Loss Of Specificity Research Articles

Normal size of benign upper neck nodes on MRI: parotid, submandibular, occipital, facial, retroauricular and level IIb nodal groups

Nodal size is an important imaging criterion for differentiating benign from malignant nodes in the head and neck cancer staging. This study evaluated the size of normal nodes in less well-documented nodal groups in the upper head and neck on magnetic resonance imaging (MRI). Analysis was performed on 289 upper head and neck MRIs of patients without head and neck cancer. The short axial diameters (SAD) of the largest node in the parotid, submandibular, occipital, facial, retroauricular and Level IIb of the upper internal jugular nodal groups were documented and compared to the commonly used threshold of ≥ 10mm for diagnosis of a malignant node. Normal nodes in the parotid, occipital, retroauricular and Level IIb groups were small with a mean SAD ranging from 3.8 to 4.4mm, nodes in the submandibular group were larger with a mean SAD of 5.5mm and facial nodes were not identified. A size ≥ 10mm was found in 0.8% of submandibular nodes. Less than 10% of the other nodal group had a SAD of ≥ 6mm and none of them had a SAD ≥ 8mm. To identify malignant neck nodes in these groups there is scope to reduce the size threshold of ≥ 10mm to improve sensitivity without substantial loss of specificity.

Chromatin Sensing by the Auxiliary Domains of KDM5C Regulates Its Demethylase Activity and Is Disrupted by X-linked Intellectual Disability Mutations

The H3K4me3 chromatin modification, a hallmark of promoters of actively transcribed genes, is dynamically removed by the KDM5 family of histone demethylases. The KDM5 demethylases have a number of accessory domains, two of which, ARID and PHD1, lie between the segments of the catalytic domain. KDM5C, which has a unique role in neural development, harbors a number of mutations adjacent to its accessory domains that cause X-linked intellectual disability (XLID). The roles of these accessory domains remain unknown, limiting an understanding of how XLID mutations affect KDM5C activity. Through in vitro binding and kinetic studies using nucleosomes, we find that while the ARID domain is required for efficient nucleosome demethylation, the PHD1 domain alone has an inhibitory role in KDM5C catalysis. In addition, the unstructured linker region between the ARID and PHD1 domains interacts with PHD1 and is necessary for nucleosome binding. Our data suggests a model in which the PHD1 domain inhibits DNA recognition by KDM5C. This inhibitory effect is relieved by the H3 tail, enabling recognition of flanking DNA on the nucleosome. Importantly, we find that XLID mutations adjacent to the ARID and PHD1 domains break this regulation by enhancing DNA binding, resulting in the loss of specificity of substrate chromatin recognition and rendering demethylase activity lower in the presence of flanking DNA. Our findings suggest a model by which specific XLID mutations could alter chromatin recognition and enable euchromatin-specific dysregulation of demethylation by KDM5C.

Design and performance characteristics of the Elecsys anti-SARS-CoV-2 S assay.

Automated, high throughput assays are required to quantify the immune response after infection with or vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study on the Roche Elecsys® Anti-SARS-CoV-2 S (ACOV2S) assay provides insights on the assay design and performance. The ACOV2S assay quantifies antibodies to the receptor-binding domain of the SARS-CoV-2 spike protein. The assigned units and the underlying standardization were compared to the international reference standard in BAU/mL. Assay specificity was assessed in samples (n=5981) collected prior to the COVID-19 pandemic and in samples from patients with non-COVID-19 respiratory infections (n=697) or other infectious diseases (n=771). Sensitivity was measured in 1313 samples from patients with mild COVID-19 and 297 samples from patients hospitalized with COVID-19. Comparison of results was performed to a comparator semi-quantitative anti-S1 assay of indirect detection format as well as a commercially available and an in-house version of a surrogate neutralization assay (ACE2-RBD). The originally assigned units for the ACOV2S assay were shown to be congruent to the units of the First International WHO Standard for anti-SARS-CoV-2 immunoglobulins. Overall specificity was 99.98% with no geographical differences noted and no loss of specificity in samples containing potentially cross-reacting antibodies. High sensitivity was observed, with 98.8% of samples reported to be reactive >14 days after infection and sustained detection of antibodies over time. For all samples, ACOV2S titers and neutralization capacities developed with comparable dynamics. Robust standardization and assay setup enable excellent reproducibility of results, independent of lot or analyzer used. The results from this study confirmed that ACOV2S is a highly sensitive and specific assay and correlates well with surrogate neutralization assays. The units established for ACOV2S are also interchangeable with the units of the First International WHO Standard for anti-SARS-CoV-2 immunoglobulins. Worldwide availability of the assay and analyzers render ACOV2S a highly practical tool for population-wide assessment and monitoring of the humoral response to SARS-CoV-2 infection or vaccination.

Utility of extended HPV genotyping for the triage of self-sampled HPV-positive women in a screen-and-treat strategy for cervical cancer prevention in Cameroon: a prospective study of diagnostic accuracy

ObjectiveTo explore the utility of extended Human Papillomavirus (HPV) genotyping to detect cervical intraepithelial neoplasia grade 2 or more (CIN2+) in a ‘screen-and-treat’ strategy for HPV-positive women in low-resource settings.DesignProspective...

Expansion of KRAS hotspot mutations reactive T cells from human pancreatic tumors using autologous T cells as the antigen-presenting cells.

Adoptive cell therapy (ACT) with expanded tumor-infiltrating lymphocytes (TIL) or TCR gene-modified T cells (TCR-T) that recognize mutant KRAS neo-antigens can mediate tumor regression in patients with advanced pancreatic ductal adenocarcinoma (PDAC) (Tran et al in N Engl J Med, 375:2255-2262, 2016; Leidner et al in N Engl J Med, 386:2112-2119, 2022). The mutant KRAS-targeted ACT holds great potential to achieve durable clinical responses for PDAC, which has had no meaningful improvement over 40years. However, the wide application of mutant KRAS-centric ACT is currently limited by the rarity of TIL that recognize the mutant KRAS. In addition, PDAC is generally recognized as a poorly immunogenic tumor, and TILs in PDAC are less abundant than in immunogenic tumors such as melanoma. To increase the success rate of TIL production, we adopted a well-utilized K562-based artificial APC (aAPC) that expresses 4-1BBL as the costimulatory molecules to enhance the TIL production from PDCA. However, stimulation with K562-based aAPC led to a rapid loss of specificity to mutant KRAS. To selectively expand neo-antigen-specific T cells, particularly mKRAS, from the TILs, we used tandem mini gene-modified autologous T cells (TMG-T) as the novel aAPC. Using this modified IVS protocol, we successfully generated TIL cultures specifically reactive to mKRAS (G12V). We believe that autologous TMG-T cells provide a reliable source of autologous APC to expand a rare population of neoantigen-specific T cells in TILs.

Value of Dual-Energy Computed Tomography for Detecting Small Pancreatic Ductal Adenocarcinoma.

The aim of the study is to evaluate the usefulness of virtual monoenergetic imaging (VMI) generated from dual-energy computed tomography (DECT) in detecting small pancreatic ductal adenocarcinomas (PDACs). This study included 82 patients pathologically diagnosed with small PDAC (≤30 mm) and 20 without pancreatic tumors who underwent triple-phase contrast-enhanced DECT. To assess diagnostic performance for small PDAC detection via a receiver operating characteristic analysis, 3 observers reviewed 2 image sets (conventional computed tomography [CT] set and combined image set [conventional CT + 40-keV VMI from DECT]). The tumor-to-pancreas contrast-to-noise ratio was compared between conventional CT and 40-keV VMI from DECT. The area under the receiver operating characteristic curve of the 3 observers were 0.97, 0.96, and 0.97 in conventional CT set and 0.99, 0.99, and 0.99 in combined image set (P = 0.017-0.028), respectively. The combined image set yielded a better sensitivity than the conventional CT set (P = 0.001-0.023), without a loss of specificity (all P > 0.999). The tumor-to-pancreas contrast-to-noise ratios of 40-keV VMI from DECT were approximately threefold higher than those of conventional CT at all phases. The addition of 40-keV VMI from DECT to conventional CT had better sensitivity for detecting small PDACs without compromising specificity.

Mapping Lymph Node during Indocyanine Green Fluorescence-Imaging Guided Gastric Oncologic Surgery: Current Applications and Future Directions.

Simple SummaryThe intraoperative navigation techniques develop rapidly, we present an update on current use and research on indocyanine green enhanced fluorescence imaging (ICG-FI) guided lymphangiography in gastric oncological surgery. ICG serves as a promising tattooed agent for lymphangiography, its application was restricted by the false negative lymph nodes and loss of specificity in targeting tumor cells. Besides, we summarized the current approaches for gain in sensitivity and specificity of ICG-FI guided lymphangiography in gastric oncological surgery. The next direction for reinforced ICG-FI was quantification of ICG intensity and detection of ICG distribution pattern, combining with intraoperative biopsy method.Huge strides have been made in the navigation of gastric cancer surgery thanks to the improvement of intraoperative techniques. For now, the use of indocyanine green (ICG) enhanced fluorescence imaging has received promising results in detecting sentinel lymph nodes (SLNs) and tracing lymphatic drainages, which make it applicable for limited and precise lymphadenectomy. Nevertheless, issues of the lack of specificity and unpredictable false-negative lymph nodes were encountered in gastric oncologic surgery practice using ICG-enhanced fluorescence imaging (ICG-FI), which restrict its application. Here, we reviewed the current application of ICG-FI and assessed potential approaches to improving ICG-FI.

Real-life validation of a sample pooling strategy for screening of hepatitis C

ObjectivesTo test a real-life sample pooling screening strategy which contributes to increasing the diagnostic capacity of clinical laboratories and expanding access to massive screening of hepatitis C. MethodsAfter evaluating the sensitivity of the pooling strategy for seven different commercial assays which are used to determine the concentration of hepatitis C virus (HCV)-RNA in the plasma or serum, consecutive samples submitted for HCV diagnosis during the first 3 weeks of November 2021 were tested for HCV antibodies and, in parallel and in a blinded way, were pooled into 100 samples and tested for HCV-RNA. When the result was positive, a strategy to un-mask the positive(s) pool(s), which needed up to 15 total HCV-RNA tests, was used. ResultsAll platforms were able to detect the presence of HCV-RNA in a single sample from a patient with viremic HCV present in pools of up to at least 10 000 HCV-RNA-free samples. A total of 1700 samples (17 pools) were analysed, with an overall prevalence of anti-HCV and HCV-RNA of 0.24%. After pooling, we could detect all samples previously detected using standard diagnosis tests (reflex testing) with a specificity and sensitivity of 100% (CI, 99.78–100%). Given the median current prices of anti-HCV and HCV-RNA on the market in Spain as well as personnel costs, testing using the pooling strategy would have resulted in a save of 3320€. ConclusionsHere, we demonstrated that by improving cost effectiveness, with no loss of sensitivity and specificity, the strategy of pooling samples may serve as an appropriate tool for use in large-scale screening of HCV.

The Pathogenesis of African Trypanosomiasis.

African trypanosomes are bloodstream protozoan parasites that infect mammals including humans, where they cause sleeping sickness. Long-lasting infection is required to favor parasite transmission between hosts. Therefore, trypanosomes have developed strategies to continuously escape innate and adaptive responses of the immune system, while also preventing premature death of the host. The pathology linked to infection mainly results from inflammation and includes anemia and brain dysfunction in addition to loss of specificity and memory of the antibody response. The serum of humans contains an efficient trypanolytic factor, the membrane pore-forming protein apolipoprotein L1 (APOL1). In the two human-infective trypanosomes, specific parasite resistance factors inhibit APOL1 activity. In turn, many African individuals express APOL1 variants that counteract these resistance factors, enabling them to avoid sleeping sickness. However, these variants are associated with chronic kidney disease, particularly in the context of virus-induced inflammation such as coronavirus disease 2019. Vaccination perspectives are discussed.

Clinical Performance of the RealTime High Risk HPV Assay on Self-Collected Vaginal Samples within the VALHUDES Framework.

ABSTRACTThe VALHUDES framework (NCT03064087) was established to evaluate the clinical accuracy of HPV testing on self-samples compared with HPV testing on matched clinician-taken cervical samples. Women referred to colposcopy due to previous cervical abnormalities were recruited at five Belgian colposcopy centers. A total of 486 pairs of matched cervical samples and vaginal self-samples were included in the analysis (228 collected with Evalyn Brush and 258 with Qvintip). The dry vaginal brushes were transferred into 20 mL ThinPrep PreservCyt solution. All specimens were tested with the Abbott RealTime High Risk HPV assay (Abbott RT). Testing on vaginal and cervical specimens was considered the index and comparator tests, respectively, and colposcopy and histology as the reference standard. The clinical sensitivity for CIN2+ of Abbott RT (cutoff ≤32 cycle number [CN]) on vaginal self-samples (Evalyn Brush and Qvintip combined) was 8% lower than on the cervical clinician-collected samples (ratio = 0.92 [95% CI, 0.87 to 0.98]), while the specificity was similar (ratio = 1.04 [95% CI, 0.97 to 1.12]). Sensitivity (ratio = 0.95 [95% CI, 0.89 to 1.02]) and specificity (ratio = 1.11 [95% CI, 0.995 to 1.23]) on Evalyn Brush samples was similar to cervical, while on Qvintip samples, the sensitivity was 12% lower than cervical samples (ratio = 0.88 [95% CI, 0.78 to 0.998]) with similar specificity (0.99 [95% CI, 0.90 to 1.10]). Exploratory cutoff optimization (cutoff ≤35 CN) resulted in an improvement of the relative sensitivity (self-sampling versus clinician sampling: ratio = 0.96 [95% CI, 0.91 to 1.02]) but yielded a loss in relative specificity (ratio = 0.92 [0.85 to 1.00]). The clinical accuracy of Abbott RT differed from the self-sampling device. However, after cutoff optimization, the sensitivity on self-samples taken with either of two vaginal brushes became similar to clinician-collected samples.IMPORTANCE Self-samples are becoming a crucial part of HPV-based cervical cancer screening programs to reach nonattendee women and increase screening coverage. Therefore, the VALHUDES framework was established to validate and evaluate HPV tests and devices on self-samples. Here, in the present manuscript, we evaluated the accuracy of the RealTime High Risk HPV assay (Abbott RT) on two different vaginal devices to detect cervical intraepithelial neoplasia grade two or higher (CIN2+). The study results demonstrated that the Abbott RT assay is similarly accurate on vaginal self-samples as on matched clinician-taken cervical samples after adjusting cutoff values. Moreover, we observed that some vaginal devices perform better than others in CIN2+ detection. We also underline the necessity of standardization and validation of general workflow and sample handling procedures for vaginal self-samples.

Records of Human Deaths from Echinococcosis in Brazil, 1995-2016.

Simple SummaryEchinococcosis is a zoonotic disease relevant to public health in many countries. The disease is present in Brazil; however, it is often underreported due to the lack of mandatory notification of cases across all Brazilian states. The records of two national databases were accessed during the period of 1995–2016 to describe the registered cases and deaths from echinococcosis in the country. Demographic, epidemiological, and health care data related to the occurrence of disease, and deaths attributed to echinococcosis are described. During the study period, 7955 hospitalizations were recorded due to echinococcosis, with 185 deaths. In a second database recording just mortality, a further 113 deaths were documented. Deaths were observed in every state of Brazil. When comparing between states, there was great variability in mortality rates, possibly indicating differences in the quality of health care received by patients and reinforcing the need to expand the compulsory notification of the disease across the country.Echinococcosis is a zoonotic disease relevant to public health in many countries, on all continents except Antarctica. The objective of the study is to describe the registered cases and mortality from echinococcosis in Brazil, from 1995 to 2016. The records of two national databases, the Hospital Information System (HIS) and the Mortality Information System (MIS), were accessed during the period of 1995–2016. Demographic, epidemiological, and health care data related to the occurrence of disease and deaths attributed to echinococcosis in Brazil are described. The results showed that 7955 records of hospitalizations were documented in the HIS, during the study period, with 185 deaths from echinococcosis, and 113 records of deaths were documented in the MIS Deaths in every state of Brazil in the period. When comparing between states, the HIS showed great variability in mortality rates, possibly indicating heterogeneity in diagnosis and in the quality of health care received by patients. Less severe cases that do not require specialized care are not recorded by the information systems, thus the true burden of the disease could be underrepresented in the country. A change in the coding of disease records in the HIS in the late 1990s, (the integration of echinococcosis cases with other pathologies), led to the loss of specificity of the records. The records showed a wide geographic distribution of deaths from echinococcosis, reinforcing the need to expand the notification of the disease in Brazil. Currently, notification of cases is compulsory in the state of Rio Grande do Sul.

Improving power in functional magnetic resonance imaging by moving beyond cluster-level inference

Inference in neuroimaging typically occurs at the level of focal brain areas or circuits. Yet, increasingly, well-powered studies paint a much richer picture of broad-scale effects distributed throughout the brain, suggesting that many focal reports may only reflect the tip of the iceberg of underlying effects. How focal versus broad-scale perspectives influence the inferences we make has not yet been comprehensively evaluated using real data. Here, we compare sensitivity and specificity across procedures representing multiple levels of inference using an empirical benchmarking procedure that resamples task-based connectomes from the Human Connectome Project dataset (∼1,000 subjects, 7 tasks, 3 resampling group sizes, 7 inferential procedures). Only broad-scale (network and whole brain) procedures obtained the traditional 80% statistical power level to detect an average effect, reflecting >20% more statistical power than focal (edge and cluster) procedures. Power also increased substantially for false discovery rate- compared with familywise error rate-controlling procedures. The downsides are fairly limited; the loss in specificity for broad-scale and FDR procedures was relatively modest compared to the gains in power. Furthermore, the broad-scale methods we introduce are simple, fast, and easy to use, providing a straightforward starting point for researchers. This also points to the promise of more sophisticated broad-scale methods for not only functional connectivity but also related fields, including task-based activation. Altogether, this work demonstrates that shifting the scale of inference and choosing FDR control are both immediately attainable and can help remedy the issues with statistical power plaguing typical studies in the field.

Deep learning for brain metastasis detection and segmentation in longitudinal MRI data.

Brain metastases (BM) occur frequently in patients with metastatic cancer. Early and accurate detection of BM is essential for treatment planning and prognosis in radiation therapy. Due to their tiny sizes and relatively low contrast, small BM are very difficult to detect manually. With the recent development of deep learning technologies, several res earchers have reported promising results in automated brain metastasis detection. However, the detection sensitivity is still not high enough for tiny BM, and integration into clinical practice in regard to differentiating true metastases from false positives (FPs) is challenging. The DeepMedic network with the binary cross-entropy (BCE) loss is used as our baseline method. To improve brain metastasis detection performance, a custom detection loss called volume-level sensitivity-specificity (VSS) is proposed, which rates metastasis detection sensitivity and specificity at a (sub)volume level. As sensitivity and precision are always a trade-off, either a high sensitivity or a high precision can be achieved for brain metastasis detection by adjusting the weights in the VSS loss without decline in dice score coefficient for segmented metastases. To reduce metastasis-like structures being detected as FP metastases, a temporal prior volume is proposed as an additional input of DeepMedic. The modified network is called DeepMedic+ for distinction. Combining a high-sensitivity VSS loss and a high specificity loss for DeepMedic+, the majority of true positive metastases are confirmed with high specificity, while additional metastases candidates in each patient are marked with high sensitivity for detailed expert evaluation. Our proposed VSS loss improves the sensitivity of brain metastasis detection, increasing the sensitivity from 85.3% for DeepMedic with BCE to 97.5% for DeepMedic with VSS. Alternatively, the precision is improved from 69.1% for DeepMedic with BCE to 98.7% for DeepMedic with VSS. Comparing DeepMedic+ with DeepMedic with the same VSS loss, 44.4% of the FP metastases are reduced in the high-sensitivity model and the precision reaches 99.6% for the high-specificity model. The mean dice coefficient for all metastases is about 0.81. With the ensemble of the high-sensitivity and high-specificity models, on average only 1.5 FP metastases per patient need further check, while the majority of true positive metastases are confirmed. Our proposed VSS loss and temporal prior improve brain metastasis detection sensitivity and precision. The ensemble learning is able to distinguish high confidence true positive metastases from metastases candidates that require special expert review or further follow-up, being particularly well-fit to the requirements of expert support in real clinical practice. This facilitates metastasis detection and segmentation for neuroradiologists in diagnostic and radiation oncologists in therapeutic clinicalapplications.

Sensitivity and Specificity for Skin Cancer Diagnosis in Primary Care Providers: a Systematic Literature Review and Meta-analysis of Educational Interventions and Diagnostic Algorithms.

In areas without convenient access to dermatology care, primary care providers (PCPs) serve as an important patient resource for early skin cancer detection. To determine the most effective strategy for skin cancer detection training in PCPs, we conducted a systematic review of educational interventions and performed a meta-analysis on sensitivity and specificity outcomes in PCPs. To summarize data on skin cancer sensitivity and specificity outcomes for PCP-targeted training programs and diagnostic algorithms. Our PCP cohort included practicing physicians, trainee physicians, and advanced practice practitioners. A literature search was performed in MEDLINE, Embase, Web of Science, and the Cochrane Library for relevant English-language articles published worldwide from 2000 onward. Results were screened for eligibility, and overlapping datasets were reconciled. Data extracted included the educational intervention, diagnostic algorithm, and outcomes of interest (sensitivity and specificity). Outcomes were pooled across interventions that taught the same diagnostic algorithm. A bivariate model was fit to compare different interventions/algorithms. This review followed the PRISMA guidelines. In total, 21 articles were included in this review, encompassing over 58,610 assessments of skin lesions by about 1529 participants worldwide. Training programs that implemented the triage-amalgamated dermoscopic algorithm (TADA) demonstrated high pooled sensitivity (91.7%) and high pooled specificity (81.4%) among PCPs. Overall, this systematic review and meta-analysis showed that dermoscopy training in PCPs was generally associated with gains in skin cancer sensitivity without loss of specificity. Clinically, this correlates with fewer skin cancers overlooked by PCPs and fewer excisions of benign lesions.

Stability selection for mixed effect models with large numbers of predictor variables: A simulation study

Covariate selection when the number of available variables is large relative to the number of observations is problematic in epidemiology and remains the focus of continued research. Whilst a variety of statistical methods have been developed to attempt to overcome this issue, at present very few methods are available for wide data that include a clustered outcome. The purpose of this research was to make an empirical evaluation of a new method for covariate selection in wide data settings when the dependent variable is clustered. We used 3300 simulated datasets with a variety of defined structures and known sets of true predictor variables to conduct an empirical evaluation of a mixed model stability selection procedure. Comparison was made with an alternative method based on regularisation using the least absolute shrinkage and selection operator (Lasso) penalty. Model performance was assessed using several metrics including the true positive rate (proportion of true covariates selected in a final model) and false discovery rate (proportion of variables selected in a final model that were non-true (false) variables). For stability selection, the false discovery rate was consistently low, generally remaining ≤ 0.02 indicating that on average fewer than 1 in 50 of the variables selected in a final model were false variables. This was in contrast to the Lasso-based method in which the false discovery rate was between 0.59 and 0.72, indicating that generally more than 60% of variables selected in a final model were false variables. In contrast however, the Lasso method attained higher true positive rates than stability selection, although both methods achieved good results. For the Lasso method, true positive rates remained ≥ 0.93 whereas for stability selection the true positive rate was 0.73–0.97. Our results suggest both methods may be of value for covariate selection with high dimensional data with a clustered outcome. When high specificity is needed for identification of true covariates, stability selection appeared to offer the better solution, although with a slight loss of sensitivity. Conversely when high sensitivity is needed, the Lasso approach may be useful, even if accompanied by a substantial loss of specificity. Overall, the results indicated the loss of sensitivity when employing stability selection is relatively small compared to the loss of specificity when using the Lasso and therefore stability selection may provide the better option for the analyst when evaluating data of this type.

Ultra-specific fluorescence detection of DNA modifying enzymes by dissipation system

Abnormal expression of DNA modifying enzymes (DMEs) is linked to a variety of diseases including cancers. It is desirable to develop accurate methods for DME detection. However, the substrate-based probe for target DMEs is disturbed by various non-target DMEs that have similar activity resulting in a loss of specificity. Here we utilized dissipative DNA networks to develop an ultra-specific fluorescence assay for DME, absolutely distinguishing between target and non-target enzymes. Unlike the conventional sensors in which the discrimination of target and non-target relies on signal intensity, in our system, target DMEs exhibit featured fluorescence oscillatory signals, while non-target DMEs show irreversible ‘one-way’ fluorescence increase. These dissipation-enabled probes (DEPs) exhibit excellent generality for various types of DMEs including DNA repair enzyme apurinic/apyrimidinic endonuclease 1 (APE1), polynucleotide kinase (T4 PNK), and methyltransferase (Dam). DEPs provide a novel quantification mode based on area under curve which is more robust than those intensity-based quantifications. The detection limits of APE1, T4 PNK, and Dam reach 0.025 U/mL, 0.44 U/mL, and 0.113 U/mL, respectively. DEPs can accurately identify their corresponding DMEs with excellent specificity in cell extracts. Fluorescence sensors based on DEPs herein represent a conceptually new class of methods for enzyme detection, which can be easily adapted to other sensing platforms such as electrochemical sensors.

How Consumers Process Unexpected Online Advertisements

The distinctiveness of neural information representation is crucial for successful memory performance but declines with advancing age. Computational models implicate age-related neural dedifferentiation on the level of item representations, but previous studies mostly focused on age differences of categorical information representation in higher-order visual regions. In an age-comparative fMRI study, we combined univariate analyses and whole-brain searchlight pattern similarity analyses to elucidate age differences in neural distinctiveness at both category and item levels and their relation to memory. Thirty-five younger (18-27 years old) and 32 older (67-75 years old) women and men incidentally encoded images of faces and houses, followed by an old/new recognition memory task. During encoding, age-related neural dedifferentiation was shown as reduced category-selective processing in ventral visual cortex and impoverished item specificity in occipital regions. Importantly, successful subsequent memory performance built on high item stability, that is, high representational similarity between initial and repeated presentation of an item, which was greater in younger than older adults. Overall, we found that differences in representational distinctiveness coexist across representational levels and contribute to interindividual and intraindividual variability in memory success, with item specificity being the strongest contributor. Our results close an important gap in the literature, showing that older adults9 neural representation of item-specific information in addition to categorical information is reduced compared with younger adults. <b>SIGNIFICANCE STATEMENT</b> A long-standing hypothesis links age-related cognitive decline to a loss of neural specificity. While previous evidence supports the notion of age-related neural dedifferentiation of category-level information in ventral visual cortex, whether or not age differences exist at the item level was a matter of debate. Here, we observed age group differences at both levels as well as associations between both categorical distinctiveness and item specificity to memory performance, with item specificity being the strongest contributor. Importantly, age differences in occipital item specificity were largely due to reduced item stability across repetitions in older adults. Our results suggest that age differences in neural representations can be observed across the entire cortical hierarchy and are not limited to category-level information.

Contrast-Enhanced Ultrasound Using Perfluorobutane: Impact of Proposed Modified LI-RADS Criteria on Hepatocellular Carcinoma Detection.

BACKGROUND. Contrast-enhanced ultrasound (CEUS) LI-RADS version 2017 (v2017) applies only to CEUS examinations performed using pure blood pool agents, noting that future versions will address combined blood pool and Kupffer cell agents such as perfluorobutane. Such agents may improve hepatocellular carcinoma (HCC) detection by visualization of a defect in the Kupffer phase (obtained ≥ 10 minutes after injection). OBJECTIVE. The purpose of our study was to compare the diagnostic performance of the LR-5 category for HCC detection in at-risk patients between CEUS LI-RADS v2017 and proposed modified criteria for CEUS examinations performed using perfluorobutane. METHODS. This retrospective study included 293 patients at risk for HCC (259 men, 34 women; mean age, 55 ± 12 [SD] years) who underwent CEUS using perfluorobutane from March 1, 2020, to October 30, 2020, showing a total of 304 observations (274 HCC, 14 non-HCC malignancy, and 16 benign lesions). Two readers independently assessed examinations and assigned categories using both CEUS LI-RADS v2017 and the proposed modified criteria. In the modified criteria, observations 10 mm or greater with not rim arterial phase hyperenhancement (APHE), no washout, and a Kupffer defect were upgraded from LR-4 to LR-5, and observations 10 mm or greater with not rim APHE, early washout, and a mild Kupffer defect were reassigned from LR-M to LR-5. Interreader agreement was assessed, and consensus interpretations were reached. Diagnostic performance was evaluated. RESULTS. Interreader agreement for LI-RADS category assignments, expressed using kappa coefficients, was 0.839 for CEUS LI-RADS v2017 and 0.854 for the modified criteria. Modified criteria upgraded 35 observations from LR-4 to LR-5 on the basis of a Kupffer defect, of which 34 were HCC and one was benign. Modified criteria reassigned 22 observations from LR-M to LR-5 on the basis of a mild Kupffer defect, of which all were HCC. LR-5 using modified criteria, compared with CEUS LI-RADS v2017, had significantly increased sensitivity (89% vs 69%, p < .001), a nonsignificant decrease in specificity (83% vs 87%, p > .99), and significantly increased accuracy (89% vs 71%, p < .001) for HCC. CONCLUSION. When using perfluorobutane for CEUS in at-risk patients, modified criteria incorporating Kupffer defects significantly improve sensitivity without significant loss of specificity in HCC detection. CLINICAL IMPACT. Future CEUS LI-RADS updates seeking to address the use of combined blood pool and Kupffer cell agents should consider adoption of the explored criteria.

Altering enhancer-promoter linear distance impacts promoter competition in cis and in trans.

In Drosophila, pairing of maternal and paternal homologs can permit trans-interactions between enhancers on one homolog and promoters on another, an example of a phenomenon called transvection. When chromosomes are paired, promoters in cis and in trans to an enhancer can compete for the enhancer's activity, but the parameters that govern this competition are as yet poorly understood. To assess how the linear spacing between an enhancer and promoter can influence promoter competition in Drosophila, we employed transgenic constructs wherein the eye-specific enhancer GMR is placed at varying distances from a heterologous hsp70 promoter driving a fluorescent reporter. While GMR activates the reporter to a high degree when the enhancer and promoter are spaced by a few hundred base pairs, activation is strongly attenuated when the enhancer is moved 3kb away. By examining transcription of endogenous genes near the point of transgene insertion, we show that linear spacing of 3 kb between GMR and the hsp70 promoter results in elevated transcription of neighboring promoters, suggesting a loss of specificity between the enhancer and its intended transgenic target promoter. Furthermore, increasing spacing between GMR and hsp70 by just 100 bp can enhance transvection, resulting in increased activation of a promoter on a paired homolog at the expense of a promoter in cis to the enhancer. Finally, cis-/trans-promoter competition assays in which one promoter carries mutations to key core promoter elements show that GMR will skew its activity toward a wild-type promoter, suggesting that an enhancer is in a balanced competition between its potential target promoters in cis and in trans.

New diagnostic index for prediction of severe irAEs in patients with metastatic melanoma taking checkpoint inhibitors.

e21565 Background: Immune-related adverse events (irAEs) occur in up to 50% of patients treated with immune checkpoint inhibitors (ICI). Severe forms of toxicity are observed in 3% of patients and require systemic steroid therapy and constant monitoring. One of the considered predictor biomarkers of irAEs development is HLA-genotypes. This research aims to evaluate the diagnostic significance of HLA-DRB1 genotypes and other clinical, laboratory parameters to predict the development of irAEs. Methods: The study involved 28 patients (pts) with metastatic melanoma taking ICI (nivo 53.6%, ipi+nivo 32.1%, other 14.3%). The PD-L1 expression, HLA-DRB1 genotype were evaluated. After 2-3 months the development of irAES was assessed. The complications of 3-4 grade or multi-organ damage were termed as a severe irAEs. Statistical analysis was performed in GraphPad Prism 6 (Graph Pad Software, USA) using Fisher, Mann-Whitney, ROC statistical analysis. The project is supported by a grant (14. W03.31.0009). Results: Different IrAEs developed in 57.1% (16/28) of patients, while severe irAEs in 35.7% (10/28). Among all patients HLA-DRB1 genotypes associated with the risk of autoimmune diseases were found in 78.5% (22/28). The PD-L1 expression was detected in 60.7% (17/28) of individuals.Combination treatment increases the risk of toxicity, p = 0.003, with a diagnostic sensitivity (S) of 56% and a diagnostic specificity (Sp) of 100% (RR = 2.71, OR = 31.67). The analysis of specific complications revealed associations between HLA-DRB1*04 with diabetes mellitus, p = 0.026 (OR = 33.57, S = 100%, Sp = 88.5%), HLA-DRB1*04/15 with autoimmune hepatitis or increased transaminases, p = 0.037 (OR = 17.27, S = 100%, Sp = 72%). An index based on the parameters studied (HLA-DRB1, the absence of PD-L1 expression, type of treatment) was created. With index value ≥2 a sensitivity for predicting severe toxicity is 40.00% and a specificity is 83.33%, p = 0.0126. Conclusions: According to the results obtained it can be assumed that the development of severe forms of irAES has a multifactorial origin, in particular, combination therapy, the absence of PD-L1 expression, which can lead to the loss of ICI drug specificity, and the presence of HLA-DRB1 genotypes associated with the risk of developing autoimmune diseases. The new diagnostic index to predict severe complications based on these parameters was created and showed a sensitivity of 40.00% and a specificity of 83.33%. The authors consider the limitations of the study, such as the small sample, the short observational period.