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Sample records for non-invasive stress tests

  1. An open-source framework for stress-testing non-invasive foetal ECG extraction algorithms.

    PubMed

    Andreotti, Fernando; Behar, Joachim; Zaunseder, Sebastian; Oster, Julien; Clifford, Gari D

    2016-05-01

    Over the past decades, many studies have been published on the extraction of non-invasive foetal electrocardiogram (NI-FECG) from abdominal recordings. Most of these contributions claim to obtain excellent results in detecting foetal QRS (FQRS) complexes in terms of location. A small subset of authors have investigated the extraction of morphological features from the NI-FECG. However, due to the shortage of available public databases, the large variety of performance measures employed and the lack of open-source reference algorithms, most contributions cannot be meaningfully assessed. This article attempts to address these issues by presenting a standardised methodology for stress testing NI-FECG algorithms, including absolute data, as well as extraction and evaluation routines. To that end, a large database of realistic artificial signals was created, totaling 145.8 h of multichannel data and over one million FQRS complexes. An important characteristic of this dataset is the inclusion of several non-stationary events (e.g. foetal movements, uterine contractions and heart rate fluctuations) that are critical for evaluating extraction routines. To demonstrate our testing methodology, three classes of NI-FECG extraction algorithms were evaluated: blind source separation (BSS), template subtraction (TS) and adaptive methods (AM). Experiments were conducted to benchmark the performance of eight NI-FECG extraction algorithms on the artificial database focusing on: FQRS detection and morphological analysis (foetal QT and T/QRS ratio). The overall median FQRS detection accuracies (i.e. considering all non-stationary events) for the best performing methods in each group were 99.9% for BSS, 97.9% for AM and 96.0% for TS. Both FQRS detections and morphological parameters were shown to heavily depend on the extraction techniques and signal-to-noise ratio. Particularly, it is shown that their evaluation in the source domain, obtained after using a BSS technique, should be

  2. Non-Invasive Testing, Non-Invasive Counseling.

    PubMed

    Rebouché, Rachel

    2015-01-01

    This article describes a new prenatal genetic test that is painless, early, and increasingly available. State legislatures have reacted by prohibiting abortion for reason of fetal sex or of fetal diagnosis and managing genetic counseling. This article explores these legislative responses and considers how physicians and genetic counselors currently communicate post-testing options. The article then examines the challenges ahead for genetic counseling, particularly in light of the troubling grip of abortion politics on conversations about prenatal diagnosis. PMID:26242943

  3. Lactate is an ideal non-invasive marker for evaluating temporal alterations in cell stress and toxicity in repeat dose testing regimes.

    PubMed

    Limonciel, Alice; Aschauer, Lydia; Wilmes, Anja; Prajczer, Sinikka; Leonard, Martin O; Pfaller, Walter; Jennings, Paul

    2011-12-01

    Technological developments are driving in vitro methods towards integrated "omic" strategies. However, there is still an over reliance on classical viability assays for dose range finding. Such assays are not readily suited to the investigation of subtle alterations in cell function and most require termination of the experiment, which makes it difficult to monitor temporal alterations in repeat-dose long term exposure experiments. To this end, we investigated the use of lactate production as a marker of cell stress in long term repeat dose experiments. We conducted daily exposures to eight compounds at five concentrations for 14 days on human renal proximal tubular cells (RPTEC/TERT1), human hepatoma cells (HepaRG) and mouse fibroblasts (BALB-3T3) cells. Compounds were chosen from a training set used in the 7th EU Framework project Predict-IV and consisted of amiodarone, diclofenac, troglitazone, cadmium chloride, cephaloridine, cidofovir, cyclosporine A and buflomedil. At days 1, 3, 7 and 14, lactate was measured in the supernatant medium. At day 14, cells were assayed for resazurin reduction capability and subsequently lysed in methanol for ATP determination. Compound-induced loss of viability was comparable across all cell lines. For all cell types, when cell viability was compromised at day 14, lactate production was induced during the treatment period. In some situations, lactate also fell below control values, indicating cell death. Thus, temporal alterations in supernatant lactate provides information on the time and concentration of stress induction and the time and concentration where cell death becomes the dominant factor. Supernatant lactate production is a simple, cheap and non-invasive parameter. Since many molecular pathways converge on the glycolytic pathway, enhanced lactate production may be considered as a global marker of sub-lethal injury and thus an ideal marker for investigating temporal alterations in long term repeat dose testing in vitro

  4. [Non-invasive prenatal testing: challenges for future implementation].

    PubMed

    Henneman, Lidewij; Page-Chrisiaens, G C M L Lieve; Oepkes, Dick

    2015-01-01

    The non-invasive prenatal test (NIPT) is an accurate and safe test in which blood from the pregnant woman is used to investigate if the unborn child possibly has trisomy 21 (Down's syndrome), trisomy 18 (Edwards' syndrome) or trisomy 13 (Patau syndrome). Since April 2014 the NIPT has been available in the Netherlands as part of the TRIDENT implementation project for those in whom the first trimester combined test showed an elevated risk (> 1:200) of trisomy, or on medical indication, as an alternative to chorionic villous sampling or amniocentesis. Since the introduction of the NIPT the use of these invasive tests, which are associated with a risk of miscarriage, has fallen steeply. The NIPT may replace the combined test. Also the number of conditions that is tested for can be increased. Modification of current prenatal screening will require extensive discussion, but whatever the modification, careful counseling remains essential to facilitate pregnant women's autonomous reproductive decision making. PMID:26530119

  5. Stress detection in bivalve mollusk using non-invasive bioelectric monitoring of myoneural behavior

    SciTech Connect

    Morgan, E.L.; Hardison, B.S.; Dawson, V.K.; Waller, D.; Waller, W.T.; Dickson, K.L.; Allen, H.J.

    1995-12-31

    Few studies have demonstrated cause-and-effect linkages between extrinsic environmental factors and intrinsic bioelectric action potentials of bivalve mollusk using non-invasive, non-destructive approaches. A non-invasive, external probe configuration and detection system, similar to one used previously with native unionids, was developed for continuously monitoring bioelectric activities of clams and mussels. Using remote probes and differential amplifiers, bioelectric activities were recorded for cardiac, adductor, siphon and foot responses using a computer equipped with integrating software. To test if remote, non-invasive probes would detect similar information to that recorded by invasive needle electrodes, two individuals of zebra mussel (Dreissenia polymorpha), and Asiatic clam (Corbicula fluminea) were each configured with two sets of probes. One set was inserted between the valves and along the inside surface of the shelf; the other set was positioned remotely about the outside margins of the valves. Signal validation was made by simultaneously recording bioelectric responses for the same animal from both sets of probes. In preliminary stress tests monitored bivalves were subjected to changes in temperatures over 2 to 3 hr intervals from ambient to potentially lethal levels (20 to 30 C for zebra, 25 C to 40 C for corbicula). Dramatic increases resulted in both number and amplitude of cardiac events as temperature increased. Planned studies will use this approach to evaluate bivalve myoneural behavior patterns in response to chemical and non-chemical stimuli.

  6. An optical approach for non-invasive blood clot testing

    NASA Astrophysics Data System (ADS)

    Kalchenko, Vyacheslav; Brill, Alexander; Fine, Ilya; Harmelin, Alon

    2007-02-01

    Physiological blood coagulation is an essential biological process. Current tests for plasma coagulation (clotting) need to be performed ex vivo and require fresh blood sampling for every test. A recently published work describes a new, noninvasive, in vivo approach to assess blood coagulation status during mechanical occlusion1. For this purpose, we have tested this approach and applied a controlled laser beam to blood micro-vessels of the mouse ear during mechanical occlusion. Standard setup for intravital transillumination videomicroscopy and laser based imaging techniques were used for monitoring the blood clotting process. Temporal mechanical occlusion of blood vessels in the observed area was applied to ensure blood flow cessation. Subsequently, laser irradiation was used to induce vascular micro-injury. Changes in the vessel wall, as well as in the pattern of blood flow, predispose the area to vascular thrombosis, according to the paradigm of Virchow's triad. In our experiments, two elements of Virchow's triad were used to induce the process of clotting in vivo, and to assess it optically. We identified several parameters that can serve as markers of the blood clotting process in vivo. These include changes in light absorption in the area of illumination, as well as changes in the pattern of the red blood cells' micro-movement in the vessels where blood flow is completely arrested. Thus, our results indicate that blood coagulation status can be characterized by non-invasive, in vivo methodologies.

  7. Public viewpoints on new non-invasive prenatal genetic tests.

    PubMed

    Farrimond, Hannah R; Kelly, Susan E

    2013-08-01

    Prenatal screening programmes have been critiqued for their routine implementation according to clinical rationale without public debate. A new approach, non-invasive prenatal diagnosis (NIPD), promises diagnosis of fetal genetic disorders from a sample of maternal blood without the miscarriage risk of current invasive prenatal tests (e.g. amniocentesis). Little research has investigated the attitudes of wider publics to NIPD. This study used Q-methodology, which combines factor analysis with qualitative comments, to identify four distinct "viewpoints" amongst 71 UK men and women: 1. NIPD as a new tool in the ongoing societal discrimination against the disabled; 2. NIPD as a positive clinical application offering peace of mind in pregnancy; 3. NIPD as a medical option justified for severe disorders only; and 4. NIPD as a valid expansion of personal choice. Concerns included the "trivialisation of testing" and the implications of commercial/direct-to-consumer tests. Q-methodology has considerable potential to identify viewpoints and frame public debate about new technologies. PMID:23885055

  8. Non-invasive prenatal testing: ethical issues explored

    PubMed Central

    de Jong, Antina; Dondorp, Wybo J; de Die-Smulders, Christine E M; Frints, Suzanne G M; de Wert, Guido M W R

    2010-01-01

    This paper explores the ethical implications of introducing non-invasive prenatal diagnostic tests (NIPD tests) in prenatal screening for foetal abnormalities. NIPD tests are easy and safe and can be performed early in pregnancy. Precisely because of these features, it is feared that informed consent may become more difficult, that both testing and selective abortion will become ‘normalized', and that there will be a trend towards accepting testing for minor abnormalities and non-medical traits as well. In our view, however, the real moral challenge of NIPD testing consists in the possibility of linking up a technique with these features (easy, safe and early) with new genomic technologies that allow prenatal diagnostic testing for a much broader range of abnormalities than is the case in current procedures. An increase in uptake and more selective abortions need not in itself be taken to signal a thoughtless acceptance of these procedures. However, combining this with considerably enlarging the scope of NIPD testing will indeed make informed consent more difficult and challenge the notion of prenatal screening as serving reproductive autonomy. If broad NIPD testing includes later-onset diseases, the ‘right not to know' of the future child will become a new issue in the debate about prenatal screening. With regard to the controversial issue of selective abortion, it may make a morally relevant difference that after NIPD testing, abortion can be done early. A lower moral status may be attributed to the foetus at that moment, given the dominant opinion that the moral status of the foetus progressively increases with its development. PMID:19953123

  9. The fear-factor stress test: an ethical, non-invasive laboratory method that produces consistent and sustained cortisol responding in men and women.

    PubMed

    du Plooy, Christopher; Thomas, Kevin G F; Henry, Michelle; Human, Robyn; Jacobs, W Jake

    2014-06-01

    We describe a method to administer a controlled, effective stressor to humans in the laboratory. The method combines the Trier Social Stress Test (TSST) and the Cold Pressor Test into a single, believable procedure called the Fear-Factor Stress Test (FFST). In the procedure, participants imagine auditioning for the reality television show Fear Factor. They stand before a video recorder and a panel of judges while (a) delivering a motivational speech, (b) performing a verbal arithmetic task, and (c) placing one hand into a bucket of ice water for up to 2 min. We measured subjective anxiety, heart rate, and salivary cortisol in three groups of young adults (n = 30 each, equal numbers of men and women): FFST, TSST, and Control (a placebo version of the FFST). Although the FFST and TSST groups were not distinguishable at the cortisol measure taken 5 min post-manipulation, at 35 min postmanipulation average cortisol levels in the TSST group had returned to baseline, whereas those in the FFST group continued to rise. The proportion of individual cortisol responders (≥ 2 nmol/l increase over baseline) in the TSST and FFST groups did not differ at the 5-min measure, but at the 35-min measure the FFST group contained significantly more responders. The findings indicate that the FFST induces a more robust and sustained cortisol response (which we assume is a marker of an HPA-axis response) than the TSST, and that it does so without increasing participant discomfort or incurring appreciably greater resource and time costs. PMID:24435939

  10. Non-invasive reproductive and stress endocrinology in amphibian conservation physiology.

    PubMed

    Narayan, E J

    2013-01-01

    Non-invasive endocrinology utilizes non-invasive biological samples (such as faeces, urine, hair, aquatic media, and saliva) for the quantification of hormones in wildlife. Urinary-based enzyme immunoassay (EIA) and radio-immunoassay have enabled the rapid quantification of reproductive and stress hormones in amphibians (Anura: Amphibia). With minimal disturbance, these methods can be used to assess the ovarian and testicular endocrine functions as well as physiological stress in captive and free-living populations. Non-invasive endocrine monitoring has therefore greatly advanced our knowledge of the functioning of the stress endocrine system (the hypothalamo-pituitary-interrenal axis) and the reproductive endocrine system (the hypothalamo-pituitary-gonadal axis) in the amphibian physiological stress response, reproductive ecology, health and welfare, and survival. Biological (physiological) validation is necessary for obtaining the excretory lag time of hormone metabolites. Urinary-based EIA for the major reproductive hormones, estradiol and progesterone in females and testosterone in males, can be used to track the reproductive hormone profiles in relationship to reproductive behaviour and environmental data in free-living anurans. Urinary-based corticosterone metabolite EIA can be used to assess the sublethal impacts of biological stressors (such as invasive species and pathogenic diseases) as well as anthropogenic induced environmental stressors (e.g. extreme temperatures) on free-living populations. Non-invasive endocrine methods can also assist in the diagnosis of success or failure of captive breeding programmes by measuring the longitudinal patterns of changes in reproductive hormones and corticosterone within captive anurans and comparing the endocrine profiles with health records and reproductive behaviour. This review paper focuses on the reproductive and the stress endocrinology of anurans and demonstrates the uses of non-invasive endocrinology for

  11. Non-invasive reproductive and stress endocrinology in amphibian conservation physiology

    PubMed Central

    Narayan, E. J.

    2013-01-01

    Non-invasive endocrinology utilizes non-invasive biological samples (such as faeces, urine, hair, aquatic media, and saliva) for the quantification of hormones in wildlife. Urinary-based enzyme immunoassay (EIA) and radio-immunoassay have enabled the rapid quantification of reproductive and stress hormones in amphibians (Anura: Amphibia). With minimal disturbance, these methods can be used to assess the ovarian and testicular endocrine functions as well as physiological stress in captive and free-living populations. Non-invasive endocrine monitoring has therefore greatly advanced our knowledge of the functioning of the stress endocrine system (the hypothalamo–pituitary–interrenal axis) and the reproductive endocrine system (the hypothalamo–pituitary–gonadal axis) in the amphibian physiological stress response, reproductive ecology, health and welfare, and survival. Biological (physiological) validation is necessary for obtaining the excretory lag time of hormone metabolites. Urinary-based EIA for the major reproductive hormones, estradiol and progesterone in females and testosterone in males, can be used to track the reproductive hormone profiles in relationship to reproductive behaviour and environmental data in free-living anurans. Urinary-based corticosterone metabolite EIA can be used to assess the sublethal impacts of biological stressors (such as invasive species and pathogenic diseases) as well as anthropogenic induced environmental stressors (e.g. extreme temperatures) on free-living populations. Non-invasive endocrine methods can also assist in the diagnosis of success or failure of captive breeding programmes by measuring the longitudinal patterns of changes in reproductive hormones and corticosterone within captive anurans and comparing the endocrine profiles with health records and reproductive behaviour. This review paper focuses on the reproductive and the stress endocrinology of anurans and demonstrates the uses of non-invasive endocrinology

  12. Non-invasive cortisol measurements as indicators of physiological stress responses in guinea pigs

    PubMed Central

    Pschernig, Elisabeth; Wallner, Bernard; Millesi, Eva

    2016-01-01

    Non-invasive measurements of glucocorticoid (GC) concentrations, including cortisol and corticosterone, serve as reliable indicators of adrenocortical activities and physiological stress loads in a variety of species. As an alternative to invasive analyses based on plasma, GC concentrations in saliva still represent single-point-of-time measurements, suitable for studying short-term or acute stress responses, whereas fecal GC metabolites (FGMs) reflect overall stress loads and stress responses after a species-specific time frame in the long-term. In our study species, the domestic guinea pig, GC measurements are commonly used to indicate stress responses to different environmental conditions, but the biological relevance of non-invasive measurements is widely unknown. We therefore established an experimental protocol based on the animals’ natural stress responses to different environmental conditions and compared GC levels in plasma, saliva, and fecal samples during non-stressful social isolations and stressful two-hour social confrontations with unfamiliar individuals. Plasma and saliva cortisol concentrations were significantly increased directly after the social confrontations, and plasma and saliva cortisol levels were strongly correlated. This demonstrates a high biological relevance of GC measurements in saliva. FGM levels measured 20 h afterwards, representing the reported mean gut passage time based on physiological validations, revealed that the overall stress load was not affected by the confrontations, but also no relations to plasma cortisol levels were detected. We therefore measured FGMs in two-hour intervals for 24 h after another social confrontation and detected significantly increased levels after four to twelve hours, reaching peak concentrations already after six hours. Our findings confirm that non-invasive GC measurements in guinea pigs are highly biologically relevant in indicating physiological stress responses compared to circulating

  13. Non-invasive cortisol measurements as indicators of physiological stress responses in guinea pigs.

    PubMed

    Nemeth, Matthias; Pschernig, Elisabeth; Wallner, Bernard; Millesi, Eva

    2016-01-01

    Non-invasive measurements of glucocorticoid (GC) concentrations, including cortisol and corticosterone, serve as reliable indicators of adrenocortical activities and physiological stress loads in a variety of species. As an alternative to invasive analyses based on plasma, GC concentrations in saliva still represent single-point-of-time measurements, suitable for studying short-term or acute stress responses, whereas fecal GC metabolites (FGMs) reflect overall stress loads and stress responses after a species-specific time frame in the long-term. In our study species, the domestic guinea pig, GC measurements are commonly used to indicate stress responses to different environmental conditions, but the biological relevance of non-invasive measurements is widely unknown. We therefore established an experimental protocol based on the animals' natural stress responses to different environmental conditions and compared GC levels in plasma, saliva, and fecal samples during non-stressful social isolations and stressful two-hour social confrontations with unfamiliar individuals. Plasma and saliva cortisol concentrations were significantly increased directly after the social confrontations, and plasma and saliva cortisol levels were strongly correlated. This demonstrates a high biological relevance of GC measurements in saliva. FGM levels measured 20 h afterwards, representing the reported mean gut passage time based on physiological validations, revealed that the overall stress load was not affected by the confrontations, but also no relations to plasma cortisol levels were detected. We therefore measured FGMs in two-hour intervals for 24 h after another social confrontation and detected significantly increased levels after four to twelve hours, reaching peak concentrations already after six hours. Our findings confirm that non-invasive GC measurements in guinea pigs are highly biologically relevant in indicating physiological stress responses compared to circulating levels

  14. Personalized management of cirrhosis by non-invasive tests of liver fibrosis.

    PubMed

    Wong, Grace Lai-Hung; Espinosa, Wendell Zaragoza; Wong, Vicnent Wai-Sun

    2015-09-01

    Owing to the high prevalence of various chronic liver diseases, cirrhosis is one of the leading causes of morbidity and mortality worldwide. In recent years, the development of non-invasive tests of fibrosis allows accurate diagnosis of cirrhosis and reduces the need for liver biopsy. In this review, we discuss the application of these non-invasive tests beyond the diagnosis of cirrhosis. In particular, their role in the selection of patients for hepatocellular carcinoma surveillance and varices screening is highlighted. PMID:26523265

  15. Non-invasive Prenatal Testing (NIPT): Better Meet an Expert!

    PubMed Central

    Ohnhaeuser, T.; Schmitz, D.

    2016-01-01

    While NIPT is being implemented rapidly, the implementation of a corresponding specialized counselling process in many respects lags behind. As a consequence, legal requirements and other testing conditions sometimes are not fulfilled adequately. The reported case illustrates the importance of trained personnel in the counselling and NIPT process and shows so far neglected risks for the pregnant woman and her reproductive autonomy. PMID:27064737

  16. Rapid non-invasive tests for diagnostics of infectious diseases

    NASA Astrophysics Data System (ADS)

    Malamud, Daniel

    2014-06-01

    A rapid test for an infectious disease that can be used at point-of-care at a physician's office, a pharmacy, or in the field is critical for the prompt and appropriate therapeutic intervention. Ultimately by treating infections early on will decrease transmission of the pathogen. In contrast to metabolic diseases or cancer where multiple biomarkers are required, infectious disease targets (e.g. antigen, antibody, nucleic acid) are simple and specific for the pathogen causing the disease. Our laboratory has focused on three major infectious disease; HIV, Tuberculosis, and Malaria. These diseases are pandemic in much of the world thus putting natives, tourists and military personnel at risk for becoming infected, and upon returning to the U.S., transmitting these diseases to their contacts. Our devices are designed to detect antigens, antibodies or nucleic acids in blood or saliva samples in less than 30 minutes. An overview describing the current status of each of the three diagnostic platforms is presented. These microfluidic point-of-care devices will be relatively inexpensive, disposable, and user friendly.

  17. Attitudes Towards Non-Invasive Prenatal Testing for Aneuploidy Among United States Adults of Reproductive Age

    PubMed Central

    Sayres, Lauren C.; Goodspeed, Taylor A.; Cho, Mildred K.

    2014-01-01

    Objective(s) To determine how adults in the United States (US) view non-invasive prenatal testing using cell-free fetal DNA (cffDNA testing) in order to help estimate uptake. Study Design A national sample of 1,861 US-based adults was surveyed using a validated online survey instrument. The survey was administered by a commercial survey research company. Respondents were randomized to receive a survey about prenatal testing for trisomy 13 and 18 or trisomy 21. Participants were asked to select among testing modalities, including cffDNA testing, and rank the features of testing that they considered most important to decision making. Results There was substantive interest in the use of cffDNA testing rather than traditional screening mechanisms with a minority of respondents reporting that they would support the use of both methods in combination. The lower rates of false negative and false positive test results and the ability to use the test earlier in the pregnancy were the most highly rated benefits of cffDNA testing. Participants expressed strong support for diagnostic confirmation via invasive testing after a positive result from either screening or cffDNA testing. However, almost one-third of participants reported that they would not endorse the use of either invasive or non-invasive prenatal testing. Conclusion(s) There appears to be support for uptake of non-invasive prenatal tests. Clinical guidelines should therefor go forward in providing guidance on how to integrate non-invasive methods into current standard of care. However, our findings indicate that even when accuracy, which is rated by patients as the most important aspect of prenatal testing, is significantly improved over existing screening methods and testing is offered non-invasively, the number of individuals who reported that they would decline any testing remained the same. Attention should therefor be directed at ensuring that the right of informed refusal of prenatal testing is not impacted

  18. Thermal Imaging to Study Stress Non-invasively in Unrestrained Birds.

    PubMed

    Jerem, Paul; Herborn, Katherine; McCafferty, Dominic; McKeegan, Dorothy; Nager, Ruedi

    2015-01-01

    Stress, a central concept in biology, describes a suite of emergency responses to challenges. Among other responses, stress leads to a change in blood flow that results in a net influx of blood to key organs and an increase in core temperature. This stress-induced hyperthermia is used to assess stress. However, measuring core temperature is invasive. As blood flow is redirected to the core, the periphery of the body can cool. This paper describes a protocol where peripheral body temperature is measured non-invasively in wild blue tits (Cyanistes caeruleus) using infrared thermography. In the field we created a set-up bringing the birds to an ideal position in front of the camera by using a baited box. The camera takes a short thermal video recording of the undisturbed bird before applying a mild stressor (closing the box and therefore capturing the bird), and the bird's response to being trapped is recorded. The bare skin of the eye-region is the warmest area in the image. This allows an automated extraction of the maximum eye-region temperature from each image frame, followed by further steps of manual data filtering removing the most common sources of errors (motion blur, blinking). This protocol provides a time series of eye-region temperature with a fine temporal resolution that allows us to study the dynamics of the stress response non-invasively. Further work needs to demonstrate the usefulness of the method to assess stress, for instance to investigate whether eye-region temperature response is proportional to the strength of the stressor. If this can be confirmed, it will provide a valuable alternative method of stress assessment in animals and will be useful to a wide range of researchers from ecologists, conservation biologists, physiologists to animal welfare researchers. PMID:26575985

  19. Thermal Imaging to Study Stress Non-invasively in Unrestrained Birds

    PubMed Central

    Jerem, Paul; Herborn, Katherine; McCafferty, Dominic; McKeegan, Dorothy; Nager, Ruedi

    2015-01-01

    Stress, a central concept in biology, describes a suite of emergency responses to challenges. Among other responses, stress leads to a change in blood flow that results in a net influx of blood to key organs and an increase in core temperature. This stress-induced hyperthermia is used to assess stress. However, measuring core temperature is invasive. As blood flow is redirected to the core, the periphery of the body can cool. This paper describes a protocol where peripheral body temperature is measured non-invasively in wild blue tits (Cyanistes caeruleus) using infrared thermography. In the field we created a set-up bringing the birds to an ideal position in front of the camera by using a baited box. The camera takes a short thermal video recording of the undisturbed bird before applying a mild stressor (closing the box and therefore capturing the bird), and the bird’s response to being trapped is recorded. The bare skin of the eye-region is the warmest area in the image. This allows an automated extraction of the maximum eye-region temperature from each image frame, followed by further steps of manual data filtering removing the most common sources of errors (motion blur, blinking). This protocol provides a time series of eye-region temperature with a fine temporal resolution that allows us to study the dynamics of the stress response non-invasively. Further work needs to demonstrate the usefulness of the method to assess stress, for instance to investigate whether eye-region temperature response is proportional to the strength of the stressor. If this can be confirmed, it will provide a valuable alternative method of stress assessment in animals and will be useful to a wide range of researchers from ecologists, conservation biologists, physiologists to animal welfare researchers. PMID:26575985

  20. Best Ethical Practices for Clinicians and Laboratories in the Provision of Non-Invasive Prenatal Testing

    PubMed Central

    Allyse, MA; Sayres, LC; Havard, M; King, JS; Greely, HT; Hudgins, L; Taylor, J; Norton, ME; Cho, MK; Magnus, D; Ormond, KE

    2014-01-01

    Objective To provide an ethical framework for clinicians and companies providing non-invasive prenatal testing using cell-free fetal DNA or whole fetal cells. Method In collaboration with an NIH-supported research ethics consultation committee, together with feedback from an inter-disciplinary group of clinicians, members of industry, legal experts and genetic counselors we developed a set of best practices for the provision of non-invasive prenatal genetic testing. Results Principal recommendations include the amendment of current informed consent procedures to include attention to the non-invasive nature of new testing and the potential for a broader range of results earlier in the pregnancy. We strongly recommend that tests should only be provided through licensed medical providers and not direct-to-consumer. Conclusion Prenatal tests, including new methods using cell-free fetal DNA, are not currently regulated by government agencies and limited professional guidance is available. In the absence of regulation, companies and clinicians should cooperate to adopt responsible best ethical practices in the provision of these tests. PMID:23613322

  1. Non-invasive monitoring of stress hormones in the bat Eptesicus isabellinus - Do fecal glucocorticoid metabolite concentrations correlate with survival?

    PubMed

    Kelm, Detlev H; Popa-Lisseanu, Ana G; Dehnhard, Martin; Ibáñez, Carlos

    2016-01-15

    Chronic stress may negatively impact fitness and survival in wildlife. Stress hormone analysis from feces is a non-invasive tool for identifying stressors and deducing about individual and population level fitness. Although many bat populations are endangered, fecal stress hormone analysis has not been established in bats as a method for focusing conservation efforts. The isabelline serotine bat, Eptesicus isabellinus, is exposed to human disturbance as its roosts are mostly found in anthropogenic structures. Moreover, this bat is host to various diseases and survival rates between colonies may vary significantly. To validate the analysis of fecal glucocorticoid metabolites, we applied an adrenocorticotropic hormone (ACTH) challenge and tested four different enzyme immunoassays (EIA) for measuring glucocorticoid concentrations. Cortisol and its metabolites showed the highest increase in blood and feces after the ACTH challenge, but corticosterone and its metabolites also increased significantly. Baseline fecal cortisol metabolite (FCM) concentrations did not increase until 1.5h after the animals were captured, which is a convenient time lag for sample collection from captured animals. We furthermore compared baseline FCM concentrations between five colonies of E. isabellinus in Andalusia, Spain, and tested for their correlation with survival rates. FCM concentrations did not vary between colonies, but FCM levels increased with the animals' age. FCM analysis may prove a useful tool for identifying bat colonies that experience uncommon environmental stress. However, inter-individual variation in hormone secretion, due to factors such as age, may require additional information to properly interpret differences in hormone concentrations. PMID:26673871

  2. Non-invasive, serum DNA pregnancy testing leading to incidental discovery of cancer: a good thing?

    PubMed

    Prasad, Vinay

    2015-11-01

    Cell-free DNA for perinatal screening is a growing industry. Non-invasive prenatal testing (NIPT) is based on the premise that foetal DNA is able to cross the placental barrier and enter the mother's circulation, where it can be examined for chromosomal abnormalities, such as trisomy 13, 18 or 21. Such tests are expected to be widely used by pregnant women, with the annual market expected to surpass $1 billion. Recently, a number of case reports have emerged in the haematology-oncology literature. The routine use of NIPT has led to the discovery of maternal neoplasms. Most writers have concluded that this is yet another benefit of the test; however, a closer examination of the cases reveals that this incidental detection may not improve patient outcomes. In some cases, early detection provides lead time bias, but does not change the ultimate clinical outcome, and in other cases, detection constitutes earlier knowledge of a cancer whose natural history cannot be altered. Here, we explore in detail cases where cancer was incidentally discovered among women undergoing routine non-invasive pregnancy testing, and investigate whether or not these women were benefitted by the discovery. PMID:26278647

  3. 13CO2 breath tests in non-invasive hepatological diagnosis

    PubMed Central

    Musialik, Joanna; Kasicka-Jonderko, Anna; Buschhaus, Magdalena

    2015-01-01

    In liver diagnostics, a simple, non-invasive test with high sensitivity and specificity is permanently being sought in order to assess the degree of liver damage. In addition to liver biopsy, algorithms using blood parameters or elastometry are used in clinical practice. However, these methods do not provide information about the true liver reserve, so the liver breath test seem to be a promising diagnostic tool. The basis of this test depends on the ability of particular hepatocyte enzyme systems to metabolise a tested substance labelled with a stable carbon isotope. The kinetics of 13CO2 elimination with expiratory air then permits quantitative assessment of the functional liver reserve and the degree of organ damage. In this paper the most commonly used tests, grouped according to the main metabolic pathways, are described. The usefulness of liver breath tests in specific clinical situations, both as a diagnostic and prognostic tool, is presented. PMID:25960807

  4. Questioning the costs and benefits of non-invasive prenatal testing.

    PubMed

    Stoll, Katie; Lutgendorf, Monica; Knutzen, Dana; Nielsen, Peter E

    2014-04-01

    Prenatal testing for Down syndrome through the use of non-invasive prenatal testing (NIPT) has been increasingly implemented in clinical practice and a recent cost analysis suggests that NIPT is cost effective when compared to other screening modalities in high risk populations. However, this anaylsis makes many assumptions regarding uptake of testing and pregnancy termination, which cannot be applied to all populations in the United States. Additionally, this cost analysis, which hinges on fewer Down syndrome births, does not align with the goals of prenatal testing to support autonomous and value consistent decisions. NIPT is an expensive new technology and more careful analysis is needed to determine the impact of NIPT on outcomes and overall healthcare costs. PMID:23808328

  5. [Clinical Application of Non-invasive Diagnostic Tests for Liver Fibrosis].

    PubMed

    Shin, Jung Woo; Park, Neung Hwa

    2016-07-25

    The diagnostic assessment of liver fibrosis is an important step in the management of patients with chronic liver diseases. Liver biopsy is considered the gold standard to assess necroinflammation and fibrosis. However, recent technical advances have introduced numerous serum biomarkers and imaging tools using elastography as noninvasive alternatives to biopsy. Serum markers can be direct or indirect markers of the fibrosis process. The elastography-based studies include transient elastography, acoustic radiation force imaging, supersonic shear wave imaging and magnetic resonance elastography. As accumulation of clinical data shows that noninvasive tests provide prognostic information of clinical relevance, non-invasive diagnostic tools have been incorporated into clinical guidelines and practice. Here, the authors review noninvasive tests for the diagnosis of liver fibrosis. PMID:27443617

  6. Non invasive blood flow measurement in cerebellum detects minimal hepatic encephalopathy earlier than psychometric tests

    PubMed Central

    Felipo, Vicente; Urios, Amparo; Giménez-Garzó, Carla; Cauli, Omar; Andrés-Costa, Maria-Jesús; González, Olga; Serra, Miguel A; Sánchez-González, Javier; Aliaga, Roberto; Giner-Durán, Remedios; Belloch, Vicente; Montoliu, Carmina

    2014-01-01

    AIM: To assess whether non invasive blood flow measurement by arterial spin labeling in several brain regions detects minimal hepatic encephalopathy. METHODS: Blood flow (BF) was analyzed by arterial spin labeling (ASL) in different brain areas of 14 controls, 24 cirrhotic patients without and 16 cirrhotic patients with minimal hepatic encephalopathy (MHE). Images were collected using a 3 Tesla MR scanner (Achieva 3T-TX, Philips, Netherlands). Pulsed ASL was performed. Patients showing MHE were detected using the battery Psychometric Hepatic Encephalopathy Score (PHES) consisting of five tests. Different cognitive and motor functions were also assessed: alterations in selective attention were evaluated using the Stroop test. Patients and controls also performed visuo-motor and bimanual coordination tests. Several biochemical parameters were measured: serum pro-inflammatory interleukins (IL-6 and IL-18), 3-nitrotyrosine, cGMP and nitrates+nitrites in plasma, and blood ammonia. Bivariate correlations were evaluated. RESULTS: In patients with MHE, BF was increased in cerebellar hemisphere (P = 0.03) and vermis (P = 0.012) and reduced in occipital lobe (P = 0.017). BF in cerebellar hemisphere was also increased in patients without MHE (P = 0.02). Bimanual coordination was impaired in patients without MHE (P = 0.05) and much more in patients with MHE (P < 0.0001). Visuo-motor coordination was impaired only in patients with MHE (P < 0.0001). Attention was slightly affected in patients without MHE and more strongly in patients with MHE (P < 0.0001). BF in cerebellar hemisphere and vermis correlated with performance in most tests of PHES [(number connection tests A (NCT-A), B (NCT-B)and line tracing test] and in the congruent task of Stroop test. BF in frontal lobe correlated with NCT-A. Performance in bimanual and visuomotor coordination tests correlated only with BF in cerebellar hemisphere. BF in occipital lobe correlates with performance in the PHES battery and with

  7. Enabling non-invasive assessment of an engineered endothelium on ePTFE vascular grafts without increasing oxidative stress.

    PubMed

    Jiang, Bin; Perrin, Louisiane; Kats, Dina; Meade, Thomas; Ameer, Guillermo

    2015-11-01

    Magnetic resonance imaging (MRI) in combination with contrast enhancement is a potentially powerful tool to non-invasively monitor cell distribution in tissue engineering and regenerative medicine. The most commonly used contrast agent for cell labeling is super paramagnetic iron oxide nanoparticles (SPIONs). However, uptake of SPIONs triggers the production of reactive oxygen species (ROS) in cells often leading to a pro-inflammatory phenotype. The objective of this study was to develop a labeling system to non-invasively visualize an engineered endothelium in vascular grafts without creating excessive oxidative stress. Specifically, we investigated: (1) chitosan-coated SPIONs (CSPIONs) as an antioxidant contrast agent for contrast enhancement, and (2) poly(1,8-octamethylene citrate) (POC) as an antioxidant interface to support cell adhesion and function of labeled cells on the vascular graft. While SPION-labeled endothelial cells (ECs) experienced elevated ROS formation and altered cell morphology, CSPION-labeled ECs cultured on POC-coated surfaces mitigated SPION-induced ROS formation and maintained EC morphology, phenotype, viability and functions. A monolayer of labeled ECs exhibited sufficient contrast with T2-weighed MR imaging. CSPION labeling of endothelial cells in combination with coating the graft wall with POC allows non-invasive monitoring of an engineered endothelium on ePTFE grafts without increasing oxidative stress. PMID:26283158

  8. Non-invasive prenatal testing for aneuploidy: current status and future prospects.

    PubMed

    Benn, P; Cuckle, H; Pergament, E

    2013-07-01

    Non-invasive prenatal testing (NIPT) for aneuploidy using cell-free DNA in maternal plasma is revolutionizing prenatal screening and diagnosis. We review NIPT in the context of established screening and invasive technologies, the range of cytogenetic abnormalities detectable, cost, counseling and ethical issues. Current NIPT approaches involve whole-genome sequencing, targeted sequencing and assessment of single nucleotide polymorphism (SNP) differences between mother and fetus. Clinical trials have demonstrated the efficacy of NIPT for Down and Edwards syndromes, and possibly Patau syndrome, in high-risk women. Universal NIPT is not cost-effective, but using NIPT contingently in women found at moderate or high risk by conventional screening is cost-effective. Positive NIPT results must be confirmed using invasive techniques. Established screening, fetal ultrasound and invasive procedures with microarray testing allow the detection of a broad range of additional abnormalities not yet detectable by NIPT. NIPT approaches that take advantage of SNP information potentially allow the identification of parent of origin for imbalances, triploidy, uniparental disomy and consanguinity, and separate evaluation of dizygotic twins. Fetal fraction enrichment, improved sequencing and selected analysis of the most informative sequences should result in tests for additional chromosomal abnormalities. Providing adequate prenatal counseling poses a substantial challenge given the broad range of prenatal testing options now available. PMID:23765643

  9. An easy test but a hard decision: ethical issues concerning non-invasive prenatal testing for autosomal recessive disorders.

    PubMed

    Skirton, Heather; Goldsmith, Lesley; Chitty, Lyn S

    2015-08-01

    Prenatal testing based on cell-free fetal DNA in maternal serum is now possible for specific monogenic conditions, and studies have shown that the use of non-invasive testing is supported by prospective parents and health professionals. However, some ethical issues have been raised concerning informed consent and paternal rights. The objective of this study was to explore ethical aspects of the use of non-invasive prenatal diagnostic testing for autosomal recessive disorders. We used a qualitative cross-sectional design, based on Thematic Analysis, and recruited 27 individuals of reproductive age who were carriers of one of four conditions: thalassaemia, sickle cell disease, cystic fibrosis or spinal muscular atrophy. Data were collected via focus groups or interviews. Participants were aware of the potential for such tests to be viewed as routine and suggested that obtaining written consent and allowing time for consideration is needed to facilitate autonomous choice and informed consent. All participants felt that mothers should be able to request such tests, but fathers who declined carrier testing should be made aware that fetal test results may reveal their status. We suggest that a written record of consent for non-invasive prenatal diagnosis should be used as a standard to help reinforce the serious nature of the test results. Where the father's carrier status could be revealed through fetal testing, he should be made aware of this before the results are available. Health professionals should discuss with the pregnant woman the best way to manage unsought information about the father's carrier status to minimise family disruption. PMID:25351779

  10. Performance of Momguard, a new non-invasive prenatal testing protocol developed in Korea

    PubMed Central

    Lee, Mi-Young; Cho, Dae-Yeon; Hwang, Ah Reum; Jeong, Bada; Kim, Jihun; Oh, Mijin

    2015-01-01

    Objective To evaluate the performance of Momguard, non-invasive prenatal test (NIPT) for detecting trisomy (T) 21, T18, T13, and sex-chromosome abnormalities recently developed in Korea. Methods This preliminary study formed part of a large prospective cohort study conducted at Asan Medical Center, Seoul, Korea. Only pregnant women who underwent both NIPT and confirmatory karyotyping were included in this study. NIPT results were compared with those of karyotype analyses. Results Among 93 eligible cases, NIPT results could not be obtained in one case due to a low fetal cell-free DNA fraction. Based on NIPT, eight cases of fetal aneuploidies, including T21 (n=5), T18 (n=2), and T13 (n=1), were identified. For T21 and T18, the sensitivity and specificity of NIPT were both 100%, with a false-positive and false-negative rate of 0% and a positive-predictive value of 100%. One patient classified as having intermediate risk for T13 by NIPT was confirmed to have T13 by karyotyping, and there were no false-negative cases. No cases of sex-chromosome anomalies were detected by NIPT or karyotyping during the study period. Conclusion Momguard is a reliable screening tool for detecting T21 and T18. For T13 and sex-chromosome anomalies, further prospective studies are necessary to confirm its utility. PMID:26430657

  11. Limited Clinical Utility of Non-invasive Prenatal Testing for Subchromosomal Abnormalities

    PubMed Central

    Lo, Kitty K.; Karampetsou, Evangelia; Boustred, Christopher; McKay, Fiona; Mason, Sarah; Hill, Melissa; Plagnol, Vincent; Chitty, Lyn S.

    2016-01-01

    The use of massively parallel sequencing of maternal cfDNA for non-invasive prenatal testing (NIPT) of aneuploidy is widely available. Recently, the scope of testing has increased to include selected subchromosomal abnormalities, but the number of samples reported has been small. We developed a calling pipeline based on a segmentation algorithm for the detection of these rearrangements in maternal plasma. The same read depth used in our standard pipeline for aneuploidy NIPT detected 15/18 (83%) samples with pathogenic rearrangements > 6 Mb but only 2/10 samples with rearrangements < 6 Mb, unless they were maternally inherited. There were two false-positive calls in 534 samples with no known subchromosomal abnormalities (specificity 99.6%). Using higher read depths, we detected 29/31 fetal subchromosomal abnormalities, including the three samples with maternally inherited microduplications. We conclude that test sensitivity is a function of the fetal fraction, read depth, and size of the fetal CNV and that at least one of the two false negatives is due to a low fetal fraction. The lack of an independent method for determining fetal fraction, especially for female fetuses, leads to uncertainty in test sensitivity, which currently has implications for this technique’s future as a clinical diagnostic test. Furthermore, to be effective, NIPT must be able to detect chromosomal rearrangements across the whole genome for a very low false-positive rate. Because standard NIPT can only detect the majority of larger (>6 Mb) chromosomal rearrangements and requires knowledge of fetal fraction, we consider that it is not yet ready for routine clinical implementation. PMID:26708752

  12. Limited Clinical Utility of Non-invasive Prenatal Testing for Subchromosomal Abnormalities.

    PubMed

    Lo, Kitty K; Karampetsou, Evangelia; Boustred, Christopher; McKay, Fiona; Mason, Sarah; Hill, Melissa; Plagnol, Vincent; Chitty, Lyn S

    2016-01-01

    The use of massively parallel sequencing of maternal cfDNA for non-invasive prenatal testing (NIPT) of aneuploidy is widely available. Recently, the scope of testing has increased to include selected subchromosomal abnormalities, but the number of samples reported has been small. We developed a calling pipeline based on a segmentation algorithm for the detection of these rearrangements in maternal plasma. The same read depth used in our standard pipeline for aneuploidy NIPT detected 15/18 (83%) samples with pathogenic rearrangements > 6 Mb but only 2/10 samples with rearrangements < 6 Mb, unless they were maternally inherited. There were two false-positive calls in 534 samples with no known subchromosomal abnormalities (specificity 99.6%). Using higher read depths, we detected 29/31 fetal subchromosomal abnormalities, including the three samples with maternally inherited microduplications. We conclude that test sensitivity is a function of the fetal fraction, read depth, and size of the fetal CNV and that at least one of the two false negatives is due to a low fetal fraction. The lack of an independent method for determining fetal fraction, especially for female fetuses, leads to uncertainty in test sensitivity, which currently has implications for this technique's future as a clinical diagnostic test. Furthermore, to be effective, NIPT must be able to detect chromosomal rearrangements across the whole genome for a very low false-positive rate. Because standard NIPT can only detect the majority of larger (>6 Mb) chromosomal rearrangements and requires knowledge of fetal fraction, we consider that it is not yet ready for routine clinical implementation. PMID:26708752

  13. Non-invasive prenatal testing for aneuploidy and beyond: challenges of responsible innovation in prenatal screening

    PubMed Central

    Dondorp, Wybo; de Wert, Guido; Bombard, Yvonne; Bianchi, Diana W; Bergmann, Carsten; Borry, Pascal; Chitty, Lyn S; Fellmann, Florence; Forzano, Francesca; Hall, Alison; Henneman, Lidewij; Howard, Heidi C; Lucassen, Anneke; Ormond, Kelly; Peterlin, Borut; Radojkovic, Dragica; Rogowski, Wolf; Soller, Maria; Tibben, Aad; Tranebjærg, Lisbeth; van El, Carla G; Cornel, Martina C

    2015-01-01

    This paper contains a joint ESHG/ASHG position document with recommendations regarding responsible innovation in prenatal screening with non-invasive prenatal testing (NIPT). By virtue of its greater accuracy and safety with respect to prenatal screening for common autosomal aneuploidies, NIPT has the potential of helping the practice better achieve its aim of facilitating autonomous reproductive choices, provided that balanced pretest information and non-directive counseling are available as part of the screening offer. Depending on the health-care setting, different scenarios for NIPT-based screening for common autosomal aneuploidies are possible. The trade-offs involved in these scenarios should be assessed in light of the aim of screening, the balance of benefits and burdens for pregnant women and their partners and considerations of cost-effectiveness and justice. With improving screening technologies and decreasing costs of sequencing and analysis, it will become possible in the near future to significantly expand the scope of prenatal screening beyond common autosomal aneuploidies. Commercial providers have already begun expanding their tests to include sex-chromosomal abnormalities and microdeletions. However, multiple false positives may undermine the main achievement of NIPT in the context of prenatal screening: the significant reduction of the invasive testing rate. This document argues for a cautious expansion of the scope of prenatal screening to serious congenital and childhood disorders, only following sound validation studies and a comprehensive evaluation of all relevant aspects. A further core message of this document is that in countries where prenatal screening is offered as a public health programme, governments and public health authorities should adopt an active role to ensure the responsible innovation of prenatal screening on the basis of ethical principles. Crucial elements are the quality of the screening process as a whole (including non

  14. Non-invasive prenatal testing for aneuploidy and beyond: challenges of responsible innovation in prenatal screening.

    PubMed

    Dondorp, Wybo; de Wert, Guido; Bombard, Yvonne; Bianchi, Diana W; Bergmann, Carsten; Borry, Pascal; Chitty, Lyn S; Fellmann, Florence; Forzano, Francesca; Hall, Alison; Henneman, Lidewij; Howard, Heidi C; Lucassen, Anneke; Ormond, Kelly; Peterlin, Borut; Radojkovic, Dragica; Rogowski, Wolf; Soller, Maria; Tibben, Aad; Tranebjærg, Lisbeth; van El, Carla G; Cornel, Martina C

    2015-11-01

    This paper contains a joint ESHG/ASHG position document with recommendations regarding responsible innovation in prenatal screening with non-invasive prenatal testing (NIPT). By virtue of its greater accuracy and safety with respect to prenatal screening for common autosomal aneuploidies, NIPT has the potential of helping the practice better achieve its aim of facilitating autonomous reproductive choices, provided that balanced pretest information and non-directive counseling are available as part of the screening offer. Depending on the health-care setting, different scenarios for NIPT-based screening for common autosomal aneuploidies are possible. The trade-offs involved in these scenarios should be assessed in light of the aim of screening, the balance of benefits and burdens for pregnant women and their partners and considerations of cost-effectiveness and justice. With improving screening technologies and decreasing costs of sequencing and analysis, it will become possible in the near future to significantly expand the scope of prenatal screening beyond common autosomal aneuploidies. Commercial providers have already begun expanding their tests to include sex-chromosomal abnormalities and microdeletions. However, multiple false positives may undermine the main achievement of NIPT in the context of prenatal screening: the significant reduction of the invasive testing rate. This document argues for a cautious expansion of the scope of prenatal screening to serious congenital and childhood disorders, only following sound validation studies and a comprehensive evaluation of all relevant aspects. A further core message of this document is that in countries where prenatal screening is offered as a public health programme, governments and public health authorities should adopt an active role to ensure the responsible innovation of prenatal screening on the basis of ethical principles. Crucial elements are the quality of the screening process as a whole (including non

  15. A non-invasive test for receptor binding applied to nephrogenic diabetes insipidus.

    PubMed Central

    Britton, K. E.; Tedder, R. S.; Khokhar, A. M.; Brown, N. J.; Davison, A.; Slater, J. D.

    1977-01-01

    Studies in animals have determined the importance of specific receptors to the action of many hormones and drugs. In man, a non-invasive external counting technique has been used and absence of receptor function has been demonstrated in a patient with nephrogenic diabetes insipidus using radioactively labelled arginine vasopressin. This is in contrast to the findings in a patient with pituitary diabetes insipidus and a normal control. These results suggest a model for the study of hormone and drug kinetics in man avoiding multiple samplings of biological fluids. PMID:196275

  16. For your interest? The ethical acceptability of using non-invasive prenatal testing to test 'purely for information'.

    PubMed

    Deans, Zuzana; Clarke, Angus J; Newson, Ainsley J

    2015-01-01

    Non-invasive prenatal testing (NIPT) is an emerging form of prenatal genetic testing that provides information about the genetic constitution of a foetus without the risk of pregnancy loss as a direct result of the test procedure. As with other prenatal tests, information from NIPT can help to make a decision about termination of pregnancy, plan contingencies for birth or prepare parents to raise a child with a genetic condition. NIPT can also be used by women and couples to test purely 'for information'. Here, no particular action is envisaged following the test; it is motivated entirely by an interest in the result. The fact that NIPT can be performed without posing a risk to the pregnancy could give rise to an increase in such requests. In this paper, we examine the ethical aspects of using NIPT 'purely for information', including the competing interests of the prospective parents and the future child, and the acceptability of testing for 'frivolous' reasons. Drawing on several clinical scenarios, we claim that arguments about testing children for genetic conditions are relevant to this debate. In addition, we raise ethical concerns over the potential for objectification of the child. We conclude that, in most cases, using NIPT to test for adult-onset conditions, carrier status or non-serious traits presenting in childhood would be unacceptable. PMID:25521970

  17. The impact of new trends in POCTs for companion diagnostics, non-invasive testing and molecular diagnostics.

    PubMed

    Huckle, David

    2015-06-01

    Point-of-care diagnostics have been slowly developing over several decades and have taken on a new importance in current healthcare delivery for both diagnostics and development of new drugs. Molecular diagnostics have become a key driver of technology change and opened up new areas in companion diagnostics for use alongside pharmaceuticals and in new clinical approaches such as non-invasive testing. Future areas involving smartphone and other information technology advances, together with new developments in molecular biology, microfluidics and surface chemistry are adding to advances in the market. The focus for point-of-care tests with molecular diagnostic technologies is focused on advancing effective applications. PMID:25990929

  18. 13C-egg white breath test: a non-invasive test of pancreatic trypsin activity in the small intestine

    PubMed Central

    Evenepoel, P; Hiele, M; Geypens, B; Geboes, K; Rutgeerts, P; Ghoos, Y

    2000-01-01

    BACKGROUND—The recent availability of egg white protein highly enriched with 13C has allowed breath test technology to be adapted for the study of protein digestion and absorption. Pancreatic trypsin is considered to be the key enzyme in the proteolytic cascade.
AIM—To evaluate trypsin activity in the small intestine of healthy volunteers and patients with pancreatic disease by a recently developed 13C-egg white breath test.
METHODS—A total of 48 healthy volunteers and 30 patients with pancreatic disease were studied after ingestion of a test meal consisting of 22 g 13C-labelled egg protein. Breath samples were taken before and after ingestion of the meal and analysed for 13CO2 concentration. Moreover, pancreatic trypsin output after maximal stimulation was measured in 13 patients and nine healthy volunteers.
RESULTS—The six hour cumulative 13CO2 excretion in breath was significantly lower in patients than controls (mean (SEM): 6.23 (0.82)% v 19.16 (0.58)%, p<0.0001). An excellent correlation was found between the six hour cumulative 13CO2 excretion and trypsin activity after maximal pancreatic stimulation.
CONCLUSION—The non-invasive 13C-egg white breath test is promising as an indirect pancreatic proteolytic function test.


Keywords: breath test; pancreatic disease; trypsin; protein; assimilation PMID:10601055

  19. Non-invasive prenatal testing for fetal chromosome abnormalities: review of clinical and ethical issues

    PubMed Central

    Gekas, Jean; Langlois, Sylvie; Ravitsky, Vardit; Audibert, François; van den Berg, David Gradus; Haidar, Hazar; Rousseau, François

    2016-01-01

    Genomics-based non-invasive prenatal screening using cell-free DNA (cfDNA screening) was proposed to reduce the number of invasive procedures in current prenatal diagnosis for fetal aneuploidies. We review here the clinical and ethical issues of cfDNA screening. To date, it is not clear how cfDNA screening is going to impact the performances of clinical prenatal diagnosis and how it could be incorporated in real life. The direct marketing to users may have facilitated the early introduction of cfDNA screening into clinical practice despite limited evidence-based independent research data supporting this rapid shift. There is a need to address the most important ethical, legal, and social issues before its implementation in a mass setting. Its introduction might worsen current tendencies to neglect the reproductive autonomy of pregnant women. PMID:26893576

  20. Non-invasive prenatal testing for fetal chromosome abnormalities: review of clinical and ethical issues.

    PubMed

    Gekas, Jean; Langlois, Sylvie; Ravitsky, Vardit; Audibert, François; van den Berg, David Gradus; Haidar, Hazar; Rousseau, François

    2016-01-01

    Genomics-based non-invasive prenatal screening using cell-free DNA (cfDNA screening) was proposed to reduce the number of invasive procedures in current prenatal diagnosis for fetal aneuploidies. We review here the clinical and ethical issues of cfDNA screening. To date, it is not clear how cfDNA screening is going to impact the performances of clinical prenatal diagnosis and how it could be incorporated in real life. The direct marketing to users may have facilitated the early introduction of cfDNA screening into clinical practice despite limited evidence-based independent research data supporting this rapid shift. There is a need to address the most important ethical, legal, and social issues before its implementation in a mass setting. Its introduction might worsen current tendencies to neglect the reproductive autonomy of pregnant women. PMID:26893576

  1. Non-invasive prenatal aneuploidy testing at chromosomes 13, 18, 21, X, and Y, using targeted sequencing of polymorphic loci

    PubMed Central

    Zimmermann, Bernhard; Hill, Matthew; Gemelos, George; Demko, Zachary; Banjevic, Milena; Baner, Johan; Ryan, Allison; Sigurjonsson, Styrmir; Chopra, Nikhil; Dodd, Michael; Levy, Brynn; Rabinowitz, Matthew

    2012-01-01

    Objective Develop a non-invasive prenatal test based on analysis of cell-free DNA in maternal blood to detect fetal aneuploidy at chromosomes 13, 18, 21, X, and Y. Methods 166 samples from pregnant women, including eleven trisomy 21, three trisomy 18, two trisomy 13, two 45,X, and two 47,XXY samples were analyzed using an informatics-based method. Cell-free DNA from maternal blood was isolated and amplified using a multiplex PCR assay targeting 11,000 SNPs on chromosomes 13, 18, 21, X, and Y in a single reaction, then sequenced. A Bayesian-based Maximum Likelihood statistical method was applied to determine the chromosomal count of the five chromosomes interrogated in each sample, along with a sample-specific calculated accuracy for each test result. Results The algorithm correctly reported the chromosome copy number at all five chromosomes in 145 samples that passed a DNA quality test, for a total of 725/725 correct calls. The average calculated accuracy for these samples was 99.92%. Twenty-one samples did not pass the DNA quality test. Conclusions This informatics-based method non-invasively detected fetuses with trisomy 13, 18, and 21, 45,X, and 47,XXY with high sample-specific calculated accuracies for each individual chromosome and across all five chromosomes. PMID:23108718

  2. Comparison of accuracy of fibrosis degree classifications by liver biopsy and non-invasive tests in chronic hepatitis C

    PubMed Central

    2011-01-01

    Background Non-invasive tests have been constructed and evaluated mainly for binary diagnoses such as significant fibrosis. Recently, detailed fibrosis classifications for several non-invasive tests have been developed, but their accuracy has not been thoroughly evaluated in comparison to liver biopsy, especially in clinical practice and for Fibroscan. Therefore, the main aim of the present study was to evaluate the accuracy of detailed fibrosis classifications available for non-invasive tests and liver biopsy. The secondary aim was to validate these accuracies in independent populations. Methods Four HCV populations provided 2,068 patients with liver biopsy, four different pathologist skill-levels and non-invasive tests. Results were expressed as percentages of correctly classified patients. Results In population #1 including 205 patients and comparing liver biopsy (reference: consensus reading by two experts) and blood tests, Metavir fibrosis (FM) stage accuracy was 64.4% in local pathologists vs. 82.2% (p < 10-3) in single expert pathologist. Significant discrepancy (≥ 2FM vs reference histological result) rates were: Fibrotest: 17.2%, FibroMeter2G: 5.6%, local pathologists: 4.9%, FibroMeter3G: 0.5%, expert pathologist: 0% (p < 10-3). In population #2 including 1,056 patients and comparing blood tests, the discrepancy scores, taking into account the error magnitude, of detailed fibrosis classification were significantly different between FibroMeter2G (0.30 ± 0.55) and FibroMeter3G (0.14 ± 0.37, p < 10-3) or Fibrotest (0.84 ± 0.80, p < 10-3). In population #3 (and #4) including 458 (359) patients and comparing blood tests and Fibroscan, accuracies of detailed fibrosis classification were, respectively: Fibrotest: 42.5% (33.5%), Fibroscan: 64.9% (50.7%), FibroMeter2G: 68.7% (68.2%), FibroMeter3G: 77.1% (83.4%), p < 10-3 (p < 10-3). Significant discrepancy (≥ 2 FM) rates were, respectively: Fibrotest: 21.3% (22.2%), Fibroscan: 12.9% (12.3%), FibroMeter2G: 5

  3. Non-invasive assessment of reproductive status and stress in captive Asian elephants in three south Indian zoos.

    PubMed

    Kumar, Vinod; Palugulla Reddy, Vivekananda; Kokkiligadda, Adiseshu; Shivaji, Sisinthy; Umapathy, Govindhaswamy

    2014-05-15

    Asian elephants in captivity need immediate attention to be bred so as to meet the increasing demand for captive elephants and to overcome the dependence on supplementing the captive stock with wild animals. Unfortunately, captive breeding programs across the globe have met with limited success and therefore more effort is needed to improve breeding in captivity. Endocrine profiling of reproductive hormones (progestagens and androgens) and the stress hormone (glucocorticoids) could facilitate better management and breeding strategies. In the present study, we investigated reproductive and stress physiology of 12 captive Asian elephants for 10-27 months using a non-invasive method based on steroid analysis of 1700 elephant dung samples. Most of the elephants were cycling regularly. Males during musth showed increased fecal androgen metabolite concentrations and exhibited a slight increase in fecal glucocorticoid metabolite levels. Elephants used in public festivals and processions showed significantly increased in faecal glucocorticoid metabolite levels. The results indicate that captive elephants require periodic health care, better husbandry practices and scientific management for sustainable captive population. PMID:24698789

  4. Non-invasive assessment of hemispheric language dominance by optical topography during a brief passive listening test: A pilot study

    PubMed Central

    Bembich, Stefano; Demarini, Sergio; Clarici, Andrea; Massaccesi, Stefano; Grasso, Domenico Leonardo

    2011-01-01

    Summary Background The Wada test is usually used for pre-surgical assessment of language lateralization. Considering its invasiveness and risk of complications, alternative methods have been proposed but they are not always applicable to non-cooperative patients. In this study we explored the possibility of using optical topography (OT) – a multichannel near-infrared system – for non-invasive assessment of hemispheric language dominance during passive listening. Material/Methods Cortical activity was monitored in a sample of healthy, adult Italian native speakers, all right-handed. We assessed changes in oxy-haemoglobin concentration in temporal, parietal and posterior frontal lobes during a passive listening of bi-syllabic words and vowel-consonant-vowel syllables lasting less then 3 minutes. Activated channels were identified by t tests. Results Left hemisphere showed significant activity only during the passive listening of bi-syllabic words. Specifically, the superior temporal gyrus, the supramarginal gyrus and the posterior inferior parietal lobe were activated. Conclusions During passive listening of bi-syllabic words, right handed healthy adults showed a significant activation in areas already known to be involved in speech comprehension. Although more research is needed, OT proved to be a promising alternative to the Wada test for non-invasive assessment of hemispheric language lateralization, even if using a particularly brief trial, which has been designed for future applications with non-cooperative subjects. PMID:22129900

  5. Use of Entero-Test, a simple approach for non-invasive clinical evaluation of the biliary disposition of drugs

    PubMed Central

    Guiney, William J; Beaumont, Claire; Thomas, Steve R; Robertson, Darren C; McHugh, Simon M; Koch, Annelize; Richards, Duncan

    2011-01-01

    AIM To evaluate the non-invasive collection of bile from healthy human subjects for the qualitative characterization of the biliary disposition of a drug, using spectrometric techniques. METHODS Twenty subjects underwent non-invasive bile capture using a peroral string test (Entero-Test) device prior to and following a single oral dose of simvastatin (80 mg). The device, consisting of a weighted gelatin capsule containing a highly absorbent nylon string, was swallowed by each subject with the proximal end of the string taped to the face. Once the weighted string was judged to have reached the duodenum, gallbladder contraction was stimulated in order to release bile. The string was then retrieved via the mouth, and bile samples were analysed for drug-related material using spectrometric and spectroscopic techniques following solvent extraction. RESULTS Numerous metabolites of simvastatin were detected, and the major metabolites were consistent with those reported from studies where bile was collected using invasive techniques from patients dosed with [14C]-simvastatin. CONCLUSIONS The results from this study demonstrate the utility of deploying the Entero-Test in human studies to provide structural information on biliary metabolites. This can be readily applied in drug development studies, including those in the target patient population and may eliminate the need for more invasive sampling techniques. PMID:21366667

  6. The impact of oxidative stress on islet transplantation and monitoring the graft survival by non-invasive imaging.

    PubMed

    Ramkumar, K M; Sekar, T V; Bhakkiyalakshmi, E; Foygel, Kira; Rajaguru, P; Berger, F; Paulmurugan, R

    2013-01-01

    and C-peptide levels. These biochemical measurements provide markers at only the late stages of islet rejection. Use of molecular imaging techniques has the potential for real-time non-invasive monitoring of the functional status and viability of transplanted islet grafts in living animals. This review mainly focuses on the current status of islet transplantations, potential preventive strategies used to reduce oxidative stress-mediated toxicity in islet grafts, and use of molecular imaging as a tool to quantitatively evaluate the functional status of the transplanted islets in living animals. PMID:23317098

  7. An Optimized Method for Accurate Fetal Sex Prediction and Sex Chromosome Aneuploidy Detection in Non-Invasive Prenatal Testing

    PubMed Central

    Li, Haibo; Ding, Jie; Wen, Ping; Zhang, Qin; Xiang, Jingjing; Li, Qiong; Xuan, Liming; Kong, Lingyin; Mao, Yan; Zhu, Yijun; Shen, Jingjing; Liang, Bo; Li, Hong

    2016-01-01

    Massively parallel sequencing (MPS) combined with bioinformatic analysis has been widely applied to detect fetal chromosomal aneuploidies such as trisomy 21, 18, 13 and sex chromosome aneuploidies (SCAs) by sequencing cell-free fetal DNA (cffDNA) from maternal plasma, so-called non-invasive prenatal testing (NIPT). However, many technical challenges, such as dependency on correct fetal sex prediction, large variations of chromosome Y measurement and high sensitivity to random reads mapping, may result in higher false negative rate (FNR) and false positive rate (FPR) in fetal sex prediction as well as in SCAs detection. Here, we developed an optimized method to improve the accuracy of the current method by filtering out randomly mapped reads in six specific regions of the Y chromosome. The method reduces the FNR and FPR of fetal sex prediction from nearly 1% to 0.01% and 0.06%, respectively and works robustly under conditions of low fetal DNA concentration (1%) in testing and simulation of 92 samples. The optimized method was further confirmed by large scale testing (1590 samples), suggesting that it is reliable and robust enough for clinical testing. PMID:27441628

  8. An Optimized Method for Accurate Fetal Sex Prediction and Sex Chromosome Aneuploidy Detection in Non-Invasive Prenatal Testing.

    PubMed

    Wang, Ting; He, Quanze; Li, Haibo; Ding, Jie; Wen, Ping; Zhang, Qin; Xiang, Jingjing; Li, Qiong; Xuan, Liming; Kong, Lingyin; Mao, Yan; Zhu, Yijun; Shen, Jingjing; Liang, Bo; Li, Hong

    2016-01-01

    Massively parallel sequencing (MPS) combined with bioinformatic analysis has been widely applied to detect fetal chromosomal aneuploidies such as trisomy 21, 18, 13 and sex chromosome aneuploidies (SCAs) by sequencing cell-free fetal DNA (cffDNA) from maternal plasma, so-called non-invasive prenatal testing (NIPT). However, many technical challenges, such as dependency on correct fetal sex prediction, large variations of chromosome Y measurement and high sensitivity to random reads mapping, may result in higher false negative rate (FNR) and false positive rate (FPR) in fetal sex prediction as well as in SCAs detection. Here, we developed an optimized method to improve the accuracy of the current method by filtering out randomly mapped reads in six specific regions of the Y chromosome. The method reduces the FNR and FPR of fetal sex prediction from nearly 1% to 0.01% and 0.06%, respectively and works robustly under conditions of low fetal DNA concentration (1%) in testing and simulation of 92 samples. The optimized method was further confirmed by large scale testing (1590 samples), suggesting that it is reliable and robust enough for clinical testing. PMID:27441628

  9. Non-invasive panel tests for gastrointestinal motility monitoring within the MARS-500 Project

    PubMed Central

    Roda, Aldo; Mirasoli, Mara; Guardigli, Massimo; Simoni, Patrizia; Festi, Davide; Afonin, Boris; Vasilyeva, Galina

    2013-01-01

    AIM: To develop an integrated approach for monitoring gastrointestinal motility and inflammation state suitable for application in long-term spaceflights. METHODS: Breath tests based on the oral administration of 13C-labeled or hydrogen-producing substrates followed by the detection of their metabolites (13CO2 or H2) in breath were used to measure gastrointestinal motility parameters during the 520-d spaceflight ground simulation within the MARS-500 Project. In particular, the gastric emptying rates of solid and liquid contents were evaluated by 13C-octanoic acid and 13C-acetate breath tests, respectively, whereas the orocecal transit time was assessed by an inulin H2-breath test, which was performed simultaneously with the 13C-octanoic acid breath test. A ready-to-eat, standardized pre-packaged muffin containing 100 mg of 13C-octanoic acid was used in the 13C-octanoic acid breath test to avoid the extemporaneous preparation of solid meals. In addition, a cassette-type lateral flow immunoassay was employed to detect fecal calprotectin, a biomarker of intestinal inflammation. Because no items could be introduced into the simulator during the experiment, all materials and instrumentation required for test performance during the entire mission simulation had to be provided at the beginning of the experiment. RESULTS: The experiments planned during the simulation of a manned flight to Mars could be successfully performed by the crewmembers without any external assistance. No evident alterations (i.e., increasing or decreasing trends) in the gastric emptying rates were detected using the 13C-breath tests during the mission simulation, as the gastric emptying half-times were in the range of those reported for healthy subjects. In contrast to the 13C-breath tests, the results of the inulin H2-breath test were difficult to interpret because of the high variability of the H2 concentration in the breath samples, even within the same subject. This variability suggested that

  10. Nondestructive testing and evaluation of composites by non-invasive IR Imaging techniques

    NASA Astrophysics Data System (ADS)

    Mulaveesala, Ravibabu; Siddiqui, Juned A.; Arora, Vanita; Ghali, S. V.; Muniyappa, Amarnath; Takei, Masahiro

    2013-05-01

    InfraRed Thermography (IRT) is one of the promising technique for non-destructive testing method for characterization of materials. This technique relies on evaluation of the surface temperature variations to detect the presence of surface and subsurface anomalies within the material. Due to its whole field and remote testing capabilities, IRT has gained significant importance in testing of Glass Fiber Reinforced Plastic (GFRP) materials. A GFRP sample with defects of various sizes at a given depth was inspected using non-stationary thermographic techniques. In order to highlight the defect detection capabilities of the proposed non-stationary schemes, a comparison has been made using matched excitation energy in frequency domain by taking signal to noise ratio into consideration.

  11. The urea breath test: a non-invasive clinical tool for detecting Helicobacter pylori infection.

    PubMed

    Perri, F; Ghoos, Y; Hiele, M; Andriulli, A; Rutgeerts, P

    1995-03-01

    The urea breath test exploits the urease enzyme of Helicobacter pylori. The hydrolysis of labelled urea releases labelled carbon dioxide that is excreted in the breath. Distribution of urea throughout the stomach prevents sampling errors and allows for semiquantitative assessment of the extent of Helicobacter pylori infection. The urea breath test is very specific and sensitive and can be proposed as the method of choice for detecting Helicobacter pylori infection in ulcer patients before and after eradicating treatment as well as in epidemiological studies. PMID:7579592

  12. Positive Attitudes towards Non-Invasive Prenatal Testing (NIPT) in a Swedish Cohort of 1,003 Pregnant Women

    PubMed Central

    Nordenskjöld, Magnus; Gustavsson, Peter; Wincent, Josephine

    2016-01-01

    Objective The clinical utilization of non-invasive prenatal testing (NIPT) for identification of fetal aneuploidies is expanding worldwide. The aim of this study was to gain an increased understanding of pregnant women’s awareness, attitudes, preferences for risk information and decision-making concerning prenatal examinations with emphasis on NIPT, before its introduction into Swedish healthcare. Method Pregnant women were recruited to fill in a questionnaire, including multiple-choice questions and Likert scales, at nine maternity clinics located in different areas of Stockholm, Sweden. Results In total, 1,003 women participated in the study (86% consent rate). The vast majority (90.7%) considered examinations aiming to detect fetal abnormalities to be good. Regarding NIPT, 59.8% stated that they had heard about the method previously, yet 74.0% would like to use the test if available. The main factor affecting the women’s decision to undergo prenatal chromosomal screening was worry about the baby’s health (82.5%), followed by the urge to have as much information as possible about the fetus (54.5%). Most women (79.9%) preferred to receive NIPT information orally. Conclusion The overwhelming majority of a cohort of 1,003 pregnant women considered prenatal examinations good. Moreover, the majority had a positive attitude towards NIPT and would like to use the test if available. PMID:27195496

  13. Attitudes of pregnant women and male partners towards non-invasive prenatal testing and widening the scope of prenatal screening

    PubMed Central

    van Schendel, Rachèl V; Kleinveld, Johanna H; Dondorp, Wybo J; Pajkrt, Eva; Timmermans, Danielle R M; Holtkamp, Kim C A; Karsten, Margreet; Vlietstra, Anne L; Lachmeijer, Augusta M A; Henneman, Lidewij

    2014-01-01

    Non-invasive prenatal testing (NIPT) and its potential to test for multiple disorders has received much attention. This study explores attitudes of women and men towards NIPT, and their views on widening the scope of prenatal testing in a country with a low uptake of prenatal screening (The Netherlands). Five focus groups with low-risk pregnant women (n=28), three focus groups with men (n=19) and 13 interviews with high- and low-risk pregnant women were conducted. Participants felt that current prenatal screening has great disadvantages such as uncertain results and risk of miscarriage from follow-up diagnostics. Characteristics of NIPT (accurate, safe and early testing) could therefore diminish these disadvantages of prenatal screening and help lower the barrier for participation. This suggests that NIPT might allow couples to decide about prenatal testing based mostly on their will to test or not, rather than largely based on fear of miscarriage risk or the uncertainty of results. The lower barrier for participation was also seen as a downside that could lead to uncritical use or pressure to test. Widening the scope of prenatal testing was seen as beneficial for severe disorders, although it was perceived difficult to determine where to draw the line. Participants argued that there should be a limit to the scope of NIPT, avoiding testing for minor abnormalities. The findings suggest that NIPT could enable more meaningful decision-making for prenatal screening. However, to ensure voluntary participation, especially when testing for multiple disorders, safeguards on the basis of informed decision-making will be of utmost importance. PMID:24642832

  14. Non-invasive prenatal testing: a review of international implementation and challenges

    PubMed Central

    Allyse, Megan; Minear, Mollie A; Berson, Elisa; Sridhar, Shilpa; Rote, Margaret; Hung, Anthony; Chandrasekharan, Subhashini

    2015-01-01

    Noninvasive prenatal genetic testing (NIPT) is an advance in the detection of fetal chromosomal aneuploidies that analyzes cell-free fetal DNA in the blood of a pregnant woman. Since its introduction to clinical practice in Hong Kong in 2011, NIPT has quickly spread across the globe. While many professional societies currently recommend that NIPT be used as a screening method, not a diagnostic test, its high sensitivity (true positive rate) and specificity (true negative rate) make it an attractive alternative to the serum screens and invasive tests currently in use. Professional societies also recommend that NIPT be accompanied by genetic counseling so that families can make informed reproductive choices. If NIPT becomes more widely adopted, States will have to implement regulation and oversight to ensure it fits into existing legal frameworks, with particular attention to returning fetal sex information in areas where sex-based abortions are prevalent. Although there are additional challenges for NIPT uptake in the developing world, including the lack of health care professionals and infrastructure, the use of NIPT in low-resource settings could potentially reduce the need for skilled clinicians who perform invasive testing. Future advances in NIPT technology promise to expand the range of conditions that can be detected, including single gene disorders. With these advances come questions of how to handle incidental findings and variants of unknown significance. Moving forward, it is essential that all stakeholders have a voice in crafting policies to ensure the ethical and equitable use of NIPT across the world. PMID:25653560

  15. Non-Invasive Prenatal Testing Using Cell Free DNA in Maternal Plasma: Recent Developments and Future Prospects

    PubMed Central

    Benn, Peter

    2014-01-01

    Recent advances in molecular genetic technologies have facilitated non-invasive prenatal testing (NIPT) through the analysis of cell-free fetal DNA in maternal plasma. NIPT can be used to identify monogenic disorders including the identification of autosomal recessive disorders where the maternally inherited mutation needs to be identified in the presence of an excess of maternal DNA that contains the same mutation. In the future, simultaneous screening for multiple monogenic disorders is anticipated. Several NIPT methods have been developed to screen for trisomy. These have been shown to be effective for fetal trisomy 21, 18 and 13. Although the testing has been extended to sex chromosome aneuploidy, robust estimates of the efficacy are not yet available and maternal mosaicism for gain or loss of an X-chromosome needs to be considered. Using methods based on the analysis of single nucleotide polymorphisms, diandric triploidy can be identified. NIPT is being developed to identify a number of microdeletion syndromes including α-globin gene deletion. NIPT is a profoundly important development in prenatal care that is substantially advancing the individual patient and public health benefits achieved through conventional prenatal screening and diagnosis. PMID:26237390

  16. Non-invasive prenatal testing for fetal sex determination: is ultrasound still relevant?

    PubMed

    Colmant, Claire; Morin-Surroca, Michèle; Fuchs, Florent; Fernandez, Hervé; Senat, Marie-Victoire

    2013-12-01

    Early prenatal diagnosis of fetal sex is necessary to optimize pregnancy management in families known to be at risk of some heritable disorders. The demonstration of cell-free fetal DNA (cffDNA) in the mother's blood has made it possible to identify Y chromosome sequences in maternal blood and to determine fetal sex noninvasively, during the first trimester. This procedure can significantly reduce the number of invasive procedures for women with fetuses at risk of sex-linked diseases and optimize the management of these pregnancies. Fetal sex can be diagnosed by ultrasound with the same sensitivity and specificity, but later in pregnancy. We performed a review of the published literature evaluating the use of cffDNA and ultrasound for prenatal determination of fetal sex during the first trimester of pregnancy. We present the feasibility of the two methods and their impact on clinical practice. We applied a sensitive search of multiple bibliographic databases including Pubmed (MEDLINE), EMBASE, the Cochrane Library and Web of science between 1998 and 2013. Sixteen reports of the determination of fetal sex in maternal blood and 13 reports of the determination by ultrasound met our inclusion criteria. We found a sensitivity and specificity of nearly 100% from 8 weeks of gestation for cffDNA and from 13 weeks of gestation for ultrasound respectively. Based on this review, we conclude that fetal sex can be determined with a high level of accuracy by analyzing cffDNA and at an earlier gestation than ultrasound. Ten years after the first feasibility study, the French National Authority for Health (HAS) released a technological assessment report on the determination of fetal sex in maternal blood, which has resulted in validating this test for reimbursement by the national health insurance fund for the following indications: X-linked recessive disease and congenital adrenal hyperplasia. PMID:24094458

  17. DNA methylome profiling of maternal peripheral blood and placentas reveal potential fetal DNA markers for non-invasive prenatal testing.

    PubMed

    Xiang, Yuqian; Zhang, Junyu; Li, Qiaoli; Zhou, Xinyao; Wang, Teng; Xu, Mingqing; Xia, Shihui; Xing, Qinghe; Wang, Lei; He, Lin; Zhao, Xinzhi

    2014-09-01

    Utilizing epigenetic (DNA methylation) differences to differentiate between maternal peripheral blood (PBL) and fetal (placental) DNA has been a promising strategy for non-invasive prenatal testing (NIPT). However, the differentially methylated regions (DMRs) have yet to be fully ascertained. In the present study, we performed genome-wide comparative methylome analysis between maternal PBL and placental DNA from pregnancies of first trimester by methylated DNA immunoprecipitation-sequencing (MeDIP-Seq) and Infinium HumanMethylation450 BeadChip assays. A total of 36 931 DMRs and 45 804 differentially methylated sites (DMSs) covering the whole genome, exclusive of the Y chromosome, were identified via MeDIP-Seq and Infinium 450k array, respectively, of which 3759 sites in 2188 regions were confirmed by both methods. Not only did we find the previously reported potential fetal DNA markers in our identified DMRs/DMSs but also we verified fully the identified DMRs/DMSs in the validation round by MassARRAY EpiTYPER. The screened potential fetal DNA markers may be used for NIPT on aneuploidies and other chromosomal diseases, such as cri du chat syndrome and velo-cardio-facial syndrome. In addition, these potential markers may have application in the early diagnosis of placental dysfunction, such as pre-eclampsia. PMID:24996894

  18. Development and validation of a measure of informed choice for women undergoing non-invasive prenatal testing for aneuploidy

    PubMed Central

    Lewis, Celine; Hill, Melissa; Skirton, Heather; Chitty, Lyn S

    2016-01-01

    Non-invasive prenatal testing (NIPT) using cell-free DNA for aneuploidy is a highly accurate screening test; however, concerns exist around the potential for routinisation of testing. The multidimensional measure of informed choice (MMIC) is a quantitative instrument developed to assess informed choice for Down syndrome screening (DSS). We have validated a modified MMIC for NIPT and measured informed choice among women offered NIPT in a public health service. The measure was distributed to women recruited across eight maternity units in the United Kingdom who had accepted DSS. Construct validity was assessed by simultaneously conducting qualitative interviews. Five hundred and eighty-five questionnaires were completed and 45 interviews conducted after blood-draw (or equivalent for those that declined NIPT). The measure demonstrated good internal consistency and internal validity. Results indicate the vast majority of women (89%) made an informed choice; 95% were judged to have good knowledge, 88% had a positive attitude and 92% had deliberated. Of the 11% judged to have made an uninformed choice, 55% had not deliberated, 41% had insufficient knowledge, and 19% had a negative attitude. Ethnicity (OR=2.78, P=0.003) and accepting NIPT (OR=16.05, P=0.021) were found to be significant predictors of informed choice. The high rate of informed choice is likely to reflect the importance placed on the provision of pre-test counselling in this study. It will be vital to ensure that this is maintained once NIPT is offered in routine clinical practice. PMID:26508572

  19. Development and validation of a measure of informed choice for women undergoing non-invasive prenatal testing for aneuploidy.

    PubMed

    Lewis, Celine; Hill, Melissa; Skirton, Heather; Chitty, Lyn S

    2016-06-01

    Non-invasive prenatal testing (NIPT) using cell-free DNA for aneuploidy is a highly accurate screening test; however, concerns exist around the potential for routinisation of testing. The multidimensional measure of informed choice (MMIC) is a quantitative instrument developed to assess informed choice for Down syndrome screening (DSS). We have validated a modified MMIC for NIPT and measured informed choice among women offered NIPT in a public health service. The measure was distributed to women recruited across eight maternity units in the United Kingdom who had accepted DSS. Construct validity was assessed by simultaneously conducting qualitative interviews. Five hundred and eighty-five questionnaires were completed and 45 interviews conducted after blood-draw (or equivalent for those that declined NIPT). The measure demonstrated good internal consistency and internal validity. Results indicate the vast majority of women (89%) made an informed choice; 95% were judged to have good knowledge, 88% had a positive attitude and 92% had deliberated. Of the 11% judged to have made an uninformed choice, 55% had not deliberated, 41% had insufficient knowledge, and 19% had a negative attitude. Ethnicity (OR=2.78, P=0.003) and accepting NIPT (OR=16.05, P=0.021) were found to be significant predictors of informed choice. The high rate of informed choice is likely to reflect the importance placed on the provision of pre-test counselling in this study. It will be vital to ensure that this is maintained once NIPT is offered in routine clinical practice. PMID:26508572

  20. An Economic Analysis of Cell-Free DNA Non-Invasive Prenatal Testing in the US General Pregnancy Population

    PubMed Central

    Benn, Peter; Curnow, Kirsten J.; Chapman, Steven; Michalopoulos, Steven N.; Hornberger, John; Rabinowitz, Matthew

    2015-01-01

    Objective Analyze the economic value of replacing conventional fetal aneuploidy screening approaches with non-invasive prenatal testing (NIPT) in the general pregnancy population. Methods Using decision-analysis modeling, we compared conventional screening to NIPT with cell-free DNA (cfDNA) analysis in the annual US pregnancy population. Sensitivity and specificity for fetal aneuploidies, trisomy 21, trisomy 18, trisomy 13, and monosomy X, were estimated using published data and modeling of both first- and second trimester screening. Costs were assigned for each prenatal test component and for an affected birth. The overall cost to the healthcare system considered screening costs, the number of aneuploid cases detected, invasive procedures performed, procedure-related euploid losses, and affected pregnancies averted. Sensitivity analyses evaluated the effect of variation in parameters. Costs were reported in 2014 US Dollars. Results Replacing conventional screening with NIPT would reduce healthcare costs if it can be provided for $744 or less in the general pregnancy population. The most influential variables were timing of screening entry, screening costs, and pregnancy termination rates. Of the 13,176 affected pregnancies undergoing screening, NIPT detected 96.5% (12,717/13,176) of cases, compared with 85.9% (11,314/13,176) by conventional approaches. NIPT reduced invasive procedures by 60.0%, with NIPT and conventional methods resulting in 24,596 and 61,430 invasive procedures, respectively. The number of procedure-related euploid fetal losses was reduced by 73.5% (194/264) in the general screening population. Conclusion Based on our analysis, universal application of NIPT would increase fetal aneuploidy detection rates and can be economically justified. Offering this testing to all pregnant women is associated with substantial prenatal healthcare benefits. PMID:26158465

  1. Development of new non-invasive tests for colorectal cancer screening: The relevance of information on adenoma detection

    PubMed Central

    Haug, Ulrike; Knudsen, Amy B.; Lansdorp-Vogelaar, Iris; Kuntz, Karen M.

    2014-01-01

    Researchers are actively pursuing the development of a new non-invasive test (NIT) for colorectal cancer (CRC) screening as an alternative to fecal occult blood tests (FOBTs). The majority of pilot studies focus on the detection of invasive CRC rather than precursor lesions (i.e., adenomas). We aimed to explore the relevance of adenoma detection for the viability of an NIT for CRC screening by considering a hypothetical test that does not detect adenomas beyond chance. We used the Simulation Model of Colorectal Cancer (SimCRC) to estimate the effectiveness of CRC screening and the lifetime costs (payers’ perspective) for a cohort of US 50-year-olds to whom CRC screening is offered from age 50–75. We compared annual screening with guaiac and immunochemical FOBTs (with sensitivities up to 70% and 24% for CRC and adenomas, respectively) to annual screening with a hypothetical NIT (sensitivity of 90% for CRC, no detection of adenomas beyond chance, specificity and cost similar to FOBTs). Screening with the NIT was not more effective, but was 29–44% more costly than screening with FOBTs. The findings were robust to varying the screening interval, the NIT’s sensitivity for CRC, adherence rates favoring the NIT, and the NIT’s unit cost. A comparative modelling approach using a model that assumes a shorter adenoma dwell time (MISCAN-COLON) confirmed the superiority of the immunochemical FOBT over a NIT with no ability to detect adenomas. Information on adenoma detection is crucial to determine whether a new NIT is a viable alternative to FOBTs for CRC screening. Current evidence thus lacks an important piece of information to identify marker candidates that hold real promise and deserve further (large-scale) evaluation. PMID:25403937

  2. Introducing the non-invasive prenatal test for trisomy 21 in Belgium: a cost-consequences analysis

    PubMed Central

    Neyt, Mattias; Hulstaert, Frank; Gyselaers, Wilfried

    2014-01-01

    Background The first- and second-trimester screening for trisomy 21 (T21) are reimbursed for all pregnant women in Belgium. Using a cut-off risk of 1:300 for T21, about 5% of all pregnant women are referred for definitive prenatal diagnosis using an invasive test, at a sensitivity of (only) 72.5%. The sensitivity and specificity of the non-invasive prenatal test (NIPT) are over 99% but come at a cost of €460 (£373) per test. The objective is to estimate the consequences of introducing NIPT for the detection of T21. Methods A cost-consequences analysis was performed presenting the impact on benefits, harms and costs. Context-specific real-world information was available to set up a model reflecting the current screening situation in Belgium. This model was used to construct the second and first line NIPT screening scenarios applying information from the literature on NIPT's test accuracy. Results Introducing NIPT in the first or second line reduces harm by decreasing the number of procedure-related miscarriages after invasive testing. In contrast with NIPT in the second line, offering NIPT in the first line additionally will miss fewer cases of T21 due to less false-negative test results. The introduction of NIPT in the second line results in cost savings, which is not true for NIPT at the current price in the first line. If NIPT is offered to all pregnant women, the price should be lowered to about €150 to keep the screening cost per T21 diagnosis constant. Conclusions In Belgium, the introduction and reimbursement of NIPT as a second line triage test significantly reduces procedure-related miscarriages without increasing the short-term screening costs. Offering and reimbursing NIPT in the first line to all pregnant women is preferred in the long term, as it would, in addition, miss fewer cases of T21. However, taking into account the government's limited resources for universal reimbursement, the price of NIPT should first be lowered substantially before this

  3. In-vivo testing of a non-invasive prototype device for the continuous monitoring of intracerebral hemorrhage

    PubMed Central

    Kandadai, Madhuvanthi A.; Korfhagen, Joseph; Beiler, Shauna; Beiler, Chris; Wagner, Kenneth; Adeoye, Opeolu M.; Shaw, George J.

    2014-01-01

    Background Intracerebral hemorrhage (ICH) is a stroke subtype with the highest mortality rate. Hematoma expansion and re-bleeding post-ICH are common and exacerbate the initial cerebral insult. There is a need for continuous monitoring of the neurologic status of patients with an ICH injury. New Method A prototype device for non-invasive continuous monitoring of an ICH was developed and tested in-vivo using a porcine ICH model. The device consists of receiving and transmitting antennae in the 400–1000 MHz frequency range, placed directly in line with the site of the ICH. The device exploits the differences in the dielectric properties and geometry of tissue media of a healthy brain and a brain with an ICH injury. The power received by the receiving antenna is measured and the percent change in power received immediately after infusion of blood and 30 minutes after the infusion, allowing for the blood to clot, is calculated. Results An increase in the received power in the presence of an ICH is observed at 400 MHz, consistent with previous in-vitro studies. Frequency sweep experiments show a maximum percent change in received power in the 750–1000 MHz frequency range. Comparison with existing methods Currently, CT, MRI and catheter angiography (CA) are the main clinical neuroimaging modalities. However, these techniques require specialized equipment and personnel, substantial time, and patient- transportation to a radiology suite to obtain results. Moreover, CA is invasive and uses intra-venous dye or vascular catheters to accomplish the imaging. Conclusions The device has the potential to significantly improve neurologic care in the critically ill brain-injured patient. PMID:24997340

  4. AB148. The introduction of a contingent model of first trimester screening using non-invasive prenatal testing

    PubMed Central

    Richmond, Zara; Fleischer, Ron; Chopra, Maya; Pinner, Jason; D’Souza, Mario; Fridgant, Yelena; Hyett, Jon

    2015-01-01

    Background and objective The availability of non-invasive prenatal testing (NIPT) has resulted in a paradigm shift in prenatal screening for Down syndrome and other common aneuploidies. NIPT has been validated in both high and low risk populations. The test has now reached a price-point (under AU$500) where consumer demand is high and services need to devise a model under which NIPT is made available. This article aims to describe our experience from 2012 as the first centre in Sydney to offer NIPT, and the progression towards the adoption of a contingent model of aneuploid screening in the first trimester. Methods An audit of the first 118 NIPT patients was undertaken by retrospective file review. Following this, a prospective study was undertaken by questionnaire and structured interview in an additional 84 NIPT patients. Maternal anxiety at the time of NIPT and 1 week following results delivery was measured using the Spielberger State-Trait Anxiety Inventory (STAI). Results (I) Contingent screening is a model that will increase the detection rate of Down syndrome beyond that of combined first trimester screening as well as reducing the number of miscarriages related to invasive testing; (II) receiving a low risk NIPT result leads to a significant decrease in maternal anxiety (P<0.01) and alters decision making regarding invasive testing; (III) we have identified women’s motivations for NIPT beyond that of their first trimester screening result. Conclusions Following review of the first cohort of patients to undergo NIPT, we established a contingent model of aneuploidy screening in the first trimester. Under this model, the offer of NIPT is contingent on the patient’s result from combined First trimester screening. NIPT is offered to patients with an aneuploidy risk higher than 1:1,000, though the potential benefit of invasive testing for those with a risk higher than 1:50 is also discussed. Our results demonstrate that NIPT is considered a valuable addition

  5. Eco-photonics: application of optical diagnostic modalities for non-invasive monitoring and evaluation of stress conditions of aquatic organisms

    NASA Astrophysics Data System (ADS)

    Gurkov, A. N.; Axenov-Gribanov, D. V.; Pavlichenko, V. V.; Shakhtanova, N. S.; Bedulina, D. S.; Timofeyev, M. A.; Kalchenko, V.; Meglinski, I.

    2012-03-01

    The growing interest in monitoring ecological change has been stimulated by a global climate change, combined with the day-to-day human anthropogenic activities, that heavily influence the environment. A global warming accompanied by a anthropogenic activities falling within the freshwater ecosystem result a dramatic enhance of the overall stress for most of aquatic organisms. We explore the applicability of optical spectroscopy and advanced non-invasive imaging techniques, that have been used earlier in various biomedical applications, to study an influence of climatic changes on the physiological and biochemical processes that take place in living aquatic organisms. In current report we demonstrate that optical spectroscopy and modern imaging techniques can be successfully used to observe and evaluate thermal and/or hypoxic stress, experienced by freshwater organisms, such as Baikal amphipods.

  6. Aerial Imagery and Other Non-invasive Approaches to Detect Nitrogen and Water Stress in a Potato Crop

    NASA Astrophysics Data System (ADS)

    Nigon, Tyler John

    Post-emergence nitrogen (N) fertilizer is typically split applied to irrigated potato (Solanum tuberosum L.) in Minnesota in order to minimize the likelihood of nitrate leaching and to best match N availability to crop demands. Petiole nitrate-nitrogen (NO3-N) concentration is often used as a diagnostic test to determine the rate and timing of split applications, but using this approach for variable rate applications is difficult. Canopy-level spectral measurements, such as hyperspectral and multispectral imagery, have the potential to be a reliable tool for making in-season N management decisions for precision agriculture applications. The objectives of this two year field study were to evaluate the effects of variety, N treatment, and water stress on growth characteristics and the ability of and canopy-level reflectance to predict N stress in potato. Treatments included two irrigation regimes (unstressed and stressed), five N regimes categorized by three N rates (34 kg N ha-1, 180 kg N ha-1, and 270 kg N ha-1) in which the 270 kg N ha-1 rate had post-emergence N either split applied or applied early in the season, and two potato varieties (Russet Burbank and Alpine Russet). Higher N rates and split applications generally resulted in higher tuber yield for both varieties. Insufficient supplemental water was found to reduce tuber yield and plant N uptake. Of the broadband indices, narrowband indices, and partial least squares regression (PLS) models evaluated, the best predictor of N stress as measured by leaf N concentration was the PLS model using derivative reflectance (r2 of 0.79 for RB and 0.77 for AR). However, the best technique for determining N stress level for variable rate application of N fertilizer was MTCI (MERIS Terrestrial Chlorophyll Index) due to its good relationship with leaf N concentration and high accuracy. As a final aspect of the study, results from the experimental plots were used to predict N stress in a

  7. Portable oxidative stress sensor: dynamic and non-invasive measurements of extracellular H₂O₂ released by algae.

    PubMed

    Koman, Volodymyr B; Santschi, Christian; von Moos, Nadia R; Slaveykova, Vera I; Martin, Olivier J F

    2015-06-15

    Reactive oxygen species (ROS) generated by aerobic organisms are essential for physiological processes such as cell signaling, apoptosis, immune defense and oxidative stress mechanisms. Unbalanced oxidant/antioxidant budgets are involved in many diseases and, therefore, the sensitive measurement of ROS is of great interest. Here, we present a new device for the real-time monitoring of oxidative stress by measuring one of the most stable ROS, namely hydrogen peroxide (H2O2). This portable oxidative stress sensor contains the heme protein cytochrome c (cyt c) as sensing element whose spectral response enables the detection of H2O2 down to a detection limit of 40 nM. This low detection limit is achieved by introducing cyt c in a random medium, enabling multiscattering that enhances the optical trajectory through the cyt c spot. A contact microspotting technique is used to produce reproducible and reusable cyt c spots which are stable for several days. Experiments in static and microfluidic regimes, as well as numerical simulations demonstrate the suitability of the cyt c/H2O2 reaction system for the real-time sensing of the kinetics of biological processes without H2O2 depletion in the measurement chamber. As an example, we detect the release of H2O2 from the green alga Chlamydomonas reinhardtii exposed to either 180 nM functionalized CdSe/ZnS core shell quantum dots, or to 10 mg/l TiO2 nanoparticles. The continuous measurement of extracellular H2O2 by this optical sensor with high sensitivity is a promising new means for real-time cytotoxicity tests, the investigation of oxidative stress and other physiological cell processes. PMID:25588702

  8. Nuclear stress test

    MedlinePlus

    ... Persantine stress test; Thallium stress test; Stress test - nuclear; Adenosine stress test; Regadenoson stress test; CAD - nuclear stress; Coronary artery disease - nuclear stress; Angina - nuclear ...

  9. Prediction of rectal temperature using non-invasive physiologic variable measurements in hair pregnant ewes subjected to natural conditions of heat stress.

    PubMed

    Vicente-Pérez, Ricardo; Avendaño-Reyes, Leonel; Mejía-Vázquez, Ángel; Álvarez-Valenzuela, F Daniel; Correa-Calderón, Abelardo; Mellado, Miguel; Meza-Herrera, Cesar A; Guerra-Liera, Juan E; Robinson, P H; Macías-Cruz, Ulises

    2016-01-01

    Rectal temperature (RT) is the foremost physiological variable indicating if an animal is suffering hyperthermia. However, this variable is traditionally measured by invasive methods, which may compromise animal welfare. Models to predict RT have been developed for growing pigs and lactating dairy cows, but not for pregnant heat-stressed ewes. Our aim was to develop a prediction equation for RT using non-invasive physiological variables in pregnant ewes under heat stress. A total of 192 records of respiratory frequency (RF) and hair coat temperature in various body regions (i.e., head, rump, flank, shoulder, and belly) obtained from 24 Katahdin × Pelibuey pregnant multiparous ewes were collected during the last third of gestation (i.e., d 100 to lambing) with a 15 d sampling interval. Hair coat temperatures were taken using infrared thermal imaging technology. Initially, a Pearson correlation analysis examined the relationship among variables, and then multiple linear regression analysis was used to develop the prediction equations. All predictor variables were positively correlated (P<0.01; r=0.59-0.67) with RT. The adjusted equation which best predicted RT (P<0.01; Radj(2)=56.15%; CV=0.65%) included as predictors RF and head and belly temperatures. Comparison of predicted and observed values for RT indicates a suitable agreement (P<0.01) between them with moderate accuracy (Radj(2)=56.15%) when RT was calculated with the adjusted equation. In general, the final equation does not violate any assumption of multiple regression analysis. The RT in heat-stressed pregnant ewes can be predicted with an adequate accuracy using non-invasive physiologic variables, and the final equation was: RT=35.57+0.004 (RF)+0.067 (heat temperature)+0.028 (belly temperature). PMID:26724191

  10. A Non-invasive Platform for Functional Characterization of Stem-Cell-Derived Cardiomyocytes with Applications in Cardiotoxicity Testing

    PubMed Central

    Maddah, Mahnaz; Heidmann, Julia D.; Mandegar, Mohammad A.; Walker, Chase D.; Bolouki, Sara; Conklin, Bruce R.; Loewke, Kevin E.

    2015-01-01

    Summary We present a non-invasive method to characterize the function of pluripotent stem-cell-derived cardiomyocytes based on video microscopy and image analysis. The platform, called Pulse, generates automated measurements of beating frequency, beat duration, amplitude, and beat-to-beat variation based on motion analysis of phase-contrast images captured at a fast frame rate. Using Pulse, we demonstrate recapitulation of drug effects in stem-cell-derived cardiomyocytes without the use of exogenous labels and show that our platform can be used for high-throughput cardiotoxicity drug screening and studying physiologically relevant phenotypes. PMID:25801505

  11. Non-Invasive Assessment of the Interrelationships of Diet, Pregnancy Rate, Group Composition, and Physiological and Nutritional Stress of Barren-Ground Caribou in Late Winter

    PubMed Central

    Joly, Kyle; Wasser, Samuel K.; Booth, Rebecca

    2015-01-01

    The winter diet of barren-ground caribou may affect adult survival, timing of parturition, neonatal survival, and postpartum mass. We used microhistological analyses and hormone levels in feces to determine sex-specific late-winter diets, pregnancy rates, group composition, and endocrine-based measures of physiological and nutritional stress. Lichens, which are highly digestible but contain little protein, dominated the diet (> 68%) but were less prevalent in the diets of pregnant females as compared to non-pregnant females and males. The amount of lichens in the diets of pregnant females decreased at higher latitudes and as winter progressed. Pregnancy rates (82.1%, 95% CI = 76.0 – 88.1%) of adult cows were within the expected range for a declining herd, while pregnancy status was not associated with lichen abundance in the diet. Most groups (80%) were of mixed sex. Male: female ratios (62:100) were not skewed enough to affect the decline. Levels of hormones indicating nutritional stress were detected in areas of low habitat quality and at higher latitudes. Levels of hormones indicated that physiological stress was greatest for pregnant cows, which faced the increasing demands of gestation in late winter. These fecal-based measures of diet and stress provided contextual information for the potential mechanisms of the ongoing decline. Non-invasive techniques, such as monitoring diets, pregnancy rates, sex ratios and stress levels from fecal samples, will become increasingly important as monitoring tools as the industrial footprint continues to expand in the Arctic. PMID:26061003

  12. Non-Invasive Assessment of the Interrelationships of Diet, Pregnancy Rate, Group Composition, and Physiological and Nutritional Stress of Barren-Ground Caribou in Late Winter.

    PubMed

    Joly, Kyle; Wasser, Samuel K; Booth, Rebecca

    2015-01-01

    The winter diet of barren-ground caribou may affect adult survival, timing of parturition, neonatal survival, and postpartum mass. We used microhistological analyses and hormone levels in feces to determine sex-specific late-winter diets, pregnancy rates, group composition, and endocrine-based measures of physiological and nutritional stress. Lichens, which are highly digestible but contain little protein, dominated the diet (> 68%) but were less prevalent in the diets of pregnant females as compared to non-pregnant females and males. The amount of lichens in the diets of pregnant females decreased at higher latitudes and as winter progressed. Pregnancy rates (82.1%, 95% CI = 76.0 - 88.1%) of adult cows were within the expected range for a declining herd, while pregnancy status was not associated with lichen abundance in the diet. Most groups (80%) were of mixed sex. Male: female ratios (62:100) were not skewed enough to affect the decline. Levels of hormones indicating nutritional stress were detected in areas of low habitat quality and at higher latitudes. Levels of hormones indicated that physiological stress was greatest for pregnant cows, which faced the increasing demands of gestation in late winter. These fecal-based measures of diet and stress provided contextual information for the potential mechanisms of the ongoing decline. Non-invasive techniques, such as monitoring diets, pregnancy rates, sex ratios and stress levels from fecal samples, will become increasingly important as monitoring tools as the industrial footprint continues to expand in the Arctic. PMID:26061003

  13. A non-invasive method for detecting the metabolic stress response in rodents: characterization and disruption of the circadian corticosterone rhythm.

    PubMed

    Thanos, P K; Cavigelli, S A; Michaelides, M; Olvet, D M; Patel, U; Diep, M N; Volkow, N D

    2009-01-01

    Plasma corticosterone (CORT) measures are a common procedure to detect stress responses in rodents. However, the procedure is invasive and can influence CORT levels, making it less than ideal for monitoring CORT circadian rhythms. In the current paper, we examined the applicability of a non-invasive fecal CORT metabolite measure to assess the circadian rhythm. We compared fecal CORT metabolite levels to circulating CORT levels, and analyzed change in the fecal circadian rhythm following an acute stressor (i.e. blood sampling by tail veil catheter). Fecal and blood samples were collected from male adolescent rats and analyzed for CORT metabolites and circulating CORT respectively. Fecal samples were collected hourly for 24 h before and after blood draw. On average, peak fecal CORT metabolite values occurred 7-9 h after the plasma CORT peak and time-matched fecal CORT values were well correlated with plasma CORT. As a result of the rapid blood draw, fecal production and CORT levels were altered the next day. These results indicate fecal CORT metabolite measures can be used to assess conditions that disrupt the circadian CORT rhythm, and provide a method to measure long-term changes in CORT production. This can benefit research that requires long-term glucocorticoid assessment (e.g. stress mechanisms underlying health). PMID:18380537

  14. A Non-Invasive Method for Detecting the Metabolic Stress Response in Rodents: Characterization and Disruption of the Circadian Corticosterone Rhythm

    PubMed Central

    Thanos, Panayotis K.; Cavigelli, Sonia A.; Michaelides, Michael; Olvet, Doreen M.; Patel, Ujval; Diep, Mai N.; Volkow, Nora D.

    2009-01-01

    1. Summary Plasma corticosterone (CORT) measures are a common procedure to detect stress responses in rodents. However, the procedure is invasive and can influence CORT levels, making it less than ideal for monitoring CORT circadian rhythms. In the current paper, we examined the applicability of a non-invasive fecal CORT metabolite measure to assess the circadian rhythm. We compared fecal CORT metabolite levels to circulating CORT levels, and analyzed change in the fecal circadian rhythm following an acute stressor (i.e. blood sampling by tail veil catheter). Fecal and blood samples were collected from male adolescent rats and analyzed for CORT metabolites and circulating CORT respectively. Fecal samples were collected hourly for 24 hours pre- and post-blood draw. On average, peak fecal CORT metabolite values occurred 7–9 hours after the plasma CORT peak and time-matched fecal CORT values were well correlated with plasma CORT. As a result of the rapid blood draw, fecal production and CORT levels were altered the next day. These results indicate fecal CORT metabolite measures can be used to assess conditions that disrupt the circadian CORT rhythm, and provide a method to measure long-term changes in CORT production. This can benefit research that requires long-term glucocorticoid assessment (e.g. stress mechanisms underlying health). PMID:18380537

  15. Non-invasive monitoring and quantitative analysis of patch test reactions by reflectance spectrophotometry, laser Doppler flowmetry and transepidermal water loss

    NASA Astrophysics Data System (ADS)

    Eikje, Natalja Skrebova; Arase, Seiji

    2008-02-01

    Reflectance spectrophotometry (RS), laser Doppler flowmetry (LDF) and transepidermal water loss (TEWL) techniques were simultaneously used to non-invasively monitor skin colour (SC), skin blood flow (SBF) and barrier function damage (BFD) in routinely patch-tested Japanese patients in dermatology clinic. The analytical quality, reliability and reproducibility of each technique were compared and analyzed in correlated to visual scoring patch test (PT) reactions as negative (-), doubtful (+?), weak (+) and strong (++/+++) at 48- and 72-hour monitoring. An attempt was made to quantify predominant in the clinic "+?"- and "+'"-PT-reactions. The relationship between 48 h and 72 h measurements in different reaction groups was poor for TEWL, LDF showed a tendency to decrease at 72 h, but good for RS. A correlation between visual scorings and instrumental mean values was poor for TEWL, good for LDF and excellent for RS. So, measurements by RS were the most statistically significant to non-invasively monitor and quantify doubtful, weak and strong PT reactions, accordingly providing continuous data grading of reaction intensity suitable in the clinic. Moreover, monitoring of SC changes was the most reliable parameter for the quantitative distinguishing of doubtful and weak reactions in pigmented skin.

  16. Emerging stool-based and blood-based non-invasive DNA tests for colorectal cancer screening: the importance of cancer prevention in addition to cancer detection.

    PubMed

    Pickhardt, Perry J

    2016-08-01

    Colorectal cancer (CRC) screening can be undertaken utilizing a variety of distinct approaches, which provides both opportunities and confusion. Traditionally, there has often been a trade-off between the degree of invasiveness of a screening test and its ability to prevent cancer, with fecal occult blood testing (FOBT) and optical colonoscopy (OC) at each end of the spectrum. CT colonography (CTC), although currently underutilized for CRC screening, represents an exception since it is only minimally invasive, yet provides accurate evaluation for advanced adenomas. More recently, the FDA approved a multi-target stool DNA test (Cologuard) and a blood-based test (Epi proColon) for average-risk CRC screening. This commentary will provide an overview of these two new non-invasive tests, including the clinical indications, mechanism of action, and diagnostic performance. Relevance to radiology practice, including a comparison with CTC, will also be discussed. PMID:27259335

  17. Validation of AshTest as a Non-Invasive Alternative to Transjugular Liver Biopsy in Patients with Suspected Severe Acute Alcoholic Hepatitis

    PubMed Central

    Rudler, Marika; Mouri, Sarah; Charlotte, Frederic; Cluzel, Philippe; Ngo, Yen; Munteanu, Mona; Lebray, Pascal; Ratziu, Vlad; Thabut, Dominique; Poynard, Thierry

    2015-01-01

    Background/Aims According to guidelines, the histological diagnosis of severe alcoholic steatohepatitis (ASH) can require liver biopsy if a specific treatment is needed. The blood test AshTest (BioPredictive, Paris, France) has been initially validated for the non-invasive diagnosis of ASH in a large population of heavy drinkers. The aim was to validate the AshTest accuracy in the specific context of use of patients with suspected severe ASH, in order to reduce the need for transjugular biopsy before deciding treatment. Methods The reference was liver biopsy, performed using the transjugular route, classified according to its histological severity as none, minimal, moderate or severe. Biopsies were assessed by the same experienced pathologist, blinded to simultaneous AshTest results. Results A total of 123 patients with severe clinical ASH (recent jaundice and Maddrey function greater or equal to 32) were included, all had cirrhosis and 80% had EASL histological definition of ASH. 95% of patients received prednisolone; and the 2-year mortality was 63%. The high AshTest performance was confirmed both for the binary outcome [AUROC = 0.803 (95%CI 0.684–0.881)] significantly higher than the AST/ALT AUROC [0.603 (0.462–0.714); P<0.001], and for the severity of ASH-score system by the Obuchowski measures for [mean (SE) 0.902 (0.017) vs. AST/ALT 0.833 (0.023); P = 0.01], as well as for the diagnosis and severity of ballooning, PMN and Mallory bodies. According to attributability of discordances, AshTest had a 2–7% risk of 2 grades misclassification. Conclusion These results confirmed the diagnostic performance of AshTest in cirrhotic patients with severe clinical ASH, in the specific context of use of corticosteroid treatment. AshTest is an appropriate non-invasive alternative to transjugular liver biopsy. PMID:26252713

  18. Design and testing of an MRI-compatible cycle ergometer for non-invasive cardiac assessments during exercise

    PubMed Central

    2012-01-01

    Background Magnetic resonance imaging (MRI) is an important tool for cardiac research, and it is frequently used for resting cardiac assessments. However, research into non-pharmacological stress cardiac evaluation is limited. Methods We aimed to design a portable and relatively inexpensive MRI cycle ergometer capable of continuously measuring pedalling workload while patients exercise to maintain target heart rates. Results We constructed and tested an MRI-compatible cycle ergometer for a 1.5 T MRI scanner. Resting and sub-maximal exercise images (at 110 beats per minute) were successfully obtained in 8 healthy adults. Conclusions The MRI-compatible cycle ergometer constructed by our research group enabled cardiac assessments at fixed heart rates, while continuously recording power output by directly measuring pedal force and crank rotation. PMID:22423637

  19. A simulation test of the effectiveness of several methods for error-checking non-invasive genetic data

    USGS Publications Warehouse

    Roon, David A.; Waits, L.P.; Kendall, K.C.

    2005-01-01

    Non-invasive genetic sampling (NGS) is becoming a popular tool for population estimation. However, multiple NGS studies have demonstrated that polymerase chain reaction (PCR) genotyping errors can bias demographic estimates. These errors can be detected by comprehensive data filters such as the multiple-tubes approach, but this approach is expensive and time consuming as it requires three to eight PCR replicates per locus. Thus, researchers have attempted to correct PCR errors in NGS datasets using non-comprehensive error checking methods, but these approaches have not been evaluated for reliability. We simulated NGS studies with and without PCR error and 'filtered' datasets using non-comprehensive approaches derived from published studies and calculated mark-recapture estimates using CAPTURE. In the absence of data-filtering, simulated error resulted in serious inflations in CAPTURE estimates; some estimates exceeded N by ??? 200%. When data filters were used, CAPTURE estimate reliability varied with per-locus error (E??). At E?? = 0.01, CAPTURE estimates from filtered data displayed < 5% deviance from error-free estimates. When E?? was 0.05 or 0.09, some CAPTURE estimates from filtered data displayed biases in excess of 10%. Biases were positive at high sampling intensities; negative biases were observed at low sampling intensities. We caution researchers against using non-comprehensive data filters in NGS studies, unless they can achieve baseline per-locus error rates below 0.05 and, ideally, near 0.01. However, we suggest that data filters can be combined with careful technique and thoughtful NGS study design to yield accurate demographic information. ?? 2005 The Zoological Society of London.

  20. Non-invasive monitoring of reproductive and stress hormones in the endangered red panda (Ailurus fulgens fulgens).

    PubMed

    Beaulah Budithi, Neema Raja; Kumar, Vinod; Yalla, Suneel Kumar; Rai, Upashna; Umapathy, Govindhaswamy

    2016-09-01

    The red panda (Ailurus fulgens fulgens) is classified as endangered due to its declining population, habitat fragmentation and poaching. Efforts are being made to breed them in captivity as part of nationwide conservation breeding program. This study aimed to standardize Enzyme immunoassays (EIAs) to monitor reproductive (Progesterone metabolite, Testosterone) and stress hormone (Cortisol) in red panda. For this purpose, we collected 1471 faecal samples from four females and one male over a period of one year from Padmaja Naidu Himalayan Zoological Park, Darjeeling, India. HPLC confirmed the presence of immunoreactive 5α-pregnan-3α-ol-20-one, testosterone and cortisol metabolites in faecal samples. Using 5α-pregnan-3α-ol-20-one EIA, we were able to monitor reproduction and detect pregnancy in one of the females, which successfully conceived and delivered during the study period. We were also able to monitor testosterone and cortisol in faecal samples of the red panda. Faecal testosterone levels were found in higher concentration in breeding season than in non-breeding season. Faecal cortisol concentrations showed a negative relationship with ambient temperature and peaked during winter months in all animals. Standardization of EIAs and faecal hormone monitoring would facilitate red panda conservation breeding programs in India and elsewhere. PMID:27481551

  1. Non-invasive prenatal diagnostic test accuracy for fetal sex using cell-free DNA a review and meta-analysis

    PubMed Central

    2012-01-01

    Background Cell-free fetal DNA (cffDNA) can be detected in maternal blood during pregnancy, opening the possibility of early non-invasive prenatal diagnosis for a variety of genetic conditions. Since 1997, many studies have examined the accuracy of prenatal fetal sex determination using cffDNA, particularly for pregnancies at risk of an X-linked condition. Here we report a review and meta-analysis of the published literature to evaluate the use of cffDNA for prenatal determination (diagnosis) of fetal sex. We applied a sensitive search of multiple bibliographic databases including PubMed (MEDLINE), EMBASE, the Cochrane library and Web of Science. Results Ninety studies, incorporating 9,965 pregnancies and 10,587 fetal sex results met our inclusion criteria. Overall mean sensitivity was 96.6% (95% credible interval 95.2% to 97.7%) and mean specificity was 98.9% (95% CI = 98.1% to 99.4%). These results vary very little with trimester or week of testing, indicating that the performance of the test is reliably high. Conclusions Based on this review and meta-analysis we conclude that fetal sex can be determined with a high level of accuracy by analyzing cffDNA. Using cffDNA in prenatal diagnosis to replace or complement existing invasive methods can remove or reduce the risk of miscarriage. Future work should concentrate on the economic and ethical considerations of implementing an early non-invasive test for fetal sex. PMID:22937795

  2. Non invasive assessment of the human tear film dynamics.

    PubMed

    Ring, M H; Rabensteiner, D F; Horwath-Winter, J; Boldin, I; Schrödl, F; Reitsamer, H; Haslwanter, T

    2015-11-01

    Dry eye disease, or keratoconjunctivitis sicca, is a multifactorial syndrome with altered tear film homeostasis leading to ocular irritations. These alterations cause discomfort and stress for the patient, but only a few objective parameters allow for proper differential diagnosis into different subtypes of this condition. The mostly invasively performed standard assessment procedures for tear film diagnosis are manifold, but often correlate quite poorly with the subjectively reported symptoms. Due to the inherent limitations, e.g. the subjectivity of the commonly performed invasive tests, a number of devices have been developed to assess the human tear film non-invasively. Since the production, delivery, distribution and drainage of the tear film is a dynamic process, we have focused our review on non-invasive methods which are capable of continuous or repetitive observations of the tear film during an inter-blink interval. These dynamic methods include (1) Interferometry, (2) Pattern Projection, (3) Aberrometry, (4) Thermography; and (5) Evaporimetry. These techniques are discussed with respect to their diagnostic value, both for screening and differential diagnostic of Dry Eye Disease. Many of the parameters obtained from these tests have been shown to have the potential to reliably discriminate patients from healthy subjects, especially when the tests are performed automatically and objectively. The differentiation into subtypes based solely on a single, dynamic parameter may not be feasible, but the combination of non-invasively performed procedures may provide good discrimination results. PMID:26406882

  3. Decision-making for non-invasive prenatal testing for Down syndrome: Hong Kong Chinese women's preferences for individual vs relational autonomy.

    PubMed

    Lau, J Y C; Yi, H; Ahmed, S

    2016-05-01

    Individual autonomy in antenatal screening is internationally recognized and supported. Policy and practice guidelines in various countries place emphasis on the woman's right to make her own decision and are related to concepts such as self-determination, independence, and self-sufficiency. In contrast, the dominant perspective in Chinese medical ethics suggests that the family is pivotal in making medical decisions, hence providing support for relational autonomy. This study explored Hong Kong Chinese pregnant women's preferences for individual vs relational autonomy for non-invasive prenatal testing (NIPT) for Down syndrome. A qualitative study was carried out using semi-structured interviews with 36 women who had undertaken NIPT in Hong Kong. The findings show that most Hong Kong Chinese women valued aspects of both relational and individual autonomy in decision-making for NIPT. Women expected support from doctors as experts on the topic and wanted to involve their husband in decision-making while retaining control over the outcome. Somewhat surprisingly, the findings do not provide support for the involvement of family members in decision-making for NIPT. The adequacy of current interpretations of autonomy in prenatal testing policies as an individual approach needs discussion, where policy developers need to find a balance between individual and relational approaches. PMID:26864268

  4. Non-invasive cardiac index monitoring during cardiopulmonary functional testing provides additional prognostic value in patients after acute heart failure.

    PubMed

    Lee, Ming-Feng; Chen, Wei-Siang; Fu, Tieh-Cheng; Liu, Min-Hui; Wang, Jong-Shyan; Hsu, Chih-Chin; Huang, Yu-Yen; Cherng, Wen-Jin; Wang, Chao-Hung

    2012-01-01

    The prognostic value of parameters derived from a cardiopulmonary exercise test (CPET) is well established in patients stabilized after acute heart failure (HF). Under multidisciplinary disease management, this study sought to test whether noninvasive cardiac output (CO) monitoring (NICOM) during the CPET provides additional prognostic value. In total, 131 patients stabilized after acute HF agreed to undergo the CPET with NICOM. Outcome follow-up focused on composite events of death and HF-related rehospitalization. Patients with a peak cardiac index (CI) of ≤ 4.5 L/minute/ m(2) (n = 32), compared to those with a peak CI of > 4.5 L/minute/m(2) (n = 99), had higher incidences of diabetes mellitus (DM) and hypertension, but had lower hemoglobin levels, estimated glomerular filtration rates (eGFR), oxygen uptake efficiency slope (OUES), and peak oxygen uptake (VO(2)). During the 1.2 ± 0.7 years of follow-up, there were 8 (6.1%) deaths, and 16 (12.2%) HF-related rehospitalizations. In a Cox univariable analysis, a lower event-free survival was associated with a history of DM, a higher Ve/VCO(2) slope, lower peak VCO(2) and eGFR, and a peak CI of ≤ 4.5 L/minute/ m(2) (P < 0.05). The Cox multivariable analysis showed that the Ve/VCO(2) slope (hazard ratio (HR) = 1.08, 95% confidence interval (CI): 1.01~1.16, P = 0.02) and peak CI of ≤ 4.5 L/minute/m(2 )(HR = 3.26, 95% CI: 1.18~9.01, P = 0.02) were significant independent predictors. In conclusion, NICOM during the CPET was demonstrated to provide prognostic information in addition to traditional risk factors, biomarkers, and other well-established CPET parameters. PMID:23258137

  5. Could Digital PCR Be an Alternative as a Non-Invasive Prenatal Test for Trisomy 21: A Proof of Concept Study

    PubMed Central

    El Khattabi, Laïla Allach; Rouillac-Le Sciellour, Christelle; Le Tessier, Dominique; Luscan, Armelle; Coustier, Audrey; Porcher, Raphael; Bhouri, Rakia; Nectoux, Juliette; Sérazin, Valérie; Quibel, Thibaut; Mandelbrot, Laurent; Tsatsaris, Vassilis

    2016-01-01

    Objective NIPT for fetal aneuploidy by digital PCR has been hampered by the large number of PCR reactions needed to meet statistical requirements, preventing clinical application. Here, we designed an octoplex droplet digital PCR (ddPCR) assay which allows increasing the number of available targets and thus overcomes statistical obstacles. Method After technical optimization of the multiplex PCR on mixtures of trisomic and euploid DNA, we performed a validation study on samples of plasma DNA from 213 pregnant women. Molecular counting of circulating cell-free DNA was performed using a mix of hydrolysis probes targeting chromosome 21 and a reference chromosome. Results The results of our validation experiments showed that ddPCR detected trisomy 21 even when the sample’s trisomic DNA content is as low as 5%. In a validation study of plasma samples from 213 pregnant women, ddPCR discriminated clearly between the trisomy 21 and the euploidy groups. Conclusion Our results demonstrate that digital PCR can meet the requirements for non-invasive prenatal testing of trisomy 21. This approach is technically simple, relatively cheap, easy to implement in a diagnostic setting and compatible with ethical concerns regarding access to nucleotide sequence information. These advantages make it a potential technique of choice for population-wide screening for trisomy 21 in pregnant women. PMID:27167625

  6. Women's Experiences and Preferences for Service Delivery of Non-Invasive Prenatal Testing for Aneuploidy in a Public Health Setting: A Mixed Methods Study.

    PubMed

    Lewis, Celine; Hill, Melissa; Chitty, Lyn S

    2016-01-01

    Non-invasive prenatal testing (NIPT) for aneuploidy is currently only available in the UK through the private sector outside of the research arena. As part of an implementation study in the UK National Health Service we conducted a mixed methods study to assess women's experience of being offered NIPT using validated measures of decisional conflict, decisional regret and anxiety. Clinical service preferences were also explored. Women with a Down syndrome screening risk >1:1000 were invited to take part in the study and offered NIPT, NIPT and invasive testing (for women with a risk above 1:150) or no further testing. A cross-sectional survey and semi-structured interviews were conducted at two time points; at the time of testing and one month following receipt of results (or equivalent for NIPT decliners). In total, 845 questionnaires and 81 interviews were analysed. The main motivation to accept NIPT was for reassurance (30.8%). Decisional conflict occurred in a minimal number of cases (3.8%), however, none of the participants experienced decisional regret. Around a third (29.9%) of women had elevated anxiety at the time of testing, including intermediate risk women who traditionally would not be offered further testing (54.4% high risk; 20.1% medium risk), a finding supported through the qualitative interviews where prolonged or additional anxiety was found to occur in some medium risk cases. Women were overwhelmingly positive about the opportunity to have a test that was procedurally safe, accurate, reduced the need for invasive testing and identified cases of Down syndrome that might otherwise have been missed. Reassurance was identified as the main motivator for accepting NIPT, particularly amongst medium risk women, with high risk women inclined to accept NIPT to inform decisions around invasive testing. The current turnaround time for test result was identified as a key limitation. All the women interviewed thought NIPT should be adopted as part of NHS

  7. Women’s Experiences and Preferences for Service Delivery of Non-Invasive Prenatal Testing for Aneuploidy in a Public Health Setting: A Mixed Methods Study

    PubMed Central

    Lewis, Celine; Hill, Melissa; Chitty, Lyn S.

    2016-01-01

    Non-invasive prenatal testing (NIPT) for aneuploidy is currently only available in the UK through the private sector outside of the research arena. As part of an implementation study in the UK National Health Service we conducted a mixed methods study to assess women’s experience of being offered NIPT using validated measures of decisional conflict, decisional regret and anxiety. Clinical service preferences were also explored. Women with a Down syndrome screening risk >1:1000 were invited to take part in the study and offered NIPT, NIPT and invasive testing (for women with a risk above 1:150) or no further testing. A cross-sectional survey and semi-structured interviews were conducted at two time points; at the time of testing and one month following receipt of results (or equivalent for NIPT decliners). In total, 845 questionnaires and 81 interviews were analysed. The main motivation to accept NIPT was for reassurance (30.8%). Decisional conflict occurred in a minimal number of cases (3.8%), however, none of the participants experienced decisional regret. Around a third (29.9%) of women had elevated anxiety at the time of testing, including intermediate risk women who traditionally would not be offered further testing (54.4% high risk; 20.1% medium risk), a finding supported through the qualitative interviews where prolonged or additional anxiety was found to occur in some medium risk cases. Women were overwhelmingly positive about the opportunity to have a test that was procedurally safe, accurate, reduced the need for invasive testing and identified cases of Down syndrome that might otherwise have been missed. Reassurance was identified as the main motivator for accepting NIPT, particularly amongst medium risk women, with high risk women inclined to accept NIPT to inform decisions around invasive testing. The current turnaround time for test result was identified as a key limitation. All the women interviewed thought NIPT should be adopted as part of NHS

  8. Accuracy of non-invasive prenatal testing using cell-free DNA for detection of Down, Edwards and Patau syndromes: a systematic review and meta-analysis

    PubMed Central

    Taylor-Phillips, Sian; Freeman, Karoline; Geppert, Julia; Agbebiyi, Adeola; Uthman, Olalekan A; Madan, Jason; Clarke, Angus; Quenby, Siobhan; Clarke, Aileen

    2016-01-01

    Objective To measure test accuracy of non-invasive prenatal testing (NIPT) for Down, Edwards and Patau syndromes using cell-free fetal DNA and identify factors affecting accuracy. Design Systematic review and meta-analysis of published studies. Data sources PubMed, Ovid Medline, Ovid Embase and the Cochrane Library published from 1997 to 9 February 2015, followed by weekly autoalerts until 1 April 2015. Eligibility criteria for selecting studies English language journal articles describing case–control studies with ≥15 trisomy cases or cohort studies with ≥50 pregnant women who had been given NIPT and a reference standard. Results 41, 37 and 30 studies of 2012 publications retrieved were included in the review for Down, Edwards and Patau syndromes. Quality appraisal identified high risk of bias in included studies, funnel plots showed evidence of publication bias. Pooled sensitivity was 99.3% (95% CI 98.9% to 99.6%) for Down, 97.4% (95.8% to 98.4%) for Edwards, and 97.4% (86.1% to 99.6%) for Patau syndrome. The pooled specificity was 99.9% (99.9% to 100%) for all three trisomies. In 100 000 pregnancies in the general obstetric population we would expect 417, 89 and 40 cases of Downs, Edwards and Patau syndromes to be detected by NIPT, with 94, 154 and 42 false positive results. Sensitivity was lower in twin than singleton pregnancies, reduced by 9% for Down, 28% for Edwards and 22% for Patau syndrome. Pooled sensitivity was also lower in the first trimester of pregnancy, in studies in the general obstetric population, and in cohort studies with consecutive enrolment. Conclusions NIPT using cell-free fetal DNA has very high sensitivity and specificity for Down syndrome, with slightly lower sensitivity for Edwards and Patau syndrome. However, it is not 100% accurate and should not be used as a final diagnosis for positive cases. Trial registration number CRD42014014947. PMID:26781507

  9. The non-invasive 13C-methionine breath test detects hepatic mitochondrial dysfunction as a marker of disease activity in non-alcoholic steatohepatitis

    PubMed Central

    2011-01-01

    Introduction Mitochondrial dysfunction plays a central role in the general pathogenesis of non-alcoholic fatty liver disease (NAFLD), increasing the risk of developing steatosis and subsequent hepatocellular inflammation. We aimed to assess hepatic mitochondrial function by a non-invasive 13C-methionine breath test (MeBT) in patients with histologically proven NAFLD. Methods 118 NAFLD-patients and 18 healthy controls were examined by MeBT. Liver biopsy specimens were evaluated according to the NASH scoring system. Results Higher grades of NASH activity and fibrosis were independently associated with a significant decrease in cumulative 13C-exhalation (expressed as cPDR(%)). cPDR1.5h was markedly declined in patients with NASH and NASH cirrhosis compared to patients with simple steatosis or borderline diagnosis (cPDR1.5h: 3.24 ± 1.12% and 1.32 ± 0.94% vs. 6.36 ± 0.56% and 4.80 ± 0.88% respectively; p < 0.001). 13C-exhalation further declined in the presence of advanced fibrosis which was correlated with NASH activity (r = 0.36). The area under the ROC curve (AUROC) for NASH diagnosis was estimated to be 0.87 in the total cohort and 0.83 in patients with no or mild fibrosis (F0-1). Conclusion The 13C-methionine breath test indicates mitochondrial dysfunction in non-alcoholic fatty liver disease and predicts higher stages of disease activity. It may, therefore, be a valuable diagnostic addition for longitudinal monitoring of hepatic (mitochondrial) function in non-alcoholic fatty liver disease. PMID:21810560

  10. Non-invasive physiological measurements

    SciTech Connect

    Rolfe, P.

    1983-01-01

    This book discusses the diagnostic techniques of nondestructive type for monitoring the physiology of various organ systems. The topics covered are: non-invasive assessment of gastric activity; uterine activity, intestinal activity; monitoring of fetal cardiovascular system and bilirubin physiology of infants. Respiratory system of infants is monitored and ultrasonography of heart is discussed.

  11. Excreted Thiocyanate Detects Live Reef Fishes Illegally Collected Using Cyanide—A Non-Invasive and Non-Destructive Testing Approach

    PubMed Central

    Vaz, Marcela C. M.; Rocha-Santos, Teresa A. P.; Rocha, Rui J. M.; Lopes, Isabel; Pereira, Ruth; Duarte, Armando C.; Rubec, Peter J.; Calado, Ricardo

    2012-01-01

    Cyanide fishing is a method employed to capture marine fish alive on coral reefs. They are shipped to markets for human consumption in Southeast Asia, as well as to supply the marine aquarium trade worldwide. Although several techniques can be used to detect cyanide in reef fish, there is still no testing method that can be used to survey the whole supply chain. Most methods for cyanide detection are time-consuming and require the sacrifice of the sampled fish. Thiocyanate anion (SCN−) is a metabolite produced by the main metabolic pathway for cyanide anion (CN−) detoxification. Our study employed an optical fiber (OF) methodology (analytical time <6 min) to detect SCN− in a non-invasive and non-destructive manner. Our OF methodology is able to detect trace levels (>3.16 µg L−1) of SCN− in seawater. Given that marine fish exposed to cyanide excrete SCN− in the urine, elevated levels of SCN− present in the seawater holding live reef fish indicate that the surveyed specimens were likely exposed to cyanide. In our study, captive-bred clownfish (Amphiprion clarkii) pulse exposed for 60 s to either 12.5 or 25 mg L−1 of CN− excreted up to 6.96±0.03 and 9.84±0.03 µg L−1 of SCN−, respectively, during the 28 days following exposure. No detectable levels of SCN− were recorded in the water holding control organisms not exposed to CN−, or in synthetic seawater lacking fish. While further research is necessary, our methodology can allow a rapid detection of SCN− in the holding water and can be used as a screening tool to indicate if live reef fish were collected with cyanide. PMID:22536375

  12. The scale epithelium as a novel, non-invasive tool for environmental assessment in fish: Testing exposure to linear alkylbenzene sulfonate.

    PubMed

    Alves, R M S; Pereira, B F; Ribeiro, R G L G; Pitol, D L; Ciamarro, C M; Valim, J R T; Caetano, F H

    2016-07-01

    Increasing pollution levels have turned our attention to assessing lethal and sublethal effects of toxic agents using the most informative techniques possible. We must seek non-invasive or non-lethal sampling methods that represent an attractive alternative to traditional techniques of environmental assessment in fish. Detergents are amongst the most common contaminants of water bodies, and LAS (Linear Alkylbenzene Sulfonate) is one of the most used anionic surfactant on the market. Our study analyzed morphological alterations (histological and histochemical) of the scale epithelium of Prochilodus lineatus under exposure to two concentrations of LAS, 3.6mg/L and 0.36mg/L, for a period of 30 days and evaluated at 14, 21 and 30 days. In order to establish morphological analysis of the scale epithelium as a new non-lethal environmental assessment tool that is reliable and comparable to classic methods, the relative sensibility of this technique was compared to a commonly used method of environmental assessment in fish, the estimation of the effects of pollutants upon branchial morphology. Two experiments were carried out, testing animals in tanks, and in individual aquariums. Results of analyses on gill tissue show that exposure to 3.6mg/L of surfactant caused severe damage, including hyperplasia, hypertrophy and fusion at 14 days, with aneurisms at 21 and 30 days; while exposure to 0.36mg/L had lighter effects on the organ, mainly lower incidence of fusion and hyperplasia. Aditionally, scale morphology was altered severely in response to 3.6mg/L of LAS, consistently showing increased mucous and club cell production. Epithelial thickness was the most variable parameter measured. Scale epithelium sensibility has the potential to be a reliable environmental marker for fish species since it has the advantage of being less invasive when compared to traditional methods. However, more studies are required to increase the robustness of the technique before it can be

  13. Motivations for Undertaking DNA Sequencing-Based Non-Invasive Prenatal Testing for Fetal Aneuploidy: A Qualitative Study with Early Adopter Patients in Hong Kong

    PubMed Central

    Yi, Huso; Hallowell, Nina; Griffiths, Sian; Yeung Leung, Tak

    2013-01-01

    Background A newly introduced cell-free fetal DNA sequencing based non-invasive prenatal testing (DNA-NIPT) detects Down syndrome with sensitivity of 99% at early gestational stage without risk of miscarriage. Attention has been given to its public health implications; little is known from consumer perspectives. This qualitative study aimed to explore women’s motivations for using, and perceptions of, DNA-NIPT in Hong Kong. Methods and Findings In-depth interviews were conducted with 45 women who had undertaken DNA-NIPT recruited by purposive sampling based on socio-demographic and clinical characteristics. The sample included 31 women identified as high-risk from serum and ultrasound based Down syndrome screening (SU-DSS). Thematic narrative analysis examined informed-decision making of the test and identified the benefits and needs. Women outlined a number of reasons for accessing DNA-NIPT: reducing the uncertainty associated with risk probability-based results from SU-DSS, undertaking DNA-NIPT as a comprehensive measure to counteract risk from childbearing especially at advanced age, perceived predictive accuracy and absence of risk of harm to fetus. Accounts of women deemed high-risk or not high-risk are distinctive in a number of respects. High-risk women accessed DNA-NIPT to get a clearer idea of their risk. This group perceived SU-DSS as an unnecessary and confusing procedure because of its varying, protocol-dependent detection rates. Those women not deemed high-risk, in contrast, undertook DNA-NIPT for psychological assurance and to reduce anxiety even after receiving the negative result from SU-DSS. Conclusions DNA-NIPT was regarded positively by women who chose this method of screening over the routine, less expensive testing options. Given its perceived utility, health providers need to consider whether DNA-NIPT should be offered as part of universal routine care to women at high-risk for fetal aneuploidy. If this is the case, then further development

  14. Paternity testing using the poisonous sting in captive white-spotted eagle rays Aetobatus narinari: a non-invasive tool for captive sustainability programmes.

    PubMed

    Janse, M; Kappe, A L; Van Kuijk, B L M

    2013-03-01

    A group of captive white-spotted eagle rays Aetobatus narinari produced 20 offspring, with an unknown father. Part of the poisonous sting was removed from each fish and DNA was extracted from the epidermis for paternity research using eight microsatellite markers of which four were from another species Aetobatus flagellum. This non-invasive sampling technique can be applied on all members of Myliobatiformes. PMID:23464564

  15. Uptake, outcomes, and costs of implementing non-invasive prenatal testing for Down’s syndrome into NHS maternity care: prospective cohort study in eight diverse maternity units

    PubMed Central

    Wright, David; Hill, Melissa; Verhoef, Talitha I; Daley, Rebecca; Lewis, Celine; Mason, Sarah; McKay, Fiona; Jenkins, Lucy; Howarth, Abigail; Cameron, Louise; McEwan, Alec; Fisher, Jane; Kroese, Mark; Morris, Stephen

    2016-01-01

    Objective To investigate the benefits and costs of implementing non-invasive prenatal testing (NIPT) for Down’s syndrome into the NHS maternity care pathway. Design Prospective cohort study. Setting Eight maternity units across the United Kingdom between 1 November 2013 and 28 February 2015. Participants All pregnant women with a current Down’s syndrome risk on screening of at least 1/1000. Main outcome measures Outcomes were uptake of NIPT, number of cases of Down’s syndrome detected, invasive tests performed, and miscarriages avoided. Pregnancy outcomes and costs associated with implementation of NIPT, compared with current screening, were determined using study data on NIPT uptake and invasive testing in combination with national datasets. Results NIPT was prospectively offered to 3175 pregnant women. In 934 women with a Down’s syndrome risk greater than 1/150, 695 (74.4%) chose NIPT, 166 (17.8%) chose invasive testing, and 73 (7.8%) declined further testing. Of 2241 women with risks between 1/151 and 1/1000, 1799 (80.3%) chose NIPT. Of 71 pregnancies with a confirmed diagnosis of Down’s syndrome, 13/42 (31%) with the diagnosis after NIPT and 2/29 (7%) after direct invasive testing continued, resulting in 12 live births. In an annual screening population of 698 500, offering NIPT as a contingent test to women with a Down’s syndrome screening risk of at least 1/150 would increase detection by 195 (95% uncertainty interval −34 to 480) cases with 3368 (2279 to 4027) fewer invasive tests and 17 (7 to 30) fewer procedure related miscarriages, for a non-significant difference in total costs (£−46 000, £−1 802 000 to £2 661 000). The marginal cost of NIPT testing strategies versus current screening is very sensitive to NIPT costs; at a screening threshold of 1/150, NIPT would be cheaper than current screening if it cost less than £256. Lowering the risk threshold increases the number of Down’s syndrome cases detected and

  16. Non-invasive monitoring of physiological stress in the Western lowland gorilla (Gorilla gorilla gorilla): validation of a fecal glucocorticoid assay and methods for practical application in the field.

    PubMed

    Shutt, Kathryn; Setchell, Joanna M; Heistermann, Michael

    2012-11-01

    Enzymeimmunoassays (EIAs) allow researchers to monitor stress hormone output via measurement of fecal glucocorticoid metabolites (FGCMs) in many vertebrates. They can be powerful tools which allow the acquisition of otherwise unobtainable physiological information from both captive animals and wild animals in remote forest habitats, such as great apes. However, methods for hormone measurement, extraction and preservation need to be adapted and validated for field settings. In preparation for a field study of Western lowland gorillas (Gorilla gorilla gorilla) in the Central African Republic we used samples from captive gorillas collected around opportunistic stressful situations to test whether four different glucocorticoid EIAs reflected adrenocortical activity reliably and to establish the lag-time from the stressor to peak excretion. We also validated a field extraction technique and established a simple, non-freezer-reliant method to preserve FGCMs in extracts long-term. We determined the rate of FGCM change over 28 days when samples cannot be extracted immediately and over 12h when feces cannot be preserved immediately in alcohol. Finally, we used repeat samples from identified individuals to test for diurnal variation in FGCM output. Two group-specific assays measuring major cortisol metabolites detected the predicted FGCM response to the stressor reliably, whereas more specific cortisol and corticosterone assays were distinctly less responsive and thus less useful. We detected a lag time of 2-3 days from stressor to peak FGCM excretion. Our field extraction method performed as well as an established laboratory extraction method and FGCMs in dried extracts stored at ambient temperatures were as stable as those at -20 °C over 1 yr. Hormones in non-extracted feces in alcohol were stable up to 28 days at ambient temperatures. FGCMs in un-fixed gorilla feces deteriorated to almost 50% of the original values within 6h under field conditions. We detected no diurnal

  17. “Don’t Want No Risk and Don’t Want No Problems”: Public Understandings of the Risks and Benefits of Non-Invasive Prenatal Testing in the United States

    PubMed Central

    Allyse, Megan; Sayres, Lauren Carter; Goodspeed, Taylor; Michie, Marsha; Cho, Mildred K

    2014-01-01

    Background The recent availability of new non-invasive prenatal genetic tests for fetal aneuploidy has raised questions concerning whether and how these new tests will be integrated into prenatal medical care. Among the many factors to be considered are public understandings and preferences about prenatal testing mechanisms and the prospect of fetal aneuploidy. Methods To address these issues, we conducted a nation-wide mixed-method survey of 2,960 adults in the United States to explore justifications for choices among prenatal testing mechanisms. Open responses were qualitatively coded and grouped by theme. Results Respondents cited accuracy, followed by cost, as the most significant aspects of prenatal testing. Acceptance of testing was predicated on differing valuations of knowledge and on personal and religious beliefs. Trust in the medical establishment, attitudes towards risk, and beliefs about health and illness were also considered relevant. Conclusions Although a significant portion of the sample population valued the additional accuracy provided by the new non-invasive tests, they nevertheless expressed concerns over high costs. Furthermore, participants continued to express reservations about the value of prenatal genetic information per se, regardless of how it was obtained. PMID:25932463

  18. Nuclear Stress Test

    MedlinePlus

    ... Scan Diagnostic Tests and Procedures Echocardiography Electrocardiogram Electrophysiology Studies Exercise Stress Test Holter Monitoring Intravascular Ultrasound Nuclear Ventriculography Optical ...

  19. Non-invasive glucose monitor

    NASA Technical Reports Server (NTRS)

    Lambert, James L. (Inventor); Borchert, Mark S. (Inventor)

    2001-01-01

    A non-invasive method for determining blood level of an analyte of interest, such as glucose, comprises: generating an excitation laser beam (e.g., at a wavelength of 700 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor in the anterior chamber is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated aqueous humor; and then determining the blood glucose level (or the level of another analyte of interest) for the subject from the Raman spectrum. Preferably, the detecting step is followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing method is also disclosed.

  20. Can the material properties of regenerate bone be predicted with non-invasive methods of assessment? Exploring the correlation between dual X-ray absorptiometry and compression testing to failure in an animal model of distraction osteogenesis.

    PubMed

    Monsell, Fergal; Hughes, Andrew William; Turner, James; Bellemore, Michael C; Bilston, Lynne

    2014-04-01

    Evaluation of the material properties of regenerate bone is of fundamental importance to a successful outcome following distraction osteogenesis using an external fixator. Plain radiographs are in widespread use for assessment of alignment and the distraction gap but are unable to detect bone formation in the early stages of distraction osteogenesis and do not quantify accurately the structural properties of the regenerate. Dual X-ray absorptiometry (DXA) is a widely available non-invasive imaging modality that, unlike X-ray, can be used to measure bone mineral content (BMC) and density quantitatively. In order to be useful as a clinical investigation; however, the structural two-dimensional geometry and density distributions assessed by DXA should reflect material properties such as modulus and also predict the structural mechanical properties of the regenerate bone formed. We explored the hypothesis that there is a relationship between DXA assessment of regenerate bone and structural mechanical properties in an animal model of distraction osteogenesis. Distraction osteogenesis was carried out on the tibial diaphysis of 41 male, 12 week old, New Zealand white rabbits as part of a larger study. Distraction started after a latent period of 24 h at a rate of 0.375 mm every 12 h and continued for 10-days, achieving average lengthening of 7.1 mm. Following an 18-day period of consolidation, the regenerate bone was subject to bone density measurements using a total body dual-energy X-ray densitometer. This produced measurement of BMC, bone mineral density (BMD) and volumetric bone mineral density (vBMD). The tibiae were then disarticulated and cleaned of soft tissue before loading in compression to failure using an Instron mechanical testing machine (Instron Corporation, Massachusetts USA). Using Spearman rank correlation and linear regression, there was a significant correlation between vBMD and the Modulus of Elasticity, Yield Stress and Failure Stress of the

  1. Efficacy and cost-effectiveness of the 13C-urea breath test as the primary diagnostic investigation for the detection of Helicobacter pylori infection compared to invasive and non-invasive diagnostic tests

    PubMed Central

    Nocon, Marc; Kuhlmann, Alexander; Leodolter, Andreas; Roll, Stephanie; Vauth, Christoph; Willich, Stefan N.; Greiner, Wolfgang

    2009-01-01

    Background Helicobacter pylori (H. pylori) is one of the most common bacterial infections in humans. There is a risk factor for gastric or duodenal ulcers, gastric cancer and MALT (Mucosa Associated Lymphoid Tissue)-Lymphomas. There are several invasive and non-invasive methods available for the diagnosis of H. pylori. The 13C-urea breath test is a non-invasive method recommended for monitoring H. pylori eradication therapy. However, this test is not yet used for primary assessment of H. pylori in Germany. Objectives What are the clinical and health economic benefits of the 13C-urea breath test in the primary assessment of H. pylori compared to other invasive and non-invasive methods? Methods A systematic literature search including a hand search was performed for studies investigating test criteria and cost-effectiveness of the 13C-urea breath test in comparison to other methods used in the primary assessment of H. pylori. Only studies that directly compared the 13C-urea breath test to other H. pylori-tests were included. For the medical part, biopsy-based tests were used as the gold standard. Results 30 medical studies are included. Compared to the immunoglobulin G (IgG) test, the sensitivity of the 13C-urea breath test is higher in twelve studies, lower in six studies and one study reports no differences. The specificity is higher in 13 studies, lower in three studies and two studies report no differences. Compared to the stool antigen test, the sensitivity of the 13C-urea breath test is higher in nine studies, lower in three studies and one study reports no difference. The specificity is higher in nine studies, lower in two studies and two studies report no differences. Compared to the urease test, the sensitivity of the 13C-urea breath test is higher in four studies, lower in three studies and four studies report no differences. The specificity is higher in five studies, lower in five studies and one study reports no difference. Compared to histology, the

  2. Non-invasive determination of the complete elastic moduli of spider silks

    NASA Astrophysics Data System (ADS)

    Koski, Kristie J.; Akhenblit, Paul; McKiernan, Keri; Yarger, Jeffery L.

    2013-03-01

    Spider silks possess nature’s most exceptional mechanical properties, with unrivalled extensibility and high tensile strength. Unfortunately, our understanding of silks is limited because the complete elastic response has never been measured—leaving a stark lack of essential fundamental information. Using non-invasive, non-destructive Brillouin light scattering, we obtain the entire stiffness tensors (revealing negative Poisson’s ratios), refractive indices, and longitudinal and transverse sound velocities for major and minor ampullate spider silks: Argiope aurantia, Latrodectus hesperus, Nephila clavipes, Peucetia viridans. These results completely quantify the linear elastic response for all possible deformation modes, information unobtainable with traditional stress-strain tests. For completeness, we apply the principles of Brillouin imaging to spatially map the elastic stiffnesses on a spider web without deforming or disrupting the web in a non-invasive, non-contact measurement, finding variation among discrete fibres, junctions and glue spots. Finally, we provide the stiffness changes that occur with supercontraction.

  3. Non-invasive determination of the complete elastic moduli of spider silks.

    PubMed

    Koski, Kristie J; Akhenblit, Paul; McKiernan, Keri; Yarger, Jeffery L

    2013-03-01

    Spider silks possess nature's most exceptional mechanical properties, with unrivalled extensibility and high tensile strength. Unfortunately, our understanding of silks is limited because the complete elastic response has never been measured-leaving a stark lack of essential fundamental information. Using non-invasive, non-destructive Brillouin light scattering, we obtain the entire stiffness tensors (revealing negative Poisson's ratios), refractive indices, and longitudinal and transverse sound velocities for major and minor ampullate spider silks: Argiope aurantia, Latrodectus hesperus, Nephila clavipes, Peucetia viridans. These results completely quantify the linear elastic response for all possible deformation modes, information unobtainable with traditional stress-strain tests. For completeness, we apply the principles of Brillouin imaging to spatially map the elastic stiffnesses on a spider web without deforming or disrupting the web in a non-invasive, non-contact measurement, finding variation among discrete fibres, junctions and glue spots. Finally, we provide the stiffness changes that occur with supercontraction. PMID:23353627

  4. Non-invasive assessment of animal exercise stress: real-time PCR of GLUT4, COX2, SOD1 and HSP70 in avalanche military dog saliva.

    PubMed

    Diverio, S; Guelfi, G; Barbato, O; Di Mari, W; Egidi, M G; Santoro, M M

    2015-01-01

    Exercise has been shown to increase mRNA expression of a growing number of genes. The aim of this study was to assess if mRNA expression of the metabolism- and oxidative stress-related genes GLUT4 (glucose transporter 4), COX2 (cyclooxygenase 2), SOD1 (superoxide dismutase 1) and HSP70 (heat shock protein 70) in saliva changes following acute exercise stress in dogs. For this purpose, 12 avalanche dogs of the Italian Military Force Guardia di Finanza were monitored during simulation of a search for a buried person in an artificial avalanche area. Rectal temperature (RT) and saliva samples were collected the day before the trial (T0), immediately after the descent from a helicopter at the onset of a simulated avalanche search and rescue operation (T1), after the discovery of the buried person (T2) and 2 h later (T3). Expressions of GLUT4, SOD1, COX2 and HSP70 were measured by real-time PCR. The simulated avalanche search and rescue operation was shown to exert a significant effect on RT, as well as on the expression of all metabolism- and oxidative stress-related genes investigated, which peaked at T2. The observed expression patterns indicate an acute exercise stress-induced upregulation, as confirmed by the reductions in expression at T3. Moreover, our findings indicate that saliva is useful for assessing metabolism- and oxidative stress-related genes without the need for restraint, which could affect working dog performance. PMID:25245143

  5. Non-Invasive Imaging of Vascular Inflammation

    PubMed Central

    Ammirati, Enrico; Moroni, Francesco; Pedrotti, Patrizia; Scotti, Isabella; Magnoni, Marco; Bozzolo, Enrica P.; Rimoldi, Ornella E.; Camici, Paolo G.

    2014-01-01

    In large-vessel vasculitides, inflammatory infiltrates may cause thickening of the involved arterial vessel wall leading to progressive stenosis and occlusion. Dilatation, aneurysm formation, and thrombosis may also ensue. Activated macrophages and T lymphocytes are fundamental elements in vascular inflammation. The amount and density of the inflammatory infiltrate is directly linked to local disease activity. Additionally, patients with autoimmune disorders have an increased cardiovascular (CV) risk compared with age-matched healthy individuals as a consequence of accelerated atherosclerosis. Molecular imaging techniques targeting activated macrophages, neovascularization, or increased cellular metabolic activity can represent effective means of non-invasive detection of vascular inflammation. In the present review, novel non-invasive imaging tools that have been successfully tested in humans will be presented. These include contrast-enhanced ultrasonography, which allows detection of neovessels within the wall of inflamed arteries; contrast-enhanced CV magnetic resonance that can detect increased thickness of the arterial wall, usually associated with edema, or mural enhancement using T2 and post-contrast T1-weighted sequences, respectively; and positron emission tomography associated with radio-tracers such as [18F]-fluorodeoxyglucose and the new [11C]-PK11195 in combination with computed tomography angiography to detect activated macrophages within the vessel wall. Imaging techniques are useful in the diagnostic work-up of large- and medium-vessel vasculitides, to monitor disease activity and the response to treatments. Finally, molecular imaging targets can provide new clues about the pathogenesis and evolution of immune-mediated disorders involving arterial vessels. PMID:25183963

  6. Brain oxidative stress: detection and mapping of anti-oxidant marker 'Glutathione' in different brain regions of healthy male/female, MCI and Alzheimer patients using non-invasive magnetic resonance spectroscopy.

    PubMed

    Mandal, Pravat K; Tripathi, Manjari; Sugunan, Sreedevi

    2012-01-01

    Glutathione (GSH) serves as an important anti-oxidant in the brain by scavenging harmful reactive oxygen species that are generated during different molecular processes. The GSH level in the brain provides indirect information on oxidative stress of the brain. We report in vivo detection of GSH non-invasively from various brain regions (frontal cortex, parietal cortex, hippocampus and cerebellum) in bilateral hemispheres of healthy male and female subjects and from bi-lateral frontal cortices in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). All AD patients who participated in this study were on medication with cholinesterase inhibitors. Healthy young male (age 26.4±3.0) and healthy young female (age 23.6±2.1) subjects have higher amount of GSH in the parietal cortical region and a specific GSH distribution pattern (parietal cortex>frontal cortex>hippocampus ~ cerebellum) has been found. Overall mean GSH content is higher in healthy young female compared to healthy young male subjects and GSH is distributed differently in two hemispheres among male and female subjects. In both young female and male subjects, statistically significant (p=0.02 for young female and p=0.001 for young male) difference in mean GSH content is found when compared between left frontal cortex (LFC) and right frontal cortex (RFC). In healthy young female subjects, we report statistically significant positive correlation of GSH content between RFC and LFC (r=0.641, p=0.004) as well as right parietal cortex (RPC) and left parietal cortex (LPC) (r=0.797, p=0.000) regions. In healthy young male subjects, statistically significant positive correlation of GSH content was observed between LFC and LPC (r=0.481, p=0.032) regions. This statistical analysis implicates that in case of a high GSH content in LPC of a young male, his LFC region would also contain high GSH and vice versa. The difference in mean of GSH content between healthy young female control and female AD

  7. Non-invasive and invasive imaging of vulnerable coronary plaque.

    PubMed

    Celeng, Csilla; Takx, Richard A P; Ferencik, Maros; Maurovich-Horvat, Pál

    2016-08-01

    Vulnerable plaque is characterized by a large necrotic core and an overlying thin fibrous cap. Non-invasive imaging modalities such as computed tomography angiography (CTA) and magnetic resonance imaging (MRI) allow for the assessment of morphological plaque characteristics, while positron emission tomography (PET) enables the detection of metabolic activity within the atherosclerotic lesions. Invasive imaging modalities such as intravascular ultrasound (IVUS), optical-coherence tomography (OCT), and intravascular MRI (IV-MRI) display plaques at a high spatial resolution. Near-infrared spectroscopy (NIRS) allows for the detection of chemical components of atherosclerotic plaques. In this review, we describe state-of-the-art non-invasive and invasive imaging modalities and stress the combination of their advantages to identify vulnerable plaque features. PMID:27079893

  8. Non-invasive sensing for food reassurance.

    PubMed

    Xiaobo, Zou; Xiaowei, Huang; Povey, Malcolm

    2016-03-01

    Consumers and governments are increasingly interested in the safety, authenticity and quality of food commodities. This has driven attention towards non-invasive sensing techniques used for rapid analyzing these commodities. This paper provides an overview of the state of the art in, and available alternatives for, food assurance based on non-invasive sensing techniques. The main food quality traits of interest using non-invasive sensing techniques are sensory characteristics, chemical composition, physicochemical properties, health-protecting properties, nutritional characteristics and safety. A wide range of non-invasive sensing techniques, from optical, acoustical, electrical, to nuclear magnetic, X-ray, biosensor, microwave and terahertz, are organized according to physical principle. Some of these techniques are now in a period of transition between experimental and applied utilization and several sensors and instruments are reviewed. With continued innovation and attention to key challenges, such non-invasive sensors and biosensors are expected to open up new exciting avenues in the field of portable and wearable wireless sensing devices and connecting with mobile networks, thus finding considerable use in a wide range of food assurance applications. The need for an appropriate regulatory framework is emphasized which acts to exclude unwanted components in foods and includes needed components, with sensors as part of a reassurance framework supporting regulation and food chain management. The integration of these sensor modalities into a single technological and commercial platform offers an opportunity for a paradigm shift in food reassurance. PMID:26835653

  9. Non-Invasive Neuromodulation for Headache Disorders.

    PubMed

    Zhu, Shuhan; Marmura, Michael J

    2016-02-01

    Migraine and other chronic headache disorders are common and if inadequately treated, can lead to significant disability. The effectiveness of medications can be limited by side effects, drug interactions, and comorbid diseases necessitating alternative methods. Technological developments in the past 5 years have made it possible to use non-invasive methods of neuromodulation to treat primary headache disorders. This field includes technologies such as supraorbital transcutaneous stimulation (STS), transcranial magnetic stimulation (TMS), and non-invasive vagal nerve stimulation (nVNS). Existing trials show these modalities are safe and well tolerated and can be combined with standard pharmacotherapy. We review the technologies, biological rationales, and trials involving non-invasive neuromodulation for the treatment of primary headache disorders. PMID:26750126

  10. Non-invasive methods to establish the diagnosis of terra firma-forme dermatosis: The SMART (Skin Modified by Alcohol Rubbing Test) evaluation and dermoscopy.

    PubMed

    Greywal, Tanya; Cohen, Philip R

    2016-01-01

    Terra firma-forme dermatosis may mimic a variety of hyper pigmented dermatoses.  The diagnosis can be characterized using dermoscopy and confirmed with the SMART (Skin Modified by Alcohol Rubbing Test) evaluation.  When terra firma-forme dermatosis (Duncan's dirty dermatosis) is clinically suspected, clearance of the dermatosis follows rubbing the affected skin with 70% isopropyl alcohol. PMID:27617614

  11. Non-invasive Intratracheal Instillation in Mice

    PubMed Central

    Ortiz-Muñoz, Guadalupe; Looney, Mark R.

    2016-01-01

    The intratracheal instillation technique is used to deliver a variety of agents to the lungs ranging from pathogens (bacteria, viruses), toxins, to therapeutic agents. To model lung inflammation and injury, LPS can be administrated via intranasal, intratracheal, or aerosol approaches. Each technique has its limitations. The intratracheal technique can involve the non-invasive instillation method (via the oro-tracheal route) or a direct injection into the trachea. Here, we describe an optimized method for direct visual instillation of LPS via the non-invasive oro-tracheal route.

  12. STRESS TESTING OF WOODSTOVES

    EPA Science Inventory

    The paper discusses stress testing of woodstoves. tress testing is a way to test the long- term durability of woodstove models in the laboratory in a 1 to 2 week time frame. (NOTE: Woodstove field studies have shown that new technology woodstoves designed to have low particulate ...

  13. Congenital coronary artery anomalies silent until geriatric age: non-invasive assessment, angiography tips, and treatment

    PubMed Central

    Rigatelli, Gianluca; Dell'Avvocata, Fabio; Van Tan, Nguyen; Daggubati, Rames; Nanijundappa, Aravinda

    2015-01-01

    Coronary artery anomalies (CAAs) may be discovered more often as incidental findings during the normal diagnostic process for other cardiac diseases or less frequently on the basis of manifestations of myocardial ischemia. The cardiovascular professional may be involved in their angiographic diagnosis, functional assessment and eventual endovascular treatment. A complete angiographic definition is mandatory in order to understand the functional effects and plan any intervention in CAAs: computed tomography and magnetic resonance imaging are useful non-invasive tools to detect three-dimensional morphology of the anomalies and its relationships with contiguous cardiac structures, whereas coronary arteriography remains the gold standard for a definitive anatomic picture. A practical idea of the possible functional significance is mandatory for deciding how to manage CAAs: non-invasive stress tests and in particular the invasive pharmacological stress tests with or without intravascular ultrasound monitoring can assess correctly the functional significance of the most CAAs. Finally, the knowledge of the particular endovascular techniques and material is of paramount importance for achieving technical and clinical success. CAAs represent a complex issue, which rarely involve the cardiovascular professional at different levels. A timely practical knowledge of the main issues regarding CAAs is important in the management of such entities. PMID:25678906

  14. Non-invasive monitoring of spreading depression.

    PubMed

    Bastany, Zoya J R; Askari, Shahbaz; Dumont, Guy A; Speckmann, Erwin-Josef; Gorji, Ali

    2016-10-01

    Spreading depression (SD), a slow propagating depolarization wave, plays an important role in pathophysiology of different neurological disorders. Yet, research into SD-related disorders has been hampered by the lack of non-invasive recording techniques of SD. Here we compared the manifestations of SD in continuous non-invasive electroencephalogram (EEG) recordings to invasive electrocorticographic (ECoG) recordings in order to obtain further insights into generator structures and electrogenic mechanisms of surface recording of SD. SD was induced by KCl application and simultaneous SD recordings were performed by scalp EEG as well as ECoG electrodes of somatosensory neocortex of rats using a novel homemade EEG amplifier, AgCl recording electrodes, and high chloride conductive gel. Different methods were used to analyze the data; including the spectrogram, bi-spectrogram, pattern distribution, relative spectrum power, and multivariable Gaussian fit analysis. The negative direct current (DC) shifts recorded by scalp electrodes exhibited a high homogeneity to those recorded by ECoG electrodes. Furthermore, this novel method of recording and analysis was able to separate SD recorded by scalp electrodes from non-neuronal DC shifts induced by other potential generators, such as the skin, muscles, arteries, dura, etc. These data suggest a novel application for continuous non-invasive monitoring of DC potential changes, such as SD. Non-invasive monitoring of SD would allow early intervention and improve outcome in SD-related neurological disorders. PMID:27397413

  15. Non-invasive assessment of intracranial pressure.

    PubMed

    Robba, C; Bacigaluppi, S; Cardim, D; Donnelly, J; Bertuccio, A; Czosnyka, M

    2016-07-01

    Monitoring of intracranial pressure (ICP) is invaluable in the management of neurosurgical and neurological critically ill patients. Invasive measurement of ventricular or parenchymal pressure is considered the gold standard for accurate measurement of ICP but is not always possible due to certain risks. Therefore, the availability of accurate methods to non-invasively estimate ICP has the potential to improve the management of these vulnerable patients. This review provides a comparative description of different methods for non-invasive ICP measurement. Current methods are based on changes associated with increased ICP, both morphological (assessed with magnetic resonance, computed tomography, ultrasound, and fundoscopy) and physiological (assessed with transcranial and ophthalmic Doppler, tympanometry, near-infrared spectroscopy, electroencephalography, visual-evoked potentials, and otoacoustic emissions assessment). At present, none of the non-invasive techniques alone seem suitable as a substitute for invasive monitoring. However, following the present analysis and considerations upon each technique, we propose a possible flowchart based on the combination of non-invasive techniques including those characterizing morphologic changes (e.g., repetitive US measurements of ONSD) and those characterizing physiological changes (e.g., continuous TCD). Such an integrated approach, which still needs to be validated in clinical practice, could aid in deciding whether to place an invasive monitor, or how to titrate therapy when invasive ICP measurement is contraindicated or unavailable. PMID:26515159

  16. [Pulmonary non invasive infection by Scedosporium apiospermum].

    PubMed

    Cruz, Rodrigo; Barros, Manuel; Reyes, Mirtha

    2015-08-01

    We reported a case of non-invasive pulmonary infection by Scedosporium apiospermum in 67 years old female with bronchiectasis and caverns secondary to tuberculosis. Diagnosis was made with lung CT and bronchial lavage cultures. The patient was initially treated with itraconazole for six weeks without success and then voriconazole for 16 weeks, with good clinical response. PMID:26436797

  17. Bisulfite Conversion of DNA: Performance Comparison of Different Kits and Methylation Quantitation of Epigenetic Biomarkers that Have the Potential to Be Used in Non-Invasive Prenatal Testing

    PubMed Central

    Leontiou, Chrysanthia A.; Hadjidaniel, Michael D.; Mina, Petros; Antoniou, Pavlos; Ioannides, Marios; Patsalis, Philippos C.

    2015-01-01

    Introduction Epigenetic alterations, including DNA methylation, play an important role in the regulation of gene expression. Several methods exist for evaluating DNA methylation, but bisulfite sequencing remains the gold standard by which base-pair resolution of CpG methylation is achieved. The challenge of the method is that the desired outcome (conversion of unmethylated cytosines) positively correlates with the undesired side effects (DNA degradation and inappropriate conversion), thus several commercial kits try to adjust a balance between the two. The aim of this study was to compare the performance of four bisulfite conversion kits [Premium Bisulfite kit (Diagenode), EpiTect Bisulfite kit (Qiagen), MethylEdge Bisulfite Conversion System (Promega) and BisulFlash DNA Modification kit (Epigentek)] regarding conversion efficiency, DNA degradation and conversion specificity. Methods Performance was tested by combining fully methylated and fully unmethylated λ-DNA controls in a series of spikes by means of Sanger sequencing (0%, 25%, 50% and 100% methylated spikes) and Next-Generation Sequencing (0%, 3%, 5%, 7%, 10%, 25%, 50% and 100% methylated spikes). We also studied the methylation status of two of our previously published differentially methylated regions (DMRs) at base resolution by using spikes of chorionic villus sample in whole blood. Results The kits studied showed different but comparable results regarding DNA degradation, conversion efficiency and conversion specificity. However, the best performance was observed with the MethylEdge Bisulfite Conversion System (Promega) followed by the Premium Bisulfite kit (Diagenode). The DMRs, EP6 and EP10, were confirmed to be hypermethylated in the CVS and hypomethylated in whole blood. Conclusion Our findings indicate that the MethylEdge Bisulfite Conversion System (Promega) was shown to have the best performance among the kits. In addition, the methylation level of two of our DMRs, EP6 and EP10, was confirmed

  18. Exercise stress testing

    NASA Technical Reports Server (NTRS)

    Schuster, B.

    1975-01-01

    Positive maximum stress tests in the management of coronary patients are discussed. It is believed that coronary angiography would be the ultimate test to predict the future of patients with coronary heart disease. Progression of angina, myocardial infarction, and death due to heart disease were analyzed.

  19. Non-invasive blood sampling from primates using laboratory-bred blood-sucking bugs (Dipetalogaster maximus; Reduviidae, Heteroptera).

    PubMed

    Thomsen, Ruth; Voigt, Christian C

    2006-10-01

    Primates are easily stressed by the conventional veterinary blood sampling routine and consequently, measured blood parameters may be biased. In this study, we tested blood-sucking bugs (Dipetalogaster maximus) on one lemur and two ape species (Microcebus murinus, Pongo abelii, Pan paniscus) as an alternative, non-invasive technique for bleeding primates. Within time periods of between 6 and 62 min we obtained blood volumes of 0.01-2.4 ml in 11 out of 12 trials from all three species. Therefore, we conclude that these bugs represent a new, gentle and effective tool for bleeding captive primates without stress. PMID:16741605

  20. Stress Corrosion Testing

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Advanced testing of structural materials was developed by Lewis Research Center and Langley Research Center working with the American Society for Testing and Materials (ASTM). Under contract, Aluminum Company of America (Alcoa) conducted a study for evaluating stress corrosion cracking, and recommended the "breaking load" method which determines fracture strengths as well as measuring environmental degradation. Alcoa and Langley plan to submit the procedure to ASTM as a new testing method.

  1. Non-invasive diagnosis of advanced fibrosis and cirrhosis.

    PubMed

    Sharma, Suraj; Khalili, Korosh; Nguyen, Geoffrey Christopher

    2014-12-01

    Liver cirrhosis is a common and growing public health problem globally. The diagnosis of cirrhosis portends an increased risk of morbidity and mortality. Liver biopsy is considered the gold standard for diagnosis of cirrhosis and staging of fibrosis. However, despite its universal use, liver biopsy is an invasive and inaccurate gold standard with numerous drawbacks. In order to overcome the limitations of liver biopsy, a number of non-invasive techniques have been investigated for the assessment of cirrhosis. This review will focus on currently available non-invasive markers of cirrhosis. The evidence behind the use of these markers will be highlighted, along with an assessment of diagnostic accuracy and performance characteristics of each test. Non-invasive markers of cirrhosis can be radiologic or serum-based. Radiologic techniques based on ultrasound, magnetic resonance imaging and elastography have been used to assess liver fibrosis. Serum-based biomarkers of cirrhosis have also been developed. These are broadly classified into indirect and direct markers. Indirect biomarkers reflect liver function, which may decline with the onset of cirrhosis. Direct biomarkers, reflect extracellular matrix turnover, and include molecules involved in hepatic fibrogenesis. On the whole, radiologic and serum markers of fibrosis correlate well with biopsy scores, especially when excluding cirrhosis or excluding fibrosis. This feature is certainly clinically useful, and avoids liver biopsy in many cases. PMID:25492996

  2. The VITRO Score (Von Willebrand Factor Antigen/Thrombocyte Ratio) as a New Marker for Clinically Significant Portal Hypertension in Comparison to Other Non-Invasive Parameters of Fibrosis Including ELF Test

    PubMed Central

    Hametner, Stephanie; Ferlitsch, Arnulf; Ferlitsch, Monika; Etschmaier, Alexandra; Schöfl, Rainer; Ziachehabi, Alexander; Maieron, Andreas

    2016-01-01

    Background Clinically significant portal hypertension (CSPH), defined as hepatic venous pressure gradient (HVPG) ≥10 mmHg, causes major complications. HVPG is not always available, so a non-invasive tool to diagnose CSPH would be useful. VWF-Ag can be used to diagnose. Using the VITRO score (the VWF-Ag/platelet ratio) instead of VWF-Ag itself improves the diagnostic accuracy of detecting cirrhosis/ fibrosis in HCV patients. Aim This study tested the diagnostic accuracy of VITRO score detecting CSPH compared to HVPG measurement. Methods All patients underwent HVPG testing and were categorised as CSPH or no CSPH. The following patient data were determined: CPS, D’Amico stage, VITRO score, APRI and transient elastography (TE). Results The analysis included 236 patients; 170 (72%) were male, and the median age was 57.9 (35.2–76.3; 95% CI). Disease aetiology included ALD (39.4%), HCV (23.4%), NASH (12.3%), other (8.1%) and unknown (11.9%). The CPS showed 140 patients (59.3%) with CPS A; 56 (23.7%) with CPS B; and 18 (7.6%) with CPS C. 136 patients (57.6%) had compensated and 100 (42.4%) had decompensated cirrhosis; 83.9% had HVPG ≥10 mmHg. The VWF-Ag and the VITRO score increased significantly with worsening HVPG categories (P<0.0001). ROC analysis was performed for the detection of CSPH and showed AUC values of 0.92 for TE, 0.86 for VITRO score, 0.79 for VWF-Ag, 0.68 for ELF and 0.62 for APRI. Conclusion The VITRO score is an easy way to diagnose CSPH independently of CPS in routine clinical work and may improve the management of patients with cirrhosis. PMID:26895398

  3. Non-invasive Mapping of Cardiac Arrhythmias.

    PubMed

    Shah, Ashok; Hocini, Meleze; Haissaguerre, Michel; Jaïs, Pierre

    2015-08-01

    Since more than 100 years, 12-lead electrocardiography (ECG) is the standard-of-care tool, which involves measuring electrical potentials from limited sites on the body surface to diagnose cardiac disorder, its possible mechanism, and the likely site of origin. Several decades of research has led to the development of a 252-lead ECG and computed tomography (CT) scan-based three-dimensional electro-imaging modality to non-invasively map abnormal cardiac rhythms including fibrillation. These maps provide guidance towards ablative therapy and thereby help advance the management of complex heart rhythm disorders. Here, we describe the clinical experience obtained using non-invasive technique in mapping the electrical disorder and guide the catheter ablation of atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beats), and ventricular pre-excitation (Wolff-Parkinson-White syndrome). PMID:26072438

  4. Ultrasonic non invasive techniques for microbiological instrumentation

    NASA Astrophysics Data System (ADS)

    Elvira, L.; Sierra, C.; Galán, B.; Resa, P.

    2010-01-01

    Non invasive techniques based on ultrasounds have advantageous features to study, characterize and monitor microbiological and enzymatic reactions. These processes may change the sound speed, viscosity or particle distribution size of the medium where they take place, which makes possible their analysis using ultrasonic techniques. In this work, two different systems for the analysis of microbiological liquid media based on ultrasounds are presented. In first place, an industrial application based on an ultrasonic monitoring technique for microbiological growth detection in milk is shown. Such a system may improve the quality control strategies in food production factories, being able to decrease the time required to detect possible contaminations in packed products. Secondly, a study about the growing of the Escherichia coli DH5 α in different conditions is presented. It is shown that the use of ultrasonic non invasive characterization techniques in combination with other conventional measurements like optical density provides complementary information about the metabolism of these bacteria.

  5. [Non-invasive assessment of liver fibrosis].

    PubMed

    Cohen-Ezra, Oranit; Ben-Ari, Ziv

    2015-03-01

    Chronic liver diseases represent a major public health problem, accounting for significant morbidity and mortality worldwide. Prognosis and management of chronic liver diseases depend on the amount of liver fibrosis. Liver biopsy has long remained the gold standard for assessment of liver fibrosis. Liver biopsy is an invasive procedure with associated morbidity, it is rarely the cause for mortality, and has a few limitations. During the past two decades, in an attempt to overcome the limitations of liver biopsy, non-invasive methods for the evaluation of liver fibrosis have been developed, mainly in the field of viral hepatitis. This review will focus on different methods available for non-invasive evaluation of liver fibrosis including a biological approach which quantifies serum levels of biomarkers of fibrosis and physical techniques which measure liver stiffness by transient elastography, ultrasound or magnetic resonance based elastography, their accuracy, advantages and disadvantages. PMID:25962254

  6. Non-invasive quantification of lower limb mechanical alignment in flexion

    PubMed Central

    Deakin, Angela; Fogg, Quentin A.; Picard, Frederic

    2014-01-01

    Objective Non-invasive navigation techniques have recently been developed to determine mechanical femorotibial alignment (MFTA) in extension. The primary aim of this study was to evaluate the precision and accuracy of an image-free navigation system with new software designed to provide multiple kinematic measurements of the knee. The secondary aim was to test two types of strap material used to attach optical trackers to the lower limb. Methods Seventy-two registrations were carried out on 6 intact embalmed cadaveric specimens (mean age: 77.8 ± 12 years). A validated fabric strap, bone screws and novel rubber strap were used to secure the passive tracker baseplate for four full experiments with each knee. The MFTA angle was measured under the conditions of no applied stress, valgus stress, and varus stress. These measurements were carried out at full extension and at 30°, 40°, 50° and 60° of flexion. Intraclass correlation coefficients, repeatability coefficients, and limits of agreement (LOA) were used to convey precision and agreement in measuring MFTA with respect to each of the independent variables, i.e., degree of flexion, applied coronal stress, and method of tracker fixation. Based on the current literature, a repeatability coefficient and LOA of ≤3° were deemed acceptable. Results The mean fixed flexion for the 6 specimens was 12.8° (range: 6–20°). The mean repeatability coefficient measuring MFTA in extension with screws or fabric strapping of the baseplate was ≤2°, compared to 2.3° using rubber strapping. When flexing the knee, MFTA measurements taken using screws or fabric straps remained precise (repeatability coefficient ≤3°) throughout the tested range of flexion (12.8–60°); however, using rubber straps, the repeatability coefficient was >3° beyond 50° flexion. In general, applying a varus/valgus stress while measuring MFTA decreased precision beyond 40° flexion. Using fabric strapping, excellent repeatability

  7. [Non-invasive assessment of fatty liver].

    PubMed

    Egresi, Anna; Lengyel, Gabriella; Hagymási, Krisztina

    2015-04-01

    As the result of various harmful effects (infectious agents, metabolic diseases, unhealthy diet, obesity, toxic agents, autoimmune processes) hepatic damage may develop, which can progress towards liver steatosis, and fibrosis as well. The most common etiological factors of liver damages are hepatitis B and C infection, alcohol consumption and non-alcoholic fatty liver disease. Liver biopsy is considered as the gold standard for the diagnosis of chronic liver diseases. Due to the dangers and complications of liver biopsy, studies are focused on non-invasive markers and radiological imaging for liver steatosis, progression of fatty liver, activity of the necroinflammation and the severity of the fibrosis. Authors review the possibilities of non-invasive assessment of liver steatosis. The statistical features of the probes (positive, negative predictive values, sensitivity, specificity) are reviewed. The role of radiological imaging is also discussed. Although the non-invasive methods discussed in this article are useful to assess liver steatosis, further studies are needed to validate to follow progression of the diseases and to control therapeutic response. PMID:25819147

  8. Physiology of non-invasive respiratory support.

    PubMed

    Alexiou, Stamatia; Panitch, Howard B

    2016-06-01

    Non-invasive ventilation (NIV) is used in neonates to treat extrathoracic and intrathoracic airway obstruction, parenchymal lung disease and disorders of control of breathing. Avoidance of airway intubation is associated with a reduction in the incidence of chronic lung disease among preterm infants with respiratory distress syndrome. Use of nasal continuous positive airway pressure (nCPAP) may help establish and maintain functional residual capacity (FRC), decrease respiratory work, and improve gas exchange. Other modes of non-invasive ventilation, which include heated humidified high-flow nasal cannula therapy (HHHFNC), nasal intermittent mandatory ventilation (NIMV), non-invasive pressure support ventilation (NI-PSV), and bi-level CPAP (SiPAP™), have also been shown to provide additional benefit in improving breathing patterns, reducing work of breathing, and increasing gas exchange when compared with nCPAP. Newer modes, such as neurally adjusted ventilatory assist (NAVA), hold the promise of improving patient-ventilator synchrony and so might ultimately improve outcomes for preterm infants with respiratory distress. PMID:26923501

  9. Instrumentation for Non-Invasive Assessment of Cardiovascular Regulation

    NASA Technical Reports Server (NTRS)

    Cohen, Richard J.

    1999-01-01

    It is critically important to be able to assess alterations in cardiovascular regulation during and after space flight. We propose to develop an instrument for the non-invasive assessment of such alterations that can be used on the ground and potentially during space flight. This instrumentation would be used by the Cardiovascular Alterations Team at multiple sites for the study of the effects of space flight on the cardiovascular system and the evaluation of countermeasures. In particular, the Cardiovascular Alterations Team will use this instrumentation in conjunction with ground-based human bed-rest studies and during application of acute stresses e.g., tilt, lower body negative pressure, and exercise. In future studies, the Cardiovascular Alterations Team anticipates using this instrumentation to study astronauts before and after space flight and ultimately, during space flight. The instrumentation may also be used by the Bone Demineralization/Calcium Metabolism Team, the Neurovestibular Team and the Human Performance Factors, Sleep and Chronobiology Team to measure changes in autonomic nervous function. The instrumentation will be based on a powerful new technology - cardiovascular system identification (CSI) - which has been developed in our laboratory. CSI provides a non-invasive approach for the study of alterations in cardiovascular regulation. This approach involves the analysis of second-to-second fluctuations in physiologic signals such as heart rate and non-invasively measured arterial blood pressure in order to characterize quantitatively the physiologic mechanisms responsible for the couplings between these signals. Through the characterization of multiple physiologic mechanisms, CSI provides a closed-loop model of the cardiovascular regulatory state in an individual subject.

  10. [Non invasive ventilation in the emergency setting].

    PubMed

    Wilhelm, Laetitia; Della Santa, Vincent; Hanhart, Walter-Alexandre

    2015-08-12

    Before the development of non invasive ventilation (NIV), endotracheal intubation was the only ventilatory therapy available in case of severe respiratory distress and acute respiratory failure. NIV used to be employed in intensive care settings only. Nowadays, the use of NIV has been democratized to include the emergency room, and the pre-hospital care setting for treatment of acute respiratory failure. Cardiogenic pulmonary edema and acute exacerbation of COPD are indications of choice, since NIV improves mortality. The efficiency of the therapy depends on early treatment; however, endotracheal intubation should not be delayed when it becomes necessary. PMID:26449102

  11. Examination of postmortem retinal folds: A non-invasive study.

    PubMed

    Oshima, Toru; Yoshikawa, Hiroshi; Ohtani, Maki; Mimasaka, Sohtaro

    2015-02-01

    The postmortem retinal fold has been previously documented, but its mechanism of formation is not known. All previous studies of the fold involved invasive techniques and the postmortem ocular fundus has yet to be non-invasively examined. Our study used the non-invasive techniques of monocular indirect ophthalmoscopy and ocular echography to examine 79 postmortem eyes of 42 bodies. We examined whether the postmortem retinal fold was associated with postmortem time, position, and/or age. Age was significantly associated with postmortem retinal fold formation (Mann-Whitney U test, P = 0.013), which led us to examine the effect of posterior vitreous detachment (PVD) on retinal folds. The absence of a PVD was statistically associated with the presence of a retinal fold (Fisher's exact test, P < 0.0001). Interestingly, the presence of a PVD was also significantly correlated with retinal fold height (Mann-Whitney U test, P < 0.0001). Therefore, we hypothesized that retinal folds result from postmortem vitreoretinal traction caused by eyeball flaccidity. We also believe that the loss of retinochoroidal hydrostatic pressure plays a role. It is important that forensic pathologists not confuse a postmortem retinal fold with traumatic retinal detachment or perimacular retinal folds caused by child abuse. When child abuse is suspected, forensic pathologists should perform enucleation and a subsequent histological examination for confirmation. PMID:25623189

  12. Tissue-informative mechanism for wearable non-invasive continuous blood pressure monitoring.

    PubMed

    Woo, Sung Hun; Choi, Yun Young; Kim, Dae Jung; Bien, Franklin; Kim, Jae Joon

    2014-01-01

    Accurate continuous direct measurement of the blood pressure is currently available thru direct invasive methods via intravascular needles, and is mostly limited to use during surgical procedures or in the intensive care unit (ICU). Non-invasive methods that are mostly based on auscultation or cuff oscillometric principles do provide relatively accurate measurement of blood pressure. However, they mostly involve physical inconveniences such as pressure or stress on the human body. Here, we introduce a new non-invasive mechanism of tissue-informative measurement, where an experimental phenomenon called subcutaneous tissue pressure equilibrium is revealed and related for application in detection of absolute blood pressure. A prototype was experimentally verified to provide an absolute blood pressure measurement by wearing a watch-type measurement module that does not cause any discomfort. This work is supposed to contribute remarkably to the advancement of continuous non-invasive mobile devices for 24-7 daily-life ambulatory blood-pressure monitoring. PMID:25331013

  13. Tissue-Informative Mechanism for Wearable Non-invasive Continuous Blood Pressure Monitoring

    NASA Astrophysics Data System (ADS)

    Woo, Sung Hun; Choi, Yun Young; Kim, Dae Jung; Bien, Franklin; Kim, Jae Joon

    2014-10-01

    Accurate continuous direct measurement of the blood pressure is currently available thru direct invasive methods via intravascular needles, and is mostly limited to use during surgical procedures or in the intensive care unit (ICU). Non-invasive methods that are mostly based on auscultation or cuff oscillometric principles do provide relatively accurate measurement of blood pressure. However, they mostly involve physical inconveniences such as pressure or stress on the human body. Here, we introduce a new non-invasive mechanism of tissue-informative measurement, where an experimental phenomenon called subcutaneous tissue pressure equilibrium is revealed and related for application in detection of absolute blood pressure. A prototype was experimentally verified to provide an absolute blood pressure measurement by wearing a watch-type measurement module that does not cause any discomfort. This work is supposed to contribute remarkably to the advancement of continuous non-invasive mobile devices for 24-7 daily-life ambulatory blood-pressure monitoring.

  14. Costs and clinical outcomes for non-invasive versus invasive diagnostic approaches to patients with suspected in-stent restenosis

    PubMed Central

    Hasegawa, James T.; Machacz, Susanne F.; O’Day, Ken

    2015-01-01

    This study compared costs and clinical outcomes of invasive versus non-invasive diagnostic evaluations for patients with suspected in-stent restenosis (ISR) after percutaneous coronary intervention. We developed a decision model to compare 2 year diagnosis-related costs for patients who presented with suspected ISR and were evaluated by: (1) invasive coronary angiography (ICA); (2) non-invasive stress testing strategy of myocardial perfusion imaging (MPI) with referral to ICA based on MPI; (3) coronary CT angiography-based testing strategy with referral to ICA based on CCTA. Costs were modeled from the payer’s perspective using 2014 Medicare rates. 56 % of patients underwent follow-up diagnostic testing over 2 years. Compared to ICA, MPI (98.6 %) and CCTA (98.1 %) exhibited lower rates of correct diagnoses. Non-invasive strategies were associated with reduced referrals to ICA and costs compared to an ICA-based strategy, with diagnostic costs lower for CCTA than MPI. Overall 2-year costs were highest for ICA for both metallic as well as BVS stents ($1656 and $1656, respectively) when compared to MPI ($1444 and $1411) and CCTA. CCTA costs differed based upon stent size and type, and were highest for metallic stents >3.0 mm followed by metallic stents <3.0 mm, BVS < 3.0 mm and BVS > 3.0 mm ($1466 vs. $1242 vs. $855 vs. $490, respectively). MPI for suspected ISR results in lower costs and rates of complications than invasive strategies using ICA while maintaining high diagnostic performance. Depending upon stent size and type, CCTA results in lower costs than MPI. PMID:26335370

  15. Saliva as a non-invasive diagnostic tool for inflammation and insulin-resistance

    PubMed Central

    Desai, Gauri S; Mathews, Suresh T

    2014-01-01

    Saliva has been progressively studied as a non-invasive and relatively stress-free diagnostic alternative to blood. Currently, saliva testing is used for clinical assessment of hormonal perturbations, detection of HIV antibodies, DNA analysis, alcohol screening, and drug testing. Recently, there has been increasing interest in evaluating the diagnostic potential of saliva in obesity, inflammation, and insulin-resistance. Current literature has demonstrated elevated levels of inflammatory biomarkers including C-reactive protein, tumor necrosis factor-α, interleukin-6, and interferon-γ in saliva of obese/overweight children and adults. Salivary antioxidant status has also been studied as a measure of oxidative stress in individuals with type 2 diabetes. Further, several studies have demonstrated correlations of salivary markers of stress and insulin resistance including cortisol, insulin, adiponectin, and resistin with serum concentrations. These findings suggest the potential diagnostic value of saliva in health screening and risk stratification studies, particularly in the pediatric population, with implications for inflammatory, metabolic and cardiovascular conditions. However, additional studies are required to standardize saliva collection and storage procedures, validate analytical techniques for biomarker detection, and establish reference ranges for routine clinical use. The purpose of this review is to summarize and evaluate recent advancements in using saliva as a diagnostic tool for inflammation and insulin-resistance. PMID:25512775

  16. Capacitive Sensing for Non-Invasive Breathing and Heart Monitoring in Non-Restrained, Non-Sedated Laboratory Mice.

    PubMed

    González-Sánchez, Carlos; Fraile, Juan-Carlos; Pérez-Turiel, Javier; Damm, Ellen; Schneider, Jochen G; Zimmermann, Heiko; Schmitt, Daniel; Ihmig, Frank R

    2016-01-01

    Animal testing plays a vital role in biomedical research. Stress reduction is important for improving research results and increasing the welfare and the quality of life of laboratory animals. To estimate stress we believe it is of great importance to develop non-invasive techniques for monitoring physiological signals during the transport of laboratory animals, thereby allowing the gathering of information on the transport conditions, and, eventually, the improvement of these conditions. Here, we study the suitability of commercially available electric potential integrated circuit (EPIC) sensors, using both contact and contactless techniques, for monitoring the heart rate and breathing rate of non-restrained, non-sedated laboratory mice. The design has been tested under different scenarios with the aim of checking the plausibility of performing contactless capture of mouse heart activity (ideally with an electrocardiogram). First experimental results are shown. PMID:27399713

  17. Capacitive Sensing for Non-Invasive Breathing and Heart Monitoring in Non-Restrained, Non-Sedated Laboratory Mice

    PubMed Central

    González-Sánchez, Carlos; Fraile, Juan-Carlos; Pérez-Turiel, Javier; Damm, Ellen; Schneider, Jochen G.; Zimmermann, Heiko; Schmitt, Daniel; Ihmig, Frank R.

    2016-01-01

    Animal testing plays a vital role in biomedical research. Stress reduction is important for improving research results and increasing the welfare and the quality of life of laboratory animals. To estimate stress we believe it is of great importance to develop non-invasive techniques for monitoring physiological signals during the transport of laboratory animals, thereby allowing the gathering of information on the transport conditions, and, eventually, the improvement of these conditions. Here, we study the suitability of commercially available electric potential integrated circuit (EPIC) sensors, using both contact and contactless techniques, for monitoring the heart rate and breathing rate of non-restrained, non-sedated laboratory mice. The design has been tested under different scenarios with the aim of checking the plausibility of performing contactless capture of mouse heart activity (ideally with an electrocardiogram). First experimental results are shown. PMID:27399713

  18. Non-invasive diagnostic methods in dentistry

    NASA Astrophysics Data System (ADS)

    Todea, Carmen

    2016-03-01

    The paper, will present the most important non-invasive methods for diagnostic, in different fields of dentistry. Moreover, the laser-based methods will be emphasis. In orthodontics, 3D laser scanners are increasingly being used to establish database for normative population and cross-sectional growth changes but also to asses clinical outcomes in orthognatic surgical and non-surgical treatments. In prevention the main methods for diagnostic of demineralization and caries detection in early stages are represented by laser fluorescence - Quantitative Light Florescence (QLF); DiagnoDent-system-655nm; FOTI-Fiberoptic transillumination; DIFOTI-Digital Imaging Fiberoptic transillumination; and Optical Coherence Tomography (OCT). In odontology, Laser Doppler Flowmetry (LDF) is a noninvasive real time method used for determining the tooth vitality by monitoring the pulp microcirculation in traumatized teeth, fractured teeth, and teeth undergoing different conservative treatments. In periodontology, recently study shows the ability of LDF to evaluate the health of gingival tissue in periodontal tissue diseases but also after different periodontal treatments.

  19. Accelerated Stress-Corrosion Testing

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Test procedures for accelerated stress-corrosion testing of high-strength aluminum alloys faster and provide more quantitative information than traditional pass/fail tests. Method uses data from tests on specimen sets exposed to corrosive environment at several levels of applied static tensile stress for selected exposure times then subsequently tensile tested to failure. Method potentially applicable to other degrading phenomena (such as fatigue, corrosion fatigue, fretting, wear, and creep) that promote development and growth of cracklike flaws within material.

  20. Non-invasive measurments of intense relativistic electron beam size

    NASA Astrophysics Data System (ADS)

    Ekdahl, Carl; McCuistian, Trent; Moir, David; Rodriguez, Patrick; Broste, William; Johnson, Jeff

    2000-10-01

    To understand relativistic electron beam transport dynamics the size of the beam is often measured using invasive techniques such as imaging the Cerenkov or OTR light emitted from a screen inserted into the beam. These techniques would completely disrupt the DARHT 2 beam, so we are developing a non-invasive method using diamagnetic loops. We show that through conservation of canonical angular momentum the RMS radius of the beam can be found by measuring the magnetic flux excluded by the diamagnetic beam. Furthermore, this measurement is shown to be independent of the details of the beam radial current profile for DARHT 2 parameters. We present results from our test and calibration experiments, as well as results of beam radius measurements on the 20-MeV DARHT 1 accelerator.

  1. Non-invasive diagnosis of alcoholic liver disease.

    PubMed

    Mueller, Sebastian; Seitz, Helmut Karl; Rausch, Vanessa

    2014-10-28

    Alcoholic liver disease (ALD) is the most common liver disease in the Western world. For many reasons, it is underestimated and underdiagnosed. An early diagnosis is absolutely essential since it (1) helps to identify patients at genetic risk for ALD; (2) can trigger efficient abstinence namely in non-addicted patients; and (3) initiate screening programs to prevent life-threatening complications such as bleeding from varices, spontaneous bacterial peritonitis or hepatocellular cancer. The two major end points of ALD are alcoholic liver cirrhosis and the rare and clinically-defined alcoholic hepatitis (AH). The prediction and early diagnosis of both entities is still insufficiently solved and usually relies on a combination of laboratory, clinical and imaging findings. It is not widely conceived that conventional screening tools for ALD such as ultrasound imaging or routine laboratory testing can easily overlook ca. 40% of manifest alcoholic liver cirrhosis. Non-invasive methods such as transient elastography (Fibroscan), acoustic radiation force impulse imaging or shear wave elastography have significantly improved the early diagnosis of alcoholic cirrhosis. Present algorithms allow either the exclusion or the exact definition of advanced fibrosis stages in ca. 95% of patients. The correct interpretation of liver stiffness requires a timely abdominal ultrasound and actual transaminase levels. Other non-invasive methods such as controlled attenuation parameter, serum levels of M30 or M65, susceptometry or breath tests are under current evaluation to assess the degree of steatosis, apoptosis and iron overload in these patients. Liver biopsy still remains an important option to rule out comorbidities and to confirm the prognosis namely for patients with AH. PMID:25356026

  2. Non-invasive diagnosis of alcoholic liver disease

    PubMed Central

    Mueller, Sebastian; Seitz, Helmut Karl; Rausch, Vanessa

    2014-01-01

    Alcoholic liver disease (ALD) is the most common liver disease in the Western world. For many reasons, it is underestimated and underdiagnosed. An early diagnosis is absolutely essential since it (1) helps to identify patients at genetic risk for ALD; (2) can trigger efficient abstinence namely in non-addicted patients; and (3) initiate screening programs to prevent life-threatening complications such as bleeding from varices, spontaneous bacterial peritonitis or hepatocellular cancer. The two major end points of ALD are alcoholic liver cirrhosis and the rare and clinically-defined alcoholic hepatitis (AH). The prediction and early diagnosis of both entities is still insufficiently solved and usually relies on a combination of laboratory, clinical and imaging findings. It is not widely conceived that conventional screening tools for ALD such as ultrasound imaging or routine laboratory testing can easily overlook ca. 40% of manifest alcoholic liver cirrhosis. Non-invasive methods such as transient elastography (Fibroscan), acoustic radiation force impulse imaging or shear wave elastography have significantly improved the early diagnosis of alcoholic cirrhosis. Present algorithms allow either the exclusion or the exact definition of advanced fibrosis stages in ca. 95% of patients. The correct interpretation of liver stiffness requires a timely abdominal ultrasound and actual transaminase levels. Other non-invasive methods such as controlled attenuation parameter, serum levels of M30 or M65, susceptometry or breath tests are under current evaluation to assess the degree of steatosis, apoptosis and iron overload in these patients. Liver biopsy still remains an important option to rule out comorbidities and to confirm the prognosis namely for patients with AH. PMID:25356026

  3. Non-invasive prenatal screening for trisomy 21: Consumers' perspectives.

    PubMed

    Higuchi, Emily C; Sheldon, Jane P; Zikmund-Fisher, Brian J; Yashar, Beverly M

    2016-02-01

    Non-invasive prenatal screening (NIPS) has the potential to dramatically increase the prenatal detection rate of Down syndrome because of improvements in safety and accuracy over existing tests. There is concern that NIPS could lead to more negative attitudes towards Down syndrome and less support for individuals with Down syndrome. To assess the impact of NIPS on support for prenatal testing, decision-making about testing, and beliefs or attitudes about Down syndrome, we performed an Internet-based experiment using adults (N = 1,789) recruited through Amazon Mechanical Turk. Participants were randomly assigned to read a mock news article about NIPS, a mock news article about amniocentesis, or no article. The content in the two articles varied only in their descriptions of the test characteristics. Participants then answered questions about their support for testing, hypothetical testing decision, and beliefs and attitudes about Down syndrome. Reading the mock NIPS news article predicted increased hypothetical test uptake. In addition, the NIPS article group also agreed more strongly that pregnant women, in general, should utilize prenatal testing. We also found that the more strongly participants supported prenatal testing for pregnant women, the less favorable their attitudes towards individuals with Down syndrome; providing some evidence that NIPS may indirectly result in more negative perceptions of individuals with this diagnosis. PMID:26553705

  4. Non invasive sensing technologies for cultural heritage management and fruition

    NASA Astrophysics Data System (ADS)

    Soldovieri, Francesco; Masini, Nicola

    2016-04-01

    The relevance of the information produced by science and technology for the knowledge of the cultural heritage depends on the quality of the feedback and, consequently, on the "cultural" distance between scientists and end-users. In particular, the solution to this problem mainly resides in the capability of end-users' capability to assess and transform the knowledge produced by diagnostics with regard to: information on both cultural objects and sites (decay patterns, vulnerability, presence of buried archaeological remains); decision making (management plan, conservation project, and excavation plan). From our experience in the field of the cultural heritage and namely the conservation, of monuments, there is a significant gap of information between technologists (geophysicists/physicists/engineers) and end-users (conservators/historians/architects). This cultural gap is due to the difficulty to interpret "indirect data" produced by non invasive diagnostics (i.e. radargrams/thermal images/seismic tomography etc..) in order to provide information useful to improve the historical knowledge (e.g. the chronology of the different phases of a building), to characterise the state of conservation (e.g. detection of cracks in the masonry) and to monitor in time cultural heritage artifacts and sites. The possible answer to this difficulty is in the set-up of a knowledge chain regarding the following steps: - Integrated application of novel and robust data processing methods; - Augmented reality as a tool for making easier the interpretation of non invasive - investigations for the analysis of decay pathologies of masonry and architectural surfaces; - The comparison between direct data (carrots, visual inspection) and results from non-invasive tests, including geophysics, aims to improve the interpretation and the rendering of the monuments and even of the archaeological landscapes; - The use of specimens or test beds for the detection of archaeological features and

  5. Non invasive monitoring in mechanically ventilated pediatric patients.

    PubMed

    Al-Subu, Awni M; Rehder, Kyle J; Cheifetz, Ira M; Turner, David A

    2014-12-01

    Cardiopulmonary monitoring is a key component in the evaluation and management of critically ill patients. Clinicians typically rely on a combination of invasive and non-invasive monitoring to assess cardiac output and adequacy of ventilation. Recent technological advances have led to the introduction: of continuous non-invasive monitors that allow for data to be obtained at the bedside of critically ill patients. These advances help to identify hemodynamic changes and allow for interventions before complications occur. In this manuscript, we highlight several important methods of non-invasive cardiopulmonary monitoring, including capnography, transcutaneous monitoring, pulse oximetry, and near infrared spectroscopy. PMID:25119483

  6. Improving non-invasive ventilation documentation.

    PubMed

    Smith, Matthew; Elkheir, Natalie

    2014-01-01

    Record keeping for patients on non-invasive ventilation (NIV) at St. Georges Hospital is poor. The initial NIV prescription is often not recorded, and changes to the NIV prescription or the rationale for the changes (ABG results) are also poorly documented. This leads to confusion for nurses/doctors as to what the correct settings are, meaning patients could receive ineffective ventilation. The use of NIV is also poorly recorded by nursing staff meaning that doctors are unsure if the prescribed NIV is being achieved. This can lead to treatment being escalated unnecessarily in the event of treatment failure. Non-invasive ventilation (NIV) is the provision of ventilatory support in the form of positive pressure via the patient's upper airway using a mask or similar device. NIV is indicated for treatment of acute hypercapnic respiratory failure, of which there are many causes, though COPD is the indication in up to 70% of cases.[1] British Thoracic Society (BTS) guidelines for NIV suggest that the rationale for commencing a patient on NIV and the proposed settings should be clearly documented.[2] Clinicians cannot effectively tailor changes to the patients NIV settings if this information is not clearly recorded, which could lead to increased time requiring NIV or NIV failure. Three main areas were considered important to measure for this project. The initial prescription of the NIV, changes to the NIV settings, and nursing documentation surrounding NIV. A baseline measurement of NIV documentation for two weeks found NIV documentation to globally very poor. NIV was formally prescribed 29% of the time, full detail of intended settings were documented 57% of the time, the decision to commence NIV was discussed with the respiratory consultant/SpR just 29% of the time and on no occasion was a decision regarding escalation of treatment recorded. Eighteen changes were made to the NIV settings. These were formally prescribed 22% of the time and detail of the intended

  7. Modern non-invasive mechanical ventilation turns 25.

    PubMed

    Díaz Lobato, Salvador; Mayoralas Alises, Sagrario

    2013-11-01

    The history of non-invasive mechanical ventilation goes back more than 100 years, but it was not until 1987 when what we could call "modern" non-invasive mechanical ventilation was developed. The description of Delaubier and Rideau of a patient with Duchenne's disease who had been effectively ventilated through a nasal mask marked the start of a new era in the history of non-invasive mechanical ventilation. Over these last 25years, we have witnessed exponential growth in its use, field of activity and technological advances on an exciting fast-paced track. We believe that it is time to review the main milestones that have marked the development of non-invasive mechanical ventilation to date, while paying homage to this therapeutic method that has contributed so much to the advancement of respiratory medicine in the last 25years. PMID:23347549

  8. Non-Invasive Investigation of Bone Adaptation in Humans to Mechanical Loading

    NASA Technical Reports Server (NTRS)

    Whalen, R.

    1999-01-01

    Experimental studies have identified peak cyclic forces, number of loading cycles, and loading rate as contributors to the regulation of bone metabolism. We have proposed a theoretical model that relates bone density to a mechanical stimulus derived from average daily cumulative peak cyclic 'effective' tissue stresses. In order to develop a non-invasive experimental model to test the theoretical model we need to: (1) monitor daily cumulative loading on a bone, (2) compute the internal stress state(s) resulting from the imposed loading, and (3) image volumetric bone density accurately, precisely, and reproducibly within small contiguous volumes throughout the bone. We have chosen the calcaneus (heel) as an experimental model bone site because it is loaded by ligament, tendon and joint contact forces in equilibrium with daily ground reaction forces that we can measure; it is a peripheral bone site and therefore more easily and accurately imaged with computed tomography; it is composed primarily of cancellous bone; and it is a relevant site for monitoring bone loss and adaptation in astronauts and the general population. This paper presents an overview of our recent advances in the areas of monitoring daily ground reaction forces, biomechanical modeling of the forces on the calcaneus during gait, mathematical modeling of calcaneal bone adaptation in response to cumulative daily activity, accurate and precise imaging of the calcaneus with quantitative computed tomography (QCT), and application to long duration space flight.

  9. Exercise stress test

    MedlinePlus

    ... must not eat, smoke, or drink beverages containing caffeine or alcohol for 3 hours (or more) before ... most cases, you will be asked to avoid caffeine for 24 hours before the test. This includes: ...

  10. Nuclear stress test

    MedlinePlus

    ... to take medicines. You will need to avoid caffeine for 24 hours before the test. This includes: ... coffee All sodas, even ones that are labeled caffeine-free Chocolates, and certain pain relievers that contain ...

  11. A computer controlled non-invasive haemodynamic monitoring system.

    PubMed

    McMenemin, I M; Kenny, G N

    1988-10-01

    A system for the non-invasive monitoring, recording and storing haemodynamic indices has been developed using an Apple II microcomputer, a Dinamap automatic arterial pressure monitor and a non-invasive cardiac output monitor based on bio-electrical impedance. This system was used during the induction and maintenance of anaesthesia. Numerical and graphical displays of heart rate, arterial pressure, cardiac output and systemic vascular resistance are available. A print-out of data can be produced for later analysis. PMID:3190976

  12. Serum Ferritin is a Reliable, Non-invasive Test for Iron Status in Pregnancy: Comparison of Ferritin with Other Iron Status Markers in a Longitudinal Study on Healthy Pregnant Women; Erythropoiesis.

    PubMed

    Byg, Keld-Erik; Milman, Nils; Hansen, Stig; Agger, Anders O.

    2000-01-01

    Background and Aims: To assess the true positive and false positive rates of the iron status markers (serum iron, serum transferrin, transferrin saturation, haemoglobin, haematocrit, mean corpuscular volume (MCV), mean cell haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), erythrocyte count) in the diagnosis of depleted iron stores (iron depletion) during normal pregnancy and postpartum. Methods: Among 120 pregnant women, 58 were randomised to placebo-treatment and 62 to iron-treatment (66 mg ferrous iron daily from 14 weeks of gestation). Iron status markers were measured every 4th week during pregnancy and 8 weeks postpartum. Iron depletion was defined by a serum ferritin concentration < 16 &mgr;g/L. The 5th percentiles for the other iron status markers in the group of iron-treated women were used as cut-off values. Calculations were made in the 2nd and 3rd trimester, praepartum and postpartum. Results: In general, the true positive rates of other iron status markers in the diagnosis of iron depletion (serum ferritin < 16 &mgr;g/L) were low ranging from 0% to 52% during pregnancy and from 9% to 64% postpartum. Transferrin saturation and MCH displayed the highest true positive rates. The false positive rates ranged from 0% to 13% during pregnancy and from 4% to 17% postpartum. Haemoglobin and MCH displayed the highest false positive rates. Conclusions: The sensitivities of the other iron status markers were too low and the false positive rates too high to be of clinical value in the diagnosis of iron depletion. Despite physiologic variations due to haemodilution, the serum ferritin concentration is currently the most reliable non-invasive marker of iron status in pregnancy and postpartum. PMID:11399631

  13. Systolic time intervals: a review of the method in the non-invasive investigation of cardiac function in health, disease and clinical pharmacology.

    PubMed Central

    Hassan, S.; Turner, P.

    1983-01-01

    Measurement of systolic time intervals is a valuable, non-invasive procedure to assess left ventricular performance, particularly when influenced by drugs. In this review, we discuss various factors affecting systolic time intervals, the therapeutic implications of the technique and its place among other non-invasive tests of cardiac function. PMID:6353394

  14. Testing the stress shadow hypothesis

    NASA Astrophysics Data System (ADS)

    Felzer, Karen R.; Brodsky, Emily E.

    2005-05-01

    A fundamental question in earthquake physics is whether aftershocks are predominantly triggered by static stress changes (permanent stress changes associated with fault displacement) or dynamic stresses (temporary stress changes associated with earthquake shaking). Both classes of models provide plausible explanations for earthquake triggering of aftershocks, but only the static stress model predicts stress shadows, or regions in which activity is decreased by a nearby earthquake. To test for whether a main shock has produced a stress shadow, we calculate time ratios, defined as the ratio of the time between the main shock and the first earthquake to follow it and the time between the last earthquake to precede the main shock and the first earthquake to follow it. A single value of the time ratio is calculated for each 10 × 10 km bin within 1.5 fault lengths of the main shock epicenter. Large values of the time ratio indicate a long wait for the first earthquake to follow the main shock and thus a potential stress shadow, whereas small values indicate the presence of aftershocks. Simulations indicate that the time ratio test should have sufficient sensitivity to detect stress shadows if they are produced in accordance with the rate and state friction model. We evaluate the 1989 MW 7.0 Loma Prieta, 1992 MW 7.3 Landers, 1994 MW 6.7 Northridge, and 1999 MW 7.1 Hector Mine main shocks. For each main shock, there is a pronounced concentration of small time ratios, indicating the presence of aftershocks, but the number of large time ratios is less than at other times in the catalog. This suggests that stress shadows are not present. By comparing our results to simulations we estimate that we can be at least 98% confident that the Loma Prieta and Landers main shocks did not produce stress shadows and 91% and 84% confident that stress shadows were not generated by the Hector Mine and Northridge main shocks, respectively. We also investigate the long hypothesized existence

  15. Tissue Damage Characterization Using Non-invasive Optical Modalities

    NASA Astrophysics Data System (ADS)

    Diaz, David

    The ability to determine the degree of cutaneous and subcutaneous tissue damage is essential for proper wound assessment and a significant factor for determining patient treatment and morbidity. Accurate characterization of tissue damage is critical for a number of medical applications including surgical removal of nonviable tissue, severity assessment of subcutaneous ulcers, and depth assessment of visually open wounds. The main objective of this research was to develop a non-invasive method for identifying the extent of tissue damage underneath intact skin that is not apparent upon visual examination. This work investigated the relationship between tissue optical properties, blood flow, and tissue viability by testing the hypotheses that (a) changes in tissue oxygenation and/or microcirculatory blood flow measurable by Diffuse Near Infrared Spectroscopy (DNIRS) and Diffuse Correlation Spectroscopy (DCS) differ between healthy and damaged tissue and (b) the magnitude of those changes differs for different degrees of tissue damage. This was accomplished by developing and validating a procedure for measuring microcirculatory blood flow and tissue oxygenation dynamics at multiple depths (up to 1 centimeter) using non-invasive DCS and DNIRS technologies. Due to the lack of pressure ulcer animal models that are compatible with our optical systems, a proof of concept was conducted in a porcine burn model prior to conducting clinical trials in order to assess the efficacy of the system in-vivo. A reduction in total hemoglobin was observed for superficial (5%) and deep burns (35%) along with a statistically significant difference between the optical properties of superficial and deep burns (p < 0.05). Burn depth and viable vessel density were estimated via histological samples. 42% of vessels in the dermal layer were viable for superficial burns, compared to 25% for deep burns. The differences detected in optical properties and hemoglobin content by optical measurements

  16. Non-invasive photo acoustic approach for human bone diagnosis.

    PubMed

    Thella, Ashok Kumar; Rizkalla, James; Helmy, Ahdy; Suryadevara, Vinay Kumar; Salama, Paul; Rizkalla, Maher

    2016-12-01

    The existing modalities of bone diagnosis including X-ray and ultrasound may cite drawback in some cases related to health issues and penetration depth, while the ultrasound modality may lack image quality. Photo acoustic approach however, provides light energy to the acoustic wave, enabling it to activate and respond according to the propagating media (which is type of bones in this case). At the same time, a differential temperature change may result in the bio heat response, resulting from the heat absorbed across the multiple materials under study. In this work, we have demonstrated the features of using photo acoustic modality in order to non-invasively diagnose the type of human bones based on their electrical, thermal, and acoustic properties that differentiate the output response of each type. COMSOL software was utilized to combine both acoustic equations and bio heat equations, in order to study both the thermal and acoustic responses through which the differential diagnosis can be obtained. In this study, we solved both the acoustic equation and bio heat equations for four types of bones, bone (cancellous), bone (cortical), bone marrow (red), and bone marrow (yellow). 1 MHz acoustic source frequency was chosen and 10(5) W/m(2) power source was used in the simulation. The simulation tested the dynamic response of the wave over a distance of 5 cm from each side for the source. Near 2.4 cm was detected from simulation from each side of the source with a temperature change of within 0.5 K for various types of bones, citing a promising technique for a practical model to detect the type of bones via the differential temperature as well as the acoustic was response via the multiple materials associated with the human bones (skin and blood). The simulation results suggest that the PA technique may be applied to non-invasive diagnosis for the different types of bones, including cancerous bones. A practical model for detecting both the temperature change via

  17. Non-invasive subcutaneous fat reduction: a review.

    PubMed

    Kennedy, J; Verne, S; Griffith, R; Falto-Aizpurua, L; Nouri, K

    2015-09-01

    The risks, financial costs and lengthy downtime associated with surgical procedures for fat reduction have led to the development of a number of non-invasive techniques. Non-invasive body contouring now represents the fastest growing area of aesthetic medicine. There are currently four leading non-invasive techniques for reducing localized subcutaneous adipose tissue: low-level laser therapy (LLLT), cryolipolysis, radio frequency (RF) and high-intensity focused ultrasound (HIFU). To review and compare leading techniques and clinical outcomes of non-invasive subcutaneous fat reduction. The terms 'non-invasive', 'low-level laser', 'cryolipolysis', 'ultrasound' and 'radio frequency' were combined with 'lipolysis', 'fat reduction' or 'body contour' during separate searches in the PubMed database. We identified 31 studies (27 prospective clinical studies and four retrospective chart reviews) with a total of 2937 patients that had been treated with LLLT (n = 1114), cryolipolysis (n = 706), HIFU (n = 843) or RF (n = 116) or other techniques (n = 158) for fat reduction or body contouring. A majority of these patients experienced significant and satisfying results without any serious adverse effects. The studies investigating these devices have all varied in treatment regimen, body locations, follow-up times or outcome operationalization. Each technique differs in offered advantages and severity of adverse effects. However, multiple non-invasive devices are safe and effective for circumferential reduction in local fat tissue by 2 cm or more across the abdomen, hips and thighs. Results are consistent and reproducible for each device and none are associated with any serious or permanent adverse effects. PMID:25664493

  18. An Acetone Nanosensor For Non-invasive Diabetes Detection

    NASA Astrophysics Data System (ADS)

    Wang, L.; Yun, X.; Stanacevic, M.; Gouma, P. I.

    2009-05-01

    Diabetes is a most common disease worldwide. Acetone in exhaled breath is a known biomarker of Type- 1 diabetes. An exhaled breath analyzer has been developed with the potential to diagnose diabetes as a non-invasive alternative of the currently used blood-based diagnostics. This device utilizes a chemiresistor based on ferroelectric tungsten oxide nanoparticles and detects acetone selectively in breath-simulated media. Real-time monitoring of the acetone concentration is feasible, potentially making this detector a revolutionary, non- invasive, diabetes diagnostic tool.

  19. Non-invasive brain stimulation in early rehabilitation after stroke.

    PubMed

    Blesneag, A V; Popa, L; Stan, A D

    2015-01-01

    The new tendency in rehabilitation involves non-invasive tools that, if applied early after stroke, promote neurorecovery. Repetitive transcranial magnetic stimulation and transcranial direct current stimulation may correct the disruption of cortical excitability and effectively contribute to the restoration of movement and speech. The present paper analyses the results of non-invasive brain stimulation (NIBS) trials, highlighting different aspects related to the repetitive transcranial magnetic stimulation frequency, transcranial direct current stimulation polarity, the period and stimulation places in acute and subacute ischemic strokes. The risk of adverse events, the association with motor or language recovery specific training, and the cumulative positive effect evaluation are also discussed. PMID:26361512

  20. Non-invasive assessment of adrenocortical function in captive Nile crocodiles (Crocodylus niloticus).

    PubMed

    Ganswindt, Stefanie B; Myburgh, Jan G; Cameron, Elissa Z; Ganswindt, Andre

    2014-11-01

    The occurrence of stress-inducing factors in captive crocodilians is a concern, since chronic stress can negatively affect animal health and reproduction, and hence production. Monitoring stress in wild crocodiles could also be beneficial for assessing the state of health in populations which are potentially threatened by environmental pollution. In both cases, a non-invasive approach to assess adrenocortical function as a measure of stress would be preferable, as animals are not disturbed during sample collection, and therefore sampling is feedback-free. So far, however, such a non-invasive method has not been established for any crocodilian species. As an initial step, we therefore examined the suitability of two enzyme-immunoassays, detecting faecal glucocorticoid metabolites (FGMs) with a 11β,21-diol-20-one and 5β-3α-ol-11-one structure, respectively, for monitoring stress-related physiological responses in captive Nile crocodiles (Crocodylus niloticus). An adrenocorticotropic hormone (ACTH) challenge was performed on 10 sub-adult crocodiles, resulting in an overall increase in serum corticosterone levels of 272% above the pre-injection levels 5h post-injection. Saline-treated control animals (n=8) showed an overall increase of 156% in serum corticosterone levels 5h post-administration. Faecal samples pre- and post-injection could be obtained from three of the six individually housed crocodiles, resulting in FGM concentrations 136-380% above pre-injection levels, always detected in the first sample collected post-treatment (7-15 days post-injection). FGM concentrations seem comparatively stable at ambient temperatures for up to 72 h post-defaecation. In conclusion, non-invasive hormone monitoring can be used for assessing adrenocortical function in captive Nile crocodiles based on FGM analysis. PMID:25066028

  1. Non-Invasive Assessment of Liver Function

    PubMed Central

    Helmke, Steve; Colmenero, Jordi; Everson, Gregory T.

    2015-01-01

    Purpose of review It is our opinion that there is an unmet need in Hepatology for a minimally- or noninvasive test of liver function and physiology. Quantitative liver function tests (QLFTs) define the severity and prognosis of liver disease by measuring the clearance of substrates whose uptake or metabolism is dependent upon liver perfusion or hepatocyte function. Substrates with high affinity hepatic transporters exhibit high “first-pass” hepatic extraction and their clearance measures hepatic perfusion. In contrast, substrates metabolized by the liver have low first-pass extraction and their clearance measures specific drug metabolizing pathways. Recent Findings We highlight one QLFT, the dual cholate test, and introduce the concept of a disease severity index (DSI) linked to clinical outcome that quantifies the simultaneous processes of hepatocyte uptake, clearance from the systemic circulation, clearance from the portal circulation, and portal-systemic shunting. Summary It is our opinion that dual cholate is a relevant test for defining disease severity, monitoring the natural course of disease progression, and quantifying the response to therapy. PMID:25714706

  2. Non-invasive assessment of liver fibrosis

    PubMed Central

    Papastergiou, Vasilios; Tsochatzis, Emmanuel; Burroughs, Andrew K.

    2012-01-01

    The presence and degree of hepatic fibrosis is crucial in order to make therapeutic decisions and predict clinical outcomes. Currently, the place of liver biopsy as the standard of reference for assessing liver fibrosis has been challenged by the increasing awareness of a number of drawbacks related to its use (invasiveness, sampling error, inter-/intraobserver variability). In parallel with this, noninvasive assessment of liver fibrosis has experienced explosive growth in recent years and a wide spectrum of noninvasive methods ranging from serum assays to imaging techniques have been developed. Some are validated methods, such as the Fibrotest/ Fibrosure and transient elastography in Europe, and are gaining a growing role in routine clinical practice, especially in chronic hepatitis C. Large-scale validation is awaited in the setting of other chronic liver diseases. However, noninvasive tests used to detect significant fibrosis and cirrhosis, the two major clinical endpoints, are not yet at a level of performance suitable for routine diagnostic tests, and there is still no perfect surrogate or method able to completely replace an optimal liver biopsy. This article aims to review current noninvasive tests for the assessment of liver fibrosis and the perspectives for their rational use in clinical practice. PMID:24714123

  3. Non-invasive assessment of liver fibrosis.

    PubMed

    Papastergiou, Vasilios; Tsochatzis, Emmanuel; Burroughs, Andrew K

    2012-01-01

    The presence and degree of hepatic fibrosis is crucial in order to make therapeutic decisions and predict clinical outcomes. Currently, the place of liver biopsy as the standard of reference for assessing liver fibrosis has been challenged by the increasing awareness of a number of drawbacks related to its use (invasiveness, sampling error, inter-/intraobserver variability). In parallel with this, noninvasive assessment of liver fibrosis has experienced explosive growth in recent years and a wide spectrum of noninvasive methods ranging from serum assays to imaging techniques have been developed. Some are validated methods, such as the Fibrotest/ Fibrosure and transient elastography in Europe, and are gaining a growing role in routine clinical practice, especially in chronic hepatitis C. Large-scale validation is awaited in the setting of other chronic liver diseases. However, noninvasive tests used to detect significant fibrosis and cirrhosis, the two major clinical endpoints, are not yet at a level of performance suitable for routine diagnostic tests, and there is still no perfect surrogate or method able to completely replace an optimal liver biopsy. This article aims to review current noninvasive tests for the assessment of liver fibrosis and the perspectives for their rational use in clinical practice. PMID:24714123

  4. Non-invasive investigation of inflammatory bowel disease

    PubMed Central

    Tibble, JA; Bjarnason, I

    2001-01-01

    The assessment of inflammatory activity in intestinal disease in man can be done using a variety of different techniques. These range from the use of non-invasive acute phase inflammatory markers measured in plasma such as C reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) (both of which give an indirect assessment of disease activity) to the direct assessment of disease activity by intestinal biopsy performed during endoscopy in association with endoscopic scoring systems. Both radiology and endoscopy are conventional for the diagnosis of inflammatory bowel disease (IBD). However these techniques have severe limitations when it comes to assessing functional components of the disease such as activity and prognosis. Here we briefly review the value of two emerging intestinal function tests. Intestinal permeability, although ideally suited for diagnostic screening for small bowel Crohn’s disease, appears to give reliable predictive data for imminent relapse of small bowel Crohn’s disease and it can be used to assess responses to treatment. More significantly it is now clear that single stool assay of neutrophil specific proteins (calprotectin, lactoferrin) give the same quantitative data on intestinal inflammation as the 4-day faecal excretion of 111Indium labelled white cells. Faecal calprotectin is shown to be increased in over 95% of patients with IBD and correlates with clinical disease activity. It reliably differentiates between patients with IBD and irritable bowel syndrome. More importantly, at a given faecal calprotectin concentration in patients with quiescent IBD, the test has a specificity and sensitivity in excess of 85% in predicting clinical relapse of disease. This suggests that relapse of IBD is closely related to the degree of intestinal inflammation and suggests that targeted treatment at an asymptomatic stage of the disease may be indicated. PMID:11819811

  5. Non-invasive, non-radiological quantification of anteroposterior knee joint ligamentous laxity

    PubMed Central

    Russell, D. F.; Deakin, A. H.; Fogg, Q. A.; Picard, F.

    2013-01-01

    Objectives We performed in vitro validation of a non-invasive skin-mounted system that could allow quantification of anteroposterior (AP) laxity in the outpatient setting. Methods A total of 12 cadaveric lower limbs were tested with a commercial image-free navigation system using trackers secured by bone screws. We then tested a non-invasive fabric-strap system. The lower limb was secured at 10° intervals from 0° to 60° of knee flexion and 100 N of force was applied perpendicular to the tibia. Acceptable coefficient of repeatability (CR) and limits of agreement (LOA) of 3 mm were set based on diagnostic criteria for anterior cruciate ligament (ACL) insufficiency. Results Reliability and precision within the individual invasive and non-invasive systems was acceptable throughout the range of flexion tested (intra-class correlation coefficient 0.88, CR 1.6 mm). Agreement between the two systems was acceptable measuring AP laxity between full extension and 40° knee flexion (LOA 2.9 mm). Beyond 40° of flexion, agreement between the systems was unacceptable (LOA > 3 mm). Conclusions These results indicate that from full knee extension to 40° flexion, non-invasive navigation-based quantification of AP tibial translation is as accurate as the standard validated commercial system, particularly in the clinically and functionally important range of 20° to 30° knee flexion. This could be useful in diagnosis and post-operative evaluation of ACL pathology. Cite this article: Bone Joint Res 2013;2:233–7. PMID:24184443

  6. Non-invasive method of measuring cerebral spinal fluid pressure

    NASA Technical Reports Server (NTRS)

    Borchert, Mark S. (Inventor); Lambert, James L. (Inventor)

    2000-01-01

    The invention provides a method of non-invasively determining intracranial pressure from measurements of an eye. A parameter of an optic nerve of the eye is determined, along with an intraocular pressure of the eye. The intracranial pressure may be determined from the intraocular pressure and the parameter.

  7. Non-invasive Prediction of Pork Loin Tenderness

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present experiment was conducted to develop a non-invasive method to predict tenderness of pork loins. Boneless pork loins (n = 901) were evaluated either on line on the loin boning and trimming line of large-scale commercial plants (n = 465) or at the U.S. Meat Animal Research Center abattoir ...

  8. NON-INVASIVE NEUROTOXICITY ASSAY USING LARVAL MEDAKA

    EPA Science Inventory

    We present a method for non-invasive electrophysiological analysis of rapid escape responses in intact, freely behaving larval medaka (Oryzias latipes) before and after short-term exposure to environmental toxicants. ecordings are obtained as a larval medaka swims in a small cham...

  9. Non-invasive treatment options for focal cortical dysplasia

    PubMed Central

    WANG, TING-TING; ZHOU, DONG

    2016-01-01

    Focal cortical dysplasia (FCD) presents a strong clinical challenge especially for the treatment of the associated epilepsy. Epilepsy in FCD is often treatment-resistant and constitutes 50% of treatment-resistant cases. Antiepileptic drugs (AEDs) have been widely used in the treatment of FCD. However, evidence to suggest their specific effect on the treatment of FCD remains to be established. In view of this resistance, several alternative treatments have been suggested. Although treatment currently involves surgical management, non-invasive treatments have been identified. The aim of the present review, was to assess non-invasive management strategies including, i) mammalian target of rapamycin (mTOR) inhibitors, ii) ketogenic diet (KD), and iii) vagus nerve stimulation (VNS). In addition, we discussed the literature available regarding the use of AEDs in FCD. Experiments conducted with mammals detailing rapamycin gene mutations in FCD have produced vital information for exploring treatment options using mTOR inhibitors. Of note is the importance of KD in children with FCD. This diet has been shown to modify disease progression by attenuating chromatin modification, a master regulator for gene expression and functional adaptation of the cell. FCD has also been studied widely with neurostimulation techniques. The outcomes of these techniques have been found to be variable. For widespread dysplasias, VNS has been shown to produce responder rates of >50%. Nevertheless, non-invasive cranial nerve stimulation techniques such as transcutaneous VNS and non-invasive VNS are gaining better patient compatibility, albeit their efficacy remains to be established. PMID:27168769

  10. Reliable, Low Mass, Non-Invasive Pressure Transducers

    NASA Technical Reports Server (NTRS)

    Hartley, F.; Tovey, M.

    1999-01-01

    Mass is a major driver for future spacecraft and missions exposed to high radiation levels (i.e. Europa Orbiter) present even more challenge. A variety of non-invasive measurement techniques are in development that enables determination of pressures within a propulsion network.

  11. Method for non-invasive detection of ocular melanoma

    DOEpatents

    Lambrecht, Richard M.; Packer, Samuel

    1984-01-01

    There is described an apparatus and method for diagnosing ocular cancer that is both non-invasive and accurate which comprises two radiation detectors positioned before each of the patient's eyes which will measure the radiation level produced in each eye after the administration of a tumor-localizing radiopharmaceutical such as gallium-67.

  12. Method for non-invasive detection of ocular melanoma

    DOEpatents

    Lambrecht, R.M.; Packer, S.

    1984-10-30

    An apparatus and method is disclosed for diagnosing ocular cancer that is both non-invasive and accurate. The apparatus comprises two radiation detectors positioned before each of the patient's eyes which will measure the radiation level produced in each eye after the administration of a tumor-localizing radiopharmaceutical such as gallium-67. 2 figs.

  13. Eyeblink Conditioning: A Non-Invasive Biomarker for Neurodevelopmental Disorders

    ERIC Educational Resources Information Center

    Reeb-Sutherland, Bethany C.; Fox, Nathan A.

    2015-01-01

    Eyeblink conditioning (EBC) is a classical conditioning paradigm typically used to study the underlying neural processes of learning and memory. EBC has a well-defined neural circuitry, is non-invasive, and can be employed in human infants shortly after birth making it an ideal tool to use in both developing and special populations. In addition,…

  14. Strategies for non-invasive delivery of biologics.

    PubMed

    Chung, Seung Woo; Hil-lal, Taslim A; Byun, Youngro

    2012-07-01

    Macromolecular therapeutics, in particular, many biologics, is the most advancing category of drugs over conventional chemical drugs. The potency and specificity of the biologics for curing certain disease made them to be a leading compound in the pharmaceutical industry. However, due to their intrinsic nature, including high molecular weight, hydrophilicity and instability, they are difficult to be administered via non-invasive route. This is a major quest especially in biologics, as they are frequently used clinically for chronic disorders, which requires long-term administration. Therefore, many efforts have been made to develop formulation for non-invasive administration, in attempt to improve patient compliance and convenience. In this review, strategies for non-invasive delivery, in particular, oral, pulmonary and nasal delivery, that are recently adopted for delivery of biologics are discussed. Insulin, calcitonin and heparin were mainly focused for the discussion as they could represent protein, polypeptide and polysaccharide drugs, respectively. Many recent attempts for non-invasive delivery of biologics are compared to provide an insight of developing successful delivery system. PMID:22632037

  15. Non-invasive in vivo measurement of macular carotenoids

    NASA Technical Reports Server (NTRS)

    Lambert, James L. (Inventor); Borchert, Mark S. (Inventor)

    2009-01-01

    A non-invasive in vivo method for assessing macular carotenoids includes performing Optical Coherence Tomography (OCT) on a retina of a subject. A spatial representation of carotenoid levels in the macula based on data from the OCT of the retina can be generated.

  16. Non-invasive cardiac assessment in high risk patients (The GROUND study): rationale, objectives and design of a multi-center randomized controlled clinical trial

    PubMed Central

    de Vos, Alexander M; Rutten, Annemarieke; van de Zaag-Loonen, Hester J; Bots, Michiel L; Dikkers, Riksta; Buiskool, Robert A; Mali, Willem P; Lubbers, Daniel D; Mosterd, Arend; Prokop, Mathias; Rensing, Benno J; Cramer, Maarten J; van Es, H Wouter; Moll, Frans L; van de Pavoordt, Eric D; Doevendans, Pieter A; Velthuis, Birgitta K; Mackaay, Albert J; Zijlstra, Felix; Oudkerk, Matthijs

    2008-01-01

    Background Peripheral arterial disease (PAD) is a common disease associated with a considerably increased risk of future cardiovascular events and most of these patients will die from coronary artery disease (CAD). Screening for silent CAD has become an option with recent non-invasive developments in CT (computed tomography)-angiography and MR (magnetic resonance) stress testing. Screening in combination with more aggressive treatment may improve prognosis. Therefore we propose to study whether a cardiac imaging algorithm, using non-invasive imaging techniques followed by treatment will reduce the risk of cardiovascular disease in PAD patients free from cardiac symptoms. Design The GROUND study is designed as a prospective, multi-center, randomized clinical trial. Patients with peripheral arterial disease, but without symptomatic cardiac disease will be asked to participate. All patients receive a proper risk factor management before randomization. Half of the recruited patients will enter the 'control group' and only undergo CT calcium scoring. The other half of the recruited patients (index group) will undergo the non invasive cardiac imaging algorithm followed by evidence-based treatment. First, patients are submitted to CT calcium scoring and CT angiography. Patients with a left main (or equivalent) coronary artery stenosis of > 50% on CT will be referred to a cardiologist without further imaging. All other patients in this group will undergo dobutamine stress magnetic resonance (DSMR) testing. Patients with a DSMR positive for ischemia will also be referred to a cardiologist. These patients are candidates for conventional coronary angiography and cardiac interventions (coronary artery bypass grafting (CABG) or percutaneous cardiac interventions (PCI)), if indicated. All participants of the trial will enter a 5 year follow up period for the occurrence of cardiovascular events. Sequential interim analysis will take place. Based on sample size calculations about

  17. Ultrasonic vocalizations during intermittent swim stress forecasts resilience in subsequent forced swim and spatial learning tests.

    PubMed

    Drugan, Robert C; Warner, Timothy A; Papallo, Tristan A; Castracane, Laura L; Stafford, Nathaniel P

    2014-02-01

    The examination of stress resilience has substantially increased in recent years. However, current paradigms require multiple behavioral procedures, which themselves may serve as secondary stressors. Therefore, a novel predictor of stress resilience is needed to advance the field. Ultrasonic vocalizations (USVs) have been observed as a behavioral correlate of stress in various rodent species. It was recently reported that rats that emitted ultrasonic vocalizations during intermittent swim stress (ISS) later showed resilience when tested on an instrumental swim escape test. In the current study, we extend this earlier observation on two additional behavioral endpoints. Rats were subjected to ISS, and USVs were recorded. Twenty-four hours later, behavioral performance was evaluated in either the forced swim test or Morris water maze. Rats that emitted ultrasonic vocalizations were resilient to the effects of ISS as indicated by performance similar to controls on both measures. These results extend the original findings that ISS-induced USVs are associated with resilience and are related to subsequent aversively motivated behavior. Such a non-invasive forecast of stress responsivity will allow future work to utilize USVs to examine the neural correlates of initial stress resistance/resilience, thereby eliminating potential confounds of further behavioral testing. Future studies can utilize USVs to target potentially unappreciated neural systems to provide novel pharmacotherapeutic strategies for treatment-resistant depression. PMID:24475493

  18. Changes within lipid fractions offer a new way to non-invasively monitor seed viability during storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monitoring seed viability using germination tests consumes large quantities of seeds and does not predict when seed viability will crash. Non-invasive tests that show the progress of seed aging would provide greater efficiency. This study investigates the changes in the chemical and physical propert...

  19. Non-invasive assessment of sciatic nerve stiffness during human ankle motion using ultrasound shear wave elastography.

    PubMed

    Andrade, Ricardo J; Nordez, Antoine; Hug, François; Ates, Filiz; Coppieters, Michel W; Pezarat-Correia, Pedro; Freitas, Sandro R

    2016-02-01

    Peripheral nerves are exposed to mechanical stress during movement. However the in vivo mechanical properties of nerves remain largely unexplored. The primary aim of this study was to characterize the effect of passive dorsiflexion on sciatic nerve shear wave velocity (an index of stiffness) when the knee was in 90° flexion (knee 90°) or extended (knee 180°). The secondary aim was to determine the effect of five repeated dorsiflexions on the nerve shear wave velocity. Nine healthy participants were tested. The repeatability of sciatic nerve shear wave velocity was good for both knee 90° and knee 180° (ICCs≥0.92, CVs≤8.1%). The shear wave velocity of the sciatic nerve significantly increased (p<0.0001) during dorsiflexion when the knee was extended (knee 180°), but no changes were observed when the knee was flexed (90°). The shear wave velocity-angle relationship displayed a hysteresis for knee 180°. Although there was a tendency for the nerve shear wave velocity to decrease throughout the repetition of the five ankle dorsiflexions, the level of significance was not reached (p=0.055). These results demonstrate that the sciatic nerve stiffness can be non-invasively assessed during passive movements. In addition, the results highlight the importance of considering both the knee and the ankle position for clinical and biomechanical assessment of the sciatic nerve. This non-invasive technique offers new perspectives to provide new insights into nerve mechanics in both healthy and clinical populations (e.g., specific peripheral neuropathies). PMID:26725218

  20. Non-invasive prediction of hemoglobin levels by principal component and back propagation artificial neural network

    PubMed Central

    Ding, Haiquan; Lu, Qipeng; Gao, Hongzhi; Peng, Zhongqi

    2014-01-01

    To facilitate non-invasive diagnosis of anemia, specific equipment was developed, and non-invasive hemoglobin (HB) detection method based on back propagation artificial neural network (BP-ANN) was studied. In this paper, we combined a broadband light source composed of 9 LEDs with grating spectrograph and Si photodiode array, and then developed a high-performance spectrophotometric system. By using this equipment, fingertip spectra of 109 volunteers were measured. In order to deduct the interference of redundant data, principal component analysis (PCA) was applied to reduce the dimensionality of collected spectra. Then the principal components of the spectra were taken as input of BP-ANN model. On this basis we obtained the optimal network structure, in which node numbers of input layer, hidden layer, and output layer was 9, 11, and 1. Calibration and correction sample sets were used for analyzing the accuracy of non-invasive hemoglobin measurement, and prediction sample set was used for testing the adaptability of the model. The correlation coefficient of network model established by this method is 0.94, standard error of calibration, correction, and prediction are 11.29g/L, 11.47g/L, and 11.01g/L respectively. The result proves that there exist good correlations between spectra of three sample sets and actual hemoglobin level, and the model has a good robustness. It is indicated that the developed spectrophotometric system has potential for the non-invasive detection of HB levels with the method of BP-ANN combined with PCA. PMID:24761296

  1. Cell-free nucleic acids as a non-invasive route for investigating atherosclerosis.

    PubMed

    Cerne, Darko; Bajalo, Jana Lukac

    2014-01-01

    Metabolic syndrome is directly linked with atherosclerotic burden and cell-free nucleic acids (cf-NA) analysis has recently emerged as a novel research tool in atherosclerosis practice and research. cf-NA are nucleic acids (DNA, mRNA, miRNA, mitochondrial DNA) found in plasma and cell-free fractions of various other biological fluids. They have all the characteristics of the nucleic acids in the cells of their origin, thus constituting an emerging field for non-invasive assessment. Initially, quantitative and qualitative analysis of cf-NA has been accepted as clinically useful in non-invasive prenatal diagnosis, and in the diagnosis and monitoring of numerous cancers. As to atherosclerosis, cf-NA analysis poses an important challenge in diagnosis and prognostic evaluation of acute coronary syndrome, in prediction of cardiovascular disease, in non-invasive early detection of atherosclerosis and understanding its pathological mechanism in vivo, in assessing various issues of treatment for atherosclerosis in vivo, and in the unique simultaneous measurement of mRNA levels and protein concentrations in a single sample of plasma. Examples of its use are presented in this review. Besides the advances in technologies, the precise evaluation and optimization of pre-analytical and analytical aspects of cf-NA analysis have impacted importantly on the reliability of test results. We have, therefore, reviewed the most important analytical considerations. Further clinical studies and analytical improvements will answer the question as to whether cf-NA, as novel biomarkers, can be reliably applied clinically in non-invasive, early diagnosis and monitoring of the vulnerable atherosclerotic plaques of patients who could suffer from acute coronary syndrome. PMID:24320033

  2. Continuous non-invasive monitoring improves blood pressure stability in upright position: randomized controlled trial.

    PubMed

    Benes, Jan; Simanova, Alena; Tovarnicka, Tereza; Sevcikova, Silvie; Kletecka, Jakub; Zatloukal, Jan; Pradl, Richard; Chytra, Ivan; Kasal, Eduard

    2015-02-01

    Intermittent blood pressure (BP) monitoring is the standard-of-care during low and intermediate risk anaesthesia, yet it could lead to delayed recognition of BP fluctuations. Perioperative hypotension is known to be associated with postoperative complications. Continuous, non-invasive methods for BP monitoring have been developed recently. We have tested a novel non-invasive, continuous monitor (using the volume clamp method) to assist with maintaining BP in safe ranges for patients undergoing surgery in a beach chair position. Forty adult patients undergoing thyroid gland surgery in an upright position were included in this prospective randomised controlled trial. Patients were equally allocated to the group with continuous monitoring of BP using the CNAP® Monitor and to the control group managed using an intermittent oscillometric BP cuff. The absolute and proportional time spent outside the range of ±20% of the target BP along with other hemodynamic and clinical parameters were evaluated. The continuous monitoring decreased the anaesthesia time spent below -20% pressure range [absolute: 12 min (4-20) vs. 27 min (16-34); p=0.001; relative to procedure length: 14% (7-20) vs. 33.5% (17.5-53); p=0.003]. No significant differences were observed in postoperative morbidity or in hospital length of stay. Continuous non-invasive BP monitoring via the CNAP® Monitor allows for better BP management in patients undergoing surgery in a beach chair position. In our randomised trial the time spent in hypotension was significantly shorter using continuous monitoring. PMID:24841333

  3. Non-invasive Markers of Liver Fibrosis: Adjuncts or Alternatives to Liver Biopsy?

    PubMed Central

    Chin, Jun L.; Pavlides, Michael; Moolla, Ahmad; Ryan, John D.

    2016-01-01

    Liver fibrosis reflects sustained liver injury often from multiple, simultaneous factors. Whilst the presence of mild fibrosis on biopsy can be a reassuring finding, the identification of advanced fibrosis is critical to the management of patients with chronic liver disease. This necessity has lead to a reliance on liver biopsy which itself is an imperfect test and poorly accepted by patients. The development of robust tools to non-invasively assess liver fibrosis has dramatically enhanced clinical decision making in patients with chronic liver disease, allowing a rapid and informed judgment of disease stage and prognosis. Should a liver biopsy be required, the appropriateness is clearer and the diagnostic yield is greater with the use of these adjuncts. While a number of non-invasive liver fibrosis markers are now used in routine practice, a steady stream of innovative approaches exists. With improvement in the reliability, reproducibility and feasibility of these markers, their potential role in disease management is increasing. Moreover, their adoption into clinical trials as outcome measures reflects their validity and dynamic nature. This review will summarize and appraise the current and novel non-invasive markers of liver fibrosis, both blood and imaging based, and look at their prospective application in everyday clinical care. PMID:27378924

  4. Non-invasive pressure difference estimation from PC-MRI using the work-energy equation

    PubMed Central

    Donati, Fabrizio; Figueroa, C. Alberto; Smith, Nicolas P.; Lamata, Pablo; Nordsletten, David A.

    2015-01-01

    Pressure difference is an accepted clinical biomarker for cardiovascular disease conditions such as aortic coarctation. Currently, measurements of pressure differences in the clinic rely on invasive techniques (catheterization), prompting development of non-invasive estimates based on blood flow. In this work, we propose a non-invasive estimation procedure deriving pressure difference from the work-energy equation for a Newtonian fluid. Spatial and temporal convergence is demonstrated on in silico Phase Contrast Magnetic Resonance Image (PC-MRI) phantoms with steady and transient flow fields. The method is also tested on an image dataset generated in silico from a 3D patient-specific Computational Fluid Dynamics (CFD) simulation and finally evaluated on a cohort of 9 subjects. The performance is compared to existing approaches based on steady and unsteady Bernoulli formulations as well as the pressure Poisson equation. The new technique shows good accuracy, robustness to noise, and robustness to the image segmentation process, illustrating the potential of this approach for non-invasive pressure difference estimation. PMID:26409245

  5. Non-invasive pressure difference estimation from PC-MRI using the work-energy equation.

    PubMed

    Donati, Fabrizio; Figueroa, C Alberto; Smith, Nicolas P; Lamata, Pablo; Nordsletten, David A

    2015-12-01

    Pressure difference is an accepted clinical biomarker for cardiovascular disease conditions such as aortic coarctation. Currently, measurements of pressure differences in the clinic rely on invasive techniques (catheterization), prompting development of non-invasive estimates based on blood flow. In this work, we propose a non-invasive estimation procedure deriving pressure difference from the work-energy equation for a Newtonian fluid. Spatial and temporal convergence is demonstrated on in silico Phase Contrast Magnetic Resonance Image (PC-MRI) phantoms with steady and transient flow fields. The method is also tested on an image dataset generated in silico from a 3D patient-specific Computational Fluid Dynamics (CFD) simulation and finally evaluated on a cohort of 9 subjects. The performance is compared to existing approaches based on steady and unsteady Bernoulli formulations as well as the pressure Poisson equation. The new technique shows good accuracy, robustness to noise, and robustness to the image segmentation process, illustrating the potential of this approach for non-invasive pressure difference estimation. PMID:26409245

  6. The potential of label-free nonlinear optical molecular microscopy to non-invasively characterize the viability of engineered human tissue constructs.

    PubMed

    Chen, Leng-Chun; Lloyd, William R; Kuo, Shiuhyang; Kim, Hyungjin Myra; Marcelo, Cynthia L; Feinberg, Stephen E; Mycek, Mary-Ann

    2014-08-01

    Nonlinear optical molecular imaging and quantitative analytic methods were developed to non-invasively assess the viability of tissue-engineered constructs manufactured from primary human cells. Label-free optical measures of local tissue structure and biochemistry characterized morphologic and functional differences between controls and stressed constructs. Rigorous statistical analysis accounted for variability between human patients. Fluorescence intensity-based spatial assessment and metabolic sensing differentiated controls from thermally-stressed and from metabolically-stressed constructs. Fluorescence lifetime-based sensing differentiated controls from thermally-stressed constructs. Unlike traditional histological (found to be generally reliable, but destructive) and biochemical (non-invasive, but found to be unreliable) tissue analyses, label-free optical assessments had the advantages of being both non-invasive and reliable. Thus, such optical measures could serve as reliable manufacturing release criteria for cell-based tissue-engineered constructs prior to human implantation, thereby addressing a critical regulatory need in regenerative medicine. PMID:24854093

  7. Skin rejuvenation with non-invasive pulsed electric fields.

    PubMed

    Golberg, Alexander; Khan, Saiqa; Belov, Vasily; Quinn, Kyle P; Albadawi, Hassan; Felix Broelsch, G; Watkins, Michael T; Georgakoudi, Irene; Papisov, Mikhail; Mihm, Martin C; Austen, William G; Yarmush, Martin L

    2015-01-01

    Degenerative skin diseases affect one third of individuals over the age of sixty. Current therapies use various physical and chemical methods to rejuvenate skin; but since the therapies affect many tissue components including cells and extracellular matrix, they may also induce significant side effects, such as scarring. Here we report on a new, non-invasive, non-thermal technique to rejuvenate skin with pulsed electric fields. The fields destroy cells while simultaneously completely preserving the extracellular matrix architecture and releasing multiple growth factors locally that induce new cells and tissue growth. We have identified the specific pulsed electric field parameters in rats that lead to prominent proliferation of the epidermis, formation of microvasculature, and secretion of new collagen at treated areas without scarring. Our results suggest that pulsed electric fields can improve skin function and thus can potentially serve as a novel non-invasive skin therapy for multiple degenerative skin diseases. PMID:25965851

  8. Skin Rejuvenation with Non-Invasive Pulsed Electric Fields

    PubMed Central

    Golberg, Alexander; Khan, Saiqa; Belov, Vasily; Quinn, Kyle P.; Albadawi, Hassan; Felix Broelsch, G.; Watkins, Michael T.; Georgakoudi, Irene; Papisov, Mikhail; Mihm Jr., Martin C.; Austen Jr., William G.; Yarmush, Martin L.

    2015-01-01

    Degenerative skin diseases affect one third of individuals over the age of sixty. Current therapies use various physical and chemical methods to rejuvenate skin; but since the therapies affect many tissue components including cells and extracellular matrix, they may also induce significant side effects, such as scarring. Here we report on a new, non-invasive, non-thermal technique to rejuvenate skin with pulsed electric fields. The fields destroy cells while simultaneously completely preserving the extracellular matrix architecture and releasing multiple growth factors locally that induce new cells and tissue growth. We have identified the specific pulsed electric field parameters in rats that lead to prominent proliferation of the epidermis, formation of microvasculature, and secretion of new collagen at treated areas without scarring. Our results suggest that pulsed electric fields can improve skin function and thus can potentially serve as a novel non-invasive skin therapy for multiple degenerative skin diseases. PMID:25965851

  9. Non-invasive microsensors for studying cell/tissue physiology

    NASA Astrophysics Data System (ADS)

    Vanegas, D. C.; Taguchi, M.; Chaturvedi, P.; Burrs, S.; McLamore, E. S.

    2013-05-01

    Non-invasive tools that allow real-time quantification of molecules relevant to metabolism, homeostasis, and cell signaling in cells and tissue are of great importance for studying physiology. Several microsensor technologies have been developed to monitor concentration of molecules such as ions, oxygen, electroactive molecules (e.g., nitric oxide, hydrogen peroxide), and biomolecules (e.g., sugars, hormones). The major challenges for microsensors are overcoming relatively low sensitivity and low signal-to-noise ratio. Modern approaches for enhancing microsensor performance focus on the incorporation of catalytic nanomaterials to increase sensitivity, reduce response time, and increase operating range. To improve signal-to-noise ratio, a non-invasive microsensor modality called self-referencing (SR) is being applied. The SR technique allows measurement of temporal and spatial transport dynamics at the cell, tissue, organ, and organismal level.

  10. Non invasive ventilation as an additional tool for exercise training.

    PubMed

    Ambrosino, Nicolino; Cigni, Paolo

    2015-01-01

    Recently, there has been increasing interest in the use of non invasive ventilation (NIV) to increase exercise capacity. In individuals with COPD, NIV during exercise reduces dyspnoea and increases exercise tolerance. Different modalities of mechanical ventilation have been used non-invasively as a tool to increase exercise tolerance in COPD, heart failure and lung and thoracic restrictive diseases. Inspiratory support provides symptomatic benefit by unloading the ventilatory muscles, whereas Continuous Positive Airway Pressure (CPAP) counterbalances the intrinsic positive end-expiratory pressure in COPD patients. Severe stable COPD patients undergoing home nocturnal NIV and daytime exercise training showed some benefits. Furthermore, it has been reported that in chronic hypercapnic COPD under long-term ventilatory support, NIV can also be administered during walking. Despite these results, the role of NIV as a routine component of pulmonary rehabilitation is still to be defined. PMID:25874110

  11. Skin Rejuvenation with Non-Invasive Pulsed Electric Fields

    NASA Astrophysics Data System (ADS)

    Golberg, Alexander; Khan, Saiqa; Belov, Vasily; Quinn, Kyle P.; Albadawi, Hassan; Felix Broelsch, G.; Watkins, Michael T.; Georgakoudi, Irene; Papisov, Mikhail; Mihm, Martin C., Jr.; Austen, William G., Jr.; Yarmush, Martin L.

    2015-05-01

    Degenerative skin diseases affect one third of individuals over the age of sixty. Current therapies use various physical and chemical methods to rejuvenate skin; but since the therapies affect many tissue components including cells and extracellular matrix, they may also induce significant side effects, such as scarring. Here we report on a new, non-invasive, non-thermal technique to rejuvenate skin with pulsed electric fields. The fields destroy cells while simultaneously completely preserving the extracellular matrix architecture and releasing multiple growth factors locally that induce new cells and tissue growth. We have identified the specific pulsed electric field parameters in rats that lead to prominent proliferation of the epidermis, formation of microvasculature, and secretion of new collagen at treated areas without scarring. Our results suggest that pulsed electric fields can improve skin function and thus can potentially serve as a novel non-invasive skin therapy for multiple degenerative skin diseases.

  12. Non-invasive assessment of leaf water status using a dual-mode microwave resonator.

    PubMed

    Dadshani, Said; Kurakin, Andriy; Amanov, Shukhrat; Hein, Benedikt; Rongen, Heinz; Cranstone, Steve; Blievernicht, Ulrich; Menzel, Elmar; Léon, Jens; Klein, Norbert; Ballvora, Agim

    2015-01-01

    The water status in plant leaves is a good indicator for the water status in the whole plant revealing stress if the water supply is reduced. The analysis of dynamic aspects of water availability in plant tissues provides useful information for the understanding of the mechanistic basis of drought stress tolerance, which may lead to improved plant breeding and management practices. The determination of the water content in plant tissues during plant development has been a challenge and is currently feasible based on destructive analysis only. We present here the application of a non-invasive quantitative method to determine the volumetric water content of leaves and the ionic conductivity of the leaf juice from non-invasive microwave measurements at two different frequencies by one sensor device. A semi-open microwave cavity loaded with a ceramic dielectric resonator and a metallic lumped-element capacitor- and inductor structure was employed for non-invasive microwave measurements at 150 MHz and 2.4 Gigahertz on potato, maize, canola and wheat leaves. Three leaves detached from each plant were chosen, representing three developmental stages being representative for tissue of various age. Clear correlations between the leaf- induced resonance frequency shifts and changes of the inverse resonator quality factor at 2.4 GHz to the gravimetrically determined drying status of the leaves were found. Moreover, the ionic conductivity of Maize leaves, as determined from the ratio of the inverse quality factor and frequency shift at 150 MHz by use of cavity perturbation theory, was found to be in good agreement with direct measurements on plant juice. In conjunction with a compact battery- powered circuit board- microwave electronic module and a user-friendly software interface, this method enables rapid in-vivo water amount assessment of plants by a handheld device for potential use in the field. PMID:25918549

  13. Non-invasive optical detection of glucose in cell culture nutrient medium

    NASA Technical Reports Server (NTRS)

    Cote, Gerald L.

    1993-01-01

    The objective of the proposed research was to begin the development of a non-invasive optical sensor for measuring glucose concentration in the output medium of cell cultures grown in a unique NASA bioreactor referred to as an integrated rotating-wall vessel (IRWV). The input, a bovine serum based nutrient media, has a known glucose concentration. The cells within the bioreactor digest a portion of the glucose. Thus, the non-invasive optical sensor is needed to monitor the decrease in glucose due to cellular consumption since the critical parameters for sustained cellular productivity are glucose and pH. Previous glucose sensing techniques have used chemical reactions to quantify the glucose concentration. Chemical reactions, however, cannot provide for continuous, real time, non-invasive measurement as is required in this application. Our effort while in the fellowship program was focused on the design, optical setup, and testing of one bench top prototype non-invasive optical sensor using a mid-infrared absorption spectroscopy technique. Glucose has a fundamental vibrational absorption peak in the mid-infrared wavelength range at 9.6 micron. Preliminary absorption data using a CO2 laser were collected at this wavelength for water based glucose solutions at different concentrations and one bovine serum based nutrient medium (GTSF) with added glucose. The results showed near linear absorption responses for the glucose-in-water data with resolutions as high at 108 mg/dl and as low as 10 mg/dl. The nutrient medium had a resolution of 291 mg/dl. The variability of the results was due mainly to thermal and polarization drifts of the laser while the decrease in sensitivity to glucose in the nutrient medium was expected due to the increase in the number of confounders present in the nutrient medium. A multispectral approach needs to be used to compensate for these confounders. The CO2 laser used for these studies was wavelength tunable (9.2 to 10.8 micrometers), however

  14. Non-Invasive Diagnosis of Helicobacter pylori: Evaluation of Two Enzyme Immunoassays, Testing Serum IgG and IgA Response in the Anand District of Central Gujarat,India

    PubMed Central

    Patel, Jagdish Shantilal; Agravat, Harihar Hardas; Singh, Navneet kumar Ramdayal

    2014-01-01

    Context: Validation of an accurate and less cumbersome noninvasive method to detect current Helicobacter pylori infection is a requisite for any laboratory. Objectives: The purpose of this study is to corroborate the usefulness of two commercially available kits NovaTec ELISA-A and ELISA-G, in the detection of ongoing H.pylori infection. Materials and Methods: Two hundred and twenty eight consecutive serum samples of symptomatic patients who attended the endoscopy unit of “Deep” surgical hospital, Anand, which were collected during the period from 27th February 2008 to 31st august 2011, were studied. The sera were processed and tested for the detection of the H.pylori IgG and IgA antibody by using a solid phase; capture micro well ELISA, procured from Nova Tec immunodiagnostica GmbH Germany. Results: IgG ELISA showed 100% sensitivity and Negative predictive value (NPV), while IgA ELISA was better in terms of specificity (61.4%) and accuracy (63%) as compared to IgG ELISA. We found 7% (16/228) of IgA positive cases with IgG negative response. IgG response was more common in reflux esophagitis patients (OR 1.451, 95%CI-0.850-2.477) and then in gastritis (OR 0.962, 95%CI-0.570-1.621) and duodenitis(OR-0.806, 95%CI-0.112-5.827), while IgA positive response was more common in duodenitis patients (OR-1.383, 95%CI-0.191-9.995) and reflux esophagitis patients (OR 1.289, 95% CI-0.756-2.197) and least in duodenal ulcer patients (OR 0.670, 95%CI-0.222-2.029). Conclusion: IgG update is reliable and accurate test and can be expedient as a screening test and thus serve as an alternative to endoscopy. For the purpose of excluding infection with H.pylori, the performance of IgG is moderate (low specificity) but can be improved by conjunctional IgA testing which will offer some additional diagnostic value. PMID:25120979

  15. SQUID magnetometry applied as non-invasive electroanalytic chemical technique

    SciTech Connect

    Jette, B.D.; MacVicar, M.L.A. )

    1991-03-01

    This paper reports on a SQUID magnetometer, employed as a highly sensitive ammeter, used to perform standard electroanalytic chemical measurements non- invasively. Specifically, the magnetic fields generated by the net ionic movement in the solution of a driven electrochemical system is detected by the gradiometer coils. The SQUID signal can then be compared to conventional current measurements. One such standard measurement investigated is Cyclic Voltametry (CV) which determines the I-V characteristics of an electrochemical system yielding critical kinetic parameters.

  16. Cellular phone enabled non-invasive tissue classifier.

    PubMed

    Laufer, Shlomi; Rubinsky, Boris

    2009-01-01

    Cellular phone technology is emerging as an important tool in the effort to provide advanced medical care to the majority of the world population currently without access to such care. In this study, we show that non-invasive electrical measurements and the use of classifier software can be combined with cellular phone technology to produce inexpensive tissue characterization. This concept was demonstrated by the use of a Support Vector Machine (SVM) classifier to distinguish through the cellular phone between heart and kidney tissue via the non-invasive multi-frequency electrical measurements acquired around the tissues. After the measurements were performed at a remote site, the raw data were transmitted through the cellular phone to a central computational site and the classifier was applied to the raw data. The results of the tissue analysis were returned to the remote data measurement site. The classifiers correctly determined the tissue type with a specificity of over 90%. When used for the detection of malignant tumors, classifiers can be designed to produce false positives in order to ensure that no tumors will be missed. This mode of operation has applications in remote non-invasive tissue diagnostics in situ in the body, in combination with medical imaging, as well as in remote diagnostics of biopsy samples in vitro. PMID:19365554

  17. Chronic non-invasive corticosterone administration abolishes the diurnal pattern of tph2 expression

    PubMed Central

    Donner, Nina C.; Montoya, Christian D.; Lukkes, Jodi L.; Lowry, Christopher A.

    2011-01-01

    Both hypothalamic-pituitary-adrenal (HPA) axis activity and serotonergic systems are commonly dysregulated in stress-related psychiatric disorders. We describe here a non-invasive rat model for hypercortisolism, as observed in major depression, and its effects on physiology, behavior, and the expression of tph2, the gene encoding tryptophan hydroxylase 2, the rate-limiting enzyme for brain serotonin (5-hydroxytryptamine; 5-HT) synthesis. We delivered corticosterone (40 µg/ml, 100 µg/ml or 400 µg/ml) or vehicle to adrenal-intact adult, male rats via the drinking water for three weeks. On days 15, 16, 17 and 18, respectively, the rats’ emotionality was assessed in the open-field (OF), social interaction (SI), elevated plus-maze (EPM), and forced swim tests (FST). On day 21, half of the rats in each group were killed 2 h into the dark phase of a 12/12 h reversed light/dark cycle; the other half were killed 2 h into the light phase. We then measured indices of HPA axis activity, plasma glucose and interleukin-6 (IL-6) availability, and neuronal tph2 expression at each time point. Chronic corticosterone intake was sufficient to cause increased anxiety- and depressive-like behavior in a dose-dependent manner. It also disrupted the diurnal pattern of plasma adrenocorticotropin (ACTH), corticosterone, and glucose concentrations, caused adrenal atrophy, and prevented regular weight gain. No diurnal or treatment-dependent changes were found for plasma levels of IL-6. Remarkably, all doses of corticosterone treatment abolished the diurnal variation of tph2 mRNA expression in the brainstem dorsal raphe nucleus (DR) by elevating the gene’s expression during the animals’ inactive (light) phase. Our data demonstrate that chronic elevation of corticosterone creates a vulnerability to a depression-like syndrome that is associated with increased tph2 expression, similar to that observed in depressed patients. PMID:21924839

  18. Stress Testing of Data-Communication Networks

    NASA Technical Reports Server (NTRS)

    Leucht, Kurt; Bedette, Guy

    2006-01-01

    NetStress is a computer program that stress-tests a data-communication network and components thereof. NetStress comprises two components running, respectively, in a transmitting system and a receiving system connected to a network under test

  19. Detecting the exposure to Cd and PCBs by means of a non-invasive transcriptomic approach in laboratory and wild contaminated European eels (Anguilla anguilla).

    PubMed

    Baillon, Lucie; Pierron, Fabien; Oses, Jennifer; Pannetier, Pauline; Normandeau, Eric; Couture, Patrice; Labadie, Pierre; Budzinski, Hélène; Lambert, Patrick; Bernatchez, Louis; Baudrimont, Magalie

    2016-03-01

    Detecting and separating specific effects of contaminants in a multi-stress field context remain a major challenge in ecotoxicology. In this context, the aim of this study was to assess the usefulness of a non-invasive transcriptomic method, by means of a complementary DNA (cDNA) microarray comprising 1000 candidate genes, on caudal fin clips. Fin gene transcription patterns of European eels (Anguilla anguilla) exposed in the laboratory to cadmium (Cd) or a polychloro-biphenyl (PCBs) mixture but also of wild eels from three sampling sites with differing contamination levels were compared to test whether fin clips may be used to detect and discriminate the exposure to these contaminants. Also, transcriptomic profiles from the liver and caudal fin of eels experimentally exposed to Cd were compared to assess the detection sensitivity of the fin transcriptomic response. A similar number of genes were differentially transcribed in the fin and liver in response to Cd exposure, highlighting the detection sensitivity of fin clips. Moreover, distinct fin transcription profiles were observed in response to Cd or PCB exposure. Finally, the transcription profiles of eels from the most contaminated site clustered with those from laboratory-exposed fish. This study thus highlights the applicability and usefulness of performing gene transcription assays on non-invasive tissue sampling in order to detect the in situ exposure to Cd and PCBs in fish. PMID:26566612

  20. Prediction of human core body temperature using non-invasive measurement methods

    NASA Astrophysics Data System (ADS)

    Niedermann, Reto; Wyss, Eva; Annaheim, Simon; Psikuta, Agnes; Davey, Sarah; Rossi, René Michel

    2014-01-01

    The measurement of core body temperature is an efficient method for monitoring heat stress amongst workers in hot conditions. However, invasive measurement of core body temperature (e.g. rectal, intestinal, oesophageal temperature) is impractical for such applications. Therefore, the aim of this study was to define relevant non-invasive measures to predict core body temperature under various conditions. We conducted two human subject studies with different experimental protocols, different environmental temperatures (10 °C, 30 °C) and different subjects. In both studies the same non-invasive measurement methods (skin temperature, skin heat flux, heart rate) were applied. A principle component analysis was conducted to extract independent factors, which were then used in a linear regression model. We identified six parameters (three skin temperatures, two skin heat fluxes and heart rate), which were included for the calculation of two factors. The predictive value of these factors for core body temperature was evaluated by a multiple regression analysis. The calculated root mean square deviation (rmsd) was in the range from 0.28 °C to 0.34 °C for all environmental conditions. These errors are similar to previous models using non-invasive measures to predict core body temperature. The results from this study illustrate that multiple physiological parameters (e.g. skin temperature and skin heat fluxes) are needed to predict core body temperature. In addition, the physiological measurements chosen in this study and the algorithm defined in this work are potentially applicable as real-time core body temperature monitoring to assess health risk in broad range of working conditions.

  1. Estimating Trabecular Bone Mechanical Properties From Non-Invasive Imaging

    NASA Technical Reports Server (NTRS)

    Hogan, Harry A.; Webster, Laurie

    1997-01-01

    An important component in developing countermeasures for maintaining musculoskeletal integrity during long-term space flight is an effective and meaningful method of monitoring skeletal condition. Magnetic resonance imaging (MRI) is an attractive non-invasive approach because it avoids the exposure to radiation associated with X-ray based imaging and also provides measures related to bone microstructure rather than just density. The purpose of the research for the 1996 Summer Faculty Fellowship period was to extend the usefulness of the MRI data to estimate the mechanical properties of trabecular bone. The main mechanical properties of interest are the elastic modulus and ultimate strength. Correlations are being investigated between these and fractal analysis parameters, MRI relaxation times, apparent densities, and bone mineral densities. Bone specimens from both human and equine donors have been studied initially to ensure high-quality MR images. Specimens were prepared and scanned from human proximal tibia bones as well as the equine distal radius. The quality of the images from the human bone appeared compromised due to freezing artifact, so only equine bone was included in subsequent procedures since these specimens could be acquired and imaged fresh before being frozen. MRI scans were made spanning a 3.6 cm length on each of 5 equine distal radius specimens. The images were then sent to Dr. Raj Acharya of the State University of New York at Buffalo for fractal analysis. Each piece was cut into 3 slabs approximately 1.2 cm thick and high-resolution contact radiographs were made to provide images for comparing fractal analysis with MR images. Dual energy X-ray absorptiometry (DEXA) scans were also made of each slab for subsequent bone mineral density determination. Slabs were cut into cubes for mechanical using a slow-speed diamond blade wafering saw (Buehler Isomet). The dimensions and wet weights of each cube specimen were measured and recorded. Wet weights

  2. Non-Invasive Measurement of Adrenocortical Activity in Blue-Fronted Parrots (Amazona aestiva, Linnaeus, 1758)

    PubMed Central

    Ferreira, João C. P.; Fujihara, Caroline J.; Fruhvald, Erika; Trevisol, Eduardo; Destro, Flavia C.; Teixeira, Carlos R.; Pantoja, José C. F.; Schmidt, Elizabeth M. S.; Palme, Rupert

    2015-01-01

    Parrots kept in zoos and private households often develop psychological and behavioural disorders. Despite knowing that such disorders have a multifactorial aetiology and that chronic stress is involved, little is known about their development mainly due to a poor understanding of the parrots’ physiology and the lack of validated methods to measure stress in these species. In birds, blood corticosterone concentrations provide information about adrenocortical activity. However, blood sampling techniques are difficult, highly invasive and inappropriate to investigate stressful situations and welfare conditions. Thus, a non-invasive method to measure steroid hormones is critically needed. Aiming to perform a physiological validation of a cortisone enzyme immunoassay (EIA) to measure glucocorticoid metabolites (GCM) in droppings of 24 Blue-fronted parrots (Amazona aestiva), two experiments were designed. During the experiments all droppings were collected at 3-h intervals. Initially, birds were sampled for 24 h (experiment 1) and one week later assigned to four different treatments (experiment 2): Control (undisturbed), Saline (0.2 mL of 0.9% NaCl IM), Dexamethasone (1 mg/kg IM) and Adrenocorticotropic hormone (ACTH; 25 IU IM). Treatments (always one week apart) were applied to all animals in a cross-over study design. A daily rhythm pattern in GCM excretion was detected but there were no sex differences (first experiment). Saline and dexamethasone treatments had no effect on GCM (not different from control concentrations). Following ACTH injection, GCM concentration increased about 13.1-fold (median) at the peak (after 3–9 h), and then dropped to pre-treatment concentrations. By a successful physiological validation, we demonstrated the suitability of the cortisone EIA to non-invasively monitor increased adrenocortical activity, and thus, stress in the Blue-fronted parrot. This method opens up new perspectives for investigating the connection between behavioural

  3. Non-Invasive Measurement of Adrenocortical Activity in Blue-Fronted Parrots (Amazona aestiva, Linnaeus, 1758).

    PubMed

    Ferreira, João C P; Fujihara, Caroline J; Fruhvald, Erika; Trevisol, Eduardo; Destro, Flavia C; Teixeira, Carlos R; Pantoja, José C F; Schmidt, Elizabeth M S; Palme, Rupert

    2015-01-01

    Parrots kept in zoos and private households often develop psychological and behavioural disorders. Despite knowing that such disorders have a multifactorial aetiology and that chronic stress is involved, little is known about their development mainly due to a poor understanding of the parrots' physiology and the lack of validated methods to measure stress in these species. In birds, blood corticosterone concentrations provide information about adrenocortical activity. However, blood sampling techniques are difficult, highly invasive and inappropriate to investigate stressful situations and welfare conditions. Thus, a non-invasive method to measure steroid hormones is critically needed. Aiming to perform a physiological validation of a cortisone enzyme immunoassay (EIA) to measure glucocorticoid metabolites (GCM) in droppings of 24 Blue-fronted parrots (Amazona aestiva), two experiments were designed. During the experiments all droppings were collected at 3-h intervals. Initially, birds were sampled for 24 h (experiment 1) and one week later assigned to four different treatments (experiment 2): Control (undisturbed), Saline (0.2 mL of 0.9% NaCl IM), Dexamethasone (1 mg/kg IM) and Adrenocorticotropic hormone (ACTH; 25 IU IM). Treatments (always one week apart) were applied to all animals in a cross-over study design. A daily rhythm pattern in GCM excretion was detected but there were no sex differences (first experiment). Saline and dexamethasone treatments had no effect on GCM (not different from control concentrations). Following ACTH injection, GCM concentration increased about 13.1-fold (median) at the peak (after 3-9 h), and then dropped to pre-treatment concentrations. By a successful physiological validation, we demonstrated the suitability of the cortisone EIA to non-invasively monitor increased adrenocortical activity, and thus, stress in the Blue-fronted parrot. This method opens up new perspectives for investigating the connection between behavioural

  4. Towards a smart non-invasive fluid loss measurement system.

    PubMed

    Suryadevara, N K; Mukhopadhyay, S C; Barrack, L

    2015-04-01

    In this article, a smart wireless sensing non-invasive system for estimating the amount of fluid loss, a person experiences while physical activity is presented. The system measures three external body parameters, Heart Rate, Galvanic Skin Response (GSR, or skin conductance), and Skin Temperature. These three parameters are entered into an empirically derived formula along with the user's body mass index, and estimation for the amount of fluid lost is determined. The core benefit of the developed system is the affluence usage in combining with smart home monitoring systems to care elderly people in ambient assisted living environments as well in automobiles to monitor the body parameters of a motorist. PMID:25686913

  5. Non-Invasive Optical Biosensor for Probing Cell Signaling

    PubMed Central

    Fang, Ye

    2007-01-01

    Cell signaling mediated through a cellular target is encoded by spatial and temporal dynamics of downstream signaling networks. The coupling of temporal dynamics with spatial gradients of signaling activities guides cellular responses upon stimulation. Monitoring the integration of cell signaling in real time, if realized, would provide a new dimension for understanding cell biology and physiology. Optical biosensors including resonant waveguide grating (RWG) biosensor manifest a physiologically relevant and integrated cellular response related to dynamic redistribution of cellular matters, thus providing a non-invasive means for cell signaling study. This paper reviews recent progresses in biosensor instrumentation, and theoretical considerations and potential applications of optical biosensors for whole cell sensing.

  6. A simple highly efficient non invasive EMG-based HMI.

    PubMed

    Vitiello, N; Olcese, U; Oddo, C M; Carpaneto, J; Micera, S; Carrozza, M C; Dario, P

    2006-01-01

    Muscle activity recorded non-invasively is sufficient to control a mobile robot if it is used in combination with an algorithm for its asynchronous analysis. In this paper, we show that several subjects successfully can control the movements of a robot in a structured environment made up of six rooms by contracting two different muscles using a simple algorithm. After a small training period, subjects were able to control the robot with performances comparable to those achieved manually controlling the robot. PMID:17945773

  7. Non-invasive techniques for determining musculoskeleton body composition

    SciTech Connect

    Cohn, S.H.

    1984-01-01

    In vivo neutron activation analysis, combined with gamma spectrometry, has ushered in a new era of clinical diagnosis and evaluation of therapies, as well as investigation into and modelling of body composition in both normal individuals and patients suffering from various diseases and dysfunctions. Body composition studies have provided baseline data on such vital constituents as nitrogen, potassium and calcium. The non-invasive measurement techniques are particularly suitable for study of the musculo-skeletal changes in body composition. Of particular relevance here is the measurement of calcium loss in astronauts during prolonged space flights.

  8. Neurophotonics: non-invasive optical techniques for monitoring brain functions.

    PubMed

    Torricelli, Alessandro; Contini, Davide; Dalla Mora, Alberto; Pifferi, Antonio; Re, Rebecca; Zucchelli, Lucia; Caffini, Matteo; Farina, Andrea; Spinelli, Lorenzo

    2014-01-01

    The aim of this review is to present the state of the art of neurophotonics, a recently founded discipline lying at the interface between optics and neuroscience. While neurophotonics also includes invasive techniques for animal studies, in this review we focus only on the non-invasive methods that use near infrared light to probe functional activity in the brain, namely the fast optical signal, diffuse correlation spectroscopy, and functional near infrared spectroscopy methods. We also present an overview of the physical principles of light propagation in biological tissues, and of the main physiological sources of signal. Finally, we discuss the open issues in models, instrumentation, data analysis and clinical approaches. PMID:25764252

  9. Non-Invasive Prenatal Diagnosis of Lethal Skeletal Dysplasia by Targeted Capture Sequencing of Maternal Plasma

    PubMed Central

    Wang, Yaoshen; Chen, Chao; Gao, Changxin; Yu, Song; Liu, Yan; Song, Wei; Asan; Zhu, Hongmei; Yang, Ling; Deng, Hongmei; Su, Yue; Yi, Xin

    2016-01-01

    Background Since the discovery of cell-free foetal DNA in the plasma of pregnant women, many non-invasive prenatal testing assays have been developed. In the area of skeletal dysplasia diagnosis, some PCR-based non-invasive prenatal testing assays have been developed to facilitate the ultrasound diagnosis of skeletal dysplasias that are caused by de novo mutations. However, skeletal dysplasias are a group of heterogeneous genetic diseases, the PCR-based method is hard to detect multiple gene or loci simultaneously, and the diagnosis rate is highly dependent on the accuracy of the ultrasound diagnosis. In this study, we investigated the feasibility of using targeted capture sequencing to detect foetal de novo pathogenic mutations responsible for skeletal dysplasia. Methodology/Principal Findings Three families whose foetuses were affected by skeletal dysplasia and two control families whose foetuses were affected by other single gene diseases were included in this study. Sixteen genes related to some common lethal skeletal dysplasias were selected for analysis, and probes were designed to capture the coding regions of these genes. Targeted capture sequencing was performed on the maternal plasma DNA, the maternal genomic DNA, and the paternal genomic DNA. The de novo pathogenic variants in the plasma DNA data were identified using a bioinformatical process developed for low frequency mutation detection and a strict variant interpretation strategy. The causal variants could be specifically identified in the plasma, and the results were identical to those obtained by sequencing amniotic fluid samples. Furthermore, a mean of 97% foetal specific alleles, which are alleles that are not shared by maternal genomic DNA and amniotic fluid DNA, were identified successfully in plasma samples. Conclusions/Significance Our study shows that capture sequencing of maternal plasma DNA can be used to non-invasive detection of de novo pathogenic variants. This method has the potential

  10. Comparison of Non-Invasive Methods for the Detection of Coronary Atherosclerosis

    PubMed Central

    Bampi, Angela Bacelar Albuquerque; Rochitte, Carlos Eduardo; Favarato, Desiderio; Lemos, Pedro Alves; da Luz, Protásio Lemos

    2009-01-01

    BACKGROUND: Non-invasive detection of atherosclerosis is critical for its prevention. Objective: To correlate non-invasively detectable indicators of coronary atherosclerosis, or Coronary Artery Disease (i.e., classical risk factors, hs-CRP test results, carotid intima-media thickness, endothelial function, ankle-brachial index and calcium score by computed tomography) with the extent of coronary disease assessed by the Friesinger index from conventional coronary angiography. METHODS: We conducted a prospective study of 100 consecutive patients, mean age 55.1 ± 10.7 years, 55% men and 45% women. Patients with acute coronary syndrome, renal dialytic insufficiency, collagen disease and cancer were not included. All patients were subjected to clinical evaluation and laboratory tests. Endothelial function of the brachial artery and carotid artery were evaluated by high-resolution ultrasound; ankle-brachial index and computed tomography for coronary determination of calcium score were also performed, and non-HDL cholesterol and TG/HDL-c ratio were calculated. All patients were subjected to coronary angiography at the request of the assistant physician. We considered patients without an obstructive lesion (< 29% stenosis) demonstrated by coronary angiography to be normal. RESULTS: Univariate analysis showed that calcium score, HDL-c, TG/HDL ratio and IMT were significantly correlated with the Friesinger index. However, multivariate analysis indicated that only calcium score and low HDL-c levels correlated significantly with the extension of CAD. On the other hand, hs-CRP, LDL-c, flow-mediated dilation, and Framingham score did not correlate with the Friesinger index. ROC analysis showed that calcium score, HDL-c and TG-HDL ratio accurately predicted extensive CAD in a statistically significant manner. CONCLUSION: It is possible to approximately determine the presence and extent of CAD by non-invasive methods, especially by calcium score, HDL-c and TG/HDL-c ratio assays

  11. Near-Infrared Spectroscopy as a Novel Non-Invasive Tool to Assess Spiny Lobster Nutritional Condition.

    PubMed

    Simon, Cedric J; Rodemann, Thomas; Carter, Chris G

    2016-01-01

    Rapid non-invasive monitoring of spiny lobster nutritional condition has considerable application in the established fishery, live market and prospective aquaculture. The aim of this research was to test the feasibility of near-infrared spectroscopy (NIRS) as a novel non-invasive tool to assess the nutritional condition of three lobster species. Lobster (n = 92) abdominal muscle dry matter (AMDM) and carbon content (AMC) correlated significantly with indices of nutritional condition including hepatopancreas dry matter (HPDM; rho = 0.83, 0.78), total lipid content (HPTL; rho = 0.85, 0.87) and haemolymph total protein (TP; rho = 0.89, 0.87 respectively). Abdominal muscle nitrogen content (AMN) was a poor correlate of nutritional condition. Models based on FT-NIR scanning of whole lobster tails successfully predicted AMDM, AMN and AMC (RMSECV = 1.41%, 0.35% and 0.91%; R2 = 0.75, 0.65, 0.77, respectively), and to a lower accuracy HPDM, HPTL and TP (RMSECV = 6.22%, 8.37%, 18.4 g l-1; R2 = 0.51, 0.70, 0.83, respectively). NIRS was applied successfully to assess the condition of spiny lobsters non-invasively. This pilot study paves the way for the development of crustacean condition models using portable non-invasive devices in the laboratory or in the field. PMID:27442242

  12. Near-Infrared Spectroscopy as a Novel Non-Invasive Tool to Assess Spiny Lobster Nutritional Condition

    PubMed Central

    Rodemann, Thomas; Carter, Chris G.

    2016-01-01

    Rapid non-invasive monitoring of spiny lobster nutritional condition has considerable application in the established fishery, live market and prospective aquaculture. The aim of this research was to test the feasibility of near-infrared spectroscopy (NIRS) as a novel non-invasive tool to assess the nutritional condition of three lobster species. Lobster (n = 92) abdominal muscle dry matter (AMDM) and carbon content (AMC) correlated significantly with indices of nutritional condition including hepatopancreas dry matter (HPDM; rho = 0.83, 0.78), total lipid content (HPTL; rho = 0.85, 0.87) and haemolymph total protein (TP; rho = 0.89, 0.87 respectively). Abdominal muscle nitrogen content (AMN) was a poor correlate of nutritional condition. Models based on FT-NIR scanning of whole lobster tails successfully predicted AMDM, AMN and AMC (RMSECV = 1.41%, 0.35% and 0.91%; R2 = 0.75, 0.65, 0.77, respectively), and to a lower accuracy HPDM, HPTL and TP (RMSECV = 6.22%, 8.37%, 18.4 g l-1; R2 = 0.51, 0.70, 0.83, respectively). NIRS was applied successfully to assess the condition of spiny lobsters non-invasively. This pilot study paves the way for the development of crustacean condition models using portable non-invasive devices in the laboratory or in the field. PMID:27442242

  13. Accelerated stress testing of terrestrial solar cells

    NASA Technical Reports Server (NTRS)

    Prince, J. L.; Lathrop, J. W.

    1979-01-01

    A program to investigate the reliability characteristics of unencapsulated low-cost terrestrial solar cells using accelerated stress testing is described. Reliability (or parametric degradation) factors appropriate to the cell technologies and use conditions were studied and a series of accelerated stress tests was synthesized. An electrical measurement procedure and a data analysis and management system was derived, and stress test fixturing and material flow procedures were set up after consideration was given to the number of cells to be stress tested and measured and the nature of the information to be obtained from the process. Selected results and conclusions are presented.

  14. Non-invasive diagnosis of liver fibrosis and cirrhosis

    PubMed Central

    Lurie, Yoav; Webb, Muriel; Cytter-Kuint, Ruth; Shteingart, Shimon; Lederkremer, Gerardo Z

    2015-01-01

    The evaluation and follow up of liver fibrosis and cirrhosis have been traditionally performed by liver biopsy. However, during the last 20 years, it has become evident that this “gold-standard” is imperfect; even according to its proponents, it is only “the best” among available methods. Attempts at uncovering non-invasive diagnostic tools have yielded multiple scores, formulae, and imaging modalities. All are better tolerated, safer, more acceptable to the patient, and can be repeated essentially as often as required. Most are much less expensive than liver biopsy. Consequently, their use is growing, and in some countries the number of biopsies performed, at least for routine evaluation of hepatitis B and C, has declined sharply. However, the accuracy and diagnostic value of most, if not all, of these methods remains controversial. In this review for the practicing physician, we analyze established and novel biomarkers and physical techniques. We may be witnessing in recent years the beginning of the end of the first phase for the development of non-invasive markers. Early evidence suggests that they might be at least as good as liver biopsy. Novel experimental markers and imaging techniques could produce a dramatic change in diagnosis in the near future. PMID:26556987

  15. Non-invasive diagnostic imaging of colorectal liver metastases

    PubMed Central

    Mainenti, Pier Paolo; Romano, Federica; Pizzuti, Laura; Segreto, Sabrina; Storto, Giovanni; Mannelli, Lorenzo; Imbriaco, Massimo; Camera, Luigi; Maurea, Simone

    2015-01-01

    Colorectal cancer is one of the few malignant tumors in which synchronous or metachronous liver metastases [colorectal liver metastases (CRLMs)] may be treated with surgery. It has been demonstrated that resection of CRLMs improves the long-term prognosis. On the other hand, patients with un-resectable CRLMs may benefit from chemotherapy alone or in addition to liver-directed therapies. The choice of the most appropriate therapeutic management of CRLMs depends mostly on the diagnostic imaging. Nowadays, multiple non-invasive imaging modalities are available and those have a pivotal role in the workup of patients with CRLMs. Although extensive research has been performed with regards to the diagnostic performance of ultrasonography, computed tomography, positron emission tomography and magnetic resonance for the detection of CRLMs, the optimal imaging strategies for staging and follow up are still to be established. This largely due to the progressive technological and pharmacological advances which are constantly improving the accuracy of each imaging modality. This review describes the non-invasive imaging approaches of CRLMs reporting the technical features, the clinical indications, the advantages and the potential limitations of each modality, as well as including some information on the development of new imaging modalities, the role of new contrast media and the feasibility of using parametric image analysis as diagnostic marker of presence of CRLMs. PMID:26217455

  16. Diagnosis and therapies for gastric non-invasive neoplasia

    PubMed Central

    Kato, Motohiko

    2015-01-01

    There has been a great discrepancy of pathological diagnosis for gastric non-invasive neoplasia/dysplasia between Japanese and western pathologists. In Japan, lesions that most western pathologists diagnose as dysplasia are often considered adenocarcinoma based on nuclear and structural atypia regardless of the presence of invasion. In the Vienna classification, gastric non-invasive intraepithelial neoplasia (NIN) were divided into low grade and high grade (including intra-mucosal cancer of Japanese criteria). The diagnosis by both endoscopy and pathology of biopsy specimen is difficult. Recent advances of diagnostic modality such as magnified endoscopy and imaged enhanced endoscopy is expected to improve the diagnostic yield for NIN. There are two treatment strategies for NIN, observation and diagnostic therapy by endoscopic resection (ER). ER is acceptable because of its less invasiveness and high local control rate, on the other hand, cancer-developing rate of low-grade NIN is reported to be low. Therefore there is controversy for the treatment of gastric NIN. Prospective study based on unified pathological definition is required in the future. PMID:26640329

  17. Influence of hemoglobin on non-invasive optical bilirubin sensing

    NASA Astrophysics Data System (ADS)

    Jiang, Jingying; Gong, Qiliang; Zou, Da; Xu, Kexin

    2012-03-01

    Since the abnormal metabolism of bilirubin could lead to diseases in the human body, especially the jaundice which is harmful to neonates. Traditional invasive measurements are difficult to be accepted by people because of pain and infection. Therefore, the real-time and non-invasive measurement of bilirubin is of great significance. However, the accuracy of currently transcutaneous bilirubinometry(TcB) is generally not high enough, and affected by many factors in the human skin, mostly by hemoglobin. In this talk, absorption spectra of hemoglobin and bilirubin have been collected and analyzed, then the Partial Least Squares (PLS) models have been built. By analyzing and comparing the Correlation and Root Mean Square Error of Prediction(RMSEP), the results show that the Correlation of bilirubin solution model is larger than that of the mixture solution added with hemoglobin, and its RMSEP value is smaller than that of mixture solution. Therefore, hemoglobin has influences on the non-invasive optical bilirubin sensing. In next step, it is necessary to investigate how to eliminate the influence.

  18. Use of Doppler ultrasound for non-invasive urodynamic diagnosis

    PubMed Central

    Ozawa, Hideo; Watanabe, Toyohiko; Uematsu, Katsutoshi; Sasaki, Katsumi; Inoue, Miyabi; Kumon, Hiromi

    2009-01-01

    Objectives: A totally non-invasive transperineal urodynamic technique using Doppler ultrasonography has been developed. Methods: Since normal urine does not have blood cells, urine was thought not to produce the Doppler effects. However, basic studies confirmed that the decrease of pressure at high velocity (Bernouilli effect) caused dissolved gas to form microbubbles, which are detected by Doppler ultrasonography. Subjects sat and the probe was advanced via remote control to achieve gentle contact with the perineal skin. The digital uroflow data signals and the color Doppler ultrasound video images were processed on a personal computer. The flow-velocity curves from two sites; the distal prostatic urethra just above the external sphincter (V1) and the sphincteric urethra (V2) were plotted against time. The parameters of both the pressure-flow studies and the Doppler ultrasound urodynamic studies were compared in men who had various degrees of obstruction. Results: Functional cross-sectional area at prostatic urethra (A1), calculated by Qmax/V1, was lower in the group of bladder outlet obstruction (BOO) vs. control group. Velocity ratio (VR), which was calculated by V1/V2, was the parameter having the best correlation with BOO index, though A1 had a similar correlation. This method is viable to diagnose the degree of BOO. Conclusions: The development of non-invasive Doppler ultrasound videourodynamics (Doppler UDS) will dramatically expand the information on voiding function. PMID:19468440

  19. Non-invasive methodology for diagnostics of bearing impacts

    NASA Astrophysics Data System (ADS)

    Chi, John N.

    2007-04-01

    Various events in reciprocating machinery, such as connecting rod or piston movement, and diesel combustion produce a series of highly transient forces within the machine. These events generate force transients of short duration and broad frequency content. Even though these events may be part of a machine cycle and therefore periodic, it is often more appropriate to treat them on an individual basis because more diagnostics information is available from a single waveform during a cycle than from averages over several cycles. However, it is very rare for one to have direct access to source waveforms because of the expense and reliability problems associated with the required instrumentation, and non-invasive techniques will have to be used. This paper explores the use of cepstral smoothing and minimum phase extraction technique for non-invasive diagnostics of bearing impacts in reciprocating machinery. The methodology is based on extracting diagnostic signals from vibration measurements taken at a "convenient" location such as the crankshaft casing or bearing end-cap, and consists of source identification, diagnostic signature recovery, and diagnostic system decision-making. A dynamic simulation with lumped mass model is developed to analyze bearing impacts for the big end bearings, experimental measurements from accelerometers, transfer functions of vibration, and the structural response are presented.

  20. Modulation of Untruthful Responses with Non-Invasive Brain Stimulation

    PubMed Central

    Fecteau, Shirley; Boggio, Paulo; Fregni, Felipe; Pascual-Leone, Alvaro

    2013-01-01

    Deceptive abilities have long been studied in relation to personality traits. More recently, studies explored the neural substrates associated with deceptive skills suggesting a critical role of the prefrontal cortex. Here we investigated whether non-invasive brain stimulation over the dorsolateral prefrontal cortex (DLPFC) could modulate generation of untruthful responses about subject’s personal life across contexts (i.e., deceiving on guilt-free questions on daily activities; generating previously memorized lies about past experience; and producing spontaneous lies about past experience), as well as across modality responses (verbal and motor responses). Results reveal that real, but not sham, transcranial direct current stimulation (tDCS) over the DLPFC can reduce response latency for untruthful over truthful answers across contexts and modality responses. Also, contexts of lies seem to incur a different hemispheric laterality. These findings add up to previous studies demonstrating that it is possible to modulate some processes involved in generation of untruthful answers by applying non-invasive brain stimulation over the DLPFC and extend these findings by showing a differential hemispheric contribution of DLPFCs according to contexts. PMID:23550273

  1. Non-Invasive Prediction of Histologic Chorioamnionitis in Women with Preterm Premature Rupture of Membranes

    PubMed Central

    Kim, Su Ah; Lee, Seung Mi

    2016-01-01

    Purpose To develop a model based on non-invasive clinical and ultrasonographic parameters for predicting the likelihood of subsequent histologic chorioamnionitis in women with preterm premature rupture of membranes (PPROM) and to determine whether the inclusion of invasive test results improves the predictive value of the model. Materials and Methods This retrospective cohort study included 146 consecutive women presenting with PPROM (20–33 weeks). Transvaginal ultrasonographic assessment of cervical length was performed. Maternal serum C-reactive protein (CRP) levels and white blood cell (WBC) counts were measured after amniocentesis. Amniotic fluid (AF) obtained by amniocentesis was cultured, and interleukin-6 (IL-6) levels and WBC counts were determined. The primary outcome measure was histologic chorioamnionitis. Results Risk scores based on serum CRP concentrations and gestational age (model 1) were calculated for each patient. The model was shown to have adequate goodness of fit and an area under the receiver operating characteristic curve (AUC) of 0.742. When including AF test results (e.g., AF IL-6 levels) in model 1, serum CRP concentrations were found to be insignificant, and thus, were excluded from model 2, comprising AF IL-6 levels and gestational age. No significant difference in AUC was found between models 1 and 2. Conclusion For women with PPROM, the newly developed model incorporating non-invasive parameters (serum CRP and gestational age) was moderately predictive of histologic chorioamnionitis. The inclusion of invasive test results added no predictive information to the model in this setting. PMID:26847301

  2. Non-invasive assessment of liver fibrosis in patients with alcoholic liver disease

    PubMed Central

    Lombardi, Rosa; Buzzetti, Elena; Roccarina, Davide; Tsochatzis, Emmanuel A

    2015-01-01

    Alcoholic liver disease (ALD) consists of a broad spectrum of disorders, ranging from simple steatosis to alcoholic steatohepatitis and cirrhosis. Fatty liver develops in more than 90% of heavy drinkers, however only 30%-35% of them develop more advanced forms of ALD. Therefore, even if the current “gold standard” for the assessment of the stage of alcohol-related liver injury is histology, liver biopsy is not reasonable in all patients who present with ALD. Currently, although several non-invasive fibrosis markers have been suggested as alternatives to liver biopsy in patients with ALD, none has been sufficiently validated. As described in other liver disease, the diagnostic accuracy of such tests in ALD is acceptable for the diagnosis of significant fibrosis or cirrhosis but not for lesser fibrosis stages. Existing data suggest that the use of non-invasive tests could be tailored to first tier screening of patients at risk, in order to diagnose early patients with progressive liver disease and offer targeted interventions for the prevention of decompensation. We review these tests and critically appraise the existing evidence. PMID:26494961

  3. Future Imaging Alternatives: The Clinical Non-invasive Modalities in Diagnosis of Oral Squamous Cell Carcinoma (OSCC)

    PubMed Central

    Omar, Esam

    2015-01-01

    Background : Oral squamous cell carcinoma (OSCC) has a remarkably high incidence worldwide, and a fairly serious prognosis. This is encouraging further research into advanced technologies for non-invasive methods of making early diagnoses, ideally in primary care settings. Method : In this article, the available objective Non-imaging methods for diagnosing OSCC have been reviewed. MEDLINE, EMBASE, the Cochrane Library, and CINAHL have been searched for advanced technologies of non-invasive methods in diagnosis of OSCC, including oral brush biopsy, optical biopsy, saliva-based oral cancer diagnosis and others. Results : Toluidine blue, one of the oldest non-invasive methods for diagnosing OSCC, is unreliable because of its subjectivity, as it is dependent on the experience of the examiner. The diagnosis of Oral carcinoma by Oral brush biopsy with exfoliative cytology based on nano-bio-chip sensor platform shows 97–100% sensitivity and 86% specificity. Another promising non-invasive technique for OSCC diagnosis is saliva-based oral cancer diagnosis, which is an alternative to serum testing. Optical biopsy, which uses the technology of spectroscopy, can be used to detect changes at a sub-cellular level; thus, it provides information that may not be available with conventional histology with reliable sensitivity and specificity. Conclusion : It is clearly evident that screening and early effective detection of cancer and pre-cancerous lesions have the potential to reduce the morbidity and mortality of this disease. The imaging technologies are subjective procedures since all of them require interpretation and significantly affected by the examiner experience. These make further research for advanced objective procedures. Saliva-based oral cancer diagnosis and optical biopsy are promising objective non-invasive methods for diagnosing OSCC. They are easy to perform clinically at primary care set. They show promising pathways for future development of more effective

  4. Urine Exosomes for Non-Invasive Assessment of Gene Expression and Mutations of Prostate Cancer

    PubMed Central

    Sadeghi, Neda; Salazar, Guillermo; Shapiro, Edan; Ahn, Jennifer; Lipsky, Michael; Lin, James; Hruby, Greg W.; Badani, Ketan K.; Petrylak, Daniel P.; Benson, Mitchell C.; Donovan, Michael J.; Comper, Wayne D.; McKiernan, James M.

    2016-01-01

    Purpose The analysis of exosome/microvesicle (extracellular vesicles (EVs)) and the RNA packaged within them (exoRNA) has the potential to provide a non-invasive platform to detect and monitor disease related gene expression potentially in lieu of more invasive procedures such as biopsy. However, few studies have tested the diagnostic potential of EV analysis in humans. Experimental Design The ability of EV analysis to accurately reflect prostate tissue mRNA expression was examined by comparing urinary EV TMPRSS2:ERG exoRNA from pre-radical prostatectomy (RP) patients versus corresponding RP tissue in 21 patients. To examine the differential expression of TMPRSS2:ERG across patient groups a random urine sample was taken without prostate massage from a cohort of 207 men including prostate biopsy negative (Bx Neg, n = 39), prostate biopsy positive (Bx Pos, n = 47), post-radical prostatectomy (post-RP, n = 37), un-biopsied healthy age-matched men (No Bx, n = 44), and young male controls (Cont, n = 40). The use of EVs was also examined as a potential platform to non-invasively differentiate Bx Pos versus Bx Neg patients via the detection of known prostate cancer genes TMPRSS2:ERG, BIRC5, ERG, PCA3 and TMPRSS2. Results In this technical pilot study urinary EVs had a sensitivity: 81% (13/16), specificity: 80% (4/5) and an overall accuracy: 81% (17/21) for non-invasive detection of TMPRSS2:ERG versus RP tissue. The rate of TMPRSS2:ERG exoRNA detection was found to increase with age and the expression level correlated with Bx Pos status. Receiver operator characteristic analyses demonstrated that various cancer-related genes could differentiate Bx Pos from Bx Neg patients using exoRNA isolated from urinary EVs: BIRC5 (AUC 0.674 (CI:0.560–0.788), ERG (AUC 0.785 (CI:0.680–0.890), PCA3 (AUC 0.681 (CI:0.567–0.795), TMPRSS2:ERG (AUC 0.744 (CI:0.600–0.888), and TMPRSS2 (AUC 0.637 (CI:0.519–0.754). Conclusion This pilot study suggests that urinary EVs have the potential

  5. 77 FR 62417 - Annual Stress Test

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-15

    ... accept the CCAR and the Board of Governors' Board FR Y-14A form submissions for annual stress tests of a.... \\10\\ 77 FR 52718 (Aug. 30, 2012). Title of Information Collection: Annual Stress Test Reporting... NPR, with certain modifications as described further below. \\3\\ 77 FR 3166 (Jan. 23, 2012)....

  6. 77 FR 16484 - Annual Stress Test

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-21

    ... in the ] proposed rule.\\2\\ Please submit your comments using only one method. \\2\\ See 77 FR 3166... CORPORATION 12 CFR Part 325 RIN 3064-AD91 Annual Stress Test AGENCY: Federal Deposit Insurance Corporation... Corporation with total consolidated assets of more than $10 billion to conduct annual stress tests. \\1\\...

  7. Non-invasive health status detection system using Gabor filters based on facial block texture features.

    PubMed

    Shu, Ting; Zhang, Bob

    2015-04-01

    Blood tests allow doctors to check for certain diseases and conditions. However, using a syringe to extract the blood can be deemed invasive, slightly painful, and its analysis time consuming. In this paper, we propose a new non-invasive system to detect the health status (Healthy or Diseased) of an individual based on facial block texture features extracted using the Gabor filter. Our system first uses a non-invasive capture device to collect facial images. Next, four facial blocks are located on these images to represent them. Afterwards, each facial block is convolved with a Gabor filter bank to calculate its texture value. Classification is finally performed using K-Nearest Neighbor and Support Vector Machines via a Library for Support Vector Machines (with four kernel functions). The system was tested on a dataset consisting of 100 Healthy and 100 Diseased (with 13 forms of illnesses) samples. Experimental results show that the proposed system can detect the health status with an accuracy of 93 %, a sensitivity of 94 %, a specificity of 92 %, using a combination of the Gabor filters and facial blocks. PMID:25722202

  8. A servo-mechanical load frame for in situ, non-invasive, imaging of damage development

    SciTech Connect

    Breunig, T.M.; Nichols, M.C.; Gruver, J.S.; Kinney, J.H.; Haupt, D.L.

    1993-12-31

    The X-ray tomographic microscope (XTM) is a non-invasive X-ray imaging instrument for characterizing a material`s structure three-dimensionally with microscopic spatial resolution. The authors have designed a servomechanical load frame for use with the XTM which will allow imaging of samples under load. The load frame is capable of generating tensile or compressive forces up to 15.6 kN with a design system stiffness of 8.76 {times} 10{sup 8} N/m. The test specimen can be rotated through 360{degree}, without induced bending or torque. Torqueless motion is accomplished by synchronously rotating the grips on precision bearings with an accuracy of 0.01{degree}. With this load frame it will be possible, for the first time, to image the initiation and accumulation of internal damage (0.5 {mu}m detectability) formed in a 6 mm diameter specimen during the application of a monotonic or low frequency cyclic load. This is accomplished by interrupting the test and maintaining a fixed load (or displacement) during the non-invasive XTM data collection procedure. This paper describes the in situ load frame design and experimental capabilities. This system can be used to enhance the understanding of failure in composite materials.

  9. In vivo non-invasive multiphoton tomography of human skin

    NASA Astrophysics Data System (ADS)

    König, Karsten; Riemann, Iris; Ehlers, Alexander; Le Harzic, Ronan

    2005-10-01

    High resolution non-invasive 3D imaging devices are required to detect pathogenic microorganisms such as Anthrax spores, bacteria, viruses, fungi and chemical agents entering biological tissues such as the epidermis. Due to the low light penetration depth and the biodamage potential, ultraviolet light sources can not be employed to realize intratissue imaging of bio- and chemohazards. We report on the novel near infrared laser technology multiphoton tomography and the high resolution 4D imaging tool DermaInspect for non-invasive detection of intratissue agents and their influence on cellular metabolism based on multiphoton autofluorescence imaging (MAI) and second harmonic generation (SHG). Femtosecond laser pulses in the spectral range of 750 nm to 850 nm have been used to image in vivo human skin with subcellular spatial and picosecond temporal resolution. The non-linear induced autofluorescence of both, skin tissues and microorganisms, originates mainly from naturally endogenous fluorophores/protein structures like NAD(P)H, flavins, keratin, collagen, elastin, porphyrins and melanin. Bacteria emit in the blue/green spectral range due to NAD(P)H and flavoproteins and, in certain cases, in the red spectral range due to the biosynthesis of Zn-porphyrins, coproporphyrin and protoporphyrin. Collagen and exogenous non-centrosymmetric molecules can be detected by SHG signals. The system DermaInspect consists of a wavelength-tunable compact 80/90 MHz Ti:sapphire laser, a scan module with galvo scan mirrors, piezo-driven objective, fast photon detector and time-resolved single photon counting unit. It can be used to perform optical sectioning and 3D autofluorescence lifetime imaging (τ-mapping) with 1 μm spatial resolution and 270 ps temporal resolution. The parameter fluorescence lifetime depends on the type of fluorophore and its microenvironment and can be used to distinguish bio- and chemohazards from cellular background and to gain information for pathogen

  10. [Elemental research on intelligent non-invasive temporary pacemakers].

    PubMed

    Nie, Bang-ji; Xu, Long; Xin, Xue-gang; Wang, Cheng-lai; Wu, Min-shan

    2005-01-01

    Some research on intelligent non-invasive temporary pacemakers is introduced in this paper. An industrial computer, some IC chips and other elements are used to construct its hardware, and its software is in C++ language. The experimental device has some intelligent functions of recognizing some arrhythmia. The system has a pacemaker module and an ECG monitor module. Its software includes a main program, a RS-232C communication program, a printer VxD, a pacing control VxD and ECG signal pretreatment and recognizing program and so on. The pacing-generating circuit is employed to make the precision control of pacing current. The communication between industrial-computer system and ECG module is completed through the DLL. The real time processing of ECG signals is based on filter method for a higher recognizing ratio. The system calculates several parameters to recognize certain arrhythmia and uses MIT/BIH database to validate the reliability of ECG recognition. PMID:15875682

  11. Non-invasive neuroimaging using near-infrared light

    NASA Technical Reports Server (NTRS)

    Strangman, Gary; Boas, David A.; Sutton, Jeffrey P.

    2002-01-01

    This article reviews diffuse optical brain imaging, a technique that employs near-infrared light to non-invasively probe the brain for changes in parameters relating to brain function. We describe the general methodology, including types of measurements and instrumentation (including the tradeoffs inherent in the various instrument components), and the basic theory required to interpret the recorded data. A brief review of diffuse optical applications is included, with an emphasis on research that has been done with psychiatric populations. Finally, we discuss some practical issues and limitations that are relevant when conducting diffuse optical experiments. We find that, while diffuse optics can provide substantial advantages to the psychiatric researcher relative to the alternative brain imaging methods, the method remains substantially underutilized in this field.

  12. Non-invasive Respiratory Support and Severe Retinopathy of Prematurity.

    PubMed

    Raghu, Rahul; Fisher, Marilyn; Cerone, Jennifer; Barry, Gerard

    2016-01-01

    The authors describe two premature infants who developed stage 3, zone I retinopathy of prematurity (ROP) with plus disease in both eyes, despite limited exposure to supra-ambient oxygen. Both infants received noninvasive respiratory support for several weeks. Both cases are notable because the ROP was more posterior and aggressive than is typical for the gestational ages or birth weights. These cases are insufficient to make definitive conclusions regarding the factors that cause ROP. Further investigation is required to determine if there is an association between the use of non-invasive respiratory support, even in the absence of supra-ambient oxygen, and severe ROP development. [J Pediatr Ophthalmol Strabismus. 2016;53:e47-e50.]. PMID:27537495

  13. Eyeblink conditioning: a non-invasive biomarker for neurodevelopmental disorders.

    PubMed

    Reeb-Sutherland, Bethany C; Fox, Nathan A

    2015-02-01

    Eyeblink conditioning (EBC) is a classical conditioning paradigm typically used to study the underlying neural processes of learning and memory. EBC has a well-defined neural circuitry, is non-invasive, and can be employed in human infants shortly after birth making it an ideal tool to use in both developing and special populations. In addition, abnormalities in the cerebellum, a region of the brain highly involved in EBC, have been implicated in a number of neurodevelopmental disorders including autism spectrum disorders (ASDs). In the current paper, we review studies that have employed EBC as a biomarker for several neurodevelopmental disorders including fetal alcohol syndrome, Down syndrome, fragile X syndrome, attention deficit/hyperactivity disorder, dyslexia, specific language impairment, and schizophrenia. In addition, we discuss the benefits of using such a tool in individuals with ASD. PMID:23942847

  14. Hybrid CARS for Non-Invasive Blood Glucose Monitoring

    NASA Astrophysics Data System (ADS)

    Wang, Xi; Pestov, Dmitry; Zhang, Aihua; Murawski, Robert; Sokolov, Alexei; Welch, George; Laane, Jaan; Scully, Marlan

    2007-10-01

    We develop a spectroscopy technique that combines the advantages of both the frequency-resolved coherent anti-Stokes Raman scattering (CARS) and the time-resolved CARS. We use broadband preparation pulses to get an instantaneous coherent excitation of multiplex molecular vibration levels and subsequent optically shaped time-delayed narrowband probing pulse to detect these vibrations. This technique can suppress the nonresonant background and retrieve the molecular fingerprint signal efficiently and rapidly. We employ this technique to glucose detection, the final goal of which is accurate, non-invasive (i.e. painless) and continuous monitoring of blood glucose concentration in the Diabetes diagnosis to replace the current glucose measurement process, which requires painful fingerpricks and therefore cannot be performed more than a few times a day. We have gotten the CARS spectra of glucose aqueous solution down to 2 mM.

  15. Neurophotonics: non-invasive optical techniques for monitoring brain functions

    PubMed Central

    Torricelli, Alessandro; Contini, Davide; Mora, Alberto Dalla; Pifferi, Antonio; Re, Rebecca; Zucchelli, Lucia; Caffini, Matteo; Farina, Andrea; Spinelli, Lorenzo

    2014-01-01

    Summary The aim of this review is to present the state of the art of neurophotonics, a recently founded discipline lying at the interface between optics and neuroscience. While neurophotonics also includes invasive techniques for animal studies, in this review we focus only on the non-invasive methods that use near infrared light to probe functional activity in the brain, namely the fast optical signal, diffuse correlation spectroscopy, and functional near infrared spectroscopy methods. We also present an overview of the physical principles of light propagation in biological tissues, and of the main physiological sources of signal. Finally, we discuss the open issues in models, instrumentation, data analysis and clinical approaches. PMID:25764252

  16. Ultrahigh-speed non-invasive widefield angiography

    NASA Astrophysics Data System (ADS)

    Blatter, Cedric; Klein, Thomas; Grajciar, Branislav; Schmoll, Tilman; Wieser, Wolfgang; Andre, Raphael; Huber, Robert; Leitgeb, Rainer A.

    2012-07-01

    Retinal and choroidal vascular imaging is an important diagnostic benefit for ocular diseases such as age-related macular degeneration. The current gold standard for vessel visualization is fluorescence angiography. We present a potential non-invasive alternative to image blood vessels based on functional Fourier domain optical coherence tomography (OCT). For OCT to compete with the field of view and resolution of angiography while maintaining motion artifacts to a minimum, ultrahigh-speed imaging has to be introduced. We employ Fourier domain mode locking swept source technology that offers high quality imaging at an A-scan rate of up to 1.68 MHz. We present retinal angiogram over ˜48 deg acquired in a few seconds in a single recording without the need of image stitching. OCT at 1060 nm allows for high penetration in the choroid and efficient separate characterization of the retinal and choroidal vascularization.

  17. Non-invasive imaging of microcirculation: a technology review

    PubMed Central

    Eriksson, Sam; Nilsson, Jan; Sturesson, Christian

    2014-01-01

    Microcirculation plays a crucial role in physiological processes of tissue oxygenation and nutritional exchange. Measurement of microcirculation can be applied on many organs in various pathologies. In this paper we aim to review the technique of non-invasive methods for imaging of the microcirculation. Methods covered are: videomicroscopy techniques, laser Doppler perfusion imaging, and laser speckle contrast imaging. Videomicroscopy techniques, such as orthogonal polarization spectral imaging and sidestream dark-field imaging, provide a plentitude of information and offer direct visualization of the microcirculation but have the major drawback that they may give pressure artifacts. Both laser Doppler perfusion imaging and laser speckle contrast imaging allow non-contact measurements but have the disadvantage of their sensitivity to motion artifacts and that they are confined to relative measurement comparisons. Ideal would be a non-contact videomicroscopy method with fully automatic analysis software. PMID:25525397

  18. [Non-invasive brain stimulation for Parkinson's disease].

    PubMed

    Gajo, Gianandrea; Pollak, Pierre; Lüscher, Christian; Benninger, David

    2015-04-29

    Parkinson's disease (PD) is a major socio-economic burden increasing with the aging population. In advanced PD, the emergence of symptoms refractory to conventional therapy poses a therapeutic challenge. The success of deep brain stimulation (DBS) and advances in the understanding of the pathophysiology of PD have raised interest in non-invasive brain stimulation (NIBS) as an alternative therapeutic tool. NIBS could offer an alternative approach for patients at risk who are excluded from surgery and/or to treat refractory symptoms. The treatment of the freezing of gait, a major cause of disability and falls in PD patients, could be enhanced by transcranial direct current stimulation (tDCS). A therapeutic study is currently performed at the Department of Neurology at the CHUV. PMID:26062225

  19. Non-invasive assessment of skeletal muscle activity

    NASA Astrophysics Data System (ADS)

    Merletti, Roberto; Orizio, Claudio; di Prampero, Pietro E.; Tesch, Per

    2005-10-01

    After the first 3 years (2002-2005), the MAP project has made available: - systems fo electrodes, signal conditioning and digital processing for multichannel simultaneously-detected EMG and MMG as well as for simultaneous electrical stimulation and EMG detection with artifact cancellation. - innovative non-invasive techniques for the extraction of individual motor unit action potentials (MUAPS) and individual motor and MMG contributions from the surface EMG interference signal and the MMG signal. - processing techniques for extractions of indicators of progressive fatigue from the electrically-elicited (M-wave) EMG signal. - techniques for the analysis of dynamic multichannel EMG during cyclic or explosive exercise (in collaboration with project EXER/MAP-MED-027).

  20. Non-invasive ventilation in exacerbations of COPD

    PubMed Central

    Ambrosino, Nicolino; Vagheggini, Guido

    2007-01-01

    Randomized controlled trials have confirmed the evidence and helped to define when and where non invasive mechanical ventilation (NIV) should be the first line treatment of acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Noninvasive ventilation has its best indication in moderate-to-severe respiratory acidosis in patients with AECOPD. For this indication, studies conducted in ICU, in wards and in accident and emergency departments confirmed its effectiveness in preventing endotracheal intubation and reducing mortality. The skill of the health care team promotes proper NIV utilization and improves the patient outcome. Patients with severe acidosis or with altered levels of consciousness due to hypercapnic acute respiratory failure are exposed to high risk of NIV failure. In these patients a NIV trial may be attempted in closely monitored clinical settings where prompt endotracheal intubation may be assured. PMID:18268921

  1. Non-invasive Loading Model of Murine Osteoarthritis.

    PubMed

    Poulet, Blandine

    2016-07-01

    Osteoarthritis is the commonest degenerative joint disease, leading to joint pain and disability. The mouse has been the primary animal used for research, due to its size, relatively short lifespan, and the availability of genetically modified animals. Importantly, they show pathogenesis similar to osteoarthritis in humans. Mechanical loading is a major risk factor for osteoarthritis, and various mouse models have been developed to study the role and effects of mechanics on health and disease in various joints. This review describes the main mouse models used to non-invasively apply mechanical loads on joints. Most of the mouse models of osteoarthritis target the knee, including repetitive loading and joint injury such as ligament rupture, but a few studies have also characterised models for elbow, temporomandibular joint, and whole-body vibration spinal loading. These models are a great opportunity to dissect the influences of various types of mechanical input on joint health and disease. PMID:27177901

  2. Clinical non-invasive measurement of effective pulmonary capillary blood flow.

    PubMed

    Winter, S M

    1995-01-01

    Since traditional pulmonary function testing is centered on measurements of air flow and lung volume, a method to assess the pulmonary circulation might improve our ability to evaluate diseases that impact upon pulmonary hemodynamics. We have developed a PC based application that rapidly calculates pulmonary blood flow. Subjects rebreath a mixture of 10% argon and 3.5% freon for 20 seconds. Gas concentrations at the mouth are monitored by a clinical mass spectrometer and signals are acquired and processed with off-the-shelf hardware. To test the accuracy and reproducibility of this technique, patients with pulmonary artery catheters were assessed by standard thermodilution methods and the rebreathing test. Measurements using this non-invasive technology closely corelate with invasive thermodilution methods (r = 0.980) and show equivalent reproducibility (average standard error = 2.5%). This application of signal processing technology can extend the role of pulmonary function testing to include routine evaluation of the pulmonary circulation. PMID:8583166

  3. Continuous non-invasive finger blood pressure monitoring in children.

    PubMed

    Tanaka, H; Thulesius, O; Yamaguchi, H; Mino, M; Konishi, K

    1994-06-01

    We evaluated the performance of continuous non-invasive finger arterial pressure measurement using the volume-clamp technique (Finapres). This study was designed to compare finger arterial pressure with brachial blood pressure estimated by the auscultatory method in 217 children (90 boys and 127 girls) aged 4-16 years and in 38 adults (aged 18-45 years). Finger and brachial artery pressure readings were obtained consecutively from the ipsilateral side in the supine position. Finger arterial pressure waveforms were recorded in all children except 4 with small and thin fingers. There was good agreement for systolic pressure with only a slight underestimation of 1.9 mmHg and 5.1 mmHg lower for diastolic pressure. This difference most probably reflects inaccuracy of the auscultatory cuff method rather than an error in the Finapres. There was large inter-individual variability in Finapres recordings which might be due to differences in vasomotor tone, as demonstrated by systolic amplification in 5 patients with anorexia. However, Finapres showed a small within-subject variability (3.8 mmHg for systolic and 4.1 mmHg for diastolic pressure) determined in 5 patients during phenylephrine infusion, and as good reproducibility as the auscultatory method. These results suggest that finger arterial pressure measurement in children older than 6 years of age has similar accuracy as that in adults, and that this method is useful for clinical applications in children, especially for the non-invasive evaluation of autonomic control and cardiovascular reflexes involving transient and rapid blood pressure changes. PMID:7919764

  4. It Takes Two: Non Invasive Brain Stimulation Combined with Neurorehabilitation

    PubMed Central

    Page, Stephen J.; Cunningham, David A; Plow, Ela; Blazak, Brittani

    2015-01-01

    The goal of post-acute neurorehabilitation is to maximize patients' function, ideally by using surviving brain and central nervous system tissue when possible. Yet the structures incorporated into neurorehabilitative approaches often differ from this target, which may explain why efficacy of conventional clinical treatments targeting neurological impairments varies widely. Non-invasive brain stimulation such as with Transcranial Magnetic Stimulation (TMS) and transcranial direct current stimulation (tDCS) offers the possibility of directly targeting brain structures to facilitate or inhibit their activity so as to steer neural plasticity in recovery, and measure neuronal output and interactions for evaluating progress. Latest advances as stereotactic navigation and electric field modeling are enabling more precise targeting of patient's residual structures in diagnosis and therapy. Given its promise, this supplement illustrates the wide-ranging significance of TMS and tDCS in neurorehabilitation, including in stroke, pediatrics, traumatic brain injury, focal hand dystonia, neuropathic pain and spinal cord injury. TMS and tDCS are still not widely used and remain poorly understood in neurorehabilitation. Thus, the present supplement includes articles that highlight ready clinical application of these technologies, including their comparative diagnostic capabilities relative to neuroimaging, their therapeutic benefit, their optimal delivery, the stratification of likely responders, and the variable benefits associated with their clinical use due to interactions between pathophysiology and the innate reorganization of the patient's brain. Overall, the supplement concludes that whether provided in isolation or in combination, non-invasive brain stimulation with neuro-rehabilitation are synergistic in the potential to transform clinical practice. PMID:25813373

  5. Non-invasive assessment of microvascular and endothelial function.

    PubMed

    Cheng, Cynthia; Daskalakis, Constantine; Falkner, Bonita

    2013-01-01

    The authors have utilized capillaroscopy and forearm blood flow techniques to investigate the role of microvascular dysfunction in pathogenesis of cardiovascular disease. Capillaroscopy is a non-invasive, relatively inexpensive methodology for directly visualizing the microcirculation. Percent capillary recruitment is assessed by dividing the increase in capillary density induced by postocclusive reactive hyperemia (postocclusive reactive hyperemia capillary density minus baseline capillary density), by the maximal capillary density (observed during passive venous occlusion). Percent perfused capillaries represents the proportion of all capillaries present that are perfused (functionally active), and is calculated by dividing postocclusive reactive hyperemia capillary density by the maximal capillary density. Both percent capillary recruitment and percent perfused capillaries reflect the number of functional capillaries. The forearm blood flow (FBF) technique provides accepted non-invasive measures of endothelial function: The ratio FBF(max)/FBF(base) is computed as an estimate of vasodilation, by dividing the mean of the four FBF(max) values by the mean of the four FBFbase values. Forearm vascular resistance at maximal vasodilation (FVR(max)) is calculated as the mean arterial pressure (MAP) divided by FBF(max). Both the capillaroscopy and forearm techniques are readily acceptable to patients and can be learned quickly. The microvascular and endothelial function measures obtained using the methodologies described in this paper may have future utility in clinical patient cardiovascular risk-reduction strategies. As we have published reports demonstrating that microvascular and endothelial dysfunction are found in initial stages of hypertension including prehypertension, microvascular and endothelial function measures may eventually aid in early identification, risk-stratification and prevention of end-stage vascular pathology, with its potentially fatal

  6. Non-invasive glucose determination in the human eye

    NASA Astrophysics Data System (ADS)

    Schrader, Wolfgang; Meuer, Petra; Popp, Jürgen; Kiefer, Wolfgang; Menzebach, Johannes-Ulrich; Schrader, Bernhard

    2005-02-01

    For non-invasive in vivo glucose determinations by means of near-infrared spectroscopy, the anterior chamber of the human eye is a promising site. An optical set-up for the non-invasive glucose determination in the human eye precisely in the anterior chamber with a beam reflected from the surface of the eye lens is presented here. As the anterior chamber has a depth of 3.13±0.50 mm, the beam follows an optical path of 5.3-7.3 mm depending on the angle of incidence, which is individually constant. We will show that it is possible to acquire good concentration predictions for physiological glucose concentrations with such a long optical path. A chemometric study of NIR glucose spectra with concentrations of glucose in water of 10-350 mg/dL (0.56-1.94 mmol/L) resulted in a calibration model which was able to predict physiological glucose concentrations with a root mean square error of prediction RMSEPTest=15.41 mg/dL. The Clarke error grid diagram shows that the model performs well according to medical impact. Using a first in vivo set-up, the precision is not sufficient for a reliable prediction of glucose concentration, especially due to the flickering of the patient's eye and the low reflectivity of the eye lens. Therefore, we have designed a new in vivo set-up: a prototype for a self-monitoring device with controlled geometry and laser radiation at several distinct wavelengths instead of the halogen lamp as light source. This allows a far higher signal/noise ratio under much better reproducible geometrical conditions and at the same time a much smaller necessary light flux.

  7. Novel non invasive diagnostic strategies in bladder cancer

    PubMed Central

    TRUTA, ANAMARIA; POPON, TUDOR ADRIAN HODOR; SARACI, GEORGE; GHERVAN, LIVIU; POP, IOAN VICTOR

    2016-01-01

    Bladder cancer is one of the most commonly diagnosed malignancies worldwide, derived from the urothelium of the urinary bladder and defined by long asymptomatic and atypical clinical picture. Its complex etiopathogenesis is dependent on numerous risk factors that can be divided into three distinct categories: genetic and molecular abnormalities, chemical or environmental exposure and previous genitourinary disorders and family history of different malignancies. Various genetic polymorphisms and microRNA might represent useful diagnostic or prognostic biomarkers. Genetic and molecular abnormalities - risk factors are represented by miRNA or genetic polymorphisms proved to be part of bladder carcinogenesis such as: genetic mutations of oncogenes TP53, Ras, Rb1 or p21 oncoproteins, cyclin D or genetic polymorhisms of XPD,ERCC1, CYP1B1, NQO1C609T, MDM2SNP309, CHEK2, ERCC6, NRF2, NQO1Pro187Ser polymorphism and microRNA (miR-143, −145, −222, −210, −10b, 576-3p). The aim of our article is to highlight the most recent acquisitions via molecular biomarkers (miRNAs and genetic polymorphisms) involved in bladder cancer in order to provide early diagnosis, precise therapy according to the molecular profile of bladder tumors, as well as to improve clinical outcome, survival rates and life quality of oncological patients. These molecular biomarkers play a key role in bladder carcinogenesis, clinical evolution, prognosis and therapeutic response and explain the molecular mechanisms involved in bladder carcinogenesis; they can also be selected as therapeutic targets in developing novel therapeutic strategies in bladder malignancies. Moreover, the purpose in defining these molecular non invasive biomarkers is also to develop non invasive screening programs in bladder malignancies with the result of decreasing bladder cancer incidence in risk population. PMID:27152066

  8. Analysis of uncultured extremophilic snow algae by non-invasive single cell Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Beer, Thomas; Tanaka, Zuki; Netzter, Nathan; Rothschild, Lynn J.; Chen, Bin

    2011-10-01

    The study of life in extreme environments is a critical component of Astrobiology. But many of the so-called "extremophiles" are not readily cultivatable and therefore difficult to study under laboratory conditions. An example of such an extremophile is the snow alga Chlamydomonas cd. nivalis which expresses still unstudied secondary metabolites within its life cycle. In this paper, we present the first time the non-invasive single cell Raman spectroscopy of the life cycle dependent metabolite composition of C. nivalis. These secondary metabolites are likely related to the adaptation of C. nivalis to various stress factors. Normalized carotenoid Raman spectra intensities reveal characteristic ratio differences that allow identification of life cycle stages and putative secondary metabolites.

  9. High Definition Oscillometry: Non-invasive Blood Pressure Measurement and Pulse Wave Analysis.

    PubMed

    Egner, Beate

    2015-01-01

    Non-invasive monitoring of blood pressure has become increasingly important in research. High-Definition Oscillometry (HDO) delivers not only accurate, reproducible and thus reliable blood pressure but also visualises the pulse waves on screen. This allows for on-screen feedback in real time on data validity but even more on additional parameters like systemic vascular resistance (SVR), stroke volume (SV), stroke volume variances (SVV), rhythm and dysrhythmia. Since complex information on drug effects are delivered within a short period of time, almost stress-free and visible in real time, it makes HDO a valuable technology in safety pharmacology and toxicology within a variety of fields like but not limited to cardiovascular, renal or metabolic research. PMID:26091643

  10. Residual Stress Testing of Outer 3013 Containers

    SciTech Connect

    Dunn, K.

    2004-02-12

    A Gas Tungsten Arc Welded (GTAW) outer 3013 container and a laser welded outer 3013 container have been tested for residual stresses according to the American Society for Testing Materials (ASTM) Standard G-36-94 [1]. This ASTM standard describes a procedure for conducting stress-corrosion cracking tests in boiling magnesium chloride (MgCl2) solution. Container sections in both the as-fabricated condition as well as the closure welded condition were evaluated. Significantly large residual stresses were observed in the bottom half of the as-fabricated container, a result of the base to can fabrication weld because through wall cracks were observed perpendicular to the weld. This observation indicates that regardless of the closure weld technique, sufficient residual stresses exist in the as-fabricated container to provide the stress necessary for stress corrosion cracking of the container, at the base fabrication weld. Additionally, sufficiently high residual stresses were observed in both the lid and the body of the GTAW as well as the laser closure welded containers. The stresses are oriented perpendicular to the closure weld in both the container lid and the container body. Although the boiling MgCl2 test is not a quantitative test, a comparison of the test results from the closure welds shows that there are noticeably more through wall cracks in the laser closure welded container than in the GTAW closure welded container.