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Biomedical subjects

C Blanc

Publications and source records attributed to C Blanc.

At least 73 records · Page 4Linked to original sources
PubMed1991

Characterization of normal human bone marrow by flow cytometry.

Fifteen bone marrow samples were obtained from consenting donors for allogenic bone marrow transplantation and were studied by flow cytometry. The simultaneous analysis, cell by cell, of size (forward angle light scattering), structure (right angle light scattering) and surface antigenic expression with 20 monoclonal antibodies allowed selection of ten reproducible cell subsets which were sorted and studied by microscopic examination in order to confirm their distinct characteristics. This very accurate analysis of a bone marrow cytogram should find applications in view of a better characterization of normal and pathological human bone marrow.

Adult↗
PubMed1990

Proliferation of early human myeloid precursors induced by interleukin-1 and recombinant soluble CD23.

Low affinity Fc epsilon receptors (Fc epsilon RII/CD23) or their soluble fragments have various biologic effects on B- and T-cell lineages. In this study, we have assessed the effect of recombinant soluble CD23 (rsCD23) on the proliferation of human bone marrow (BM)-derived myeloid precursors with or without recombinant interleukin-1 (rIL-1) addition. Non-adherent CD2- or CD34+ BM cell subsets were used as target cells. Our results show that rsCD23 in synergy with rIL-1 displays an interleukin-3-like activity as it promotes the proliferation of multipotential marrow precursors. This effect was abolished by anti-CD23 addition to these cultures, but was not affected by anti-IL-3 monoclonal antibody. Furthermore, sequential study indicates that rIL-1 induces bone marrow cell responsiveness to rsCD23.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1990

Stage specific phosphoinositides turnover capacity of human intrathymic T cells following CD2-triggering.

Triggering of distinct CD2 epitopes on human T lymphocytes increases their phosphatidylinositol (PI) cycle-related metabolism. In this work, we investigated the relationship between this signal transduction pathway following surface CD2 antigen triggering and intrathymic T cell development. Therefore, various thymocyte subsets were incubated with co-mitogenic CD2I+III mAb. The cells were then tested for their various phosphoinositides levels as well as their ability to proliferate in response to recombinant interleukin-2 (rIL-2). Our results indicate that immature CD4- CD8- cells have high PI metabolism while more mature CD4+CD8+ and unfractionated thymocytes display significantly lower PI-turnover. Mature CD4+CD8- and CD4-CD8+ thymocytes regain this transduction capacity. Thus, PI-turnover following CD2- triggering is linked to the developmental fate of thymocyte subclasses.

Antigens, CD↗
PubMed1990

Treatment of herniated lumbar disc by percutaneous nucleotomy with aspiration. Preliminary results in 70 cases.

Seventy patients suffering from lumbar pain with sciatica, radiculalgia or lumbodynia were reviewed at least 3 months after automated percutaneous nucleotomy (Nucleotome). There were 26 women and 44 men, aged from 19 to 72 years. Results were highly satisfactory in 39 patients (56.5%). Among these, 10 had lumbar pain of discal origin, 15 had pure radiculalgia and 14 had lumbar pain and radiculalgia. Incomplete improvement requiring medical treatment was obtained in 11 patients (15.5%). The procedure was unsuccessful in 20 patients (28.5%) with persistence or worsening of the initial symptoms; 5 of them subsequently underwent chemonucleolysis with 4 good medium-term results and 1 failure. These preliminary results show that percutaneous nucleotomy seems to be effective in lumbar pain of discal origin, with a 66.5% success rate. In patients with pure radiculalgia or lumbar pain cum radiculalgia the results are less impressive, with a success rate of about 50%. However, this well-tolerated technique may be used as first-line treatment of herniated discs when the discs are small, subligamentous and non migrated.

Adult↗
PubMed1989

[Children with cerebral palsy and the need for speech therapy].

This paper is an attempt to bring up to date the importance of speech therapy as regards the help given to cerebral palsy. While recognising the importance of physiotherapy, it tries to show that a new approach to the language problems of the physically handicapped child, enables one to have a greater understanding and therefore to respond better to the needs of the cerebral palsy.

Cerebral Palsy↗
PubMed1988

Ambulatory computer system for recording and controlling locomotion.

Description of an original miniature computer system capable of recording biomechanical parameters during locomotion, providing auditory signals which can be used in biofeedback locomotor learning, and triggering functional electrical stimulation of nerves and muscles at preselected moments in the locomotor cycle. The system, which is worn on the patient's back, is connected to appropriate gauges with which it is possible to measure knee angle and to record the time of heel contact with the ground. The relevant data are stored in the system memory and can be transferred to a microcassette and later displayed as a function of time on a video screen or printed on paper. The same data can be used on-line to provide a patient with a sound signal as a basis for biofeedback training. This kind of training has been successfully used to correct knee hyperextension during locomotion in hemiplegic patients. The system can also be used to trigger a stimulator and thus constitutes a valuable tool for investigations and treatments involving functional electrical stimulation. Many other applications may be developed, both in basic research and in various fields where motor training is required.

Biofeedback, Psychology↗
PubMed1988

Phenotypic heterogeneity of B- and T-cell differentiation antigens in B-CLL.

Peripheral blood from 38 B-CLL patients was studied by flow cytometry with 25 clustered or non-clustered monoclonal antibodies (moAbs) in order to characterize the cell surface phenotype of lymphoid cells. All moAbs chosen detected B or CD1-8 T-cell differentiation antigens or MHC class II antigens. The results showed a heterogeneity in the leukemic cell reactivity with the various moAbs and between patients. The restricted B-cell antigens recognized by BL14, Y2955 and anti-class II moAbs were constantly expressed in leukemic cells, while B-cell antigens reacting with FMC7 and BL13 moAbs were variably detected. In addition to CD5 antigens, other T-cell markers, including several epitopes of the CD1 group, were also found to be present on the leukemic cell surface in several cases. The relationship between the various clinical and/or biological features of the disease and the cell surface phenotype was studied. Our results indicated a correlation between the lymphoid cell reactivity with M241 (CD1) and BL13 (CD21) and the severity of the disease.

Antibodies, Monoclonal↗
PubMed1988

CD1 expression in B-CLL cells.

The peripheral blood from 38 B-CLL patients was studied by flow cytometry with 25 clustered or not clustered monoclonal antibodies (moAbs) in order to characterize the cell surface phenotype of lymphoid cells. All moAbs were chosen since they detected B or CD1-8 T cell differentiation antigens or MHC class II antigens. The results showed a heterogeneity in the leukemic cell reactivity with the various moAbs and between patients. The restricted B cell antigens recognized by BL14, Y2955 and anti-class II moAbs were constantly expressed in leukemic cells, while B-cell antigens reacting with FMC7 and BL13 moAbs were variably detected. In addition to CD5 antigens, other T cell markers including several epitopes of the CD1 group were also found to be present on the leukemic cell surface in several cases. To further extend these data, 6 cases were selected for labelling with a battery of 6 CD1a, 2 CD1b and 1 CD1c moAbs. These results suggested that CD1a,c epitopes can be detected on leukemic B cells in addition to other T cell differentiation antigens.

Antibodies, Monoclonal↗
PubMed1987

A T chronic lymphocytic leukemia with large granular lymphocytes. Phenotype and functions of leukemic cells under in vitro treatment by differentiation inducers.

We reported the morphologic, phenotypic and functional characteristics of leukemic cells with natural killer (NK) properties in a case of T chronic lymphocytic leukemia with large granular lymphocytes. These cells were cytologically and cytochemically characterized as phosphatase acid positive large granular lymphocytes (LGL), and presented parallel tubular arrays at the ultra structural level. They displayed a CD2, CD3, CD8, CD11, Leu 7, and Leu 11 positive phenotype while they lacked B cell markers including surface immunoglobulins. In addition, they expressed human leukocyte antigens (HLA) Class I, but no Class II antigens. These phenotypic studies were also performed after cells were cultured in vitro with 12-0-tetradecanoyl phorbol 13-acetate, gamma interferon, 5-azacytidine, sodium butyrate, phytohemagglutinin, and interleukin 2 (IL2). The cell surface markers underwent several significant changes. Among them we noted a higher percentage of labeled cells with anti-CD6 and CD7 monoclonal antibodies (moAbs), and a positivity with an anti-CD19 (B4) moAb. The leukemic LGL spontaneously developed a NK activity on K 562 tumor cells, which was not affected under the various T and B cells growth factors because they became more sensitive to IL2; but they were also stimulated by a 50-kilodalton (KD) B cell growth factor (BCGF) factor devoid of any T cell proliferation activity. Together these results gave a better characterization of azurophilic granules containing T chronic lymphocytic leukemia, and enabled the documentation of the differentiation of LGL with NK activity.

Adult↗
PubMed1987

Sickness absence at the French National Electric and Gas Company.

The certified sickness absence of workers in the French National Electric and Gas Company was studied for 12 months and has been described according to the demographic and occupational characteristics of the employees. The results showed that the principal factors affecting absence are sex, job, and salary. The high percentage of absent women was explained by neither the type of occupation nor family status. Respiratory diseases, accidents, and musculoskeletal and psychiatric disorders were the leading diagnostic categories. Indices of severity, duration, and frequency were calculated and compared between groups. The duration of absence increased with the severity of the medical cause of absence and with the patient's age.

Absenteeism↗
PubMed1987

[Description and performance of a flow cytometry apparatus: the EPICS].

This is a report on our experience with the EPICS C (Coultronics) cytometric flux apparatus, a screening cell analyzer, employing a laser ray (2 or 5 watts); we obtained good results to analyze immunologically-tagged mononuclear blood cells with or without prior separation: for rhythm, repeatability, and contamination. The EPICS C machine proved to be effective to study the cell cycle using lymphoblastic cells, epithelial cells and cells from a breast cancer. Several screening trials were carried out with fluorescent ball bearings of various sizes; the quality of screening (purity and yield) appear optimal at a speed ranging from 500 to 1,000 bearings per second, using three parameters: the logarithm of green fluorescence, the integral function of green fluorescence, the diffraction of light to small angles. Thus, if results obtained for this analysis are entirely satisfactory, the screening function remains limited because it is slow.

Cell Cycle↗
PubMed1986

Expression of MHC class II and Tac antigens on IL2-activated human T cell clones that can stimulate in MLR, AMLR, PLT and can present antigen.

The expression of interleukin 2 (IL2) receptor and HLA-DR, DQ, and DP antigens on the surface of four diphtheria toxoïd (DT)-specific T lymphocyte clones (TLC) and two TLC specific for an allogeneic EBV-transformed cell line was investigated with the use of monoclonal antibodies (MoAbs) that recognize defined molecules or epitopes. Incubation of a resting TLC with IL2 resulted in a 10- to 30-fold increase in the level of DR, DQ, and Tac antigen expression. On the other hand, incubation of an activated TLC with IL2 decreased for 1 to 6 hr the level of expression of these three antigens. Anti-FA MoAbs did not react with any of the TLC tested suggesting that the expression of DR, DQ, and DP antigens is dissociated on activated TLC. Surface-marker analysis with anti-DR MoAbs indicated that DR epitopes were differently expressed at some activation stages of the TLC. Functional studies showed that activated TLC can stimulate in MLR, AMLR, and PLT. These proliferative responses were inhibited by preincubating the TLC with anti-DR MoAbs suggesting that the stimulatory determinants were predominantly DR molecules. In addition, some TLC can act as antigen presenting cells in DT-specific proliferative responses. These results indicate that MHC class II molecules on activated T lymphocytes may be relevant for the control of specific immunologic responses in vivo.

Antibodies, Monoclonal↗
PubMed1986

CD 1-8 antigens on human diphtheria toxoid T lymphocyte clones: expression and modulation by TPA, sodium butyrate, and 5-azacytidine.

The modulation of antigen expression on the surface of TLC by different differentiation inducers as well as the inhibition of the TLC proliferative response by specific MoAbs may lead to a clarification of the role of various surface molecules studied in antigen-specific T-cell response. We investigated the expression of CD 1-8 antigens on the surface of diphtheria toxoid or varidase specific TLC with a series of MoAb. CD1 and CD8 antigens were not expressed on the proliferative TLC. CD2, CD3, CD4, and CD5 antigens were homogeneously expressed on all TLC in contrast to CD6 and CD7 antigens which were present on only a fraction of the cells in a given TLC. In functional assays, anti-CD2, anti-DR VI-15C, and anti-CD25 MoAbs blocked the proliferative response to DT and anti-CD3, anti-CD4, anti-D44 MoAbs had intermediate inhibition effects. Anti-CD5, anti-CD6, and anti-CD7 MoAbs did not inhibit the proliferative response. Surface marker analysis revealed that the expression of CD2 to CD7 antigens (and also CD25) may be modified following incubation of the TLC with TPA or sodium butyrate but not with 5-azacytidine. TPA greatly decreased the expression of CD3 and CD4 antigens after a 6-hr exposure. Preincubation of TLC cells with TPA inhibited the mitogenic effect of anti-CD3 MoAbs on TLC cells in proliferative assays, but did not inhibit their capacity to proliferate in response to DT despite low levels of CD3 and CD4.

Antibodies, Monoclonal↗
PubMed1985

Differences in carbohydrate specificities and complement-activating capacity of guinea pig and human antibodies to neuraminidase-treated autologous erythrocytes.

Guinea pig erythrocytes desialated by treatment with neuraminidase from Vibrio cholerae were lyzed in autologous serum through a natural-antibody-dependent activation of the classical complement pathway. Lysis was inhibited when a mannose, glucose, galactose or N-acetyl-glucosamine was added to the incubation mixture. Methyl-alpha- or -beta-D-galactopyranosides were poorly effective and N-acetyl-D-galactosamine was not effective at all. Inhibition of lysis by the carbohydrates was due neither to an anti-complementary effect nor to a modification of the osmotic pressure since: (a) they did not alter the total complement haemolytic activity of guinea pig serum, and (b) they did not inhibit lysis of desialated guinea pig erythrocytes in human serum through activation of the alternative complement pathway. The presence of mannose, glucose, galactose or N-acetyl-glucosamine in the incubation mixture resulted in an impaired fixation of natural auto-antibodies on antigenic sites, namely the T-antigen (Thomsen-Friedenreich), which were unmasked following membrane sialic acid removal. When tested under the same conditions, only small percentage of the normal human population showed the phenomenon of lysis of desialated erythrocytes in autologous serum. Lysis was not due to a particular susceptibility of erythrocytes from these individuals to complement-mediated lysis but to the presence in their serum of complement-activating anti-T antibodies. As expected, the activity of human anti-T antibodies was inhibited by galactose and N-acetyl-galactosamine, which are the immunodominant sugars of the human T-antigen. Mannose and glucose had no effect, and methyl- alpha- or - beta-D-galactopyranosides were almost as effective as galactose. The heterogeneity of the human population with regard to the complement-activating capacity of anti-T antibodies could be of significance for the individual response of the host to an infection by a neuraminidase-producing microorganism. That the immunodominant sugars of the T-antigen were different between humans and guinea pigs was further assessed by absorption experiments. We have demonstrated that guinea pig anti-T antibodies were not removed during contact with desialated human red cells which do not have the mannose specificity, whereas human antibodies were almost entirely retained on desialated guinea pig red cells which, beside mannose, express galactose. These results also suggest that guinea pig antibodies are mostly directed towards mannose and glucose.

Agglutination Tests↗