Restoring Carboxylates on Highly Modified Alginates Improves Gelation, Tissue Retention and Systemic Capture

Alginate hydrogels are gaining traction for use in drug delivery, regenerative medicine, and as tissue engineered scaffolds due to their physiological gelation conditions, high tissue biocompatibility, and wide chemical versatility. Traditionally, alginate is decorated at the carboxyl group to carry drug payloads, peptides, or proteins. While low degrees of substitution do not cause noticeable mechanical changes, high degrees of substitution can cause significant losses to alginate properties including complete loss of calcium cross-linking. While most modifications used to decorate alginate deplete the carboxyl groups, we propose that alginate modifications that replenish the carboxyl groups could overcome the loss in gel integrity and mechanics. In this report, we demonstrate that restoring carboxyl groups during functionalization maintains calcium cross-links as well as hydrogel shear-thinning and self-healing properties. In addition, we demonstrate that alginate hydrogels modified to a high degree with azide modifications that restore the carboxyl groups have improved tissue retention at intramuscular injection sites and capture blood-circulating cyclooctynes better than alginate hydrogels modified with azide modifications that deplete the carboxyl groups. Taken together, alginate modifications that restore carboxyl groups could significantly improve alginate hydrogel mechanics for clinical applications. STATEMENT OF SIGNIFICANCE: Chemical modification of hydrogels provides a powerful tool to regulate cellular adhesion, immune response, and biocompatibility with local tissues. Alginate, due to its biocompatibility and easy chemical modification, is being explored for tissue engineering and drug delivery. Unfortunately, modifying alginate to a high degree of substitution consumes carboxyl group, which are necessary for ionic gelation, leading to poor hydrogel crosslinking. We introduce alginate modifications that restore the alginate's carboxyl groups. We demonstrate that modifications that reintroduce carboxyl groups restore gelation and improve gel mechanics and tissue retention. In addition to contributing to a basic science understanding of hydrogel properties, we anticipate our approach will be useful to create tissue engineered scaffolds and drug delivery platforms.

[Mutational spectrum and its prognostic significance in childhood acute lymphoblastic leukemia based on next-generation sequencing technology]

Objective: This study analyzed the correlation between genetic mutation and prognostic significance in childhood acute lymphoblastic leukemia (ALL) . Methods: Targeted exome by next-generation sequencing (NGS) technology was used to carry out molecular profiling of untreated 141 children with ALL in Fujian Medical University Union Hospital from November 2016 to December 2019. Correlation of genetic features and clinical features and outcomes was analyzed. Results: Among the 141 pediatric patients with ALL, 160 somatic mutations were detected in 83 patients (58.9% ) , including 37 grade Ⅰ mutations and 123 grade Ⅱ mutations. Single nucleotide variation was the most common type of mutation. KRAS was the most common mutant gene (12.5% ) , followed by NOTCH1 (11.9% ) , and NRAS (10.6% ) . RAS pathway (KRAS, FLT3, PTPN11) , PAX5 and TP53 mutations were only detected, and NRAS mutations was mainly found in B-ALL while FBXW7 and PTEN mutations were only found, and NOTCH1 mutation was mainly detected in T-ALL. The average number of mutations detected in each child with T-ALL was significantly higher than in children with B-ALL (4.16±1.33 vs 2.04±0.92, P=0.004) . The children were divided into mutation and non-mutation groups according to the presence or absence of genetic variation. There were no statistically significant differences in sex, age, newly diagnosed white blood cell count, minimal or measurable residual disease monitoring results, expected 3-year event-free survival (EFS) and overall survival (OS) between the two groups (P>0.05) . On the other hand, the proportion of T-ALL and fusion gene negative children in the mutant group was significantly higher than the non-mutation group (P=0.021 and 0.000, respectively) . Among the patients without fusion gene, the EFS of children with grade I mutation was significantly lower than children without grade I mutation (85.5% vs 100.0% , P=0.039) . Among children with B-ALL, the EFS of those with TP53 mutation was significantly lower than those without TP53 mutation (37.5% vs 91.2% , P<0.001) . Conclusion: Genetic variation is more common in childhood ALL and has a certain correlation with clinical phenotype and prognosis. Therefore, targeted exome by NGS can be used as an important supplement to the traditional morphology, immunology, cytogenetics, and molecular biology classification.

Therapeutic Effects of Small Incision Open Reduction and Internal Fixation and Arthroscopic High Strength Non-Absorbable Suture on Tibial Insertion Avulsion Fracture of the Anterior Cruciate Ligament

PURPOSE OF THE STUDY To evaluate the therapeutic effects of small incision open reduction and internal fixation and arthroscopic high strength non-absorbable suture on tibial insertion avulsion fracture of the anterior cruciate ligament (ACL). MATERIAL AND METHODS In this prospectively study, 72 patients with ACL tibial insertion avulsion fracture treated from December 2017 to June 2020 were enrolled and divided into group A (treated with small incision open reduction and cannulated screw internal fixation) and group B (treated with arthroscopic high strength non-absorbable suture) using a random number table (n=36). Their general data, surgical indices and incidence of postoperative adverse reactions were compared. Knee function indices were compared before and after treatment, and evaluated by random walk model. RESULTS No significant differences were found in the general data, intraoperative blood loss, preoperative Lysholm score, International Knee Documentation Committee (IKDC) score, Tegner score, knee range of motion and difference of bilateral tibial forward displacement distance, and total incidence rate of postoperative adverse reactions between the two groups (P>0.05). Group B had significantly longer operation time, and significantly shorter hospital stay, time of first ambulation after operation and bone healing time than group A (P<0.05). Both groups had improved Lysholm score, IKDC score, Tegner score and knee range of motion after treatment, especially in group B (P<0.05). The difference of bilateral tibial forward displacement distance significantly reduced in both groups after treatment, particularly in group B (P<0.05). The random walk model revealed that group B had better improvement of knee function than group A. CONCLUSIONS Arthroscopic high strength non-absorbable suture in the treatment of ACL tibial insertion avulsion fracture can dramatically improve the knee function indices of patients, with rapid recovery and high safety, so it has a broad prospect of clinical application. Key words: small incision open reduction and internal fixation, arthroscopic high strength non-absorbable suture, tibial insertion avulsion fracture, anterior cruciate ligament, random walk model.

[Value of purple sign for predicting rebleeding events in cirrhotic patients following endoscopic selective varices devascularization]

OBJECTIVE

To assess the value of the purple sign for predicting long-term rebleeding events in cirrhotic patients following endoscopic selective varices devascularization.

METHODS

We retrospectively analyzed the clinical data of 97 patients with liver cirrhosis, who had a history of gastroesophageal variceal bleeding and underwent endoscopic selective varices devascularization. Thirty-two of the patients showed purple sign after endoscopic treatment. We used propensity score matching (PSM) to minimize the selection bias of the patients (purple sign vs no purple sign) and reduce the intergroup differences of clinical characteristics. The primary outcome measure of this study was cumulative rebleeding events after endoscopic selective varices devascularization.

RESULTS

The 1-year rebleeding rate (27.0% vs 36.7%) or 6-month rebleeding rate (10.9% vs 26.9%) following endoscopic treatment was not significantly different between the purple sign group and no purple sign group before PSM (P=0.2385). But after PSM, the 1-year rebleeding rate (28.2% vs 56.4%) and 6-month rebleeding rate (5.0% vs 37.0%) were significantly lower in the purple sign group than in the no purple sign group (P=0.0304).

CONCLUSIONS

The presence of purple sign indicates a lower risk of rebleeding after endoscopic treatment of cirrhotic gastroesophageal varices and a potentially favorable treatment response after endoscopic therapy, thus providing a clinical indicator for stratification of the patients for sequential endoscopic sessions.

A prospective study on vulvovaginal candidiasis: multicentre molecular epidemiology of pathogenic yeasts in China

BACKGROUND

Vulvovaginal candidiasis (VVC) is frequent in women of reproductive age, but very limited data are available on the epidemiology in cases of VVC in China.

OBJECTIVES

The current study has been conducted to reveal the prevalence, species distribution of yeast causing VVC and molecular genetics of Candida albicans in China.

METHODS

Vaginal swabs were collected from 543 VVC outpatients recruited in 12 hospitals in China between September 2017 and March 2018. They were preliminarily incubated on Sabouraud dextrose agar and then positive subjects of which were then transmitted to our institute for further identification. CHROMagar™ was used to isolate Candida species, and all isolates were finally identified by DNA sequencing. Multilocus sequence typing (MLST) was used to analyse phylogenetic relationships of the various C. albicans isolates.

RESULTS

Eleven different yeast species were identified in 543 isolates, among which C. albicans (84.7%) was the most frequent, followed by C. glabrata (8.7%). We obtained 117 unique diploid sequence types from 451 clinical C. albicans isolates and 92 isolates (20.4%) belonged to a New Clade. All the strains appearing in the New Clade were from northern China and they were isolated from non-recurrent VVC.

CONCLUSIONS

Our findings suggest that C. albicans are still the main cause of VVC in China and the majority of C. albicans isolates belongs to Clade 1 with DST 79 and DST 45 being two most common. Moreover, the New Clade revealed in our study seems to be specific to northern China.

[A cohort study on the incidence of HIV infection in drug abusers among men who have sex with men in Shanghai and Tianjin]

Objective: To analyze the incidence of HIV infection and identify associated risk factors in drug abusers among men who have sex with men (MSM) in Tianjin and Shanghai through a cohort study and provide a basis for HIV prevention in this population. Methods: A prospective cohort study was conducted among MSM who had a history of drug abuse in the past six months from June 2016 to June 2018 in the two cities. MSM were investigated to obtain information on sociodemographic characteristics, HIV-related sexual behaviors, and drug abuse. Follow-up investigation and HIV testing were carried out based on the baseline survey and testing. Cox regression analysis was conducted to identify the risk factors for HIV infection. Results: There were 455 eligible subjects, and 16 new HIV infection cases were identified in the 2-year follow-up survey. The cumulative follow-up time was 586.08 person-years, and the incidence of HIV infection was 2.73/100 person-years. The multivariate Cox regression analysis results showed that compared with those aged ≥25 years, consistent condom use during anal sex with men in the past six months, without mixed-use of drugs, these aged <25 years (HR=5.01, 95%CI: 1.09-23.11), inconsistent condom use during anal sex with men in the past six months (HR=1.58, 95%CI: 1.04-2.41) and mixed-use of drugs (HR=1.92, 95%CI: 1.08-3.40) were significantly associated with HIV infection in this cohort. Conclusions: The younger age, inconsistent condom use during anal sex with men, and mixed drug use appeared as risk factors of new HIV infection in drug abusers among MSM. HIV prevention and intervention in this population should be further strengthened.

[Mini-incision with endoscope-assisted surgery for bilateral congenital second branchial cleft fistula and a pedigree report]

Objective: To investigate the feasibility and efficacy of mini-incision with endoscope-assisted resection for bilateral congenital second branchial cleft fistula, and to report on a rare pedigree. Methods: The clinical data of 5 patients with bilateral congenital second branchial fistula admitted in Fujian Provincial Hospital from April 2007 to December 2018 were retrospectively reviewed, including 2 males and 3 females, aged from 3 to 31 years old. The surgical strateges and clinical experience of single mini-incision with endoscope-assisted fistulectomy were summarized, and a rare pedigree was reported. Results: In five patients, Case 1 to Case 4 were treated with bilateral endoscopic-assisted fistula high ligation with titanium clips and removal through a single small incision under general anesthesia. No obvious complications occurred after the operation. The patients were followed up for 40-164 months with no fistula recurrence. Case 5 gave up surgical resection and was followed up for 24 months with acute infection attack once. Case 2 and Case 4 came from the same family. In this family, 7 out of 31 members of four generations had second branchial cleft fistulas, of which 4 were bilateral and 3 were right. Pedigree analysis was consistent with autosomal dominant inheritance. No deafness, preauricular tag, external and middle ear deformity and kidney malformation were found in the family members. Conclusions: Bilateral congenital second branchial cleft fistula is rare. Surgical resection is the preferred treatment. Mini-incision with endoscopic-assisted fistula high ligation with titanium clip and resection has clear operative field, ideal cosmetic effect and definite curative effect.

A thermal adaptation landscape related to virulence in Mucor irregularis transcriptional profiles

OBJECTIVES

Our study aimed to better understand the different thermal adaptation in Mucor irregularis (M. irregularis) strains under high temperature and the involved virulence-related genes, and to offer more appropriate explanation for the diverse pathogenicity of M. irregularis in human infections.

METHODS

M. irregularis isolates were incubated at 30 and 35°C for Illumina HiSeq technology (RNA-seq), as well as the virulence difference detected through Galleria mellonella infection models. We verified their transcriptional profile with RT-PCR and analysed differentially expressed genes with GO and KEGG annotations.

RESULTS

All 25 isolates formed the biggest colonies at 28°C and did not grow at 37°C, while were differently inhibited at 22 and 35°C. Six selected M. irregularis displayed virulence in sync with their growth condition at high temperature. From the outcomes of RNA-seq, a total of 1559 differentially expressed genes (FC ≥ 2, FDR < 0.05) were obtained, of which 1021 genes were upregulated, and 538 genes were downregulated. Cell wall structure genes related to Ras-like and GH16 proteins, influx-efflux pumps consist of transmembrane proteins as ABC and MFS proteins, and metabolic genes as DGKɛ and Hsfs, seem to be essential in thermal adaptation and virulence of M. irregularis.

CONCLUSION

We found some common genes expressed at high temperature, while some others specifically related to M. irregularis isolates with different virulence and thermal adaptation. Further research of genes involved in the pathogenic process is needed for the development of potential targeted antifungal.

Selpercatinib for lung and thyroid cancers with RET gene mutations or fusions

Aberrations in oncogene RET (rearranged during transfection) have been found to be the cause of different kinds of malignancies, especially in lung and thyroid cancers. Targeted therapy of RET-altered cancers using multi-kinase inhibitors (MKIs) has demonstrated limited clinical efficacy due to off-target toxicity. In May 2020, the U.S. Food and Drug Administration (FDA) approved a novel specific RET inhibitor for use in some subtypes of lung and thyroid cancers with RET alterations. In this review, we summarize the mechanism of action, pharmaceutical properties and clinical data of selpercatinib, and share some of our perspectives.

Growth Curves of Subependymal Giant Cell Tumors in Tuberous Sclerosis Complex

BACKGROUND AND PURPOSE

Growth of subependymal giant cell tumor and subependymal nodules has not been well-characterized. The purpose of this study was to determine whether growth curves can differentiate subependymal giant cell tumors from subependymal nodules.

MATERIALS AND METHODS

Brain MR imaging of patients with tuberous sclerosis complex were retrospectively reviewed from 2002 to 2018. All lesions in the region of the foramen of Monro were measured. Lesions were categorized on the basis of maximal diameter at the most recent scan: small lesions (<1 cm), indeterminate lesions (>1 cm), and resected lesions (>1 cm and surgically resected). Growth velocity and acceleration on serial imaging were analyzed, and growth rates were calculated between 0 and 20 years of age and compared among the 3 categories.

RESULTS

Forty-one patients were analyzed. The average age at the earliest scan was 5.9 (SD = 5.7) years. One hundred twenty-six small, 27 indeterminate, and 10 resected lesions were measured. Subependymal giant cell tumors grew faster than indeterminate lesions between 6 and 15 years of age. Indeterminate lesions grew faster than small lesions at 0-10 years of age. Resected lesions showed increased velocity and acceleration of growth compared with indeterminate lesions and small lesions on serial imaging.

CONCLUSIONS

Growth differentiates subependymal nodules and subependymal giant cell tumors within the first 20 years of life, and the use of velocity and acceleration of growth may refine the diagnostic criteria of subependymal giant cell tumors. Additionally, 6-15 years of age may be an important period to monitor subependymal giant cell tumors at the foramen of Monro because increased growth may help to identify subependymal giant cell tumors that will continue to grow and result in obstructive hydrocephalus.

Characterization of mitogenomes from four Mucorales species and insights into pathogenicity

BACKGROUND

Mucorales, as one major order of Zygomycetes fungi, can infect human beings and cause serious consequence. We have noticed the pathogenicity of Mucorales is closely related to energy metabolism, while mitochondria play the role of energy factories in almost all biological activities.

METHODS

Virulence of M irregularis, M hiemalis, L corymbifera and R arrhizus were verified in Galleria mellonella larvae, as well as mitochondrial gene copies analysed with RT-qPCR. Mitogenomes of the four Mucorales species were sequenced based on illumina NovaSeq technology to study their characteristic features and functional regions.

RESULTS

Variant virulence of M irregularis, M hiemalis, L corymbifera and R arrhizu were verified by clinical retrospective data and our G mellonella infection models, also copies of mitochondrial genes indicated the significant associations with pathogenicity. A total of 274.18 clean reads were generated to be assembled; the complete mitogenomes of the four Mucorales species were obtained with totally different length. After the genomes annotated and compared, M irregularis was found more similar with M hiemalis than those of L corymbifera and R arrhizus, especially the small (rrns) and large (rrnl) subunits of mitochondrial ribosomal RNA (rRNA) genes. The GC content, ncRNAs and the distribution of the SNPs and InDels were also compared, and the GC content rate of fungi seems to be related to the fungal thermal adaptability. In addition, linear mitogenomes of these four Mucorales showed diverse arrangements of orf genes and directionality of some conserved gene elements.

CONCLUSION

This study uncovered the pathogenicity variances among the four Mucorales species and the relationship between their mitogenomic features and clinical pathogenicity. Further studies like spatial structure of mitochondrial genomes and the comprehensive analysis of transcription regulation are needed.

Efficacy and secondary infection risk of tocilizumab, sarilumab and anakinra in COVID-19 patients: A systematic review and meta-analysis

As the pandemic progresses, the pathophysiology of coronavirus disease 2019 (COVID‐19) is becoming clearer and the potential for immunotherapy is increasing. However, clinical efficacy and safety of immunosuppressants (including tocilizumab, sarilumab and anakinra) treatment in COVID‐19 patients are not yet known. We searched PubMed, Embase Medline, Web of Science and MedRxiv using specific search terms in studies published from 1 January 2020 to 20 December 2020. In total, 33 studies, including 3073 cases and 6502 controls, were selected for meta‐analysis. We found that immunosuppressant therapy significantly decreased mortality in COVID‐19 patients on overall analysis (odds ratio = 0.71, 95% confidence interval = 0.57–0.89, p = 0.004). We also found that tocilizumab and anakinra significantly decreased mortality in patients without any increased risk of secondary infection. In addition, we found similar results in several subgroups. However, we found that tocilizumab therapy significantly increased the risk of fungal co‐infections in COVID‐19 patients. This represents the only systematic review and meta‐analysis to investigate the efficacy and secondary infection risk of immunosuppressant treatment in COVID‐19 patients. Overall, immunosuppressants significantly decreased mortality but had no effect on increased risk of secondary infections. Our analysis of tocilizumab therapy showed a significantly increased risk of fungal co‐infections in these patients.

[Introduction of World Health Organization Strategies and the Technical Advisory Committee actions on viral hepatitis control and status of the elimination of viral hepatitis in China]

Viral hepatitis has been causing big threat to public health globally. The number of annual deaths caused by hepatitis surpassed the deaths caused by AIDS, tuberculosis, and malaria. World Health Organization (WHO) issued the global health sector strategy on viral hepatitis 2016-2020 (GHSS) to control its epidemic. It established the Strategies and Technical Advisory Committee on HIV, viral hepatitis, and sexually transmitted infections (STAC). This paper summarizes the GHSS goals and the keynote of the 2020 STAC meeting, analyzes the challenges and opportunities faced by China in eliminating viral hepatitis, and provides the comments on the papers on this issue, which could guide further actions.

[Analysis on hepatitis B cases reported from surveillance points in China, 2019]

Objective: To understand the characteristics of hepatitis B cases reported through the National Notifiable Disease Reported System (NNDRS) of China in 2019, analyze the quality of hepatitis B reporting. Methods: The survey forms and reporting cards of hepatitis B cases in 200 surveillance points in China in 2019 were collected from NNDRS, the completeness rate of the reporting card was calculated, and the reported hepatitis B cases were verified based on the diagnostic criteria (WS 299-2008). The clinical types of the cases after verification were compared with the reported ones, the consistency was evaluated with Kappa test. The reasons for the inconsistent clinical types of the cases were analyzed. Results: In 2019, a total of 64 686 hepatitis B cases were reported through NNDRS. Acute, chronic and unclassified hepatitis B cases accounted for 5.8%, 92.4% and 1.8%, respectively. The average age of reported cases was 47 (47±15) years, and males accounted for 64.4%. The average level of alanine aminotransferase was 214.2 (214.2±1 253.4) U/L. The reported cases mainly worked in agriculture, forestry, animal husbandry, fishery, and water conservancy (50.6%, 32 722). The proportions of cases reported from the eastern, western and central regions were 42.5% (27 501),22.1% (14 315) and 35.4% (22 870), respectively. The consistent rate of the clinical types between the reported cases and the verified cases was 58.8%, with a Kappa value of 0.15. For the 39 271 cases confirmed as acute and chronic hepatitis B cases in the reporting cards, the consistent rate of the clinical types between the reported cases and the verified cases was 96.9%, with a Kappa value of 0.73. In 94.5% (24 267/25 681) of the cases with inconsistent clinical types, the reporting card information were incomplete. Conclusion: The diagnosis of hepatitis B has been improved in the hepatitis B surveillance in China, but it is necessary to improve the completeness of the reporting cards of hepatitis B cases to NNDRS.

[Cost-benefit analysis of the hepatitis B vaccination to prevent mother-to-child transmission strategies in China, 1992-2019]

Objective: To make a cost-benefit analysis of the hepatitis B vaccination (HepB) to prevent mother-to-child transmission (PMTCT) strategies in China, 1992-2019. Methods: We built a decision analytic-Markov model to estimate the birth cohorts of 1992-2019. The parameters in our model were referred from literature, published yearbooks, and data from Chinese Center for Disease Control and Prevention. We conducted a univariate sensitivity analysis to test the robustness of the model. Results: For the 28 birth cohorts, the Chinese government has invested 37.43 billion RMB Yuan in direct costs and 47.61 billion RMB Yuan in societal costs on HepB vaccination and HBV prevention of mother to child transmission (PMTCT). And we estimated that about 50 million chronic HBV infections and 12.5 million premature deaths due to HBV-related diseases would be averted. China would save 2.89 trillion RMB Yuan and 6.92 trillion RMB Yuan for the direct and societal medical burden on HBV-related conditions. The direct and societal net benefit was 2.85 trillion RMB yuan 6.87 trillion RMB yuan, respectively. The direct and societal benefit-cost ratios (BCRs) were 77.21 and 145.29, respectively. Conclusion: The strategies of HepB vaccination for HBV PMTCT prevention were cost-effective in China during 1992-2019.

[Estimation of incidence of viral hepatitis B and analysis on case characteristics in China,2013-2020]

Objective: To understand the epidemiological characteristics of hepatitis B in China, evaluate the performance of elimination hepatitis B in China and provide scientific evidence for the prevention and control of hepatitis B. Methods: An analysis was conducted by using the data of hepatitis B cases reported to the National Notifiable Disease Reporting System (NNDRS) from the areas with low, moderate and high hepatitis B prevalence in China from 2013 to 2020, and the information about the diagnoses of the hepatitis B cases were collected, the incidence of hepatitis B was estimated according to the reporting and diagnosis information and the characteristics of acute and chronic hepatitis B were compared. Results: A total of 27 013 hepatitis B cases were reported to NNDRS, including 4 070 acute cases, 21 971 chronic cases and 972 unclassified cases. Among the reported acute hepatitis B cases, 69.9% (2 845/4 070) were confirmed. Among the reported chronic hepatitis B cases, 89.0% (19 548/21 971) were confirmed, and 2.1% (452/21 971) were confirmed as acute cases. It was estimated that the incidence of acute hepatitis B was 4.6/100 000 and the incidence of chronic hepatitis B cases was 54.5/100 000. The case number of acute hepatitis B in age group 31-45 years was highest, accounting for 35.3% (1 164/3 297). The case number of acute hepatitis B in children under 15 years old was lowest, accounting for 0.4% (13/3 297). The case number of chronic hepatitis B in age group 46-60 years was highest, accounting for 34.4% (7 211/20 932). Conclusions: The incidence of acute hepatitis B was in decrease and the incidence of chronic of hepatitis B was in increase in China year by year. It is important to strengthen the standardized diagnosis and treatment of chronic hepatitis B to decrease the morbidity and mortality of hepatitis B. At the same time, it is necessary to standardize the management and reporting of hepatitis B cases reported to NNDRS to improve the accuracy of the reporting of hepatitis B.

[Hesitancy of parents towards vaccines in national immunization program in three regions in China: a cross-sectional study]

Objective: To investigate the incidence and determinants of vaccine hesitancy towards national immunization program in China and understand the current status of parents' hesitancy to different vaccines used in national immunization program. Methods: A cross-sectional survey was conducted in Beijing, Sichuan and Gansu. The methods of proportional probability sampling and convenience sampling were used to select the eligible study subjects for questionnaire surveys. Results: A total of 3 592 parents were enrolled in the study, in whom 38.22% fully accepted all the vaccines, 59.35% agreed to let their children to receive all the vaccines but showed slight concern, and 2.42% had hesitancy to the vaccines. The vaccine with the most hesitancy was polio vaccine (0.89%), followed by diphtheria pertussis tetanus vaccine (0.70%) and hepatitis A vaccine (0.64%). The dominant reason for vaccine hesitancy was the risk-benefit perception of vaccination (31.03%), followed by the low awareness of the parents (21.84%) and the inconvenience caused by distance and time (21.84%). Conclusions: The incidence of vaccine hesitancy towards national immunization program was low in parents in China, but over 50% of the parents showed concern to the vaccines. It is essential to improve the service quality of national immunization program and strengthen the health education about the vaccination to reduce the incidence of vaccine hesitancy in parents.

[Development and outlook on human challenge trial of vaccine]

Human challenge trial (HCT) is a test in which human volunteers are intentionally infected with pathogens in order to evaluate the efficacy of candidate preventive or therapeutic drugs. During the COVID-19 pandemic, the HCT of vaccines has aroused people's attention due to its significant advantages over clinical trial. This paper introduces the concept, development and application of HCT, the advantages and limitations of HCT for vaccine evaluation, and the consideration of future HCT of COVID-19 vaccine in China.

[Efficacy of intravascular ultrasound-guided rotational atherectomy combined with cutting balloon for pretreatment of severe coronary artery calcified lesions]

OBJECTIVE

To investigate the efficacy and safety of intravascular ultrasound (IVUS)-guided rotational atherectomy (RA) combined with cutting balloon for pretreatment of severe calcified lesions in the coronary artery before stent placement.

METHODS

A total of 120 patients with severe coronary artery calcifications detected by IVUS that required percutaneous coronary intervention (PCI) were recruited from our hospital between January, 2016 to January, 2019. The patients were randomized into two groups for pretreatment of the lesions with semicompliant balloon (SB group, 60 cases) or RA combined with CB (RA+CB group, 60 cases), and drug-eluting stents were implanted after the procedure. The immediate success rate of PCI, vascular parameters detected by IVUS after PCI, and the rates of residual stenosis < 10% were compared between the two groups. The incidences of intraoperative complications and major adverse cardiac events (MACE) within 24 months after the surgery were also observed in the two groups.

RESULTS

The immediate success rate was significantly higher in RA+CB group than in SB group (P=0.032). After pretreatment and stent placement, the minimum stent lumen diameter (P=0.035), minimum stent lumen cross-sectional area (P=0.029), immediate lumen acquisition, immediate lumen cross-sectional area acquisition and the rate of residual stenosis < 10% were all significantly higher in RA+CB group than in SB group (P < 0.001). The patients in RA+ CB group showed obviously less residual stenosis of lumen cross-sectional area than those in SB group after the surgery (χ²= 7.859, P=0.005). The incidences of intraoperative complications (χ²=5.997, P=0.014) and MACE within 24 months after the operation (χ²=4.285, P=0.038) were significantly lower in RA+CB group than in SB group.

CONCLUSION

For patients with severe coronary artery calcifications eligible for PCI, RA combined with CB angioplasty can significantly improve the success rate of immediate PCI, expand the lumen diameter and cross-sectional area of the stent after PCI, enhance immediate lumen gain, and reduce the incidence of intraoperative complications and MACE after the operation.

[Relationship between age at menarche and obesity in women]

Objective: To explore the relationship between age at menarche and general obesity (based on BMI) and central obesity (based on WC or WHtR) in middle-aged and elderly women in China. Methods: A total of 6 363 women from the China Health and Retirement Longitudinal Study were included. Restricted cubic splines based on binary logistic regressions were used to analyze the relationship between age at menarche and the risk of obesity. Age at menarche was divided into four groups: ≤13, 14- (control group), 16- , and ≥18 years old. Binary logistic regressions were applied to analyze the relationship between the continuous or grouped variable of age at menarche and the risk of obesity. Results: After adjusting potential confounders, the age at menarche showed a negative linear relationship with the risk of general obesity and central obesity. The risk for obesity based on BMI, WC and WHtR significantly decreased by 6% (OR=0.94, 95%CI: 0.90-0.99), 4% (OR=0.96, 95%CI: 0.92-1.00), and 6% (OR=0.94, 95%CI: 0.90-0.99) for each 1 year increase in age at menarche. Compared with participants who had menarche at age 14- years old, the risk for obesity based on BMI (OR=0.71, 95%CI: 0.55-0.91), WC (OR=0.75, 95%CI: 0.62-0.92) and WHtR (OR=0.76, 95%CI: 0.61-0.96) significantly decreased by 29%, 25%, and 24% in participants who had menarche at age ≥18 years old. Conclusions: There was a negative linear relationship between age at menarche and the risk for general obesity and central obesity in middle-aged and elderly women in China. Older age at menarche might be negatively associated with risk for obesity in middle-aged and elderly women.

A further survey of the quantitative trait loci affecting swine body size and carcass traits in five related pig populations

Breeding for good meat quality performance while maintaining large body size and desirable carcass traits has been the major challenge for modern swine selective breeding. To address this goal, in the present work we studied five related populations produced by two commercial breeds (Berkshire and Duroc) and two Chinese breeds (Licha black pig and Lulai black pig). A single-trait GWAS performed on 20 body size and carcass traits using a self-developed China Chip-1 porcine SNP50K BeadChip identified 11 genome-wide significant QTL on nine chromosomes and 22 suggestive QTL on 15 chromosomes. For the 11 genome-wide significant QTL, eight were detected in at least two populations, and the rest were population-specific and only mapped in Shanxia black pig. Most of the genome-wide significant QTL were pleiotropic; for example, the QTL around 75.65 Mb on SSC4 was associated with four traits at genome-wide significance level. After screening the genes within 50 kb of the top SNP for each genome-wide significant QTL, NR6A1 and VRTN were chosen as candidate genes for vertebrae number; PLAG1 and BMP2 were identified as candidate genes for body size; and MC4R was the strong candidate gene for body weight. The four genes have been reported as candidates for thoracic vertebrae number, lumbar vertebrae number, carcass length and body weight respectively in previous studies. The effects of VRTN on thoracic vertebrae number, carcass length and body length have been verified in Shanxia black pig. Therefore, the VRTN genotype could be used in gene-assisted selection, and this could accelerate genetic improvement of body size and carcass traits in Shanxia black pig.

Comparative Genomics and Molecular Analysis of Epidermophyton floccosum

Epidermophyton floccosum is one of the most common agents of human superficial fungal infections, compared with genus Trichophyton and Microsporum, it possesses uniqueness in ecology traits and rarely causing hair infections. E. floccosum is so far the only representative species of genera Epidermophyton, and it is known as anthropophilic dermatophytes. To further reveal the genome sequences and clues of virulence factors, thus in this study, we sequenced the genome of E. floccosum (CGMCC (F) E1d), and performed comparative genomic analysis with other dermatophytes. It is revealed that E. floccosum owns the largest genome size and similar GC content compared with other dermatophytes. A total of 7565 genes are predicted. By comparing with the closest species N. gypseum, our study reveals that number and structure of adhesion factors, secreted proteases and LysM domain might contribute to the pathogenic and ecological traits of E. floccosum. Mating genes is also detected in genome data. Furthermore, we performed AFLP analysis trying to discuss intraspecific differences of E. floccosum, but no significant relationship is found between genotype and geographical distribution. Upon above, our study provides a deeper understanding and strong foundation for future researches about E. floccosum.