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Biomedical subjects

G Salles

Publications and source records attributed to G Salles.

104 records · Page 6Linked to original sources
PubMed1993

Inhibition of CD10/neutral endopeptidase 24.11 promotes B-cell reconstitution and maturation in vivo.

The common acute lymphoblastic leukemia antigen [(CALLA) CD10, neutral endopeptidase 24.11 (NEP)] is a cell-surface zinc metalloprotease expressed by a subpopulation of early murine B-lymphoid progenitors and by bone marrow stromal cells that support the earliest stages of B lymphopoiesis. In previous in vitro studies in which uncommitted murine hematopoietic progenitors plated on a stromal cell layer differentiate into immature B cells, the inhibition of CD10/NEP increased early lymphoid colony numbers. To further characterize CD10/NEP function during lymphoid ontogeny in vivo, we utilized a Ly5 congenic mouse model in which the lymphoid differentiation of uncommitted hematopoietic progenitors from Ly5.1 donors was followed in sublethally irradiated Ly5.2 recipients treated with a specific long-acting CD10/NEP inhibitor (N-[L-(1-carboxy-2-phenyl)ethyl]-L-phenylalanyl-beta- alanine (SCH32615)). The expression of Ly5.1, B220, and surface IgM (sIgM) was utilized to characterize donor-derived hematopoietic cells (Ly5.1+), B lymphocytes (B220+), and mature B cells (B220+ sIgM+) from the lymphoid organs of recipient animals treated with SCH32615 or vehicle alone. SCH32615-treated animals had higher percentages of Ly5.1+ donor splenocytes than animals treated with vehicle alone (16.9% vs. 10.4%, 63% increase, P = 0.013). Animals treated with the CD10/NEP inhibitor also had relatively more Ly5.1+ splenic B (B220+) cells than vehicle-treated animals (14.4% vs. 8.2%, 75% increase, P = 0.018). To more specifically characterize the effects of CD10/NEP inhibition on B-cell differentiation, Ly5.1+ splenocytes from animals treated with SCH32615 or vehicle alone were analyzed for coexpression of B220 and sIgM. Animals treated with the CD10/NEP inhibitor had a significantly higher percentage of mature donor B cells (Ly5.1+ B220+ sIgM+, 10.2% vs. 5.2%, 90% increase, P = 0.006) and a more modest relative increase in immature donor B cells (Ly5.1+ B220+ sIgM-, 4.7% vs. 3.4%, 38% increase, P = not significant). Taken together, these results suggest that CD10/NEP inhibition promotes the reconstitution and maturation of splenic B cells. Therefore, CD10/NEP may function to regulate B-cell ontogeny in vivo by hydrolyzing a peptide substrate that stimulates B-cell proliferation and/or differentiation.

Animals↗
PubMed1993

[Clinical study of 12 cases of malignant non-Hodgkin's lymphoma of the orbital region].

Over an 8-year period in the Departments of Hematology, Ophthalmology and Internal Medicine of our hospital, 12 cases of orbital and adnexal malignant non-Hodgkin's lymphoma were reported. Diagnostic elements varied, including local tumefaction, watering eyes, uveitis, and unexplained, long-term fever. Nine patients had primary paraocular lymphomas involving either orbital structures, the lacrimal gland or the eyeball, but after appropriate staging, the disease was found to be disseminated in 5; the 3 other cases were secondary orbital lymphomas. Intermediate or high grade histological types were predominant (9 patients) in our series. Radiation therapy, alone or combined (5 patients) with chemotherapy, was administered in 8 cases; other treatments consisted of chemotherapy (2 cases) or steroids (2 cases). Evolution was poor, with only 4 patients surviving at 34-180 months of follow-up. The main prognostic factors were tumor stage and histological grade. The clinical characteristics of this group are compared to those reported in the literature.

Adult↗
PubMed1992

CD10/NEP is expressed on Thy-1low B220+ murine B-cell progenitors and functions to regulate stromal cell-dependent lymphopoiesis.

To further characterize the function of the common acute lymphoblastic leukemia antigen (CALLA; CD10, neutral endopeptidase 24.11, NEP) in early lymphoid development, we have identified murine lymphoid progenitors expressing CD10/NEP and analyzed the effects of inhibiting the enzyme in in vitro assays of murine lymphoid differentiation. CD10/NEP transcripts and enzymatic activity were primarily restricted to the subpopulation of murine lymphoid progenitors, termed pro-B cells, which were isolated from bone marrow (BM) and modified Whitlock-Witte cultures and defined by coexpression of B220 and low levels of Thy-1. CD10/NEP transcripts and cell surface enzymatic activity were also detected in BM stromal cells known to support the development of B-lymphoid progenitors. In contrast, Abelson and H-ras transformed pre-B-cell lines were CD10/NEP- as were Thy-1-B220+ pre-B cells from BM and modified Whitlock-Witte cultures and Thy-1lowLin- (B220-Mac-1-GR-1-Ly-2/3-) uncommitted hematopoietic progenitors from BM. The expression of CD10/NEP on murine pro-B cells and BM stromal cells suggests a role for the enzyme in early B-cell ontogeny. In modified Whitlock-Witte cultures in which Thy-1lowLin- progenitors plated on BM stromal cells differentiate into Thy-1lowB220+ pro-B and Thy-1-B220+ pre-B cells, the addition of specific CD10/NEP inhibitors increased the number of lymphoid colonies at days 5 through 7 by 34% (P < .001). The results suggest that CD10/NEP participates in the regulation of the earliest stages of stromal cell-dependent B lymphopoiesis.

Animals↗
PubMed1992

Murine common acute lymphoblastic leukemia antigen (CD10 neutral endopeptidase 24.11). Molecular characterization, chromosomal localization, and modeling of the active site.

To further analyze CD10/NEP function in lymphoid and nonlymphoid cells using well characterized murine systems, we isolated the murine CD10/NEP homologue, determined its chromosomal location, and modeled the enzyme's active site. The murine CD10/NEP cDNA predicts a 750-amino acid (aa) type II integral membrane protein with 90% identity to the human CD10 sequence and 100% conservation of critical aa and functional motifs. The latter include the pentapeptide consensus sequence required for zinc binding and catalytic activity, additional aa associated with substrate binding, and the extracellular cysteines that participate in disulfide bonds required for enzymatic activity. Like its human homologue, murine CD10/NEP has multiple alternative 5'-untranslated region sequences. The gene is localized on the proximal half of murine chromosome 3. In Northern analysis, murine CD10/NEP transcripts are abundant in bone marrow stromal cells that support pre-B cell differentiation but are undetectable in representative Abelson transformed pre-B cell lines. The murine CD10/NEP active site was modeled by aligning critical conserved CD10/NEP residues with comparable residues in the active site of thermolysin, a bacterial metalloprotease with similar substrate specificity. The model predicts that the two enzymes have similar clefts that comprise the active site and permit zinc-dependent substrate interactions.

Amino Acid Sequence↗
PubMed1991

Antiemetic activity of high-dose methylprednisolone associated with continuous-infusion metoclopramide and oral alprazolam during multiple-day chemotherapy.

The addition of high-dose methylprednisolone (120 mg given i.v. and repeated after a 4-h interval) to a conventional antiemetic regimen consisting of metoclopramide (0.5 mg/kg given as an i.v. bolus over 30 min followed by 1 mg/kg given as a continuous infusion over 24 h) and alprazolam (0.5 mg given p.o.) was evaluated in a randomized study of leukemic patients undergoing anthracycline-containing multiple-day chemotherapy. Double-blind analysis was done in 30 patients who completed a total of 40 treatment courses. Cumulative 3-day results revealed complete control of nausea in 66% of patients and complete control of emesis in 77% of cases. The addition of methylprednisolone significantly reduced the occurrence of nausea (p = 0.003) and emesis (P = 0.06). Moreover, antiemetic rescue with chlorpromazine was less frequently necessary in patients receiving corticosteroids (P = 0.02). No harmful side effect was observed, and the incidence of severe infectious episodes was similar in both arms. We conclude that high-dose methylprednisolone can improve the efficacy of metoclopramide and alprazolam in controlling nausea and emesis induced by anthracycline-containing multiple-day chemotherapy in patients with acute myeloblastic leukemia.

Adolescent↗
PubMed1991

Aggressive primary gastrointestinal lymphomas: review of 91 patients treated with the LNH-84 regimen. A study of the Groupe d'Etude des Lymphomes Agressifs.

PURPOSE: Patients with aggressive primary gastrointestinal lymphoma undergoing the LNH-84 chemotherapy regimen were analyzed to determine the efficacy of intensive combination chemotherapy, the role of surgical debulking in patients treated with combination chemotherapy, and the toxicity associated with each of these modalities. PATIENTS AND METHODS: Ninety-one patients with primary gastrointestinal lymphoma who participated in the prospective multicenter LNH-84 combination chemotherapy trial (total number of patients in trial, 737) were analyzed. These 91 patients included 69 (76%) with diffuse large cell, nine (10%) with diffuse mixed, and seven (8%) with small noncleaved cell lymphoma. Two patients (2%) had stage IE, 54 patients (59%) stage IIE, and 35 patients (38%) stage IV disease; all patients with stage IE, 22 with stage IIE, and 18 with stage IV disease had bulky (greater than or equal to 10 cm) tumors. Specific sites of gastrointestinal involvement included stomach (47%), small bowel (38%), ileocecum (14%), colon (11%), and rectum (7%). Although surgical resection was attempted in 71 patients (78%), only 28 (31%) had complete tumor excision. All patients received three or four cycles of ACVB (defined in text) induction therapy followed by sequential consolidation as previously described. RESULTS: Responses to treatment in the 91 patients included 71 (78%) complete remissions, six (7%) partial remissions, five (5%) nonresponses, and nine (10%) deaths. With a median follow-up of 3 years, 10 patients (14%) have had relapses; predicted 4-year disease-free survival of complete responders is 85% and predicted 4-year survival of the entire group is 62%. In patients with stage IE or IIE disease, the complete response, survival, and disease-free survival rates were similar in those who underwent complete surgical resection or incomplete or no surgical resection prior to the administration of combination chemotherapy. Prognostic factors predicting for survival in the 91 patients with primary gastrointestinal lymphoma were similar to those in the 646 other patients treated with the LNH-84 regimen. CONCLUSIONS: Patients with aggressive gastrointestinal lymphoma treated with intensive chemotherapy have outcomes and prognostic factors comparable to those of patients with similar-stage aggressive lymphoma without primary gastrointestinal involvement. Surgical resection prior to the administration of combination chemotherapy did not influence the complete response rate, survival rate, or disease-free survival rate in this small group of patients.

Adolescent↗
PubMedDate not supplied

Anaphylactoid reaction with bronchospasm following intravenous cyclophosphamide administration.

Anaphylactoid reaction to cyclophosphamide administration in a 85-year old woman is described. Symptomatology was restricted to bronchospasm, which regressed within one hour. This incomplete and rapidly regressive symptomatology might be explained by previous administration of methylprednisolone. No anaphylactoid symptoms were observed following continuation of therapy with ifosfamide.

Aged↗
PubMedDate not supplied

Autologous peripheral blood stem cell transplantation for non-Hodgkin's lymphoma.

High-dose chemotherapy supported with autologous peripheral stem cell transplantation is now widely used in the treatment of lymphoma patients. The benefit of high-dose therapy has been clearly established after relapse in patients with an aggressive histological subtype who respond to salvage therapy. However, the use of such treatment also deserves further evaluation in the first line of therapy in patients with adverse prognostic factors. In follicular lymphoma, autologous transplantation seems able to induce long-term responses in selected clinical situations, but randomized studies are awaited to evaluate the potential benefit of this approach. In other lymphoma subtypes, the use of high-dose therapy remains experimental and should still be tested in clinical trials. Given the feasibility and the limited toxicity of autologous peripheral stem cell transplantation, the comparison of different therapeutic strategies (optimal timing, treatments modalities) will be facilitated and will allow us to assess the best ways of using this treatment in lymphoma patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Mucosal ulcerations revealing primitive hypereosinophilic syndrome.

We report the case of a 27 year-old man developing recurrent oral aphtosis associated with fever and 8 kg of weight loss. Moderate splenomegaly was observed on physical examination and neurological and cardiac examination were normal. Laboratory findings included marked eosinophilia at 3280 giga/l. Bone marrow (BM) examination revealed a myeloproliferative syndrome with mature eosinophils. Splenectomy was performed because of a suspected nodule on the BM, the histopathology revealed a myeloid metaplasia. The diagnosis of myeloproliferative form of hypereosinophilic syndrome (HES) was made. He was treated with interferon-alfa and hydroxyurea. After two years of treatment he had no ulcer recurrence and eosinophil count was at 180 giga/l. Mucosal manifestations as a prodromal symptom of HES are rare. The histology of the lesions shows numerous eosinophils; immunohistochemical analysis confirms the presence of eosinophil peroxydase, major basic protein and eosinophil derived neurotoxin. A few cases have been described. Death occurs 11 months to 5 years after the diagnosis of oral ulcerations. The treatment consists of interferon-alfa and hydroxyurea.

Adult↗
PubMedDate not supplied

[Treatment of aggressive primary lymphomas of the digestive system by intensive chemotherapy. Experience of the Study Group on Lymphomas in Adults with the LNH-84 protocol].

Ninety-one patients with primary gastrointestinal lymphoma included in the LNH-84 multicentric regimen were analyzed to determine the efficacy and the toxicity of intensive combination chemotherapy and of surgical debulking. All these patients had aggressive histological subtypes: 56 patients had localize disease, stage IE or IIE, and 35 patients had stage IV disease; 40 patients had bulky disease. Specific sites included stomach (43 cases), small bowel (35), ileo-cecum (13), colon (10), and rectum (6). Although 71 patients (78%) had an attempted surgical resection, only 28 (31%) had complete tumor excision. Patients were treated with 3 or 4 cycles of ACVB chemotherapy followed by sequential consolidation. Nine patients died during chemotherapy. With a median follow-up of 3 years, 10 patients have relapsed and predicted 4-year survival of the entire group is 62%. In stage IE or IIE patients, survival and disease-free survival are similar in patients who underwent complete resection or incomplete or no surgical resection prior to the administration of chemotherapy. Prognostic factors predicting for survival were similar to the entire group of patients treated with the LNH-84 regimen. Aggressive gastrointestinal lymphoma patients treated with intensive chemotherapy have outcome and prognostic factors comparable to those of other similarly staged aggressive lymphoma patients. Surgical resection prior to the administration of combination chemotherapy did not influence survival or disease-free survival in patients with localized disease.

Adolescent↗
PubMedDate not supplied

[Hepatocellular carcinoma and hyperestrogenia in a male].

The case of a 38 year-old man with hepatocellular carcinoma in a non-cirrhotic liver is reported. Hyperestrogenosis with gynecomastia, polycythemia and proteinuria were present. After complete removal of the tumor, estrogen levels, red blood-cell volume and urine analysis did not return to normal and these pathologic findings were probably not paraneoplastic syndromes. Outcome was good, the patient remaining completely well without evidence of recurrence during the ensuing 30 months. The likely explanation for the persistent hyperestrogenosis was an excessive conversion of sexual hormones. The authors suggest that this abnormal hyperestrogenic state could promote hepatic neoplasia as it has been established in animals.

Adult↗
PubMedDate not supplied

Mechanisms of action of the tumor necrosis factor and lymphotoxin ligand-receptor system.

In the past few years, a number of experimental observations have provided more insight into the mechanisms of action of tumor necrosis factor (TNF)/lymphotoxin (LT) ligand-receptor system. This system consists of three ligands, TNF, LT alpha (LT alpha) and LT beta (LT beta), and three membrane-associated receptors, p55, p75 and LT beta-receptor (LT beta-R). Like TNF, LT alpha is a secreted protein which in solution forms a homotrimer molecule, with a conformation similar to that of TNF. LT beta is a transmembrane protein that provides the membrane anchor for the attachment to the cell surface of the heteromeric complex of LT alpha and LT beta. This complex retains a structure related to TNF and LT alpha homotrimers, with the homology regions interacting in a heterotypic fashion. The LT alpha 1:LT beta 2 heteromer has been found to be a predominant form of surface LT. The biological effects of TNF and LT alpha homotrimers are mediated by p55 and p75 receptors, while the heteromeric complex of LT alpha/LT beta transduces its cellular signal via LT beta-R. Membrane-associated receptor affinities as well as final biological effects of TNF/LT can be modulated by the influence of naturally occurring soluble receptors, derived from the cell surface by proteolytic cleavage. The multimerization of receptor cytoplasmic domains upon TNF/LT ligation is postulated to activate the intracellular signal-transduction pathways. One of them is the activation of phospholipase A2 (PL-A2) resulting in the production of arachidonic acid (AA) and other metabolites, including leukotriens, phosphatidycholine-specific phospholipase C (PC-PLC) with subsequent production of diacylglycerol (DAG) and activation of protein kinase C (PKC). As a third signaling pathway, TNF/LT employ the sphingomyelinase (SMase)-mediated hydrolysis of membrane sphingomyelin (SM) to ceramide. The final link in the TNF/LT signaling is activation of nuclear transcription factors, such as NF-kappa B, AP-1, interferon regulatory factors-1 and -2 (IRF-1, IRF-2), and NF-GMa. Since induction of AP-1, IRF-1 and IRF-2 as well as NF-GMa proceeds through translational event, the posttranslational TNF/LT-driven activation of NF-kappa B remains the only cellular event identified so far that serves as a direct target in their signaling cascade.

Animals↗