TNFSF14 mediates the impact of docosahexaenoic acid on atopic dermatitis: a Mendelian randomization study.

OBJECTIVE: While current research suggests potential value for docosahexaenoic acid (DHA) in the prevention and management of atopic dermatitis (AD), the causal relationship between DHA and AD remains unclear, and the underlying mechanisms are not well understood. MATERIALS AND METHODS: To investigate the potential causal relationship between DHA and AD, as well as to explore potential mediating mechanisms, we employed the Mendelian randomization (MR) methods. To study these potential relationships, we conducted MR analysis using publicly available Genome-Wide Association Studies (GWAS) data. Effect estimates were computed using the random-effects inverse-variance weighted method. RESULTS: Our study demonstrates a negative correlation between DHA levels and AD risk (OR: 0.915, 95% CI: 0.858-0.975, p=0.007). Furthermore, in MR analysis using tumor necrosis factor ligand superfamily member 14 (TNFSF14) levels as an outcome, DHA levels also show a negative association with TNFSF14 levels (OR: 0.933, 95% CI: 0.879-0.990, p=0.022). Subsequently, we performed further analysis to explore the relationship between TNFSF14 and AD risk, revealing a positive correlation (OR: 1.069, 95% CI: 1.005-1.137, p=0.033). This suggests a potential mediating role of TNFSF14 in the impact of DHA on AD risk. CONCLUSIONS: In summary, our study employs MR analysis to offer genetic evidence indicating a potential role of DHA in reducing the risk of AD, as well as opening avenues for further in-depth investigation into potential mechanisms. These findings emphasize the importance of ongoing research in this field.

Enhancing Nasopharyngeal Carcinoma Cell Separation with Selective Fibronectin Coating and Topographical Modification on Polydimethylsiloxane Scaffold Platforms.

The extracellular matrix (ECM) serves as a complex scaffold with diverse physical dimensions and surface properties influencing NPC cell migration. Polydimethylsiloxane (PDMS), a widely used biocompatible material, is hydrophobic and undesirable for cell seeding. Thus, the establishment of a biomimetic model with varied topographies and surface properties is essential for effective NPC43 cell separation from NP460 cells. This study explored how ECM surface properties influence NP460 and NPC43 cell behaviors via plasma treatments and chemical modifications to alter the platform surface. In addition to the conventional oxygen/nitrogen (O2/N2) plasma treatment, O2 and argon plasma treatments were utilized to modify the platform surface, which increased the hydrophilicity of the PDMS platforms, resulting in enhanced cell adhesion. (3-aminopropyl)triethoxysilane and fibronectin (FN) were used to coat the PDMS platforms uniformly and selectively. The chemical coatings significantly affected cell motility and spreading, as cells exhibited faster migration, elongated cell shapes, and larger spreading areas on FN-coated surfaces. Furthermore, narrower top layer trenches with 5 µm width and a lower concentration of 10 µg/mL FN were coated selectively on the platforms to limit NP460 cell movements and enhance NPC43 cell separation efficiency. A significantly high separation efficiency of 99.4% was achieved on the two-layer scaffold platform with 20/5 µm wide ridge/trench (R/T) as the top layer and 40/10 µm wide R/T as the bottom layer, coupling with 10 µg/mL FN selectively coated on the sidewalls of the top and bottom layers. This work demonstrated an innovative application of selective FN coating to direct cell behavior, offering a new perspective to probe into the subtleties of NPC cell separation efficiency. Moreover, this cost-effective and compact microsystem sets a new benchmark for separating cancer cells.

Sialendoscopic removal of metastatic adenocarcinoma in a mucous plug from Stensen's duct.

Sialendoscopy is a minimally invasive technique used mainly in the diagnosis and treatment of obstructive salivary gland disorders. There has yet to be a report on its use in the diagnosis of metastatic disease. While metastatic cancer has been described in numerous head and neck anatomic subsites, it has not been reported to be found in a mucous plug in Stensen's duct. Sialendoscopy was performed in a 68-year-old female patient who presented with symptoms of ductal obstruction. Basket removal of a mucous plug was done and histopathological analysis of this specimen found adenocarcinoma. The overall clinical picture, imaging, and final histopathological results suggested that this patient had metastatic breast carcinoma to a mucous plug in Stensen's duct, the diagnosis of which was made with the aid of interventional sialendoscopy. This is the first report in which metastatic cancer was identified in a mucous plug in Stensen's duct. Sialendoscopy can be a useful tool to aid in the diagnosis of metastatic diseases in rare and unusual clinical situations.

[Risk factors and chemoprophylaxis of ulcerative colitis-colorectal cancer].

Ulcerative colitis-colorectal cancer (UC-CRC) is one of the most serious complications in patients with ulcerative colitis (UC), with worse prognosis and higher mortality than sporadic colorectal cancer (CRC). Since most UC-CRC developed through the "inflammation-dysplasia-carcinoma" approach, early detection of dysplasia through identification of high-risk groups reasonable monitoring and active prevention are extremely important. However, there is no consensus on the risk factors of UC carcinogenesis and the drugs that can be used for chemoprevention currently. This article combined with relevant literature at home and abroad, reviewed the current risk factors and chemopreventive drugs for UC carcinogenesis, in order to provide reference for early prevention, early detection and early diagnosis of UC-CRC.

[Predicting value on short-term outcome of various established risk prediction models in extracorporeal membrane oxygenation treated cardiogenic shock patients due to ST-segment elevation myocardial infarction].

Objective: To investigate the predicting value of different risk prediction models for short-term death in patients with ST-segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock and treated with extracorporeal membrane oxygenation (ECMO). Methods: This study was a retrospective case-control study. Forty patients with STEMI complicated by cardiogenic shock who hospitalized in the First Affiliated Hospital of Zhengzhou University from April 2017 to August 2021 and treated with percutaneous coronary intervention (PCI) and ECMO, were enrolled in this study. Patients were divided into survival group and death group according to their clinical outcomes at 30 days after ECMO implantation, and clinical data of the two groups were collected and analyzed. Receiver operating characteristic (ROC) curve and decision curve analysis (DCA) were used to compare the predictive value of ACEF, AMI-ECMO, Encourage and SAVE risk scores for mortality at 30 days after ECMO implantation. According to the evaluation results of DCA, the optimal risk score was selected. Kaplan-Meier curve estimating the 30-day survival after ECMO implantation was plotted by grouping risk scores with reference to previous literatures. Results: A total of 40 patients with STEMI combined with cardiogenic shock were included, age was (57.4±16.7) years, 31 (77.5%) patients were male, there were 21 (52.5%) patients in the death group and 19 (47.5%) in the survival group. Compared with the survival group, patients in the death group had higher lactic acid values, higher proportion of anterior descending artery or left main artery lesions, and a higher proportion of acute renal failure and continuous renal replacement therapy during hospitalization (all P<0.05). Compared with survival group, ACEF, AMI-ECMO and Encourage scores were higher in death group, SAVE score was lower in death group (all P<0.05). The ROC curve analysis showed that the area under the curve (AUC) of ACEF, AMI-ECMO, Encourage and SAVE scores in predicting mortality were 0.707, 0.816, 0.757, and 0.677 respectively (P>0.05). ACEF score demonstrated the highest sensitivity (90.5%) and Encourage score exhibited the highest specificity (89.5%). DCA indicated that the AMI-ECMO and Encourage scores had the best performance in predicting the 30-day mortality after ECMO therapy. Kaplan-Meier survival curve analysis showed that the 30-day mortality after ECMO implantation increased with the increase of AMI-ECMO and Encourage scores (log-rank P≤0.001). Conclusions: The 4 scoring systems are all suitable for predicting 30-day mortality after VA-ECMO therapy in patients with ST-segment elevation myocardial infarction complicated by cardiogenic shock. Among them, AMI-ECMO and Encourage scores have better predicting performance.

The inhibitory effect of LINC00261 upregulation on the pancreatic cancer EMT process is mediated by KLF13 via the mTOR signaling pathway

PurposeThe long noncoding RNA LINC00261 was reported to be involved in carcinogenesis and has been validated as a tumor suppressor in pancreatic cancer (PC); however, how LINC00261 is regulated has not been fully examined. Here, we attempted to investigate the upstream and downstream targets of LINC00261 in PC.MethodsLINC00261 expression in PC tissues was examined by the Gene Expression Omnibus (GEO) datasets and the Gene Expression Profiling Interactive Analysis (GEPIA) database. The quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays were performed to detect the expression level of LINC00261 in PC cells. The location of LINC00261 in PC cells was identified by RNA fluorescence in situ hybridization (RNA-FISH). Cell Counting Kit-8 (CCK-8), cell apoptosis assay, transwell invasion and migration assays testified the critical role of LINC00261 in PC. The luciferase reporter assay was applied to confirm the binding of LINC00261 to its upstream transcription factor KLF13. The changes in LINC00261 related target protein levels were analyzed by Western blotting assay.ResultsLINC00261 was significantly lower in PC tissues and was mainly concentrated in the nucleus. Overexpression of LINC00261 inhibited the invasion and migration of PC cells. Mechanistically, transcription factor KLF13 was confirmed to inhibit the epithelial-mesenchymal transition (EMT) process of PC cells by promoting the transcription of LINC00261 and suppressing the expression of metastasis-associated proteins, such as matrix metalloproteinase MMP2 and vimentin, thus inhibiting the metastasis of PC.ConclusionLINC00261 regulates PC cell metastasis through the “KLF13-LINC00261-mTOR-P70S6K1-S6” signaling pathway, which provides a significant set of potential PC therapeutic targets.

Engineered barriers regulate osteoblast cell migration in vertical direction.

Considering cell migration is essential for understanding physiological processes and diseases. The vertical migration of cells in three dimensions is vital, but most previous studies on cell migration have only focused on two-dimensional horizontal migration. In this paper, cell migration in the vertical direction was studied. Barriers with a height of 1, 5, 10, and 25 µm with grating and arrows in channels as guiding patterns were fabricated. The effects of barrier height and guiding patterns on the vertical migration of MC3T3 cells were explored. The study revealed that taller barriers hinder vertical migration of MC3T3 cells, whereas grating and arrows in channels promote it. The time-lapse and micrograph images showed that as the barrier height increased, the cell climbing angle along the barrier sidewall decreased, and the time taken to climb over the barrier increased. These results indicate that taller barriers increase the difficulty of vertical migration by MC3T3 cells. To promote the vertical migration of MC3T3 cells, 10 µm tall barriers with 18° and 40° sloped sidewalls were fabricated. For barriers with 18° sloped sidewalls, the probability for MC3T3 cells to climb up and down the 10 µm tall barriers was 40.6% and 20.3%, respectively; this is much higher than the migration probability over vertical barriers. This study shows topographic guidance on the vertical migration of MC3T3 cells and broadens the understanding of cell migration in the vertical direction.

[Early effect of extracorporeal membrane oxygenation and factors related to early outcome in adult patients with fulminant myocarditis].

Objective: To evaluate the efficacy within the first 24 h post extracorporeal membrane pulmonary oxygenation (ECMO) and the impact of early efficacy on the prognosis of adult patients with fulminant myocarditis (FM). Methods: This retrospective case analysis study included hospitalized patients (age≥18 years) who were diagnosed with fulminant myocarditis from November 2016 to May 2021 in the First Affiliated Hospital of Zhengzhou University. Patients were divided into survival or non-survival groups according to treatment outcomes. The age, sex, treatments, drug use, ECMO use, clinical and laboratory data (before and 24 h after the use of ECMO) were analyzed. The change rate of clinical and laboratory data after 24 h use of ECMO was calculated to find differences between two groups. Multivariate logistic regression was used to analyze the related factors with in-hospital death and complication between the two groups. Results: A total of 38 FM patients treated with ECMO were included. There were 23 cases (60.5%) in the survival group, aged (39.6±13.7) years, and 17 (73.9%) cases were female. The total ECMO time was (134.4±71.3)h. There were 15 cases (39.5%) in non-survival group, aged (40.0±15.8) years, and there were 12(80.0%) female, the ECMO time was (120.1±72.4) h in this group. The proportion of tracheal intubation and continuous renal replacement therapy in the survivor group and dosage of norepinephrine within 24 h after ECMO implantation were significantly less than in non-survival group (all P<0.05). There was no significant difference in all efficacy related biochemical indexes between two groups before ECMO use. The levels of lactic acid, procalcitonin, creatinine, alanine aminotransferase, aspartate aminotransferase, creatine kinase-MB, cardiac troponin I and N-terminal B-type natriuretic peptide prosoma were significantly less in survival group than in non-survival group at 24 h after the use of ECMO (all P<0.05). Results of multivariate logistic regression analysis showed that the higher 24 h change rate of creatinine (OR=0.587, 95%CI 0.349-0.986, P=0.044) and creatine kinase-MB (OR=0.177, 95%CI 0.037-0.841, P=0.029) were positively correlated with reduced risk of in-hospital mortality. The central hemorrhage and acute kidney injury in survival group were less than in non-survivor group (P<0.05). Conclusions: After 24 h early use of ECMO in FM patients, the improvement of various efficacy related biochemical test indexes in the survival group was better than that in the non-survival group. Faster reduction of creatine kinase-MB and creatinine values within 24 h ECMO use is positively correlated with reduced risk of in-hospital mortality in adult patients with FM.

The inhibitory effect of LINC00261 upregulation on the pancreatic cancer EMT process is mediated by KLF13 via the mTOR signaling pathway.

PURPOSE: The long noncoding RNA LINC00261 was reported to be involved in carcinogenesis and has been validated as a tumor suppressor in pancreatic cancer (PC); however, how LINC00261 is regulated has not been fully examined. Here, we attempted to investigate the upstream and downstream targets of LINC00261 in PC. METHODS: LINC00261 expression in PC tissues was examined by the Gene Expression Omnibus (GEO) datasets and the Gene Expression Profiling Interactive Analysis (GEPIA) database. The quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays were performed to detect the expression level of LINC00261 in PC cells. The location of LINC00261 in PC cells was identified by RNA fluorescence in situ hybridization (RNA-FISH). Cell Counting Kit-8 (CCK-8), cell apoptosis assay, transwell invasion and migration assays testified the critical role of LINC00261 in PC. The luciferase reporter assay was applied to confirm the binding of LINC00261 to its upstream transcription factor KLF13. The changes in LINC00261 related target protein levels were analyzed by Western blotting assay. RESULTS: LINC00261 was significantly lower in PC tissues and was mainly concentrated in the nucleus. Overexpression of LINC00261 inhibited the invasion and migration of PC cells. Mechanistically, transcription factor KLF13 was confirmed to inhibit the epithelial-mesenchymal transition (EMT) process of PC cells by promoting the transcription of LINC00261 and suppressing the expression of metastasis-associated proteins, such as matrix metalloproteinase MMP2 and vimentin, thus inhibiting the metastasis of PC. CONCLUSION: LINC00261 regulates PC cell metastasis through the "KLF13-LINC00261-mTOR-P70S6K1-S6" signaling pathway, which provides a significant set of potential PC therapeutic targets.

RAS and BRAF genes as biomarkers and target for personalised colorectal cancer therapy: An update.

Colorectal cancer (CRC) remains among the most commonly diagnosed cancers and has been on the rise. It is also one of the most lethal diseases globally, being the third leading cause of cancerrelated death. Depending on the stages and disease conditions, CRC is treated by surgery, chemo-, radio-therapy, immunotherapy or in combination. However, these therapies have subpar results with unwanted side effects, hence continuous effort is ongoing to explore new type of therapeutic modalities. Among the sub-types of CRC, KRAS, BRAF and NRAS mutated CRC comprise approximately 43%, 10% and 3% of the total cases, respectively. These mutations are associated with tumour progression and anti-epidermal growth factor receptor (EGFR) treatment resistance. Due to their important role in CRC, these genes have thus become targets in the development of novel treatments. In this paper, we discuss the current and upcoming treatment on CRC by targeting these mutated genes, with more focus on KRAS and BRAF due to the higher occurrence of mutations in CRC.

[Comparison of efficacy and safety of insulin aspart injection Rishulin and NovoRapid for treatment of diabetes: a multicenter, randomized, open-labeled, controlled trial].

Objective: To compare the efficacy and safety of Tonghua Dongbao's insulin aspart injection (Rishulin) and NovoRapid (Novo Nordisk) in the treatment of diabetes. Methods: A 26-week, randomized, open-label, parallel-group, positive control drug and non-inferiority trial was conducted in 23 centers in China. A total of 563 diabetes with poor blood glucose control treated with insulin for at least 3 months before were included. The subjects were randomized(stratified block random method) into those receiving Rishulin or NovoRapid at a ratio of 3∶1. Both groups were combined with basal insulin (Lantus). The primary endpoint was the change in glycosylated hemoglobin (HbA1c) from baseline to the end of 24 weeks of treatment. Results: For full analysis set, after 24 weeks of treatment, HbA1c level of Ruishulin group decreased from (8.66±1.28)% to (7.77±1.09)% (P<0.001), and that of NovoRapid group decreased from (8.47±1.28) % to (7.65±0.97) % (P<0.001). Treatment difference in HbA1c (NovoRapid group-Ruishulin group) was -0.061% (95%CI -0.320-0.199). HbA1c<7.0% target reacing rates were 24.26% and 21.21% (P=0.456), and HbA1c<6.5% target reacing rates were 9.65% and 6.82% (P=0.310) in Ruishulin group and NovoRapid group, repectively. The standard 2 hours postprandial blood glucose (2hPG) in Ruishulin group decreased from (16.23±5.22) mmol/L to (12.65±4.57) mmol/L (P<0.001), and 2hPG in NovoRapid group decreased from (16.13±5.37) mmol/L to (11.91)±4.21) mmol/L (P<0.001). The fingertips blood glucose at 7-point of both groups exhibited varying degrees of reduction compared with those at baseline, repectively. Positive ratios of specific antibodies were 31.68% in Ruishulin group and 36.36% in NovoRapid group (P=0.320). Ratios of negative to positive were 7.43% and 10.61% (P=0.360), and ratios of positive to negative were 10.40% and 7.58% (P=0.360) in Ruishulin group and NovoRapid group, respectively. The incidence of hypoglycemia was 60.05% and 55.40% (P=0.371), and the incidence of adverse events was 76.60% and 77.70% (P=0.818) in Ruishulin group and NovoRapid group, respectively. Conclusions: Rishulin is not inferior to NovoRapid, and has shown good efficacy and safety. It can be an ideal choice for clinicians in patients with poor blood glucose control with insulin.

Long noncoding RNA OIP5-AS1 exhibits oncogenic activity in bladder cancer through miR-217 and MTDH.

OBJECTIVE: The aim of this study was to investigate the role of long non-coding Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) in bladder cancer (BCa), and the mechanism of OIP5-AS1/microRNA-217 (miR-217)/metadherin (MTDH) in promoting the progression of BCa. PATIENTS AND METHODS: OIP5-AS1, miR-217 and MTDH expressions in BCa tissues and cells were detected by qRT-PCR or Western blot. CCK-8 and transwell assays were used to determine the proliferation and invasion of BCa cells. The correlation between OIP5-AS1 and miR-217, miR-217 and MTDH, and OIP5-AS1 and MTDH were studied by Luciferase reporter assay and Spearman correlation analysis. Statistical analysis of test data was performed using t-test. RESULTS: OIP5-AS1 was upregulated in BCa tissues and cells, and OIP5-AS1 knockdown could inhibit the proliferation and invasion of BCa cells. MiR-217 was a direct-acting target of OIP5-AS1, and MTDH was a target of miR-217. OIP5-AS1 knockdown inhibits human BCa cell proliferation and invasion through miR-217/MTDH axis. CONCLUSIONS: This study systematically explored the effect of OIP5-AS1 in human BCa. MiR-217/MTDH pathway mediated the promotion of OIP5-AS1 in BCa cells proliferation and invasion. OIP5-AS1, as an oncogene, could be used as a biomarker for the treatment of BCa.

Lipocalin-2: a role in hepatic gluconeogenesis via AMP-activated protein kinase (AMPK).

PURPOSE: Evidence is accumulating that lipocalin2 (LCN2) is implicated in insulin resistance and glucose homeostasis, but the underlying possible mechanisms remain unclear. This study is to investigate the possible linkage between LCN2 and AMP-activated protein kinase (AMPK) or forkhead transcription factor O1 (FoxO1), which influences insulin sensitivity and gluconeogenesis in liver. METHODS: LCN2 knockout (LCN2KO) mice and wild-type littermates were used to evaluate the effect of LCN2 on insulin sensitivity and hepatic gluconeogenesis through pyruvate tolerance test (PTT), glucose tolerance test (ipGTT), insulin tolerance test (ITT), and hyperinsulinemic-euglycemic clamps, respectively. LCN2KO mice and WT mice in vivo, and in vitro HepG2 cells were co-transfected with adenoviral FoxO1-siRNA (Ad-FoxO1-siRNA) or adenovirus expressing constitutively active form of AMPK (Ad-CA-AMPK), or dominant negative adenovirus AMPK (Ad-DN-AMPK), the relative mRNA and protein levels of two key gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6P) were measured. RESULTS: Improved insulin sensitivity and inhibited gluconeogenesis in the LCN2KO mice were confirmed by pyruvate tolerance tests and hyperinsulinemic-euglycemic clamps. Nuclear FoxO1 and its downstream genes PEECK and G6P were decreased in the livers of the LCN2KO mice, and AMPK activity was stimulated and directly phosphorylated FoxO1. In vitro, AMPK activity was inhibited in HepG2 cells overexpressing LCN2 leading to a decrease in phosphorylated FoxO1 and an increase in nuclear FoxO1. CONCLUSION: The present study demonstrates that LCN2 regulates insulin sensitivity and glucose metabolism through inhibiting AMPK activity, and regulating FoxO1 and its downstream genes PEPCK/G6P, which regulate hepatic gluconeogenesis.

Separation of nasopharyngeal epithelial cells from carcinoma cells on 3D scaffold platforms.

Scaffold microstructures were developed to mimic a three-dimensional extracellular matrix in studying cell migration and invasion. The multiple-layer scaffold platforms were designed to investigate cell migration and separation from top to bottom layer. Two cell lines including immortalized nasopharyngeal epithelial (NP460) cells and nasopharyngeal carcinoma (NPC43) cells with Epstein-Barr virus were compared in this study. On one-layer platforms with trench depth of 15 µm, both NP460 and NPC43 cells were guided to migrate along the 18-µm-wide trenches, and exhibited random migration directions when the trench width was 10 or 50 µm. Nearly no cell was found to migrate in the 10-µm-wide trenches on one-layer platforms. However, the NP460 and NPC43 cells showed very different probability in the narrow trenches on two-layer platforms, making it possible to separate the nasopharyngeal epithelial cells from the carcinoma cells. Moreover, 1-µm deep grating topography on the top layer inhibited NP460 cells to migrate from top ridges to the 10-µm-wide trenches, but promoted such behavior for NPC43 cells. The results demonstrated in This study suggest that the engineered multiple-layer scaffold platforms could be used to separate carcinoma cells in NPC tumor as a potential treatment of NPC.

Does reducing radiation levels for procedures affect image quality and radiation to proceduralists? A double-blinded randomised study of two protocols.

AIM: To evaluate the ultra-lose dose imaging protocol (ULDP), compared to the standard low-dose imaging protocol (LDP), which are used for haemodialysis access, in terms of radiation exposure and image quality. MATERIAL AND METHODS: This was a single-centre, institutional review board-approved, prospective, double-blinded randomised controlled study to compare radiation exposure and image quality of the ULDP and LDP. Ten proceduralists, two radiographers, and 11 nurses were enrolled. Radiation exposure during 80 procedures (40 angioplasties and 40 thrombolysis) was recorded (direct radiation to patients from protocol report and scattered radiation to participants from the RaySafe i2 real-time dosimetry system). Baseline characteristics of procedure were recorded. Image quality was assessed subjectively using questionnaires based on the five-point Likert scale after each procedure. RESULTS: Compared with LDP, the use of ULDP was associated with a significantly lower rate of radiation exposure to proceduralists, patients, and scrub nurses (0.506±0.430 versus 0.847±0.965 µSv/s, p=0.044; 0.571±1.284 versus 1.284±1.007 mGy/s, p<0.001; and 0.052±0.071 versus 0.141±0.185 µSv/s, p=0.005, respectively). No significant difference in image quality or duration of procedure was observed (all p values >0.05). CONCLUSION: Compared with LDP, the use of ULDP was associated with a significantly lower rate of radiation exposure to proceduralists, patients, and scrub nurses without compromising the image quality or duration of procedure.

Effects of topographical guidance cues on osteoblast cell migration.

Cell migration is a fundamental process that is crucial for many biological functions in the body such as immune responses and tissue regeneration. Dysregulation of this process is associated with cancer metastasis. In this study, polydimethylsiloxane platforms with various topographical features were engineered to explore the influence of guiding patterns on MC3T3-E1 osteoblast cell migration. Focusing on the guiding effects of grating patterns, variations such as etch depth, pattern discontinuity, and bending angles were investigated. In all experiments, MC3T3-E1 cells on patterned surfaces demonstrated a higher migration speed and alignment when compared to flat surfaces. The study revealed that an increase in etch depth from 150 nm to 4.5 µm enhanced cell alignment and elongation along the grating patterns. In the presence of discontinuous elements, cell migration speed was accelerated when compared to gratings of the same etch depth. These results indicated that cell directionality preference was influenced by a high level of pattern discontinuity. On patterns with bends, cells were more inclined to reverse on 45° bends, with 69% of cells reversing at least once, compared to 54% on 135° bends. These results are attributed to cell morphology and motility mechanisms that are associated with surface topography, where actin filament structures such as filopodia and lamellipodia are essential in sensing the surrounding environment and controlling cell displacement. Knowledge of geometric guidance cues could provide a better understanding on how cell migration is influenced by extracellular matrix topography in vivo.

Traversing behavior of tumor cells in three-dimensional platforms with different topography.

Three-dimensional polydimethylsiloxane platforms were developed to mimic the extracellular matrix with blood vessels by having scaffolds with micropatterns, porous membrane and trenches. Precisely controlled physical dimensions, layouts, and topography as well as different surface chemical treatments were applied to study their influences on nasopharyngeal carcinoma cell (10-15 µm in diameter) migration in mimicked platforms over 15-hour of time-lapse imaging. By placing the pores at different distance from the edges of the trenches, pores with different trench sidewall exposures and effective sizes were generated. Pores right next to the trench sidewalls showed the highest cell traversing probability, most likely related to the larger surface contact area with cells along the sidewalls. Straight grating oriented perpendicular to trenches below the top layer increased cell traversing probability. Pore shape as well as pore size influenced the cell traversing probability and cells could not traverse through pores that were 6 µm or less in diameter, which is much smaller than the cell size. Trench depth of 15 µm could induce more cells to traverse through the porous membrane, while shallower trenches impeded cell traversing and longer time was needed for cells to traverse because 3 and 6 µm deep trenches were much smaller than cell size which required large cell deformation. Hydrophobic surface coating on the top layer and fibronectin in pores and trenches increased the cell traversing probability and reduced the pore size that cells could traverse from 8 to 6 µm, which indicated that cells could have larger deformation with certain surface coatings.

Evaluation of the Haemophilus influenzae EUCAST and CLSI disc diffusion methods to recognize aminopenicillin and amoxicillin/clavulanate resistance.

OBJECTIVES: Implementation of EUCAST susceptibility testing in an Australian hospital laboratory demonstrated higher rates of aminopenicillin and amoxicillin/clavulanate resistance in Haemophilus influenzae than previously recognized. This study aimed to better define the variability in the detection of ß-lactam resistance based on EUCAST and CLSI disc diffusion (DD) methodology, by comparison with the recommended reference method, broth microdilution (BMD), and by concordance with genomic analysis. METHODS: A total of 100 random H. influenzae isolates were assessed for ampicillin and amoxicillin/clavulanate susceptibility by EUCAST and CLSI DD and BMD. WGS was used to analyse the ftsI gene of a subset of isolates with ß-lactam resistance, other than that due to isolated ß-lactamase production. RESULTS: Of the 100 isolates, 32 were categorized as either ß-lactamase negative, ampicillin resistant (BLNAR) (n = 18) or ß-lactamase positive, amoxicillin/clavulanate resistant (BLPACR) (n = 14) by EUCAST DD. All 18 EUCAST BLNAR isolates were genotypically confirmed by WGS. Five of 18 BLNAR isolates were concordant by CLSI DD, 12 by EUCAST BMD and 4 by CLSI BMD. Nine of 14 EUCAST BLPACR isolates were confirmed by WGS; the remaining 5 were 1 mm below the EUCAST DD breakpoint. Only one isolate was detected as BLPACR by CLSI DD. Group III mutations associated with high-level ampicillin resistance were identified in 10/32 isolates. CONCLUSIONS: The EUCAST DD susceptibility method is more reliable than either CLSI or BMD for the detection of genotypically defined BLNAR resistance. However, accurate categorization of amoxicillin/clavulanate resistance remains problematic. Continuous and reproducible surveillance of resistance is needed; for this to be possible, robust susceptibility methods are required.