Recombinant production and characterization of a novel esterase from a hypersaline lake, Acigöl, by metagenomic approach.

The aim of this study was to isolate a novel esterase from a hypersaline lake by sequence-based metagenomics. The metagenomic DNA was isolated from the enriched hypersaline lake sediment. Degenerate primers targeting the conserved regions of lipolytic enzymes of halophilic microorganisms were used for polymerase chain reaction (PCR) and a whole gene was identified by genome walking. The gene was composed of 783 bp, which corresponds to 260 amino acids with a molecular weight of 28.2 kDa. The deduced amino acid sequence best matched with the esterase from Halomonas gudaonensis with an identity of 91%. Recombinantly expressed enzyme exhibited maximum activity towards pNP-hexanoate with a kcat value of 12.30 s-1. The optimum pH and temperature of the enzyme were found as 9 and 30 °C, respectively. The effects of NaCl, solvents, metal ions, detergents and enzyme inhibitors were also studied. In conclusion, a novel enzyme, named as hypersaline lake "Acigöl" esterase (hAGEst), was identified by sequence-based metagenomics. The high expression level, the ability to maintain activity at cold temperatures and tolerance to DMSO and metal ions are the most outstanding properties of the hAGEst.

Investigation of Rotavirus with Various Methods in Children with Acute Gastroenteritis and Determination of Its Molecular Epidemiology in Kayseri Province, Turkey.

BACKGROUND: In this study, the fresh stool samples from 254 children under 5 years of age with acute gastroenteritis which were delivered between October 2012 and December 2013 were collected. METHODS: In the stool samples, rotavirus antigens were investigated using two different immunochromatographic methods which are routinely used at different times, namely the RIDA® QUICK Rotavirus/Adenovirus Combi Test (R-Biopharm AG, Germany) and the Genx® Rotavirus Test (Diamed-Lab, Turkey), in addition to the Rotavirus Ag (Stool) ELISA (DRG, Germany) kit. The results were compared with reverse transcriptase PCR (RT-PCR). RESULTS: When the Genx® Rotavirus Test and RIDA® QUICK Rotavirus/Adenovirus Combi Test immunochromatographic methods were compared with RT-PCR, their sensitivity and specificity were found as 97.1%, 100%, and 80.4%, 72%, respectively. As to the Rotavirus Ag (Stool) ELISA method, on the other hand, its sensitivity was found to be 95.1% and its specificity was 86.5%. The most common genotype was G9P[8] (40%), which was followed by the G1P[8] (18.7%) and G3P[8] (9.6%) genotypes. CONCLUSION: Consequently, it was revealed that the sensitivity of ELISA and immunochromatographic methods, which provide results in a short time and are used in the investigation of rotavirus antigen, was high and their specificity was low; further studies to determine the distribution of G and P genotypes will contribute to establishing strategies for vaccine development for rotavirus in the world.

Generation of Acid Mine Lakes Associated with Abandoned Coal Mines in Northwest Turkey.

A total of five acid mine lakes (AMLs) located in northwest Turkey were investigated using combined isotope, molecular, and geochemical techniques to identify geochemical processes controlling and promoting acid formation. All of the investigated lakes showed typical characteristics of an AML with low pH (2.59-3.79) and high electrical conductivity values (1040-6430 µS/cm), in addition to high sulfate (594-5370 mg/l) and metal (aluminum [Al], iron [Fe], manganese [Mn], nickel [Ni], and zinc [Zn]) concentrations. Geochemical and isotope results showed that the acid-generation mechanism and source of sulfate in the lakes can change and depends on the age of the lakes. In the relatively older lakes (AMLs 1 through 3), biogeochemical Fe cycles seem to be the dominant process controlling metal concentration and pH of the water unlike in the younger lakes (AMLs 4 and 5). Bacterial species determined in an older lake (AML 2) indicate that biological oxidation and reduction of Fe and S are the dominant processes in the lakes. Furthermore, O and S isotopes of sulfate indicate that sulfate in the older mine lakes may be a product of much more complex oxidation/dissolution reactions. However, the major source of sulfate in the younger mine lakes is in situ pyrite oxidation catalyzed by Fe(III) produced by way of oxidation of Fe(II). Consistent with this, insignificant fractionation between δ(34) [Formula: see text] and δ(34) [Formula: see text] values indicated that the oxidation of pyrite, along with dissolution and precipitation reactions of Fe(III) minerals, is the main reason for acid formation in the region. Overall, the results showed that acid generation during early stage formation of an AML associated with pyrite-rich mine waste is primarily controlled by the oxidation of pyrite with Fe cycles becoming the dominant processes regulating pH and metal cycles in the later stages of mine lake development.

Generation and geochemical characteristics of acid rock drainage (ARD) in Barton Peninsula, King George Island (KGI), maritime, Antarctica.

This study deals with the generation, geochemical characteristics, and environmental impacts of acid rock drainage (ARD), a global environmental problem, on the Barton Peninsula. To elucidate the governing processes and to assess the environmental hazards of ARD, we present chemical data from lakes, ponds, and creeks with a wide range of pH values. We also provide mineralogical and geochemical compositions of sediments and bedrocks. Compared to weak-acidic and neutral waters, waters that display typical characteristics of ARD with low pH (3.7 to 4.2), high sulfate (46 to 92 mg/L), and Fe (0.8 to 16.5 mg/L) occur in the northern tip of the peninsula. Acidic waters with the highest cation (e.g., K, Na, Si, and Ca) and anion (e.g., SO4) compositions indicate ARD-enhanced rock weathering in the peninsula. Consistently, quantifying of chemical weathering degree yields the highest chemical index of alteration (CIA) and the mafic index of alteration (MIA) with the lowest ICV values for sediments from the acidic waters. Enrichment factors (EFs) calculated for As, Co, Cd, Cu, Pb, Zn, and Ni indicate severe to minor enrichment for As and Pb metals, respectively in the acidic water-associated sediments. Heavy metal concentrations of acidic waters also display the highest values for the peninsula, with Fe, Cu, and Cd metals exceeding the chronic aquatic toxicity limit (CAT). Therefore, geochemical records of acidic waters and sediments, especially lakes, may help in tracing the long-term environmental impacts of ARD, while sediments obtained from the weak acidic and near-neutral waters, together with water chemistry data, may provide a better representative composition of the bedrocks with neutralizing potential. The data presented here may contribute to predicting the source/s, and extent of future ARD generation in the peninsula, which is likely to be enhanced by increased chemical weathering due to climate warming.

Morphological and Microbial Diversity of Hydromagnesite Microbialites in Lake Salda: A Mars Analog Alkaline Lake.

Lake Salda, a terrestrial analog for the paleolake in Jezero Crater on Mars, hosts active, subfossil, and fossil hydromagnesite microbialites, making it an ideal location to study microbialite formation and subsequent processes. Our understanding of this record is still limited by an incomplete knowledge of the macro- and mesoscale morphotypes of microbialites, along with their spatial distribution and correlation with microbial and geochemical processes that influence microbialite formation. In this study, we investigated the spatial distribution, morphotypes, mineralogy, geochemistry, and microbial diversity of the microbialites and identified six distinct zones (Zone I to Zone VI) with major microbialite build-ups in Lake Salda. Newly identified microbialites were classified based on the macro- and mesostructures. Our work shows that the lake contains stromatolites, thrombolites, stromatolitic thrombolites, dendrolites, and microbially induced sedimentary structures. At macroscale, Lake Salda microbialites exhibit hemispheres, stacked domes, and laterally linked columnar structures while minicolumns, knobs, mesoclots, laminae, and botryoidal structures are common at mesoscale. The macro- and mesoscale distribution of different microbialite types spatially correlates with microbial community composition and water depth. Deep-growing microbialites with a low abundance of Cyanobacteria (∼1%-4%) and high abundance of Firmicutes (28%-93%) exhibit steeply convex lamination, producing finger-like minicolumnar mesostructures. In contrast, shallow-growing microbialites with a low abundance of Firmicutes (0%-5%) and high abundance of Cyanobacteria (11%-37%) have well-preserved gently convex millimeter-scale lamination, resulting in cauliflower mesostructures. Palygorskite ((Mg, Al)2Si4O10(OH)) is identified in the diatom-rich microbial layer of the deep-growing microbialites. Regardless of the microbialite types, hydromagnesite and aragonite are present in the extracellular polymeric substance (EPS)-rich zone of the shallow and deep-growing microbialites. Overall, environmental changes (e.g., water depth and, accommodation space) play a major role in the formation and spatial distribution of different microbialite morphologies at the macro- and mesoscale. Differences in the relative abundance of dominant microorganisms between mesostructured types suggest that mesomorphology may be influenced by changes in microbial diversity. Spatial variations in the microbialite morphotypes, along with the abundant presence of entombed biomass (e.g., mineralized filaments), may indicate areas that have a high potential for the preservation of biosignatures.

The impact of augmenter of liver regeneration in blunt liver trauma: An experimental model analysis.

BACKGROUND: Traumatic liver injury is an acute event that triggers liver repair. The augmenter of liver regeneration (ALR) has been identified as a growth factor involved in this process. This study evaluates the impact of ALR on isolated liver blunt trauma and examines its relationship with various time intervals. METHODS: Forty healthy female Wistar albino rats were divided into five groups (n=8 each). Isolated blunt liver trauma was induced using a custom-designed trauma platform in all groups except for Group 1. The groups were categorized by the timing of euthanasia post-trauma: 2nd (15 minutes), 3rd (30 minutes), 4th (45 minutes), and 5th (60 minutes). Assessments included plasma ALR levels, liver tissue ALR levels (both intact and lacerated), biochemical indices, and liver histological analysis. RESULTS: Plasma ALR levels in Group 4 were higher than in Groups 1 and 2 (p<0.01). Intact liver ALR levels in Groups 3 and 4 exceeded those in Group 1 (p<0.05, p<0.01, respectively). Intact liver tissue ALR levels in Group 5 were lower than in Groups 3 and 4 (p<0.05, p<0.01, respectively). Lacerated liver tissue ALR levels in Group 5 were higher than those in Groups 2 and 3. In Group 1, the plasma ALR level was higher than the intact liver tissue ALR level (p<0.05). In Group 2, plasma ALR levels exceeded those in intact liver tissue ALR levels (p<0.01). In Group 3, plasma ALR levels surpassed both lacerated and intact liver tissue ALR levels (p<0.05, p<0.001, respectively). In Group 4, the plasma ALR level was higher than the intact liver tissue ALR level (p<0.01), and the lacerated liver tissue level was higher than the intact liver ALR level (p<0.001). Additionally, inflammation scores were higher in Groups 3, 4, and 5 compared to Group 2 (p<0.05, p<0.01, p<0.01, respectively). CONCLUSION: This study is the first to explore the role of ALR in isolated blunt liver trauma. Following blunt liver trauma, both plasma and liver tissue ALR levels change within minutes.

Measurement of optic nerve sheath diameter on computed tomography for the differentiation of transient ischemic attacks.

OBJECTIVE: The objective of this study was to investigate whether the measurement of mean optic nerve sheath diameter in patients with transient ischemic attack could be used to distinguish between control groups, the acute ischemic stroke group, and subgroups within the acute ischemic stroke category. METHODS: Retrospectively, the mean optic nerve sheath diameters of patients aged 18 years and older belonging to control, transient ischemic attack, acute ischemic stroke, and subgroups within the acute ischemic stroke category were measured with initial computed tomography conducted in the emergency department. RESULTS: Out of the 773 patients included in the study, 318 (41.1%) were in the control group, 77 (10%) had transient ischemic attack, and 378 (49%) were categorized as stroke patients. The average mean optic nerve sheath diameter was significantly higher in both the stroke and transient ischemic attack groups compared with the control group (p<0.001 for both comparisons). Furthermore, the mean optic nerve sheath diameter in the stroke subgroups was significantly higher than in both the transient ischemic attack and control groups (p<0.001 for all comparisons). In transient ischemic attack patients, the mean optic nerve sheath diameter showed a significant ability to predict transient ischemic attack (AUC=0.913, p<0.001), with a calculated optimal cutoff value of 4.72, sensitivity of 94.8%, and specificity of 73.9%. CONCLUSION: The mean optic nerve sheath diameter of patients in the transient ischemic attack group was lower compared with those in the stroke subgroups but higher compared with the control group.

Lithological controls on lake water biogeochemistry in Maritime Antarctica.

Although the Antarctic lakes are of great importance for the climate and the carbon cycle, the lithological influences on the input of elements that are necessary for phytoplankton in lakes have so far been insufficiently investigated. To address this issue, we analyzed phytoplankton cell concentrations and chemical compositions of water samples from lakes, ponds and a stream on Fildes and Ardley Islands of King George Island in the South Shetland Archipelago. Furthermore, lake sediments, as well as soil and rock samples collected from the littoral zone were analyzed for their mineralogical/petrographic composition and pollutant contents of polycyclic aromatic hydrocarbons (PAHs). In addition, leaching experiments were carried out to with the lithologic samples to investigate the possible changes in pH, alkalinity, macronutrients (N, P, Si), micronutrients (e.g. Fe, Zn, Cu, Mn), anions (S, F, Br), and other cations (e.g. Na, K, Mg, Ca, Al, Ti, V, Cr, Co, Ni, As, Se, Pb, Sb, Mo, Ag, Cd, Sn, Ba, Tl, B). Our results showed that phytoplankton levels varied between 15 and 206 cells/mL. Chlorophyll-a concentrations showed high correlations with NH4, NO3. The low levels of PO4 (<0.001 mg/L) indicated a possible P-limitation in the studied lakes. The composition of rock samples ranged from basalt to trachybasalt with variable major oxide (e.g. SiO2, Na2O and K2O) contents and consist mainly quartz, albite, calcite, dolomite and zeolite minerals. The concentrations of total PAHs were below the toxic threshold levels (9.55-131.25 ng g-1 dw). Leaching experiments with lithologic samples indicated major increase in pH (up to 9.77 ± 0.02) and nutrients, especially PO4 (1.03 ± 0.04 mg/L), indicating a strong P-fertilization impact in increased melting scenarios. Whereas, toxic elements such as Pb, Cu, Cd, Al and As were also released from the lithology, which may reduce the phytoplankton growth.

Bacterial community composition of sediments from artificial Lake Maslak, Istanbul, Turkey.

Small artificial lakes are ubiquitous in various natural environments. Small impoundments increase the residence time of water, thereby increasing the potential for retention of nutrients through biological and physical processes. We examined bacterial community structure of Lake Maslak, a small freshwater impoundment located in a densely populated region. The objective of our study was to investigate bacterial communities of the lake sediment which has not been determined and to elucidate the factors controlling bacterial diversity and the biogeochemical processes within the lake. For these purposes, surface water, lake bed sediments, and one core sample were collected. Microbiological characteristic of the lake bed and core sediments was determined by denaturing gradient gel electrophoresis targeting the 16S rRNA gene. Along with the microbiological studies, physicochemical (O(2), pH, temperature) and geochemical properties of the surface (NO (3) (-) , NO (2) (-) , NH (4) (+) ,PO (4) (-) ,SO (4) (2-) , K(+), Mg(2+), Ca(2+)) and pore water (K(+), Mg(2+), Ca(2+)) were determined in addition to heavy metals contents (Co Cu, Fe, Zn, Pb, Cd). Eight lake bed and one core sediments were also collected and analyzed for heavy metals and elemental compositions. Nitrate concentration in the surface water ranges from 0.27-1.8 mg/L, and ammonium (0.0-0.83 mg/L) appears to follow nitrate concentration. Sulfate concentration in the surface water (mean 60 mg/L) is greater than those measured in the pore water (mean, 37.5 mg/L). Fe, Zn, Pb, and Cd were not determined in the surface water, whereas Co was significantly higher both in the surface and pore water. Unlike Co, Pb, Zn, and Cd were not measured in the pore water. Lakebed and core sediments show significant enrichment in Pb, Zn, and Cu, indicating anthropogenic pollution. Consistent with geochemical parameters, microbiological analysis suggests a diverse bacterial community in the lake sediments and influence of anthropogenic pollution (e.g., atmospheric emission) on bacterial community.

Draft Genome Sequence of Virgibacillus sp. Strain AGTR, Isolated from Hypersaline Lake Acigöl in Turkey.

Virgibacillus sp. strain AGTR, which is a haloalkaliphilic microorganism, was isolated from a sediment sample collected in hypersaline Lake Acigöl in Turkey. It has the potential to produce biotechnologically essential proteases. Here, the whole-genome sequence and its annotations are reported.

Obstetric Outcomes among Syrian Refugees: A Comparative Study at a Tertiary Care Maternity Hospital in Turkey.

OBJECTIVE: The aim of this study was to analyze and compare obstetric and neonatal outcomes between Syrian refugees and ethnic Turkish women. METHODS: Retrospective, observational study. A total of 576 Syrian refugees and 576 ethnic Turkish women were included in this study, which was conducted between January 2015 and December 2015 at a tertiary maternity training hospital in Ankara, Turkey. The demographic characteristics, obstetric and neonatal outcomes were compared. The primary outcomes were pregnancy outcomes and cesarean rates between the groups RESULTS: The mean age was significantly lower in the refugee group (p < 0.001). Mean gravidity, proportion of adolescent pregnancies, proportion of pregnant women aged 12 to 19 years, and number of pregnancies at < 18 years were significantly higher among the refugee women (p < 0.001). Rates of antenatal follow-up, double testing, triple testing, gestational diabetes mellitus (GDM) screening, and iron replacement therapy were significantly lower in the refugee group (p < 0.001). The primary Cesarean section rate was significantly lower in the refugee group (p = 0.034). Pregnancies in the refugee group were more complicated, with higher rates of preterm delivery (< 37 weeks), preterm premature rupture of membranes (PPROM), and low birth weight (< 2,500 g) when compared with the control group (4.2% versus 0.7%, p < 0.001; 1.6% versus 0.2%, p = 0.011; and 12% versus 5.8%, p < 0.001, respectively). Low education level (odds ratio [OR] = 1.7, 95% confidence interval [CI] = 0.5-0.1), and weight gain during pregnancy (OR = 1.7, 95% CI = 0.5-0.1) were found to be significant indicators for preterm birth/PPROM and low birthweight. CONCLUSION: Syrian refugees had increased risks of certain adverse obstetric outcomes, including preterm delivery, PPROM, lower birth weight, and anemia. Several factors may influence these findings; thus, refugee women would benefit from more targeted care during pregnancy and childbirth.

Intracranial symptomatic giant arachnoid cyst of the interhemispheric fissure presenting with frontal lobe syndrome.

Symptomatic interhemispheric arachnoid cysts (ACs) are extremely rare lesions seen more frequently in the elderly. Only 13 cases of symptomatic interhemispheric ACs in the elderly have previously been reported. Herein, we describe a 70-year-old female with symptoms of vertigo, memory and behavior disturbances. Magnetic resonance imaging (MRI) revealed a giant arachnoid cyst (AC) on the interhemispheric fissure, which was exerting a mass effect and displacement on the corpus callosum and anterior cerebral vessels, with a massive midline shift. The patient was treated with a cysto-peritoneal shunt. Reports to date have reviewed the pathology, clinical presentation, radiology and surgical management of interhemispheric symptomatic arachnoid cysts in elderly patients.

Tetrathionate and Elemental Sulfur Shape the Isotope Composition of Sulfate in Acid Mine Drainage.

Sulfur compounds in intermediate valence states, for example elemental sulfur, thiosulfate, and tetrathionate, are important players in the biogeochemical sulfur cycle. However, key understanding about the pathways of oxidation involving mixed-valance state sulfur species is still missing. Here we report the sulfur and oxygen isotope fractionation effects during the oxidation of tetrathionate (S4O62-) and elemental sulfur (S°) to sulfate in bacterial cultures in acidic conditions. Oxidation of tetrathionate by Acidithiobacillus thiooxidans produced thiosulfate, elemental sulfur and sulfate. Up to 34% of the tetrathionate consumed by the bacteria could not be accounted for in sulfate or other intermediate-valence state sulfur species over the experiments. The oxidation of tetrathionate yielded sulfate that was initially enriched in 34S (ε34SSO4-S4O6) by +7.9‰, followed by a decrease to +1.4‰ over the experiment duration, with an average ε34SSO4-S4O6 of +3.5 ± 0.2‰ after a month of incubation. We attribute this significant sulfur isotope fractionation to enzymatic disproportionation reactions occurring during tetrathionate decomposition, and to the incomplete transformation of tetrathionate into sulfate. The oxygen isotope composition of sulfate (δ18OSO4) from the tetrathionate oxidation experiments indicate that 62% of the oxygen in the formed sulfate was derived from water. The remaining 38% of the oxygen was either inherited from the supplied tetrathionate, or supplied from dissolved atmospheric oxygen (O2). During the oxidation of elemental sulfur, the product sulfate became depleted in 34S between -1.8 and 0‰ relative to the elemental sulfur with an average for ε34SSO4-S0 of -0.9 ± 0.2‰ and all the oxygen atoms in the sulfate derived from water with an average normal oxygen isotope fractionation (ε18OSO4-H2O) of -4.4‰. The differences observed in δ18OSO4 and the sulfur isotope composition of sulfate (δ34SSO4), acid production, and mixed valence state sulfur species generated by the oxidation of the two different substrates suggests a metabolic flexibility in response to sulfur substrate availability. Our results demonstrate that microbial processing of mixed-valence-state sulfur species generates a significant sulfur isotope fractionation in acidic environments and oxidation of mixed-valence state sulfur species may produce sulfate with characteristic sulfur and oxygen isotope signatures. Elemental sulfur and tetrathionate are not only intermediate-valence state sulfur compounds that play a central role in sulfur oxidation pathways, but also key factors in shaping these isotope patterns.

Obstetric outcomes among syrian refugees: A comparative study at a tertiary care Maternity Hospital in Turkey

Abstract Objective The aim of this study was to analyze and compare obstetric and neonatal outcomes between Syrian refugees and ethnic Turkish women. Methods Retrospective, observational study. A total of 576 Syrian refugees and 576 ethnic Turkish women were included in this study, which was conducted between January 2015 and December 2015 at a tertiary maternity training hospital in Ankara, Turkey. The demographic characteristics, obstetric and neonatal outcomes were compared. The primary outcomes were pregnancy outcomes and cesarean rates between the groups Results The mean age was significantly lower in the refugee group (p< 0.001). Mean gravidity, proportion of adolescent pregnancies, proportion of pregnant women aged 12 to 19 years, and number of pregnancies at < 18 years were significantly higher among the refugee women (p< 0.001). Rates of antenatal follow-up, double testing, triple testing, gestational diabetes mellitus (GDM) screening, and iron replacement therapy were significantly lower in the refugee group (p< 0.001). The primary Cesarean section rate was significantly lower in the refugee group (p= 0.034). Pregnancies in the refugee group were more complicated, with higher rates of preterm delivery (< 37 weeks), preterm premature rupture of membranes (PPROM), and low birth weight (< 2,500 g) when compared with the control group (4.2% versus 0.7%, p< 0.001; 1.6% versus 0.2%, p= 0.011; and 12% versus 5.8%, p< 0.001, respectively). Low education level (odds ratio [OR] = 1.7, 95% confidence interval [CI] = 0.5-0.1), and weight gain during pregnancy (OR = 1.7, 95% CI = 0.5-0.1) were found to be significant indicators for preterm birth/PPROM and low birthweight. Conclusion Syrian refugees had increased risks of certain adverse obstetric outcomes, including preterm delivery, PPROM, lower birth weight, and anemia. Several factors may influence these findings; thus, refugee women would benefit from more targeted care during pregnancy and childbirth.