How the Conformational Movement of the Substrate Drives the Regioselective C-N Bond Formation in P450 TleB: Insights from Molecular Dynamics Simulations and Quantum Mechanical/Molecular Mechanical Calculations.

P450 TleB catalyzes the oxidative cyclization of the dipeptide N-methylvalyl-tryptophanol into indolactam V through selective intramolecular C-H bond amination at the indole C4 position. Understanding its catalytic mechanism is instrumental for the engineering or design of P450-catalyzed C-H amination reactions. Using multiscale computational methods, we show that the reaction proceeds through a diradical pathway, involving a hydrogen atom transfer (HAT) from N1-H to Cpd I, a conformational transformation of the substrate radical species, and a second HAT from N13-H to Cpd II. Intriguingly, the conformational transformation is found to be the key to enabling efficient and selective C-N coupling between N13 and C4 in the subsequent diradical coupling reaction. The underlined conformational transformation is triggered by the first HAT, which proceeds with an energy-demanding indole ring flip and is followed by the facile approach of the N13-H group to Cpd II. Detailed analysis shows that the internal electric field (IEF) from the protein environment plays key roles in the transformation process, which not only provides the driving force but also stabilizes the flipped conformation of the indole radical. Our simulations provide a clear picture of how the P450 enzyme can smartly modulate the selective C-N coupling reaction. The present findings are in line with all available experimental data, highlighting the crucial role of substrate dynamics in controlling this highly valuable reaction.

Prevalence and risk factors of oral human papillomavirus infection among 4212 healthy adults in Hebei, China.

BACKGROUND: Human papillomavirus (HPV) infection is an essential cause of oropharyngeal squamous cell carcinoma that is increasing in incidence worldwide. However, little is known about the epidemiology of oral HPV infection among healthy adults in China. METHODS: A study in northern China was conducted in 2021 as baseline data of Diverse Life-Course Cohort (DLCC). Residents who aged above 20 were eligible to participate. Oral swab specimens and questionnaires were collected from 4226 participants. HPV DNA in oral exfoliated cells was tested by Nested Polymerase Chain Reaction approach and sequencing. Univariate and multivariate analyses were performed to assess the associations between exposure factors and oral HPV infection. RESULTS: Overall prevalence of oral HPV infection was 4.08% (95%CI, 3.69%-4.68%). The most prevalent HPV type detected was HPV-81 (1.35%; 95% CI, 1.00%-1.70%), followed by HPV-16 (0.64%; 95% CI, 0.40%-0.88%). Oral HPV infection presented a bimodal pattern with respect to age in male and female participants. Oral HPV prevalence of male participants was significantly higher than prevalence of female participants (5.0% versus 3.6%, P = 0.041). Prevalence of oral HPV was higher among current smokers (OR = 1.59; 95% CI, 1.11-2.29; P = 0.039) and current drinkers (OR = 1.60; 95% CI, 1.14-2.25; P = 0.023). Current alcohol consumption was independently associated with oral HPV infection (OR = 1.74; 95% CI, 1.22-2.50; P = 0.010). CONCLUSIONS: Among healthy adults aged above 20 in Hebei, China, the prevalence of high-risk HPV infection was 1.92% (95%CI, 1.51%-2.34%). Oral HPV prevalence was independently associated with alcohol consumption. More tailored prevention strategies are needed to prevent oral HPV infection through smoking cessation, reduction of alcohol consumption, and HPV vaccination.

Correlation of immune makers with HPV 16 infections and the prognosis in oropharyngeal squamous cell carcinoma.

OBJECTIVES: This study aims to investigate the association of immune markers with high risk human papillomavirus 16 (HPV 16) infection status and to evaluate the prognostic value of programmed death ligand-1 (PD-L1) in patients with oropharyngeal squamous cell carcinoma (OPSCC). MATERIALS AND METHODS: This retrospective study collected 50 cases of HPV positive and HPV negative OPSCC from January 2011 to December 2015. The correlation of CD8 + tumor infiltrating lymphocytes (TILs), programmed death-1 (PD-1), and PD-L1 expression with HPV 16 infection status was analyzed via immunofluorescent staining and quantitative real-time PCR. RESULTS: There was no significant difference in the baseline data between the two groups. Patients with HPV + OPSCC had better prognosis compared to HPV - patients (5-year overall survival [OS], 66% vs. 40%, P = 0.003; 5-year disease specific survival [DSS], 73% vs. 44%, P = 0.001). The expressions of immunity related makers were significantly higher in the HPV + group than the HPV - group (CD8 + TIL: P = 0.039; PD-L1: P = 0.005; PD-1: P = 0.044). Positive CD8 + TIL and PD-L1 were independent factors for better prognosis of OPSCC (DSS, P < 0.001; OS, P < 0.001, respectively). Kaplan-Meier survival analysis indicated that patients with TILs of high HPV + /CD8 + expression were more likely to have better prognosis than those with TILs of low HPV + /CD8 + expression (DSS, P < 0.001; OS, P < 0.001), TILs of high expression of HPV - /CD8 + (DSS, P = 0.010; OS, P = 0.032), and TILs of low expression of HPV - /CD8 + (DSS, P < 0.001; OS, P < 0.001). Furthermore, HPV + /PD-L1 + OPSCC patients had significant better prognosis compared to patients with HPV + /PD-L1 - (DSS, P < 0.001; OS, P = 0.004), HPV - /PD-L1 + (DSS, P = 0.010; OS, P = 0.048) and HPV - /PD-L1 - (DSS, P < 0.001; OS, P < 0.001). CONCLUSIONS: HPV + OPSCC had a significantly better prognosis, and PD-L1 expression was elevated in HPV + OPSCC. PD-L1 positivity might be related to the better prognosis of HPV + OPSCC. CLINICAL RELEVANCE: This study provides a theoretical basis and baseline data for the application of immune checkpoint inhibitors in head and neck tumors.

Association between pathological differentiation and survival outcomes of patients with laryngeal squamous cell carcinoma.

PURPOSE: To investigate the prognostic value of histopathological differentiation for the survival of patients with laryngeal squamous cell carcinoma (LSCC). MATERIALS AND METHODS: Retrospective clinical and histopathological differentiation data on consecutive cases of LSCC from a single institution over a 10-years period were collected and analyzed in this study. Oncological outcomes were assessed based on disease-specific survival (DSS), disease-free survival (DFS), and overall survival (OS) using the Kaplan-Meier method and Cox proportional hazards regression analysis. Propensity score matching (PSM) was performed to reduce or eliminate the bias due to confounding variables. RESULTS: A total of 998 LSCC cases were identified in this study. As compared to well to moderately differentiated LSCC, poorly differentiated tumors had adjusted hazard ratios (aHRs) of 1.78 (95% confidence interval [CI] 1.31-2.43), 2.00 (95% CI 1.51-2.65), and 1.72 (95% CI 1.28-2.31) for DSS, DFS, and OS, respectively. The new patient cohort consisted of 138 patients with well to moderately differentiated LSCC and 138 patients with poorly differentiated LSCC after PSM. The survival outcomes of patients with well to moderately differentiated LSCCs were significantly better than those of patients with poorly differentiated tumors in DSS (aHR 1.91; 95% CI 1.24-2.95), DFS (aHR 2.07; 95% CI 1.37-3.12), and OS (aHR 2.14; 95% CI 1.39-3.28). CONCLUSION: This study showed that survival outcomes of patients with poorly differentiated LSCC were significantly worse than those of patients with well to moderately differentiated LSCC. In addition, histopathological differentiation is an important prognostic factor for LSCC survival. Therefore, further treatment plans should focus on poorly differentiated LSCC to improve the survival outcomes.

Circular RNA Expression Profile in Laryngeal Squamous Cell Carcinoma Revealed by Microarray.

BACKGROUND/AIMS: A growing body of evidence has suggested that circular RNAs (circRNAs) have crucial functions in the regulation of gene expression, and their dysregulation has been implicated in various types of cancers. However, the roles of circRNAs in laryngeal cancer remain largely unknown. This study investigated the global changes in the expression pattern of circRNAs in laryngeal squamous cell carcinoma (LSCC) to identify potential differentially expressed circRNAs. METHODS: Microarray-based circRNA expression was determined in LSCC and paired normal laryngeal tissues. Pathway analyses of the genes producing differentially expressed circRNAs were performed to predict the function of circRNAs using standard enrichment computational methods. Expression levels of candidate circRNAs and microRNAs (miRNAs) were detected by quantitative real-time PCR. The circRNA/ miRNA interactions were constructed using bioinformatics methods to predict the binding of miRNA with circRNA. RESULTS: We identified 506 differentially expressed circRNAs from human LSCC and normal laryngeal mucosa tissues. We confirmed that hsa_circ_0044520 and hsa_circ_0044529 were significantly upregulated in LSCC tissues. The most likely potential target miRNAs for hsa_ circ_0044520 and hsa_circ_0044529 were hsa-miR-4726-5p and hsa-miR-4640-5p, respectively. Functional analysis showed that hsa_circ_0044520 and hsa_circ_0044529 were involved in the process of collagen synthesis. CONCLUSION: Competitive endogenous RNA network prediction and bioinformatics functional analysis revealed that hsa_circ_0044520 and hsa_circ_0044529 play important regulatory roles by sponging hsa-miR-4726-5p and hsa-miR-4640-5p, thereby providing novel insights into the tumorigenesis of LSCC.

Theoretical Insight into the Fluorescence Spectral Tuning Mechanism: A Case Study of Flavin-Dependent Bacterial Luciferase.

Bioluminescence of bacteria is widely applied in biological imaging, environmental toxicant detection, and many other situations. Understanding the spectral tuning mechanism not only helps explain the diversity of colors observed in nature but also provides principles for bioengineering new color variants for practical applications. In this study, time-dependent density functional theory (TD-DFT) and quantum mechanics and molecular mechanics (QM/MM) calculations have been employed to understand the fluorescence spectral tuning mechanism of bacterial luciferase with a focus on the electrostatic effect. The spectrum can be tuned by both a homogeneous dielectric environment and oriented external electric fields (OEEFs). Increasing the solvent polarity leads to a redshift of the fluorescence emission maximum, λF, accompanied by a substantial increase in density. In contrast, applying an OEEF along the long axis of the isoalloxazine ring (X-axis) leads to a significant red- or blue-shift in λF, depending on the direction of the OEEF, yet with much smaller changes in intensity. The effect of polar solvents is directionless, and the red-shifts can be attributed to the larger dipole moment of the S1 state compared with that of the S0 state. However, the effect of OEEFs directly correlates with the difference dipole moment between the S1 and S0 states, which is directional and is determined by the charge redistribution upon deexcitation. Moreover, the electrostatic effect of bacterial luciferase is in line with the presence of an internal electric field (IEF) pointing in the negative X direction. Finally, the key residues that contribute to this IEF and strategies for modulating the spectrum through site-directed point mutations are discussed.

[Analysis of clinical diagnosis and treatment of Behet's disease with sore throat as the first symptom].

Objective:To summarize the clinical and diagnostic characteristics of Behet's disease with sore throat as the first symptom, so as to improve clinicians' understanding of the disease. Methods:The clinical data of 28 patients with Behet's disease who were first treated in Department of Otorhinolaryngology, Peking Union Medical College Hospital from January 2015 to January 2022 were analyzed retrospectively. All patients were examined by electronic laryngoscopy at the first visit and treated with local symptomatic therapy. Twenty-one patients were examined for C-reactive protein and blood sedimentation, and some patients were examined for immunological parameters. After the diagnosis of leukoaraiosis was confirmed, treatment was based on immunosuppression and could be supplemented with oral hormone therapy depending on the extent of the lesion and other organ involvement. Results:Sore throat was the first symptom of all patients, which could be accompanied by dysphagia or dyspnea. Endoscopy revealed oropharyngeal ulcer in 25 cases（89.3%）, laryngeal ulcer in 15 cases（53.6%）, hypopharyngeal ulcer in 14 cases（50.0%）, and adhesion of nasopharynx or throat in 8 cases（28.6%）. All patients had oral ulcer at the same time, including 21 cases（75.0%） with genital ulcer, 18 cases（64.3%） with skin damage, and 11 cases（39.3%） with eye disease. In the course of disease, there were 4 cases（14.3%） with joints involvement, 3 cases（10.7%） with nervous system disease, and 1 case（3.6%） with digestive system disease. The treatment is mainly immunosuppressive, and oral hormone therapy can be supplemented according to the extent of the disease and the involvement of other organs. Conclusion:The clinical manifestations of Behet's disease, with sore throat as the first symptom, are diverse. The ulcer may involve multiple parts of the throat, and a few patients may involve multiple systems of the whole body. Clinical attention should be paid to the early diagnosis and timely treatment to prevent or delay the involvement of the lesion in important organs or systems.

Preorganized Internal Electric Field Promotes a Double-Displacement Mechanism for the Adenine Excision Reaction by Adenine DNA Glycosylase.

Adenine DNA glycosylase (MutY) is a monofunctional glycosylase, removing adenines (A) misinserted opposite 8-oxo-7,8-dihydroguanine (OG), a common product of oxidative damage to DNA. Through multiscale calculations, we decipher a detailed adenine excision mechanism of MutY that is consistent with all available experimental data, involving an initial protonation step and two nucleophilic displacement steps. During the first displacement step, N-glycosidic bond cleavage is accompanied by the attack of the carboxylate group of residue Asp144 at the anomeric carbon (C1'), forming a covalent glycosyl-enzyme intermediate to stabilize the fleeting oxocarbenium ion. After departure of the excised base, water nucleophiles can be recruited to displace Asp144, completing the catalytic cycle with retention of stereochemistry at the C1' position. The two displacement reactions are found to mostly involve the movement of the oxocarbenium ion, occurring with large charge reorganization and thus sensitive to the internal electric field (IEF) exerted by the polar protein environment. Intriguingly, we find that the negatively charged carboxylate group is a good nucleophile for the oxocarbenium ion, yet an unactivated water molecule is not, and that the electric field catalysis strategy is used by the enzyme to enable its unique double-displacement reaction mechanism. A strong IEF, pointing toward 5' direction of the substrate sugar ring, greatly facilitates the second displacement reaction at the expense of elevating the barrier of the first one, thereby allowing both reactions to occur. These findings not only increase our understanding of the strategies used by DNA glycosylases to repair DNA lesions, but also have important implications for how internal/external electric field can be applied to modulate chemical reactions.

Sleeve resection with end-to-end anastomosis in the reconstruction of tracheal defects exceeding six rings: a clinical feasibility study and safety assessment.

Objectives: Reconstruction is always required for tracheal defects and sleeve resection with end-to-end anastomosis is the most common used. The aim of the study was to present surgical techniques and evaluate the outcomes of sleeve resection with end-to-end anastomosis in the reconstruction of tracheal defects exceeding six rings. Methods: The study included patients with primary or secondary malignancies and tracheal stenosis from 2014 to 2019, who were treated with sleeve resection exceeding six tracheal rings, and reconstructed with end-to-end anastomosis. Airway status and patient outcomes were the principal follow-up measures. Results: A total of 16 patients were enrolled in the study including three primary tracheal malignancies, 12 invasive thyroid carcinomas and one with tracheal stenosis. The extent of tracheal resection ranged from seven to nine rings, and the primary end-to-end anastomosis was performed in all 16 patients. Performance of tracheostomy or cricothyroidotomy was done in 6 patients with decannulation at a median of 42 days (range, 28-56). No anastomotic dehiscence, infection or bleeding occurred postoperatively, and all 16 patients maintained an unobstructed airway through the end of follow-up. Conclusions: Sleeve resection reconstructed with end-to-end anastomosis can serve as an appropriate therapeutic strategy for the tracheal defects even exceeding six rings. Adequate laryngeal release is the key to surgical success.

A novel classification of tracheal defects and the reconstruction strategies: A retrospective study based on 106 cases.

Objective: The study aims to present a novel classification of tracheal defects and the corresponding reconstruction strategies. Methods: The retrospective study was designed to analyze patients with diagnosed primary or secondary tracheal tumors from 1991 to 2020. Surgical techniques, complications and prognosis were reviewed. Airway status and patient outcomes were the principal follow-up measures. Tracheal defects were classified into two plane sizes (vertical (V) and horizontal (H) planes). Vertical defects were further categorized into three groups based on their tracheal ring numbers (V1, ≤ 5 rings; V2, 6-10 rings; and V3, > 10 rings). Tracheal defects with horizontal plane size H1 and H2 represent defects less and more than one-half the circumference of trachea. Thus, suitable reconstruction strategies were planned primarily based on "V" and "H" classifications. The reconstruction strategies performed were sleeve resection followed by an end-to-end anastomosis, window resection with sternocleidomastoid myoperiosteal flap reconstruction, defects conversion with rotation anastomosis, and modified tracheostomy with secondary flap reconstruction. Results: A total of 106 patients diagnosed with tracheal defects were enrolled in the study, of whom 59 patients underwent sleeve resection followed by end-to-end anastomosis; 40 patients received window resection alongside sternocleidomastoid (SCM) myoperiosteal flap reconstruction; five patients received converting defects with rotation anastomosis and two patients underwent modified tracheostomy with secondary stage flap reconstruction. Lumen stenosis occurred in three V2H1 defect cases and were treated by a second reconstruction surgery. Iatrogenic unilateral recurrent laryngeal nerve paralysis occurred in two patients with the V3H2 defect type, who were treated by temporary tracheotomy and partial vocal cord resection and extubated successfully during follow-up. All 106 patients achieved airway patency with adequate laryngeal function at the end of follow-up. No anastomotic dehiscence or bleeding occurred in any patient postoperatively. Conclusion: Though a significant number of multicenter studies concerning the reconstruction and classification of tracheal defects are needed, the study herein provides a novel classification of tracheal defects, which is primarily developed on the defect size. Therefore, the study might serve as a potential source for identifying suitable reconstruction strategies for practitioners.

Epidemiology of Oral Human Papillomavirus Infection among Diverse Chinese Adults in Typical Areas of China: Findings from the DLCC Study.

BACKGROUND: Human papillomavirus (HPV) infection is a predominant cause of oropharyngeal squamous cell carcinoma. However, there is limited knowledge about the epidemiology of oral HPV infections among adults in China. METHODS: We collected data from a prospective cohort that enrolled participants in Mainland China. A total of 9,867 participants ages at least 20 years provided oral swab specimens in typical areas of China (Hebei and Guangdong provinces) in 2021. HPV DNA in oral exfoliated cells was tested using nested PCR and sequencing. Prevalence among subpopulations was compared. Multivariable logistic regression models were employed to assess possible factors influencing oral HPV infection. RESULTS: The overall prevalence of oral HPV infection was 3.0% [95% confidence interval (CI): 2.68-3.36]. Among those infected, 1.3% (1.08-1.53) were infected with high-risk HPV types. Men had a higher age-standardized HPV infection prevalence (3.6%, 2.96-4.29) compared with their female counterparts (2.7%, 2.35-3.12). People in Hebei had a higher age- and sex-standardized prevalence (4.1%, 3.50-4.70) than those in Guangdong (2.2%, 1.80-2.56). Generally, men (OR and 95% CI: 1.42, 1.09-1.85) and people in Hebei (2.01, 1.53-2.65) had higher odds of any type of HPV infection. In addition, people living in urban areas had a 2.15-fold (1.43-3.26) higher odds of high-risk HPV infection. CONCLUSIONS: This study reveals a low prevalence of oral HPV infection with significant geographic and sex differences among Chinese population. IMPACT: This is the first study to report the epidemiologic characteristics of oral HPV infection among Chinese adults in diverse geographic areas with large sample size.

Clinical characteristics of paraneoplastic syndromes in patients with head and neck cancer.

Background: To summarize the clinical manifestations, diagnosis, and prognosis of head and neck cancer (HNC) patients with paraneoplastic syndromes (PNS). Methods: The clinical data of 1958 patients with HNC admitted to our hospital from January 1996 to December 2020 were retrospectively analyzed. Demographic and cancer-related characteristics were extracted. Kaplan-Meier survival curves were compared by log-rank test. Cox regression was performed to evaluate prognostic factors and hazard ratio. Results: Totally 40 HNC patients with PNS were included in the final analysis, including 36 men and four women with a mean age of 60.4 years (range 40-82). PNS was dermatologic or cutaneous in 23 (57.50%) patients, endocrine in 10 (25.00%), neurologic in five (12.50%), and osteoarticular or rheumatologic in two (5.00%). Twenty-five (62.50%) patients had Stage III/IV cancer. PNS regressed after antitumor therapy in 28 (70.00%) patients. Recurrence of PNS was observed in nine of 12 (75.00%) patients with cancer recurrence or metastasis. The 5-year overall survival (OS) and disease-free survival (DFS) rates of patients with PNS were 51.52% and 44.44%, respectively. The DFS (p = .001) and OS (p = .003) of patients presented with PNS prior to HNC diagnosis were significantly longer than those of patients with synchronous or metachronous PNS. PNS diagnosed before HNC (adjusted hazard ratio [aHR]: 0.31, 95% confidence interval [CI]: 0.11-0.85, p = .02), Stage IV disease (aHR: 3.27, 95% CI: 1.18-9.05, p = .02), and smoking history (aHR: 3.69, 95% CI: 1.04-13.05, p = .04) were significantly associated with OS and DFS. Conclusions: Early recognition of PNS could provide clues about underlying tumor condition and result in early diagnosis. Prompt detection of cancer-associated syndromes could lead to a more favorable prognosis for these patients.

Matched-pair analysis of survival in patients with poorly differentiated versus well and moderately differentiated hypopharyngeal squamous cell carcinoma.

Hypopharyngeal squamous cell carcinoma (HPSCC) is among the most common malignances of the head and neck and is associated with a poor prognosis. Although both differentiation and tumor-node-metastasis stage affect tumor aggressiveness, the effect of differentiation on the prognosis of HPSCC at different stages is unclear. The aim of this study was to compare survival outcomes between patients with poorly differentiated versus well-differentiated and moderately differentiated HPSCC. Patients with well/moderately differentiated and poorly differentiated HPSCC were matched based on age, sex, smoking status, alcohol use, comorbidity score, tumor stage, and therapeutic strategies. The Kaplan-Meier curve and Cox proportional hazards model were used to analyze survival. A total of 204 patients with newly diagnosed HPSCC were included after matching 102 well/moderately differentiated cases and 102 poorly differentiated cases from Peking Union Medical College Hospital. Patients with well/moderately differentiated HPSCC had significantly better disease-specific survival (P = .003) and overall survival (P = .006) than patients with poorly differentiated HPSCC. Additionally, multivariable analysis indicated that increased differentiation was associated with a significantly reduced risk of overall death (adjusted hazard ratio, 0.51; 95% confidence interval, 0.34-0.78, P = .002), and death due to disease (adjusted hazard ratio, 0.44; 95% confidence interval, 0.28-0.69, P < .001). Survival outcomes differed significantly between the well/moderately differentiated and poorly differentiated HPSCC patients. Treatment strategies based on the level of pathological differentiation might be necessary to improve survival outcomes in patients with HPSCC.

Oncological outcomes from surgical vs. non-surgical treatments for advanced hypopharyngeal squamous cell carcinoma: a surveillance, epidemiology, and end results-based study.

OBJECTIVE: Patients with advanced hypopharyngeal squamous cell carcinomas (HSCCs) have poor prognoses. The use of surgical or non-surgical treatments for these patients remains a topic of debate. This study compared survival following surgical and non-surgical treatments of patients with advanced HSCC based on the Surveillance, Epidemiology and End Results (SEER) database. METHODS: Patients diagnosed with hypopharyngeal cancer from 2004 to 2018 were identified from the SEER database. Patients were divided into non-surgical group and surgical group, and patients in the surgical group were further divided into three groups: surgery-only, surgery with adjuvant radiation therapy and surgery with adjuvant chemoradiation therapy. The primary endpoint was overall survival (OS), and the secondary outcome was cancer-specific survival (CSS). Outcomes were analyzed using Kaplan-Meier analysis. A multivariate Cox regression analysis was also used to identify independent prognostic factors. RESULTS: The records of 1568 eligible patients with stage III or IV HSCC were examined. Receipt of surgery was associated with a longer OS [hazard ratio (HR) = 0.47, 95% confidence interval (CI): 0.4-0.56] and a longer CSS (HR = 0.47, 95% CI: 0.38-0.57) after adjusting for age, sex, race, tumor site, tumor size, tumor grade, TNM stage, AJCC stage, number of carcinomas, prior cancer, receipt of radiotherapy, and receipt of chemotherapy. The results for OS were similar in an exploratory analysis of different patient subgroups. CONCLUSION: Among patients with advanced HSCC in the SEER database, treatment with surgery was associated with longer OS and CSS than treatment with a non-surgical modality.

The prognostic significance of tumor deposits in patients with head and neck squamous cell carcinomas.

BACKGROUND: A tumor deposit (TD) is a phenomenon that has not been well studied in head and neck squamous cell carcinoma (HNSCC) but might have prognostic significance. The present study was conducted to explore the presence and the prognostic significance of TDs in patients with HNSCCs. METHODS: Six hundred forty-two pathologically confirmed HNSCC patients with neck dissection samples were enrolled in this retrospective study. Patients were followed up and evaluated every 3 months in the first 3 years after surgery, and every 6 months thereafter by physical examination and computed tomography (CT)/magnetic resonance imaging (MRI) scans. The five-year overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) were compared in the TD and non-TD groups using multivariable analyses and propensity score matching (PSM) methodology (1:1). RESULTS: The 5-year OS, DSS, and RFS rate of all patients was 77.3%, 80.6%, and 71.9%, respectively. In the multivariable analyses, poorer rates of OS (HR =2.345, P<0.001), DSS (HR =2.818, P<0.001), and RFS (HR =2.536, P<0.001) were observed in the TD versus the non-TD group. In the PSM cohort, eighty-one patients who had TDs were paired with 70 patients without TDs. Significantly diminished rates of DSS (P=0.040) and RFS (P=0.004) were found in the TD versus the non-TD group. CONCLUSIONS: In response to sparse reports regarding TDs in HNSCCs, the present study proposes the TD as an independent poor prognostic factor meriting further research because of its association with diminished OS, DSS, and RFS rates.

Extramedullary Plasmacytoma: Long-Term Clinical Outcomes in a Single-Center in China and Literature Review.

The aim is to analyze the clinical outcomes of patients with extramedullary plasmacytoma (EMP) and review the characteristics of this disease. We retrospectively reviewed the clinical data of a cohort of 22 patients diagnosed with EMP between 1983 and 2017. Baseline characteristics and progression data were collected to calculate the incidence of progression to multiple myeloma (MM) and to analyze survival rates and outcomes. Previous major cohort studies were reviewed and compared with this study. Extramedullary plasmacytomas were located in the head and neck in 17 (77%) of the 22 patients. The median time between onset and diagnosis was 7 months, and the median age at diagnosis was 52.5 years (range 15-72 years). Extramedullary plasmacytoma occurred more frequently in men with an approximate ratio of 2.1:1. The majority of patients underwent surgery (13/22, 59.1%) and half received radiation (11/22, 50%). A small proportion of patients received chemotherapy (2/22, 9.1%). There was a median follow-up time of 98.5 months. The 5-year overall survival, progression-free survival, and MM-free survival rates were 84.2%, 67.3% and 75.9%, respectively. Complete resection without major functional damage is a promising option that can favorably improve prognosis in patients with resectable disease. Patients with regional lymph node metastasis or positive immunoelectrophoresis results require more aggressive treatment and may have poorer prognosis.

Tracheal window resection and reconstruction via sternocleidomastoid flap for invasive thyroid carcinoma.

OBJECTIVES: The aim of this study was to present surgical techniques and evaluate outcomes of a sternocleidomastoid muscle (SCM) myoperiosteal flap used for the reconstruction of tracheal or laryngotracheal defects after the radical resection of invasive thyroid carcinoma. METHODS: A retrospective study was performed for patients at Peking Union Medical College Hospital from January 2008 to December 2018 of papillary thyroid carcinoma with tracheal or laryngotracheal invasion. Patients were enrolled only when they received window resection and reconstruction via an SCM myoperiosteal flap. The primary outcome was a stable airway, and the secondary outcome was survival. RESULTS: A total of 15 invasive thyroid carcinoma patients were enrolled in this study. Laryngotracheal and tracheal reconstruction were performed in 11 and 4 patients respectively, with a median vertical defect of 3.5 cm (3.0, 4.5). A stable airway was achieved in 14 patients postoperatively. One patient experienced tracheal stenosis and received a second operation of tracheal sleeve resection and end-to-end anastomosis 105 days after the first operation. Tracheostomy was conducted in 5 out of 15 patients in whom the vertical defects were larger than 4 cm, and the tubes were extubated after a median time of 56 days (32, 84). The median observation time was 55 months (48, 86), and all 15 patients achieved a stable airway and showed no evidence of local recurrence at the end of follow-up. CONCLUSIONS: For thyroid carcinoma with tracheal or laryngotracheal invasions, window resection with the SCM myoperiosteal flap reconstruction presented positive results in terms of a stable airway as well as oncological outcomes. The SCM myoperiosteal flap can be an appropriate reconstruction strategy, especially when the defects reach the thyroid cartilage.

Reprogramming microbial populations using a programmed lysis system to improve chemical production.

Microbial populations are a promising model for achieving microbial cooperation to produce valuable chemicals. However, regulating the phenotypic structure of microbial populations remains challenging. In this study, a programmed lysis system (PLS) is developed to reprogram microbial cooperation to enhance chemical production. First, a colicin M -based lysis unit is constructed to lyse Escherichia coli. Then, a programmed switch, based on proteases, is designed to regulate the effective lysis unit time. Next, a PLS is constructed for chemical production by combining the lysis unit with a programmed switch. As a result, poly (lactate-co-3-hydroxybutyrate) production is switched from PLH synthesis to PLH release, and the content of free PLH is increased by 283%. Furthermore, butyrate production with E. coli consortia is switched from E. coli BUT003 to E. coli BUT004, thereby increasing butyrate production to 41.61 g/L. These results indicate the applicability of engineered microbial populations for improving the metabolic division of labor to increase the efficiency of microbial cell factories.

Microbial cell engineering to improve cellular synthetic capacity.

Rapid technological progress in gene assembly, biosensors, and genetic circuits has led to reinforce the cellular synthetic capacity for chemical production. However, overcoming the current limitations of these techniques in maintaining cellular functions and enhancing the cellular synthetic capacity (e.g., catalytic efficiency, strain performance, and cell-cell communication) remains challenging. In this review, we propose a strategy for microbial cell engineering to improve the cellular synthetic capacity by utilizing biotechnological tools along with system biology methods to regulate cellular functions during chemical production. Current strategies in microbial cell engineering are mainly focused on the organelle, cell, and consortium levels. This review highlights the potential of using biotechnology to further develop the field of microbial cell engineering and provides guidance for utilizing microorganisms as attractive regulation targets.

Postoperative Concurrent Chemoradiotherapy versus Postoperative Radiotherapy Alone for Larynx Squamous Cell Carcinoma Patients with Lymphovascular Invasion: A Propensity Score Matching Study.

PURPOSE: To date, no guidelines have been proposed for the ideal treatment of postoperative larynx squamous cell carcinoma (LSCC) patients with lymphovascular invasion due to a lack of similar studies. The present study was conducted to compare the survival and toxicity in LSCC patients with lymphovascular invasion receiving either postoperative radiotherapy (PORT) or postoperative chemoradiotherapy (POCRT). The results can be applied for more appropriate treatment of these patients. PATIENTS AND METHODS: Three hundred eighty-eight eligible LSCC patients with lymphovascular invasion were enrolled in this retrospective study. Survival and treatment-related toxicities were compared in the POCRT and PORT group using propensity score matching (PSM) methodology (1:1). RESULTS: Five-year overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) of all patients were 48.7%, 58.2%, and 56.0%, respectively. Significantly, higher RFS rates (P=0.040) were found in the POCRT group than the PORT group in the PSM cohort. In the multivariate analysis, higher OS, DSS, and RFS rates were observed in the POCRT group than the PORT group (P=0.049, 0.024, and 0.011 respectively). Patients in the POCRT group presented more acute toxicities than those in the PORT group such as hematological toxicities (25.0% vs 0.9%, P<0.001) and mucositis (35.0% vs 19.1%, P=0.002). CONCLUSION: In the context of no ideal treatment for LSCC patients with lymphovascular invasion, the present study proposes POCRT as a preferable modality compared with PORT, as POCRT was associated with higher RFS rates. Higher RFS, DFS, and OS rates were also observed in the POCRT group in the multivariate analysis.