[The Development of SpCas9 Variants with High Specificity and Efficiency Based on the HH Theory].

Streptococcus pyogenes Cas9 (SpCas9) is the most popular tool in gene editing; however, off-target mutagenesis is one of the biggest impediments in its application. In our previous study, we proposed the HH theory, which states that sgRNA/DNA hybrid (hybrid) extrusion-induced enhancement of hydrophobic interactions between the hybrid and REC3/HNH is a key factor in cleavage initiation. Based on the HH theory, we analyzed the interactions between the REC3 domain and hybrid and obtained 8 mutant sites. We designed 8 SpCas9 variants (V1-V8), used digital droplet PCR to assess SpCas9-induced DNA indels in human cells, and developed high-fidelity variants. Thus, the HH theory may be employed to further optimize SpCas9-mediated genome editing systems, and the resultant V3, V6, V7, and V8 SpCas9 variants may be valuable for applications requiring high-precision genome editing.

[Study on risk factors of abnormal pulmonary function among dust-exposed workers and prediction model].

Objective: To explore the influencing factors of abnormal pulmonary function in dust-exposed workers and establish the risk prediction model of abnormal pulmonary function. Methods: In April 2021, a total of 4255 dust exposed workers from 47 enterprises in 2020 were included in the study. logistic regression was used to analyze the influencing factors of abnormal pulmonary function in dust-exposed workers, and the corresponding nomogram prediction model was established. The model was evaluated by ROC curve, Calibrationpolt and decision analysis curve. Results: logistic regression analysis showed that age (OR=1.03, 95%CI=1.02~1.05, P<0.001) , physical examination type (OR=4.52, 95%CI=1.69~12.10, P=0.003) , dust type (Comparison with coal dust, Cement dust, OR=3.45, 95%CI=1.45~8.18, P=0.005, Silica dust (OR=2.25, 95%CI=1.01~5.03, P=0.049) , blood pressure (OR=1.63, 95%CI=1.22~2.18, P=0.001) , creatinine (OR=0.08, 95%CI=0.05~0.12, P<0.001) , daily exposure time (OR=1.06, 95%CI=1.10~1.12, P=0.034) and total dust concentration (OR=1.29, 95%CI=1.08~1.54, P=0.005) were the influencing factors of abnormal pulmonary function. The area under the ROC curve of risk prediction nomogram model was 0.764. The results of decision analysis curve showed that the nomogram model had reference value in the prevention and intervention of abnormal pulmonary function when the threshold probability exceeded 0.05. Conclusion: The accuracy ofthe nomogram model constructed by logistic regression werewell in predicting the risk of abnormal lung function of dust-exposed workers.

[Effect of rebamipide on the acute gouty arthritis in rats induced by monosodium urate crystals].

OBJECTIVE: To investigate the role of rebamipide in the treatment of acute gout arthritis rats induced by monosodium urate (MSU) crystal. METHODS: Forty-two male rats were randomly divided into three groups (n=14). Group A was treated with oral rebamipide, group B with oral colchicine, and group C with oral placebo. The rats were monitored for the induction of arthritis with clinical manifestations and pathological changes, and the levels of interleukin (IL)-1ß、IL-6、IL-10, and tumor necrosis factor (TNF)-α in serum were measured. RESULTS: In group C, the clinical score and swelling index reached the maximum in 24 h, and then gradually decreased to 72 h. After 24 h of model induced, the clinical scores in group C were significantly higher than those in group A and group B [2 (1-3) vs. 0 (0-1) vs. 1 (0-2), P < 0.01], the swelling indexes in group C were significantly higher than those in group A and group B [0.36 (0.16-0.52) vs. 0.11 (0-0.20) vs. 0.12 (0-0.16), P < 0.01]. Histologically, after 24 h of model induced, there was a large number of neutrophil infiltration in the synovium of group C [scale score: 4 (2-4)], and there was no significant inflammatory cell infiltration in group A [1 (0-2)] and group B [1 (0-2)], the difference was statistically significant (P < 0.001). After 24 h of model induced, the levels of IL-1ß, IL-6, IL-10, and TNF-α in serum of group C were significantly higher than those in group A and B [IL-1ß: (41.86±5.72) vs. (27.35±7.47) vs. (27.76±5.28) ng/L, IL-6: (1 575.55±167.11) vs. (963.53±90.22) vs. (964.08±99.31) ng/L, IL-10: (37.96±3.76) vs. (21.68±4.83) vs. (16.20±2.49) ng/L, TNF-α: (21.32±1.34) vs. (15.82±2.54) vs. (17.35±7.47) µg/L, P < 0.001]. CONCLUSION: Rebamipide has a protective effect on acute gout arthritis rats induced by MUS crystals.

[Efficacy and safety of intraoperative ultrasound-assisted neuroendoscopy in the treatment of hypertensive intracerebral hemorrhage via transsylvian approach].

Objective: To explore the efficacy and safety of intraoperative ultrasound-assisted neuroendoscopy for treating hypertensive intracerebral hemorrhage (HICH) via lateral fissure and insula approach. Methods: The clinical data of 66 patients with HICH in basal ganglia who underwent intraoperative ultrasound-assisted neuroendoscopy via lateral fissure and insula approach for hematoma evacuation were retrospectively analyzed, including operative data and follow-up results. All patients had no brain hernia before operation. The hematoma was located by the ultrasound and then the path into the hematoma cavity was determined. Meanwhile, the residual hematoma was also detected by using the ultrasound. The clearance rate of hematoma was observed by CT. Barthel index was used to evaluate the activity of daily living. Results: The amount of residual hematoma was less than 10% in 63 ases and 10%-20% in 3 cases. There were 11 cases of postoperative pneumonia, of whom 9 cases underwent percutaneous tracheotomy. Rebleeding occurred in 2 cases, but the amount was small, and there was no need for reoperation. Meanwhile, there was 1 case of secondary intracranial infection and 1 case of secondary hydrocephalus. No case of cerebral contusion was reported. Half a year after the operation, Barthel Index grading showed that there were 3 cases of grade I, 25 cases of grade Ⅱ, 34 cases of grade Ⅲ, 3 cases of grade Ⅳ and 1 case of death, respectively. Conclusions: Intraoperative ultrasound-assisted neuroendoscopy via lateral fissure and insula approach can improve the efficacy and safety of treatment for HICH.

Very high external quantum efficiency and wall-plug efficiency 527 nm InGaN green LEDs by MOCVD.

We demonstrate very high luminous efficacy InGaN-based green light-emitting diodes (LEDs) grown on c-plane patterned sapphire substrates (PSS) using metal organic chemical vapor deposition (MOCVD). The 527 nm green LEDs show a peak external quantum efficiency (EQE) of 53.3%, a peak wall-plug efficiency (WPE) of 54.1% and a peak luminous efficacy of 329 lm/W, respectively. A high EQE of 38.4%, a WPE of 32.1% and a very low forward voltage of 2.86 V were obtained at a typical working current density of 20 A/cm2. By operating low cost green LEDs at a low current density, our devices (0.5 mm2) demonstrating an EQE and a WPE higher than 50% and an efficacy of 259 lm/W at 4 A/cm2 with an output power of 24 mW. High crystal quality of the InGaN/GaN MQWs was characterized by X-ray diffraction (XRD) and the advantage of the epitaxy design was investigated by APSYS software simulation. These results provide a simple way to achieve very high efficiency InGaN green LEDs.

[Analysis on chromosome aberration rate, micronucleus cell rate and related factors of 3021 radiation workers in Changzhou].

Objective: To investigate the chromosomal aberration rate, micronucleus cell rate and the related factors of radiation workers in Changzhou, provide evidence for the occupational health and safety of radiation workers. Methods: Descriptive analysis of the chromosomal aberration rate, micronucleus cell rate and the related factors of 3021 radiation workers who conducted occupational health examination in the Changzhou Center for Disease Control and prevention in 2017, multivariate logistic regression was used to analyze the data. Results: The abnormal rate of chromosome aberration and micronucleus cells of 3021radiation workers in Changzhou were 1.32% and 3.34% respectively. The results of multivariate logistic regression showed that the exposure year (OR=1.501, 95%CI:1.078~2.089, P=0.016) was a risk factor for chromosome aberration. The risk of chromosome aberration in radiation therapy (OR=6.417, 95%CI:1.360~30.280, P=0.019) and interventional radiology (OR=4.598, 95%CI:1.688~12.524, P=0.003) was higher than that of industrial application. the exposure year (OR=1.245, 95%CI:1.007~1.539, P=0.043) is also a risk factor for micronucleus cell rate. The micronucleus cell rate abnormality Risk of nuclear medicine (OR=3.934, 95%CI:1.305~11.858, P=0.015) , radiation therapy (OR=3.802, 95%CI:1.101~13.128, P=0.035) , and interventional radiology (OR=2.953, 95%CI:1.324~6.584, P=0.008) is higher than industrial application. Conclusion: The chromosome aberration rate and micronucleus rate of workers who are exposed to low dose ionizing radiation for long time are related to the exposure year of radiation workers and the occupational categories involved.

DNA methylation alterations in the pathogenesis of lupus.

Although lupus is, by definition, associated with genetic and immunological factors, its molecular mechanisms remain unclear. The up-to-date research findings point out that various genetic and epigenetic factors, especially gene-specific and site-specific methylation, are believed to contribute to the initiation and development of systemic lupus erythematosus (SLE). This review presents and summarizes the association between abnormal DNA methylation of immune-related cells and lupus-like diseases, as well as the possible mechanisms of immune disorder caused by DNA methylation, aiming at a better understanding of the roles of aberrant DNA methylation in the initiation and development of certain forms of lupus and providing a new insight into promising therapeutic regimens in lupus-like diseases.

Optically pumped lasing with a Q-factor exceeding 6000 from wet-etched GaN micro-pyramids.

We report the observation of room-temperature optically pumped lasing modes from a single GaN pyramid microcavity on a metallic mirror. The mode at 367.2 nm exhibits a low threshold (0.4-0.5 MW/cm2) and a narrow linewidth (0.054 nm), by which the quality factor can be estimated to be >6000. These lasing behaviors can be attributed to the specific wet-etching approach by selectively etching away defects and pyramid geometry with bottom Ag reflectors for better light confinement. Optical resonances in these pyramids are further investigated in combination with three-dimensional finite-difference time-domain simulations.

Epigallocatechin gallate inhibits the growth of salivary adenoid cystic carcinoma cells via the EGFR/Erk signal transduction pathway and the mitochondria apoptosis pathway.

ACC is one of the most malignant tumors in salivary gland, and of poor prognosis. A critical role in ACC development and progression is played by EGFR family members including EGFR. EGCG, a low molecular weight polyphenol contained in green tea, has broad anticancer properties, but whether EGCG regulates activity of ACC is unknown. In the present study, the effects of EGCG were investigated in vitro with particular attention to the pathway of EGFR/Erk and mitochondria apoptosis in SACC-83 cell lines. The results of MTS assay and flow cytometry demonstrated that EGCG (20-80 µM) could inhibit proliferation and promote apoptosis of SACC-83 cells. Furthermore, by Western blotting with antibodies specific for EGFR, Erk 1/2 (p-Erk 1/2), Mek (p-Mek), Bcl-2, and Bax, it was demonstrated that EGCG could reduce the expression of EGFR, inhibit phosphorylation of Erk 1/2 and Mek, downregulate Bcl-2, and upregulate Bax. In addition, it was also shown that EGCG could inhibit mRNA expression of P90 RSK by RT-PCR. In conclusion, the results suggest that EGCG might be a potential therapeutic or adjuvant strategy for the treatment of patients with ACC, by inhibiting proliferation and inducing the apoptosis of the tumor cells.

[Clinical efficacy of acute intraoperative encephalocele prevention strategy for severe traumatic brain injury].

Objective: To explore the clinical efficacy of prevention strategy for acute intraoperative encephalocele of patients with severe traumatic brain injury (sTBI). Methods: A total of 173 patients with sTBI, who treated in Emergency Neurosurgery Department of Shandong University Qilu Hospital from January, 2011 to September, 2015 were collected and divided into research group and control group, according to their therapeutic strategy.The clinical data during hospitalization and prognosis 1 year after injury was analyzed retrospectively to clarify the effect of acute encephalocele prevention strategy. Results: There were no statistically significant differences in sex, age, preoperative Glasgow coma scale score and imaging type of lesion between patients from the two groups.The highest intraoperative intracranial pressure in the research group and control group were (35.71±4.13) mmHg and(34.85±3.81) mmHg, respectively.The acute encephalocele incidence of the research group (7 cases, 6.5%) was significantly lower than that of the control group (13 cases, 19.7%) (P<0.01). Subgroup analysis showed that the incidence of acute encephalocele in patients with only unilateral lesions was low (1.3%), while higher (19.4%) in patients with both unilateral lesions and other secondary lesions or diffuse brain swelling.The prognosis of the patients was evaluated by Glasgow Outcome Scale according to the follow-up 1 year after injury, and it was suggested that the percentage of patients with good outcome in the research group (62 cases, 57.9%) was remarkably higher than that in the control group (26 cases, 39.4%) (P=0.018). Conclusions: For sTBI patients with high risk of acute encephalocele, prevention strategy was found to be able to retard the progression of delayed hematoma and diffuse brain swelling, prevent the acute encephalocele during operation, and then significantly improve the prognosis.

[Clinical efficacy of rivaroxaban in prevention and treatment of postoperative deep vein thrombosis for severe traumatic brain injury].

Objective: To explore the clinical efficacy of rivaroxaban in the prevention and treatment of postoperative deep vein thrombosis (DVT) for severe traumatic brain injury (sTBI). Methods: Patients with sTBI who met the inclusion criteria were enrolled in this study, including 119 males (75.8%) and 38 females (24.2%), aged (38.75 ± 11.98) years old. DVT was prevented and treated according to the DVT screening and anticoagulation regimen. Intermittent venous compression was used on all of the patients to prevent DVT, and D-dimer dynamic monitoring and regular ultrasound were performed to screen for DVT. For patients with stable intracranial hemorrhage, rivaroxaban was used when the D-dimer was declining continuously and high risks exist at the same time, or the DVT was diagnosed. Drug withdrawal was performed according to the regimen. The clinical information, D-dimer dynamic changes, rivaroxaban application, DVT, and bleeding complications were analyzed retrospectively. Results: None of the patients with continuously declining D-dimer was diagnosed with DVT according to the ultrasound examination. Of the 45 patients without progressively declining D-dimer, 43 cases were diagnosed with DVT. Rivaroxaban was used in 47 cases (29.9%) to prevent DVT and 43 cases (27.4%) to treat DVT, and the medication time was (16.3±6.5) and (49.3 ± 9.9) days, respectively. None was diagnosed with DVT after prophylactic administration, and 1 case relapsed after therapeutic administration. During the 6-months follow-up after injury, hematuria occurred in 3 cases, tracheotomy errhysis in 1 case and hemorrhoids bleeding in 1 case. Symptomatic pulmonary embolism, intracranial hemorrhage and fatal bleeding did not occur in any of the cases. Conclusions: The application of rivaroxaban is safe and effective in preventing and treating the postoperative DVT.

Body mass index, waist-to-hip ratio, waist circumference and waist-to-height ratio cannot predict male semen quality: a report of 1231 subfertile Chinese men.

There were controversial results between obesity-associated markers and semen quality. In this study, we investigated the correlations between age, obesity-associated markers including body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and waist circumference (WC), the combination of age and obesity-associated markers, semen parameters and serum reproductive hormone levels in 1231 subfertile men. The results showed that BMI, WC, WHR and WHtR were positively related to age, and there were also positive relations between BMI, WHR, WC and WHtR and between sperm concentration (SC), total sperm count (TSC), progressive motility (PR), sperm motility and per cent of normal sperm morphology (NSM). However, age, each of obesity-associated markers and the combination of obesity-associated markers and age were unrelated to any of semen parameters including total normal-progressively motile sperm count (TNPMS). Age, BMI, WHR, WC and WHtR were negatively related to serum testosterone and SHBG levels. However, only serum LH and FSH levels were negatively related to sperm concentration, NSM and sperm motility. In a conclusion, although age and obesity have significant impacts on reproductive hormones such as testosterone, SHBG and oestradiol, semen parameters related to FSH and LH could not be influenced, indicating that obesity-associated markers could not predict male semen quality.

Expression of macrophage migration-inhibitory factor in duodenal ulcer and its relation to Helicobacter pylori infection.

The aim of this study was to examine the expression of macrophage migration-inhibitory factor (MIF) in duodenal ulcer epithelial cells and its relation to Helicobacter pylori (Hp) infection, and to discuss the pathogenic roles of MIF expression and Hp infection in duodenal ulcer. MIF protein and mRNA expression was examined in samples from patients with duodenal ulcer with and without Hp infection (N = 40 each, experimental group), and in normal duodenal bulb mucosal tissue (N = 40, control group) using immunohistochemistry and in situ hybridization. Patients without Hp infection received routine treatment, and treatment was provided to the patients positive for Hp to eradicate Hp infection. Hp and MIF expression levels before treatment and after the ulcer had been cured were compared. The positive rates of MIF protein and mRNA in patients with Hp infection before treatment were 67.5 and 65%, respectively, and were 18.9 and 21.6% in the 37 patients from whom Hp was eliminated. These were statistically different both before and after treatment compared with controls (P < 0.05). In the patients without Hp infection, the positive rates of MIF protein and mRNA expression before (45 and 47.5%, respectively) and after (32.5 and 30%) treatment were not significantly different (P > 0.05). The results of this study suggested that MIF is related to the development of duodenal ulcer, and that the presence of Hp is closely related with the expression of MIF in the duodenal mucosa and the development of duodenal ulcer.

Roles of p38 MAPK in the regulation of the inflammatory response to swine influenza virus-induced acute lung injury in mice.

Swine influenza virus (SIV), one of the most important zoonotic agents, is associated with major public health concerns. The current study was conducted to investigate the role of p38 mitogen-activated protein kinase (p38 MAPK) in the regulation of the inflammatory response to acute lung injury (ALI) induced by SIV of H9N2 subtype (H9N2-SIV) in mice. For this purpose, BALB/c mice were intranasally infected with 20 LD(50) of H9N2-SIV (infected group), while non-infected mice served as control (control group). To assess the effect of p38 MAPK, its specific inhibitor SB203580 was employed followed by SIV infection (SB group). At various times after infection, mouse lungs were subjected to pathological and histological observations and detection of inflammatory cytokines tumor necrosis factor α (TNF)-α, interleukin (IL)-1ß, IL-6, and IL-10 and phosphorylated p38 MAPK. The obtained results showed obvious inflammatory responses, injury and raised levels of inflammatory cytokines and phosphorylated p38 MAPK in the lungs of virus-infected mice. In the mice inoculated with the virus alone, the level of phosphorylated p38 MAPK increased from day 2 and peaked at day 6 post infection (p.i.). However, SB203580 caused lower increases in inflammatory cytokines and phosphorylated p38 MAPK and a milder lung injury. These findings indicate that the activation of p38 MAPK upregulated the inflammatory responses to H9N2-SIV-induced ALI, increased its severity and promoted the production of inflammatory cytokines.

Caudal dexmedetomidine combined with bupivacaine inhibit the response to hernial sac traction in children undergoing inguinal hernia repair.

BACKGROUND: Caudal bupivacaine is widely used for inguinal hernia repair in children, but often cannot totally eliminate responses to hernial sac traction. The current study examined whether supplementation of caudal bupivacaine with dexmedetomidine could achieve better results. METHODS: Sixty children aged 12-72 months undergoing unilateral inguinal hernia repair received standardized premedication with midazolam, i.v. ketamine anaesthesia, and then were randomly assigned to receive either bupivacaine 0.25% (1 ml kg(-1); Group B) or bupivacaine plus dexmedetomidine (1 µg kg(-1); Group BD). The response to hernial sac traction was defined as an increase in heart rate or systolic arterial pressure by >20%, and was treated with ketamine rescue (2 mg kg(-1)). After the surgery, fentanyl was administered as needed with a nurse-controlled analgesia pump. RESULTS: Only one subject in Group BD (3.33%) needed ketamine rescue, as opposed to 13 subjects in Group B (43.33%; P<0.001). The first fentanyl injection occurred at a much later time point in Group BD (median: 860 vs 320 min in Group B; P<0.001). Total fentanyl consumption of fentanyl was significantly lower in Group BD [2.5 (1.2) vs 6.9 (1.6) µg kg(-1) 24 h(-1) in Group B; P=0.008]. CONCLUSIONS: The addition of dexmedetomidine to caudal bupivacaine could reduce the response to hernial sac traction, and prolong the duration of postoperative analgesia in children undergoing inguinal hernia repair.

Brain injury due to anaphylactic shock as a result of formocresol used during root canal treatment.

AIM: Formocresol is still used in many parts of the world despite concerns over its toxicity. A case of a 45-year-old women who experienced brain injury after an analyphlactic reaction to formocresol is presented. SUMMARY: During routine root canal treatment, the patient experienced nausea and vomiting after formocresol was used as an antibacterial agent in the pulp chamber. The procedure was discontinued and the symptoms resolved. Four days later, the treatment was continued by a different dentist, and the patient developed anaphylactic shock within 10 min of placement of a formocresol-soaked cotton pellet. She received emergency medical treatment and magnetic resonance imaging (MRI) revealed brain injury characterized by swelling of the gyrus in the cerebral watershed territory of the left parietal-occipital lobe. The patient subsequently made a full recovery after supportive treatment. KEY LEARNING POINTS: A type-I allergic reaction can be induced by formocresol. The reasons for the brain injury are thought to be cerebral hypoxia, which was induced by the anaphylactic shock and/or cerebral parenchymal oedema. All dentists should be aware of the risks involved in the use of formocresol and avoid using materials containing formocresol and related agents.

Cerebral and renal abscess and retino-choroiditis secondary to Candida albicans in preterm infants: eight case retrospective study.

OBJECTIVES: To assess the tissues and organs commonly involved and the clinical features in the invasive fungal infection (IFI) of Candida albicans in the preterm infants. MATERIALS AND METHODS: Eight preterm infants who developed IFI with positive blood culture for Candida albicans were retrospectively studied. All infants received selected clinical and laboratory parameters evaluation, such as blood culture, cerebral magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) biochemical test, routine urine test, urine culture, renal ultrasonography, renal computer tomography (CT), and fundus examination. The re-examinations were performed after one to two months follow-up. RESULTS: Cerebral abscesses were detected in six infants. Five cases developed renal systemic fungal infection, among which one had renal abscess. Three cases were complicated with fungal retino-choroiditis. CONCLUSIONS: Preterm infants, especially very-low-birthweight (VLBW) and extremely-low-birth-weight (ELBW) infants are susceptible to fungi. The majority of preterm late-onset fungal infections are due to Candida albicans. The organs commonly involved in the IFI of Candida albicans are central nervous system (CNS), kidney and fundus, among which renal systemic fungal infection are prone to recur, calling for a prolonged anti-fungi treatment course.