Biomedical subjects

I Mansour

Publications and source records attributed to I Mansour.

24 records · Page 2Linked to original sources

PubMed1990

A rapid technique for lymphocyte preparation prior to two-color immunofluorescence analysis of lymphocyte subsets using flow cytometry. Comparison with density gradient separation.

A technique is described for lymphocyte preparation which permits analyses by two-color immunofluorescence and flow cytometry. It consists, briefly, of the lysis of red blood cells and washing of white blood cells prior to labeling. We tested this technique with a large panel of monoclonal antibodies in mono- and dual immunofluorescence. By comparing these results to those obtained after density gradient separation, we found the following statistically significant differences: the count of the phenotype B1+ was higher after whole blood lysis preparation than after density gradient separation; whereas, the corresponding counts of OKT4+ and Leu-4-Leu-7+ phenotypes were lower. No difference was detected with OKT8+, Leu-4+, OKT8+Leu-4+, OKT8+Leu-4-, OKT8-Leu-4+, OKT8+Leu-7+, Leu-4+Leu-7+, Leu-4-Leu-11c+, OKT8+Leu-11c+ and OKT8+Leu-15+ phenotypes. We have studied the reproducibility of both methods and the correlation between them. The disparity of the lymphocyte subset count between these two methods, though statistically significant, was relatively weak and seems to be due to the density gradient separation. Since the preparation of lymphocytes using the density gradient method is time consuming, we propose whole blood lysis as an alternative lymphocyte separation method when assessing immune status in human disease by flow cytometry. It offers the following advantages: (i) it does not require additional steps, (ii) it permits two-color immunofluorescence through the labeling of white blood cells after washing, (iii) it is reliable, (iv) it is reproducible, and (v) it is helpful in studies of lymphopenia since it offers the possibility of lymphocyte enrichment.

Antigens, CD↗

PubMed1990

Triple labeling with two-color immunofluorescence using one light source: a useful approach for the analysis of cells positive for one label and negative for the other two.

Many laboratories do not have access to a flow cytometer allowing three-color immunofluorescence analysis through the use of multiple light sources. In view of the usefulness of such analyses in the dissection of cell parameters, we describe an approach permitting the study of three labels by using one light source and the two-color immunofluorescence assay. It is useful for the enumeration of cell subpopulations positive for one label and negative for two or more others as well as for qualitative analysis concerning the expression of these labels. This approach is simple and rapid; it does not require additional material and technical steps other than that used in the two-color immunofluorescence assay. Briefly, it consists of the use of a label coupled to a dye (PE or FITC or instance) and two different labels coupled to the other dye. An argon ion laser, operating at 488 nm and 60 mW, excites both fluorescein and phycoerythrin conjugated antibodies. We provided a general example, using three hypothetical labels (X, Y, and Z), and four practical applications: CD3+CD4CD8- and CD8+CD16-CD3- peripheral blood lymphocytes, CD2+CD16-CD3- and CD56+CD16-CD3- peripheral blood, and decidual infiltrating lymphocytes.

Antibodies, Monoclonal↗

PubMed1990

CD16+ NK cells decrease in all stages of HIV infection through a selective depletion of the CD16+CD8+CD3- subset.

Natural killer (NK) cell-related phenotypes were analyzed in human immunodeficiency virus (HIV) infection. Our study involved 168 HIV-infected patients (72 CDC Stage II, 48 Stage III, and 46 Stage IV) and 60 healthy individuals. Analyses were conducted using flow cytometry and monoclonal antibodies. In comparison to the control group, all patient groups showed a significant decrease (p less than 0.001) of the CD16+ and CD16+CD3- phenotypes; furthermore, the comparison among patient groups showed no significant difference. It seems, therefore, that the decrease begins in the asymptomatic stage (CDC II) and remains constant during the infection. CD16+ NK cells were further divided into two subsets: CD16+CD8+ and CD16+CD8-. This subdivision shows a severe selective depletion of the CD16+CD8+ subset, but not in the CD16+CD8- subset. The depletion of the CD16+CD8+ subset also appears in the CDC asymptomatic stage and remains constant in CDC stages III and IV. Elsewhere, we observed that CD16+CD8+ lymphocytes are CD3-; complementary analysis of CD3-CD8+ cells showed a depletion comparable to that of the CD16+CD8+ phenotype. Depletion of the CD3-CD8+ subset, which belongs to the NK cell compartment, was observed although the total CD8 population showed a statistically significant increase. We conclude that, in HIV infection, there is a quantitative decrease of the NK CD16+ cell population, which appears to be due to a selective depletion of the CD16+CD8+CD3- compartment. This severe depletion appears to begin early in the infection.

Adult↗

PubMed1990

Circadian variations in plasma levels of hypophyseal, adrenocortical and testicular hormones in men infected with human immunodeficiency virus.

Alterations in the circadian time structure of the secretion of several hormones were investigated in 13 male patients infected with human immunodeficiency virus (HIV). Seven were asymptomatic (classified CDC II, according to the criteria of the Atlanta Centers for Disease Control), and 6 had acquired immunodeficiency syndrome (CDC IV). Ten healthy males volunteered as controls. Plasma levels of dehydroepiandrosterone (DHEA) and its sulfate (DHEA-S), cortisol, testosterone, ACTH, and beta-endorphin were determined by RIA in blood samples obtained every 4 h from 0830-0830 h the next morning. Data were analyzed both by two-way analysis of variance and the cosinor method. Circadian rhythms were statistically validated for each of the six hormones in each of the three groups of subjects. Compared with the control subjects, mesors (24-h adjusted means) were significantly higher for cortisol and lower for DHEA, DHEA-S, and ACTH (P less than 0.001 for all four hormones) in all HIV-infected patients. Plasma testosterone mesors were similar in controls and CDC II patients, but decreased significantly in the CDC IV patient group (P less than 0.05). Analysis of the circadian rhythms of plasma hormone levels clearly indicated an altered adrenal hormonal state in HIV-infected male patients, even during the asymptomatic period of the infection. For instance, plasma cortisol at 0430 h was more than twice as high in HIV-infected patients as it was in time-qualified controls. Although patients already had elevated plasma cortisol and lowered adrenal androgen levels at this stage, hypogonadism was not observed, as gauged by plasma testosterone concentrations. We speculate that the primary hormonal defect in HIV-infected patients is increased cortisol secretion resulting from circadian-varying stimulation of the adrenal cortex by a factor other than pituitary ACTH. This factor might be a stimulating substance secreted primarily by infected immune cells. Excess cortisol would lower adrenal androgen secretion by shifting adrenal steroid biosynthesis toward glucocorticoids and decreasing pituitary ACTH secretion via a negative feedback mechanism.

Acquired Immunodeficiency Syndrome↗

PubMed1989

[Early disturbance of the circadian rhythm of T and B lymphocytes in human immunodeficiency virus infection].

Circadian rhythms in circulating B and T (CD3, CD4, CD8) lymphocyte subsets and in plasma cortisol were studied in 13 HIV-infected men and 14 healthy male controls. The circadian maximum (acrophase) of plasma cortisol was similar in both groups, approximately 8.00 A.M., however, a statistically significant increase was found in the 24 hour-mean value (mesor) of infected patients as compared to healthy controls. Circadian rhythms were statistically validated in all lymphocyte subsets of healthy controls, whereas, large alterations were found in patients with acquired immunodeficiency syndrome (AIDS), already in asymptomatic infected individuals. The alterations concern the mesor and the amplitude for B and CD4 lymphocytes and all cycle parameters for CD3 and CD8 lymphocytes.

Acquired Immunodeficiency Syndrome↗

PubMed1984

Closed cardiovascular surgery in the first year of life--experience with 40 consecutive cases.

A review of 40 consecutive infants with cardiovascular lesions requiring surgical intervention, without the use of the heart-lung machine, during a 3 year period is presented. Twenty-one patients were cyanotic and 19 were non-cyanotic preoperatively. In the former group, an operation was performed on an urgent or emergency basis in 8 patients (38%). In the latter group, 12 patients (63%) were in congestive heart failure and needed digitalis and diuretics preoperatively. The most frequent lesions among both groups were TOF and aortic coarctation, each being encountered in 6 patients, to be followed by d-TGA, PDA, and vascular ring, each being observed in 5 patients. The youngest patient was 8 hours old, had ectopia cordis associated with omphalocele, and the oldest was 12 months old, had a vascular ring. The lightest infant weighed 1.6 kg and had ligation of PDA at the age of one month. The most common surgical procedure was a systemic pulmonary artery shunt (13 patients), closure of PDA (5 patients), followed by repair of aortic coarctation using the LSA as a patch (6 patients), and division of vascular ring (5 patients). The operative M.R. was 15% in the whole series, 19% among the 21 cyanotic babies, 11% among the 19 non-cyanotic infants and 40% among the 10 patients operated in the first month of life. No death was noted among the 14 patients operated after the age of 6 months. Late mortality occurred in 4 patients giving a total mortality rate of 38% in this group of 21 infants with cyanotic malformations.(ABSTRACT TRUNCATED AT 250 WORDS)

Cyanosis↗