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Biomedical subjects

M Lopez

Publications and source records attributed to M Lopez.

At least 307 records · Page 17Linked to original sources
PubMed1989

Immunophenotyping of acute myeloid leukaemia: relevance of analysing different lineage-associated markers.

The immunophenotype of 135 previously untreated patients with FAB defined acute myeloid leukaemia (AML) was studied at diagnosis. The panel of reagents included monoclonal antibodies (MoAb) recognising myeloid-associated determinants (CD11, CD13, CD14, CD33 and others) as well as MoAb directed towards lymphoid antigens (CD7, CD10, CD19) and TdT. The results indicate that CD13 and/or CD33 are consistently expressed in AML and only rarely in ALL blasts (131/135 + ve cases, versus 4/130 in ALL). Lymphoid antigen expression was rarely detected when CD10 and CD19 were investigated in AML (0.9% and 2% + ve cases, respectively), whereas significant positivities were found for TdT and CD7 (20% and 10% respectively). Concerning FAB subtypes, two new MoAb (LAM3 and LAM7) proved very useful in the specific recognition of AML with monocytic features. The phenotype CD13+ and/or CD33+, CD9+, HLA-DR- was found to be almost exclusive for M3 AML. The response to induction chemotherapy was analysed in CD7+ and in TdT+ patients. In the latter group a statistically significant lower response rate was found with respect to TdT-ve-AML patients.

Adolescent↗
PubMed1989

Laboratory tests.

Explore the source record for details and available documents.

Blood Grouping and Crossmatching↗
PubMed1989

Bronchoprovocation studies in basidiospore-sensitive allergic subjects with asthma.

Bronchoprovocation challenge with basidiospore extracts was performed in eight subjects with asthma and with positive wheal-and-flare skin reactivity and RAST to basidiospore allergens. Five of the eight patients demonstrated a significant decrease in FEV1 ranging from 20% to 47% after basidiospore-extract challenge. Both immediate and late-phase reactivity was observed. Six atopic control subjects with asthma and with negative skin reactivity to basidiospore extracts did not exhibit significant bronchospasm after basidiospore challenge. These results demonstrate that basidiospore extracts can induce bronchospasm in subjects with asthma who demonstrate IgE antibodies to basidiospore allergens.

Allergens↗
PubMed1989

Pilot phase I study using zidovudine in association with a 10-day course of anti-CD4 monoclonal antibody in seven AIDS patients.

Experimental evidence has demonstrated that monoclonal antibody (MAb) 13B8.2, a workshop-qualified anti-CD4 MAb, (1) inhibits in vitro syncytium formation as well as in vitro HIV infection of CD4+ T cells; (2) delivers negative signals to T cells, thus preventing T-cell activation and viral replication; (3) contributes to CD4+ T-cell clearance by its Fc portion, and (4) induces an immune response by the patient, contributing potentially to an anti-idiotypic response of interest for the control of the immune parameters of the disease. On this basis a phase I study combining zidovudine treatment and a 10-day course of anti-CD4 MAb was performed in seven AIDS patients (Centers for Disease Control group IV). The treatment was well tolerated. MAb dosage and schedule were adjusted on the basis of circulating CD4+ cells and MAb pharmacokinetics; immunological and virological parameters were also monitored. One patient presented a transient increment in CD4+ T cells associated with augmented T-cell function, the suppression of p24 in the serum and a negative RT assay. A second patient had a steady increment of CD4+ T cells after completion of the treatment, with a transient decrease of serum p24 5 days after completion of the anti-CD4 protocol.

Acquired Immunodeficiency Syndrome↗
PubMed1989

CD7 positive acute myeloid leukaemia: a subtype associated with cell immaturity.

Seventeen patients with acute myeloid leukaemia (AML) whose blasts co-expressed the T-cell associated CD7 antibody were identified among 160 consecutive AML cases. Fourteen had FAB defined AML according to morphocytochemical criteria, whereas three patients were classified as 'MO' on the basis of immunophenotype. The incidence of CD7 positively was particularly significant in the less differentiated subtypes M0 and M1 compared with other FAB groups (P less than 0.001). In all cases the myeloid determinants CD13 and/or CD33 were associated with CD7 expression. Other B-lymphoid (CD10, CD19) or T-lymphoid (CD2, surface and cytoplasmic CD3) markers were analysed and found to be negative. Five out of 15 cases examined were TdT+. Clonal rearrangements of the immunoglobulin heavy chain (IgH) and/or T-cell receptor (TcR) beta chain genes were identified in only three out of 13 cases. Among these, one out of five co-expressing TdT showed IgH rearrangement when analysed at the DNA level. Clinical features at presentation and response to induction therapy did not allow us to consider CD7+ AML patients as a distinct subgroup with prognostic significance. Our data indicate that CD7 expression is a common finding in immature AML, being generally found in the absence of other T-cell features. Rather than suggesting the occurrence of 'mixed leukaemia', such cases confirm a broader spectrum of CD7 reactivity and its possible identification of a particular subset of myeloid progenitors.

Antigens, CD7↗
PubMed1989

Migraine-related stroke: brain infarction in superior cerebellar artery territory demonstrated by nuclear magnetic resonance.

We report 4 cases of migraine-related stroke in young females. Two patients were taking oral contraceptives and one was pregnant. The results of the computerized tomography of the brain were negative in 3 patients and partially positive in one, while NMR showed ischemic lesions in the posterior fossa in each case. We would like to highlight the value of NMR in the assessment of migraine associated with prolonged focal neurologic deficiencies when the clinical examination revealed brain stem or cerebellar signs and the peculiar localization of the ischemic lesion that corresponded in all 4 cases to the area irrigated by the superior cerebellar artery. An hormonal factor is suspected as the precipitating event of this complication in 3 of these patients.

Adult↗
PubMed1989

5-Fluorouracil, adriamycin, cyclophosphamide (FAC) vs. 5-fluorouracil, epirubicin, cyclophosphamide (FEC) in metastatic breast cancer.

94 evaluable patients with metastatic breast cancer were randomly assigned to 5-fluorouracil, adriamycin, and cyclophosphamide (FAC) or 5-fluorouracil, epirubicin, and cyclophosphamide (FEC), with cycles repeated every 3 weeks. The objective response rate to FAC was 46% versus 44% to FEC. There was no significant difference in the median duration of response and median survival for the two regimens. Toxicity was more frequent and more pronounced in patients receiving FAC. Results indicate therapeutic equivalence of the two regimens and reduced toxicity of the epirubicin arm.

Adult↗
PubMed1989

Learned helplessness.

1. Nurses described learned helplessness solely in terms of residents not performing the daily activities they were capable of. 2. The relatively strong correlation between the learned helplessness subscale of the MDI and the Beck Depression Inventory suggests that learned helplessness can be maladaptive and dysfunctional. 3. Analysis of attributional style found that personal, stable, and global attributions for negative events were closely associated with LH scores and self-reported depressive symptomatology in this sample. 4. Residents, except in the areas of meals and privacy, generally reported satisfaction with the amount of control they had in their treatment setting.

Aged↗
PubMed1989

Influence of inducers and inhibitors on the metabolism in vitro and neurochemical effects in vivo of MDMA.

(S)-(+)- and (R)-(-)-3,4-methylenedioxymethamphetamine (MDMA) were metabolized in vitro by rat liver microsomes via N-demethylation to 3,4-methylenedioxyamphetamine (MDA). Whereas no difference was found in the biotransformation of the two enantiomers in the male rat or in the phenobarbital (PB) treated animals of either sex, more than twice as much MDA was formed from (S)-(+)- than from (R)-(-)-MDMA in the untreated female rat. Although 3-methylcholanthrene (3MC) pretreated rat liver microsomes were less active than those from the untreated rats of the same sex, they formed more MDA from (+)- than from (-)-MDMA. The enantioselective metabolism thus appears to be associated with the relative abundance of individual cytochrome P-450 isozymes. (S)-(+)- and (R)-(-)-MDMA.HCl (20 mg/kg) were about equipotent in depleting serotonin (5-HT) levels in the frontal cortex at 3 hrs and 1 wk following oral administration to female rats. Pretreatment of rats with SKF-525A attenuated and that with PB enhanced the 5-HT depleting potential of either isomer at 3 hrs. The 5-HT depleting potency of (+)-MDMA was significantly greater than that of its (-)-antipode at 3 hr in PB pretreated, but not in SKF-525A pretreated animals. The results suggest that the neurochemical effects of MDMA are caused by the formation of an active metabolite in vivo, and since both enantiomers were N-demethylated in vitro to approximately the same extent by PB pretreated rat liver microsomes, the active metabolite may be other than MDA.

3,4-Methylenedioxyamphetamine↗
PubMed1989

[The cytotoxicity of oxidized lipoproteins].

The peroxidation of low-density lipoproteins (LDL) and their subsequent cytotoxicity is believed to be involved in the atherogenesis. The aim of this work was to determine the possible involvement of lipid peroxides in the cytotoxicity of lipoproteins. We report a new experimental model system constituted by lipoproteins treated by short-UV radiations which result in a major lipid peroxidation without functional alteration of apoproteins. UV radiations induced the following lipid modifications: the content of polyunsaturated fatty acids decreased considerably in all lipid classes; the level of natural antioxidants, i.e. vitamin E and carotene, dropped dramatically; conjugated dienes and thiobarbituric acid reactive substances (TBARS) were notably increased; apoproteins from LDL exhibited little structural modification but no functional alteration. The cytotoxicity was studied in lymphoblastoid cell lines established from lymphocytes derived from normal subjects or from patients with familial hypercholesterolemia. High density lipoproteins (HDL) were shown to inhibit the cytotoxicity induced by low doses of peroxidized LDL; the protective effect of HDL was complete up to the ratio ApoB/ApoA close to 1. In addition, vitamin E and catechin, two well known antioxidants, blocked the cytotoxicity of peroxidized LDL. These results corroborate the possibility of the synergic effect of HDL and antioxidant molecules for the protection of cells against oxidized LDL that are incorporated through the LDL-receptor pathway.

Antioxidants↗
PubMed1989

Translocation (3;21) in Philadelphia positive chronic myeloid leukemia: high resolution chromosomal analysis and immunological study on five new cases.

Translocation t(3;21)(q26;q22) is a rare but nonrandom event occurring in Philadelphia positive chronic myeloid leukemia. We describe five new cases (two males, three females) where t(3;21) is associated with the progression of the disease. Using FACS analysis, we confirm the myeloid type of the blast crisis. High resolution chromosomal analysis allowed us to define more precisely the chromosomal breakpoints to 3q26.2 and 21q22.2, close to the respective localizations of two genes important in cell proliferation and cancer pathogenesis: the transferrin receptor gene and the ets.2 proto-oncogene.

Adult↗
PubMed1988

Triggering CD 28 molecules synergize with CD 2 (T 11.1 and T 11.2)-mediated T cell activation.

Pairs of monoclonal antibodies (mAb) defining epitopes T 11.1 and T 11.2 on the CD 2 molecule are mitogenic for purified human T cells in the presence of a submitogenic dose of 12-O-tetradecanoylphorbol 13-acetate (TPA). Anti-CD 28 mAb can substitute for the action of TPA in the anti-CD 2-induced proliferative response of resting T cells, whereas each signal alone is unable to mediate this effect. Co-stimulation by anti-CD 2 plus anti-CD 28 mAb is monocyte independent and besides resting T cells also induces strong proliferation of thymocytes and pre-activated T cells. Modulation of the CD 3-T cell receptor complex does not inhibit the co-stimulatory effects of anti-CD 2 plus anti-CD 28 mAb. The effect is largely dependent on endogenously produced interleukin 2, since the response is strongly inhibited in the presence of mAb against the 55-kDa interleukin 2 receptor chain.

Antibodies, Monoclonal↗