Risk factors and a simple scoring system for predicting bowel resection in infants with NEC

Background and aimsWe intended to investigate the predictors for bowel resection in infants with necrotizing enterocolitis (NEC). We further developed a scoring system for better predicting bowel resection.MethodsA total of 207 infants who underwent surgical management at Children's Hospital, Chongqing Medical University between April 2008 and December 2020 were identified for the following investigation. Bowel resection was reviewed among the infants who underwent the procedure. Potential parameters related to bowel resection were explored using a multiple logistic regression method, and then a scoring system was developed.ResultsAmong the 207 patients who underwent operative intervention that were reviewed, 109 infants underwent bowel resection. Multivariate logistic regression analysis showed that birth weight, hypotension, neutropenia, pneumoperitoneum, acidosis, and intestinal wall thickness were predictors related to the occurrence of bowel resection. A 6-point scoring system was further developed based on the obtained total coefficient, and the infants could be divided into low-, moderate- and high-risk groups according to cut values of 7 and 13.ConclusionThe results of this study demonstrated that severe NEC features and low birth weight were associated with bowel resection. The risk scoring system could accurately separate infants that were suspected to have bowel loss during surgery.     

GE宝石能谱CT故障分析

简要介绍了GE宝石能谱CT(Discovery CT750 HD)的技术特点,详细阐述了日常使用中出现的间歇性停机、无法进行Fastcal(快速空气校正)以及扫描中断和gantry(扫描架)自动复位3例故障的维修过程,为医院维修人员维修类似故障提供了参考。最后总结了医疗设备常见故障及主要故障原因,提出了快速排查CT故障的方法,并建议在日常使用中及时保养维护以降低设备故障率。     

Magnesium intake and primary liver cancer incidence and mortality in the Prostate,Lung, Colorectal and Ovarian Cancer Screening Trial

Epidemiological studies on magnesium intake and primary liver cancer (PLC) are scarce, and no prospective studies have examined the associations of magnesium intake with PLC incidence and mortality. We sought to clarify whether higher magnesium intake from diet and supplements was associated with lower risks of PLC incidence and mortality in the US population. Magnesium intake from diet and supplements was evaluated through a food frequency questionnaire in a cohort of 104,025 participants. Cox regression was employed to calculate hazard ratios for PLC incidence and competing risk regression was employed to calculate subdistribution hazard ratios for PLC mortality. Restricted cubic spline regression was employed to test nonlinearity. We documented 116 PLC cases during 1,193,513.5 person-years of follow-up and 100 PLC deaths during 1,198,021.3 person-years of follow-up. Total (diet + supplements) magnesium intake was found to be inversely associated with risks of PLC incidence (hazard ratio_{tertile 3 vs. 1}: 0.44; 95% confidence interval: 0.24, 0.80; p_trend = 0.0065) and mortality (subdistribution hazard ratio_{tertile 3 vs. 1}: 0.37; 95% confidence interval: 0.19, 0.71; p_trend = 0.0008). Similar results were obtained for dietary magnesium intake. Nonlinear inverse dose–response associations with PLC incidence and mortality were observed for both total and dietary magnesium intakes (all p_nonlinearity < 0.05). In summary, in the US population, a high magnesium intake is associated with decreased risks of PLC incidence and mortality in a nonlinear dose–response manner. These findings support that increasing the consumption of foods rich in magnesium may be beneficial in reducing PLC incidence and mortality.     

A highly tumor-targeted nanoparticle of podophyllotoxin penetrated tumor core and regressed multidrug resistant tumors

Podophyllotoxin (PPT) exhibited significant activity against P-glycoprotein mediated multidrug resistant (MDR) tumor cell lines; however, due to its poor solubility and high toxicity, PPT cannot be dosed systemically, preventing its clinical use for MDR cancer. We developed a nanoparticle dosage form of PPT by covalently conjugating PPT and polyethylene glycol (PEG) with acetylated carboxymethyl cellulose (CMC-Ac) using one-pot esterification chemistry. The polymer conjugates self-assembled into nanoparticles (NPs) of variable sizes (20–120 nm) depending on the PPT-to-PEG molar ratio (2–20). The conjugate with a low PPT/PEG molar ratio of 2 yielded NPs with a mean diameter of 20 nm and released PPT at ∼5%/day in serum, while conjugates with increased PPT/PEG ratios (5 and 20) produced bigger particles (30 nm and 120 nm respectively) that displayed slower drug release (∼2.5%/day and ∼1%/day respectively). The 20 nm particles exhibited 2- to 5-fold enhanced cell killing potency and 5- to 20-fold increased tumor delivery compared to the larger NPs. The biodistribution of the 20 nm PPT-NPs was highly selective to the tumor with 8-fold higher accumulation than all other examined tissues, while the larger PPT-NPs (30 and 120 nm) exhibited increased liver uptake. Within the tumor, >90% of the 20 nm PPT-NPs penetrated to the hypovascular core, while the larger particles were largely restricted in the hypervascular periphery. The 20 nm PPT-NPs displayed significantly improved efficacy against MDR tumors in mice compared to the larger PPT-NPs, native PPT and the standard taxane chemotherapies, with minimal toxicity.     

Helicobacter pylori and gastric hyperacidity,and their association with recurrent aphthous stomatitis

Helicobacter pylori is an established cause of gastric ulcers. Its role in causing recurrent aphthous stomatitis (RAS) remains controversial. Fifty-two RAS patients and 52 sex-matched controls were recruited in this case–control study. All subjects were screened for hematinic deficiencies and H. pylori. The latter was assessed quantitatively using the ¹⁴C-urea breath test. The χ² test and Wilcoxon signed ranks test were used to compare H. pylori and hematinic indices between cases and controls, while conditional logistic regression was used to assess the associations between the occurrence of RAS and independent factors. H. pylori was positive in 56.7% of the overall sample, with no difference between RAS patients (50.8%) and controls (49.2%) (P = 0.843). The median H. pylori and haematological indices values did not show any association with ulcer diameter, number, or frequency. Interestingly, gastric hyperacidity was significantly associated with RAS, and this association was independent from tobacco smoking, alcohol drinking, and H. pylori (odds ratio 14.99, 95% confidence interval 2.47–90.95; P = 0.003). This study found no association between H. pylori and RAS. The association between RAS and gastric hyperacidity suggests that gastric refluxate, not H. pylori, has an effect on the oral mucosa that favours an ulcerative change.     

Three-dimensional finite element analysis of intramedullary nail with different materials in the treatment of intertrochanteric fractures

Intramedullary nails are the common treatment options for femoral intertrochanteric fractures. However, aseptic loosening is considered to be one of the primary forms of failure that can be caused by the stress shielding between the bone and implants. The matching in mechanical properties of implant and bone is a key issue to prevent this failure. Polyetheretherketone (PEEK) and Function-graded (FG) materials are widely used in clinical because of their excellent mechanical properties. In this study, to investigate the biomechanical behaviors of intramedullary nails made of Ti-6Al-4V alloy, Stainless Steel (SS), PEEK and two FG materials, three-dimensional finite element models of intertrochanteric fracture femur with intramedullary nail were constructed with ABAQUS. The maximum von Mises stress on the femoral fracture surface fixed by PEEK intramedullary nail was the largest, followed by FG intramedullary nail, which help stimulate bone growth and subsequently reduce fracture healing time. Compared with traditional metal intramedullary nails, PEEK and FG implants might increase von Mises stress along the same path in the proximal femur. The results showed that PEEK and FG intramedullary nails obviously changed the stress distributions in the bone and reduced stress shielding. This finding indicated that PEEK and FG intramedullary nails have the potential to become alternatives to the conventional metal intramedullary nails.     

AAV-hVEGF165及AAV-TGFβ1转染兔椎间盘纤维环细胞的实验研究

目的探讨应用hVEGF165与TGFβ1基因逆转椎间盘退变的可行性。方法用分子克隆技术，从pcDNA3（＋）-AAV-hVEGF165获得AAV-hVEGF165cDNA，并克隆至AAV包装质粒pSNAV上，构建成pSNAV-hVEGF165的AAV重组质粒。经酶切及测序鉴定后，用脂质体介导pSNAV-hVEG165转染HEK293细胞和血管内皮细胞。荧光免疫组化方法检测hVEGF165蛋白，并用MTT法测定hVEGF165对血管内皮细胞增殖的影响。由本元正阳公司对pSNAV-hVEGF165进行AAV-hVEGF165包装。AAV-hVEGF165与AAV-TGFβ1联合转染退变的椎间盘纤维环细胞，Western blot检测hVEGF165与TGFβ1的表达以及纤维环细胞Ⅰ型胶原表达量的变化。结果经酶切鉴定及基因测序证实AAV包装质粒pSNAV-hVEGF165构建完成，荧光免疫组化显示hVEGF165蛋白表达，MTT法显示hVEGF165蛋白对血管内皮细胞增殖有促进作用。本元正阳公司包装出具有生物学功能的AAV-hVEGF165与AAV-hVEGF165构建成功。Western blot显示hVEGF165与TGFβ1在纤维环细胞中表达，AAV-hVEGF165与AAV-TGFβ1双基因联合转染的纤维环细胞Ⅰ型胶原表达量较hVEGF165与TGFβ1基因各自单独转染的细胞Ⅰ型胶原表达量明显增多。结论hVEGF165在体外能够协同TGFβ1促进退变纤维环细胞Ⅰ型胶原表达增加。     

GIEBEL系统在胫骨高位截骨术中的应用

[目的]探讨GIEBEL内固定系统固定的胫骨高位截骨术治疗膝内翻畸形的效果。[方法]对19例31膝,平均53.5岁的膝内翻患者进行评价。术前内翻畸形平均12.29°;膝关节症状以内侧间室疼痛为主。不伴有其他关节间室病变。对患膝进行精确的胫骨高位截骨术后应用GIEBEL系统内固定截骨端。手术前后拍摄双下肢负重位全长X线片,测量内翻角、机械轴线和解剖轴线。记录内外侧关节间隙距离的差值以及关节活动度。同时进行Lysholm评分。术后对患者进行主观满意度调查。[结果]对19例患者平均随访22个月。术后1例腓总神经一过性麻痹,2例切口脂肪液化延迟愈合。截骨处至术后12~16周均骨性愈合。测量矫正角度平均12.32°。3例患者残留膝前疼痛和关节绞锁症状。在随访期间膝内外侧间隙无明显退变加重。手术效果优良率为89.5%。84.2%患者对手术效果表示满意。除膝关节活动度外,Lysholm评分、内外关节间隙差以及内翻角度在手术前后差异均有统计学显著性差异。[结论]GIEBEL系统可有效地固定胫骨高位截骨术截骨端,对轻中度膝关节内翻畸形患者固定强度大,骨愈合率高。