Molecular architecture and functional dynamics of the pre-incision complex in nucleotide excision repair.

Nucleotide excision repair (NER) is vital for genome integrity. Yet, our understanding of the complex NER protein machinery remains incomplete. Combining cryo-EM and XL-MS data with AlphaFold2 predictions, we build an integrative model of the NER pre-incision complex(PInC). Here TFIIH serves as a molecular ruler, defining the DNA bubble size and precisely positioning the XPG and XPF nucleases for incision. Using simulations and graph theoretical analyses, we unveil PInC's assembly, global motions, and partitioning into dynamic communities. Remarkably, XPG caps XPD's DNA-binding groove and bridges both junctions of the DNA bubble, suggesting a novel coordination mechanism of PInC's dual incision. XPA rigging interlaces XPF/ERCC1 with RPA, XPD, XPB, and 5' ssDNA, exposing XPA's crucial role in licensing the XPF/ERCC1 incision. Mapping disease mutations onto our models reveals clustering into distinct mechanistic classes, elucidating xeroderma pigmentosum and Cockayne syndrome disease etiology.

The utility and outcomes of the temporalis muscle flap for palate reconstruction after maxillectomy for malignancy.

BACK GROUND: A common pedicled facial technique in head and neck reconstruction is the TMF It can be utilised to replace missing tissues in a variety of conditions, including oral deformities of the hard and soft palate. AIM: Aim of the study was to document the utility and outcomes with the reconstruction of the palate using TM flaps following Maxillectomy For maxillary sinus malignancies. METHODOLOGY: The study included 24 patients who were operated on for cancer maxilla and eligible for maxillectomy and reconstruction of the Palate using temporalis flap. Follow-up was planned for at least 12 months postoperative. Postoperative physical and speech therapy are initiated to help improve speech and swallow outcomes and to prevent trismus. RESULTS: The current study included 24 cases with Maxillary sinus cancer with a mean age of 42.34 ± 4.67. The mean operative time was 5.4 ± 1.22 h with no reported intraoperative bleeding or injury of important structures. No cases of facial palsy or trismus were reported while partial flap loss was reported in one case where oronasal fistula was evident. The donor site complications were minimal where seroma occurred in two patients and alopecia, wound infection and dehiscence were reported in one case each. The donor site depression was evident in 25 % of cases. CONCLUSION: TMF is an excellent option for the reconstruction of many craniofacial defects, it is easy to be harvested with good blood supply with minimal postoperative complications.

Bar adsorptive microextraction and liquid chromatography-diode array detection of synthetic cannabinoids in oral fluid.

In recent years, synthetic cannabinoids (SCs) have become a major public health issue. For this reason, there is a need for innovative analytical methods that allow its monitoring in biological matrices. In this work, we propose a novel methodology to screen eight SCs (AM-694, cumyl-5F-PINACA, MAM-2201, 5F-UR-144, JWH-018, JWH-122, UR-144 and APINACA) in oral fluids. A bar adsorptive microextraction method followed by microliquid desorption combined with high-performance liquid chromatography with diode array detection (BAµE-µLD/HPLC-DAD) was developed to monitor the target SCs. The main factors affecting the BAµE technology were fully optimized for oral fluid analysis. Under optimized experimental conditions, the proposed methodology showed good linear dynamic ranges from 20.0 to 2000.0 µg L-1 (r2 > 0.99, relative residuals < 15%), limits of detection between 2.0 and 5.0 µg L-1 and suitable average recovery yields (87.9-100.5%) for the eight studied SCs. The intra- and interday accuracies (bias ≤ ± 14.7%) and precisions (RSD ≤ 14.9%) were also evaluated at three spiking levels. The validated methodology was then assayed to oral fluid samples collected from several volunteers. The proposed analytical approach showed remarkable performance and could be an effective alternative for routine monitoring of the target compounds in oral fluid.

Effectiveness and safety of intra-articular interventions for knee and hip osteoarthritis based on large randomized trials: A systematic review and network meta-analysis.

OBJECTIVE: To quantify the effectiveness and safety of intra-articular interventions for knee and hip osteoarthritis (OA) through a systematic review and Bayesian random-effects network meta-analysis. DESIGN: We searched CENTRAL and regulatory agency websites (inception-2023) for large, English-language, randomized controlled trials (RCTs) (≥100 patients/group) examining any intra-articular intervention. PRIMARY OUTCOME: pain intensity. SECONDARY OUTCOMES: physical function and safety outcomes. Pain and function outcomes were analyzed at 2, 6, 12, 24, and 52 weeks post-randomization, and presented as standardized mean differences (SMDs) (95% credible intervals, 95% CrI). The prespecified minimal clinically important between-group difference (MID) was -0.37 SMD. Safety outcomes were presented as odds ratios (OR) (95% CrI). FINDINGS: Among 57 RCTs (22,795 participants) examining 18 intra-articular interventions, usual care or placebo, treatment effects were larger in 35 high-risk-of-bias trials than in 22 low/unclear-risk-of-bias trials. In the main analysis (excluding high-risk-of-bias trials), triamcinolone had the highest probabilities of reaching the MID at weeks 2 and 6 (75.3% and 90%, respectively) with corresponding SMDs of -0.48 (95% CrI,-0.85 to -0.10) and -0.53 (95% CrI,-0.79 to -0.27) compared to placebo (1 trial). The complex homeopathic products Tr14/Ze14 showed therapeutic potential at week 6 compared to placebo (SMD:-0.42, 95% CrI,-0.71 to -0.11, 63.5% probability of reaching the MID, 1 trial). Hyaluronic acid had no effect on pain (SMD:-0.04, 95% CrI,-0.19 to 0.11, 11 trials) but a higher risk of dropouts due to adverse events (OR: 2.01, 95% CrI,1.08 to 3.77) and serious adverse events (OR: 1.86, 95% CrI, 1.16 to 3.03) than placebo. CONCLUSION: Triamcinolone had the highest probabilities to have a treatment effect beyond the MID at weeks 2-6. Large RCTs with lower risk of bias indicate that the effects of 16 intra-articular interventions in knee or hip OA were smaller than the MID, and that most were consistent with placebo effects. Lack of evidence of long-term effectiveness underscores the need for further research beyond 24 weeks.

Designing Rigorous and Efficient Clinical Utility Studies for Early Detection Biomarkers.

Before implementing a biomarker in routine clinical care, it must demonstrate clinical utility by leading to clinical actions that positively affect patient-relevant outcomes. Randomly controlled early detection utility trials, especially those targeting mortality endpoint, are challenging due to their high costs and prolonged duration. Special design considerations are required to determine the clinical utility of early detection assays. This commentary reports on discussions among the National Cancer Institute's Early Detection Research Network investigators, outlining the recommended process for carrying out single-organ biomarker-driven clinical utility studies. We present the early detection utility studies in the context of phased biomarker development. We describe aspects of the studies related to the features of biomarker tests, the clinical context of endpoints, the performance criteria for later phase evaluation, and study size. We discuss novel adaptive design approaches for improving the efficiency and practicality of clinical utility trials. We recommend using multiple strategies, including adopting real-world evidence, emulated trials, and mathematical modeling to circumvent the challenges in conducting early detection utility trials.

Baseline status of the levels and distribution of rare, noble, and fissionable elements from the Northern Nile Delta black sand deposits.

This study examined the composition, distribution, and origins of rare, Noble, and fissionable elements for the first time in black sand deposits from the Northern Delta coastal region. The findings showed that among the elements under investigation, Fe, Ti, Mn, and Sn had the greatest mean levels, while Hf, Cd, and As had the lowest mean amounts. According to the study's elemental composition, black sand is thought to have economic worth for Ti, Zr, Hf, Sn, Ag, and W. The Zr, Co, Cd, Cu, Hf, V, W, and Zn correlation points to the same source origin. It is clear that the accessory mineral composition in the sediments under study especially the heavy ones controls the geochemical patterns of trace elements. The trace element concentrations of interest show a pattern of element variability related to the mineralogy of the sands, as indicated by the principal component analysis and cluster analysis. To explore and exploit heavy minerals in the research region, the study's findings are important.

Financial Hardship Among Patients With Early-Stage Colorectal Cancer.

Importance: The degree of cancer patients' financial hardship is dynamic and can change over time. Objective: To assess longitudinal changes in financial hardship among patients with early-stage colorectal cancer. Design, Setting, and Participants: In this prospective longitudinal cohort study, English-speaking adult patients with a new diagnosis of stage I to III colorectal cancer being treated with curative intent at National Cancer Institute (NCI) Community Oncology Research Program (NCORP) practices between May 2018 and July 2020 and who had not started chemotherapy and/or radiation were included. Data analysis was conducted from March to December 2023. Main Outcomes and Measures: Patients completed surveys at baseline as well as at 3, 6, 12, and 24 months after enrollment. Cost-related care nonadherence and material hardship, as adopted by Medical Expenditure Panel Survey, were measured. Factors associated with financial hardship were assessed using longitudinal multivariable logistic regression models with time interaction. Results: A total of 451 patients completed baseline questions, with 217 (48.1%) completing the 24-month follow-up. Mean (SD) age was 61.0 (12.0) years (210 [46.6%] female; 33 [7.3%] Black, 380 [84.3%] White, and 33 [7.3%] American Indian or Alaska Native, Asian, multiracial, or Native Hawaiian or Other Pacific Islander individuals or those who did not report race or who had unknown race). Among 217 patients with data at baseline and 24 months, 19 (8.8%) reported cost-related care nonadherence at baseline vs 20 (9.2%) at 24 months (P = .84), and 125 (57.6%) reported material hardship at baseline vs 76 (35.0%) at 24 months (P < .001). In multivariable analysis, lower financial worry (odds ratio [OR], 0.90; 95% CI, 0.87-0.93), higher education (OR, 0.34; 95% CI, 0.15-0.77), and older age (OR, 0.94; 95% CI, 0.91-0.98) were associated with lower nonadherence. Receipt of chemotherapy was associated with higher material hardship (OR, 2.68; 95% CI, 1.15-6.29), while lower financial worry was associated with lower material hardship (OR, 0.83; 95% CI, 0.80-0.96). Over 24 months, female sex was associated with lower nonadherence (OR, 0.90; 95% CI, 0.85-0.96), while higher education was associated with higher nonadherence (OR, 1.09; 95% CI, 1.03-1.17). Being employed was associated with lower material hardship (OR, 0.85; 95% CI, 0.78-0.93), while receipt of care at safety-net hospitals was associated with higher hardship (OR, 1.09; 95% CI, 1.01-1.17). Conclusions and Relevance: In patients with early-stage colorectal cancer, material hardship was more common than cost-related cancer care nonadherence and decreased over time, while nonadherence remained unchanged. Early and longitudinal financial screening and referral to intervention are recommended to mitigate financial hardship.

Dual SARS-CoV-2 and MERS-CoV inhibitors from Artemisia monosperma: isolation, structure elucidation, molecular modelling studies, and in vitro activities.

The COVID-19 pandemic has spread throughout the whole globe, so it is imperative that all available resources be used to treat this scourge. In reality, the development of new pharmaceuticals has mostly benefited from natural products. The widespread medicinal usage of species in the Asteraceae family is extensively researched. In this study, compounds isolated from methanolic extract of Artemisia monosperma Delile, a wild plant whose grows in Egypt's Sinai Peninsula. Three compounds, stigmasterol 3-O-ß-D-glucopyranoside 1, rhamnetin 3, and padmatin 6, were first isolated from this species. In addition, five previously reported compounds, arcapillin 2, jaceosidin 4, hispidulin 5, 7-O-methyleriodictyol 7, and eupatilin 8, were isolated. Applying molecular modelling simulations revealed two compounds, arcapillin 2 and rhamnetin 3 with the best docking interactions and energies within SARS-CoV-2 Mpro-binding site (-6.16, and -6.70 kcal mol-1, respectively). The top-docked compounds (2-3) were further evaluated for inhibitory concentrations (IC50), and half-maximal cytotoxicity (CC50) of both SARS-CoV-2 and MERS-CoV. Interestingly, arcapillin showed high antiviral activity towards SARS-CoV-2 and MERS-CoV, with IC50 values of 190.8 µg mL-1 and 16.58 µg mL-1, respectively. These findings may hold promise for further preclinical and clinical research, particularly on arcapillin itself or in collaboration with other drugs for COVID-19 treatment.

Atlas of Metastatic Gastric Cancer Links Ferroptosis to Disease Progression and Immunotherapy Response.

BACKGROUND & AIMS: Metastases from gastric adenocarcinoma (GAC) lead to high morbidity and mortality. Developing innovative and effective therapies requires a comprehensive understanding of the tumor and immune biology of advanced GAC. Yet, collecting matched specimens from advanced, treatment-naïve patients with GAC poses a significant challenge, limiting the scope of current research, which has focused predominantly on localized tumors. This gap hinders deeper insight into the metastatic dynamics of GAC. METHODS: We performed in-depth single-cell transcriptome and immune profiling on 68 paired, treatment-naïve, primary metastatic tumors to delineate alterations in cancer cells and their tumor microenvironment during metastatic progression. To validate our observations, we conducted comprehensive functional studies both in vitro and in vivo, using cell lines and multiple patient-derived xenograft and novel mouse models of GAC. RESULTS: Liver and peritoneal metastases exhibited distinct properties in cancer cells and dynamics of tumor microenvironment phenotypes, supporting the notion that cancer cells and their local tumor microenvironments co-evolve at metastatic sites. Our study also revealed differential activation of cancer meta-programs across metastases. We observed evasion of cancer cell ferroptosis via GPX4 up-regulation during GAC progression. Conditional depletion of Gpx4 or pharmacologic inhibition of ferroptosis resistance significantly attenuated tumor growth and metastatic progression. In addition, ferroptosis-resensitizing treatments augmented the efficacy of chimeric antigen receptor T-cell therapy. CONCLUSIONS: This study represents the largest single-cell dataset of metastatic GACs to date. High-resolution mapping of the molecular and cellular dynamics of GAC metastasis has revealed a rationale for targeting ferroptosis defense in combination with chimeric antigen receptor T-cell therapy as a novel therapeutic strategy with potential immense clinical implications.

Synthesis of N-Alkyl-3-[2-oxoquinolin-1(2H)-yl]propanoic Acid Derivatives and Related Compounds: Cytotoxicity and EGFR Inhibition of Some Propanamide Derivatives.

A series of 20 new structure-modified quinolin-2-one derivatives were prepared for biological evaluation. This was successfully achieved based on chemoselective reactions of heterocyclic amides with acrylic acid derivatives, which gave 3-[2-oxoquinolin-1-(2H)-yl] propanoic acid derivatives (N-substitution via a unique behavior). The ester was reacted with hydrazine to afford the corresponding hydrazide. Both the corresponding ester and hydrazide were used as building blocks to modify the quinolone structure and give N-hydroxyl propanamides, oxadiazoles, and thiosemicarbazides. The corresponding carboxylic acid and hydrazide were used to prepare several amides: N-alkyl-3-[2-oxoquinolin-1(2H)-yl]propanamides via azide and dicyclohexyl carbodiimide coupling methods. Among derivatives, compound 9e exhibited potent cytotoxicity against MCF-7 cells with an IC50 value of 1.32 µM compared to doxorubicin with an IC50 value of 1.21 µM. Additionally, it caused potent EGFR inhibition by 97% with an IC50 value of 16.89 nM compared to Erlotinib with an IC50 value of 29.8 nM. Finally, the binding mode of compound interactions toward EGFR was highlighted using a molecular docking study; compound 9e exhibited good binding affinity with a binding energy of -17.89 kcal/mol, and it formed H-bond interactions with Met 769 as the key amino acid of interaction. Accordingly, compound 9e may be developed as an EGFR-oriented chemotherapeutic antibreast cancer agent.

Adsorption of cationic dye onto Raphanus seeds: optimization, adsorption kinetics, thermodynamic studies.

Dyes are one of the common contaminants in industrial wastewater. Adsorption is the most widely method which used to treat dye-contaminated water due to their easy use, cost-effectiveness, and their efficiency was high. The aim of this study is the investigating of the utilization of the activated carbon which prepared from Raphanus seeds solid residual (ACRS) as a low cost adsorbent for removing of cationic Methylene Blue dye (MB)from wastewater. measuring the surface area using BET methods and SEM. The FT‒IR and XRD was measured. Different variables (e.g.: initial concentration of the dye, pH, contact time, and dosage) have been studied. Process has been systematically investigated experimentally at (25 ± 1 °C). The % removal of MB reached 99.4% after 90-min MB adsorption (40 mg/L) was observed within 5 min of contact time for the Raphanus seeds solid residual (ACRS) dosage of 4 g/L. MB initial concentration (10 ppm) Raphanus seeds solid residual (ACRS) effectively adsorbed MB (> 99%) over a widely range of pH (from pH 2 to pH 8). However, a swift decline in removal was observed when the pH was set at 7. The results of the adsorption kinetics analysis indicate a strong correlation with the pseudo-second-order model, as evidenced by the high regression coefficients. However, the adsorption capacity diminished with a rise in temperature. Thermodynamic calculations of (MB) onto Raphanus seeds solid residual (ACRS) is an exothermic reaction. The results have been indicated that the effectiveness of MB removal by activated carbon prepared from Raphanus seeds solid residual is favorable under neutral conditions, Raphanus seeds solid residual (ACRS) can be considered an efficient, environmentally friendly, readily available, and economical adsorbent that could treat industrial wastewater contaminated with cationic textile dyes. The objective of the experiments was to investigate the impact of various factors on the response of a process or formulation. To accomplish this goal, response surface methodology (RSM) has employed as a statistical model. RSM is an efficient and effective method for optimizing processes through the use of a quadratic polynomial model. The utilization of RSM allows for a reduction in the number of experiments needed, thus minimizing the associated costs of extensive analysis. This method has been done using Box-Behnken Design (BBD) to optimize % removal of MB. The optimal conditions as obtained from the RSM is pH 7,contact time 120 min, initial concentration 10 ppm, ACRS dosage 1 g, adsorption temperature 45 °C.

Decline in Explanatory Power of Trauma Mortality Models With Age: Varying Contribution of Glasgow Coma Scale, Injury Severity Score, Comorbidities, and Frailty.

INTRODUCTION: Adjusting for confounding variables is critical for objective comparison of outcomes. The explanatory power of variables used in adjusted models for injury and their relative utility across age groups has not been well-defined. This study aimed to assess the explanatory power of covariates commonly adjusted in injury research and their relative performance across age groups. METHODS: Inpatients 18-100 y (2017-2022) were selected from 90 hospital trauma registries. Patients were grouped into sequential 5-y age blocks. Mortality was defined as the proportion of patients "expired + hospice". Dominance analysis was used to determine the average contribution (McFadden's R2) for covariates commonly included in multivariable logistic regressions. RESULTS: Three hundred seventeen-thousand one hundred thirty-six patients were included (51.1% male, mean age: 63, mean injury severity score [ISS]: 9.8, mean Glasgow Coma Scale: 14.3, 93.5% blunt). Total explanatory power (McFadden's R2) for mortality was highest in youngest age group (52.7% in 18-24 group) and decreased with age, with the lowest R2 (19.6%) in 95-100 group. Regardless of age, the Glasgow Coma Scale was the most important covariate (R2 ranging from 9.0% to 20.4%). At age 18-24 y, ISS was a more dominant contributor than Elixhauser Score, but beyond 55 y, Elixhauser Score became more dominant than ISS. CONCLUSIONS: The explanatory power of adjustment models including common covariates is limited and varies significantly across age groups, decreasing linearly with age. Adjusting for outcomes using these covariates may limit objective comparisons especially for older adults. Additional research is needed to identify covariates that enhance the explanatory power of adjustment models to allow for more objective comparisons across all ages.

Antiplatelet Reversal is not Associated With Decreased Progression of Intracranial Hemorrhage in Near-Isolated Traumatic Brain Injury: A Retrospective Clustered Analysis From Two Trauma Centers.

INTRODUCTION: Antiplatelet agents (AAs) may increase the risk of intracranial hemorrhage (ICH). It is unclear whether reversal of antiplatelet effects (REV = desmopressin acetate [DDAVP] + Platelets) decreases ICH progression. The goal of the study was to determine whether REV was associated with decreased progression of ICH on repeat brain computed tomography (CT) scan. METHODS: This is a clustered study (November 2019 to March 2022) at two regionally distinct trauma centers (TCs) with differing standards of practice in patients with ICH, one reversal with DDAVP + Platelets (REV+) and the other no reversal with DDAVP + Platelets (REV-). Using electronic and manual chart review, data were collected on inpatients aged ≥ 18 y on preinjury AAs with CT proven ICH (abbreviated injury scale head ≥ 2) and no other abbreviated injury scale > 2 injuries, who had at least one repeat CT scan within 120 h of admission. ICH progression on repeat brain CT scan, mortality, and resource utilization were compared via univariate analysis (α = 0.05). RESULTS: One hundred fourteen patients were enrolled: 72 REV+ at the first TC and 42 REV- at the second TC. REV+ group had fewer White patients and a lower proportion on preinjury aspirin but were otherwise similar. ICH progression rate was 24/72 (33.3%) for REV+ and 11/42 (26.2%) for REV- (P = 0.43). Isolated subarachnoid hemorrhage was the most common lesion, followed by isolated subdural hemorrhage. No patients required cranial surgery. All-cause mortality (expired + hospice) was 5/72 (6.9%) and 1/42 (2.4%), respectively (P = 0.29). CONCLUSIONS: In this study of patients on preinjury AAs, REV was not associated with decreased ICH progression, lower mortality, or less resource utilization. These findings should be confirmed in a larger, prospective study.

Solitary Intraosseous Myofibroma of the Mandible in a Nine-Year-Old Child: A Case Report and Literature Review.

Myofibroma (MF) is a benign neoplasm derived from myofibroblasts. While they are infrequent, these tumors are predominantly found in the pediatric group and seldom manifest as intraosseous mandibular tumors. Herein, we present a 9-year-old female with a radiolucent lesion in the left mandible associated with malposed left lower canine and 1st premolar teeth. Clinical examination revealed a slightly tender 5×4 cm firm mass resulting in an expansion of the buccal and lingual aspects of the mandible in the canine and first premolar region. An incisional biopsy revealed a benign tumor consisting of spindle cells organized in fascicles, alongside dispersed thin-walled blood vessels. Tumor cells tested positive for α-smooth muscle actin (SMA) and vimentin. Given these findings, a diagnosis of MF was established. To the best of our knowledge, only 45 cases of solitary MF of the mandible have been reported in the pediatric age group in the literature. We describe one additional case and provide a review of the literature.

Enantiocomplementary Asymmetric Reduction of 2-Haloacetophenones Using TeSADH: Synthesis of Enantiopure 2-Halo-1-arylethanols.

Enantiopure 2-halo-1-arylethanols are essential precursors for the synthesis of pharmaceuticals, agrochemicals, and fine chemicals. This study investigates the asymmetric reduction of 2-haloacetophenones and their substituted analogs to obtain their corresponding optically active 2-halo-1-arylethanols using secondary alcohol dehydrogenase from Thermoanaerobacter pseudethanolicus (TeSADH) mutants. Specifically, the ΔP84/A85G and P84S/A85G TeSADH mutants were evaluated for the asymmetric reduction of 2-haloacetophenones, generating their corresponding optically active halohydrins with high enantioselectivities. The asymmetric reduction of 2-haloacetophenones and their substituted analogs using the ΔP84/A85G TeSADH mutant yielded their corresponding (S)-2-halo-1-arylethanols with high enantiopurity in accordance with the anti-Prelog's rule. Conversely, the P84S/A85G TeSADH mutant produced (R)-alcohols when reducing 2-chloro-4'-chloroacetophenone, 2-chloro-4'-bromoacetophenone, and 2-bromo-4'-chloroacetophenone, while generating the (S)-configured halohydrin from 2-chloro-4'-fluoroacetophenone. Asymmetric reduction of the unsubstituted 2-bromoacetophenone, 2-chloroacetophenone, and 2,2,2-trifluoroacetophenone resulted in production of their (S)-halohydrins with the tested mutants, which reflects the importance of the nature of the substituent on the substrate's ring in controlling the stereopreference of these TeSADH-catalyzed reduction reactions. These findings contribute to the understanding and application of TeSADH in synthesizing optically active compounds and aid in the design of further mutants with the desired stereopreference.

Single-molecule characterization of SV40 replisome and novel factors: human FPC and Mcm10.

The simian virus 40 (SV40) replisome only encodes for its helicase; large T-antigen (L-Tag), while relying on the host for the remaining proteins, making it an intriguing model system. Despite being one of the earliest reconstituted eukaryotic systems, the interactions coordinating its activities and the identification of new factors remain largely unexplored. Herein, we in vitro reconstituted the SV40 replisome activities at the single-molecule level, including DNA unwinding by L-Tag and the single-stranded DNA-binding protein Replication Protein A (RPA), primer extension by DNA polymerase δ, and their concerted leading-strand synthesis. We show that RPA stimulates the processivity of L-Tag without altering its rate and that DNA polymerase δ forms a stable complex with L-Tag during leading-strand synthesis. Furthermore, similar to human and budding yeast Cdc45-MCM-GINS helicase, L-Tag uses the fork protection complex (FPC) and the mini-chromosome maintenance protein 10 (Mcm10) during synthesis. Hereby, we demonstrate that FPC increases this rate, and both FPC and Mcm10 increase the processivity by stabilizing stalled replisomes and increasing their chances of restarting synthesis. The detailed kinetics and novel factors of the SV40 replisome establish it as a closer mimic of the host replisome and expand its application as a model replication system.

Structure of Aquifex aeolicus lumazine synthase by cryo-electron microscopy to 1.42†Šresolution.

Single-particle cryo-electron microscopy (cryo-EM) has become an essential structural determination technique with recent hardware developments making it possible to reach atomic resolution, at which individual atoms, including hydrogen atoms, can be resolved. In this study, we used the enzyme involved in the penultimate step of riboflavin biosynthesis as a test specimen to benchmark a recently installed microscope and determine if other protein complexes could reach a resolution of 1.5 Šor better, which so far has only been achieved for the iron carrier ferritin. Using state-of-the-art microscope and detector hardware as well as the latest software techniques to overcome microscope and sample limitations, a 1.42 Šmap of Aquifex aeolicus lumazine synthase (AaLS) was obtained from a 48 h microscope session. In addition to water molecules and ligands involved in the function of AaLS, we can observe positive density for ∼50% of the hydrogen atoms. A small improvement in the resolution was achieved by Ewald sphere correction which was expected to limit the resolution to ∼1.5 Šfor a molecule of this diameter. Our study confirms that other protein complexes can be solved to near-atomic resolution. Future improvements in specimen preparation and protein complex stabilization may allow more flexible macromolecules to reach this level of resolution and should become a priority of study in the field.

Correction: Sugar-Sweetened Beverage Consumption and Its Association With Dental Caries Among Adolescents in Erbil, Iraq: A Cross-Sectional Study.

[This corrects the article DOI: 10.7759/cureus.58471.].

Derangement in Nicotinamide Adenine Dinucleotide Metabolism is Observed During Acute Kidney Injury Among Male Agricultural Workers at Risk for Mesoamerican Nephropathy.

Introduction: Mesoamerican nephropathy (MeN) is a chronic kidney disease (CKD) which may be caused by recurrent acute kidney injury (AKI). We investigated urinary quinolinate-to-tryptophan ratio (Q/T), a validated marker of nicotinamide adenine dinucleotide (NAD+) biosynthesis that is elevated during ischemic and inflammatory AKI, in a sugarcane worker population in Nicaragua with high rates of MeN. Methods: Among 693 male sugarcane workers studied, we identified 45 who developed AKI during the harvest season. We matched them 1:1 based on age and job category with 2 comparison groups: (i) "no kidney injury," active sugarcane workers with serum creatinine (sCr) <1.1 mg/dl; and (ii) "CKD," individuals no longer working in sugarcane due to their CKD, who had additional 1:1 matching for sCr. We measured urine metabolites using liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) and compared Q/T and other metabolic features between the AKI and comparison groups. Results: Urine Q/T was significantly higher in workers with AKI than in those with no kidney injury (median interquartile Range [IQR]: 0.104 [0.074-0.167] vs. 0.060 [0.045-0.091], P < 0.0001) and marginally higher than in workers with CKD (0.086 [0.063-0.142], P = 0.059). Urine levels of the NAD+ precursor nicotinamide were lower in the AKI group than in comparison groups. Conclusion: Workers at risk for MeN who develop AKI demonstrate features of impaired NAD+ biosynthesis, thereby providing new insights into the metabolic mechanisms of injury in this population. Therapeutic use of oral nicotinamide, which may ameliorate NAD+ biosynthetic derangement and fortify against kidney injury, should be investigated to prevent AKI in this setting.

Central Giant Cell Granuloma of the Mandible and Maxilla: A Clinicopathological Study of 21 Cases.

Background Central giant cell granuloma (CGCG) presents as a locally invasive, intraosseous lesion characterized by the accumulation of multinucleated giant cells amidst a matrix of hemorrhage and reactive fibrous tissue that infiltrates bone trabeculae. This idiopathic non-neoplastic proliferative lesion primarily affects the mandible, typically presenting as either unilocular or multilocular radiolucencies on X-rays. Although trauma or intraosseous hemorrhages are potential triggers, the precise histogenesis and etiology remain unclear. CGCG predominantly occurs in children and young adults, with a slight female predilection. Methods and materials A retrospective analysis of 21 cases of CGCG diagnosed at the Oral Pathology/Pathology department of Temple University Hospital between 2015 and 2022 was conducted. Each case was evaluated based on various parameters, including age, gender, presenting symptoms, radiographic findings, clinical differential diagnosis, and histological confirmation. The primary radiographic technique employed for diagnosis was X-ray imaging of the mandible and maxilla. The histological examination involved cutting paraffin-embedded tissue into 5-micrometer-thick sections, which were then stained using routine hematoxylin and eosin (H&E) stain. Notably, no specialized histochemical or immunohistochemical stains were utilized in the evaluation process. Results In our study, we reviewed 21 cases; 9 were male, 11 were female, and one had no available gender data. The age range was 15-76 years, with a mean of 50 years. The mandible was the most commonly affected location (17 cases; 81%) while the maxilla was less commonly involved (4 cases; 19%). Many CGCG lesions were asymptomatic (13 cases; 62%); eight cases (38%) were symptomatic, with pain and fullness of the affected dental region being the main manifestations. In a few cases, conditions such as brown tumor (severe hyperparathyroidism) and odontogenic neoplasms, such as ameloblastoma, were suspected clinically and radiographically. The diagnosis of CGCG with associated acute and chronic inflammation was confirmed in all the cases. Histological evaluation of routinely stained slides was the main diagnostic tool utilized. No special stains or molecular studies were required to establish the final diagnosis. Conclusions Our investigation has determined that CGCG exhibits a non-neoplastic nature, displaying a spectrum of behaviors ranging from non-aggressive to aggressive tendencies. While CGCG is predominantly observed in the mandible, rare instances of involvement in the maxilla have also been documented. Importantly, no confirmed association with neoplastic lesions was identified during our analysis. The clinical course of CGCG tends to be indolent, with some cases presenting in association with impacted teeth. It's noteworthy that CGCG can present features mimicking neoplastic conditions, such as ameloblastoma, or localized lesions linked to systemic disorders such as hyperparathyroidism (brown tumor).