Isolation and characterization of halophilic bacteria from Urmia Lake in Iran

Urmia Lake is one of the most permanent hypersaline lakes in the world which is threatened by hypersalinity and serious dryness. In spite of its importance no paper has been published regarding bacterial community of this lake. Accordingly, the present study aimed to investigate the halophilic bacteria in the aforementioned lake. In so doing, thirty seven strains were isolated on six different culture media. The isolated strains were characterized using phenotypic and genotypic methods. Growth of the strains occurred at 25–35°C, pH 6–9 and 7 to 20% (w/v) NaCl indicating that most of the isolates were moderately halophiles. Catalase, oxidase and urease activities were found to be positive for the majority of the isolates. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolated bacteria belonged to two major taxa: Gammaproteobacteria (92%, including Salicola [46%], Pseudomonas [13.5%], Marinobacter [11%], Idiomarina [11%], and Halomonas [8%]) and Firmicutes (8%, including Bacillus [5%] and Halobacillus [3%]). In addition, a novel bacterium whose 16S rRNA gene sequence showed almost 98% sequence identity with the taxonomically troubled DSM 3050^T, Halovibrio denitrificans HGD 3^T and Halospina denitriflcans HGD 1–3, each, was isolated. 16S rRNA gene similarity levels along with phenotypic characteristics suggest that some of the isolated strains could be regarded as potential type strain for novel species, on which further studies are recommended.     

Computational modelling and analysis of mechanical conditions on cell locomotion and cell–cell interaction

Between other parameters, cell migration is partially guided by the mechanical properties of its substrate. Although many experimental works have been developed to understand the effect of substrate mechanical properties on cell migration, accurate 3D cell locomotion models have not been presented yet. In this paper, we present a novel 3D model for cells migration. In the presented model, we assume that a cell follows two main processes: in the first process, it senses its interface with the substrate to determine the migration direction and in the second process, it exerts subsequent forces to move. In the presented model, cell traction forces are considered to depend on cell internal deformation during the sensing step. A random protrusion force is also considered which may change cell migration direction and/or speed. The presented model was applied for many cases of migration of the cells. The obtained results show high agreement with the available experimental and numerical data.     

Changes in anti-heat shock protein 27 antibody and C-reactive protein levels following cardiac surgery and their association with cardiac function in patients with cardiovascular disease

The relationship between serum anti-heat shock protein (Hsp)27 antibody and high sensitive C-reactive protein (hs-CRP) levels and indices of cardiac function were investigated in patients undergoing coronary artery bypass grafting (CABG) or heart valve replacement. The changes in anti-Hsp27 antibody titers and hs-CRP levels were compared among patients undergoing off-pump and on-pump CABG or valvular heart replacement. Fifty-three patients underwent off-pump, on-pump CABG, and heart valvular replacement in each group. Serum anti-Hsp27 titers and hs-CRP values were measured 24 h before and after the operation and at discharge. Echocardiography was performed before surgery and before discharge. The results were compared with values from 83 healthy controls. hs-CRP levels increased and anti-Hsp27 antibody decreased following surgery (P < 0.001 and P < 0.05, respectively), although these changes were independent of operative procedure (P = 0.361 and P = 0.120, respectively). Anti-Hsp27 antibody levels were higher at the time of discharge (P = 0.016). Only in coronary patients were anti-Hsp27 antibody levels negatively associated with E/E′ (r = −0.268, P = 0.022), a marker of pulmonary capillary wedge pressure. In conclusions, anti-Hsp27 antibody levels are associated with indices of cardiac function in coronary patients. Cardiopulmonary bypass had no significant effect on the induction of changes in anti-Hsp27 levels. Moreover, anti-Hsp27 antibody levels fell in all groups postoperatively; this may be due to the formation of immune complexes of antigen–antibody, and antibody levels were higher at the time of discharge.

Electronic supplementary material

The online version of this article (doi:10.1007/s12192-012-0358-y) contains supplementary material, which is available to authorized users.     

Length‐weight relationships for five Clupeiformes species from the Persian Gulf and Oman Sea

Length‐weight relationships (LWRs) were determined for five Clupeiformes species representing three families collected from the Persian Gulf and Oman Sea. These are the first references on length‐weight relationships for two of these species (Ilisha megaloptera and Sardinella sindensis). A new maximum length record was obtained for one species (Ilisha melastoma).     

Pregnane X receptor-agonists down-regulate hepatic ATP-binding cassette transporter A1 and scavenger receptor class B type I

Pregnane X receptor (PXR) is the molecular target for a wide variety of endogenous and xenobiotic compounds. It regulates the expression of genes central to the detoxification (cytochrome P-450 enzymes) and excretion (xenobiotic transporters) of potentially harmful compounds. The aim of the present investigation was to determine the role of PXR in regulation of high-density lipoprotein (HDL) cholesterol metabolism by studying its impact on ATP-binding cassette transporter A1 (ABCA1) and scavenger receptor class B type I (SR-BI) expression in hepatocytes. ABCA1 and SR-BI are major factors in the exchange of cholesterol between cells and HDL. Expression analyses were performed using Western blotting and quantitative real time RT-PCR. Luciferase reporter gene assays were used to measure promoter activities. Total cholesterol was measured enzymatically after lipid extraction (Folch's method). The expression of ABCA1 and SR-BI was inhibited by the PXR activators rifampicin and lithocholic acid (LCA) in HepG2 cells and pregnenolone 16alpha-carbonitrile (PCN) in primary rat hepatocytes. Thus, PXR appears to be a regulator of hepatic cholesterol transport by inhibiting genes central to cholesterol uptake (SR-BI) and efflux (ABCA1).     

Ontogenetic Otolith Development in an Endemic Tooth-Carp,Aphanius vladykovi (Teleostei: Aphaniidae)

Journal of Ichthyology - Otolith morphology in the tooth-carp/killifish genus Aphanius is an important source of taxonomic information. However, little is known about the range of ontogenetic...     

Ventricular arrhythmias after reperfusion: is there a correlation with infarct size?

The aim of this investigation was to examine whether any correlation exists between enzymatically estimated infarct size and arrhythmias arising in response to coronary reperfusion. Four hour occlusion of the left anterior coronary artery followed by reperfusion was carried out in conscious dogs. Serum creatine phosphokinase (CPK) analysis and planimetric determination of infarct size were performed. The Holter monitoring technique was used to analyze the arrhythmias. A good correlation was observed between the number of premature ventricular complexes (PVC) occurring during 4-h coronary artery occlusion and peak serum CPK values (CPKmax; r = 0.74). While PVC in the early 2-h reperfusion phase and on days 1 and 2 of the late reperfusion phase did not show a correlation with CPKmax nor with occlusion arrhythmias, arrhythmic activity on day 3 of the late reperfusion phase correlated well with CPKmax (r = 0.71) and occlusion arrhythmias (r = 0.75). Whereas it cannot be ruled out that arrhythmias on days 1 and 2 are related to coronary reperfusion as well as to the established infarction, we speculated that arrhythmias on day 3 are delayed arrhythmias in response to the occlusion procedure and not a consequence of reperfusion. Providing that arrhythmias occurring in the early reperfusion phase are almost exclusively induced by the arrhythmogenic phenomenon of reperfusion, we conclude that in contrast to occlusion arrhythmias, reperfusion arrhythmias are not markers of infarct size. Thus, a higher number of arrhythmias after reperfusion is not necessarily associated with a larger infarct size.     

Yeast Cell Microcapsules as a Novel Carrier for Cholecalciferol Encapsulation: Development,Characterization and Release Properties

In this study Saccharomyces cerevisiae yeast cells was used as a novel vehicle for encapsulation of vitamin D₃. The effects of initial cholecalciferol concentration (100,000 and 500,000 IU/g yeast), yeast cell pretreatment (plasmolysis with NaCl) and drying method (spray or freeze drying) on microcapsules properties were investigated. It was found that the vitamin concentration and drying method had significant influence on encapsulation efficiency (EE) and size of yeast microcapsules. Furthermore, EE values were more increased by the plasmolysis treatment. The highest EE was obtained for plasmolysed and spray dried yeast cells prepared using initial cholecalciferol concentration of 2.5 mg per gram of yeast cells (76.10?±?6.92%). The values of mean particle size were 3.43–7.91 μm. The presence of cholecalciferol in yeast microcapsules was confirmed by X-ray diffraction (XRD) and Fourier transform-infrared (FT-IR) analyses. The in vitro cholecalciferol release from yeast microcapsules in phosphate buffer saline solution (PBS) followed a controlled release manner consistent with a Fickian diffusion mechanism. In addition, the release studies in simulated gastrointestinal tract showed sustained release of cholecalciferol in the stomach condition and significant release in intestinal medium.