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

Using a method involving elution of hemoglobin bands from cellulose acetate strips following electrophoresis of hemolysates, hemoglobin A2 (Ab A2) was quantitated in bloods from 300 healthy individuals and 904 patients. The percentage of Hb A2 was elevated in beta-thalassemia heterozygotes and some patients who had megaloblastic anemia. In the latter, the highest Hb A2 levels were observed in patients with the most severe anemia. Low Hb A2 percentages were found in iron-deficiency anemia, hereditary persistance of fetal hemoglobin, and Hb H disease. In iron-deficiency anemia, the lowest levels of Hb A2 were observed in association with the most severe anemia. Iron and folate deficiency each suppressed Hb A2 levels in beta-thalassemia heterozygotes; however, vitamin B12 deficiency did not alter the percentage of Hb A2 in thalassemia. Malignant tumors, renal and hepatic insufficiency, chronic infections and inflammation, hemolytic disease, lead poisoning, aplastic anemia, leukemia, myelofibrosis, and hypothyroidism did not change Hb A2 levels. The pathogenesis of altered Hb A2 levels and their clinical significance in various diseases are discussed.
 ...
PMID:Hemoglobin A2 levels in health and various hematologic disorders. 26 35

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.
 ...
PMID:Quantitative cytochemistry of glycogen in blood cells. Methods and clinical application. 107 52

The records of 30 patients presenting radiological evidence of masses of extramedullary myeloadipose (hemopoietic) tissue, 25 patients suffering from thalassemia, one from sickle-cell anemia, and one from myelofibrosis were studied. Three patients presented with primary myelolipomas. Most of the patients with thalassemia presented with masses of hemopoiesis in the costovertebral angle and five patients presented with spinal cord compression. Magnetic resonance imaging is the best method for visualization and assessment of the extent of the masses in the thorax and spinal canal. Radiotherapy is the treatment of choice for spinal cord compression. One patient with thalassemia and one patient with myelofibrosis presented with masses of extramedullary hemopoiesis in the adrenals. All five patients with masses of myeloadipose tissue in the adrenals were treated surgically.
 ...
PMID:Masses of myeloadipose tissue: radiological and clinical considerations. 221 Dec 67

Extramedullary hematopoiesis (EMH) is observed in people suffering from severe anemia of prolonged duration and appears to be a compensatory mechanism for disturbed medullary hematopoiesis. The hemoglobinopathies (such as thalassemia, spherocytosis, and sickle cell disease), neoplastic diseases such as leukemia and lymphoma, and others, including myelofibrosis and osteitis fibrosa cystica, are associated with EMH. These diseases and their resultant anemia have in common the ability to stimulate erythropoietin production, which in turn may stimulate hematopoiesis in organs of mesenchymal origin. The liver and spleen are the most common sites of EMH; however, other sites, including the falx cerebri, thoracic cavity, retroperitoneal area and pelvis have been reported. When present, intrathoracic EMH is most frequently associated with thalassemia. Spinal cord compression and hemothorax have also been reported as complications of intrathoracic EMH.
 ...
PMID:Asymptomatic intrathoracic extramedullary hematopoiesis: a report of three cases. 262 Nov 1

A 64-year-old man was found to have a hemolytic anemia with a hematocrit of 0.28 (28%) during a routine evaluation. One month before this his hematocrit had been normal. Further studies revealed a myelodysplastic syndrome and acquired hemoglobin H disease. Eighteen months later this transformed into acute megakaryoblastic leukemia with disappearance of hemoglobin H, and shortly thereafter he had myelofibrosis develop. Acquired hemoglobin H disease, which is an alpha-thalassemia-like syndrome, results in the formation of an unstable hemoglobin composed of beta chain tetramers. This condition has been associated with preleukemia, sickle cell anemia, and hematologic malignancies. Although idiopathic myelofibrosis also has been described as a setting in which this thalassemic syndrome occurs, the present case is unusual in that the myelofibrosis was preceded by refractory anemia with leukemic transformation.
 ...
PMID:Myelodysplastic syndrome with acquired hemoglobin H disease. Evolution through megakaryoblastic transformation into myelofibrosis. 327 51

Four patients with idiopathic myelofibrosis were found to have microcytic and/or hypochromic red cell indexes. The alpha/beta globin synthetic ratio determined by incubating peripheral blood with [14C]leucine was within normal limits in all patients studied. This is unlike a recent report of acquired hemoglobin H disease with decreased alpha/beta synthetic ratio in primary myelofibrosis. This indicates that mechanisms other than alpha-thalassemia-like defects may also be involved in the production of microcytic and hypochromic red cells in myelofibrosis.
 ...
PMID:Balanced globin synthesis in idiopathic myelofibrosis. 722 30

Four cases of endometrial extramedullary haemopoiesis are reported, all with associated haematological disease. The diagnoses of a myeloproliferative disorder and thalassaemia trait were made as a consequence of the histological observations and subsequent haematological investigations in two cases. The third case occurred in a patient with an established diagnosis of chronic myeloid leukaemia. The diagnosis of extramedullary haemopoiesis in the final case was made on autopsy material from a patient with multiple myeloma. The endometrium from five other women with known myelofibrosis was examined but extramedullary haemopoiesis was not found. Endometrium from 32 fetuses did not contain haemopoietic elements, excluding the likelihood of the endometrium being a common site for extramedullary haemopoiesis in development. Endometrial extramedullary haemopoiesis is an uncommon finding, but it is worthy of note, as it may herald the presence of an underlying haematological abnormality.
 ...
PMID:Endometrial extramedullary haemopoiesis. 761 62

Extramedullary hematopoiesis is a compensatory process for some hematologic diseases, such as spherocytosis, myelofibrosis and thalassemia. We report a 34-year-old man with beta-thalassemia intermedia who developed intrathoracic extramedullary hematopoiesis with recurrent pleural effusion. Diagnosis of extramedullary hematopoiesis of the pleura and soft tissue was established after thoracoscopic biopsy. Subsequently, the pleural effusion was controlled with intrapleural minocycline instillation. To our knowledge, this is the first case of extramedullary hematopoiesis described in the parietal pleura associated with massive pleural effusion and successfully treated with minocycline.
 ...
PMID:A case of intrathoracic extramedullary hematopoiesis with massive pleural effusion: successful pleurodesis with intrapleural minocycline. 792 88

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.
 ...
PMID:Spinal cord compression due to extramedullary hematopoiesis in the proliferative phase of polycythemia vera. 892 92

We performed an open, nonrandomized, multicenter phase-II trial to evaluate the efficacy and toxicity of 1 year of treatment with the oral iron chelator deferiprone in 38 mainly nonthalassemic patients with transfusional iron overload. Initial serum ferritin varied between 996 and 11.644 micrograms/l. Patients were treated with 3-6 g of deferiprone daily. Mean urinary iron excretion (UIE) in 36 evaluable patients was 21.0 mg/24 h and was significantly higher in the patients with thalassemia than in those with myelodysplasia. Negative iron balance was achieved in 20 patients (56%). The median duration of treatment was 10 months; due to side effects and other causes only 20 patients completed 1 year of treatment. Mean serum ferritin levels decreased from 3563 micrograms/l at the start of the trial to 2767 micrograms/l at 6 months (26 patients, p < 0.004) and to 2186 micrograms/l at 12 months (20 patients, p < 0.005). Serum ferritin levels normalized in two patients who were no longer transfusion dependent. Deferiprone was clearly not effective in three patients (two with myelofibrosis, one with myelodysplasia). One patient with myelodysplasia developed agranulocytosis after 12 months of treatment; this was rapidly reversible after stopping deferiprone. Three patients had a mild and transient decrease in white blood cell count. Other side effects leading to withdrawal from the trial consisted mainly of nausea (3 patients), arthralgia (2), and skin rash (1). No clinical signs of zinc deficiency were seen, although zinc excretion was increased in three patients. No changes were seen in liver enzymes, creatinine, antinuclear factor, T-cell subsets, cardiac function, visual acuity, and audiogram. Although our results confirm deferiprone as an effective iron chelator in patients with thalassemia and in some patients with other forms of iron overload, there is still some concern about the safety of this drug, which therefore, at this time, should be used exclusively in well-controlled clinical trials.
 ...
PMID:Long-term treatment of transfusional iron overload with the oral iron chelator deferiprone (L1): a Dutch multicenter trial. 895 43


1 2 3 4 Next >>