Immunocytochemical analysis of apoprotein E distribution in human tissues

Localization of apoprotein E (apo E) has been studied in different human tissues. For this aim the immunoperoxidase method and peroxidase-antiperoxidase complex, polyclonal and monoclonal antibodies, to apo E have been used. In every human tissue analysed apo E-containing cells have been revealed. To the latter the following cell types belong: hepatocytes and hepatic sinusoidal cells, macrophages of the spleen, lymph nodes and pulmonary tissues, glial cells and cells in all layers of the adrenals, skin keratinocytes, cells of the glomerular capsule and convoluted tubules of the kidney, spermatocytes and smooth muscle cells of the testis. Besides, apo E is revealed in endothelium of some vessels. As demonstrate the results obtained, apo E is found practically in all human tissues. A suggestion is made that besides its participation in reverse cholesterol transport, this protein performs a number of additional functions, such as regulation of local hormonal homeostasis of an organ.     

The sym plasmid pRP2JI and at least two other loci of Rhizobium leguminosarum biovar phaseoli can confer resistance to infection by the virulent bacteriophage RL38

Abstract The virulent Rhizobium bacteriophage RL38 did not form plaques on R.leguminosarum by phaseoli but did so at high efficiency on a derivative of that strain lacking its symbiotic plasmid pRP2JI. Other strains with large deletions in pRP2JI which removed many nod and nif genes retained resistance to RL38, showing that the gene which confers phage resistance lies elsewhere on the plasmid. Although the wild-type strain of R. leguminosarum bv. phaseoli failed to plate RL38, it was possible to transduce chromosomal markers into this strain, indicating that the 'block' was not at an early stage in the infection process. Two different recombinant plasmids obtained from a clone bank of genomic DNA of R. leguminosarum bv. phaseoli , which appeared to have no DNA in common, both conferred resistance to RL38. Surprisingly, the DNA cloned in each of these plasmids did not originate from pRP2JI. Therefore, several different loci both on the Sym plasmid and elsewhere on the bacterial genome can be involved in conferring resistance to this bacteriophage.     

The immunoassay of gibberellins

The development of sensitive and specific solid-phase enzyme immunoassays for gibberellic acid and gibberellins A₄ and A₇ is reported. The use of antisera of high apparent affinity (K_a over 10¹⁰ l mol^-1) in conjunction with alkaline phosphatase-labeled gibberellins allows, with minimum procedural effort, the quantitative determination of sub-picogram amounts of these gibberellins. The assays reported here are applicable to most gibberellins and can be set up with 1–1.5 mg of starting material. They represent the most sensitive methods for gibberellin determination known.Abbreviations GA gibberellin - GA₃ gibberellic acid - TLC thin-layer-chromatography     

Generic distribution patterns in subsaharan African Rubiaceae (Angiospermae)

A survey of the distribution of the Rubiaceae from subsaharan African (continental part: 1,900 species in 164 genera; Madagascar: 675 species in 83 genera) is given. Genera are classified in nine major distribution patterns, most of which are further subdivided. General statistics of the data are given, and the patterns are discussed in the light of (i) the phytogeographical literature relating to tropical Africa and (ii) existing evolutionary hypotheses on the Rubiaceae.