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Biomedical subjects

A Bernard

Publications and source records attributed to A Bernard.

At least 379 records · Page 21Linked to original sources
PubMed1990

Modulation of lymphokine release and cytolytic activities by activating peripheral blood lymphocytes via CD2.

We had previously shown that the signal of activation delivered via CD2 varies according to the mitogenic pair of CD2 mAb used. We had selected two typical mAb pairs, D66 + T11(1) and GT2 + T11(1), the former delivering the "richest" signal, the latter the poorest. Here we analyzed the cytolytic activities generated within PBL-stimulated by these two pairs. When purified CD2+,3- cells were cultured with either one of these two pairs, no significant lymphokine-activated killer (LAK) activity--namely the activity exerted on NK-resistant malignant cell lines or fresh tumor cells--was detected, thereby demonstrating the inability of CD2 mAb pairs to directly trigger the LAK precursors. By contrast, when purified CD2+,3+ cells were cultured, only D66 + T11(1) was able to trigger a potent CTL activity, as judged by targeting their activity, at the effector phase, with a bridging CD3 mAb on a FcR+ target cell or by using heteroaggregates on FcR- malignant cells. When whole PBL were used, a similar and moderate LAK activity was generated after culture with either one of the 2 CD2 mAb pairs. This, in fact, masked quite different events. The amounts of endogeneous IL-2 released in PBL cultures with GT2 + T11(1) was rather low, although it was sufficiently high in PBL cultures with D66 + T11(1) to generate a potent LAK activity. Yet, PBL stimulated with D66 + T11(1) released concomitantly a high amount of IL-4 which inhibited the development of the LAK activity, as demonstrated by unmasking this activity with an anti-IL4 antiserum and which did not inhibit the T CTL activity; this IL-4 secretion was not seen with GT2 + T11(1). Therefore, stimulation by these two typical CD2 mAb pairs induce a striking different pattern of IL synthesis.

Antigen-Antibody Reactions↗
PubMed1990

Hydrocarbon exposure, hypertension and kidney function tests.

Control and hydrocarbon exposed workers participated in a cross-sectional study about the nephrotoxicity of chronic hydrocarbon exposure. Different markers of glomerular and tubular function as well as the celluria were examined and compared. The results show that the interaction between hypertension and hydrocarbon exposure has an influence on the kidney function. For the clearance the interaction age-exposure seems to play a more important role than age or exposure alone. The most useful markers appear to be the albuminuria, the N-acetyl-beta-D-glucosaminidase activity, the retinol-binding-protein concentration and the creatinine clearance.

Adult↗
PubMed1990

Electrophysiologic effects of intravenous xamoterol in patients with sinus node dysfunction.

The electrophysiologic effects of xamoterol were studied in ten patients with electrophysiologic evidence of sinus node dysfunction. A significant shortening of mean sinus cycle length, maximal corrected sinus-node recovery time, and the mean of the three longest corrected sinus-node recovery times was observed after intravenous administration of 0.1 mg/kg of xamoterol. The atrioventricular (AV) conduction time and the effective and functional refractory periods of the AV node were shortened as the effective refractory period of the atrium. These effects suggest that xamoterol could be tried safely for the treatment of patients with moderate symptoms due to sinus-node disease.

Adrenergic beta-Agonists↗
PubMed1990

H19, a surface membrane molecule involved in T-cell activation, inhibits channel formation by human complement.

Here we compare the properties of leukocyte antigens H19 and CD59 with those of the PI-linked 18,000-20,000 Mr molecules which inhibit lysis of human cells by the autologous terminal complement components C5b-9. H19, a 19,000 Mr protein found on human erythrocytes, monocytes, neutrophils, T-lymphocytes and other cells, is one of the ligands involved in the spontaneous rosette formation between human T-lymphocytes and erythrocytes. Recent evidence indicates that H19 also participates in T-cell activation. CD59 is a widely distributed 18,000-25,000 Mr protein anchored to the cell membrane by phosphatidylinositol (PI). The function of CD59 is unknown. Affinity-purified H19 incorporates into cell membranes and inhibits channel formation by human C5b-9 on guinea pig erythrocytes. Significant inhibition is achieved with picogram quantities of H19, corresponding to approximately 600 molecules per erythrocyte. H19 is most effective when C9 is limiting but quite active when C5b-7 or C8 are limiting, indicating that it may interact with several of the structurally related terminal complement components. The inhibitory activity is blocked by mAbs to either CD59 or to H19. H19 is PI-anchored: it is released from the cell membrane by treatment with PI-specific phospholipase C, and it is absent from cells from a patient with paroxysmal nocturnal hemoglobinuria (PNH). Analysis of PNH erythrocytes after treatment with terminal complement proteins shows that the H19-negative erythrocytes are more susceptible to C5b-9-mediated lysis. Treatment of normal human erythrocytes with either anti-H19 or anti-CD59 renders them more susceptible to lysis by human C5b-9. We conclude that H19 and CD59 are probably the same molecule and are identical or closely related to the recently described inhibitors of C5b-9 channel formation.

Antibodies, Monoclonal↗
PubMed1990

Effect of albumin on oleic acid lymphatic absorption in rats.

1. The aim of this study was to investigate how fatty acid absorption was affected when exogenous fatty acids were complexed with albumin in absence of bile. Experiments were carried out in vivo, in order to study overall absorption processes. 2. An equimolar mixture of 14C oleic acid, palmitic acid and monopalmitin was infused intraduodenally in bile- and pancreatic juice-diverted rats. 3. Lipids were emulsified with either sodium taurocholate or fatty acids complexed with albumin. 4. Lymphatic lipid output was compared during the 6 hr following infusion of 90 mumol of the radioactive lipid mixture. 5. Lymphatic radioactive lipid recovery was significantly decreased by albumin. 6. Only 17% of the infused radioactivity was recovered in lymph when fatty acids were complexed with albumin against 37% when lipids were emulsified with sodium taurocholate. 7. Unrecovered lymph radioactivity was found at the distal part of intestine. Moreover, albumin significantly decreased lymph flow. 8. We conclude that undigested albumin acted at the luminal level of lipid absorption processes and specifically decreased fatty acid uptake.

Absorption↗
PubMed1990

K20 and ICO-10 monoclonal antibodies (gp120/200; Thy-1): immunophenotyping of human solid tumours.

Solid tumour cells were shown to express VLA-beta and Thy-1 antigens. For identification of these molecules two monoclonal antibodies, K-20 and ICO-10, characterised in detail previously, were used. Four groups of solid tumours have been identified according to their immunophenotype: VLA-beta+ and Thy-1-; VLA-beta+ and Thy-1+; VLA-beta- and Thy-1+; VLA-beta- and Thy-1-. To a certain extent these groups have been shown to reflect tumour histogenesis: tumours of epithelial origin never expressed an ICO-10+, K20-phenotype while soft tissue sarcomas and neuroblastoma cells never expressed the beta-chain of VLA molecular complexes.

Antibodies, Monoclonal↗
PubMed1990

Immunoregulatory functions of paf-acether. VI. Inhibition of T cell activation via CD3 and potentiation of T cell activation via CD2.

In the present report we further explored the role of paf-acether (paf), a phospholipid cytokine, in the modulation of T cell activation induced via the CD2 and the CD3 pathways. Evidence was obtained that paf inhibited T cell proliferation induced by immobilized CD3 mAb (OKT3i), but potentiated that induced by a combination with the CD2 mAb, anti-(T11.1 + D66). Both effects were dose-dependent between 2 and 10 microM paf, and specific in that lysoPC, a phospholipid closely related to paf, had no effect. The inhibition became apparent after 48 h and was maintained up to 144 h of culture, whereas the enhancement was observed only by 96 h of culture. Interestingly, paf was able to inhibit OKT3i mAb response when added to cultures as late as 24-48 h after the initiation of a 96 h incubation. By contrast, paf enhanced the proliferative response only when added concomitantly with anti-(T11.1 + D66) mAb, suggesting that it modulates an early event of T cell activation. paf, which enhanced T cell proliferation induced via the CD2 pathway, also led to a substantial up-regulation of IL-2 secretion and CD25 expression. Moreover, paf markedly augmented IL-4 secretion upon CD2 mAb stimulation. Finally, when T cells were triggered via the CD3 molecule, paf inhibited the proliferative response but also down-modulated CD25 expression without impairing IL-2 secretion. When considered together, these data demonstrate that paf, a phospholipid cytokine released during inflammatory reactions, play a differential regulatory role in T cell activation induced via the CD3 and CD2 (T11.1 + D66) pathways.

Antibodies, Monoclonal↗
PubMed1990

IVF pregnancy after induction of an ovulatory endogenous gonadotrophin surge using an LHRH agonist nasal spray.

A successful human twin IVF pregnancy is reported after using a single 50 micrograms dose of LHRH agonist nasal spray (Buserelin) to induce an ovulatory endogenous gonadotrophin surge 34 h prior to oocyte collection. The couple had 10 years of primary male factor infertility, associated with significant anti-sperm antibodies. The clinical features and endocrine profile are presented.

Administration, Intranasal↗
PubMed1990

Health effects of environmental exposure to cadmium: objectives, design and organization of the Cadmibel Study: a cross-sectional morbidity study carried out in Belgium from 1985 to 1989.

Cadmium is a cumulative environmental pollutant. For the general population mainly exposed by the oral route and through tobacco smoke inhalation, the kidney is the critical organ. Belgium is the principal producer of cadmium in Europe, and certain areas of the country are polluted by cadmium mainly because of past emissions from nonferrous industries. Preliminary studies carried out in one polluted area have suggested that environmental pollution might lead to an increased uptake of cadmium by the human body and possibly to health effects. Thus, a large-scale morbidity study has been initiated to assess the validity of this hypothesis. The present paper describes the protocol of this study. Its main objectives are to determine to what extent environmental exposure to cadmium resulting from industrial emissions may lead to accumulation of the metal in the human organism; to establish whether or not environmental exposure may induce renal changes and/or influence blood pressure; and to assess the acceptable internal dose of cadmium for the general population. The study design takes advantage of the fact that biological indicators of exposure, body burden, and early nephrotoxic effects of cadmium are available, which increase the likelihood of detecting a cause-effect relationship.

Adult↗
PubMed1990

[The expression of leukocytic and related antigens on the cells of human breast cancer cells].

Certain expression regularities of different markers in human breast cancer cells are demonstrated. Monomorphic determinants of HLA class II antigen are detected only in case of HLA class I expression and cancer-embryonal antigen (CEA); the latter is combined with HLA class I and ICO-84 antigens at a significantly higher rate. The expression effect of CEA and HLA-DR on the metastatic spreading rate of regional lymph nodes is marked. A heterogeneity of the single tumour and in patients with malignant breast cancer is determined by the presence of the "leucocytic" antigens and CEA. In parallel studies monoclonal antibodies (MAB) HMFG-1 and a common epithelial antigen are assayed. The antigen interacting with MAB HEA-125 is characterized by the monomorphic expression.

Adult↗
PubMed1990

[A case of liver angiosarcoma arising in a pre-existing cavernous hemangioma].

A 36-year-old woman presented with a solitary hepatic tumor. Macroscopically, the tumor measured 9 cm in greatest diameter, and was well encapsulated; it was reddish, and showed multiple foci of hemorrhage. Microscopic examination revealed two different patterns: a peripheral angiosarcoma surrounding a centrally located cavernous haemangioma. To our knowledge, such an entity has not been reported up to now. Possible pathomechanisms, radiological and pathological findings of this angiosarcoma of liver arising within a cavernous haemangioma are commented.

Adult↗
PubMed1990

Effect of in vivo therapy with a CD8 monoclonal antibody on delayed engraftment after autologous bone marrow transplantation.

Very long delay to engraftment (or non-engraftment) was observed in eight patients presenting common immunological features, i.e. excess of blood and bone marrow lymphocytes coexpressing CD8 and CD57 (HNK1) antigens. They were therefore treated by CD8 immunotherapy. Such treatment induced a complete clearance of CD8+, CD57+ cells from the blood and bone marrow in five cases, a partial clearance in one, the absence of clearance in one and a modulation in the last case. No toxic side effects were observed. Platelet recovery was observed in only two patients, but long-lasting granulocyte recovery was seen in six of the cases from day 6 to day 30 after the beginning of CD8 infusion (median = 17 days).

Adolescent↗
PubMed1990

[Factors influencing survival after resection of cancer of the cardia. Comparison of total esophagogastrectomy and upper pole esophagogastrectomy].

Total oesophagogastrectomy (TOG) is the best surgical technique for carcinoma of the cardia. However, oesophagogastric anastomosis is easier in upper pole oesophagogastrectomy (UPOG). This is a retrospective study excluding post-operative deaths and palliative surgery. We studied the factors affecting the survival and then compared TOG (n = 15) and UPOG (n = 26) in carcinomas of the cardia. Bad prognosis was related to several factors: poorly differentiated adenocarcinomas, tumor size, lymph node involvement and residual tumor at the resection margins. The survival rate of resected carcinomas of the cardia was 22 +/- 13%. No difference was noted between extended and limited resections. 5-year survival after UPOG was 20 + 18% and after TOG 11% (0-30) (p = 0.21). In stage 1B, 5-year survival after UPOG 11% and TOG was 50% (19-81) and 33% (0-82) (p = 0.54). In stages II and III A, 3-year survival after UPOG and TOG was 7% (0-20) and 0% (p = 0.16). For a given tumor size, 5-year survival is the same whatever the technique.

Adenocarcinoma↗
PubMed1990

Comparison of outcome, clinical, laboratory, and immunological features in 164 children and adults with T-ALL. The Groupe d'Etude Immunologique des Leucémies.

T cell acute lymphoblastic leukemia (T-ALL) is a disease of poor prognosis, usually studied separately in adults or children. Controversial clinical or biological prognostic factors have been reported, and little information is available regarding the frequency and prognostic value of membrane markers identified on blast cells. We report an extensive investigation of the incidence and prognostic value of immunophenotypic, clinical, and laboratory data in T-ALL, performed as a multicenter study in 164 patients. CD7, CD5, and CD2 were the most frequently expressed T cell antigens, and CD2 and CD4 were more frequently observed in children than in adults. MHC class II, CD9, and CD10 were observed in 16, 22, and 21% of the patients, respectively. The male prevalence of T-ALL, and the more frequent presence of a tumoral syndrome in children were confirmed, but mediastinal enlargement and high leukocyte counts were observed in less than half the patients. A poor prognosis was associated with the expression of MHC class II in adults. The presence of a mediastinal mass appeared to be of good prognosis in adults, as well as a leukocyte count lower than 100 x 10(9)/l whatever the age of the patient.

Adolescent↗
PubMed1990

[Pulmonary metastasis with left intra-atrial extension of liposarcoma. Apropos of a case].

The direct extension of a neoplastic thrombus of the pulmonary veins into the left atrium is extremely rare. The authors report the case of a pulmonary metastasis from a liposarcoma of the thigh extending into the pulmonary veins and prolapsing into the left atrium. The patient was successfully treated by tumorectomy under cardiopulmonary bypass then by left upper lobectomy.

Adult↗
PubMed1990

[Post-traumatic retroligamentary pneumatocele. Apropos of a case].

A case-report of a 17 year-old man admitted for thoracic trauma associated with a vertical air and fluid collection located behind the pulmonary ligament raises the question of the exact nature of retroligamentary pulmonary pneumatoceles. They may be intraparenchymatous pneumatoceles or simple loculated pneumothorax but whatever the actual lesion, exact recognition of this radiological image avoids drainage and operation. This lesion resolves spontaneously within several weeks.

Adolescent↗
PubMed1989

Correlations between acute lymphoid leukemia (ALL) immunophenotype and clinical and laboratory data at presentation. A study of 350 patients.

The phenotypes of malignant cells from 350 untreated patients with acute lymphoblastic leukemia (ALL) were determined at diagnosis with the use of a panel of monoclonal antibodies to leukocyte antigens. According to the phenotypes seen, the cases were divided into five groups, pre-B ALL, B-ALL, T-ALL, MO-ALL, and undifferentiated ALL. Each group was subdivided, resulting in 11 defined immunologic subtypes. Correlations between clinical and laboratory features were investigated at presentation. ALL of early-B phenotype associated with elevated cell counts occurred more often in female and infant patients than in male patients. Involvement of the central nervous system was frequent in B-ALL, which occurred mostly in male patients. A male prevalence was also seen in ALL of T-lineage in which significant differences regarding clinical characteristics and leukocyte counts appeared among the four subtypes. The clinical relevance of phenotypic subcategorization is supported by our observations.

Antibodies, Monoclonal↗