Online professional development across institutions and borders.

Professional development (PD) is a key element for enhancing the quality of academic teaching. An increasing number of PD activities have moved to blended and online formats, especially since the COVID-19 pandemic. Due to the desire, potential, and need for collaboration among educators to learn from innovative and best practices, several institutions have started to pool their resources and expertise together and have started to implement cross-institutional and cross-national online professional development (OPD). The questions of what type of a (cross-)institutional OPD educators might prefer, and whether educators learn effectively from (and with) peers in such cross-cultural context have not been adequately explored empirically. In this case-study across three European countries, we explored the lived experiences of 86 educators as a result of a cross-institutional OPD. Using a mixed methods design approach our pre-post findings indicated that, on average, participants made substantial gains in knowledge. In addition, several cultural differences were evident in the expectations and lived experiences in ODP, as well as the intention to transfer what had been learned into one's own practice of action. This study indicates that while substantial economic and pedagogical affordances are provided with cross-institutional OPD, cultural differences in context might impact the extent to which educators implement lessons learned from OPD.

CRUSH SYNDROME IN EARTHQUAKES - STAY AND PLAY OR LOAD AND GO?

Earthquakes are unpredictable natural disasters accompanied by material damage and many victims. In the case of a person remaining trapped under the collapsed material, the development of crush syndrome can occur. Crush syndrome is the result of traumatic rhabdomyolysis and is present in 2%-15% of all injured persons in an earthquake. It is not easy to recognize, and proper treatment is challenging. Persons who have a clear crush injury and/or have been immobilized for more than four hours should be considered potential victims of crush syndrome. Therefore, knowledge about crush syndrome must be comprehensive and accessible to all parties involved. In this paper, the management of crush syndrome victims, which includes the principles of triage, and medical and logistic principles as well, is presented. Triage principles are presented at the level of triage priorities, places, and diagnoses. Medical principles, crucial for crush syndrome, are presented regarding the duration of compression and time before or after extraction of the patient. Logistic principles provide an overview of the priorities and modes of transport in relation to distance of health institutions, and the importance of management and education associated with crush syndrome. Each country with recognized disasters (natural or man-made) in which crush-related victims are expected, will benefit if the knowledge about triage, medical and logistic principles for crush syndrome is incorporated in their educational programs and regularly updated.

Flipped classrooms in higher education during the COVID-19 pandemic: findings and future research recommendations.

Flipped classroom (FC) approaches have gotten substantial attention in the last decade because they have a potential to stimulate student engagement as well as active and collaborative learning. The FC is generally defined as a strategy that flips the traditional education setting, i.e., the information transmission component of a traditional face-to-face lecture is moved out of class time. The FC relies on technology and is therefore suitable for online or blended learning, which were predominant forms of learning during the COVID-19 pandemic (March 2020-July 2021). In this paper we present a systematic literature review (SLR) of studies that covered online FC approaches in higher education during the pandemic. We analyzed 205 publications in total and 18 in detail. Our research questions were related to the main findings about the success of implementation of online FC and recommendations for future research. The findings indicated that those who had used FC approaches in face-to-face or blended learning environments more successfully continued to use them in online environments than those who had not used it before. The SLR opened possible questions for future research, such as the effectiveness of the FC for different courses and contexts, the cognitive and emotional aspects of student engagement, and students' data protection. It pointed to the need to examine different aspects of online delivery of the FC more comprehensively, and with more research rigor.

Incidence of Dentinal Microcracks during Root Canal Preparation with Self Adjusting File, Reciproc Blue and ProTaper Next.

Introduction: Forces formed during root canal instrumentation could cause the crack formation in dentinal walls. Their propagation may result in vertical root fracture and eventually tooth loss. The aim of the study was to explore microcrack formation after root canal preparation with Self-adjusting File (SAF), Reciproc Blue (RB), and ProTaper Next (PTN) instruments on young premolars by means of micro-computed tomography (micro CT). Methods and Materials: Forty-five upper premolars with two canals, were extracted due to orthodontic reasons from patients aged 16 to 20 years and stored for up to two months. The teeth were scanned with a micro-CT (Nikon XT H 225, Tring, UK) at structural resolution of 20.2 µm and randomly divided into three groups: SAF, RB, and PTN. Specimens were instrumented and irrigation was performed with 12 mL of 2.5% sodium hypochlorite (NaOCl) and 4 mL of 17% ethylenediaminetetraacetic acid (EDTA) per root canal. Subsequently, the specimens were scanned under the same conditions as before, in wet condition and 24 h after drying. The presence of microcracks in dentinal walls was evaluated using the image-processing software Volume Graphics VGStudio Max 3. Results: No dentinal defect was found in any evaluated specimen, neither in pre-nor post-operative scans in wet and dry condition. Conclusion: Under the circumstances of this in vitro study instruments with improved design and metallurgy do not cause dentinal microcracks in young premolar teeth.

Calmodulin kinase II constitutively binds, phosphorylates, and inhibits brush border Na+/H+ exchanger 3 (NHE3) by a NHERF2 protein-dependent process.

The epithelial brush border (BB) Na(+)/H(+) exchanger 3 (NHE3) accounts for most renal and intestinal Na(+) absorption. Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) inhibits NHE3 activity under basal conditions in intact intestine, acting in the BB, but the mechanism is unclear. We now demonstrate that in both PS120 fibroblasts and polarized Caco-2BBe cells expressing NHE3, CaMKII inhibits basal NHE3 activity, because the CaMKII-specific inhibitors KN-93 and KN-62 stimulate NHE3 activity. This inhibition requires NHERF2. CaMKIIγ associates with NHE3 between aa 586 and 605 in the NHE3 C terminus in a Ca(2+)-dependent manner, with less association when Ca(2+) is increased. CaMKII inhibits NHE3 by an effect on its turnover number, not changing surface expression. Back phosphorylation demonstrated that NHE3 is phosphorylated by CaMKII under basal conditions. This overall phosphorylation of NHE3 is not affected by the presence of NHERF2. Amino acids downstream of NHE3 aa 690 are required for CaMKII to inhibit basal NHE3 activity, and mutations of the three putative CaMKII phosphorylation sites downstream of aa 690 each prevented KN-93 stimulation of NHE3 activity. These studies demonstrate that CaMKIIγ is a novel NHE3-binding protein, and this association is reduced by elevated Ca(2+). CaMKII inhibits basal NHE3 activity associated with phosphorylation of NHE3 by effects requiring aa downstream of NHE3 aa 690 and of the CaMKII-binding site on NHE3. CaMKII binding to and phosphorylation of the NHE3 C terminus are parts of the physiologic regulation of NHE3 that occurs in fibroblasts as well as in the BB of an intestinal Na(+)-absorptive cell.

NHERF1 and NHERF2 are necessary for multiple but usually separate aspects of basal and acute regulation of NHE3 activity.

Na(+)/H(+) exchanger 3 (NHE3) is expressed in the brush border (BB) of intestinal epithelial cells and accounts for the majority of neutral NaCl absorption. It has been shown that the Na(+)/H(+) exchanger regulatory factor (NHERF) family members of multi-PDZ domain-containing scaffold proteins bind to the NHE3 COOH terminus and play necessary roles in NHE3 regulation in intestinal epithelial cells. Most studies of NHE3 regulation have been in cell models in which NHERF1 and/or NHERF2 were overexpressed. We have now developed an intestinal Na(+) absorptive cell model in Caco-2/bbe cells by expressing hemagglutinin (HA)-tagged NHE3 with an adenoviral infection system. Roles of NHERF1 and NHERF2 in NHE3 regulation were determined, including inhibition by cAMP, cGMP, and Ca(2+) and stimulation by EGF, with knockdown (KD) approaches with lentivirus (Lenti)-short hairpin RNA (shRNA) and/or adenovirus (Adeno)-small interfering RNA (siRNA). Stable infection of Caco-2/bbe cells by NHERF1 or NHERF2 Lenti-shRNA significantly and specifically reduced NHERF protein expression by >80%. NHERF1 KD reduced basal NHE3 activity, while NHERF2 KD stimulated NHE3 activity. siRNA-mediated (transient) and Lenti-shRNA-mediated (stable) gene silencing of NHERF2 (but not of NHERF1) abolished cGMP- and Ca(2+)-dependent inhibition of NHE3. KD of NHERF1 or NHERF2 alone had no effect on cAMP inhibition of NHE3, but KD of both simultaneously abolished the effect of cAMP. The stimulatory effect of EGF on NHE3 was eliminated in NHERF1-KD but occurred normally in NHERF2-KD cells. These findings show that both NHERF2 and NHERF1 are involved in setting NHE3 activity. NHERF2 is necessary for cGMP-dependent protein kinase (cGK) II- and Ca(2+)-dependent inhibition of NHE3. cAMP-dependent inhibition of NHE3 activity requires either NHERF1 or NHERF2. Stimulation of NHE3 activity by EGF is NHERF1 dependent.

Prognostic value of venoarterial carbon dioxide gradient in patients with severe sepsis and septic shock.

AIM: To investigate the changes in the venoarterial carbon-dioxide gradient (V-a Pco(2)) and its prognostic value for survival of patients with severe sepsis and septic shock. METHODS: The study was conducted in General Hospital Holy Spirit from January 2004 to December 2007 and included 71 conveniently sampled adult patients (25 women and 46 men), who fulfilled the severe sepsis and septic shock criteria and were followed for a median of 8 days (interquartile range, 12 days). The patients were divided in two groups depending on whether or not they had been mechanically ventilated. Both groups of patients underwent interventions with an aim to achieve hemodynamic stability. Mechanical ventilation was applied in respiratory failure. Venoarterial carbon dioxide gradient was calculated from the difference between the partial pressure of arterial CO(2) and the partial pressure of mixed venous CO(2), which was measured with a pulmonary arterial Swan-Ganz catheter. The data were analyzed using Kaplan-Meier survival analysis, along with a calculation of the hazard ratios. RESULTS: There was a significant difference between non-ventilated and ventilated patients, with almost 4-fold greater hazard ratio for lethal outcome in ventilated patients (3.85; 95% confidence interval, 1.64-9.03). Furthermore, the pattern of changes of many other variables was also different in these two groups (carbon dioxide-related variables, variables related to acid-base status, mean arterial pressure, systemic vascular resistance, lactate, body mass index, Acute Physiology and Chronic Health Evaluation II, Simplified Acute Physiology II Score, and Sepsis-related Organ Failure Assessment score). Pco(2) values (with a cut-off of 0.8 kPa) were a significant predictor of lethal outcome in non-ventilated patients (P=0.015) but not in ventilated ones (P=0.270). CONCLUSION: V-a Pco(2) was a significant predictor of fatal outcome only in the non-ventilated group of patients. Ventilated patients are more likely to be admitted with a less favorable clinical status, and other variables seem to have a more important role in their outcome.

cGMP inhibition of Na+/H+ antiporter 3 (NHE3) requires PDZ domain adapter NHERF2, a broad specificity protein kinase G-anchoring protein.

Electroneutral NaCl absorption mediated by Na+/H+ exchanger 3 (NHE3) is important in intestinal and renal functions related to water/Na+ homeostasis. cGMP inhibits NHE3 in intact epithelia. However, unexpectedly it failed to inhibit NHE3 stably transfected in PS120 cells, even upon co-expression of cGMP-dependent protein kinase type II (cGKII). Additional co-expression of NHERF2, the tandem PDZ domain adapter protein involved in cAMP inhibition of NHE3, restored cGMP as well as cAMP inhibition, whereas NHERF1 solely restored cAMP inhibition. In vitro conditions were identified in which NHERF2 but not NHERF1 bound cGKII. The NHERF2 PDZ2 C terminus, which binds NHE3, also bound cGKII. A non-myristoylated mutant of cGKII did not support cGMP inhibition of NHE3. Although cGKI also bound NHERF2 in vitro, it did not evoke inhibition of NHE3 unless a myristoylation site was added. These results show that NHERF2, acting as a novel protein kinase G-anchoring protein, is required for cGMP inhibition of NHE3 and that cGKII must be bound both to the plasma membrane by its myristoyl anchor and to NHERF2 to inhibit NHE3.