Haemostasis and oral contraceptives

Selected hemostasis parameters were assayed in 131 women ingesting different kinds of oral contraceptives and 36 control women. No differences were noted in the plasma levels of fibrinogen, antithrombin III, prekallikrein, alpha 2 antiplasmin, fibrinopeptide A, platelet factor 4 and beta-thromboglobulin. Protein C and plasminogen levels were significantly higher in pill users (p less than 0.001, p less than 0.01) and fibronectin levels were lower (p less than 0.05). Canonical correlation, performed between clinical parameters and hemostasis data, revealed a negative correlation between antithrombin III levels and family history for thromboembolic diseases. A positive correlation was noted between fibrinogen and fibronectin levels in obese OC users. The data suggest that women taking OCs are not in a state of "hypercoagulability."     

Characterization oftrans-acting regulatory elements affecting the expression of Mn-superoxide dismutase (sodA) inEscherichia coli

Escherichia coli strains harboringtrans-acting mutations affecting the expression of Mn-superoxide dismutase (SOD) gene (sodA) were used to studysodA regulation. Complementation studies revealed that eitherarc (aerobic respiratory control) orfur (ferric uptake regulation) loci independently complemented anaerobic expression of asodA::lacZ protein fusion in one mutant strain (UV16). This mutant exhibited phenotypes (i.e., elevated outer membrane proteins, enzyme activity, and dye sensitivity) typical offur andarc mutants. When these mutations were introduced into an otherwise wild-type background, anaerobicsodA expression occurred only when botharc andfur mutations were present simultaneously, suggesting cooperative roles of Fur and Arc insodA repression. The reconstructedfur arcA andfur arcB double mutants were still inducible by iron chelators, suggesting the possible involvement of another iron-containing repressor protein. A second independent mutant strain harboring atrans-acting regulatory mutation (UV14) was only partially complemented by multicopy plasmids carryingfur ⁺ orarc ⁺ genes, implicating other genetic elements insodA regulation.     

Early increase in lymphocyte cyclic nucleotide phosphodiesterase activity upon mitogenic activation of human peripheral blood mononuclear cells.

Cyclic nucleotide phosphodiesterase activity of human peripheral blood mononuclear cells was significantly increased following a short (30 min) incubation with the mitogenic lectin Concanavalin A. Con A stimulated phosphodiesterase activity to the same extent whatever the subcellular compartment (homogenate, cytosol or pellet). Further separation of the Con A-activated mononuclear cells into lymphocyte-enriched and monocyte-enriched populations showed that the Con A-induced increase of phosphodiesterase activity exclusively affected the lymphocyte-enriched population. In lymphocytes, cyclic GMP phosphodiesterase activity was more importantly enhanced by Con A (+275%) than cyclic AMP phosphodiesterase activity (+75%). The increase of both activities occurred as early as from 10 min of Con A incubation and proved to be maximal with Con A doses of 2.5 and 5 micrograms per 10(6) cells, lower and higher doses being less effective. Inhibition experiments with reference inhibitors suggested that, among the high affinity phosphodiesterase isoforms, the cyclic GMP-inhibited enzyme might be more selectively enhanced by Con A than the cyclic AMP-specific, Rolipram-sensitive one. The non-mitogenic lectin Helix pomatia hemagglutinin, was not able to enhance cyclic nucleotide phosphodiesterase activity of human mononuclear cells whereas anti-CD3 monoclonal antibody, although being less effective than Con A, exhibited a significant stimulatory effect. Putting together these results suggest that the early increase in phosphodiesterase activity might be a normal step involved in the mitogenic activation of human lymphocyte.     

Evolutionary profile of the family Calliphoridae,with notes on the origin of myiasis

The family Calliphoridae is a group of heterogenous calyptrate flies with a worldwide distribution including species of ecological, veterinary, medical, and forensic importance. Notorious for their parasitic habits, the larvae of many blowflies are characterised – like some other dipteran larvae – by their ability to develop in animal flesh. When parasitism affects a living host, it is termed “myiasis”. This has led the Calliphoridae to be considered as a pivotal family in its relationship with a man. Nevertheless, even after more than 50 years of research, the phylogenetic relationships among calliphorid subfamilies together with the evolutionary origin of myiasis remain unclear. In order to elucidate these problems, we constructed three phylogenetic trees by using nucleotide sequence data from cytochrome oxidase subunit one (COI), representing a mitochondrial conservative gene, and nuclear 28S subunit of ribosomal RNA gene (28S rRNA) in order to interpret the evolutionary profile of myiasis in the family Calliphoridae. The sequenced data represented species associated with ectoparasitic life-styles, either saprophagy or facultative and obligate parasitism. A total number of 50 accessions were collected for 28S rRNA, 56 for COI, and 38 for combined sequences phylogeny. Molecular Evolutionary Genetics Analysis (MEGA) software was used to align 2197 nucleotide positions of 28S rRNA and 1500 nucleotide positions of COI with a gap opening penalties and gap extension penalties equalling 20 and 0.1 respectively. The results reveal the non-monophyly of the family Calliphoridae despite the stable monophyletic status of the Chrysomyinae, Luciliinae, and Auchmeromyiinae. Also, our findings recommend ranking the Toxotarsinae as a separate family. Furthermore, comparative analysis of the phylogenetic trees shows that the habit of obligatory myiasis originated independently more than five times. This strengthens our hypothesis that the origin of eating fresh meat is a case of convergent evolution that has taken place after speciation events millions of years ago. Finally, estimating the divergence dates between lineages from molecular sequences provides a better chance of understanding their evolutionary biology.     

Phenotype and Micro-array characterization of duplication 11q22.1-q25 and review of the literature

Partial duplication of 11q is related to several malformations like growth retardation, intellectual disability, hypoplasia of corpus callosum, short nose, palate defects, cardiac, urinary tract abnormalities and neural tube defects. We have studied the clinical and molecular characteristics of a patient with severe intellectual disabilities, dysmorphic features, congenital inguinal hernia and congenital cerebral malformation which is referred to as cytogenetic exploration. We have used FISH and array CGH analysis for a better understanding of the double chromosomic aberration involving a 7p microdeletion along with a partial duplication of 11q due to adjacent segregation of a paternal reciprocal translocation t(7;11)(p22;q21) revealed after banding analysis. The patient's karyotype formula was: 46,XY,der(7)t(7;11)(p22;q21)pat. FISH study confirmed these rearrangement and array CGH technique showed precisely the loss of at least 140 Kb on chromosome7p22.3pter and 33.4 Mb on chromosome11q22.1q25. Dysmorphic features, severe intellectual disability and brain malformations could result from the 11q22.1q25 trisomy. Our study provides an additional case for better understanding and delineating the partial duplication 11q.     

Segregostat: a novel concept to control phenotypic diversification dynamics on the example of Gram-negative bacteria

Controlling and managing the degree of phenotypic diversification of microbial populations is a challenging task. This task not only requires detailed knowledge regarding diversification mechanisms but also advanced technical set-ups for the real-time analyses and control of population behaviour on single-cell level. In this work, set-up, design and operation of the so called segregostat are described which, in contrast to a traditional chemostat, allows the control of phenotypic diversification of microbial populations over time. Two exemplary case studies will be discussed, i.e. phenotypic diversification dynamics of Eschericia coli and Pseudomonas putida based on outer membrane permeabilization, emphasizing the applicability and versatility of the proposed approach. Upon nutrient limitation, cell population tends to diversify into several subpopulations exhibiting distinct phenotypic features (non-permeabilized and permeabilized cells). Online analysis leads to the determination of the ratio between cells in these two states, which in turn triggers the addition of glucose pulses in order to maintain a predefined diversification ratio. These results prove that phenotypic diversification can be controlled by means of defined pulse-frequency modulation within continuously running bioreactor set-ups. This lays the foundation for systematic studies, not only of phenotypic diversification but also for all processes where dynamics single-cell approaches are required, such as synthetic co-culture processes.     

Chemodiversity of Volatile Oils in Thapsia garganica L. (Apiaceae)

The chemical composition of the volatile oils obtained from the roots, leaves, flowers, and stems of Thapsia garganica of Tunisian origin was investigated by GC‐FID and GC/MS analyses. Sesquiterpene hydrocarbons and oxygenated monoterpenes were predominant in the oils of all plant parts. Bicyclogermacrene (21.59–35.09%) was the main component in the former compound class, whereas geranial (3.31–14.84%) and linalool (0.81–10.9%) were the most prominent ones in the latter compound class. Principal‐component (PCA) and hierarchical‐cluster (HCA) analyses revealed some common constituents, but also significant variability amongst the oils of the different plant parts. This organ‐specific oil composition was discussed in relation to their biological and ecological functions. For the evaluation of the intraspecific chemical variability in T. garganica, the composition of the flower volatile oils from four wild populations was investigated. Bicyclogermacrene, linalool, and geranial were predominant in the oils of three populations, whereas epicubenol, β‐sesquiphellandrene, and cadina‐1,4‐diene were the most prominent components of the oil of one population. PCA and HCA allowed the separation of the flower oils into three distinct groups, however, no relationship was found between the volatile‐oil composition and the geographical distribution and pedoclimatic conditions of the studied populations.     

Essential oil composition of Hypericum triquetrifolium Turra. aerial parts

The essential oil obtained by hydrodistillation from the aerial parts of Tunisian endemic Hypericum triquetrifolium Turra (Clusiaceae) was analyzed using GC and GC-MS. One hundred and nine compounds consisting of 92.2% of total detected constituents were identified. Sesquiterpene hydrocarbons were the main constituents (59.37%), Alpha-humulene, cis-calamenene, delta-cadinene, bicyclogermacrene, eremophilene, betacaryophyllene and (E)-gamma-bisabolene were found as the main ones. Alpha-pinene (10.33%) was detected as the main monoterpene hydrocarbons (12.19%). The oxygenated sesquiterpenes constituted (9.33%); caryophyllene oxide (1.38%) was reported as the main constituent of this fraction. The oxygenated monoterpenes were weakly represented (4.62%) and consisted of constituents in low percentages (<1%).     

Characterization of <Emphasis Type="Italic">Deinococcus sahariens</Emphasis> sp. nov., a radiation-resistant bacterium isolated from a Saharan hot spring

An ultraviolet-radiation-resistant, Gram-positive, orange-pigmented, thermophilic and strictly aerobic cocci was isolated from Saharan water hot spring in Tunisia. The newly isolated bacterium, designated HAN-23^T, was identified based on polyphasic taxonomy including genotypic, phenotypic and chemotaxonomic characterization. Phylogenetic analysis based on 16S rRNA gene sequences placed this strain within Deinococcus genus. However, strain HAN-23^T is different from recognized species of the genus Deinococcus, showing less than 94.0% similarity values to its closest relatives. The predominant cellular fatty acids determined by gas chromatography were iso-C_15:0, iso-C_17:0 and iso C_17:1 ω9c. The major respiratory quinone was MK-8. The DNA G + C content was 66.9 mol%. DNA–DNA hybridization measurements revealed low DNA relatedness (6%) between the novel isolate and its closest neighbor, the type strain Deinococcus geothermalis DSM 11300. On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain HAN-23^T represents a novel species of the genus Deinococcus, for which the name Deinococcus sahariens sp. nov. is proposed, the type strain being HAN-23^T (=DSM 18496^T; LMG 23756^T).