Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0002874 (aplastic anemia)
 5,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We recently reported the development of several monoclonal antibodies (MoAbs) to native human erythropoietin (Ep). In the present study we have used the two antibodies with highest affinity to develop a two-sided or sandwich enzyme-linked immunosorbent assay (ELISA) to measure Ep in human serum. In this assay Ep is incubated in microtiter wells precoated with the first (IgE) anti-Ep antibody. Assay wells are then incubated with the second (IgG1) anti-Ep antibody, which is labeled noncovalently with the enzyme alkaline phosphatase (AP) by means of bispecific tetrameric antibody complexes consisting of IgG1 anti-Ep cross-linked to IgG1 anti-AP using rat MoAbs specific for mouse IgG1. Application of this noncovalent labeling procedure, in combination with substrate amplification, results in a detection sensitivity of 0.5 to 1.0 mU/sample (5 to 10 mU/mL), which makes this assay suitable for measuring normal serum Ep levels. The validity of this ELISA for quantitating Ep in biological fluids was demonstrated by the parallelism obtained between pure recombinant Ep dose-response curves and those obtained with plasma and serum from healthy donors and patients with various hematologic disorders. Normal plasma Ep levels detected with this ELISA ranged from 9 to 101 mU/mL with a mean of 32 +/- 23 (SD) mU/mL. Ep levels in sera from patients with polycythemia vera were in the low to normal range, whereas Ep levels in sera from patients with secondary polycythemia and patients with aplastic anemia were moderately to strongly elevated. These results demonstrate that the Ep-ELISA is a sensitive, reliable, and nonradioactive immunologic method for quantitating Ep levels and should prove useful in a variety of clinical and laboratory settings.
 ...
PMID:An enzyme-linked immunosorbent assay for erythropoietin using monoclonal antibodies, tetrameric immune complexes, and substrate amplification. 247 3

The toxic effects of environmental factors at work places on the hematopoietic and immune systems are of basic importance due to the time of exposure, lasting on average 8 hours daily during one week. Porphyrinurias and porphyrias have been observed after exposure to hexachlorobenzene, chlorinated dibenzodioxins, polychlorinated biphenyls, polybrominated biphenyls, vinyl chloride and lead. Aplastic anemia may occur after exposure to benzene, pesticides, arsenic, cadmium and copper compounds. Megaloblastic anemia has been noted in subjects exposed to arsenic, chlordane, benzene and nitrous oxide. Methemoglobinemia is induced by aromatic nitro and amino compounds. Hemolytic reactions caused by arsenic, methyl chloride, naphthalene, lead, cadmium and mercury compounds represent a separate problem. Immunodeficiencies resulting in decreased antitumor and antiinfectious immunity have been reported in subjects exposed to asbestos, ozone, dimethylsulphoxide, vinilidene chloride, and benzene homologues. Lymphocytopenia may be induced by manganese, lead, toluene and industrial noise. Neutropenia was marked after exposure to carbon disulphide, arsenic compounds, benzene and electromagnetic fields. Only a few reports concern the lymphocyte T3, T4 and T8 subpopulations. Electromagnetic fields (microwaves) cause an imbalance of that subpopulation, consisting of a decrease in the T8 cell count. The neutrophil enzymes, such as myeloperoxidase and alkaline phosphatase, decrease in their activity after exposure to polychlorinated biphenyls, carbon disulphide, chlorobenzene and DDT. A majority of agents cited include genotoxic effects reflected in chromosome aberrations and increased sister chromatid exchange and abnormal unscheduled DNA synthesis. Leukemia or lymphoma risk is increased after exposure to pesticides, electromagnetic fields, benzene and irradiation.
 ...
PMID:Immunotoxic and hematotoxic effects of occupational exposures. 817 62

Leucocyte alkaline phosphatase (LAP) is an enzyme expressed on the external aspect of the neutrophilic granulocyte plasma membrane, and represents a specific marker for the fully differentiated granulocyte. In this report we characterize 1B12.1, a monoclonal antibody raised against human bone alkaline phosphatase, by its ability to recognize the LAP protein. As assessed by Western blot analysis, following electrophoresis under non-reducing conditions, the antibody specifically reacts with LAP upon forced expression of the protein in simian COS-7 fibroblasts. In addition, the 1B12.1 antibody recognizes partially purified LAP isolated from peripheral blood granulocytes. With this antibody we developed a quantitative flow-cytometry-based method for the determination of LAP. Double fluorescence flow cytometry demonstrated that the LAP protein was present in relatively high amounts in neutrophilic granulocytes, but not in monocytes, natural killer cells, or B and T lymphocytes of normal individuals. The protein was completely absent in granulocytes obtained from chronic myeloid leukaemia and paroxysmal nocturnal haemoglobinuria patients. Higher than normal levels of LAP protein were evident in neutrophilic granulocytes of patients suffering from polycythaemia vera, essential thrombocythaemia and severe aplastic anaemia. However, the highest amounts of LAP protein were present in the granulocytes of normal individuals treated with G-CSF for the isolation of peripheral blood stem cells.
 ...
PMID:Flow cytometry of leucocyte alkaline phosphatase in normal and pathologic leucocytes. 907 26

Expression of alkaline phosphatase (ALP) on the surface membrane of neutrophils (mNAP) was studied by immunofluorescence using an anti-ALP monoclonal antibody. Fluorescent intensity distribution of mNAP was analyzed using FACS (fluorescence-activated cell sorter). The mean fluorescent intensity (MFI) of the mNAP in this assay was well correlated with the neutrophil ALP (NAP) score demonstrated cytochemically (r = 0.832). mNAP levels in various hematological disorders were evaluated by % mNAP+ cells and MFI. The levels in aplastic anemia and polycythemia vera were significantly higher, and in chronic myelocytic leukemia and paroxysmal nocturnal hemoglobinuria (PNH), the levels were significantly lower compared with the levels in healthy volunteers. Two-color immunofluorescence with anti-ALP and anti-CD16 showed that the PNH clone was essentially negative for mNAP, whereas residual normal neutrophils (CD16+) had levels slightly higher than those in normal individuals. Highly reproducible results were obtained in the blood samples which were stored at 4 degrees C for at least 24 hr without any treatment prior to immunofluorescent staining. No degradation of fluorescent intensity was seen 4 days after staining and fixation. The mNAP assay is simple, without subjective evaluation for quantification, and is useful for differential diagnosis of hematological disorders.
 ...
PMID:Assessment of alkaline phosphatase on the surface membrane of neutrophils by immunofluorescence. 988

The content of cytochrome oxidase (CCO), succinate dehydrogenase (SDH) and neutrophil alkaline phosphatase (NAP) in bone marrow cells in 68 cases of aplastic anemia before and after treatment was determined by computerized graphical analysis and compared with that of normal volunteers (control group). The significantly lowered CCO and SDH levels and the markedly increased NAP content before treatment (P < 0.01) became approximately normal after that of supplementing the kidney and removing blood stasis (P > 0.05).
 ...
PMID:An enzymologic study on bone marrow cells in patients with aplastic anemia treated by supplementing the kidney and removing blood stasis. 1103 75

It has previously been shown that patients with aplastic anemia (AA) have a stem cell defect both of proliferation and differentiation. This has been shown by long-term bone marrow (BM) culture, long-term initiating cell assays, and committed progenitor assays. We present, for the first time, data on megakaryocyte (Mk) colony formation from purified BM CD34(+) cells from patients with AA. The results are compared with those from normal controls and from patients with paroxysmal nocturnal hemoglobinuria (PNH) and the myelodysplastic syndromes (MDSs). Those treated for AA had previously received immunosuppression (antithymocyte globulin and/or cyclosporin). No patients had received bone marrow transplantation. A total of 13 AA patients (five untreated, eight treated), six PNH, six MDS, and 13 normal donors were studied. BM CD34(+) cells were purified by indirect labeling and then cultured in a collagen-based Mk assay kit (MegaCult-C, StemCell Technologies). The cultures were fixed on day 12, and the Mk colonies were identified by the alkaline phosphatase anti-alkaline phosphatase technique using the monoclonal antibody CD41 (GP IIb/IIIa). The slides were scored for Mk colony-forming units (CFU-Mks) (3-20 and >20 cells), Mk burst-forming units (BFU-Mks) (>50 cells), and mixed colonies. The results show that total Mk colony formation in AA was significantly lower than in normal donors (p<0.0001), both in untreated patients/nonresponders to treatment (p = 0.0001) and in complete/partial responders (p<0.002). There was no significant difference in Mk colony formation in treated and untreated patients (p = 0.05). Patients with AA had a lower total colony formation than PNH patients (p = 0.0002). PNH patients exhibited lower colony formation than normal controls (p = 0.03), as shown by MDS patients, although the considerable number of variables resulted in a lack of statistically significant difference from normal controls (p = 0.2). We have now shown that Mk colony formation from purified BM CD34(+) cells is significantly reduced, supporting previous evidence that AA results from a stem cell defect.
 ...
PMID:In vitro proliferation and differentiation of megakaryocytic progenitors in patients with aplastic anemia, paroxysmal nocturnal hemoglobinuria, and the myelodysplastic syndromes. 1107 31

In order to investigate the clinical characteristics of hematological abnormality in patients with systemic lupus erythematosus (SLE) and inquire into the basis for differential diagnosis, the hematological data of 92 cases with lupus erythematosus-related hematological disorder (SLERHD) were retrospectively analyzed by use of SPSS/PC software. The results showed that these patients were short of specificity in clinical manifestation and hemogram, however, all cases possessed multiple SLE-related autoantibodies, increase of serum globulin level and varying extent dermal and arthral signs. The incidence of primary or initial symptom in the 92 cases was as follow: 65 anemia (72.8%), 39 purpura (42.4%), 17 hemolytic anemia (18.5%), 56 leukopenia (60.9%), 54 thrombocytopenia (58.7%), and 41 pancytopenia (44.6%). The bone marrow examinations showed that the cellularity of nucleated cells was mostly normal, and active proliferation in 57 cases (61.9%) and hypercellularity in 35 cases (38.1%); the G/E ratio was normal in majority, and G/E ratio > 3 in 59 cases (64.1%) and < 3 in 33 cases (35.9%) and G/E < 1 in 17 cases with hemolytic anemia Coombs' test positive; megakaryocyte counts were normal in 11 cases (11.9%), increase in 80 cases (86.9%) and lower than 7/marrow smear in 1 case (1.1%). Neutrophil alkaline phosphatase staining was negative in all of the cases. From above data it is concluded that patients with SLERHD are varied in clinical and blood pictures, but all patients are provided with multiple SLE-related autoantibodies, globulinemia and dermal and arthral signs. It is easy to identify SLERHD from aplastic anemia, myelodysplastic syndrome, idiopathic thrombocytopenic purpura, autoimmune hemolytic anemia and Evans' syndrome by comprehensive and detailed clinical and laboratory examinations.
 ...
PMID:[Clinical features of hematological abnormality in systemic lupus erythematosus-related hematological disorders]. 1251 74

Clinicopathologic features of 45 patients with fulminant hepatic failure due to massive or submassive hepatic necrosis were studied. Both percutaneous biopsies and liver explants were available in 23 patients, whole livers only in 11 cases, and biopsies only in 11 cases. An etiologic diagnosis was established in 16 cases (36%). A further 3 cases (7%) were associated with aplastic anemia. Established etiologies included drug reactions (n = 7); autoimmune hepatitis, type 2 (n = 3); halothane hepatitis (n = 1); ischemia/hypotension (n = 1); mushroom poisoning (n = 1); mitochondrial disorder (n = 1); hemophagocytic lymphohistiocytosis (n = 1); and adenoviral hepatitis (n = 1). The extent of necrosis on liver biopsy correlated poorly with that in liver explants (mean difference, 32% +/- 23.8%). Almost all cases could be classified into one of 2 broad patterns of necrosis, namely, (1) zonal coagulative necrosis or (2) panlobular (nonzonal) necrosis. These patterns differed significantly with respect to several clinical parameters including sex ratio, peripheral blood white cell count, serum aspartate transaminase and alanine transaminase, conjugated bilirubin, and alkaline phosphatase levels. Livers with panlobular necrosis showed a spectrum of histopathologic findings that included central venulitis (76%), lymphocytic infiltration of large duct/gallbladder epithelium (54%), and syncytial giant cell transformation (18%). These features were not seen in livers with zonal coagulative necrosis which frequently showed prominent steatosis (91%). Both patterns of necrosis frequently showed ductular proliferation (100%) and cholangiolitis (80%). The diagnostic yield of ancillary studies (histochemistry, immunohistochemistry, and electron microscopy) was very low (<1%). The small proportion of cases with etiologic diagnoses precluded correlation of clinical and histopathological parameters with specific etiologies. In summary, this study describes the spectrum of changes seen in massive and submassive necrosis in children and identifies clinical features that might differentiate between 2 broad patterns of necrosis.
 ...
PMID:Clinicopathologic spectrum of massive and submassive hepatic necrosis in infants and children. 1912 48

The pathogenesis of severe aplastic anemia (SAA) has not been completely understood, and insufficiency of the hematopoietic microenvironment can be an important factor. Here, we compared the basic properties of mesenchymal stem cells (MSCs), a major component of bone marrow microenvironment, from five SAA children with those of MSCs from five controls. Although MSCs from SAA children and controls were similar in morphology and immunophenotypic profile, SAA MSCs had slower expansion rate and smaller cumulative population doubling (1.83 +/- 1.21 vs 3.36 +/- 0.87; p = 0.046), indicating lower proliferative capacity. After osteogenic induction, SAA MSCs showed lower alkaline phosphatase activity (optical density, 1.46 +/- 0.04 vs 2.27 +/- 0.32; p = 0.013), less intense von Kossa staining, and lower gene expression of core binding factor alpha1 (0.0015 +/- 0.0005 vs 0.0056 +/- 0.0017; p = 0.013). Following adipogenic induction, SAA MSCs showed less intense Oil red O staining (optical density, 0.86 +/- 0.22 vs 1.73 +/- 0.42; p = 0.013) and lower lipoprotein lipase expression (0.0105 +/- 0.0074 vs 0.0527 +/- 0.0254; p = 0.013). These findings provided evidence that defects in bone marrow MSCs of SAA children do exist.
 ...
PMID:Poor potential of proliferation and differentiation in bone marrow mesenchymal stem cells derived from children with severe aplastic anemia. 2008 82

Transient hyperphosphatasemia (TH) is defined as marked elevation of serum alkaline phosphatase (ALP), predominantly its bone or liver isoform. It is a rare condition and is usually detected on laboratory examination in patients without any clinical symptoms. In typical patients with TH, ALP spontaneously normalizes, but no apparent cause of TH has been identified. Some drugs are suspected triggers of TH, but no clear evidence of their association with TH has been shown to date. We herein report three cases of TH in pediatric patients. Two patients were treated with cyclosporine for frequently relapsing nephrotic syndrome, and one was also taking cyclosporine for aplastic anemia. Interestingly, ALP immediately decreased after termination of cyclosporine in two patients, whereas TH lasted 4 months in the one patient who continued cyclosporine. Clearly, cyclosporine is associated with the pathophysiology of TH in children.
...
PMID:Transient hyperphosphatasemia in three pediatric patients treated with cyclosporine. 2717 22


1