Predicting the Efficacy of Polycyclic Aromatic Hydrocarbon Bioremediation in Creosote-Contaminated Soil Using Bioavailability Assays

Nonexhaustive extraction (propanol, butanol, hydroxypropyl-β-cyclodextrin [HPCD]), persulfate oxidation and biodegradability assays were employed to determine the bioavailability of polycyclic aromatic hydrocarbons (PAHs) in creosote-contaminated soil. After 16 weeks incubation, greater than 89% of three-ring compounds (acenaphthene, anthracene, fluorene, and phenanthrene) and 21% to 79% of four-ring compounds (benz[a]anthracene, chrysene, fluoranthene, and pyrene) were degraded by the indigenous microorganisms under biopile conditions. No significant decrease in five- (benzo[a]pyrene, benzo[b+k]fluoranthene) and six-ring compounds (benz[g,h,i]perylene, indeno[1,2,3-c,d]pyrene) was observed. Desorption of PAHs using propanol or butanol could not predict PAH biodegradability: low-molecular-weight PAH biodegradability was underestimated whereas high-molecular-weight PAH biodegradability was overestimated. Persulfate oxidation and HPCD extraction of creosote-contaminated soil was able to predict three- and four-ring PAH biodegradability; however, the biodegradability of five-ring PAHs was overestimated. These results demonstrate that persulfate oxidation and HPCD extraction are good predictors of PAH biodegradability for compounds with octanol-water partitioning coefficients of < 6.     

Saturated phospholipids are required for nano- to micron-size transformation of cholesterol-containing liposomes upon QS21 addition

Abstract

Liposomes containing cholesterol and monophosphoryl lipid A (such as ALFQ and AS01B) are vaccine adjuvants. During construction of the formulations, addition of QS21 to nano-size (50–100?nm) liposomes resulted in extremely large (up to ～30 µm) liposomes in ALFQ, but AS01B liposomes remained small nano-vesicles. Here, we show that saturation of phospholipid chains is essential for production of large liposomes by QS21.     

Use of assisted reproduction for the improvement of milk production in dairy camels (Camelus dromedarius)

Despite their production potential and ability to survive on marginal resources in extreme conditions, dromedaries have not been exploited as an important food source. Camels have not been specifically selected for milk production, and genetic improvement has been negligible. High individual variation in milk production both within the population and within breeds provides a good base for selection and genetic progress. In this paper, we discuss the possibilities and constraints of selective breeding for milk production in camels, and include a summary of the use of embryo transfer at the world's first camel dairy farm. Embryo transfer is an integral part of the breeding strategy at the camel dairy farm because it increases selection intensity and decreases the generation interval. Using high milk-producing camels as donors and low producing camels as recipients, 146 embryos were recovered (6.1 ± 1.0 embryos/donor; range: 0–18). Embryos were transferred non-surgically into 111 recipients (83 single and 28 twin embryo transfers). Pregnancy rate at 21 days and 5 months was 55% (61/111) and 45% (50/111), respectively. Finally, a total of 46 recipients delivered a live calf. These results document the utility of embryo transfer using high milk producing dromedaries as donors.     

Platelets and Erythrocyte-Bound Platelets Bind Infectious HIV-1 in Plasma of Chronically Infected Patients

Chronic HIV-1 infection is associated with persistent viremia in most patients, but it remains unclear how free virus may survive the potential hostile effects of plasma. We investigated whether sites might exist on the surfaces of circulating blood cells for protection of infectious HIV-1 particles. Red blood cells (RBC) either from blood of uninfected normal individuals, or from blood obtained without EDTA from chronically infected HIV-1 patients, invariably contained a small number of RBC having attached platelets as determined by flow cytometry, light microscopy, and immunofluorescence microscopy. After mixing normal RBC with platelet-rich plasma, discrete populations of RBC, platelets, and complexes of platelets attached to RBC were purified by fluorescence-activated cell sorting. Upon incubation of purified cells or platelets with HIV-1 followed by washing and co-incubation with CD4-positive peripheral blood mononuclear cells (PBMC), platelets, and platelet-RBC complexes, but not platelet-free RBC, caused infection of PBMC. Infection was prevented by pre-treating the platelet-RBC complexes with EDTA. Plasma and RBC (comprising a RBC/platelet-RBC mixture) from chronically infected patients with low viral loads were also co-incubated with PBMC ex vivo to determine the presence of infectious HIV-1. All freshly isolated plasmas from the HIV-1-infected donors, obtained in the absence of anticoagulant, were noninfectious. Interestingly, the RBC from most of the patients caused cell-cell infection of PBMC that was prevented by stripping the RBC with EDTA. A monoclonal antibody to DC-SIGN partially inhibited cell-cell HIV-1 infection of PBMC by normal RBC pre-incubated with platelets and HIV-1. We conclude: (a) platelet-free EDTA-free plasma from chronically infected HIV-1 patients, although containing viral RNA, is an environment that lacks detectable infectious HIV-1; (b) platelets and platelet-RBC complexes, but not purified RBC, bind infectious HIV-1; (c) DC-SIGN, and possibly other C-type lectins, may represent binding sites for infectious HIV-1 on platelets and platelet-RBC complexes.     

Hyaluronan bound mature sperm count (HB-MaSC) is a more informative indicator of fertility than conventional sperm parameters: Correlations with Body Mass Index (BMI)

The relationship between overweight and male fertility is well studied, still the correlation of obesity and decreased sperm quality is a subject to debate. The widely used conventional spermatological examinations alone seem to be inadequate to assess fertilization potential. Hyaluronan Binding Assay (HBA^®) is one of the available validated tests that allows the functional examination of sperm. Data of 72 male patients (mean age 33.9 (24–43) years) from infertile couples were analysed. Body Mass Index (BMI) determination, conventional semen analysis and HBA were performed. Additionally, a relatively new Hyaluronan Bound Matured Sperm Count (HB-MaSC) -index, first introduced by the authors in 2015, was calculated. This index reflects fertilization potential of sperm more precisely. With the increase of BMI, sperm count decreased significantly until about 25?kg/m², above 25?kg/m² no further decrease was observed, although sperm count remained permanently low. Greater body weight (in the 70–90?kg range) was observed to have a significant negative effect only on the progressive sperm motility. In addition to sperm concentration and motility, sperm fertilization potential is also negatively affected by obesity, but is irrespective of body weight, as evaluated using BMI + HB-MaSC linear regression analyses adjusted for age and weight. This correlation between male BMI and sperm fertilization potential – as opposed to the conventional correlations with sperm concentration or motility – appears to provide more helpful information in the identification of real capability for fertilization.     

Variability in the Effect of 5-HTTLPR on Depression in a Large European Population: The Role of Age,Symptom Profile,Type and Intensity of Life Stressors

Background

Although 5-HTTLPR has been shown to influence the risk of life stress-induced depression in the majority of studies, others have produced contradictory results, possibly due to weak effects and/or sample heterogeneity.

Methods

In the present study we investigated how age, type and intensity of life-stressors modulate the effect of 5-HTTLPR on depression and anxiety in a European population cohort of over 2300 subjects. Recent negative life events (RLE), childhood adversity (CHA), lifetime depression, Brief Symptoms Inventory (BSI) depression and anxiety scores were determined in each subject. Besides traditional statistical analysis we calculated Bayesian effect strength and relevance of 5-HTTLPR genotypes in specified models.

Results

The short (s) low expressing allele showed association with increased risk of depression related phenotypes, but all nominally significant effects would turn to non-significant after correction for multiple testing in the traditional analysis. Bayesian effect strength and relevance analysis, however, confirmed the role of 5-HTTLPR. Regarding current (BSI) and lifetime depression 5-HTTLPR-by-RLE interactions were confirmed. Main effect, with other words direct association, was supported with BSI anxiety. With more frequent RLE the prevalence or symptoms of depression increased in ss carriers. Although CHA failed to show an interaction with 5-HTTLPR, in young subjects CHA sensitized towards the depression promoting effect of even mild RLE. Furthermore, the direct association of anxiety with the s allele was driven by young (≤30) individuals.

Limitations

Our study is cross-sectional and applies self-report questionnaires.

Conclusions

Albeit 5-HTTLPR has only weak/moderate effects, the s allele is directly associated with anxiety and modulates development of depression in homogeneous subgroups.     

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues

S-Adenosyl-l-methionine (AdoMet or SAM)-dependent methyltransferases (MTase) catalyze the transfer of the activated methyl group from AdoMet to specific positions in DNA, RNA, proteins and small biomolecules. This natural methylation reaction can be expanded to a wide variety of alkylation reactions using synthetic cofactor analogues. Replacement of the reactive sulfonium center of AdoMet with an aziridine ring leads to cofactors which can be coupled with DNA by various DNA MTases. These aziridine cofactors can be equipped with reporter groups at different positions of the adenine moiety and used for Sequence-specific Methyltransferase-Induced Labeling of DNA (SMILing DNA). As a typical example we give a protocol for biotinylation of pBR322 plasmid DNA at the 5’-ATCGAT-3’ sequence with the DNA MTase M.BseCI and the aziridine cofactor 6BAz in one step. Extension of the activated methyl group with unsaturated alkyl groups results in another class of AdoMet analogues which are used for methyltransferase-directed Transfer of Activated Groups (mTAG). Since the extended side chains are activated by the sulfonium center and the unsaturated bond, these cofactors are called double-activated AdoMet analogues. These analogues not only function as cofactors for DNA MTases, like the aziridine cofactors, but also for RNA, protein and small molecule MTases. They are typically used for enzymatic modification of MTase substrates with unique functional groups which are labeled with reporter groups in a second chemical step. This is exemplified in a protocol for fluorescence labeling of histone H3 protein. A small propargyl group is transferred from the cofactor analogue SeAdoYn to the protein by the histone H3 lysine 4 (H3K4) MTase Set7/9 followed by click labeling of the alkynylated histone H3 with TAMRA azide. MTase-mediated labeling with cofactor analogues is an enabling technology for many exciting applications including identification and functional study of MTase substrates as well as DNA genotyping and methylation detection.