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Biomedical subjects

A Morell

Publications and source records attributed to A Morell.

At least 91 records · Page 5Linked to original sources
PubMed1985

Effect of ascorbic acid on human natural killer cells.

Ascorbic acid (vitamin C) was found to inhibit human natural killer cell (NK cell) activity in a dose-dependent manner. Neither effector/target cell binding nor interferon (IFN)- or interleukin-2 (IL-2)-induced increases of NK activity were affected by vitamin C. Lymphocytes incubated for 1 h at 4 degrees C with vitamin C showed a normal NK activity, whereas lymphocytes incubated for 1 h at 37 degrees C with vitamin C exhibited low NK activity. Our findings suggest that vitamin C influences NK cells, probably by acting as a radical scavenger which inactivates killing factors of NK cells.

Ascorbic Acid↗
PubMed1985

Effect of cations and cation channel blockers on human natural killer cells.

We studied the influence of various extracellular Ca++ and Mg++ concentrations on human natural killer (NK) cells and found that NK cell-mediated target cell lysis requires the presence of both divalent cations. The calcium channel blocker verapamil and the local anaesthetics procaine and lidocaine inhibited NK cell-mediated killing of K 562 target cells, whereas the selective K+ channel blocker tetraethylammonium and the selective Na+ channel blocker tetrodotoxin had no effect on NK activity. Our results demonstrate an important role of extracellular Ca++ and Mg++ for NK cell-mediated killing and suggest that a free transmembrane Ca++ passage is required for target cell lysis.

Anesthetics, Local↗
PubMed1985

Heterogeneity of Ia antigen expression on myeloblastic leukaemias: correlation with stage of maturation defined by cytochemical markers.

The expression of Ia-like antigen (Ia) has been studied in 55 cases of acute myeloid leukaemia (AML) in correlation with the expression of both Sudan Black (SB) and naphthol AS-D chloroacetate esterase (NCAE) stains. Operationally the AML cases were divided into three groups using only NCAE expression on the leukaemic cells: the first group with early maturation stage (MS1) consisted of 30 cases with less than 10% NCAE positive cells (SB: 15-100%): the MS2 group of 14 cases with 10-70% NCAE positive cells (SB: 65-100%) and the MS3 group of 11 cases with 70-100% NCAE positive cells (SB: 89-100%). Ia expression was determined by complement-dependent cytotoxicity, immunofluorescence and immunoperoxidase methods. A similar high percentage (80%) of patients from both group MS1 and MS2 expressed Ia on the surface of 32-100% of the cells. Furthermore, individual comparison of all cases from these two groups showed no correlation between Ia, NCAE and SB expression. Only in the 11 cases from the MS3 group, which included nine cases of promyelocytic leukaemias, was there a correlation between very low expression of Ia antigen with the high NCAE expression. Thus, for AML with a low degree of differentiation the expression of Ia seems to be independent of conventional cytochemical markers of cell maturation.

Antigens, Surface↗
PubMed1985

T-lymphocyte subsets and immunoglobulin concentrations in bronchoalveolar lavage of patients with sarcoidosis and high and low intensity alveolitis.

Reproducible volumes of bronchoalveolar lavage (BAL) fluid were recovered from 19 patients with pulmonary sarcoidosis and from 6 control subjects using a standardized technique. Studies of cell surface markers showed that BAL from 9 patients contained more than 8 X 10(6) helper T-cells. These patients were classified as having high intensity alveolitis, whereas in 10 patients with lower cell counts, low intensity alveolitis was diagnosed. Activated helper T-cells coexpressing Leu-3a and Ia-antigens were significantly more numerous in BAL from patients with high intensity alveolitis than in BAL from the other patients and the control subjects. Concentrations of IgM, IgA, and IgG, but not of albumin were markedly increased in BAL from patients with high intensity alveolitis when compared with the other subjects. In BAL from both patient and control groups, numbers of helper T-cells and particularly of activated helper T-cells were correlated with immunoglobulin concentrations. In 4 patients with high intensity alveolitis, prednisone-induced and spontaneous clinical improvement were paralleled by a decrease in helper and activated helper T-cells and in immunoglobulin concentrations in BAL, indicating conversion of high to low intensity disease. No change was observed in 4 patients with low intensity alveolitis.

Adult↗
PubMed1985

Characterization of acute undifferentiated leukemia by combined analysis of plasma membrane-associated gamma-glutamyltranspeptidase and soluble terminal transferase.

gamma-Glutamyltranspeptidase (gamma-GT) is a plasma membrane-associated enzyme present in blasts of certain acute leukemias. We analyzed 90 cases of undifferentiated and differentiated acute leukemias for gamma-GT, using a colorimetric assay. Blasts of all patients with common acute lymphoblastic leukemia (ALL) and T-ALL were negative for gamma-GT (less than 5 units). In contrast, gamma-GT was significantly elevated in acute myeloblastic or monoblastic leukemia blasts (P less than .001). In 16 cases of acute undifferentiated leukemia (AUL) studied, the levels of gamma-GT ranged from 0 to 93 units; in eight cases, gamma-GT was positive (greater than 5 units), and six of these had 2% to 5% Sudan black-positive leukemic cells in the blast-enriched suspension. Combined gamma-GT/TdT analysis revealed that both enzyme markers were mutually exclusive in 75% of AUL cases, suggesting that gamma-GT+/TdT-blasts are of nonlymphoid origin, and gamma-GT-/TdT+ blasts are of lymphoid origin. Two cases were devoid of both enzyme activities and could represent truly undifferentiated leukemia. Thus, combined gamma-GT/TdT analysis underlines the heterogeneity of AUL and appears to be useful in defining the lineage commitment of undifferentiated leukemic blasts.

Acute Disease↗
PubMed1985

Acquired immunodeficiency syndrome (AIDS) in pediatric patients. Case report and review.

The first pediatric case of acquired immunodeficiency syndrome (AIDS) observed in Switzerland is described. The 3-year-old African/Swiss patient was most probably vertically infected from her asymptomatic, HTLV-III antibody positive Zairian mother. Clinical symptomatology started at 14 months of age, and diagnosis was made at 22 months when medical care and comprehensive investigation were initiated at this clinic. Review of the literature revealed 125 pediatric patients with AIDS. Based on these data, relevant and practically orientated information is given concerning definition, epidemiology, clinical presentation, laboratory findings, management, and prognosis of this newly recognized entity.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Production of immunoglobulins and alloantibodies by lymphocytes from lung cancer patients.

Spontaneous and PWM stimulated production of immunoglobulins (Igs) were measured in culture of lymphocytes isolated from peripheral blood (PBL) of lung cancer patients, blood donors and patients with benign lung diseases. Culture supernatants were tested for antibody activity against lung cancer cells and normal cells and some of them were absorbed with normal lung cells and fetal liver cells. Igs levels and antibody activity in culture supernatants were measured by radioimmunometric assay. Significantly increased level of Igs in unstimulated culture of PBL and low index of PWM-stimulated production of Igs was found in lung cancer patients in contrast to the controls. Supernatants of PBL cultures from lung cancer patients had significant low antibody activity to lung cancer cells and were effectively absorbed by normal lung cells and fetal liver cells. The results suggest in vivo polyclonal activation of B cells in patients with lung cancer and simultaneously diminished production of alloantibodies with some features of natural antibodies following polyclonal activation in vitro.

Adenocarcinoma↗
PubMed1984

[Determination of the activity and control of the course of sarcoidosis using bronchoalveolar lavage].

The active stage of sarcoidosis is marked by lymphocyte-rich alveolitis with predominance of helper-T-lymphocytes. 8 patients with sarcoidosis were investigated by bronchoalveolar lavage. Of these patients, 5 proved to have high-intensity and 3 low-intensity alveolitis. It was observed that the total number of helper-T-lymphocytes in the lavage liquid was many times higher than in the patients with low-intensity alveolitis. 4 of the 5 patients with high-intensity alveolitis were treated with prednisone. Parallel to the radiological, functional and clinical improvement, a significant decrease in the absolute number of helper-T-lymphocytes was observed in the lavage liquid, as well as a decrease in the ratio of helper- to suppressor-T-lymphocytes.

Adult↗
PubMed1984

Impaired neutrophil locomotion associated with hyperadhesiveness in a patient with Chédiak-Higashi syndrome.

Neutrophils from a patient with Chédiak-Higashi (CH) syndrome exhibited defective directional locomotion in a gradient of activated plasma. Further analysis of the nature of this defect showed that CH neutrophils could respond normally to stimulation with f-Met-Leu-Phe, by increasing both their motility and polarization, provided the cells were kept in suspension. Contact with the substratum resulted in the loss of both motility and polarity in the majority of cells. CH neutrophils, in contrast to normal cells, did not respond chemokinetically to f-Met-Leu-Phe. Unstimulated random locomotion of CH neutrophils was also depressed, and this correlated with increased spreading on the substratum. Our results indicate that motility, locomotion and polarisation of CH neutrophils on the substratum are depressed because of excessive adhesion.

Cell Adhesion↗
PubMed1984

Correlation of natural killer cell function with Leu 7 reactivity in patients with humoral immunodeficiency.

We studied the surface markers Leu 7, Leu 1, Leu 2a and Leu 3a on lymphocytes of 54 healthy blood donors and 19 patients with humoral immunodeficiencies and compared the relative numbers of positive cells with the natural killer cell (NK) activity. In controls, and in 12 out of 19 patients (group A) the percentage of the Leu 7+ cells was positively correlated with NK activity. Seven of 19 patients had increased relative numbers of Leu 7+ cells and low NK activity (group B). In controls and group A patients about 40% of the Leu 7+ cells simultaneously expressed the cell markers Leu 1 and Leu 2a. In group B patients approximately 70% of the Leu 7+ cells carried T cell antigens. Furthermore, a distinct suppressor T cell predominance was noticed and the large granular lymphocytes of these patients showed morphological abnormalities.

Adolescent↗
PubMed1983

[Spontaneous radial segmentation of cell nuclei: morphologic marker of T-cell neoplasms?].

Radial segmentation (RS) of leukocyte nuclei has been observed, for example, in leukemias (Rieder cells). In 6 of 8 patients with T-ALL, RS of neoplastic cells was found in the peripheral blood, whereas in 14 patients with non-T-ALL no RS cells were present. RS may be a morphologic marker for certain T-cell neoplasms, and with regard to ultrastructure it seems to be identical to heat-induced RS of non-neoplastic cells.

Cell Nucleus↗
PubMed1983

Immunoglobulin G subclass restriction of antibodies against hepatitis B surface antigen.

Immunoglobulin G (IgG) antibodies against hepatitis B surface antigen were found to be restricted to subclasses IgG1 and IgG3 in serum samples of 17 individuals. Quantitative determinations showed that in 10 samples the minor serum subclass IgG3 contained more antibodies than the predominant subclass IgG1. Ranges of concentrations were between 0.72 and 16.50 micrograms/ml for IgG3 antibodies and between 0.55 and 6.19 micrograms/ml for antibodies of subclass IgG1.

Adult↗
PubMed1983

Radial segmentation of nuclei (Rieder cells): a morphological marker of T-cell neoplasms?

Pretreatment blood smears of adult patients with acute lymphoblastic leukemia were examined for neoplastic cells showing nuclear radial segmentation (RS). RS was present in 6 of 7 patients with immunologically proven T-cell leukemia, but not in 11 patients whose leukemic cells lacked T-cell markers. Electron microscopic studies of neoplastic cells showed multiple nuclear indentations and abundant cytoplasmic microfilaments and microtubuli in connection with pericentriolar dense material. RS formation was decreased in 1 patient after chemotherapy with a vincristine-containing regimen, while the white cell count remained unchanged. Radial segmentation (RS) of leukocyte nuclei is a well-known phenomenon, which is observed ex vivo (Rieder cells), and can be induced in vitro. Convoluted or multilobulated nuclei in lymphoid neoplasms are similar to RS nuclei both with regard to their structure and their sensitivity to spindle-blocking drugs. We propose that the nuclear alterations observed in a variety of different T-cell neoplasms are identical with RS, and suggest that RS might be a morphological marker for subsets of lymphoproliferative disorders of T-cell origin.

Adult↗
PubMed1982

[Use of broncho-alveolar lavage in the diagnosis, activity determination and follow-up of sarcoidosis. Preliminary report].

Pulmonary sarcoidosis is associated with granulomas and alveolitis at certain stages with accumulation of helper T-lymphocytes. The activity of alveolitis was determined by analysis of T-lymphocytes recovered by bronchoalveolar lavage. Only the alveolitis stage of sarcoidosis is influenced by treatment. 3 patients of a total of 5 fulfilled the criteria of active sarcoidosis. The course in 5 cases is discussed.

Adolescent↗