Characterization of a Novel Protein Induced by Progressive or Rapid Drought and Salinity in Brassica napus Leaves.

Under progressive drought stress, Brassica napus displays differential leaf modifications. The oldest leaves, developed before the onset of water deficit, wilt gradually, whereas the youngest leaves harden. Hardening was distinguished by leaf turgor and bluish wax bloom when the shoot water potential was below -3 MPa and the leaf water saturation deficit was about 60%. This adaptive change was accompanied by modifications in two-dimensional protein profiles. Ten percent of the polypeptides had altered abundance or were unique to drought-stressed plants. Two-dimensional analysis of in vitro translation products did not reveal a general decrease in mRNA population. A 22-kD double polypeptide was increased by progressive or rapid water stress and salinity and disappeared upon rehydration. These polypeptides have a common N-terminal sequence, which does not reveal homology with any known water-stress protein but which contains the signature motif of soybean Künitz trypsin inhibitors. Immunoprecipitation allowed these polypeptides to be identified on two-dimensional gels of in vitro translation products. They appeared to be synthesized as a 24-kD precursor, and their transcript was present in the control well-watered leaves, where the polypeptides were never detected, indicating a possible translational regulation. A putative function of this protein, named BnD22, in the retardation of drought-induced leaf senescence is discussed.

A Brassica napus transcript encoding a protein related to the Künitz protease inhibitor family accumulates upon water stress in leaves, not in seeds.

A cDNA clone encoding a Brassica napus drought-induced 22 kDa (BnD22) protein has been isolated and characterized. The BnD22 transcript accumulated in response to drought reversibly, and to other conditions of leaf water deficit such as rapid water stress or salt acclimation, but not to cold acclimation or heat shock. Exogenously applied abscisic acid induced both changes in leaf morphology similar to the drought-adaptive response and a pronounced accumulation of the BnD22 mRNA. In control and drought-adapted plants, the BnD22 transcript was expressed in an organ-specific manner: the mRNA level was highest in leaves, low in hypocotyls and undetectable in roots. Sequence analysis indicates that the BnD22 protein is related to the Künitz family of protease inhibitors. In contrast to most members of this family, and also to most polypeptides expressed in vegetative tissues upon drought, the BnD22 mRNA was absent in seeds, before or during the seed desiccation phase. The BnD22 gene represents a new class of genes which are strictly induced in vegetative tissues upon environmental stress, and its pattern of expression shows that the responses to water deficit differ, at least partially, in seeds and in leaves.

Serological characterization of murine monoclonal antibodies directed against acquired B red cells.

Balb/c mice were immunized with acquired B red cells. Twelve clones specific for acquired B red cells were obtained from two fusions. A detailed investigation of three clones is reported here. These antibodies appear to be directed to the B-like epitope since they are inhibited by galactosamine and fail to react after acetylation of red cells. E 231 is an example of a series of antibodies closely specific for acquired B red cells which can be useful in elucidating some AB0 typing problems. E 167 and F 47 showed a cross-reactivity with A1 red cells and a synthetic A trisaccharide. No affinity for B antigen could be demonstrated for any of the antibodies.

False negative results in a competitive immunoassay for anti-HIV-antibodies due to the presence of rheumatoid factors.

One serum from a blood donor, which had both HIV-antibodies and rheumatoid factor, gave positive results with EIA anti-HIV screening tests and Western blot, but negative results with the Abbott's ENVACOR assay. Moreover, this serum and 5 out of 6 sera containing only rheumatoid factors were able to interfere with ENV and CORE reactions. Rheumatoid factors bind to the beads used in ENVACOR test and are also able to react with the conjugate. Most of the rheumatoid factors bind to the ENV conjugate, though with a wide range of activity. Obvious binding of rheumatoid factors to the CORE conjugate could not be demonstrated. Binding of rheumatoid factors both to the bead and to the conjugate leads to high optical density values and therefore results in the negative range according to the normal interpretation of the ENVACOR competition procedure.

[True hermaphroditism in a child with a chimeric XX/XY chromosome, a double erythrocyte population and an unusual Lewis (a+ b+) phenotype]. / Hermaphrodisme vrai chez un enfant porteur d'une chimère chromosomique XX/XY, d'une double population erythrocytaire et d'un phénotype Lewis (a+ b+) inhabituel.

A 2 years-old Korean girl is seen because of ambiguous external genitalia. Surgical exploration shows the right gonad to be an ovary and the left one to be an ovotestis, thus demonstrating a true hermaphroditism. Cytogenetic studies of peripheral lymphocytes reveal a mixture of 46,XX and 46,XY cells, with a predominant XX cell line. The patient's red cells are composed of two distinct populations differing in three genetically independent blood group systems. The ratios of the two cell lines in various tissues, especially among the cells secreting Lewis antigens, appear to be very different and suggest several hypothesis to explain the highly unusual red cell Lewis phenotype Le (a+ b+). We conclude to a dispermic chimera, however the adopted status of this child prevents any identification of the maternal or paternal contributions. Because of the physical aspect it was decided to remove the ovotestis, to repair the external genitalia and to bring up this child as a female.

An acute leukaemia augured before clinical signs by blood group antigen abnormalities and low levels of A and H blood group transferase activities in erythrocytes.

A mixed field agglutination pattern with anti-A reagents and very low levels of A and H blood group antigen specific transferase activities were found in the erythrocytes of a 4-year-old girl who presented no clinical signs of haematological disease. Blood and marrow examination displayed some features consistent with a moderate dysmyelopoietic state. 18 months later an acute myeloblastic leukaemia confirmed the suspected haematological malignancy.

[Reaction of anti-I auto-antibodies with erythrocytes from the pig and monkey]. / Réactivité des auto-anticorps anti-I avec les hématies de porc et de singe.

Starting from 5 human sera containing anti-I cold autoagglutinins, it was possible, using adsorption/elution trials with pig's and rhesus monkey's RBC, to separate 8 anti-I antibodies because 3 of the initial sera were heterogeneous. Each of them had 2 anti-I different as regards the reactivity with the animal RBC and the anti-ID or the anti-IF reactivity. On the whole, among 8 separated fractions 1 reacted only on pig's RBC and had the characteristics of an anti-ID; 3 reacted only on rhesus monkey's RBC and were anti-IF; 4 had a cross-reactivity with pig's and monkey's RBC: 2 of them were anti-IF and 2 anti-ID. Anti-ID fixed preferably on pig's RBC and anti-IF on rhesus monkey's RBC but monkey's RBC are not entirely lacking in ID determinants and pig's RBC in IF determinants.

An anti-I cold auto-agglutinin enhanced in the presence of sodium azide.

Difficulty in determining the ABO blood group led to the discovery of an anti-I cold auto-agglutinin in the serum of a blood donor. The peculiarity of this antibody is that its activity is enhanced in the presence of a preservative found in manufactured anti-sera: sodium azide. At 4 degrees C, the auto-antibody agglutinates RBCs even without NaN3 but the drug increases its effect in the cold. At 22 degrees C, the drug is necessary for the adsorption of the antibody on red cells.

[Immunohematological study of 7 cases of acquired B transformation using anti-B and selected acquired anti-B]. / Etude immunohématologique de 7 transformations B acquis à l'aide d'anti-B et d'anti-B acquis sélectionnés.

Seven acquired B samples were studied with selected anti-B sera. Eight sera came from group A subjects, four from group O subjects. The anti-B sera reacting with the acquired B antigen are always a mixture of two kinds of antibodies: a fraction that is only reactive with B antigen, another that is cross-reactive with B and acquired B antigens. In some sera, especially those coming from group O subjects, there is, in addition, a potent antibody of polyagglutination for acquired B red cells. The polyagglutinability associated with acquired B red cells is analysed. According to the results obtained using lectins, four red cell samples are merely acquired B, the three others are acquired B + Tk. The polyagglutinability associated with Tk transformation is non sensitive to acetylation of red cells. The polyagglutinability specific for acquired B is sensitive to acetylation but appears complex in itself. According to the reactivity of selected sera for acquired B samples and the studies of inhibition with simple sugars, there are at least two antigens involved. One of them is present in all of the acquired B samples and it is likely to have arisen from the action of a deacetylase on a structure including N-acetylgalactosamine.

[Acquired B antigen: a new case]. / Antigène B acquis: une nouvelle observation.

A 86 year old woman, in good health but "Escherichia coli" urinary infection, was found to have an abnormality in blood group determination. 3 years ago, blood group of this patient was group A and now, precise determination shows the existence of an acquired B antigen. Disappearance of this acquired B Ag was obtained in 3 months after the urinary infection's treatment. The most cases of acquired B Ag result from neoplasic diseases or infection with enterobacteriacea. Physiopathology of acquired B Ag is secondary to the action of a deacetylase enzyme produced by enterobacteriacea, on group A1 erythrocytes.

[The use of an agglutination micromethod for erythrocyte phenotyping. Importance of improved blood transfusion safety]. / Application d'une micro-méthode d'agglutination au phénotypage érythrocytaire: intérêt pour une meilleure sécurité transfusionnelle.

The authors describe an easy, sensitive and inexpensive micromethod for red blood cell typing within the Rhesus, Kell and Lewis systems.