👤 Shreya Singh Kushwaha

Vicarious trauma, the psychological distress from witnessing others' suffering, is an increasingly recognized precursor to depression and anxiety. However, the underlying neurobiological mechanisms remain poorly understood and appear to be sex-dependent. This study investigated the behavioral, physiological, and molecular consequences of purely psychological stress using a novel rodent model of vicarious learned helplessness (VLH). Male and female C57BL/6J mice were used to establish VLH paradigm. Observer mice witnessed conspecifics receiving inescapable foot shocks through a partitioned chamber allowing multisensory interaction. Following 7 days of conditioning, behavioral assays assessed anxiety and depressive symptoms. Prefrontal cortex tissue was analyzed using RT-qPCR and immunoblotting to identify molecular alterations. Vicarious stress induced depression phenotype in both sexes, characterized by active avoidance deficits, anhedonia and anxiety, comparable to direct physical trauma. Physiological assessments revealed hypothalamic-pituitary-adrenal (HPA) axis hyperactivity with elevated plasma corticosterone in both sexes. While molecular analysis showed shared downregulation of metabotropic glutamate receptor 2 (mGluR2) and elevated Il6 mRNA in the prefrontal cortex, distinct sexual dimorphism emerged. Males displayed specific deficits in neurotrophic support ( Vicarious trauma is sufficient to drive depression-like pathology through distinct molecular trajectories in males and females. These findings are suggestive of the critical necessity for sex-specific therapeutic strategies when treating trauma-related psychiatric disorders. Show less

Fluoroquinolones (FQs) are key components of World Health Organization (WHO)-recommended regimens for multidrug-resistant tuberculosis (MDR-TB). Accurate detection of FQ resistance is essential for optimizing treatment. This study evaluated the concordance between the Second-Line Line Probe Assay (SL-LPA) and Liquid Culture Drug Susceptibility Testing (LC-DST) for detecting FQ resistance in Mycobacterium tuberculosis isolates. In this retrospective study, 1402 non-duplicate clinical isolates of MDR TB were tested using SL-LPA and LC-DST at a reference laboratory. Genotypic resistance was identified through mutations in the gyrA and gyrB genes identified by SL-LPA, while phenotypic resistance was determined using MGIT-based LC-DST at critical concentrations for fluoroquinolones. Targeted nanopore sequencing was performed on a subset of isolates with discordant molecular and phenotypic results to investigate resistance-associated mutations. SL-LPA detected FQ resistance in 907 (64.7%) isolates, whereas LC-DST identified resistance in 852 (60.8%) isolates. Using LC-DST as the reference standard, SL-LPA showed a sensitivity of 93.2%, specificity of 98.6%, positive predictive value of 99.2%, and negative predictive value of 88.7%. Overall concordance between the two methods was observed in 1292 (92.2%) isolates. Discordant results occurred in 110 (7.8%) isolates, mainly involving low-level resistance mutations or inferred resistance due to missing wild-type bands on SL-LPA. Nanopore sequencing of 15 discordant isolates identified high-confidence mutations (Asp94Tyr, Asp94Gly, Asp94Asn) and interim or low-confidence mutations (Ala90Val, Ser91Pro, Asp94Ala, gyrB Asn499Asp, Asp461Asn). SL-LPA demonstrates excellent specificity and positive predictive value for detecting FQ resistance; however, discordance associated with low-confidence mutations and heteroresistance highlights the importance of integrating molecular assays with phenotypic DST and sequencing to improve MDR-TB resistance detection and guide treatment decisions. Show less

Alzheimer's Disease (AD) is a devastating neurological condition characterized by a progressive decline in cognitive function, including memory loss, reasoning difficulties, and disorientation. Its hallmark features include the formation of neurofibrillary tangles and neuritic plaques in the brain, disrupting normal neuronal function. Neurofibrillary tangles, composed of phosphorylated tau protein and neuritic plaques, containing amyloid-β protein (Aβ) aggregates, contribute to the degenerative process. The discovery of the beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) in 1999 revolutionized our understanding of AD pathogenesis. BACE1 plays a crucial role in the production of Aβ, the toxic protein implicated in AD progression. Elevated levels of BACE1 have been observed in AD brains and bodily fluids, underscoring its significance in disease onset and progression. Despite setbacks in clinical trials of BACE1 inhibitors due to efficacy and safety concerns, targeting BACE1 remains a promising therapeutic strategy for early-stage AD. Natural flavonoids have emerged as potential BACE1 inhibitors, demonstrating the ability to reduce Aβ production in neuronal cells and inhibit BACE1 activity. In our review, we delve into the pathophysiology of AD, highlighting the central role of BACE1 in Aβ production and disease progression. We explore the therapeutic potential of BACE1 inhibitors, including natural flavonoids, in controlling AD symptoms. Additionally, we provide insights into ongoing clinical trials and available patents in this field, shedding light on future directions for AD treatment research. Show less

Pfeiffer syndrome is a rare syndromic craniosynostosis characterized by bilateral coronal craniosynostosis, midface hypoplasia, beaked nasal tip, broad and medially deviated thumbs and great toes. It is caused by mutations affecting the fibroblast growth factor receptors type 1 or 2 (FGFR1 or FGFR2), with autosomal dominant inheritance. It displays substantial clinical and genetic heterogeneity. The disorder is usually detected in the neonatal period, and very few prenatally diagnosed cases have been reported. Show less