Correlation of quantitative parameters of magnetic resonance perfusion-weighted imaging with vascular endothelial growth factor, microvessel density and hypoxia-inducible factor-1α in nasopharyngeal carcinoma: Evaluation on radiosensitivity study

OBJECTIVES

To investigate the correlation of parameters of magnetic resonance perfusion-weighted imaging (MR-PWI) with the expression of vascular endothelial growth factor (VEGF), hypoxia-inducible factor-1α (HIF-1α) and microvessel density (MVD) in nasopharyngeal carcinoma (NPC) so as to explore the value of predicting radiosensitivity.

DESIGN

A prospective study.

SETTING

Department of Head-and-neck radiotherapy in Hunan Cancer Hospital.

PARTICIPANTS

Ninety-four patients of NPC were included between December 2013 and December 2014.

MAIN OUTCOME MEASURES

The expression of VEGF, MVD and HIF-1α was studied by immunohistochemistry, and magnetic resonance perfusion-weighted imaging (MR-PWI) was performed before and after undergoing radiotherapy (20 Gy dose). Parameters of MR-PWI, volume of primary tumour and rate of tumour remission were measured and calculated. Patients with primary local tumour were then divided into completely response group (CR group) and partially response group (non-CR group) according to tumour regression condition. Relevant parameters were analysed by Spearman, and diagnostic efficiency of radiosensitivity was analysed by receiver operating characteristic curve (ROC).

RESULTS

The expression of VEGF was positively correlated with MVD (r = .322,P < .05), but the expression of HIF-1α was no significant correlations with VEGF and MVD. The expression VEGF was in positive correlation with fractional plasma volume (fpv) (r = .339, P = .05) before radiotherapy. There was a significant difference in the quantitative parameters of MR-PWI between CR group and non-CR group during the course of radiotherapy and at the end of radiotherapy treatment. The change of blood reflux constant (Δkep20) and extravascular extracellular space volume fraction (ΔVe20) before and after treatment was positively correlated with primary local tumour remission condition after 3 month treatment; Δkep and ΔVe were negatively correlated with primary local tumour remission condition after 3 months. Tumour regression rate was only positively correlated with Ve and the average volume of primary tumour after 2 week treatment (V1). ROC curve showed that R20 ≥ 65.69%, and was considered as a threshold to predict primary local tumour remission, with a sensitivity of 0.84 and specificity of 0.69, and area under the curve was 0.819 (P = .000).

CONCLUSIONS

The parameters of MR-PWI with the expression of VEGF, HIF-1α and MVD could be guidance for predicting radiosensitivity in NPC.

Impact of graft preservation solutions for liver transplantation on early cytokine release and postoperative organ dysfunctions. A pilot study

INTRODUCTION

During liver transplantation, graft ischemia-reperfusion injury leads to a systemic inflammatory response producing postoperative organ dysfunctions. The aim of this observational and prospective study was to compare the impact of Solution de conservation des organes et tissus (SCOT) 15 and University of Wisconsin (UW) preservation solutions on early cytokine release, postreperfusion syndrome and postoperative organ dysfunctions.

METHODS

Thirty-seven liver transplantations were included: 21 in UW Group and 16 in SCOT 15 group. Five cytokines were measured in systemic blood after anesthetic induction, 30minutes after unclamping portal vein and on postoperative day 1.

RESULTS

Following unclamping portal vein, cytokines were released in systemic circulation. Systemic cytokine concentrations were higher in UW than in SCOT 15 group: Interleukin-10, Interleukine-6. In SCOT 15 group, significant reduction of postreperfusion syndrome incidence and acute kidney injury were observed. Alanine and aspartate aminotransferase peak concentrations were higher in SCOT 15 group than in UW group. However, from postoperative day 1 to day 10, aminotransferase returned to normal values and did not differ between groups.

CONCLUSIONS

Compared to UW, SCOT 15 decreases systemic cytokine release resulting from graft ischemia-reperfusion injury and reduces incidence of postreperfusion syndrome and postoperative renal failure.

Miscellanea Dependent generalized functional linear models

This paper considers testing for no effect of functional covariates on response variables in multivariate regression. We use generalized estimating equations to determine the underlying parameters and establish their joint asymptotic normality. This is then used to test the significance of the effect of predictors on the vector of response variables. Simulations demonstrate the importance of considering existing correlation structures in the data. To explore the effect of treating genetic data as a function, we perform a simulation study using gene sequencing data and find that the performance of our test is comparable to that of another popular method used in sequencing studies. We present simulations to explore the behaviour of our test under varying sample size, cluster size and dimension of the parameter to be estimated, and an application where we are able to confirm known associations between nicotine dependence and neuronal nicotinic acetylcholine receptor subunit genes.

[The combined effects of family history of cardiovascular disease and overweight on ischemic stroke incidence among the Mongolian population]

Objective: To investigate the cumulative effect of family history of cardiovascular disease(CVD)and overweight on ischemic stroke events in the Mongolian population. Methods: Study participants were recruited from 32 villages from May 2002 to August 2012 in Kezuohou Banner(county)and Naiman Banner in Inner Mongolia, China. Among 3 457 Mongolian people aged ≥20 years old living in these villages, 2 589 were selected to participate in this study. None of the participants had chronic kidney disease, malignant tumor, thyroid disease or adrenalopathy, or acute infectious disease. The 2 589 participants were followed for a mean of 9.2 years. Six participants were lost to follow up, resulting in a follow-up rate of 99.8%. Information collected included demographic characteristics, lifestyle risk factors, alcohol consumption, cigarette smoking, history of disease, family history of CVD, and physical examination. Ischemic stroke incidence information was collected during follow-up. All participants were categorized into four subgroups according to family history of CVD and overweight status. Cox proportional hazards models were used to estimate the hazard ratios(HR)and 95% CI of ischemic stroke events among subgroups, compared with the subgroup with no family history of CVD and body mass index(BMI)<24 kg/m²(the reference group). Results: Among 2 589 participants, 76 ischemic stroke events occurred after follow-up, and 8 were excluded because of lack of key data. Finally, 2 581 participants were included in the analysis, and the incidence density was 323/100 000 person-years. The cumulative incidence rates of ischemic stroke were 2.48%, 1.86%, 6.67% and 9.00% in the no family history of CVD and BMI <24 kg/m², no family history of CVD and BMI ≥24 kg/m², family history of CVD and BMI <24 kg/m² and family history of CVD and BMI ≥ 24 kg/m² subgroups, respectively. Using the Cox proportional hazards model, after further adjustment for age, gender, smoking, drinking, FPG, hypertension, total cholesterol, triglycerides, and heart rate, the risk of ischemic stroke in the subgroup with a family history of CVD and BMI ≥24 kg/m² was higher than the reference group(HR: 2.61, 95% CI: 1.16-5.87). However, the risk of ischemic stroke in other two groups was not statistically significant compared with the reference group. The HR(95% CI)values in the no family history of CVD and BMI ≥24 kg/m²and family history of CVD and BMI <24 kg/m² subgroups were 1.18(0.5- 2.39)and 1.27(0.67- 2.42), respectively. Conclusion: In the Mongolian population, a family history of CVD and coexistent overweight may increase the risk of ischemic stroke events, suggesting that in people with family history of cardiovascular disease, weight control is conducive to the prevention of ischemic stroke.

Simulation of ECM with Silk and Chitosan Nanocomposite Materials

Extracellular matrix (ECM) is a system used to model the design of biomaterial matrices for tissue regeneration. Various biomaterial systems have been developed to mimic the composition or microstructure of the ECM. However, emulating multiple facets of the ECM in these systems remains a challenge. Here, a new strategy is reported which addresses this need by using silk fibroin and chitosan (CS) nanocomposite materials. Silk fibroin was first assembled into ECM-mimetic nanofibers in water and then blended with CS to introduce the nanostructural cues. Then the ratios of silk fibroin and CS were optimized to imitate the protein and glycosaminoglycan compositions. These biomaterial scaffolds had suitable compositions, hierarchical nano-to-micro structures, and appropriate mechanical properties to promote cell proliferation in vitro, and vascularization and tissue regeneration in vivo. Compared to previous silk-based scaffolds, these scaffolds achieved improvements in biocompatibility, suggesting promising applications in the future in tissue regeneration.

Hypertrophic cardiomyopathy and left ventricular hypertrophy in hypertensive heart disease with mildly reduced or preserved ejection fraction: insight from altered mechanics and native T1 mapping

AIM

To explore the relationship between extracellular volume (ECV), native T1, and systolic strain in hypertrophic cardiomyopathy (HCM) and hypertensive patients with left ventricular hypertrophy (HTN LVH) with mildly reduced or preserved ejection fraction.

MATERIALS AND METHODS

T1 mapping was performed in 45 patients with late gadolinium enhancement positive (LGE+) HCM (mean age, 53±6 years), 11 patients with LGE- (LGE-) HCM (mean age, 56±5 years), and 20 patients with HTN LVH (mean age, 55±6 years) on at 3 T magnetic resonance imaging (MRI) using the modified look-locker inversion-recovery (MOLLI) pulse sequence. Mean T1 value, ECV and circumferential strain parameters were determined for each patient.

RESULTS

Overall, the HCM patients had higher native T1 values (1242.92±68.94) and ECV (0.31±0.05) in comparison to those of the HTN LVH patients (1197±46.80, 0.27±0.04; p<0.05). In the subgroup analysis, the HCM LGE+ patients had the highest native T1 values among the three groups. The HCM LGE+ patients had higher ECV than the LGE- patients. HCM LGE- patients had higher ECV than HTN LVH patients (p<0.05). Peak systolic circumferential strain and early diastolic strain rates were reduced in the HCM LGE+ patients in comparison to the HCM LGE- and HTN LVH patients (p<0.05). Reduced peak systolic and early diastolic circumferential strain rates were associated with increased levels of ECV and native T1 values among all the patients.

CONCLUSION

HCM LGE+ patients had higher native T1 values, higher ECV, and an associated reduction in early diastolic strain rates and peak systolic circumferential strains when compared to the HCM LGE- and HTN LVH patients with mildly reduced or preserved ejection fraction.

[Impacts of early metoprolol intervention on connexin 43 and phosphorylated connexin 43 expression in rabbits with experimental myocardial infarction]

Objective: To investigate the early intervention effects of metoprolol on connexin 43(Cx43) and phosphorylated Cx43 (p-Cx43) expression in rabbits with post myocardial infarction. Methods: A total of 24 adult male New Zealand white rabbits were divided into sham group (n=6), early treatment group(n=6), routine treatment group(n=6), and myocardial infarction group(n=6) with a randomized block design blocked by weight. Myocardial infarction was induced by left anterior descending coronary artery (LAD) ligation. Rabbits in sham group received similar surgical procedure without LAD ligation. Metoprolol (12.5 mg/kg dissolved in 2 ml distilled water) was applied to rabbits in early treatment group and routine treatment group per gavage immediately after recovery from anesthesia and at 24 hours after myocardial infarction, respectively, then treated daily for 40 days. Rabbits in sham group and myocardial infarction group received 2 ml distilled water per gavage daily for 40 days. Plasma lactate dehydrogenase (LDH) and creatine kinase (CK) level were detected by automatic biochemistry analyzer after 6 hours in all rabbits. Ventricular fibrillation threshold (VFT) was measured in vivo by bipolar pacing electrodes at 40 days. Cx43 and p-Cx43 distribution in ventricular tissue was detected by immunofluorescence analyses. Cx43 and p-Cx43 protein level in ventricular tissue was determined by Western blot. Results: (1) Plasma LDH ((851.7±85.9)U/L vs. (332.3±39.6)U/L, P<0.01) and CK ((1 192.7±105.3)U/L vs. (462.3±65.6)U/L, P<0.01) were significantly higher in myocardial infarction group than in sham group (both P<0.01). (2) VFT was significantly lower in myocardial infarction group than that in sham group ((470.0±91.0) beats per minute vs. (683.3±60.9) beats per minute, P<0.05), and VFT was significantly higher in early treatment group ((633.3±43.2) beats per minute) and routine treatment group ((645.0±30.8) beats per minute) than in the myocardial infarction group (both P<0.05). (3) Immunofluorescence analyses showed that Cx43 was mainly localized in the intercalated disk, which was perpendicular to the cell long axis with linear arrangement, and less lateral distribution in sham group, early treatment group and routine treatment group, which was significantly different as the case in the myocardial infarction group. The expression of p-Cx43 in myocardial infarction group was less than in sham group, which was significantly upregulated in in early treatment group and routine treatment group when compared with myocardial infarction group, and expression of p-Cx43 was significantly higher in early treatment group than in routine treatment group. (4)The p-Cx43/Cx43 ratio of protein was significantly lower in myocardial infarction group than in sham group (0.165±0.011 vs. 0.363±0.046, P<0.05), and significantly higher in early treatment group (0.720±0.063) and routine treatment group (0.364±0.030) than in myocardial infarction group (both P<0.05), and this ratio was significantly higher in early treatment group than in routine treatment group (P<0.05). Conclusion: Metoprolol treatment, especially the early metoprolol treatment (within 24 hours after LAD ligation), could significantly improve VFT by ameliorating the distribution and dephosphorylation of myocardial Cx43 in rabbits with experimental myocardial infarction.

Modelling metaldehyde in catchments: a River Thames case-study

The application of metaldehyde to agricultural catchment areas to control slugs and snails has caused severe problems for drinking water supply in recent years. In the River Thames catchment, metaldehyde has been detected at levels well above the EU and UK drinking water standards of 0.1 μg l^-1 at many sites across the catchment between 2008 and 2015. Metaldehyde is applied in autumn and winter, leading to its increased concentrations in surface waters. It is shown that a process-based hydro-biogeochemical transport model (INCA-contaminants) can be used to simulate metaldehyde transport in catchments from areas of application to the aquatic environment. Simulations indicate that high concentrations in the river system are a direct consequence of excessive application rates. A simple application control strategy for metaldehyde in the Thames catchment based on model results is presented.

Simultaneous esophagectomy and off-pump coronary artery bypass grafting: a practicable approach with good survival

Surgery continues to be the mainstay of esophageal cancer treatment. However, it is a big challenge for the surgical treatment of patients with both esophageal cancer and coronary artery disease (CAD). We reported, here, the first case series of esophageal cancer patients treated with simultaneous esophagectomy and off-pump coronary artery bypass grafting (CABG). From August 2010 to August 2012, 2154 esophageal or esophageal gastric junction (EGJ) cancer patients underwent surgical treatment in Tangdu Hospital, Xi'an, China. Among them, six patients with esophageal or EGJ esophageal gastric junction cancer complicated with CAD were given simultaneous esophagectomy and off-pump CABG, and were followed up until August 2014. Four patients were operated through left lateral thoracotomy and two patients were operated through median sternotomy plus upper midline laparotomy. All the patients survived the operation well and the postoperative morbidity rate was 67% (one anastomosis leakage, three cardiac arrhythmias). There was no postoperative mortality. The mean follow-up time was 34.5 ± 7.8 months (range, 24-46 months). One patient died 36 months later due to tumor recurrence and all the other patients survived until the time to follow up. Simultaneous esophagectomy and off-pump CABG approach might be a safe and effective procedure with good survival in selected patients with both esophageal cancer and CAD.

Fate and transport of polychlorinated biphenyls (PCBs) in the River Thames catchment - Insights from a coupled multimedia fate and hydrobiogeochemical transport model

The fate of persistent organic pollutants (POPs) in riverine environments is strongly influenced by hydrology (including flooding) and fluxes of sediments and organic carbon. Coupling multimedia fate models (MMFMs) and hydrobiogeochemical transport models offers unique opportunities for understanding the environmental behaviour of POPs. While MMFMs are widely used for simulating the fate and transport of legacy and emerging pollutants, they use greatly simplified representations of climate, hydrology and biogeochemical processes. Using additional information about weather, river flows and water chemistry in hydrobiogeochemical transport models can lead to new insights about POP behaviour in rivers. As most riverine POPs are associated with suspended sediments (SS) or dissolved organic carbon (DOC), coupled models simulating SS and DOC can provide additional insights about POPs behaviour. Coupled simulations of river flow, DOC, SS and POP dynamics offer the possibility of improved predictions of contaminant fate and fluxes by leveraging the additional information in routine water quality time series. Here, we present an application of a daily time step dynamic coupled multimedia fate and hydrobiogeochemical transport model (The Integrated Catchment (INCA) Contaminants model) to simulate the behaviour of selected PCB congeners in the River Thames (UK). This is a follow-up to an earlier study where a Level III fugacity model was used to simulate PCB behaviour in the Thames. While coupled models are more complex to apply, we show that they can lead to much better representation of POPs dynamics. The present study shows the importance of accurate sediment and organic carbon simulations to successfully predict riverine PCB transport. Furthermore, it demonstrates the important impact of short-term weather variation on PCB movement through the environment. Specifically, it shows the consequences of the severe flooding, which occurred in early 2014 on sediment PCB concentrations in the River Thames.

New Insights Into Cellular Stress Responses to Environmental Metal Toxicants

Exposures to metal toxicants in the environment disrupt normal physiological functions and have been linked to the development of a myriad of human diseases. While the molecular and cellular mechanisms underlying metal toxicities remain to be fully understood, it is well appreciated that metal toxicants induce cellular stresses and that how cells respond to the stresses plays an important role in metal toxicity. In this review, we focus on how metal exposures induce stresses in the endoplasmic reticulum (ER) to elicit the unfolded protein response (UPR). We document the emerging evidence that induction of ER stress and UPR in the development of human diseases is associated with metal exposures. We also discuss the role of the interplay between ER stress and oxidative stress in metal toxicity. Finally, we review recent advances in functional genomics approaches and discuss how applications of these new tools could help elucidate the molecular mechanisms underlying cellular stresses induced by environmental metal toxicants.

Modeling Alkaline Phosphatase Inactivation in Bovine Milk During High-Temperature Short-Time Pasteurization

Alkaline phosphatase (AP) is used as the indicator enzyme for proper pasteurization of bovine milk. Predictive modeling of AP inactivation during high-temperature short-time (HTST) pasteurization would support regulations; thus ensuring the safety of heat treated milk. Activation energy (Ea) of AP in milk was measured experimentally using the capillary tube method, and Ea was found to be 429252 J/mol. The Ea was used to develop a nonlinear model to describe the thermal inactivation of milk in a small-scale HTST pasteurizer with a plate heat exchanger. Integrated pasteurization effect (PE) was obtained at different holding temperatures (62–72°C) and holding times (3–25 s), by converting times at different temperatures in various sections of the pasteurizer to the equivalent time at the reference temperature (72°C). A nonlinear function was developed to relate the log(% residual AP activity) to PE. The r2 varied from 0.7488 to 0.8311. The validation trial indicated that the model could predict AP activity accurately for the% residual AP activity >1%.

AAV-mediated transduction and targeting of retinal bipolar cells with improved mGluR6 promoters in rodents and primates

Adeno-associated virus (AAV) vectors have been a powerful gene delivery vehicle to the retina for basic research and gene therapy. For many of these applications, achieving cell type-specific targeting and high transduction efficiency is desired. Recently, there has been increasing interest in AAV-mediated gene targeting to specific retinal bipolar cell types. A 200-bp enhancer in combination with a basal SV40 promoter has been commonly used to target transgenes into ON-type bipolar cells. In the current study, we searched for additional cis-regulatory elements in the mGluR6 gene for improving AAV-mediated transduction efficiency into retinal bipolar cells. Our results showed that the combination of the endogenous mGluR6 promoter with additional enhancers in the introns of the mGluR6 gene markedly enhanced AAV transduction efficiency as well as made the targeting more selective for rod bipolar cells in mice. Furthermore, the AAV vectors with the improved promoter could target to ON bipolar cells with robust transduction efficiency in the parafovea and the far peripheral retina of marmoset monkeys. The improved mGluR6 promoter constructs could provide a valuable tool for genetic manipulation in rod bipolar cells in mice and facilitate clinical applications for ON bipolar cell-based gene therapies.

[Application of Postmortem Biochemistry in Forensic Diagnosis of Diabetic Ketoacidosis]

Diabetic ketoacidosis is a serious complication results from the high blood levels of glucose and ketone in diabetes mellitus patients that cause metabolic overbalance. An analysis of postmortem biochemical indexes is needed in such cases without specific signs of the routine forensic medicine examination. Postmortem biochemistry is a kind of examinations that collecting the body fluids of the corpses to determine the metabolic state of their life time to estimate the cause of death. This paper reviews the basic features and signs of the forensic medicine examination in the dead cases of diabetic ketoacidosis, and emphatically analyzes the postmortem biochemical indexes of diabetic ketoacidosis, and summarizes new ideas of forensic medicine diagnosis in diabetic ketoacidosis death.

Epigenetically mediated spontaneous reduction of NFAT1 expression causes imbalanced metabolic activities of articular chondrocytes in aged mice

OBJECTIVE

Abnormal metabolic activities of chondrocytes may cause articular cartilage (AC) degradation, but key transcription factors regulating metabolic activities in AC of aging individuals remain unknown. This study aimed to investigate the role of transcription factor NFAT1 in regulating the expression of anabolic and catabolic molecules in AC of aged mice.

METHODS

The hip, knee, and shoulder joints of BALB/c mice were harvested at 6, 12, 15, 18, and 24 months of age for histopathological and immunohistochemical (IHC) analyses. Total RNA was isolated from AC for gene expression. Genomic DNA and chromatin were prepared from AC for methylated DNA immunoprecipitation (MeDIP) and chromatin immunoprecipitation (ChIP) assays.

RESULTS

NFAT1 expression in AC of mice was significantly decreased after 12 months of age, which was associated with reduced proteoglycan staining, decreased expression of chondrocyte markers, and increased expression of interleukin-1β. Forced Nfat1 expression in chondrocytes from aged mice significantly reversed the abnormal metabolic activities. ChIP assays confirmed that NFAT1 bound to the promoter of the Acan, Col2a1, Col9a1, Col11a1, Il1b, Mmp13 and Tnfa genes in articular chondrocytes of aged mice. ChIP and MeDIP assays revealed that reduced NFAT1 expression in AC of aged mice was regulated by epigenetic histone methylation at the promoter region and was correlated with increased DNA methylation at introns 1 and 10 of the Nfat1 gene.

CONCLUSION

NFAT1 is a transcriptional regulator of multiple anabolic and catabolic genes in AC of aged mice. Epigenetically mediated reduction of NFAT1 expression causes imbalanced metabolic activities of articular chondrocytes in aged mice.

High frequency of mitochondrial DNA mutations in HIV-infected treatment-experienced individuals

OBJECTIVES

We recently observed a decrease in deoxyribonucleotide (dNTP) pools in HIV-infected individuals on antiretroviral therapy (ART). Alterations in dNTPs result in mutations in mitochondrial DNA (mtDNA) in cell culture and animal models. Therefore, we investigated whether ART is associated with mitochondrial genome sequence variation in peripheral blood mononuclear cells (PBMCs) of HIV-infected treatment-experienced individuals.

METHODS

In this substudy of a case-control study, 71 participants were included: 22 'cases', who were HIV-infected treatment-experienced patients with mitochondrial toxicity, 25 HIV-infected treatment-experienced patients without mitochondrial toxicity, and 24 HIV-uninfected controls. Total DNA was extracted from PBMCs and purified polymerase chain reaction (PCR) products were subjected to third-generation sequencing using the PacBio Single Molecule Real-Time (SMRT) sequencing technology. The sequences were aligned against the revised Cambridge reference sequence for human mitochondrial DNA (NC_012920.1) for detection of variants.

RESULTS

We identified a total of 123 novel variants, 39 of them in the coding region. HIV-infected treatment-experienced patients with and without toxicity had significantly higher average numbers of mitochondrial variants per participant than HIV-uninfected controls. We observed a higher burden of mtDNA large-scale deletions in HIV-infected treatment-experienced patients with toxicity compared with HIV-uninfected controls (P = 0.02). The frequency of mtDNA molecules containing a common deletion (mt.δ4977) was higher in HIV-infected treatment-experienced patients with toxicity compared with HIV-uninfected controls (P = 0.06). There was no statistically significant difference in mtDNA variants between HIV-infected treatment-experienced patients with and without toxicity.

CONCLUSIONS

The frequency of mtDNA variants (mutations and large-scale deletions) was higher in HIV-infected treatment-experienced patients with or without ART-induced toxicity than in uninfected controls.