Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chediak-Higashi syndrome (CHS) is characterized morphologically by the presence of giant lysosomal granules resulting from the dysregulated fusion of primary lysosomes. Lysosome-associated membrane proteins comprise a family of highly glycosylated proteins which are postulated to facilitate many aspects of normal lysosomal function. In this study, Epstein-Barr virus-transformed lymphoblastoid cell lines derived from a patient with CHS were analyzed for the presence of giant granules and the expression of the lysosome-associated membrane proteins lamp1 and lamp2. Giant myeloperoxidase positive granules typical of CHS, which had a complex structure when examined by electron microscopy, could be demonstrated in the lymphoblastoid cell lines. In situ immunofluorescence with antibodies directed against lamp1 and lamp2 demonstrated abundant expression of each of these proteins in the giant CHS granules. Lack of expression of lysosomal cathepsin G in these granules was also noted. These observations suggest that the lymphoblastoid cell lines provide a convenient model for the study of Chediak-Higashi granules and the lysosome-associated membrane proteins and provide additional evidence that CHS is a "lysosomal" disease. Further study will be necessary to delineate whether the function of these membrane proteins is altered in Chediak-Higashi syndrome.
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PMID:Chediak-Higashi lymphoblastoid cell lines: granule characteristics and expression of lysosome-associated membrane proteins. 133 77

Leukemic cells from acute promyelocytic leukemia containing pseudo-Chediak-Higashi (P-CH) granules in a 38-year-woman were studied with ultrastructural and cytochemical techniques to evaluate the origin and nature of the granules. Wright-Giemsa stain revealed giant granules to be azurophilic. Cytochemical stain revealed p-CH granules ot the basic of their peroxidase and glycoprotein content. Electron microscopy revealed numerous giant granules formed by fusion of azurophilic granules these morphological, different type granules were classified into four types, 1) circular granule with homogeneous matrix, 2) circular granule with heterogeneous change by autolysis, 3) Auer body-like granule with crystalline arrangement, 4) vacuolar formation. The results demonstrate that the Auer body-like granule of P-CH granules in leukemic cells is a morphologically variant type of the classical Auer body observed in common acute myeloid leukemia.
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PMID:[Studies on pseudo-Chediak-Higashi granules formation in acute promyelocytic leukemia]. 140 62

An antigen-capture sandwich enzyme-linked immunosorbent assay (ELISA) was developed for a novel protein granulophysin, a constituent of the platelet dense granule (DG) membrane and used to characterize patients with dense granule storage pool deficiency (delta-SPD). The assay uses two monoclonal antibodies against the protein, one of which is conjugated to peroxidase. Purified DGs, an enriched source of the protein, were used for the standard curve. Granulophysin levels were only low in forms of delta-SPD associated with albinism. Granulophysin levels in platelet homogenates of 30 patients with the Hermansky-Pudlak syndrome form of delta-SPD were 1/4 to 1/5 of levels in controls or obligate heterozygotes. Two patients with the Chediak-Higashi form of delta-SPD syndrome also had markedly reduced levels of granulophysin. Patients with other forms of delta-SPD had normal levels of granulophysin. Two sisters with delta-SPD in one family had normal granulophysin present in empty dense granule membrane vesicles. Three members of another family with delta-SPD had low DG counts but normal granulophysin levels, indicating that in this group the level of granulophysin was maintained despite the reduction in granule formation. Thus, granulophysin quantitation facilitates characterization of delta-SPD patients and may provide clues to the nature of defective granules in delta-SPD subtypes.
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PMID:Quantification of a novel dense granule protein (granulophysin) in platelets of patients with dense granule storage pool deficiency. 151 40

We report the biological characteristics of leukaemic blasts from two cases of acute leukaemia with an interstitial deletion of the long arm of chromosome 9 (9q-). Case 1 (FAB: M1) showed del(9)(q12q22) as the sole karyotypic anomaly, and case 2 (FAB: M1) presented del(9) (q12q22) in association with trisomy 10. In both cases, leukaemic blasts presented unique cytological features, such as prominent vacuoles on Giemsa staining, or strong localization of myeloperoxidase resembling 'pseudo-Chediak-Higashi' granules. Immunophenotyping of blasts revealed the biphenotypic expression of T-lymphoid/myeloid antigens (CD2, CD7/CD33) in addition to CD34. Neither T-cell receptor beta (TCRB), T-cell receptor gamma (TCRG) nor Ig heavy chain (IGH) genes were clonally rearranged. Furthermore, there was neither rearrangement nor expression of ABL, which is located at 9q34, indicating that the deletion involved bands centrometric to 9q34 did not induce the activation of ABL. DNA synthesis of the blasts was stimulated (stimulation index greater than 2.0) in the presence of interleukin (IL)-3, IL-4, granulocyte colony-stimulating factor or erythropoietin (Epo). IL-3 and IL-4 could also support the in vitro growth of leukaemic blast colonies, and the IL-3- or IL-4-dependent blast colony growth was synergistically enhanced by the addition of IL-6 or Epo. These observations imply that T-lymphoid/myeloid or pluripotent stem cells may be closely involved in the development of 9q- AML.
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PMID:Interstitial 9q deletion in T-lymphoid/myeloid biphenotypic leukaemia. 155 Jul 72

Blasts from 5 cases of AML with pseudo-Chediak-Higashi granules were examined ultrastructurally and histocytochemically using peroxidase, acid phosphatase, high iron diamine (HID) and periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) stainings. Pseudo-Chediak-Higashi granules, which appeared as vacuole-like inclusions by light microscopy, generally contained electron-lucent materials. All pseudo-Chediak-Higashi granules were, positive for peroxidase but some were negative for acid phosphatase. Pseudo-Chediak-Higashi granules were HID positive, indicating that they contained sulfated glycoconjugates. Glycogen-like particles were observed in the pseudo-Chediak-Higashi granules with the PA-TCH-SP method, as occasionally observed in granules in drug resistant ALL blasts. In conclusion, the contents of pseudo-Chediak-Higashi granules, which seems to be formed by fusion of small granules, differed from those of normal azurophillic granules.
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PMID:[Electron microscopic cytochemistry of pseudo-Chediak-Higashi granules in 5 cases of AML]. 221 71

Chediak-Higashi syndrome (CHS) is an autosomal recessive disease of humans, mink, cattle, mice, killer whales, cats, and blue and silver foxes. The disease is characterized by incomplete oculocutaneous albinism, recurrent and severe pyogenic infections, a bleeding tendency secondary to a platelet storage pool deficiency, and enlarged granules in many types of cells. Humans with CHS usually die during childhood. It has been suggested that the prenatal diagnosis of CHS should be possible by the demonstration of enlarged granules in neutrophils of fetal blood. We tested this hypothesis using 20 cat fetuses obtained 18 days at prepartum. Two litters (6 fetuses) were from CHS to CHS matings and four litters (14 fetuses) were from CHS male to heterozygous female matings. Fetuses were identified as CHS or phenotypically normal by histologic examination of the size of melanin granules in the ciliary body and by the size of periodic acid-Schiff-positive granules in renal tubular epithelial cells. The diameter of the peroxidase-positive granules in neutrophils of the 15 CHS fetuses ranged from 0.3 to 3.0 microns whereas those of the five normal fetuses ranged from 0.3 to 1.0 micron. All 20 fetuses were correctly classified as CHS or phenotypically normal. These data indicate that examination of the size of fetal blood neutrophil granules can be used to diagnose CHS prenatally.
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PMID:Chediak-Higashi syndrome: prenatal diagnosis by fetal blood examination in the feline model of the disease. 254 22

Azurophil granules of normal neutrophils are known to be primary lysosomes and contain myeloperoxidase activity. The present study has used ultrastructural cytochemistry to selectively stain myeloperoxidase containing granules of normal and Chediak-Higashi syndrome neutrophils and serial thin sections to determine if all peroxidase-positive organelles in Chediak-Higashi syndrome cells are protrusions of the huge inclusions characteristic of the disorder. Peroxidase-positive organelles in polymorphonuclear leukocytes from three patients with Chediak-Higashi syndrome varied in size from vesicles and normal-sized lysosomes to the huge bodies filling the cytoplasm. Serial sections demonstrated that the small and normal-sized organelles were commonly present and independent of the giant granules. One type of the normal-sized lysosomes contained small vesicles free of peroxidase activity, conveying a honeycomb-like appearance to the matrix. This variety, in particular, was identified in various stages of fusion with giant organelles in circulating Chediak-Higashi syndrome neutrophils.
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PMID:Normal-sized primary lysosomes are present in Chediak-Higashi syndrome neutrophils. 282 73

Oxygen radical generation was measured using peritoneal exudate polymorphonuclear leucocytes (PMN) from a strain of beige mice, an animal model of the Chediak-Higashi syndrome. These PMN have been shown to exhibit delayed microbial killing and impaired phagosome-lysosome fusion. The amount of superoxide anion released by the PMN of the beige mice was similar to that released by the PMN of the control mice. The PMN of beige mice generated slightly less hydrogen peroxide than the control. Hydroxyl radical (.OH) generation and luminol-dependent chemiluminescence were significantly lowered in beige PMN stimulated with opsonized zymosan (OZ) or phorbol myristate acetate (PMA). Cytochalasin B-treated beige PMN showed a decreased ability to degranulate myeloperoxidase in response to OZ or PMA. We demonstrated the significant decrease in .OH generation and chemiluminescence in beige PMN, which might be one of the reasons to explain delayed microbial killing.
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PMID:Oxygen radical generation by polymorphonuclear leucocytes of beige mice. 283 72

Although inherited forms of phagocyte defects affect a small proportion of the general population, their clinical course can be altered dramatically by a physician's awareness of these diseases and modifications of the approach to and treatment of affected patients. The most common syndromes are chronic granulomatous disease of childhood (CGD), the Chediak-Higashi syndrome (CHS), the hyperimmunoglobulin-E-recurrent infection (Job's) syndrome (HIE), and myeloperoxidase (MPO) deficiency. CGD patients have defects in the oxidative metabolism involved in killing catalase-positive organisms. CHS patients have giant granules defective in fusing with phagosomes and subsequent killing of ingested organisms. HIE patients have abnormal chemotaxis and elevated IgE levels and are susceptible to skin infections with Staphylococcus aureus and recurrent sinopulmonary infections. MPO-deficient patients often go undetected since they rarely have recurrent infections unless they have a concomitant disease such as diabetes mellitus. Patients with a recently described syndrome, C3bi receptor deficiency, have recurrent bacterial infections and persistent leukocytosis, and their neutrophils have abnormal adherence and phagocytosis. The absence of specific granules is a more rare entity but these patients also have recurrent infections thought to be secondary to a chemotactic defect and a minor abnormality of microbial killing exhibited by their neutrophils. This review will focus on the clinical presentation and management of these patients.
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PMID:Phagocyte defects. 294 Nov 93

A complete evaluation of neutrophil function including: chemotaxis; adhesion; aggregation; phagocytosis; granule content and degranulation; respiratory burst activity; and bacterial killing; is expensive and requires the services of a specialized laboratory. However, preliminary screening of a patient with a predisposition toward infection, can be carried out using simple and inexpensive methods. These include examination of blood films, which may prove helpful in the diagnosis of Chediak-Higashi syndrome and specific granule deficiency; the Rebuck skin window test, which estimates chemotactic defects; the NBT test, which screens for chronic granulomatous disease patients; and peroxidase staining of the blood film in order to estimate the content of myeloperoxidase, when myeloperoxidase deficiency is suspected. For final diagnosis and determination of genetic transmission and radical treatment, ie, bone marrow transplantation, specific tests are indicated. Neutrophil function studies have also proved useful in detecting diseases in which defects in neutrophil function are secondary to the primary disorder. Indeed, increased neutrophil chemotaxis has been reported in the active phase of diseases such as: familial Mediterranean fever; psoriasis vulgaris, Behcet's syndrome and Sweet's syndrome. In these disorders the neutrophil chemotaxis assay has aided in the diagnosis and follow-up, particularly in evaluating the response to antiinflammatory agents, such as colchicine.
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PMID:Neutrophil function studies in clinical medicine. 298 Feb 76


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