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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The thalassemias are a heterogeneous group of genetically determined disorders of hemoglobin synthesis and can be divided into alpha-thalassemias and beta-thalassemias. The genes for these disorders are carried as relatively harmless traits which can be detected in the laboratory by a series of tests. As there are several variant genes in each group, heterozygotes for two slightly different genes occur, and interaction of these thalassemia genes with the hemoglobinopathies is quite common. Severe clinical disease usually only occurs in homozygotes, as in Cooley's anemia. The problem for the laboratory is to distinguish thalassemia trait from other causes of microcytosis and hypochromia in an economical and efficient way. The various proposed schemes are discussed, and it is suggested that detection of these traits should be part of a comprehensive screening program for hemoglobinopathies and thalassemias.
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PMID:Laboratory detection of thalassemia. 67 57

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.
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PMID:Use of partial exchange transfusion preoperatively in patients with sickle cell hemoglobinopathies. 69 86

The structure, properties, genetics, and clinical and biochemical expression of hemoglobins Lepore (deltabeta) and anti-Lepore (betadelta) are described. In addition to the three Lepore variants (Lepore Hollandia, Lepore Baltimore and Lepore Washington) at least four anti-Lepore variants (Miyada, P Nilotic (P Congo), Coventry and Lincoln Park) are known at the present time. All known hemoglobins Lepore and anti-Lepore are products of non-homologous crossing-over between the delta and the beta genes. Although the Hb Lepore condition is expressed phenotypically and clinically as beta thalassemia, the presence of about 10% of Hb Lepore distinguishes the condition hematologically from beta thalassemia. Data on the hematological and biochemical expression of this hemoglobinopathy are presented. In contrast to the anemia in the Lepore condition, there is no phenotypic evidence of thalassemia in persons with hemoglobin anti-Lepore, because no beta chain deficiency accompanies the latter condition. Although no adequate explanation has been advanced concerning the factors which maintain a low synthesis of the Lepore and anti-Lepore chains, it has been suggested that multiple rare codons may introduce rate-limiting steps or that the deltabeta and betadelta mRNAs may be unstable. Data on the geographical distribution and structural identification of Hb Lepore are presented.
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PMID:Hemoglobins Lepore and anti-Lepore. 70 Oct 81

The predictive value of a prolonged glycerol lysis time (GLT50) was assessed by analysis of case records of 100 consecutive subjects with values greater than 73 seconds (normal = 26--73 seconds) reported by the clinical laboratory of The New York Hospital. There were 72 cases of hemoglobinopathy: 65 thalassemia trait, four sickle-thalassemia, and one each of Hb D-thalassemia, sickle-C disease, and sickle-cell anemia. Nine of the remaining subjects had iron-deficiency anemia, three had chronic renal disease, and seven had miscellaneous disorders. Four subjects were apparently normal, and in five cases there was insufficient information for a diagnosis. Of 78 patients who had both a prolonged GLT50 and microcytosis, 67 (86%) had thalassemia trait and seven (9%) had iron-deficiency anemia. In 74 patients with GLT50 greater than 100 seconds, thalassemia trait was found 16 times as often as uncomplicated iron-deficiency anemia. All 31 subjects with GLT50 greater than 180 seconds had hemoglobinopahy. A prolonged GLT50 strongly suggests thalassemia trait, especially when greater than 100 seconds or associated with microcytosis.
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PMID:The diagnostic significance of a prolonged erythrocytic glycerol lysis time (GLT50). 70 32

A regional laboratory for the diagnosis and investigation of hemoglobinopathies was established by the Hamilton District Program in Laboratory Medicine in October 1970. Specimens from patients suspected of having a hemoglobinopathy were referred to the regional laboratory from all the hospitals participating in the program. Between October 1970 and October 1974, 3547 specimens were screened for an abnormal hemoglobin and thalassemia; 758 cases of thalassemia, 165 cases of abnormal hemoglobin and 14 mixed cases were diagnosed. Before 1970, 110 cases of thalassemia and 12 cases of abnormal hemoglobin were on record in the Hamilton region. Regionalization of laboratory services provides a more effective means of screening for abnormalities in hemoglobin structure and synthesis and facilitates the opportunity for improving diagnostic procedures.
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PMID:Hemoglobinopathies in the Hamilton region. I. A 4-year survey. 80 45

Seven patients had sickle cell trait (hemoglobin AS) and vasoproliferative retinopathy. The retinal abnormalities in these seven patients were indistinguishable from those seen in patients with clinically significant sickling hemoglobinopathies (sickle cell-hemoglobin C disease, hemoglobin S-thalassemia disease, and sickle cell anemia). All seven patients also had some evidence of associated systemic disease such as diabetes, syphilis, tuberculosis, or sarcoidosis. In the presence of an associated systemic disease, marked retinopathy can occur in the ordinarily benign condition of sickle cell trait.
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PMID:Proliferative retinopathy in sickle cell trait. Report of seven cases. 84 50

The availability of sophisticated laboratory procedures has made the diagnosis of many hemoglobinopathies and thalassemias simple. Structural alteration of the polypeptide chains and defects in the rate of synthesis of any of the polypeptide chains are the most common abnormalities: hemoglobins S, C and D are examples of the former, and the thalassemias are examples of the latter. The pathophysiology, clinical manifestations and individual variation of each abnormality are significantly different. Early diagnosis and the knowledge of the pathophysiology together with careful and frequent follow-up are necessary for providing better medical care. Pregnancy in a patient with a diagnosis of hemoglobinopathy or thalassemia certainly speaks for risks to both the mother and fetus. Management of each case has to be planned individually to provide optimal medical and supportive care. We have found a special combined hematology-obstetrics clinic to be helpful in the follow-up of these high-risk patients.
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PMID:Pregnancy in patients with hemoglobinopathies and thalassemias. 91 81

We attempted prenatal diagnosis of hemoglobinopathies in 15 cases--11 for beta-thalassemia and four for sickle-cell disease. Fetoscopy was used in seven cases, and placental aspiration in eight. One premature labor, with fetal loss, followed placental aspiration. Globin synthesis was assessed by incubation of samples with 3H-leucine and chain separation on carboxymethylcellulose columns. Homozygous disease was predicted in two pregnancies, which were interrupted, and the diagnosis confirmed. In one case homozygosity was suspected. A repeat test was advised but not accepted. The fetus had thalassemia trait. One pregnancy was interrupted despite our prediction of thalassemia trait. Eight pregnancies went to term. Seven predictions that the infants would not have homozygous disease were confirmed. One prediction of sickle trait proved to be sickle-cell disease. Although prenatal diagnosis of hemoglobinopathies is feasible, the present frequency of fetal loss and diagnostic error indicates need for improvement.
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PMID:Prenatal diagnosis of hemoglobinopathies. A review of 15 cases. 99 41

Formamide gel electrophoresis separates the mRNA fraction from reticulocyte polyribosomes of adult humans into two major RNA species with migratory rates identical to those of the alpha- and beta-globin mRNAs of the rabbit. That these two RNAs of human origin are the globin mRNAs is further supported by the deficiency of the presumed beta mRNA in reticulocyte polyribosomes of fetuses and premature infants, whose cells make gamma chains in preference to beta chains. The globin mRNAs of reticulocyte polyribosomes from patients with hematological disorders were estimated by scanning the stained formamide gels. In contrast to individuals with either hemolytic anemia without hemoglobinopathy or sickle cell anemia who had beta mRNA to alpha mRNA ratios of approximately one, a patient with Hb S-beta-thalassemia had a ratio of beta mRNA to alpha mRNA of 0.75 while two subjects with homozygous beta-thalassemia had severe deficiencies of beta mRNA. Conversely, a patient with alpha-thalassemia (Hb H disease) had a ratio of beta mRNA to alpha mRNA on reticulocyte polyribosomes of 6. These data provide further evidence of a quantitative deficiency of chain-specific globin mRNA in patients with the thalassemia syndromes.
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PMID:Further evidence of a quantitative deficiency of chain-specific globin mRNA in the thalassemia syndromes. 105 38

Porotic hyperostosis was observed in 34 percent of 539 crania excavated from sites in Arizona and New Mexico. Common causes of this cranial pathology in the Old World (thalassemia, sickel cell anemia, and malargia) do not explain its occurrence in the American Southwest, as malaria and hemoglobinopathies are not known to have existed in the New World prior to European contact. Iron deficiency anemia which may also be assoicated with porotic hyperostosis occurs on a mass level only with hookworm infestation or nutritionally-related iron deficiency. Since hookworm infestation is rare in the American southwest and has not been reported in prehistoric southwestern American Indians, the hypothesis of nutritional anemia was examined. In canyon bottom sites where the diet was heavily dependent on maize, which is low in iron and also contains an inhibitor of iron absorption, significantly more crania had porotic hyperostosis than in sage plain sites, where the diet included ample animal protein rich in easily absorbable iron (p less than .001). Furthermore, canyon bottom children, who were more susceptible to iron deficiency anemia, had a higher incidence of porotic hyperostosis lesions than adults (p less than .0001).
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PMID:The paleoepidemiology of porotic hyperostosis in the American Southwest: Radiological and ecological considerations. 110 84


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