Glutamine synthetase content and immunochemical analysis of different strains of Bordetella pertussis

In this investigation 3 groups of strains isolated from pertussis patients have been studied: typical (group 1), atypical in their cultural properties (group 2), unidentified Gram-negative bacilli agglutinated by pertussis and parapertussis antitoxins (group 3). Besides, B. pertussis cultures, obtained by subculturing 2 museum strains and 2 newly isolated strains on synthetic casein-charcoal agar with subinhibiting doses of antibiotics or specific immune sera added, have been studied. As indicated by the results of this study, strains belonging to groups 1 and 2 contain glutamine synthetase, while in strains of group 3 this enzyme is absent. In immunoelectrophoresis strains of group 3 have been found to contain not a single antigen similar to the antigens of strains belonging to groups 1 and 2. Electrophoresis in polyacrylamide gel has revealed to differences in the protein spectrum of the strains of these 3 groups. The investigation has shown that the determination of glutamine synthetase and immunoelectrophoresis can be used for the differentiation of B. pertussis from similar Gram-negative bacilli. B. pertussis strains, changed as the result of experiments with antibiotics and specific immune sera, have also been shown to retain their antigenic composition and protein spectrum and to have no essential difference in the content of glutamine synthetase.     

Proteomic analysis of human placental syncytiotrophoblast microvesicles in preeclampsia

Background

Placental syncytiotrophoblast microvesicles (STBM) are shed into the maternal circulation during normal pregnancy. STBM circulate in significantly increased amounts in preeclampsia (PE) and are considered to be among contributors to the exaggerated proinflammatory, procoagulant state of PE. However, protein composition of STBM in normal pregnancy and PE remains unknown. We therefore sought to determine the protein components of STBM and whether STBM protein expressions differ in preeclamptic and normal pregnancies.Patients with PE (n = 3) and normal pregnant controls (n = 6) were recruited. STBM were prepared from placental explant culture supernatant. STBM proteins were analyzed by a combination of 1D Gel-LC-MS/MS. Protein expressions levels were quantified using spectral counts and validated by immunohistochemistry.

Results

Over 400 proteins were identified in the STBM samples. Among these, 25 proteins were found to be differentially expressed in preeclampsia compared to healthy pregnant controls, including integrins, annexins and histones.

Conclusion

STBM proteins include those that are implicated in immune response, coagulation, oxidative stress, apoptosis as well as lipid metabolism pathways. Differential protein expressions of STBM suggest their pathophysiological relevance in PE.

Electronic supplementary material

The online version of this article (doi:10.1186/1559-0275-11-40) contains supplementary material, which is available to authorized users.     

Abnormal development of gonads of dwarf females and low survival of their offspring as the cause of rarity of resident populations of atlantic salmon (Salmo salar L.)

Fecundity and mass of egg, as well as survival of offspring, of hatchery-reared small (less than 406 g) females of Atlantic salmon are determined. The absolute fecundity and mass of egg of artificially reared fish are sufficiently less than that of anadromous spawners. Small females are characterized by delayed spawning; histological analysis has demonstrated significant asynchrony in oocyte development of some specimens. Survival of offspring of dwarf females at the early stages of development is lower than of anadromous females. Our results agree completely with the published data. It is suggested that dwarf females are not able to withstand intraspecific and interspecific competition because of low reproductive ability. This explains rarity of natural populations of dwarf (landlocked) forms of Atlantic salmon.     

Exogenous brassinosteroids activate cytokinin signalling pathway gene expression in transgenic Arabidopsis thaliana

Transgenic Arabidopsis thaliana plants carrying the GUS reporter gene fused to the promoter of the gene of primary response to cytokinins (CKs), ARR5, were used to estimate the influence of several brassinosteroids (BRs): brassinolide (BL), epibrassinolide (EBL), homobrassinolide (HBL), and 6-o-carboxymethyloxohomocastasterone (CHC) on the expression of CK signalling genes. BRs tested differed in their ability to activate the ARR5 gene promoter in 4-day-old seedlings and 3-week-old plants. BL caused the most prominent effect, yet it was considerably less than that of 6-benzylaminopurine (BA). An increase in GUS activity was observed in both dark and light conditions; however, the rate of elevation was higher in dark conditions. The activation of the P _ARR5 :GUS fusion was accompanied by a moderate induction of the P _AHK :GUS constructs, in which the reporter GUS gene was fused to the promoter of one of the CK receptor histidine kinases. The effects of BL on the AHK gene promoters were organ specific and correlated with the ability of a particular AHK gene to respond to BA treatment. BL activated the AHK3 promoter in 4-day-old seedlings and in shoots and roots of 3-week-old plants without any effect in detached leaves. The AHK2 gene promoter was activated by BA and BL only in seedlings, whereas the AHK4 gene promoter was activated only in roots. BL treatment caused the coordinate elevation of the CK levels in leaves to the same degree as the activation of the P _AHK :GUS construct, suggesting that the accumulation of CKs was the reason for the activation by BRs of the CK signalling genes. The data obtained provide the evidence for the involvement of BRs in the regulation of the genes of the CK signalling pathway through an increase in the CK levels. However, the exact molecular mechanisms underlying BR-induced elevation of the CK content are unclear and warrant identification in the future.     

Transport of large organic ions through syringomycin channels in the membranes containing dipole modifiers

The effect of the membrane dipole potential (Phid) on a conductance and a steady-state number of functioning channels formed by cyclic lipodepsipeptide syringomycin E (SRE) in bilayer lipid membranes made from phosphocholine and bathed in 0.4 M solution of sodium salts of aspartate, gluconate and chloride was shown. The magnitude of Phid was varied with the introduction to membrane bathing solutions of phloretin, which reduces the Phid, and RH 421, increasing the Phid. It was established that in all studied systems the increase in the membrane dipole potential cause a decrease in the steady-state number of open channels. In the systems containing sodium salts of aspartate (Asp) or gluconate (Glc), changes in the number of functioning channels are in an order of magnitude smaller than in systems containing sodium chloride. At the same time, the conductance (g) of single SRE-channels on the membranes bathed in NaCI solution increases with the increase in Phid, and in the systems containing NaAsp or NaGlc the conductance of single channels does not depend on the Phid. The latter is due to the lack of cation/anion selectivity of the SRE-channels in these systems. The different channel-forming activity of SRE in the experimental systems is defined by the gating charge of the channel and the partition coefficient of the dipole modifiers between the lipid and aqueous phases.     

Level of natural autoantibodies to interferon-alpha and characteristics of interferon status during chronic hepatitis and liver cirrhosis

Level of autoantibodies to interferon-alpha and characteristics of interferon status were studied in 118 patients with chronic diffuse liver diseases (CDLD). During formation of liver cirrhosis in patients with CDLD level of natural autoantibodies to endogenous interferon-alpha increased. During progression of CDLD, decrease of interferon-alpha level and its functional activity were observed as well as change in the ratio between active fraction of interferon-alpha and its inactivated forms towards increase of the latter. One cause of observed decrease in biological functional activity of interferon-alpha in patients with chronic hepatitis and liver cirrhosis was increased titer of interferon-alpha neutralizing autoantibodies in blood. Level of natural autoantibodies to interferon-alpha, its antiviral activity and concentration during chronic hepatitis and liver cirrhosis can be used as markers of disease severity and predictors of its outcome.     

Accumulation of oxacarbocyanine dyes with different length of the alkyl chain in marrow cells and hepatocytes

The incorporation of the fluorescent probe 3,3-dialkyloxacarbocyanine bromide H-510 (where alkyl is ethyl- (C2), nonyl- (C9), or octadecyl (C18) groups) into cells of different kind has been explored. It has been revealed that the length of alkyl chains significantly influences the dynamics and mechanisms of accumulation of the probe by the cells. It has been found by microfluorimetry that all probe species have similar spectral characteristics in bone marrow cells, indicating that all probes, independently on their lipophilic properties, are incorporated into micelle-like structures formed probably by cell phospholipids. Spectroscopy experiments have shown that, in hepatocytes, the fluorescent probes 3,3-diethyloxacarbocyanine bromide (H-510/C2) and 3,3-dinonyloxacarbocyanine bromide (H-510/C9) are mainly accumulated in weakly polar media (nonpolar and weakly polar lipids of these cells). The luminescence maximum of the H-510/C18 probe in hepatocytes is blue-shifted and coincides with that in an albumin solution. We suppose that the incorporation of the probe into cells occurs by endocytosis when the probe binds to surface proteins.     

Physiological mechanisms of enhancing salt tolerance of oilseed rape plants with brassinosteroids

The ability of brassinosteroids, such as 24-epibrassinolide (EBL) to increase the resistance of oilseed rape plants (Brassica napus L.) to salt stress (175 mM NaCl) was investigated along with the possible mechanisms of their protective action. Seedlings were grown for three weeks on the Hoagland-Snyder medium under controlled conditions. The experimental plants were treated with either (1) 175 mM NaCl, or (2) 10^?10 M EBL, or (3) 175 mM NaCl plus 10^?10 M EBL by adding the corresponding components to the growth medium. The exposure was 7 and 14 days. As compared to the control, salinization inhibited plant height by 33–35%, reduced leaf area by 2.0–2.5 times, reduced 2.5- and 2-fold plant fresh and dry weight, respectively, reduced water content of plant tissues by 26–31% and, twofold, the content of chlorophylls a and b. Plants responded to NaCl by developing oxidative stress conditions, lowering the osmotic potential of the cell contents down to ?2 MPa, accumulating proline (by 43–52 times) and low-molecular-weight phenolics (by 1.9–2.7 times). Oilseed rape plants were shown to respond to salinization with an increase of endogenous content of steroid hormones: 24-epibrassinosteroids (24-epibrassinolide and 24-epicastasterone), 24S-methyl-brassinosteroids (brassinolide and castasterone), and 28-homobrassinosteroids (28-homobrassinolide and 28-homocastasterone); such evidence indirectly confirms the involvement of brassinosteroids in the development of salt tolerance. Adding EBL to the nutrient medium under optimal growth conditions did not significantly affect the indices under study. Under salt stress, EBL showed a pronounced protective effect: stem growth was fully restored, plant assimilation area increased by as much as 67–76% as compared to the control index, fresh and dry weight largely recovered (up to 85–92% of the control values), and the inhibitory effect of NaCl on photosynthetic pigments was diminished. Exogenous EBL impeded the development of NaCl-dependent lipid peroxidation and increased the osmotic potential of the leaf cell contents. The protective effect of EBL under salt stress was probably associated with EBL antioxidant effect, rather than the hormone-induced accumulation of proline and of low-molecula-weight phenolics, as well as with the ability to regulate water status by maintaining intracellular ion homeostasis.