Isolation and characterization of long-chain alkane–degrading Acinetobacter sp. BT1A from oil-contaminated soil in Diyarbakır,in the Southeast of Turkey

A strain of long-chain alkane–degrading bacteria, BT1A, was isolated from oil-contaminated soil in Diyarbak?r, in the southeast of Turkey. Morphological, biochemical, and physiological characterization and 16S rRNA gene sequence analysis showed that the strain BT1A was a member of Acinetobacter genus, and it was found to be closely related to Acinetobacter baumannii. The strain BT1A was able to utilize crude petroleum as carbon and energy sources in order to grow. Among the aliphatic hydrocarbons, growth was observed only in the medium containing long-chain alkanes (tridecane, pentadecane, and hexadecane) and squalene. Hexadecane was the most preferred hydrocarbon among the long-chain alkanes. Gas chromatography–mass spectrometry (GC-MS) analysis showed that BT1A degraded 83% of n-alkanes of 1% crude oil in 7 days. The present study indicates that the isolated strain can well be used for biodegradation of hydrocarbons in oil-contaminated sites.     

The intersection of social determinants of health,the microbiome,and health outcomes in immigrants: A scoping review

In the present scoping review, we explore whether existing evidence supports the premise that social determinants of health (SDoH) affect immigrant health outcomes through their effects on the microbiome. We adapt the National Institute on Minority Health and Health Disparities' research framework to propose a conceptual model that considers the intersection of SDoH, the microbiome, and health outcomes in immigrants. We use this conceptual model as a lens through which to explore recent research about SDoH, biological factors associated with changes to immigrants' microbiomes, and long-term health outcomes. In the 17 articles reviewed, dietary acculturation, physical activity, ethnicity, birthplace, age at migration and length of time in the host country, socioeconomic status, and social/linguistic acculturation were important determinants of postmigration microbiome-related transformations. These factors are associated with progressive shifts in microbiome profile with time in host country, increasing the risks for cardiometabolic, mental, immune, and inflammatory disorders and antibiotic resistance. The evidence thus supports the premise that SDoH influence immigrants' health postmigration, at least in part, through their effects on the microbiome. Omission of important postmigration social-ecological variables (e.g., stress, racism, social/family relationships, and environment), limited research among minoritized subgroups of immigrants, complexity and inter- and intra-individual differences in the microbiome, and limited interdisciplinary and biosocial collaboration restrict our understanding of this area of study. To identify potential microbiome-based interventions and promote immigrants' well-being, more research is necessary to understand the intersections of immigrant health with factors from the biological, behavioral/psychosocial, physical/built environment, and sociocultural environment domains at all social-ecological levels.     

RETRACTED ARTICLE: Acaricidal and pathogenic effects of the entomopathogenic fungus Beauveria bassiana on engorged females of the fowl tick,Argas persicus (Argasidae)

Experimental and Applied Acarology - This study examined the acaricidal, histopathological and genotoxic effects of the entomopathogenic fungus Beauveria bassiana on engorged females of the fowl...     

Trace element concentrations and superoxide dismutase and catalase activities in benign and malignant larynx tumors

The plasma and erythrocyte levels of zinc, copper, and magnesium and the activities of red-cell copper-zinc superoxide dismutase (Cu/Zn-SOD) and catalase (CAT) were determined in patients with benign and malignant tumors of the larynx. Blood samples from patients and healthy controls were drawn using heparinized tubes. The erythrocyte Cu/Zn-SOD and CAT activities were determined spectrophotometrically and the zinc, copper, and magnesium concentrations were determined in erythrocyte and plasma by atomic absorption spectrometry. Variance analysis was employed in the statistical evaluation of the findings. There was a significant increase in red-cell Cu/Zn-SOD activity in the subjects with malignant and benign tumors compared to controls (p<0.001). The CAT activity increased only in the benign tumor group (p<0.01). The plasma zinc concentrations were significantly lower in the malignant tumor group (p<0.05) and significantly higher in the benign tumor group (p<0.01). The erythrocyte copper concentrations were significantly lower in both benign and malignant tumor groups (p<0.001). The plasma copper and magnesium and the erythrocyte magnesium concentrations did not show significant differences relative to controls (p>0.05). The increases in the activities of SOD and CAT activities and the changes in trace elements concentrations can indicate the presence of increased reactive oxygen species that might play a part in the pathogenesis larynx tumors. Presented at the IX Asian-Pacific Congress of Clinical Biochemistry, March 9–14, 2002, New Delhi, India.     

The influence of aquatic predators on mosquito abundance in animal drinking troughs in New Zealand

The occurrence and abundance of mosquito populations may be associated with the abundance of predators. We examined the relationship between aquatic predators and populations of mosquitoes in animal water troughs in Waikanae, New Zealand. We also investigated the effects of water volume and environmental factors (temperature, rainfall, wind speed, humidity, and pressure) in order to further understand factors influencing mosquito and predator populations. Logistic regression indicated that the presence or absence of mosquitoes was primarily affected by three factors: predator abundance, week of observation, and water volume. Pearson's correlation indicated that the presence of predators had a positive correlation with water volume (r²= 0.176, p< 0.05). Otherwise, the presence of mosquito larvae in water troughs was negatively correlated with water volume (r²=?0.159, p=0.022) and wind speed (r²=0.142, p=0.041). We established a translocation experiment in which predators or mosquitoes were moved between troughs in order to examine the prey survival rate after exposure to Anisops wakefieldi predators. The survival rate of mosquitoes was not significantly different, between 0–0.1%, irrespective of the number of predators translocated (1–9) or the initial mosquito density (20–70 larvae). Our results suggested that A. wakefieldi predators may have the potential to be a promising biological control tool for the control of mosquito populations by altering mosquito population dynamics.     

Effects of Thymus kotschyanus var. glabrescens Boiss. extract on mitomycin-C induced chromosomal aberrations and sister chromatid exchanges in human lymphocytes

In this investigation, clastogenic effects of Thymus kotschyanus var. glabrescens Boiss. extract (TE) and anticlastogenic effects of this extract against Mitomycin C (MMC) induced chromosome damage have been evaluated in human peripheral blood lymphocytes in vitro. Two series of experiments were conducted. In the first, only 10⁻⁵, 10⁻⁴, 10⁻³ and 10⁻² μl ml⁻¹ concentrations of TE were used for 48 h to detect potential clastogenicity. In the second, MMC (0.38 μg ml⁻¹) plus 10⁻⁵, 10⁻⁴, 10⁻³ and 10⁻² μl ml⁻¹ concentrations of TE were used for 48 h to determine anticlastogenic effects. TE did not increase sister chromatid exchanges (SCEs) (except 10⁻² μl ml concentration) and chromosome aberrations (CAs) significantly compared with negative and solvent controls. However, it decreased the frequency of MMC induced chromosome aberrations. Decreasing was significant at 10⁻⁴, 10⁻³ and 10⁻² μl ml⁻¹ concentrations. On the other hand, TE significantly increased MMC-induced SCEs for all treatment groups compared with positive control.     

Synthesis, antimicrobial activity and conformational analysis of novel substituted pyridines: BF(3)-promoted reaction of hydrazine with 2-alkoxy pyridines

Some new 2-alkoxy-3-cyano-4,6-diarylpyridines 3,4 were synthesized by condensation of different alpha,beta-unsaturated ketones 1 with malononitrile 2, followed by cyclization in sodium alkoxide/alcohol system. Lewis acid-catalyzed reaction of 4 with hydrazine afforded the corresponding 1H-pyrazolo[3,4-b]pyridines 5. The potency of the results as antimicrobial agents has been evaluated. The structure of the newly prepared compounds was assessed by microanalysis, IR and NMR spectra. Molecular mechanics (MM2) and semiemperical (AM1) molecular orbital calculations have been performed for the most biologically active compounds 5b and c to get insight into their molecular structures and to learn more about their stable molecular conformations.     

Antigenic mapping of a human λ light chain: Correlation with three dimensional structure

Although the amino acid sequence and three-dimensional structure of human immunoglobulin light chains have been known for more than 15 years, the location of antigenic markers characteristic of chains has not been determined. Here, we use a set of synthetic overlapping peptides to completely model the sequence of the chain Mcg and test these for the binding or rabbit and goat antisera specific for chain determinants. We assess peptide contributions to -antigenic reactivity and also to identify a portion of C-region where conformational factors contribute to the antigenicity. Specific determinants occur both in the constant and variable (first and third framework) domains of the molecule. The fourth framework of the variable region, a segment specified by the joining gene, is also recognized and cross-reacts antigenically with the homologous region of T cell receptor chains. Major specific determinants are localized in the N- and C-terminal segments, which are linear and devoid of major conformational folding. Other segments that are strongly antigenic, such as the third framework of the V region (residue 78–93) and a segment of the constant region (residues 177–192), show strong conformational dependence in antigenicity.     

Synthesis of New Bis(pyrazolo[1,5-a]pyrimidines) Linked to Different Spacers as Potential MurB Inhibitors

An efficient protocol was adopted to efficiently prepare three new series of bis(pyrazolo[1,5-a]pyrimidines) linked to different spacers. The new bis(pyrazolo[1,5-a]pyrimidines) were prepared in 80–90 % yields by reacting the respective bis(enaminones) and 4-(4-substituted benzyl)-1H-pyrazole-3,5-diamines in pyridine at reflux temperature for 5–7 h. The new products showed a wide spectrum of antibacterial activity against six different bacterial strains. In general, propane- and butane-linked bis(pyrazolo[1,5-a]pyrimidines), which are attached to 3-(4-methyl- or 4-methoxybenzyl) units, had the best antibacterial activity with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values up to 2.5 and 5.1 μM, respectively. Additionally, the previous products demonstrated promising MurB inhibitory activity with IC₅₀ values up to 7.2 μM.