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International audience; Due to the willingness to extend the nuclear power plants length of life, it is of prime importance to understand long term ageing effect on all constitutive materials. For this purpose gamma-irradiation effects on insulation of instrumentation and control cables are studied. Mid-infrared spectroscopy and principal components analysis (PCA) were used to highlight molecular modifications induced by gamma-irradiation under oxidizing conditions. In order to be closer to real world conditions, a low dose rate of 11 Gy h−1 was used to irradiate insulations in full cable or alone with a dose up to 58 kGy. Spectral differences according to irradiation dose were extracted using PCA. It was then possible to observe different behaviors of the insulation constitutive compounds i.e. ethylene vinyl acetate (EVA), ethylene propylene diene monomer (EPDM) and aluminium trihydrate (ATH). Irradiation of insulations led to the oxidation of their constitutive polymers and a modification of filler-polymer ratio. Moreover all these modifications were observed for insulations alone or in full cable indicating that oxygen easily diffuses into the material. Spectral contributions were discussed considering different degradation mechanisms.

International audience

In a hypothetical severe accident in a Pressurised Water Reactor (PWR), Fission Products (FPs) can be released from the overheated nuclear fuel and partially transported by gases, composed of a mixture of superheated steam and hydrogen, to the reactor containment. Subsequent air ingress into a damaged reactor core may lead to enhanced fuel oxidation, affecting some FP release, especially that of ruthenium. Ruthenium is of particular interest because of its high radiotoxicity and its ability to form very volatile oxides. In the reactor containment, such volatile forms are very hazardous as they are much less efficiently trapped than particulate forms by emergency filtered venting. In the four and a half years of SARNET, collaborative research dedicated to the "ruthenium story" has been performed by several partners. This paper presents the main achievements over the whole project period. Starting from experimental observations showing that fuel could be extensively oxidised by air to, and that a significant fraction of ruthenium inventory can be released, rather satisfactory models have been developed. In addition, the effect of the air interaction with Zircaloy cladding, as well as with UO2 itself, has been studied. Experiments on the complex transformations of ruthenium oxides upon cooling through the reactor circuit have been performed. An unexpectedly large effect of temperature on the decomposition rate of gaseous ruthenium compounds has been found, as well as effects of the nature of circuit internal surfaces and other FP deposits. So it has been highlighted that various forms of ruthenium can reach the containment, but the most probable gaseous species under these conditions is ruthenium tetroxide. Preliminary analysis of ruthenium transport supports these conclusions. Experiments and analysis have also been launched on the radio-chemical reactions undergone by these ruthenium oxides in the reactor containment. Competing effects of gaseous decomposition to solid particles and re-volatilization from these ruthenium deposits have been demonstrated and modelled. The paper concludes by identifying the remaining work needed to achieve full resolution of the ruthenium source term issue. Recommendations are made for future research activities in the follow-up programme SARNET2. © 2009 Elsevier Ltd. All rights reserved.

Fourteen monoclonal antibodies recognizing monomorphic and polymorphic epitopes on class I and class II antigens of the human MHC have been assayed on lymphocytes of a panel of 20-150 BoLA typed bovine animals from 12 different breeds. Some monomorphic antibodies cross-reacted and others did not. Two polymorphic monoclonal antibodies in man recognize a polymorphism in cows that follows allospecificities (BoLA-w3, w9) already described. Immunoprecipitation experiments with monomorphic anti-B2m and anti-HLA-DR monoclonal antibodies have shown that these cross-reactions concern BoLA antigens. They also revealed that Ia-like antigens in cattle present the same two chain features characterized in other species.

H-2 antigens are expressed in substantial amounts of murine blood platelets (for H-2 antigenic content 1 lymphocyte approximately 50 platelets) whereas Ia antigens are probably not expressed at all (minimal Ia antigenic content more than 35 times lower than for H-2). This property of blood platelets makes them very useful for the selective absorption of anti-H-2 antibodies from complex sera and for the preparation of specific anti-Ia antibodies from such sera. In 20 sera produced against the complete H-2 complex, 12 sera contained anti-Ia antibodies beside the expected anti-H-2 antibodies. In two sera, separation of the anti-Ia antibodies was easily obtained by absorption of the anti-H--2 antibodies on platelets. The analysis of one serum (C3H.Q X B10.D2) anti-C3H [(q X d) anti-k] showed that, in addition to be expected anti-H--2.23 and anti-Ia.2 antibodies, it contained at least three other Ia antibodies, separable by absorption on lymphocytes, which recognized three antigens--Ia.17, determined by the haplotypes k, f, s, r, j; Ia.18, determined by the haplotypes k, f, s; and Ia.19 determined by the haplotypes k and r. The genes are located in the I--A and/or I--B subregions of the H--2 complex.

A review of the literature and discussions at the preliminary meeting of the 9th International Histocompatibility Workshop (Munich, March 1982) have highlighted the growing importance of HLA monoclonal antibodies (McAb) for immunogenetic, biochemical and functional studies. Thus it would seem necessary to establish a registry to provide permanent information on the subject.

Blood groups and HL-A antigens were determined in 12 members of a family in which chronic lymphocytic leukaemia (CLL) occurs in four siblings. The same HL-A haplotype [Da25 (W30 + W31), HL-A13] was observed in the three diseased siblings tested. This case, together with that of a similar family studied by Schweitzer et al. (1973), in which three out of five diseased siblings shared two antigens - HL-A2 and W5 - suggests a possible linkage between HL-A and susceptibility to CLL.

Using molecular biological methods, 58 unrelated Chinese from Shanghai were typed for HLA-DR and DQ. The Shanghai population possesses the principal HLA-DR and DQ characteristics of the oriental populations but with an increase of the DRB1* 12 allele. So HLA typing of populations appears to be important not only for anthropological studies but also for transplantations and HLA associations with diseases.

Amino acid sequences and structural data on HLA class I molecules are now available, making possible a comparison of the serological and structural definitions of allelic series. 1) A hierarchy of differences between molecules is observed. Certain molecules show a low level of differences (1.2% of amino acids) and represent variants of original molecules. Other molecules are recombinants derived from two parent molecules (2.5% difference). Original molecules from an allelic series have a higher level of difference (7.6.%). Maximum differences (13.5%) are observed between products from different loci. Serologically related specificities (cross-reacting groups) show a relatively low level of difference (6.4%). 2) In most specificities an exclusive residue can be considered as responsible for the formation of a serologically recognized determinant. Certain specificities do not have an exclusive residue; they can then be characterized either by a unique determinant made by the association of several non-exclusive residues, or by an unique association of several non-exclusive (shared) determinants. There is a significant correlation between the absence of an exclusive residue and the absence of monoclonal antibodies recognizing certain specificities. This suggests two kinds of definition of serological specificities, either by a single exclusive determinant (monotopic recognition) or by several shared determinants (polytopic recognition). Private and public specificities are recognized at the structural level. T-cell receptor (TCR) recognizes either a xenogeneic peptide in the context of self HLA molecules (restricted CTL [Cytotoxic T Lymphocyte]), or allogeneic HLA molecules. Determinants recognized by CTL (restricted or allogeneic) on HLA molecules have been identified. It is not possible to ascertain whether determinants recognized by antibodies and TCRs are identical, but they are probably very similar. 3) HLA class I molecule is made of 75% conserved residues (mostly in the α3 and β2-m domains) and of 25% variable residues (mostly in the α1+α2 domains). Conserved residues maintain the general shape of the molecule, its outward orientation on the cell membrane, its association with T cells CD8 molecule, and the structure of the peptide binding site, a groove at the top of molecule. Variable residues are responsible for the capacity of each molecule to bind and to present a large number of different peptides to the TCR. Each molecule carries several (3–10?) variable sites; certain are localized into the groove and are recognition sites while others, more exposed on the surface of the molecule, are sites recognized by TCRs and antibodies. Both conserved and variable regions are necessary to the function of the HLA molecule.

TaqI, BamHI and HinddIII polymorphisms of the C4 genes were studied with a 500-bp C4 cDNA probe (pAT-A153) specific for the 5' end of the gene. The restriction patterns obtained were correlated with the C4A and C4B genotypes in 35 patients suffering from insulin-dependent diabetes mellitus (IDDM), and results were compared to those from 40 healthy individuals. The controls, all Caucasian, were genotyped for HLA-A, B, C, DR, Bf, C2 and C4, together with 10 diabetics and their families; haplotypes for the other patients had been deduced using DNA and protein polymorphism, and taking into consideration linkage disequilibrium for neighbouring loci. No significant difference between genotypes at the C4A locus was seen in either population. The C4A gene deletion, associated with a C4B "short" gene (66.7%), was found mainly in the haplotype B8,Cw7,DR3,BfS,C2C, C4AQOB1, and the C4B gene deletion in the haplotype B18,Cw5,DR3,BfF1, C2C,C4A3BQO. When diabetic patients were compared with normal individuals, we observed, at the C4B locus, a decrease in the C4B "long" gene (22% vs. 49% respectively, p less than 0.001). A compensatory increase was observed in patients vs. controls for the frequency of C4BQO, both in the deleted and intact form (26% vs. 10% respectively, p less than 0.03).

To better understand the composite character of amino acids EPR spectra, the radiolysis and reactions which occurred after irradiation of amino acids, a comparative EPR study of a few simple amino acids has been made in order to identify qualitatively and quantitatively the different radiation-induced radicals in amino acid powders. A spin-trapping methodology has been developed and carried out on irradiated glycine, alanine and valine.

Agglutination tests with preparations of parenchymatous organs were developed. The tissue suspensions were dried at room temperature after they had been spread as a very thin layer on a glass plate, or otherwise, they were lyophilized. The dried preparations were pulverized and then prepared as stable suspensions in saline. The agglutination test was conducted on a slide by mixing one drop of the tested serum at a convenient dilution with one drop of tissue powder suspension. Agglutination in the form of readily discernible clumps could be assessed after 1-10 min. By means of this procedure, species-specific reactions were studied using suspensions of kidneys of various species. Organ-specific reactions were noted with suspensions of brain and thyroid. Agglutination of thyroid powder was observed with rabbit anti-rabbit thyroid sera as well as with many, albeit not all, sera of patients with Hashimoto's disease.

Publisher Summary This chapter discusses the theory of major presentation and histocompatibility complex (MPHC). The MPHC can be defined as a group of molecules involved in the presentation of peptides to T-cell receptors (TCR). This definition concerns antigen presenting molecules (APM) and other molecules, which may contribute to the presentation function. This functional definition is completed by a genetic definition of the MPHC as the chromosome region, which contains the genes controlling the structure and expression of APM. The two definitions are complementary, but somewhat different. It is indeed possible for MPHC products to exercise functions other than presentation. The MPHC is qualified as a complex because it is made up of a group of genes functioning in a coordinated manner. Other histocompatibility antigens exist outside the MPHC; even when MPHC identity is obtained between a graft donor and recipient, this graft may be rejected. MPHC genes and products can be grouped into three classes—I, II, and III—depending on their biochemical properties, phenotypic expression, and function. Class I products (MPHC1) are glycoproteins comprising a heavy chain (α) associated with β2 microglobulin, expressed on the membrane of practically all nucleated cells in the organism. They present an endocellular peptide to CD4 – 8 + T lymphocytes. Certain related products are qualified as being class Mike. Class II products (MPHC2) are glycoproteins made up of two chains (α and β) expressed on the membrane of B lymphocytes, monocyte-macrophages, and activated T lymphocytes. They present a peptide arising from an endocytosed extracellular or membrane protein to CD4 – 8 + T lymphocytes. Class III products constitute the C2, Bf, and C4 molecules in the complement system.

The major histocompatibility complex (HLA system in Man) is characterized by its extensive degree of allelic polymorphism. After the serological and cellular methods, the molecular biological methods appeared to be a powerful tool in detecting HLA-class II polymorphism. Restriction fragment length polymorphism (RFLP), using restriction endonucleases, represented an efficient method of HLA-DR, DQ, and DP genotyping. Recently, the polymerase chain reaction (PCR) permitted the development of two major class II genotyping techniques: the PCR allele specific oligonucleotide typing and the PCR-RFLP typing. By these new methods, a refined and accurate determination of DRB, DQB, DQA, and DPB alleles is possible. The major application of a refined HLA class II typing is in transplantation especially for unrelated bone marrow grafts. Moreover, it permits the identification of the amino acids implicated in the cellular response which by itself is important for the fundamental immunological studies.

Resume Apres typage des marqueurs de classe III (Bf, C2, C4) et de classe II (DR), nous avons analyse le polymorphisme de l'ADN des 4 locus adjacents du CMH (C4, 21-OHA, C4B, 21-OHB) de 54 malades atteints de sclerose en plaques et de 40 sujets temoins; la population malade comparee aux temoins, montre une legere augmentation de la frequence de C4AQ0 (0,25 vs 0,16 ns) et une augmentation significative de BfSS, HLA-DR2 (0,47 vs 0,20 p=0,007) (risque relatif=3,54) et de C4AQ0, HLA-DR2 (0,25 vs 0.05 p=0,009) (risque relatif=6,40). Chez les sujets porteurs du phenotype C4AQ0, le gene intact (present non exprime) et le gene delete associe a une deletion constante de 21-OHA ont une distribution differente chez les malades par rapport aux temoins (0,30 vs 0,15 p

In a study carried out for patients receiving intrafamilial HLA-A,B,DR identical, MLC negative bone marrow transplants, RFLP profiles of HLA-class II for 27 donor recipient pairs were analyzed. Twenty-four pairs were found HLA-class II identical while three pairs were HLA-DP incompatible. The patients of these three pairs did not reveal any acute GVHD greater than or equal to grade II. The seven cases of acute GVHD greater than or equal to grade II found in our panel were HLA-DR, DQ, and DP compatible. Thus, in practical terms pretransplantation HLA-DP typing does not seem necessary for intrafamilial HLA-identical, MLC negative BMT. On the other hand, this work confirmed that it is possible to type for HLA-DP using molecular biological techniques, and this in itself may have some important implications for unrelated BMT.

In 23 cases of chronic myelogenous leukemia (CML) in remission, HLA class II typing was performed by complement fixation technique on phytohemagglutin (PHA) activated lymphocytes. In 10 cases satisfactory results were obtained, whereas in 13 cases the cells were weakly or non reactive, making impossible a correct determination of HLA-DR,DQ specificities. In the 13 cases a conditioned medium containing Interleukin-2 (Il-2) and gamma interferon (IFN) was added to PHA, inducing a good HLA class II reactivity and making possible a satisfactory definition of HLA-DR,DQ specificities. The complement fixation technique on lymphocytes cultured with PHA, Il-2 and gamma IFN made possible a correct HLA-DR,DQ typing in 23 consecutive cases of CML, while such a typing is often difficult or impossible when using the microlymphocytotoxicity technique on B lymphocyte targets.

Summary The different methods proposed for preparation of B lymphocyte suspensions are not always simple, rapid and reliable. Presence of monocytes in the B cell suspension makes difficult HLA-DQ typing. For these reasons we propose a method using monoclonal antibodies (McAb) and complement to lyse the non B cells. Mononuclear cells, isolated from peripheral blood by Ficoll-Hypaque, are suspended in a mixture of anti-CD2, CD3, CD11 b (OKM1 recognizing monocytes and granulocytes) McAb. This method of preparation of B cell suspension is rapid and provide better typing reactions than did the suspensions prepared by depletion of sheep red blood cell rosetting cells.

The HL-A antigens used for most of the biochemical studies in the past have been solubilized from cellular materials. However in such cases the recovery of purified active molecules is always low, no matter which solubilization technique is used. Accordingly. a richer and/or more abundant source of HL-A antigens which can easily be purified had to be sought. Two recent publications have reported such sources: Billing and Terasaki [l] showed that large quantities of HL-A antigens are present in human serum, and Robert et al. [2] were able to demonstrate the presence of HL-A antigens in the urine of patients suffering from tubular proteinuria. Since urine is abundant and easy to collect, we have partially purified HL-A antigens from that of diseased and of normal individuals.

Serologic evidence for the existence of beta 2-microglobulin-, (beta 2m) like and H-2-like antigenic determinants in Drosophila are presented. Drosophila-cultured cells and larvae extract were shown to react specifically with a rabbit anti-rat beta 2m and a rabbit anti-mouse beta 2m antisera. G-200 pooled fractions from Drosophila larvae were shown to react with beta 2m-eluted and glycin-absorbed antisera, but not with beta 2m-absorbed or glycin-eluted antisera. These fractions also quantitatively inhibited the heterologous reaction between the anti-beta 2m antisera and purified human and rat beta 2m. The lack of reactivity of other rabbit antisera or normal serum with Drosophila, as well as the efficiency of absorption of anti-beta 2m reactivity by either rat or KCO% (Drosophila) cells, further supports the presence of beta 2m epitopes on Drosophila cells. Data are also presented showing that certain anti-H-2 alloantisera react with Drosophila. That this reactivity is indeed due to anti-H-2 antibodies is suggested by several lines of evidence, including the removal of cytotoxic alloantibodies and lack of reactivity by other mouse antisera and monoclonal reagents. Preliminary data suggest that the H-2-like and beta 2m-like determinants are physically associated on the cell surface of Drosophila cells. These findings have important implications on current concepts concerning the evolutionary origin and physiologic role of beta 2m and the major histocompatibility complex.

RESUME Des bilans hydriques comparatifs ont ete etablis par des mesures (pluies, ruissellement, humidite du sol) et des calculs (evapotranspiration, drainage) dans six parcelles experimentales d'Afrique Occidentale le long d'une sequence bioclimatique allant de la Basse Cote d'Ivoire a la Haute-Volta Centrale. Ces bilans montrent l'evolution de termes du bilan hydrique en fonction du bioclimat, de l'utilisation du sol et des caracteristiques pedologiques. Dans les parcelles non amenagees (vegetation naturelle), le terme ruissellement reste faible quel que soit le couvert vegetal (1% a 2% des pluies annuelles). Le drainage profond tend vers zero quand les pluies annuelles deviennent inferieures a 900–1000 mm (regions equatoriales) et a 700–800 mm (regions tropicales). Dans les parcelles cultivees, le ruissellement augmente beaucoup, mais l'ecoulement total (ruissellement + ecoulement de base) n'augmente pas necessairement. Les sols profonds, a forte reserve hydrique, favorisent l'augmentation de l'evapotra...

A detailed study of water movement in a multi-layered bare soil is presented. The main objective was to determine the possibilities of water table recharge by natural rains in semi-arid zones (south Tunisia). Systematic measurements of the soil water balance, using neutron probe and tensiometers have been run during infiltration and redistribution of water in a monolithic soil. The water was applied at the soil surface at a constant rate by a rain simulator. In Part I the following points are developed: experimental analysis of the processes of infiltration and redistribution and determination of the hydrodynamic properties for each layer of soil during the redistribution of water without and with evaporation through the soil surface. It is notably shown that water table recharge is possibly due to the high values of hydraulic conductivity of a gypsum layer located at a depth of 90 cm. This is of particular interest since until now this layer was considered to be impermeable.

A serum from a patient (LAR), immunized by pregnancies and blood transfusions, reacted with cells carrying HLA-DR2 and/or -DR7 specificities (titer 1:200-1:1000). Absorption-elution experiments showed that the allo-serum recognized a determinant shared by DR2 and DR7 cells. The high correlation coefficients (0.90-1) with these specificities suggested that the supertypic specificity LAR was carried by the first DR molecule encoded by DRB1 gene. LAR is another example of new supertypic specificities, reflecting structural homologies between alleles at HLA class II loci.

HLA-A9 and HLA-B12 antigens have been purified from urine. The highly purified molecules were devoid of β 2 -microglobulin and were characterized as glycoproteins with a molecular weight of about 32 000 and isoelectric points of about 5.1 for HLA-A9 and 4.7 for HLA-B12 antigens.

Cytolytic T lymphocytes (CTL) specific for the virus-induced and leukemia-associated Friend, Moloney, Rauscher (FMR) antigen are easily detected in the spleens of primary and secondary stimulated H-2b or H-2d mice. They react, respectively, with H-2Db + FMR and H-2Kd + FMR; Dd and Kb never being involved. On the other hand, recombinant (KbDd) mice are relatively low responders that produce CTL only after secondary stimulation. Competition and blocking experiments with monospecific anti-H-2 antibodies have demonstrated that on the same H-2b tumor cells, C57BL/6 (H-2b) lymphocytes recognize Db + FMR, whereas B10.A(5R) lymphocytes recognize Kb + FMR, the restriction cannot, therefore be explained by a specific association of viral molecules with certain H-2 products. The CTL response of (B10 X 5R)F1 hybrids is (a) easily detected in primary reaction, the high responder anti-FMR phenotype being dominant and (b) directed against Db + FMR, F1 mice being low responder against Kb + FMR like the B10 parent. These results suggest that a D region-associated immune response gene controls the cell-mediated anti-FMR reaction, the best available H-2 + FMR antigenic association being chosen by CTL precursors.

It was demonstrated previously that the cytolysis of murine viral lymphoma cells by anti-murine sarcoma virus (MSV) syngeneic T-killer lymphocytes was restricted by some products of the H-2 complex. The respective role of the products of different regions of the H-2 complex were studied with six H-2(b) and three H-2(d) lymphomas induced by five different type C viruses. They were tested in a classical chromium release test against anti-MSV T-killer cells obtained from different inbred strains of mice, including several H-2 recombinants. Tumors o£ the H-2(b) haplotype were lysed only when effectors and target cells have in common the D(b) region. On the contrary an identity limited to the K end of the H-2 complex is necessary and sufficient in the H-2(d) haplotype. An in vitro restimulation of the spleen cells with concanavalin A strongly increased the activity of in vivo-primed T lymphocytes but did not provide any response for in vivo-primed but nonresponder cells. Preincubation of the tumor cells with anti-H-2 sera abolished the lysis by syngeneic anti-MSV effector lymphocytes. The same results were obtained by preincubating the H-2(b) targets with anti-H-2D(b), or the H-2(d) target with anti-H-2K(d). Preincubation with anti-H-2K(b) or anti- H-2D(d) were ineffective. These results show that the T-killer/target cells interaction in the MSV system involved some products of the H-2 complex which might be different with the various H-2 haplotypes and could possibly vary according to the antigenic specificity. A specific association of a viral product with a normal cellular structure, directed by the H-2 region during the viral budding could explain the observed results.

During the 10th International Histocompatibility Workshop (10th WS), 181 HLA MoAbs were studied using lymphocytotoxicity micro-technique (LCT) and/or enzyme immuno-assay (EIA), and their capacity to serve as typing reagents was evaluated. 129 MoAbs were tested by both techniques. Results obtained with 92 class I and 86 class II polymorphic MoAbs (10th WS) were compared to published data concerning 180 class I and 176 class II polymorphic MoAbs, listed in an HLA-MoAbs Register maintained in our laboratory. The following conclusions can be proposed: 1/HLA-A, B typing by LCT with MoAbs is possible for about 14 specificities. Some specificities are clearly recognized (HLA-A3, B8, B13, Bw4, Bw6), others are recognized as cross-reacting groups (B7+27+w22+40), others are not currently recognized by any MoAb with restricted specificity (B5, B15). Several MoAbs confirmed the existence of shared epitopes between products from a single locus (A2-A28, A25-A32), or from A and B loci (A2-B17, Bw4-A9-A32). A single HLA-Cw MoAb has been described. 2/HLA class II typing by LCT with MoAbs is more difficult than class I typing. DR2, DR3, DR4, DR5 and DR7 as well as DRw52 and DRw53 are well defined; other DR specificities are poorly or not at all defined. Particular associations (DR1+DR4, DR3+DRw6, all DR except DR7) are recognized by several MoAbs. All DQw specificities are well recognized, including new specificities defined only by MoAbs: WA (DQw4), TA10 (DQw7), 2B3 (DQw6+w8+w9). Only two HLA-DP MoAbs have been described. 3/Satisfactory results, similar to those of LCT, were obtained with EIA using lymphoid cell lines as targets. 4/Human MoAbs (12 in the Register) are satisfactory typing reagents. They could represent in the future a significant contribution to HLA typing with MoAbs.

Epstein-Barr virus (EBV)-carrying Burkitt lymphoma (BL) cells are relatively or completely resistant to the lytic effect of major histocompatibility complex class I HLA antigen-restricted cytotoxic T lymphocytes (CTLs) generated by stimulating lymphocytes of EBV-seropositive donors with the autologous EBV-transformed lymphoblastoid cell line (LCL). We previously found that EBV-negative and EBV-carrying BL lines derived from HLA-A11-positive donors were not only resistant to lysis by the HLA-A11-restricted CTL generated by stimulation with the autologous LCL, but also to HLA-A11-specific CTL derived from lymphocytes of an EBV-seronegative donor stimulated with an allogeneic LCL. Using the same and additional cell lines, we now show that the CTL resistance of the BL lines is probably due to a selective down-regulation of HLA-A11. We also show that the EBV-encoded latent membrane protein is expressed at a lower level in the EBV-carrying BL lines than in EBV-transformed LCLs. Only one of eight in vitro EBV-converted BL lines that shifted to a more LCL-like growth pattern expressed LMP at a high level. This line also reexpressed the HLA-A11 antigen that was undetectable in its EBV-negative progenitor. Our findings suggest that the typical BL cell phenotype is associated with low expression of both proteins.

Resume La frequence de l'allo-immunisation fœto-maternelle anti-leucoplaquettaire chez des femmes ayant eu 3 grossesses ou plus est de 0,54 % lorsqu'elle est demontree par une reaction de fixation du complement sur antigene plaquettaire et de 13,6 % lorsqu'elle est demontree par les reactions de leuco-agglutination et/ou de lymphocytotoxicite. Trois nouveau-nes de meres immunisees n'ont presente ni thrombopenie, ni syndrome hemorragique. Dix cas de thrombopenie neo-natale ont ete etudies serologiquement. Dans 4 des 6 cas ou l'origine immunologique de la thrombopenie etait tres vraisemblable, l'allo-immunisation maternelle a pu etre demontree serologiquement : deux fois par la reaction de fixation du complement, et deux fois par le test de consommation de l'antiglobuline. Parmi 24 immuns-serums etudies, 18 presentaient une specificite pour l'un des antigenes du systeme majeur d'histocompatibilite HL-A. Dans les conditions de l'allo-immunisation fœto-maternelle les antigenes 1 et 5 de ce systeme semblent les plus immunogenes. Ces immuns-serums sont utilisables comme serums tests pour la determination des antigenes de groupes tissulaires.

The HL-A system of leukocyte group antigens is a system of great complexity and polymorphism, governed by an autosomal region which includes a number of subunits or subloci. It constitutes the principal system of histo-compatibility in man. Extensive population and family studies have resulted in the identification of two HL-A subloci. The first sublocus determines antigens HL-A 1, 2, 3, 9, Da 15 and Da 17 as alternative alleles. Antigens HL-A 5, 7, 8, Da 4, Da 6, HN, and probably Da 9 and Da 18 are determined in similar fashion at a second sublocus. The products of 20 per cent of the genes of the first sublocus, and of 29 per cent of the genes of the second sublocus are still unknown. Study of 113 families has documented 226 human HL-A genotypes and 452 haplotypes. The observed gene and haplotype frequencies were in close agreement with the anticipated values calculated on the basis of Mendelian laws. This result supports the concept that the HL-A system is in equilibrium. Although the HL-A system plays a major role as a determinant of human allograft responses, its primordial function may be of relevance to other fundamental biological problems, with particular reference to host defenses against microorganisms, viruses and neoplastic cells.

Resume Une thrombopenie neo-natale par incompatibilite fœto-maternelle dans le systeme HL-A a ete mise en evidence chez le quatrieme enfant d'une famille dont on a pu etudier le genotype chez les parents et trois des quatre enfants. Un anticorps anti-HL-A5 a ete retrouve dans le serum de la mere et de l'enfant a des taux significatifs pour expliquer la maladie. Une hypovitaminose K a sensibilise l'expression clinique de la thrombopenie qui a necessite une exsanguinotransfusion et s'est corrigee en quelques semaines apres une hypoplasie medullaire transitoire.

Summary The presence of Rh antigen has been demonstrated on human platelets and leucocytes from blood samples containing D positive red cells by means of anti-D consumption tests and especially of antiglobulin consumption tests. Resume L'antigene D (Rh) a ete mis en evidence sur les plaquettes et sur les leucocytes humains dans les sangs dont les erythrocytes possedent l'antigene D par la methode de consommation de l'anti-D et surtout de consommation de l'antiglobuline. Zusammenfassung Mit Hilfe von Absorptionsversuchen unter Verwendung von inkompletten Anti-D-Seren und des Antiglobulinkomsumptionstestes gelang es, an den Plattchen und Leukozyten rhesuspositiver Individuen das Rhesusantigen D nachzuweisen.