Milk fat globule epidermal growth factor 8 alleviates liver injury in severe acute pancreatitis by restoring autophagy flux and inhibiting ferroptosis in hepatocytes

BACKGROUND

Liver injury is common in severe acute pancreatitis (SAP). Excessive autophagy often leads to an imbalance of homeostasis in hepatocytes, which induces lipid peroxidation and mitochondrial iron deposition and ultimately leads to ferroptosis. Our previous study found that milk fat globule epidermal growth factor 8 (MFG-E8) alleviates acinar cell damage during SAP via binding to αvβ3/5 integrins. MFG-E8 also seems to mitigate pancreatic fibrosis via inhibiting chaperone-mediated autophagy.

AIM

To speculate whether MFG-E8 could also alleviate SAP induced liver injury by restoring the abnormal autophagy flux.

METHODS

SAP was induced in mice by 2 hly intraperitoneal injections of 4.0 g/kg L-arginine or 7 hly injections of 50 μg/kg cerulein plus lipopolysaccharide. mfge8-knockout mice were used to study the effect of MFG-E8 deficiency on SAP-induced liver injury. Cilengitide, a specific αvβ3/5 integrin inhibitor, was used to investigate the possible mechanism of MFG-E8.

RESULTS

The results showed that MFG-E8 deficiency aggravated SAP-induced liver injury in mice, enhanced autophagy flux in hepatocyte, and worsened the degree of ferroptosis. Exogenous MFG-E8 reduced SAP-induced liver injury in a dose-dependent manner. Mechanistically, MFG-E8 mitigated excessive autophagy and inhibited ferroptosis in liver cells. Cilengitide abolished MFG-E8's beneficial effects in SAP-induced liver injury.

CONCLUSION

MFG-E8 acts as an endogenous protective mediator in SAP-induced liver injury. MFG-E8 alleviates the excessive autophagy and inhibits ferroptosis in hepatocytes by binding to integrin αVβ3/5.

[Preliminary evaluation of immunogenicity and protective effect of multicomponent recombinant protein vaccine EPRHP014 against tuberculosis]

Objective: To evaluate the immunogenicity and protective effect of a multicomponent recombinant protein vaccine EPRHP014 constructed independently and provide a scientific basis for developing new tuberculosis (TB) vaccine and effective prevention and control of TB. Methods: Three full-length Mycobacterium (M.) tuberculosis protein antigens (EsxH, Rv2628, and HspX) and two epitope-predicted and optimized epitope-dominant protein antigens (nPPE18 and nPstS1) were selected, from which five protein antigens were used to construct a protein antigen composition EPRHP014, including a fusion expression multi-component protein antigen (EPRHP014f) and a multi-component mixed protein antigen (EPRHP014m) formed with the five single protein using clone, purification, and purification respectively. Multicomponent protein vaccines EPRHP014f and EPRHP014m were prepared with aluminum adjuvant, and the BCG vaccine was used as a control. ELISA detected the titer of serum-specific antibodies, the secretion of various cytokines was detected by ELISpot and Luminex, and immune protection was observed by the M. tuberculosis growth inhibition test in vitro. The results were statistically analyzed by t-test or rank sum test, and P<0.05 was considered a statistically significant difference. Results: Mice Immunized with EPRHP014m and EPRHP014f could produce highly effective IgG antibodies and their subtypes IgG1 and IgG2a, and the antibody titers were similar to those of mice immunized with BCG, with no statistical significance (P>0.05). The number of spot-forming cells (SFC) secreting IFN-γ and IL-4 induced by EPRHP014f group was significantly higher than those by EPRHP014m group and BCG group (P<0.05), but there was no significant difference in the number of SFC for IFN-γ and IL-4 induced between EPRHP014m group and BCG group (P>0.05). The secretion levels of GM-CSF and IL-12p70 induced by the EPRHP014m group were higher than those of the BCG group (P<0.05), but there was no significant difference in the levels of IL-6 and IL-10 induced between EPRHP014m group and BCG group (P>0.05). There was no significant difference in the secretions of IL-6, IL-10, IL-12, and GM-CSF between the EPRHP014f and BCG groups (P>0.05). EPRHP014m group, EPRHP014f group, and BCG group had obvious antibacterial effects in vitro, and the difference was insignificant (P>0.05). Conclusion: Both EPRHP014f and EPRHP014m can induce strong humoral and cellular immune responses in mice after immunization, and have a strong ability to inhibit the growth of M. tuberculosis in vitro, indicating that the antigen composition EPRHP014 has good potential in the development and application of TB vaccine.

Effectiveness of Cisplatin in P16+ Oropharyngeal Cancer According to Relative Risk for Cancer Events: Ancillary Analysis of RTOG 1016

PURPOSE/OBJECTIVE(S)

To test the hypothesis that the effectiveness of cisplatin in p16+ oropharyngeal squamous cell carcinoma (OPSCC) increases with patients' relative risk for cancer events.

MATERIALS/METHODS

Ancillary analysis of 805 patients enrolled on RTOG 1016 accessed via Project DataSphere. Eligible patients had p16+ OPSCC, AJCC 7th T1-T2 N2a-N3 or T3-T4 N0-N3 M0, ECOG PS 0-1. Patients were randomized to RT with concurrent cisplatin vs. cetuximab. Relative risk for competing events was quantified using the Head and Neck Cancer Intergroup predictive classifier (omega score). Higher scores indicate higher relative risk for cancer events (LRF or distant metastasis) vs. competing mortality. We compared this to favorable, unfavorable/low, and unfavorable/intermediate risk groups using standard criteria: NRG HN005 eligible/low RTOG risk (Ang et al.), HN005 ineligible/low RTOG risk, and intermediate RTOG risk. Omega score cutoffs were selected to match numbers in standard risk strata. HRs for the effect of cisplatin vs. cetuximab on PFS and OS were compared for standard vs. relative risk strata. 1-tailed interaction tests were used to test whether cisplatin effectiveness increased within risk strata.

RESULTS

There were 354, 219, and 232 patients in standard favorable, unfavorable/low, and unfavorable/intermediate risk groups. Omega score cutoffs were 0.80 and 0.84 to define low, intermediate, and high relative risk groups. Discordant standard vs. relative risk classifications occurred in 559 patients (69.4%). Increasing omega score was associated with significantly higher relative HR (rHR) for cancer events (3.40, 95% CI: 1.66-6.96) and increasing effectiveness of cisplatin vs. cetuximab (Table), but standard risk grouping was not (rHR 0.80, 95% CI: 0.49-1.32). The effect of cisplatin on PFS significantly increased with higher omega score (interaction -0.30, p = .046), but decreased with increasing standard risk strata (interaction +0.27, p = NS).

CONCLUSION

The effectiveness of cisplatin in p16+ OPSCC increased with higher omega score but not with standard risk group. Relative risk for cancer events should be taken into account when designing deintensification strategies.

Comparison of Standard vs. Relative Risk Models to Define Candidates for Deintensification in Locoregionally Advanced P16+ Oropharyngeal Cancer

PURPOSE/OBJECTIVE(S)

Various methods to identify candidates for treatment deintensification with p16+ oropharyngeal squamous cell carcinoma (OPSCC) have been used, but the optimal approach is unknown.

MATERIALS/METHODS

Multi-institutional cohort study of 385 patients with previously untreated p16+ OPSCC undergoing definitive radiotherapy (RT) with or without systemic therapy between 2009-2020. Chemotherapy intensity was categorized as high (bolus cisplatin and/or induction chemotherapy), medium (weekly cisplatin), or low (non-cisplatin or RT alone). Standard favorable vs. unfavorable risk was defined using NRG HN005 eligibility criteria. High vs. low relative risk (RR) group was defined using the HNCIG omega score (≥ 0.80 vs. < 0.80), which quantifies the proportion of a patient's overall event risk due to cancer. We used multivariable ordinal logistic regression to estimate effects of age (yrs), sex, performance status (PS), Charlson comorbidity index (CCI), T/N (AJCC 8th), current smoking, and pack-years (> 10 vs. ≤ 10) on treatment allocation. Effects on relative event hazards were estimated using generalized competing event regression.

RESULTS

Median follow-up time was 44.2 months. Chemotherapy intensity was high in 206 (54%), medium in 108 (28%), and low in 71 (18%). 280 patients (73%) were unfavorable risk and 197 (51%) were high RR. 178 patients (46%) had discordant risk classification. On univariable analysis, significant predictors of higher intensity chemotherapy (normalized odds ratio (OR)) were CCI 0-1 (OR 1.49, 95% CI: 1.23-1.79), high omega score (OR 1.46; 1.20-1.77), decreased age (OR 1.43; 1.18-1.74), and PS 0 (OR 1.22; 1.01-1.48). Controlling for CCI, higher omega score was associated with significantly higher odds of intensive chemotherapy (OR 1.35; 1.10-1.65, but unfavorable risk (HN005 ineligibility) was not (OR 1.19; 0.98-1.44). Higher omega score was also associated with significantly higher RR for cancer recurrence (Rec) vs. competing mortality (CM) events (relative HR (rHR) 1.76; 1.12-2.75), but unfavorable risk was not (rHR 1.05; 0.63-1.75). Among patients receiving cisplatin, 50 favorable risk patients (58%) had high RR; all of their event risk was due to cancer recurrence (Table). The 110 unfavorable risk patients (48%) with low omega score had significantly lower RR for cancer events compared to the high omega score group (rHR 0.49; 0.29-0.84).

CONCLUSION

Many patients with favorable risk p16+ OPSCC have high relative risk for cancer events, which correlates with a benefit of intensive treatment. The HNCIG omega score is a strong predictor of allocation to intensive chemotherapy and may help identify candidates for deintensification.

[Measurement and analysis of the crown conical degree of maxillary incisors in patients with congenital tooth agenesis caused by different gene mutations]

Objective: To measure the crown conical degree of the remaining maxillary incisors in patients with congenital tooth agenesis, and to analyze the influence of different gene mutations on the crown conical degree of patients. Methods: Whole exome sequencing was performed on 85 patients with congenital tooth agenesis (50 males, 35 females, median age 19 years old) who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology from January 2019 to January 2023. The pathogenic gene was identified. The width of the crowns of the maxillary central and lateral incisors at the incisal 1/3 and gingival 1/3 were measured on the panoramic radiograph, and the ratio was defined as the crown conical degree. The smaller the ratio is, the more likely is the crown to be peg shaped teeth. The control group was matched by age and gender with 85 other patients with intact maxillary permanent incisors who were treated in the Department of Prosthodontics, Peking University School and Hospital of Stomatology from January 2019 to January 2023. The conical degree of the tooth agenesis group was compared with the control group by t-test, and the differences in the crown conical degree in different gene mutation groups were compared using one-way analysis of variance, and the multiple comparisons among gene groups were carried out using the LSD method. Results: Among the 85 tooth agenesis patients, the numbers of patients in each gene mutation group were 20 in ectodysplasin A (EDA) group, 8 in ectodysplasin A receptor (EDAR) group, 15 in wingless-type MMTV integration site family, member 10A (WNT10A) group, 16 in paired box 9 (PAX9) group, 10 in Msh homeobox 1 (MSX1) group, 10 in low-density lipoprotein receptor related protein 6 (LRP6) group, and 6 in bone morphogenetic protein4 (BMP4) group. The number of missing teeth were 1-27, median number 15 among the tooth agenesis patients. There was no significant difference in the conical degree between the left and right homonymous teeth in the congenital tooth agenesis group and the control group (P>0.05). The crown conical degree of maxillary central incisor and lateral incisor in the congenital missing teeth group (0.95±0.24, 0.90±0.22) was significantly smaller than that in the control group (1.12±0.09, 1.13±0.09) (t=-8.50, P<0.001; t=-11.47, P<0.001). In WNT10A mutants, the conical degree of lateral incisors (0.89±0.18) was less than that of central incisors (1.07±0.15)(t=3.68, P<0.001). The conical degree of central incisors and lateral incisors (0.70±0.23, 0.57±0.15) of EDA mutants was significantly lower than that in patients with other gene mutations (P>0.05). Conclusions: Compared with the normal control group, the remaining maxillary central and lateral incisors of the seven gene mutation groups of patients with congenital tooth agenesis all had different degrees of conical crown. Among them, the crown conical degree of maxillary central and lateral incisors of the EDA mutation was the most severe, and the WNT10A mutation affected the maxillary lateral incisors more specifically.

[Analysis of the characteristic of clinical symptoms and cone-beam CT imaging changes in temporomandibular joint osteoarthritis patients with chewing side preference]

Objective: To investigate the clinical symptoms and cone-beam CT (CBCT) imaging characteristics of temporomandibular joint osteoarthritis (TMJOA) with chewing side preference (CSP). Methods: One hundred patients with TMJOA diagnosed in the Department of Stomatology, General Hospital of the Chinese PLA from January 2018 to December 2020 were enrolled, including 32 males and 68 females, with an median age of 27.5 years (16-71 years). According to the habit of CSP, 100 cases were divided into 71 cases of TMJOA with CSP group and 29 cases of TMJOA without CSP group. The clinical symptoms were observed, including pain, TMJ sounds, limited mouth opening as well as the radiograph imaging changes of condylar bone. When analyzing the radiograph imaging changes of condylar, the cases with bilateral TMJ symptoms were excluded and the remaining cases were divided into symptomatic sides and asymptomatic sides with CSP or without CSP according to the symptoms of the chief complaint. SPSS 25.0 was used to analyze the statistical data. Age data did not conform to normal distribution so that median and quartile spacing were used for description, and Mann-Whitney U test was used for nonparametric test. Qualitative data such as gender, clinical symptoms and condylar lesion types were described by composition ratio and Chi-Square test was performed. Results: There was no statistical significance in age and gender of TMJOA patients in the group with or without CSP (P>0.05). There incidence of pain in CSP group [83.1% (59/71)] was margina uy higher than that in non-CSP group but without statistical difference[65.5% (19/29)] (χ²=3.71, P=0.054). There was also no significant difference in TMJ sounds and limitation of mandibular movement between the two groups(χ²=0.11, P=0.742; χ²=0.48, P=0.489). Among all of joints, the most common types of TMJOA were articular flattening and shortening and erosion. CBCT showed that erosion [65.0% (130/200)], flattening and shortening [73.0% (146/200)], subcortical sclerosis [42.0% (84/200)], osteophyte [30.5% (61/200)] and subcortical cystic [15.5% (31/200)]. According to the different groups of chief complaint sides, intra-group comparisons show that the proportion of erosion in symptomatic sides of CSP group [80.0% (40/50)] was significantly higher than that in asymptomatic sides of CSP group [50.0% (25/50)] (χ²=9.89, P=0.002). Inter-group comparisons show that the proportion of condyle flattening and shortening in symptomatic sides of CSP group [84.0% (42/50)] was significantly higher than that in bilateral joint of non-CSP group (8/15) (χ²=8.81, P=0.032). There was no significant difference in the proportion of subcortical sclerosis, osteophyte and subcortical cystic between the group with or without CSP (P>0.05). Conclusions: TMJOA patients with CSP may be more prone to clinical symptoms of pain and CBCT imaging changes of condyle erosion as well as flattening and shortening. CSP may be a promoting factor for the development of TMJOA.

[Medical properties and development orientation of dental implants]

This paper focuses on the medical properties of dental implants from different perspectives, and points out that oral rehabilitation with dental implants are a systematic engineering to repair the defects and missing dentitions and maintain the integrity of human oral and maxillofacial organs, restore oral function, and maintain oral and general health. It is necessary to strictly follow the medical rules and medical standards to prevent the deviation of dental implant medical research and clinical guidance. In order to meet the needs of people with more than 2 billion missing teeth in China, including nearly 20 million edentulous individuals, and to solve the contradiction between the needs of the public and the imbalance of dental implant medical development, it is proposed to build a high-level dental implant professional team of general practitioners and specialists with Chinese characteristics. Multidisciplinary research and development and original brand research and development in the field of dental implant in China, especially the transformation and promotion of the results, should be strengthened. By focusing on the development of digital network remote artificial intelligence dental implant popularization and improvement, the goal of systematic, standardized and homogeneous dental implant repair medical quality and quantity improvement can be achieved simultaneously. The diagnosis and treatment capabilities of difficult and complicated cases of dental implant in China could be improved.

[Analysis of the correlation between chewing side preference and disc displacement types and clinical symptoms in patients with anterior disc displacement of temporomandibular joint]

Objective: To analyze the clinical symptoms and types of disc displacement of patients with anterior disc displacement (ADD) of temporomandibular joint (TMJ) and to explore the correlation between chewing side preference (CSP) and the clinical symptoms and types of disc displacement of ADD patients. Methods: This was a cross-sectional study of the ADD patients diagnosed by clinical symptoms and MRI findings of TMJ in the Department of Stomatology, General Hospital of Chinese PLA from January 2018 to December 2019. A total of 111 ADD patients [33 males and 78 females, aged(31.0±10.9) years old] were included. The patients were divided into two groups according to whether they had CSP: non-CSP group (n=40) and CSP group (n=71). The clinical symptoms and types of ADD were observed and recorded. According to the specific side of CSP in the CSP group, the patients were further divided into the ipsilateral side and the contralateral side of CSP. The pain, TMJ sounds and the ADD types were also observed. Chi square test was used to compare the pain, TMJ sounds, limited mouth opening and ADD types of the two groups. Binary Logistic regression model was used to analyze the correlation between CSP and clinical symptoms and ADD characteristics. Results: The incidence of pain in the CSP group [89% (63/71)] was significantly higher than that in the non-CSP group [70% (28/40)] (P<0.05). In CSP patients, the incidences of pain and joint sounds on the ipsilateral side of CSP were significantly higher than that on the contralateral side (P<0.05). MRI showed that the incidence of bilateral ADD in the CSP group [58%(41/71)] was significantly higher than that in the non-CSP group [37%(15/40)] (P<0.05).There were significant differences in the incidences of no disc displacement (DD), anterior disk displacement with reduction(ADDwR) and anterior disk displacement without reduction (ADDwoR) between ipsilateral and contralateral joints of the CSP patients (P<0.05). There were no significant differences in the incidences of no DD, ADDwR and ADDwoR between left and right joints of the non-CSP patients (P>0.05). The incidence of ADDwoR in ipsilateral side of the CSP patients was significantly higher than that in contralateral side (P<0.05). Pain (OR=3.375) and the side of disc displacement (OR=2.278) in patients with ADD were positively correlated with CSP (P<0.05). Conclusions: The clinical symptoms and types of disc displacement between patients with and without CSP were significantly different. The incidences of pain and bilateral disc displacement in the CSP group were significantly higher than those in the non-CSP group. In addition, the incidences of pain, TMJ sounds and anterior disk displacement without reduction on the ipsilateral side of patients with CSP were significantly higher than those on the contralateral side. The pain symptoms and side of disc displacement were positively related to CSP.

Advances in External Beam Radiation Therapy and Brachytherapy for Cervical Cancer

The standard of care for the definitive treatment of locoregionally advanced cervical cancer is external beam radiation therapy (EBRT) with concurrent chemotherapy followed by a brachytherapy boost. Historically, EBRT was delivered via a two-dimensional technique based primarily on bony landmarks. This gave way to three-dimensional conformal radiation therapy, which allows for dose calculation and adjustment based on individual tumour and patient anatomy. Further technological advances have established intensity-modulated radiation therapy (IMRT) as a standard treatment modality, given the ability to maintain tumoricidal doses to target volumes while reducing unwanted radiation dose to nearby critical structures, thereby reducing toxicity. Routine image guidance allows for increased confidence in patient alignment prior to treatment, and the ability to visualise the daily position of the targets and organs at risk has been instrumental in allowing safe reductions in treated volumes. Additional EBRT technologies, including proton therapy and stereotactic body radiation therapy, may further improve the therapeutic index. In the realm of brachytherapy, a shift from point-based dose planning to image-guided brachytherapy has been associated with improved local control and reduced toxicity, with additional refinement ongoing. Here we will discuss these advances, the supporting data and future directions.

[Management of major complications in surgical treatment of mandibular osteoradionecrosis by using vascularized free flaps]

Objective: To retrospectively analyze of the prevention and management of major complications in surgical treatment of osteoradionecrosis (ORN) of the mandible by using vascularized free flaps and to provide a reference for improving clinical treatments. Methods: All cases diagnosed as mandibular ORN and received surgical treatment in the Department of Oral and Maxillofacial Surgery, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University from August 2014 to March 2019 were included. The patients' clinical data, mainly including general information, primary tumor, interval time between radiotherapy and osteoradionecrosis, surgical methods and postoperative complications, were collected. The data of surgical methods and postoperative complications of these patients were compared with the similar data of patients with malignant tumor surgically treated by using vascularized free flaps during the same period. Results: The postoperative follow-up data of 104 patients with mandibular ORN, who underwent surgery in our hospital, were collected. In the control group, surgeries of vascularized free flap transfer were performed in 430 patients with malignant tumor. Among the 34 ORN cases (34/104, 32.7%) of segmental resection with vascularized free flap transfer, there were 13 cases (13/34, 38.2%) of postoperative local infection in maxillofacial area, 6 cases (17.6%) of pulmonary infection, 2 cases (5.9%) of venous thrombosis, 3 cases (8.8%) of anastomotic artery rupture and 5 cases (14.7%) of vascular crisis. One case died of depression and misanthropy. Meanwhile, among 430 patients with malignant tumor who underwent surgeries of vascular free flap reconstruction, 25 cases (5.8%) had postoperative local infection and 29 cases (6.7%) had pulmonary infection. Vascular crisis occurred in 12 cases (2.8%) and anastomotic artery rupture in 1 case (0.2%). No venous thrombosis and misanthropy occurred. The incidence of postoperative complications in mandibular ORN was much higher than that of vascularized free flap transfer surgeries in malignant tumor cases (P<0.05). Conclusions: Compared with patients with malignant tumors undergoing vascularized free flap transfer surgeries, patients with mandibular ORN undergoing same surgeries are more likely to have postoperative complications. This study may help clinicians to fully understand the local, general and psychological conditions during the perioperative period of ORN patients.

[Artificial intelligence stomatology]

Artificial intelligence (AI) is a kind of technology which is rapidly developed on the basis of computer technology. AI makes it possible for machines to learn from experience, adjust to new inputs and perform human-like tasks. It has been applied in many fields of human society, and is more and more widely used in medical field. The development and application of AI in stomatology will lead the future of stomatology to a certain extent. It is very important for stomatology professionals to recognize, learn and master AI, to keep pace with the pace of the new era of medical treatment and to apply it in medical practice. This paper introduces the application and progress of AI in stomatology clinic, research and teaching field, analyzes the existing and possible problems, and prospects the development of AI in the field of stomatology.

[Experts consensus on MRI examination specification and diagnostic criteria of temporomandibular joint disc displacement]

The document represented the consensus amongst the professionals from the Society of TMD & Occlusion, Chinese Stomatological Association and provided guidelines with the MRI examination specification and diagnostic criteria of temporomandibular joint disc displacement.

[Cellular immunity evaluation of five mycobacterium tuberculosis recombinant proteins and their compositions]

Objective: The cellular immunity of 5 Mycobacterium tuberculosis recombinant proteins and their compositions was evaluated. Method: A total of 88 fresh venous blood from peripheral heparin anticoagulant population, 42 of which were from tuberculosis patients treated by The Tuberculosis Prevention and Treatment Center of Changping District, Beijing, and 46 of healthy volunteers were provided by the Infection Diseases of Chinese Center for Disease Control and Prevention. Healthy volunteers without a history of tuberculosis exposure and any clinical signs and symptoms. Using the Mycobacterium tuberculosis standard strain H37Rv DNA as a template, complete genes of the selected 5 recombinant proteins Rv3874, Rv3875, Rv2031c, Rv1411c and Rv3418c by PCR amplified; 5 recombinant proteins were cloned, expressed and purified as stimulants by genetic recombination and protein purification techniques, and the effector T cell enzyme-linked immunospot assay (ELISPOT) was used to detect cellular immunity in the population. Results: The recombinant proteins Rv3874, Rv3875, Rv2031c, Rv1411c and Rv3418c were successfully cloned, expressed and purified; And the sensitivities were 50.00%, 71.43%, 69.04%, 73.81% and 76.19%, and the specificities were 86.96%, 76.09%, 71.74%, 39.13% and 36.96%. In addition, the positive predictive value, negative predictive value, area under the curve and Youden index were 52.46% to 77.78%, 62.96% to 74.47%, 0.511 to 0.754 and 0.129 to 0.475, respectively. Except for Rv1411c and Rv3418c, the number of spot-forming cell (SFC) detected by Rv3874, Rv3875 and Rv2031c in tuberculosis patients was higher than healthy volunteers, and the differences were statistically significant (P<0.001). Among the 26 compositions composed of 5 recombinant proteins, the sensitivity was 80.95% to 95.24%, and the specificity was 68.89% to 24.44%. As the number of recombinant proteins in the composition increases, the sensitivity gradually increased, but the specificity decreased. Conclusion: The recombinant proteins of Mycobacterium tuberculosis Rv3874, Rv3875 and Rv2031c have strong ability to stimulate T cells to produce immune response, and have certain antigenicity. The efficacy of Rv1411c and Rv3418c alone as diagnostic antigens is not ideal, and the composition composed of multi-component antigens has certain application value. This article provides experimental evidence for the immune diagnosis of tuberculosis and the preparation of new anti-tuberculosis vaccines.

[Analysis on drug sensitivity spectrum of 167 multidrug-resistant Mycobacterium tuberculosis in China]

Objective: To investigate the drugs-sensitivity spectrum of multidrug-resistant tuberculosis (MDR-TB) in China and provide a scientific evidence for the drug selection in clinical therapy and the control of MDR-TB. Methods: A total of 167 strains of MDR-TB were included in this study. Every strain was genotyped by lysX gene sequencing and their sensitivity to 13 different anti-TB drugs was tested by using MicroDST(TM) and BACTEC(TM) MGIT 960(TM) liquid-culturing method. The association between drug resistance and genotypes as well as cross drug resistance was also analyzed. The results were analyzed by means of the comparison of enumeration data between two groups with χ(2) test. Results: The overall resistance rate of 167 MDR-TB strains to 11 anti-TB drugs, except isoniazide and rifampicin, was 95.81%, the rates of pre-extensive drug-resistance (pre-XDR) and extensive drug-resistance were 31.14%(52/167) and 6.59% (11/167), respectively. The streptomycin resistance rate of Beijing genotypes was significantly higher than that of the non-Beijing genotypes ( χ(2)=30.682, P<0.05), while the pre-XDR proportion in Beijing genotypes was lower than that in non-Beijing genotypes (χ(2)=5.332, P<0.05). The resistance rates of Ofloxacin and Pyrazinamide in the modern Beijing genotype were significantly higher than those in classical ones (χ(2)=4.105 and χ(2)=3.912, P<0.05). In addition, the cross-resistance rate to rifampicin and rifabutin was 86.23%. A significant difference in drug-resistance rate to rifabutin was seen among groups with different levels of rifampicin resistance (χ(2)=45.912, P<0.05). There was positive correlation not only between ofloxac resistance and moxifloxac resistance, but also between amikacin resistance and kanamycin resistance, with the coefficient of 0.87 and 0.91, respectively. Conclusions: In this study, we observed that there were high incidences of the resistance to 11 anti-TB drugs in 167 clinical MDR-TB strains and the cross resistance phenomena between drugs of the same type were quite serious. The majority of MDR-TB strains belonged to Beijing genotype, which was highly associated with streptomycin resistance.

[Analysis on drug resistance-associated mutations of multi-drug resistant Mycobacterium tuberculosis based on whole-genome sequencing in China]

Objective: To analyze the resistance mutational profiles of multi-drug resistant Mycobacterium tuberculosis in China and the correlation between major mutation types and genotypes based on the whole-genome sequencing data. Methods: Search and download of the genome-wide sequencing data of M. tuberculosis published in China by August 2019 on NCBI database were conducted. Mutation frequency of drug resistance-related gene loci based on whole-genome sequencing was used to predict the molecular susceptibility of strains, and the correlation between mutation types and genotypes was analyzed. Results: According to the results of molecular resistance and susceptibility profiles, 1 024 MDR strains were identified from 2 019 M. tuberculosis strains. The major mutation types of resistance-related genes to common drugs were katG S315T (73.2%, isoniazid), rpoB S450L (63.1%, rifampicin), rpsL K43R (70.0%, streptomycin), embB M306V (37.4%, ethambutol), pncA_promoter T (-11)C (7.9%, pyrazinamide), gyrA A90V (32.3%, fluoroquinolones), rrs A1401G (67.7%, second-line injection drugs), fabG1_promoter C (-15) T (87.0%, Ethionamide), folC I43T (30.4%, P-aminosalicylic acid). Among them, the frequencies of katG S315T, embB M306V, rpsL K43R, gyrA A90V in lineage 2 were significantly higher than those in lineage 4, and folC I43T was only found in lineage 2. The proportion of katG S315T was significantly higher in the ancient Beijing genotype compared to the modern genotype, in contrast, the proportion of rpsL K43R was significantly higher in modern Beijing genotype, the differences were significant (all P<0.05). Conclusions: The results showed the main mutation types of resistance-related genes of MDR strains to many commonly used anti-tuberculosis drugs in China based on whole-genome sequencing, providing a basis for the development of sensitive and specific rapid molecular detection methods. At the same time, it was also found that the major mutation types of MDR-related genes were related to the genotype of the strains.

[Analysis on the technical characteristics and clinical efficacy of robotic-assisted intersphincteric resection for patients with low rectal cancer]

Objective: To explore the technical characteristics and short-term clinical efficacy of robotic-assisted intersphincteric resection (ISR) for patients with low rectal cancer. Methods: A retrospective cohort study was used. Inclusion criteria: (1) rigid colonoscopy showed lower margin of the tumor ≤5 cm from the anal verge; (2) preoperative rectal MRI or endorectal ultrasound revealed staging T1-2, or T3 patients receiving concurrent chemoradiotherapy; (3) patients less than 70 years old with good function of anal sphincter before surgery; (4) no synchronous multiple primary carcinoma, and no distant metastasis; (5) the method of operation was agreed by the patient. Exclusion criteria: (1) T4 stage tumors; (2) sphincter dysfunction before operation; (3) recurrent tumors; (4) lower edge of tumors beyond the dentate line; (5) death due to non-rectal cancer during follow-up and unsatisfactory follow-up data. The clinical data of 21 patients with low rectal cancer meeting inclusion criteria undergoing robotic-assisted ISR at our department from January 2015 to June 2018 were collected. Parameters during and after operation were observed. Anorectal manometry was performed at 3, 6, and 12 months after the operation, and anal function was evaluated at 3, 6, and 12 months after the closure of the stoma by Kirwan classification and Wexner fecal incontinence score. The key steps of the operation are as follows: according to the principle of total mesorectal excision, the robot continued to enter into the levator ani hiatusdistally, and dissectin the sphincter space; according to the scope of sphincter resection, ISRwas divided into partial ISR, subtotal ISR, and total ISR; subtotal and total ISR usually needed to be combined with transanal pathway. The reconstruction of digestive tract was performed by double stapler anastomosis under laparoscope orhand-sewnanastomosis under direct vision, and preventive ileostomy was completed in the right lower abdomen. Results: Of 21 patients, 13 were male and 8 were female with mean age of (57.5±16.3) years. All the patients successfully completed the operation without conversion to laparotomy. Fourteen cases (66.7%) adopted partial ISR through complete transabdominal approach, 6 cases (28.6%) adopted the subtotal ISR through combined transabdominal and transanal approachs, and 1 case (4.8%) adopted the total ISR through the combined transabdominal and transanal approachs. The total operation time was (213.1±56.3) minutes, including (27.3±5.4) minutes for mechanical arm installation and (175.7±51.6) minutes for robotic operation. The amount of intraoperative hemorrhage was (62.8±23.2) ml, and no blood transfusion was performed in any patient. All patients underwent prophylactic ileostomy, and the stoma was closed 3-6 months after the operation. Except one case of anastomotic leakage, all other stomas were closed successfully. The postoperative hospitalization time was (7.6±2.2) days, and time to fluid intake was (3.3±0.9) days. One case of anastomotic leakage, one case of anastomotic stenosis, one case of inflammatory external hemorrhoids and one case of urinary retention occurred after surgery,and all of them were cured by conservative treatment. The mean diameter of tumors was (2.9±1.2) cm, and the number of harvested lymph node was 12.8 ± 3.3. In the whole group, the circumcision margin was negative, the proximal margin was (12.2 ± 2.1) cm, the distal margin was (1.1 ± 0.4) with all negative, and the R0 resection rate was 100%. The results of anorectal manometry showed that the preoperative rest pressure, rectal maximum squeeze pressure, initial sensory volume and maximum tolerated volume were (45.19±8.46) mmHg, (128.18±18.80) mmHg, (44.33±10.11) ml and (119.00±19.28) ml, respectively;these parameters reduced significantly 3 months after operation and they were (23.44±5.54) mmHg, (93.72±12.15) mmHg, (17.72±5.32) ml and (70.44±10.9) ml, respectively. The differences were statistically significant (all P<0.001). The resting pressure and the rectal maximum squeeze pressure returned to preoperative levels 12 months after operation, which were (39.33±6.64) mmHg and (120.58±16.47) mmHg, respectively (both P>0.05), while the initial sensory volume and the maximum tolerated volume failed to reach the preoperative state, which were (30.67±7.45) ml and (92.25±10.32) ml, respectively (both P<0.05). The patients were followed up for (22.1±10.6) months without local recurrence and distant metastasis. Eighteen patients were evaluated for anal function: Kirwan classification was grade I for 6 cases, grade II for 7 cases, grade III for 4 cases, and grade IV for 1 case; Wexner incontinence score was 8.6±0.8; 14 cases had good defecation control. Conclusion: The clinical efficacy of ISR with Da Vinci robot in the treatment of low rectal cancer is satisfactory.

[Application of ARIMA model in predicting the incidence of tuberculosis in China from 2018 to 2019]

Objective: Autoregressive integrated moving average (ARIMA) model was used to predict the incidence of tuberculosis in China from 2018 to 2019, providing references for the prevention and control of pulmonary tuberculosis. Methods: The monthly incidence data of tuberculosis in China were collected from January 2005 to December 2017. R 3.4.4 software was used to establish the ARIMA model, based on the monthly incidence data of tuberculosis from January 2005 to June 2017. Both predicted and actual data from July to December 2017 were compared to verify the effectiveness of this model, and the number of tuberculosis cases in 2018-2019 also predicted. Results: From 2005 to 2017, a total of 13 022 675 cases of tuberculosis were reported, the number of pulmonary tuberculosis patients in 2017 was 33.68% lower than that in 2005, and the seasonal character was obvious, with the incidence in winter and spring was higher than that in other seasons. According to the incidence data from 2005 to 2017, we established the model of ARIMA (0,1,2)(0,1,0)(12). The relative error between the predicted and actual values of July to December 2017 fitted by the model ranged from 1.67% to 6.80%, and the predicted number of patients in 2018 and 2019 were 789 509 and 760 165 respectively. Conclusion: The ARIMA (0, 1, 2)(0, 1, 0)(12) model well predicted the incidence of tuberculosis, thus can be used for short-term prediction and dynamic analysis of tuberculosis in China, with good application value.

[Detection and functional analysis of BMP2 gene mutation in patients with tooth agenesis]

OBJECTIVE

To screen for BMP2 mutation with functional impact in patients with congenital tooth agenesis and to make oral and skeletal phenotype record and functional analysis with in vitro experiments.

METHODS

We enrolled eighteen patients with congenital tooth agenesis. The medical and dental history was collected,and clinical and dental examinations including the X-ray examination of oral-facial and skeletal bone were performed for the phenotypic analysis. Blood samples were collected to extract DNA and whole exome sequencing was conducted. The genes involved in oral-facial development and congenital skeletal diseases were investigated for mutation screening. The mutations with functional impact were then investigated. In one patient, the BMP2 mutation with putative functional impact was selected for functional analysis. Wild type and mutant BMP2 plasmids with green fluorescent protein (GFP) tag were constructed and transfected into HEK293T cells. Subcellular protein distribution was observed under laser scanning confocal microscope. The activation of downstream SMAD1/5/9 phosphorylation by BMP2 was detected by Western blotting to investigate the functional impact and genetic pathogenicity.

RESULTS

BMP2 mutation NM_001200.3:c.393A>T (p.Arg131Ser), rs140417301 was detected in one patient with congenital tooth agenesis, while for other genes involved in oral-facial development and congenital skeletal diseases, no functionally significant mutation was found. The proband's parents didn't carry this mutation. The father had normal dentition, while the mother lacked one premolar, and both the parents showed normal palate and maxilla. The patient also had maxillary hypoplasia in both sagittal and coronal planes, palatal dysmorphology, and malocclusion, and was diagonsed with osteopenia after the X-ray examnination of his skeletal bone. Functional analysis showed this mutation had normal subcelluar localization but reduced phosphorylation of SMAD1/5/9 (reduction by 32%, 22%, and 27% in three independent replicates). Taken together with family co-segregation, this mutaion was considered as "likely pathogenic".

CONCLUSION

BMP2 mutation c.393A>T (p. Arg131Ser) affects bone morphogenetic protein signaling activity, and may affect the number of teeth, growth of maxilla and palate, and bone mineral density.

[The diagnosis and treatment of traumatic optic nerve neuropathy combined with carotid artery injury]

Objective: To discuss the diagnosis and treatment strategy of traumatic optic nerve neuropathy (TON) combined with carotid artery injury. Methods: Retrospective analyses were performed 397 cases of TON at Neurosurgery department of Beijing Tongren Hospital, Capital Medical University (CMU), from January 2016 to December 2017.The clinical experience was concluded. Results: 9 cases of Traumatic Pseudo Aneurysm (TPA) and 16 cases of Traumatic Carotid Artery-Cavernous Sinus Fistula (TCCF) were found.7 cases of TPA were treated by covered stent, the other 2 cases were treated by detachable balloons.11 cases of TCCF were treated by detachable balloons, and 5 cases of fistulas were found spontaneously closed by DSA after 1-3 months.There was no disability rate and mortality in this study. Conclusion: TON combined with carotid artery injury was a critical situation, and sometime without obvious symptoms and sign, which was easily miss diagnosed.It should be with more concern in diagnosing and treating in such cases, to avoid disability rate and mortality.

[Genetic variants analysis and histological observation of teeth in a patient with hereditary opalescent dentin]

OBJECTIVE

To analyze the clinical characteristics and the genetic cause of a Chinese patient with hereditary opalescent dentin, and to make an observation of the histologic and elemental features of the affected teeth.

METHODS

We enrolled a patient affected with hereditary opalescent dentin. The medical history was collected and clinical examinations were performed for the phenotypic analyses. The blood sample was collected for DNA extraction and PCRs of the coding sequence of DSPP were done for sanger sequencing. The teeth samples were collected for histological evaluation and elemental analysis.

RESULTS

The patient showed typical clinical manifestations of opalescent dentin and had enamel dysplasia and skeletal class III malocclusion. Several polymorphisms (c.727G>A, c.897A>G, c.2053_2054ins18bp, c.2548G>A, c.2645_2646ins9bp, c.2706T>C, c.2878A>G, c.3004A>G, c.3069_3086del18bp, c.3249A>C, c.3264T>C, c.3266_3400del135bp, c.3418A>G, c.3454G>A, c.3461_3462ins18bp, c.3606C>T) but no pathogenic mutations were identified in DSPP. The histological analyses of the patient's teeth showed characteristic abnormalities that were significantly different from normal teeth. The dentin tubules of the affected teeth were decreased in number and sparsed in arrangement, while in the control teeth, they were more regular. The enamel-dentin junction of the affected teeth was abnormal in its less scallopped outline compared with the control teeth under the scanning electronic microscopy. The Mg proportion of the patient's teeth (0.615 0%±0.261 6%) was lower than that of the control teeth (1.283 3%±0.322 1%), the P value was 0.040. The Ca proportion was the higher compared with the control teeth (34.865 0%±0.388 9% vs. 29.221 7%±2.248 4%), the P value was 0.015. The Ca/P ration of the patient's teeth was 1.981 2±0.019 3, which was higher than that of control teeth (1.775 9±0.111 6), the P value was 0.049. The differences of Mg, Ca proportion and Ca/P ration between the affected teeth and the control teeth were significant. The C and O proportion of the patient's teeth were lower and the P proportion was higher compared with the control teeth, however, the differences were not significant.

CONCLUSION

Our study of clinical manifestation analysis, genetic variants sequencing and histological observation has enlarged the phenotypic spectrum of hereditary opalescent dentin, and the genetic and histological results would contribute to further studies.

[Cloning expression and serological evaluation on Mycobacterium tuberculosis four new antigens]

Objective: To evaluate the serological diagnostic value of Mycobacterium (M.) tuberculosis four new antigens Rv0432, Rv0674, Rv1566c and Rv1547. Methods:Rv0432, Rv0674, Rv1566c and Rv1547 were amplified from M. tuberculosis strain H37Rv genomic DNA by using PCR, among which Rv1547 was divided into two segments for amplification (Rv1547-1 and Rv1547-2). The segments were cloned into expression vector PET-32a while the recombinant proteins were purified by affinity chromatography. Serums were incubated with BL21 (DE3) proteins. Antibodies IgG against M. tuberculosis were tested with 151 serum samples (41 healthy people and 110 TB patients) by using ELISA. The diagnostic efficiency of antigens was analyzed by means of receiver operating characteristic curve. Difference of the objective proteins in TB patients and healthy controls was compared by t-test. Results: Recombinant antigens Rv0432, Rv0674, Rv1566c, Rv1547-1 and Rv1547-2 were successfully expressed and purified. Results from ELISA showed that the sensitivity, specificity, positive predictive value, negative predictive value, Youden index and area under the curve of Rv0432, Rv0674, Rv1566c, Rv1547-1 and Rv1547-2, as 43.64%-92.73%, 80.49%-92.68%, 0.92-0.94, 0.38-0.80, 0.363-0.732 and 0.649-0.915. All the objective proteins showed significantly higher antibody levels in TB patients, when compared to the healthy controls (P<0.000 1). Conclusion: The newly identified antigens Rv0432, Rv0674, Rv1566c, Rv1547-1 and Rv1547-2 all performed well when being used for TB serological diagnosis, thus were expected to be new candidate antigens used for TB diagnosis.

[Influence of gender, age and season on thyroid hormone reference interval]

Objective: Using clinical "big data" , to investigate the factors that affect the levels of thyroid hormones, and to explore the partitioning criteria for reference intervals (RI) of these hormones. Methods: An observation study was conducted. Information of 107 107 individuals undergoing routine physical examination in Peking Union Medical College Hospital from September 1(st,) 2013 to August 31(st,) 2016 was collected, thyroid hormone of these subjects were detected. To explore the test results distribution and differences of TSH, FT4 and FT3 by gender and age; according to the seasonal division standard of China Meteorological Administration, the study period was divided into four seasons, and the seasonal fluctuation on TSH was analyzed.To define the appropriate partition by gender, age and season according to significant difference analysis. Results: In male and female, the distributions of TSH were 1.779(0.578-4.758), 2.023(0.420-5.343)mU/L, respectively, and the level of TSH in female was higher than in male (Z=-37.600, P<0.001). The distributions of FT4 were 0.127(0.098-0.162), 0.117(0.091-0.151) μg/L, the distributions of FT3 were 3.33(2.47-3.74), 3.01(2.35-3.57)ng/L. And the level of FT4, FT3 in female were significantly lower than in male (Z=-94.000, -154.600, all P<0.001). Furthermore, males were divided into two groups by 65 years old and female were divided by 50 years old, respectively, and the distributions of TSH in male and female of older group were 1.818(0.528-5.240), 2.111(0.348-5.735)mU/L, in younger group were 1.778(0.582-4.696), 1.991(0.427-5.316)mU/L. The level of TSH in older group was significantly higher than in younger group (Z=-2.269, -10.400, all P<0.05), and the distribution of TSH in older group was much wider than in younger. The distribution of whole in spring, summer and autumn was 1.869( 0.510-5.042)mU/L, in winter was 1.978(0.527-5.250) mU/L, and the difference between them had statistical significance (Z=-15.000, P<0.001). Conclusions: Gender and age significantly affect the serum levels of TSH, FT4, and FT3, the distribution of TSH in female and elder group are wider than in male, and that of FT4, FT3 are lower.Seasons significantly affect the serum TSH level, the peak value is observed in winter. There are obviously differences between "rough" RIs and manufacture recommended RIs. Each laboratory should establish reference intervals for thyroid hormones on the premise of appropriate grouping.

[Identification and drug susceptibility testing of Mycobacterium thermoresistibile and Mycobacterium elephantis isolated from a cow with mastitis]

Objective: To understand the etiological characteristics and drug susceptibility of Mycobacterium thermoresistibile and Mycobacterium elephantis isolated from a cow with mastitis and provide evidence for the prevention and control of infectious mastitis in cows. Methods: The milk sample was collected from a cow with mastitis, which was pretreated with 4% NaOH and inoculated with L-J medium for Mycobacterium isolation. The positive cultures were initially identified by acid-fast staining and multi-loci PCR, then Mycobacterium species was identified by the multiple loci sequence analysis (MLSA) with 16S rRNA, hsp65, ITS and SodA genes. The drug sensitivity of the isolates to 27 antibiotics was tested by alamar blue assay. Results: Two anti-acid stain positive strains were isolated from the milk of a cow with mastitis, which were identified as non-tuberculosis mycobacterium by multi-loci PCR, and multi-loci nucleic acid sequence analysis indicated that one strain was Mycobacterium thermoresistibile and another one was Mycobacterium elephantis. The results of the drug susceptibility test showed that the two strains were resistant to most antibiotics, including rifampicin and isoniazid, but they were sensitive to amikacin, moxifloxacin, levofloxacin, ethambutol, streptomycin, tobramycin, ciprofloxacin and linezolid. Conclusions:Mycobacterium thermoresistibile and Mycobacterium elephantis were isolated in a cow with mastitis and the drug susceptibility spectrum of the pathogens were unique. The results of the study can be used as reference for the prevention and control the infection in cows.

[Identification and evaluation of T cell epitopes of Rv0585c from Mycobacterium tuberculosis]

Objective: To investigate the human T cell epitopes of Mycobacterium (M.) tuberculosis Rv0585c protein antigen and their immunogenicity and provide evidence for the development of specific tuberculosis immune diagnostic techniques and tuberculosis vaccine. Methods: We synthesized peptides from M. tuberculosis Rv0585c protein antigen predicted by TE-predict and IEDB human T cell epitope prediction tool. The cellular immunoreactivity of the predicted peptides was evaluated through ELISpot assay with the peripheral blood monouclear cells (PBMC) of clinical tuberculosis patients. In animal experiments, BALB/c mice were respectively immunized with high dose (100 μg/mice) and low dose (50 μg/mice) of the peptides of Rv0585c, at the same time, high dose (50 μg/mice) and low dose (20 μg/mice) of Ag85B protein were used in positive control group. The levels of IFN-γ, IL-2, IL-4 and IL-10 were tested with ELISA kit respectively. Results: By means of bioinformatics technique, 66 human T cell epitopes of Rv0585c were predicted, from which9 peptides concentrated epitopes were synthesized for the animal immune experiments. Peptides P10110, P10112 and P10117 were confirmed to be antigenic. The sensitivity and specificity of P10110, P10112 and P10117 were 14.00%, 12.00%, 6.00% and 100.00%, 100.00%, 97.96% respectively when they were used as diagnostic reagents of tuberculosis. The sensitivity and specificity were 22.00% and 97.96% when the epitopes were combined together. The results of animal immunity test showed that high levels of cytokines IFN-γ, IL-2, IL-4 and IL-10 were induced by high and low dose of P10110, and high levels of IFN-γ、IL-2 and IL-10 were induced by high and low dose of P10112, which were much higher than that in negative controls, respectively (P<0.001). Conclusion: Rv0585c, including its human T cell epitopes, has good immunogenicity and immunoreactivity, stimulating the body to produce a stronger cellular immune response and has better potential application value in cellular diagnosis of tuberculosis and the development of new type of tuberculosis vaccine.

[EDA mutation screening and phenotype analysis in patients with tooth agenesis]

OBJECTIVE

To screen the ectodysplasin A (EDA) gene mutation in the patients with non-syndromic tooth agenesis and ectodermal dysplasia, and to analyze the phenotype of missing teeth pattern in these two groups of patients.

METHODS

In the study, 174 patients with tooth agenesis (143: non-syndromic, 31: ectodermal dysplasia) and 451 health control volunteers were enrolled from the clinic, and the genome DNA was extracted from either peripheral blood or oral mucosal swab. The coding region of EDA gene was then amplified by PCR, sequenced and blasted to online NCBI database. The missing teeth were recorded for all patients, and the missing teeth from patients with EDA mutation were compared among the different dentition sites.

RESULTS

33 patients were identified with EDA mutation. In the non-syndromic patients, 13/143(9.09%) were identified with EDA mutation, while in patients with ectodermal dysplasia, 20/31(64.52%) were found with EDA mutation. Ten novel EDA mutations were identified (c.769G>C[p.G257R ],c.936C>G[p.I312M],c.223G>A[p.E75K], .1166C>T[p.P389L],c.133G>C[p.G45R],c.1109G>A[p.E370K],c.914G>T[p.S305I], c.916C>T[p.Q306X],c.602G>T[p.G201V],c.88-89insG[p.A30GfsX69]). For each dentition site there was no statistic difference in the number of missing teeth between the left and right sides, so the number from both sides were combined later in the analysis. In the patients with EDA mutation, the non-syndromic patients had fewer missing teeth (15.9±6.4 missing teeth for each, 207/364 in total) than the patients with ectodermal dysplasia (23.9±4.3, 478/560). In the non-syndromic patients with EDA mutation, the maxillay central incisors and first molars were less affected, with the same missing rate as 19.2% (5/26). While the mandibular central incisors (with a missing rate of 76.9%, 20/26), the maxillary lateral incisors (the missing rate: 88.5%, 23/26), the mandibular lateral incisors (the missing rate: 80.8%, 21/26), and the maxillary first premolars (the missing rate: 80.8%, 21/26) were more likely to be missing. In the ectodermal dysplasia patients with EDA mutation, only maxillary central incisors (the missing rate: 60%, 24/40), maxillary canines (the missing rate: 70%, 28/40), mandibular canines (the missing rate: 67.5%, 27/40), maxillary first molars (the missing rate: 65%, 26/40) and mandibular first molars (the missing rate: 72.5%, 29/40) had higher possibility of persistence. Teeth at other dentition sites were more likely to be affected (the minimum missing rate: 87.5%, 35/40).

CONCLUSION

The findings would help to reveal the EDA gene and its function in ectodermal organogenesis.

[Analysis on the polymorphisms of human B cell epitopes of 5 specificity antigens in Mycobacterium tuberculosis in China]

OBJECTIVE

To study the diversities of human B cell epitopes of five proteins (Mpt83, Mpt70, LpqH, PstS3, GroES) in Mycobacterium tuberculosis isolates from China.

METHODS

We selected 179 strains isolated from patients with tuberculosis in different regions of China, and cultured these strains by L-J medium. The gene sequences of these 5 proteins were amplified and sequenced by PCR. The variations (single nucleotide polymorphisms, SNP) of the DNA sequences were compared and analyzed according to the immune epitope database (IEDB). The synonymous mutation rate (dS), non-synonymous mutation rate (dN) and dN/dS values were calculated with MEGA6 software.

RESULTS

Among the 179 clinical MTBC isolates, 7 SNP mutations were found in the mpt83gene. The dN/dS value of the whole mpt83 gene was 0.88. One SNP mutation was found in the mpt70 gene. The dN/dS values of the whole pstS3 gene and non-B epitopes areas were 1.74 and 1.40 respectively. But no mutation was found in the groES gene.

CONCLUSION

The mpt83, lpqH and pstS3 genes of 179 MTBC strains contain gene SNPs and human B cell epitopes diversities, while the coding gene and human B cell epitopes of protein mpt70 and groES were conservative.

[EDA mutation screening and phenotype analysis in patients with tooth agenesis]

OBJECTIVE

To screen the ectodysplasin A (EDA) gene mutation in the patients with non-syndromic tooth agenesis and ectodermal dysplasia, and to analyze the phenotype of missing teeth pattern in these two groups of patients.

METHODS

In the study, 174 patients with tooth agenesis (143: non-syndromic, 31: ectodermal dysplasia) and 451 health control volunteers were enrolled from the clinic, and the genome DNA was extracted from either peripheral blood or oral mucosal swab. The coding region of EDA gene was then amplified by PCR, sequenced and blasted to online NCBI database. The missing teeth were recorded for all patients, and the missing teeth from patients with EDA mutation were compared among the different dentition sites.

RESULTS

33 patients were identified with EDA mutation. In the non-syndromic patients, 13/143(9.09%) were identified with EDA mutation, while in patients with ectodermal dysplasia, 20/31(64.52%) were found with EDA mutation. Ten novel EDA mutations were identified (c.769G>C[p.G257R ],c.936C>G[p.I312M],c.223G>A[p.E75K], .1166C>T[p.P389L],c.133G>C[p.G45R],c.1109G>A[p.E370K],c.914G>T[p.S305I], c.916C>T[p.Q306X],c.602G>T[p.G201V],c.88-89insG[p.A30GfsX69]). For each dentition site there was no statistic difference in the number of missing teeth between the left and right sides, so the number from both sides were combined later in the analysis. In the patients with EDA mutation, the non-syndromic patients had fewer missing teeth (15.9±6.4 missing teeth for each, 207/364 in total) than the patients with ectodermal dysplasia (23.9±4.3, 478/560). In the non-syndromic patients with EDA mutation, the maxillay central incisors and first molars were less affected, with the same missing rate as 19.2% (5/26). While the mandibular central incisors (with a missing rate of 76.9%, 20/26), the maxillary lateral incisors (the missing rate: 88.5%, 23/26), the mandibular lateral incisors (the missing rate: 80.8%, 21/26), and the maxillary first premolars (the missing rate: 80.8%, 21/26) were more likely to be missing. In the ectodermal dysplasia patients with EDA mutation, only maxillary central incisors (the missing rate: 60%, 24/40), maxillary canines (the missing rate: 70%, 28/40), mandibular canines (the missing rate: 67.5%, 27/40), maxillary first molars (the missing rate: 65%, 26/40) and mandibular first molars (the missing rate: 72.5%, 29/40) had higher possibility of persistence. Teeth at other dentition sites were more likely to be affected (the minimum missing rate: 87.5%, 35/40).

CONCLUSION

The findings would help to reveal the EDA gene and its function in ectodermal organogenesis.

[Influence of implant restoration on traditional restoration idea]

Implant restoration affected the traditional restoration idea. Artificial implant restoration has a profound influence on the design of dental restoration. Implant supported prostheses have not only changed the method of oral rehabilitation, but also integrated revolutionary concept with the traditional treatment protocol. By using implants, posterior missing molars can be effectively restored and thus eliminating the disadvantages of traditional removable partial denture for Kennedy classification Ⅰ, Ⅱ partically edentulous dentition. Full edentulous arch can also be restored with implant fixed denture which provide much better oral health related quality of life compared with the traditional complete denture. It is useful to master the theory and skills of artificial implant restoration, and to provide a reference for the restoration of oral physiological function.

Applying the Back-Propagation Neural Network model and fuzzy classification to evaluate the trophic status of a reservoir system

The trophic state index, and in particular, the Carlson Trophic State Index (CTSI), is critical for evaluating reservoir water quality. Despite its common use in evaluating static water quality, the reliability of the CTSI may decrease when water turbidity is high. Therefore, this study examines the reliability of the CTSI and uses the Back-Propagation Neural Network (BPNN) model to create a new trophic state index. Fuzzy theory, rather than binary logic, is implemented to classify the trophic status into its three grades. The results show that compared to the CTSI with traditional classification, the new index with fuzzy classification can improve trophic status evaluation with high water turbidity. A reliable trophic state index can correctly describe reservoir water quality and allow relevant agencies to address proper water quality management strategies for a reservoir system.

Effects of environmental temperature and dietary manganese on egg production performance, egg quality, and some plasma biochemical traits of broiler breeders

An experiment was conducted to investigate the effects of environmental temperature and dietary Mn on egg production performance, egg quality, and some plasma biochemical traits of broiler breeders. A completely randomized factorial design involved 2 environmental temperatures (a normal temperature, 21 ± 1°C, and a high temperature, 32 ± 1°C) × 3 dietary Mn treatments (a Mn-unsupplemented corn–soybean meal basal diet or the basal diet supplemented with 120 mg of Mn/kg of diet as either MnSO4·H2O or manganese proteinate). There were 6 treatments with 6 replicates (4 birds per replicate). High temperature decreased egg weight (P < 0.0001), laying rate (P < 0.0001), egg yield (P < 0.0001), feed intake (P < 0.0001), egg:feed ratio (P < 0.0001), eggshell strength (P < 0.05) and thickness (P < 0.0001), plasma triiodothyronine level (P < 0.05), and alkaline phosphatase activity (P < 0.04) whereas it increased rectal temperature (P < 0.0001); plasma malondialdehyde level (P < 0.02); and activities (P < 0.002) of lactic dehydrogenase, aspartate aminotransferase, and creatine kinase. Broiler breeders fed the diets supplemented with Mn regardless of source had greater (P < 0.05) eggshell strength and lower (P ≤ 0.05) plasma triiodothyronine level and protein carbonyl content than those fed the control diet. The broiler breeders fed the diet supplemented with the organic Mn had greater (P < 0.01) eggshell thickness than those fed the control diet. There were interactions (P < 0.05) between environmental temperature and dietary Mn in laying rate, egg yield, feed intake, and egg:feed ratio. Under normal temperature, dietary Mn did not affect the above 4 parameters; however, under high temperature, broiler breeders fed the diet supplemented with the organic Mn showed greater (P < 0.03) improvements in these 4 parameters than those fed the control diet. The results from this study indicated that high temperature significantly impaired egg production performance and eggshell quality and induced lipid peroxidation and tissue damage whereas dietary supplementation of either organic or inorganic Mn improved eggshell strength and thermotolerance and reduced protein oxidation and that the organic Mn could alleviate the negative effect of high temperature on egg production performance of broiler breeders at the period of 32 to 45 wk of age.

Selection for Duration of Fertility and Mule Duck White Plumage Colour in a Synthetic Strain of Ducks (Anas platyrhynchos)

A synthetic strain of ducks (Anas platyrhynchos) was developed by introducing genes for long duration of fertility to be used as mother of mule ducklings and a seven-generation selection experiment was conducted to increase the number of fertile eggs after a single artificial insemination (AI) with pooled Muscovy semen. Reciprocal crossbreeding between Brown Tsaiya LRI-2 (with long duration of fertility) and Pekin L-201 (with white plumage mule ducklings) ducks produced the G0. Then G1 were intercrossed to produce G2 and so on for the following generations. Each female duck was inseminated 3 times, at 26, 29, and 32 weeks of age. The eggs were collected for 14 days from day 2 after AI. Individual data regarding the number of incubated eggs (Ie), the number of fertile eggs at candling at day 7 of incubation (F), the total number of dead embryos (M), the maximum duration of fertility (Dm) and the number of hatched mule ducklings (H) with plumage colour were recorded. The selection criterion was the breeding values of the best linear unbiased prediction animal model for F. The results show high percentage of exhibited heterosis in G2 for traits to improve (19.1% for F and 12.9% for H); F with a value of 5.92 (vs 3.74 in the Pekin L-201) was improved in the G2. Heritabilities were found to be low for Ie (h (2) = 0.07±0.03) and M (h (2) = 0.07±0.01), moderately low for Dm (h (2) = 0.13±0.02), of medium values for H (h (2) = 0.20±0.03) and F (h (2) = 0.23±0.03). High and favourable genetic correlations existed between F and Dm (rg = 0.93), between F and H (rg = 0.97) and between Dm and H (rg = 0.90). The selection experiment showed a positive trend for phenotypic values of F (6.38 fertile eggs in G10 of synthetic strain vs 5.59 eggs in G4, and 3.74 eggs in Pekin L-201), with correlated response for increasing H (5.73 ducklings in G10 vs 4.86 in G4, and 3.09 ducklings in Pekin L-201) and maximum duration of the fertile period without increasing the embryo mortality rate. The average predicted genetic response for F was 40% of genetic standard deviation per generation of selection. The mule ducklings' feather colour also was improved. It was concluded that this study provided results for a better understanding of the genetics of the duration of fertility traits in the common female duck bred for mule and that the selection of a synthetic strain was effective method of improvement.

Determination of thin hydrodynamic lubricating film thickness using dichromatic interferometry

This paper introduces the application of dichromatic interferometry for the study of hydrodynamic lubrication. In conventional methods, two beams with different colors are projected consecutively on a static object. By contrast, the current method deals with hydrodynamic lubricated contacts under running conditions and two lasers with different colors are projected simultaneously to form interference images. Dichromatic interferometry incorporates the advantages of monochromatic and chromatic interferometry, which are widely used in lubrication research. This new approach was evaluated statically and dynamically by measuring the inclination of static wedge films and the thickness of the hydrodynamic lubricating film under running conditions, respectively. Results show that dichromatic interferometry can facilitate real-time determination of lubricating film thickness and is well suited for the study of transient or dynamic lubricating problems.

Asp68His mutation in the A1 domain of human factor V causes impaired secretion and ineffective translocation

Congenital factor V (FV) deficiency is a rare inherited disorder. We determined the mechanism of a missense mutation, Asp68His, in the A1 domain of the FV protein, is associated with severe FV deficiency. We characterized the mutant FV-Asp68His protein using in vitro expression studies by using specific secretion and degradation pathway inhibitors and analysed the intracellular translocation of the mutant protein by immunofluorescence staining. The Asp68His mutation caused very low levels of FV protein in the conditioned media, with normal specific FV activity. Similar mRNA degradation rates between FV-wild-type (wt) and FV-Asp68His mRNA showed that the Asp68His mutation does not affect FV expression at the transcriptional level. A specific secretion pathway inhibitor, brefeldin A, was used to demonstrate that the lower efficiency of transport to the outside of the cell for FV-Asp68His mutant protein compared with that of the FV-wt protein. Furthermore, we showed that the Asp68His mutation resulted in increased intracellular degradation through a MG132-mediated proteasomal degradation pathway. In the transfected cell lysates, FV-wt protein had multiple posttranslational modified forms, but the FV-Asp68His protein was not completely glycosylated. We further observed that the FV-Asp68His protein was retrieved in the endoplasmic reticulum only and did not undergo transport to the Golgi apparatus, leading to impaired secretion. These results strongly suggest that the Asp68His mutation may result in intracellular defective trafficking and enhanced degradation, and impaired secretion of FV protein.

Association between rs11001553 of DKK1 and non-syndromic tooth agenesis in the Chinese Han population

Tooth agenesis is one of the most common anomalies of human dentition. Recent genetic studies have provided information regarding a number of genes related to both syndromic and non-syndromic forms of hypodontia. In a previous study, we found that polymorphism in rs11001553 of DKK1 was associated with hypodontia in the Chinese Han population. In this study, we extended this investigation to 89 individuals diagnosed with sporadic non-syndromic oligodontia (40 males and 49 females). These individuals were analyzed with 268 subjects (123 males and 145 females) diagnosed with non-syndromic hypodontia and 190 healthy control subjects (99 males and 91 females). DNA was obtained from whole blood or saliva samples and genotyping was performed by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Significant differences were observed in the allele and genotype frequencies of rs11001553 of DKK1. These data demonstrated an association between rs11001553 of DKK1, a tooth development-associated gene, and non-syndromic tooth agenesis in Chinese Han individuals. This information may provide further understanding of the molecular mechanisms of tooth agenesis. Furthermore, DKK1 can be regarded as a marker gene for the risk of tooth agenesis.

Pharmacokinetics of niacin, simvastatin and their metabolites in healthy Chinese subjects after single and multiple doses of a fixed dose combination tablet of niacin extended release/simvastatin

OBJECTIVE

A fixed dose combination tablet of niacin extended release (ER)/simvastatin was recently developed in China. This study was designed to assess and compare the pharmacokinetics of niacin, simvastatin and their metabolites in healthy Chinese subjects after single and multiple doses administration.

METHODS

From day 1 to day 7, 12 Chinese subjects were given a tablet every day at approximately 10 p.m. Serial blood samples were collected. Niacin and nicotinuric acid (NUA) in plasma, niacin, NUA, N-methylnicotinamide (MNA) and N-methyl-2-pyridone-5-carboxamide (2PY) in urine, simvastatin and simvastatin acid in plasma were determined by LC/MS/MS methods. Pharmacokinetic parameters on days 1 and 7 were compared.

RESULTS

The main pharmacokinetic parameters for the single and multiple doses were as -follows: Niacin: Tmax were 3.8±1.5 h and 3.9±2.0 h; Cmax were 2 091±1 315 ng/ml and 2 323±1 542 ng/ml; AUC0-t were 4 123.88±3 138.48 ng ∙ h/ml and 4 385.98±3 127.05 ng ∙ h/ml. NUA: Tmax were 4.7±1.7 h and 3.8±1.5 h; Cmax were 1 057±549 ng/ml and 1 087±470 ng/ml; AUC0-t were 4 012.49±2 168.68 ng ∙ h/ml and 4 040.45±1 886.57 ng ∙ h/ml. Simvastatin: Tmax were 1.8±1.0 h and 2.5±2.5 h; Cmax were 3.15±1.67 ng/ml and 4.87±4.11 ng/ml; AUC0-t were 9.03±5.10 ng ∙ h/ml and 17.63±13.93 ng ∙ h/ml. Simvastatin acid: Tmax were 5.8±1.7 h and 6.5±1.4 h; Cmax were 4.22±2.10 ng/ml and 9.30±8.09 ng/ml; AUC0-t were 34.65±16.89 ng ∙ h/ml and 61.62±46.41 ng ∙ h/ml. Urine Recovery rate of total niacin: (40.55±7.38)% and (62.87±12.04)%.

CONCLUSION

Compared with those after a single dose, pharmacokinetics of niacin and NUA was similar; total urine recovery of niacin was higher; exposure to simvastatin and simvastatin acid were higher following multiple doses.

QSAR studies on imidazopyrazine derivatives as Aurora A kinase inhibitors

Aurora kinases have emerged as attractive targets for the development of novel anti-cancer agents. A combined study of molecular docking, pharmacophore modelling and 3D-QSAR was performed on a series of imidazo [1, 2-a] pyrazines as novel Aurora kinase inhibitors to gain insights into the structural determinants and their structure-activity relationship. An ensemble of conformations based on molecular docking was used for PHASE pharmacophore studies. The developed best-fitted pharmacophore model was validated by diverse chemotypes of Aurora A kinase inhibitors and was consistent with the structural requirements for the docked binding mechanism. Subsequently, the pharmacophore-based alignment was used to develop PHASE and comparative molecular similarity indices analysis (CoMSIA) 3D-QSAR models. The best CoMSIA model showed good statistics (q (2 )= 0.567, r (2 )= 0.992), and the predictive ability of the model was validated using an external test set of 13 compounds giving a satisfactory prediction ([Formula: see text]). The 3D contour maps provided insight into the binding mechanism and highlighted key structural features that are essential to the inhibitory activity. Based on the PHASE and CoMSIA 3D-QSAR results, a set of novel Aurora A inhibitors were designed that showed excellent potencies.

Terahertz quantum cascade lasers operating up to ∼ 200 K with optimized oscillator strength and improved injection tunneling

A new temperature performance record of 199.5 K for terahertz quantum cascade lasers is achieved by optimizing the lasing transition oscillator strength of the resonant phonon based three-well design. The optimum oscillator strength of 0.58 was found to be larger than that of the previous record (0.41) by Kumar et al. [Appl. Phys. Lett. 94, 131105 (2009)]. The choice of tunneling barrier thicknesses was determined with a simplified density matrix model, which converged towards higher tunneling coupling strengths than previously explored and nearly perfect alignment of the states across the injection and extraction barriers at the design electric field. At 8 K, the device showed a threshold current density of 1 kA/cm2, with a peak output power of ∼ 38 mW, and lasing frequency blue-shifting from 2.6 THz to 2.85 THz with increasing bias. The wavelength blue-shifted to 3.22 THz closer to the maximum operating temperature of 199.5 K, which corresponds to ∼ 1.28ħω/κB. The voltage dependence of laser frequency is related to the Stark effect of two intersubband transitions and is compared with the simulated gain spectra obtained by a Monte Carlo approach.

Near-room-temperature mid-infrared quantum well photodetector

We demonstrate InGaAs mid-infrared quantum well infrared photodetectors (MIR PV-QWIPs) that enable cost-effective mature GaAs-based detection and imaging technologies, with exceptional material uniformity, reproducibility, and yield, over a large area, with high spectral selectivity, innate polarization sensitivity, radiation hardness, high detectivity, and high speed operation at TEC temperatures without bias.

Nontraumatic hemorrhagic stroke in young adults in taiwan

We reviewed the medical records and imaging studies on the in-hospital patients to investigate the clinical and etiological patterns in hemorrhagic stroke in young patients. We evaluated 210 patients (131 males and 79 females) aged 15-45 years who had traumatic hemorrhagic stroke between April 1, 1986, and November 30, 1992. Nontraumatic intracerebral hemorrhage was diagnosed in 170 patients (80.9%). The main causes of nontraumatic intracerebral hemorrhage were hypertension, ruptured arteriovenous malformation, and blood dyscrasia. A cause was not found in 42 patients (24.7%). Subarachnoid hemorrhage was found in 40 patients (19.1%). The main causes were ruptured aneurysms and arteriovenous malformations. The overall in-hospital survival of young patients with hemorrhagic stroke was 64.7%. Young adults with nontraumatic intracerebral and subarachnoid hemorrhage are a heterogeneous group. Hypertension accounts for about one-third of intracerebral hemorrhage and is an important preventable cause of hemorrhagic stroke in young adults in Taiwan.

Electrically switching transverse modes in high power THz quantum cascade lasers

The design and fabrication of a high power THz quantum cascade laser (QCL), with electrically controllable transverse mode is presented. The switching of the beam pattern results in dynamic beam switching using a symmetric side current injection scheme. The angular-resolved L-I curves measurements, near-field and far-field patterns and angular-resolved lasing spectra are presented. The measurement results confirm that the quasi-TM(01) transverse mode lases first and dominates the lasing operation at lower current injection, while the quasi-TM(00) mode lases at a higher threshold current density and becomes dominant at high current injection. The near-field and far-field measurements confirm that the lasing THz beam is maneuvered by 25 degrees in emission angle, when the current density changes from 1.9 kA/cm(2) to 2.3 kA/cm(2). A two-dimension (2D) current and mode calculation provides a simple model to explain the behavior of each mode under different bias conditions.

Mode-locked pulses from mid-infrared quantum cascade lasers

In this study, we report the unequivocal demonstration of midinfrared mode-locked pulses from quantum cascade lasers. The train of short pulses was generated by actively modulating the current and hence the gain of an edge-emitting quantum cascade laser (QCL). Pulses with duration of about 3 ps at full-width-at-half-maxima and energy of 0.5 pJ were characterized using a second-order interferometric autocorrelation technique based on a nonlinear quantum well infrared photodetector. The mode-locking dynamics in the QCLs was modeled based on the Maxwell-Bloch equations in an open two-level system. Our model reproduces the overall shape of the measured autocorrelation traces and predicts that the short pulses are accompanied by substantial wings as a result of strong spatial hole burning. The range of parameters where short mode-locked pulses can be formed is found.

Terahertz two-photon quantum well infrared photodetector

A two-photon detector based on intersubband transitions in GaAs/AlGaAs quantum wells operating in the Terahertz regime below the Reststrahlenband is reported. Resonantly enhanced optical nonlinearities enables sensitive quadratic detection at pJ pulse energies. We demonstrate its use in a quadratic autocorrelator for far-infrared picosecond pulses at around 7 THz.

Normal incidence detection of ultraviolet, visible, and mid-infrared radiation in a single GaAs/AlGaAs device

A GaAs/AlGaAs detector is demonstrated showing multiple detection capabilities. This detector exhibits a broad spectral response in the 200-870 nm (ultraviolet-visible) range for forward bias and in the 590-870 nm (visible) range for reverse bias. In the mid-IR region, two peaks at 5 and 8.9 microm can be observed for low and high forward bias voltages, respectively. In addition, the peak at 8.9 microm is sensitive to the polarization of the incoming radiation.

Quantum dots for terahertz generation

Nanostructures made of semiconductors, such as quantum wells and quantum dots (QD), are well known, and some have been incorporated in practical devices. Here we focus on novel structures made of QDs and related devices for terahertz (THz) generation. Their potential advantages, such as low threshold current density, high characteristic temperature, increased differential gain, etc, make QDs promising candidates for light emitting applications in the THz region. Our idea of using resonant tunneling through QDs is presented, and initial results on devices consisting of self-assembled InAs QDs in an undoped GaAs matrix, with a design incorporating a GaInNAs/GaAs short period superlattice, are discussed. Moreover, shallow impurities are also being explored for possible THz emission: the idea is based on the tunneling through bound states of individual donor or acceptor impurities in the quantum well. Initial results on devices having an AlGaAs/GaAs double-barrier resonant tunneling structure are discussed.

Two-photon photocurrent autocorrelation using intersubband transitions at nearly-resonant excitation

We investigate nonlinear mid-infrared detection via two-photon transitions involving two bound subbands and one continuum resonance in an n-type multiple quantum well. By varying the excitation energy, we have tuned the two-photon transition from resonant, yielding optimum resonant enhancement with a real intermediate state, to nearly-resonant, with a virtual but resonantly enhanced intermediate state. For autocorrelation purposes, the latter configuration improves time resolution whilst partially retaining a resonant enhancement of the two-photon transition strength.

Direct observation of polarons in electron populated quantum dots by resonant Raman scattering

The general problem of the pairing of strongly interacting elementary excitations producing new quasiparticles such as polarons arises in many areas of solid state physics. Recent interest in polaron formation in semiconductor quantum dots has been motivated by the need to understand the physical nature of the carrier relaxation processes and their role in quantum-dot based devices. We report on the direct observation of polarons in InAs/GaAs self-assembled quantum dots populated by few electrons where the polarons are strongly coupled modes of quantum dot phonons and electron intersublevel transitions. The degree of coupling is varied in a systematic way in a set of samples having electron intersublevel spacing changing from larger to smaller than the longitudinal optical phonon energy. The signature of polarons is evidenced clearly by the observation of a large (12-20 meV) anticrossing for both InAs and GaAs-like quantum dot phonons using resonant Raman spectroscopy.