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Query: UMLS:C0019045 (hemoglobinopathies)
2,704 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tentative conclusions concerning the role of recognition and ingestion of microorganisms by phagocytes in host defense and the consequences of disorders of phagocytosis can be derived by correlating a) knowledge about recognition and ingestion derived from studies in vitro, b) investigations of the clearance of particulate matter from the circulation of animals and man, and c) analyses of the behavior of phagocytes in patients susceptible to recurrent pyogenic infections. Deficiency of the major serum recognition-conferring (immunoglobulins and complement proteins that deposit a fragment of C3 on microbes) prevents the optimal clearance of virulent encapsulated pathogens by fixed mononuclear phagocytes. Confrontation of phagocytes with particulate matter appearing in pathologic states (viruses, immune complexes, damaged erythrocytes in sickle cell anemia and other hemoglobinopathies) diverts them from their normal task of clearing opsonized encapsulated microorganisms. Corticosteroids impair the phagocytic capacity by an unknown mechanism. Major impediments to progress in this field are inadequate assays for phagocytosis and the difficulty in measuring phagocytosis in the intact organism.
Am J Pathol 1977 Sep
PMID:Phagocytosis. Clinical disorders of recognition and ingestion. 32 84

Samples of whole blood from four hematologically normal adults and from two individuals with increased fetal hemoglobin levels were shipped to laboratories participating in the 1976 and 1977 Center for Disease Control (CDC) hemoglobinopathy proficiency testing surveys. The data from these surveys were used to evaluate the interlaboratory variability of current methods used to quantitate hemoglobin F (Hb F). Results of Hb F quantitation obtained from more than 100 laboratories than voluntarily participated in the survey were compared with those obtained from 21 reference laboratories. Individual values for all samples varied greatly among laboratories and among methods. Results returned by most of the laboratories were outside two standard deviations of the reference laboratory mean and were not accurate enough to differentiate between a normal level and an increased, abnormal level.
Am J Clin Pathol 1979 Sep
PMID:Quantitation of hemoglobin F. An interlaboratory study. 47 23

Prenatal diagnosis of the hemoglobinopathies has been increasingly reported. This article discusses those ethical issues stemming from pregnancy studies by fetoscopy or placental aspiration: diagnostic accuracy and safety for mother and fetus, abortion of the fetus diagnosed as homozygous for thalassemia or sickle cell diseases, and access to prenatal diagnosis for those who cannot afford it. The author's position on these issues attempts to mediate between the poles in current ethical debate on abortion in public policy.
Am J Obstet Gynecol 1979 Sep 01
PMID:Prenatal diagnosis of the hemoglobinopathies: ethical issues. 47 61

The hemoglobinopathies constitute a major medical problem in the black community of Baltimore. A sickle cell service should be designed to discover, educate, and, if necessary, treat. Screening is sound preventive medicine and may serve to introduce the patient to the concept of continuing medical surveillance. The prevention of serious complications in patients with the more severe types of hemoglobinopathy should be a basic goal in the program.
J Natl Med Assoc 1979 Sep
PMID:Experience of a sickle cell screening program in Baltimore. 50 51

The disc sign is the presence of dark red spots on the optic disc of patients with a sickling hemoglobinopathy. The dark spots appear to be plugs of deoxygenated erythrocytes in small surface disc vessels. The occlusions, which are transient and do not produce clinically detectable visual impairment, were seen most often in patients with homozygous sickle cell anemia and may be the result of clogging of small vessels by irreversibly sickled erythrocytes.
Arch Ophthalmol 1978 Sep
PMID:The disc sign in sickling hemoglobinopathies. 68

Sickle cell anemia and other severe sickle cell disorders (hemoglobin SC and hemoglobin S-thalassemia) are known to complicate surgical procedures in susceptible patients. Although transfusions have been used preoperatively to increase the packed cell volume, we have recently used the method of partial exchange transfusion in the treatment of patients with these disorders in the preoperative period. Forty-two patients with significant sickle cell hemoglobinopathies underwent operative procedures on various surgical services. The goal was to obtain a hemoglobin A percentage of 40 or above in each case, and this required 480 to 1,150 c.c. of buffy coat poor washed red cells (mean 820 c.c.). The number of complications in the intraoperative and postoperative period in this study was compared to those found in the literature. There was a significant decrease in morbidity and mortality rates noted with the use of these transfusions. There appeared to be a great advantage on a cost-benefit ratio, as well as an improvement in the physiologic state of the patient. Although the results of this study show significant improvement over previous investigations, there are many facets unknown concerning the use of this modality under these and other conditions. Therefore, further investigation of this method and restriction of the method of Level III referral centers is advocated until enough patients have been studied to assess the long- and short-term complications of the procedure.
Am J Obstet Gynecol 1978 Sep 01
PMID:Use of partial exchange transfusion preoperatively in patients with sickle cell hemoglobinopathies. 69 86

We report the results of a systematic survey carried on 8.961 healthy Guadeloupean blood donors, where we looked for hemoglobinopathies. The results are expressed in regard of the race and site of living (urban or rural) of the subjects. Of these 8.961 subjects, aged 18 to 60, 7.75% were sickle cell trait carriers, 2.36% were heterozygous for Hb C and 0,2% had a significant elevation of Hb F. Were also report some less frequent phenotypes : three Hb AD, five Hb SC, one Hb CC, two Hb SF, one Hb CF and one case of isolated Hb, A2 elevation. Two rare hemoglobinopathies are reported: a case of Hb Korle Bu associated with Hb S an a case of Hb N-Baltimore. Our datas regarding race and sex of Hb S and Hb C carriers are evaluated. These results are compared to previous studies carried on healthy blood donors in Guadeloups. Problems related to the detection of hemoglobin abnormalities in a blood transfusion center are reviewed.
Rev Fr Transfus Immunohematol 1978 Sep
PMID:[Systematic screening of hemoglobinopathies in blood donors in Guadeloupe (French West Indies)]. 73 6

The mean hemoglobin level of persons of Tibetan ancestry living at 4000 m in the Nepal Himalayas was found similar to that expected at an altitude of 2300 m and an arterial O2 saturation of 92%. Plasma volumes were normal, and deficiency states and hemoglobinopathies were not significant. Possible reasons for this finding are discussed.
Proc Soc Exp Biol Med 1975 Sep
PMID:Hemoglobin levels in persons of tibetan ancestry living at high altitude. 116 72

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.
JAMA 1975 Sep 15
PMID:Genetic disorders of human red blood cells. 117 73

There is considerable interest in identifying nontoxic differentiation inducers for the treatment of various malignant and nonmalignant blood disorders, including inborn beta-chain hemoglobinopathies. Using the human leukemic K562 cell line as a model, we explored the efficacy of phenylacetate, an amino acid derivative with a low toxicity index when administered to humans. Treatment of K562 cultures with pharmacologically attainable concentrations of phenylacetate resulted in erythroid differentiation, evident by the reduced growth rate and increased hemoglobin production. The effect was time- and dose-dependent, further augmented by glutamine starvation (phenylacetate is known to deplete circulating glutamine in vivo), and reversible upon cessation of treatment. Molecular analysis showed that phenylacetate induced gamma globin gene expression with subsequent accumulation of the fetal form of hemoglobin (HbF). Interestingly, the addition of phenylacetate to antitumor agents of clinical interest, eg, hydroxyurea and 5-azacytidine, caused superinduction of HbF biosynthesis. The results suggest that phenylacetate, used alone or in combination with other drugs, might offer a safe and effective new approach to treatment of some hematopoietic neoplasms and severe hemoglobinopathies.
Blood 1992 Sep 15
PMID:Induction of erythroid differentiation and fetal hemoglobin production in human leukemic cells treated with phenylacetate. 138 30


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