Platycodin D ameliorates ammonia-induced pulmonary fibrosis by repressing TGF-β1-mediated extracellular matrix remodeling

Ammonia can induce pulmonary fibrosis in humans and animals. Platycodin D (PLD) possesses various bioactive activities including anti-fibrotic properties. In this study, we aimed to explore the activity and mechanism of PLD in pulmonary fibrosis induced by ammonia. The mouse model of ammonia-induced lung fibrosis was established, and the role of PLD was assessed by H&E and Masson's trichrome staining. The differentially expressed genes (DEGs) were identified by RNA-seq and subjected to GO and KEGG pathway analyses. BEAS-2B cells were treated with NH4 Cl alone or along with PLD. Results showed that PLD attenuated ammonia-induced pulmonary inflammation and fibrosis in vivo. The extracellular matrix (ECM)-receptor interaction pathway was predicted as a prominent pathway underlying the anti-fibrotic function of PLD. In ammonia-induced mouse models and NH4 Cl-treated BEAS-2B cells, PLD could repress the activation of the TGF-β1 pathway. By incubating lung fibroblast HFL1 cells with the conditioned medium of BEAS-2B cells treated with NH4Cl alone or along with PLD, PLD was confirmed to attenuate NH4 Cl-induced ECM deposition in HFL1 cells. Our findings demonstrate that PLD exerts a protective function in ammonia-induced pulmonary fibrosis by repressing TGF-β1-mediated ECM remodeling, suggesting the potential therapeutic value of PLD in this disease.

Metabolomic and microbiome analysis of the protective effects of Puerarin against Salmonella Enteritidis Infection in chicks

BACKGROUND

Salmonella Enteritidis is a zoonotic pathogen and poses a substantial risk to human health, as well as significant financial losses to the livestock and poultry industries. It is currently urgent to identify alternatives to antibiotic treatment.

RESULTS

In this study, we explored the influence of Puerarin on the immunological response, intestinal flora, serum metabolome, and growth performance of chicks infected with Salmonella Enteritidis. Chicks were weighed at specific time points and the average daily gain (ADG) was calculated. Serum, intestinal, and cecal content samples were collected on days 10 and 17. The results showed that 100 mg/kg of Puerarin significantly suppressed inflammation and enhanced immune function. Metabolomic analysis showed significant differences in serum metabolites after Puerarin treatment and suggested that Puerarin may regulate abnormal amino acid and lipid metabolism after Salmonella Enteritidis infection through the autophagic and ABC transporter pathways. In addition, Puerarin suppressed Salmonella Enteritidis-induced intestinal flora dysbiosis through modulation of the microbial community structures (increased Lactobacillus, Faecalibacterium, and Subdoligranulum), as demonstrated by 16S rRNA analysis.

CONCLUSIONS

In conclusion, Puerarin can improve growth performance in chicks, suppress the inflammatory response in vivo, enhance immunity, and regulate lipid and amino acid metabolism and the intestinal flora.

TMT-based quantitative proteomics reveals the targets of andrographolide on LPS-induced liver injury

BACKGROUND

Andrographolide (Andro) is a diterpenoid derived from Andrographis paniculate, which has anti-inflammatory, antibacterial, antiviral and hepatoprotective activities. Gram-negative bacterial infections can cause varying degrees of liver injury in chickens, although Andro has been shown to have a protective effect on the liver, its underlying mechanism of action and effects on liver proteins are not known.

METHODS

The toxicity of Andro on the viability of leghorn male hepatoma (LMH) cells at different concentrations and times was analyzed by CCK-8 assays. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in the culture supernatants were measured using an automatic biochemical analyzer to evaluate the protective effect of androscopolide on LPS-induced injury of LMH cells. Subsequently, TMT proteomics analysis were performed on the negative control group (NC group), LPS, and LPS-Andro groups, and bioinformatics analysis was performed on the differentially expressed proteins (DEPs).

RESULTS

It was found that Andro reduced ALT and AST levels in the cell supernatant and alleviated LPS-induced injury in LMH cells. Proteomic analysis identified 50 and 166 differentially expressed proteins in the LPS vs. NC group and LPS-Andro vs. LPS group, respectively. Andro may be involved in steroid metabolic processes, negative regulation of MAPK cascade, oxidative stress, and other processes to protect against LPS-induced liver injury.

CONCLUSIONS

Andro protects against LPS-induced liver injury, HMGCS1, HMGCR, FDPS, PBK, CAV1, PRDX1, PRDX4, and PRDX6, which were identified by differential proteomics, may be the targets of Andro. Our study may provide new theoretical support for Andro protection against liver injury.

[Pachymic acid protects against Crohn's disease-like intestinal barrier injury and colitis in miceby suppressingintestinal epithelial cell apoptosis via inhibiting PI3K/AKT signaling]

OBJECTIVE

To investigate the effect of pachymic acid (PA) against TNBS-induced Crohn's disease (CD)-like colitis in mice and explore the possible mechanism.

METHODS

Twenty-four C57BL/6J mice were randomized equally into control group, TNBS-induced colitis model group and PA treatment group. PA treatment was administered via intraperitoneal injection at the daily dose of 5 mg/kg for 7 days, and the mice in the control and model groups were treated with saline. After the treatments, the mice were euthanized for examination of the disease activity index (DAI) of colitis, body weight changes, colon length, intestinal inflammation, intestinal barrier function and apoptosis of intestinal epithelial cells, and the expressions of TNF-α, IL-6 and IL-1β in the colonic mucosa were detected using ELISA. The possible treatment targets of PA in CD were predicted by network pharmacology. String platform and Cytoscape 3.7.2 software were used to construct the protein-protein interaction (PPI) network. David database was used to analyze the GO function and KEGG pathway; The phosphorylation of PI3K/AKT in the colonic mucosal was detected with Western blotting.

RESULTS

PA significantly alleviated colitis in TNBS-treated mice as shown by improvements in the DAI, body weight loss, colon length, and histological inflammation score and lowered levels of TNF-α, IL-6 and IL-1β. PA treatment also significantly improved FITC-dextran permeability, serum I-FABP level and colonic transepithelial electrical resistance, and inhibited apoptosis of the intestinal epithelial cells in TNBS-treated mice. A total of 248 intersection targets were identified between PA and CD, and the core targets included EGFR, HRAS, SRC, MMP9, STAT3, AKT1, CASP3, ALB, HSP90AA1 and HIF1A. GO and KEGG analysis showed that PA negatively regulated apoptosis in close relation with PI3K/AKT signaling. Molecular docking showed that PA had a strong binding ability with AKT1, ALB, EGFR, HSP90AA1, SRC and STAT3. In TNBS-treated mice, PA significantly decreased p-PI3K and p-AKT expressions in the colonic mucosa.

CONCLUSION

PA ameliorates TNBS-induced intestinal barrier injury in mice by antagonizing apoptosis of intestinal epithelial cells possibly by inhibiting PI3K/AKT signaling.

[Diosmetin regulates intestinal immune balance by inhibiting PI3K/AKT signaling to relieve 2, 4, 6-trinitrobenzene sulfonic acid-induced Crohn's disease-like colitis in mice]

OBJECTIVE

To investigate the therapeutic mechanism of diosmetin on 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)-induced Crohn's disease (CD)-like colitis in mice.

METHODS

Wild-type C57BL/6 mice were randomized into control group, TNBS-induced CD-like colitis group (TNBS group) and 50 mg·kg^-1·d^-1 diosmetin-treated group (n=8). Disease activity (DAI) scores, body weight changes, histological scores, colon lengths and colon mucosal levels of TNF-α, IFN-γ, and IL-17A were measured to evaluate the severity of colitis. The changes of T lymphocyte subsets (Th1/Th2 and Th17/Treg) in the mesenteric lymph nodes were analyzed by flow cytometry. Network pharmacology and molecular docking were used to analyze the effect of diosmetin on PI3K/AKT pathway.

RESULTS

Compared with TNBS group, diosmetin treatment significantly lowered DAI scores, histological scores, body weight loss and colon mucosal levels of TNF-α, IFN-γ, and IL-17A (P < 0.05) and increased the colon length of the rat models, but these improvements did not reach the control levels (P < 0.05). Diosmetin significantly lowered the percentages of Th1/Th17 cells in the mesenteric lymph nodes in TNBS-treated mice, which remained higher than the control levels (P < 0.05); The percentages of Th2/Treg cells were significantly higher in diosmetin group than in TNBS group (P < 0.05) and the control group (P < 0.05). Network pharmacologic analysis identified 46 intersection targets of diosmetin and CD, and among them AKT1, EGFR, SRC, ESR1, MMP9 and PTGS2 were the top 6 core targets. GO and KEGG analyses showed that the PI3K/AKT signaling pathway was closely related with the therapeutic effect of diosmetin on CD-like colitis. Molecular docking suggested strong binding of diosmetin to the key core targets. Diosmetin significantly reduced the levels of p-PI3K and p-AKT in the colon mucosa in TNBS-treated mice (P < 0.05), but their levels remained higher than those in the control group (P < 0.05).

CONCLUSION

Diosmetin ameliorates TNBS-induced CDPlike colitis in mice possibly by regulating Th1/Th2 and Th17/Treg balance to improve intestinal immune disorder through inhibition of PI3K/AKT signaling.

Airway Phenotypes and Nocturnal Wearing of Dentures in Elders with Sleep Apnea

The objective of this study was to examine to what extent the anatomic characteristics of the upper airway can influence the effect of nocturnal wearing of dentures on the sleep of edentulous elders with untreated sleep apnea. This study used the data from a randomized crossover clinical trial and an exploratory approach to address its objectives. Cone beam computed tomography scans of 65 edentulous individuals (female, n = 37; male, n = 28; mean ± SD age, 74.54 ± 6.42 y) with untreated obstructive sleep apnea (OSA) were used to identify anatomic variables. Polysomnography data were collected by means of one portable overnight recording. The respiratory variable values, including apnea-hypopnea index (AHI), with and without denture worn during sleep were used to calculate the change. Statistical analyses included multiple linear regressions, cluster analysis, and binary logistic regressions. A receiver operator characteristic curve was used to illustrate the accuracy of the statistical model. The regression model explained 15.8% (R²) of AHI change. An increase in the lateral dimension of the minimum cross-sectional area was associated with a decrease in AHI, oxygen desaturation index, and respiratory arousal index changes (P ≤ 0.041). Furthermore, an increase in the length of the hypopharynx was associated with an increase in AHI and oxygen desaturation index changes (P ≤ 0.027). An increase in the lateral dimension of the minimum cross-sectional area of the upper airway was associated with a decreased likelihood of being in the group having a worsened AHI (odds ratio = 0.85; 95% CI, 0.76 to 0.95; P = 0.006). An increase in the length of the oropharynx was associated with an increased likelihood of having increased AHI (odds ratio = 1.10; 95% CI, 1.01 to 1.20; P = 0.026). The nocturnal aggravation of respiratory variables in edentulous individuals with OSA who wear dentures at night can be linked to certain anatomic characteristics of the upper airway. Replication of these findings may open novel avenues for personalized advice regarding nocturnal wearing of dentures in edentulous individuals with OSA (ClinicalTrials.gov: NCT01868295).

TMT-based comparative proteomic analysis of Dezhou donkey spermatozoa related to freezability

The freezability difference between donkey ejaculates is a limiting factor of sperm cryopreservation. Our recent study shows that the freezability of donkey semen is related to the seminal plasma proteome. In this study, we aimed to identify the different abundance sperm proteins in good freezability ejaculates (GFEs) and poor freezability ejaculates (PFEs) using a Tandem Mass Tag (TMT) peptide labeling coupled with LC-MS/MS approach. A total of 2682 proteins were identified, among which 58 were significantly up-regulated in GFEs and 16 were down-regulated compared with PFEs. Bioinformatic analysis results revealed that the majority of different abundance proteins (DAPs) participated in copper and calcium binding, regulation of RNA biosynthetic process, positive regulation of innate immune response, and negative regulation of programmed cell death. KEGG pathway enrichment analysis showed the up-regulated proteins in GF group were mainly involved in N-Glycan biosynthesis and protein processing in endoplasmic reticulum. Our study was the first to analyze the proteome of sperm from donkey ejaculates with different freezabilities. The identified candidate proteins might be used to explore the molecular mechanism related to donkey sperm cryotolerance and might improve the screening of jacks with good sperm freezability. SIGNIFICANCE: Cryopreserved semen has been widely used in assisted reproductive technology. However, semen cryopreservation is a damaging process, which can cause oxidative stress, reduce sperm motility and motility. There are differences in sperm freezability reported to exist between or within breeds, and even between fractions coming from the same ejaculate. The freezability difference between donkey ejaculates is a limiting factor of sperm cryopreservation. The mechanisms that affect the freezing difference in sperm quality remain to be investigated, and freezability differences was found to be related to protein composition of spermatozoa. Some protein markers that can indicate good freezability or poor freezability semen have been identified in mammals. Until now, there is no information about the relationship between donkey spermatozoa proteome and freezability. Additional novel biomarkers of semen freezability in donkey spermatozoa are also needed. The identified candidate proteins might be used to explore the molecular mechanism related to donkey sperm cryotolerance and might improve the screening of jacks with good sperm freezability.

Assessment of semen quality and anti-oxidative enzyme activity between bovine sex-sorted and non-sex-sorted frozen-thawed semen

In the current study, the difference between the sex-sorted and non-sex-sorted frozen semen of Holstein Friesian breed cattle was investigated. Significant variation (p < .05) was found in the semen quality parameters such as motility; vitality; acrosome integrity rate; the anti-oxidative enzyme activity including GSH (glutathione); SOD (superoxide dismutase); CAT (catalase); GSH-Px (glutathione peroxidase) and the rate of fertilization. The results showed that the sperm acrosome integrity and motility of the non-sorted sperm were higher compared to sex-sorted sperm (p < .05). The linearity index and mean coefficient analysis revealed that the percentage of 'grade a' in sex-sorted sperm were significantly (p < .05) lower than non-sorted sperm. Interestingly, low SOD level and high CAT level was found in the non-sexed semen than in the sexed semen (p < .05). Furthermore, the GSH and GSH-Px activity in the sexed semen was found lower than the non-sexed semen (p < .05). In conclusion, sperm motility characteristics were lower in sex-sorted semen than in non-sex-sorted semen. This might be related to the complex process of sexed semen production, which could reduce sperm motility and movement characteristics, acrosomal integrity, CAT, SOD, GSH and GSH-Px, and finally lead to the decline in the fertilization rate.

Porphyromonas gingivalis Evades Immune Clearance by Regulating Lysosome Efflux

Porphyromonas gingivalis, a major periodontal pathogen, invades autophagosomes of cells, including gingival epithelial cells, endothelial cells, gingival fibroblasts, macrophages, and dendritic cells, to escape antimicrobial autophagy and lysosome fusion. However, it is not known how P. gingivalis resists autophagic immunity, survives within cells, and induces inflammation. Thus, we investigated whether P. gingivalis could escape antimicrobial autophagy by promoting lysosome efflux to block autophagic maturation, leading to intracellular survival, and whether the growth of P. gingivalis within cells results in cellular oxidative stress, causing mitochondrial damage and inflammatory responses. P. gingivalis invaded human immortalized oral epithelial cells in vitro and mouse oral epithelial cells of gingival tissues in vivo. The production of reactive oxygen species (ROS) increased upon bacterial invasion, as well as mitochondrial dysfunction-related parameters with downregulated mitochondrial membrane potential and intracellular adenosine triphosphate (ATP), upregulated mitochondrial membrane permeability, intracellular Ca²⁺ influx, mitochondrial DNA expression, and extracellular ATP. Lysosome excretion was elevated, the number of intracellular lysosomes was diminished, and lysosomal-associated membrane protein 2 was downregulated. Expression of autophagy-related proteins, microtubule-associated protein light chain 3, sequestosome-1, the NLRP3 inflammasome, and interleukin-1β increased with P. gingivalis infection. P. gingivalis may survive in vivo by promoting lysosome efflux, blocking autophagosome-lysosome fusion, and destroying autophagic flux. As a result, ROS and damaged mitochondria accumulated and activated the NLRP3 inflammasome, which recruited the adaptor protein ASC and caspase 1, leading to the production of proinflammatory factor interleukin-1β and inflammation.

Changes of sperm metabolites of Dezhou donkey after cryopreservation

Sperm cryopreservation technology has laid the foundation for promoting the popularity of artificial insemination in donkey reproduction, but the freeze-thaw process can cause sperm damage, and the viability of frozen sperm is greatly reduced, resulting in low insemination ability. Sperm metabolites play an important role in the freezing process of spermatozoa and have a major influence on the freezability of spermatozoa. The aim of this study was to explore the differential metabolites in donkey spermatozoa before and after cryopreservation by liquid chromatography tandem mass spectrometry (LC-MS/MS). We analysed ejaculate samples from male donkeys obtained before and after freezing and identified 1323 metabolites. Compared with fresh sperm (F), the metabolites of cryopreserved sperm (CRY) were significantly changed, and 570 metabolites were significantly different between the two groups (P < 0.05). Among them, 277 metabolites were higher in frozen sperm, while the opposite was true for 293 metabolites. These metabolites mainly include phospholipids, lysophospholipids, and amino acids., most of which are associated with oxidative stress and sperm capacitation. We describe significantly different metabolites before and after freezing that are significantly associated with decreased sperm motility postfreezing and can be used as biomarkers of decreased sperm motility postfreezing.

[Centromere protein U is highly expressed in colorectal cancer and associated with a poor long-term prognosis]

OBJECTIVE

To analyze the expression of centromere protein U (CENPU) in colorectal cancer and its predictive value for long-term prognosis of the patients.

METHODS

We retrospectively analyzed the data of 102 patients with colorectal cancer undergoing radical resection in our hospital between January, 2005 and December, 2011. The expression level of CENPU in colorectal cancer tissue was detected immunohistochemically, and its association with clinicopathological characteristics of the patients were analyzed. The patients were divided into low expression group (n=51) and high expression group (n=51) based on the median CENPU expression level for analysis the value of CENPU for predicting long-term prognosis of the patients after radical resection of the tumors. In the in vitro study, we constructed colorectal cancer cell lines with CENPU interference and CENPU overexpression by lentiviral transfection and assessed the changes in the proliferation, migration and invasion of the cells using CCK-8 assay and Transwell assay.

RESULTS

The protein expression level of CENPU was significantly higher in colorectal cancer tissues than in the adjacent tissues (P < 0.05) and was positively correlated with the expressions levels of Ki67 (r=0.569, P < 0.05) and VEGF-C (r=0.629, P < 0.05). CENPU expression level in colorectal cancer tissue was closely related with tumor progression and clinicopathological stage of the tumor (P < 0.05). Kaplan-Meier survival analysis showed that the patients with high CENPU expression had significantly decreased postoperative overall survival (χ²=11.155, P < 0.05); Cox multivariate regression analysis suggested that CENPU expression level was an independent risk factor affecting the overall survival of the patients after radical resection (HR=1.848, P < 0.05). The results of cell experiments demonstrated that high CENPU expression significantly promoted the proliferation, migration and invasion of the tumor cells.

CONCLUSION

CENPU is highly expressed in colorectal cancer tissues in closely correlation with tumor progression and may serve as a potential biomarker for evaluating the long-term prognosis of colorectal cancer patients.

Comparative Whey Proteome Profiling of Donkey Milk With Human and Cow Milk

Donkey milk (DM), similar to human milk (HM) in chemical composition, has been suggested as the best potential hypoallergenic replacement diet for babies suffering from Cow milk (CM) protein allergy. In order to better understand DM protein, many studies based on proteomic have been performed. In this study, the label-free quantitative proteomic approach was conducted to quantitatively identify the differentially expressed whey proteins (DEPs) in DM vs. HM group and DM vs. CM group. In total, 241 and 365 DEPs were found in these two groups, respectively. Bioinformatics analysis of DEPs showed that the majority of DEPs participated in the lipoprotein metabolic process, regulation of cytokine production, chemical homeostasis, and catabolic process. The Kyoto Encyclopedia of Gene and Genomes (KEGG) pathways analysis found that these DEPs mainly participated in an antigen processing, complement, and coagulation cascades. These results may provide valuable information in the composition of milk whey proteins in DM, HM, and CM, especially for low abundant components, and expand our knowledge of different biological functions between DM and HM or CM.

[ALDH3B1 expression is correlated with histopathology and long-term prognosis of gastric cancer]

OBJECTIVE

To investigate the expression of aldehyde dehydrogenase 3B1 (ALDH3B1) in gastric cancer and explore its correlation with the pathological parameters and long-term prognosis of the patients.

METHODS

We analyzed the clinical data of 101 patients who underwent radical gastrectomy for gastric cancer in our hospital between January, 2013 and November, 2016, and examined the expression of ALDH3B1 in paraffin-embedded samples of gastric cancer tissues and adjacent tissues from these cases by immunohistochemical staining. We evaluated the correlation between ALDH3B1 expressions and histopathological parameters and assessed the predictive value of ALDH3B1 expression for long-term survival of the patients. We also examined the effect of lentivirus-mediated interference and overexpression of ALDH3B1 on the malignant behaviors of MGC-803 gastric cancer cells.

RESULTS

The expressions of ALDH3B1 and Ki67 were significantly higher in gastric cancer tissues than in adjacent tissues (P < 0.05). In gastric cancer patients, ALDH3B1 expression was positively correlated with peripheral blood CEA and CA19-9 levels (P < 0.01). The proportion of patients with CEA ≥5 μg/L, CA19-9 ≥37 kU/L, T stage of 3- 4, and N stage of 2-3 was significantly greater in high ALDH3B1 expression group than in low expression group. Kaplan-Meier survival analysis showed that the 5-year survival rate was significantly lower in gastric cancer patients with high ALDH3B1 expressions (P < 0.01). Univariate and Cox multiple regression analyses identified a high expression of ALDH3B1 (P < 0.05, HR= 0.231, 95% CI: 0.064-0.826), CEA≥5 μg/L (P < 0.01, HR=4.478, 95% CI: 1.530-13.110), CA19-9≥37 kU/L (P < 0.01, HR=3.877, 95% CI: 1.625-9.247), T stage of 3-4 (P < 0.01, HR=4.953, 95% CI: 1.768-13.880), and N stage of 2-3 (P < 0.05, HR=2.152, 95% CI: 1.152-4.022) as independent risk factors affecting 5-year survival after radical gastrectomy. The relative ALDH3B1 expression level, at the cut-off point of 4.66, showed a sensitivity of 76.47% and a specificity of 76% for predicting 5-year postoperative death (P < 0.01). In the cell experiment, overexpression of ALDH3B1 obviously promoted the proliferation, migration and invasion of MGC-803 cells.

CONCLUSION

As an independent risk factor affecting 5-year survival after radical gastrectomy, ALDH3B1 is highly expressed in gastric cancer and correlated with pathological parameters of the tumor, and a high ALDH3B1 expression may promote proliferation, invasion and metastasis of gastric cancer cells.

The role of KLF4 in melanogenesis and homeostasis in sheep melanocytes

KLF4 expression has been associated with hair color in mammals and has also been found to regulate melanoma cell growth. Here, we assessed the influence of KLF4 on coat color formation and melanocytes. We found that KLF4 was highly expressed in the black skin of sheep both at the mRNA and protein levels compared with white skin. KLF4 immunostaining further showed that KLF4 protein was mainly expressed in epidermal, outer root, and hair bulb regions. In sheep melanocytes, the proliferation of melanocytes was inhibited by KLF4 overexpression and this decrease in cell proliferation was coupled with induction of the S phase, cell cycle arrest, and apoptosis. In vitro cell migration assays showed that KLF4 suppressed cell migration. In addition, KLF4 overexpression significantly increased melanin production and pigment-related gene expression. Collectively, our findings show that KLF4 is important for coat color formation and melanocyte homeostasis.

Lipid droplets are dysregulated in the adult dentate gyrus during seizure

Introduction/Objective

Dentate gyrus (DG), a neurogenic niche, is a metabolically dense subregion of the hippocampus. Continuous production and integration of new neurons in the existing circuit and harmonious relationship between excitatory and inhibitory neurons accompanied by neuron-glia coupling is essential to maintain hippocampal homeostasis throughout adulthood. Imbalance in the neuronal activity generates seizures and can result in mesial temporal lobe epilepsy (MTLE). MTLE affects 50 million people across the globe and impairs the overall hippocampal network and its associated functions such as memory and cognition. Although altered lipid metabolism has been associated with status epilepticus, the role of lipid droplets (LDs), the minuscule metabolically active organelle known to provide a substrate for cellular energy, has not been explored in DG during seizure. LDs are composed of neutral lipids and surrounded by phospholipid monolayer, which is studded with a structural Perilipin family of proteins 1-5, reported to be involved in lipid metabolism.

Methods/Case Report

To study LDs in the brain, we used a novel approach by injecting Bodipy, a lipid dye in the tail vein of mice, and successfully labeled LDs in the DG. We used the pilocarpine-induced seizure model. After Bodipy injection followed by seizure induction, mice were sacrificed at four time-points 0.5, 1-, 3- and 18 hours.

Results (if a Case Study enter NA)

We found a significant increase in Bodipy signal and Perilipin 4, LDs specific marker expression at four time-points post-seizure than in the control cohort. To elucidate the role of neuron-glia metabolic coupling in DG, we measured LDs in microglia and astrocytes and found a significant increase in LDs in seizure mice than control groups suggesting the role of glia in lipid regulation in DG.

Conclusion

Overall, this novel study will highlight the undiscovered role of LDs in dentate gyrus during seizure and, in the future, can be used as a therapeutic target to alleviate the MTLE phenotype.

Association of delayed time in the emergency department with the clinical outcomes for critically ill patients

BACKGROUND

Previous studies have shown the association of waiting time in the emergency department with the prognosis of critically ill patients, but these studies linking the waiting time to clinical outcomes have been inconsistent and limited by small sample size.

AIM

To determine the relationship between the waiting time in the emergency department and the clinical outcomes for critically ill patients in a large sample population.

DESIGN

A retrospective cohort study of 13 634 patients.

METHODS

We used the Medical Information Mart for Intensive Care III database. Multivariable logistic regression was used to determine the independent relationships of the in-hospital mortality rate with the delayed time and different groups. Interaction and stratified analysis were conducted to test whether the effect of delayed time differed across various subgroups.

RESULTS

After adjustments, the in-hospital mortality in the ≥6 h group increased by 38.1% (OR 1.381, 95% CI 1.221-1.562). Moreover, each delayed hour was associated independently with a 1.0% increase in the risk of in-hospital mortality (OR 1.010, 95% CI 1.008-1.010). In the stratified analysis, intensive care unit (ICU) types, length of hospital stay, length of ICU stay, simplified acute physiology score II and diagnostic category were found to have interactions with ≥6 h group in in-hospital mortality.

CONCLUSIONS

In this large retrospective cohort study, every delayed hour was associated with an increase in mortality. Furthermore, clinicians should be cautious of patients diagnosed with sepsis, liver/renal/metabolic diseases, internal hemorrhage and cardiovascular disease, and if conditions permit, they should give priority to transferring to the corresponding ICUs.

[Value of prediction models for prognosis prediction of colorectal cancer: an analysis based on TCPA database]

OBJECTIVE

To assess the value of the combination of multiple proteins in predicting the prognosis of colorectal cancer (CRC) through bioinformatics analysis.

OBJECTIVE

The protein expression and clinical data were downloaded from TCPA database. Perl and R were used to screen the prognostic-related proteins, and through Cox analysis, the proteins that served as independent prognostic factors of CRC were identified to build the prediction model. Survival analyses were conducted for each of the proteins included in the prediction model and the risk score of the model, and risk curves was drawn for the risk score and the patients' survival status to verify the performance of the model. Independent prognosis analysis and ROC analysis were used to assess the value and advantages of the model in prognosis prediction. The interactions between the proteins included in the model and the differential expressions of the key genes related with the proteins were analyzed.

OBJECTIVE

Six proteins were screened for model construction. Compared with a single gene, the model showed much greater prognostic value for CRC. Independent prognostic analysis showed that the risk score of the prediction model was significantly related with the prognosis (P < 0.001), and the model could be used as an independent risk factor for prognostic assessment of the patients. ROC analysis showed that the model had good specificity and sensitivity for prognostic prediction (AUC=0.734). Protein interactions showed that BID, SLC1A5 and SRC_pY527 were significantly correlated with other proteins (P < 0.001), and SLC1A5 and SRC_pY527 had the most significant interactions with other proteins (P < 0.001). Except for those of INPP4B, the key genes related with the proteins in the prediction model had significant differential expressions at the mRNA level in CRC (P < 0.05).

OBJECTIVE

The prediction model constructed based on 6 proteins has good prognostic value for CRC. The proteins SLC1A5 and SRC_pY527 play key roles in the prognosis of CRC, and SRC_pY527 may regulate the occurrence and progression of CRC through the SRC/AKT/MAPK signal axis and thus may serve as a new therapeutic target of CRC.

CRISPR-mediated BMP9 ablation promotes liver steatosis via the down-regulation of PPARα expression

Obesity drives the development of nonalcoholic fatty liver disease (NAFLD) characterized by hepatic steatosis. Several bone morphogenetic proteins (BMPs) except BMP9 were reported related to metabolic syndrome. This study demonstrates that liver cytokine BMP9 is decreased in the liver and serum of NAFLD model mice and patients. BMP9 knockdown induces lipid accumulation in Hepa 1-6 cells. BMP9-knockout mice exhibit hepatosteatosis due to down-regulated peroxisome proliferator-activated receptor α (PPARα) expression and reduced fatty acid oxidation. In vitro, recombinant BMP9 treatment attenuates triglyceride accumulation by enhancing PPARα promoter activity via the activation of p-smad. PPARα-specific antagonist GW6471 abolishes the effect of BMP9 knockdown. Furthermore, adeno-associated virus-mediated BMP9 overexpression in mouse liver markedly relieves liver steatosis and obesity-related metabolic syndrome. These findings indicate that BMP9 plays a critical role in regulating hepatic lipid metabolism in a PPARα-dependent manner and may provide a previously unknown insight into NAFLD therapeutic approaches.

[Research progress in relationship between tooth loss and Alzheimer's disease]

Tooth loss is a common disease in the elderly, and periodontitis is the main cause of tooth loss. Alzheimer's disease is a primary degenerative brain disease which etiology remains unknown. The patients often demonstrate cognitive impairment with characteristic neuropathological and neurochemical changes. The present article reviewed the relationship and associated mechanisms between tooth loss and Alzheimer's disease.

[Study on the safety and immunogenicity of simultaneous vaccination on both hepatitis E and hepatitis B vaccines]

Objective: Safety and immunogenicity regarding simultaneous vaccination on both hepatitis E and hepatitis B vaccines were studied. Methods: A total of 600 healthy subjects aged 18-60 were recruited in Chaoyang district of Beijing city, from September 2015 to December 2016. Subjects meeting the inclusion and exclusion criteria were randomly divided into 3 groups: the simultaneous vaccination group of hepatitis E and hepatitis B, the hepatitis B vaccination group and the hepatitis E vaccination group. Members of the 3 groups were all inoculated according to the procedure of '0, 1 and 6 months'. Safety and immunogenicity of the simultaneous vaccination group was compared with the individual vaccination groups. Results: Vaccination groups had 601 subjects, involved with having 150 subjects of hepatitis E vaccination group, 159 subjects of hepatitis B vaccination group, and 292 subjects of simultaneous vaccination of hepatitis E and hepatitis B. Local adverse reactions that mostly common seen, would include pain (25.0%, 73/292), redness (12.7%, 37/292), pruritus (9.2%, 27/292), callus (8.9%, 26/292), swelling (8.2%, 24/292) at the inoculation sites. Systemic adverse reactions would include fever (7.2%, 21/292), headache (5.8%, 17/292), muscle pain (5.5%, 16/292) and fatigue (3.4%, 10/292). No serious adverse reactions associated with vaccination were seen. In addition to the higher incidence of pain at the inoculation sites, rest of the adverse reactions was similar to the simultaneous vaccination group or the individual vaccination groups. One month after the completed immunization process, positive rate and geometric mean concentration(GMC) of the HBsAb were not inferior to that of the hepatitis B vaccine group (94.2% vs. 93.8%, 611.6 WU/ml vs. 745.1 WU/ml). Positive rate and GMC of the HEV IgG were not inferior to that of the hepatitis E vaccinated group (98.8% vs. 100.0%, 11.0 WU/ml vs. 18.0 WU/ml). Conclusions: Simultaneous vaccination strategy on hepatitis E and hepatitis B vaccines showed good safety and immunogenicity. It is recommended that hepatitis E and hepatitis B vaccines should be administered to the susceptible population at the same time, in order to protect the liver functions.

Retraction Note: circRNA_100290 plays a role in oral cancer by functioning as a sponge of the miR-29 family

The Editors and Publisher have agreed to retract the above paper following a request from the authors.

Protein Classification of Diffuse-Type Gastric Cancer Using Formalin-Fixed Paraffin-Embedded Samples

Background: Gastric cancer (GC) is the third leading cause of cancer deaths in the world. It is highly heterogeneous. Many molecular therapies for GC have entered clinical trials but, apart from trastuzumab, apatinib and ramucirumab, all have failed. One important reason is that insufficient attention is paid to the underlying subtypes and characteristics of GC, especially the diffuse-type gastric cancer (DGC) according to the Lauren classification with worst clinical outcomes. Aim: Here we firstly investigated formalin-fixed paraffin-embedded (FFPE) samples of DGC to establish clinically relevant molecular classification based on proteomics analysis. Also, we tried to generate a suitable classifier of DGC that can guide patient therapy. Methods: We screened a total of 2548 cases retrospectively, who underwent GC resection at Beijing Cancer Hospital from October 2006 to December 2011. We used a fast mass spectrometry workflow for proteome profiling. Finally we carried out proteome profiling of 99 DGC paired tumor-nearby tissues from FFPE sections. Median overall survival of the whole population was 55.0 months. Proteome profiling data from these samples were used to develop a subtype prediction model. We used consensus clustering to identify molecular subtypes based on differentially expressed proteins. The pathway enrichment was performed by GSEA, and the prediction classifier was generated by elastic-net machine learning. Kaplan-Meier survival analysis and Cox regression multivariate analysis were used. Results: A total of 8201 gene products were identified in this study, and 1249 differential expressed proteins between tumor and nearby-normal tissue was detected (FDR q-value < 0.01 by SAM). Tumor upregulated proteins mostly enriched into pathways including RNA processing, epithelial-mesenchymal transition (EMT), immune response and inflammation related pathways. Tumor downregulated proteins mostly enriched into metabolic pathways such as oxidative phosphorylation pathway. Based on proteome profiling alone, DGC can be subtyped into 3 major classes (PX1-3) that exhibit distinct proteome features and correlate with distinct clinical outcomes. PX1 (31 patients) exhibits RNA processing proteins and associates with the best prognosis; PX2 (26 patients) exhibits highly expressed cell cycle features, and the patients have poorer prognosis than those with cluster1 but better prognosis than those with cluster3; PX3 (42 patients) features EMT and the worst prognosis. We built a classifier of 12 marker proteins that can stratify DGC patients into these 3 subtypes, opening a door for protein classification in clinical application and intervention. Conclusion: Our study demonstrated that proteome profiling alone from FFPE samples was able to subtype DGC into 3 protein subtypes that were linked to distinct patterns of molecular alterations and prognosis. The prediction model need to be further verified in more clinical cohorts.

Novel characterization method of impedance cardiography signals using time-frequency distributions

The purpose of this document is to describe a methodology to select the most adequate time-frequency distribution (TFD) kernel for the characterization of impedance cardiography signals (ICG). The predominant ICG beat was extracted from a patient and was synthetized using time-frequency variant Fourier approximations. These synthetized signals were used to optimize several TFD kernels according to a performance maximization. The optimized kernels were tested for noise resistance on a clinical database. The resulting optimized TFD kernels are presented with their performance calculated using newly proposed methods. The procedure explained in this work showcases a new method to select an appropriate kernel for ICG signals and compares the performance of different time-frequency kernels found in the literature for the case of ICG signals. We conclude that, for ICG signals, the performance (P) of the spectrogram with either Hanning or Hamming windows (P = 0.780) and the extended modified beta distribution (P = 0.765) provided similar results, higher than the rest of analyzed kernels. Graphical abstract Flowchart for the optimization of time-frequency distribution kernels for impedance cardiography signals.

[The state of the art research findings on the relationship between chronic periodontitis and Alzheimer's disease: a review]

Along with the development of periodontal medicine, there is a growing number of evidence showing that periodontitis could influence systemic health. Periodontitis is a chronic inflammatory disease caused by microbial infection mediated by dental plaque. Periodontal pathogenic microorganisms and its toxic products can disseminate through the blood stream or may cause the host immune response, which may lead to pathological changes of cerebral vessels and brain tissues to establish connection with Alzheimer's disease (AD). AD is a progressive neurodegenerative disease characterized by progressive memory loss, language and cognitive dysfunction. This article reviewed the association between chronic periodontitis and AD.

Effects of curcumin plus Soy oligosaccharides on intestinal flora of rats with ulcerative colitis

To explore the therapeutic effect of curcumin (Cur) and soybean oligosaccharides (SBOS) on ulcerative colitis (UC) through testing the intestinal flora and ulcerative colitis (UC). 80 male SD rats were selected divided into four groups with 20 rats in each group: normal group, sulfasalazine (SASP) group, model group and group of curcumin plus soy oligosaccharide. All animals were treated for 4 weeks. In the fifth week rats were decapitated. Macroscopic damage scores of colonic mucosa were calculated. A 4mL blood sample was taken to detect the contents of serum tumor necrosis factor -α (TNF-α) and interleukin 8 (IL-8) by the double antibody sandwich ABC-ELISA method (enzyme-linked immunosorbent assay). Colonic tissues with the most obvious lesions were obtained using a surgical scissor. A routine hematoxylin-eosin (HE) staining method was used to stain pathological specimens and images of staining results were obtained. Histological injury scores of colonic mucosa were calculated. Ulcerative colitis model rats had the highest macroscopic damage scores and histological injury scores of colonic mucosa. After treatment the contents of TNF-α and IL-8 decreased significantly in the group of curcumin plus soy oligosaccharide compared with the model group with statistical significance (P <0.01) while the contents were close to those in the SASP group. There was no statistical significance (P> 0.05). The treatment could decrease TNF-α and IL- 8 expression and reduce colonic mucosa inflammation and tissue damage.

Identification of atypical porcine pestivirus infection in swine herds in China

Atypical porcine pestivirus (APPV) have been detected in swine herds from the USA, Germany, the Netherlands, Spain and most recently in Austria, suggesting a wide geographic distribution of this novel virus. Here, for the first time, we reported APPV infection in swine herds in China. Newborn piglets from two separate swine herds in Guangdong province were found showing typical congenital tremors in July and August 2016. RT-PCR, sequencing and phylogenetic analysis showed APPV infection occurred. Phylogenetic analysis showed that Chinese APPV strains, GD1 and GD2, formed independent branch from the USA, Germany and the Netherlands. Nucleotide identities between members of the APPV ranged between 83.1% and 83.5%, and this showed APPV is highly diverse. It is apparent that this provides the first molecular evidence of APPV infection in swine herds in China.

The prevalence of latent tuberculosis infection in rural Jiangsu, China

OBJECTIVES

Diagnosis and interventional treatment of latent tuberculosis (TB) infection (LTBI) are important components in tuberculosis control. But systematic studies regarding the epidemic of LTBI are still rare in China. The objective of this study was to assess the prevalence and risk factors associated with LTBI based on the results of a domestic TB-specific gamma interferon (IFN-γ) release assay (TB-IGRA) in rural Jiangsu, China.

STUDY DESIGN

Cross-sectional study of subjects registered in eight villages in Jiangsu, China.

METHODS

This study was conducted in 2012 in eight villages. After recruitment, individuals with active TB or a history of TB were excluded. The TB-IGRA was performed for diagnosis of LTBI.

RESULTS

2169 of 2185 subjects met the requirement and were analysed in this study. 524 (24.3%) had a positive result, and positive rate gradually increased with age (P for trend <0.001). Multivariate analyses showed that increasing age, male gender and a history of TB exposure were risk factors associated with LTBI. Bacillus Calmette-Guérin (BCG) vaccination did not reduce the risk of TB infection in participants (aged ≥20 years).

CONCLUSIONS

The findings of this study demonstrate that the prevalence of LTBI in China might be overestimated by tuberculin skin test compared with IFN-γ release assay (IGRA). The degree of TB exposure is related to Mycobacterium tubercuium (MTB) infection, and BCG vaccination offers little protection against MTB infection in adults. The early and effective detection and treatment of active TB patients, and screening and intervention for LTBI patients with a high risk of developing active TB could be cost-effective methods for TB control in China.

Aortic dissection is associated with reduced polycystin-1 expression, an abnormality that leads to increased ERK phosphorylation in vascular smooth muscle cells

The vascular smooth muscle cell (VSMC) phenotypic switch is a key pathophysiological change in various cardiovascular diseases, such as aortic dissection (AD), with a high morbidity. Polycystin-1 (PC1) is significantly downregulated in the VSMCs of AD patients. PC1 is an integral membrane glycoprotein and kinase that regulates different biological processes, including cell proliferation, apoptosis, and cell polarity. However, the role of PC1 in intracellular signaling pathways remains poorly understood. In this study, PC1 downregulation in VSMCs promoted the expression of SM22α, ACTA2 and calponin 1 (CNN1) proteins. Furthermore, PC1 downregulation in VSMCs upregulated phospho-MEK, phospho-ERK and myc, but did not change phospho-JNK and phospho-p38. These findings suggest that the MEK/ERK/myc signaling pathway is involved in PC1-mediated human VSMC phenotypic switch. Opposite results were observed when an ERK inhibitor was used in VSMCs downregulated by PC1. When the C-terminal domain of PC1 (PC1 C-tail) was overexpressed in VSMCs, the expression levels of phosphor-ERK, myc, SM22α, ACTA2 and CNN1 proteins were downregulated. The group with the overexpressed mutant protein (S4166A) in the PC1 C-tail showed similar results to the group with the downregulated PC1 in VSMCs. These results suggest that the Ser at the 4166 site in PC1 is crucial in the PC1 mediated MEK/ERK/myc signaling pathway, which might be the key pathophysiological cause of AD.

JC polyomavirus viremia and progressive multifocal leukoencephalopathy in human leukocyte antigen-sensitized kidney transplant recipients desensitized with intravenous immunoglobulin and rituximab

BACKGROUND

Desensitization (DES) with intravenous immunoglobulin (IVIG) + rituximab is effective, safe, and increases the transplantation rate in human leukocyte antigen-sensitized patients. However, reports of progressive multifocal leukoencephalopathy (PML) caused by JC polyomavirus (JCPyV) in autoimmune patients treated with rituximab is concerning. Here, we report on the JCPyV viremia and PML status in kidney transplant patients with/without DES (non-DES).

METHODS

In total 1195 and 699 DNA samples from plasma in 117 DES (78% lymphocyte-depleting [LyD] induction) and 100 non-DES patients (45% LyD), respectively, were submitted for JCPyV-polymerase chain reaction. Results were compared in both groups.

RESULTS

No patients in either DES or non-DES developed PML or presented with any neurological symptoms. The JCPyV viremia rate was similar in DES and non-DES patients (3/117 vs. 9/100, P = 0.07). The JCPyV levels were low (median peak levels, 1025 copies/mL) and JCPyV viremia was observed only once during the study period in most patients. All 3 DES patients with JCPyV(+) received 1 dose rituximab and no DES patients with >1 dose rituximab showed JCPyV(+). All 3 JCPyV(+) DES patients received LyD induction, while only 2 of 9 JCPyV(+) non-DES patients did so, and the remaining 7 received non-LyD or no induction. JCPyV in leukocyte was mostly negative in DES and non-DES patients. Immunosuppression in patients with or without JCPyV(+) was similar. BK polyomavirus viremia was observed more commonly in patients with JCPyV(+) than in those without (P < 0.02).

CONCLUSIONS

Patients with IVIG + rituximab DES followed by transplantation with LyD induction and additional rituximab rarely show JCPyV viremia and appear at low risk for PML.

Liver Transplantation in a Patient With CD40 Ligand Deficiency and Hyper-IgM Syndrome: Clinical and Immunological Assessments

Monoclonal antibodies that disrupt CD40-CD40 ligand (CD40L) interactions are likely to have use in human transplantation. However, the extent of the immunosuppressive effects of CD40-CD40L blockade in humans is unknown. Hyper-IgM syndrome (HIGM) is a rare primary immunodeficiency syndrome characterized by defects in the CD40-CD40L pathway, severe immune deficiency (IgG), and high or normal IgM levels. However, the effects of CD40L deficiency on T- and natural killer (NK)-cell function is not established. Here, we present a patient with HIGM syndrome who underwent liver transplantation for hepatitis C virus infection. Posttransplantation, NK-cell antibody-dependent cytokine release (γ-interferon) to alloantigens and T cell responses to viral antigens and mitogens were assessed and showed normal CD4⁺ , CD8⁺ , and NK-cell responses. We also examined antibody-dependent cellular cytotoxicity against a CD40⁺ and HLA-expressing cell line. These experiments confirmed that the patient's NK cells were equivalent to those of normal subjects in mediating antibody-dependent cellular cytotoxicity despite the absence of CD40-CD40L interactions. Mitogenic stimulation of the patient's peripheral blood mononuclear cells showed no expression of CD40L on T and NK cells compared with increased expression in normal subjects. Taken together, these data suggest that absence of CD40L expression is responsible for aberrant B cell immunity but had little impact on NK- and T cell immune responses in vitro.

The association between ankle-brachial index and asymptomatic cranial-carotid stenosis: a population-based, cross-sectional study of 5440 Han Chinese

BACKGROUND AND PURPOSE

Routine screening for asymptomatic cranial-carotid stenosis (ACCS) is controversial and recommendation in clinical practice is vague. The ankle-brachial index (ABI) is reported as a predictor for cardiovascular disease. However, there is a scarcity of data about the association between abnormal ABI and ACCS. A population-based cross-sectional study was conducted to explore the relationship between ABI and ACCS.

METHODS

A sample of 5440 Chinese adults aged 40-94 years old was recruited from 2010 to 2011. The ABI was measured using a portable Doppler device and ACCS was evaluated by bilateral carotid duplex ultrasound and portable examination devices. A logistic regression model was used to analyse the association between ABI and ACCS after adjusting for potential confounding factors.

RESULTS

A low ABI was associated with ACCS [odds ratio (OR) 1.95, 95% confidence interval (CI) 1.42-2.67] after adjusting for potential confounders. When the data were stratified by age and sex, the correlation remained statistically significant in the male (OR 2.32, 95% CI 1.60-3.37) and elderly (OR 3.07, 95% CI 1.97-4.78) subgroups compared to the female (OR 1.26, 95% CI 0.67-2.39) and middle-aged groups (OR 1.27, 95% CI 0.77-2.12), respectively.

CONCLUSION

This study demonstrated that low ABI is a significant risk factor for ACCS in male and elderly Chinese adults.

Zoledronic acid suppresses callus remodeling but enhances callus strength in an osteoporotic rat model of fracture healing

MINI-ABSTRACT

In this study, we demonstrated that the use of zoledronic acid does not impair fracture healing, but results in superior callus size and resistance at the fracture site, which could be the consequence of a lower rate of bone turnover due to its anti-catabolic effect.

OBJECTIVE

To investigate the effect of inhibition of bone remodeling by the bisphosphonate, zoledronic acid, on callus properties in an osteoporotic rat model of fracture healing.

METHODS

Ovariectomized (OVX) rats were randomly divided into four treatment groups (n=24 per group): saline control (CNT); and three systemic zoledronic acid-injected groups (0.1mg/kg), administered 1 day (ZOLD1), 1 week (ZOLW1), and 2 weeks (ZOLW2) after fracture. Rats were killed at either 6 or 12 weeks postoperatively. Postmortem analyses included radiography, microcomputed tomography, histology, histomorphometry, biomechanical tests, and nanoindentation tests.

RESULTS

Treatment with zoledronic acid led to a significant increase in trabecular bone volume within the callus, as well as in callus resistance, compared to those in the saline control rats; delayed administration (ZOLW2) reduced intrinsic material properties, including ultimate stress and elastic modulus, and microarchitecture parameters, including bone volume/total volume (BV/TV), trabecular thickness (Tb.Th), and connectivity density (Conn.D), compared with ZOLD1 at 12 weeks after surgery. OVX had a negative effect on the progression of endochondral ossification at 6 weeks. Zoledronic acid administration at an early stage following fracture may bind to early callus, and thus not affect subsequent callus formation and endochondral ossification, while delayed administration (ZOLW2) mildly suppresses bony callus remodeling.

CONCLUSION

The superior results obtained with zoledronic acid (ZOLD1, ZOLW1, and ZOLW2) compared to CNT in terms of callus size and resistance could be the consequence of a lower rate of bone turnover at the fracture site due to the anti-catabolic effect of zoledronic acid. Mild suppression of callus remodeling by delayed administration did not impair the initial phase of the fracture healing process.

INDUCED SEISMICITY. High-rate injection is associated with the increase in U.S. mid-continent seismicity

An unprecedented increase in earthquakes in the U.S. mid-continent began in 2009. Many of these earthquakes have been documented as induced by wastewater injection. We examine the relationship between wastewater injection and U.S. mid-continent seismicity using a newly assembled injection well database for the central and eastern United States. We find that the entire increase in earthquake rate is associated with fluid injection wells. High-rate injection wells (>300,000 barrels per month) are much more likely to be associated with earthquakes than lower-rate wells. At the scale of our study, a well's cumulative injected volume, monthly wellhead pressure, depth, and proximity to crystalline basement do not strongly correlate with earthquake association. Managing injection rates may be a useful tool to minimize the likelihood of induced earthquakes.

Expression of cytokeratins in enamel organ, junctional epithelium and epithelial cell rests of Malassez

BACKGROUND AND OBJECTIVE

After tooth formation is complete, it is suggested that continuity exists between the epithelial cell rests of Malassez (ERM), reduced enamel epithelium (REE) and subsequently the junctional epithelium. However, the junctional epithelium was reported to differ from REE and ERM. The developmental relationships between and among them remain controversial. Therefore, in the present study we examined the expression of cytokeratins in the three types of epithelia to investigate the epithelial phenotypes.

MATERIAL AND METHODS

The maxillae of Wistar rats, 1, 2, 3 and 7 wk of age, were used, and the expression of CK14, CK17, CK19, CK10/CK13 and AE1/AE3 was detected using immunoperoxidase techniques.

RESULTS

There was negative staining for CK10/CK13 in all the epithelia. ERM stained strongly for AE1/AE3, CK14, CK17 and CK19. During the transformation of inner enamel epithelial (IEE) cells into reduced ameloblasts and subsequently into junctional epithelium, strong staining for CK14 was evident in IEE, REE and junctional epithelium, whereas the expression of AE1/AE3 and of CK19 were initially negative in IEE and then strong in REE and junctional epithelium, respectively. In particular, the expression of CK17 was strongly positive in ERM and REE, but was negative in IEE and junctional epithelium.

CONCLUSION

ERM are of odontogenic origin and junctional epithelium has an epithelial phenotype different from REE and ERM. This is the first report to demonstrate that CK17 can be used as a marker to distinguish junctional epithelium from ERM.

Effect of friction on vibrotactile sensation of normal and dehydrated skin

BACKGROUND

Vibrotactile sensation mediated is highly dependent on surface mechanical and frictional properties. Dehydration of skin could change these properties.

OBJECTIVES

To investigate the relationship between friction and vibrotactile sensation of normal and dehydrated skin.

METHODS

Vibrations were firstly measured during surface exploration using a biomimetic sensor. Piglet skin was used as human skin model to study frictional properties for both normal and dehydrated skin using an atomic force microscope on nanoscale and a pin-on-disk tribometer on macroscale. Effect of vibrational frequency on friction and vibrotactile perception was also observed on nano and macro scale for normal and dehydrated skin.

RESULTS

The result indicated that dehydrated skin was less sensitive than normal skin. The coefficient of friction of dehydrated skin is smaller than that of normal skin on both nano and macro scale. The coefficient of friction increases as increasing scanning frequencies.

CONCLUSION

There is a positive correlation between coefficient of friction and vibrotactile sensation on nanoscale and macroscale.