Recently a novel DNA virus (Torque Teno Virus (TTV) has been identified in Japan and shown to be associated with elevated aminotransferase s levels after transfusion. However the exact role of TTV in pathogenesis of liver disease is yet to be established. The purpose of this study was to determine the prevalence of TTV in thalassemic patients and its relationship with elevated alanine-aminotransfrase (ALT) and aspartateaminotransfrase (AST). This cross-sectional analysis study was conducted on 452 thallasemic patients. Serums were collected from all of the patients, first ALT and AST levels were determined. Then, after DNA extraction, TTV DNA was amplified and detected using semi-nested PCR, followed by gel electrophoresis. Demographic characteristics and clinical data were collected from each participant for statistical analysis. The findings showed that 160 of 452 (35.4%) samples had TTV DNA detected by PCR. From 160 TTV DNA positive, 98 (61.20%) were female and 62 (38.80%) of them were male (P=0.549). The mean ALT and AST values in TTV positive group were higher than in TTV negative group, and the difference was statistically significant (p<0.0001). The result showed that the prevalence of TTV in thalassemic patients in Jahrom is less than other studies in Iran and the mean ALT and AST values in TTV positive individuals were about 2 times more than in TTV negative individuals.

/pdf/molecular-prevalence-and-clinical-importance-of-torque-teno-2fi9z1ixeg.pdf

Molecular Prevalence and Clinical Importance of Torque Teno Virus Infection in Thalassemia Patients as High Risk Individuals

▪ Abstract New and exciting developments in boron research in the past few years greatly contributed to better understanding of the role of boron in plants. Purification and identification of the first boron-polyol transport molecules resolved much of the controversy about boron phloem mobility. Isolation and characterization of the boron-polysaccharide complex from cell walls provided the first direct evidence for boron crosslinking of pectin polymers. Inhibition and recovery of proton release upon boron withdrawal and restitution in plant culture medium demonstrated boron involvement in membrane processes. Rapid boron-induced changes in membrane function could be attributed to boron-complexing membrane constituents. Boron may affect metabolic pathways by binding apoplastic proteins to cis-hydroxyl groups of cell walls and membranes, and by interfering with manganese-dependent enzymatic reactions. In addition, boron has been implicated in counteracting toxic effects of aluminum on root growth of dicotyle...

/pdf/boron-in-plant-structure-and-function-4fem6y1f8e.pdf

Boron in plant structure and function

The interest of biologists in boron (B) has largely been focused on its role in plants for which B was established as essential in 1923 (Warington, 1923[296]). Evidence that B has a biological role in other organisms was first indicated by the establishment of essentiality of B for diatoms (Smyth and Dugger, 1981[296]) and cyanobacteria (Bonilla et al., 1990[296]; Garcia-Gonzalez et al., 1991[296]; Bonilla et al., 1997[296]). Recently, B was shown to stimulate growth in yeast (Bennett et al., 1999[296]) and to be essential for zebrafish (Danio rerio) (Eckhert and Rowe, 1999[296]; Rowe and Eckhert, 1999[296]) and possibly for trout (Oncorhynchus mykiss) (Eckhert, 1998[296]; Rowe et al., 1998[296]), frogs (Xenopus laevis) (Fort et al., 1998[296]) and mouse (Lanoue et al., 2000[296]). There is also preliminary evidence to suggest that B has at least a beneficial role in humans (Nielsen, 2000[296]).

While research into the role of B in plants has been ongoing for 80 years it has only been in the past 5 years that the first function of B in plants has been defined. Boron is now known to be essential for cell wall structure and function, likely through its role as a stabilizer of the cell wall pectic network and subsequent regulation of cell wall pore size. A role for B in plant cell walls, however, is inadequate to explain all of the effects of B deficiency seen in plants. The suggestion that B plays a broader role in biology is supported by the discovery that B is essential for animals where a cellulose-rich cell wall is not present. Careful consideration of the physical and chemical properties of B in biological systems, and of the experimental data from both plants and animals suggests that B plays a critical role in membrane structure and hence function. Verification of B association with membranes would represent an important advance in modern biology.

For several decades there has been uncertainty as to the mechanisms of B uptake and transport within plants. This uncertainty has been driven by a lack of adequate methodology to measure membrane fluxes of B at physiologically relevant concentrations. Recent experimentation provides the first direct measurement of membrane permeability of B and illustrates that passive B permeation contributes sufficient B at adequate levels of B supply, but would be inadequate at conditions of marginal B supply. The hypothesis that an active, carrier mediated process is involved in B uptake at low B supply is supported by research demonstrating that B uptake can be stimulated by B deprivation, that uptake rates follow a Michaelis-Menton kinetics, and can be inhibited by application of metabolic inhibitors. Since the mechanisms of element uptake are generally conserved between species, an understanding of the processes of B uptake is relevant to studies in both plants and animals.

The study of B in plant biology has progressed markedly in the last decade and we are clearly on the cusp of additional, significant discoveries. Research in this field will be greatly stimulated by the discovery that B is essential for animals, a discovery that will not only encourage the participation of a wider cadre of scientists but will refocus the efforts of plant biologists toward a determination of roles for B outside the plant cell wall. Determination of the function of B in biology and of the mechanisms of B uptake in biological systems, is essential to our understanding and management of B deficiency and toxicity in plants and animals in both agricultural and natural environments. Through an analysis of existing data and the development of new hypotheses, this review aims to provide a vision of the future of research into the biology of boron.

Boron in Plant Biology

The extensive development of surface and subsurface drainage systems to facilitate agricultural production throughout North America has significantly altered the hydrology of landscapes compared to historical conditions. Drainage has transformed nutrient and hydrologic dynamics, structure, function, quantity, and configuration of stream and wetland ecosystems. In many agricultural regions, more than 80% of some catchment basins may be drained by surface ditches and subsurface drain pipes (tiles). Natural channels have been straightened and deepened for surface drainage ditches with significant effects on channel morphology, instream habitats for aquatic organisms, floodplain and riparian connectivity, sediment dynamics, and nutrient cycling. The connection of formerly isolated wetland basins to extensive networks of surface drainage and the construction of main channel ditches through millions of acres of formerly low-lying marsh or wet prairie, where no defined channel may have previously existed, have r...

Effects of Agricultural Drainage on Aquatic Ecosystems: A Review

The whole classification of cyanobacteria (species, genera, families, orders) has undergone extensive restructuring and revision in recent years with the advent of phylogenetic analyses based on molecular sequence data. Several recent revisionary and monographic works initiated a revision and it is anticipated there will be further changes in the future. However, with the completion of the monographic series on the Cyanobacteria in Süsswasserflora von Mitteleuropa, and the recent flurry of taxonomic papers describing new genera, it seems expedient that a summary of the modern taxonomic system for cyanobacteria should be published. In this review, we present the status of all currently used families of cyanobacteria, review the results of molecular taxonomic studies, descriptions and characteristics of new orders and new families and the elevation of a few subfamilies to family level. All recently defined cyanobacterial genera (some still invalid) are listed in the family to which they are likely to belong and an indication is given of their taxonomic validity and level of polyphasic characterization of each genus.

Taxonomic classification of cyanoprokaryotes (cyanobacterial genera) 2014, using a polyphasic approach

The effect of boron on heterocystous and nonheterocystous dinitrogen fixing Cyanobacteria was examined. The absence of boron in culture media inhibited growth and nitrogenase activity in Nodularia sp., Chlorogloeopsis sp., and Nostoc sp. cultures. Examinations of boron-deficient cultures showed changes in heterocyst morphology. However, cultures of nonheterocystous Cyanobacteria, Gloeothece sp. and Plectonema sp., grown in the absence of boron did not show any alteration in growth or nitrogenase activity. These results suggest a requirement of boron only by heterocystous Cyanobacteria. A possible role for this element in the early evolution of photosynthetic organisms is proposed.

/pdf/boron-requirement-in-cyanobacteria-its-possible-role-in-the-2fxoe9jdsf.pdf

Boron requirement in cyanobacteria : its possible role in the early evolution of photosynthetic organisms.

The relationship between the requirement for boron and the form of N supplied in nutrient media to cyanobacterium Anabaena sp. PCC 7119 was investigated. When cells were grown in a medium which contained nitrate or ammonium-N, boron deficiency in the nutrient media did not inhibit growth or change cell composition. However, when cells were dependent on N2 fixation, the lack of boron inhibited growth (i.e. growth ceased after 96 hours under these conditions). Additionally, boron-deficient cells showed a significant decrease in their content of phycobiliproteins and chlorophyll and accumulated carbohydrates within 24 hours of removing boron from the nutrient media. Inhibition of photosynthetic O2 evolution accompanied the decrease in photosynthetic pigments. Boron deficiency symptoms were relieved when either boron or combined N was added to boron-deficient cultures. The degree of recovery depended upon the age of the cultures. Assays of nitrogenase activity showed that, after 2 hours of growth, nitrogenase activity of boron-deficient cells was inhibited by 40%. After 24 hours a total inactivation of nitrogenase activity was observed in boron-deficient cells. These results strongly suggest an involvement of boron in N2 fixation in cyanobacteria.

/pdf/essentiality-of-boron-for-dinitrogen-fixation-in-anabaena-sp-4xc1e3gcrg.pdf

Essentiality of Boron for Dinitrogen Fixation in Anabaena sp. PCC 7119

Cyanobacteria are a key biotic component as primary producers in biocrusts, topsoil communities that have important roles in the functioning of drylands. Yet, major knowledge gaps exist regarding the composition of biocrust cyanobacterial diversity and distribution in Mediterranean ecosystems. We describe cyanobacterial diversity in Mediterranean semiarid soil crusts along an aridity gradient by using next-generation sequencing and bioinformatics analyses, and detect clear shifts along it in cyanobacterial dominance. Statistical analyses show that temperature and precipitation were major parameters determining cyanobacterial composition, suggesting the presence of differentiated climatic niches for distinct cyanobacteria. The responses to temperature of a set of cultivated, pedigreed strains representative of the field populations lend direct support to that contention, with psychrotolerant vs thermotolerant physiology being strain dependent, and consistent with their dominance along the natural gradient. Our results suggest a possible replacement, as global warming proceeds, of cool-adapted by warm-adapted nitrogen-fixing cyanobacteria (such as Scytonema) and a switch in the dominance of Microcoleus vaginatus by thermotolerant, novel phylotypes of bundle-forming cyanobacteria. These differential sensitivities of cyanobacteria to rising temperatures and decreasing precipitation, their ubiquity, and their low generation time point to their potential as bioindicators of global change.

https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/nph.15355

Cyanobacterial biocrust diversity in Mediterranean ecosystems along a latitudinal and climatic gradient

Use of cyanobacteria to assess water quality in running waters.

Spatial and temporal changes in water quality in a Spanish river

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