Plantlet regeneration via somatic embryogenesis in anther callus of Vitis latifolia L.

Anthers of Vitis latifolia L. (wild grape) cultured on Nitsch and Nitsch medium supplemented with 20 μM 2,4-D and 9 μM BAP produced callus after 4–6 weeks. Subculture of callus onto Nitsch and Nitsch medium containing 10 μM NAA produced somatic embryos within 6 weeks. On growth regulator-free Nitsch and Nitsch basal medium somatic embryos converted to plantlets in 6–8 weeks. One gram of callus produced more than 400 somatic embryos with 13.7% being converted to complete plantlets, which were subsequently established in soil. Regenerated plants were found to have mixoploid populations of cells, 2n = 38 and n = 19. Received: 23 May 1998 / Revision received: 21 September 1998 / Accepted: 10 October 1998     

Extracellular secretion of levansucrase from Zymomonas mobilis in Escherichia coli

Secretion of levansucrase from Zymomonas mobilis in Escherichiacoli by glycine supplement was investigated. A significant amount of levansucrase (about 25% of total activity) was found in intact whole-cells. Cell fractionation experiments showed that levansucrase was found both in the periplasmic space and in the cytoplasmic fraction of E. coli. None or only trace amounts of levansucrase was detected in the extracellular culture broth at 24 h of cultivation and it accrued with the increasing concentration of glycine in the culture medium and duration of the culture period. Optimal glycine concentration for the maximum secretion of levansucrase was in the range of 0.8-1%, in which approximately 20-50% of levansucrase was released into the extracellular fraction at 24 h of cultivation, although glycine retarded the bacterial growth.     

Method of sampling chorionic villi in first trimester of pregnancy under guidance of real time ultrasound.

Samples of chorionic villi were obtained in the first trimester by aspiration using a cannula passed transcervically under the guidance of real time ultrasound. In initial studies in 47 anaesthetised patients immediately before therapeutic abortion a method was developed giving a success rate of 89%. In 10 patients successful sampling was performed as an outpatient procedure without anaesthesia. In all, seven diagnostic procedures were undertaken and four of the five unaffected pregnancies continued. The technique of chorionic villous sampling using real time ultrasound is simple to learn and yields material for biochemical analysis and chromosomal study without the need for tissue culture. The exact obstetric risk, however, remains to be defined.     

Lymphocyte-mediated modulation of the functional activity of macrophages by individual antigenic complexes of Trichophyton cells

The capacity of antigenic complexes of the causative agent of zoo- and anthroponotic trichophytosis for inducing the factors, that modify the functional activity of macrophages, in mice and in spleen cell cultures has been studied. These complexes are capable of inducing the T-lymphocyte-mediated suppression and of stimulating the fungicidal activity (and oxygen-dependent metabolism) of phagocytes. The production of fungicidal activity suppressing lymphokines is linked with the presence of alkali-insoluble components of fungal cell walls and cytoplasmic antigens (the latter appear only in interactions of antigens with the lymphocytes of immunized animals) in the above-mentioned complexes.     

HDL-induced cardiac prostacyclin synthesis: relative contribution of HDL apoprotein and lipid

The objective of this study was to determine if the apoprotein or lipid constituents of high density lipoproteins (HDL) mediate HDL-induced prostacyclin synthesis in the Langendorff-perfused rabbit heart. Acetylation, acetoacetylation, or partial removal by trypsin digestion of HDL apoprotein did not reduce the ability of the lipoprotein to stimulate cardiac prostacyclin synthesis. Delipidated apoproteins were less effective in stimulating cardiac prostacyclin synthesis in comparison to intact HDL. In contrast, protein-free lipid vesicles, made from HDL lipids, caused a pronounced stimulation of cardiac prostacyclin synthesis. These results suggest that HDL apoproteins, in their native state, are not essential for HDL-induced cardiac prostacyclin synthesis. The stimulation of cardiac prostacyclin synthesis by HDL may depend on the lipoprotein's lipid rather than on its apoprotein constituents.     

Routine smoking cessation intervention in health care systems.

Everyone agrees that insurance for long-term care is inadequate in the United States. Disagreement exists, however, on whether such insurance should be provided through the private or public sector. Private insurance generally uses the experience-rating principle that persons with higher risk of illness are charged higher premiums. For private insurance for long-term care, this principle creates a dilemma. Most policies will be purchased by the elderly; yet, because the elderly have a high risk of needing long-term care, only about 20% of them can afford the cost of premiums. A public-private partnership by which the government partially subsidizes private long-term-care insurance is unlikely to resolve this dilemma. Only a social insurance program for long-term care can provide universal, affordable, and equitable coverage.     

The distribution of carbohydrate side chains along the polypeptide chain of glucoamylase

Glucoamylase is a starch-hydrolyzing enzyme with a glycoprotein structure, used industrially for the conversion of starch to glucose, citric acid, corn syrups, and high-fructose sweeteners. This enzyme possesses an unusual type of structure in which many carbohydrate side chains are linked O-glycosidically to serine and threonine residues of the polypeptide chain. The carbohydrate side chains may be single monosaccharide residues or oligosaccharides of mannose, glucose, galactose, and in some cases N-acetylglucosamine. New data from experiments on the CNBr fragmentation of glucoamylase followed by chemical and immunological characterization of the fragments show that the carbohydrate side chains are distributed randomly along the polypeptide chain. Such a structure is appropriately termed a random model reprensentation for the glucoamylase molecule.     

A composite transposon 3'' to the cow fetal globin gene binds a sequence specific factor.

Two unusual sequence organizations were found within the beta-globin locus of the cow. Each was a composite, consisting of closely linked Alu-type repeats with a short stretch of genomic non-repetitive sequence, called a lagan, sandwiched between. One lagan was found 3' to the fetal globin gene, while the second lay between the adult globin gene and a globin pseudogene. Southern blot analysis indicated that both lagans appeared twice within the cow haploid genome, with the second copies lying outside the cow beta-globin locus. One of these non-globin locus homologues was cloned and subjected to sequence analysis. Comparison of the DNA sequence data showed that the lagan-Alu composite was transposed as a unit. The lagan 3' to the cow fetal globin gene contains the recognition site for a sequence specific DNA binding factor. This factor was present in extracts from fetal, but not from adult cow tissues.