梁苹茂治疗痤疮经验

痤疮是临床常见疾病,梁苹茂教授根据多年临床经验,采用中药汤剂内服辨证治疗,每获良效。     

Analysis of the tumor microenvironment and mutation burden identifies prognostic features in thymic epithelial tumors

Thymic epithelial tumors (TETs) are one of the rarest adult malignancies in the anterior mediastinum. Thymic carcinomas (TCs) are less prevalent among TETs, but they are more clinically aggressive. Immunotherapy has emerged as a promising therapeutic approach for refractory TETs, even though chemotherapy remains the conventional treatment for the advanced disease. However, limited attention has been paid to the features of the tumor microenvironment (TME) which might provide clinically relevant information and guide treatment regimen design. Especially, to date, there have been only a few studies focusing on the differences between the TME and genomic features preserved by TETs and TCs. We analyzed the TME and genomic characteristics of TETs using RNA sequencing and whole-exome sequencing, finding that distinct characteristics of TME in different pathogenic subtypes of TETs. According to those findings, we found that thymic carcinomas had significantly lower expression of HMGB1, a pro-inflammatory cytokine-related gene, than thymomas, and low HMGB1 expression was linked to a poor prognosis. Additionally, higher mutation burdens were significantly associated with the later stage and more advanced pathological types. Thymoma patients with lower mutation burdens tended to relapse within 3 years. In summary, different characteristics of TME and genomic features between thymoma and thymic carcinoma were associated with clinical outcomes of TETs and presented promisingly predictive value for efficacy and toxicity of immunotherapy.     

Wear Mechanisms and Notch Formation of Whisker-Reinforced Alumina and Sialon Ceramic Tools during High-Speed Turning of Inconel 718

Nickel-based alloys, referred to as the most difficult-to-cut materials, pose a great challenge to cutting tool materials due to their excellent high-temperature properties. Ceramic tools have the potential to improve the machinability of these alloys with the advance of toughening mechanisms. In this work, the wear mechanisms of SiC whisker-reinforced alumina and Sialon when high-speed turning Inconel 718 alloy under dry cutting condition were investigated. The results showed that the wear process of Al₂O₃-SiC_w WG300 was dominated by the notch wear, while the flank wear characterized by ridges and grooves perpendicular to the cutting edge was the main wear mode for Sialon SX9. A Ti−enriched belt was found at the boundary of the wear band for both ceramic tools. The SEM inspection and EDS analysis for this belt suggested the trace of diffusion between the workpiece material and tool matrix. As for the notch formation, the periodically adhesive action of the workpiece material at the depth-of-cut line combined with the thermal shock resistance of ceramic tools were considered to account for its formation. In addition, the oxidation of the workpiece material at the depth-of-cut line played a positive role in reducing the adhesive affinity and consequent notch wear.     

Numerical Investigation of the Influence of Ultimate-Strength Heterogeneity on Crack Propagation and Fracture Toughness in Welded Joints

The mechanical properties of dissimilar metal-welded joint materials are heterogeneous, which is an obstacle to the safety evaluation of key welded structures. The variation of stress–strain conditions at the crack tip caused by mismatch of material mechanical properties in dissimilar metal-welded joints is an important factor affecting crack propagation behavior. To understand the influence of uneven distribution of ultimate strength of the base metal and the welded metal on the crack propagation path, fracture toughness, as well as the mechanical field at the crack tip in the small-scale yield range, the user-defined field variable subroutine method is used to express continuous variation characteristics of welded joint ultimate strength in finite element software. In addition, the J-integral during crack propagation is calculated, and the effect of the ultimate strength on the J-integral and the stress field at the crack tip are analyzed. The results show that as the crack propagation direction is perpendicular to the direction of ultimate strength, the gradient of ultimate strength increases from |G_y|= 50 to |G_y|= 100 MPa/mm, the crack deflection angle increases by 0.018%, and the crack length increases by 1.46%. The fracture toughness of the material decreased slightly during crack propagation. Under the condition that the crack propagation direction is the same as the direction of ultimate strength, the crack propagation path is a straight line. As the gradient of ultimate strength increases from G_x = 50 to G_x = 100 MPa/mm, the crack propagation length decreases by 5.17%, and the slope of fracture toughness curve increases by 51.63%. On the contrary, as the crack propagates to the low ultimate strength side, the crack propagation resistance decreases, the ultimate strength gradient increases from G_x = −100 to G_x = −50 MPa/mm, and the slope of the fracture toughness curve decreases by 51.01%. It is suggested to consider the relationship between crack growth behavior and ultimate strength when designing and evaluating the structural integrity of cracks at the material interface of dissimilar metal-welded joints.     

Exposure to Per- and Polyfluoroalkyl Substances and Mortality in U.S. Adults: A Population-Based Cohort Study

Background: Per- and polyfluoroalkyl substances (PFAS) are widespread environmental contaminants associated with diseases such as cancer and dyslipidemia. However, few studies have investigated the association between PFAS mixture exposure and mortality in general populations.Objectives: This study aimed to explore the association between PFAS mixture, perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS) and mortality in U.S. adults by a nationally representative cohort.Methods: Adults ≥18 years of age who were enrolled in the National Health and Nutrition Examination Survey (NHANES) (1999–2014) were included in our study. Baseline serum concentrations of seven PFAS were measured and individuals were followed up to 31 December 2015. Hazard ratios (HRs) and confidence intervals (CIs) were estimated using Cox proportional hazards models. Association between PFAS mixture exposure and mortality was analyzed using the k-means method by clustering PFAS mixtures into subgroups. Association between PFOA/PFOS exposure and mortality was subsequently analyzed in both continuous and categorical models.Results: During the follow-up period, 1,251 participants died. In the mixture analysis, the k-means algorithm clustered participants into low-, medium-, and high-exposure groups. Compared with the low-exposure group, participants in the high-exposure group showed significantly higher risks for all-cause mortality (HR=1.38; 95% CI: 1.07, 1.80), heart disease mortality (HR=1.58; 95% CI: 1.05, 2.51), and cancer mortality (HR=1.70; 95% CI: 1.08, 2.84). In single PFAS analysis, PFOS was found to be positively associated with all-cause mortality (third vs. first tertile HR=1.57; 95% CI: 1.22, 2.07), heart disease mortality (third vs. first tertile HR=1.65; 95% CI: 1.09, 2.57), and cancer mortality (third vs. first tertile HR=1.75; 95% CI: 1.10, 2.83), whereas PFOA exposure had no significant association with mortality. Assuming the observed association is causal, the number of deaths associated with PFOS exposure (≥17.1 vs. <7.9 ng/mL) was ∼382,000 (95% CI: 176,000, 588,000) annually between 1999 and 2015, and it decreased to 69,000 (95% CI: 28,000, 119,000) annually between 2015 and 2018. The association between PFOS and mortality was stronger among women and people without diabetes.Discussion: We observed a positive association between PFAS mixture exposure and mortality among U.S. adults. Limitations of this study include the potential for unmeasured confounding, selection bias, a relatively small number of deaths, and only measuring PFAS at one point in time. Further studies with serial measures of PFAS concentrations and longer follow-ups are necessary to elucidate the association between PFAS and mortality from specific causes. https://doi.org/10.1289/EHP10393     

辛伐他汀治疗无症状性颈动脉粥样硬化的疗效观察

目的采用颈动脉超声观察辛伐他汀治疗无症状性颈动脉粥样硬化的疗效。方法对参加我院健康体检时经彩超检查发现有颈动脉斑块的观察病例68例，每晚服用辛伐他汀，连续4月，观察颈动脉斑块的面积变化以及血脂的动态改变。结果68例观察者共发现斑块112个，服药4月后发现低回声斑块面积消退幅度达32％，混合性斑块达25％，高回声斑块只有9％，平均消退幅度22％，除高回声斑块外，其他均有明显统计学意义（P〈0．05）。患者的TC下降与治疗前比较有显著差异（P〈0．01），TG、LDL的下降与治疗前比较有明显差异（P〈0．05），HDL有所升高，但无统计学意义。结论通过观察服用辛伐他汀4月后斑块的面积变化以及血脂的改变结果表明，坚持服用他汀类药物，可以达到稳定与消退斑块的作用。     

Extremely high serum CA19-9 level along with elevated D-dimer in assisting detection of ruptured ovarian endometriosis

BackgroundTo clarify clinical importance of serum CA19-9, CA-125, and plasma D-dimer (D-D) levels in detecting spontaneously ruptured ovarian endometriosis (OE).Materials and MethodsWe retrospectively examined 173 patients with endometriosis out of 735 cases of OE between 2013 and 2019. Among these, 21 cases were diagnosed as “spontaneously ruptured” after surgery, while the remaining cases were unruptured. Venous blood was collected pre-operatively to detect CA19-9, CA-125, and D-D levels. A receiver operating characteristic curve analysis was applied to test clinical value of each marker.ResultsAmong the 21 patients with ruptured OE, 16 had a history of pelvic cysts, 19 claimed sudden onsets of lower abdominal pain, and fluid accumulation were detected in cul-de-sac in only six participants by ultrasound. For serological investigation, both CA19-9 and D-D were significantly elevated in the ruptured OE group (343.09 ± 367.67 U/ml vs. 36.84 ± 40.01 U/ml, 3.39 ± 4.90 mg/L vs. 0.43 ± 0.29 mg/L, both p < .0001). The area under curve (AUC) value for the combination of CA19-9 and D-D was 0.975 (95% CI, 0.939 − 0.993), with specificity of 96.69%, and sensitivity of 85.71%. The combination of CA-125, CA19-9 and D-D showed the highest AUC value that up to 0.976 (95% CI, 0.940–0.993), with sensitivity of 95.24%, and specificity of 87.50%.ConclusionThe combination of CA19-9 and D-D can be chosen as an effective and economical indicators to identify patients with spontaneously ruptured OE in pre-operation assessment. However, from the perspective of differential diagnosis, the combination of CA-125, CA19-9 and D-D is the best choice.

Key messages

• Taking into account the economic effect, the combination of CA19-9 and D-D can be chosen as an effective indicators to identify patients with spontaneously ruptured OE in pre-operation assessment.
• From the perspective of differential diagnosis, the combination of CA-125, CA19-9 and D-D is the best choice to identify patients with spontaneously ruptured OE.

     

趋化因子受体4及其配体12在下咽鳞状细胞癌中的表达及其临床意义

目的 探究趋化因子受体4(CXCR4)及趋化因子配体12(CXCL12)在下咽鳞状细胞癌(HSCC)中的表达及其临床意义。方法 以2017年1月—2022年11月收治的90例HSCC患者为研究对象,以HSCC患者手术切除的HSCC组织、癌旁组织为实验材料,采用免疫组织化学染色法检测HSCC组织和癌旁组织中CXCR4、CXCL12的表达情况;采用实时荧光定量PCR(qRT-PCR)法检测HSCC组织和癌旁组织中CXCR4 mRNA、CXCL12 mRNA水平;收集并记录HSCC患者临床病理特征,分析CXCR4、CXCL12表达水平与患者临床病理特征的关系;采用Pearson分析CXCR4与CXCL12水平相关性。结果 CXCR4在HSCC组织中的表达率为60.00%,明显高于癌旁组织的17.78%(P＜0.05);CXCL12在HSCC组织中的表达率为57.78%,明显高于癌旁组织的24.44%(P＜0.05)。HSCC组织中CXCR4、CXCL12水平均与淋巴结是否转移、TNM分期、分化程度有关(P＜0.05)。与癌旁组织相比较,HSCC组织CXCR4、CXCL12水平均显著升高(P＜0.05)。Pearson分析显示,HSCC患者中CXCR4水平与CXCL12水平呈正相关(r=0.538,P＜0.05)。结论 CXCR4、CXCL12在HSCC组织中呈高表达,两者与HSCC淋巴结转移、分化程度、TNM分期有关。     

Pre-attack and pre-episode symptoms in cluster headache: a multicenter cross-sectional study of 327 Chinese patients

BackgroundThere have been a few studies regarding the pre-attack symptoms (PAS) and pre-episode symptoms (PES) of cluster headache (CH), but none have been conducted in the Chinese population. The purpose of this study was to identify the prevalence and features of PAS and PES in Chinese patients, as well as to investigate their relationships with pertinent factors.MethodsThe study included patients who visited a tertiary headache center and nine other headache clinics between January 2019 and September 2021. A questionnaire was used to collect general data and information about PAS and PES.ResultsAmong the 327 patients who met the CH criteria (International Classification of Headache Disorders, 3rd edition), 269 (82.3%) patients experienced at least one PAS. The most common PAS were head and facial discomfort (74.4%). Multivariable logistic regression analysis depicted that the number of triggers (OR = 1.798, p = 0.001), and smoking history (OR = 2.067, p = 0.026) were correlated with increased odds of PAS. In total, 68 (20.8%) patients had PES. The most common symptoms were head and facial discomfort (23, 33.8%). Multivariable logistic regression analysis showed that the number of triggers were associated with increased odds of PES (OR = 1.372, p = 0.005).ConclusionsPAS are quite common in CH patients, demonstrating that CH attacks are not comprised of a pain phase alone; investigations of PAS and PES could help researchers better understand the pathophysiology of CH.