Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 74-year-old Japanese male with a 4-year history of refractory anemia with excess of blasts is reported here. Chromosome study revealed the bone marrow cells of this patient to contain a t(3;4)(q26;q21). Ultrastructural analysis of platelet peroxidase and immunocytochemical study using monoclonal antibody for platelet antigen revealed a large number of blasts in the bone marrow to be megakaryoblasts. Thus, this case was thought to be one of a myelodysplastic syndrome with excess of blasts including megakaryoblastic proliferation showing chromosome changes at 3q26 and 4q21. The relationship of the anomaly on the long arm of a chromosome #3, especially at band 3q26, to abnormal megakaryoblastic proliferation is discussed.
 ...
PMID:Translocation t(3;4)(q26;q21) in myelodysplastic syndrome with megakaryoblastic proliferation. 339 94

Although it is well recognized that granulocytic sarcoma can cause localized lymphadenopathy, widespread nodal involvement by acute myelocytic leukemia (AML), clinically mimicking non-Hodgkin's lymphoma, has only been previously described twice. We report the clinicopathological, immunological, and cytochemical features of two patients who had widespread, prominent lymphadenopathy secondary to AML as well as concurrent marrow leukemia (M1 and M2). For one patient the lymphadenopathy was the predominant abnormality prompting him to seek medical attention, while the second patient had symptoms of infection following a 9-month history of myelodysplasia. The disease in both patients was aggressive; one patient survived only 1 week and the other survived only 5 weeks after diagnosis. In both cases the granulocytic sarcoma was confirmed by cytochemistry studies (naphthol ASD-chloroacetate esterase on tissue sections and myeloperoxidase on imprint smears), and electron microscopy, including morphology (both cases) or ultrastructural localization of myeloperoxidase (case 2). Non-specific esterase activity was not detected in either patient's blasts, although serum lysozyme was elevated in both cases. Immunological studies revealed reactivity of both patients' cells with panleukocyte, MY4, MY7, OKM-1, and Leu-M1 monoclonal antibodies and with alpha-1-antitrypsin and muramidase antibodies. The cells of one of these patients also reacted with anti-S-100 protein. Although the cytochemical studies indicated that both cases exhibited only myeloid differentiation, the immunological markers suggested that the tumor cells possessed some features of monocytes, perhaps explaining their propensity for widespread tumor formation. Morphological, immunological, cytochemical, and ultrastructural methods of diagnosing granulocytic sarcoma are presented.
 ...
PMID:Acute myelocytic leukemia manifested by prominent generalized lymphadenopathy: report of two cases with immunological, ultrastructural, and cytochemical studies. 345 62

Quantitative cytochemistry of components of blood neutrophil azurophilic granules (myeloperoxidase, chloroacetate esterase, beta-glucuronidase, and acid phosphatase) and specific granules (lactoferrin) has been performed by scanning and integrating microdensitometry in 13 patients with a myelodysplastic syndrome and 11 patients with chronic granulocytic leukaemia. Both patient groups showed a reduction of enzyme activity in azurophilic granules, and also of lactoferrin, consistent with abnormal development of neutrophil granules. These cytochemical changes in blood neutrophils are similar to those found in acute myeloid leukaemia, are consistent with a leukaemic maturation defect, and may be of diagnostic value.
 ...
PMID:Quantitative cytochemistry of blood neutrophils in myelodysplastic syndromes and chronic granulocytic leukaemia. 609 32

We have tried to improve existing methods for demonstration of platelet peroxidase (PPO) in human platelets and megakaryocytes by introducing a fixation of 0.1% glutaraldehyde prior to incubation in the DAB medium. This prefixation with low concentration of glutaraldehyde preserves excellent morphological detail and does not inhibit PPO activity. All 23 platelet-rich plasma samples show PPO reaction product in the dense tubular system after incubation in DAB medium with 0.003% H2O2. When 0.01% H2O2 is used in excessive DAB medium, PPO activity can also be demonstrated in platelets and megakaryocytes of bone-marrow cell suspensions. This method can be used for the identification of megakaryoblasts in acute non-lymphocytic leukemia, myelodysplastic syndromes and in blastic crisis of chronic myeloid leukemia. PPO cytochemistry can be combined with postfixation in a OsO4-ruthenium red mixture. This method reveals alpha-granules, dense bodies, microtubuli, glycogen, mitochondria, dense tubular system and invaginated membrane system in the same platelet and is useful for investigation of platelet ultrastructure.
 ...
PMID:A reliable method with good cell preservation for the demonstration of peroxidase activity in human platelets and megakaryocytes. 619 33

Neutrophil myeloperoxidase (MPO) activity was analyzed by a semi-quantitative cytochemical method in 268 subjects divided into several groups. 17 subjects with significantly reduced MPO activity were found: 11 of 23 in the preleukemia group, 2/14 AMLs, 1/20 myeloproliferative syndrome, 1/7 carcinoma with bone marrow metastases, 1/33 diabetes mellitus and 1/50 normals. Only in the preleukemia group, was MPO significantly reduced in comparison to the normal group (p less than 0.005). The high frequency of acquired MPO deficiency in preleukemia represents a useful criterium for this diagnosis. Furthermore, in these patients, as well as in the other subjects studied, no apparent correlation between MPO level and infection could be demonstrated.
 ...
PMID:Partial myeloperoxidase deficiency. 628 28

In seven subjects with partial and apparently acquired form of myeloperoxidase (MPO) deficiency, some functional properties of neutrophils (PMNs) were studied. Five patients suffered from preleukemia, one from diabetes mellitus and one from carcinoma of the breast with bone marrow metastases. Intracellular bactericidal activity, oxygen consumption and superoxide radical production were within normal limits. In three patients with preleukemia, the serum opsonic activity was markedly reduced (less than m-3SD) in an autologous system, but normal in the presence of pooled normal serum. Decreased opsonic activity was also found when these patient's sera were assayed in the presence of normal PMNs. Since the levels of IgG and C3 were comparable in the patients' sera and the pooled serum, a deficiency of another unknown opsonin or the presence of an opsonization inhibitor has to be postulated. The partial MPO defect apparently doesn't decrease the intracellular killing of Staphylococcus aureus by PMNs. The known susceptibility to bacterial infections in preleukemia may be explained by the reduction of serum opsonization conducing to a secondary decrease of the ingestion and killing of bacteria by the PMNs.
 ...
PMID:Partial myeloperoxidase deficiency in preleukemia. 630 46

Neutrophil function studies have been carried out in a series of 44 patients with primary myelodysplastic syndromes (MDS). In vitro tests of phagocytosis and killing of Candida guilliermondii and Staphylococcus aureus identified 13 patients with abnormal neutrophil function at presentation and a further 10 who developed abnormalities during the course of their disease. The incidence of defective function in the five disease categories in this series was: refractory cytopenia (RC) 8/17; refractory cytopenia with sideroblastic change (RC + SC) 5/8; acquired idiopathic sideroblastic anaemia (AISA) 2/4; refractory anaemia with excess blasts (RAEB) 7/11; chronic myelomonocytic leukaemia (CMML) 1/4. Eleven of 23 patients with defective neutrophil function experienced severe infective complications; in only three of these patients were neutrophil counts less than 1 X 10(9)/l and susceptibility to infection was considered to reflect, at least partially, qualitative neutrophil abnormalities. There was no correlation between absolute neutrophil count and defective function. Abnormal overall neutrophil microbicidal activity was equally associated with impaired and normal phagocytosis. Some patients with intracellular killing defects had reduced myeloperoxidase (MPO) activities and one had reduced hexose monophosphate shunt (HMPS) activity. In two patients, whose neutrophils showed markedly impaired candidacidal activity, levamisole corrected function when added in vitro at 10(-7) M and also when administered in therapeutic dosage. It is suggested that deranged function, probably reflecting abnormalities in maturation of the granulocyte series, occurs across the myelodysplastic spectrum and that several microbicidal mechanisms may be defective.
 ...
PMID:Defective neutrophil function and microbicidal mechanisms in the myelodysplastic disorders. 631 78

Morphological and functional abnormalities of the megakaryocytic series have been well described in myelodysplastic syndromes. Platelet peroxidase has always been demonstrated in abnormal megakaryocytes and early megakaryoblasts in such syndromes. We have studied a case of myelodysplastic syndrome with marked morphological abnormalities of megakaryocytes in which ultrastructural studies showed the coexistence of platelet peroxidase positive and platelet peroxidase negative megakaryocytes. This enzymatic deficiency was confirmed by the ultrastructural study of circulating platelets. This case appears to be the first report of a partial platelet peroxidase deficiency. It adds to the enzymatic abnormalities in myelodysplastic syndrome already described for the red cells and the granulocytic cells.
 ...
PMID:Platelet peroxidase deficiency in a case of myelodysplastic syndrome with myelofibrosis. 663 May 73

We describe a 68-year-old Japanese male with hypoplastic acute myelogenous leukemia (AML) who achieved complete hematological reconstitution following granulocyte colony-stimulating factor (G-CSF) administration. The patient had pancytopenia and the bone marrow was hypocellular with 19 to 36% peroxidase-positive blasts without morphological abnormalities suggestive of myelodysplasia. After receiving G-CSF as a supportive therapy for pneumonia, the blood count became normal and the bone marrow was normocellular with less than 5% of blasts. Without subsequent chemotherapy, he relapsed as a form of overt leukemia and died of pneumonia. Chemotherapy may be necessary to maintain remission in hypoplastic AML after hematopoietic reconstitution by G-CSF.
 ...
PMID:Successful hematopoietic reconstitution with granulocyte colony-stimulating factor in a patient with hypoplastic acute myelogenous leukemia. 749 88

Expression of P-glycoprotein (PGP), the product of the multi-drug resistance mdr1 gene was studied by immunocytochemistry on bone marrow slides using JSB1 monoclonal antibody and the alkaline phosphatase-antialkaline phosphatase (APAAP) and avidin-biotin-peroxidase (ABC) techniques in 82 cases of untreated myelodysplastic syndromes (MDS), of whom ten had evolved to AML (MDS-AML). The relationship between PGP expression, myeloperoxidase activity and immunophenotype of blast cells, karyotype and outcome was also analyzed. PGP expression was found in the blasts of 34 of the 82 patients (41%), the majority of blasts being stained in positive cases. PGP positivity was rare in 'low risk' MDS (RA and RARS: 2/12 cases) as opposed to 'high risk' MDS (RAEB, RAEB-T, CMML: 25/60 cases) and MDS-AML (7/10 cases) (p = 0.04). PGP expression was positively correlated to the presence of myeloperoxidase activity in less than 3% of blasts (p = 0.025), and CD34 antigen expression (p = 0.04), whereas CD33 antigen expression had borderline significance (p = 0.07), demonstrating that PGP expression predominated in blasts with an immature phenotype. An abnormal karyotype, and especially the presence of monosomy 7, was not correlated to a higher incidence of PGP expression, however. There was a trend for more frequent progression to AML and for shorter survival in PGP-positive cases, but differences with PGP-negative cases were not significant. Twenty patients received intensive anthracycline-Ara-C chemotherapy and ten (50%) achieved complete response, including 9/13 (69%) PGP-negative cases and 1/7 (14%) PGP-positive cases (p = 0.03). Twenty other patients were treated with low-dose Ara-C and ten (50%) responded (complete or partial response). PGP-positivity did not negatively affect response to low-dose Ara-C: 4/11 responses in PGP-negative, and 6/9 responses in PGP-positive patients (p = 0.18). Because the treatment choice in advanced MDS (especially between anthracycline-Ara-C or low-dose Ara-C, chemotherapy) is difficult, our preliminary therapeutic results suggest that the analysis of PGP expression could have practical importance in MDS. These findings however, will have to be confirmed on larger numbers of patients. Clinical trials using drugs potentially reverting mdr, activity could also be warranted in MDS.
 ...
PMID:Expression of the multidrug resistance P-glycoprotein and its relationship to hematological characteristics and response to treatment in myelodysplastic syndromes. 751 32


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>