Antioxidant, anticancer and hepatoprotective activities of Cotoneaster horizontalis Decne extract as well as α-tocopherol and amygdalin production from in vitro culture

The phytochemical analysis of the ethanolic extract of branches of Cotoneaster horizontalis, Decne revealed the presence of: β-carotene, ascorbic acid and less amounts of α-tocopherol and amygdalin (vitamin B₁₇) in proportions of: 2,500, 70, 0.093, 0.334 mg 100 g^?1, respectively. Acute oral toxicity test revealed its safety profile. In vitro study revealed its good 2, 2-diphenyl-1-picrylhydrazyl radical scavenging and anticancer activities. Invivo study, simultaneous administration of this extract at a dose of 100 or 200 mg kg^?1 body weight for 4 weeks, exhibited a significant protection in a dose-dependant manner against hepatotoxicity induced by repeated dose of acetaminophen (1 g kg^?1 body weight day^?1, p.o.) by preserving the liver function parameters, hepatic redox state and serum lipid profile near the healthy levels. Consequently, in vitro culture was carried out on full or half strength of Murashige and Skoog medium supplemented with different concentrations of benzyl amino purine or kinetin provided shootlets production; different concentrations of 2,4-dichlorophenoxy acetic acid and naphthalene acetic acid showed an increase of callus. Determination of α-tocopherol and amygdalin in different shootlets and callus extracts showed a pronounced increases up to 30.62 and 3.69 mg 100 g^?1 in shootlet extract, respectively as well as 26.61 and 12.71 mg 100 g^?1 in callus extract, respectively, as compared with those of the mother plant (0.76 and 0.11 mg 100 g^?1 extract, respectively).     

Aphid (Hemiptera: Aphidoidea) diversity in Tunisia in relation to seed potato production

Winged morphs of aphids were investigated from 2002 to 2004 in 4 Tunisian regions of potato seeds production in order to know the aphid diversity and the potential vectors of Potato Virus Y. This is a very important contribution to the knowledge of aphid fauna in Maghreb. A total of 50,030 aphids were caught using yellow water traps and one suction trap. 130 taxa were identified including 103 species. Ten species are well represented in all regions prospected and typical species were also observed in every region. Some differences in species diversity appeared between regions which are discussed considering weather condition and vegetation.     

Inferences of Demography and Selection in an African Population of Drosophila melanogaster

It remains a central problem in population genetics to infer the past action of natural selection, and these inferences pose a challenge because demographic events will also substantially affect patterns of polymorphism and divergence. Thus it is imperative to explicitly model the underlying demographic history of the population whenever making inferences about natural selection. In light of the considerable interest in adaptation in African populations of Drosophila melanogaster, which are considered ancestral to the species, we generated a large polymorphism data set representing 2.1 Mb from each of 20 individuals from a Ugandan population of D. melanogaster. In contrast to previous inferences of a simple population expansion in eastern Africa, our demographic modeling of this ancestral population reveals a strong signature of a population bottleneck followed by population expansion, which has significant implications for future demographic modeling of derived populations of this species. Taking this more complex underlying demographic history into account, we also estimate a mean X-linked region-wide rate of adaptation of 6 × 10⁻¹¹/site/generation and a mean selection coefficient of beneficial mutations of 0.0009. These inferences regarding the rate and strength of selection are largely consistent with most other estimates from D. melanogaster and indicate a relatively high rate of adaptation driven by weakly beneficial mutations.     

Stevens-Johnson Syndrome Associated with Drugs and Vaccines in Children: A Case-Control Study

Objective

Stevens-Johnson Syndrome (SJS) is one of the most severe muco-cutaneous diseases and its occurrence is often attributed to drug use. The aim of the present study is to quantify the risk of SJS in association with drug and vaccine use in children.

Methods

A multicenter surveillance of children hospitalized through the emergency departments for acute conditions of interest is currently ongoing in Italy. Cases with a diagnosis of SJS were retrieved from all admissions. Parents were interviewed on child’s use of drugs and vaccines preceding the onset of symptoms that led to the hospitalization. We compared the use of drugs and vaccines in cases with the corresponding use in a control group of children hospitalized for acute neurological conditions.

Results

Twenty-nine children with a diagnosis of SJS and 1,362 with neurological disorders were hospitalized between 1^st November 1999 and 31^st October 2012. Cases were more frequently exposed to drugs (79% vs 58% in the control group; adjusted OR 2.4; 95% CI 1.0–6.1). Anticonvulsants presented the highest adjusted OR: 26.8 (95% CI 8.4–86.0). Significantly elevated risks were also estimated for antibiotics use (adjusted OR 3.3; 95% CI 1.5–7.2), corticosteroids (adjusted OR 4.2; 95% CI 1.8–9.9) and paracetamol (adjusted OR 3.2; 95% CI 1.5–6.9). No increased risk was estimated for vaccines (adjusted OR: 0.9; 95% CI 0.3–2.8).

Discussion

Our study provides additional evidence on the etiologic role of drugs and vaccines in the occurrence of SJS in children.     

Transmissibility of the Monkeypox Virus Clades via Respiratory Transmission: Investigation Using the Prairie Dog-Monkeypox Virus Challenge System

Monkeypox virus (MPXV) is endemic within Africa where it sporadically is reported to cause outbreaks of human disease. In 2003, an outbreak of human MPXV occurred in the US after the importation of infected African rodents. Since the eradication of smallpox (caused by an orthopoxvirus (OPXV) related to MPXV) and cessation of routine smallpox vaccination (with the live OPXV vaccinia), there is an increasing population of people susceptible to OPXV diseases. Previous studies have shown that the prairie dog MPXV model is a functional animal model for the study of systemic human OPXV illness. Studies with this model have demonstrated that infected animals are able to transmit the virus to naive animals through multiple routes of exposure causing subsequent infection, but were not able to prove that infected animals could transmit the virus exclusively via the respiratory route. Herein we used the model system to evaluate the hypothesis that the Congo Basin clade of MPXV is more easily transmitted, via respiratory route, than the West African clade. Using a small number of test animals, we show that transmission of viruses from each of the MPXV clade was minimal via respiratory transmission. However, transmissibility of the Congo Basin clade was slightly greater than West African MXPV clade (16.7% and 0% respectively). Based on these findings, respiratory transmission appears to be less efficient than those of previous studies assessing contact as a mechanism of transmission within the prairie dog MPXV animal model.     

PrimPol-deficient cells exhibit a pronounced G2 checkpoint response following UV damage

PrimPol is a recently identified member of the archaeo-eukaryote primase (AEP) family of primase-polymerases. It has been shown that this mitochondrial and nuclear localized enzyme plays roles in the maintenance of both unperturbed replication fork progression and in the bypass of lesions after DNA damage. Here, we utilized an avian (DT40) knockout cell line to further study the consequences of loss of PrimPol (PrimPol^?/?) on the downstream maintenance of cells after UV damage. We report that PrimPol^?/? cells are more sensitive to UV-C irradiation in colony survival assays than Pol η-deficient cells. Although this increased UV sensitivity is not evident in cell viability assays, we show that this discrepancy is due to an enhanced checkpoint arrest after UV-C damage in the absence of PrimPol. PrimPol^?/? arrested cells become stalled in G2, where they are protected from UV-induced cell death. Despite lacking an enzyme required for the bypass and maintenance of replication fork progression in the presence of UV damage, we show that PrimPol^?/? cells actually have an advantage in the presence of a Chk1 inhibitor due to their slow progression through S-phase.