Objective To construct markless gene deletion mutant at the clpP loci on the chromosome of Streptococcus mutans(S.mutans).Methods ASp resistance gene was amplified by PCR,to construct the Sp resistance cassette where the Sp resistance gene was flanked with two loxP site.After the clpP gene was cloned into the pGEM-T-Easy TA cloning vector,it was digested and linked with the Sp resistance cassette,yielding homologous recombination vector pIB △ clpP-Sp.The vector was linearized and used for the transformation of S.mutans UA159,with transformants selected on TPY plates containing Sp.The selected strain was transformed with the thermosensitive plasmid pCrePA to excise the Sp resistance gene.The pCre-PA was then easily eliminated at nonpermissive temperature,resulting in a markless mutant strain carrying a deletion at the clpP loci,which was verified by PCR and DNA sequencing.Results The result of the PCR analysis and DNA sequencing indicated that a part of the clpP gene was deleted.There was a loxP at this loci without the Sp resistance gene.Conclusion The markless clpP-deletion mutant of S.mutans was constructed successfully,which laid a foundation for further study of its biological function and its influence on the cariogenicity of S.mutans.

Microalgae is an easy-to-obtain natural biological material with many varieties and abundant natural reserves. Microalgae are rich in natural fluorescein, which can be used as a contrast agent for fluorescence imaging and photoacoustic imaging for medical imaging. With its active surface, microalgae can effectively adsorb functional molecules, metal elements, etc., and have good application prospects in the field of drug delivery. Microalgae can generate oxygen through photosynthesis to increase local oxygen concentration, reverse local hypoxia to enhance the efficacy of hypoxic tumors and promote wound healing. In addition, microalgae have good biocompatibility, and different administration methods have no obvious toxicity. This paper reviews the research progress on the biomedical application of microalgae in bioimaging, drug delivery, hypoxic tumor treatment, wound healing.
Drug Delivery Systems ; Humans ; Hypoxia ; Microalgae ; Oxygen ; Wound Healing

Objective: To investigate the relationship between core members' social capital and performance among HIV/AIDS-related community-based organizations (CBO). Methods: From July to December in 2015, a total of 327 core members from 212 HIV/AIDS-related CBO in 8 provinces were recruited based on the prevalence of HIV/AIDS (e.g., Yunnan, Hunan, and Sichuan are in high epidemic level; Anhui, Hubei, Shandong, and Jilin are in middle epidemic level; and Gansu is in low epidemic level) by multistage stratified cluster sampling and convenient sampling method. A questionnaire was administered in this study, including general demographic information, core members' social capital, individual performance and organizational performance. Multivariate logistic regression model was used to analyze the relationship between core members' social capital and performance among CBO. Results: Among the 327 individuals, the proportion of male was 201(61.47%). The proportion of core members from grassroots CBO was 66.97% (219/327). Core members from non-grassroots organizations were more likely to publish articles, the OR (95%CI) was 2.58 (1.30-5.14); Social network had a positive impact on the AIDS experts, the OR (95%CI) was 2.41(1.47-3.95); Core members from registered CBO were more likely to secure funding for the organization, the OR (95%CI) was 3.42 (1.65-7.10); Social network and the core members from high endemic areas were significantly correlated with the number of HIV/AIDS patients, the OR (95%CI) were 2.79 (1.27-6.14) and 1.99 (1.21-3.27). Conclusions We should use the core members' social network to establish relationship and communication with organizations and institutions, ultimately accelerating the growth of HIV/AIDS prevention and care.

Objective:To explore the safety of inactivating coronavirus disease 2019(covid-19)vaccine in liver transplantation(LT)recipients.Methods:Retrospective analysis was performed for clinical data of 151 LT recipients from March 2003 to October 2019.They had stable conditions and completed the course of covid-19 vaccine.Frequencies of pain at injection site, fatigue, headache and pruritus after vaccination were recorded.The safety profiles were compared between recipients with and without local and general adverse reactions after vaccination.At the same time, recipients completing two doses of covid-19 vaccines were grouped.According to vaccine companies, they were classified into Sinovac Biotech Ltd and Beijing Biological.Based upon more than or less than 60 years, they were grouped into <60 years and ≥60 years.The safety profiles of inactivating COVID-19 vaccine were compared in subgroups.Results:Among 151 eligible LT recipients, 98 of them were in group of age <60 years and 53 in group of age >60 years.The median period between vaccination and LT was 8.44(4.37, 12.39)years and the median concentration of tacrolimus 2.5(1.8, 3.9)ng/L.Eighty-three cases completed two doses of Sinovac Biotech Ltd(Sinovac Biotech Ltd group)and 40 cases Beijing Biological(Beijing Biological group); 14 cases had combined course of Sinovac Biotech Ltd and Beijing Biological, four recipients were vaccinated with inactivated vaccine from other companies and ten recipients did not know their inactivated vaccine' companies.After immunization, 24/151(15.9%)recipients had a local and general adverse reaction.The prevalence of pain at injection site, fatigue, headache and pruritus was 9.9%( n=15), 5.2%( n=8), 1.3%( n=2)and 0.7%( n=1)respectively.No significant differences existed in age( P=0.602), gender( P=0.752), period after LT( P=0.890), trough concentration of tacrolimus( P=0.377)or versions of covid-19 vaccine( P=0.582)between 24 cases with general adverse reaction and 127 without.Local and general reactions occurred in 16/83(19.3%)in Sinovac group and 5/40(12.5%)in Beijing Biological.There was no significant inter-group difference( P=0.769). There were 98 cases(64.9%)in <60 years group, 17 cases(17.3%)had local and general reaction, 53 cases(35.1%)in ≥60 years group and 7 cases(13.2%)had a local and systemic reaction.There was no significant inter-group difference( P=0.507). Conclusions:Covid-19 vaccine is safe for long-term survival LT recipients with normal liver function.Few participants present with mild fatigue and pain at injection site.

Objective To study the effect and mechanism of berberine (BBR) on the lung metastasis of mouse breast cancer via epithelial-mesenchymal transition (EMT). Methods CCK-8 and Transwell migration assays were utilized to investigate the proliferation and migration properties of breast cancer 4T1 cells after BBR treatment.Mouse 4T1-Luc cells were injected into mice under the fourth mammary fat pad, and the mice were then randomly divided into the control and BBR groups.The mice in the BBR group received daily intraperitoneal injections of BBR working solution and those in the control group were continuously intraperitoneally injected with the same volume of the solvent used to dissolve BBR powder.Tumor metastasis in the lungs of living mice was detected by using an in vivo imaging system.After 42 days of administration, lung metastasis was measured via microscopy and HE staining.Western blot analysis was used to examine the effects of BBR on the expression of EMT-related proteins (Vimentin and Snail) as well as the activation of the Akt and ERK signaling pathways. Results BBR significantly promoted 4T1 cell migration (P < 0.05).In vivo experiments showed that the number of lung metastases in the BBR group had significantly increased compared with that in control group (P < 0.05) as observed under microcopy and histological staining.Compared with the control group, BBR upregulated the expression levels of Vimentin and Snail as well as the phosphorylated levels of p-Akt and p-ERK (P < 0.05). Conclusion BBR may promote EMT and lung metastasis of breast cancer 4T1 cells by activating the expression of proteins in the p-Akt and p-ERK pathways.

Adult ; Cholesteatoma ; diagnosis ; Ear Canal ; abnormalities ; Humans ; Male ; Young Adult

Background Sleep quality is one of the important factors affecting soldiers’ task performance. Objective To explore the effects of mindful attention awareness, burnout, and occupational stress on sleep quality among soldiers in plateau areas. Methods A total of 1090 soldiers were selected from four units in plateau areas by cluster sampling method and were asked to participate a cross-sectional questionnaire survey using the Pittsburgh Sleep Quality Index (PQSI), Occupational Stress Inventory (OSI), Maslach Burnout Inventory-General Survey (MBI-GS), and Mindful Attention Awareness Scale (MAAS). Correlation analysis, regression analysis, and mediated effect test were conducted for the study. Results Of the 1090 soldiers recruited, 1082 soldiers returned valid questionnaires, and the valid recovery rate was 99.26%. The median (P₂₅, P₇₅) score of PSQI was 4.00 (2.00,7.00), the median score of OSI was 26.00 (17.00, 34.00), the median score of MBI-GS was 3.53 (3.13, 4.00), and the median score of MAAS was 71.00 (59.00, 82.00). The burnout and mindful attention awareness levels varied among military personnel of different age groups (P<0.05), so did the burnout and occupational stress levels among military personnel of different length of service groups (P<0.05), and the occupational stress, PSQI, burnout, and mindful attention awareness levels among military personnel with different educational backgrounds and genders (P<0.05). The results of mediated effect test showed that occupational stress and burnout had both a parallel mediated effect and a sequential mediating effect on the relationship between mindful attention awareness and sleep quality, with effect sizes of 15.3%, 21.5% and 31.8%, respectively. Conclusion There is a mediated effect on the relationship between mindful attention awareness and sleep quality by the occupational stress and burnout of military personnel in plateau areas, and sleep quality is also affected by mindful attention awareness through the chain-mediated effect of occupational stress and burnout.

Objective: To discuss the safety and efficacy of simultaneous procedures of vibrant soundbridge implantation and auricular reconstruction with congenital external and middle ear malformation. Methods: This is a retrospective study, including 6 patients, 5 boys and 1 girl, aged 7-12 years. All patients received simultaneous operations of vibrant soundbridge implantation and auricular reconstruction. The mean preoperative air conduction threshold was 64.8 dB HL at 0.5, 1, 2, and 4 kHz. The VSB was placed in the third stage of auricle reconstruction, if the soft tissue expansion was performed; otherwise, the VSB was implanted in the second stage. The satisfaction with reconstructed auricle, surgical complications, hearing improvement and speech discrimination scores were evaluated 6 months after surgery. Results: All patients and their families reported satisfaction with their reconstructed auricle. There was no complications, including cartilage framework exposion, infection, hematoma, skin flap necrosis, facial paralysis, tinnitus, vertigo or others. Post-operatively, mean VSB-aided hearing threshold was 36.7 dB HL, which was reduced by 28.1 dB HL. The mean speech discrimination scores measured in a sound field with a presentation level of 65 dB SPL and 80 dB SPL were improved. Conclusions The simultaneous operations of auricle reconstruction and Vibrant Soundbridge implantation is an alternative method for patients with congenital microtia and atresia.

Objective: To evaluate the auditory efficacy of Bonebridge implantation in patients with bilateral congenital malformation of external and middle ear. Methods: Eleven cases (6 males and 5 females) had unilateral Bonebridge implantation. The age ranged from 8 to 26 and the average age was 16.9. Seven to ten days after operation, the first fitting was undergone. In acoustic sound field, the average auditory thresholds were respectively measured for unaided ears and Bonebridge implanted ears by pure tone auditory (PTA, 0.25, 0.5, 1, 2 and 4 kHz). For the group over 12-year-old, MSTM was applied to evaluate speech discrimination score (SDS). For the other cases, MLNT was used as the test material. The auditory efficacy post Bonebridge implantation would be analyzed and evaluated by comparing the differences between unaided ears and Bonebridge implanted ears. Results: The bone conduction audibility threshold after Bonebridge implantation was as well as the preoperative. The auditory threshold with Bonebridge aided was improved to 25-35 dB HL, when compared to that of the unaided ears in the sound field. The SDS in the group over 12-year-old was improved about 50%; the efficacy was slightly limited for the other two cases (both less than 12 years old). Statistical analysis showed that there were significant differences between unaided ears and Bonebridge implanted ears in the sound field and SDS(P<0.05). Conclusions The auditory efficacy of Bonebridge is significant and noticeable in patients with bilateral congenital malformation of external and middle ear. Bonebridge provides a new and effective way for patient with congenital malformation of external and middle ear to reconstruct hearing.