Search PubMed⌕ Search

Biomedical subjects

M Lopez

Publications and source records attributed to M Lopez.

At least 361 records · Page 20Linked to original sources

Anti-CD2 (sheep red blood cell receptor) monoclonal antibodies and T cell activation. I. Pairs of anti-T11.1 and T11.2 (CD2 subgroups) are strongly mitogenic for T cells in presence of 12-O-tetradecanoylphorbol 13-acetate.

A large collection of monoclonal antibodies (mAb) directed against sheep red blood cell (SRBC) receptor (cluster of differentiation 2: CD2) were classified according to three criteria: their inhibitory effect on T cell-SRBC rosette formation; the epitopic cluster recognized on the CD2 molecule; their reactivity with resting or activated T cells. All mAb were then tested in a two by two checkerboard fashion for possible T cell mitogenicity, in presence or absence of a submitogenic dose of 12-O-tetra-decanoylphorbol 13-acetate (TPA), an agent known to be comitogenic for T cells, presumably in delivering a second signal, usually accessory cell dependent. The combined data demonstrate that in the absence of TPA only few pairs of mAb directed at distinct epitopes of the CD2 molecule were mitogenic for T cells (in approximately 30% of the population tested), and in the presence of a submitogenic dose of TPA the majority of T11.1 anti-CD2-mAb (9 out of 11) were strongly mitogenic for T cells of all individuals tested when paired with T11.2 anti-CD2 mAb. The two anti-T11.1 mAb, noncomplementary to anti-T11.2 mAb, were, however, strongly mitogenic when added to mAb of the T11.3 subgroup, represented by 1-Mono-2A6. Taken together, these data strongly suggest that the main characteristic of T cell mitogenesis triggered by anti-CD2 mAb is the requirement for a signal delivered simultaneously to two different epitopes of the CD2 molecule, whether these epitopes are T11.1, T11.2 or T11.3.

Antibodies, Monoclonal↗

Failure of bone marrow cryopreservation in chronic granulocytic leukemia: relation to excessive granulo-macrophagic progenitor pool.

Autologous bone marrow transplantation (ABMT) in chronic granulocytic leukemia (CGL) aims at reversing the acute or acceleration phases by injection of stem cells collected during the chronic phase. This study was designed to explain an unusual rate of delayed engraftment (50%) in our experience of ABMT in CGL patients. We investigated all the factors possibly responsible for abnormal perpetuation of aplasia following infusion of cryopreserved marrow stem cells. The study of CFU-gm recovery in 41 bags of frozen marrow from 25 patients revealed an overall deficiency with a mean CFU-gm recovery of 55 +/- 38% in CGL patients versus 73 +/- 15% in the control group (p less than 0.001). Our data also showed an inverse linear relation (r = -0.40, p less than 0.05) between CFU-gm concentration and recovery after freezing. A good CFU-gm recovery (greater than or equal to = 50%) was observed in 70% of cases when the concentration was less than 3700 CFU-gm/ml as compared to 30% of cases when the concentration was over 3700 CFU-gm/ml (p less than 0.001). The lack of improvement by diluting rich CFU-gm marrows to reduce CFU-gm concentration/ml, as well as the absence of relationship between CFU-gm recovery after freezing and nucleated cells concentration, suggest a particular fragility of CGL stem cells to freezing, probably related to their excessive amplification. At the present time, we strongly recommend that the highest possible dose of progenitor cells be cryopreserved, preferably at a low concentration, in patients with CGL, and particular attention devoted to the freezing procedure in each individual patient, with numerous appropriate efficiency tests.

Bone Marrow Cells↗

Phase II trial with oral idarubicin in advanced breast cancer.

Idarubicin, a new analogue of daunorubicin, was administered to 27 patients with advanced breast cancer in a phase II trial. The drug was given orally at a dose of 30-35 mg/m2 every 3 weeks. Twenty-two patients were evaluable for response. All evaluable patients were previously treated with one or more chemotherapeutic regimens, including an anthracycline in more than 50% of the cases. Partial remissions were obtained in 5 patients, for a response rate of 23%. The median duration of response was 191 days. Mild nausea and vomiting were common. Diarrhea, which occurred in less than 50% of the patients, was usually short-lived. Alopecia was generally minimal. Myelosuppression was the dose-limiting toxic effect. Leukopenia was frequently seen, with full recovery by day 28 in 81% of the courses. Thrombocytopenia was less common than leukopenia. Four cases of grade 1 acute cardiac toxicity were recorded. This study suggests that idarubicin can induce regressions in advanced carcinoma of the breast, and justifies further studies in combination with other agents.

Administration, Oral↗

Oral idarubicin in non-Hodgkin's lymphomas.

Idarubicin (DMDR), a new analogue of daunorubicin, was administered orally once every 3 weeks at the dose of 40 to 45 mg/m2 to 20 evaluable patients with non-Hodgkin's lymphomas (NHL). Eighty-six percent of patients with favorable histology and 54% with unfavorable histology (intermediate and high grade as IWF) achieved a response with an overall response rate of 65% (two complete and 11 partial responses). Response rates were higher (85%) in previously untreated patients than in those with prior exposure to chemotherapy (29%). Gastrointestinal and hematologic toxicity was generally mild to moderate. No signs or symptoms of cardiotoxicity were recorded. Although the quality of response, as well as the relatively low response rate in previously treated patients and in those with unfavorable histology, makes it unlikely that DMDR can replace standard anthracyclines in NHL, the drug appears attractive in selected instances, such as in elderly patients and in those with slow-growing NHL with favorable histology.

Administration, Oral↗

Decreased NK activity in hairy cell leukemia (HCL): an analysis at the cellular level.

Peripheral blood lymphocytes (PBL) of eleven patients with Hairy Cell Leukemia were studied for surface phenotype and for NK activity against the K 562 cell line (using both the standard 51Cr Release Assay and the Single Cell Cytotoxicity Assay on poly-L-lysine coated coverslips). A significant reduction in NK activity, target binding cells (TBC) and NK active cells (NKa) was detected. In some cases however, despite a very low percentage of NKa, residual NK activity was observed, suggesting an efficient recycling capacity.

Adult↗

A technical bias: differences in cooling rates prevent ampoules from being a reliable index of stem cell cryopreservation in large volumes.

Ampoule tests are commonly used as an index of the cryopreservation efficiency of marrow stem cells in bags. We have studied the recovery of hematopoietic progenitor cells (CFU-GM, BFUe) in 52 ampoules and compared it to the recovery in 83 standard bags. Our data showed significantly deficient CFU-GM and BFUe recoveries (respectively 47 +/- 31% and 31 +/- 30%) in ampoules when compared to bags (respectively 72 +/- 22% and 64 +/- 19%; P less than 0.001). Moreover, a good progenitor cell recovery (greater than or equal to 50%) was observed in only 46% of frozen ampoules versus 100% observed in frozen bags (P less than 0.05). We were able to relate this nonoptimal recovery to an excessively rapid freezing rate of -9 degrees C/min following the release of fusion heat which occurred in ampoules, while the freezing rate was constantly maintained at -2 degrees C/min in the corresponding bags. We therefore conclude that the cooling conditions have to be carefully controlled to ensure that the bags and ampoules are both cooled under the same conditions. Otherwise, ampoules would not be a reliable index of the true progenitor cells' cryopreservation efficiency in bags.

Bone Marrow Cells↗

Basidiomycete mycelia and spore-allergen extracts: skin test reactivity in adults with symptoms of respiratory allergy.

One hundred fifty adults, with respiratory-allergic disease, and 14 control subjects, without symptoms of respiratory allergy, were skin prick tested with 16 common inhalant allergens, 12 extracts of mycelia from Basidiomycetes grown in vitro, and/or 10 to 15 basidiospore extracts. Eighty-three subjects (58%) had positive skin tests to two or more of the common inhalant allergens. Twenty-seven percent of the study subjects had positive skin reactions to one or more of the Basidiomycete mycelia extracts, and 32% demonstrated positive skin reactions to one or more basidiospore extracts. None of the 14 control subjects had positive skin reactivity to basidiospore extracts. Skin prick reactivity of study subjects to 15 different basidiospore extracts ranged from 5% for Cantharellus cibarius to 17% for Scleroderma sp. The prevalence of skin test reactivity to basidiospores did not differ significantly from the reactivity to commercial mold extracts of several common species of the Fungi Imperfecti (6% for Cladosporium herbarum or Penicillium notatum to 13% for Alternaria tenuis). These results demonstrate that a significant number of individuals reporting symptoms of respiratory allergy have skin test reactivity to basidiospores and suggest that these spores are important fungal aeroallergens in the New Orleans environment.

Adult↗

Immunochemistry of urinary calcium oxalate crystal growth inhibitor (CGI).

Calcium oxalate crystal growth inhibitor (CGI) was isolated from human urine in monomeric form (14,000 daltons). Antibody was elicited and purified to monospecificity by affinity chromatography. Tamm-Horsfall protein was isolated from human urine and an antibody to Tamm-Horsfall protein compared to anti-CGI. The anti-CGI reacted with its antigen on immunodiffusion, by ELISA and by Western Blotting of polyacrylamide gel electrophoresis-separated antigen. Immunofluorescent localization of CGI was found in distal renal tubules. This was precisely the localization of Tamm-Horsfall protein. Isolated Tamm-Horsfall protein was found to bind CGI which could only be partially removed with EDTA. While anti-CGI is suitable to assay CGI in human urine by ELISA techniques, it will also detect CGI that is complexed to THP. While the CGI found in human urine possesses 90% of the urinary macromolecular crystal growth inhibitor activity, THP is without effect on crystal growth, in spite of bound CGI. The balance between free CGI and that bound to Tamm-Horsfall protein may be important in the overall balance of urinary macromolecules that affect calcium oxalate nephrolithiasis.

Calcium Oxalate↗

An acute leukaemia augured before clinical signs by blood group antigen abnormalities and low levels of A and H blood group transferase activities in erythrocytes.

A mixed field agglutination pattern with anti-A reagents and very low levels of A and H blood group antigen specific transferase activities were found in the erythrocytes of a 4-year-old girl who presented no clinical signs of haematological disease. Blood and marrow examination displayed some features consistent with a moderate dysmyelopoietic state. 18 months later an acute myeloblastic leukaemia confirmed the suspected haematological malignancy.

ABO Blood-Group System↗

Chronic fatigue.

Explore the source record for details and available documents.

Anxiety↗

Treatment of advanced measurable gastric carcinoma with 5-fluorouracil, adriamycin, and BCNU.

61 patients with advanced measurable gastric carcinoma were treated with 5-fluorouracil, adriamycin and BCNU (FAB). Of 50 evaluable patients, 48% achieved a response (3 complete and 21 partial responses), and 24% experienced disease stabilization. The median duration of response was 9 months, and median survival of all patients was 7 months. Responding patients survived significantly longer than nonresponders (p less than 0.001). Toxicity was generally mild to moderate, rarely requiring dose reduction or prolongation of treatment intervals. These results indicate that FAB regimen is an active combination in metastatic or locally advanced gastric cancer, and can be used as first-line treatment in patients with this disease.

Adult↗

Demonstration of mitral valve function by cine computed tomography using a new long axis view.

Comparison was made between contrast enhanced cine computed tomography (Cine/CT) and echocardiography in the imaging of the mitral valve in 14 patients. The mitral valve was seen in all 14 patients by Cine/CT using a new long axis view. There was agreement with echocardiography in 12 patients. Abnormalities in mitral valve movement were detected by Cine/CT. Left atrial size and contraction was measured by Cine/CT with a difference in left atrial ejection fraction observed between 13 patients with no evidence of mitral disease and 3 patients with mitral disease.

Adult↗

Pseudotumor of the quadrate lobe in hepatic sonography: a sign of generalized fatty infiltration.

Sonograms of 43 patients demonstrated a focal area of decreased echogenicity in the medial segment of the left hepatic lobe (quadrate lobe). The shape ranged from ovoid to sheetlike, and the diameter ranged from 0.7 to 8.6 cm. The echogenicity of the right hepatic lobe was abnormally increased in 34 of 37 scans graded. In 20 patients with follow-up sonograms, 11 showed no change, six disappeared and three decreased in size. In 12 patients with unenhanced CT scans, 10 had decreased attenuation of the hepatic parenchyma and normal attenuation in the observed quadrate lobe focus. The hypoechoic focus in the quadrate lobe represents focal sparing in generalized fatty infiltration of the liver. When present, this focus represents a useful qualitative sign of generalized fatty infiltration in the rest of the liver.

Adult↗

[Diltiazem and digoxin interaction. Development of digoxin plasma levels and electrocardiographic parameters in healthy subjects].

In order to determine the interaction between diltiazem and digoxin, plasma digoxin concentrations and the principal ECG parameters (24 hour Holter monitoring) were measured in 10 healthy volunteers under basal conditions (P0), with 0.375 mg/day of digoxin (P1 = 17 days), during association with 240 mg/day of diltiazem (P2 = 17 days) and then again on digoxin alone (P3 = 10 days). The addition of diltiazem was associated with a 20.4% rise in plasma digoxin concentrations (0.59 ng/ml vs 0.49 ng.ml). There was no significant variation of plasma digoxin after withdrawal of diltiazem; in some cases it remained unchanged, in others it fell or continued to rise. During the administration of digoxin and diltiazem, the mean RR period and the duration of the maximal pauses increased (p less than 0.05); the RR interval also increased (p less than 0.01) but the mean QRS duration and the QTc interval did not change significantly with respect to their values on digoxin alone. After withdrawal of diltiazem, the PR interval was the only parameter to decrease significantly (p less than 0.05). These results suggest that patients receiving this drug association should be followed up carefully.

Adult↗