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We present slow-light photonic crystal waveguide designs that provide a ×8.6 improvement of the local density of optical states at a fully chiral point over previous designs. [ABSTRACT FROM AUTHOR]

Abstract Motivated by the unexplored potential of in vitro neural systems for computing and by the corresponding need of versatile, scalable interfaces for multimodal interaction, an accurate, modular, fully customizable, and portable recording/stimulation solution that can be easily fabricated, robustly operated, and broadly disseminated is presented. This approach entails a reconfigurable platform that works across multiple industry standards and that enables a complete signal chain, from neural substrates sampled through micro‐electrode arrays (MEAs) to data acquisition, downstream analysis, and cloud storage. Built‐in modularity supports the seamless integration of electrical/optical stimulation and fluidic interfaces. Custom MEA fabrication leverages maskless photolithography, favoring the rapid prototyping of a variety of configurations, spatial topologies, and constitutive materials. Through a dedicated analysis and management software suite, the utility and robustness of this system are demonstrated across neural cultures and applications, including embryonic stem cell‐derived and primary neurons, organotypic brain slices, 3D engineered tissue mimics, concurrent calcium imaging, and long‐term recording. Overall, this technology, termed “mind in vitro” to underscore the computing inspiration, provides an end‐to‐end solution that can be widely deployed due to its affordable (>10× cost reduction) and open‐source nature, catering to the expanding needs of both conventional and unconventional electrophysiology.

BRAN2020 (2020 version of the Bluelink ReANalysis) is an ocean reanalysis that combines observations with an eddy-resolving, near-global ocean general circulation model to produce a four-dimensional estimate of the ocean state. The data assimilation system employed is ensemble optimal interpolation, implemented with a new multiscale approach that constrains the broad-scale ocean properties and the mesoscale circulation in two steps. There is a separation in the scales that are corrected in the two steps: the high-resolution step corrects the mesoscale dynamics in the same way as previous versions of BRAN, while the extra coarse step is effective at correcting biases that develop at large scales. The reanalysis currently spans January 1993 to December 2019 and assimilates observations of in situ temperature and salinity, as well as of satellite sea-level anomaly and sea surface temperature. BRAN2020 is planned to be updated to within months of real time after this initial release, until an updated version of BRAN is available. Reanalysed fields from BRAN2020 generally show much closer agreement to observations than all previous versions with misfits between reanalysed and observed fields reduced by over 30 % for some variables, for subsurface temperature and salinity in particular. The BRAN2020 dataset is comprised of daily averaged fields of temperature, salinity, velocity, mixed-layer depth and sea level. Reanalysed fields realistically represent all of the major current systems within 75∘ S and 75∘ N, excluding processes relating to sea ice but including boundary currents, equatorial circulation, Southern Ocean variability and mesoscale eddies. BRAN2020 is publicly available at https://doi.org/10.25914/6009627c7af03 (Chamberlain et al., 2021b) and is intended for use by the research community.

AbstractNeural information processing is widely understood to depend on correlations in neuronal activity. However, whether correlation is favorable or not is contentious. Here, we sought to determine how correlated activity and information processing are related in cortical circuits. Using recordings of hundreds of spiking neurons in organotypic cultures of mouse neocortex, we asked whether mutual information between neurons that feed into a common third neuron increased synergistic information processing by the receiving neuron. We found that mutual information and synergistic processing were positively related at synaptic timescales (0.05–14 ms), where mutual information values were low. This effect was mediated by the increase in information transmission—of which synergistic processing is a component—that resulted as mutual information grew. However, at extrasynaptic windows (up to 3,000 ms), where mutual information values were high, the relationship between mutual information and synergistic processing became negative. In this regime, greater mutual information resulted in a disproportionate increase in redundancy relative to information transmission. These results indicate that the emergence of synergistic processing from correlated activity differs according to timescale and correlation regime. In a low-correlation regime, synergistic processing increases with greater correlation, and in a high-correlation regime, synergistic processing decreases with greater correlation.

Blue Maps aims to exploit the versatility of an ensemble data assimilation system to deliver gridded estimates of ocean temperature, salinity, and sea-level with the accuracy of an observation-based product. Weekly maps of ocean properties are produced on a 1/10°, near-global grid by combining Argo profiles and satellite observations using ensemble optimal interpolation (EnOI). EnOI is traditionally applied to ocean models for ocean forecasting or reanalysis, and usually uses an ensemble comprised of anomalies for only one spatiotemporal scale (e.g., mesoscale). Here, we implement EnOI using an ensemble that includes anomalies for multiple space- and time-scales: mesoscale, intraseasonal, seasonal, and interannual. The system produces high-quality analyses that produce mis-fits to observations that compare well to other observation-based products and ocean reanalyses. The accuracy of Blue Maps analyses is assessed by comparing background fields and analyses to observations, before and after each analysis is calculated. Blue Maps produces analyses of sea-level with accuracy of about 4 cm; and analyses of upper-ocean (deep) temperature and salinity with accuracy of about 0.45 (0.15) degrees and 0.1 (0.015) practical salinity units, respectively. We show that the system benefits from a diversity of ensemble members with multiple scales, with different types of ensemble members weighted accordingly in different dynamical regions.

We have developed an inductively coupled plasma etching technique using a Faraday cage to create suspended gallium-nitride devices in a single step. The angle of the Faraday cage, gas mix, and chamber condition define the angle of the etch and the cross-sectional profile, which can feature undercut angles of up to 45°. We fabricate singly- and doubly-clamped cantilevers of a triangular cross section and show that they can support single optical modes in the telecom C-band.

Sea surface temperature (SST) is a fundamental physical variable for understanding, quantifying and predicting complex interactions between the ocean and the atmosphere. Such processes determine how heat from the sun is redistributed across the global oceans, directly impacting large- and small-scale weather and climate patterns. The provision of daily maps of global SST for operational systems, climate modeling and the broader scientific community is now a mature and sustained service coordinated by the Group for High Resolution Sea Surface Temperature (GHRSST) and the CEOS SST Virtual Constellation (CEOS SST-VC). Data streams are shared, indexed, processed, quality controlled, analyzed, and documented within a Regional/Global Task Sharing (R/GTS) framework, which is implemented internationally in a distributed manner. Products rely on a combination of low-Earth orbit infrared and microwave satellite imagery, geostationary orbit infrared satellite imagery, and in situ data from moored and drifting buoys, Argo floats, and a suite of independent, fully characterized and traceable in situ measurements for product validation (Fiducial Reference Measurements, FRM). Research and development continues to tackle problems such as instrument calibration, algorithm development, diurnal variability, derivation of high-quality skin and depth temperatures, and areas of specific interest such as the high latitudes and coastal areas. In this white paper, we review progress versus the challenges we set out 10 years ago in a previous paper, highlight remaining and new research and development challenges for the next 10 years (such as the need for sustained continuity of passive microwave SST using a 6.9 GHz channel), and conclude with needs to achieve an integrated global high-resolution SST observing system, with focus on satellite observations exploited in conjunction with in situ SSTs. The paper directly relates to the theme of Data Information Systems and also contributes to Ocean Observing Governance and Ocean Technology and Networks within the OceanObs2019 objectives. Applications of SST contribute to all the seven societal benefits, covering Discovery; Ecosystem Health & Biodiversity; Climate Variability & Change; Water, Food, & Energy Security; Pollution & Human Health; Hazards and Maritime Safety; and the Blue Economy.

We use slow-light photonic crystals to enhance optical switching and modulation in silicon. By using dispersion-engineered designs, a switch as short as 5 ¿m was achieved, in which we have demonstrated rerouting of optical pulses on a 3-ps time scale through the absorption of a femtosecond pulse. We additionally demonstrate a modulator with a Mach-Zehnder interferometer (MZI) configuration with flat-band slow-light photonic crystal phase shifters that is designed to give a large group-index-bandwidth product. An extinction ratio in excess of 15 dB is obtained over the entire 11-nm bandwidth of the modulator.

Understanding how ensembles of neurons collectively interact will be a key step in developing a mechanistic theory of cognitive processes. Recent progress in multineuron recording and analysis techniques has generated tremendous excitement over the physiology of living neural networks. One of the key developments driving this interest is a new class of models based on the principle of maximum entropy. Maximum entropy models have been reported to account for spatial correlation structure in ensembles of neurons recorded from several different types of data. Importantly, these models require only information about the firing rates of individual neurons and their pairwise correlations. If this approach is generally applicable, it would drastically simplify the problem of understanding how neural networks behave. Given the interest in this method, several groups now have worked to extend maximum entropy models to account for temporal correlations. Here, we review how maximum entropy models have been applied to neuronal ensemble data to account for spatial and temporal correlations. We also discuss criticisms of the maximum entropy approach that argue that it is not generally applicable to larger ensembles of neurons. We conclude that future maximum entropy models will need to address three issues: temporal correlations, higher-order correlations, and larger ensemble sizes. Finally, we provide a brief list of topics for future research.

It has been notoriously difficult to understand interactions in the basal ganglia because of multiple recurrent loops. Another complication is that activity there is strongly dependent on behavior, suggesting that directional interactions, or effective connections, can dynamically change. A simplifying approach would be to examine just the direct, monosynaptic projections from cortex to striatum and contrast this with the polysynaptic feedback connections from striatum to cortex. Previous work by others on effective connectivity in this pathway indicated that activity in cortex could be used to predict activity in striatum, but that striatal activity could not predict cortical activity. However, this work was conducted in anesthetized or seizing animals, making it impossible to know how free behavior might influence effective connectivity. To address this issue, we applied Granger causality to local field potential signals from cortex and striatum in freely behaving rats. Consistent with previous results, we found that effective connectivity was largely unidirectional, from cortex to striatum, during anesthetized and resting states. Interestingly, we found that effective connectivity became bidirectional during free behaviors. These results are the first to our knowledge to show that striatal influence on cortex can be as strong as cortical influence on striatum. In addition, these findings highlight how behavioral states can affect basal ganglia interactions. Finally, we suggest that this approach may be useful for studies of Parkinson's or Huntington's diseases, in which effective connectivity may change during movement.

Recent studies have emphasized the importance of multiplex networks--interdependent networks with shared nodes and different types of connections--in systems primarily outside of neuroscience. Though the multiplex properties of networks are frequently not considered, most networks are actually multiplex networks and the multiplex specific features of networks can greatly affect network behavior (e.g. fault tolerance). Thus, the study of networks of neurons could potentially be greatly enhanced using a multiplex perspective. Given the wide range of temporally dependent rhythms and phenomena present in neural systems, we chose to examine multiplex networks of individual neurons with time scale dependent connections. To study these networks, we used transfer entropy--an information theoretic quantity that can be used to measure linear and nonlinear interactions--to systematically measure the connectivity between individual neurons at different time scales in cortical and hippocampal slice cultures. We recorded the spiking activity of almost 12,000 neurons across 60 tissue samples using a 512-electrode array with 60 micrometer inter-electrode spacing and 50 microsecond temporal resolution. To the best of our knowledge, this preparation and recording method represents a superior combination of number of recorded neurons and temporal and spatial recording resolutions to any currently available in vivo system. We found that highly connected neurons ("hubs") were localized to certain time scales, which, we hypothesize, increases the fault tolerance of the network. Conversely, a large proportion of non-hub neurons were not localized to certain time scales. In addition, we found that long and short time scale connectivity was uncorrelated. Finally, we found that long time scale networks were significantly less modular and more disassortative than short time scale networks in both tissue types. As far as we are aware, this analysis represents the first systematic study of temporally dependent multiplex networks among individual neurons.

Understanding the detailed circuitry of functioning neuronal networks is one of the major goals of neuroscience. Recent improvements in neuronal recording techniques have made it possible to record the spiking activity from hundreds of neurons simultaneously with sub-millisecond temporal resolution. Here we used a 512-channel multielectrode array system to record the activity from hundreds of neurons in organotypic cultures of cortico-hippocampal brain slices from mice. To probe the network structure, we employed a wavelet transform of the cross-correlogram to categorize the functional connectivity in different frequency ranges. With this method we directly compare, for the first time, in any preparation, the neuronal network structures of cortex and hippocampus, on the scale of hundreds of neurons, with sub-millisecond time resolution. Among the three frequency ranges that we investigated, the lower two frequency ranges (gamma (30-80 Hz) and beta (12-30 Hz) range) showed similar network structure between cortex and hippocampus, but there were many significant differences between these structures in the high frequency range (100-1000 Hz). The high frequency networks in cortex showed short tailed degree-distributions, shorter decay length of connectivity density, smaller clustering coefficients, and positive assortativity. Our results suggest that our method can characterize frequency dependent differences of network architecture from different brain regions. Crucially, because these differences between brain regions require millisecond temporal scales to be observed and characterized, these results underscore the importance of high temporal resolution recordings for the understanding of functional networks in neuronal systems.

Transfer entropy (TE) is an information-theoretic measure which has received recent attention in neuroscience for its potential to identify effective connectivity between neurons. Calculating TE for large ensembles of spiking neurons is computationally intensive, and has caused most investigators to probe neural interactions at only a single time delay and at a message length of only a single time bin. This is problematic, as synaptic delays between cortical neurons, for example, range from one to tens of milliseconds. In addition, neurons produce bursts of spikes spanning multiple time bins. To address these issues, here we introduce a free software package that allows TE to be measured at multiple delays and message lengths. To assess performance, we applied these extensions of TE to a spiking cortical network model (Izhikevich, 2006) with known connectivity and a range of synaptic delays. For comparison, we also investigated single-delay TE, at a message length of one bin (D1TE), and cross-correlation (CC) methods. We found that D1TE could identify 36% of true connections when evaluated at a false positive rate of 1%. For extended versions of TE, this dramatically improved to 73% of true connections. In addition, the connections correctly identified by extended versions of TE accounted for 85% of the total synaptic weight in the network. Cross correlation methods generally performed more poorly than extended TE, but were useful when data length was short. A computational performance analysis demonstrated that the algorithm for extended TE, when used on currently available desktop computers, could extract effective connectivity from 1 hr recordings containing 200 neurons in ∼5 min. We conclude that extending TE to multiple delays and message lengths improves its ability to assess effective connectivity between spiking neurons. These extensions to TE soon could become practical tools for experimentalists who record hundreds of spiking neurons.

Background: Artificial intelligence (AI)-assisted image interpretation is a fast-developing area of clinical innovation. Most research to date has focused on the performance of AI-assisted algorithms in comparison with that of radiologists rather than evaluating the algorithms' impact on the clinicians who often undertake initial image interpretation in routine clinical practice. This study assessed the impact of AI-assisted image interpretation on the diagnostic performance of frontline acute care clinicians for the detection of pneumothoraces (PTX)., Methods: A multicentre blinded multi-case multi-reader study was conducted between October 2021 and January 2022. The online study recruited 18 clinician readers from six different clinical specialties, with differing levels of seniority, across four English hospitals. The study included 395 plain CXR images, 189 positive for PTX and 206 negative. The reference standard was the consensus opinion of two thoracic radiologists with a third acting as arbitrator. General Electric Healthcare Critical Care Suite (GEHC CCS) PTX algorithm was applied to the final dataset. Readers individually interpreted the dataset without AI assistance, recording the presence or absence of a PTX and a confidence rating. Following a 'washout' period, this process was repeated including the AI output., Results: Analysis of the performance of the algorithm for detecting or ruling out a PTX revealed an overall AUROC of 0.939. Overall reader sensitivity increased by 11.4% (95% CI 4.8, 18.0, p=0.002) from 66.8% (95% CI 57.3, 76.2) unaided to 78.1% aided (95% CI 72.2, 84.0, p=0.002), specificity 93.9% (95% CI 90.9, 97.0) without AI to 95.8% (95% CI 93.7, 97.9, p=0.247). The junior reader subgroup showed the largest improvement at 21.7% (95% CI 10.9, 32.6), increasing from 56.0% (95% CI 37.7, 74.3) to 77.7% (95% CI 65.8, 89.7, p<0.01)., Conclusion: The study indicates that AI-assisted image interpretation significantly enhances the diagnostic accuracy of clinicians in detecting PTX, particularly benefiting less experienced practitioners. While overall interpretation time remained unchanged, the use of AI improved diagnostic confidence and sensitivity, especially among junior clinicians. These findings underscore the potential of AI to support less skilled clinicians in acute care settings., Competing Interests: Competing interests: AS, SG and AB are employed by GE HealthCare, a key NCIMI stakeholder. AN and CB have undertaken paid consultancy work for GEHC. PA, SA and FG are employees of Report and Image Quality Control (www.raiqc.com), a spin-out company from Oxford University Hospitals NHS Foundation Trust., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Deficiencies in risk assessment for patients with pulmonary nodules (PNs) contribute to unnecessary invasive testing and delays in diagnosis., Research Question: What is the accuracy of a novel PN risk model that includes plasma proteins and clinical factors? How does the accuracy compare with that of an established risk model?, Study Design and Methods: Based on technology using magnetic nanosensors, assays were developed with seven plasma proteins. In a training cohort (n = 429), machine learning approaches were used to identify an optimal algorithm that subsequently was evaluated in a validation cohort (n = 489), and its performance was compared with the Mayo Clinic model., Results: In the training set, we identified a support vector machine algorithm that included the seven plasma proteins and six clinical factors that demonstrated an area under the receiver operating characteristic curve of 0.87 and met other selection criteria. The resulting risk reclassification model (RRM) was used to recategorize patients with a pretest risk of between 10% and 84%, and its performance was assessed across five risk strata (low, ≤ 10%; moderate, 10%-34%; intermediate, 35%-70%; high, 71%-84%; very high, > 85%). Stratification by the RRM decreased the proportion of intermediate-risk patients from 26.7% to 10.8% (P < .001) and increased the low-risk and high-risk strata from 16.8% to 21.9% (P < .001) and from 3.7% to 12.1% (P < .001), respectively. Among patients classified as low risk by the RRM and Mayo Clinic model, the corresponding true-negative to false-negative ratios were 16.8 and 19.5, respectively. Among patients classified as very high risk by the RRM and Mayo Clinic model, the corresponding true-positive to false-positive ratios were 28.5 and 17.0, respectively. Compared with the Mayo Clinic model, the RRM provided higher specificity at the low-risk threshold and higher sensitivity at the very high-risk threshold., Interpretation: The RRM accurately reclassified some patients into low-risk and very high-risk categories, suggesting the potential to improve PN risk assessment., (Copyright © 2022 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

The present study is part of a larger project aiming to more closely integrate theory with empirical research into dynamic risk. It seeks to generate empirical findings with the dynamic risk factors contained in the Violence Risk Scale-Sexual Offense version (VRS-SO) that might constrain and guide the further development of Thornton's theoretical model of dynamic risk. Two key issues for theory development are (a) whether the structure of pretreatment dynamic risk factors is the same as the structure of the change in the dynamic risk factors that occurs during treatment, and (b) whether theoretical analysis should focus on individual dynamic items or on the broader factors that run through them. Factor analyses and item-level prediction analyses were conducted on VRS-SO pretreatment, posttreatment, and change ratings obtained from a large combined sample of men ( N s = 1,289-1,431) convicted and treated for sexual offenses. Results indicated that the latent structure of pretreatment dynamic risk was best described by a three-factor model while the latent structure of change items was two dimensional. Prediction analyses examined the degree to which items were predictive beyond prediction obtained from the broader factor that they loaded on. Results showed that for some items, their prediction appeared to be largely carried by the three broad factors. In contrast, other items seem to operate as funnels through which the broader factors' predictiveness flowed. Implications for theory development implied by these results are identified.

Background: The increase in lung cancer screening is intensifying the need for a noninvasive test to characterize the many indeterminate pulmonary nodules (IPN) discovered. Correctly identifying non-cancerous nodules is needed to reduce overdiagnosis and overtreatment. Alternatively, early identification of malignant nodules may represent a potentially curable form of lung cancer., Objective: To develop and validate a plasma-based multiplexed protein assay for classifying IPN by discriminating between those with a lung cancer diagnosis established pathologically and those found to be clinically and radiographically stable for at least one year., Methods: Using a novel technology, we developed assays for plasma proteins associated with lung cancer into a panel for characterizing the risk that an IPN found on chest imaging is malignant. The assay panel was evaluated with a cohort of 277 samples, all from current smokers with an IPN 4-30 mm. Subjects were divided into training and test sets to identify a Support Vector Machine (SVM) model for risk classification containing those proteins and clinical factors that added discriminatory information to the Veteran's Affairs (VA) Clinical Factors Model. The algorithm was then evaluated in an independent validation cohort., Results: Among the 97 validation study subjects, 68 were grouped as having intermediate risk by the VA model of which the SVM model correctly identified 44 (65%) of these intermediate-risk samples as low (n=16) or high risk (n=28). The SVM model negative predictive value (NPV) was 94% and its sensitivity was 94%., Conclusion: The performance of the novel plasma protein biomarker assay supports its use as a noninvasive risk assessment aid for characterizing IPN. The high NPV of the SVM model suggests its application as a rule-out test to increase the confidence of providers to avoid aggressive interventions for their patients for whom the VA model result is an inconclusive, intermediate risk.

Background: In the National Lung Screening Trial, 96.4% of nodules had benign etiology. To avoid unnecessary actions and exposure to harm, individuals with benign disease must be identified. We describe herein the analytical validation of a multi-analyte immunoassay for characterizing the risk that a lung nodule found on CT is malignant. Those at lower risk may be considered for serial surveillance to avoid unnecessary and potentially harmful procedures. While those nodules characterized at higher risk may be appropriate for more aggressive actions., Objective: To validate the analytical performance of multiplexed plasma protein assays used in a novel test for lung nodule characterization., Methods: A multiplexed immunoassay panel for the measurement of plasma proteins in current smokers who present with a lung nodule on CT scan was evaluated in a clinical testing laboratory. Assay analytical sensitivity, reproducibility, precision, and recovery of Epidermal Growth Factor Receptor (EGFR), Prosurfactant protein B (ProSB), and Tissue Inhibitor of Metalloproteinases 1 (TIMP1) from human EDTA plasma samples were evaluated across multiple runs, lots, and technicians. Interfering substances and sample pre-analytical storage conditions were evaluated for their effect on analyte recovery. The lung nodule risk score reproducibility was assessed across multiple lots., Results: The assay sensitivities were 0.10 ng/mL EGFR, 0.02 ng/mL ProSB, and 0.29 ng/mL TIMP1 with over three orders of magnitude in the assay dynamic ranges. The assays and analytes are robust to pre-analytical sample handling and the plasma can be stored for up to 4 days at 4°C either when freshy collected or thawed after long-term storage at -80°C. Total imprecision after 20 days of testing remained under 9% for all three assays. Risk score variability remained within a ± 10% risk score range., Conclusions: The three protein assays comprising the multi-analyte plasma test for lung nodule characterization performed quite acceptably in a clinical laboratory.

The anterior cruciate ligament (ACL) is the most commonly reconstructed ligament of the knee. Most often, the goal of surgical reconstruction is to recreate stability within the knee and prevent joint degeneration. To date, clinical studies have not demonstrated the ability of various reconstruction techniques in establishing complete knee stability when comparing rates of osteoarthritis. Rates of osteoarthritis commonly resemble those of knees which have not be reconstructed and in this light, may not demonstrate a successful outcome. As modern medicine continues to develop and in the understanding of underlying biological processes grows, some surgeons have turned their attention back to an ACL repair technique. The purpose of this clinical commentary is to discuss the parameters associated with a phase progression for an isolated ACL repair. Physiological healing time frames, along with objective clinical assessment, following a criterion-based progression is described in accordance with post-operative healing parameters to serve as a reference for a rehabilitation specialist., Level of Evidence: 5.

Ballistic imaging systems can help solve crimes by comparing images of cartridge cases, which are recovered from a crime scene or test-fired from a gun, to a database of images obtained from past crime scenes. Many U.S. municipalities lack the resources to process all of their cartridge cases. Using data from Stockton, CA, we analyze two problems: how to allocate limited capacity to maximize the number of cartridge cases that generate at least one hit, and how to prioritize the cartridge cases that are processed to maximize the usefulness (i.e., obtained before the corresponding criminal case is closed) of hits. The number of hits can be significantly increased by prioritizing crime scene evidence over test-fires, and by ranking calibers by their hit probability and processing only the higher ranking calibers. We also estimate that last-come first-served increases the proportion of hits that are useful by only 0.05 relative to first-come first-served., (© 2017 American Academy of Forensic Sciences.)

Background: Hyperlipidemia and insulin resistance are risk factors for the development of metabolic syndrome and cardiovascular disease. We have previously observed that supplementation with essential amino acids (EAA) could lower plasma triglycerides, and may improve glucose metabolism., Objective: We sought to determine whether EAA's combined with whey protein and phytosterols would facilitate improvements in plasma lipids and insulin sensitivity in adults with mild hypertriglyceridemia., Design: We enrolled nine subjects who were 50 years or older, had a documented plasma TG >150 mg/dl, and had not recently taken statin medications (within 6 weeks). Each subject served as his or her own control. These individuals underwent an oral glucose tolerance test (OGTT) before and after four weeks consumption of the oral nutritional supplement without dietary counseling or recommendations for physical activity., Results: Plasma total cholesterol and LDL levels decreased in all nine volunteers ( P <0.005 for cholesterol and P <0.02 for LDL). In six of these individuals, plasma triglycerides (TG) fell by 95±13 mg/dl ( P =0.007); while the other three showed no TG reduction. Genotyping revealed that in two of the three individuals that did not have TG reduction in response to the nutritional supplementation. Insulin sensitivity (ISI) and the total AUC ins/glucose were significantly reduced by leucine/EAAs and phytosterol supplementation ( P =0.008)., Conclusions: These findings suggest that a dietary supplementation of EAAs and phytosterols may promote favorable reductions of blood lipids as well as insulin resistance in individuals with hypertriglyceridemia. Future larger studies of SNPs and TG response to dietary supplements will be of interest.

We examined the use of risk-change information in sexual offender risk assessments featuring the Violence Risk Scale-Sexual Offender version (VRS-SO), a sex offender risk assessment and treatment planning tool. The study featured a combined international sample of 539 sex offenders followed up an average of 15.5 years post-release. Pre- and posttreatment VRS-SO ratings were amalgamated from two treated samples of sex offenders from Canada and New Zealand. Analyses focused on examinations and applications of change data and its relationship to sexual and violent recidivism. VRS-SO change scores were significantly associated with decreases in these outcome criteria with, and without, controlling for indicators of pretreatment risk (e.g., Static-99R score) and individual differences in follow-up time. Applications of logistic regression using fixed 5-year follow-ups generated estimated rates of sexual and violent recidivism at different VRS-SO score thresholds. The use of logistic regression demonstrated a clinically useful and systematic means of combining risk and change information into posttreatment risk appraisals. Implications for the use of change information in the assessment and management of sexual offender risk are discussed., (© The Author(s) 2013.)

Objectives: The goal of this study is to determine the cost-effectiveness of MIRISK VP, a next generation coronary heart disease risk assessment score, in correctly reclassifying and appropriately treating asymptomatic, intermediate risk patients., Study Design: A Markov model was employed with simulated subjects based on the Multi-Ethnic Study of Atherosclerosis (MESA). This study evaluated three treatment strategies: (i) practice at MESA enrollment, (ii) current guidelines, and (iii) MIRISK VP in MESA., Methods: The model assessed patient healthcare costs and outcomes, expressed in terms of life years and quality-adjusted life years (QALYs), over the lifetime of the cohort from the provider and payer perspective. A total of 50,000 hypothetical individuals were used in the model. A sensitivity analysis was conducted (based on the various input parameters) for the entire cohort and also for individuals aged 65 and older., Results: Guiding treatment with MIRISK VP leads to the highest net monetary benefits when compared to the 'Practice at MESA Enrollment' or to the 'Current Guidelines' strategies. MIRISK VP resulted in a lower mortality rate from any CHD event and a modest increase in QALY of 0.12-0.17 years compared to the other two approaches., Limitations: This study has limitations of not comparing performance against strategies other than the FRS, the results are simulated as with all models, the model does not incorporate indirect healthcare costs, and the impact of patient or physician behaviors on outcomes were not taken into account., Conclusions: MIRISK VP has the potential to improve patient outcomes compared to the alternative strategies. It is marginally more costly than both the 'Practice at MESA Enrollment' and the 'Current Guidelines' strategies, but it provides increased effectiveness, which leads to positive net monetary benefits over either strategy.

Background: Current coronary heart disease (CHD) risk assessments inadequately assess intermediate-risk patients, leaving many undertreated and vulnerable to heart attacks. A novel CHD risk-assessment (CHDRA) tool was developed for intermediate-risk stratification using biomarkers and established risk factors to significantly improve CHD risk discrimination., Hypothesis: Physicians will change their treatment plan in response to more information about a patient's CHD risk level provided by the CHDRA test., Methods: A Web-based survey of cardiology, internal medicine, family practice, and obstetrics/gynecology physicians (n = 206) was conducted to assess the CHDRA clinical impact. Each physician was shown 3 clinical vignettes representing community-based cohort participants randomly selected from 8 total vignettes. For each, the physicians assessed the individual's CHD risk and selected preferred therapies based on the individual's comorbidities, physical examination, and laboratory results. The individual's CHDRA score was then provided and the physicians were queried for changes to their initial treatment plans., Results: After obtaining the CHDRA result, 70% of the physician responses indicated a change to the patient's treatment plan. The revised lipid-management plans agreed more often (74.6% of the time) with the current Adult Treatment Panel III guidelines than did the original plans (57.6% of the time). Most physicians (71.3%) agreed with the statement that the CHDRA result provided information that would impact their current treatment decisions., Conclusions: The CHDRA test provided additional information to which physicians responded by more often applying appropriate therapy and actions aligned with guidelines, thus demonstrating the clinical utility of the test., (© 2013 The Authors. Clinical Cardiology published by Wiley Periodicals, Inc.)

Broadly conserved, mitogen-activated/stress-activated protein kinases (MAPK/SAPK) of the p38 family regulate multiple cellular processes. They transduce signals via dimeric, basic leucine zipper (bZIP) transcription factors of the ATF/CREB family (such as Atf2, Fos, and Jun) to regulate the transcription of target genes. We report additional mechanisms for gene regulation by such pathways exerted through RNA stability controls. The Spc1 (Sty1/Phh1) kinase-regulated Atf1-Pcr1 (Mts1-Mts2) heterodimer of the fission yeast Schizosaccharomyces pombe controls the stress-induced, posttranscriptional stability and decay of sets of target RNAs. Whole transcriptome RNA sequencing data revealed that decay is associated nonrandomly with transcripts that contain an M26 sequence motif. Moreover, the ablation of an M26 sequence motif in a target mRNA is sufficient to block its stress-induced loss. Conversely, engineered M26 motifs can render a stable mRNA into one that is targeted for decay. This stress-activated RNA decay (SARD) provides a mechanism for reducing the expression of target genes without shutting off transcription itself. Thus, a single p38-ATF/CREB signal transduction pathway can coordinately induce (promote transcription and RNA stability) and repress (promote RNA decay) transcript levels for distinct sets of genes, as is required for developmental decisions in response to stress and other stimuli.

Background: Coronary heart disease (CHD) remains prevalent despite efforts to improve CHD risk assessment. The authors developed a multi-analyte immunoassay-based CHD risk assessment (CHDRA) algorithm, clinically validated in a multicenter study, to improve CHDRA in intermediate risk individuals., Objective: Clinical laboratory validation of the CHDRA biomarker assays' analytical performance., Methods: Multiplexed immunoassay panels developed for the seven CHDRA assays were evaluated with donor sera in a clinical laboratory. Specificity, sensitivity, interfering substances and reproducibility of the CHDRA assays, along with the effects of pre-analytical specimen processing, were evaluated., Results: Analytical measurements of the CHDRA panel proteins (CTACK, Eotaxin, Fas Ligand, HGF, IL-16, MCP-3 and sFas) exhibited acceptable accuracy (80 - 120%), cross-reactivity (< 1%), interference (< 30% at high concentrations of bilirubin, lipids, hemoglobin and HAMA), sensitivity and reproducibility (< 20% CV across multiple runs, operators and instruments). Recoveries from donor sera subjected to typical clinical laboratory pre-analytical conditions were within 80 - 120%. The pre-analytical variables did not substantively impact the CHDRA scores., Conclusions: The CHDRA panel analytical validation in a clinical laboratory meets or exceeds the specifications established during the clinical utility studies. Risk score reproducibility across multiple test scenarios suggests the assays are not susceptible to clinical laboratory pre-analytical and analytical variation.

Aviir, Inc. is a venture-funded biotechnology company developing and commercializing laboratory tests to provide personalized information to physicians and patients, with the goal of preventing cardiovascular disease and metabolic syndromes. Leveraging advanced research, Aviir developed and launched MIRISK VP™, a risk assessment test to better identify individuals at risk of a heart attack. Aviir also offers an extensive menu of other cardiovascular and metabolic tests through its Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory. Efforts are likewise focused on expanding genomics testing capability to address sudden cardiac death attributed to inherited cardiovascular diseases. This completes their integrated precision diagnostics approach that combines biomarker immunoassays with genomic and transcription analysis, along with core clinical chemistry to deliver a comprehensive personal health solution.

Background: Many coronary heart disease (CHD) events occur in individuals classified as intermediate risk by commonly used assessment tools. Over half the individuals presenting with a severe cardiac event, such as myocardial infarction (MI), have at most one risk factor as included in the widely used Framingham risk assessment. Individuals classified as intermediate risk, who are actually at high risk, may not receive guideline recommended treatments. A clinically useful method for accurately predicting 5-year CHD risk among intermediate risk patients remains an unmet medical need., Objective: This study sought to develop a CHD Risk Assessment (CHDRA) model that improves 5-year risk stratification among intermediate risk individuals., Methods: Assay panels for biomarkers associated with atherosclerosis biology (inflammation, angiogenesis, apoptosis, chemotaxis, etc.) were optimized for measuring baseline serum samples from 1084 initially CHD-free Marshfield Clinic Personalized Medicine Research Project (PMRP) individuals. A multivariable Cox regression model was fit using the most powerful risk predictors within the clinical and protein variables identified by repeated cross-validation. The resulting CHDRA algorithm was validated in a Multiple-Ethnic Study of Atherosclerosis (MESA) case-cohort sample., Results: A CHDRA algorithm of age, sex, diabetes, and family history of MI, combined with serum levels of seven biomarkers (CTACK, Eotaxin, Fas Ligand, HGF, IL-16, MCP-3, and sFas) yielded a clinical net reclassification index of 42.7% (p < 0.001) for MESA patients with a recalibrated Framingham 5-year intermediate risk level. Across all patients, the model predicted acute coronary events (hazard ratio = 2.17, p < 0.001), and remained an independent predictor after Framingham risk factor adjustments., Limitations: These include the slightly different event definition with the MESA samples and inability to include PMRP fatal CHD events., Conclusions: A novel risk score of serum protein levels plus clinical risk factors, developed and validated in independent cohorts, demonstrated clinical utility for assessing the true risk of CHD events in intermediate risk patients. Improved accuracy in cardiovascular risk classification could lead to improved preventive care and fewer deaths.

Background: In estrogen responsive MCF-7 cells, estradiol (E₂) binding to ERα leads to transcriptional regulation of genes involved in the control of cell proliferation and survival. MicroRNAs (miRNAs) have emerged as key post-transcriptional regulators of gene expression. The aim of this study was to explore whether miRNAs were involved in hormonally regulated expression of estrogen responsive genes., Methods: Western blot and QPCR were used to determine the expression of estrogen responsive genes and miRNAs respectively. Target gene expression regulated by miRNAs was validated by luciferase reporter assays and transfection of miRNA mimics or inhibitors. Cell proliferation was evaluated by MTS assay., Results: E₂ significantly induced bcl-2, cyclin D1 and survivin expression by suppressing the levels of a panel of miRNAs (miR-16, miR-143, miR-203) in MCF-7 cells. MiRNA transfection and luciferase assay confirmed that bcl-2 was regulated by miR-16 and miR-143, cyclinD1 was modulated by miR-16. Importantly, survivin was found to be targeted by miR-16, miR-143, miR-203. The regulatory effect of E₂ can be either abrogated by anti-estrogen ICI 182, 780 and raloxifene pretreatment, or impaired by ERα siRNA, indicating the regulation is dependent on ERα. In order to investigate the functional significance of these miRNAs in estrogen responsive cells, miRNAs mimics were transfected into MCF-7 cells. It revealed that overexpression of these miRNAs significantly inhibited E₂-induced cell proliferation. Further study of the expression of the miRNAs indicated that miR-16, miR-143 and miR-203 were highly expressed in triple positive breast cancer tissues, suggesting a potential tumor suppressing effect of these miRNAs in ER positive breast cancer., Conclusions: These results demonstrate that E₂ induces bcl-2, cyclin D1 and survivin by orchestrating the coordinate downregulation of a panel of miRNAs. In turn, the miRNAs manifest growth suppressive effects and control cell proliferation in response to E₂. This sheds a new insight into the integral post-transcriptional regulation of cell proliferation and survival genes by miRNAs, a potential therapeutic option for breast cancer.

PTEN is one of the most frequently mutated tumor suppressor genes in human cancers. Mutations occur in either heritable or sporadic fashion. Sequencing of cDNA from patients and normal individuals often reveals splicing variants (SVs) of PTEN, some of which are non-mutation related. To investigate whether these SVs were the result of illegitimate splicing (a general decrease of fidelity in splicing site selection in "aged" samples), we tested "aged" blood from individuals who had normal PTEN transcripts in their "fresh" mononuclear cells. Blood from 20 normal individuals was collected and split into two aliquots. Total RNA and DNA were extracted immediately ("fresh") and 48 h later ("aged"), respectively. Using RT-PCR, subcloning and sequencing, we found seven types of SVs. No mutation was detected in the related intron-exon flanking region in genomic DNA in either "fresh" or "aged" samples. Some of the SVs were also consistently present in both the "fresh" and "aged" EBV-transformed lymphoblastoid cells from six normal individuals. Western blot data indicated that the PTEN protein level (in full length) was not altered in the "fresh" EBV-transformed lymphoblastoid cells with SVs. In conclusion, our data demonstrate that PTEN illegitimate splicing often occurs in "aged" blood and EBV-transformed lymphoblastoid cells. Therefore, it is critical to note the time point of RNA extraction when investigating for PTEN aberrant transcripts. We hope that our data will increase awareness about the sample status, because gene expression data may be potentially flawed from "aged" samples, particularly when dealing with clinical samples.

Sulfotransferase isoform 1A1 (SULT1A1) is the most highly expressed hepatic sulfotransferase and is involved in the biotransformation of a wide variety of endo- and xenobiotics. A common single nucleotide polymorphism (SNP) in the coding region of SULT1A1, several proximal promoter SNPs, and copy number variation (CNV) are associated with altered enzymatic activity, but these variants do not fully account for the observed variation of SULT1A1 activity in human populations. In order to identify additional SNPs modulating SULT1A1 activity, we examined the 3'-untranslated region (UTR) of SULT1A1 in 97 liver samples. Direct sequencing revealed that two SNPs in the 3'-UTR (902A > G [rs6839] and 973C > T [rs1042157]) and one SNP in the 3'-flanking region (1307G > A [rs4788068]) were common. These SNPs are in absolute linkage disequilibrium with each other and in tight linkage with SULT1A1 1/2 (linkage coefficient D' 0.83) and are significantly associated with SULT1A1 messenger RNA (p = 0.001, 0.029, 0.021) and enzymatic activity (p = 0.022, 0.012, 0.027). We then examined the collective effects of 3'-UTR SNPs, SULT1A1 1/2, and CNV on SULT1A1 activity in 498 Caucasian and 127 African-American subjects by haplotype analysis. This analysis revealed that SULT1A1 1/2 does not contribute to the variation in SULT1A1 enzymatic activity when the 3'-UTR SNPs are included in the statistical model. Two major haplotypes (ACG and GTA) were significantly correlated with SULT1A1 activity, and when stratified by copy number, the SULT1A1 3'-UTR SNPs remain significantly associated with SULT1A1 enzymatic activity in Caucasians, but not in African-Americans. Subsequent functional characterization revealed that a microRNA, miR-631, regulates SULT1A1 expression in a genotype-specific manner.

Increasing the output from discovery is currently a major objective for the pharmaceutical industry aimed at reversing recent downward trends in productivity. Although significant attention has been focused on innovative assay and process technologies, these only address specific points in the discovery process. Little effort has been made to manage the multiple interconnected steps within discovery effectively. This manifests itself in low utilization rates of component elements and low expectations of delivery to any agreed timescale.

HTS is a key component of pharmaceutical lead identification process. Over recent years, the pharmaceutical industry has experienced significant increases in the throughput capabilities of its HTS functions. In those companies where HTS has been effectively deployed, it is now possible to screen the entire corporate compound collection against a pharmacological target within a timescale of several weeks to a few months. This capability has been realized, not as a result of the purchase of any one particular piece of hardware, but rather through the development of a truly effective HTS infrastructure that matches the needs of the parent organization. Central to this is the need to understand how to effectively combine the use of the different types of hardware available to the HTS specialist. The use of both modular workstations and single-arm robotic systems have underpinned most HTS groups operations. Recent advances in the field of multiple-arm robotic systems and dedicated automation systems offer even further potential for increasing productivity. This article describes our experience with the use of a dedicated automation system for HTS applications.

High throughput screening is now established as a key component of the pharmaceutical lead identification process in many pharmaceutical companies. Over recent years, thanks to advances in assay technology, process automation, and logistics control, the throughput capacity of HTS groups has increased significantly. It is now entirely possible to screen corporate compound collections against an individual pharmacological target within a timescale of several weeks. Despite these improvements, many HTS groups find that their capacity is limited by the rate at which they can provide test compounds in a "screen-ready" format. This limitation is usually imposed by the capacity and productivity of the single-armed robotic systems utilized. We have recently constructed a robotic system aimed at overcoming this particular problem. This system uses purpose-built microplate stacker units that provide high-capacity microplate storage and, importantly, provide an easy and fast interface between the robotic system and the human operators. This paper describes this automation project and the benefits that have resulted from its deployment.

Setting: Mycobacterium tuberculosis (M. tuberculosis) isolates from various parts of the USA which have few copies of the insertion sequence IS6110., Objectives: To characterize the sites of insertion of IS6110 among M. tuberculosis isolates that have one to six copies of the insertion sequence., Design: The mixed-linker polymerase chain reaction (ML-PCR) procedure was used to amplify the terminal repeats on the ends of IS6110 and adjacent flanking sequences. From the ML-PCR products, sequences flanking 14 copies of IS6110 in strains containing less than seven copies of the insertion were determined. Sequence information from the flanking deoxyribonucleic acid was used to construct flanking primers that can be used to indicate the presence of IS6110 at a particular site when paired with outbound IS6110 primers in a PCR. Over 200 strains of diverse origin were screened for the insertion of IS6110 at several distinct sites using this procedure., Results: The direct repeat (DR) locus has been described as a highly preferred site for insertion of IS6110 in strains of M. tuberculosis. Another highly preferred site of insertion of IS6100, DK1, is herein described. Insertions at DK1 are highly prevalent in M. tuberculosis strains harboring two to six copies of IS6110. The prevalence of insertions at this site decreases in strains with more than six copies of IS6110, even though the sequence itself is present in strains lacking a copy of IS6110 at this site., Conclusion: In addition to the DR locus there are other conserved sites of insertion among M. tuberculosis strains. The data further suggest a separate lineage for the high copy and the low copy strains, and a possible sequential insertion of IS6110 in strains of M. tuberculosis with less than seven copies.

Plasmid pLUC10, carrying the firefly luciferase gene, was transformed by electroporation into Mycobacterium avium A5. Bioluminescence production by strain A5(pLUC10), as measured in a microdilution plate luminometer, was approximately 1 relative light unit per 2 x 10(6) viable bacilli, whereas it was 0.0005 relative light unit for an equal number of parental cells. The susceptibility of strain A5(pLUC10) to eight concentrations of each of eight antimicrobial agents was evaluated by the luciferase microplate assay in parallel with a conventional broth macrodilution method with antimicrobial agents. Decreases in bioluminescence to levels that were < or = 10% of those of drug-free controls were observed in microplate wells containing inhibitory concentrations of drugs in as few as 3 days. The close correlation of these inhibitory concentrations with the MICs determined by a conventional broth macrodilution method suggests that the luciferase microplate method may offer a convenient and reliable means of evaluating the in vitro activities of antimicrobial agents against the M. avium complex.

Interleukin-1 beta (IL-1 beta) has been implicated in the pathogenesis of insulin-dependent diabetes mellitus. In the present study we have investigated the effects of IL-1 beta on glucose metabolism in clonal HIT-T15 beta cells. In the short-term (1 h), 25 U/ml IL-1 beta significantly increased the rates of insulin release and glucose utilisation, but not glucose oxidation. In contrast, after 48 h, IL-1 beta inhibited insulin release and glucose utilisation and oxidation. By assaying enzymes (hexokinase, glucokinase, pyruvate dehydrogenase, glucose 6-phosphatase) and nucleotides (ATP, ADP) associated with the regulation of glycolysis and glucose oxidation, we conclude that the inhibitory effects of IL-1 beta may be due to impaired glucokinase activity.

The effect of the cytokine interleukin-1 beta on the insulin secretory responsiveness of single beta-cells (HIT-T15) was investigated. In the short-term, IL-1 beta induced a dosage-dependent stimulation of insulin release. In contrast, in the long-term, IL-1 beta, inhibited both basal and secretagogue-stimulated insulin secretion. We also demonstrate the simultaneous presence of specific high and low affinity binding sites for IL-1 beta on beta-cells. IL-1 beta, which has been implicated in the pathogenesis of insulin-dependent diabetes, may therefore mediate its opposing effects on beta-cells through a specific plasma membrane receptor.

The activity of branched-chain 2-oxo acid dehydrogenase kinase was 3-fold greater in extracts of heart mitochondria than in extracts of liver mitochondria from rats fed on normal diet. Feeding rats on a 0%-casein diet for 10 days increased the activity of branched-chain kinase 4-fold in extracts of liver mitochondria and in branched-chain dehydrogenase complex purified from such extracts; starvation (48 h) was without effect. In extract of heart mitochondria, kinase activity was increased 2-fold by feeding on 0%-casein diet and 1.5-fold by 48 h of starvation.

Four mitochondrial marker enzymes were used to show that: (1) high-protein (24%) diet increased the rat liver concentration and content of total branched-chain 2-oxo acid dehydrogenase complex (BCDC) by 31% by increasing mitochondrial specific activity of BCDC; (2) starvation increased the liver concentration of BCDC by 25% by decreasing liver weight; the liver content of mitochondria and the mitochondrial specific activity of BCDC were unchanged; (3) protein-free diet decreased rat liver BCDC concentration and content by 20%, by decreasing the liver concentration and content of mitochondria. Protein-free diet increased liver mitochondrial specific activities of L-glutamate, 2-oxoglutarate and NAD-isocitrate dehydrogenases. The validity of a mitochondrial method for the determination of the liver concentration of BCDC and the percentage in the active form in vivo is confirmed, and improvements are described. The experimental basis of criticisms of its use in this regard by Zhang, Paxton, Goodwin, Shimomura & Harris [(1987) Biochem. J. 246, 625-631] was not confirmed. The finding by Harris, Powell, Paxton, Gillim & Nagae [(1985) Arch. Biochem. Biophys. 243, 542-555], that starvation has no effect on the percentage of BCDC in the active form in rat liver, is confirmed.

The effect of protein-free diet to decrease liver activity of branched-chain (-2-oxoacid) dehydrogenase (BCD) complex (active form) and increase BCD kinase activity was unaffected by preparation of hepatocytes, but partially reversed by 25 h of culture of hepatocytes in medium 199. Activation of BCD complex preceded loss of BCD kinase. The effect of culture on BCD complex was completely prevented by omission of branched-chain amino acids and partially prevented by 1 mM-alpha-cyano-4-hydroxycinnamate or 0.2 mM-pyruvate/2 mM-lactate. Protein-free diet decreased plasma branched-chain amino and oxo ('keto') acids and increased plasma pyruvate and lactate. It is concluded: (1) that branched-chain amino acids are involved directly in regulation of activities of BCD complex and BCD kinase; (2) that mitochondrial uptake of branched-chain oxo acids is necessary for regulation of BCD complex activity; and (3) that the stable increase in BCD kinase may function as a hysteresis mechanism.

The effect of chlordane on the susceptibility of Madin-Darby canine kidney cells and African Green monkey kidney cells to infection with influenza type A/PR/8/34 (HON1) virus and herpes simplex type 1 virus was determined. Exposure of both cell lines to various concentrations of chlordane for 24 h at 37 degrees C (acute exposure) effected a marked reduction in the efficiency of influenza type A virus infection, except at a dose of 0.025 ppm. Acute exposure of the monkey cells did not alter their susceptibility to herpes simplex virus infection. Viral adsorption studies at 4 and 37 degrees C revealed a marked reduction in the attachment of influenza type A virus to both cell lines following acute exposure to 10 ppm chlordane. Viral inactivation studies carried out at 4 and 37 degrees C failed to reveal differences in the level of influenza type A virus inactivation in the presence or absence of chlordane. Madin-Darby canine kidney cells exposed to 10 ppm chlordane for 60 d (chronic exposure) manifested a decrease in the efficiency of influenza type A virus infection, whereas cells chronically exposed to 0.025 ppm chlordane manifested an increase in the efficiency of influenza type A virus infection relative to mock-treated control cells. When chronically exposed cells were passaged six times in the absence of chlordane, these effects were reversed. Viral adsorption studies carried out at 4 and 37 degrees C on cells chronically exposed to 10 ppm chlordane revealed a decrease in the adsorption of influenza type A virus. Quantitation of the levels of cell-surface sialic acid, the essential terminal sugar on the receptor for influenza type A virus, indicated that the reduced adsorption of influenza type A virus to Madin-Darby canine kidney cells was not due to a loss of cell-surface sialic acid. Our findings indicate that chlordane alters the susceptibility of cells to infection with influenza type A virus but not to herpes simplex type 1 virus.

Feeding rats 0% casein diet decreased liver activities of branched-chain ketoacid dehydrogenase complex (active form) and of activator protein (complete within 4 days), and increased activity of branched-chain ketoacid dehydrogenase kinase (complete within 9-10 days). Refeeding normal diet to rats fed 0% casein diet for 10 days resulted in a rapid and partial (approx. 50%) reversal of the above effects within 24 h; complete reversal required 20-30 days of refeeding.