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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ultrastructure and adenine nucleotide metabolism of platelets from patients with acute leukemia were studied to elucidate possible mechanisms for the platelet dysfunction observed in this clinical setting. Nonstimulated (resting) platelets from leukemic patients varied greatly in size; exhibited marked variation in the number of alpha granules present per cell; had poorly delineated circumferential bands of microtubules; and often grossly dilated open channel systems or cytoplasmic vacuolization. The intracellular concentrations of ATP and ADP were significantly below normal, and the specific radioactivity of ATP and ADP of nonstimulated platelets in leukemia was equivalent to or exceeded that seen in stimulated normal platelets. Addition of ADP or collagen to platelets from leukemic patients was followed by retarded and incomplete shape change, delayed and incomplete centripetal migration of subcellular organelles, impaired degranulation, and the formation of loose aggregates composed of relatively few platelets. Stimulation of "leukemic" platelets with collagen led to the release of significantly subnormal amounts of ATP and ADP and no significant change in the specific radioactivity of the intracellular nucleotides. In contrast to the results in normal platelets, the conversion of ATP to inosine monophosphate and hypoxanthine in platelets in leukemia failed to increase significantly with collagen stimulation. The results indicate that abnormalities exist in the storage pool of adenine nucleotides and the release mechanism of platelets in acute leukemia. These defects appear to contribute to an impairment in the release reaction in these platelets. Many of the ultrastructural and metabolic defects seen in acute leukemia occur in platelets in preleukemia.
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PMID:The platelet defect in leukemia. Platelet ultrastructure, adenine nucleotide metabolism, and the release reaction. 4 18

Recent revival of interest in the use of vincristine (VCR) for the treatment of idiopathic thrombocytopenic purpura prompted us to evaluate the platelet function of our patients on VCR. Eighteen patients with acute lymphoblastic leukaemia (ALL) in remission, and nine children with solid tumours were studied on 80 occasions at different time intervals after their last VCR dose. A mildly elevated threshold for epinephrine-induced second phase aggregation and a delay in the onset of collagen-induced aggregation was found in patients with ALL not on VCR. Vincristine induced unobtainable second phase aggregation to epinephrine in 67%, 38%, 30% and to ADP in 53%, 13%, 33% of the patients 1 week, 2-3 weeks and 4 weeks respectively after administration. The thrombocytopathy was relative, not absolute, since collagen induced aggregation at all times. Platelet counts, uptake and release of serotonin, bleeding times, clot retractions and release of platelet factor 3 were normal. Platelet adhesion was abnormal in five of 12 patients tested. In vitro platelets are a hundred-fold less sensitive to VCR than in vivo. Cyclic adenosine monophosphate, cyclic guanosine monophosphate and dimethylsulfoxide do not protect platelets from VCR. The exact mechanism by which VCR abolishes second phase aggregation in patients is uncertain. Because of VCR's narrow therapeutic index between thrombocytopenia and thrombocythaemia, the use of VCR should be reserved for life-threatening haematologic disorders when treating non-malignant conditions.
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PMID:Platelet dysfunction in vincristine treated patients. 17 22

An antigen immunologically related to a group-specific antigen (gp52, a 52,000-dalton glycoprotein) of the mouse mammary tumor virus has been identified in paraffin sections of human breast cancers by means of the indirect immunoperoxidase technique. The specificity of the reaction with antibody against mouse mammary tumor virus was examined by absorption of the IgG with the following: (a) purified gp52; (b) a number of virus preparations (mouse mammary tumor virus, Rauscher leukemia virus, simian sarcoma virus, baboon endogenous virus, and Mason-Pfizer monkey virus); (c) normal plasma, leukocytes, breast tissue, milk, actin, collagen, and hyaluronic acid, all of human origin; (d) sheep erythrocytes and mucin. Only mouse mammary tumor virus (from C(3)H or Paris RIII strains and grown in either murine or feline cells) and purified gp52 eliminated the immunohistochemical reaction in the human breast tumors. Positive reactions were seen in 51 of 131 (39%) breast carcinomas of various histologic types, a minimal estimate in view of the limited number of sections from each tumor that could be examined. Negative reactions were obtained in all 119 benign breast lesions (cystic disease, fibroadenoma, papilloma, gynecomastia) and in all 18 normal breast tissues. With one exception, 99 carcinomas from 13 organs other than breast and 8 cystosarcomas were all negative.
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PMID:Detection in human breast carcinomas of an antigen immunologically related to a group-specific antigen of mouse mammary tumor virus. 20 5

Platelets from patients with myeloid leukaemia showed reduced aggregation with collagen or thrombin. These platelets also had a lower capacity to bind thrombin. This lower thrombin binding is due to a decrease in the total quantity of receptors available and not because of a change in the affinity. In the presence of the patients' plasma, the aggregation behaviour of normal platelets induced by thrombin as well as the clotting time of fibrinogen remained unchanged. The results suggest that the platelet dysfunction in myeloid leukaemia is partially due to a membrane defect involving the thrombin receptors which leads to an impaired induction of the initial stimulation.
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PMID:Defective binding of thrombin to platelets in myeloid leukaemia. 27 56

Platelet function was evaluated in eight patients with chronic granulocytic leukaemia (CGL), seven Ph1 positive and one Ph1 negative. Seven of the eight patients' platelets had an absence of the second wave of adrenaline induced aggregation on at least one occasion, while five had impaired collagen aggregation. The platelets of all seven patients with abnormal responses to adrenaline, aggregated with arachidonic acid, thus ruling out a cyclo-oxygenase deficiency. A marked decrease in the ADP, serotonin, and dense body content of platelets was found in all five patients evaluated. Mixtures of CGL patient platelets with platelets from normal donors who had ingested aspirin gave a normal biphasic response to adrenaline. Normal release of the storage pool contents from aspirin treated platelets was shown by stirring a mixture of CGL platelets and 14C-serotonin labelled aspirin treated platelets with adrenaline. The CGL platelets alone or in the mixture produced malondialdehyde in response to adrenaline. These experimental results suggest that CGL platelets have a storage pool deficiency but can synthesize prostaglandins and thromboxanes in response to arachidonic acid and adrenaline.
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PMID:Platelet storage pool deficiency and prostaglandin synthesis in chronic granulocytic leukaemia. 28 70

Platelets from a patient with eosinophilic leukaemia were not aggregated by ristocetin. The defect was not corrected by normal human plasma and was due to a platelet abnormality. The patient's platelets also showed a diminished sensitivity to aggregation by bovine factor VIIIVWF. The defect was not associated with a prolonged bleeding time. No abnormalities were detected in ADP, collagen or thrombin-induced platelet aggregation. Biochemical studies showed that the platelets were deficient in sialic acid. This deficiency was associated with a reduced staining for glycoprotein I following SDS-polyacrylamide gel electrophoresis. The results suggest an acquired platelet surface abnormality.
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PMID:A platelet defect in a patient with eosinophilic leukaemia: absent ristocetin-induced platelet aggregation associated with a reduced platelet sialic acid content. 45 58

A quantitative study of various aspects of platelet function was carried out in eight patients with typical hairy-cell leukaemia (HCL). In at least two patients platelet aggregation was convincingly reduced to more than one aggregating agent (ADP, adrenaline, collagen, thrombin, and ristocetin). Granular storage capacity for {(14)C} 5-HT was reduced in five of the six patients tested. The two patients with definitely abnormal aggregation had the greatest reduction in granular storage pool and the longest bleeding times of those tested but, like the other patients, they did not have a clinical haemostatic defect. It was concluded that a granular storage pool defect (SPD) was at least partly responsible for aggregation abnormalities in HCL since the platelet release reaction in response to thrombin appeared to be normal. All our patients ran a chronic course uncomplicated by any of the factors known to predispose to a platelet SPD acquired in the circulation. Although in the one patient tested before and after splenectomy there was some improvement in platelet aggregation after operation, there was no clear general relationship between defective platelet function and either previous splenectomy or platelet count. Since a direct involvement of the megakaryocytic series in the underlying cell proliferation of HCL seems unlikely, it is concluded that the platelet defect can most reasonably be attributed to the production of abnormal platelets as a result of marrow fibrosis and/or infiltration by hairy cells.
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PMID:Platelet function in hairy-cell leukaemia. 51 41

In vitro aggregation of the platelets from four patients with refractory anemia and two patients with acute myelomonocyctic leukemia revealed distinctive abnormalities. In five patients, there was deficient or minimal aggregation with adenosine diphosphate (ADP), epinephrine, or collagen and only one wave of aggregation could be elicited with ADP at any concentration. Ultrastructural studies revealed numerous isolated platelets, small aggregates with few platelet pseudopods, and the presence of a characteristic type of aggregate with heterogeneous platelet composition combining features of both the primary and the secondary waves of aggregation. These "mixed aggregates" were particularly abundant in the four patients who had refractory anemia and may constitute the structural basis of the single wave of aggregation observed.
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PMID:Ultrastructure of platelet aggregation in refractory anemia and myelomonocytic leukemia. I. Ultrastructure of aggregation in normal controls and general defects in refractory anemia and myelomonocytic leukemia. 106 6

A case of epithelial thymoma occurring synchronously with Philadelphia chromosome-positive chronic myelogenous leukemia and urinary bladder carcinoma in a 76-year-old man is described. Thymomas have been associated with numberous hematologic, collagen-vascular and autoimmune disease states, as well as with an increased incidence of nonthymic malignancy. Human thymoma-associated leukemia is, however, extremely unusual, despite the well-documented role of the thymus in leukemogenesis in experimental animals. No previous literature reports of thymoma associated with chronic myelogeneous leukemia were found. A review of long-term followup data of surviving thymoma patients is necessary to determine if an increased propensity to develop leukemia is present in present in patients with thymoma.
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PMID:Thymoma and chronic myelogenous leukemia: a case report. 106 82

A retrospective study of 116 children with Hodgkin's disease diagnosed in the period 1935-1970 was undertaken to assess the prognostic role of histopathologic classiciation and clinical extent of the disease. The ages of the 80 boys and 36 girls ranged from 2.5 years to 15.0 years (mean, 10.0 years). The histopathologic diagnosis by lymph node biopsy revealed lymphocyte predominance in 22, nodular sclerosis in 67, mixed cellularity in 24, and lymphocyte depletion in 3. Within the subgroup of nodular sclerosis, 47 biopsies had classic well-developed collagenous bands, whereas 20 were in the cellular phase (10 without collagenous bands and 10 with minimal collagen). The clinical extent of disease was determined. There were 33 patients with Stage I disease, 38 with Stage IIA, 12 with Stage IIB, 24 with Stage III, and 9 with Stage IV. Survival correlated with histopathologic type and clinical stage, but not with age or sex. Survival was not dependent on the degree of collagenization in nodular sclerosis. There were 28 patients who survived for more than 10 years. Four of these 29 subsequently died owing to acute myelomonocytic leukemia, carcinoma of the breast, sepsis, and progression of Hodgkin's disease, respectively. Neoplasms developed in two other long-term survivors (thyroid carcinoma in one, and multiple basal cell carcinomas in the other).
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PMID:Hodgkin's disease in childhood. 120 66


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