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Biomedical subjects

B Brando

Publications and source records attributed to B Brando.

At least 19 recordsLinked to original sources
PubMed1991

Specific binding sites for H-ferritin on human lymphocytes: modulation during cellular proliferation and potential implication in cell growth control.

Interactions between human recombinant H- and L-ferritins and human lymphocytes were studied in vitro by direct binding assays and by flow cytometry. L-ferritin did not cause detectable specific binding, whereas H-ferritin showed a specific and saturable binding that increased markedly in phytohemagglutinin (PHA)-stimulated cells. This ferritin bound up to 30% of CD4+ and CD8+ T-lymphocytes and most B cells, indicating that expression of ferritin binding sites is not related to cell lineage or function. Dual-color flow cytometry experiments showed that ferritin binding sites were present on cells expressing the proliferation markers HLA-DR, MLR3, interleukin 2 (IL-2), and transferrin receptors (Tf-R). In addition, after PHA induction, the time course of the expression of H-ferritin binding sites was similar to those of the above proliferation markers. Ferritin binding sites were observed in lymphocytes at all cell cycle phases, including the early S-phase. H-Ferritin at nanomolar and picomolar concentrations had an inhibitory effect on PHA-induced blastogenesis. We propose that H-ferritin binding sites behave like proliferation markers, with the unusual function of downregulating proliferation.

Antigens, Surface↗
PubMed1991

Flow cytometry for clinical estimation of circulating hematopoietic progenitors for autologous transplantation in cancer patients.

Optimum methods of harvesting circulating hematopoietic progenitors for autologous transplantation to support myeloablative cancer therapy are still uncertain, mostly because of the lack of an assay for marrow-repopulating stem cells. The CFU-GM assay, the commonly used indirect indicator of the quality of the graft, is poorly standardized and provides results evaluable only retrospectively. Based on the knowledge that hematopoietic progenitors express CD34 and CD33 differentiation antigens, we developed a dual-color direct immunofluorescence flow cytometry assay with the aim of replacing the CFU-GM assay advantageously. For this purpose, we applied both assays to 157 blood samples obtained daily throughout 20 different recoveries from pancytopenia induced by high-dose cyclophosphamide or etoposide cancer therapy with or without recombinant human GM colony-stimulating factor (rhGM-CSF). The appearance of CD34+ cells in the circulation indicated that hematopoietic progenitors had increased to more than 500 CFU-GM/mL, a level clinically adequate for large-scale harvest by leukapheresis. Total CD34+ cells correlated well with CFU-GM (r = .89), and data could be fitted by a linear regression line described by the equation y = 388.3 + 64.0x, where y = CFU-GM/mL and x = CD34+ cells per microliter. Moreover, in a series of six patients treated with myeloablative chemoradiotherapy, early hematopoietic recovery of marrow functions was predicted more accurately by the number of transplanted CD34+/CD33+ cells than by either total nucleated cells, CFU-GM, CD34+/CD33- cells, or CD34-/CD33+ cells. Data presented in this article favor clinical use of the CD34/CD33 flow cytometry assay to guide harvesting of circulating hematopoietic progenitors for autologous transplantation and contribute to better understanding of the role played by circulating hematopoietic progenitor cell subsets in marrow recovery after myeloablative cancer therapy.

Antigens, CD↗
PubMed1991

Methodologies to estimate circulating hematopoietic progenitors for autologous transplantation in cancer patients.

Optimal criteria for harvesting circulating hematopoietic progenitors (CHP) for autologous transplantation to support myeloablative cancer therapy are still uncertain mostly because the CFU-GM assay, the commonly used indirect indicator of the hematopoietic recovery of the graft, is poorly standardized and provides information evaluable only retrospectively. Based on the knowledge that CHP express CD34 and CD33 differentiation antigens and facilitated by the availability of a very efficient fluorescein-conjugated CD34 antibody (8G12), we developed a direct immunofluorescence flow cytometry assay with the aim of replacing the CFU-GM assay advantageously. Recently, in a comparative study, both assays were applied to 157 blood samples obtained daily throughout 20 different recoveries from pancytopenia induced by high-dose cyclophosphamide (7 g/m2) cancer therapy w/ or w/o rhGM-CSF. Results showed that: a) detectability of CD34+ CHP indicated an increase to greater than 500 CFU-GM/mL, a level clinically adequate for harvesting CHP; b) CD34+ cells correlated well with CFU-GM (R=0.89) and data fitted a linear regression line (y=388.3 + 64.0x; y=CFU-GM/mL and x=CD34+/uL); c) in a series of 8 patients treated with myeloablative chemoradiotherapy, early recovery of marrow functions was predicted more accurately by the number of transplanted blood CD34+/CD33+ cells than by nucleated cells, CFU-GM, CD34+/CD33-cells, or CD34-/CD33+ cells. As a guideline, provided platelets are greater than 70,000/uL, harvest of CHP by leukapheresis during recovery from chemotherapy induced pancytopenia should be started as soon as CD34+ cells appear in the circulation and continued until the threshold dose of 7.8x10(6) CD34+ cells/kg, equivalent to 50 x 10(4) CFU-GM/kg, is achieved.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1991

Impaired efficacy of selective LDL-apheresis in primary biliary cirrhosis.

Low-density lipoprotein apheresis (LDL-apheresis) was done with either cascade filtration (DF) or dextran sulfate cellulose adsorption (DSC) in a patient with primary biliary cirrhosis who developed severe dyslipidemia associated with cholestasis and accumulation of lipoprotein-X (LP-X). The extracorporeal treatment was initially performed weekly, and resulted in a sharp drop in total cholesterol from 1038 to 430 mg/dl. During the next four months the patient was treated every 10-15 days, and pre-apheresis cholesterol levels were maintained between 438 and 505 mg/dl, until an orthotopic liver transplantation was successfully performed. With semi-selective DF a mean 47.1% of total cholesterol was removed per procedure compared to 30.0% with DSC, although the volume of treated plasma was 38.0 vs 49.9 ml/kg body weight. The changes in plasma cholesterol levels during DSC and DF showed that the kinetics of cholesterol removal were similar with both techniques, but the efficacy differed; DF removed both LDL and LP-X from plasma, whereas DSC selectively lowered the LDL content. Cascade filtration may therefore be considered as a first-choice treatment for patients with LP-X accumulation due to cholestasis.

Adult↗
PubMed1989

Circulation of CD34+ hematopoietic stem cells in the peripheral blood of high-dose cyclophosphamide-treated patients: enhancement by intravenous recombinant human granulocyte-macrophage colony-stimulating factor.

We report that hematopoietic progenitor cells expressing the CD34 antigen (CD34+ cells) transiently circulate in the peripheral blood (PB) of cancer patients treated with 7 g/m2 cyclophosphamide (HD-CTX) with or without recombinant human granulocyte macrophage-colony stimulating factor (rHuGM-CSF). In adult humans, CD34+ cells represent a minor fraction (1% to 4%) of bone marrow (BM) cells, comprising virtually all hematopoietic colony-forming progenitors in vitro and probably also stem cells capable of restoring hematopoiesis of lethally irradiated hosts. We show that CD34+ cell circulation is fivefold enhanced by rHuGM-CSF 5.5 protein micrograms/kg/day by continuous intravenous infusion for 14 days after HD-CTX. During the third week after HD-CTX (ie, when CD34+ cells peak in the circulation), large-scale collection of PB leukocytes by three to four continuous-flow leukaphereses allows the yield of 2.19 to 2.73 x 10(9) or 0.45 to 0.56 x 10(9) CD34+ cells depending on whether or not patients receive rHuGM-CSF. The number of CD34+ cells retrieved from the circulation by leukaphereses exceeds the number that can be harvested by multiple BM aspirations under general anesthesia. Thus, after therapy with HD-CTX and rHuGM-CSF, PB represents a rich source of hematopoietic progenitors possibly usable for restoring hematopoiesis after myeloablative chemoradiotherapy. To determine whether CD34+ cells found in the PB are equivalent to their marrow counterpart, we evaluated their in vitro growth characteristics and immunological phenotype by colony assays and dual-color immunofluorescence, respectively. We show that PB CD34+ cells possess qualitatively normal hematopoietic colony growth and high cloning efficiency comparable to that observed with BM CD34+ cells. In addition, PB CD34+ cells display heterogeneous surface membrane differentiation antigens analogous to BM CD34+ cells. The availability of large quantities of CD34+ cells by leukapheresis is relevant to the field of stem cell transplantation and possibly to genetic manipulations of the hematopoietic system in humans.

Antigens, CD34↗
PubMed1989

Abnormal DNA content in liver-cell dysplasia: a flow cytometric study.

To clarify the true nature of liver-cell dysplasia (LCD), a flow cytometric study has been performed. The DNA content of hepatocytes from 26 cases of cirrhosis with diffuse areas of LCD was investigated and compared to that of hepatocytes from 21 control patients with non-neoplastic and neoplastic liver conditions. Flow cytometric analysis was performed on propidium-stained nuclei from archival paraffin-embedded material. Analysis was directed to assessment of diploid as well as non-diploid peaks by calculation of DNA index (DI), using normal hepatocytes present in each sample as individual and specific references. Since only samples containing at least 10,000 nuclei were considered suitable for analysis, 4 of the 26 LCD cases were discarded. Eight of 22 LCD cases had an abnormal DNA content compared with 0/11 non-neoplastic cases (p less than 0.05) and 8/10 hepatocellular carcinomas (p less than 0.05). Non-neoplastic control cases displayed uniformly diploid stemlines whereas hepatocellular carcinomas had in 8/10 cases bimodal or trimodal populations. Thus, LCD is a heterogeneous lesion in terms of ploidy, and the abnormal DNA content observed in some cases supports its pre-neoplastic nature.

DNA↗
PubMed1989

Immunotoxin-mediated inhibition of chronic lymphocytic leukemia cell proliferation in humans.

We evaluated the cytotoxicity of the immunotoxin OKT1-SAP on fresh B-chronic lymphocytic leukemia (B-CLL) cells from 31 consecutive patients. OKT1-SAP comprised the OKT1 (CD5) monoclonal antibody disulfide linked to saporin-6 (SAP) ribosome-inactivating protein from the plant Saponaria officinalis. The effect of OKT1-SAP on target CD5-positive B-CLL cells was estimated using an in vitro proliferation inhibition assay in which control or OKT1-SAP-treated B-CLL cells were induced to proliferate by sequential stimulation with insolubilized anti-C3b receptor CB04 (CD35) antibody and low molecular weight B-cell growth factor. In 90% of patients, OKT1-SAP specifically suppressed B-CLL cell proliferation in a dose-related manner (50% inhibitory concentration, 4.0-6.8 nM). Taken together the findings reported in this article provide information relevant to the clinical development of immunotoxins because: (a) the in vitro conditions under which B-CLL cell proliferation is inhibited by OKT1-SAP are achievable in vivo without nonspecific toxicity according to our previous toxicology and pharmacokinetics studies in primates; and (b) the B-CLL cell proliferation inhibition assay described here provides a basis for future comparative studies.

Aged↗
PubMed1989

Fluorocytometric analysis of anti-HLA class 2 autoantibodies in patients with lupus nephritis.

Systemic lupus erythematosus (SLE) patients are known to produce a variety of autoantibodies (AAb), some of which may be directed against immunocompetent cells. Anti-B cell autoimmunity may encompass reactivity against HLA-class 2 molecules, which are also expressed on kidney tissue. We studied 15 patients with moderate to severe renal involvement and 5 lupus patients with no clinical renal disease, in order to detect the presence of anti-HLA class 2 AAb. Flow cytometry was employed in an inhibitory assay using patient sera, autologous cells and two anti-class 2 monoclonals, to establish the specificity of anti-B cell AAb. Seven out of 15 nephritis patients had detectable anti-class 2 AAb with an epitopic heterogeneity, as demonstrated by different degrees of inhibition on the binding of non-overlapping monoclonals. The specificity of the reaction was confirmed by the lack of inhibition of non-class 2 antibody binding. The presence of such AAb was not correlated with disease activity but with the presence of a diffuse proliferative glomerulonephritis on renal biopsy. Anti-class 2 AAb may be a marker of SLE diffuse proliferative nephritis.

Adolescent↗
PubMed1988

Selective and semiselective low-density lipoprotein apheresis in familial hypercholesterolemia.

Seven patients with familial hypercholesterolemia were treated fortnightly for 3 months by selective low-density lipoprotein apheresis with dextran-sulfate cellulose column (DSC). Subsequently, 4 of them were treated with semiselective double filtration. No cholesterol-lowering drugs were given. Plasma processed ranged from 39 to 58 ml/kg body weight/procedure. Fractional removals from plasma filtrate at the secondary treatment (adsorption or fractionation) for total cholesterol, high-density lipoprotein cholesterol, and albumin, respectively, were 0.84, 0.06, and 0.03 with DSC and 0.74, 0.47 and 0.35 with double filtration. Postapheresis reductions of total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were 57, 15, and 59% with DSC and 47,35, and 48% with double filtration. Both methods are suitable for clinical use, but with a 15-day treatment schedule, lowering circulating lipid fraction levels are maintained with DSC.

Adolescent↗
PubMed1988

The role of donor and recipient factors in initial renal graft non-function.

ATN is a deleterious problem in the outcome of kidney transplantation. This complication is usually related to multiple factors including donor parameters, surgical technique, ischemic time, and recipient variables. In order to develop prophylactic measures, out of 430 kidney transplants performed in our Department, a series of 90 consecutive cadaveric renal allografts has been considered in this study. The overall incidence of IGNF was 23/90 (25.5%). Kidneys from MOD revealed a lower rate of IGNF (7/35 = 20%) when compared with organs from SOD (16/55 = 29%, P = NS). No difference was noted when kidneys were removed together with heart and/or liver and/or pancreas. Out of the donor factors, only CID was significant (17 +/- 9 hours in IGNF v 11 +/- 10 hours in patients with IGF, P = less than .05). Analysis of data concerning the fate of paired kidneys revealed two cases of IGNF in both kidneys from the same donor v 14 cases of IGNF in only one of the two paired grafts (P = NS). We conclude that: 1. Donor factors are clearly associated with a minority of IGNF. 2. The introduction of multiorgan procurement programs does not complicate early function. 3. Recipient factors (immunological events and intraoperative fluid management) provides important additive effects on initial graft nonfunction.

Adolescent↗