国人头发直径的调查

作者用显微镜目镜测微尺对571人的4272根头发的直径进行了测量,发现其平均直径为84.01±23.07微米,从而确定了国人头发直径的正常参考值,为头发的病理生理及美容提供了参考。     

SIRT1 acts as a potential tumor suppressor in oral squamous cell carcinoma

Background

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor in oral cancer, however, the mechanism underlying OSCC tumorigenesis is unknown. SIRT1, has been considered a prominent tumor-suppressing/promoting gene in various solid tumors, although the precise role of SIRT1 in OSCC progression remains unknown.

壮族人群少精不育患者雌激素β受体基因RsaⅠ多态性研究

目的:探讨精子细胞雌激素受体β(ERβ)基因RsaⅠ位点多态性与少精症的关系。方法:应用等位基因特异性聚合酶链反应法(AS-PCR)和限制性内切酶消化法对105例壮族少精不育患者(观察组)及140例健康男性(对照组)精子ERβ基因RsaⅠ位点进行多态性研究。结果:观察组的突变型基因(AA+AG=70.5%)高于对照组(AA+AG=40.0%),差异有统计学意义(P<0.05)。结论:精子ERβ基因RsaⅠ位点多态性与男性少精症有着较为密切的联系,其具体作用机制有待进一步研究。     

Artificial Neural Network Modelling of the Effect of Vanadium Addition on the Tensile Properties and Microstructure of High-Strength Tempcore Rebars

In high-strength rebar, the various microstructures obtained by the Tempcore process and the addition of V have a complex effect on the strength improvement of rebar. This study investigated the mechanism of strengthening of high-strength Tempcore rebars upon the addition of vanadium through artificial neural network (ANN) modelling. Various V contents (0.005, 0.072 and 0.14 wt.%) were investigated, and a large amount of bainite and V(C, N) were precipitated in the core of the Tempcore rebar in the high-V specimens. In addition, as the V content increased, the number of these fine precipitates (10–30 nm) increased. The precipitation strengthening proposed by the Ashby–Orowan model is a major contributing factor to the yield-strength increase (35 MPa) of the Tempcore rebar containing 0.140 wt.% V. The ANN model was developed to predict the yield and tensile strengths of Tempcore rebar after the addition of various amounts of V and self-tempering at various temperatures, and it showed high reproducibility compared to the experimental values (R-square was 93% and the average relative error was 2.6%). ANN modelling revealed that the yield strength of the Tempcore rebar increased more significantly with increasing V content (0.01–0.2 wt.%.) at relatively high self-tempering temperatures (≥530 °C). These results provide guidelines for selecting the optimal V content and process conditions for manufacturing high-strength Tempcore rebars.     

pH and Redox-Dual Sensitive Chitosan Nanoparticles Having Methyl Ester and Disulfide Linkages for Drug Targeting against Cholangiocarcinoma Cells

The aim of this study is to prepare pH- and redox-sensitive nanoparticles for doxorubicin (DOX) delivery against DOX-resistant HuCC-T1 human cholangiocarcinoma (CCA) cells. For this purpose, L-histidine methyl ester (HIS) was attached to chitosan oligosaccharide (COS) via dithiodipropionic acid (abbreviated as ChitoHISss). DOX-incorporated nanoparticles of ChitoHISss conjugates were fabricated by a dialysis procedure. DOX-resistant HuCC-T1 cells were prepared by repetitive exposure of HuCC-T1 cells to DOX. ChitoHISss nanoparticles showed spherical morphology with a small diameter of less than 200 nm. The acid pH and glutathione (GSH) addition induced changes in the size distribution pattern of ChitoHISss nanoparticles from a narrow/monomodal distribution pattern to a wide/multimodal pattern and increased the fluorescence intensity of the nanoparticle solution. These results indicate that a physicochemical transition of nanoparticles can occur in an acidic pH or redox state. The more acidic the pH or the higher the GSH concentration the higher the drug release rate was, indicating that an acidic environment or higher redox states accelerated drug release from ChitoHISss nanoparticles. Whereas free DOX showed decreased anticancer activity at DOX-resistant HuCC-T1 cells, DOX-incorporated ChitoHISss nanoparticles showed dose-dependent anticancer activity. Intracellular delivery of DOX-incorporated ChitoHISss nanoparticles was relatively increased at an acidic pH and in the presence of GSH, indicating that DOX-incorporated ChitoHISss nanoparticles have superior acidic pH- and redox-sensitive behavior. In an in vivo tumor xenograft model, DOX-incorporated ChitoHISss nanoparticles were specifically delivered to tumor tissues and then efficiently inhibited tumor growth. We suggest that ChitoHISss nanoparticles are a promising candidate for treatment of CCA.     

Acute Tubular Necrosis Associated with Angiotensin Receptor-neprilysin Inhibitor

Sacubitril/valsartan, an angiotensin receptor-neprilysin inhibitor (ARNI), significantly reduces mortality and morbidity in patients with chronic heart failure with a reduced ejection fraction (HFrEF). However, a considerable number of patients treated with sacubitril/valsartan experience hypotension, oliguria, progressive azotemia, and renal failure as adverse events. These issues have been linked to significant gaps in the usage and dosing of guideline-directed medical therapy with ARNI in patients with HFrEF. We herein report a relevant case of pathologically proven acute tubular necrosis after the first dose of sacubitril/valsartan, highlighting the importance of optimizing the medical therapy in an outpatient with HFrEF.     

Initial Abdominal CT and Laboratory Findings Prior to Diagnosis of Crohn’s Disease in Children

PurposeTo identify initial abdominal computed tomography (CT) and laboratory findings prior to a diagnosis of Crohn’s disease (CD) in children.Materials and MethodsIn this retrospective study, patients (≤18 year-old) who were diagnosed with CD from 2004 to 2019 and had abdominal CT just prior to being diagnosed with CD were included in the CD group. Patients (≤18 years old) who were diagnosed with infectious enterocolitis from 2018 to 2019 and had undergone CT prior to being diagnosed with enterocolitis were included as a control group. We assessed the diagnostic performances of initial CT and laboratory findings for the diagnosis of CD using logistic regression and the area under the curve (AUC).ResultsIn total, 107 patients (50 CD patients, 57 control patients) were included, without an age difference between groups (median 13 years old vs. 11 years old, p=0.119). On univariate logistic regression analysis, multisegmental bowel involvement, mesenteric vessel engorgement, higher portal vein/aorta diameter ratio, longer liver longitudinal diameter, lower hemoglobin (≤12.5 g/dL), lower albumin (≤4 g/dL), and higher platelet (>320×10³/µL) levels were significant factors for CD. On multivariate analysis, multisegmental bowel involvement [odds ratio (OR) 111.6, 95% confidence interval (CI) 4.778–2605.925] and lower albumin levels (OR 0.9, 95% CI 0.891–0.993) were significant factors. When these two features were combined, the AUC value was 0.985 with a sensitivity of 96% and specificity of 100% for differentiating CD.ConclusionMultisegmental bowel involvement on CT and decreased albumin levels can help differentiate CD from infectious enterocolitis in children prior to a definite diagnosis of CD.     

Machine Learning Model for Classifying the Results of Fetal Cardiotocography Conducted in High-Risk Pregnancies

PurposeFetal well-being is usually assessed via fetal heart rate (FHR) monitoring during the antepartum period. However, the interpretation of FHR is a complex and subjective process with low reliability. This study developed a machine learning model that can classify fetal cardiotocography results as normal or abnormal.Materials and MethodsIn total, 17492 fetal cardiotocography results were obtained from Ajou University Hospital and 100 fetal cardiotocography results from Czech Technical University and University Hospital in Brno. Board-certified physicians then reviewed the fetal cardiotocography results and labeled 1456 of them as gold-standard; these results were used to train and validate the model. The remaining results were used to validate the clinical effectiveness of the model with the actual outcome.ResultsIn a test dataset, our model achieved an area under the receiver operating characteristic curve (AUROC) of 0.89 and area under the precision-recall curve (AUPRC) of 0.73 in an internal validation dataset. An average AUROC of 0.73 and average AUPRC of 0.40 were achieved in the external validation dataset. Fetus abnormality score, as calculated from the continuous fetal cardiotocography results, was significantly associated with actual clinical outcomes [intrauterine growth restriction: odds ratio, 3.626 (p=0.031); Apgar score 1 min: odds ratio, 9.523 (p<0.001), Apgar score 5 min: odds ratio, 11.49 (p=0.001), and fetal distress: odds ratio, 23.09 (p<0.001)].ConclusionThe machine learning model developed in this study showed precision in classifying FHR signals. This suggests that the model can be applied to medical devices as a screening tool for monitoring fetal status.     

Development of a Checklist for Predicting Suicidality Based on Risk and Protective Factors: The Gwangju Checklist for Evaluation of Suicidality

Objective The aim of the study was to develop a checklist for mental health clinicians to predict and manage suicidality. Methods A literature review of the risk and protective factors for suicide was conducted to develop a checklist for evaluating suicidality. Results The fixed risk factors included sex (male), age (older individuals), history of childhood adversity, and a family history of suicide. Changeable risk factors included marital status (single), economic status (poverty), physical illness, history of psychiatric hospitalization, and history of suicide attempts. Recent discharge from a mental hospital and a recent history of suicide attempts were also included. Manageable risk factors included depression (history and current), alcohol problems (frequent drinking and alcohol abuse), hopelessness, agitation, impulsivity, impaired reality testing, and command hallucinations. Protective factors included responsibility to family, social support, moral objections to suicide, religiosity, motivation to get treatment, ability to cope with stress, and a healthy lifestyle. A final score was assigned based on the sum of the risk and protective factor scores. Conclusion We believe that the development of this checklist will help mental health clinicians to better assess those at risk for suicidal behavior. Further studies are necessary to validate the checklist.