Identification of HLA-B44 subtypes associated with extended MHC haplotypes

The HLA class I antigen B44 is found in each of two different extended major histocompatibility haplotypes (allele combinations of HLA-B, HLA-DR, and complement genes BF, C2, C4A, and C4B in linkage disequilibrium). Using isoelectric focusing, two variants of HLA-B44 were identified. The basic variant was found in all cell lines with the extended haplotype HLA-B44, DR7, FC31, and the acidic variant in all cell lines with the extended haplotype HLA-B44, DR4, SC30. The occurrence of each antigen variant with a unique extended haplotype explains previous observations concerning the nonrandom association of B44 variants with DR antigens.     

Electro-insertion of xeno-glycophorin into the red blood cell membrane

The electroporation technique, with field strengths slightly below the critical value Ec for electroporation of red blood cells (RBC), enables the insertion of xeno-proteins into the RBC membrane without damaging the cells. The electro-insertion has been used to insert biotinylated human glycophorin into human RBC membrane and human glycophorin into murine RBC membrane. Binding anti-human glycophorin antibody (10F7) to the murine RBC bearing human glycophorin indicates extracellular orientation of inserted glycophorin. Insertion of about 10(5) glycophorin molecule per cell has been estimated by whole cell ELISA.     

Association of polymorphisms in the HLA-B region with extended haplotypes

Genomic probes from the HLA-B region of the major histocompatibility complex (MHC) were used to study the association of restriction fragment length polymorphisms (RFLPs) with various MHC alleles, complotypes, and extended haplotypes. The two DNA probes, M20A and R5A, were derived from previously cloned cosmids and are located 38 and 110 kilobases (kb) centromeric to HLa-B, respectively. Five different RFLP variants occuring in five different haplotypic combinations were detected within a panel of 40 homozygous-typing cells and cells from 21 families using Bst EII. In two informative families with HLA-B/DR recombinations the inheritance of the RFLP variants was consistent with their mapping between HLA-B and complotypes. The R5A/M20A haplotypic pattern 6.5 kb/3.0 kb (A) had a normal Caucasian frequency of approximately 0.43 and was found in all independent examples of the extended haplotypes [HLA-B8,SC01,DR3], [HLA-B18,F1C30, DR3], [HLa-Bw62,SC33,Dr4], [HLa-B44,SC30,Dr4], and [HLA-Bw47,FC91,0DR7]. The patterns of 6.9 kb/ 3.0 kb (B), 6.5 kb/4.7 kb (C), 1.45 kb/3.0 kb (D), and 6.9 kb/4.7 kb (E) had normal Caucasian frequencies of approximately 0.23, 0.15, 0.15, and 0.04 and were found on all independent examples of [HLA-B38,SC21, DR4], [HLA-Bw57,SC61,DR7], [HLA-B7,SC31,DR2], and [HLA-B44,FC31,DR7], respectively. Individual complotypes or HLA-B alleles which were markers of extended haplotypes showed variable associations. For example, HLA-B7 and the complotype SC31 were associated with all R5A/M20A RFLP haplotypes except haplotype E, although [HLA-B7,SC31,DR7] was associated exclusively with haplotype D. HLA-B27, not known to be part of an extended haplotype, was suprisingly exclusively associated with the 6.5 kb/4.7 kb or C haplotypic pattern in all five instances tested. These findings support the concept of regional conservation of DNA on independent examples of extended haplotypes. The results also further characterize these haplotypes.     

Metabolism of viprostol — A synthetic vasolidator PGE2 analog

Metabolic studies were done with ¹⁴C-Viprostol (I) administered by various routes (I.V., oral and topical) to six animal species and to man. Total radioactivity and metabolic profiles were analyzed in plasma, tissues and excreta. The main metabolites were isolated and identified by capillary GC/MS.Plasma and urinary metabolic profiles were qualitatively similar across species, with two major metabolic reactions being predominant: rapid hydrolysis to the pharmacologically active free acid (II)_ and oxidation of the alpha-chain to dinor and tetranor acids (III, IV). In the monkey and man, reduction of the 9-keto group lead to PGF₂ type metabolites (VI–VIII). In the rat, omega oxidation of the beta-chain occurred as well, resulting in the formation of dicarboxylic acids (V).     

Somatic embryogenesis and plant regeneration in Cichorium intybus L. (Witloof,Compositae)

Somatic embryogenesis of Cichorium intybus L. var. Carolus is induced using cubical pieces of mature tap roots with an intervening callus phase. A Murashige and Skoog's (MS) semi solid basal medium supplemented with 2,4-dichlorophenoxyacetic acid (0.02 or 0.2 mg/l) and benzylaminopurine (0.25 mg/l) and a liquid MS medium devoid of growth regulators are used respectively for induction of callus and somatic embryoids and for further development and germination. Regeneration from the nodular proembryonal stage to the full grown embryoids occurs following different morphological pathways depending on the physical and chemical environment of the culture. Further development of these embryos into plantlets and the possibilities of application of this technique in plantbreeding have been discussed.Abbreviations MS Murashige and Skoog medium - BAP benzylaminopurine - 2,4-D 2,4-dichlorophenoxyacetic acid     

Production of auto-anti-idiotypic antibody during the normal immune response: IX. Characteristics of the auto-anti-idiotype antibody and its production

Using hapten-reversible inhibition of plaque formation as an assay for auto-anti-idiotype antibody (anti-Id) and as a means for following idiotype (Id) expression, we have obtained evidence that following immunization with trinitrophenyl (TNP) conjugates (a) there are differences in Id expression in the anti-TNP antibody response to different TNP conjugates although there is some overlap; (b) different strains, although showing some differences in Id expression, tend to produce cross-reactive Ids, thus no obvious allotype linked inheritance of Id expression is observed in this heterogeneous immune response; (c) the auto-anti-Id produced following immunization with TNP-Brucella abortus or TNP-Ficoll tends to be of the IgG_2a and IgG_2b isotypes.