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Biomedical subjects

C Lahoz

Publications and source records attributed to C Lahoz.

106 records · Page 6Linked to original sources
PubMed1987

Occurrence of immunoblastic B-cell lymphoma in hairy cell leukemia.

A 47-year-old man, was referred for evaluation of asymptomatic splenomegaly in September 1981, and a diagnosis of hairy cell leukemia (HCL) at the initial clinical stage was made. The patient remained asymptomatic until May 1985, when splenectomy was performed because of anemia and splenomegaly. Bone marrow and liver biopsy specimens showed diffuse infiltration by abnormal tartase resistant acid phosphatase (TRAP) positive lymphocytes with typical aspect of hairy cells. Four months later, he developed fever of unknown origin and, at laparotomy, diffuse retroperitoneal lymph node enlargement and metastatic liver nodules were seen. Lymph node and liver biopsy specimens showed diffuse infiltration by abnormal large lymphocytes, which bore monoclonal surface immunoglobulin M and light chain kappa. Only six cases of non-Hodgkin's lymphoma associated with HCL have been published to date. This report describes an additional case of immunoblastic B-cell lymphoma, preceded 4 years earlier by the diagnosis of HCL.

B-Lymphocytes↗
PubMed1987

Incidence and clinical significance of peripheral and bone marrow basophilia.

We reviewed 2110 bone marrow aspirations from the same number of patients to establish the incidence and associations of peripheral and bone marrow basophilia. Of these, 125 cases of marrow basophilia (5.9% incidence) and 63 cases of peripheral basophilia (3.0% incidence) were identified. There were 33 patients with simultaneous marrow and peripheral basophilia, which was only significantly associated with chronic myelogenous leukemia (24 cases). Isolated peripheral basophilia was rarely seen (30 patients, 1.4% incidence) and it did not reflect any significant pathologic association. Marrow basophilia was significantly present in chronic myeloproliferative disorders, idiopathic myelodysplasia, certain erythrocyte disorders, such as iron deficiency anemia, and aplastic anemia. The incidence of marrow basophilia in patients with lymphoma, acute leukemia, or solid carcinoma was not significantly different from what it would be as a chance occurrence. Our findings suggest that marrow basophilia is a specific, but not sensitive, marker of myeloproliferative and dysmyelopoietic syndromes.

Adult↗
PubMed1985

T cell dependence of human IgE response: quantitative and functional studies.

In 108 allergic and nonallergic patients T3, T4 and T8 cells were quantified. No significant differences were found when comparing healthy and allergic individuals. Functionally, the role of T8 suppressor and cytotoxic population was studied by removing this subset, comparing the IgE produced in vitro by peripheral blood lymphocytes of unfractionated and T8-depleted cultures. Results indicate a statistically significant increase of the in vitro IgE production when cultures from healthy people and 'normoproducer' allergics (in vitro spontaneous IgE production no more than 900 pg/ml/10(7) cells) were depleted of T8 cells. The same experiments in 'hyperproducer' allergics (in vitro spontaneous IgE production more than 900 pg/ml/10(7) cells) show no significant difference in the IgE production when T8 cells were depleted.

Humans↗
PubMed1984

Transmethylation reactions in human basophils induced by anti-IgE or specific antigen.

The activation of methyl transferases in the membrane of human basophilic leukocytes was measured by incorporation of 3H-methyl groups into phospholipids. Basophils of healthy individuals were activated by anti-IgE, those of pollen allergic patients by the specific antigen, Lolium perenne extract. Basophil-rich fraction was obtained from peripheral blood by centrifugation in a gradient of Ficoll/metrizamide (g = 1.085). After incubation with anti-IgE an increase in the 3H-methyl incorporation was detected during the first 30 s of the reaction. The maximal incorporation in basophils of the pollen allergic patients, activated by L. perenne extract, was enhanced at 15 s. Appropriate controls showed that the activation of methyl transferases occurred in basophils only.

Animals↗
PubMed1982

IgG antibodies: in vitro blocking activity of IgE mediated reactions.

Sera from 177 atopic patients treated by immunotherapy were screened in order to detect IgD antibodies against a purified fraction of Lollium perenne (fractions C). IgD antibodies were found in 23% of the subjects. Eight of these sera were selected and their IgD isolated by means of immunoabsorption. The in vitro biological activity of the IgD antibodies against fraction C was tested by three methods: basophil degranulation, histamine release and RAST inhibition test. In all these assays, the data obtained indicated a possible blocking effect of the IgD antibodies upon the IgE in vitro mediated reactions.

Antibodies, Anti-Idiotypic↗
PubMed1982

Fractionation and biological characterization of Olea europea pollen extract.

Preliminary fractionation of Olea european pollen extract has been performed. At least 10 antigenic fractions have been found by crossed electrophoresis. After Sephadex gel filtration, two fractions with a molecular weight of 160,000 and 65,000 have been obtained. The fractions were evaluated for allergenic activity by two in vitro techniques: polystyrene tube radioimmunoassay (PTRIA) and basophil degranulation test (BDT), and by skin tests. All tests indicated that the most reactive fractions were those in the 65,000 molecular weight peak. BDT has been shown to be a very reliable method as compared with histamine release and other parameters. Although common antigenic fractions have been found for Lollium perenne and O. europea, no cross-allergenicity has been shown by PTRIA inhibition.

Basophils↗
PubMed1981

Role of T gamma cells in the in vitro IgE response after antigenic stimulation.

Fifteen patients with seasonal allergic pollenosis and five controls were investigated to elucidate the role of the T gamma-cell population in the in vitro IgE response by peripheral blood lymphocytes (PBL). In vitro IgE production by PBL of atopic patients after antigenic stimulation was measured in culture supernatants. The optimal dose for antigenic stimulation was found to be 0.16 micrograms/20 X 10(6) cells of purified antigen. No difference was found when comparing the percentages of T cells (E rosettes) between the two groups: mean per cent for controls was 69.2 +/- 5.76 versus 69.54 +/- 4.42 for the allergic group. With regard to the T gamma-cell population, the values obtained by rosetting with ox erythrocytes sensitized with IgG antibody were 12 +/- 0.71% in normals and 9.8 +/- 1.32% in those with allergic pollenosis. This difference, although significant, may not be enough to explain the different pattern when the in vitro IgE production of both groups investigated was compared. In order to detect the role of T gamma cells in this system, lymphocyte cultures, depleted of T gamma cells, were performed and compared with unfractionated cultures from the same donors. Our results show no differences in the in vitro IgE production when T gamma cells were depleted as compared with the unfractionated cultures.

Humans↗
PubMed1980

Evidence of sensitized basophils in renal transplanted patients.

The participation of basophil polymorphonuclear leukocytes in the response to kidney allografts in man has hardly been studied. In 23 patients, followed from the immediate post-transplant period for several years, the number of circulating basophils, expressed either as absolute number or as percentage of leukocytes, was significantly low in relation to that of controls. IgE on the basophil surface was determined by radioimmunoassay in 14 patients. All patients but one had elevated numbers of IgE molecules per basophil, values being higher in patients with cadaver grafts and in patients with a graft functioning at 6 months or less. When the count of circulating basophils was roughly normal, six of the eight patients showed a positive basophil degranulation test against the donor lymphocytes. These results suggest the existence of specific IgE antibodies for HLA antigens in renal transplanted patients.

Basophils↗
PubMed1980

Evidence of an immediate hypersensitivity mechanism in systemic lupus erythematosus.

In 30 patients with systemic lupus erythematosus the number of a circulating basophils was countered in different stages of activity. An inverse correlation was found between the absolute basophils count and anti-DNA antibodies and presumptive circulating immune complexes (as judged by polyethylene glycol precipitation of serum). A positive correlation was found between the absolute basophil count and C3 or C4 levels. IgE on the basophil surface was determined by radioimmunoassay in 7 patients. All of them showed a significantly higher surface IgE number. When the count of circulating basophils was roughly normal, 5 out of the 6 patients showed a positive basophil degranulation test with native DNA. These results suggest the existence of an anti-DNA specific IgE in lupus patients. Depression of the circulating basophil count may be a useful index of lupus activity.

Antibodies, Antinuclear↗
PubMed1979

In vitro production of IgE and IgG by sensitized human peripheral lymphocytes.

Antigenic stimulation of peripheral lymphocytes was made in two different groups of atopic patients, testing their capabilities to produce IgE and IgG in vitro. For this purpose, Marbrook's technique was used in the cultures. The immunoglobulins produced were measured in the supernatants by a sensitive double-antibody method. Results demonstrate that it is possible to produce enough IgE and IgG to be detected. Some important parameters had to be considered: appropriate selection of the patients and the antigens used in the antigenic stimulation, as well as the number of cells and the duration of the culture.

Allergens↗
PubMed1978

Quantitation of IgE on the basophil surface in atopic patient.

A radioimmunoassay was employed in order to quantitate IgE on the basophil surface in 6 normal and 10 pollen sensitive subjects. A basophil-rich fraction obtained from whole blood in a Ficoll gradient was incubated with specific anti-IgE; the inhibition produced by surface IgE was standard inhibition curve. Atopic patients had on the average about 10-30 times as many IgE molecules per basophil as control subjects. Total and specific IgE as well as degranulation by Lollium perenne crude extract were also studied in both populations and their results compared with those of basophil IgE quantitation.

Basophils↗