Immunogenetic aspects of allotransplantation

It now appears unequivocal that three markers exist in a linkage group in chromosome 6 of man: HLA-A, HLA-B and PGM3 (Fig. 1.) Tentatively, two other HLA loci and one Ir gene have been mapped close to HLA-B. The probable map order is HLA-A - HLA-C - HLA-B - HLA-D - Ir. The biological functions of these loci are unknown. However, HLA-A, B and C are important in allograft rejection. Other closely linked loci (HDR, CML) appear to be important in the first events of the allograft rejection (first set) and in generation of killer cells. HLA-D might be important in cellular recognition and graft-versus-host reactions (matching at HLA-D decreases the incidence and severity of graft-versus-host disease), and the Ir genes in the defense against infections. HLA-B and HLA-D loci are important markers in studies of disease susceptibility. HLA-B locus antigens HLA-B27 and HLA-B8 are frequently associated with arthritic or autoimmune disorders. HLA-D determinants have been found in association with multiple sclerosis and C2 deficiency (HLA-DW2); juvenile diabetes and Addison's disease (HLA-DW3) and adult type of rheumatoid arthritis (HLA-DW4).

Light dependent promotion and inhibition of adventitious root formation by gibberellic acid

Cuttings from plants of Pisum sativum L. cv. "Alaska" which had been grown at an irradiance of 16 W m(-2) formed a higher number of roots than cuttings from plants grown at 38 W m(-2). (Irradiance during the rooting period always 16 W m(-2).) High concentrations of gibberellic acid (GA3) inhibited rooting in cuttings from both types of stock plants. Low concentrations (10(-9)-10(-6) M) of GA3 were without effect in cuttings from plants irradiated with 38 W m(-2), but promoted rooting when the stock plants had been grown at 16 W m(-2).

Beryllium mineralization in the Ilímaussaq intrusion, South Greenland

In the peralkaline Ilimaussaq intrusion in South Greenland minor quantities of beryllium minerals are widespread in hydrothermal veins. Concentrations of veins rich in beryllium minerals are known from the Taseq slope and the Kvanefjeld area in the northern part of the intrusion. Up to now 10 beryllium minerals have been found, the most important being chkalovite. The hydrothermal veins range in width from about 1 mm to 2 m but are mostly a few cm thick. The most important minerals in the veins are analcime, sodalite, ussingite, natrolite, aegirine, arfvedsonite, epistolite and chkalovite. A field beryllometer based on the photoneutron method of determining beryllium is described. With a 100 mCi Sb124 activation source the instrument has a limit of detection ofless than 10 ppm BeO. The effective measuring area is ca. 40 cm2. Beryllium has a log-normal distribution in the rocks of the area.