EP300—A miRNA‐regulated metastasis suppressor gene in ductal adenocarcinomas of the pancreas

Genetic and epigenetic alterations during development of pancreatic ductal adenocarcinomas (PDACs) are well known. This study investigates genetic and epigenetic data together with tumor biology to find specific alterations responsible for metastasis formation. Using 16 human PDAC cell lines in a murine orthotopic PDAC model, local infiltration and metastatic spread were assessed by standardized dissemination scores. The cell lines were further classified into 3 hierarchical groups according to their metastatic potential. Their mRNA and microRNA (miRNA) expression was profiled via mRNA‐microarray as well as Taqman Low Density Array, and validated by single quantitative RT‐PCR and Western blotting. In the highly metastatic group, a significant induction of EP300 targeting miRNAs miR‐194 (fold change: 26.88), miR‐200b (fold change: 61.65), miR‐200c (fold change: 19.44) and miR‐429 (fold change: 21.67) (p < 0.05) was detected. Corresponding to this, decreased expression of EP300 mRNA (p < 0.0001) and protein (p < 0.05) were detected in the highly metastatic PDAC cell lines with liver metastases compared to the nonmetastatic or marginally metastatic cell lines, while no correlation with local tumor growth was found. In conclusion, epigenetic alterations with upregulated EP300 targeting miRNAs miR‐194, miR‐200b, miR‐200c and miR‐429 are related to reduced EP300 mRNA and protein in PDAC. These results demonstrate that miRNAs might be able to modulate the expression of metastasis‐specific suppressor genes and metastatic behavior in PDAC, suggesting diagnostic and therapeutic opportunities for EP300 and its targeting miRNAs in PDAC.     

Proliferation and Morphological Assessment of Human Periodontal Ligament Fibroblast towards Bovine Pericardium Membranes: An In Vitro Study

Over the past decade regenerative branches of dentistry have taken on more and more importance, resulting in the development of performing scaffold materials. These should induce cell adhesion, support, and guide the tissues’ growth. Among the developed materials, we can include resorbable or non-membranes. The purpose of this study was to investigate the proliferation abilities and the attachment of human periodontal ligament fibroblasts (HPLIFs) over two bovine pericardium membranes with different thicknesses, 0.2 mm and 0.4 mm, respectively. These membranes have been decellularized by the manufacturer, preserving the three-dimensional collagen’s structure. The HPLFs were cultured in standard conditions and exposed to the tested materials. XTT was performed to assess cell proliferation, while light microscopy (LM) and scanning electron microscopy (SEM) observations assessed fibroblast morphology at different times (T1, T2, and T3). Proliferation assays have shown a statistically significant difference in growth at T1 (p < 0.05) in the cells cultured with a thicker membrane compared to the thinner one. LM analysis showed healthy fibroblasts in contact with the membranes, appearing larger and with a polygonal shape. SEM observation demonstrated thickening of the fibroblasts which continued to adhere to the membrane’s surface, with enlarged polygonal shape and developed filipodia and lamellipodia. These results showed a similar cell behavior over the two bovine pericardium membranes, demonstrating a cellular migration along and within the layers of the membrane, binding with membrane fibers by means of filopodial extensions. Knowledge of the effects of the collagen membranes derived from bovine pericardium on cellular behavior will help clinicians choose the type of scaffolds according to the required clinical situation.     

Involvement of CD40 Targeting miR-224 and miR-486 on the Progression of Pancreatic Ductal Adenocarcinomas

Background  Genetic and epigenetic alterations during development of pancreatic ductal adenocarcinomas (PDAC) are well known. Genetic and epigenetic data were correlated with tumor biology to find specific alterations responsible for invasion and metastasis in pancreatic ductal adenocarcinomas. Methods  A total of 16 human PDAC cell lines were used in murine orthotopic PDAC models. By means of standardized dissemination scores, local invasion and metastatic spread were assessed. mRNA and microRNA expression were studied by microarray and TaqMan low-density array. Quantitative real-time–polymerase chain reaction and flow cytometry were used for expression validation. Results   CD40 was detected as a relevant target gene for differentially expressed miRNAs observed in highly invasive and metastatic PDAC only. A significant overexpression (P < .05) of CD40-related miRNAs miR-224 and miR-486 was detected in highly invasive and metastatic PDAC, whereas CD40 mRNA expression was not significantly altered. Instead, CD40 protein expression at cell surfaces of these highly invasive and metastatic PDAC was significantly reduced (P < .01). Conclusions  Epigenetic alterations with upregulated CD40-targeting miR-224 and miR-486 are related to downregulated CD40 protein expression at cell surfaces in highly invasive and metastatic PDAC. Thus, miRNA-regulated CD40 expression seems to play an important role in progression of PDAC. These data suggest a diagnostic and therapeutic potential for CD40 and/or its targeting miRNAs in PDAC.     

Blended learning in surgery using the Inmedea Simulator

Background

Recently, medical education in surgery has experienced several modifications. We have implemented a blended learning module in our teaching curriculum to evaluate its effectiveness, applicability, and acceptance in surgical education.

Methods

In this prospective study, the traditional face-to-face learning of our teaching curriculum for fourth-year medical students (n?=?116) was augmented by the Inmedea Simulator, a web-based E-learning system, with six virtual patient cases. Student results were documented by the system and learning success was determined by comparing patient cases with comparable diseases (second and sixth case). The acceptance among the students was evaluated with a questionnaire.

Results

After using the Inmedea Simulator, correct diagnoses were found significantly (P?<?0.05) more often, while an incomplete diagnostic was seen significantly (P?<?0.05) less often. Significant overall improvement (P?<?0.05) was seen in sixth case (62.3?±?5.6 %) vs. second case (53.9?±?5.6 %). The questionnaire revealed that our students enjoyed the surgical seminar (score 2.1?±?1.5) and preferred blended learning (score 2.5?±?1.2) to conventional teaching.

Conclusion

The blended learning approach using the Inmedea Simulator was highly appreciated by our medical students and resulted in a significant learning success. Blended learning appears to be a suitable tool to complement traditional teaching in surgery.     

QT dispersion and myonecrosis after stent percutaneous coronary intervention]

BACKGROUND: QT dispersion (QTd) is the difference between the maximum and the minimum QT interval in the 12-lead ECG. There is currently no information on the relationship between QTd and creatine kinase (CK)-MB release in patients undergoing percutaneous coronary intervention (PCI). METHODS: Among 118 patients undergoing successful PCI stenting, QTd and corrected QTd (QTdc) were measured at standard 12-lead ECG before PCI and at 6 and 18 hours after PCI. The median of QTdc variation (deltaQTdc = baseline QTdc - QTdc at 6 hours) was 9.5 ms (range -48 / +89 ms). Patients were divided into two groups according to deltaQTdc: group A "recoverers" (deltaQTdc > 9.5 ms, n = 59, 50%), group B "non-recoverers" (deltaQTdc < 9.5 ms, n = 59, 50%). CK-MB release was compared in the two groups. RESULTS: Eighty-three percent of patients were male, with mean age of 62 years (range 41-80 years). Unstable angina was present in 35% of cases, with similar distribution in the two groups. PCI was performed in 1.94 lesions/patient with the implantation of 1.6 stent/patient. Compared to baseline, a reduction in both QTc and QTdc was documented at 6 and 18 hours after PCI (p < 0.05). Periprocedural variations (CK-MB > 2 upper limit of normal) was detected in 4 patients (7%) of group A and 12 patients (20%) in group B (p = 0.06). Peak CK-MB release was significantly lower in group A (13 +/- 14.3 IU/l) compared to group B (23.2 +/- 35 IU/l, p < 0.05). CONCLUSIONS: After successful coronary stenting there is a rapid normalization of QTd and QTdc. The lack of recovery of both QTd and QTdc is related to minor elevations of CK-MB and may therefore be further explored as a useful non-invasive marker of heterogeneous reperfusion after PCI.     

Hydroxyethyl starch normalizes platelet and leukocyte adhesion within pulmonary microcirculation during LPS-induced endotoxemia

Growing evidence supports substantial pathophysiological impact of platelets and their interactions on the development of septic lung failure. We developed a rat model of endotoxemia for direct in situ visualization of pulmonary microcirculation by in vivo fluorescence videomicroscopy. Male Sprague-Dawley rats were assigned to control, endotoxemia (Escherichia coli LPS, 15 mg/kg, i.v.), and fluid management for treatment of LPS-induced hypovolemia (Ringer lactate, hydroxyethyl starch [HES] 6%) groups (n = 7 each). Leukocytes were labeled in vivo by rhodamine, and 5 x 10(6) Calcein-AM-labeled nonactivated platelets were injected. Microcirculatory parameters (vessel diameter, ventilation-perfusion ratio) and adhesive characteristics of platelets and leukocytes (velocity, rolling, sticking) within the pulmonary microcirculation were quantified after endotoxin application under various regimens of fluid substitution for 60 min. A reduction of cell velocity and enhanced cell adhesion was seen in leukocytes and platelets (P < 0.05) after LPS injection. Fluid treatment with HES 6% resulted in a significant increase of platelet's velocity compared with the LPS group (442.86 +/- 20.60 vs. 343.93 +/- 11.17; P < 0.05), whereas Ringer lactate showed no beneficial effects. Similarly, HES 6% normalized LPS-induced platelet rolling and sticking as well as alterations in ventilation-perfusion ratio. Using direct visualization of the pulmonary microcirculation, we observed that platelet and leukocyte interactions are enhanced in the lung during LPS endotoxemia. Fluid therapy with HES 6% seems to have restorative effects on these cellular functions within the pulmonary microcirculation.     

MicroRNAs: Novel Diagnostic and Therapeutic Tools for Pancreatic Ductal Adenocarcinoma?

Pancreatic ductal adenocarcinoma (PDAC) is known for its very poor overall prognosis, making tools for early diagnosis and new therapeutic modalities urgently needed. MicroRNAs (miRNAs), endogenous noncoding RNA molecules of ~22 nt, have gained attention as an epigenetic component involved in the development of many cancers, including PDAC. miRNA expression profiles of varying pancreatic tissues have identified a number of differentially expressed miRNAs and seem to be able to differentiate between three tissues of clinical importance: normal pancreas, chronic pancreatitis, and PDAC. This article gathers our current knowledge of differentially expressed miRNAs in pancreatic tissues with relevance to PDAC and presents potential diagnostic and therapeutic opportunities.