Biocides formulation of essential oils having antimicrobial activity

Essential oils of fennel, peppermint, caraway, eucalyptus, geranium and lemon were tested for their antimicrobial activities against some plant pathogenic micro-organisms (Fusarium oxysporum, Alternaria alternate, Penicilium italicum Penicilium digitatum and Botyritus cinerea). Essential oils of fennel, peppermint, caraway were selected as an active ingredient for the formulation of biocides due to their efficiency in controlling the tested micro-organisms. Successful emulsifiable concentrates (biocides) were prepared from these oils using different emulsifiers (Emulgator B.L.M. Tween20 and Tween80) and different fixed oils (sesame, olive, cotton and soybean oils). Physico-chemical properties of the formulated biocide (spontaneous emulsification, emulsion stability test, cold stability and heat stability tests as well as viscosity, surface tension and pH) were measured. The prepared biocides were ready to be tested for application in a future work as a safe pesticide against different pathogens.     

Phytochemical Compounds from the Crop Byproducts of Tunisian Globe Artichoke Cultivars

The phytochemical composition in two Tunisian globe artichoke cultivars (bracts, leaves, and floral stems) was evaluated in the plant byproducts. The results indicated that the bracts contain the highest levels of total phenols, o‐diphenols, and flavonoids, whereas tannins seem to be more abundant in the leaves. Bracts from the ‘Violet d'Hyères’ cultivar possessed more total phenols (160.8 mg/g DW), flavonoids (64.9 mg/g DW), and anthocyanins (15.3 μg/g DW) than the ‘Blanc d'Oran’ bracts (134.5 mg/g DW, 51.2 mg/g DW, and 8.3 μg/g DW, resp.). Sixty‐four volatile compounds were identified in the headspace of globe artichoke material, particularly in the bracts. The volatile profile showed that sesquiterpene hydrocarbons and non‐terpene derivatives were the main volatiles emitted by the bracts in both cultivars. These results suggest that globe artichoke byproducts might represent a potential source of natural compounds, which could be used as nutraceuticals or as ingredients in the design of functional foods.     

Pregnancy and labor increase the capacity of human myometrial cells to secrete parathyroid hormone-related protein

Parathyroid hormone-related protein (PTHrP), a oncofetal gene product possessing smooth muscle relaxant properties, has been found in rat and human uterine smooth muscle cells (USMC) where it is postulated to regulate myometrial tone and/or blood flow. Studies investigating the gestational regulation of PTHrP in human USMC have not been performed. This study was conducted to determine if pregnancy alters the capacity of USMC to secrete or respond to PTHrP. USMC cultures were established from 8 hysterectomy specimens (H) and 7 non-laboring (NP) and 5 laboring term pregnant uterine biopsies (LP). PTHrP secretion was measured at baseline and in response to TGF-beta1 using a immunoradiometric assay. The USMC response to PTHrP was assessed by incubating cultures with human (1-34)PTHrP and measuring cellular cAMP by radioimmunoassay. We found that cultures from the groups did not differ with respect to basal PTHrP secretion. TGF-beta1, on the other hand, produced dose-dependent increases in secreted PTHrP in each group such that LP>NP>H at 12 hrs and LP>NP and H 24 hrs. Maximal responses were found at 24 hrs in cells treated with 10 ng/ml TGF-beta1 (LP: 2034+/-366 vs NP: 1485+/-427; H: 1250+/-202 fmol/mg). Incubation of cultures with PTHrP produced dose-dependent increases in cAMP production, with 10(-7) M increasing levels by 64%. Neither pregnancy nor labor significantly affected the cAMP response. These findings indicate that the human myometrium has the capacity to increase PTHrP secretion during pregnancy and labor through a TGF-beta-dependent pathway. Such findings are consistent with a role of PTHrP in enhancing uterine blood flow.     

Discovery and SAR of 2-aminothiazole inhibitors of cyclin-dependent kinase 5/p25 as a potential treatment for Alzheimer's disease

High-throughput screening with cyclin-dependent kinase 5 (cdk5)/p25 led to the discovery of N-(5-isopropyl-thiazol-2-yl)isobutyramide (1). This compound is an equipotent inhibitor of cdk5 and cyclin-dependent kinase 2 (cdk2)/cyclin E (IC(50)=ca. 320nM). Parallel and directed synthesis techniques were utilized to explore the SAR of this series. Up to 60-fold improvements in potency at cdk5 and 12-fold selectivity over cdk2 were achieved.     

Defining reference sequences for Nocardia species by similarity and clustering analyses of 16S rRNA gene sequence data

Background

The intra- and inter-species genetic diversity of bacteria and the absence of ‘reference’, or the most representative, sequences of individual species present a significant challenge for sequence-based identification. The aims of this study were to determine the utility, and compare the performance of several clustering and classification algorithms to identify the species of 364 sequences of 16S rRNA gene with a defined species in GenBank, and 110 sequences of 16S rRNA gene with no defined species, all within the genus Nocardia.

Methods

A total of 364 16S rRNA gene sequences of Nocardia species were studied. In addition, 110 16S rRNA gene sequences assigned only to the Nocardia genus level at the time of submission to GenBank were used for machine learning classification experiments. Different clustering algorithms were compared with a novel algorithm or the linear mapping (LM) of the distance matrix. Principal Components Analysis was used for the dimensionality reduction and visualization.

Results

The LM algorithm achieved the highest performance and classified the set of 364 16S rRNA sequences into 80 clusters, the majority of which (83.52%) corresponded with the original species. The most representative 16S rRNA sequences for individual Nocardia species have been identified as ‘centroids’ in respective clusters from which the distances to all other sequences were minimized; 110 16S rRNA gene sequences with identifications recorded only at the genus level were classified using machine learning methods. Simple kNN machine learning demonstrated the highest performance and classified Nocardia species sequences with an accuracy of 92.7% and a mean frequency of 0.578.

Conclusion

The identification of centroids of 16S rRNA gene sequence clusters using novel distance matrix clustering enables the identification of the most representative sequences for each individual species of Nocardia and allows the quantitation of inter- and intra-species variability.     

Remediation of Pb and Cd Polluted Soils Using In Situ Immobilization and Phytoextraction Techniques

In situ immobilization and phytoextraction techniques have been used for remediation of Pb and Cd polluted soils. Three rates (0.25, 0.5 and 1.0%) of seven immobilizing agents (cement, slag, phosphate rock, bitumen, Fe- and Al-gels, and δ-MnO₂) were tested on three soils containing various levels of Pb (48–192.0 ug/g) and Cd (0.75–3.45 ug/g). All immobilizing agents reduced the plant available Pb and Cd as extracted by DTPA (diethylenetriaminepentaacetic acid). The effectiveness of the various agents in immobilizing Pb and Cd followed the descending order: bitumen > cement > slag > Fe-gel > Al-gel > phosphate rock > δ -MnO₂. Cement and phosphate rock fixed Pb and Cd mainly in the carbonate form, whereas the slag, bitumen, Fe-gel, Al-gel and δ -MnO₂ fixed the metals mainly in the oxide form.

The results of pot experiment proved the high ability of barnyard grass (Echinnochloa stagninum) to accumulate elevated amounts of Pb and Cd (ranging from 291–2421 and 6.1–45.9 ug metal/g dry matter, respectively). These amounts are higher than those reported for hyperaccumulators, particularly for Pb. The amounts of Pb and Cd removed by barnyard grass represent, on average, 46 and 72% of their initial total contents in the soils, respectively. These results proved that, without any other soil treatments, barnyard grass is highly efficient in removing considerable amounts of Pb and Cd from polluted soil within a reasonably short period of time. Therefore, use of barnyard grass for the phytoremediation of Pb and Cd polluted soils is feasible and recommended as an environmentally safe and cheap method. The most significant finding of this study is to name the barnyard grass as an efficient lead accumulator plant.