Biomedical subjects

N Masir

Publications and source records attributed to N Masir.

4 recordsLinked to original sources

PubMed2006

Jaw1/LRMP, a germinal centre-associated marker for the immunohistological study of B-cell lymphomas.

Jaw1, also known as lymphoid-restricted membrane protein (LRMP), is an endoplasmic reticulum-associated protein. High levels of Jaw1/LRMP mRNA have been found in germinal centre B-cells and in diffuse large B-cell lymphomas of 'germinal centre' subtype. This paper documents Jaw1/LRMP expression at the protein level in human tissues by immunohistochemical and western blotting analysis using an antibody reactive with paraffin-embedded tissues. Jaw1/LRMP was highly expressed in germinal centre B-cells (in keeping with gene expression data), in 'monocytoid B-cells', and in splenic marginal zone B-cells. It was absent, or present at only low levels, in mature T-cells, although cortical thymocytes were weakly positive. Among lymphoid neoplasms, Jaw1/LRMP was found in germinal centre-derived lymphomas (follicle centre lymphoma, Burkitt's lymphoma, lymphocyte-predominant Hodgkin's disease) but not in T-cell neoplasms (with the exception of a single T lymphoblastic lymphoma). Classical Hodgkin's disease and myeloma lacked Jaw1/LRMP but many cases of chronic lymphocytic leukaemia (but not mantle zone lymphoma) were Jaw1/LRMP-positive. Approximately half of the marginal zone lymphomas were Jaw1/LRMP-positive. In diffuse large B-cell lymphomas, Jaw1/LRMP was found in three-quarters (24/32) of the cases classified phenotypically as being of 'germinal centre' type, but it was also expressed in almost half (13/28) of the 'non-germinal centre' cases. A similar proportion of 'non-germinal centre' cases were positive for the protein products of two other genes expressed highly in germinal centre cells (HGAL/GCET2 and PAG). The fact that all three of these proteins are expressed in a significant proportion of diffuse large B-cell lymphomas assigned to the 'non-germinal centre' category indicates that the immunophenotypic categorization of diffuse large B-cell lymphoma according to cellular origin may be more complicated than currently understood. Finally, the expression of Jaw1/LRMP in other types of lymphoma and in non-lymphoid tissues/tumours may be of interest in differential diagnosis and research.

Adrenal Glands↗

PubMed2006

Loss of CD19 expression in B-cell neoplasms.

AIMS: To investigate whether an antibody against an intracellular epitope can detect CD19 in routine biopsy specimens and thus to document in detail its expression in human lymphomas. METHOD AND RESULTS: A polyclonal antibody to the C terminus of CD19 was used to immunostain paraffin-embedded samples of normal and neoplastic lymphoid tissues. CD19 was widely expressed in normal B cells and in extramedullary plasma cells. It was found in most B-cell neoplasms, but expression in follicular lymphoma was weak (33/69) or negative (four cases). Similarly, CD19 expression in diffuse large B-cell lymphomas was weak (28/56) or negative (eight cases). In T-cell-rich B-cell lymphomas, CD19 was also weak (4/10) or negative (three cases). CD19 was often absent in post-transplant B lymphoproliferative disease, classical Hodgkin's disease and plasma cell neoplasms. An unexpected finding was the frequent absence of CD19 in the neoplastic cells in lymphocyte predominant Hodgkin's disease. CONCLUSIONS: CD19 can now be detected in routine biopsy specimens. In contrast to the classical pan-B marker CD20, CD19 is not always strongly expressed in B-cell neoplasms. Furthermore, the lymphocytic and histiocytic (L&H) cells of lymphocyte predominant Hodgkin's disease (which express most B-cell-associated markers) commonly lack CD19.

Antigens, CD19↗

PubMed2000

A cervical ectopic masquerading as a molar pregnancy.

We report a case of cervical pregnancy complicated by life threatening hemorrhage. An initial diagnosis of molar pregnancy was made preoperatively. During uterine evacuation she developed profuse hemorrhage which required an emergency hysterectomy for uncontrolled bleeding. Histopathological examination confirmed a cervical pregnancy. The clinical and pathological criteria for the diagnosis and the etiology of cervical pregnancy are discussed.

Adult↗

PubMed1999

Osteosarcoma in a sixteen-month old boy.

We report a case of a sixteen-month old boy with osteosarcoma of the left humerus. To the best of our knowledge this is the youngest case reported in Malaysia. This case illustrates that osteosarcoma although rare does occur in a very young child. The child died six weeks after presentation due to disseminated disease.

Bone Neoplasms↗