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Biomedical subjects

A Valls

Publications and source records attributed to A Valls.

At least 37 records · Page 2Linked to original sources
PubMed1993

CD23 expression on B-lymphocytes and its modulation by cytokines in allergic patients.

The aim of this study was to assess the expression of CD23 on peripheral blood B-cells, and its in vitro modulation by recombinant human interferon-gamma (IFN-gamma) in phytohaemagglutinin-(PHA) or recombinant human interleukin-4 (IL-4)-stimulated cultures in atopic patients with Dermatophagoides pteronyssinus hypersensitivity and in healthy non-atopic subjects. Atopic patients with asthma not receiving allergen-specific immunotherapy (n = 21) were studied and further compared with a group of atopic subjects with asthma under allergen-specific immunotherapy (n = 21). They were age-(+/- 5 yr) and sex-matched. The results were also compared with those obtained in the non-atopic group (n = 11). CD23 expression on B-lymphocytes and its modulation were analyzed by flow cytometry using conjugated monoclonal antibodies with a double immunofluorescence method. Atopic patients had an increase in the percentage of B-cells expressing CD23 in peripheral blood. Phytohaemagglutinin and IL-4 induced a rise in the percentage of CD23-positive B-cells in both atopic groups and non-atopic subjects. Phytohaemagglutinin provoked an increase in the intensity of CD23 expression on B-cells from stimulated cultures in all groups, while IL-4 only produced a significant increase in atopic patients. The presence of IFN-gamma decreased the CD23 expression on B-cells in PHA-stimulated culture of atopic patients, whereas it caused an increase in CD23 expression in the non-atopic group. Furthermore, the presence of IFN-gamma in IL-4-stimulated cultures induced a decrease in CD23 expression on B-cells in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

IgE antibodies against bovine serum albumin in a case of eosinophilic gastroenteritis.

Eosinophilic gastroenteritis is a disease characterized histologically by an eosinophilic infiltration of the gut. The cause of this disease remains unclear, although both food allergy and food intolerance have been implicated in its pathogenesis. We report the case of a 22-year-old man in whom gastrointestinal symptoms first appeared in childhood, with involvement of mucosa and muscularis layers of stomach and bowel. He presented high IgE blood levels, and his prick test was positive to bovine, pig, and lamb sera. Immunoblots from calf, pig, and lamb sera, incubated with the patient's serum and revealed by autoradiography, demonstrated the presence of a 65-kDa protein band that was recognized by IgE antibodies but not by IgG. This band corresponded to bovine serum albumin, while IgE did not show reactivity with human albumin. These data suggest a possible role for IgE-mediated hypersensitivity mechanisms in the pathogenesis of eosinophilic gastroenteritis.

Adult↗
PubMed1993

A single dose of granulocyte colony-stimulating factor modifies radiation-induced death in B6D2F1 mice.

Granulocyte colony stimulating factor (G-CSF) stimulates the proliferation of progenitor cells committed to myeloid differentiation. In animal models, G-CSF is able to stimulate granulocyte recovery and promote survival after lethal or sublethal irradiation when administered as daily injections, suggesting an influence on the residual hematopoietic primitive precursors surviving irradiation. In this study, we clearly demonstrate that a single dose of G-CSF (1 mg/kg) administered to B6D2F1 mice 2 hours after a lethal dose 95/30 irradiation achieves a 78% survival at day +30 after irradiation. Survival of G-CSF treated mice compares favourably with that of syngenic bone marrow transplantation recipients (78% vs 90%, ns).

Animals↗
PubMed1993

Autologous bone marrow transplantation for acute leukemia: results and prognostic factors in 90 consecutive patients.

The results of autologous bone marrow transplantation (ABMT) in acute leukemia (AL) and the prognostic factors for outcome were analyzed in a series of 90 consecutive patients treated at a single institution (mean +/- SD age: 25 +/- 11 years). Diagnosis was: AML (n = 43), ALL (n = 44), acute undifferentiated leukemia (n = 2) and acute bilineage (n = 1). Disease stage at ABMT was: first complete remission (CR1) 46 cases, CR2 33, other stages 11. Conditioning consisted of cyclophosphamide and total body irradiation in 88 patients. The 3 year probability of disease-free survival (DFS) was influenced by disease stage at ABMT: CR1 48%, CR2 28%, CR3 plus CR4 15%. The characteristics associated with a high probability of relapse were: in AML a FAB subtype other than M1 or M3 (p = 0.01) and in ALL an interval between CR1 and ABMT of < 3 months (p = 0.002). A WBC > 15 x 10(9)/l at diagnosis (p = 0.01), splenomegaly at diagnosis (p = 0.002) and time to CR1 > 4 weeks (p = 0.06) increased the risk of relapse in the entire group in CR1. In multivariate analysis, WBC at diagnosis (p = 0.006) and disease stage at ABMT (p = 0.03) independently influenced DFS. This study confirms the encouraging results of ABMT in CR1 but further antileukemia measures are necessary in patients with adverse prognostic features.

Acute Disease↗
PubMed1993

Interstitial pneumonitis after BMT: 15 years experience in a single institution.

Data from 311 patients with hematological malignancies who received an autologous, allogeneic or syngeneic BMT in a single institution were analyzed. Interstitial pneumonia (IPn) was observed in 58 patients. Two years actuarial probability of IPn was 26.8%. In 50% of cases CMV was detected. In 23 patients (39.7%) IPn was considered idiopathic. The median time from BMT to IPn was 63.5 (range 7-720) days. Patients submitted to allogeneic BMT had a significantly higher risk of developing IPn than patients receiving syngeneic or autologous BMT (34.1% vs 16.7% and 4.9%, respectively; p = 0.0006). Among 230 patients receiving allogeneic transplant, factors with a higher risk for IPn in univariate analysis were: age over 20 years, CML, alloimmunized donor, previous splenectomy, acute and chronic GVHD. When the analysis was restricted to patients with a CMV-associated IPn, all factors except alloimmunization maintained their significance. Multivariate analysis showed that only acute GVHD (p < 0.0001) and a diagnosis of CML (p < 0.001) in the whole group of allogeneic transplants, and acute GVHD (p < 0.001) and splenectomy (p < 0.003) in CMV-associated IPn, maintained their significance. These results are discussed within the frame work of the clinical application of BMT.

Adolescent↗
PubMed1992

Lymphocyte immunophenotyping by flow cytometry in normal adults. Comparison of fresh whole blood lysis technique, Ficoll-Paque separation and cryopreservation.

In the present report we have assessed the extent to which Ficoll-Paque separation and cryopreservation of mononuclear cells alter the measurement of lymphocyte subsets by flow cytometry. Standard Ficoll-Paque separation increased the percentage of CD4+, CD19+ and CD4+CD45RA+ cells, as well as decreasing that of CD8+, and CD4+CD29+ cells, compared to the fresh whole blood lysis technique. Moreover, cryopreservation caused a depletion of CD4+ p80+ cells, but normal whole blood values were restored following a short incubation.

Adult↗
PubMed1992

Autologous hemopoietic reconstitution after fetal liver infusion in patients with bone marrow failure: consequence or coincidence?

In the past 4 years we have treated four patients with a total of 19 fetal liver infusions (FLI). Two cases of refractory anemia with excess blasts in transformation (RAEB-t) were conditioned with cyclophosphamide and total body irradiation (1400 cGy) and were treated with FLI. In spite of such intensive conditioning, one patient recovered autologous hemopoiesis 3 weeks later, remaining in remission 4 years after this procedure. The second patient died with aplastic marrow on day 154, and the third suffered from severe aplastic anemia refractory to several types of conventional treatment. After FLI and without previous conditioning therapy a partial fetal engraftment was documented. This was transient and followed by autologous hemopoietic recovery and cure of the disease. The fourth patient had bone marrow failure in the setting of a severe pneumonia following autologous bone marrow transplantation. Ten days after FLI the hematological parameters dramatically improved and the pneumonia resolved. Autologous reconstitution of hemopoiesis was demonstrated. These experiences suggest that FLI might stimulate autologous hemopoiesis. This therapeutic approach may be useful to treat bone marrow failure when there is no response to first-line therapy. In hematologic malignancies with an indication for stem cell transplantation, other sources such as allogeneic or autologous bone marrow seem preferable to fetal liver cells.

Adolescent↗
PubMed1991

[Efficacy of sucralfate in the prophylaxis of diarrhea secondary to acute radiation-induced enteritis. Preliminary results of a double-blind randomized trial].

BACKGROUND: Pelvic radiation therapy is usually associated with intestinal symptoms, especially diarrhea. Sucralfate has been demonstrated to be effective in peptic ulcers, and seems to provide some benefits in chemotherapy induced mucositis and radiogenic rectitis and enteritis. METHODS: Thirty-four patients between 20-80 years of age, without diarrea and with a Karnofsky index greater than 60%, undergoing whole pelvic irradiation (46 Gy total dose, 2 Gy/day, 5 days/week) have been randomized to receive: sucralfate (1g/6h) (18 patients) or placebo (16 patients) during the treatment period and 3 weeks later. RESULTS: The statistical analysis of the clinical records show that patients receiving sucralfate do better during the whole treatment period (p = 0.03), and they need other complementary measures against diarrhea, as diet (p = 0.03) or pharmacologic support (p = 0.002), later in the course of the radiotherapy. Nevertheless, the incidence and severity of diarrea and other associated simptoms show no differences between both groups. CONCLUSIONS: Sucralfate increases the enteric tolerance during pelvic irradiation in cancer patients.

Acute Disease↗
PubMed1991

Dosimetry and use of an immobilization system for head and neck radiotherapy treatments.

The day-to-day reproducibility of planned radiotherapy treatment is an important precondition for achieving good clinical results and reducing toxic effects. This reproducibility is difficult to achieve in the irradiation of head and neck malignancies because of the mobility of this anatomical area. This paper presents a dosimetric study and analysis of the utility of a facial mask immobilization system prepared from an orthopedic glass-fiber bandage. The dosimetric study conducted on a lucite phantom shows that the interposition of one, two, or three layers of the bandage reduces the deep absorbed dose by about 1% at 0.5 cm2, while increasing the absorbed surface dose by 12% (for a field of 15 X 15 cm2 and one layer of bandage) to 46% (for a field of 5 X 5 cm and three layers of bandage). The dosimetric study conducted on a Rando Anderson manikin shows an average increase in the skin dose of about 8% and a maximum increase of about 20%. The good dosimetric results and the practicality of this system of immobilization have persuaded us to propose it as an alternative to the systems currently on the market, which, although rather more sophisticated, are also more expensive.

Head and Neck Neoplasms↗
PubMed1990

Fractionated total body irradiation for bone marrow transplantation: clinical results on 66 patients.

Short term clinical results of bone marrow transplantation on 66 patients conditioned with fractionated total body irradiation (12 Gy in 6 fractions and 3 days) are presented here. An acute toxic effects incident, similar to that obtained previously, a 27.6% interstitial pneumonitis associated with acute severe graft versus host disease in 77% of cases, 19.2% relapses, and 41% total crude survival with an actuarial probability of surviving for more than two years of 46% for ALL, 64% for AML and 28% for CML, are the results obtained since now.

Adolescent↗
PubMed1989

[Bone marrow autotransplant: preliminary results in 20 patients with acute leukemia].

The results of bone marrow autograft (BMAG) in 20 patients with acute leukemia (AL) consecutively treated from October 1985 and May 1988 are reported. The follow up was continued until November 1988. The mean age of the patients was 20 years (range 10-48) and their diagnoses were acute myeloblastic leukemia (AML) in 12 and acute lymphoblastic leukemia (ALL) in 8. The preparation for BMAG included cyclophosphamide and whole body radiation in all cases. The procedure was carried out in the first complete remission (CR-1) in 5 patients, in CR-2 in 11, in CR-3 in 2, and in CR-4 in another 2. Two patients died as a direct consequence of BMAG, 11 relapsed and 7 are alive and free from relapse. The likelihood of survival free from prolonged illness was calculated as 24% for the whole series, 60% for the cases of BMAG in CR-1 and 50% for the group of patients with AML. The results were poor in the cases of BMAG carried out for AL in an advanced stage. On the basis of these results the experience of other authors with this therapeutic modality is reviewed, and its current indications are discussed.

Adolescent↗
PubMed1989

Total body irradiation in bone marrow transplantation: fractionated vs single dose. Acute toxicity and preliminary results.

The usefulness of total body irradiation (TBI) plus chemotherapy as a preparative regimen prior to bone marrow transplantation has been widely documented. However, the procedure can be highly toxic. Fractionated and low dose rate TBI has been said to enhance therapeutic ratio by increasing normal tissue tolerance and increasing leukemic cell kill. We report here the acute toxic effects and preliminary results on 2 consecutively groups of patients, treated with bone marrow transplantation (BMT) for leukemia or multiple myeloma, and conditioned by 2 TBI regimens. Group A patients received 10 Gy-Co-60 single dose of TBI plus 120 mg/kg of cyclophosphamide over a period of 2 days (8 Gy lungs). Group B received 12 Gy Co-60 of TBI in 6 fractions (2/day), (8 Gy lungs) plus 120 mg/kg of cyclophosphamide over a period of 3 days. The acute toxic effects recorded were similar in both groups. Only a 40% vs 0% (P = 0.02) incidence of parotiditis in groups A and B favors fractionation. Other results obtained to date are as follows: an incidence of interstitial pneumonitis of 39% and 31% (ns); relapses of 10% and 20% (ns), and mortality of 55% and 60% for each group respectively. An interesting finding was that IP was associated with acute grade II-IV graft vs host disease in 87% and 100% of cases of group A and B, respectively. We conclude that fractionated TBI is at least as effective as single dose TBI as a conditioning regimen; however, only randomized trials would allow definitive conclusions.

Adolescent↗
PubMed1987

Effects of irradiation on human platelets stored at 20 degrees C.

The morphologic and functional properties of platelets after irradiation with 2500 rads and storage, in first-generation containers, for 48 h in a liquid phase at 20 degrees C with continuous horizontal agitation have been analyzed and compared with a control group of the same platelets which were not irradiated. The preservation technique induced changes in the morphology and aggregation stimulated by ADP and collagen. However, no significant differences were found between the irradiated and non-irradiated groups. Irradiation is not a conditioning factor to add to the hazards of preserving platelets in a liquid phase.

Adenosine Diphosphate↗