of
   nonhematologic disease and in the evaluation of dietary status.
   
   MeSH Terms:
     * Anemia, Hemolytic, Congenital/enzymology
     * Anemia, Hemolytic, Congenital/genetics
     * Anemia, Hypochromic/diagnosis
     * Diagnosis, Differential
     * Erythrocytes/enzymology
     * Genetic Counseling
     * Glucosephosphate Dehydrogenase Deficiency/genetics
     * Glycolysis
     * Heinz Bodies
     * Hemoglobinopathies/genetics
     * Hemoglobins, Abnormal/analysis
     * Heterozygote
     * Homozygote
     * Human
     * Support, U.S. Gov't, P.H.S.
     * Thalassemia/diagnosis
     * Thalassemia/genetics
       
   
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