Background: Myeloperoxidase staining is used to differentiate leukemias since several decades. Despite implementation of flow cytometric, cytogenetic and molecular techniques for identification of leukemic blasts, his...Background: Myeloperoxidase staining is used to differentiate leukemias since several decades. Despite implementation of flow cytometric, cytogenetic and molecular techniques for identification of leukemic blasts, histochemical stains such as myeloperoxidase stain are persistently used for better classification of leukemias. The myeloperoxidase staining is a time consuming and hazardous procedure. The present report describes a sensitive, rapid and easy method for assessment of peroxidase activity. Materials and Methods: Bone marrow aspiration slides were stained with Dako product: Code number: K3467 containing DAB chromogen (3,3-diaminobenzidine in chromogen solution) and substrate buffer (Imidasole-HCL buffer, PH 7.5 containing hydrogen peroxide and an anti microbial agent) in a rapid procedure taking only ten minutes time. The staining needs no material preparation steps. Neutrophils in the slide are taken as positive control or another normal smear was costained to be used as control. All cases were followed up with flow cytometry and cytogenetic studies. Result: The reaction product of this stain is brown and granular. Promyelocytes and myelocytes are the most strongly staining cells with positive (primary) granules. Lymphoblasts are negative. The result of classification of leukemias with this technique was in concordance with flow cytometric immunophenotyping. Discussion: Many practical techniques have been described using benzidine as an indicator for myeloperoxidase staining. Benzidine is a carcinogenic material and its usage is severely restricted in laboratory. Formerly we prepared requisite materials for myeloperoxidase staining by hazardous ways (boiling), but we decided to apply ready to use 3,3-diaminobenzidine (DAB), which is used in final step of immunohistochemistry stains. Conclusion: Use of 3,3-diaminobenzidine (DAB) is highly recommended for myeloperoxidase staining, while the result is extraordinary and fully compatible with flow cytometry and the method is safe and rapid.展开更多
Introduction: Microvillous inclusion disease (MVD) or microvillous atrophy disorder is a congenital disorder of the small intestinal epithelial cells that presents with persistent and severe diarrhea and it is charact...Introduction: Microvillous inclusion disease (MVD) or microvillous atrophy disorder is a congenital disorder of the small intestinal epithelial cells that presents with persistent and severe diarrhea and it is characterized by enterocytes abnormalities [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003300380035003800380033003700360030000000 . For these children, prognosis is generally poor due to metabolic acidosis with poor compensation. To our experiment, this disease is very rare in Iran and it is yet unreported, so we decided to report two consecutive siblings with the same disease from Iran. Report of Cases: Two siblings were born to healthy parents. Parents were cousins. Both siblings were hospitalized due to severe diarrhea starting shortly after breast feeding. The frequency of diarrhea in both cases was 10 to 17 times per day and their stools were loose and green. Histological studies of both siblings revealed duodenal mucosa with complete flattening of villi (total villous atrophy). Superficial lining cells showed atrophy. Crypts showed no hyperplasia, however it showed distortion and difference in size. By PAS staining and CD10 staining, a poorly developed brush border and typical inclusions were seen in apical boarder of enterocytes. Electron microscopy was performed for the second case and showed microvillous involution and inclusions in the apical part of the epithelial cells. Discussion: Microvillous congenital atrophy is a rare congenital disorder. Due to rareness of congenital microvillous atrophy (CMA), it is crucial to distinguish it from other diseases with persistent and severe diarrhea as soon as possible.展开更多
文摘Background: Myeloperoxidase staining is used to differentiate leukemias since several decades. Despite implementation of flow cytometric, cytogenetic and molecular techniques for identification of leukemic blasts, histochemical stains such as myeloperoxidase stain are persistently used for better classification of leukemias. The myeloperoxidase staining is a time consuming and hazardous procedure. The present report describes a sensitive, rapid and easy method for assessment of peroxidase activity. Materials and Methods: Bone marrow aspiration slides were stained with Dako product: Code number: K3467 containing DAB chromogen (3,3-diaminobenzidine in chromogen solution) and substrate buffer (Imidasole-HCL buffer, PH 7.5 containing hydrogen peroxide and an anti microbial agent) in a rapid procedure taking only ten minutes time. The staining needs no material preparation steps. Neutrophils in the slide are taken as positive control or another normal smear was costained to be used as control. All cases were followed up with flow cytometry and cytogenetic studies. Result: The reaction product of this stain is brown and granular. Promyelocytes and myelocytes are the most strongly staining cells with positive (primary) granules. Lymphoblasts are negative. The result of classification of leukemias with this technique was in concordance with flow cytometric immunophenotyping. Discussion: Many practical techniques have been described using benzidine as an indicator for myeloperoxidase staining. Benzidine is a carcinogenic material and its usage is severely restricted in laboratory. Formerly we prepared requisite materials for myeloperoxidase staining by hazardous ways (boiling), but we decided to apply ready to use 3,3-diaminobenzidine (DAB), which is used in final step of immunohistochemistry stains. Conclusion: Use of 3,3-diaminobenzidine (DAB) is highly recommended for myeloperoxidase staining, while the result is extraordinary and fully compatible with flow cytometry and the method is safe and rapid.
文摘Introduction: Microvillous inclusion disease (MVD) or microvillous atrophy disorder is a congenital disorder of the small intestinal epithelial cells that presents with persistent and severe diarrhea and it is characterized by enterocytes abnormalities [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003300380035003800380033003700360030000000 . For these children, prognosis is generally poor due to metabolic acidosis with poor compensation. To our experiment, this disease is very rare in Iran and it is yet unreported, so we decided to report two consecutive siblings with the same disease from Iran. Report of Cases: Two siblings were born to healthy parents. Parents were cousins. Both siblings were hospitalized due to severe diarrhea starting shortly after breast feeding. The frequency of diarrhea in both cases was 10 to 17 times per day and their stools were loose and green. Histological studies of both siblings revealed duodenal mucosa with complete flattening of villi (total villous atrophy). Superficial lining cells showed atrophy. Crypts showed no hyperplasia, however it showed distortion and difference in size. By PAS staining and CD10 staining, a poorly developed brush border and typical inclusions were seen in apical boarder of enterocytes. Electron microscopy was performed for the second case and showed microvillous involution and inclusions in the apical part of the epithelial cells. Discussion: Microvillous congenital atrophy is a rare congenital disorder. Due to rareness of congenital microvillous atrophy (CMA), it is crucial to distinguish it from other diseases with persistent and severe diarrhea as soon as possible.
