Melatonin sensitizes human hepatoma cells to endoplasmic reticulum stress-induced apoptosis

Endoplasmic reticulum stress-mediated cell apoptosis is implicated in the development of cancer. Melatonin induces apoptosis in hepatocellular carcinoma (HCC) in experimental studies, but the effects of melatonin on endoplasmic reticulum (ER) stress-induced apoptosis in HCC have not been tested. Differences in ER stress-induced apoptosis in human hepatoma cells and normal human hepatocyte were investigated by exposure to tunicamycin (ER stress inducer). Significant differences were observed in the rate of apoptosis between HepG2 cells (hepatoma cells) and HL-7702 cells (normal human hepatocyte cells). The expression of cyclooxygenase-2 (COX-2) was increased in HepG2 cells but not in HL-7702 cells. Furthermore, down-regulation of COX-2 expression using the COX-2 inhibitor, celecoxib, increased tunicamycin-induced apoptosis concomitant with the up-regulation of pro-apoptotic transcription factor CHOP (GADD153) and down-regulation of B-cell lymphoma 2/Bcl-2-associated X protein (Bcl-2/Bax) ratio, suggesting that inhibition of COX-2 sensitized human hepatoma cells to ER stress-induced apoptosis. Interestingly, co-treatment with tunicamycin and melatonin also decreased the expression of COX-2 and significantly increased the rate of apoptosis by elevating the levels of CHOP and reducing the Bcl-2/Bax ratio. These results demonstrate that melatonin sensitizes human hepatoma cells to ER stress-induced apoptosis by down-regulating COX-2 expression, increasing the levels of CHOP and decreasing the Bcl-2/Bax ratio.

Optimized ultra-fast imaging sequence (OUFIS)

The DUFIS sequence can make ultra-fast images (approximately 10 ms) without the use of rapidly switched gradients. The RF excitation sequence is spatially selective so that only a small fraction of the magnetization in each imaging pixel is used which produces a poor imaging signal to noise ratio (SNR). We have developed several alternative RF sequences that use RF pulses with multiple phases, and also with just 0 degrees and 180 degrees phases to excite almost all the magnetization in a pixel and greatly improve the SNR. The optimization of these pulse sequences (now called OUFIS) have been conducted both analytically and by numerical searches, with various linear and nonlinear models. Both theoretical and computational methods used in the optimizations are described in detail. Preliminary experimental results are briefly presented with several possible applications of the OUFIS excitation sequences suggested.

Altered expression of Krüppel-like factor 4 and β-catenin in human gastric cancer

The effects of the interaction between KLF4 and β-catenin may be significant in human carcinogenesis and tumor development. This study aimed to determine whether the expression of KLF4 and β-catenin in gastric cancer tissues is associated with clinicopathological characteristics. Western blot analysis and immunohistochemistry were performed to detect KLF4 and β-catenin expression in tumor and corresponding non-cancerous tissues from 49 patients. The data revealed that KLF4 expression was significantly reduced in gastric cancer tissues compared with normal tissues. By contrast, the expression of the β-catenin protein was significantly increased in all tumor tissues, but was not expressed in distant normal mucosae. The altered expression of the KLF4 and β-catenin proteins was associated with advanced tumor stage and gastric cancer. In addition, the expression of the KLF4 and β-catenin proteins was inversely associated in moderately differentiated human gastric cancers. This study showed that β-catenin expression is significantly increased and KLF4 protein expression is markedly decreased in gastric cancer tissues, thus showing that the expression of KLF4 is inversely correlated with that of β-catenin in gastric cancer. The altered expression of the two proteins is associated with advanced tumor stage in gastric cancer.

Lung recruitment maneuver during proportional assist ventilation of preterm infants with acute respiratory distress syndrome

OBJECTIVE

To investigate the effect of lung recruitment maneuver (LRM) with positive end-expiratory pressure (PEEP) on oxygenation and outcomes in preterm infants ventilated by proportional assist ventilation (PAV) for respiratory distress syndrome (RDS).

STUDY DESIGN

Preterm infants on PAV for RDS after surfactant randomly received an LRM (group A, n=12) or did not (group B, n=12). LRM entailed increments of 0.2 cm H2O PEEP every 5 min, until fraction of inspired oxygen (FiO2)=0.25. Then PEEP was reduced and the lung volume was set on the deflation limb of the pressure/volume curve. When saturation of peripheral oxygen fell and FiO2 rose, we reincremented PEEP until SpO2 became stable.

RESULT

Group A and B infants were similar: gestational age 29.5 ± 1.0 vs 29.4 ± 0.9 weeks; body weight 1314 ± 96 vs 1296 ± 88 g; Silverman Anderson score for babies at start of ventilation 8.6 ± 0.8 vs 8.2 ± 0.7; initial FiO2 0.56 ± 0.16 vs 0.51 ± 0.14, respectively. The less doses of surfactant administered in group A than that in group B (P<0.05). Groups A and B showed different max PEEP during the first 12 h of life (8.4 ± 0.5 vs 6.7 ± 0.6 cm H2O, P=0.00), time to lowest FiO2 (101 ± 18 versus 342 ± 128 min; P=0.000) and O2 dependency (7.83 ± 2.04 vs 9.92 ± 2.78 days; P=0.04). FiO2 levels progressively decreased (F=43.240, P=0.000) and a/AO2 ratio gradually increased (F=30.594, P=0.000). No adverse events and no differences in the outcomes were observed.

CONCLUSION

LRM led to the earlier lowest FiO2 of the first 12 h of life and a shorter O2 dependency.

Application of Demirjian's and Cameriere's Method in Dental Age Estimation of 8-16 Year Old Adolescents from Hunan Han Nationality

Abstract

Objective To apply Demirjian's and Cameriere's method for dental age estimation of adolescents from Hunan Han nationality, and compare the accuracy of the two methods. Methods A total of 480 orthopantomograms of?8-16 year?old adolescents from Hunan Han nationality?with no special diseases and good nutritional status were collected?by Xiangya Stomatological Hospital of Central South University from January, 2016 to July, 2017, among them 236 males and 244 females. The dental age of each adolescent was determined by Demirjian's method and Cameriere's method, respectively, and the paired t-test of the estimated dental age and the chronological age determined by the two methods was conducted by SPSS 20.0 software to compare the difference between estimated dental age and chronological age. Results Mean chronological age of males and females was 11.91 and 11.88 years, respectively. The estimated dental age determined by Demirjian's method showed an underestimate of chronological age by an average of 0.11 years （males） and 0.15 years （females）, while the estimated dental age determined by Cameriere's method showed an underestimate of chronological age by an average of 0.83 years （males） and 0.72 years （females）. Conclusion Demirjian's method is more accurate than Cameriere's method in dental age estimation of adolescents from Hunan Han nationality, therefore more suitable for dental age estimation of adolescents in this region.

Rab37 Promotes Endothelial Differentiation and Accelerates ADSC-Mediated Diabetic Wound Healing through Regulating Secretion of Hsp90α and TIMP1

Accumulating evidence indicates that adipose tissue-derived mesenchymal stem cells (ADSCs) are an effective treatment for diabetic refractory wounds. However, the application of ADSCs to diabetic wounds is still limited, indicating that we still lack sufficient knowledge regarding regulators/mediators of ADSCs during wound healing. Rab37, a member of RabGTPase, may function as regulator of vesicle trafficking, which is a crucial event for the secretion of cytokines by ADSCs. Our previous study indicated that Rab37 promotes the adiopogenic differentiation of ADSCs. In this study, we explored the role of Rab37 in ADSC-mediated diabetic wound healing. An in vivo study in db/db diabetic mice showed that Rab37-expressing ADSCs shortened the wound closure time, improved re-epithelialization and collagen deposition, and promoted angiogenesis during wound healing. An in vitro study showed that Rab37 promoted the proliferation, migration and endothelial differentiation of ADSCs. LC-MS/MS analysis identified Hsp90α and TIMP1 as up-regulated cytokines in conditioned media of Rab37-ADSCs. The up-regulation of Rab37 enhanced the secretion of Hsp90α and TIMP1 during endothelial differentiation and under high-glucose exposure. Interestingly, Rab37 promoted the expression of TIMP1, but not Hsp90α, during endothelial differentiation. PLA showed that Rab37 can directly bind to Hsp90α orTIMP1 in ADSCs. Moreover, Hsp90α and TIMP1 knockdown compromised the promoting effects of Rab37 on the proliferation, migration and endothelial differentiation of ADSCs. In conclusion, Rab37 promotes the proliferation, migration and endothelial differentiation of ADSCs and accelerates ADSC-mediated diabetic wound healing through regulating the secretion of Hsp90α and TIMP1.

Genetic Polymorphisms of 21 STR Loci in Hunan Province-based Han Population

OBJECTIVES

To investigate the genetic polymorphisms of 21 short tandem repeat （STR） loci （D3S1358, D13S317, D7S820, D16S539, Penta E, D2S441, TPOX, TH01, D2S1338, CSF1PO, Penta D, D10S1248, D19S433, vWA, D21S11, D18S51, D6S1043, D8S1179, D5S818, D12S391 and FGA）.

METHODS

A total of 560 blood samples were collected from unrelated healthy individuals of Han population in Hunan Province. Chelex-100 extraction method was applied to the extraction of genomic DNA, and an AGCU EX22 Kit and 9700 STR amplification was used in amplification reactions. The products were separated and analyzed on 310 Genetic Analyzer.

RESULTS

A total of 248 alleles were observed, the allelic frequencies ranging from 0.001 to 0.518. Observation of genotype distributions for each locus showed no deviations from Hardy-Weinberg equilibrium except Penta E （P=0.023）. The combined power of discrimination, combined power of exclusion, and combined matching probability of the 21 STR loci were approximately 0.999 999 999 999 999 999 999 999 8, 0.999 999 998, and 1.36×10⁻²⁵, respectively.

CONCLUSIONS

The 21 STR loci show high polymorphisms in the Han population, which can provide valuable data and a theoretical basis for forensic individual identification and paternity testing.

Evaluation of a new Spin-echo diffusion-weighted sequence on a 0.35 T open magnetic resonance imaging (MRI)-system: first experiences within 3 h after acute stroke

In acute stroke, diffusion-weighted magnetic resonance imaging helps to select patients who are eligible for thrombolysis, but is almost exclusively implemented on closed-bore scanners, which make monitoring of patients difficult. We developed and tested a cardiac gated Spin-echo diffusion-weighted sequence with prescan finetrim and motion correction on an open system with 0.35 T. Nineteen stroke patients appropriate for thrombolytic therapy by clinical criteria were enrolled in a prospective study on an intention-to-treat basis. In all but one patient, computed tomography and magnetic resonance imaging including the new diffusion-weighted sequence were performed within 3 h after symptom onset. Images were evaluated for acute cerebral ischemia and hemorrhage by two radiologists blinded to clinical information. Magnetic resonance imaging required a mean total acquisition time of 26 min. Sensitivity for early infarction was 94% in diffusion-weighted imaging and 73% in computed tomography. Six patients were excluded from thrombolysis due to an infarct size of more than 1/3 of the territory of the middle cerebral artery exclusively diagnosed with diffusion-weighted imaging. Hemorrhage was recognised by both, magnetic resonance imaging and computed tomography. We conclude that in acute stroke, diffusion-weighted imaging with an open system at 0.35 T is practicable. The implemented sequence reliably demonstrated the size of the infarction and improved the selection of patients who are eligible for thrombolysis.

A method for the calculation of currents on shielded gradient coils

Alternate expressions for the current density on the shielding surface of a gradient coil are derived for cylindrical, planar, and hyperbolic gradient coils. For the planar and hyperbolic geometries, these expressions allow more rapid high-precision calculations of current densities than the conventional solution.

Activated AXL Ameliorates Alcohol-associated Steatotic Liver Ischemia-Reperfusion Injury by Inhibiting ER stress and Mitochondria-associated Apoptosis

Hepatic ischemia-reperfusion (I/R) injury can cause poor prognosis of liver transplantation and hepatectomy, especially in patients with alcohol-associated liver disease (ALD). Apoptosis is closely related to different stages of liver injury, and the death of hepatocytes caused by endoplasmic reticulum (ER) and mitochondria homeostasis perturbation may be key to liver injury. The receptor tyrosine kinases AXL encoded by the gene axl, is a member of the TAM (TYRO3, AXL, and MERTK) family, which participates in various biological processes by binding to the ligand of growth arrest-specific protein 6 (Gas6). However, whether AXL is involved in apoptosis pathways, and the detailed mechanism in hepatic I/R injury remains unknown. In the present study, we found that total AXL is up-regulated while phosphorylated AXL (p-AXL, the active form of AXL) was down-regulated after I/R in human liver tissues from liver transplantation. Consistently, total AXL was found up-regulated while p-AXL was down-regulated during hepatic I/R injury in mice. Pretreatment with Gas6 increased p-AXL expression, reduced ER stress-associated cell apoptosis, alleviated liver damage, and restored ER and mitochondria ultrastructure during hepatic I/R in mice. Furthermore, the ALD model was established by chronic-plus-binge ethanol feeding to explore the role of AXL in I/R liver injury with ethanol-associated steatosis. We found that ALD mice had a lower p-AXL level and were more susceptible to hepatic I/R injury. Importantly, activated AXL ameliorated liver injury by inhibiting IRE1 and PERK pathway to reduce ER stress-associated apoptosis. In conclusion, activated AXL protects alcohol-associated steatotic liver against I/R injury by inhibiting ER stress and mitochondria-associated apoptosis, suggesting that targeting AXL serves as a potential strategy for liver I/R injury, particularly for marginal liver donors with alcohol-associated steatosis.

Role of low-density lipoprotein in mediating the effect of air pollution on coronary heart disease: a two-step multivariate Mendelian randomization study

OBJECTIVE

Air pollution is affecting the health of millions of people all over the world. The causal correlations of PM2.5, PM10, and nitrogen dioxide (NOx), as the main fine particulate matter, and coronary heart disease (CHD) are yet to be explored. Low-density lipoprotein (LDL) has been a principal factor in the pathogenesis of CHD. It is an interesting issue to consider whether LDL mediates the effect of air pollutants in CHD pathogenesis.

MATERIALS AND METHODS

A genome-wide association study (GWAS) on the European population, followed up from 2010 to 2018, involving over 400,000 participants, was based on a land-use regression model. The annual mean concentrations of major air pollutant particles, PM2.5 (n=423,796), PM10 (n=423,796), and NOx (n=456,380), were recorded. The large GWAS database of CHD covered over ten million SNPs with independent single nucleotide polymorphisms (SNPs). LDL database collected major biochemical blood parameters from over 400,000 patients (n=440,546). Taken together, we conducted independent two-sample Mendelian randomization (MR) analyses for the causality between air pollutants (PM2.5, PM10, and NOx) and CHD. Multivariate MR analysis was conducted using causal relationships to determine the direct effects of exposure on outcome. The fixed-effect inverse variance weighted (IVW2) method was mainly employed to assess this relationship, with a confidence interval of 95% for the odds ratio (OR). Also, MR-Egger, weighted median, maximum likelihood ratio method, and random-effects inverse variance-weighted (IVW1) method were adopted as supplementary methods.

RESULTS

Two-sample MR results based on the IVW2 method suggested positive correlations between PM2.5 and CHD [OR 1.875 (1.279-2.748), p=0.001], PM10 and CHD [OR 2.586 (1.479-4.523), p=0.001], and NOx and CHD [OR 2.991 (2.021-4.427), p=4.37E-08]. The direct effect and mediating proportion were calculated using multivariable Mendelian randomization (MVMR). Lastly, the mediating proportions of LDL in the regulatory roles of PM2.5, PM10, and NOx in CHD were 2.82%, 4.73%, and 9.54%, respectively.

CONCLUSIONS

PM2.5, PM10, and NOx share direct causal associations with CHD, and LDL performs a mediating role in this pathogenic process. Early prevention against air pollution (such as increasing green areas and reducing large-scale industrial dust emissions) and early lipid-lowering treatment can effectively prevent the occurrence of CHD.

[Research Progress of Vitreous Humor Detection Technique on Estimation of Postmortem Interval]

Estimation of postmortem interval （PMI） plays a crucial role in forensic study and identification work. Because of the unique anatomy location, vitreous humor is considered to be used for estima- ting PMI, which has aroused interest among scholars, and some researches have been carried out. The detection techniques of vitreous humor are constantly developed and improved which have been gradually applied in forensic science, meanwhile, the study of PMI estimation using vitreous humor is updated rapidly. This paper reviews various techniques and instruments applied to vitreous humor detection, such as ion selective electrode, capillary ion analysis, spectroscopy, chromatography, nano-sensing technology, automatic biochemical analyser, flow cytometer, etc., as well as the related research progress on PMI estimation in recent years. In order to provide a research direction for scholars and promote a more accurate and efficient application in PMI estimation by vitreous humor analysis, some inner problems are also analysed in this paper.

The Origin and Development of Medical Jurisprudence in Xiangya

The origin of medical jurisprudence in China can be traced back to as early as 1920s, and since then, the discipline has undergone a great development. This paper, based on the disciplinary development of medical jurisprudence at Xiangya School of Medicine, illustrates its evolution in three aspects covering the scientific and theoretic foundation, legal system and policy support. The current investigation reflected a glimpse of the modern forensic science in China, providing useful historical reference for the development of Chinese forensic science.