👤 Yehia Z Gad

Arsenic trioxide (ATO) remains vital in acute promyelocytic leukemia therapy, yet its clinical use is limited by cumulative organ toxicities, particularly neurotoxicity, which compromise tolerability and outcomes. Perindopril and L‑Arginine exert cytoprotective effects through antioxidant and anti‑inflammatory mechanisms. This study evaluated their neuroprotective efficacy against ATO‑induced neurotoxicity, emphasizing mechanistic pathways. Male rats were assigned to five groups: Control, ATO‑only (7.5 mg/kg, intraperitoneally, 14 days), Perindopril (2 mg/kg, orally), L‑Arginine (200 mg/kg, orally), and combined therapy. Interventions commenced seven days prior to the ATO challenge and continued for 21 days. Body weight was documented at baseline and endpoint; survival indices were monitored. Biochemical, histopathological, and molecular evaluations examined oxidative stress, inflammatory mediators, and apoptotic signaling. ATO exposure increased malondialdehyde (MDA) and nitric oxide derivatives (NOx), while reducing glutathione (GSH), superoxide dismutase (SOD), and catalase activities. It elevated tumor necrosis factor‑α (TNF‑α), interleukin‑1β (IL‑1β), and interleukin‑6 (IL‑6), while suppressing brain‑derived neurotrophic factor (BDNF) and nuclear factor erythroid 2‑related factor 2/heme oxygenase‑1 (Nrf2/HO‑1) signaling. Upregulation of Kelch‑like ECH‑associated protein 1/Nuclear factor kappa‑light‑chain‑enhancer of activated B cells (Keap1/NF‑κB), cleaved caspase‑3, and caspase‑3, alongside downregulation of B cell lymphoma‑2 (Bcl‑2), was evident. Histopathological lesions substantiated neurotoxicity. Perindopril and L‑Arginine markedly reversed these perturbations, reinstating molecular and structural homeostasis. Their combination afforded superior neuroprotection compared with monotherapies. Both agents mitigate ATO‑induced neurotoxicity through antioxidant, anti‑inflammatory, and anti‑apoptotic mechanisms, with their co‑administration surpassing individual efficacy. The Keap‑1/Nrf2/HO‑1 axis emerges as a critical therapeutic node, underscoring the translational potential of combined intervention. Show less

While the diagnosis of frontotemporal dementia (FTD) is based mostly on clinical features, [ The purpose of this study is to conduct a systematic review and meta-analysis on the diagnostic performance of ASL MRI in patients with FTD and compare it with that of [ A systematic search of PubMed, Scopus, and Embase was conducted until March 13, 2024. Inclusion criteria were original articles, patients with FTD and/or its variants, use of ASL MR perfusion imaging with or without [ The quality of eligible studies was assessed by using the Quality Assessment of Diagnostic Accuracy Studies-2. Pooled sensitivity, specificity, and diagnostic odds ratio (DOR) for [ Seven eligible studies were identified, which included a total of 102 patients with FTD. Aside from some of the studies showing, at worst, an unclear risk of bias in patient selection, index test, flow, and timing, all studies showed low risk of bias and applicability concerns in all categories. Data from 4 studies were included in our meta-analysis for ASL MRI and 3 studies for [ The number of studies was relatively small, with a small sample size. The studies used different scanning protocols as well as a mix of diagnostic metrics, all of which might have introduced heterogeneity in the data. While ASL MRI performed worse than [ Show less

The mutual interplay between neuroinflammation, synaptic plasticity, and autophagy has piqued researchers' interest, particularly when it comes to linking their impact and relationship to cognitive deficits. Being able to reduce inflammation and apoptosis, melatonin has shown to have positive neuroprotective effects; that is why we thought to check the possible role of agomelatine (AGO) as a promising candidate that could have a positive impact on cognitive deficits. In the current study, AGO (40 mg/kg/day, p.o., 7 days) successfully ameliorated the cognitive and learning disabilities caused by lipopolysaccharide (LPS) in rats (250 μg/kg/day, i.p., 7 days). This positive impact was supported by improved histopathological findings and improved spatial memory as assessed using Morris water maze. AGO showed a strong ability to control BACE1 activity and to rein in the hippocampal amyloid beta (Aβ) deposition. Also, it improved neuronal survival, neuroplasticity, and neurogenesis by boosting BDNF levels and promoting its advantageous effects and by reinforcing the pTrkB expression. In addition, it upregulated the pre- and postsynaptic neuroplasticity biomarkers resembled in synapsin I, synaptophysin, and PSD-95. Furthermore, AGO showed a modulatory action on Sortilin-related receptor with A-type repeats (SorLA) pathway and adjusted autophagy. It is noteworthy that all of these actions were abolished by administering PD98059 a MEK/ERK pathway inhibitor (0.3 mg/kg/day, i.p., 7 days). In conclusion, AGO administration significantly improves memory and learning disabilities associated with LPS administration by modulating the ERK/SorLA/BDNF/TrkB signaling pathway parallel to its capacity to adjust the autophagic process. Show less

Mutations in the HSD17B3 gene are associated with a 46,XY disorder of sexual development (46,XY DSD) as a result of low testosterone production during embryogenesis. To elucidate the molecular basis of the disorder by chemically analyzing four missense mutations in HSD17B3 (T54A, M164T, L194P, G289S) from Egyptian patients with 46,XY DSD. Expression plasmids for wild-type 17β-hydroxysteroid hydrogenase type 3 (17β-HSD3) and mutant enzymes generated by site-directed mutagenesis were transiently transfected into human HEK-293 cells. Protein expression was verified by western blotting and activity was determined by measuring the conversion of radiolabeled Δ Testosterone formation by wild-type and mutant 17β-HSD3 enzymes was compared. Mutations T54A and L194P, despite normal protein expression, completely abolished 17β-HSD3 activity, explaining their severe 46,XY DSD phenotype. Mutant M164T could still produce testosterone, albeit with significantly lower activity compared with wild-type 17β-HSD3, resulting in ambiguous genitalia or a microphallus at birth. The substitution G289S represented a polymorphism exhibiting comparable activity to wild-type 17β-HSD3. Sequencing of the SRD5A2 gene in three siblings bearing the HSD17B3 G289S polymorphism disclosed the homozygous Y91H mutation in the former gene, thus explaining the 46,XY DSD presentations. Molecular modeling analyses supported the biochemical observations and predicted a disruption of cofactor binding by mutations T54A and M164T and of substrate binding by L196P, resulting in the loss of enzyme activity. In contrast, the G289S substitution was predicted to disturb neither the three-dimensional structure nor enzyme activity. Biochemical analysis of mutant 17β-HSD3 enzymes is necessary to understand genotype-phenotype relationships. Biochemical analysis combined with molecular modeling provides insight into disease mechanism. However, the stability of mutant proteins in vivo cannot be predicted by this approach. The 17β-HSD3 G289S substitution, previously reported in other patients with 46,XY DSD, is a polymorphism that does not cause the disorder; thus, further sequence analysis was required and disclosed a mutation in SRD5A2, explaining the cause of 46,XY DSD in these patients. Engeli RT, Tsachaki M, Hassan HA, et al. Biochemical Analysis of Four Missense Mutations in the HSD17B3 Gene Associated With 46,XY Disorders of Sex Development in Egyptian Patients. J Sex Med 2017;14:1165-1174. Show less

17-β-Hydroxysteroid dehydrogenase type 3 deficiency is a rare autosomal recessive cause of 46,XY disorder of sex development. Worldwide, about 30 mutations in the hydroxysteroid (17-beta) dehydrogenase 3 (HSD17B3) gene have been reported, involving all exons except exon 1. Herein, we investigated an Egyptian female with 46,XY karyotype and low testosterone/Δ4-androstenedione ratio. Genomic DNA was extracted from blood samples, and then, direct DNA sequencing of HSD17B3 gene was performed. The patient had a homozygous mutation c.198G>A in exon 1 resulting in a stop codon (p.W50X). The study presents the first mutation to be reported in exon 1 of the HSD17B3 gene. Show less