A gram-negative colonizer of the oral cavity, Fusobacterium nucleatum not only interacts with many pathogens in the oral microbiome but also has the ability to spread to extraoral sites including placenta and amniotic fluid, promoting preterm birth. To date, however, the molecular mechanism of interspecies interactions-termed coaggregation-by F. nucleatum and how coaggregation affects bacterial virulence remain poorly defined. Here, we employed genome-wide transposon mutagenesis to uncover fusobacterial coaggregation factors, revealing the intertwined function of a two-component signal transduction system (TCS), named CarRS, and a lysine metabolic pathway in regulating the critical coaggregation factor RadD. Transcriptome analysis shows that CarR modulates a large regulon including radD and lysine metabolic genes, such as kamA and kamD, the expression of which are highly up-regulated in the ΔcarR mutant. Significantly, the native culture medium of ΔkamA or ΔkamD mutants builds up abundant amounts of free lysine, which blocks fusobacterial coaggregation with streptococci. Our demonstration that lysine-conjugated beads trap RadD from the membrane lysates suggests that lysine utilizes RadD as its receptor to act as a metabolic inhibitor of coaggregation. Lastly, using a mouse model of preterm birth, we show that fusobacterial virulence is significantly attenuated with the ΔkamA and ΔcarR mutants, in contrast to the enhanced virulence phenotype observed upon diminishing RadD (ΔradD or ΔcarS mutant). Evidently, F. nucleatum employs the TCS CarRS and environmental lysine to modulate RadD-mediated interspecies interaction, virulence, and nutrient acquisition to thrive in the adverse environment of oral biofilms and extraoral sites.The construction and maturation of the postsynaptic apparatus are crucial for synapse and dendrite development. The fundamental mechanisms underlying these processes are most often studied in glutamatergic central synapses in vertebrates. Whether the same principles apply to excitatory cholinergic synapses, such as those found in the insect central nervous system, is not known. To address this question, we investigated a group of projection neurons in the Drosophila larval visual system, the ventral lateral neurons (LNvs), and identified nAchRα1 (Dα1) and nAchRα6 (Dα6) as the main functional nicotinic acetylcholine receptor (nAchR) subunits in the larval LNvs. Using morphological analyses and calcium imaging studies, we demonstrated critical roles of these two subunits in supporting dendrite morphogenesis and synaptic transmission. Furthermore, our RNA sequencing analyses and endogenous tagging approach identified distinct transcriptional controls over the two subunits in the LNvs, which led to the up-regulation of Dα1 and down-regulation of Dα6 during larval development as well as to an activity-dependent suppression of Dα1 Additional functional analyses of synapse formation and dendrite dynamics further revealed a close association between the temporal regulation of individual nAchR subunits and their sequential requirements during the cholinergic synapse maturation. Together, our findings support transcriptional control of nAchR subunits as a core element of developmental and activity-dependent regulation of central cholinergic synapses. While the impact of trainee involvement in other surgical fields is well established, there is a paucity of literature assessing this relationship in orthopaedic spine surgery. The goal of this study was to further elucidate this relationship. A retrospective cohort study was initiated on patients undergoing 1-3 level lumbar spine fusion at a single academic center. Operative reports from cases were examined, and patients were divided into 2 groups depending on whether a fellow or resident (F/R) or a physician's assistant (PA) was used as the primary assist. Patients with less than 1-year follow-up were excluded. Multiple linear regression was used to assess change in each patient-reported outcome, and multiple binary logistic regression was used to determine significant predictors of revision, infection, and 30- or 90-day readmission. One hundred and seventy-two patients were included in the F/R group compared with 178 patients in the PA group. No differences existed between groups for total surgery time, length of stay, 30- or 90-day readmissions, infection, or revision rates. https://www.selleckchem.com/products/u18666a.html No differences existed between groups in terms of patient-reported outcomes preoperatively or postoperatively. In addition, presence of a surgical trainee was not a significant predictor of patient outcomes or rates of infection, overall revision, or 30- and 90-day readmission rates. The results of this study indicate the presence of an orthopaedic spine F/R does not increase complication rates and does not affect short-term patient-reported outcomes in lumbar decompression and fusion surgery. 3. 3. Currently, no authors of existing studies have attempted to classify the signal characteristics of disc herniation on magnetic resonance imaging (MRI) and their temporal relationship to symptoms of lumbar radiculopathy. The purpose of this study was to determine whether the MRI signal characteristics are predictive of acuity of symptoms in patients with lumbar disc herniation (LDH). A retrospective cohort study was conducted on patients treated at an academic center for LDH from 2015 to 2018. Patients were divided into 2 groups based on symptom duration (acute ≤6 weeks; or chronic >4 months). Two independent observers measured T1, T2 signal, and other MRI characteristics at the affected disc level. Univariate analysis was used to compare differences between groups. Multiple logistic regression was used to determine predictors of acuity. Eighty-nine patients were included (33 acute, 56 chronic) with no significant baseline differences between groups. Rater 2 observed a higher proportion of disc bulges in the chronic group ( = .021) and a higher abnormal T1 herniation signal in the acute group ( = .048). Rater 1 found a higher Pfirrmann grade ( = .005) and a higher prevalence of vertebral body spurring ( = .007) in the chronic group. Interobserver agreement for T1 central and herniation signals demonstrated poor to fair agreement, whereas the remainder of the measurements showed moderate to substantial agreement (κ = 0.4-0.8). Multiple logistic regression showed that Pfirrmann Grade 5 (odds ratio = 0.12, 95% confidence interval [0.02, 0.74], = .022) and anterior/posterior spurring (odds ratio = 0.053 [0.03, 0.85], = .023) were not associated with acuity. Other than Pfirrmann grade or vertebral body spurring, no MRI characteristics could be reliably identified that correlate with acuity of symptoms. 3. 3.