Time comparison of artificial airway establishment in operating room and on slope using endotracheal intubation and laryngeal mask / 北京大学学报(医学版)

OBJECTIVE@#To compare the completion time of endotracheal intubation and laryngeal mask implantation in operating room and on slope of ski resort, and to discuss the optimal method of estab-lishing artificial airway on slope of ski resort.@*METHODS@#The simulator was placed with the head under the feet on slope of ski resort. The artificial airway was established by tracheal intubation assisted by video laryngoscope (endotracheal intubation group) and laryngeal mask placement (laryngeal mask group) respectively by an anesthesiologist who wore full set of ski suits, helmets, goggles, gloves and ski boots. Each method was repeated 5 times, and the operation time of artificial airway establishment was recorded. While the simulated human was placed flat on the operating table in an operating room of a hospital, and the artificial airway was established by the same anesthesiologist using the same methods. Time was recorded and repeated for 5 times. The completion time of endotracheal intubation and laryngeal mask placement in the operating room and on the ski slope were compared.@*RESULTS@#The operating time of tracheal intubation in the operating room was longer than that of laryngeal mask placement [(79.8±10.4) s vs. (53.4±2.7) s, P=0.005], and the operating time of endotracheal intubation on the ski slope was longer than that of laryngeal mask placement [(209.2±32.7) s vs. (72.2±3.1) s, P=0.001]. The time of endotracheal intubation group on the slope of the ski resort was longer than that in the opera-ting room(t=-7.851, P=0.001). The time of laryngeal mask group on the slope was longer than that in the operating room (t=-19.391, P < 0.001).@*CONCLUSION@#On ski slope, both of tracheal intubation assisted by video laryngoscope and laryngeal mask placement can quickly complete the establishment of artificial airway, but the time required is longer than that in the operating room. The time of laryngeal mask placement to establish artificial airway is shorter than that of tracheal intubation assisted video laryngoscope, which may have a certain advantage in ski rescue.

Loss of the posteromedial support: a risk factor for implant failure after fixation of AO 31-A2 intertrochanteric fractures / 中华医学杂志(英文版)

BACKGROUND@#The purpose of this study was to analyze cases of AO31-A2 intertrochanteric fractures (ITFs) and to identify the relationship between the loss of the posteromedial support and implant failure.@*METHODS@#Three hundred ninety-four patients who underwent operative treatment for ITF from January 2003 to December 2017 were enrolled. Focusing on posteromedial support, the A2 ITFs were divided into two groups, namely, those with (Group A, n = 153) or without (Group B, n = 241) posteromedial support post-operatively, and the failure rates were compared. Based on the final outcomes (failed or not), we allocated all of the patients into two groups: failed (Group C, n = 66) and normal (Group D, n = 328). We separately analyzed each dataset to identify the factors that exhibited statistically significant differences between the groups. In addition, a logistic regression was conducted to identify whether the loss of posteromedial support of A2 ITFs was an independent risk factor for fixation failure. The basic factors were age, sex, American Society of Anesthesiologists (ASA) score, side of affected limb, fixation method (intramedullary or extramedullary), time from injury to operation, blood loss, operative time and length of stay.@*RESULTS@#The failure rate of group B (58, 24.07%) was significantly higher than that of group A (8, 5.23%) (χ = 23.814, P < 0.001). Regarding Groups C and D, the comparisons of the fixation method (P = 0.005), operative time (P = 0.001), blood loss (P = 0.002) and length of stay (P = 0.033) showed that the differences were significant. The logistic regression revealed that the loss of posteromedial support was an independent risk factor for implant failure (OR = 5.986, 95% CI: 2.667-13.432) (P < 0.001).@*CONCLUSIONS@#For AO31-A2 ITFs, the loss of posteromedial support was an independent risk factor for fixation failure. Therefore, posteromedial wall reconstruction might be necessary for the effective treatment of A2 fractures that lose posteromedial support.

Risk factors of recurrent kyphosis in thoracolumbar burst fracture patients treated by short segmental pedicle screw fixation / 北京大学学报(医学版)

OBJECTIVE@#To analyze the risk factors of recurrent kyphosis after removal of short segmental pedicle screw fixation in patients with thoracolumbar burst fractures.@*METHODS@#Retrospective analysis was conducted of 144 cases of thoracolumbar burst fractures without neurological impairment treated in Peking University Third Hospital from January 2010 to December 2017. There were 74 males and 70 females, with an average age of (39.1±13.2) years. The distribution of the injured vertebrae was T12: 42, L1: 72 and L2: 30, with fracture types of A3: 90, B1: 25 and B2: 29. The patients were divided into two groups: Recurrent kyphosis group (n=92) and non-recurrent kyphosis group (n=52). SPSS 26.0 software was used for univariate analysis and Logistic regression analysis.@*RESULTS@#The average follow-up time was 28 (20-113) months. The imaging indexes of pre-operation, 3 days post-operation, 12 months post-operation and the last follow-up were measured and compared. Anterior vertebral body height, segmental kyphosis, vertebral wadge angle and Gardner deformity were significantly improved after operation (P < 0.05), and there were some degrees of loss in the 1-year follow-up; anterior vertebral body height and vertebral wadge angle were no longer changed after the removal of the screws; however, segmental kyphosis and Gardner deformity were still aggravated after the removal of the screws (P < 0.05). There were some degrees of collapse of the height of the upper and lower discs during the follow-up. Univariate analysis showed that there were statistically significant differences (P < 0.05) between the two groups in gender, age (36.9 years vs. 43.0 years), upper disc injury, CT value (174 vs. 160), segmental kyphosis (16.6° vs. 13.3°), vertebral wadge angle (16.7° vs. 13.6°), Gardner deformity (19.1° vs. 15.2°) and ratio of anterior vertebral body height (0.65 vs. 0.71). Logistic regression analysis showed that male (OR: 2.88, 95%CI: 1.196-6.933), upper disc injury (OR: 2.962, 95%CI: 1.062-8.258) and injured vertebral wedge angle were risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture (P < 0.05).@*CONCLUSION@#The patients with thoracolumbar burst fracture can obtain satisfactory effect immediately after posterior short segmental pedicle screw fixation, however, there may be some degree of loss during the follow-up. Male, upper disc injury and injured vertebral wedge angle are the risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture.

Analysis of risk factors for necrosis of femoral head after internal fixation surgery in young and mid-aged patients with femoral neck fracture / 北京大学学报(医学版)

OBJECTIVE@#To retrospectively analyze the risk factors of avascular necrosis of femoral head (ANFH) after internal fixation in young and mid-aged adults.@*METHODS@#From January 2007 to December 2017, femoral neck fracture patients (18-60 years old) treated by reduction and internal fixation were retrospectively studied in Peking University Third Hospital. We recorded their gender, age, body mass index (BMI), American Society of Anesthesiology (ASA) grade, reason of injury, fracture side, interval between injury and surgery, location of fracture line, Garden classification, Pauwels classification, reduction method (open or closed), internal fixation and reduction quality. The diagnosis of ANFH was confirmed based on X-ray and MRI images during the follow-up. The internal fixation method included cannulated compression screw (CCS) or dynamic hip screw (DHS, with or without anti-rotation screw). χ2 test and Logistic regression analysis were used to analyze the relationship between the various factors and postoperative ANFH.@*RESULTS@#A total of 113 patients were included in this study, including 63 males and 50 females with an average age of (43.17 ± 12.34) years. They were followed up by (25.08 ± 16.17) months. ASA grade included grade I (21 cases), grade II (55 cases) and grade III (37 cases). The reasons of injury included low-energy trauma (76 cases) and high-energy (37 cases). The fracture line included subcapital type (37 cases), transverse type (74 cases) and basal type (2 cases). Garden classification included type I (3 cases), type II (46 cases), type III (39 cases) and type IV (25 cases). Pauwels classification included type I (21 cases), type II (55 cases) and type III (37 cases). Interval between injury and surgery was (3.88 ± 3.66) days, 108 patients and 5 patients performed closed and open reduction respectively. 63 patients performed CCS, and 50 patients performed DHS. The reduction quality included grade A (91 cases), grade B (18 cases) and grade C (4 cases). 18 patients developed ANFH after surgery, the incidence rate was 15.93% (18/113). The result of χ2 test showed the reason of injury (OR=0.19, P < 0.01), Garden classification (OR=0.13, P < 0.01), Pauwels classification (OR=0.12, P = 0.02), internal fixation method (OR=3.29, P = 0.04) and reduction quality (OR=0.33, P < 0.01) were significantly associated with ANFH. These five factors were further included into the Logistic regression analysis, and its results showed that the reason of injury (OR=4.11, P = 0.03) and Garden classification (OR=4.85, P = 0.04) were statistically significant.@*CONCLUSION@#The reason of injury, Garden classification, Pauwels classification, internal fixation and reduction quality may increase the risk of ANFH after surgery, and the reason of injury and Garden classification were much more significant.

Predictors and reduction techniques for irreducible reverse intertrochanteric fractures / 中华医学杂志(英文版)

BACKGROUND@#Reverse intertrochanteric fractures are usually initially treated with closed reduction. However, sometimes these fractures are not amenable to closed reduction and require open reduction. To date, few studies have been conducted on predictors of and reduction techniques for irreducible reverse intertrochanteric fractures. Therefore, this study aimed to summarize the displacement patterns of irreducible reverse intertrochanteric fractures and corresponding reduction techniques, and explore predictors of irreducibility.@*METHODS@#We reviewed 1174 cases of trochanteric fractures treated in our hospital from January 2006 to October 2018, 113 of which were reverse intertrochanteric fractures. An irreducible fracture was determined according to intra-operative fluoroscopy imaging after closed manipulation. Fractures were assessed for displacement patterns, radiographic features of irreducibility, and reduction techniques. Logistic regression analysis was performed on potential predictors for irreducibility, including gender, age, body mass index, AO Foundation/Orthopaedic Trauma Association (AO/OTA) classification, and radiographic features.@*RESULTS@#Seventy-six irreducible fractures were identified, accounting for 67% of reverse intertrochanteric fractures. Six patterns of fracture displacement after closed manipulation were identified; the most common pattern was medial displacement and posterior sagging of the femoral shaft relative to the head-neck fragment. Multivariate logistic regression analysis identified three predictors of irreducibility: a medially displaced femoral shaft relative to the head-neck fragment on the anteroposterior (AP) view (odds ratio [OR], 8.00; 95% confidence interval [CI], 3.04-21.04; P < 0.001), a displaced lesser trochanter (OR, 3.61; 95% CI, 1.35-9.61; P = 0.010), and a displaced lateral femoral wall (OR, 2.92; 95% CI, 1.02-8.34; P = 0.046).@*CONCLUSIONS@#A high proportion of reverse intertrochanteric fractures are not amenable to closed reduction. Six patterns of fracture displacement after closed manipulation were identified. Different reduction techniques are required for different displacement patterns. Predictors of irreducibility include a medially displaced femoral shaft relative to the head-neck fragment on the AP view, a displaced lesser trochanter, and a displaced lateral femoral wall. These patients warrant special consideration in terms of recognition and management.

Inactivation of Poliovirus by Ozone and the Impact of Ozone on the Viral Genome / 生物医学与环境科学（英文）

OBJECTIVE@#To investigate the mechanisms underlying ozone-induced inactivation of poliovirus type 1 (PV1).@*METHODS@#We used cell culture, long-overlapping RT-PCR, and spot hybridization assays to verify and accurately locate the sites of action of ozone that cause PV1 inactivation. We also employed recombinant viral genome RNA infection models to confirm our observations.@*RESULTS@#Our results indicated that ozone inactivated PV1 primarily by disrupting the 5'-non-coding region (5'-NCR) of the PV1 genome. Further study revealed that ozone specifically damaged the 80-124 nucleotide (nt) region in the 5'-NCR. Recombinant viral genome RNA infection models confirmed that PV1 lacking this region was non-infectious.@*CONCLUSION@#In this study, we not only elucidated the mechanisms by which ozone induces PV1 inactivation but also determined that the 80-124 nt region in the 5'-NCR is targeted by ozone to achieve this inactivation.

Predictors and reduction techniques for irreducible reverse intertrochanteric fractures / 中华医学杂志(英文版)

Background@#Reverse intertrochanteric fractures are usually initially treated with closed reduction. However, sometimes these fractures are not amenable to closed reduction and require open reduction. To date, few studies have been conducted on predictors of and reduction techniques for irreducible reverse intertrochanteric fractures. Therefore, this study aimed to summarize the displacement patterns of irreducible reverse intertrochanteric fractures and corresponding reduction techniques, and explore predictors of irreducibility.@*Methods@#We reviewed 1174 cases of trochanteric fractures treated in our hospital from January 2006 to October 2018, 113 of which were reverse intertrochanteric fractures. An irreducible fracture was determined according to intra-operative fluoroscopy imaging after closed manipulation. Fractures were assessed for displacement patterns, radiographic features of irreducibility, and reduction techniques. Logistic regression analysis was performed on potential predictors for irreducibility, including gender, age, body mass index, AO Foundation/Orthopaedic Trauma Association (AO/OTA) classification, and radiographic features.@*Results@#Seventy-six irreducible fractures were identified, accounting for 67% of reverse intertrochanteric fractures. Six patterns of fracture displacement after closed manipulation were identified; the most common pattern was medial displacement and posterior sagging of the femoral shaft relative to the head-neck fragment. Multivariate logistic regression analysis identified three predictors of irreducibility: a medially displaced femoral shaft relative to the head-neck fragment on the anteroposterior (AP) view (odds ratio [OR], 8.00; 95% confidence interval [CI], 3.04-21.04; P < 0.001), a displaced lesser trochanter (OR, 3.61; 95% CI, 1.35-9.61; P = 0.010), and a displaced lateral femoral wall (OR, 2.92; 95% CI, 1.02-8.34; P = 0.046).@*Conclusions@#A high proportion of reverse intertrochanteric fractures are not amenable to closed reduction. Six patterns of fracture displacement after closed manipulation were identified. Different reduction techniques are required for different displacement patterns. Predictors of irreducibility include a medially displaced femoral shaft relative to the head-neck fragment on the AP view, a displaced lesser trochanter, and a displaced lateral femoral wall. These patients warrant special consideration in terms of recognition and management.

Application of the modified internal fixation method of minimally invasive percutaneous plate osteosynthesis in treatment of proximal humeral fracture / 北京大学学报(医学版)

OBJECTIVE@#To study the clinical outcomes and characteristics of fracture healing of a modified internal fixation method, which was implemented by placing four and two screws respectively at the proximal and distal end of the locking plate in the minimally invasive percutaneous plate osteosynthesis (MIPPO) for patients with proximal humeral fractures.@*METHODS@#Patients in Peking University Third Hospital from February 2010 to December 2016 were brought into this retrospective study. Based on different operation methods, they were divided into minimally invasive (MI) group and non-minimally invasive (non-MI) group, and the patients in MI group were performed with the modified internal fixation. In order to observe the varying efficacy for different fracture types between the two groups, we further investigated the patients with Neer two-part and three-part fracture, respectively. The follow-up parameters included general physical examination, X-ray, visual analogue scale (VAS) and Constant-Murley score.@*RESULTS@#A total of 117 patients with an average age of (61.5±16.2) years met the inclusion criteria, and MI group included 45 patients, non-MI group included 72 patients. According to the Neer classification, there were 46 cases of two-part fracture, 63 cases of three-part fracture and 8 cases of four-part fracture. In MI group, there were 17 males and 28 males with an average age of (62.2±17.1) years, including 18 cases of two-part fracture, 23 cases of three-part fracture and 4 cases of four-part fracture. In non-MI group, there were 27 males and 45 females with an average age of (60.1±17.7) years, including 28 cases of two-part fracture, 40 cases of three-part fracture and 4 cases of four-part fracture. There were no significant differences between the two groups in terms of gender (P=0.975), age (P=0.545) and fracture type (P=0.756). The average hospital-stay in MI group and non-MI group was (2.8±1.1) days and (4.3±1.3) days (P=0.023), the operation time was (67.8±14.9) min and (102.3±34.1) min (P<0.001), the blood loss was (21.3±6.5) mL and (181.5±55.6) mL (P<0.001), the Constant-Murley score was 6.1±0.9 and 6.5±0.8 (P=0.032) one week after surgery, and the Constant-Murley score was 66.1±4.3 and 63.4±4.9 (P=0.006) three months after surgery, MI group had significant advantages in these aspects. In terms of Neer two-part and three-part fracture, the VAS score (5.9±0.8) one week postoperatively and the Constant-Murley score (66.6±3.7) three months postoperatively were significantly superior in MI group (P<0.05). In MI group, delayed fracture healing occurred in 1 case (2.2%) and abduction was restricted in 1 case (2.2%). In non-MI group, delayed fracture healing occurred in 3 cases (4.2%) and abduction was restricted in 2 cases (2.8%). There were no internal fixation complications and humeral head necrosis in both groups.@*CONCLUSION@#Applying the modified internal fixation in MIPPO to cure proximal humeral fractures is effective clinically with thick callus formation occurring at the fracture site. The fracture can achieve normal healing and the shoulder functions can restore well, indicating the modified surgical method is a good treatment option.

Mutation analysis of beta myosin heavy chain gene in hypertrophic cardiomyopathy families / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect the gene mutations of beta-myosin heavy chain gene (MYH7) in Chinese pedigrees with hypertrophic cardiomyopathy (HCM), and to analyze the correlation between the genotype and phenotype.</p><p><b>METHODS</b>Exons 3, 5, 7-9, 11-16 and 18-23 of the MYH7 gene were amplified with PCR in three Chinese pedigrees with HCM. The products were sequenced. Sequence alignment between the detected and the standard sequences was performed.</p><p><b>RESULTS</b>A missense mutation of Thr441Met in exon 14 was identified in a pedigree, which was not detected in the controls. Several synonymous mutations of MYH7 gene were detected in the three pedigrees.</p><p><b>CONCLUSION</b>The mutation of Thr441Met, located in the actin binding domain of the globular head, was first identified in Chinese. It probably caused HCM. HCM is a heterogeneous disease. Many factors are involved in the process of its occurrence and development.</p>

Screening and analysis of the mutations on beta-myosin heavy chain gene in 3 Chinese families with hypertrophic cardiomyopathy / 中华心血管病杂志

<p><b>OBJECTIVE</b>To detect gene mutations on beta-myosin heavy chain gene MYH7 in 3 Chinese families with hypertrophic cardiomyopathy (HCM), and to analyze the correlation between genotype and phenotype.</p><p><b>METHODS</b>A denaturing high-performance liquid chromatography (DHPLC) and sequencing mutation screening of the exons (exon3-23) coding for MYH7 gene were performed in 3 Chinese families with HCM.</p><p><b>RESULTS</b>In this study, we identified several mutations in MYH7. A mutation of Thr441Met previously reported in a patient with Laing distal myopathy was first identified in one Chinese pedigree.</p><p><b>CONCLUSION</b>This study illustrated the high frequency of mutation in MYH7 gene in Chinese HCM families. Different mutations and carriers of the MYH7 gene present phenotypic heterogeneity. Mutation screening and analysis in HCM family could therefore facilitate the early HCM diagnosis and would be helpful for the prediction, prevention and early treatment of HCM linked with MYH7 gene mutation.</p>

Expression of atrial angiotensin II type 1 receptor and α7-nicotinic acetylcholine receptor during development of heart failure in rats / 第二军医大学学报

Objective: To observe the atrial expression of angiotensin II receptor type 1 (AT1R) and α7-nicotinic acetylcholine receptor(α7nAChR) during the development of heart failure in rats. Methods: Male SD rats were randomly divided into 4 groups. Abdominal aorta coarctation (AAC) was used to prepare heart failure model. Expression of AT1R and α7nAChR was determined by Western blotting analysis at 4,8,12, and 16 weeks after AAC in all the groups. Results: Compared with the control group, expression of AT1R and α7nAChR in AAC group was not significantly different at all the 4 time points after AAC. Conclusion: Our findings suggest that atrial AT1R and α7nAChR may not be involved in the early stage pathological process of AAC-induced heart failure.