Theoretical Insights into N-Glycoside Bond Cleavage of 5-Carboxycytosine by Thymine DNA Glycosylase: A QM/MM Study.

Thymine DNA glycosylase (TDG)-mediated excision of 5-formylcytosine and 5-carboxylcytosine (5-caC) is a critical step in active DNA demethylation. Herein, we employed a combined quantum mechanics/molecular mechanics approach to investigate the reaction mechanism of TDG-catalyzed N-glycosidic bond cleavage of 5-caC. The calculated results show that TDG-catalyzed 5-caC excision follows a concerted (SN2) mechanism in which glycosidic bond dissociation is coupled with nucleophile attack. Protonation of the 5-caC anion contributes to the cleavage of the N-glycoside bond, in which the N3-protonated zwitterion and imino tautomers are more favorable than carboxyl-protonated amino tautomers. This is consistent with the experimental data. Furthermore, our results reveal that the configuration rearrangement process of the protonated 5-caC would lower the stability of the N-glycoside bond and substantially reduce the barrier height for the subsequent C1'-N1 bond cleavage. This should be attributed to the smaller electrostatic repulsion between the leaving base and the negative phosphate group as a result of the structural rearrangement.

A prospective and consecutive study assessing short-term clinical and radiographic outcomes of Chinese domestically manufactured 3D printing trabecular titanium acetabular cup for primary total hip arthroplasty: evaluation of 236 cases.

Purpose: We prospectively evaluate the short-term clinical and radiographic outcomes of the only Chinese domestically produced trabecular titanium acetabular cup(3D ACT™ cup) in primary total hip arthroplasty (THA), aiming to provide evidence-based support for its clinical application. Methods: A total of 236 patients, who underwent primary THA using 3D ACT™ cup in the Department of Joint Surgery at our hospital between January 2017 and June 2019, were included in this study. General patient data, imaging information, functional scores, and complications were collected to evaluate the early clinical efficacy. Results: All patients were followed up for 33-52 months, with an average of (42.2 ± 9.2) months. At the last follow-up, the preoperative HHS score increased significantly from 43.7 ± 6.8 to 85.6 ± 9.3 points (P < 0.01). Similarly, the preoperative WOMAC scores showed significant improvement from 59.2 ± 5.8 to 13.1 ± 3.5 points (P < 0.01). 92.3% of the patients expressed satisfaction or high satisfaction with the clinical outcome. Furthermore, 87.7% of the acetabular cups were positioned within the Lewinnek safe zone, achieving successful reconstruction of the acetabular rotation center. The cup survival rate at the last follow-up was 100%. Conclusions: The utilization of the only Chinese domestically manufactured 3D printing trabecular titanium acetabular cup in primary THA demonstrated favorable short-term clinical and radiographic outcomes. The acetabular cup exhibits excellent initial stability, high survival rate, and favorable osseointegration, leading to a significant enhancement in pain relief and functional improvement. In the future, larger sample sizes and multicenter prospective randomized controlled trials will be required to validate the long-term safety and effectiveness of this 3D ACT™ cup.

Febrile urinary tract infection in children: changes in epidemiology, etiology, and antibiotic resistance patterns over a decade.

BACKGROUND: Understanding the epidemiology and prevalence of febrile urinary tract infection (fUTI) in children is important for risk stratification and selecting appropriate urine sample collection candidates to aid in its diagnosis and treatment. PURPOSE: This study aimed to analyze the epidemiology, etiology, and changes in antibiotic susceptibility patterns of the first fUTI in children. METHODS: This retrospective observational cohort study included children younger than 19 years of age who were diagnosed and treated for their first fUTI in 2006-2016. Electronic medical records were analyzed and radiologic images were evaluated. RESULTS: A total of 359 patients (median age, 5.1 months; interquartile range, 3.0-10.5 months) fit the inclusion criteria; of them, 78.0% (n=280) were younger than 12 months old. The male to female ratio was 5.3:1 for patients aged 0-2 months, 2.1:1 for those 3-5 months, and 1.6:1 for those 6-11 months. Beyond 12 months of age, there was a female predominance. Escherichia coli was the leading cause (83.8%), followed by Enterococcus species (6.7%), and Klebsiella pneumoniae (3.6%). Significant yearly increases in the proportions of multidrug-resistant strains (P<0.001) and extended-spectrum beta-lactamase (ESBL) producers (P<0.001) were observed. In patients with vesicoureteral reflux (VUR), the overall recurrence rate was 53.6% (n=15). A significantly higher recurrence rate was observed when the fUTI was caused by an ESBL versus non-ESBL producer (75.0% vs. 30.0%, P=0.03). CONCLUSION: fUTI was most prevalent in children younger than 12 months of age and showed a female predominance in patients older than 12 months of age. The proportion of ESBL producers causing fUTI is increasing. Carbapenems, rather than noncarbapenems, should be considered for treating fUTI caused by ESBL-producing enteric gram-negative rods to reduce short-term recurrence rates in children with VUR.

Does total hip arthroplasty provide better outcomes than hemiarthroplasty for the femoral neck fracture? A systematic review and meta-analysis.

PURPOSE: By comparing the outcomes of total hip arthroplasty with hemiarthroplasty in elderly patients with a femoral neck fracture to investigate the one-year mortality, dislocation, infection, reoperation rate, and thromboembolic event. METHODS: The PubMed, EMBASE databases, and Cochrane library were systematically searched from the inception dates to April 1, 2020 for relevant randomized controlled trials in English language using the keywords: "total hip arthroplasty", "hemiarthroplasty" and "femoral neck fracture" to identify systematic reviews and meta-analyses. Two reviewers independently selected articles, extracted data, assessed the quality evidence and risk bias of included trials using the Cochrane Collaboration' stools, and discussed any disagreements. The third reviewer was consulted for any doubts or uncertainty. We derived risk ratios and 95% confidence intervals. Mortality was defined as the primary outcome. Secondary outcomes were other complications, dislocation, infection, reoperation rate, and thromboembolic event. RESULTS: This meta-analysis included 10 studies with 1419 patients, which indicated that there were no significant differences between hemiarthroplasty and total hip arthroplasty in reoperation, infection rate, and thromboembolic event. However, there was a lower mortality and dislocation rate association with total hip arthroplasty at the one-year follow-up. CONCLUSION: Based on our results, we found that total hip arthroplasty was better than hemiarthroplasty for a hip fracture at one-year follow-up.

Advancements and Frontiers in the High Performance of Natural Hydrogels for Cartilage Tissue Engineering.

Cartilage injury originating from trauma or osteoarthritis is a common joint disease that can bring about an increasing social and economic burden in modern society. On account of its avascular, neural, and lymphatic characteristics, the poor migration ability of chondrocytes, and a low number of progenitor cells, the self-healing ability of cartilage defects has been significantly limited. Natural hydrogels, occurring abundantly with characteristics such as high water absorption, biodegradation, adjustable porosity, and biocompatibility like that of the natural extracellular matrix (ECM), have been developed into one of the most suitable scaffold biomaterials for the regeneration of cartilage in material science and tissue engineering. Notably, natural hydrogels derived from sources such as animal or human cadaver tissues possess the bionic mechanical behaviors of physiological cartilage that are required for usage as articular cartilage substitutes, by which the enhanced chondrogenic phenotype ability may be achieved by facilely embedding living cells, controlling degradation profiles, and releasing stimulatory growth factors. Hence, we summarize an overview of strategies and developments of the various kinds and functions of natural hydrogels for cartilage tissue engineering in this review. The main concepts and recent essential research found that great challenges like vascularity, clinically relevant size, and mechanical performances were still difficult to overcome because the current limitations of technologies need to be severely addressed in practical settings, particularly in unpredictable preclinical trials and during future forays into cartilage regeneration using natural hydrogel scaffolds with high mechanical properties. Therefore, the grand aim of this current review is to underpin the importance of preparation, modification, and application for the high performance of natural hydrogels for cartilage tissue engineering, which has been achieved by presenting a promising avenue in various fields and postulating real-world respective potentials.

[Effect of preheating on the properties of resin composite].

Resin composite, which is commonly used as a dental filling material, has some problems, such as poor wear resistance, polymerization shrinkage, and poor dentin marginal adaptability. Preheating of resin composite improves its pro-perties. This paper reviewed the effects of resin composite preheating on its monomer conversion, marginal microleakage, mechanical properties, and irritation on dental pulp.

Effect of preheating on the properties of resin composite / 华西口腔医学杂志

Resin composite, which is commonly used as a dental filling material, has some problems, such as poor wear resistance, polymerization shrinkage, and poor dentin marginal adaptability. Preheating of resin composite improves its pro-perties. This paper reviewed the effects of resin composite preheating on its monomer conversion, marginal microleakage, mechanical properties, and irritation on dental pulp.

Inhibition of YAP reverses primary resistance to EGFR inhibitors in colorectal cancer cells.

Mutant KRAS and BRAF are associated with primary EGFR inhibitor resistance in colorectal cancer (CRC). However, other biomarkers that could predict EGFR inhibitor resistance remain elusive. In the present study, immunoblotting and cell proliferation results revealed that yes­associated protein (YAP), a downstream effector of the Hippo pathway, was positively associated with primary cetuximab resistance in CRC cells. YAP knockdown enhanced the cytotoxicity of cetuximab in CRC cells. Simvastatin, a 3­hydroxy­3­methylglutaryl­coenzyme A (HMG­CoA) reductase inhibitor of the mevalonate pathway that inhibits YAP bioactivity through nuclear translocation and total YAP expression, increased the cytotoxicity of EGFR inhibitors (cetuximab and gefitinib) against CRC cells. The combination of simvastatin and EGFR inhibitors inhibited YAP and EGFR signaling more markedly than each agent alone. Adding back geranylgeranyl pyrophosphate (GGPP), a key product of the mevalonate pathway, reversed the YAP bioactivity inhibition induced by simvastatin and the cell proliferation inhibition induced by the combination of simvastatin and EGFR inhibitors. Collectively, these results revealed that YAP may be useful in identifying cetuximab resistance in CRC and indicated that targeting of both YAP and EGFR signals may present a promising therapeutic approach for CRC.

Effect of soft tissue thickness of upper lip on lip retraction in orthodontical-treated Class II, Division 1 females / 中南大学学报(医学版)

OBJECTIVE@#To establish the Chinese Han national criteria for the thickness of upper lip in Chongqing and to investigate the effect of lip thickness on lip retraction in orthodontic treatment.
@*METHODS@#A total of 240 adult patients (male=120, female=120) of Chinese Han nationality aged 18-35 years in Chongqing were treated with cephalograms and measured the thickness of upper lip. We established the Chinese Han national criteria for the thickness of upper lip in Chongqing according to the results. Sixty-eight female patients with Angle II 1 from Department of Orthodontics Stomatological Hospital of Chongqing Medical University were treated with maxillary premolars extraction, and pre- and post-treated with lateral cephalograms, then divided into 3 groups according to our criteria: a thin lips group, a normal lips group and a thick lips group. The ratio of the incisors retraction and the upper lip retraction were measured and calculated. The correlation between incisors retraction and the upper lip retraction was analyzed by the Pearson correlation method.
@*RESULTS@#There was statistical significance in the thickness of upper lip between males and females (P<0.01). The ratio of maxillary inscior retraction to the upper lip soft tissue retraction was 1.6:1, 2.2:1 and 2.9:1 in the thin lips group, the normal lips group and the thick lips group, respectively.
@*CONCLUSION@#Gender differences exist in the thickness of upper lip. Upper lip retraction with the incisors was negatively correlated with the soft tissue thickness of the upper lip in females with Angle II 1.

Simultaneous Manifestation of Gangliocytic Paraganglioma and Heterotopic Pancreas of Ampulla of Vater Treated by Endoscopic Resection / 대한췌담도학회지

Gangliocytic paraganglioma is an uncommon tumor of digestive system that is usually found in the second portion of duodenum. It is generally considered benign tumor, although few reports of local recurrences and regional lymph node metastases have been made. Gangliocytic paraganglioma is characterized by its histologic pattern including ganglion cells, spindle cells and epithelioid cells. Heterotopic pancreas, also known as ectopic pancreas, is a pancreatic tissue appeared outside of its normal location lacking anatomic or vascular connection with the pancreas. In duodenum, it is a relatively unusual lesion that may be found incidentally during surgery or endoscopy. We present a case of 39-year-old woman with gangliocytic paraganglioma combined with heterotopic pancreas in the ampulla of Vater successfully treated by endoscopic resection.

Simultaneous Manifestation of Gangliocytic Paraganglioma and Heterotopic Pancreas of Ampulla of Vater Treated by Endoscopic Resection / 대한췌담도학회지

Gangliocytic paraganglioma is an uncommon tumor of digestive system that is usually found in the second portion of duodenum. It is generally considered benign tumor, although few reports of local recurrences and regional lymph node metastases have been made. Gangliocytic paraganglioma is characterized by its histologic pattern including ganglion cells, spindle cells and epithelioid cells. Heterotopic pancreas, also known as ectopic pancreas, is a pancreatic tissue appeared outside of its normal location lacking anatomic or vascular connection with the pancreas. In duodenum, it is a relatively unusual lesion that may be found incidentally during surgery or endoscopy. We present a case of 39-year-old woman with gangliocytic paraganglioma combined with heterotopic pancreas in the ampulla of Vater successfully treated by endoscopic resection.

[Effects of Arbuscular Mycorrhizal Fungi on the Growth of Reeds in Wetland Soils with Different Salt Content].

A greenhouse pot experiment was conducted to investigate the effects of arbuscular mycorrhizal (AM) fungi Claroideoglomus etunicatum (CE), Rhizophagus intraradices (RI), Funneliformis mosseae (FM) and Glomus versiforme (GV) on AM colonization rate, biomass, mineral nutrient uptake, C: N: P ratios and Na and Cl- concentrations of reeds (Phragmites australis) grown in saline and non-saline wetland soils. The aim was to provide a technical basis for the ecological revegetation and salinity restoration of wetland ecosystem. The results indicated that symbiotic associations were successfully established between the four isolates and reeds grown in the two types of wetland soils. The average AM colonization rates ranged from 2.5% to 38%. The mean root colonization rate of CE was significantly higher than those of the other three isolates. There were no significant differences in root colonization rates between saline and non-saline wetland soils. The biomass and nutrient contents of reeds grown in non-saline wetland soils were significantly higher than those grown in saline wetland soils. However, Na+ and Cl- concentrations of reeds grown in non-saline wetland soils were significantly lower than those grown in saline wetland soils. In non-saline wetland soils, inoculation with GV significantly increased the shoot dry weight and the shoot N, P, K, Ca and Mg contents of reeds. Inoculation with GV and RI significantly improved the root P and K contents of reeds. Inoculation with the four AM fungi significantly reduced the shoot N: P ratios. Inoculation with FM and GV significantly reduced the root C : N and C : P ratios. Inoculation with the four AM fungi significantly reduced the shoot Cl- concentrations. Inoculation with RI significantly reduced the shoot Na+ concentrations. In saline wetland soils, inoculation with AM fungi had no significant effect on the biomass, mineral nutrient uptake and Na+ and Cl- concentrations of reeds. The results demonstrated that the four AM fungi isolates had different effects on the growth of reeds in wetland soils with different salt contents. Inoculation with AM fungi played a more positive role in improving the growth of reeds in non-saline wetland soil than those in saline wetland soil. Further experiments should be conducted to screen optimal AM fungi isolates under field conditions and to evaluate the practical effects of AM fungi on the growth of reeds in wetland soils with different salt contents.

A First Case of Osteomesopyknosis in Korea.

Osteomesopyknosis is a rare sclerosing bone disorder of autosomal dominant inheritance. We report a first case of osteomesopyknosis in Korea. A 16-year old girl complained of diffuse back pain for 1 year. We performed physical examination, biochemical investigations and imaging studies. A radiograph of spine revealed rugger-jersey vertebra and sandwich vertebra. Bone specific alkaline phosphatase, osteocalcin and C-terminal telopeptides of type I collagen were normal. Only an axial skeleton involvement was shown on the whole body bone scan. This patient was diagnosed to have osteomesopyknosis. Osteomesopyknosis is characterized by normal level of bone turnover marker and an axial bone involvement. Osteomesopyknosis can be occurred in Korea and needs to be considered when patients, especially young patients, suffer from back pain and have only axial osteosclerosis.

A Case of Tracheal Hamartoma Treated with Endoscopic Mucosal Resection / 계명의대학술지

A 77-year-old male patient was hospitalized due to dyspnea and cough. At chest auscultation, Rhonchi was heard from both lung fields. The chest computed tomography (CT) observed nodular lesions within mid-trachea. Bronchoscope observed salient mass from the membranous portion in the mid-trachea, and after taking a biopsy, it was diagnosed as hamartoma. Tracheal hamartoma is a rare benign tumor of lung. Similar way to the endoscopic mucosal resection (EMR), we did endoscopic resection of tracheal hamartoma. We report a case of tracheal hamartoma treated with Endoscopic mucosal resection via flexible bronchoscopy.

A First Case of Osteomesopyknosis in Korea

Osteomesopyknosis is a rare sclerosing bone disorder of autosomal dominant inheritance. We report a first case of osteomesopyknosis in Korea. A 16-year old girl complained of diffuse back pain for 1 year. We performed physical examination, biochemical investigations and imaging studies. A radiograph of spine revealed rugger-jersey vertebra and sandwich vertebra. Bone specific alkaline phosphatase, osteocalcin and C-terminal telopeptides of type I collagen were normal. Only an axial skeleton involvement was shown on the whole body bone scan. This patient was diagnosed to have osteomesopyknosis. Osteomesopyknosis is characterized by normal level of bone turnover marker and an axial bone involvement. Osteomesopyknosis can be occurred in Korea and needs to be considered when patients, especially young patients, suffer from back pain and have only axial osteosclerosis.

Reference equations for the six-minute walk distance in healthy korean adults, aged 22-59 years.

BACKGROUND: The six-minute walk test has been widely used in people with chronic cardiopulmonary disorders as an outcome assessment with regards to therapeutic or prognostic determinants. This study was undertaken to determine the six-minute walk distance (6MWD) in a sample of healthy Koreans and to create a reference equation. We also compared the 6MWD of our cohort with previously published equations. METHODS: Two hundred fifty-nine healthy subjects (95 males) aged 22-59 years performed two walking tests using a standardized protocol. 6MWD was defined as the greatest distance achieved from the two tests. The effect of anthropometrics on the 6MWD was also investigated. RESULTS: The average 6MWD was 598.5±57.92 m, with significantly longer distances by males (628.9±59.51 m) than females (580.9±47.80 m) (p<0.001). Age, height, weight, and body mass index were significantly correlated with 6MWD in univariate analysis. Stepwise multiple regression showed height to be single independent predictor of 6MWD (r(2)=0.205, p<0.001). The reference equations derived in Caucasian and North African populations tend to overestimate the distance walked by Korean subjects, while Asian equations underestimate it. CONCLUSION: The average 6MWD in these Korean populations was 600 m. The regression equation revealed that individual's height was the most significant predictor of distance, explaining 20.5% of the distance variance.

Contribution of arbuscular mycorrhizal fungi to the development of maize (Zea mays L.) grown in three types of coal mine spoils.

Coal mine spoils are usually unfavorable for plant growth and have different properties according to dumping years, weathering degree, and the occurrence of spontaneous combustion. The establishment of plant cover in mine spoils can be facilitated by arbuscular mycorrhizal fungi (AMF). A greenhouse pot experiment was conducted to evaluate the importance of AMF in plant adaptation to different mine spoils and the potential role of AMF for revegetation practices. We investigated the effects of Glomus aggregatum, Rhizophagus intraradices (syn. Glomus intraradices), and Funneliformis mosseae (syn. Glomus mosseae) on the growth, nutritional status, and metal uptake of maize (Zea mays L.) grown in recent discharged (S1), weathered (S2), and spontaneous combusted (S3) coal mine spoils. Symbiotic associations were successfully established between AMF and maize in three substrates. Mycorrhizal colonization effectively promoted plant growth by significantly increasing the uptake of nitrogen (N), phosphorus (P), and potassium (K), adjusting C:N:P stoichiometry and alleviating toxic effects of heavy metals. G. aggregatum, R. intraradices, and F. mosseae exhibited different mycorrhizal effects in response to mine spoil types. F. mosseae was the most effective in the development of maize in S1 and may be the most appropriate for revegetation of this substrate, while R. intraradices played the most beneficial role in S2 and S3. Our results suggest that inoculation with AMF can enhance plant adaptation to different types of coal mine spoils and play a positive role in the revegetation of coal mine spoil banks.

Comparison of the intrusion effects on the maxillary incisors between implants and conventional method：a Meta-analysis / 重庆医学

Objective To objectively evaluate the intrusion effects on the maxillary incisors of implants versus conventional method(J-hook headgear ,utility arch) .Methods Such online databases as Cochrane library ,PubMed ,EMbase ,VIP ,Wanfang and CNKI were searched by randomized control test and prospective case controlled study about implants vs conventional anchorage for the maxillary incisor intrusion .After study selection ,assessment and data extraction conducted ,meta-analyses were performed by u-sing the RevMan 5 .1 software .Results Totally 11 studies were included ,6 studies involving 154 patients were included in the J-hook headgear group ,5 studies involving 127 patients were included in the utility arch group .The results of meta-analyses showed that :(1)Compared with the J-hook headgear ,implants had more decrement in the distance of upper center incisior cutting to palatal plane(P0 .05) .(2)Compared with the utility arch ,implants had more decrement in the distance of the center of resistance of the upper incisor to palatal plane (P=0 .010) ,less increase in U6-PP angle (P0 .05) .Conclusion The implants anchorage intruded the maxillary incisor was better than conventional method (J-hook headgear ,utility arch) ,it has more incisor intrusion ,shorter treatment time and more comfortable for the patients ,there was no difference in root resorption between the two groups .

Reference Equations for the Six-Minute Walk Distance in Healthy Korean Adults, Aged 22-59 Years / 결핵및호흡기질환

BACKGROUND: The six-minute walk test has been widely used in people with chronic cardiopulmonary disorders as an outcome assessment with regards to therapeutic or prognostic determinants. This study was undertaken to determine the six-minute walk distance (6MWD) in a sample of healthy Koreans and to create a reference equation. We also compared the 6MWD of our cohort with previously published equations. METHODS: Two hundred fifty-nine healthy subjects (95 males) aged 22-59 years performed two walking tests using a standardized protocol. 6MWD was defined as the greatest distance achieved from the two tests. The effect of anthropometrics on the 6MWD was also investigated. RESULTS: The average 6MWD was 598.5+/-57.92 m, with significantly longer distances by males (628.9+/-59.51 m) than females (580.9+/-47.80 m) (p<0.001). Age, height, weight, and body mass index were significantly correlated with 6MWD in univariate analysis. Stepwise multiple regression showed height to be single independent predictor of 6MWD (r2=0.205, p<0.001). The reference equations derived in Caucasian and North African populations tend to overestimate the distance walked by Korean subjects, while Asian equations underestimate it. CONCLUSION: The average 6MWD in these Korean populations was 600 m. The regression equation revealed that individual's height was the most significant predictor of distance, explaining 20.5% of the distance variance.

Microsurgical treatment for parasagittal meningioma in the central gyrus region.

The aim of the present study was to determine the efficacy of microsurgery treatment for parasagittal meningioma in the central gyrus region. A microsurgical technique was used to treat 26 patients with large parasagittal meningioma in the central gyrus region. The Rolandic and draining veins and the peritumoral normal brain tissue were retained, and the associated sagittal sinus was appropriately protected. A Simpson grade I, II or III resection was performed in 8 (30.8%), 12 (46.2%) and 6 (23.1%) patients, respectively, with no post-operative mortalities. Following treatment, 9 patients exhibited hemiparalysis. No tumor recurrence was found in 21 patients during the follow-up examination. The treatment protocol described in the current study included sufficient pre-operative imaging evaluations, a skilled microsurgical technique, improved protection of the Rolandic vein and treatment of the sagittal sinus, and was found to significantly increase the total tumor removal rate and decrease post-operative recurrence.