SCENEDESMUS WALL ORNAMENTATION. I. SCENEDESMUS PARISIENSIS CULTURES1

Four strains of Scenedesmus parisiensis Chodat were studied in xenic and axenic culture in 3 media as well as in cultures incubated in sterile vessels in nature. Organized coenobia are usually produced but these may have merely short spines, spines and serrate edges, or lack wall ornamentation. Because the serrate edge is either not formed or cannot be readily detected in most cases, it is not a satisfactory morphological feature for delimiting this species. In laboratory studies it is noted that S. parisiensis might be confused with S. denticulatus rather than S. brasilien-sis. Inasmuch as both xenic and axenic cultures of the -f strains produced similar results, S. parisiensis can be readily characterized.     

Immunotoxins up to the present day

Immunotoxins consist of monoclonal or polyclonal antibodies conjugated to bacterial or plant toxins. The toxins used are typically of the A-B type in which a toxic A chain is coupled to a B chain responsible for cell binding and facilitation of A chain entry into the cytosol. Two broad strategies have been followed: coupling intact toxins, or A chains alone, to antibodies. This review examines current progress inin vitro andin vivo research, including recent clinical studies, concentrating principally on ricin or ricin A chain conjugates. The future role of conjugates using membrane-acting toxins, immunolysins, is also discussed.     

Cloning and expression of alpha-amylase from Bacillus amyloliquefaciens in a stable plasmid vector in Lactobacillus plantarum

Lactobacillus plantarum is used in a wide range of agricultural and food fermentations. In this paper we report the introduction of alpha-amylase into the organism from Bacillus amyloliquefaciens on a stable recombinant plasmid. The genetically manipulated organism grew on MRSB medium supplemented with starch and it may be a prototype for the development of lactobacilli able to use an increased range of substrates in commercial fermentations.     

The evolution of human chromosome 21: evidence from in situ hybridization in marsupials and a monotreme.

We have mapped five human chromosome 21 (HSA 21) markers in marsupials and a monotreme, two major groups of mammals that diverged from eutherians 130-150 and 150-170 million years before present (MYrBP), respectively. We have found that these genes map to two distinct autosomal sites, one containing SOD1/CBR/BCEI and the other containing ETS2/INFAR, in the marsupials Macropus eugenii and Sminthopsis macroura (which belong to orders that diverged 40-80 MYrBP), as well as in the monotreme Ornithorhynchus anatinus (the platypus). Since marsupials and monotremes diverged independently from eutherians, these data suggest that HSA 21 genes were originally located in two separate autosomal blocks. In another Sminthopsis species, SOD1 is linked to TRF (a marker on HSA 3q), suggesting that the ancestral SOD1/CBR/BCEI region also included HSA 3 markers. We suggest that these blocks became fused early in the eutherian evolution to form a HSA 3/21 chromosome, which has remained intact in artiodactyls, but has been independently disrupted in both the primate and rodent lineages.     

Vitamin A effects on UMR 106 osteosarcoma cells are not mediated by specific cytosolic receptors.

Retinol and retinoic acid at 20 microM altered cell morphology and inhibited cell proliferation of UMR 106 osteosarcoma cells in culture. No specific cytosolic binding proteins for retinol could be detected.     

The Mechanism of Microbiological Leaker Spoilage of Canned Foods: A Review

S ummary : This review summarizes the work on the subject carried out mainly in the authors'laboratories but also in the associated laboratories of Metal Box Co. Ltd., London, and Plat Manufaktor, Malmö, Sweden. Special attention is paid to the mechanism of bacterial reinfection and how it is influenced by deviations in can construction or can handling procedures. Methods of preventing bacterial reinfection at the most critical points in the canning operation are considered and certain guiding principles are derived.     

THE INTRACELLULAR LOCALIZATION OF PITUITARY THYROTROPIC HORMONE

The intracellular localization of a bovine anterior pituitary preparation of thyroid-stimulating hormone (TSH) was studied in guinea pigs and dogs. The preparation was administered intravascularly or applied directly to tissue sections. TSH was detected by an indirect technique utilizing bovine TSH antiserum and fluorescein-labeled anti-rabbit globulin; the presence of TSH in the tissue was indicated by fluorescence when the tissue was examined under the microscope with an ultraviolet light source. After either intravascular administration or direct application of the TSH preparation, striking fluorescence was found in the nuclei of the thyroid cells and to a lesser degree in the nuclei of retro-orbital fat tissue and kidney tubules in both species studied. A little fluorescence was also seen in spleen tissue. No fluorescence was noted in comparable tissues removed from control animals injected with bovine albumin or globulin or when the tissues were treated with the fluorescein-labeled globulin alone. Fluorescence was also noted in the nuclei of adrenal cells treated with unabsorbed antiserum, but this was greatly diminished when antiserum absorbed with crystalline ACTH was used. The positive reactions were all markedly decreased when the tissues were treated with antisera absorbed with the original TSH preparation. Fluorescence was noted in the cytoplasm of pituitary tissue from both treated and control animals, suggesting a cross-reaction between the bovine pituitary antisera and guinea pig or dog hypophysis. The indirect technique seems to be highly satisfactory for demonstration of the pitiutary hormone within the cell. In addition, the demonstration of immunologically active anterior pituitary TSH bound to cell nuclei offers a clue to the site of action of this hormone.