A recessive mutation leading to vertebral ankylosis in zebrafish is associated with amino acid alterations in the homologue of the human membrane-associated guanylate kinase DLG3.

We describe the characterization of the zebrafish homologue of the human gene DLG3. The zebrafish dlg3 gene encodes a membrane-associated guanylate kinase containing a single PDZ domain. This gene was cloned using a gene-trap construct inserted in the gene's first intron. The insertion co-segregates with a viable mutation called humpback (hmp), which leads to formation of ankylotic vertebrae in adult fishes. Insertion and mutation have both been mapped to chromosome 12, in a segment which is syntenic with region p12 to q12 of human chromosome 17. The hmp mutant phenotype, however, appears to be due to two point mutations in the guanylate kinase domain rather than to the transgene insertion itself. The results of this study are discussed in the light of the possible function of the guanylate kinase domain.     

Actin participates in the structure of liver intermediate filaments

A dominating protein fraction (p45) having molecular weight of 45000 and pI 5.45 was found in the intermediate filaments pellet obtained from rat liver besides the present cytokeratins. Peptide mapping and radioimmunological assays with antibodies against this protein and muscle actin proved that the p45 protein belongs to the actin group. Immunoelectron microscopy revealed that this protein is located on the liver intermediate filaments. By melting of the cytokeratin complexes in urea it was established that p45 protein is complexed with the low molecular weight cytokeratin.     

Selection of HLA compatible donors for patients with HLA antibodies

A strain of 1,507 typised donors enables 15.97 average donors to be selected for a thrombocyte transfusion in one of 75 patients selected at random with HLA antibodies being previously determined (1 to 66 donors per patient). HLA compatible donors were found for 72 patients (97.33 per cent). More than 5 HLA compatible donors could be found for 58 patients. The high number of compatible donors is based on the fact that among 1,507 donors there were 156 HLA homozygotes and 556 donors with 3 HLA-A or B-antigens respectively. Compatibility in the ABO-system was not taken into account.     

PHYLOGENETIC ANALYSIS OF THE MALE ONTOGENETIC PROGRAM IN AQUATIC AND TERRESTRIAL MONOCOTYLEDONS

The male program of ontogeny in flowering plants encompasses the events from meiosis of microsporocytes to fertilization. Three main sequences are discussed; the deposition of cell walls, changes in cytoplasmic organelles, and the program of nuclear divisions leading to the formation of two sperm cells and a vegetative cell in each pollen grain. Variations in these ontogenetic sequences are particularly apparent in the monocotyledons, which exhibit diversity in pollen morphology, wall structure, and mode of pollination. The male program of development has been compared in selected terrestrial monocotyledons belonging to the Liliaceae and Gramineae and aquatic members of the Cymodoceaceae, Najadaceae, and Zannichelliaceae. A total of 26 characters from the male program are discussed and then used to construct a cladogram derived only from developmental data for the five species. The polarity of only a few of the character transformations has been determined directly by observation of developmental sequences; most have been interpreted by outgroup analysis.     

Synthesis of intrathecal interferon in systemic lupus erythematosus with neurological complications.

Intrathecal synthesis of interferon in the absence of viral or bacterial infection was detected during the occurrence of neurological complications in two patients with systemic lupus erythematosus. The interferons displayed characteristics similar to those observed in the sera of patients with the disease. No interferon inducing activity was detected in the cerebrospinal fluid or serum of the two patients. These observations support the hypothesis of a localised mechanism of interferon induction in systemic lupus erythematosus which includes the interaction of lymphocytes with damaged tissues.     

The development of anoxia following occlusion

Following arteriolar occlusion, tissue oxygen concentration decreases and anoxic tissue eventually develops. Although anoxia first appears in the region most distal to the capillary at the venous end, it eventually spreads throughout the entire region of supply. In this paper the changing oxygen concentration, from the time of occlusion until the tissue is entirely anoxic, is examined mathematically. The equations governing oxygen transport to tissue are solved by iterating a nonlinear integral equation. This solution is valid until anoxia first appears. After anoxia develops it is necessary to solve a moving boundary problem. This is done using the method of matched asymptotic expansions, and accurate solutions are obtained for a wide range of physiological conditions.