The GC-box is an important transcriptional regulatory element present in the promoters of many mammalian genes, and is found in most, if not all, oxidative phosphorylation (OXPHOS) promoters. In the present study we examine the effects of three Sp1 family members (Sp2, Sp3, and Sp4) on the adenine nucleotide translocase 2, cytochrome c1, F1-ATPase β-subunit, and the mitochondria transcription factor (mtTFA) promoters in Drosophila SL2 cell line. Sp3, like Sp1, strongly activates transcription all four promoters. SP4 stimulates, moderately, but Sp2 had no effect. In addition, Sp3 can, like Sp1, inhibit transcription from the proximal promoter of the ANT2 gene through binding to the Cbox GC element. By contrast, Sp4 and Sp2 do not repress promoter activity. Furthermore, since Sp4 and Sp2 bind to the Cbox repression element on the ANT2 promoter, but do not repress transcription, inhibition of transcription … arabic 21 English 97
Ahmed Zaid(1-2012)

Background— The proprotein convertase subtilisin/kexin type 9 (PCSK9) promotes independently of its enzymatic activity the degradation of the low-density lipoprotein (LDL) receptor. PCSK9 gain of function in humans leads to autosomal dominant hypercholesterolemia, whereas the absence of functional PCSK9 results in ≈7-fold lower levels of LDL cholesterol. This suggests that lowering PCSK9 may protect against atherosclerosis. Methods and Results— We investigated the role of PCSK9 in atherosclerosis in C57BL/6 wild-type (WT), apolipoprotein E–deficient, and LDL receptor–deficient mouse models. Circulating cholesterol levels, fast protein liquid chromatography profiles, aortic cholesteryl esters (CE), and plaque sizes were determined. Intima-media thicknesses were measured by ultrasound biomicroscopy. First, mice expressing null (knockout [KO]), normal (WT), or high (transgenic [Tg]) levels of PCSK9 … arabic 12 English 86
Maxime Denis, Ahmed Zaid(1-2012)

COVID-19, caused by the SARS-CoV-2 virus, is spreading rapidly worldwide, with devastating consequences for patients, healthcare workers, health systems, and economies. As it reaches low- and middle-income countries, the pandemic puts healthcare workers at high risk and challenges the abilities of healthcare systems to respond to the crisis. This study measured levels of knowledge and preparedness regarding COVID-19 among physicians and nurses. A cross-sectional survey was conducted among healthcare workers in Libya between February 26 and March 10, 2020. We obtained 1,572 valid responses of a possible 2,000 (78.6%) participants from 21 hospitals, of which 65.1% were from physicians and 34.9% from nurses. The majority of participants (70%) used social media as a source of information. A total of 47.3% of doctors and 54.7% of nurses received adequate training on how to effectively use personal protective equipment. Low confidence in managing suspected COVID-19 patients was reported by 83.8% of participants. Furthermore, 43.2% of healthcare workers were aware of proper hand hygiene techniques. Less than 7% of participants received training on how to manage COVID-19 cases, whereas 20.6% of doctors and 26.3% of nurses felt that they were personally prepared for the outbreak. Awareness and preparedness for the pandemic were low among frontline workers during the study. Therefore, an effective educational training program should be implemented to ensure maintenance of appropriate practices during the COVID-19 pandemic. arabic 19 English 107
Muhammed Elhadi, Ahmed Zaid(1-2020)