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

The bone marrow macrophages of patients with homozygous beta-thalassaemia were frequently situated adjacent to collagen fibres and sometimes formed intrasinusoidal cytoplasmic protrusions. They also appeared to phagocytose processes of erythroblast cytoplasm (at times containing precipitated alpha-chains) which projected into them from neighbouring erythroblasts. The cytoplasm of the macrophages included large numbers of heavily-iron-loaded secondary lysosomes of various sizes and shapes in addition to phagocytosed erythroblasts, erythrocytes and extruded erythroblast nuclei. Numerous ferritin molecules were found in the cytoplasmic matrix but there were hardly any in the mitochondria, endoplasmic reticulum or golgi saccules. A small number of ferritin molecules were present within the nucleus. Electron microscope autoradiographs of marrow fragments which had been incubated with [3H]leucine for 1 h revealed the presence of newly-synthesized protein molecules in all types of secondary lysosomes. Light microscope autoradiographs showed the [3H]thymidine labelling index of the bone marrow macrophages was less than 1% and suggested that only a very small proportion of these cells were actively preparing for division.
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PMID:Some features of bone marrow macrophages in patients with homozygous beta-thalassaemia. 20 37

This report details the results of studies performed in nine patients with homozygous beta-thalassemia evaluating platelet function and prostaglandin formation. Platelet malonyldialdehyde (MDA) formation in the presence of N-ethyl maleimide (NEM 1 mM) or thrombin (0.5 u/ml) was used as an indicator of platelet prostaglandin synthesis. The data on the nine patients revealed two distinct subgroups of patients. Six of nine thalassemics, demonstrated platelet abnormalities. Their mean bleeding time was 7.5 +/- 2.5 min (1 SD), significantly prolonged (P less than 0.005) when compared to a value of 3.5 +/- 1.0 min in normal controls. MDA formation in the presence of NEM was significantly decreased (P less than 0.005) to 2.41 +/- 0.49 (1 SD) when compared to a control value of 3.24 +/- 0.33 nmoles MDA/10(9) platelets. Similarly, the mean value for thrombin induced MDA was 0.98 +/- 0.18 nmoles which was decreased (P less than 0.02) when compared to a value of 1.26 +/- 0.2 in the controls. Platelet aggregations with adenosine diphosphate (ADP), epinephrine, and collagen were abnormal in all six patients. However, when platelets from these patients were mixed with platelets from donors who had ingested aspirin 2-8 hr before donation mutual correction and secondary irreversible aggregation of the mixture resulted. No mutual correction was observed when the thalassemic platelets were preincubated with aspirin in vitro before mixing with platelets from donors who had recently ingested aspirin. Although the total amount of platelet malonyldialdehyde formed by the thalassemic platelets in response to NEM and thrombin was decreased when compared to normal controls, this reduction was not the cause of the platelet aggregation abnormalities. This appears to be so because the amount of MDA, and, thus, prostaglandin endoperoxides synthesized by these platelets in response to external stimuli was sufficient to cause irreversible aggregation of platelets from donors who had recently ingested aspirin, and were, therefore, unable to synthesize their own endogenous platelet endoperoxides. In the remaining three patients, bleeding times, platelet aggregation, and MDA formation was normal. No correlation was observed between the platelet abnormalities noted and the magnitude of iron overload, presence of fibrin degradation products, liver function abnormalities, or the use of iron chelators in the individual patient. Family studies were normal. Although the platelet dysfunction does not appear to be of major significance in the usual patient with thalassemia major under normal circumstances, antiplatelet aggregating agents should be used with caution. Aspirin inhibits platelet endoperoxide and prostaglandin formation and this effect may potentiate the platelet dysfunction present in some patients with thalassemia major.
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PMID:Platelet dysfunction in homozygous beta-thalassemia. 52 94

Haemorrhagic tendency, including frequent epistaxis and easy bruising, has been observed in patients with beta thalassaemia major. Disturbances in the coagulation system were also described in this condition, which probably resulted from liver damage associated with this disease. There was, however, no quantitative or qualitative correlation between the haemorrhagic manifestations on the one hand and the abnormalities in the clotting mechanism on the other. Platelet functions were studied in 15 patients with beta thalassaemia major and in 5 with thalassaemia minor. In most of the thalassaemia major patients and in some with thalassaemia minor, diminished platelet aggregation to ADP, collagen, ristocetin and epinephrine was found. These anomalies could not be corrected by the resuspension of the thalassaemic platelets in normal plasma.
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PMID:Abnormal platelet functions in beta thalassaemia. 66 57

During a study of pathogenetic mechanisms in the hepatic cirrhosis of thalassaemia major, 16 liver biopsies were examined by electron microscopy. Previous ultrastructural studies of liver cells during iron overload have shown electron-dense iron as lysosomal haemosiderin, and as lysosomal and cell-sap ferritin. In this study, all biopsies, regardless of the patient's age, showed ferritin molecules within lysosomes in a specific pattern in relationship with regularly arranged lamellae. This membrane-associated lysosomal ferritin is considered to be a stage in the segregation of iron seen in iron overload. The dimensions and electron density of individual ferritin molecules indicate differences between cell sap and lysosomal ferritin. Intracellular ferritin transport and iron-seclusion mechanisms are reconsidered in view of these findings. The liver biopsies of thalassaemic infants also provide information about the causal relationship between iron overload and collagen deposition. Since the collagen deposition precedes any morphological evidence of cellular injury (other than the increased iron content), the primary cirrhotogenic factor in thalassaemia is apparently not cell necrosis but possibly excessive collagen deposition induced by iron.
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PMID:The liver in thalassaemia major: ultrastructural observations. 105 35

Hepatosplenomegaly accompanied with different intestinal troubles is more or less a marked clinical manifestations in children. The histopathological and histochemical changes were studied in biopsied materials taken from the sigmoidal and rectal tissues of 49 children. These children had schistosomiasis mansoni (26), schistosomiasis and amoebiasis (4), schistosomiasis and tuberculosis (TB.) (2), amoebiasis (4), thalassemia (6), acute myeloid leukaemia (AML) (1), mucopolysaccharidosis (1) and bacillary dysentery (5). The pathological changes were erosion ulceration hyperplasia, atrophy, crypt-abscess and fibrosis (mucosa) and oedema, congestion, cellular infiltration (Lamina propria). The chemical changes were the mucin secretion, deposition of collagen and fibrin and activity of the argentaffin cells. Not all the disease agent had the same effect, but changes were marked mainly in children with S. mansoni and/or E. histolytica.
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PMID:Histopathological and histochemical studies on the sigmoidal and rectal tissues of hepatosplenic children with gastro-intestinal troubles. 143 Dec 83

Melioidosis is an infection of humans and animals caused by a gram-negative motile bacillus, Pseudomonas pseudomallei. Forty-nine patients with melioidosis complicating diabetes mellitus, collagen vascular disorders, leukemia/lymphoma, and other hematologic malignancies are described. Twenty-nine of these patients had disseminated/septicemic infection, two developed toxic shock syndrome, and one with AIDS experienced recrudescent melioidosis. Patients with disseminated melioidosis often have a variety of defects in cellular immunity both in vitro and in vivo. In humans with recrudescent melioidosis, cellular immunity can be transferred by a transfer factor and by levamisole, a cellular immunopotentiating agent. The results of the treatment of our patients with disseminated/septicemic melioidosis with antimicrobial agents in combination have been successful. In recent years, four cases of fungal arteritis due to Pythium species and one case of keratitis due to Pythium were seen. Almost all patients with fungal arteritis had thalassemia; all presented with pain in the lower extremities and gangrenous lesions of the toes. Pythium species, an aquatic Phycomycetes, was identified in these cases as a human pathogen on the basis of clinical features, pathologic findings, and--of greatest importance--the isolation of the etiologic fungi. These five cases with remarkably similar presentations exhibited certain similarities with and differences from cases of mucormycosis, entomophthoromycosis, and peniciliosis.
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PMID:Tropical disease in the immunocompromised host: melioidosis and pythiosis. 260 81

Collagen, the principal structural macromolecule of the body, is expressed as a family of genetically distinct protein molecules. Two main subfamilies are emerging, the interstitial, fibrillar collagens (Types I, II and III) and the cell-associated or basement membrane collagens (Types IV and V). All types are synthesized as precursor molecules of procollagen, which are trimmed by specific proteases to form the subunit of extracellular fibrils. Evidence is accumulating that the osteogenesis imperfecta group of diseases are inherited molecular pathologies of Type I collagen, the commonest collagen type. However, a variety of biochemical lesions are anticipated, in part because of the marked clinical heterogeneity of the disorder. For example, in one variant a defect is becoming evident in the primary structure of Type I procollagen which seems to inhibit its rate of secretion from the cell. In another, there is evidence of complete failure to express the collagen alpha 2 chain, a disorder perhaps analogous to the thalassemia syndromes of hemoglobin pathology.
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PMID:Concepts in collagen biochemistry: evidence that collagenopathies underlie osteogenesis imperfecta. 728 75

Although osteoarthritis is characterized by a uniform pattern of clinical and radiological manifestations, it is a syndrome that can be produced by a variety of causative factors. Rare causes of osteoarthritis can be categorized as follows: 1) systemic metabolic disorders due to known biochemical and/or genetic abnormalities, such as hemochromatosis, ochronosis, Wilson's disease, Ehlers-Danlos syndrome (and probably the "idiopathic" joint hypermobility syndrome), sickle cell anemia, and thalassemia; 2) endocrine disorders, such as acromegaly, whose joint manifestations are now well-known, and hypothyroidism; 3) Paget's disease of bone, osteopetrosis (which induces changes in bone elasticity), and other systemic bone diseases; 4) dysplasias, which form a vast group including familial polyepiphyseal dysplasia, spondyloepiphyseal dysplasia congenita (especially its milder forms), Stickler's syndrome, osteo-onychodysplasia, Kniest's dysplasia, trichorhinopharyngeal syndrome, and a group of diseases that affect the epiphyses; 5) endemic forms of osteoarthritis, e.g., Mselini disease, Kashin-Beck disease, and Malnad disease, which are unknown in western Europe but have been reported to affect thousands of individuals in endemic areas. All these disorders are usually responsible for premature osteoarthritis, whose presentation sometimes bears the imprint of the causative abnormality but can be identical to that of common osteoarthritis. The effects of toxic substances (Kashin-Beck disease) or genetically-determined collagen II abnormalities (epiphyseal dysplasias) may explain the occurrence of these rare forms of premature osteoarthritis.
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PMID:[Osteoarthritis of rare etiology]. 785 7

A scanning electron microscopy study of liver changes has been carried out in three patients affected by beta-thalassemia intermedia (BTI). Applying a new osmium maceration method, recently developed in our laboratory, we had the opportunity to obtain, at SEM, tridimensional images of intra and extracellular structures. Other than the previously reported lesions in BTI, we observed the following pathological findings: disarrangement of the cell structure by a high number of hemosiderin loaded lysosomes; alterations in shape and in diameter of the nuclear pores; presence of apoptotic bodies scattered among the parenchymal cells; deposition of collagen fibers in the space of Disse to form a perihepatocytic dam; enlargement of the sinusoidal endothelial cell fenestrae of the sieve plate. By complete digestion of liver cells, we evidenced a diffuse pericellular fibrosis, made up of interlacing fibrils. Our study evidences some not yet reported morphological lesions in BT. Since patients affected by BTI do not need blood transfusions, these lesions could be considered intrinsic of the disease.
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PMID:A 3D study of intra and extracellular structures of liver in beta-thalassemia intermedia: an OsO4 maceration analysis. 906 44

The PFA-100 device is a new instrument for the in-vitro testing of platelet function. Primary haemostasis is stimulated by recording the closure time taken for platelets to seal a 150 microm aperture in the centre of a membrane coated with collagen and either epinephrine or ADP. Patients with type 3 von Willebrand's disease (n = 4) all had infinitely prolonged closure times (> 200 s) with both types of cartridge. A patient with afibrinogenemia exhibited only slightly prolonged closure times of 111 and 166 s for the ADP and epinephrine membranes, respectively. Patients with Glanzmann's thrombasthenia (n = 6) and Bernard Soulier syndrome (n = 2) had grossly prolonged closure times (> 200 s) with both types of cartridges. These results confirmed that the PFA-100 system was highly dependent on normal von Willebrand factor, glycoprotein Ib and glycoprotein IIb/IIIa levels but not on plasma fibrinogen. Patients with storage pool disease (n = 6) and Hermansky Pudlak syndrome (n = 7) had prolonged closure times with the epinephrine cartridge. There was no evidence of enhanced platelet function in patients with antiphospholipid syndrome, in sickle-cell disease or thalassemia. However, ingestion of aspirin resulted in a near consistent and significant prolongation of the closure time for the epinephrine cartridge but not for the ADP cartridge in both normal subjects and patients. The test offers a reliable, reproducible, rapid and simple means of assessing high-shear platelet function in vitro.
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PMID:Performance of the platelet function analyser PFA-100 in testing abnormalities of primary haemostasis. 1007 Aug 32


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