[Clavien-Dindo classification and influencing factors analysis of complications after laparoscopic pancreaticoduodenectomy]

Objective: To semi-quantify the postoperative complications occurred after laparoscopic pancreaticoduodenectomy(LPD) using Clavien-Dindo score, thereafter exploring its impact factors. Methods: In this retrospective cohort study, the clinical data of 124 patients who had undergone LPD for periampullary tumor from June 2016 to June 2017 at Department of Biliary Pancreatic Surgery, Affiliated Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology were collected.Malignancy was confirmed based on postoperative pathological reports.Postoperative complications were semi-quantitated using Clavien-Dindo score.Multivariable logistic regression model was applied to explore the factors related to severe complications(Clavien-Dindo Ⅲb-Ⅴ). Results: Of the 124 patients, there were 64 males(51.6%) and 60 females(48.4%), with age of 57 years(range, 23-82 years). In total, postoperative complications occurred in 30 patients(24.2%). Among the 30 patients, 4 patients suffered Clavien-Dindo grade Ⅰ, 18 patients(14.5%) suffered Clavien-Dindo grade Ⅱ, 6 patients(4.8%) suffered Clavien-Dindo grade Ⅲa, 1 patient(0.1%) suffered Clavien-Dindo grade Ⅳb, and 1 patient(0.1%) suffered Clavien-Dindo grade Ⅴ.Intraabdominal hemorrhage occurred in 8 patients, pancreatic fistula was found in 10 patients(7 patients had biochemical leakage and 3 of them had grade B pancreatic fistula), both biliary fistula and gastrointestinal fistula were found in 1 patient.Abdominal infection occurred in 10 patients, both liver failure and renal failure occurred in one patient.Moreover, arrhythmia was found in two patients, and mortality occurred in one patient.Five patients suffered multiple complications.Univariable analysis showed that postoperative complications were associated with body mass index, American Society of Anesthesiologists(ASA) score, intraoperative blood transfusion, and pancreatic texture(P<0.05). In multivariable logistic regression, ASA grade Ⅲ, intraoperative blood transfusion, and pancreatic softness were independently related to postoperative complications after LPD(P<0.05). Conclusions: Clavien-Dindo score is feasible to be applied in management of patients with LPD.ASA score, texture of pancreas, and intraoperative blood transfusion were independently associated with postoperative complications.

[Mediating effect of hemoglobin and hematocrit on the association between alcohol consumption and blood pressure among middle-aged and elderly male residents in Guangzhou]

Objective: To explore the mediating effect of hemoglobin (Hb) and hematocrit (HCT) on the association between alcohol consumption and blood pressure, and provide evidence for the prevention and control of alcohol-attributed hypertension. Methods: 1 091 male (age >50 years old) participants with drinking habit were selected from the Guangzhou biobank cohort study (GBCS). Mediation analysis was used to evaluate the mediating effect of Hb and HCT on the association of alcohol consumption (unit/day) with systolic blood pressure (SBP), diastolic blood pressure(DBP), pulse pressure(PP) and mean arterial pressure (MAP). Results: After adjusting for age, body mass index, education level, personal annual income, smoking, occupation and physical activity, the associations of alcohol consumption with SBP, DBP, PP and MAP were partly mediated by Hb, the proportion of mediating effect was 11.8% (95%CI 4.8%-24.7%), 15.3% (95%CI 6.5%-32.0%), 8.4% (95%CI 2.2%-22.5%) and 13.5% (95%CI 5.9%-27.5%), respectively. The associations of alcohol consumption with SBP, DBP, and MAP were also partly mediated by HCT, the proportion of mediating effect was 6.3% (95%CI 1.0%-16.0%), 8.7% (95%CI 1.4%-21.4%), and 7.5% (95%CI 1.0%-18.6%), respectively. Conclusion: There is a significant mediating effect of Hb and HCT on the association between alcohol consumption and blood pressure. Besides efforts on alcohol control, the potential effects of alcohol-induced increase on Hb and HCT, which might also increase the blood pressure, need to be considered to achieve optimal monitoring and prevention of alcohol-related hypertension.

A novel mutation +5904 C>T of RUNX1 site in the erythroid cell-specific regulatory element decreases the ABO antigen expression in Chinese population

BACKGROUND

An erythroid cell-specific regulatory element (+5·8-kb) in the first intron of ABO is responsible for the antigen differential expression and the regulatory activity of the element was affected by the nucleotide mutation in the +5·8-kb region. Currently, many individuals with ABO subgroups were found in the Chinese population, but there was little information about the function of +5·8-kb region in these individuals. Here, we studied the mechanism of the mutation in the +5·8-kb region responsible for reducing of antigen expression in 30 ABO subtype Chinese individuals without mutation in the coding region or splicing site.

MATERIALS AND METHODS

The nucleotide sequence of the partial intron 1 covering the +5·8-kb site was amplified and directly sequenced. The haplotype with the novel mutation was obtained by the TOPO TA cloning. Both of the ABO promoter and the +5·8 kb regulatory element were subcloned into the basic luciferase reporter plasmid using the double endonuclease digestion. The promoter activity was examined by the dual-luciferase report vector with K562 cells.

RESULTS

A novel nucleotide substitution +5904 C>T located at RUNX1-binding site in the +5·8 kb site was identified from three individuals with B subtypes. +5890 T>G were found in three Bel and one Ael phenotypes. Cotransfection and luciferase assays demonstrated that the +5904 C>T could obviously reduce activity of the +5·8 kb site.

CONCLUSION

The study suggested that the transcriptional activity of the +5·8 kb site could be downregulated by the single point mutation of RUNX1 motif, leading to reduction in A or B antigen expression.

Influence of electrical boundary conditions on profiles of acoustic field and electric potential of shear-horizontal acoustic waves in potassium niobate plates

The profiles of an acoustic field and electric potential of the forward and backward shear-horizontal (SH) acoustic waves of a higher order propagating in X-Y potassium niobate plate have been theoretically investigated. It has been shown that by changing electrical boundary conditions on a surface of piezoelectric plates, it is possible to change the distributions of an acoustic field and electric potential of the forward and backward acoustic waves. The dependencies of the distribution of a mechanical displacement and electrical potential over the plate thickness for electrically open and electrically shorted plates have been plotted. The influence of a layer with arbitrary conductivity placed on a one or on the both plate surfaces on the profiles under study, phase and group velocities of the forward and backward acoustic waves in X-Y potassium niobate has been also investigated. The obtained results can be useful for development of the method for control of a particle or electrical charge movement inside the piezoelectric plates, as well a sensor for definition of the thin film conductivity.

Mechanisms of resistance to three mite growth inhibitors of Tetranychus urticae in hops

Mite growth inhibitors (MGIs), such as etoxazole and hexythiazox, are valuable IPM tools for Tetranychus urticae control in hops due to their unique mode of action and selectivity. Hence, it is necessary to standardize bioassay methods to evaluate the efficacy of MGIs, monitor resistance, and identify mechanisms underlying MGI resistance in the field. Here, we developed a three-tiered approach for evaluating ovicidal toxicity of MGIs to T. urticae, which simulated different MGI exposure scenarios in the field. The most effective bioassay method was direct exposure of T. urticae eggs to MGIs. With this method, four field-collected T. urticae populations showed low-to-moderate resistance to MGIs. Cross-resistance among MGIs and from MGIs to bifenazate and bifenthrin was detected. Besides target site insensitivity, enhanced cytochrome P450 and esterase activities also contribute to the MGI resistance in hop yard-collected T. urticae populations. Low-to-moderate MGI resistance in T. urticae populations may be mediated by multiple mechanisms. Positive selection pressure on the I1017F mutation is moderate in field-collected T. urticae populations. Further studies are required to identify metabolic detoxification genes that confer resistance to MGIs for precise resistance monitoring.

Adjustment of Dry Weight in Hemodialysis Patients using Intradialytic Continuous Multifrequency Bioimpedance of the Calf

Background

Current concepts of dry weight (DW) prescription are largely based on clinical symptoms because of the difficulty in assessing extracellular fluid volume (ECV) during dialysis. Intradialytic changes in ECV can be recorded as changes in extracellular resistance [Re] by continuous regional calf multifrequency bioimpedance spectroscopy (BIS). We hypothesized that relative changes in calf Re (Re at time ‘0’ over Re at time ‘t’ [Re-0/Re-t]) will become very small when ECV is reduced towards normal and individual dry weight is reached.

Method

Intradialytic continuous calf BIS was recorded repeatedly in 15 hemodialysis (HD) patients. The first measurement was performed at the prevailing clinical dry weight (CDW). Next measurements were made after post-HD body weight was gradually decreased by 0.2–0.3 kg per treatment. This procedure was iterated over several subsequent treatments until a treatment was observed where changes in Re-0/Re-t were < 1%. The weight at the end of this treatment was defined as “achieved dry weight (ADW)”. Each Re-0/Re-t curve was fitted using a Matlab program (curve fitting toolbox) to obtain the exact weight at 20 min after beginning of the flattening of the Re-0/Re-t slope (‘dry’ weight estimated from BIS, DW-BIS).

Results

Both mean ADW (80.5 ± 34.1 kg) and mean DW-BIS (80.6 ± 34.1) were significantly lower than CDW (81.4 ± 32.0 kg, p < 0.001), but there was no difference between ADW and DW-BIS. However, the average weight reduction from CDW to ADW (0.80 ± 0.15 kg) was significantly higher than from CDW to DW-BIS (0.66 ± 0.14 kg, p < 0.001, paired t-test). When ADW was achieved, pre-dialysis systolic blood pressure (SBP) was lower than at CDW (139.3 ± 32.5 mmHg, vs. 129.4 ± 33 mmHg, p < 0.05), post-HD SBP did not differ. The incidence of clinical symptoms of underhydration was similar at CDW (15 %) and DW-BIS (15 %), but higher at ADW (46 %).

Conclusion

Intradialytic continuous calf BIS allows the assessment of changes in extracellular calf resistance as an indicator of changes in extracellular fluid volume. Recording of a continuous Re-0/Re-t slope during dialysis appears to be a promising new tool for the prediction of dry weight in hemodialysis patients.

[Effects of non-muscle myosin ⅡA silenced bone marrow mesenchymal stem cells on lung damage of rats at early stage of smoke inhalation injury]

Objective: To investigate the effects of non-muscle myosin ⅡA (NMⅡA) silenced bone marrow mesenchymal stem cells (BMSCs) on the lung damage of rats at early stage of smoke inhalation injury. Methods: Forty Sprague-Dawley rats were divided into control, simple injury, NMⅡA-BMSCs, and BMSCs groups according to the completely random method, with 10 rats in each group. Rats in control group inhaled air normally, while rats in the latter 3 groups inhaled smoke to reproduce model of smoke inhalation injury. At 30 min post injury, rats in simple injury group were injected with 1 mL normal saline via caudal vein, and rats in group BMSCs were injected with 1 mL the fifth passage of BMSCs (1×10(7)/mL), and rats in group NMⅡA-BMSCs were injected with 1 mL NMⅡA silenced BMSCs (1×10(7)/mL). At post injury hour (PIH) 24, abdominal aorta blood and right lung of rats in each group were harvested, and then arterial partial pressure of oxygen (PaO(2)), arterial partial pressure of carbon dioxide (PaCO(2)), and pH value were detected by blood gas analyzer. Ratio of wet to dry weight of lung was determined by dry-wet weight method. Pathological changes of lung were observed with HE staining. Bronchoalveolar lavage fluid (BALF) were collected, and then tumor necrotic factor-α (TNF-α) and interleukin-10 (IL-10) content of BALF was determined by enzyme-linked immunosorbent assay. Data were processed with one-way analysis of variance, Kruskal-Wallis H test, and least-significant difference test. Results: (1) At PIH 24, compared with those in control group, PaO(2) values of rats in simple injury, BMSCs, and NMⅡA-BMSCs groups were obviously decreased (with P values below 0.05), and PaCO(2) values were obviously increased (with P values below 0.05). Compared with those in simple injury group, PaO(2) values of rats in groups NMⅡA-BMSCs and BMSCs were obviously increased (with P values below 0.05), while PaCO(2) values were obviously decreased (with P values below 0.05). PaO(2) value of rats in group NMⅡA-BMSCs was obviously increased as compared with that in group BMSCs (P<0.05). The pH value of arterial blood of rats in simple injury group was obviously lower than that in control group (P<0.05). (2) At PIH 24, ratios of wet to dry weight of lung of rats in control, simple injury, BMSCs, and NMⅡA-BMSCs groups were 4.36±0.15, 7.79±0.42, 5.77±0.18, and 5.11±0.20, respectively. Compared with that in control group, ratio of wet to dry weight of lung of rats was obviously increased in the other 3 groups (with P values below 0.05). Compared with that in simple injury group, ratio of wet to dry weight of lung of rats was obviously decreased in groups BMSCs and NMⅡA-BMSCs (with P values below 0.05). Compared with that in group BMSCs, ratio of wet to dry weight of lung of rats in group NMⅡA-BMSCs was obviously decreased (P<0.05). (3) At PIH 24, alveolar structure of rats in control group was complete without abnormality. Compared with those in simple injury group, lung injury and infiltration of inflammatory cells of rats in groups BMSCs and NMⅡA-BMSCs were obviously alleviated, and alveolar structure was relatively complete with no thickening of alveolar wall. (4) At PIH 24, compared with that in control group, TNF-α content of BALF of rats in simple injury and BMSCs groups was obviously increased (with P values below 0.05). Compared with that in simple injury group, TNF-α content of BALF in groups BMSCs and NMⅡA-BMSCs was obviously decreased (with P values below 0.05). Compared with that in control group, IL-10 content of BALF in simple injury, NMⅡA-BMSCs and BMSCs groups were obviously increased (with P values below 0.05). Compared with that in simple injury group, IL-10 content of BALF in groups BMSCs and NMⅡA-BMSCs was obviously increased (with P values below 0.05). Compared with that in group BMSCs, IL-10 content of BALF in group NMⅡA-BMSCs was obviously increased (P<0.05). Conclusions: NMⅡA silenced BMSCs can alleviate lung damage of rats at early stage of smoke inhalation injury, showing better effectiveness than using BMSCs only.

Identification of the novel HLA-C*07:530 allele by polymerase chain reaction sequence-based typing

HLA-C*07:530 differs from HLA-C*07:02:01 by a single nucleotide at position 363G>C.

Recyclable heat-resisting polymer poly(ether azaindole ketone)-H+via hydrogen bonding crosslinking

A novel recyclable hydrogen bonding crosslinked polymer PEAINKH⁺ was prepared, which possesses outstanding thermal stability.

[Association between body weight change during early and middle adulthood and the risk of type 2 diabetes in middle aged and elderly population]

Objective: To examine the association between weight changes during early and middle adulthood and the risk of type 2 diabetes mellitus in middle aged and elderly population. Methods: Based on the Guangzhou Biobank Cohort Study (GBCS), 28 736 residents aged ≥50 years were included in Guangzhou. Multivariate logistic regression was used to analyze the association between body weight changes during early or middle adulthood and age when the heaviest weight reaching the threshold on the risk of type 2 diabetes mellitus in middle age or elderly population. Adjustments on age, smoking, alcohol consumption, physical activity, education level, occupation, district of residence and body mass index etc., were made. Results: The mean age was 64.3 (standard deviation=6.7) years in men and 61.0 (standard deviation=7.0) years in women, with the prevalence rates of diabetes as 13.1% and 13.7% in men and women, respectively. Compared to those with stable body weight, the risk of diabetes increased with weight gain during early and middle adulthood in both men and women (both P values for trend<0.01). Participants who gained more than 20 kg during early and middle adulthood were associated with the highest risk of diabetes in men (OR=2.83, 95%CI:1.99-4.02) and women (OR=3.13, 95%CI: 2.47-3.96). Compared to those who reached the highest weight at age 20, those who reaching the highest weight at 40 to 49 years were associated with the highest risk of diabetes, with OR being 5.32 (95%CI: 1.92-14.8) in men and 3.41 (95%CI: 2.49-4.67) in women, respectively. Weight loss in adulthood was associated with self-reported but not newly diagnosed diabetic cases in both middle and older aged men and women. Conclusion: Weight gain during early and middle adulthood may increase the risk of diabetes in middle and older aged population. The detrimental effect of obesity on diabetes might become significantly visible in the next decades.

Inhibition of JAK2 Signaling Alleviates Hyperlipidemia-Intensified Caerulin-Induced Acute Pancreatitis In Vivo

RATIONALE

Studies have implied the positive association of JAK2/STAT3 signaling with the onset and severity of acute pancreatitis (AP). However, definitive functional study of JAK2/STAT3 signaling in the pathogenesis of acute pancreatitis in vivo is missing and its potential as a therapeutic target and the underlying mechanisms remain to be determined.

OBJECTIVES

The aim of this study was to explore the role of JAK2/STAT3 signaling in the pathogenesis of hyperlipidemia-intensified caerulin-induced AP and its potential as a therapeutic target.

METHODS AND RESULTS

Using the caerulin-induced acute pancreatitis rat model, we showed that JAK2/STAT3 signaling was activated in pancreas and systemic inflammation was increased during AP. Pharmacological suppression of JAK2 by its inhibitor AG490 robustly protected against tissue damage, attenuated JAK2/STAT3 signaling and inflammatory responses. Local pancreatic tissue damage and phosphor- JAK2 in the pancreatic tissue were enhanced in animals fed with high fat diet compared to chow-diet fed animals. Interestingly, JAK2 inhibitor AG490 significantly inhibited pancreas necrosis and systemic inflammation in animals fed with high fat or chow-diet, but did not affect STAT3 signaling.

CONCLUSION

These results establish that JAK2 activation plays a significant role in the pathogenesis of caerulin-induced AP in animals on both chow and high-fat diets by regulating necrosis and systemic inflammation. Thus, our results not only clarify novel signaling mechanisms in AP but also suggest that JAK2 might constitute a target in the management of hyperlipidemia-intensified caerulin-induced AP.

[Acute stress response after critical burn]

The stress response is a preexisting and adaptive behavioral mode of all living beings, which may bring deleterious consequences of dysfunction or failure of tissue and organ. This article aims to elaborate theories of stress response, summarize the manifestation and mechanism of acute stress response in critically burned patients, and help to improve clinical curative efficacy and prognosis of these patients by physiological, psychological and pharmacological methods.

Intracellular mature IL-37 suppresses tumor metastasis via inhibiting Rac1 activation

IL-37, a newly found anti-inflammatory cytokine of the IL-1 family, has both extracellular and intracellular functions. Accumulating evidences indicate that it is also involved in tumor progression. However, the mechanism and its intracellular target are unclear. In this study, clinical data from 84 patients showed that loss or reduced expression of IL-37 in lung adenocarcinoma tissues was significantly associated with tumor metastasis. We further provided evidence that IL-37 inhibited effectively tumor metastasis in vitro and in vivo. Moreover, we uncovered a novel mechanism by which IL-37 suppressed tumor cell migration via its intracellular mature form (amino acids 46-218). Intracellular mature form of IL-37, but not its extracellular form, markedly inhibited migration of multiple kinds of tumor cells through inhibiting Rac1 activation. Mechanistically, intracellular mature IL-37 directly bound to the CAAX motif in the C-terminal hypervariable region of Rac1, and then inhibited Rac1 membrane translocation and subsequent downstream signaling. Our research identifies intracellular mature IL-37 as a novel endogenous inhibitor of Rac1. Given the crucial roles of Rac1 in tumor angiogenesis and metastasis, intracellular mature IL-37 might serve as a potential strategy for the control of Rac1 activity and tumor progression.

Absence of juvenile hormone signalling regulates the dynamic expression profiles of nutritional metabolism genes during diapause preparation in the cabbage beetle Colaphellus bowringi

Temperate insects have evolved diapause, a period of programmed developmental arrest during specific life stages, to survive unfavourable conditions. During the diapause preparation phase (DPP), diapause-destined individuals generally store large amounts of fat by regulating nutrition distribution for the energy requirement during diapause maintenance and postdiapause development. Although nutritional patterns during the DPP have been investigated at physiological and biochemical levels in many insects, it remains largely unknown how nutritional metabolism is regulated during the DPP at molecular levels. We used RNA sequencing to compare gene expression profiles of adult female cabbage beetles Colaphellus bowringi during the preoviposition phase (POP) and the DPP. Most differentially expressed genes were involved in specific metabolic pathways during the DPP. Genes related to lipid and carbohydrate metabolic pathways were clearly highly expressed during the DPP, whereas genes related to protein metabolic pathways were highly expressed during the POP. Hormone challenge and RNA interference experiments revealed that juvenile hormone via its nuclear receptor methoprene-tolerant mediated the expression of genes associated with nutritional metabolism during the DPP. This work not only sheds light on the mechanisms of diapause preparation, but also provides new insights into the molecular basis of environmental plasticity in insects.

Adiposity and incident diabetes within 4 years of follow-up: the Guangzhou Biobank Cohort Study

AIM

Whether different adiposity measures predict incident diabetes differentially in general Chinese populations is unclear. We investigated this in Chinese people aged 50+ years in the Guangzhou Biobank Cohort Study.

METHODS

Waist circumference and BMI were measured at baseline, and fasting glucose was measured at both baseline and follow-up examinations. Incident diabetes was defined as fasting glucose ≥ 7.0 mmol/l, glucose after 2-h oral glucose tolerance test ≥ 11.1 mmol/l, and/or self-reported physician-diagnosed diabetes during the follow-up period.

RESULTS

Of 15 752 people without diabetes at baseline from 2003 to 2008, 1779 (11.3%) developed incident diabetes during the follow-up from 2008 to 2012 (mean = 3.6 years, sd = 1.0). After mutually adjusting each other and adjusting for other potential confounders, waist circumference showed a higher predictive value than BMI. The odds ratio (OR) (95% confidence interval (CI) was 1.50 (95% CI 1.37-1.64) for a 1 sd increment in waist circumference and 1.21 (95% CI 1.11-1.33), for a 1 sd increment in BMI. Similarly, after mutual adjustment, abdominal obesity was associated with an almost twofold odds of incident diabetes (OR 1.93, 95% CI 1.71-2.17), which was higher than that for general obesity (OR 1.76, 95% CI 1.50-2.06). The area under receiver operating characteristic curve (AUC) for waist circumference was higher than that for BMI [AUC = 0.676 (95% CI 0.660-0.686) vs. 0.665 (95% CI 0.651-0.678), P = 0.02].

CONCLUSION

Abdominal obesity predicted incident diabetes in older people better than general obesity. Our findings may be an early warning signal for local government or public health practitioners to develop and investigate more effective intervention programmes for diabetes, and should also be disseminated to the public to pay more attention to this important public health issue.

Intestinal probiotics in relieving clinical symptoms of severe hand, foot, and mouth disease and potential mechanism analysis

OBJECTIVE

In this prospective cohort study, the efficacy and action mechanism of an intestinal probiotic formulation, Golden Bifid, in severe hand, foot, and mouth disease (HFMD) were determined in 63 consecutively admitted patients successfully treated in the Pediatrics Emergency Department of our hospital.

PATIENTS AND METHODS

All patients had a persistent fever; 43 patients had rashes on hands, feet, crissum, and hips; and 45 patients had neurological signs and symptoms. Patients were treated with standard supportive therapy along with ventilator-assisted respiration combined with bedside hemofiltration for removal of circulatory toxins and to achieve acid-base equilibrium and electrolyte stability. Golden Bifid was orally administered for 2 weeks, and vaccination was performed after patients were in stable condition. Additional supportive nursing care was also provided. Patients were categorized into the effective treatment (n = 40) and ineffective treatment (n = 23) groups.

RESULTS

Serum levels of proinflammatory factors [interleukin (IL)-1β, IL-6, tumor necrosis factor-α, and interferon-γ] were significantly decreased and those of anti-inflammatory factors (IL-13, IL-4, and IL-10) were significantly increased after treatment in the effective treatment group. In contrast, in the ineffective treatment group, serum proinflammatory factor levels were significantly increased and serum anti-inflammatory factor levels were significantly decreased. Between-group difference was significant. After treatment, serum D-lactic acid, diamine oxidase, and endotoxin levels were significantly decreased in the effective group and significantly increased in the ineffective group by intra- and inter-group comparisons.

CONCLUSIONS

Intestinal probiotics were effective in relieving clinical symptoms of severe HFMD, maintaining intestinal immunity and anti-inflammatory responses, and enhancing intestinal barrier function, with better safety and efficacy, which should be further evaluated for more extensive clinical applications.

[Clinical application of three-dimensional O-arm navigation system in treating patients with dystrophic scoliosis secondary to neurofibromatosis type Ⅰ]

Objective: To investigate the clinical outcomes and the accuracy of O-arm-navigation system assisted pedicle screw insertion in dystrophic scoliosis secondary to neurofibromatosis type Ⅰ(NF-1). Methods: A retrospective study was conducted in 41 patients with dystrophic NF-1-associated thoracic scoliosis who were surgically treated at Department of Orthopaedics, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School between June 2012 and October 2014 with more than 18 months follow-up. The patients were then divided into two groups: 18 patients were under the assistance of O-arm-navigation-based pedicle screw insertion (O-arm group) and the remaining 23 patients' pedicle screws insertion were conducted by free-hand (free-hand group). The X-ray and CT were analyzed to investigate the correction rate and safety of pedicle insertion. t-test was used to analyze measurement data and χ(2) test was used to analyze accuracy of screw insertion between the two groups. Results: The mean coronal Cobb angle was 63.2°±8.7° in the O-arm group and 66.9°±7.4° in the free-hand group (P>0.05), which was then corrected into 23.1°±6.8° and 30.2°±7.6°(t=2.231, P=0.031) after surgery respectively.Operation time was (265.0±70.3)minutes and estimated blood loss was (1 024±465)ml in the O-arm group. Operation time and estimated blood loss was (243.0±49.6)minutes and (1 228±521)ml respectively in the free-hand group, which had no significant difference between the two groups. However, the implant density was higher in the O-arm group than that in the free-hand group ((64.1±10.8)% vs.(44.3±15.3)%)(t=4.652, P=0.000). The O-arm group comprised 122 screws, of which 72.9% were excellent, 22.1% were good and 4.9% were bad. The free-hand group comprised 136 screws and 48.5% of them were excellent, 33.8% were good and 17.6% were bad.Accuracy of pedicle screw insertion was higher in the O-arm group than that in the free-hand group(χ(2)=10.140, P<0.05). By June 2016, the average follow-up period was (20.9±3.4)months(ranging from18 to 26 months), including (20.3±3.1)months in the O-arm group and (21.4±5.5)months in the free-hand group. At last follow-up point, coronal correction loss was significantly higher in the free-hand group than that in the O-arm group (6.3°±2.6° vs. 4.4°±1.6°)(t=2.719, P=0.009). Conclusions: Compared with free-hand technique, O-arm-navigation technique could enhance accuracy of pedicle insertion and implant density of dystrophic region in dystrophic NF-1-associated scoliosis patients, which result in a better correction rate and less correction loss. Besides, the advantage of O-arm-navigation do not increase operative time and estimate blood loss.