Mepolizumab improves sense of smell in severe chronic rhinosinusitis with nasal polyps: SYNAPSE.

BACKGROUND: Loss of smell is one of the most bothersome and difficult-to-treat symptoms in patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP). METHODOLOGY: SYNAPSE was a 52-week Phase III study of 4-weekly mepolizumab (100 mg subcutaneously) plus standard of care in adults with severe bilateral CRSwNP. This post hoc analysis assessed changes from baseline to study end in loss of smell visual analogue scale (VAS) symptom score, in patients stratified by several baseline clinical characteristics. SinoNasal Outcomes Test (SNOT)-22 sense of smell/taste item and University of Pennsylvania Smell Identification Test (UPSIT) scores were also assessed. RESULTS: SYNAPSE enrolled 407 patients (mepolizumab=206; placebo=201) with impaired sense of smell at baseline. Improvements from baseline to study end in loss of smell VAS score were greater with mepolizumab versus placebo (treatment difference: −0.37) and most notable in patients with fewer or more recent prior surgeries (treatment difference: 1 vs 2 vs more than 2 prior surgeries,−1.29 vs −0.23 vs −0.07; =3 years since last surgery, −0.89 vs 0.22). Approximately 25% of patients had baseline UPSIT scoresavailable; among those scoring =19 by study end. The SNOT-22 sense of smell/taste item score improved with mepolizumab versus placebo. CONCLUSIONS: Mepolizumab treatment improved patients' perceived sense of smell, as measured by loss of smell VAS score and SNOT-22 sense of smell/taste item score in patients with severe refractory CRSwNP.

Evaluating treatment response to mepolizumab in patients with severe CRSwNP.

BACKGROUND: The SYNAPSE study (NCT03085797) demonstrated that mepolizumab decreased nasal polyp (NP) size and nasal obstruction in patients with chronic rhinosinusitis with NP (CRSwNP). METHODS: SYNAPSE, a randomized, double-blind study, included patients with recurrent, refractory, severe CRSwNP, eligible for repeated surgery despite receiving standard of care (SoC). Patients received 4-weekly mepolizumab 100 mg or placebo subcutaneously plus SoC for 52 weeks. This post hoc analysis further characterized treatment responses and association with patient characteristics. The proportion of patients meeting any and each of five response criteria indicating improvement in disease-specific quality of life, NP size, nasal obstruction, loss of smell, and overall symptoms at Weeks 24 and 52, were assessed in subgroups: 1) no surgery; 2) neither surgery nor systemic corticosteroids (SCS). RESULTS: Of 407 patients in the intention-to-treat population, 381 and 343 patients had no sinus surgery by Weeks 24 and 52, respectively. More mepolizumab- versus placebo-treated patients without surgery by Weeks 24 and 52 met each response criteria. Of the mepolizumab-treated patients without surgery by Week 24, 109 (55%) responded across >=3 criteria, increasing to 126 (67%) by Week 52. Similar response trends were seen for patients with neither surgery nor SCS by Weeks 24 and 52. At either timepoint, there were no major differences in baseline characteristics between mepolizumab-treated full- (5/5 categories) and non-responders (0/5 categories). CONCLUSIONS: Most patients who completed SYNAPSE required neither surgery nor SCS use and in addition achieved a progressive and sustained clinical response to mepolizumab underscoring the therapeutic benefits of mepolizumab in severe CRSwNP.

Mepolizumab improves quality of life and reduces activity impairments in patients with CRSwNP.

Mepolizumab improves quality of life and reduces activity impairments in patients with CRSwNP.

Early participant-reported symptoms as predictors of adherence to anastrozole in the International Breast Cancer Intervention Studies II.

Background: Anastrozole reduces breast cancer risk in women at high risk, but implementing preventive therapy in clinical practice is difficult. Here, we evaluate adherence to anastrozole in the International Breast Cancer Intervention Study (IBIS)-II prevention and ductal carcinoma in situ (DCIS) trials, and its association with early symptoms. Patients and methods: In the prevention trial, 3864 postmenopausal women were randomized to placebo versus anastrozole. A total of 2980 postmenopausal women with DCIS were randomized to tamoxifen versus anastrozole. Adherence to trial medication was calculated using the Kaplan-Meier method and all P-values were two-sided. Results: In the prevention trial, adherence was 65.8% [anastrozole (65.7%) versus placebo (65.9%); HR = 0.97 (0.87-1.09), P = 0.6]. Adherence was lower for those reporting arthralgia in the placebo group (P = 0.02) or gynecological symptoms in the anastrozole group (P = 0.003), compared with those not reporting these symptoms at 6 months. In the DCIS study, adherence was 66.7% [anastrozole (67.5%) versus tamoxifen (65.8%); HR = 1.06 (0.94-1.20), P = 0.4]. Hot flashes were associated with greater adherence in the anastrozole arm (P = 0.02). In both studies, symptoms were mostly mild or moderately severe, and adherence decreased with increasing severity for most symptoms. Drop-outs were highest in the first 1.5 years of therapy in both trials. Conclusions: In the IBIS-II prevention and DCIS trials, over two-thirds of women were adherent to therapy, with no differences by treatment groups. Participants who reported specific symptoms in the IBIS-II prevention trial had a small but significant effect on adherence, which strengthened as severity increased. Strategies to promote adherence should target the first year of preventive therapy.

Glucagon-like peptide-1 receptor expression on human eosinophils and its regulation of eosinophil activation.

BACKGROUND: Glucagon-like peptide-1 (GLP-1) and its receptor are part of the incretin family of hormones that regulate glucose metabolism. GLP-1 also has immune modulatory roles. OBJECTIVES: To measure the expression of the GLP-1 receptor (GLP-1R) on eosinophils and neutrophils in normal and asthmatic subjects and evaluate effects of a GLP-1 analog on eosinophil function. METHODS: Peripheral blood samples were taken from 10 normal and 10 allergic asthmatic subjects. GLP-1R expression was measured on eosinophils and neutrophils. Subsequently, the asthmatic subjects underwent allergen and diluent inhalation challenges, and GLP-1R expression was measured. Purified eosinophils, collected from mild asthmatic subjects, were stimulated with lipopolysaccharide (LPS) and a GLP-1 analog to evaluate eosinophil cell activation markers CD11b and CD69 and cytokine (IL-4, IL-5, IL-8 and IL-13) production. RESULTS: Glucagon-like peptide-1 receptor is expressed on human eosinophils and neutrophils. Eosinophil, but not neutrophil, expression of GLP-1R is significantly higher in normal controls compared to allergic asthmatics. The expression of GLP-1R did not change on either eosinophils or neutrophils following allergen challenge. A GLP-1 analog significantly decreased the expression of eosinophil-surface activation markers following LPS stimulation and decreased eosinophil production of IL-4, IL-8 and IL-13, but not IL-5. CONCLUSION AND CLINICAL RELEVANCE: Glucagon-like peptide-1 receptor is expressed on human eosinophils and neutrophils. A GLP-1 analog attenuates LPS-stimulated eosinophil activation. GLP-1 agonists may have additional adjunctive indications in treating persons with concomitant type 2 diabetes mellitus and asthma.

Inequalities in cancer screening participation: examining differences in perceived benefits and barriers.

OBJECTIVE: Inequalities exist in colorectal cancer (CRC) screening uptake, with people from lower socioeconomic status backgrounds less likely to participate. Identifying the facilitators and barriers to screening uptake is important to addressing screening disparities. We pooled data from 2 trials to examine educational differences in psychological constructs related to guaiac fecal occult blood testing. METHODS: Patients (n = 8576) registered at 7 general practices in England, within 15 years of the eligible age range for screening (45-59.5 years), were invited to complete a questionnaire. Measures included perceived barriers (emotional and practical) and benefits of screening, screening intentions, and participant characteristics including education. RESULTS: After data pooling, 2181 responses were included. People with high school education or no formal education reported higher emotional and practical barriers and were less likely to definitely intend to participate in screening, compared with university graduates in analyses controlling for study arm and participant characteristics. The belief that one would worry more about CRC after screening and concerns about tempting fate were strongly negatively associated with education. In a model including education and participant characteristics, respondents with low emotional barriers, low practical barriers, and high perceived benefits were more likely to definitely intend to take part in screening. CONCLUSIONS: In this analysis of adults approaching the CRC screening age, there was a consistent effect of education on perceived barriers toward guaiac fecal occult blood testing, which could affect screening decision making. Interventions should target specific barriers to reduce educational disparities in screening uptake and avoid exacerbating inequalities in CRC mortality.

Accurate and semi-automated analysis of bacterial association with mammalian cells.

To efficiently and accurately quantify the interactions of bacteria with mammalian cells, a reliable fluorescence microscopy assay was developed. Bacteria were engineered to become rapidly and stably fluorescent using Green Fluorescent Protein (GFP) expressed from an inducible Tet promoter. Upon application of the fluorescent bacteria onto a monolayer, extracellular bacteria could be discriminated from intracellular bacteria by antibody staining and microscopy. All bacteria could be detected by GFP expression. External bacteria stained orange, whereas internalised bacteria did not. Internalised bacteria could thus be discriminated from external bacteria by virtue of being green but not orange fluorescent. Image acquisition and counting of various fluorophore-stained entities were accomplished with a high-content screening platform. This allowed for semi-automated and accurate counting of intracellular and extracellular bacteria.

Role of local eosinophilopoietic processes in the development of airway eosinophilia in prednisone-dependent severe asthma.

BACKGROUND: In severe asthmatics with persistent airway eosinophilia, blockade of interleukin-5 has significant steroid-sparing effects and attenuates blood and sputum eosinophilia. The contribution of local maturational processes of progenitors within the airways relative to the recruitment of mature cells from the peripheral circulation to the development of airway eosinophilia is not known. We hypothesize that local eosinophilopoiesis may be the predominant process that drives persistent airway eosinophilia and corticosteroid requirement in severe asthmatics. OBJECTIVES: In a cross-sectional study, the number and growth potential of eosinophil-lineage-committed progenitors (EoP) were assayed in 21 severe eosinophilic asthmatics, 19 mild asthmatics, eight COPD patients and eight normal subjects. The effect of anti-IL-5 treatment on mature eosinophils and EoP numbers was made in severe eosinophilic asthmatics who participated in a randomized clinical trial of mepolizumab (substudy of a larger GSK sponsored global phase III trial, MEA115575) where subjects received mepolizumab (100 mg, n = 9) or placebo (n = 8), as six monthly subcutaneous injections. RESULTS: Mature eosinophil and EoP numbers were significantly greater in the sputum of severe asthmatics compared with all other subject groups. In colony-forming assays, EoP from blood of severe asthmatics demonstrated a greater response to IL-5 than mild asthmatics. Treatment of severe asthmatics with mepolizumab significantly attenuated blood eosinophils and increased EoP numbers consistent with blockade of systemic eosinophilopoiesis. There was however no significant treatment effect on mature eosinophils, sputum EoP numbers or the prednisone maintenance dose. CONCLUSIONS AND CLINICAL RELEVANCE: Patients with severe eosinophilic asthma have an exaggerated eosinophilopoeitic process in their airways. Treatment with 100 mg subcutaneous mepolizumab significantly attenuated systemic differentiation of eosinophils, but did not suppress local airway eosinophil differentiation to mature cells. Targeting IL-5-driven eosinophil differentiation locally within the lung maybe of relevance for optimal control of airway eosinophilia and asthma.

Factors affecting uptake and adherence to breast cancer chemoprevention: a systematic review and meta-analysis.

BACKGROUND: Preventive therapy is a risk reduction option for women who have an increased risk of breast cancer. The effectiveness of preventive therapy to reduce breast cancer incidence depends on adequate levels of uptake and adherence to therapy. We aimed to systematically review articles reporting uptake and adherence to therapeutic agents to prevent breast cancer among women at increased risk, and identify the psychological, clinical and demographic factors affecting these outcomes. DESIGN: Searches were carried out in PubMed, CINAHL, EMBASE and PsychInfo, yielding 3851 unique articles. Title, abstract and full text screening left 53 articles, and a further 4 studies were identified from reference lists, giving a total of 57. This review was prospectively registered with PROSPERO (CRD42014014957). RESULTS: Twenty-four articles reporting 26 studies of uptake in 21 423 women were included in a meta-analysis. The pooled uptake estimate was 16.3% [95% confidence interval (CI) 13.6-19.0], with high heterogeneity (I(2) = 98.9%, P < 0.001). Uptake was unaffected by study location or agent, but was significantly higher in trials [25.2% (95% CI 18.3-32.2)] than in non-trial settings [8.7% (95% CI 6.8-10.9)] (P < 0.001). Factors associated with higher uptake included having an abnormal biopsy, a physician recommendation, higher objective risk, fewer side-effect or trial concerns, and older age. Adherence (day-to-day use or persistence) over the first year was adequate. However, only one study reported a persistence of ≥ 80% by 5 years. Factors associated with lower adherence included allocation to tamoxifen (versus placebo or raloxifene), depression, smoking and older age. Risk of breast cancer was discussed in all qualitative studies. CONCLUSION: Uptake of therapeutic agents for the prevention of breast cancer is low, and long-term persistence is often insufficient for women to experience the full preventive effect. Uptake is higher in trials, suggesting further work should focus on implementing preventive therapy within routine care.

Escherichia coli induces platelet aggregation in an FcγRIIa-dependent manner.

BACKGROUND: The discovery of pathogen-recognition receptors such as Toll-like receptors on platelets has led to the emergence of the concept of platelets as important components of the host response to infection. Escherichia coli (E. coli)-mediated sepsis is a serious illness characterized by the occurrence of thrombocytopenia. Whereas there has been a wealth of research on platelet activation by Gram-positive bacteria, little is known about the mechanisms associated with Gram-negative bacteria-induced platelet activation with Gram-negative bacteria. OBJECTIVES: To determine the mechanisms by which Gram-negative E. coli induces platelet aggregation. METHODS: Induction of platelet aggregation with E. coli strain O157:H7 was tested in platelet-rich plasma (PRP), washed platelets, and serum depleted of complement factors. Platelet inhibitors (against αII b ß3 , glycoprotein Ibα and FcγRIIa) were used. Platelet thromboxane synthesis was analyzed after E. coli stimulation. Cell binding assays were used to assess the ability of E. coli to support platelet adhesion. Trypsinization was used to determine the role of E. coli surface proteins. RESULTS AND CONCLUSION: E. coli-induced aggregation in PRP was donor-dependent. E. coli O157:H7 induced aggregation with a lag time of 6.9 ± 1.3 min in an αII b ß3 -dependent and FcγRIIa-dependent manner. Furthermore, this interaction was enhanced by the presence of complement, and was dependent on thromboxane synthesis. These results show E. coli to be a potent inducer of platelet aggregation.

T regulatory cell phenotypes in peripheral blood and bronchoalveolar lavage from non-asthmatic and asthmatic subjects.

BACKGROUND: An unresolved issue in T regulatory cells' cell biology is the lack of consensus on phenotypic markers that accurately define the natural Treg (nTreg) population. OBJECTIVES: To examine nTreg frequency and functional capacity in healthy controls and their frequency in asthmatic subjects using three different phenotypic strategies. We hypothesized that phenotypically different nTreg are quantitatively and functionally different. METHODS: Thirty-four healthy, non-asthmatic and 17 asthmatic subjects were studied. Three nTreg phenotypes were defined as follows: nTreg1 (CD4(+) CD25(+) Foxp3(+) ), nTreg2 (CD4(+) CD25(+) CD127(low) Foxp3(+) ), and nTreg3 (CD4(+) CD25(high) Foxp3(+) ). The flow cytometric determination of nTreg frequency in peripheral blood (PB) and bronchoalveolar lavage (BAL) was performed using fluorescently labelled antibodies. Peripheral blood nTreg functional capacity was assessed using a CFSE-based suppression assay. RESULTS: There was a significantly lower frequency of PB nTreg3 compared to nTreg2 and nTreg1 (P < 0.05). Both nTreg2 and nTreg3 had a significantly greater suppressive capacity than nTreg1 at T responder (Tresp) to nTreg ratios of 16 : 1 up to 1 : 1 (P < 0.01). Asthmatics exhibited a significantly lower PB nTreg3 and nTreg1 frequency than healthy controls (P < 0.05). There were no differences between healthy controls and asthmatic subjects when comparing BAL nTreg frequency. CONCLUSIONS AND CLINICAL RELEVANCE: Phenotypically different nTreg subsets are quantitatively and functionally different and are variably observed in asthma. The CD4(+) CD25(high) Foxp3(+) phenotype was the least frequent, but demonstrated the greatest suppression, and was significantly lower in PB of asthmatic subjects. Consequently, it is imperative that nTreg phenotypes be clearly defined and that the interpretation of their frequency and function be phenotype specific.

Treatment with anti-OX40L or anti-TSLP does not alter the frequency of T regulatory cells in allergic asthmatics.

OX40-OX40L interactions and thymic stromal lymphopoietin (TSLP) are important in the induction and maintenance of Th2 responses in allergic disease, whereas T regulatory cells (Treg) have been shown to suppress pro-inflammatory Th2 responses. Both OX40L and TSLP have been implicated in the negative regulation of Treg. The effect of anti-asthma therapies on Treg is not well known. Our aim was to assess the effects of two monoclonal antibody therapies (anti-OX40L and anti-TSLP) on Treg frequency using a human model of allergic asthma. We hypothesized that the anti-inflammatory effects of these therapies would result in an increase in circulating Treg (CD4(+) CD25(+) CD127(low) Foxp3(+) cells) frequency. We measured Treg using flow cytometry, and our results showed that neither allergen challenge nor monoclonal antibody therapy altered circulating Treg frequency. These data highlight the need for assessment of airway Treg and for a more complete understanding of Treg biology so as to develop pharmacologics/biologics that modulate Treg for asthma therapy.

An interview study analysing patients' experiences and perceptions of non-laxative or full-laxative preparation with faecal tagging prior to CT colonography.

AIM: To compare patients' experiences of either non- or full-laxative bowel preparation with additional faecal tagging and subsequent computed tomographic (CT) colonography using in-depth interviews to elicit detailed responses. MATERIALS AND METHODS: Patients who received CT colonography after non- (n = 9) or full-laxative (n = 9) preparation participated in a semi-structured telephone interview at least 2 days after the investigation. Full-laxative preparation consisted of magnesium citrate and sodium picosulphate administered at home (or polyethylene glycol, if contraindicated), followed by hospital-based faecal tagging with iohexol. Non-laxative preparation was home-based barium sulphate for faecal tagging. Interviews were transcribed and thematically analysed to identify recurrent themes on patients' perceptions and experiences. RESULTS: Experiences of full-laxative preparation were usually negative and characterized by pre-test diarrhoea that caused significant interference with daily routine. Post-test flatus was common. Non-laxative preparation was well-tolerated; patients reported no or minimal changes to bowel habit and rapid return to daily routine. Patients reported worry and uncertainty about the purpose of faecal tagging. For iohexol, this also added burden from waiting before testing. CONCLUSION: Patients' responses supported previous findings that non-laxative preparation is more acceptable than full-laxative preparation but both can be improved. Faecal tagging used in combination with laxative preparation is poorly understood, adding burden and worry. Home-based non-laxative preparation is also poorly understood and patients require better information on the purpose and mechanism in order to give fully informed consent. This may also optimize adherence to instructions. Allowing home-based self-administration of all types of preparation would prevent waiting before testing.

Chronic disease and health behaviours linked to experiences of non-consensual sex among women and men.

OBJECTIVES: Few studies have examined the association between non-consensual sex and health indicators for both women and men. The current study examined this relationship as part of a large public health survey that collected information on a range of health behaviours and health risks. METHODS: The Behavioural Risk Factor Surveillance System (BRFSS) is an annual random-digit-dialled telephone survey providing surveillance of health behaviours and health risks among US adults. In 2005, an optional module on sexual violence was available for use at the discretion of each US state/territory. Over 115,000 respondents in 25 states/territories were administered the sexual violence module within the BRFSS. Logistic regression analyses were conducted from January to December 2008. RESULTS: Among both women and men, previous non-consensual sex was associated with health conditions such as high cholesterol, stroke and heart disease, and risk behaviours such as human immunodeficiency virus risk factors, smoking and excessive drinking. Sexually victimized women were more likely to report having had a heart attack or heart disease than non-victims. CONCLUSIONS: The experience of non-consensual sex is associated with a number of chronic disease outcomes and risk factors. The development and implementation of effective sexual violence prevention strategies may reduce the risk of chronic conditions among persons who have experienced sexual victimisation.

Variants in intron 13 of the ELMO1 gene are associated with diabetic nephropathy in African Americans.

Variants in the engulfment and cell motility 1 (ELMO1) gene are associated with nephropathy due to type 2 diabetes mellitus (T2DM) in a Japanese cohort. We comprehensively evaluated this gene in African American (AA) T2DM patients with end-stage renal disease (ESRD). Three hundred and nine HapMap tagging SNPs and 9 reportedly associated SNPs were genotyped in 577 AA T2DM-ESRD patients and 596 AA non-diabetic controls, plus 43 non-diabetic European American controls and 45 Yoruba Nigerian samples for admixture adjustment. Replication analyses were conducted in 558 AA with T2DM-ESRD and 564 controls without diabetes. Extension analyses included 328 AA with T2DM lacking nephropathy and 326 with non-diabetic ESRD. The original and replication analyses confirmed association with four SNPs in intron 13 (permutation p-values for combined analyses = 0.001-0.003), one in intron 1 (P = 0.004) and one in intron 5 (P = 0.002) with T2DM-associated ESRD. In a subsequent combined analysis of all 1,135 T2DM-ESRD cases and 1,160 controls, an additional 7 intron 13 SNPs produced evidence of association (P = 3.5 x 10(-5)- P = 0.05). No associations were seen with these SNPs in those with T2DM lacking nephropathy or with ESRD due to non-diabetic causes. Variants in intron 13 of the ELMO1 gene appear to confer risk for diabetic nephropathy in AA.

Efficacy and safet of pimobendan in canine heart failure caused by myxomatous mitral valve disease.

OBJECTIVES: To evaluate the clinical efficacy and safety of pimobendan by comparing it with ramipril over a six-month period in dogs with mild to moderate heart failure (HF) caused by myxomatous mitral valve disease (MMVD). METHODS: This was a prospective randomised, single-blind, parallel-group trial. Client-owned dogs (n = 43) with mild to moderate HF caused by MMVD were randomly assigned to one of two groups, which received either pimobendan (P dogs) or ramipril (R dogs) for six months. The outcome measures studied were: adverse HF outcome, defined as failure to complete the trial as a direct consequence of HF; maximum furosemide dose (mg/kg/day) administered during the study period; and any requirement for additional visits to the clinic as a direct consequence of HF. RESULTS: Treatment with pimobendan was well tolerated compared with treatment with ramipril. P dogs were 25 per cent as likely as R dogs to have an adverse HF outcome (odds ratio 4.09, 95 per cent confidence interval 1.03 to 16.3, P = 0.046). CLINICAL SIGNIFICANCE: R dogs had a higher overall score and thus may have had more advanced disease than P dogs at baseline (P = 0.04). These results should be interpreted cautiously but such a high odds ratio warrants further investigation.

Isolation and characterization of dinucleotide repeat microsatellites in Drosophila ananassae.

Drosophila ananassae is a cosmopolitan species with a geographic range throughout most of the tropical and subtropical regions of the world. Previous studies of DNA sequence polymorphism in three genes has shown evidence of selection affecting broad expanses of the genome in regions with low rates of recombination in geographically local populations in and around India. The studies suggest that extensive physical and genetic maps based on molecular markers, and detailed studies of population structure may provide insight into the degree to which natural selection affects DNA sequence polymorphism across broad regions of chromosomes. We have isolated 85 dinucleotide repeat microsatellite sequences and developed assay conditions for genotyping using PCR. The dinucleotide repeats we isolated are shorter, on average, than those isolated in many other Drosophila species. Levels of genetic variation are high, comparable to Drosophila melanogaster. The levels of variation indicate the effective population size of an Indonesian population of D. ananassae is 58,692 (infinite allele model) and 217,284 (stepwise mutation model), similar to estimates of effective population size for D. melanogaster calculated using dinucleotide repeat microsatellites. The data also show that the Indonesian population is in a rapid expansion phase. Cross-species amplification of the microsatellites in 11 species from the Ananassae, Elegans, Eugracilis and Ficusphila subgroups indicates that the loci may be useful for studies of the sister species, D. pallidosa, but will have limited use for more distantly related species.

Motion analysis.

BACKGROUND: The ability to make an objective evaluation of a surgeon's operative ability remains an elusive goal. In this study, we used motion analysis as a measure of dexterity in the performance of a simulated operation. METHODS: Fifteen surgeons performed a total of 45 laboratory-based laparoscopic cholecystectomies on a cadaveric porcine liver model. Subjects were assigned to one of three groups according to their level of experience in human laparoscopic cholecystectomy. Electromagnetic tracking devices were used to analyze the surgeon's hand movements as they performed the procedure. Movement data (time, distance, number of movements, and speed of movement) were then compared. RESULTS: Analysis of variance (ANOVA) movement scores across the three groups showed significantly better performance among the experienced laparoscopic surgeons than the novices. Learning curves across repetitions of procedures were plotted. Novices made more improvement than experts. CONCLUSIONS: Motion analysis provides useful data for the assessment of laparoscopic dexterity, and the porcine liver model is a valid simulation of the real procedure.