Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Quantitative glycogen determinations can be made in single blood and bone marrow cells, using microspectrophotometry or microfluorometry after staining with variants of the periodic acid--Schiff (PAS) reaction. These PAS variant reactions generally do not indicate the presence of non-glycogen PAS-positive substances, known to be prevalent in various hematopoietic cells, possibly due to masking of reactive groups. The specificity of the reaction in blood cells was ascertained by alpha-amylase digestion, which removed more than 95% of the PAS-positive material. Calibration of the PAS reaction was undertaken with a microdroplet model of pure leukocyte glycogen. The glycogen amounts in the droplets were determined by microinterferometry, the droplets were stained with a variant PAS reaction, and the total extinction of the reaction product in the stained droplets was determined by microspectrophotometry. The extinction coefficient (k) was obtained from the equation k equals Etot divided by M where (Etot) is the total extinction as determined by microspectrophotometry and (M) the dry glycogen amount as determined by microinterferometry. The microinterferometric dry mass determinations were calibrated by X-ray absorption in order to obtain the absolute amounts of glycogen. For practical purposes a reference system was made of normal neutrophil leukocytes. The glycogen content in the reference neutrophils was first determined with the micromodel. These neutrophils, now with a known glycogen amount, were stained with the PAS reagents and measured microspectrophotometrically in parallel with cells containing an unknown glycogen amount. Alternatively, the staining was made with a fluorescent PAS reaction, and the glycogen content determined by microfluorometry. Both methods appeared suitable for determining the glycogen content of blood cells from patients with various diseases, though the microfluorometric method was preferable for measurements of small amounts of inhomogeneously distributed glycogen. The mean glycogen content of normal neutrophil leukocytes was found to be 13.6 times 10(-12) g. The content was increased in infectious diseases such as pneumonia and tonisillitis, as well as in polycythemia vera and myelofibrosis, while low amounts were found in untreated chronic myelocytic leukemia. In chronic myelocytic leukemia in remission, the glycogen content of mature neutrophils had completely normalized. Erythroblasts normally do not contain detectable amounts of glycogen. However, in certain diseases such as beta-thalassemia and Di Guglielomo's syndrome, appreciable amounts of glycogen accumulate in the erythropoietic precursor cells. In beta-thalassemia this was associated with an arrest in the proliferation of early polychromatic erythroblasts, which accumulate glycogen in the G1 phase of the cell cycle. In all these diseases quantitative glycogen determinations in the blood cells have diagnostic importance.
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PMID:Quantitative cytochemistry of glycogen in blood cells. Methods and clinical application. 107 52

Some routine red blood cell (RBC) measurements and indexes (count, mean volume, volume dispersion, and mean hemoglobin [HGB] concentration) can be used to differentiate iron deficiency from heterozygous beta-thalassemia. A number of formulas that incorporate two or more of these measurements have been described to amplify such differences. The H*1 hematology analyzer directly measures volume and HGB concentration of individual RBCs. We have assessed the diagnostic usefulness of conventional and new RBC measurements provided by the H*1 on a learning data set that comprised 119 patients with iron deficiency and 172 patients with beta-thalassemia trait, both untreated and uncomplicated. The most striking finding was the inverse behavior of percentages of microcytes (volume, less than 60 fL) and hypochromic RBCs (HGB concentration, less than 280 g/L) in the two conditions. In 162 of 172 patients with beta-thalassemia trait, the percentage of microcytes (mean, 33.1%; central 95th percentile range, 9.2% to 54.5%) was higher than the percentage of hypochromic RBCs (mean, 13.9%; central 95th percentile range, 1.7% to 24.7%). In 105 of 119 patients with iron deficiency, on the contrary, the percentage of hypochromic cells (mean, 34.6%; central 95th percentile range, 9.7% to 73.1%) was higher than the percentage of microcytes (mean, 12.8%; central 95th percentile range, 1.7% to 29.6%). The ratio between the percentage of microcytes and the percentage of hypochromic cells provided by the H*1 (microcytic-hypochromic ratio) was useful in differentiating the two types of microcytic anemia: with the use of a discriminant value of 0.9, the discriminant efficiency of the microcytic-hypochromic ratio was 92.4% (95% confidence interval, 88.8% to 95.2%), higher than that of the five previously described discriminant formulas and simple RBC measurements. When assessed on a test data set that comprised 149 unselected cases of microcytic anemia, a microcytic-hypochromic ratio lower than 0.9 demonstrated high sensitivity (94.0%), specificity (92.3%), and predictive value (94.0%) for the presence of iron-deficient erythropoiesis in patients with isolated iron deficiency, polycythemia vera treated by phlebotomy, and iron deficiency complicating heterozygous thalassemia. In conclusion, our results showed that iron-deficient erythropoiesis is characterized by the production of RBCs with a severely decreased HGB concentration, while microcytes of beta-thalassemia trait are generally smaller, with a more preserved HGB concentration. Such properties, as assessed by the H*1 hematology analyzer, are very useful in distinguishing these two common types of microcytic anemia.
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PMID:Automated measurement of red blood cell microcytosis and hypochromia in iron deficiency and beta-thalassemia trait. 173 38

Recent studies from this department have suggested that the level of 2,3-DPG may be determined in part by the volume of the erythrocyte; this conclusion was reached on the basis of the finding of significantly elevated values of 2,3-DPG in heterozygous beta-thalassemia, even in the absence of anemia. In order to test the role of microcytosis in the formation of 2,3-DPG levels, a study was undertaken on a different patient material characterized by microcytosis without anemia or hypoxia, namely on cases of polycythemia vera (PV) rendered microcytic through therapeutic venesection (or blood loss) and on appropriate controls. Five cases of untreated PV (mean HB 18.36 +/- 1.53 g/dl, mean MCV 94.4 +/- 3.9 fl) had 2,3-DPG levels slightly lower than normal controls (13.67 +/- 0,75 mumoles/g Hb vs 14.18 +/- 1.41 mumoles/g Hb). Six microcytic iron deficient PV's (mean Hb 17.42 +/- 2.34 g/dl, mean MCV 74.5 +/- 6.2 fl) had very significantly increased 2,3-DPG levels (17.73 +/- 1.75 mumoles/g Hb). Similar high levels were obtained in five cases venesected in the past and maintained with cytostasis (mean Hb 15.22 +/- 0.67 g/dl, MCV 82.5 +/- 7.5 fl, 2,3-DPG 17.04 +/- 2.44 mumoles/g Hb). A strong linear negative correlation was obtained between 2,3-DPG values and the MCV (r = -0.736, P less than 0.001). It is concluded that microcytosis of other etiology and not only of beta-thalassemia may also lead, per se, to increased levels of 2,3-DPG. The different levels of 2,3-DPG in PV undergoing venesection vs untreated patients may explain some discrepant reports on the behavior of this metabolite in PV.
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PMID:[Erythrocyte volume and 2,3-DPG level. A study on a primary polycythemia model]. 662 51

A patient with sickle cell beta+-thalassemia had thrombocytosis and erythrocytosis due to a myeloproliferative disorder best classified as polycythemia vera. RBC counts were 6 to 8 million/cu mm and the red cell mass was 33 ml/kg. A higher red cell mass and an increased hematocrit value were prevented probably by factors related to the hemoglobinopathy, such as microcytosis and hemolysis. The diagnosis of polycythemia vera in patients with sickle cell disease may be difficult to document and the association of these disorders has not been previously reported. This patient's high red blood cell and platelet counts did not result in recurrent vasoocclusive crises.
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PMID:Sickle cell thalassemia, thrombocytosis, and erythrocytosis. 722 49

Extramedullary hematopoiesis is a common accompaniment of a variety of hematologic diseases such as hereditary spherocytosis, thalassemia and myelofibrosis. The association of extramedullary hematopoiesis with polycythemia vera in the proliferative phase is much less usual. We report a patient who presented with paraplegia due to spinal cord compression; clinical investigation revealed a paravertebral hematopoietic tumor, and the diagnosis of polycythemia vera was then established.
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PMID:Spinal cord compression due to extramedullary hematopoiesis in the proliferative phase of polycythemia vera. 892 92

Therapeutic erythrocytapheresis (TEA) has been used in different diseases such as polycythemia vera (PV), secondary erythrocytosis or hemochromatosis as a process of the less cumbersome but more expensive phlebotomy. TEA is preferred in emergency conditions such as thrombocytosis or in conditions such as porphyria cutanea tarda (PCT) or erythropoietic porphyria when plasma exchange (PEX) is often combined with TEA to reduce extracellular levels of uroporphyrin which contribute to plasma hyperviscosity. TEA is often combined with drug therapy that varies from etoposide in PV to EPO and desferoxamine which are used to mobilize and reduce iron stores in hemochromatosis. Benefits from this combination may be more long lasting than expected. Nonetheless for TEA, there is no standard protocol and, clinical experience with this therapy remains highly anecdotal. Therapeutic red cell-exchange (TREX) has been used with much interest over the years, starting with the management of hemolytic disease of the newborn and later used to correct severe anemia in thalassemia patients thereby preventing iron overload. It has also been used for the management of complications of sickle cell disease such as priapism, chest syndrome, stroke, retinal, bone, splenic and hepatic infarction or in preparation for surgery by reducing HbS to less than 30%. Automated apheresis has also favored the use of TREX in conditions such as paroxysmal nocturnal hemoglobinuria and aniline poisoning, arsenic poisoning, Na chlorate intoxications and CO intoxications, hemoglobinopathies, autoimmune hemolytic anemia, reactions due to ABO incompatibility, in preparation for ABO incompatible bone marrow transplantation or for preventing anti-D immunization after the transfusion of D(+) cells to D(-) recipients. Another field of application has been in the emergency management of intraerythrocytic parasite infections such as malaria and babesiosis. Application of TREX may be wide but its real use remains limited. In our personal experience, in 16 years, only 167 TREX procedures have been carried out in a total of 13,747 therapeutic procedures. This represents only 1.21% of the total.
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PMID:Clinical application of therapeutic erythrocytapheresis (TEA). 1083 21

A retrospective study of 126 patients with extreme thrombocytosis (defined as a platelet count > or = 1,000 x 10(9)/L) was performed during a five-year period (June 1994-June 1999). The aim of this study was to determine the etiology and to evaluate the clinical consequences of extreme thrombocytosis. Seventy patients (55.5%) had reactive thrombocytosis (RT) with an age range of 43 +/- 2.2 years, 56 (44.5%) had chronic myeloproliferative disorders (MPD) with an age range of 53 +/- 2.4 years. Underlying causes of RT were malignancy (25/70 or 35.7%), infection (16/70 or 22.9%), postsplenectomized beta-thalassemia/Hb E (11/70 or 15.7%), inflammation (12/70 or 17.1%), iron deficiency anemia (6/70 or 8.6%). Duration post splenectomy in our beta-thalassemia/Hb E patients ranged from 4 months to 21 years, with a median of 10 years. Subtypes of our MPD cases were chronic myeloid leukemia (30/56 or 53.6%), essential thrombocytosis (18/56 or 32.1%), polycythemia vera (4/56 or 7.1%), agnogenic myeloid metaplasia (3/56 or 5.4%) and unclassified MPD (1/56 or 1.8%). Bleeding and thrombotic tendency were respectively noted in 7 (12.5%) and 2 (3.6%) of MPD patients. Two patients of the MPD group (3.6%) experienced both bleeding and thrombotic episodes. One patient (1.4%) of the RT group developed vasculitis-associated thrombosis. However, none of the patients in the RT group had bleeding complications. Extreme thrombocytosis was not a rare condition in a university hospital population, and bleeding and/or thrombotic complication was more common in the MPD group.
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PMID:Etiology and incidence of thrombotic and hemorrhagic disorders in Thai patients with extreme thrombocytosis. 1086 14

A 69-year-old woman with a 14-year history of polycythemia vera suffered progressive paraparesis due to epidural involvement of hematopoietic tissue. Magnetic resonance (MR) imaging demonstrated extensive epidural masses. Decompressive surgery and radiotherapy were performed and she made an almost complete clinical recovery. Serial MR imaging showed no regrowth of the other epidural masses. Extramedullary hematopoiesis occurs in patients with various hematologic disorders involving a chronic increase in the production of red blood cells, and is often associated with thalassemia, but is less common with polycythemia vera. The most frequent sites are the spleen, liver, and kidney. Extramedullary hematopoietic tissue occurring within the spinal canal and causing cord compression is very rare. Total surgical excision is not usually feasible because of the diffuse nature of extramedullary hematopoietic tissue and the possibility of recurrence, but acute neurological deterioration does require emergency surgery. Extramedullary hematopoiesis is radiosensitive and displays a rapid response to low dosages, so radiation therapy is recommended for residual tumors. Considering the possibility of central nervous system extramedullary hematopoiesis in patients with polycythemia vera, an early diagnosis is necessary for a favorable prognosis.
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PMID:Spinal cord compression due to extramedullary hematopoiesis associated with polycythemia vera--case report. 1190 77

A 40-year-old Xhosa male presented with progressive upper lumbar back pain and weakness At examination he was emaciated and had enlarged lymph nodes in the groin and axilla. Both lower limbs were severely atrophic and weak. Sensation to touch and pain was decreased below L3 bilaterally. MR of the spine showed a discrete, contrast-enhancing epidural mass. A T10-T12 laminectomy revealed an soft, vascular extradural tumor dorsal to the cord. The mass was loosely applied to the dura and easy to remove. The operative specimen consisted of a sausage-shaped (3.5 x 2.0 x 1.2 cm), thinly-encapsulated mass of reddish-brown tissue. The cut surface had a mottled, vaguely nodular, yellowish-brown appearance. Microscopic examination revealed sheets of hematopoeitic elements, including myeloid, red cell and megakaryocytic lines, the latter showing Factor 8-related positivity. The final diagnosis was extramedullary hematopoiesis (EMH). A bone marrow biopsy performed as a result of the diagnosis showed a myeloproliferative disease and polycythemia vera. EMH in the spinal epidural space is a rare but treatable cause of progressive paraparesis in patients with a variety of hematological disorders. Since 1956 there have been more than 50 reported cases, most of which occurred in association with thalassaemia. In spinal cord compression secondary to EMH, the lesions are commonly localized to the mid-lower thoracic region.
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PMID:October 2001: 40-year-old Xhosa male with back pain and leg weakness. 1195 81

Spinal cord compression due to extramedullary hematopoiesis (EMH) is a rare complication of thalassemia and generally presents as paraparesis with sensory impairment. Complete paraplegia is extremely rare in EMH due to thalassemia although it is known to occur in polycythemia vera and sickle cell anemia. Treatment options mostly include surgery and/or radiotherapy. Whereas cases presenting with paraparesis have been treated with either surgery or radiotherapy with equal frequency and efficacy, almost all reported cases with paraplegia have been treated with surgery with or without radiation therapy. We hereby report a case of thalassemia intermedia with paraplegia treated successfully with radiotherapy.
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PMID:Paraplegia due to extramedullary hematopoiesis in thalassemia treated successfully with radiation therapy. 1740 52


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