Learning theories and principles in surgical education and technical learning

What is important to think about in surgical education and technical skills training? Technical skills training is grounded in social cognitive theory and the concepts of modeling and self-efficacy. Cognitive and nontechnical learning is critical to supplement the overall proficiency of the surgical learner in performing an operation. Technical learning is cemented by deliberate practice and there is benefit to productive struggle and failure. External cognitive load should be minimized to maximized operative skills advancement.     

The Relationship Between Air Pollution and Lung Cancer in Nonsmokers in Taiwan

Introduction

For never-smokers (smoked <100 lifetime cigarettes), lung cancer (LC) has emerged as an important issue. We aimed to investigate the effects of prevalence changes in tobacco smoking and particulate matter (PM) 2.5 (PM_2.5) levels on LC in Taiwan, in relation to contrasting PM_2.5 levels, between Northern Taiwan (NT) and Southern Taiwan (ST).

Braden scale for pressure ulcer risk predicts rehabilitation placement after pancreatic resection

BackgroundPatients undergoing pancreatic resection frequently require rehabilitation facilities after hospital discharge. We evaluated the predictive role of validated markers of frailty on rehabilitation facility placement to identify patients who may require this service.MethodsSingle-center retrospective cohort study of patients who underwent pancreatic resection from 2010 to 2015. 90-day morbidity and mortality were calculated. Postoperative validated markers of frailty (Activities of Daily Living scale, Braden scale [assesses pressure ulcer risk, lower scores = higher risk] and Morse fall scale) were evaluated via multivariate regression to identify predictors of discharge to rehabilitation facility.Results470 patients with complete data were included. Mean age was 62 and 49.2% were male. Postoperative median length of stay (LOS) was 8 (IQR 7–10). 92 (19.66%) patients were discharged to rehabilitation facilities and 138 (29.49%) patients were readmitted within 90 days. On multivariate analysis, age, sex, LOS > 8 days, inpatient Comprehensive Complication Index (CCI) and initial Braden scale were predictive of rehabilitation placement.ConclusionA marker of frailty routinely collected daily by nursing staff, the Braden scale, is available to help surgeons predict the need for postoperative rehabilitation placement after pancreatic resection. Engaging discharge planning services for at-risk patients may help prevent delayed hospital discharge and should be further evaluated.     

Cholecystectomy reduces subsequent cholangiocarcinoma risk in choledocholithiasis patients undergoing endoscopic intervention

BACKGROUNDCholangiocarcinoma is a disease with a high mortality rate. Our previous study revealed that cholelithiasis patients who undergo endoscopic sphincterotomy (ES)/endoscopic papillary balloon dilatation are at a higher risk for subsequent cholangiocarcinoma than cholelithiasis patients who undergo cholecystectomy.AIMTo clarify the relationship between recurrent biliary events and subsequent cholangiocarcinoma risk in choledocholithiasis patients.METHODSFrom one million random cases in the Taiwan National Health Insurance Research Database 2004–2011, we selected symptomatic choledocholithiasis patients older than 18 years who were admitted from January 2005 to December 2009 (study group). Cases for a control group were defined as individuals who had never been diagnosed with cholelithiasis, matched by sex and age in a 1:3 ratio. The study group was further divided into ES/endoscopic papillary balloon dilatation, both ES/endoscopic papillary balloon dilatation and cholecystectomy, and no intervention groups.RESULTSWe included 2096 choledocholithiasis patients without previous intervention or cholangiocarcinoma. A total of 12 (2.35%), 11 (0.74%), and 1 (1.00%) subsequent cholangiocarcinoma cases were diagnosed among 511 ES/endoscopic papillary balloon dilatation patients, 1485 patients with no intervention, and 100 ES/endoscopic papillary balloon dilatation and cholecystectomy patients, respectively. The incidence rates of recurrent biliary event were 527.79/1000 person-years and 286.69/1000 person-years in the subsequent cholangiocarcinoma and no cholangiocarcinoma group, showing a high correlation between subsequent cholangiocarcinoma risk and recurrent biliary events.CONCLUSIONCholedocholithiasis patients who undergo further cholecystectomy after ES/endoscopic papillary balloon dilatation have decreased subsequent cholangiocarcinoma risk due to reduced recurrent biliary events.     

Adult‐onset inflammatory linear verrucous epidermal nevus: Immunohistochemical studies and review of the literature

Adult‐onset inflammatory linear verrucous epidermal nevus (ILVEN) is an uncommon cutaneous disease compared to childhood‐onset ILVEN. The typical histopathologic features are alternating parakeratosis and orthokeratosis with an absent granular layer underneath parakeratosis, in contrast to a thickened granular layer below the foci of orthokeratosis in psoriasiform epidermal hyperplasia. Herein, we present a 49‐year‐old woman with typical clinical and histopathologic characteristics of adult‐onset ILVEN, including linear arrangement of thick scaly papules and plaques localized on the medial side of her right leg, ankle, and foot. Immunohistochemical studies included involucrin, Ki‐67, and keratin‐10. Compared to the staining pattern in psoriasis, the expression of involucrin in this case was of lower intensity and localized to upper epidermal layers with relatively less extensive staining beneath regions of parakeratosis as compared to orthokeratosis; Ki‐67 showed lower basal layer proliferative activity; and keratin‐10 showed a greater intensity of staining within suprabasal epidermis.     

Metabolic and Nutritional Issues Associated with Spinal Muscular Atrophy

Spinal muscular atrophy (SMA), the main genetic cause of infant death, is a neurodegenerative disease characterized by the selective loss of motor neurons in the anterior horn of the spinal cord, accompanied by muscle wasting. Pathomechanically, SMA is caused by low levels of the survival motor neuron protein (SMN) resulting from the loss of the SMN1 gene. However, emerging research extends the pathogenic effect of SMN deficiency beyond motor neurons. A variety of metabolic abnormalities, especially altered fatty acid metabolism and impaired glucose tolerance, has been described in isolated cases of SMA; therefore, the impact of SMN deficiency in metabolic abnormalities has been speculated. Although the life expectancy of these patients has increased due to novel disease-modifying therapies and standardization of care, understanding of the involvement of metabolism and nutrition in SMA is still limited. Optimal nutrition support and metabolic monitoring are essential for patients with SMA, and a comprehensive nutritional assessment can guide personalized nutritional therapy for this vulnerable population. It has recently been suggested that metabolomics studies before and after the onset of SMA in patients can provide valuable information about the direct or indirect effects of SMN deficiency on metabolic abnormalities. Furthermore, identifying and quantifying the specific metabolites in SMA patients may serve as an authentic biomarker or therapeutic target for SMA. Here, we review the main epidemiological and mechanistic findings that link metabolic changes to SMA and further discuss the principles of metabolomics as a novel approach to seek biomarkers and therapeutic insights in SMA.     

Interleukin-4 receptor-targeted liposomal doxorubicin as a model for enhancing cellular uptake and antitumor efficacy in murine colorectal cancer

Our previous studies showed that colorectal tumor has high interleukin-4 receptor α (IL-4Rα) expression, whereas adjacent normal tissue has low or no IL-4Rα expression. We also observed that human atherosclerotic plaque-specific peptide-1 (AP1) can specifically target to IL-4Rα. In this study, we investigated the therapeutic efficacy and systemic toxicity of AP1-conjuagted liposomal doxorubicin. AP1 bound more strongly to and was more efficiently internalized into IL-4Rα-overexpressing CT26 cells than CT26 control cells. Selective cytotoxicity experiment revealed that AP1-conjugated liposomal doxorubicin preferentially killed IL-4Rα-overexpressing CT26 cells. AP1-conjugated liposomal doxorubicin administered intravenously into mice produced significant inhibition of tumor growth and showed decreased cardiotoxicity of doxorubicin. These results indicated that AP1-conjugated liposomal doxorubicin has a potent and selective anticancer potential against IL-4Rα-overexpressing colorectal cancer cells, thus providing a model for targeted anticancer therapy.     

Identification of a novel platelet antagonist that binds to CLEC-2 and suppresses podoplanin-induced platelet aggregation and cancer metastasis

Podoplanin (PDPN) enhances tumor metastases by eliciting tumor cell-induced platelet aggregation (TCIPA) through activation of platelet C-type lectin-like receptor 2 (CLEC-2). A novel and non-cytotoxic 5-nitrobenzoate compound 2CP was synthesized that specifically inhibited the PDPN/CLEC-2 interaction and TCIPA with no effect on platelet aggregation stimulated by other platelet agonists. 2CP possessed anti-cancer metastatic activity in vivo and augmented the therapeutic efficacy of cisplatin in the experimental animal model without causing a bleeding risk. Analysis of the molecular action of 2CP further revealed that Akt1/PDK1 and PKCμ were two alternative CLEC-2 signaling pathways mediating PDPN-induced platelet activation. 2CP directly bound to CLEC-2 and, by competing with the same binding pocket of PDPN in CLEC-2, inhibited PDPN-mediated platelet activation. This study provides evidence that 2CP is the first defined platelet antagonist with CLEC-2 binding activity. The augmentation in the therapeutic efficacy of cisplatin by 2CP suggests that a combination of a chemotherapeutic agent and a drug with anti-TCIPA activity such as 2CP may prove clinically effective.     

Reducing signal loss of the parahippocampal gyrus improves imaging of the default‐mode network in 3.0‐T MRI: the effect of susceptibility‐induced field gradients

Previous investigations have indicated that the default‐mode network (DMN) is highly involved in memory processing in the parahippocampal gyrus (PHC). However, because of susceptibility‐related signal loss, parahippocampal activation in the DMN is difficult to detect in resting‐state functional MRI experiments that are conducted using a 3.0‐T MRI scanner. This study investigated the magnetic field gradients of various brain regions and attempted to compensate for signal loss in the PHC using an optimized slice orientation. The field gradients, signal intensities and DMN functional connectivity (FC) of the PHC were investigated using datasets acquired from 18 healthy volunteers. The results show that the field gradient component parallel to the main magnetic field dominates the PHC. The results indicate that the signal intensities and FC of the DMN are significantly low in the PHC when the slice orientation of the imaging plane is transversal. Whether the voxel dimension is isotropic or anisotropic exerts a minimal effect in altering the slice orientation dependence. In conclusion, the results of this study support the selection of the coronal or sagittal planes for imaging of the DMN. Copyright © 2015 John Wiley & Sons, Ltd.