Retrospective study to estimate the prevalence and describe the clinicopathological characteristics, treatments received, and outcomes of HER2-low breast cancer.

BACKGROUND: Approximately 80% of all breast cancers (BCs) are currently categorized as human epidermal growth factor receptor 2 (HER2)-negative [immunohistochemistry (IHC) 0, 1+, or 2+/in situ hybridization (ISH) negative]; approximately 60% of BCs traditionally categorized as HER2-negative express low levels of HER2. HER2-low (IHC 1+ or IHC 2+/ISH-) status became clinically actionable with approval of trastuzumab deruxtecan to treat unresectable/metastatic HER2-low BC. Greater understanding of patients with HER2-low disease is urgently needed. PATIENTS AND METHODS: This global, multicenter, retrospective study (NCT04807595) included tissue samples from patients with confirmed HER2-negative unresectable/metastatic BC [any hormone receptor (HR) status] diagnosed from 2014 to 2017. Pathologists rescored HER2 IHC-stained slides as HER2-low (IHC 1+ or IHC 2+/ISH-) or HER2 IHC 0 after training on low-end expression scoring using Ventana 4B5 and other assays at local laboratories (13 sites; 10 countries) blinded to historical scores. HER2-low prevalence and concordance between historical scores and rescores were assessed. Demographics, clinicopathological characteristics, treatments, and outcomes were examined. RESULTS: In rescored samples from 789 patients with HER2-negative unresectable/metastatic BC, the overall HER2-low prevalence was 67.2% (HR positive, 71.1%; HR negative, 52.8%). Concordance was moderate between historical and rescored HER2 statuses (81.3%; κ = 0.583); positive agreement was numerically higher for HER2-low (87.5%) than HER2 IHC 0 (69.9%). More than 30% of historical IHC 0 cases were rescored as HER2-low overall (all assays) and using Ventana 4B5. There were no notable differences between HER2-low and HER2 IHC 0 in patient characteristics, treatments received, or clinical outcomes. CONCLUSIONS: Approximately two-thirds of patients with historically HER2-negative unresectable/metastatic BC may benefit from HER2-low-directed treatments. Our data suggest that HER2 reassessment in patients with historical IHC 0 scores may be considered to help optimize selection of patients for treatment. Further, accurate identification of patients with HER2-low BC may be achieved with standardized pathologist training.

Intervention for Cognitive Reserve Enhancement in Delaying the Onset of Alzheimer's Symptomatic Expression (INCREASE) Study: Results from a Randomized Controlled Study of Medication Therapy Management Targeting a Delay in Prodromal Dementia Symptom Progression.

BACKGROUND: Cognitive reserve has been hypothesized as a mechanism to explain differences in individual risk for symptomatic expression of Alzheimer's Disease (AD). Inappropriate medications may diminish cognitive reserve, precipitating the transition from preclinical AD (pAD) to a symptomatic state. To date, there is limited data on the potential impact of medication optimization as a potential tool for slowing the symptomatic expression of AD. OBJECTIVES: (1) To test the efficacy of a medication therapy management intervention designed to bolster cognitive reserve in community-dwelling older adults without dementia. (2) To evaluate the efficacy of intervention by baseline pAD status. DESIGN: A 1-year randomized controlled trial was conducted in community-dwelling older adults without dementia. Randomization was stratified by amyloid ß positron emission tomography levels. SETTING: Community-based, Lexington, Kentucky. PARTICIPANTS: Adults 65 years or older with no evidence of dementia and reporting at least one potentially inappropriate medication as listed in the Beers 2015 criteria were recruited. The study aimed to enroll 90 participants based on the a priori sample size calculation. INTERVENTION: Medication therapy management versus standard of care. MEASUREMENTS: Primary outcomes were: (1) one-year changes in the Medication Appropriateness Index; (2) one-year changes in Trail Making Test B under scopolamine challenge. RESULTS: The medication therapy management intervention resulted in significant improvement in Medication Appropriateness Index scores. Overall, there was no beneficial effect of the medication therapy management on Trail Making Test B scores, however stratified analysis demonstrated improvement in Trail Making Test B challenged scores associated with the medication therapy management for those with elevated amyloid ß positron emission tomography levels consistent with pAD. CONCLUSIONS: Medication therapy management can reduce inappropriate medication use in older adults at risk for AD. Our study indicated beneficial cognitive effects in those with preclinical Alzheimer's Disease. No statistically significant effects were evident in the study group as a whole, or in those without preclinical cerebral amyloidosis. Further work designed to improve the effectiveness of the medication therapy management approach and defining other preclinical pathologic states that may benefit from medication optimization are readily achievable goals for promoting improved cognitive health and potentially delaying the onset of symptomatic AD.

Identifying dementia in Down syndrome with the Severe Impairment Battery, Brief Praxis Test and Dementia Scale for People with Learning Disabilities.

BACKGROUND: Individuals with Down syndrome (DS) are at high risk for dementia, specifically Alzheimer's disease. However, many measures regularly used for the detection of dementia in the general population are not suitable for individuals with DS due in part to floor effects. Some measures, including the Severe Impairment Battery (SIB), Brief Praxis Test (BPT) and Dementia Scale for People with Learning Disabilities (DLD), have been used in clinical trials and other research with this population. Validity research is limited, particularly regarding the use of such tools for detection of prodromal dementia in the DS population. The current project presents baseline cross-sectional SIB, BPT and DLD performance in order to characterise their predictive utility in discriminating normal cognition, possible dementia and probable dementia in adult DS. METHOD: Baseline SIB, BPT and DLD performances from 100 individuals (no dementia = 68, possible dementia = 16 & probable dementia = 16) were examined from a longitudinal cohort of aging individuals with DS. Receiver operating characteristic curves investigated the accuracy of these measures in relation to consensus dementia diagnoses, diagnoses which demonstrated high percent agreement with the examining neurologist's independent diagnostic impression. RESULTS: The SIB and BPT exhibited fair discrimination ability for differentiating no/possible versus probable dementia [area under the curve (AUC) = 0.61 and 0.66, respectively]. The DLD exhibited good discrimination ability for differentiating no versus possible/probable dementia (AUC = 0.75) and further demonstrated better performance of the DLD Cognitive subscale compared with the DLD Social subscale (AUC = 0.77 and 0.67, respectively). CONCLUSIONS: Results suggest that the SIB, BPT and DLD are able to reasonably discriminate consensus dementia diagnoses in individuals with DS, supporting their continued use in the clinical assessment of dementia in DS. The general performance of these measures suggests that further work in the area of test development is needed to improve on the AUCs for dementia status discrimination in this unique population. At present, however, the current findings suggest that the DLD may be the best option for reliable identification of prodromal dementia in this population, reinforcing the importance of including informant behaviour ratings in assessment of cognition for adults with DS.

Bedside hyperspectral imaging indicates a microcirculatory sepsis pattern - an observational study.

INTRODUCTION: Microcirculatory alterations are key mechanisms in sepsis pathophysiology leading to tissue hypoxia, edema formation, and organ dysfunction. Hyperspectral imaging (HSI) is an emerging imaging technology that uses tissue-light interactions to evaluate biochemical tissue characteristics including tissue oxygenation, hemoglobin content and water content. Currently, clinical data for HSI technologies in critical ill patients are still limited. METHODS AND ANALYSIS: TIVITA® Tissue System was used to measure Tissue oxygenation (StO2), Tissue Hemoglobin Index (THI), Near Infrared Perfusion Index (NPI) and Tissue Water Index (TWI) in 25 healthy volunteers and 25 septic patients. HSI measurement sites were the palm, the fingertip, and a suprapatellar knee area. Septic patients were evaluated on admission to the ICU (E), 6 h afterwards (E+6) and three times a day (t3-t9) within a total observation period of 72 h. Primary outcome was the correlation of HSI results with daily SOFA-scores. RESULTS: Serial HSI at the three measurement sites in healthy volunteers showed a low mean variance expressing high retest reliability. HSI at E demonstrated significantly lower StO2 and NPI as well as higher TWI at the palm and fingertip in septic patients compared to healthy volunteers. StO2 and TWI showed corresponding results at the suprapatellar knee area. In septic patients, palm and fingertip THI identified survivors (E-t4) and revealed predictivity for 28-day mortality (E). Fingertip StO2 and THI correlated to SOFA-score on day 2. TWI was consistently increased in relation to the TWI range of healthy controls during the observation time. Palm TWI correlated positively with SOFA scores on day 3. DISCUSSION: HSI results in septic patients point to a distinctive microcirculatory pattern indicative of reduced skin oxygenation and perfusion quality combined with increased blood pooling and tissue water content. THI might possess risk-stratification properties and TWI could allow tissue edema evaluation in critically ill patients. CONCLUSION: HSI technologies could open new perspectives in microcirculatory monitoring by visualizing oxygenation and perfusion quality combined with tissue water content in critically ill patients - a prerequisite for future tissue perfusion guided therapy concepts in intensive care medicine.

Mental Component Score (MCS) from Health-Related Quality of Life Predicts Incidence of Dementia in U.S. Males.

BACKGROUND: The Medical Outcomes Study Questionnaire Short Form 36 health survey (SF-36) measures health-related quality of life (HRQoL) from the individual's point of view and is an indicator of overall health status. OBJECTIVE: To examine whether HRQoL shows differential changes over time prior to dementia onset and investigate whether HRQoL predicts incidence of dementia. DESIGN: Prevention of Alzheimer's Disease (AD) by Vitamin E and Selenium (PREADViSE) trial, which recruited 7,547 non-demented men between 2002 and 2009. A subset of 2,746 PREADViSE participants who completed up to five SF-36 assessments at annual visits was included in the current analysis. SETTING: Secondary data analysis of PREADViSE data. PARTICIPANTS: A subset of 2,746 PREADViSE participants who completed up to five SF-36 assessments at annual visits was included in the current analysis. MEASUREMENTS: Two summary T scores were generated for analysis: physical component score (PCS) and mental component score (MCS), each with a mean of 50 (standard deviation of 10); higher scores are better. Linear mixed models (LMM) were applied to determine if mean component scores varied over time or by eventual dementia status. Cox proportional hazards regression was used to determine if the baseline component scores were associated with dementia incidence, adjusting for baseline age, race, APOE-4 carrier status, sleep apnea, and self-reported memory complaint at baseline. RESULTS: The mean baseline MCS score for participants who later developed dementia (mean± SD: 53.9±9.5) was significantly lower than for those participants who did not develop dementia during the study (mean±SD: 56.4±6.5; p = 0.005). Mean PCS scores at baseline (dementia: 49.3±7.9 vs. non-dementia: 49.8±7.8) were not significantly different (p = 0.5) but LMM analysis showed a significant time effect. For MCS, the indicator for eventual dementia diagnosis was significantly associated with poorer scores after adjusting for baseline age, race, and memory complaint. Adjusted for other baseline risk factors, the Cox model showed that a 10-unit increase in MCS was associated with a 44% decrease in the hazard of a future dementia diagnosis (95% CI: 32%-55%). CONCLUSION: The SF-36 MCS summary score may serve as a predictor for future dementia and could be prognostic in longitudinal dementia research.

ACCIDENTAL FINDING OF SYNCHRONOUS BILATERAL DUCTAL CARCINOMA IN SITU IN A YOUNG MAN REFERRED TO MASTECTOMY DUE TO GYNECOMASTIA - AND WHAT IF LIPOSUCTION HAVE BEEN USED? CASE REPORT.

Breast male cancer is a rare condition. We report a case of a synchronous bilateral ductal carcinoma in situ (DCIS) which developed in a 26-year-old man with long-standing gynecomastia. He underwent bilateral subcutaneous mastectomy. Histology revealed bilateral pure DCIS. There was no identifiable causative factor for the development of bilateral DCIS, and there was no family history of the disease. No other treatment was required, and after 18 months there were no signs of local recurrence. This case highlights the importance of staying vigilant regarding the presence of malignancy in normally benign conditions. Liposuction has become a very useful technique for gynecomastia correction, however, there is a risk of dissemination of an unknown malignant tumor. In atypical cases, en bloc surgical excision should be performed.

A preliminary study of cerebral blood flow, aging and dementia in people with Down syndrome.

BACKGROUND: People with Down syndrome (DS) develop Alzheimer's disease (AD) at an earlier age of onset than those with sporadic AD. AD neuropathology is typically present in DS by 40 years of age with an onset of dementia approximately 10 years later. This early onset is due to the overexpression of amyloid precursor protein from the third copy of chromosome 21. Cerebrovascular neuropathology is thought to contribute in 40-60% of cases sporadic AD. However, the vascular contribution to dementia in people with DS has been relatively unexplored. We hypothesised that vascular perfusion is compromised in older adults with DS relative to younger individuals and is further exacerbated in those with dementia. METHOD: Cerebral blood flow (CBF) was measured using pulsed arterial spin labelling in 35 cognitively characterised adults with DS (26-65 years). DS participants were also compared with 15 control subjects without DS or dementia (26-65 years). Linear regression evaluated the difference in CBF across groups and diagnosis along with assessing the association between CBF and cognitive measures within the DS cohort. RESULTS: Cerebral blood flow was significantly lower among DS participants with probable AD compared with controls (P = 0.02) and DS participants with no dementia (P = 0.01). Within the DS cohort, CBF was significantly associated with the Severe Impairment Battery (SIB) measure and the Dementia Questionnaire for People with Learning Disabilities (DLD) rating (F3,25  = 5.13; P = 0.007). Both the SIB (ß = 0.74; t = 2.71; P = 0.01) and DLD (ß = -0.96; t = -3.87; P < 0.001) indicated greater impairment as global CBF decreased. Age was significantly associated with CBF among participants with DS. There was a non-linear effect of age, whereby CBF declined more rapidly after 45 years of age. CONCLUSIONS: This preliminary study of CBF in DS indicates that cerebrovascular pathology may be a significant contributor to dementia in DS. CBF was associated with diagnosis, cognition and age. Notably, CBF decreases at a greater rate after age 45 and may represent a significant prodromal event in AD progression.

Effects of magnesium sulfate and dioctyl sodium sulfosuccinate on fecal hydration, output and systemic hydration in healthy horses / [Efeitos do sulfato de magnésio e do dioctil-sulfossuccinato de sódio na hidratação e eliminação fecal e sobre a hidratação sistêmica de cavalos saudáveis]

Magnesium sulphate (MS) and dioctyl sodium sulphosuccinate (DSS) are laxative drugs frequently used for the treatment of impactions. The aim of this study was to compare the effects of MS and DSS in fecal hydration, output and systemic hydration in healthy horses. Five healthy horses received 3 treatments with a 21-day interval. Treatment 1 was performed with administration of 4 liters of warm water; treatment 2: administration of 4 liters of warm water associated with 1g/kg of MS; and treatment 3: administration of 4 liters of warm water associated with 20mg/kg DSS. General and specific physical examination of the digestive system were performed, alongside with packed cell volume and total plasma protein measurement, abdominal ultrasonography and quantification of the amount and hydration of feces, before and 6, 12, 24, 36 and 48 hours after the treatments. No adverse effects were observed. The administration of laxatives promoted greater fecal output and hydration without resulting in systemic dehydration, yet no differences were observed between treatments. The absence of adverse effects of DSS demonstrates the safety of its use as a laxative drug at a dose of 20mg/kg. Studies comparing the effects of the laxative drugs in horses with large colon impaction are needed.(AU)

O sulfato de magnésio (SM) e o dioctil-sulfossuccinato de sódio (DSS) são drogas laxativas frequentemente utilizadas no tratamento da compactação. O objetivo deste estudo foi comparar os efeitos do SM e do DSS na hidratação e eliminação fecal, e na hidratação sistêmica de cavalos saudáveis. Cinco cavalos receberam três tratamentos, com intervalo de 21 dias. O tratamento 1 consistiu na administração de quatro litros de água morna; o tratamento 2: administração de quatro litros de água morna associada a 1g/kg de SM; e o tratamento 3: administração de quatro litros de água morna associada a 20mg/kg de DSS. Foram realizados exames físicos gerais e específicos do trato digestivo, hematócrito e proteína plasmática total, ultrassonografia abdominal e mensuração da quantidade e hidratação das fezes antes e após seis, 12, 24, 36 e 48 horas dos tratamentos. Não foram observados efeitos adversos. A administração de ambos os laxantes promoveu maior produção fecal e hidratação, sem resultar em desidratação sistêmica, entretanto não houve diferença entre os tratamentos. A ausência de efeitos adversos do DSS demonstra a segurança de seu uso como medicamento laxante na dose de 20mg/kg. São necessários estudos que comparem o efeito dos laxantes em equinos portadores de compactação de cólon.(AU)

Carboxymethylcellulose and psyllium effects in sand output of horses with asymptomatic sand accumulation / [Efeitos da carboximetilcelulose e do psyllium sobre a eliminação de areia de cavalos com sablose assintomática]

The aim of this study was to evaluate the effects of Psyllium (PSY) and Carboxymethylcellulose (CMC) administration on fecal elimination of sand in horses with asymptomatic sand accumulations. Eight horses were selected from sandy areas and randomly divided into 2 groups of four animals. The subjects were treated either with CMC or PSY. The presence of intestinal sand was confirmed through radiography and glove sedimentation test. The study was performed in two phases, with a 7-day interval. In phase I, all the animals received 8 liters of warm water; in phase II, the CMC group received 8 liters of water + 1g/kg of CMC, whereas the PSY group received 8 liters of water + 1g/kg of PSY. All administrations were performed through nasogastric intubation and fractionated in 2 equal volume administrations with an interval of two hours. General and specific physical examination of the digestive system were performed in conjunction with abdominal ultrasonography before the administrations and after 6, 12, 24, 36 and 48 hours, aiming to evaluate intestinal motility and presence of sand. All the feces eliminated by the animals within the 72 hours following the administrations were quantified, diluted and sedimented in order to calculate the sand output (g/kg of feces). All the animals were also subjected to radiographic examination to quantify sand accumulation prior to phase I and after 72 hours of phases I and II. No adverse effects were observed after the treatments. It was possible to notice higher sand elimination in both groups during the phase I, whereas no difference was observed in sand elimination rates between the groups in phase II. The radiographic scores presented differences between the initial timepoint and 72h in phases I and II for both groups. Based on the sand elimination rates and radiographic score, this study demonstrated that sand output was greater after administration of water alone, compared to CMC and Psyllium, leading to the inference that removal of the sandy environment and prevention of sand re-ingestion are effective measures for the elimination of sand from the colon of horses with asymptomatic sand accumulations.(AU)

O objetivo deste estudo foi avaliar os efeitos da administração do psyllium (PSY) e da carboximetilcelulose (CMC) sobre a eliminação fecal de areia em equinos com sablose assintomática. Oito equinos com confirmação radiográfica de sablose assintomática foram divididos em dois grupos (grupo CMC e grupo PSY). O estudo foi realizado em duas fases, com intervalo de sete dias. Na fase 1, todos os animais receberam 8L de água; na fase 2, o grupo CMC recebeu 8L de água + 1g/kg de CMC e o grupo PSY recebeu 8L de água + 1g/kg de PSY. Antes da administração de cada solução e após seis, 12, 24, 36 e 48 horas, foram realizados exame físico e ultrassonografia abdominal. Todas as fezes eliminadas em 72 horas foram avaliadas para quantificar a eliminação de areia (g/kg de fezes). Antes da fase 1 e após 72 horas das fases 1 e 2, o exame radiográfico foi realizado para quantificar o escore de acúmulo de areia. Houve maior eliminação de areia após a administração de água em comparação com a administração de CMC, e não se observou diferença entre a CMC e o PSY. Uma redução significativa nos escores radiográficos de acúmulo de areia foi observada após a administração de água, bem como a manutenção dos escores após a administração da CMC e do PSY. Com base na produção de areia e no escore radiográfico, este estudo sugere que a remoção do ambiente arenoso, impedindo a reingestão de areia, é uma medida eficaz para a eliminação da areia do cólon de cavalos com acúmulos de areia assintomáticos.(AU)

Discriminating changes in intracellular NADH/NAD+ levels due to anoxicity and H2 supply in R. eutropha cells using the Frex fluorescence sensor.

The hydrogen-oxidizing "Knallgas" bacterium Ralstonia eutropha can thrive in aerobic and anaerobic environments and readily switches between heterotrophic and autotrophic metabolism, making it an attractive host for biotechnological applications including the sustainable H2-driven production of hydrocarbons. The soluble hydrogenase (SH), one out of four different [NiFe]-hydrogenases in R. eutropha, mediates H2 oxidation even in the presence of O2, thus providing an ideal model system for biological hydrogen production and utilization. The SH reversibly couples H2 oxidation with the reduction of NAD+ to NADH, thereby enabling the sustainable regeneration of this biotechnologically important nicotinamide cofactor. Thus, understanding the interaction of the SH with the cellular NADH/NAD+ pool is of high interest. Here, we applied the fluorescent biosensor Frex to measure changes in cytoplasmic [NADH] in R. eutropha cells under different gas supply conditions. The results show that Frex is well-suited to distinguish SH-mediated changes in the cytoplasmic redox status from effects of general anaerobiosis of the respiratory chain. Upon H2 supply, the Frex reporter reveals a robust fluorescence response and allows for monitoring rapid changes in cellular [NADH]. Compared to the Peredox fluorescence reporter, Frex displays a diminished NADH affinity, which prevents the saturation of the sensor under typical bacterial [NADH] levels. Thus, Frex is a valuable reporter for on-line monitoring of the [NADH]/[NAD+] redox state in living cells of R. eutropha and other proteobacteria. Based on these results, strategies for a rational optimization of fluorescent NADH sensors are discussed.

Thyroid FNAC: Causes of false-positive results.

In this paper, we aim to focus on false positive results in the evaluation of thyroid aspirations, covering cystic, inflammatory, follicular and oncocytic lesions, papillary carcinoma, and medullary carcinoma of thyroid. The recently described entity noninvasive follicular thyroid neoplasm with papillary-like nuclear features is also discussed detailing the impact of its introduction on the sensitivity and specificity of thyroid FNA, as well as the use of molecular tests for diagnostics. Medicolegal issues in relation to current practice in English law are also described.

Radiofrequency-thermoablation: General principle, historical overview and modern applications for epilepsy.

Stereotactically guided radiofrequency thermoablation (RFTA) for epilepsy has been frequently applied over the last 40 years. Radiofrequency electrodes with temperature control function generate a coagulation lesion with clearly defined borders. In combination with high-resolution MRI imaging, this technique allows minimally-invasive ablation of periventricular nodular heterotopias, small focal type II dysplasias, and hypothalamic hamartomas. This review summarises the literature addressing this topic mainly regarding technical aspects. In essence, RFTA is a safe treatment option for patients suffering from epileptogenic pathologies visible on MRI-images.

Epileptogenicity and pathology - Under consideration of ablative approaches.

Besides resective epilepsy surgery, minimally invasive ablation using new diagnostic and therapeutic techniques recently became available. Optimal diagnostic approaches for these treatment options are discussed. The pathophysiology of epileptogenic networks differs depending on the lesion-types and location, requiring a differential use of non-invasive or invasive functional studies. In addition to the definition of epileptogenic zones, a challenge for pre-surgical investigation is the determination of three-dimensional epileptic networks to be removed.

Laparoscopic adjustable gastric banding in adolescents with severe obesity: Psychological aspects, decision makers of surgery, and 2-year outcomes. A case series.

BACKGROUND: The results of medical treatment of severe obesity in the adolescent population (balanced diet and physical activity) are often unsatisfactory, and bariatric surgery is questioned. The psychological determinants for requesting bariatric surgery in these adolescents are unclear. The objective of this study was to report the psychiatric and psychological aspects as well as the determinants of the medical decision for surgery in a cohort of obese adolescents requesting bariatric surgery by laparoscopic adjustable gastric banding. METHODS: Thirty-five adolescents (12.3-17.7 years of age), were recruited from January 2007 to December 2012. Semistructured interviews were conducted. RESULTS: Fifty-four percent of the adolescents had a psychiatric history and 85% had psychiatric comorbidities. In adolescents undergoing surgery, excess weight loss was 46% after 1 year and 51% after 2years. For patients not receiving surgery, excess weight loss was 0.43% after 1 year (P=0.001). Compliance with medical treatment was the only significant element contributing to the decision to perform surgery. Results in terms of satisfaction and perception 1 and 2years after surgery were encouraging. CONCLUSION: Bariatric surgery is feasible in young patients and produces good results in terms of excess weight loss. We argue that compliance with medical treatment is probably one of the most important elements for making the decision to perform bariatric surgery and in excess weight loss after surgery. We probably need to focus on the compliance of young patients and evaluate how this can be improved.

Skills improvement after observation or direct practice of a simulated laparoscopic intervention.

BACKGROUND: Laparoscopic skills are more and more often being learned on simulators. PURPOSE: To assess the respective roles of observation and direct practice in the retention of laparoscopic procedural skills. BASIC PROCEDURES: Twelve surgical residents were included in a two-session laparoscopic training course. During the first session (S1), one participant completed a cholecystectomy on the Simbionix LAPMentor™ and then observed his colleague carrying out a total hysterectomy and vice versa. During the second session (S2), each participant completed both interventions. Skills evaluation was assessed using the Objective Structured Assessment of Technical Skills (OSATS) global rating scale and LAPMentor™ metrics. MAIN FINDINGS: Mean OSATS score during the first session was 19.3±5.1, and increased by 37% in the group of former observer students (S2O, P=0.003), and by 54% in the group of former practising students (S2A, P=0.001). Self- and peer-grading results were concordant with the supervisor's evaluation. Detailed analysis of LAPMentor™ metrics showed a trend toward more parameters being improved in group S2A as compared to group S2O on both interventions. The most significant improvements concerned the time of completion for the hysterectomy and the efficiency of cautery for the cholecystectomy. CONCLUSIONS: Observation of laparoscopic skills still allows for surgical improvement, but direct practice on a virtual reality trainer provides better results. Self- and peer-grading were concordant with the supervisor's evaluation. This work may advocate the integration of both personal training on simulators and surgical observation into residents' surgical curricula.