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C Rivas

Publications and source records attributed to C Rivas.

At least 127 records · Page 7Linked to original sources
PubMed1989

A comparison between monoclonal antibody MT2 and immunoglobulin staining in the differential diagnosis of follicular lymphoid proliferations in routinely fixed wax-embedded biopsies.

Monoclonal antibody MT2 and anti-immunoglobulins were tested for their ability to discriminate between reactive lymphoid hyperplasia and follicular lymphoma (centroblastic/centrocytic; CB/CC) informalin-fixed and wax-embedded biopsies. The streptavidin biotin peroxidase complex method was used. In 46 of 49 cases of reactive follicular hyperplasia the follicle center cells were unstained by MT2 whereas the mantle zone B cells and interfollicular T cells were positive. In three reactive cases up to 30% of follicle center cells also were stained. In contrast, more than 50% of neoplastic follicle center cells were stained by MT2 in 27 of 62 cases of CB/CC, and light chain restriction was shown in 52 of 62 cases. MT2 staining and/or light chain restriction was seen in 57 of 62 cases. In 106 further cases of non-Hodgkin's lymphoma, MT2 was positive in 59 of 77 B cell lymphomas and 3 of 29 T cell lymphomas. Although not a B cell specific reagent, MT2 is useful in the differential diagnosis of reactive vs. neoplastic follicular lymphoid proliferations but is less sensitive than immunoglobulin stains.

Antibodies, Monoclonal↗
PubMed1989

[Ki-1 non-Hodgkin's lymphoma. A multihospital study of 21 cases].

The Ki-1 monoclonal antibody recognizes a specific membrane antigen of activated lymphoid cells and stains large-cell non Hodgkin's lymphomas and Hodgkin's disease. Thus, it is widely used in the diagnosis of anaplastic lymphomas. Morphologically, the Ki-1 monoclonal non Hodgkin's lymphoma are diffuse of multifocal either classical or cell anaplastic type. The clinical behaviour is similar to the rest of the high grade lymphomas, disseminated at diagnosis but may reach remission after aggressive chemotherapy. The immunophenotype showed T, B or null nature of the latter. The clinical and pathological results of our study carried out in a group of 21 cases ki-1 positive lymphomas is herewith reported.

Adolescent↗
PubMed1989

Malignant B cell immunoblastic lymphoma expressing CD30 antigen in the terminal phase of a multiple myeloma.

An acute terminal phase of a Bence Jones kappa plasma cell myeloma developed 22 months after chemotherapy is presented. The patient's symptoms were fever, cytopenias, adenomegalies and hepatomegaly. A lymph node biopsy showed an immunoblastic polymorphic kappa B cell lymphoma, expressing CD30 antigen. After new polychemotherapy the patient died because of bleeding and infection. Autopsy revealed a decrease in the tumour with defective immunophenotype. The few reported cases have been reviewed with emphasis on clinical aspects, prognosis and morphology, The significance of CD30 positivity (activation marker) in a high-grade lymphoma is discussed.

Aged↗
PubMed1988

Fluorescent labeling of nitrocellulose-bound proteins at the nanogram level without changes in immunoreactivity.

Proteins blotted on nitrocellulose were stained with either 5-dimethylamino-1-naphthalene-sulfonylchloride (dansyl chloride) or fluorescein isothiocyanate. In both cases the staining procedure can be completed in less than 30 min. The sensitivity for detecting fluorescent-labeled proteins on nitrocellulose was 0.5 ng using a dot test. This was accomplished by transparentizing the nitrocellulose with either immersion oil or toluene. Dansylated proteins were successfully utilized for optimizing the electroblotting procedure. In the presence of 0.2% sodium dodecyl sulfate and 20% methanol the distribution of proteins on the nitrocellulose was an exact replica of the protein pattern seen in the polyacrylamide gel. The fluorescent labeling did not affect the antigenic properties of proteins allowing the subsequent probing with antisera. For this procedure, only one set of samples is needed to obtain accurate photographic records of the gel, the nitrocellulose blot, and the probed blot.

Animals↗
PubMed1988

Monocytoid B-cell lymphoma, a tumour related to the marginal zone.

Monocytoid B-lymphocytes are a B-cell subset present in subcapsular sinuses in some cases of lymphadenitis. We describe a case of lymphoma of this cell type. The tumour shows a distinctive morphology characterized by concentric strands of tumour cells around lymphoid follicles with hyperplastic germinal centres and conserved mantle zones. Electron microscopy of these cells shows short cellular processes as well as moderate development of endoplasmic reticulum. The phenotype of the tumour was monoclonal IgM-kappa, distinct from other node-based B-cell subpopulations and suggesting a possible relationship to the lymphocytes of the marginal zone present peripheral to lymphoid follicles of the spleen. Morphological features that suggest a relationship with hairy cell leukaemia are contrasted by phenotypic differences and the ultrastructural absence of ribosomic lamellar complexes.

Aged↗
PubMed1987

Persistent and generalized lymphadenopathy: a lesion of follicular dendritic cells? An immunohistologic and ultrastructural study.

An immunohistochemical and ultrastructural study of 14 cases of persistent and generalized lymphadenopathy (PGL), acquired immune deficiency syndrome (AIDS) related, revealed florid follicular hyperplasia, follicular dendritic cell (FDC) lysis, lymphoid follicle invaginations, increased presence of T8 cells in germinal center, immature sinus histiocytosis (monocytoid B-cells), and inversion of T4/T8 ratio in the paracortical area. Electron microscopic examination showed viral particles of morphologic characteristics consistent with human immunodeficiency virus (HIV) virions attached to the processes of FDC in three of the nine cases studied. Lesions of the germinal center dendritic cell network are the cardinal feature of PGL. This finding lends support to the idea of a viral aggression directed against FDC as the cause of disregulation of the B-cells.

AIDS-Related Complex↗
PubMed1987

Determination of lead in hair of exposed gas station workers and in unexposed adults by microwave-aided dissolution of samples and flow injection/atomic absorption spectrometry.

Lead content in head hair of 53 gas station workers together with an equal number of normal controls was determined. Samples of hair were washed with ethanol and water and microwave-aided wet digested prior to the determination of lead by flow injection/atomic absorption spectrometry. The lead content in hair of the gas station workers (48.7 +/- 17.5 micrograms/g) was significantly higher than that of the normal controls (17.2 +/- 8.1 micrograms/g). The effects of washing and sample digestion procedures, head sampling site, hair color, age, smoking habits and duration of exposure to the metal are discussed.

Adolescent↗
PubMed1986

Immature sinus histiocytosis a monocytoid B-lymphoid reaction.

The proliferation of characteristic cells in expanded sinuses and in the perivenular area of the paracortex of lymph nodes with patients with toxoplasmosis, and homosexual and drug abusers with lymphadenopathy is referred to as 'immature sinus histiocytosis' (ISH). In a study of nine cases we have shown that these cells are monocytoid B-cells with an immunological phenotype differing from that of other node-based B-cells. The function of these cells is not known.

B-Lymphocytes↗