The influence of self-focused attention on emotional picture processing: An ERP study.

Research has documented neurophysiological indicators of anticipation (Stimulus Preceding Negativity [SPN]) and perception (Late Positive Potential [LPP]) of threat, yet little is known as to how self-focused attention manipulations influence emotion processing within the context of cued picture viewing. With self-referent attention moderating attention to external stimuli, it is necessary to document how self-focused attention impacts attention and the ability to emotionally process external threat. The goal of the present study was to evaluate the impact of self-focused attention on the anticipation and perceptual processing of unpleasant pictures within a cued-picture viewing paradigm among 33 participants. Overall, the results suggest that the self-focused attention manipulations disrupted anticipation but not processing of pictures, as indexed by the SPN and LPP respectively. Self-focused attention appears to disrupt the preparatory attention for upcoming unpleasant stimuli, potentially through loading cognitive resources or activation of associative defensive responding. Collectively, these findings demonstrate the impact of self-focused attention within the context of emotional picture processing and suggest further areas of investigation.

A qualitative analysis of pain meaning: results from the Oklahoma Study of Native American Pain Risk (OK-SNAP).

The most widely accepted definition of pain considers it a sensory and emotional experience associated with potential or actual physical harm. However, research tends to generalize findings from predominantly European American samples thereby assuming universality across cultures. Because of the high prevalence of pain within the AI group, it is important to consider whether their conceptualization of pain is similar to the universal definition. To accomplish this aim, a semi-structured interview was conducted with 152 AIs (primarily Southern Plains and eastern Oklahoma tribes) and 150 NHWs. Both groups were asked questions including what words describe hurtful experiences, the purpose of painful experiences, individual and culture-specific meanings of pain, and what constituted the opposite of pain. Many similarities were found between groups as well as differences. For example, NHWs used the word pain more often to describe physically hurtful experiences and were more likely to consider pain to be a signal or warning of an abnormality or pathology. By contrast, only AIs reported culture-specific meanings of pain, such as references to AI rituals or ceremonies. These observed differences are attenuated by small effect sizes. These findings are important to consider when hypothesizing the differences in pain among cultural groups.

Optimizing Temporal Summation of Heat Pain Using a Constant Contact Heat Stimulator.

Purpose: Temporal summation (TS) of pain occurs when pain increases over repeated presentations of identical noxious stimuli. TS paradigms can model central sensitization, a state of hyperexcitability in nociceptive pathways that promotes chronic pain onset and maintenance. Many experimenters use painful heat stimuli to measure TS (TS-heat); yet, TS-heat research faces unresolved challenges, including difficulty evoking summation in up to 30-50% of participants. Moreover, substantial variability exists between laboratories regarding the methods for evoking and calculating TS-heat. Patients and Methods: To address these limitations, this study sought to identify optimal parameters for evoking TS-heat in healthy participants with a commercially available constant contact heat stimulator, the Medoc TSA-II. Working within constraints of the TSA-II, stimulus trains with varying parameters (eg, stimulus frequency, baseline temp, peak temp, peak duration, testing site) were tested in a sample of 32 healthy, chronic pain-free participants to determine which combination best evoked TS-heat. To determine whether TS scoring method altered results, TS-heat was scored using three common methods. Results: Across all methods, only two trains successfully evoked group-level TS-heat. These trains shared the following parameters: site (palmar hand), baseline and peak temperatures (44°C and 50°C, respectively), and peak duration (0.5 s). Both produced summation that peaked at moderate pain (~50 out of 100 rating). Conclusion: Future TS-heat investigations using constant contact thermodes and fixed protocols may benefit from adopting stimulus parameters that include testing on the palmar hand, using 44°C baseline and 50°C peak temperatures, at ≥0.33 Hz stimulus frequency, and peak pulse durations of at least 0.5 seconds.

Towards an automated data cleaning with deep learning in CRESST.

The CRESST experiment employs cryogenic calorimeters for the sensitive measurement of nuclear recoils induced by dark matter particles. The recorded signals need to undergo a careful cleaning process to avoid wrongly reconstructed recoil energies caused by pile-up and read-out artefacts. We frame this process as a time series classification task and propose to automate it with neural networks. With a data set of over one million labeled records from 68 detectors, recorded between 2013 and 2019 by CRESST, we test the capability of four commonly used neural network architectures to learn the data cleaning task. Our best performing model achieves a balanced accuracy of 0.932 on our test set. We show on an exemplary detector that about half of the wrongly predicted events are in fact wrongly labeled events, and a large share of the remaining ones have a context-dependent ground truth. We furthermore evaluate the recall and selectivity of our classifiers with simulated data. The results confirm that the trained classifiers are well suited for the data cleaning task.

Secular equilibrium assessment in a CaWO4 target crystal from the dark matter experiment CRESST using Bayesian likelihood normalisation.

CRESST is a leading direct detection sub-GeVc-2 dark matter experiment. During its second phase, cryogenic bolometers were used to detect nuclear recoils off the CaWO4 target crystal nuclei. The previously established electromagnetic background model relies on Secular Equilibrium (SE) assumptions. In this work, a validation of SE is attempted by comparing two likelihood-based normalisation results using a recently developed spectral template normalisation method based on Bayesian likelihood. Albeit we find deviations from SE in some cases we conclude that these deviations are artefacts of the fit and that the assumptions of SE is physically meaningful.

[Novel uses of afterbirth tissues in regenerative medicine]. / Neue Verwendungsmöglichkeiten von Nachgeburtsgewebe für die Regenerative Medizin.

INTRODUCTION: Afterbirth tissues, which include the umbilical cord, placenta, amnion, and cord blood, are usually discarded. Recent progress in regenerative medicine suggests that we re-evaluate these tissues and assess their therapeutic potential. METHODS: Firstly the unique properties of afterbirth tissues and their current use in regenerative medicine are summarised. Then we introduce the cooperation of our institutions and our experiences regarding the collection and utilisation of afterbirth tissues. RESULTS: A literature survey suggests that besides the well-known transplantation of hematopoietic stem cells from cord blood, afterbirth tissues were also used as a source of stem cells, progenitor cells, differentiated cells, and blood vessels for tissue engineering purposes. According to our own experience, the two participating OB/GYN departments and the blood donation service were able to organise a sufficient supply of umbilical cords for research purposes. The yield correlated with incentives for the midwives. A total of more than 4,300 cords was collected for experiments designed to create small caliber vessel grafts. The contamination rate was low. Birth mode significantly affected umbilical vein function, whereas ischaemia for up to 40 h did not have any deleterious effects. Umbilical veins were cryopreserved with a moderate loss of function. Fresh umbilical veins were endothelium-denuded and reseeded with endothelial cells harvested from coronary artery disease patients to generate an autologous surface. CONCLUSIONS: Afterbirth tissues have unique properties which make them ideally suited for regenerative medicine. These tissues can be procured and utilised in research facilities even in the absence of an in-house birthing centre.

The Association Between Adverse Life Events, Psychological Stress, and Pain-Promoting Affect and Cognitions in Native Americans: Results from the Oklahoma Study of Native American Pain Risk.

Native Americans (NAs) experience higher rates of chronic pain. To examine the mechanisms for this pain inequity, we have previously shown that NAs report higher levels of pain-related anxiety and pain catastrophizing, which are in turn related to pronociceptive (pain-promoting) processes. But, it is currently unclear why NAs would report greater pain-related anxiety and catastrophizing. Given that NAs are also more likely to experience adverse life events (ALEs) and associated psychological distress, it was hypothesized that higher anxiety/catastrophizing in NAs would be partially explained by higher rates of ALEs and psychological distress. Structural equation modeling was used to analyze these pathways (NA ethnicity ➔ ALEs ➔ psychological distress ➔ pain anxiety/catastrophizing) in 305 healthy, pain-free adults (N = 155 NAs, N = 150 non-Hispanic Whites [NHWs]). Pain-related anxiety and situational pain catastrophizing were assessed in response to a variety of painful tasks. The Life Events Checklist was used to assess cumulative exposure to ALEs that directly happened to each participant. A latent psychological distress variable was modeled from self-reported perceived stress and psychological symptoms. Results found that NAs experienced more ALEs and greater psychological distress which was associated with higher rates of pain-related anxiety and pain catastrophizing. Notably, NAs did not report greater psychological distress when controlling for ALE exposure. This suggests that a higher risk of chronic pain in NAs may be due, in part, to psychological distress, pain-related anxiety, and pain catastrophizing that are promoted by exposure to ALEs. These results highlight several targets for intervention to decrease NA pain risk.

The Relationship Between Adverse Life Events and Endogenous Inhibition of Pain and Spinal Nociception: Findings From the Oklahoma Study of Native American Pain Risk (OK-SNAP).

Adverse life events (ALEs) are a risk factor for chronic pain; however, mechanisms underlying this association are not understood. This study examined whether cumulative ALE exposure impairs endogenous inhibition of pain (assessed from pain report) and spinal nociception (assessed from nociceptive flexion reflex; NFR) in healthy, pain-free Native Americans (n = 124) and non-Hispanic Whites (n = 129) during a conditioned pain modulation (CPM) task. Cumulative ALE exposure was assessed prior to testing by summing the number of potentially traumatic events experienced by each participant across their lifespan. Multilevel modeling found that ALEs were associated with NFR modulation during the CPM task even after controlling for general health, body mass index, sex, age, blood pressure, sleep quality, stimulation intensity, stimulus number, perceived stress, and psychological distress. Low exposure to ALEs was associated with NFR inhibition, whereas high exposure to ALEs was associated with NFR facilitation. By contrast, pain perception was inhibited during the CPM task regardless of the level of ALE exposure. Race/ethnicity did not moderate these results. Thus, ALEs may be pronociceptive for both Native Americans and non-Hispanic Whites by impairing descending inhibition of spinal nociception. This could contribute to a chronic pain risk phenotype involving latent spinal sensitization. PERSPECTIVE: This study found that adverse life events were associated with impaired descending inhibition of spinal nociception in a sample of Native Americans and non-Hispanic Whites. These findings expand on previous research linking adversity to chronic pain risk by identifying a proximate physiological mechanism for this association.

Pain-related anxiety promotes pronociceptive processes in Native Americans: bootstrapped mediation analyses from the Oklahoma Study of Native American Pain Risk.

INTRODUCTION: Evidence suggests Native Americans (NAs) experience higher rates of chronic pain than the general US population, but the mechanisms contributing to this disparity are poorly understood. Recently, we conducted a study of healthy, pain-free NAs (n = 155), and non-Hispanic whites (NHWs, n = 150) to address this issue and found little evidence that NAs and NHWs differ in pain processing (assessed from multiple quantitative sensory tests). However, NAs reported higher levels of pain-related anxiety during many of the tasks. OBJECTIVE: The current study is a secondary analysis of those data to examine whether pain-related anxiety could promote pronociceptive processes in NAs to put them at chronic pain risk. METHODS: Bootstrapped indirect effect tests were conducted to examine whether pain-related anxiety mediated the relationships between race (NHW vs NA) and measures of pain tolerance (electric, heat, ischemia, and cold pressor), temporal summation of pain and the nociceptive flexion reflex (NFR), and conditioned pain modulation of pain/NFR. RESULTS: Pain-related anxiety mediated the relationships between NA race and pain tolerance and conditioned pain modulation of NFR. Exploratory analyses failed to show that race moderated relationships between pain-related anxiety and pain outcomes. CONCLUSION: These findings imply that pain-related anxiety is not a unique mechanism of pain risk for NAs, but that the greater tendency to experience pain-related anxiety by NAs impairs their ability to engage descending inhibition of spinal nociception and decreases their pain tolerance (more so than NHWs). Thus, pain-related anxiety may promote pronociceptive processes in NAs to place them at risk for future chronic pain.

Assessing peripheral fibers, pain sensitivity, central sensitization, and descending inhibition in Native Americans: main findings from the Oklahoma Study of Native American Pain Risk.

Native Americans (NAs) have a higher prevalence of chronic pain than other U.S. racial/ethnic groups, but there have been few attempts to understand the mechanisms of this pain disparity. This study used a comprehensive battery of laboratory tasks to assess peripheral fiber function (cool/warm detection thresholds), pain sensitivity (eg, thresholds/tolerances), central sensitization (eg, temporal summation), and pain inhibition (conditioned pain modulation) in healthy, pain-free adults (N = 155 NAs, N = 150 non-Hispanic Whites [NHWs]). Multiple pain stimulus modalities were used (eg, cold, heat, pressure, ischemic, and electric), and subjective (eg, pain ratings and pain tolerance) and physiological (eg, nociceptive flexion reflex) outcomes were measured. There were no group differences on any measure, except that NAs had lower cold-pressor pain thresholds and tolerances, indicating greater pain sensitivity than NHWs. These findings suggest that there are no group differences between healthy NAs and NHWs on peripheral fiber function, central sensitization, or central pain inhibition, but NAs may have greater sensitivity to cold pain. Future studies are needed to examine potential within-group factors that might contribute to NA pain risk.

Filter Buffy Coats (FBC): a source of peripheral blood leukocytes recovered from leukocyte depletion filters.

In compliance with federal regulations, blood banks routinely use leukocyte depletion filters to eliminate contaminating leukocytes from blood products such as red blood cell and platelet concentrates. We developed and optimized conditions to elute leukocytes adsorbed to these filters; resulting in leukocyte suspensions which we termed Filter Buffy Coats (FBCs). These Filter Buffy Coats can replace standard buffy coats for various research applications. After optimizing both the filter elution medium as well as elution protocols, we compared commonly used leukocyte depletion filters from four different manufacturers. Relative fractions as well as total recoveries of leukocyte subsets, such as lymphocytes, monocytes and granulocytes, found in Filter Buffy Coats were identified and compared among the filters as well as to standard buffy coats and whole blood. Flow cytometric analysis of Filter Buffy Coats confirmed the presence of T- and B-lymphocytes, NK cells and monocytes. Furthermore, a significant quantity of CD34(+) hematopoietic stem or progenitor cells (HSC/HPC) was detected in Filter Buffy Coats prepared from different filters, thus making FBCs a valuable source for research on HSC/HPC. Colony assays revealed that most of these CD34(+) cells are functional. Using immunomagnetic cell sorting (MACS), we isolated a variety of leukocyte populations from FBC mononuclear cells (Filter-PBMCs) including T lymphocytes (CD4(+), CD8(+), CD3(+)), B lymphocytes (CD19(+)), NK cells (CD56(+)), HSC/HPC (CD34(+), CD133(+)) or dendritic cells (BDCA-4(+)). Functional properties of Filter-PBMCs, as well as of some of these isolated leukocyte populations, were confirmed using standard assays. In summary, Filter Buffy Coats are a valuable and convenient source of different peripheral leukocyte populations and can replace standard buffy coat preparations for research applications.

Synthesis of peptidyl fluoromethyl ketones and peptidyl alpha-keto esters as inhibitors of porcine pancreatic elastase, human neutrophil elastase, and rat and human neutrophil cathepsin G.

Comparison of MeO-Suc-Val-Pro-Phe-CO2Me (29) and MeO-Suc-Ala-Ala-Pro-Phe- CO2Me (25) with their corresponding trifluoromethyl ketones 9a and 9b, respectively, in rat and human neutrophil cathepsin G assays showed the alpha-keto esters to be more potent inhibitors. Likewise, Ac-Pro-Ala-Pro-Ala-CO2Me (21) was more potent than its corresponding trifluoromethyl ketone (9c) in both porcine pancreatic elastase and human neutrophil elastase assays. Within a set of Ala-Ala-Pro-Val-CF3 elastase inhibitors, the carbobenzyloxy (Cbz) N-protecting group conferred greater potency as a P5 site recognition unit for elastase than did dansyl, methoxysuccinyl, or tert-butyloxycarbonyl. Initial inhibition of elastase was greater when trifluoromethyl ketone 9f was added from a stock solution of dimethyl sulfoxide than when it had been buffer-equilibrated prior to assay, which suggests that the nonhydrated ketone is the more effective form of the inhibitor. The most potent elastase inhibitor we report is Na-(Ad-SO2)-N epsilon-(MeO-Suc)Lys-Pro-Val-CF3 (16) which has a Ki of 0.58 nM.

Inhibition of human neutrophil elastase. 3. An orally active enol acetate prodrug.

Several analogs of N-[4-(4-morpholinylcarbonyl)benzoyl]-L-valyl-N-[3,3,4,4,4-penta fluoro-1- (1-methylethyl)-2-oxobutyl]-L-prolinamide (1), in which the chiral center of the P1 residue has been eliminated, were synthesized and tested as inhibitors of human neutrophil elastase (HNE). Observations made during the course of this work led to the development of a single-step, stereoselective synthesis of E-enol acetate derivatives from HNE inhibitors containing a mixture of epimers at P1. In vitro studies, in the presence of added esterase, and 19F NMR studies, in biological media, indicated that the E-enol acetate derivatives should act as prodrugs in vivo. The ED50 value for (E)-N-[4-(4-morpholinylcarbonyl)benzoyl]-L-valyl-N-[2- (acetyloxy)-3,3,4,4,4-pentafluoro-1-(1-methylethyl)-1-buteny l]-L-prolinamide (20), when administered orally in the hamster lung hemorrhage model, was 9 mg/kg.

Inhibition of human neutrophil elastase with peptidyl electrophilic ketones. 2. Orally active PG-Val-Pro-Val pentafluoroethyl ketones.

Valylprolyvalyl pentafluoroethyl ketones with different N-protecting groups were evaluated in vitro and in vivo as inhibitors of human neutrophil elastase (HNE). Several of these compounds were found to be orally active in HNE-induced rat and hamster lung hemorrhage models. The compound with 4-(4-morpholinylcarbonyl)benzoyl as the protecting group, 71 (MDL 101,146), was studied in greater detail. Hydration and epimerization studies were performed on 71 and related compounds in various media, including human blood serum. High-performance liquid chromatography studies on a reversed-phase system as a measure of the lipophilicity of 71 and related compounds revealed a small range of relative retention times wherein the orally active compounds fell. The Ki value determined for 71 vs HNE was 25 nM.

Induction of mortality and malformation in Xenopus laevis embryos by water sources associated with field frog deformities.

Water samples from several ponds in Minnesota were evaluated for their capacity to induce malformations in embryos of Xenopus laevis. The FETAX assay was used to assess the occurrence of malformations following a 96-hr period of exposure to water samples. These studies were conducted following reports of high incidences of malformation in natural populations of frogs in Minnesota wetlands. The purpose of these studies was to determine if a biologically active agent(s) was present in the waters and could be detected using the FETAX assay. Water samples from ponds with high incidences of frog malformations (affected sites), along with water samples from ponds with unaffected frog populations (reference sites), were studied. Initial experiments clearly showed that water from affected sites induced mortality and malformation in Xenopus embryos, while water from reference sites had little or no effect. Induction of malformation was dose dependent and highly reproducible, both with stored samples and with samples taken at different times throughout the summer. The biological activity of the samples was reduced or eliminated when samples were passed through activated carbon. Limited evidence from these samples indicates that the causal factor(s) is not an infectious organism nor are ion concentrations or metals responsible for the effects observed. Results do indicate that the water matrix has a significant effect on the severity of toxicity. Based on the FETAX results and the occurrence of frog malformations observed in the field, these studies suggest that water in the affected sites contains one or more unknown agents that induce developmental abnormalities in Xenopus. These same factors may contribute to the increased incidence of malformation in native species.

Strategies for assessing the implications of malformed frogs for environmental health.

The recent increase in the incidence of deformities among natural frog populations has raised concern about the state of the environment and the possible impact of unidentified causative agents on the health of wildlife and human populations. An open workshop on Strategies for Assessing the Implications of Malformed Frogs for Environmental Health was convened on 4-5 December 1997 at the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina. The purpose of the workshop was to share information among a multidisciplinary group with scientific interest and responsibility for human and environmental health at the federal and state level. Discussions highlighted possible causes and recent findings directly related to frog deformities and provided insight into problems and strategies applicable to continuing investigation in several areas. Possible causes of the deformities were evaluated in terms of diagnostics performed on field amphibians, biologic mechanisms that can lead to the types of malformations observed, and parallel laboratory and field studies. Hydrogeochemistry must be more integrated into environmental toxicology because of the pivotal role of the aquatic environment and the importance of fates and transport relative to any potential exposure. There is no indication of whether there may be a human health factor associated with the deformities. However, the possibility that causal agents may be waterborne indicates a need to identify the relevant factors and establish the relationship between environmental and human health in terms of hazard assessment.

A-ring bridged steroids as potent inhibitors of aromatase.

The design and syntheses of androstenedione derivatives with bridges spanning the 2,19-, 3,19-, 4,19- and 6, 19-positions are described. 2,19-Bridged compounds bearing hydroxyl groups on the two-carbon bridge (3a and 3b) were designed as stable carbon analogs of potential lactol intermediates in the enzymatic conversion of androgens to estrogens. Compounds 3a and 3b are competitive inhibitors of aromatase. Pyran 25 is a potent, time-dependent inhibitor of aromatase with partial NADPH dependence. These data suggest a mechanism of inhibition for 25 which involves both tight-binding competitive and mechanism-based components, with the former predominating. The sulfur, amino, and all carbon analogs of pyran 25 were prepared. Thiopyran 36, piperidine 42 and the all-carbon analog 47 are also time-dependent inhibitors of aromatase. Compound 47 is the most potent inhibitor and its time-dependent inhibition is not NADPH dependent. The kinetics of piperidine 42 suggest uncompetitive inhibition.

Biological characterization of A-ring steroids.

Hydroxylated 2,19-methylene-bridged androstenediones were designed as potential mimics of enzyme oxidized intermediates of androstenedione. These compounds exhibited competitive inhibition with low micromolar affinities for aromatase. These inhibitory constants (Ki values) were 10 times greater than the 2,19-methylene-bridged androstenedione constant (Ki = 35-70 nM). However, expansion of the 2,19-carbon bridge to ethylene increased aromatase affinity by 10-fold (Ki = 2 nM). Substitution of a methylene group with oxygen and sulfur in this expanded bridge resulted in Ki values of 7 and 20 nM, respectively. When the substituent was an NH group, the apparent inhibitory kinetics changed from competitive to uncompetitive. All of these analogs exhibited time-dependent inhibition of aromatase activity following preincubation of the inhibitor with human placental microsomes prior to measuring residual enzyme activity. Part of this inhibition was NADPH cofactor-dependent for the 2,19-methyleneoxy- but not for the 2,19-ethylene-bridged androstenedione. The time-dependent inhibition for these four analogs was very rapid since they exhibited tau 50 values, the t1/2 for enzyme inhibition at infinite inhibitor concentration, of 1 to 3 min. These A-ring-bridged androstenedione analogs represent a novel series of potent steroidal aromatase inhibitors. The restrained A-ring bridge containing CH2, O, S, or NH could effectively coordinate with the heme of the P450 aromatase to allow the tight-binding affinities reflected by their nanomolar Ki values.

Treatment of ADDH in mentally retarded children: a preliminary study.

The use of CNS stimulant medication for the treatment of attention deficit disorder with hyperactivity (ADDH) in subnormal intelligence children remains controversial, and the majority of the literature does not support the use of CNS stimulants in these children, although the choice of dependent variables and research designs may have contributed to this outcome. A single case research design was used to assess the effectiveness of CNS stimulant medication (methylphenidate and dextroamphetamine) in three subnormal intelligence children with ADDH, using excessive movement and on-task behaviors as dependent variables. The results and implications for future research are discussed.

Perspectives on molecular assays for measuring mutation in humans and rodents.

The original idea for this article was to examine the new molecular techniques for detection of mutation directly at the DNA level in exposed individuals or their offspring and to assess their relative advantages and disadvantages for mutation monitoring in humans and rodents. However, an examination of the articles and a comparison of the technology indicated that our constant quests for methods improvement were leading to some loss of insight into the important health-related questions that should be guiding these endeavors. As a result, individual methods are not covered here in great technical detail. Instead, a few molecular methods are presented in a general overview, along with some of the biological issues related to the detection of induced mutations within individuals and populations. Some hypothetical scenarios are also presented because molecular approaches will continue to change rapidly, and we must continually adjust our thinking to combine the useful attributes of each current and future technical approach with the most appropriate biological questions.