An essential review of Singapore’s response to out-of-hospital cardiac arrests: improvements over a ten-year period

Care for patients who experience out-of-hospital cardiac arrest (OHCA) has rapidly evolved in the past decade. Increased sophistication of care in the community, emergency medical services (EMS) and hospital setting is associated with improved patient-centred outcomes. Notably, Utstein survival doubled from 11.6% to 23.1% between 2011 and 2016. These achievements involved collaboration between policymakers, clinicians and researchers, and were made possible by a strategic interplay of policy, research and implementation. We review the development and current state of OHCA in Singapore using primary population-based data from the Pan-Asian Resuscitation Outcomes Study and an unstructured search of research databases. We discuss the roles of important milestones in policy, community, dispatch, EMS and hospital interventions. Finally, we relate these interventions to relevant processes and outcomes, such as the relationship between the strategic implementation of bystander cardiopulmonary resuscitation and placement of automated external defibrillator with return of spontaneous circulation, survival to discharge and survival with favourable neurological outcomes.     

A review on non-edible oil as a potential feedstock for biodiesel: physicochemical properties and production technologies

There is increasing concern regarding alleviating world energy demand by determining an alternative to petroleum-derived fuels due to the rapid depletion of fossil fuels, rapid population growth, and urbanization. Biodiesel can be utilized as an alternative fuel to petroleum-derived diesel for the combustion engine. At present, edible crops are the primary source of biodiesel production. However, the excessive utilization of these edible crops for large-scale biodiesel production might cause food supply depletion and economic imbalance. Moreover, the utilization of edible oil as a biodiesel feedstock increases biodiesel production costs due to the high price of edible oils. A possible solution to overcome the existing limitations of biodiesel production is to utilize non-edible crops oil as a feedstock. The present study was conducted to determine the possibility and challenges of utilizing non-edible oil as a potential feedstock for biodiesel production. Several aspects related to non-edible oil as a biodiesel feedstock such as overview of biodiesel feedstocks, non-edible oil resources, non-edible oil extraction technology, its physicochemical and fatty acid properties, biodiesel production technologies, advantages and limitation of using non-edible oil as a feedstock for biodiesel production have been reviewed in various recent publications. The finding of the present study reveals that there is a huge opportunity to utilize non-edible oil as a feedstock for biodiesel production.

There is increasing concern regarding alleviating world energy demand by determining an alternative to petroleum-derived fuels due to the rapid depletion of fossil fuels, rapid population growth, and urbanization.     

FAK regulates cardiomyocyte survival following ischemia/reperfusion

Myocyte apoptosis is central to myocardial dysfunction following ischemia/reperfusion (I/R) and during the transition from hypertrophy to heart failure. Focal adhesion kinase (FAK), a non-receptor tyrosine kinase regulates adhesion-dependent survival signals and unopposed FAK activation has been linked to tumor development. We previously showed that conditional myocyte-specific deletion of FAK (MFKO) in the adult heart did not affect basal cardiomyocyte survival or cardiac function but led to dilated cardiomyopathy and heart failure following pressure overload. In the present study, we sought to determine if FAK functions to limit stress-induced cardiomyocyte apoptosis. We reasoned that (I/R), which stimulates robust apoptotic cell death, might uncover an important cardioprotective function for FAK. We found that depletion of FAK markedly exacerbates hypoxia/re-oxygenation-induced cardiomyocyte cell death in vitro. Moreover, deletion of FAK in the adult myocardium resulted in significant increases in I/R-induced infarct size and cardiomyocyte apoptosis with a concomitant reduction in left ventricular function. Finally, our results suggest that NF-κB signaling may play a key role in modulating FAK-dependent cardioprotection, since FAK inactivation blunted activation of the NF-κB survival signaling pathway and reduced levels of the NF-κB target genes, Bcl2 and Bcl-xl. Since the toggling between pro-survival and pro-apoptotic signals remains central to preventing irreversible damage to the heart, we conclude that targeted FAK activation may be beneficial for protecting stress-dependent cardiac remodeling.     

Dissimilarities in superoxide anion production by human neutrophils stimulated by phorbol myristate acetate or phorbol dibutyrate

Phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate (PDBU) are known to translocate protein kinase C (PKC) and to induce superoxide anion (O2-.) production in human neutrophils. They are thus currently used to probe the role of PKC in O2-. production. We show here that under certain conditions, O2-. production induced by PMA is not associated with a decrease in cytosolic PKC activity, whereas these two events are associated after PDBU stimulation. (1) In the presence of extracellular calcium (1 mM), O2-. production was related to the concentration of PMA. PMA induced O2-. production at all the concentrations studied, but this was not associated with a decrease in cytosolic PKC levels up to 5 ng/ml PMA (50% maximum O2-. production). (2) Under PDBU stimulation, even at very low O2-. production levels, cytosolic PKC decreased and the decrease as well as the O2-. production were related to the concentration of PDBU. (3) For a given decrease in cytosolic PKC, O2-. production induced by PMA was much greater than that induced by PDBU. (4) In calcium-free medium, O2-. production induced by low concentrations of PMA (up to 5 ng/ml) was lower than that observed in the presence of 1 mM calcium, whereas modifications of cytosolic PKC activity were similar. (5) Cytochalasin B had no effect on PMA-induced O2-. production, regardless of the calcium content of the medium, and had no effect on the decrease in cytosolic PKC. On the contrary, following PDBU stimulation, cytochalasin B increased O2-. production, regardless of the medium, but induced a larger decrease in cytosolic PKC when Ca2+ was present. (6) Preincubation of PMN with 100 microM H-7 (1-(5-isoquinolinylsulfonyl)-2-methylpiperazine) before stimulation with PMA or PDBU led to similar inhibition of O2-. production whatever the degree of decrease in cytosolic PKC activity. These findings show that, in contrast to PDBU, O2-. production induced by PMA is not always related to cytosolic PKC activity.     

Successful reconstruction of natural femoral anteversion using a short femoral stem in total hip arthroplasty surgery

ObjectiveTotal hip arthroplasty (THA) involves postoperative risks, such as thigh pain, periprosthetic fractures, and stress yielding. Short, anatomical, metaphyseal-fitting, cementless femoral stems were developed to reduce these postoperative risks. This study aimed to examine the “MiniMAX” prosthesis, which is a new generation, short, anatomical femoral stem made by Medacta.MethodsPatients underwent a low-dose computed tomography scan. Femoral anteversion was measured. We assessed the position and anteversion of the femoral component and compared them with the unoperated side. We also assessed the patients’ satisfaction and functional levels at 6 months postsurgery using the Harris Hip Score (HHS) and the Oxford Hip Score (OHS).ResultsNineteen individuals were recruited in this study. We found no significant difference in femoral anteversion between the operated hip and the native hip. Using the HHS and OHS questionnaires, we found clinical improvement in the 6-month postoperative scores compared with the preoperative scores.DiscussionThe new-generation, short, anatomical femoral stem made by Medacta is successful in reproducing natural femoral anteversion, while also improving patients’ functioning and lifestyle. Future large-scale, prospective comparison trials are required to further investigate this topic.     

Octreotide LAR vs. surgery in newly diagnosed patients with acromegaly: a randomized, open-label, multicentre study

Objective  This prospective randomized study evaluated the efficacy and safety of octreotide LAR vs. surgery in newly diagnosed acromegalic patients.
Methods  Totally 104 male and female patients were enrolled in a 50-week, exploratory, open-label and randomized study. Eligible patients were randomized to receive either octreotide LAR 20 mg every 28 days or to undergo surgery. Efficacy was assessed by changes in mean GH and IGF-I serum concentrations, at weeks 12, 24 and 48. Tumour volume was assessed by contrast-enhanced MRI. In both groups, treatment adjustment was performed for patients uncontrolled at week 12 or 24. Octreotide LAR patients received a dose increased to 30 mg or, if already receiving this dose, investigator and patients could decide to cross-over to surgery. Patients uncontrolled after surgery received octreotide LAR 20 mg, increased to 30 mg if acromegaly was still uncontrolled.
Results  Overall success rates at weeks 24 and 48 were 25% and 28% for the octreotide LAR group and 49% and 39% for the surgery group. Only the difference observed at week 24 was statistically significant ( P =  0·047). Both groups had a significant (> 20%) tumour shrinkage: 73% of patients in the octreotide LAR group and 95% in the surgery group. Major differences between octreotide LAR and surgery group in the occurrence of adverse events were gastrointestinal (71% vs. 27%), hepatobiliary (41% vs. 8%) and respiratory (5% vs. 28%).
Conclusion  This first randomized study in unselected patients indicates that the 48-week treatment outcome of octreotide LAR as first-line treatment of acromegaly does not significantly differ from surgery. As a complete response to surgery in GH-secreting macro-adenomas can be difficult, first-line therapy with octreotide LAR can be considered as a viable alternative for most patients with acromegaly, due to its low complication rate.     

Primary hydatid cyst of the retroperitoneum

Retroperitoneal contamination may occur during the natural history of hydatid disease. Primary hydatid cyst of the retroperitoneum is extremely rare. The authors report a case of a giant retroperitoneal hydatid cyst. Clinicians and surgeons must be aware of this possibility and follow a policy of nonsystematic puncture of an abdominal cyst and avoid spillage during surgery. Symptoms are related to the size, location, or ensuing complications of a cyst. Its occurrence should be strongly suspected ahead of any abdominal cyst, especially in an endemic area, where it may act as a parasite. Total and careful surgical excision is the gold-standard therapy.     

Altered expression of cell–cell adhesion molecules β-catenin/E-cadherin and related Wnt-signaling pathway in sporadic and syndromal keratocystic odontogenic tumors

Differential diagnosis of the keratocystic odontogenic tumor (KCOT) still represents a challenging problem especially if compared with the dentigerous cyst, which is similar in clinical and radiological course. Histological assessment of this entity may therefore draw crucial attention since various radical procedures are recommended for such lesions in contrast to dentigerous cysts. Since recent reports could prove the involvement of wingless(Wnt)-signaling pathway and β-catenin in the pathogenesis of many odontogenic and neoplastic lesions indicating impairment of cell–cell adhesion, we investigated the expression of two Wnt-signaling pathways, Wnt-1 and Wnt-10A as well as β-catenin and E-cadherin along with other related proteins in both lesions. We found a significant down-regulation in the expression of cell adhesion proteins β-catenin and E-cadherin along with alteration of Wnt-1 and Wnt-10A expression in the epithelium of KCOT. We assessed a specific focal distribution pattern of p63 in the suprabasal cell layer and a significant up-regulation of cyclin D1. Furthermore, laminin α-2 was a characteristic marker labelling only the basement membrane of dentigerous cysts. These results provide a new hypothesis explaining a molecular mechanism to understand initiating and development of KCOTs and an alternative therapeutic approach, especially for syndromal patients, where these multilocal lesions may involve and destroy wide orofacial bony structures.