Abdominal wall mass resections: single-center closure practices and outcomes following oncologic resections of abdominal wall fascia

PURPOSE

Radical resections for abdominal wall tumors are rare, thus yielding limited data on reconstruction of defects. We describe surgical management and long-term outcomes following radical tumor resection.

METHODS

This was a single-center retrospective review of patients between January 2010 and December 2022. Variables included operative characteristics, wound complications, hernia development, tumor recurrence, and reoperation. A multivariable analysis compared wound morbidity for suture and mesh repairs while adjusting for defect width, fascial closure, and CDC wound class.

RESULTS

120 patients were identified. Mean follow-up was 3.9 ± 3.4 years. Seventy-five (62.5%) of the masses were primary; most commonly desmoid (n = 25) and endometrioma (n = 27). Forty-five masses were metastases. Mean tumor width was 6.2 ± 3.4 cm; mean defect width was 8.1 ± 4.1 cm. Sixty-one patients (50.8%) had mesh placed, with variation in technique. Postoperative CT scans were available for 88 (73.3%) patients. Forty SSOs (33.3%), 11 SSIs (9.2%), and 18 (15%) SSOPIs occurred within 30 days. On multivariable analysis, increased defect width was associated with SSOPI (OR 1.17, p = 0.041) and CDC wound class II-III was associated with SSI (OR 8.38 and 49.1, p < 0.05) and SSOPI (OR 5.77 and 17.4, p < 0.05); mesh was not associated with these outcomes. Seven patients (5.8%) underwent 30-day reoperations and 35 (20.8%) required additional operations after 30 days. Thirteen percent developed abdominal wall (n = 8) or intra-abdominal tumor recurrence (n = 8) requiring reoperation. Twenty-seven (22.5%) patients developed hernias with a mean fascial defect width of 9.8 ± 7.2 cm.

CONCLUSION

Abdominal wall mass resections are morbid, often contaminated cases with high postoperative complication rates. Risks and benefits of mesh implantation should be tailored on an individual basis.

Gastroschisis ultrasound bowel characteristics demonstrate minimal impact on perinatal outcomes

BACKGROUND

Bowel dilation and bowel wall thickness are common prenatal ultrasound measurements for fetuses with gastroschisis. Data regarding antenatal sonographic bowel findings and postnatal outcomes are conflicting. Our objective was to evaluate the impact of in utero bowel measurements on perinatal outcomes in gastroschisis pregnancies.

METHODS

Retrospective cohort study of 116 pregnancies complicated by gastroschisis between 2011 and 2020. We reviewed ultrasounds documenting fetal bowel measurements. To evaluate the association of these measurements with antepartum and delivery outcomes, we ran logistic and linear models using generalized estimating equations.

RESULTS

Eleven perinatal outcomes reached statistical significance, although with minimal clinical impact given small magnitude of effect. Intra-abdominal bowel dilation was associated with a 0.5 week decrease in delivery gestational age (GA) (95% CI -0.07, -0.03) and a 6.93 g increase in birth weight (95% CI 1.54, 28.73). Intra-abdominal bowel wall thickness was associated with later GA of non-stress test (NST) start of 0.22 weeks (95% CI 0.07, 0.37), increased delivery GA of 0.08 weeks (95% CI 0.02, 0.15), 0.006 decrease in umbilical artery (UA) pH (95% CI -0.009, -0.003), 0.26 increase in UA base deficit (95% CI 0.09, 0.43), and decreased odds of cesarean delivery (OR = 0.83, 95% CI 0.70, 0.99). Extra-abdominal bowel wall thickness was associated with a 0.1 increase in UA base deficit (95% CI 0.02, 0.19) and a 0.05 increase in 5-min APGAR score (95% CI 0.01, 0.09). Stomach cross-section was associated with a 0.01 week decrease in delivery GA (95% CI -0.02, -0.001) and increased odds of receiving betamethasone (OR = 1.02, 95% CI 1.01, 1.04).

CONCLUSIONS

In utero bowel characteristics reached statistical significance for several outcomes, but with minimal meaningful clinical differences in outcomes.

Cadherin-16 (CDH16) Immunohistochemistry: A Novel Diagnostic Tool for Renal Cell Carcinoma and Papillary Carcinomas of the Thyroid

Introduction/Objective

Introduction: Cadherin-16 (CDH16), also termed kidney specific cadherin (ksp-cadherin), is a membrane-associated glycoprotein with a role in the embryonal development of tubules in kidney and thyroid. Downregulation of CDH16 RNA was found in papillary carcinomas of the thyroid.

Methods/Case Report

Methods: A set of tissue microarrays containing 14,978 samples from 149 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry to determine the expression of CDH16 in cancer and to assess the diagnostic utility of immunohistochemical CDH16 analysis.

Results (if a Case Study enter NA)

Results: Among normal tissues, a membranous CDH16 immunostaining predominated in thyroid, kidney, cauda epididymis, and in mesonephric remnants. In the thyroid, CDH16 staining was seen in 100% of normal samples, 83% of follicular adenomas, 58% of follicular carcinomas, but in only 9% of papillary carcinomas (p&lt;0.0001). Among non-thyroidal tumors, CDH16 positivity was particularly frequent in nephrogenic adenomas (100%), oncocytomas (98%), chromophobe (97%), clear cell (85%), and papillary (76%) renal cell carcinomas (RCCs), clear cell (56%), mucinous (36%), and endometroid (16%) carcinomas as well as carcinosarcomas (18%) of the ovary, adenocarcinomas of the cervix uteri (40%), serous (33%), clear cell (33%), and endometroid carcinomas (18%) of the endometrium and in various subtypes of neuroendocrine neoplasms (4-26%).

Conclusion

Given the massive loss of CDH16 expression in &gt;90% of papillary carcinomas of the thyroid, CDH16 is a highly useful diagnostic marker for these tumors. CDH16 immunohistochemistry is also useful for the identification of nephrogenic adenomas and the distinction of renal cell carcinomas from other neoplasms.

A Workflow of Integrated Resources to Catalyze Network Pharmacology Driven COVID-19 Research

In the event of an outbreak due to an emerging pathogen, time is of the essence to contain or to mitigate the spread of the disease. Drug repositioning is one of the strategies that has the potential to deliver therapeutics relatively quickly. The SARS-CoV-2 pandemic has shown that integrating critical data resources to drive drug-repositioning studies, involving host-host, host-pathogen, and drug-target interactions, remains a time-consuming effort that translates to a delay in the development and delivery of a life-saving therapy. Here, we describe a workflow we designed for a semiautomated integration of rapidly emerging data sets that can be generally adopted in a broad network pharmacology research setting. The workflow was used to construct a COVID-19 focused multimodal network that integrates 487 host-pathogen, 63 278 host-host protein, and 1221 drug-target interactions. The resultant Neo4j graph database named "Neo4COVID19" is made publicly accessible via a web interface and via API calls based on the Bolt protocol. Details for accessing the database are provided on a landing page (https://neo4covid19.ncats.io/). We believe that our Neo4COVID19 database will be a valuable asset to the research community and will catalyze the discovery of therapeutics to fight COVID-19.

A Text Messaging Intervention With Financial Incentive for Adolescents With Type 1 Diabetes

BACKGROUND

Adolescents with type 1 diabetes (T1D) have higher hemoglobin A1C (HbA1c) levels than others. In general, adolescents engage with text messaging (TM) and financial incentives, both associated with improved diabetes outcomes. This study aimed to assess the impact of a TM intervention with financial incentives on self-care behaviors and HbA1c.

METHODS

A six-month randomized controlled trial compared MyDiaText™, a TM education and support application, with standard care. The sample included 166 teens with T1D, 12-18 years old, attending a diabetes clinic. The intervention group received one daily TM and were instructed to respond. Participants who responded to TMs for the most consecutive days were eligible for a financial reward biweekly via lottery. All participants received prompts to complete the self-care inventory (SCI) at baseline, 90, and 180 days. HbA1c was collected at clinic visits. Changes in SCI and HbA1c were analyzed using a multilevel mixed-effects linear regression model. Intention-to-treat and per-protocol analyses were performed.

RESULTS

The median TM response rate was 59% (interquartile range 40.1%-85.2%) and decreased over time. After adjustment for baseline characteristics, in per-protocol analysis, there was a statistically significant difference in SCI score increase in those receiving one TM per day vs control (P = .035). HbA1c decreased overall, without significant difference between groups (P = .786).

CONCLUSIONS

A TM intervention with financial incentives for adolescents with T1D in suboptimal control was associated with increasing self-care report; however, glycemic control did not differ from controls. Further research is needed to develop digital health interventions that will impact glycemic control.

RARE PRESENTATION OF FLORID VULVA WARTS - A CASE REPORT AND REVIEW OF LITERATURE

Background

Condyloma acuminata is an extremely common cutaneous sexually transmitted disease often diagnosed clinically, on the basis of its warty, cauliflower, and verrucous appearance. It is caused by the "low risk" Human papillomavirus types 6 and 11 in 90 percent of cases. The immune system plays a critical role in determining the course of viral infection, with immune-suppression and advanced age increasing the risk for long term wart persistence. Treatment options include the use of a wide variety of topical medications as well as surgical excision by cauterisation.

Patient

A rare case of florid vulvar warts in a 21-year old nulliparous immuno-competent woman is presented and the literature reviewed. She had a 7-month history of progressive vulva swelling with associated itching, contact bleeding, and malodorous discharge. It measured about 14 × 10 cm in dimensions, occupying the posterior two-thirds of the labia majora and minora and obliterating the posterior commissure.

Intervention

There was no positive response to Podophyllin application, however, it was eventually excised and histologic analysis excluded malignancy.

Conclusion

Florid vulvar warts though rare in immune-competent patients, could occur. Patients with persistent and recurrent infection often require surgical procedures as was performed in our patient with the possibility of speedy recovery and restoration of normal anatomy and cosmesis.

Semi-automated validation and quantification of CTLA-4 in 90 different Tumor entities using multiple antibodies and artificial intelligence

Introduction/Objective

Introduction: CTLA-4 is an inhibitory immune checkpoint receptor and a negative regulator of anti-tumor T-cell function. This study aimed at a comparative analysis of CTLA-4+ entities. cells between different tumor

Methods/Case Report

Methods: To quantify CTLA-4+ cells, 4,582 tumor samples from 90 different tumor entities as well as 608 samples of 76 different normal tissue types were analyzed by immunohistochemistry in a tissue microarray format. Two different antibody clones (MSVA-152R and CAL49) were validated and quantified using a deep learning framework for automated exclusion of unspecific immunostaining.

Results (if a Case Study enter NA)

Results: Comparing both CTLA-4 antibodies revealed a clone dependent unspecific staining pattern in adrenal cortical adenoma (63%) for MSVA-152R and in pheochromocytoma (67%) as well as hepatocellular carcinoma (36%) for CAL49. After automated exclusion of non-specific staining reaction (3.6%), a strong correlation was observed for the densities of CTLA-4+ lymphocytes obtained by both antibodies (r=0.87; p&lt;0.0001). The mean density of CTLA-4+cells was 674±1482 cells/ mm2 and ranged from 71±175 cells/mm2 in leiomyoma to 5916±3826 cells/mm2 in Hodgkin’s lymphoma. Within epithelial tumors, the density of CTLA-4+ lymphocytes were higher in squamous cell (421±467 cells/ mm2) and urothelial carcinomas (419±347 cells/ mm2) than in adenocarcinomas (269±375 cells/ mm2) and renal cell neoplasms (256±269 cells/ mm2). A high CTLA-4+ cell density was linked to low pT category (p&lt;0.0001), absent lymph node metastases (p=0.0354), and PD-L1 expression in tumor cells or inflammatory cells (p&lt;0.0001 each). A high CTLA-4/CD3-ratio was linked to absent lymph node metastases (p=0.0295) and to PD-L1 positivity on immune cells (p&lt;0.0026).

Conclusion

Marked differences exist in the number of CTLA-4+ lymphocytes between tumors. Analyzing two independent antibodies by a deep learning framework can facilitate automated quantification of immunohistochemically analyzed target proteins such as CTLA-4.

P02.03 Automated cell type specific PD-L1 quantification by artificial intelligence using high throughput bleach & stain 15-marker multiplex fluorescence immunohistochemistry in human cancers

Background

The quantification of PD-L1 (programmed cell death ligand 1) has been used to predict patient’s survival, to characterize the tumor immune microenvironment, and to predict response to immune checkpoint therapies. However, a framework to assess the PD-L1 status with a high interobserver reproducibility on tumor cells and different types of immune cells has yet to be established.

Materials and Methods

To study the impact of PD-L1 expression on the tumor immune microenvironment and patient outcome, a framework for fully automated PD-L1 quantification on tumor cells and immune cells was established and validated. Automated PD-L1 quantification was facilitated by incorporating three different deep learning steps for the analysis of more than 80 different neoplasms from more than 10’000 tumor specimens using a bleach & stain 15-marker multiplex fluorescence immunohistochemistry panel (i.e., PD-L1, PD-1, CTLA-4, panCK, CD68, CD163, CD11c, iNOS, CD3, CD8, CD4, FOXP3, CD20, Ki67, CD31). Clinicopathological parameter were available for more than 30 tumor entities and overall survival data were available for 1517 breast cancer specimens.

Results

Comparing the automated deep-learning based PD-L1 quantification with conventional brightfield PD-L1 data revealed a high concordance in tumor cells (p<0.0001) as well as immune cells (p<0.0001) and an accuracy of the automated PD-L1 quantification ranging from 90% to 95.2%. Across all tumor entities, the PD-L1 expression level was significantly higher in distinct macrophage/dendritic cell (DC) subsets (identified by CD68, CD163, CD11c, iNOS; p<000.1) and in macrophages/DCs located in the Stroma (p<0.0001) as compared to intratumoral macrophages/DC subsets. Across all different tumor entities, the PD-L1 expression was highly variable and distinct PD-L1 driven immune phenotypes were identified based on the PD-L1 intensity on both tumor and immune cells, the distance between non-exhausted T-cell subsets (i.e. PD-1 and CTLA-4 expression on CD3+CD8+ cytotoxic T-cells, CD3+CD4+ T-helper cells, CD3+CD4+FOXP3+ regulatory T-cells) and tumor cells as well as macrophage/(DC) subtypes. In breast cancer, the PD-L1 fluorescence intensity on tumor cells showed a significantly higher predictive performance for overall survival with an area under receiver operating curves (AUC) of 0.72 (p<0.0001) than the percentage of PD-L1+ tumor cells (AUC: 0.54). In PD-L1 positive as well as negative breast cancers a close spatial relationship between T- cell subsets (CD3+CD4±CD8±FOXP3±PD-1±CTLA-4±) and Macrophage/DC subsets (CD68±CD163±CD11c±iNOS) was found prognostic relevant (p<0.0001).

Conclusions

In conclusion, multiplex immunofluorescence PD-L1 assessment provides cutoff-free/continuous PD-L1 data which are superior to the conventional percentage of PD-L1+ tumor cells and of high prognostic relevance. The combined analysis of spatial PD-L1/PD-1 data and more than 20 different immune cell subtypes of the immune tumor microenvironment revealed distinct PD-L1 immune phenotypes.

Disclosure Information

N.C. Blessin: None. E. Bady: None. T. Mandelkow: None. C. Yang: None. J. Raedler: None. R. Simon: None. C. Fraune: None. M. Lennartz: None. S. Minner: None. E. Burandt: None. D. Höflmayer: None. G. Sauter: None. S.A. Weidemann: None.

Undiagnosed SARS-CoV-2 seropositivity during the first 6 months of the COVID-19 pandemic in the United States

Asymptomatic SARS-CoV-2 infection and delayed implementation of diagnostics have led to poorly defined viral prevalence rates in the United States and elsewhere. To address this, we analyzed seropositivity in 9089 adults in the United States who had not been diagnosed previously with COVID-19. Individuals with characteristics that reflected the U.S. population (n = 27,716) were selected by quota sampling from 462,949 volunteers. Enrolled participants (n = 11,382) provided medical, geographic, demographic, and socioeconomic information and dried blood samples. Survey questions coincident with the Behavioral Risk Factor Surveillance System survey, a large probability-based national survey, were used to adjust for selection bias. Most blood samples (88.7%) were collected between 10 May and 31 July 2020 and were processed using ELISA to measure seropositivity (IgG and IgM antibodies against SARS-CoV-2 spike protein and the spike protein receptor binding domain). The overall weighted undiagnosed seropositivity estimate was 4.6% (95% CI, 2.6 to 6.5%), with race, age, sex, ethnicity, and urban/rural subgroup estimates ranging from 1.1% to 14.2%. The highest seropositivity estimates were in African American participants; younger, female, and Hispanic participants; and residents of urban centers. These data indicate that there were 4.8 undiagnosed SARS-CoV-2 infections for every diagnosed case of COVID-19, and an estimated 16.8 million infections were undiagnosed by mid-July 2020 in the United States.

Mapping a Pandemic: SARS-CoV-2 Seropositivity in the United States

Asymptomatic SARS-CoV-2 infection and delayed implementation of diagnostics have led to poorly defined viral prevalence rates. To address this, we analyzed seropositivity in US adults who have not previously been diagnosed with COVID-19. Individuals with characteristics that reflect the US population (n = 11,382) and who had not previously been diagnosed with COVID-19 were selected by quota sampling from 241,424 volunteers (ClinicalTrials.gov NCT04334954). Enrolled participants provided medical, geographic, demographic, and socioeconomic information and 9,028 blood samples. The majority (88.7%) of samples were collected between May 10th and July 31st, 2020. Samples were analyzed via ELISA for anti-Spike and anti-RBD antibodies. Estimation of seroprevalence was performed by using a weighted analysis to reflect the US population. We detected an undiagnosed seropositivity rate of 4.6% (95% CI: 2.6 - 6.5%). There was distinct regional variability, with heightened seropositivity in locations of early outbreaks. Subgroup analysis demonstrated that the highest estimated undiagnosed seropositivity within groups was detected in younger participants (ages 18-45, 5.9%), females (5.5%), Black/African American (14.2%), Hispanic (6.1%), and Urban residents (5.3%), and lower undiagnosed seropositivity in those with chronic diseases. During the first wave of infection over the spring/summer of 2020 an estimate of 4.6% of adults had a prior undiagnosed SARS-CoV-2 infection. These data indicate that there were 4.8 (95% CI: 2.8-6.8) undiagnosed cases for every diagnosed case of COVID-19 during this same time period in the United States, and an estimated 16.8 million undiagnosed cases by mid-July 2020.

A Workflow of Integrated Resources to Catalyze Network Pharmacology Driven COVID-19 Research

MOTIVATION

In the event of an outbreak due to an emerging pathogen, time is of the essence to contain or to mitigate the spread of the disease. Drug repositioning is one of the strategies that has the potential to deliver therapeutics relatively quickly. The SARS-CoV-2 pandemic has shown that integrating critical data resources to drive drug-repositioning studies, involving host-host, hostpathogen and drug-target interactions, remains a time-consuming effort that translates to a delay in the development and delivery of a life-saving therapy.

RESULTS

Here, we describe a workflow we designed for a semi-automated integration of rapidly emerging datasets that can be generally adopted in a broad network pharmacology research setting. The workflow was used to construct a COVID-19 focused multimodal network that integrates 487 host-pathogen, 74,805 host-host protein and 1,265 drug-target interactions. The resultant Neo4j graph database named "Neo4COVID19" is accessible via a web interface and via API calls based on the Bolt protocol. We believe that our Neo4COVID19 database will be a valuable asset to the research community and will catalyze the discovery of therapeutics to fight COVID-19.

AVAILABILITY

https://neo4covid19.ncats.io.

New genomic features of the polled intersex syndrome variant in goats unraveled by long-read whole-genome sequencing

In domestic goats, the polled intersex syndrome (PIS) refers to XX female-to-male sex reversal associated with the absence of horn growth (polled). The causal variant was previously reported as a 11.7 kb deletion at approximately 129 Mb on chromosome 1 that affects the transcription of both FOXL2 and several long non-coding RNAs. In the meantime the presence of different versions of the PIS deletion was postulated and trials to establish genetic testing with the existing molecular genetic information failed. Therefore, we revisited this variant by long-read whole-genome sequencing of two genetically female (XX) goats, a PIS-affected and a horned control. This revealed the presence of a more complex structural variant consisting of a deletion with a total length of 10 159 bp and an inversely inserted approximately 480 kb-sized duplicated segment of a region located approximately 21 Mb further downstream on chromosome 1 containing two genes, KCNJ15 and ERG. Publicly available short-read whole-genome sequencing data, Sanger sequencing of the breakpoints and FISH using BAC clones corresponding to both involved genome regions confirmed this structural variant. A diagnostic PCR was developed for simultaneous genotyping of carriers for this variant and determination of their genetic sex. We showed that the variant allele was present in all 334 genotyped polled goats of diverse breeds and that all analyzed 15 PIS-affected XX goats were homozygous. Our findings enable for the first time a precise genetic diagnosis for polledness and PIS in goats and add a further genomic feature to the complexity of the PIS phenomenon.

MyDiaText™: Feasibililty and Functionality of a Text Messaging System for Youth With Type 1 Diabetes

PURPOSE

The purpose of this study was to determine the feasibility and functionality of MyDiaText™, a website and text messaging platform created to support behavior change in adolescents with type 1 diabetes (T1DM) and to evaluate user satisfaction of the application.

METHODS

This study was a nonrandomized, prospective, pilot trial to test the feasibility and user interface with MyDiaText, a text message system for 10- to 17-year-old youths with newly diagnosed T1DM. Feasibility was evaluated by assessing for the user's ability to create a profile on the website. Functionality was defined by assessing whether a subject responded to at least 2 text messages per week and by their accumulating points on the website. User satisfaction of the text messaging system was assessed using an electronic survey. The 4 phases of this study were community engagement-advisory sessions, screening and enrollment, intervention, and follow-up.

RESULTS

Twenty subjects (14 male, 6 female) were enrolled. All subjects were able to create a profile, and of these, 86% responded to at least 2 text messages per week. A survey administered during follow-up showed that users enjoyed reading text messages, found them useful, and thought the frequency of messages was appropriate.

CONCLUSION

MyDiaText is a feasible, functional behavioral support tool for youth with T1DM. Users of the application reported high satisfaction with text messages and the reward system.

Elemental changes of hippocampal formation occurring during postnatal brain development

In this paper the elemental changes of rat hippocampal formation occurring during the postnatal development were examined. Three groups of animals were used in the study. These were naive Wistar rats at the age of 6-, 30- and 60-days and the chosen life periods corresponded to the neonatal period, childhood and early adulthood in humans, respectively. For the topographic and quantitative elemental analysis X-ray fluorescence microscopy was applied and the measurements were done at the FLUO beamline of ANKA. The detailed quantitative and statistical analysis was done for four areas of hippocampal formation, namely sectors 1 and 3 of the Ammon's horn (CA1 and CA3, respectively), dentate gyrus (DG) and its internal area (hilus of DG, H). The obtained results showed that among the all examined elements (P, S, K, Ca, Fe, Cu, Zn and Se), only the levels of Fe and Zn changed significantly during postnatal development of the hippocampal formation and both the elements were significantly higher in young adults comparing to the rats in neonatal period. The increased Fe areal density was found in all examined hippocampal areas whilst Zn was elevated in CA3, DG and H. In order to follow the dynamics of age-dependent elemental changes, the statistical significance of differences in their accumulation between subsequent moments of time was examined. The obtained results showed statistically relevant increase of Zn level only in the first observation period (between 6th and 30th day of life). Afterwards the areal density of the element did not change significantly. The increase of Fe areal density took place in both examined periods, however the observed changes were small and usually not statistically relevant.

Adherence to guidelines in requesting Oncotype DX in a publicly funded health care system

Background

Oncotype dx [odx (Genomic Health, Redwood City, CA, U.S.A.)] is an approved prognostic tool for women with node-negative, hormone receptor-positive, her2-negative breast cancer. Because of cost, optimal use of this test is crucial, especially in a publicly funded health care system. We evaluated adherence with our provincial guidelines for odx requests, the management of patients with an intermediate recurrence score (rs), and the cost impact of odx.

Methods

This retrospective study included 201 consecutive patients with an odx request from two university institutions in Quebec between May 2012 and December 2014. Concordance with provincial guidelines was estimated, with its 95% confidence interval (ci). For patients with an intermediate rs, factors influencing the final treatment decision were assessed. The cost impact of odx was derived from the proportion of patients for whom chemotherapy was not recommended.

Results

In 93.0% of patients (95% ci: 89.5% to 96.6%), odx was ordered according to guidelines. The concordance was similar in both institutions (92.7%; 95% ci: 88.1% to 97.3%; and 93.6%; 95% ci: 88.2% to 99.0%). In 112 (55.7%), 78 (38.8%), and 9 (4.5%) patients, the rs suggested low, intermediate, and high risk respectively. In the intermediate-risk group, most patients (n = 58, 74.4%) did not receive chemotherapy, mainly because of patient preference and the absence of a clear proven benefit. Savings of CA$100,000 for the study period (2.5 years) were estimated to be associated with odx use.

Conclusions

In our experience, the use of odx was concordant with published recommendations and had a positive cost impact.

Overexpression of O-polysaccharide chain length regulators in Gram-negative bacteria using the Wzx-/Wzy-dependent pathway enhances production of defined modal length O-polysaccharide polymers for use as haptens in glycoconjugate vaccines

Aims

O‐polysaccharide (OPS) molecules are protective antigens for several bacterial pathogens, and have broad utility as components of glycoconjugate vaccines. Variability in the OPS chain length is one obstacle towards further development of these vaccines. Introduction of sizing steps during purification of OPS molecules of suboptimal or of mixed lengths introduces additional costs and complexity while decreasing the final yield. The overall goal of this study was to demonstrate the utility of engineering Gram‐negative bacteria to produce homogenous O‐polysaccharide populations that can be used as the basis of carbohydrate vaccines by overexpressing O‐polysaccharide chain length regulators of the Wzx‐/Wzy‐dependent pathway.

Method and Results

The O‐polysaccharide chain length regulators wzzB and fepE from Salmonella Typhimurium I77 and wzz2 from Pseudomonas aeruginosa PAO1 were cloned and expressed in the homologous organism or in other Gram‐negative bacteria. Overexpression of these Wzz proteins in the homologous organism significantly increased the proportion of long or very long chain O‐polysaccharides. The same observation was made when wzzB was overexpressed in Salmonella Paratyphi A and Shigella flexneri, and wzz2 was overexpressed in two other strains of P. aeruginosa.

Conclusions

Overexpression of Wzz proteins in Gram‐negative bacteria using the Wzx/Wzy‐dependant pathway for lipopolysaccharide synthesis provides a genetic method to increase the production of an O‐polysaccharide population of a defined size.

Significance and Impact of the Study

The methods presented herein represent a cost‐effective and improved strategy for isolating preferred OPS vaccine haptens, and could facilitate the further use of O‐polysaccharides in glycoconjugate vaccine development.

Falls Risk Prediction for Older Inpatients in Acute Care Medical Wards: Is There an Interest to Combine an Early Nurse Assessment and the Artificial Neural Network Analysis?

BACKGROUND

Identification of the risk of falls is important among older inpatients. This study aims to examine performance criteria (i.e.; sensitivity, specificity, positive predictive value, negative predictive value and accuracy) for fall prediction resulting from a nurse assessment and an artificial neural networks (ANNs) analysis in older inpatients hospitalized in acute care medical wards.

METHODS

A total of 848 older inpatients (mean age, 83.0±7.2 years; 41.8% female) admitted to acute care medical wards in Angers University hospital (France) were included in this study using an observational prospective cohort design. Within 24 hours after admission of older inpatients, nurses performed a bedside clinical assessment. Participants were separated into non-fallers and fallers (i.e.; ≥1 fall during hospitalization stay). The analysis was conducted using three feed forward ANNs (multilayer perceptron [MLP], averaged neural network, and neuroevolution of augmenting topologies [NEAT]).

RESULTS

Seventy-three (8.6%) participants fell at least once during their hospital stay. ANNs showed a high specificity, regardless of which ANN was used, and the highest value reported was with MLP (99.8%). In contrast, sensitivity was lower, with values ranging between 98.4 to 14.8%. MLP had the highest accuracy (99.7).

CONCLUSIONS

Performance criteria for fall prediction resulting from a bedside nursing assessment and an ANNs analysis was associated with a high specificity but a low sensitivity, suggesting that this combined approach should be used more as a diagnostic test than a screening test when considering older inpatients in acute care medical ward.

Various ketogenic diets can differently support brain resistance against experimentally evoked seizures and seizure-induced elemental anomalies of hippocampal formation

In this paper the influence of two different ketogenic diets (KDs) on the seizure-evoked elemental anomalies of hippocampal formation was examined. To achieve this purpose normal and pilocarpine treated rats previously fed with one of the two high fat and carbohydrate restricted diets were compared with animals on standard laboratory diet. The ketogenic ratios of the examined KDs were equal to 5:1 (KD1) and 9:1 (KD2). KD1 and standard diet fed animals presented similar patterns of seizure-evoked elemental changes in hippocampal formation. Also the analysis of behavioral data recorded after pilocarpine injection did not show any significant differences in intensity and duration of seizures between KD1 and standard diet fed animals. Higher ketogenic ratio KD2 introduced in the normal hippocampal formation prolonged changes in the accumulation of P, K, Zn and Ca. Despite this, both the intensity and duration of seizures were significantly reduced in rats fed with KD2 which suggests that its saving action on the nerve tissue may protect brain from seizure propagation. Also seizure-evoked elemental anomalies in KD2 animals were different than those observed for rats both on KD1 and standard diets. The comparison of seizure experiencing and normal rats on KD2, did not show any statistically significant differences in elemental composition of CA1 and H hippocampal areas whilst in CA3 area only Zn level changed as a result of seizures. DG was the area mostly affected by seizures in KD2 fed rats but areal densities of all examined elements increased in this hippocampal region.

The branched-chain amino acid transaminase 1 sustains growth of antiestrogen-resistant and ERα-negative breast cancer

Antiestrogen-resistant and triple-negative breast tumors pose a serious clinical challenge because of limited treatment options. We assessed global gene expression changes in antiestrogen-sensitive compared with antiestrogen-resistant (two tamoxifen resistant and two fulvestrant resistant) MCF-7 breast cancer cell lines. The branched-chain amino acid transaminase 1 (BCAT1), which catalyzes the first step in the breakdown of branched-chain amino acids, was among the most upregulated transcripts in antiestrogen-resistant cells. Elevated BCAT1 expression was confirmed in relapsed tamoxifen-resistant breast tumor specimens. High intratumoral BCAT1 levels were associated with a reduced relapse-free survival in adjuvant tamoxifen-treated patients and overall survival in unselected patients. On a tissue microarray (n=1421), BCAT1 expression was detectable in 58% of unselected primary breast carcinomas and linked to a higher Ki-67 proliferation index, as well as histological grade. Interestingly, BCAT1 was predominantly expressed in estrogen receptor-α-negative/human epidermal growth factor receptor-2-positive (ERα-negative/HER-2-positive) and triple-negative breast cancers in independent patient cohorts. The inverse relationship between BCAT1 and ERα was corroborated in various breast cancer cell lines and pharmacological long-term depletion of ERα induced BCAT1 expression in vitro. Mechanistically, BCAT1 indirectly controlled expression of the cell cycle inhibitor p27^Kip1 thereby affecting pRB. Correspondingly, phenotypic analyses using a lentiviral-mediated BCAT1 short hairpin RNA knockdown revealed that BCAT1 sustains proliferation in addition to migration and invasion and that its overexpression enhanced the capacity of antiestrogen-sensitive cells to grow in the presence of antiestrogens. Importantly, silencing of BCAT1 in an orthotopic triple-negative xenograft model resulted in a massive reduction of tumor volume in vivo, supporting our findings that BCAT1 is necessary for the growth of hormone-independent breast tumors.

MALDI imaging mass spectrometry reveals multiple clinically relevant masses in colorectal cancer using large-scale tissue microarrays

For identification of clinically relevant masses to predict status, grade, relapse and prognosis of colorectal cancer, we applied Matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry (IMS) to a tissue micro array containing formalin-fixed and paraffin-embedded tissue samples from 349 patients. Analysis of our MALDI-IMS data revealed 27 different m/z signals associated with epithelial structures. Comparison of these signals showed significant association with status, grade and Ki-67 labeling index. Fifteen out of 27 IMS signals revealed a significant association with survival. For seven signals (m/z 654, 776, 788, 904, 944, 975 and 1013) the absence and for eight signals (m/z 643, 678, 836, 886, 898, 1095, 1459 and 1477) the presence were associated with decreased life expectancy, including five masses (m/z 788, 836, 904, 944 and 1013) that provided prognostic information independently from the established prognosticators pT and pN. Combination of these five masses resulted in a three-step classifier that provided prognostic information superior to univariate analysis. In addition, a total of 19 masses were associated with tumor stage, grade, metastasis and cell proliferation. Our data demonstrate the suitability of combining IMS and large-scale tissue micro arrays to simultaneously identify and validate clinically useful molecular marker. Copyright © 2017 John Wiley & Sons, Ltd.

Abstract P2-05-30: OncotypeDX® for breast cancer: A multigene assay that makes a difference?

Objective: OncotypeDX® (ODX) is a multigene diagnostic assay that can estimate the 10 year-risk of distant recurrence in women with hormone receptor positive (HR+) and node negative (N–) early breast cancer. The testreports a Recurrence Score® (RS) and three risk group categories have been described: low-risk (&lt;18), intermediate-risk (18-30) and high-risk (≥31). It helps the oncologist in the adjuvant chemotherapy decision process and globally leads to a reduction in the recommendation for chemotherapy use. This test is expensive and represents an economic burden in a publicly funded province. Nonetheless, its use has been approved over other gene expression profiling like Mammaprint® based on the evidence of its prognostic and predictive ability. We evaluated the adequacy of the requests for the ODX in an academic setting after the introduction in May 2012 of a reference framework for its use in Québec, Canada and the impact on chemotherapy recommendation. The costs generated by the test were also determined. Methods: We included all patients with an ODX request from two University Centers, CICM and CHUS, and estimated the concordance with the current provincial guideline for which an ODX may be ordered (invasive breast cancer HR+/Her2–/N- that is T1b with unfavorable characteristics or T1c or T2). For the intermediate-risk group, the factors influencing the final decision to use systemic chemotherapy were analysed. The projected cost-effectiveness of the ODX was derived from the proportion of patients (pts) for which the chemotherapy was not recommended. Results: Between May 2012 and December 2014, a total of 201 pts, 123 pts from CICM and 78 from CHUS, had an ODX done. In 93,0% (95%CI, 89,5-96,6) of pts, ODX was ordered correctly with respect to the guideline. There was no statistical differences between both sites (CICM: 92,7% [95%CI, 97,3-88,1]; CHUS 93,6% [95%CI, 88,2-99,0]). A total of 9 pts had high-risk RS (4,5%), 78 pts had intermediate-risk RS (38,8%) and 112 pts had low-risk RS (55,7%). Chemotherapy was recommended for 31 pts (18,2%) instead of an estimated 58,0% prior to the use of ODX according to previous reports published. In the intermediate-risk group, the majority of pts (74,4%) did not receive chemotherapy. The patient's preference and the absence of a proven benefit were the main reasons for withholding chemotherapy in this group. The additional cost associated with the use of the ODX was compensated with the reduction of the adjuvant systemic chemotherapy prescribed and its derived expenses (chemotherapy cost, nursing time and hospitalisations) and savings of 100 K were observed. Conclusions: In early breast cancer HR+ and N-, the use of ODX in two University Hospitals is concordant with published recommendations. ODX use is cost effective. This benefice does not take into account the psychological burden that comes with the decision to use adjuvant chemotherapy; neither does it evaluate potential long term complications. The widespread use of ODX must be looked at critically in face of other emerging gene signature tests like Endopredict® and PAM50®. As for the predictive ability of the ODX for adjuvant chemotherapy, one can question the strength of the actual evidence and argue if it confers this test an advantage over other multigene assays.

Citation Format: Martel S, Prady C, Simon R, Matte C. OncotypeDX® for breast cancer: A multigene assay that makes a difference? [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-30.

Synchrotron radiation micro X-ray fluorescence spectroscopy of thin structures in bone samples: comparison of confocal and color X-ray camera setups

In the quest for finding the ideal synchrotron-radiation-induced imaging method for the investigation of trace element distributions in human bone samples, experiments were performed using both a scanning confocal synchrotron radiation micro X-ray fluorescence (SR-µXRF) (FLUO beamline at ANKA) setup and a full-field color X-ray camera (BAMline at BESSY-II) setup. As zinc is a trace element of special interest in bone, the setups were optimized for its detection. The setups were compared with respect to count rate, required measurement time and spatial resolution. It was demonstrated that the ideal method depends on the element of interest. Although for Ca (a major constituent of the bone with a low energy of 3.69 keV for its Kα XRF line) the color X-ray camera provided a higher resolution in the plane, for Zn (a trace element in bone) only the confocal SR-µXRF setup was able to sufficiently image the distribution.

Polarization state transformation using two quarter wave plates: application to Mueller polarimetry

We show that there are a number of ways to transform an arbitrary polarization state into another with just two quarter wave plates (QWPs). We have verified this geometrically using the trajectories of the initial and final polarization states corresponding to all the fast axis orientations of a QWP on the Poincaré sphere. The exact analytical expression for the locus of polarization states has also been given, and describes the trajectory. An analytical treatment of the equations obtained through matrix operations corresponding to the transformation supports the geometrical representation. This knowledge can be used to obtain the Mueller matrix by just using QWPs, which has been shown experimentally by exploiting projections of the output states on the input states.

Structure-function integrity of the adult hippocampus depends on the transcription factor Bcl11b/Ctip2

The dentate gyrus is one of the only two brain regions where adult neurogenesis occurs. Throughout life, cells of the neuronal stem cell niche undergo proliferation, differentiation and integration into the hippocampal neural circuitry. Ongoing adult neurogenesis is a prerequisite for the maintenance of adult hippocampal functionality. Bcl11b, a zinc finger transcription factor, is expressed by postmitotic granule cells in the developing as well as adult dentate gyrus. We previously showed a critical role of Bcl11b for hippocampal development. Whether Bcl11b is also required for adult hippocampal functions has not been investigated. Using a tetracycline‐dependent inducible mouse model under the control of the forebrain‐specific CaMKIIα promoter, we show here that the adult expression of Bcl11b is essential for survival, differentiation and functional integration of adult‐born granule cell neurons. In addition, Bcl11b is required for survival of pre‐existing mature neurons. Consequently, loss of Bcl11b expression selectively in the adult hippocampus results in impaired spatial working memory. Together, our data uncover for the first time a specific role of Bcl11b in adult hippocampal neurogenesis and function.

Elemental changes in the hippocampal formation following two different formulas of ketogenic diet: an X-ray fluorescence microscopy study

The main purpose of the following study was the determination of elemental changes occurring within hippocampal formation as a result of high-fat and carbohydrate-restricted ketogenic diet (KD). To realize it, X-ray fluorescence microscopy was applied for topographic and quantitative analysis of P, S, K, Ca, Fe, Cu, Zn and Se in hippocampal formations taken from rats fed with two different KDs and naive controls. The detailed comparisons were done for sectors 1 and 3 of the Ammon's, the dentate gyrus and hilus of dentate gyrus. The results of elemental analysis showed that the KDs induced statistically significant changes in the accumulation of P, K, Ca, Zn and Se in particular areas of hippocampal formation and these alterations strongly depended on the composition of the diets. Much greater influence on the hippocampal areal densities of examined elements was found for the KD which was characterized by a lower content of carbohydrates, higher content of fats and increased proportion of unsaturated fatty acids. The levels of P, K and Zn decreased whilst those of Ca and Se increased as a result of the treatment with the KDs.

VELOCITY-RESOLVED [C ii] EMISSION AND [C ii]/FIR MAPPING ALONG ORION WITH HERSCHEL

We present the first ~7.5'×11.5' velocity-resolved (~0.2 km s^-1) map of the [C ii] 158 μm line toward the Orion molecular cloud 1 (OMC 1) taken with the Herschel/HIFI instrument. In combination with far-infrared (FIR) photometric images and velocity-resolved maps of the H41α hydrogen recombination and CO J=2-1 lines, this data set provides an unprecedented view of the intricate small-scale kinematics of the ionized/PDR/molecular gas interfaces and of the radiative feedback from massive stars. The main contribution to the [C ii] luminosity (~85 %) is from the extended, FUV-illuminated face of the cloud (G₀>500, n_H>5×10³ cm^-3) and from dense PDRs (G≳10⁴, n_H≳10⁵ cm^-3) at the interface between OMC 1 and the H ii region surrounding the Trapezium cluster. Around ~15 % of the [C ii] emission arises from a different gas component without CO counterpart. The [C ii] excitation, PDR gas turbulence, line opacity (from [¹³C ii]) and role of the geometry of the illuminating stars with respect to the cloud are investigated. We construct maps of the L[C ii]/L_FIR and L_FIR/M_Gas ratios and show that L[C ii]/L_FIR decreases from the extended cloud component (~10^-2-10^-3) to the more opaque star-forming cores (~10^-3-10^-4). The lowest values are reminiscent of the "[C ii] deficit" seen in local ultra-luminous IR galaxies hosting vigorous star formation. Spatial correlation analysis shows that the decreasing L[C ii]/L_FIR ratio correlates better with the column density of dust through the molecular cloud than with L_FIR/M_Gas. We conclude that the [C ii] emitting column relative to the total dust column along each line of sight is responsible for the observed L[C ii]/L_FIR variations through the cloud.

Asymmetric cell divisions constructing Arabidopsis stem cell niches: the emerging role of protein phosphatases

Plant stem cell niches (SCNs) can be maintained in time through asymmetric cell divisions (ACDs) that allow the production of new cell types while constantly renewing the pools of stem cells (SCs). ACDs in plants require the asymmetric distribution of molecular components inside the cells as well as external asymmetric positional information. These two types of asymmetric information are controlled by inter- and intracellular signalling events. Phosphorylation of proteins is a major intermediate step in these signalling events, serving either as an activator or repressor of signalling, via fast auto- and trans-phosphorylation mechanisms. Whereas protein kinases, which phosphorylate proteins on serine, threonine or tyrosine residues, have been thoroughly studied, less attention has been given to protein phosphatases, which de-phosphorylate their protein targets on these same residues. Phosphatases modulate the activity of signalling pathways by balancing the action of kinases, and are therefore critical in the regulation of ACDs in plants. In this review, we first present the different types of ACDs that operate during Arabidopsis embryonic and post-embryonic development and participate in the construction and maintenance of its root and shoot SCNs; we then give a brief description of the main protein phosphatases so far described in the Arabidopsis genome; and finally discuss their functions toward the regulation of the ACDs introduced in the first part of the paper.

8p deletion is strongly linked to poor prognosis in breast cancer

Deletions of chromosome 8p occur frequently in breast cancers, but analyses of its clinical relevance have been limited to small patient cohorts and provided controversial results. A tissue microarray with 2,197 breast cancers was thus analyzed by fluorescence in-situ hybridization using an 8p21 probe in combination with a centromere 8 reference probe. 8p deletions were found in 50% of carcinomas with no special type, 67% of papillary, 28% of tubular, 37% of lobular cancers and 56% of cancers with medullary features. Deletions were always heterozygous. 8p deletion was significantly linked to advanced tumor stage (P < 0.0001), high-grade (P < 0.0001), high tumor cell proliferation (Ki67 Labeling Index; P < 0.0001), and shortened overall survival (P < 0.0001). For example, 8p deletion was seen in 32% of 290 grade 1, 43% of 438 grade 2, and 65% of 427 grade 3 cancers. In addition, 8p deletions were strongly linked to amplification of MYC (P < 0.0001), HER2 (P < 0.0001), and CCND1 (p = 0.001), but inversely associated with ER receptor expression (p = 0.0001). Remarkably, 46.5% of 8p-deleted cancers harbored amplification of at least one of the analyzed genes as compared to 27.5% amplifications in 8p-non-deleted cancers (P < 0.0001). In conclusion, 8p deletion characterizes a subset of particularly aggressive breast cancers. As 8p deletions are easy to analyze, this feature appears to be highly suited for future DNA based prognostic breast cancer panels. The strong link of 8p deletion with various gene amplifications raises the possibility of a role for regulating genomic stability.

Glucocorticoids interact with noradrenergic activation at encoding to enhance long-term memory for emotional material in women

Evidence from the animal literature suggests that post-training glucocorticoids (GCs) interact with noradrenergic activation at acquisition to enhance memory consolidation for emotional stimuli. While there is evidence that GCs enhance memory for emotional material in humans, the extent to which this depends on noradrenergic activation at encoding has not been explored. In this study, 20-mg hydrocortisone was administered to healthy young women (18-35 yrs old) in a double-blind fashion 10 min prior to viewing a series of emotional and neutral images. Saliva samples were taken at baseline, 10 min after drug or placebo administration, immediately after viewing the images, 10, 20, and 30 min after viewing the images. Participants returned 1 week later for a surprise recall test. Results suggest that, hydrocortisone administration resulted in emotional memory enhancement only in participants who displayed an increase in endogenous noradrenergic activation, measured via salivary alpha-amylase at encoding. These results support findings in the animal literature, and suggest that GC-induced memory enhancement relies on noradrenergic activation at encoding in women.

Endometrial Carcinoma Recurrence Score (ECARS) validates to identify aggressive disease and associates with markers of epithelial-mesenchymal transition and PI3K alterations

PURPOSE

Our previously reported 29-gene expression signature identified an aggressive subgroup of endometrial cancer patients with PI3K activation. We here wanted to validate these findings by independent patient series.

PATIENTS AND METHODS

The 29-gene expression signature was assessed in fresh frozen tumor tissue from 280 primary endometrial carcinomas (three independent cohorts), 19 metastatic lesions and in 333 primary endometrial carcinomas using TCGA data, and expression was related to clinico-pathologic features and survival. The 29-gene signature was assessed by real-time quantitative PCR, DNA oligonucleotide microarrays, or RNA sequencing. PI3K alterations were assessed by immunohistochemistry, DNA microarrays, DNA sequencing, SNP arrays or fluorescence in situ hybridization. A panel of markers of epithelial-mesenchymal transition (EMT) was also correlated to the 29-gene signature score.

RESULTS

High 29-gene Endometrial Carcinoma Recurrence Score (ECARS) values consistently validated to identify patients with aggressive clinico-pathologic phenotype and reduced survival. Within the presumed favorable subgroups of low grade, endometrioid tumors confined to the uterus, high ECARS still predicted a poor prognosis. The score was higher in metastatic compared to primary lesions (P<0.001) and was significantly associated with potential measures of PI3K activation, markers of EMT and vascular invasion as an indicator of metastatic spread (all P<0.001).

CONCLUSIONS

ECARS validates to identify aggressive endometrial carcinomas in multiple, independent patients cohorts. The higher signature score in metastatic compared to primary lesions, and the potential link to PI3K activation and EMT, support further studies of ECARS in relation to response to PI3K and EMT inhibitors in clinical trials of metastatic endometrial carcinoma.

Classical light beams and geometric phases

We present a study of geometric phases in classical wave and polarization optics using the basic mathematical framework of quantum mechanics. Important physical situations taken from scalar wave optics, pure polarization optics, and the behavior of polarization in the eikonal or ray limit of Maxwell's equations in a transparent medium are considered. The case of a beam of light whose propagation direction and polarization state are both subject to change is dealt with, attention being paid to the validity of Maxwell's equations at all stages. Global topological aspects of the space of all propagation directions are discussed using elementary group theoretical ideas, and the effects on geometric phases are elucidated.

[Prognostic and predictive molecular markers for urologic cancers]

Molecular prognostic factors and genetic alterations as predictive markers for cancer-specific targeted therapies are used today in the clinic for many malignancies. In recent years, many molecular markers for urogenital cancers have also been identified. However, these markers are not clinically used yet. In prostate cancer, novel next-generation sequencing methods revealed a detailed picture of the molecular changes. There is growing evidence that a combination of classical histopathological and validated molecular markers could lead to a more precise estimation of prognosis, thus, resulting in an increasing number of patients with active surveillance as a possible treatment option. In patients with urothelial carcinoma, histopathological factors but also the proliferation of the tumor, mutations in oncogenes leading to an increasing proliferation rate and changes in genes responsible for invasion and metastasis are important. In addition, gene expression profiles which could distinguish aggressive tumors with high risk of metastasis from nonmetastasizing tumors have been recently identified. In the future, this could potentially allow better selection of patients needing systemic perioperative treatment. In renal cell carcinoma, many molecular markers that are associated with metastasis and survival have been identified. Some of these markers were also validated as independent prognostic markers. Selection of patients with primarily organ-confined tumors and increased risk of metastasis for adjuvant systemic therapy could be clinically relevant in the future.

Measuring the Mueller matrix of an arbitrary optical element with a universal SU(2) polarization gadget

We propose a new method for determining the Mueller matrix of an arbitrary optical element and verify it with three known optical elements. This method makes use of two universal SU(2) polarization gadgets to obtain the projection matrix directly from the experiment. It allows us to determine the Mueller matrix without precalibration of the setup, since the generated polarization states are fully determined by the azimuths of the wave plates. We calculate errors in determining the Mueller matrix and compare with other techniques.