Bioactive Components of Sea Buckthorn <Emphasis Type="Italic">Hippophae rhamnoides</Emphasis> L. Foliage

The composition of lipophilic components of sea buckthorn leafy shoots, a large tonnage waste in the production of sea buckthorn oil and during renewing the cultural plantings of sea buckthorn, was studied. Hexane was used as an extraction solvent for raw materials; it provides a high degree of lipophilic component extraction and is an analogue of extraction gasoline used in the food and perfume industries. The chemical composition of the hexane extract of sea buckthorn leafy shoots was studied by gas chromatography–mass spectrometry and high-performance liquid chromatography. Sixty-seven neutral and twenty-nine acidic components, including polyprenols, dolichols, triterpene alcohols and acids, sterols, were identified. β-Sitosterol was the main component of the sterol fraction. Its content was 6.9% of the extract mass, which is much higher than in the essential extracts of leaves and pulp of sea buckthorn fruit. It is mostly found in the free form in the extract. The acidic fraction contains highly active triterpene acids (up to 5% of the extract mass) along with the major aliphatic acids. Components with the chain length of 11 and 17 isoprene units predominate in the fraction of polyprenols and dolichols (up to 4.2%). The results allow us to consider sea buckthorn leafy shoots as a promising source of biologically active compounds.     

Cathepsin <Emphasis Type="Italic">G</Emphasis> in the immune defense of the human duodenum: New sources for biosynthesis

Proteases play a key role in the physiological processes of the small intestine, supporting its normal physiological functions as a part of the digestive system, in which hydrolysis and assimilation of nutrients are implemented. A high concentration of antigens in the intestinal lumen activates immunity and stimulates a chronic weakly expressed inflammatory response in a normal gastrointestinal tract (GIT). Cathepsin G, a serine protease controlling the functional state of immune cells, directly participates in the complicated system for the regulation of balance between physiological and pathological inflammations. To determine the role of cathepsin G in the small intestine, an immunofluorescent investigation of biopsies from the human duodenal mucosa were investigated using the confocal immunofluorescence microscopy method and human antibodies to cathepsin G. It has been shown for the first time that cathepsin G, which was regarded conventionally as one of the effectors of the inflammatory process, is a constitutive enzyme of the human duodenum and is constantly present in its normal mucosa. The new cell sources for the cathepsin G biosynthesis identified: intraepithelial lymphocytes (IELs), lamina propria lymphocytes, ^CD14-positive intestinal macrophages, and Paneth cells, which are specialized epitheliocytes of intestinal glands. Our data on the cathepsin G expression by immunocytes and Paneth cells in the duodenum allow us to attribute cathepsin G to the main proteases of intestinal immunity, which indicates the important role of this enzyme in the regulation of human GIT functions.     

The Thermus thermophilus 5S rRNA-protein complex: Identifications of specific binding sites for proteins L5 and L18 in 5S rRNA

Three 5S rRNA-binding ribosomal proteins (L5, L18, TL5) of extremely thermophilic bacterium Thermus thermophilus have earlier been isolated. Structural analysis of their complexes with rRNA requires identification of their binding sites in the 5S rRNA. Previously, a TL5-binding site has been identified, a TL5-RNA complex crystallized, and its structure determined to 2.3 A. The sites for L5 and L18 were characterized, and two corresponding 5S rRNA fragments constructed. Of these, a 34-nt fragment specifically interacted with L5, and a 55-nt fragment interacted with L5, L18, and with both proteins. The 34-nt fragment-L5 complex was crystallized; the crystals are suitable for high-resolution X-ray analysis.     

Clinical and microbiological features of acute enteric mixed infection caused by Hafnia alvei and rotavirus

The data obtained in the clinical and laboratory study of 72 hospitalized patients with acute enteric infection are presented. The observed outbreak was caused by H. alvei producing heat-stable enterotoxin. The role of this etiological agent is also confirmed by simultaneous occurrence of the disease after using the same foodstuff, a short incubation period, the severity of the course of the disease with pronounced symptoms of neurotoxicosis, a high detection rate of H. alvei in material taken from patients at the acute period of the disease, rapid disappearance of this agent in the period of convalescence and a pronounced rise in the titer of specific antibodies to H. alvei in the dynamics of the disease. At the same time in the feces of 8 patients rotavirus antigen was detected, which, in combination with residual catarrhal phenomena, hyperemia and granularity of the pharynx, yellow stool, was indicative of the simultaneous circulation of rotavirus among these patients.     

Focused genetic recombination of bacteriophage t4 initiated by double-strand breaks

A model system for studying double-strand-break (DSB)-induced genetic recombination in vivo based on the ets1 segCDelta strain of bacteriophage T4 was developed. The ets1, a 66-bp DNA fragment of phage T2L containing the cleavage site for the T4 SegC site-specific endonuclease, was inserted into the proximal part of the T4 rIIB gene. Under segC(+) conditions, the ets1 behaves as a recombination hotspot. Crosses of the ets1 against rII markers located to the left and to the right of ets1 gave similar results, thus demonstrating the equal and symmetrical initiation of recombination by either part of the broken chromosome. Frequency/distance relationships were studied in a series of two- and three-factor crosses with other rIIB and rIIA mutants (all segC(+)) separated from ets1 by 12-2100 bp. The observed relationships were readily interpretable in terms of the modified splice/patch coupling model. The advantages of this localized or focused recombination over that distributed along the chromosome, as a model for studying the recombination-replication pathway in T4 in vivo, are discussed.     

The properties of the cellular surface of Yersinia pestis strain EV and its achromogenic variants

The comparative study of the properties of the surface of vaccine strain Y. pestis EV and its achromogenic variants (AV) differing from the initial strain by decreased immunogenicity and by the morphology of colonies, has been made. The achromogenicity of Y. pestis colonies has been shown to correlate with the loss of the outer membrane protein with a molecular weight 22 kD. The synthesis of this protein is determined by chromosomal genes. AV have been found to have different sensitivity to bacteriophages. The analysis of the electrokinetic potential of Y. pestis EV and its AV has revealed that in the latter have surface charge is considerably greater (1.4- to 1.5-fold). As shown in this study, the hemagglutinating activity of AV with respect to red blood cells of humans with blood group I (O) and guinea pigs is decreased by 1-2 orders and these strains do not agglutinate with sheep red blood cells. The low activity of the initial stage of the phagocytosis of AV by mouse macrophages has been shown. The possible role of the 22 kD proteins as an adhesion factor is discussed.     

Identification of structural DNA variations in human cell cultures after long-term passage

Random amplified polymorphic DNA (RAPD) analysis was adapted for genomic identification of cell cultures and evaluation of DNA stability in cells of different origin at different culture passages. DNA stability was observed in cultures after no more than 5 passages. Adipose-derived stromal cells demonstrated increased DNA instability. RAPD fragments from different cell lines after different number of passages were cloned and sequenced. The chromosomal localization of these fragments was identified and single-nucleotide variations in RAPD fragments isolated from cell lines after 8–12 passages were revealed. Some of them had permanent localization, while most variations demonstrated random distribution and can be considered as de novo mutations.     

Changes in the fluorescence of chlorophyll alpha and beta-carotene under the action of hydrogen peroxide

Changes in the fluorescence of beta-carotene and chlorophyll a and their mixtures in different molar ratios under the action of hydrogen peroxide have been registered in two cases: (1) in Langmuir films and (2) in a complex with bovine serum albumin in water solution. Changes in the fluorescence of Langmuir-Shaefer films of Zn ethioporphyrine II under the action of hydrogen peroxide in different molar ratios have also been shown. No shifts of pigment band maxima have been registered.     

Situation of mycotoxins in milk, dairy products and human milk in Egypt

Abstact  Milk and dairy products purchased at Egyptian markets and breast milk from lactating mothers in Cairo and Giza governorates were analyzed for some mycotoxins. Three of 15 cows’ milk samples were found positive for Afl. M₁ with mean value 6.3 ppb. Only one sample of dried milk was positive (5 ppb). Two of 10 hard cheese samples contained detectable levels of Afl. M₁ (3and 6 ppb), whereas one sample containing Afl. B₁ and G₁ (10 and 4 ppb resp.). For soft cheese one sample of 10 was positive for Afl. M₁ (0.5 ppb). Blue veined cheeses were free of Afl. M₁ and PR-toxins. For breast milk two of 10 samples were positive for Afl. M₁ (20%) with mean value 2.75 ppb, while 3 of 10 samples were positive for Ochratoxin A (30 %).