Recent advances in Pd-catalyzed asymmetric cyclization reactions

Over the past few decades, there have been major developments in transition metal-catalyzed asymmetric cyclization reactions, enabling the convenient access to a wide spectrum of structurally diverse chiral carbo- and hetero-cycles, common skeletons found in fine chemicals, natural products, pharmaceuticals, agrochemicals, and materials. In particular, a plethora of enantioselective cyclization reactions have been promoted by chiral palladium catalysts owing to their outstanding features. This review aims to collect the latest advancements in enantioselective palladium-catalyzed cyclization reactions over the past eleven years, and it is organized into thirteen sections depending on the different types of transformations involved.

Dietary supplementation of proteases on growth performance, nutrient digestibility, blood characteristics and gut microbiota of growing pigs fed sorghum-based diets

Low-tannin sorghum is an excellent energy source in pig diets. However, sorghum contains several anti-nutritional factors that may have negative effects on nutrient digestibility. The impacts of proteases on growth performance, nutrient digestibility, blood parameters, and gut microbiota of growing pigs fed sorghum-based diets were studied in this study. Ninety-six pigs (20.66 ± 0.65 kg BW) were allocated into three groups (eight pens/group, four pigs/pen): (1) CON (control diet, sorghum-based diet included 66.98% sorghum), (2) PRO1 (CON + 200 mg/kg proteases), (3) PRO2 (CON + 400 mg/kg proteases) for 28 d. No differences were observed in growth performance and apparent total tract digestibility (ATTD) of nutrients between CON and PRO1 groups. Pigs fed PRO2 diet had increased (P < 0.05) BW on d 21 and 28, and increased (P < 0.05) average daily gain during d 14-21 and the overall period compared with pigs fed CON diet. In addition, pigs fed PRO2 diet had improved (P < 0.05) ATTD of gross energy, CP, and DM compared with pigs fed CON and PRO1 diets. Pigs fed PRO2 diet had lower (P < 0.05) plasma globulin (GLB) level and higher (P < 0.05) plasma glucose, albumin (ALB) and immunoglobulin G levels, and ALB/GLB ratio than pigs fed CON and PRO1 diets. Furthermore, pigs fed PRO2 diet had decreased (P < 0.05) the relative abundance of Acidobacteriota at the phylum level and increased (P < 0.05) the relative abundance of Prevotella_9 at the genus level. The linear discriminant analysis effect size analysis also showed that pigs fed PRO2 diet had significantly enriched short-chain fatty acid-producing bacteria, such as Subdoligranulum and Parabacteroides. In conclusion, protease supplementation at 400 mg/kg improved the growth performance of growing pigs fed sorghum-based diets, which may be attributed to the improvement of nutrient digestibility, host metabolism, immune status and associated with the altered gut microbiota profiles.

[Oligonucleotide drugs and their progress in stomatology]

Oligonucleotide drugs have the characteristics of targeting, modifiability and high biosafety. Recent studies have shown that oligonucleotide can be used to make biosensors, vaccine adjuvants, and has the functions of inhibiting alveolar bone resorption, promoting jaw and alveolar bone regeneration, anti-tumor, destroying plaque biofilm, and precise control of drug release. Therefore, it has a broad application prospect in the field of stomatology. This article reviews the classification, action mechanism and research status of oligonucleotide in stomatology. The aim is to provide ideas for further research and application of oligonucleotide.

[Oligonucleotide drugs and their progress in stomatology]

Oligonucleotide drugs have the characteristics of targeting, modifiability and high biosafety. Recent studies have shown that oligonucleotide can be used to make biosensors, vaccine adjuvants, and has the functions of inhibiting alveolar bone resorption, promoting jaw and alveolar bone regeneration, anti-tumor, destroying plaque biofilm, and precise control of drug release. Therefore, it has a broad application prospect in the field of stomatology. This article reviews the classification, action mechanism and research status of oligonucleotide in stomatology. The aim is to provide ideas for further research and application of oligonucleotide.

Palladium/TY-Phos-Catalyzed Asymmetric Heck/Tsuji-Trost Reaction of o-Bromophenols with 1,3-Dienes

2,3-Dihydrobenzofurans are crucial building blocks in the synthesis of natural products and pharmaceutical molecules. However, their asymmetric synthesis has been a long-standing formidable challenge so far. In this work, we developed a highly enantioselective Pd/TY-Phos-catalyzed Heck/Tsuji-Trost reaction of o-bromophenols with various 1,3-dienes, allowing expedient access to chiral substituted 2,3-dihydrobenzofurans. This reaction features excellent regio- and enantiocontrol, high functional group tolerance, and easy scalability. More importantly, the demonstration of this method as a highly valuable tool for the construction of optically pure natural products (R)-tremetone and fomannoxin is highlighted.

[Clinical application of laparoscopic sentinel lymph node mapping in early staged cervical cancer]

Objective: To investigate the application of sentinel lymph node biopsy (SLNB) in early-staged cervical cancer by laparoscopy. Methods: It was a prospective, single-arm, single-center clinical study. Seventy-eight cases of cervical cancer patients were collected from July 2015 to December 2018 at the Fourth Hospital of Hebei Medical University. All the patients were injected with tracer into the disease-free block of cervical tissue after anesthesia by the same surgeon who learned sentinel lymph node (SLN) mapping technique in Memorial Sloan-Kettering Cancer Center, and underwent SLN mapping followed by complete pelvic lymphadenectomy. Moreover, all the dissected lymph nodes were stained with hematoxylin eosin staining (HE) pathological examination. Besides, the negative SLN on hematoxylin-eosin staining were detected by immunohistochemistry cytokeratin staining micro-metastasis. To analyze the distribution, detection rate, false negative rate the sensitivity and negative predictive value of the SLN in early-staged cervical cancer by laparoscopy, and explore the value of SLN mapping in predicting the lymph nodes metastasis in early-staged cervical cancer. Results: The overall detection rate of SLN in cervical cancer was 99% (77/78), bilateral detection rate was 87% (68/78). The average of 12.4 lymph node (LN) and 3.6 SLN were dissected for each patients each side. SLN of cervical cancer were mainly distributed in the obturator space (61.5%, 343/558), followed by external iliac (23.5%, 131/558), common iliac (7.3%, 41/558), para-uterine (3.8%, 21/558), internal iliac (2.2%, 12/558), para abdominal aorta (1.1%, 6/558), and anterior sacral lymphatic drainage area (0.7%, 4/558). Fourteen cases of LN metastasis were found among all 78 cases. There were a total of 38 positive LN, including 26 SLN metastasis and 12 none sentinel LN metastasis. Through immunohistochemical staining and pathological ultra-staging, 1 SLN was found to be isolated tumor cells (ITC), and 5 SLNs were found to be micro-metastases (MIC), accounting for 23% (6/26) of positive SLN. SLN mapping with pathological ultra-staging improved the prediction of LN metastasis in cervical cancer (2/14). Metastatic SLN mainly distributed in the obturator space (65%, 17/26), peri-uterine region (12%, 3/26), common iliac region (15%, 4/26), and external iliac region (8%, 2/26). The consistency of the diagnosis of lymph node metastasis by SLN biopsy and postoperative retroperitoneal lymph node metastasis showed that the Kappa value was 1.000 (P<0.001), indicated that the metastasis status of SLN and retroperitoneal lymph node were completely consistent. The sensitivity, specificity, accuracy, false-negative rate, and negative predictive value of SLN biopsy in the diagnosis of lymph node metastasis were 100%, 100%, 100%, 0, and 100%, respectively. Conclusions: SLN in early-staged cervical cancer patients were mainly distributed in the obturator and external iliac space, pathalogical ultra-staging of SLN could improve the prediction of LN metastasis. Intraoperative SLN mapping is safe, feasible and could predict the state of retroperitoneal LN metastasis in early-staged cervical cancer. SLNB may replace systemic pelvic lymphadenectomy.

[Active surveillance for thyroid micro-malignant nodules]

Objective: To evaluate the effect of ultrasound diagnosis of thyroid micro-malignant nodules and accumulate practical experience for the management of active surveillance for them, so as to avoid overtreatment. Methods: A total of 949 patients who were diagnosed with thyroid malignant nodules using ultrasonography, with the nodules being less than 1 cm in size and without regional lymph node metastasis or distant metastasis, were included. They were treated by the same surgeon of the Department of Head and Neck Surgery, Cancer Hospital, Chinese Academy of Medical Sciences from February 2014 to December 2020. 112 patients chose immediate surgery. The rest patients were asked to accept ultrasound examination every 6 months to 1 year. Follow-up endpoints: tumor size growth of 3 mm, tumor volume increase greater than 50%, lymph node metastasis or distant metastasis. Results: The median follow-up time was 19 months. 713 patients underwent surveillance for more than 6 months. Of the 713 patients, 570 (79.9%) were women, with mean age at 43.5 years old. Tumor progression was observed in 47 (6.6%) patients with a cumulative incidence of 2.7% (1 year), 7.2% (2 years) and 9.5% (3 years). In multivariate analysis, patient age [HR=0.508, 95%CI: 0.275-0.939, P=0.031], lesion number [HR=2.945, 95%CI: 1.593-5.444, P=0.001] and tumor size [HR=2.245, 95%CI: 1.202-4.192, P=0.011] at the beginning of observation were independent risk factors for tumor progression in patients with minimal thyroid malignant nodules during follow-up. During a median (range) active surveillance of 19 (6-80) months, 74 patients chose surgery during the surveillance. Among the 186 patients who underwent surgery, only 3 patients were diagnosed with fibrotic nodules in pathology, while the rest were papillary thyroid carcinoma. The ultrasound accuracy reached 98.4%(183/186). Conclusions: Ultrasonography is an effective method of diagnosing malignant thyroid nodules. Thyroid micro-malignant nodules progress slowly. As a result, it is safe to observe them instead of taking immediate surgery. Patient age, lesion number and tumor size at the beginning of observation are independent risk factors for the tumor progression of malignant nodules.

[Research progress in the application of non-thermal atmospheric pressure plasma in dentin bonding]

As a convenient and effective surface modification approach, non-thermal atmospheric pressure plasma (NTAPP)can be used to improve dentin bonding, and has recently become a research focus. Studies have shown that NTAPP can alter dentin surface properties, improve the penetration and polymerization of adhesives, stimulate the cross-linking of collagen, and change the micro-morphology and element content of dentin surface, thus improve the dentin bonding quality. This article introduces the current research progress in the application of NTAPP in the field of dentin bonding, in order to provide innovative information for future research in optimization of the quality of dentin bonding.

Synthesis of W-Phos Ligand and Its Application in the Copper-Catalyzed Enantioselective Addition of Linear Grignard Reagents to Ketones

The asymmetric catalytic addition of linear Grignard reagents to ketones has been a long-standing challenge in organic synthesis. Herein, a novel family of PNP ligands (W-Phos) was designed and applied in copper-catalyzed asymmetric addition of linear Grignard reagents to aryl alkyl ketones, allowing facile access to versatile chiral tertiary alcohols in good to high yields with excellent enantioselectivities (up to 94 % yield, 96 % ee). The process can also be used to synthesize chiral allylic tertiary alcohols from more challenging α,β-unsaturated ketones. Notably, the potential utility of this method is demonstrated in the gram-scale synthesis and modification of various densely functionalized medicinally relevant molecules.

[Screening and analysis of prognostic factors of repairing single missing tooth by autotransplantation of teeth]

Objective: To screen and analyze the factors affecting the prognosis of replacing single missing tooth by autograft tooth, so as to provide reference for clinical judgment of surgical prognosis. Methods: A total of 176 patients (188 teeth) underwent autotransplantation of teeth in the Department of Oral & Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University from January 2017 to December 2019, including 85 teeth of males and 103 teeth of females were involved. The age was (33.0±9.8) years (16-65 years). The possible factors affecting the prognosis of replacing single missing tooth by autograft tooth were summarized and grouped, and the clinical and imaging data were recorded and judged. The surgical records and photographic data from the patients' previous medical records were retrospectively analyzed. The survival analysis method was used for statistical analysis to screen out the factors affecting the cumulative survival rate of transplanted teeth. Results: The 5-year cumulative survival rate of 188 transplanted teeth was 88.4%. Univariate Log-Rank analysis showed that age (P<0.001), sex (P=0.008), smoking (P<0.001), position of recipient area (P<0.001), height of alveolar bone in recipient area (P<0.001), time of donor tooth in vitro (P<0.001), use of donor model (P<0.001) and initial stability (P<0.001) were significantly correlated with cumulative survival rate of transplanted teeth. Multivariate Cox proportional hazard regression analysis showed that smoking (β=-2.812, P=0.049), alveolar bone height (β=1.521, P=0.020), donor time (β=-2.001, P=0.019), use of donor model (β=1.666, P=0.034) and initial stability (β=-1.417, P=0.033) were significantly correlated with the cumulative survival rate of transplanted teeth. Conclusions: The prognosis of autogenous tooth transplantation can be predicted by smoking, height of alveolar bone in recipient area, time of donor teeth in vitro, use of donor model and initial stability. Good prognosis of transplanted teeth can be obtained by using donor model during operation, reducing the time of donor teeth in vitro, taking effective methods to restore alveolar bone height, maintaining good initial stability, and good oral health education after operation.

Enantioselective difunctionalization of alkenes by a palladium-catalyzed Heck/borylation sequence

A palladium catalyzed enantioselective Heck/borylation reaction of alkene-tethered aryl iodides was realized, delivering a variety of 2,3-dihydrobenzofuranyl boronic esters in high yield with excellent enantioselectivity. Asymmetric synthesis of chromane boronic ester, indane boronic ester and indoline boronic ester was also accomplished. The protocol offers an efficient access to the corresponding chiral benzocyclic boronic esters, which are notably important chemical motifs in synthetic transformations.

A palladium catalyzed enantioselective Heck/borylation reaction of alkene-tethered aryl iodides was realized, delivering a variety of 2,3-dihydrobenzofuranyl boronic esters in high yield with excellent enantioselectivity.

Palladium-Catalyzed Asymmetric Cross-Coupling Reactions of Cyclobutanols and Unactivated Olefins

Transition-metal-catalyzed activations of carbon-carbons bonds of small strained rings have widespread applications in synthetic and medicinal chemistry. However, coupling reactions of cyclobutanols involving β-carbon elimination to construct C(sp³)-C(sp³) bonds have scarcely been developed. Here, we demonstrate a highly enantioselective Pd-catalyzed intermolecular C(sp³)-C(sp³) coupling reaction of a broad range of cyclobutanol derivatives and unactivated alkenes, allowing convenient access to a series of chiral benzene-fused cyclic compounds in a highly regio-, chemo-, and enantioselective manner.

[Research progress in the application of dopa-inspired compounds to improve the dentin-resin bonding]

Mussle foot protein has a main component which is named dopa. Dopa can be used to promote a relatively firm adhesion of mussels to the surface of solid materials through forming dihydrogen bonds, π-π/π-cation bonds and chelating metals,etc. To exploit these interactions, there is the opportunity to apply dopa-inspired compounds to improve the dentin-resin bonding. The current review provides valuable information concerning the mechanism of adhesion mediated by mussel foot protein and describes the application of dopa-inspired compounds in the dentin-resin bonding. The article provides novel information for future research in optimization of the properties of dentin-resin bonding.

[Establishment of model to predict lateral neck recurrence of central lymph node metastasis in papillary thyroid carcinoma]

Objective: To explore the risk factors for lateral neck recurrence of central lymph node metastasis (CLMN) in papillary thyroid cancer (PTC), and to construct a model to predict the recurrence. Methods: The records of 245 consecutive PTC patients with CLMN underwent surgical treatment from 1996 to 2009 in our department were retrospectively reviewed. The threshold value of CLNM number is determined by ROC curve. The risk factors for lateral neck recurrence were determined by using Cox regression model. The identified risk factors were incorporated into a nomogram model to predict the risk of lateral neck recurrence. Results: A total of 245 patients were enrolled in the study, among them, 32 cases occurred lateral neck lymph node recurrence and 4 cases were dead of thyroid carcinoma. Multivariate analysis revealed that primary tumor size, extrathyroidal extension, the number of metastatic CLNM >3 were independent risk factors of lateral neck recurrence (P<0.05), lateral neck recurrence was a risk factor of disease-free survival(P<0.05). The nomogram model of predicting the lateral neck recurrence was further established based on the above 3 independent risk factors, the area under the receiver operating characteristic (ROC) curve of which was 0.790. Conclusions: The nomogram model based on the independent risk factors of LN recurrence can be helpful to screen the papillary thyroid carcinoma patients with high risk of lateral neck recurrence, and provide more guidance for clinical treatment.

[Current status and quality analysis of interventional therapy for patients with atrial fibrillation in China]

Objective: To define the current status and analyze the medical quality of interventional therapy for patients with atrial fibrillation (AF) in China. Methods: This survey was performed in all seven large regions of China, one to three regional major medical centers were selected from each region. Medical records of patients underwent interventional therapy for AF in the year 2017 were randomly inspected. CHA2DS2-VASc score, prescribed anticoagulant after ablation, indication of left atrial appendage occlusion (LAAO), and complications in the medical records were analyzed. Results: A total of 10 800 AF catheter ablations and 447 LAAOs were performed in 17 regional medical centers in 2017. There were 10/17 centers performing AF catheter ablation<500 cases and 7/17 centers performing LAAO<20 cases. A total of 1 347 cases of catheter ablation and 160 cases of LAAO were selected for further analysis. Among all selected cases, 15.8% (238/1 505) non-valvar AF cases recorded CHA2DS2-VASc scores. The anticoagulation rate after AF catheter ablation was 98.6% (1 328/1 347), anticoagulation rate was higher than 90% in 16 out of 17 centers. The complication and severe complication rates of AF catheter ablation were 0.9% (12/1 347) and 0.4% (5/1 347), respectively. The differences of complication and severe complication rates in AF catheter ablation were similar between centers performing<500 cases and centers performing ≥500 cases (0.5% (2/413) vs. 1.1% (10/934), P>0.05; 0.5% (2/413) vs. 0.3% (3/934), P>0.05). The coincidence rate of LAAO indication was 81.3% (130/160), and the rate was higher in center performing ≥20 cases than in centers performing<20 cases (84.8% (106/125) vs. 68.6% (24/35), P<0.05). The complication and severe complication rates of LAAO were 3.1% (5/160) and 1.9% (3/160). The rate of complications in LAAO was higher in center performing<20 cases than in centers performing ≥20 cases (8.6% (3/35) vs. 1.6% (2/125), P<0.05), and there was no significant difference in severe complication rate (5.7% (2/35) vs. 0.8% (1/125), P>0.05). Conclusions: Interventional therapy for AF in China is generally standardized and safe. The overall incidence of complications post AF interventional ablation is low, the anticoagulation rate after AF catheter ablation is high, and the adherence rate of LAAO indication is fair. The indicators mentioned above vary widely among centers.

Insulin-Like Growth Factor Binding Protein 5: an Important Regulator of Early Osteogenic Differentiation of hMSCs

Insulin-like growth factor binding protein 5 (IGFBP5) is broadly bioactive, but its role in osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hMSCs) remains to be clarified. Here, we demonstrated that IGFBP5 expression was markedly increased during the early osteogenic differentiation of hMSCs. We then over-expressed and knocked down this gene in hMSCs and evaluated the impact of manipulation of IGFBP5 expression on osteogenic differentiation based upon functional assays, ALP staining, and expression of osteogenic markers. Together, these analyses revealed that IGFBP5 over-expression enhanced early osteogenic differentiation, as evidenced by increased ALP staining and osteogenic marker induction, whereas knocking down this gene impaired the osteogenic process. Over-expression of IGFBP5 also markedly bolstered the extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation level, while IGFBP5 knockdown suppressed this signalling activity. We additionally compared the impact of simultaneous IGFBP5 overexpression and ERK1/2 inhibitor treatment to the effect of IGFBP5 over-expression alone in these hMSCs, revealing that small molecule-mediated EKR1/2 inhibition was sufficient to impair osteogenic differentiation in the context of elevated IGFBP5 levels. These findings indicated that IGFBP5 drives the early osteogenic differentiation of hMSCs via the ERK1/2 signalling pathway. Our results offer value as a foundation for future efforts to study and treat serious bone-related diseases including osteoporosis.

[Comparison of quality of life of hypopharyngeal squamous cell carcinoma patients after laryngeal preservation surgery and total laryngectomy]

Objective: To evaluate and compare the quality of life (QOL) in patients with hypopharyngeal squamous cell carcinoma after laryngeal preservation surgery and total laryngectomy. Methods: We selected parts of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 and the Head and Neck Module (EORTC QLQ-C30 and EORTC QLQ-H&N35) and designed the QOL questionnaire. We investigated 42 patients with hypopharyngeal squamous cell carcinoma underwent laryngeal preservation surgery and 38 patients underwent total laryngectomy by QOL questionnaire and followed up their survival. Results: The somatic function dimension, psychological function dimension, and social function dimension of patients underwent laryngeal preservation surgery were (92.46±15.71), (80.56±22.67) and (90.08±19.50), respectively, which were higher than (79.39±32.75), (68.42±25.05) and (61.84±29.55) of the total laryngectomy group (P<0.05), while the economic dimension was not significantly different between the two groups (P>0.05). The social function dimension (including social support and socialization, family relationship) of laryngeal preservation surgery group were (89.04±25.47) for postoperative time < 70 months and (90.94±13.28) for postoperative time ≥70 months, which were higher than (65.48±29.14) and (57.35±30.32) of the total laryngectomy group (P<0.01). Conclusions: The somatic function dimension, psychological function and social function of patients with hypopharyngeal squamous cell carcinoma underwent laryngeal preservation surgery obtain a better QOL than patients underwent total laryngectomy. Therefore, we should improve the laryngeal function and QOL of patients under the premise of ensuring the survival rate.

[Study of methylation of mitochondrial MT-COI of benzene poisoning]

Objective: To research the mitochondrial cytochrome c oxidase subunit I (MT-COI) gene methylation levels in patients with occupational chronic benzene poisoning, and to explore effective molec μlar biomarkers in patients with occupational chronic benzene poisoning. Methods: 38 confirmed cases of occupational chronic benzene poisoning were selected in the case group. 46 healthy people who underwent physical in our hospital were selected in the control group. Pyrosequencing was used to detect the methylation sites of methylation sites, flow cytometry was used to detect peripheral blood cell count levels, and non-parametric statistical methods were used to analyze the differences in detection results between the two groups. Results: The methylation level of mitochondrial MT-COI site 1 (2.21±0.81) % in the case group was less than that in the control group, and the difference was statistically significant (P<0.05) . The methylation level of mitochondrial MT-COI site 2 (2.31±0.96%) in the case group was less than that in the control group, and the difference was statistically significant (P<0.05) . The methylation average level of mitochondrial MT-COI (2.26±0.75) % in the case group was less than that in the control group, and the difference was statistically significant (P<0.05) . Analysis of the average level of methylation found that the methylation level of mitochondrial MT-COI was correlated with WBC (P<0.05) . Analysis of the average level of methylation found that the methylation level of mitochondrial MT-COI was correlated with platelets (r=0.254、0.280, P<0.05) . Conclusion: The level of mitochondrial MT-COI gene methylation in patients with occupational chronic benzene poisoning may be related to the sensitivity to benzene exposure. Mitochondrial MT-COI gene methylation may serve as a potential predictive biomarker for benzene poisoning.

Overview of high intensity ion source development in the past 20 years at IMP

Ion source development over the last 20 years at the IMP is reviewed. For versatile purposes, several types of ion sources have been involved in the research and development work at the IMP, i.e., the highly charged ECR (Electron Cyclotron Resonance) ion source, intense microwave ion source or the 2.45 GHz intense beam ECR ion source, and laser ion source (LIS). In the development of ECR ion sources, SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou), Lanzhou ECR ion source, and Lanzhou all permanent magnet ECR ion source series have been made, which can cover the operation microwave frequency range of 10-28 GHz. The LIS with an Nd:YAG laser with a maximum output energy of 8 J in 8 ns pulse duration has been developed for very intense short pulse ion beams from solid materials such as C, Ti, Ni, Ag, and so on. Microwave ion sources have been built to produce intense pulsed or direct current beams from several mA to 100 mA for either high intensity accelerators or applications. This paper will give an overview of the high intensity ion source development at the IMP, especially on the recent progress and new results, such as the status of the fourth generation ECR ion source (first fourth generation ECR ion source), the production of recorded highly charged ion beams with SECRAL sources, key technology research studies, and so on.

[Long-term outcome of patients with pyriform sinus squamous cell carcinoma treated with planned preoperative (chemo-) radiotherapy plus laryngeal function sparing surgery]

Objective: To analyze the long-term outcome of patients with pyriform sinus squamous cell carcinoma treated with planned preoperative (chemo-) radiotherapy plus laryngeal function sparing surgery. Methods: Patients with stage Ⅲ/Ⅳ pyriform sinus squamous cell carcinoma treated with planned preoperative (chemo-) radiotherapy plus laryngeal function sparing surgery during 1999 to 2000 were retrospectively analyzed. Data including concurrent chemotherapy or not, postoperative pathological diagnosis, postoperative complications, recurrence and survival were collected. Twenty patients were treated with preoperative radiotherapy while 14 patients with preoperative chemo-radiotherapy. Results: Among 31 cases of postoperative pathological diagnosed as pyriform sinus, 12 (38.7%) cases without tumor residue, 7 (22.5%) cases with severe radiation response and 12 (38.7%) cases with tumor residue. The 5-year cumulative local recurrence rate, regional recurrence rate and distant metastasis rate was 14.5%, 13.7% and 23.5%, respectively. Five-year cumulative overall survival rate and recurrence-free survival rate were 69.6% and 65.4%, respectively. Nine deaths were attributed to distant metastasis (8 cases) and regional recurrence (1 case). Conclusion: Most patients with pyriform sinus squamous cell carcinoma acquire long-term survival after treated with planned preoperative (chemo-) radiotherapy plus laryngeal function sparing surgery, and distant metastasis is the main cause of death.

[Clinical analysis of autoimmune hemolytic anemia after allogeneic hematopoietic stem cell transplantation in thalassemia major]

目的

探讨重型地中海贫血（地贫）患者异基因造血干细胞移植（allo-HSCT）后并发自身免疫性溶血性贫血（AIHA）诊断、治疗及转归，以提高地贫患者造血干细胞移植疗效。

方法

回顾性分析2007年7月至2017年12月共计291例行allo-HSCT重型地贫患者的临床资料。

结果

重型地贫allo-HSCT后AIHA发生率为1.72%（5/291）；AIHA中位发生时间为移植后7（5~12）个月，5例移植后AIHA患者直接和间接Coombs试验均阳性，患者主要表现为头晕、乏力、面色苍白、皮肤巩膜黄染、酱油色尿。228例HLA相合同胞供者移植患者有1例（0.43%）移植后发生AIHA，而63例非亲缘供者移植患者有4例（6.36%）移植后发生AIHA。非亲缘供者移植患者AIHA发生率高于HLA相合同胞供者移植患者。1例患者单用泼尼松治疗死亡，4例患者采用甲泼尼龙联合利妥昔单抗治疗有效，目前生存良好，其中2例Coombs试验转阴。

结论

该组重型地贫患者allo-HSCT后AIHA发生率为1.72%，Coombs试验有助于诊断移植后AIHA，非亲缘供者移植病例移植后AIHA发生率高于HLA相合同胞供者移植组，利妥昔单抗联合糖皮质激素是治疗重型地贫allo-HSCT后AIHA的有效方法。

A new trifluoromethylated sulfonamide phosphine ligand for Ag(i)-catalyzed enantioselective [3 + 2] cycloaddition of azomethine ylides

A newly developed Ming-Phos ligand with a 3,5-bis(trifluoromethyl)phenyl substituent was demonstrated to be highly efficient for Ag-catalyzed asymmetric [3 + 2] cycloaddition reactions of azomethine ylides with maleimides, cyclopentene-1,3-diones, and N-(2-t-butylphenyl)maleimide. Being easily prepared on the gram scale in one step, the ligand in combination with a Ag catalyst enables the synthesis of a variety of highly functionalized bicyclic pyrrolidine derivatives in good yields and excellent enantioselectivities under mild conditions.

[Preliminary application of endonasopharyngeal ultrasound-guided transnasopharyngeal needle aspiration in the diagnosis of submucosal nasopharyngeal carcinoma]

Objective: To evaluate the feasibility, safety and clinical value of endonasopharyngeal ultrasound-guided transnasopharyngeal needle aspiration (ENUS-TNNA) in the diagnosis of submucosal nasopharyngeal carcinoma. Methods: Clinical data of 9 patients from Sichuan Cancer Hospital with submucosal nasopharyngeal carcinoma undergoing ENUS-TNNA between December 2013 and January 2018 were retrospectively analyzed. The feasibility and safety were analyed. All 9 patients were all males with a mean age of (49.2±10.9) years. Results: Needle puncture biopsies were successfully performed in all cases, and sufficient tissue sample for histopathological examination was obtained from each of the 9 patients. No major bleeding or persistent bleeding occurred during and after puncture procedures. There were 5 patients with undifferentiated nonkeratinizing carcinoma and 4 patients poorly differentiated carcinoma. Conclusion: ENUS-TNNA is a safe, feasible and effective technique to provide a diagnosis of submucosal growth type of nasopharyngeal neoplasms, which has some clinical value.

Arginine bioavailability and endothelin-1 system in the regulation of vascular function of umbilical vein endothelial cells from intrauterine growth restricted newborns

BACKGROUND AND AIMS

Intrauterine growth restriction (IUGR) is a major risk factor for perinatal morbidity and mortality, leading to long-term adverse cardiovascular outcomes. The present study aimed to investigate the potential mechanisms in IUGR-associated vascular endothelial dysfunction.

METHODS AND RESULTS

Human umbilical vein endothelial cells (HUVECs) were derived from IUGR or normal newborns. We found that the proliferation of IUGR-derived HUVECs was accelerated compared to those from normal subjects. Gene profiles related to vascular function including vasomotion, oxidative stress, and angiogenesis were dysregulated in IUGR-HUVECs. Compared with HUVECs from normal newborns, nitric oxide (NO) production was reduced, with imbalance between endothelial nitric oxide synthase (eNOS) and arginase-2 (Arg-2) in IUGR. Meanwhile, intracellular asymmetric dimethylarginine (ADMA) level was elevated with diminished dimethylarginine dimethylaminohydrolase 1 (DDAH1) expression in IUGR-HUVECs. Furthermore, endothelin-1 (ET-1) and hypoxia-inducible factor 1α (HIF-1α) expression were increased, and endothelin receptor type-B (ET_BR) was reduced in the IUGR group. IUGR-HUVECs exposed to hypoxia increased the ratio of ADMA to l-arginine, HIF-1α and protein arginine methyltransferase 1 (PRMT1) expression compared to controls.

CONCLUSIONS

The present study demonstrated that the reduction of NO bioavailability and release results from elevated Arg-2, accumulation of intracellular ADMA, and imbalance of ET-1 and ET_BR, further leading to IUGR-associated vascular endothelial dysfunction. Our study provides novel evidence on the mechanism underlying fetal programming associated with IUGR, which will serve as potential therapeutic targets in the prevention of adverse cardiovascular consequences in adulthood.

[Detection of HLA-B*13:01 gene by dual allele-specific real-time polymerase chain reaction in patients with trichlorethylene-induced dermatitis]

Objective: To investigate the detection of a human leukocyte antigen-B (HLA-B) allele HLA-B*13:01 by dual allele-specific real-time polymerase chain reaction (PCR) in patients with trichlorethylene-induced dermatitis. Methods: A total of 20 patients with trichlorethylene-induced dermatitis who were admitted and treated from January 2014 to October 2016 were enrolled as case group, and 20 persons who underwent physical examination from January to October, 2016 were enrolled as control group. Peripheral cubital venous blood samples were collected from all subjects, and dual allele-specific real-time PCR was used to detect the HLA-B*13:01 gene. The two groups were compared in terms of the proportion of subjects carrying HLA-B*13:01 gene. Results: There were no significant differences between the case group and the control group in median age (25.0 years vs 27.0 years, Z=0.30, P>0.05) and the proportion of male subjects (60.0% vs 70.0%, χ(2)=0.44, P>0.05) . The mean time of exposure to trichloroethylene was 30.8 days in the case group, while the subjects in the control group were not exposed to trichloroethylene. The case group had a significantly higher frequency of HLA-B*13:01 gene than the control group (80.0% vs 20.0%, χ(2)=14.40, P<0.01) with an odds ratio of 16.00. Conclusion: Dual allele-specific real-time PCR can be used for detection of the HLA-B*13:01 gene in patients with trichlorethylene-induced dermatitis.

Gold(I)/Xiang-Phos-Catalyzed Asymmetric Intramolecular Cyclopropanation of Indenes and Trisubstituted Alkenes

The first intramolecular enantioselective cyclopropanation of indenes and trisubstituted alkenes was accomplished by using new chiral phosphine X5 derived gold(I) complexes. This reaction is a straightforward, efficient method for constructing [5-3-6] fused-ring compounds with two vicinal all-carbon quaternary stereogenic centers, a core structure shared by numerous pharmacological products, and bioactive compounds. The salient features of this transformation include high enantioselectivity (up to >98% ee), excellent yield (>97%), and nice functional group tolerance.

[The impact of genetic variation of KDR on clinical outcomes of advanced colorectal cancer patients treated by first line bevacizumab based regimens]

Objective: To investigate the association between kinase insertion region receptor (KDR) gene genetic variation and the efficacy of bevacizumab in patients with advanced colorectal cancer(CRC) were investigated in this study. Methods: 118 patients with advanced colorectal cancer who were treated by bevacizumab based first line regimens were included in this study. Peripheral blood and the biopsy tissue specimens of the CRC patients were collected for the genotyping of genetic variation and KDR gene expression, respectively. The univariate analysis of genotypes and prognosis was carried out by Kaplan-Meier survival analysis, and multivariate were adjusted by Cox regression analysis. Results: Located in the coding region, the prevalence of 889 C>T in KDR among the study population were as follows: CC genotype 86 cases (72.88%), CT genotype 30 cases (25.42%), TT genotype 2 cases (1.70%), minor allele frequency of 889 C>T is 0.14. The distribution of three genotypes in accordance with Hardy-Weinberg Equilibrium (P=0.737). There were no statistical differences in the distribution of the genotypes in baseline clinical data. TT and CT genotype patients were merged in the comparison of clinical outcomes. The clinical outcomes analysis of patients with different genotypes found that the objective response rates (ORR) of CT/TT genotypes were 34.38% and 43.02% (P=0.395), respectively. And the median progression free survival (PFS) of patients with CT/TT genotype and CC genotype were 7.5 and 9.7 months respectively, which was statistically significant (P=0.009). In terms of overall survival (OS), the median OS of the two genotypes were 19.3 and 20.1 (P=0.025), respectively. Adjusted in multivariate Cox regression analysis of PFS, CT/TT genotypes were an independent factor for PFS (OR=1.88, P=0.023). Additionally, of the 57 biopsy tissue specimens, gene expression analysis was conducted. And the results showed that the expression of KDR in cancer tissues of the patients with CT/TT genotypes were significantly higher than those of the CC genotype patients (P<0.001). Conclusion: Among advanced colorectal cancer patients treated by bevacizumab, the polymorphism 889 C>T of KDR may impact the clinical outcomes of bevacizumab first line treatment by influencing the mRNA expression of KDR.

[Primary research of early oral feeding after total laryngectomy]

Objective: To explore whether early oral feeding after total laryngectomy is safe and effective by evaluating the incidence of pharyngocutaneous fistula (PCF) and the hospital duration. Methods: A retrospective cohort study was conducted, including 52 patients underwent total laryngectomy, plus partial tongue base resection (n=2), partial pharyngectomy (n=1), or pedicle flap (n=2) between January 2012 and October 2017. Patients who had a history of preoperative radiotherapy, chemotherapy or chemoradiotherapy, previous surgery for larynx or pharynx and who had severe complications were excluded. Early oral feeding started between 48 h and 72 h postoperatively, while delayed oral feeding started within postoperative day 8-10. The incidences of PCF in two groups were compared to evaluate whether PCF and early oral feeding was related. Multi-variables analysis was conducted to evaluate risk factors for PCF. Results: PCF rate was 19.2% among all patients, 11.1% in patients with early oral feeding and 23.5% in patients with delayed oral feeding. No significant statistically difference in PCF rate was found between two groups (χ(2)=0.506, P=0.477). Multi-variables analysis showed that oral feeding time (early or delayed) was not a independent risk factor of PCF (Two classification response variable Logistic regression, P=0.200, OR=0.242, 95%CI[0.028-2.118]). But low preoperative albumin level was observed as an independent risk factor for PCF (P=0.039, OR=0.848, 95% CI [0.726-0.992]). A negative correlation was observed between preoperative albumin level and PCF. And also there was not a significant difference in hospital duration between patients with early oral feeding and delayed oral feeding(U=268, P=0.464). Conclusion: For patients total laryngectomy with no previous history of radiotherapy, chemotherapy, chemoradiotherapy, early oral feeding after surgery is safe and effective.

High-Density Genetic Map Construction and Identification of QTLs Controlling Oleic and Linoleic Acid in Peanut using SLAF-seq and SSRs

The cultivated peanut, A. hypogaea L., is an important oil and food crop globally.High-density genetic linkage mapping is a valuable and effective method for exploring complex quantitative traits. In this context, a recombinant inbred line (RIL) of 146 lines was developed by crossing Huayu28 and P76. We developed 433,679 high-quality SLAFs, of which 29,075 were polymorphic. 4,817 SLAFs were encoded and grouped into different segregation patterns. A high-resolution genetic map containing 2,334 markers (68 SSRs and 2,266 SNPs) on 20 linkage groups (LGs) spanning 2586.37 cM was constructed for peanut. The average distance between adjacent markers was 2.25 cM. Based on phenotyping in seven environments, QTLs for oleic acid (C18:1), linoleic acid (C18:2) and the ratio of oleic acid to linoleic acid (O/L) were identified and positioned on linkage groups A03, A04, A09, B09 and B10. Marker2575339 and Marker2379598 in B09 were associated with C18:1, C18:2 and O/L in seven environments, Marker4391589 and Marker4463600 in A09 were associated with C18:1, C18:2 and O/L in six environments. This map exhibits high resolution and accuracy, which will facilitate QTL discovery for essential agronomic traits in peanut.

[Comparative study on the HIV epidemic between the Chinese and Burmese drug users in drug rehabilitation places in Dehong Prefecture, Yunnan Province]

Objective: To compare the prevalence of HIV infection and its risk factors among Chinese and Burmese drug users living in Dehong Prefecture, Yunnan Province. Methods: We obtained plasma specimens and gathered demographic data from 7 867 drug users with Chinese or Burmese nationality attending rehabilitation clinics in Dehong Prefecture from October 2014 to September 2015. Of these, 7 756 individuals who gave valid questionnaire responses, including 5 389 Chinese and 2 367 Burmese, were enrolled in the study after giving informed consent. We used the Chi-squared test to compare the demographic characteristics and HIV prevalence between the Chinese and Burmese drug users. Logistic regression was then used to identify risk factors for HIV infection. Results: The HIV infection rate of 7 756 subjects (aged (35.45 ± 10.91) years old) was 7.18%, in which Burmese with higher HIV infection rate (9.38%, 222/2 367) than Chinese (6.22%, 335/5 389) (χ²=24.21, P<0.001). In chinese drug users, OR (95%CI) of HIV infection of those aged 25-34 years old, 35-44 years old and ≥45 years old were 2.88 (1.46-5.69), 5.72 (2.87-11.40) and 3.48 (1.66-7.27),compared with those aged below 25 years;Compared with married participants, OR (95% CI) of those unmarried and divorced were 1.44 (1.08-1.93) and 1.56 (1.09-2.24); Jingpo drug users were 1.47 (1.07-2.04) times to get HIV infection,compared with Han ethnicity; OR (95%CI) of HIV infection for IDUs was 11.48 (9.73-16.01) compared with NIDUs.In Burmese drug users, OR (95% CI) of HIV infection for females was 0.50 (0.26-0.93) compared with men;Compared with those aged below 25 years,those aged 25-34,35-44 and ≥45 years had OR (95% CI) of 1.82 (1.18-2.77), 2.90 (1.82-4.62) and 2.31 (1.24-4.30), respectively; OR (95% CI) of Jingpo participants was 2.22 (1.44-3.41) compared with Han nationality; OR (95%CI) of HIV infection for IDUs was 10.61 (7.68-14.64) compared with NIDUs. Conclusion: The HIV infection rate of Burmese drug users was higher than that of Chinese drug users. Measures of HIV prevention and control should be mainly allocated in those 25 years above, non-married, Jingpo ethnicity and IDU in Chinese drug users, while in Burmese drug users,those females, 25 years above, Jingpo ethnicity and IDU should be higlighted in HIV prevention and control.

[Comparison of genotypes of hepatitis C virus between Chinese and Burmese drug users living in Dehong Prefecture, Yunnan Province]

Objective: To analyze the distribution of hepatitis C virus (HCV) genotypes among Chinese and Burmese drug users in Dehong Prefecture, Yunnan Province. Methods: Plasma specimens and relevant epidemiological data were collected from 7 545 drug users attending rehabilitation centers and methadone clinics in Dehong Prefecture from January to September in 2015, of which 752 were positive for HCV antibodies. HCV RNA was then extracted from 139 random specimens (64 Burmese and 75 Chinese) and the CE1 and NS5B regions were amplified by nested PCR. The sequences of these HCV genes were aligned, a phylogenetic tree was constructed using MEGA 6.0.6 and the average genetic discrete rate of each subtype group was calculated. We used Fisher's exact test to compare distribution of HCV subtypes from different people, using analysis of variance to compare the discrete rates of different CE1 and NS5B subtypes. Results: While we successfully amplified RNA from 43 specimens provided by Burmese patients (67%), including 31 with CE1 region and 38 with NS5B region, 52 from Chinese patients (69%) were successfully amplified including 43 with CE1 region and 45 with NS5B region. We found that 3b and 6n were the predominant subtypes and were found in 27% (n=14) and 37% (n=19) of Chinese and 28% (n=12) and 33%(n=14) of Burmese specimens. Subtypes 6u, 3a, 1a and 1b were present in 14%(n=7), 19%(n=10), 2% (n=1) and 2%(n=1) of Chinese specimens and 16%(n=7), 5%(n=2), 16%(n=7) and 2%(n=1) of Burmese specimens respectively. While the prevalence of subtype 1a was higher among samples from Burmese patients than Chinese patients (P=0.015), the presence of subtype 3a was higher among the latter (P=0.031). The discrete rates of CE1 region subtypes 1a, 1b, 3a, 3b, 6n and 6u were 0.048±0.007, 0.091±0.013, 0.074± 0.008, 0.061 ± 0.006, 0.136 ± 0.009 and 0.031 ± 0.005 (F=516.26, P<0.001). The discrete rates for NS5B region subtypes 1a, 1b, 3a, 3b, 6n and 6u, meanwhile, were 0.032±0.006, 0.065±0.012, 0.058±0.008, 0.041± 0.005, 0.059 ± 0.008, 0.045 ± 0.006 (F=45.11, P<0.001). Conclusion: Six HCV subtypes were identified among drug users in Dehong Prefecture, of which 6n and 3b were predominant. There were statistically significant differences in the distribution of subtypes 1a and 3b, which have been circulating for a long time in this population, between samples from Chinese and Burmese participants.

[Clinical analysis of secondary cervical lymph node dissection in papillary thyroid carcinoma]

Objective: To investigate the value of secondary cervical lymph node dissection in papillary thyroid carcinoma (PTC). Methods: PTC patients with recurrence re-operated in a previously dissected area at our hospital during 2000-2016 were included in this analysis. Patients were divided according to the operative interval of 6 months. The level and number of lymph node metastasis and the number of lymph node dissection were analyzed to calculate the ratio of lymph node metastasis. Results: A total of 336 PTC patients received 360 side lateral cervical lymph nodes dissection. The ratio of recurrence in unilateral lateral neck is 92.9%(312/336). The ratio of recurrence in multiple levels (more than two regions) were 47.5% (171/360). The recurrence ratio of level Ⅱ, Ⅲ, Ⅳ and Ⅴ were 55.6%(200/360), 44.2%(159/360), 59.7%(215/360) and 10.3%(37/360), respectively. Lymph node metastases were inclined to level Ⅱ (33.6%) and Ⅳ (35.8%). The mean number of lymph node dissection and metastasis in the group of operative interval ≤ 6 months was 26.56 per case and 4.37 per case, respectively. The mean number of lymph node dissection and metastasis in the group of operative interval >6 months was 16.80 per case and 3.20 per case, respectively. The number of lymph node dissection and metastasis between these two groups were significantly different (P=0.001, P<0.001). Conclusions: Lymph node metastasis of PTC patients with secondary cervical lymph node dissection are inclined to level Ⅱ and level Ⅳ. Moreover, multi-level metastasis is not rare. Level Ⅱ and level Ⅳ require more attention in the first operation. Most of the patients undergo reoperation because of residual lymph nodes from the previous treatment. Normalization and completeness of the initial dissection are particularly important to PTC patients.

[Effects of rabbit adipose-derived mesenchymal stem cells on the healing of skin deep partial-thickness scald wound of rabbit]

OBJECTIVE

To investigate the effects of local injection of rabbit adipose-derived mesenchymal stem cells (ADSCs) on the healing of skin deep partial-thickness scald wound of rabbit.

METHODS

ADSCs were isolated from adipose tissue of one New Zealand rabbit and then sub-cultured. ADSCs of the third passage were used in the following experiments. Twenty-four rabbits were divided into ADSCs group (n=12) and control group (n=12) according to the random number table, and one deep partial-thickness scald wound with diameter of 5 cm on the two sides of the back near the buttocks was made. From post injury day (PID) 2, 2 mL suspension of EdU-labeled ADSCs with the number of 5×10(5) per mL was subcutaneously injected in wounds of rabbits in ADSCs group, while the rabbits in control group were given 2 mL serum-free DMEM until the wounds were healed. Wound healing processes of rabbits in two groups were observed every day, and the healing time was recorded. On PID 7, 14, 21, and 28, areas of wound of three rabbits in two groups were measured and the healing rates were calculated, respectively. The healed wound tissue was harvested to observe the morphology by HE staining, and the expression of collagen fiber was observed by Masson staining. The distribution of EdU-labeled ADSCs in healed wound tissue on PID 28 was observed by inverted fluorescence microscope. The expressions of vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) of healed wound tissue on PID 7, 14, and 21 were detected by enzyme-linked immunosorbent assay. Data were processed with analysis of variance of factorial design and paired samples t test.

RESULTS

(1) The wound healing time of rabbits in ADSCs group was (19.5±1.1) d post injury, which was significantly shorter than that in control group [(23.3±1.5) d, t=4.50, P<0.05]. On PID 7, wounds of rabbits in two groups were dry with no obvious exudation, and redness and swelling around wounds disappeared gradually, the wound healing rate of rabbits in ADSCs group was (15.1±2.4)%, which was close to that in control group [(13.7±3.1)%, t=1.20, P>0.05]. On PID 14, wounds of rabbits in ADSCs group were dry and scabbed obviously, and the wound healing rate was (73.1±5.7)%, while wounds of rabbits in control group were little scabbed with little exudation, and the wound healing rate was significantly lower than that in ADSCs group [(52.9±5.1)%, t=8.06, P<0.01]. On PID 21, wounds of rabbits in ADSCs group were generally healed, and the wound healing rate was (95.6±3.0)%, while a few wounds still existed in rabbits of control group, and the wound healing rate was significantly lower than that in ADSCs group [(78.6±3.7)%, t=9.73, P<0.01]. On PID 28, wounds of rabbits in two groups were totally healed with the healing rate of 100%, and texture and microvascular responses of healed wound tissue in ADSCs group were better than those in control group. (2) On PID 7, fibroblasts in healed wound tissue of rabbits in two groups were all increased, and there were little vascular and collagen fiber proliferation with no obvious differences. On PID 14, the number of fibroblasts in healed wound tissue of rabbits in ADSCs group was more than that in control group, and the collagen fibers in healed wound tissue of rabbits in ADSCs group were arranged in dense and uniform, while those in control group were sparse and irregular. On PID 21, skin layers were differentiated in healed wound tissue of rabbits in two groups, and collagen fibers in healed wound tissue of rabbits in ADSCs group were still denser than that in control group. On PID 28, newborn skin was well differentiated in healed wound tissue of rabbits in ADSCs group, which was better than that in control group. There were a lot of thick collagen fibers in healed wound tissue of rabbits in two groups, and EdU-labeled ADSCs were involved in skin texture of rabbits in ADSCs group. (3) The expressions of VEGF and EGF in healed wound tissue of rabbits in two groups were similar on PID 7 (with t values respectively 0.70 and 0.91, P values above 0.05), which in ADSCs group were significantly higher than those in control group on PID 14 and 21 (with t values from 2.85 to 4.81, P values below 0.01).

CONCLUSIONS

The transplantation of ADSCs can promote the wound healing of skin deep partial-thickness scald wound of rabbit and shorten the wound healing time.

Enhancing expression of SSU1 genes in Saccharomyces uvarum leads to an increase in sulfite tolerance and a transcriptome profile change

Saccharomyces uvarum is a good wine yeast species that may have great potential for the future. However, sulfur tolerance of most S. uvarum strains is very poor. In addition there is still little information about the SSU1 gene of S. uvarum, which encodes a putative transporter conferring sulfite tolerance. In order to analyze the function of the SSU1 gene, two expression vectors that contained different SSU1 genes were constructed and transferred into a sulfite-tolerant S. uvarum strain, A9. Then sulfite tolerance, SO2 production, and PCR, sequencing, RT-qPCR and transcriptome analyses were used to access the function of the S. uvarum SSU1 gene. Our results illustrated that enhancing expression of the SSU1 gene can promote sulfite resistance in S. uvarum, and an insertion fragment ahead of the additional SSU1 gene, as seen in some alleles, could affect the expression of other genes and the sulfite tolerance level of S. uvarum. This is the first report on enhancing the expression of the SSU1 gene of S. uvarum.