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Raul C Braylan

Publications and source records attributed to Raul C Braylan.

9 recordsLinked to original sources
PubMed2005

CD58 expression decreases as nonmalignant B cells mature in bone marrow and is frequently overexpressed in adult and pediatric precursor B-cell acute lymphoblastic leukemia.

We used flow cytometry to determine the CD58 expression on nonmalignant B cells at different stages of maturation in the bone marrow and compared it with that of blasts in adult and pediatric precursor B-cell acute lymphoblastic leukemia (B-ALL). The mean fluorescence intensity (MFI) of CD58 expression decreased significantly as nonmalignant B cells differentiated in the bone marrow from an early to a mature stage. Few nonneoplastic B cells at a mid or mature stage of development expressed CD58 MFI values comparable to those seen in leukemic cases. Early-stage nonneoplastic B-cell precursors expressed relatively higher CD58 levels, which frequently overlapped with the variable level of CD58 expression observed among leukemic blasts. As a group, however, the malignant precursor B-ALL cells showed significantly higher expression of CD58 than nonmalignant B-cell populations at any maturational stage. These findings support the potential usefulness of CD58 expression in the diagnosis and monitoring of precursor B-ALL, but only when blasts express high levels of CD58.

Adolescent↗
PubMed2004

DRAQ5-based DNA content analysis of hematolymphoid cell subpopulations discriminated by surface antigens and light scatter properties.

BACKGROUND: Analysis of cell cycle kinetics offers important information regarding the behavior of normal and neoplastic cells. Most often, cell cycle determinations by flow cytometry (FCM) have been performed using whole-sample analysis with intercalating dyes like propidium iodide (PI). The cell cycle phase assessment in individual cell subsets in heterogeneous samples is best performed using combined antigen/scatter and DNA analysis. DRAQ5, a novel DNA binding dye that excites at 488 nm and emits in the far red spectra, rapidly penetrates intact live cells while preserving their light scatter properties and expression of surface antigens. We evaluated the ability of this dye to measure cell cycle phases in a variety of clinical hematolymphoid samples. METHODS: We first compared whole sample DRAQ5 and PI cell cycle analyses in 26 clinical hematolymphoid samples. Next, we analyzed cell subpopulations in 39 samples of nonpathologic bone marrow by performing simultaneous CD45/CD34 and DRAQ5 staining. We assessed cell cycle characteristics specific to each population identified by CD45/CD34/side light scatter: lymphocytes, monocytes, immature and mature granulocytes, nucleated erythroid cells, and early precursors. RESULTS: Whole sample DNA cell cycle analyses by DRAQ5 and PI showed no significant differences in S-phase. DRAQ5, however, produced slightly larger coefficients of variation. DRAQ5-based DNA content analysis was easily performed on the distinct marrow cell subpopulations, since light scatter and antigen expression were completely preserved. Significant differences in S-phase were noted between subpopulations of cells exhibiting different degrees of maturation. CONCLUSIONS: Because of its simplicity of use, excitability with 488 nm lasers, and the ability to stain viable cells, DRAQ5 should prove most useful in the kinetic evaluation of normal and neoplastic hematolymphoid cell subsets identified by light scatter and antigenic expression.

Anthraquinones↗
PubMed2003

Management of neurotropic low-grade B-cell lymphoma: report of two cases.

BACKGROUND: Low-grade lymphomas do not commonly involve the central or peripheral nervous system. METHODS: Case report and review of the literature of two cases of B-cell lymphoma of the extranodal marginal zone type involving the head and neck region with evidence of extensive neurotropism are detailed in this report. RESULTS: One patient was initially seen with a mass in the temporalis muscle and the other with a masticator space mass. The clinical course was indolent in both cases, although associated imaging studies suggested a more aggressive tumor. Both patients were treated with moderate-dose radiotherapy only. At the time of writing, one patient has no evidence of disease 6.5 years after treatment and the other at 6 months. CONCLUSIONS: This suggests that some marginal zone lymphomas exhibit a low-grade clinical course despite an aggressive radiographic pattern of perineural and neurotropic spread. This type of lymphoma might be effectively treated with moderate-dose radiotherapy.

Aged↗
PubMed2002

All-trans-retinoic acid induces CD52 expression in acute promyelocytic leukemia.

It is well known that all-trans-retinoic acid (ATRA) can induce myeloid cell differentiation in acute promyelocytic leukemia (APL) cells. In this study, we found that ATRA treatment of the APL cell line NB4 induced the expression of CD52, both at transcriptional and translational levels. CD52 is a 21- to 28-kDa nonmodulating cell surface glycosylphosphatidylinositol-linked glycoprotein expressed on lymphocytes and monocytes, but not in human myeloid cells. The ATRA-dependent induction of CD52 expression was not observed in non-promyelocytic leukemia cell lines such as K562, U937, and HL-60, suggesting that induction of CD52 by ATRA may be specific to leukemic cells that express promyelocytic leukemia-retinoic acid receptor alpha (PML-RARalpha) or are at the promyelocytic stage of myeloid development. Antibodies against CD52 are used therapeutically against lymphocytes in certain leukemias and in patients undergoing transplantation. An ATRA-induced high level of CD52 expression might potentially serve as a novel therapeutic target in treatment of APL.

Antigens, CD↗
PubMed2002

Phase II study of fludarabine combined with interferon-alpha-2a followed by maintenance therapy with interferon-alpha-2a in patients with low-grade non-hodgkin's lymphoma.

Randomized trials suggest improved disease-free survival in low-grade non-Hodgkin's lymphoma (LGNHL) when interferon is combined with multiagent chemotherapy. This phase II trial was conducted to investigate the feasibility of combining fludarabine monophosphate (fludarabine) and IFN in a regimen for treatment of LGNHL. Twenty-one patients were evaluable. Median age was 55 years, and patients had been treated with an average of 1.7 chemotherapy regimens before enrollment. Patients received 25 mg/m2 of fludarabine intravenously on days 1 through 5 followed by 2 x 10(6) U/m2 of interferon-alpha-2a subcutaneously on days 22 through 26. Cycles were repeated every 4 weeks with delays and dose modifications for significant cytopenias. Patients were restaged after cycles 4 and 8, and those with at least a partial response to therapy were given maintenance therapy consisting of 2 x 10(6) U/m2 interferon-alpha-2a subcutaneously three times per week for 6 months. The overall response rate was 76% with a 25% complete response (CR) rate. Overall response rates were 75% (3/4 with 2 CR's) for chemotherapy-naive patients and 76% (13/17 with 3 CR's) for previously treated patients. Median time to progression was 12 months, and currently two patients are without evidence of progression at a median follow-up of 55 months. Grade III or greater toxicities included neutropenia (39%), anemia (17%), thrombocytopenia (5%), fevers/chills (5%), and fatigue (5%). Fludarabine and interferon can be effectively and safely combined in a regimen with significant activity against LGNHL. A modification of this regimen may be suitable for further study.

Adult↗