Messinian palaeoenvironments and hydrology in Sicily (Italy): The dinoflagellate cyst record

Hydrological conditions prevailing before, during and after the Messinian salinity crisis in Sicily have been approached using dinoflagellate cyst records. The synthetic sequence considered is based on five classical sections from the Caltanissetta Basin. Our interpretations are based on the recognition of autochthonous, allochthonous and reworked population among the dinocyst assemblages. For the first time, sea-surface temperatures and seasonal salinity contrasts were tentatively reconstructed using a “Mutual Climatic Range Method”. Sicilian late Tortonian deposits correspond to marine environment with significant terrestrial inputs favourable to eutrophic dinocyst species. Immediately after the beginning of the Messinian Stage, euryhaline assemblages took place, followed by meso-hyperhaline taxa, within a general trend to shallowing. At the end of the Tripoli diatomitic Formation, environment appears confined, with regular oceanic inflows. Such marine inflows remain persistent during the deposition of the salt Member, witnessing the probable persistence of nearby normal marine sea-surface water conditions in the Mediterranean Sea but with possible reduced hydrological circulation and/or low nutrient component. Such inflows are slightly decreasing up to the top of the Sicilian Upper Evaporites. At the same time, river inputs appear weak during the salt deposition, as the consequence of a rather dry climatic context. As shown by reworking activity, terrestrial inputs increase progressively from the base of the Upper Evaporites. During the Lago Mare period, while climate remains rather dry (absence of freshwater algae inputs, very low amount in trees requiring humid conditions), local deposition environment is confined with mesohaline to hypohaline sea-surface waters, in a context with relatively high seasonal sea-surface salinity contrast (up to 6‰). The very high reworking observed in the Arenazzolo silts, in addition to slightly increasing water depth, led us to consider the presence of a discontinuity between the Lago Mare and the Arenazzolo Fms. We consider the Arenazzolo Formation as a transgressive facies following a deep downcutting period. The Arenazzolo Formation presents a two-step development. The first one, correlative with the presence of a G. etrusca (a species with Paratethyan affinities), corresponds to a relative high-stand sea-level with oceanic influxes, low seasonal sea-surface salinity contrast and probable more humid context, as revealed by the important freshwater algal inputs. During the second step, salinity becomes much more variable, with a clear increase of seasonal sea-surface salinity contrast, a possible slight mean sea-surface temperature increase (only few degrees) and a clear weakening of the river inputs. Taking the proposed Zanclean position of the Arenazzolo Fm. into consideration, we state that mean sea-surface temperature did not change significantly from the base of the Messinian to the earliest Zanclean. At 5.33 Ma, the suddenly achieved flooding restored a fair, deep oceanic environment characterized, at the beginning, by a clear mean sea-surface temperature cooling (up to 6-7 °C) and a nutrient depletion, associated with the basins starvation. Sea-surface salinities were normal, with very low seasonal contrast. Hydrodynamics then nutrient supply became then quite normal from c.a. 5.08 Ma. The status of the Sicilian Caltanissetta Basin as a marginal basin although fastly deepening and the stratigraphical location of the Messinian discontinuity at the base of the Arenazzolo is the scenario that best matches our dinocyst record.     

Evidence for a second gene for primary microcephaly at MCPH5 on chromosome 1

Primary microcephaly has been mapped to five loci on different chromosomes. We present here the fine mapping of one of the loci, MCPH5, to a region of only 0.58 Mb located at the 1q31.3-1q32.1 junction. A genome scan was performed on five families from the Netherlands and Jordania, with 14 patients affected by microcephaly. A maximum LOD score of 4.78 was found for marker D1S1660 at the MCPH5 locus. Haplotype analysis suggests that the gene causing microcephaly is located between markers D1S3469 and D1S1660, which excludes the previously reported ASPM gene.     

Effect of vegetation on density thresholds of adult desert locust gregarization from survey data in Mauritania

In the desert locust, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae), the threshold density inducing the gregarization phenomenon has never been determined under natural conditions. The influence of environmental factors on this phenomenon has been studied mostly in controlled environments. Based on data collected during several years by the survey teams of the National Center for Locust Control in Mauritania, we analyzed the influence of locust density, vegetation cover, and vegetation status on the probability of observing gregarious locusts. We assumed that a probability to observe gregarious locusts of 0.5 corresponded to the density threshold of gregarization. The results showed in detail the change in the threshold of gregarization according to the cover and status of the vegetation. Low cover and dry vegetation led to a low density threshold of gregarization probably due to high probability of individuals to touch each other. Dense and green vegetation favored a high threshold of gregarization probably due to a dispersion of the individuals and a low probability of individual encounters. These findings should help the management of locusts and decision making during control operations.     

A Neuro-Comparative Study between Single/Successive Thorium Dose Intoxication and Alginate Treatment

The adult male albino rats were grouped into five groups (control group and four variably treated groups with thorium (Th) in single or successive with or without alginate treatment). The IP administration of thorium nitrate (13.6 mg/kg b.wt.) induced a regional distribution and accumulation ordered as cerebellum > cerebral cortex > brain stem > hippocampus > hypothalamus > striatum. Also, it induces a significant increase in Na⁺, Ca²⁺, and Fe³⁺ ion content and malondialdehyde (MDA) level while K⁺ ions and glutathione (GSH) level were significantly decreased. On the other hand, the daily oral administration of 5% alginate showed a significant decreasing in the accumulation of thorium in the different brain areas and mitigated its hazardous effects. By the alginate treatment, Na⁺, Ca²⁺, Fe³⁺, and level of MDA were declined while K⁺ ions and GSH level showed a significant increase. The improvement of the investigated parameters was attributed to the specific chelating, regeneration, and antioxidant properties of the alginate. So, alginate administration could ameliorate the hazardous effects of thorium nitrate.     

Sulfur and molybdenum fractionation in marine and riverine alluvium paddy soils

Intermittently submergence and drainage status of paddy fields can cause alterations in morphological and chemical characteristics of soils. We conducted a sequential fractionation study to provide an insight into solubility of Sulfur (S) and Molybdenum (Mo) in flooded alluvial paddy soils. The samples (0–15 and 15–30 cm) were taken from marine and riverine alluvial soils in Kedah and Kelantan areas, respectively, and were sequentially extracted with NaHCO₃, NaOH, HCl, and HClO₄–HNO₃. Total S in upper and lower layers of Kedah and Kelantan ranged between 273 and 1121 mg kg^?1, and 177 to 1509 mg kg^?1, respectively. In upper layers and subsoil of Kedah, average total Mo were 0.34 and 0.27 mg kg^?1, respectively. Average total Mo in Kelantan were 0.25 mg kg^?1 (surface layer) and 0.28 mg kg^?1 (subsoil). Cation exchange capacity (CEC) was positively correlated with plant available amounts of Mo in upper layers of Kedah area. Also, total and medium-term plant-available S was correlated with total carbon (C) at lower layers of Kelantan soil series. But in surface layers of Kelantan soil series, CEC was strongly correlated with total and medium-term plant-available S. Our results indicates that the influence of flooding conditions on soil S and Mo contents in paddy fields may cause long-term changes in S and Mo chemical reactivities.     

Immunoregulatory effects of freeze injured whole tumour cells on human dendritic cells using an in vitro cryotherapy model

Tumour cryotherapy has been described as both immunostimulatory and immunoinhibitory in previous studies. However, previous studies have not accurately reproduced the precise conditions of current clinical cryotherapy. The objective of this study is to assess the immunological effects of cryotreated whole tumour cells on dendritic cells (DC) maturation and function using an in vitro model. Prostate cancer cells were cooled using Endocare cryo-system to mimic temperatures achieved during clinical cryotherapy. Human DC were prepared from cluster of differentiation (CD) 14 monocytes and matured with lipopolysaccharide (LPS). Cryotreated cancer cells were added to DC on day 3. On day 7, DC were harvested and phenotyped. Cytokine gene expression was assessed using real time quantitative polymerase chain reaction (RT-PCR). Functional activity of DC was assessed in allogenic mixed lymphocyte reaction (MLR) and the molecular changes using gene microarray technology. There was statistically significant upregulation of costimulatory molecules and maturation markers (CD86, CD83, CD80 and CL II) in DC loaded with cryotreated whole tumour cells compared to both control DC and DC matured with LPS (P < 0.001). There was a significant increase in stimulatory cytokines gene expression (IL-2, IL-12, IL-15, IL-18 and IFN-γ). However, IL-10 and TGF-β expression reduced significantly. The effect of different freezing temperature was equal. cDNA microarray analysis showed upregulation of interleukin 1 (IL-1) and cycline dependent kinase inhibitor 1A (CDKN1A (p21) and downregulation of Caspase 8 and BCL2. Overall, our findings suggest that the effect of cryotherapy is generally stimulatory to DC which may enhance anti-tumour effects. Therefore, the combination of cryotherapy and DC vaccine may represent a novel method to increase the efficacy of cryotherapy especially at the peripheral zones of the prostate where cells are exposed to sub-lethal temperature.     

Assessment of Synthesis Machinery of Two Antimicrobial Peptides from Paenibacillus alvei NP75

Paenibacillus alvei NP75, a Gram-positive bacterium, produces two different antimicrobial peptides, paenibacillin N and P, which has potent antimicrobial activity against many clinical pathogens. The synthesis pattern of these antimicrobial peptides by P. alvei NP75 was studied extensively. The results were outstanding in a way that the paenibacillin N was synthesized irrespective of the growth of bacteria (non-ribosomal mediated), whereas paenibacillin P production was carried out by ribosomal mediated. In addition to the antimicrobial peptides, P. alvei NP75 also produces an immunogenic extracellular protease to defend itself from its own antimicrobial peptide, paenibacillin P. Furthermore, this immunogenic protease production was impaired by the addition of protease inhibitor, phenylmethylsulfonyl fluoride (PMSF). The sodium dodecyl sulfate (SDS) treated strain (mutant) failed to produce paenibacillin P, whereas the production of neither paenibacillin N nor the protease was affected by the plasmid curing. The plasmid curing studies that divulge the genes responsible for the synthesis of paenibacillin N and protease were found to be genome encoded, and paenibacillin P was plasmid encoded. We are reporting, first of its kind, the co-production of two different antimicrobial peptides from P. alvei NP75 through non-ribosomal and ribosomal pathways that could be used as effective antibiotics.

     

Tetanus toxin selectively impairs anti-tumoral but not anti-microbial macrophage-mediated effector functions

Abstract The present study was designed to establish the susceptibility of macrophage-mediated effector functions to tetanus toxin (TT). Using the murine macrophage cell line, GG2EE, generated in vitro by v- raf /v- myc oncogenes, we have previously provided evidence that TT selectively inhibits interferon gamma (IFN-γ), but not basal, lysozyme activity. Here we show that while neither phagocytic nor candidacidal activities are affected by TT treatment, antitumoral activity is significantly impaired after exposure to TT. This phenomenon, which is dose-dependent, is fully ascribed to the holotoxin, as heat inactivated TT, C or A-B fragments result ineffective. Furthermore, C but not A-B fragment competes with TT in abrogating its inhibitory effects. Overall, these data indicate that TT is not a broad-spectrum, down-regulating signal on macrophage-mediated functions, thus implying that its toxic action is exerted on specific molecular targets.