The impact of traumatic experience on attitude towards future in refugee adolescents.

Traumatic experience has overall far reaching consequences on personality. In particular, it has significant impact on teenagers that are just approaching the phase of solving their identity problems. This research examines the relation of traumatic experience and attitude towards the future in two groups of adolescents. The first group consists of 20 adolescents-refugees from the East Slavonia that were settled in Rijeka area with their parents during the last six years. The second group consists of 20 adolescent's local inhabitants that were influenced by the war only indirectly. Results show significant difference between refugees and non-refugees in expressed interpersonal trust, frustration tolerance, and formation of close contacts, adaptability, precaution, bitterness, and social desirability. Both groups show increased depression, pessimism and poor self-control. This might be considered as general characteristic of society in war.

Identification of a novel triterpenoid saponin from Pisum sativum as a specific inhibitor of the diguanylate cyclase of Acetobacter xylinum.

A specific and highly potent inhibitor of diguanylate cyclase, the key regulatory enzyme of the cellulose synthesizing apparatus in the bacterium Acetobacter xylinum, was isolated from extracts of etiolated pea shoots (Pisum sativum). The inhibitor has been purified by a multistep procedure, and sufficient amounts of highly purified compound (3-8 mg) for spectral analysis were obtained. The structure of this compound was established as 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1--> 2)-beta-D-glucuronopyranosyl soyasapogenol B 22-O-alpha-D-glucopyranoside. The structure was elucidated on the basis of susceptibility to various enzymes, chemical and spectral methods, such as GC-MS, FAB-MS, and the following types of 2D-NMR: COSY, ROESY, TOCSEY, HMQC, HMBC analyses. An identical or a very similar compound with identical biological activity was also isolated from A. xylinum, strongly suggesting that at least certain aspects of cellulose synthesis in the bacteria and in higher plants may be regulated in a similar manner. The content of this saponin in etiolated plants was about 0.04 mumol (g fresh tissue)-1.

Isolation of transferrin from porcine gastric mucosa: comparison with porcine serum transferrin.

1. An iron-binding glycoprotein has been purified to homogeneity from porcine gastric mucosa. 2. The molecular weight (80,000), amino acid composition, carbohydrate content, N-terminal amino acid sequence, tryptic map, stoichiometry of iron binding (2 mol/mol), visible absorption spectrum of the ferric complex and chromatographic behaviour of the gastric protein are all strikingly similar to the corresponding properties of porcine serum transferrin. 3. The quantity of the gastric protein (1.3 mg/g wet weight) present in the gastric mucosa suggests that it is not serum transferrin (plasma concentration 1.8 mg/ml) contaminating the tissue. 4. A role for transferrin in the uptake of dietary iron by the gastrointestinal tract is proposed.

Molecular basis of cell recognition during fertilization in higher plants.

The molecular basis of recognition between plant cells is incompletely understood. Some principles established for recognition between animal cells may well apply to plant cell recognition, although, in contrast to animal cells, plant cells are encased by cell walls that play an active role in plant cell-cell recognition. The interaction that controls fertilization in flowering plants involves recognition between pollen or pollen tubes and the female sexual tissues. In many flowering plant families, self-incompatibility (S) genes operate to prevent inbreeding. In plants that have gametophytically controlled self-incompatibility, recognition of common S alleles in pollen tube and style results in arrest of pollen tube growth within the style. Self-incompatibility therefore provides a model cell-cell recognition system that is genetically defined. We have taken two approaches to defining cell recognition involved in gametophytic self-incompatibility in Nicotianas alata. Firstly, we have established the major features of the pollen tube wall and the matrix of the style transmitting tissue that are in contact with the growing pollen tube. Secondly, we have established the nature of style glycoproteins that are associated with the S genotype and have initiated a program to clone the genes coding for the protein component of these glycoproteins. Analyses of the pollen tube are consistent with the major polymers being a (1----3)-beta-D-glucan (callose) and a (1----5)-alpha-L-arabinan. The pollen tube has two distinct layers: gold immunocytochemistry using a monoclonal antibody directed to terminal alpha-L-arabinosyl residues shows the binding is confined to the outer layers. The major component of the extracellular matrix of the style transmitting tissue is a family of proteoglycans, the arabinogalactan-proteins. A major glycoprotein that segregates with the S2 allele is present in extracts of mature styles. This component has a high pI (greater than 9.5) and an apparent molecular weight of 32 X 10(3). It is not present in extracts of immature styles of N. alata genotypes bearing the S2 allele, or in extracts from other organs of N. alata or styles of other members of the Solanaceae. The isolated glycoprotein is an effective inhibitor of in vitro pollen tube growth. This evidence suggests that the S2-associated glycoprotein is either the product of the S2 allele, or a gene closely associated with the S gene. We have prepared a cDNA library from styles of one genotype and are screening this library with mRNA from mature and immature styles.(ABSTRACT TRUNCATED AT 400 WORDS)