Antioxidant Role of Vitamin C in Alleviating the Reproductive Toxicity of Lead Acetate in Male Rats

Environmental pollution with heavy metals represents global problem. One of these heavy metals is the lead acetate that emits from many industries such as paint, ceramics, lead containing pipes and plastics led to a manifold rise in the occurrence of free lead in biological systems and the environment. Exposure to lead acetate affects most of the body’s organs especially testes since it has a unique vascular system. Therefore, the present study aimed to evaluate the protective effect of vitamin C against lead acetate induced testicular toxicity in rats. Thirty male adult albino rats were used in this study. They were equally divided into three groups; group I "control group", group II "lead acetate treated group" and group III "lead acetate and vitamin C treated group". Administration of lead acetate (20 mg /kg body weight for 8 successive weeks) resulted in a significant decrease in serum level of testosterone. It also led to a significant increase in the testicular tissue homogenate concentration of MDA and a significant decrease in GSH concentration and catalase activity. Administration of vitamin C (20 mg/kg body weight) with lead acetate for 8 successive weeks succeeded in improving semen quality and antioxidant enzyme concentrations of testes. It can be concluded that lead acetate testicular toxicity in rats led to disturbance in serum level of the main male reproductive hormone and increased testicular contents of oxidative markers and decreased the antioxidant markers. The use of vitamin C improved these changes.  &nbsp

Biochemical Evaluation of some Natural Feed Additives against Dexamethasone-induced Metabolic Alterations in Rabbits

Glucocorticoid therapy is limited by numerous metabolic adverse effects associated with long term exposure to excess doses. Therefore, the present study aims to determine the possible protective effects of date palm and/or Saccharomyces cerevisiae probiotics on dexamethasone-induced metabolic changes in rabbits. 25 healthy male white New Zealand rabbits were grouped into group 1 (control), group 2 (2 mg/kg bw/day dexamethasone I/M), group 3 (0.5 g/kg/day date palm flesh+2 mg/kg bw/day dexamethasone I/M), group 4 (1g/kg/day S. cerevisiae probiotic + 2 mg/kg bw/day dexamethasone I/M), group 5 (date palm flesh + S. cerevisiae probiotic + dexamethasone at the aforementioned doses). Dexamethasone injection resulted in marked increases (p≤0.05) in hepatic MDA concentration and catalase activity, as well as significant decreases in hepatic GSH concentration and body weight gain. The serum levels of glucose, lipid profile (TG, cholesterol, VLDL, LDL/HDL risk ratio), and liver function biomarkers (serum total proteins, albumin, ALT, ALP) showed significant variations (P≤0.05) between control and dexamethasone treated group. The ameliorative effect of date palm fruit and/or probiotics (S. cerevisiae) was markedly indicated by restoration of these tested parameters to near normalcy. Therefore, the co-treatment with date or S. cerevisiae could be considered of great interest as potential feed additives for reduction of the adverse metabolic effects induced by dexamethasone in rabbits

STEROLS BIOACTIVITY OF RUTA GRAVEOLENS L. AND MURRAYA PANICULATA L.

Objective: Ruta graveolens L. (R. graveolens) and Murraya paniculata L. (M. paniculata) are medicinal plants belonging to Rutaceae family have many uses in traditional medicine. The aim of the present study was to investigate sterols bioactivity of the two Rutaceae plant leaves.Methods: Sterols of the two Rutaceae plant leaves were identified using GC/MS. The antioxidant activities of the sterols of these herbs were evaluated by three different methods; free radical scavenging using 2,2′-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) and total antioxidant activity. The anticancer activity of the sterols was determined by MTT assay against colorectal cancer HCT116, breast cancer MCF7, liver cancer HepG2 and lung cancer A549 cell lines. Anti-inflammatory activity was evaluated using albumin denaturation assay and antiviral activities against H5N1 virus were carried out using plaque reduction assay.Results: GC/MS assay showed β-Sitosterol (36%) as the most abundant sterols of R. graveolens followed by stigmasterol (18%), while stigmasterol (25.2%) was the most abundant one of M. paniculata steroids. The anti-inflammatory potential of R. graveolens steroids was significantly higher than that of diclofenac sodium (standard drug). M. paniculata sterols have higher antiviral activity (IC50= 0.15 of µg/ml) than R. graveolens sterols (IC50= 7.8 of µg/ml). The sterols of R. graveolens showed anticancer activity against MCF7 and A549 cells with inhibition 84.3 and 81%, at 100 µg/ml respectively. While M. paniculata sterols showed 77.3% inhibition against A549 cells.Conclusion: The current study suggests that the sterols of M. paniculata have more anti-viral activity than R. graveolens sterols which showed more anticancer and anti-inflammatory activities

Effect of Casting Conditions on the Fracture Strength of Al-5 Mg Alloy Castings

During the transient phase of filling a casting running system, surface turbulence can cause the entrainment of oxide films into the bulk liquid. Previous research has suggested that the entrained oxide film would have a deleterious effect on the reproducibility of the mechanical properties of Al cast alloys. In this work, the Weibull moduli for the ultimate tensile strength (UTS) and % elongation of sand cast bars produced under different casting conditions were compared as indicators of casting reliability which was expected to be a function of the oxide film content. The results showed that the use of a thin runner along with the use of filters can significantly eliminate the surface turbulence of the melt during mould filling which would lead to the avoidance of the generation and entrainment of surface oxide films and in turn produce castings with more reliable and reproducible mechanical properties compared to the castings produced using conventional running systems

Rapid evolution of A(H5N1) influenza viruses after intercontinental spread to North America

Highly pathogenic avian influenza A(H5N1) viruses of clade 2.3.4.4b underwent an explosive geographic expansion in 2021 among wild birds and domestic poultry across Asia, Europe, and Africa. By the end of 2021, 2.3.4.4b viruses were detected in North America, signifying further intercontinental spread. Here we show that the western movement of clade 2.3.4.4b was quickly followed by reassortment with viruses circulating in wild birds in North America, resulting in the acquisition of different combinations of ribonucleoprotein genes. These reassortant A(H5N1) viruses are genotypically and phenotypically diverse, with many causing severe disease with dramatic neurologic involvement in mammals. The proclivity of the current A(H5N1) 2.3.4.4b virus lineage to reassort and target the central nervous system warrants concerted planning to combat the spread and evolution of the virus within the continent and to mitigate the impact of a potential influenza pandemic that could originate from similar A(H5N1) reassortants

Accelerated evolution of SARS-CoV-2 in free-ranging white-tailed deer

The zoonotic origin of the COVID-19 pandemic virus highlights the need to fill the vast gaps in our knowledge of SARS-CoV-2 ecology and evolution in non-human hosts. Here, we detected that SARS-CoV-2 was introduced from humans into white-tailed deer more than 30 times in Ohio, USA during November 2021-March 2022. Subsequently, deer-to-deer transmission persisted for 2–8 months, disseminating across hundreds of kilometers. Newly developed Bayesian phylogenetic methods quantified how SARS-CoV-2 evolution is not only three-times faster in white-tailed deer compared to the rate observed in humans but also driven by different mutational biases and selection pressures. The long-term effect of this accelerated evolutionary rate remains to be seen as no critical phenotypic changes were observed in our animal models using white-tailed deer origin viruses. Still, SARS-CoV-2 has transmitted in white-tailed deer populations for a relatively short duration, and the risk of future changes may have serious consequences for humans and livestock

Reconstructing Geographical Movements and Host Species Transitions of Foot-and-Mouth Disease Virus Serotype SAT 2

ABSTRACT Of the three foot-and-mouth-disease virus SAT serotypes mainly confined to sub-Saharan Africa, SAT 2 is the strain most often recorded in domestic animals and has caused outbreaks in North Africa and the Middle East six times in the last 25 years, with three apparently separate events occurring in 2012. This study updates the picture of SAT 2 phylogenetics by using all available sequences for the VP1 section of the genome available at the time of writing and uses phylogeographic methods to trace the origin of all outbreaks occurring north of the Sahara since 1990 and identify patterns of spread among countries of endemicity. Transitions between different host species are also enumerated. Outbreaks in North Africa appear to have origins in countries immediately south of the Sahara, whereas those in the Middle East are more often from East Africa. The results of the analysis of spread within sub-Saharan Africa are consistent with it being driven by relatively short-distance movements of animals across national borders, and the analysis of host species transitions supports the role of the African buffalo (Syncerus caffer) as an important natural reservoir. IMPORTANCE Foot-and-mouth disease virus is a livestock pathogen of major economic importance, with seven distinct serotypes occurring globally. The SAT 2 serotype, endemic in sub-Saharan Africa, has caused a number of outbreaks in North Africa and the Middle East during the last decades, including three separate incidents in 2012. A comprehensive analysis of all available RNA sequences for SAT 2 has not been published for some years. In this work, we performed this analysis using all previously published sequences and 49 newly determined examples. We also used phylogenetic methods to infer the source country for all outbreaks occurring outside sub-Saharan Africa since 1990 and to reconstruct the spread of viral lineages between countries where it is endemic and movements between different host species

The evolving SARS-CoV-2 epidemic in Africa: insights from rapidly expanding genomic surveillance

Investment in SARS-CoV-2 sequencing in Africa over the past year has led to a major increase in the number of sequences generated, now exceeding 100,000 genomes, used to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence domestically, and highlight that local sequencing enables faster turnaround time and more regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and shed light on the distinct dispersal dynamics of Variants of Concern, particularly Alpha, Beta, Delta, and Omicron, on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve, while the continent faces many emerging and re-emerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century