490 research outputs found

    Use of novel serum markers in clinical follow-up of Sertoli-Leydig cell turnours

    Get PDF
    Background: Sertoli-Leyclig cell tumours of the ovary account for only 0.2% of malignant ovarian tumours. Two-thirds of all patients become apparent due to the tumour's hormone production. Methods: A 41-year-old patient (gravida 4, para 4) presented with dyspnoea, enlarged abdominal girth and melaena. Diagnostic imaging was suspicious for an ovarian cancer. The standard tumour marker for ovarian cancer (CA 125) was elevated to 984 U/mL. Results: Surgical exploration of the abdomen revealed a mouldering tumour of both adnexes extending to the level of the navel. Frozen sections showed an undifferentiated carcinoma of unknown origin. Radical surgery was performed. The final histological report described a malignant sex-cord stroma tumour, a Sertoli-Leydig cell tumour, emanating from both ovaries. Analysis of preoperative blood serum showed elevated levels of CYFRA 21-1 (10.4 ng/mL), neuron-specific enolase (36.2 ng/mL), oestradiol (485 pg/mL) and CA-125 (984 U/mL). Adjuvant chemotherapy and regional hyperthermia were performed due to the malignant potential and incomplete resection of the tumour. Conclusions: Undifferentiated Sertoli-Leyclig cell tumours show a poor clinical course. As only two-thirds of patients with this rare disease present with elevated hormone levels, new markers deserve further investigation to offer more specific, individualised tumour monitoring

    Folate catabolites in spot urine as non-invasive biomarkers of folate status during habitual intake and folic acid supplementation.

    Get PDF
    Folate status, as reflected by red blood cell (RCF) and plasma folates (PF), is related to health and disease risk. Folate degradation products para-aminobenzoylglutamate (pABG) and para-acetamidobenzoylglutamate (apABG) in 24 hour urine have recently been shown to correlate with blood folate. Since blood sampling and collection of 24 hour urine are cumbersome, we investigated whether the determination of urinary folate catabolites in fasted spot urine is a suitable non-invasive biomarker for folate status in subjects before and during folic acid supplementation. Immediate effects of oral folic acid bolus intake on urinary folate catabolites were assessed in a short-term pre-study. In the main study we included 53 healthy men. Of these, 29 were selected for a 12 week folic acid supplementation (400 µg). Blood, 24 hour and spot urine were collected at baseline and after 6 and 12 weeks and PF, RCF, urinary apABG and pABG were determined. Intake of a 400 µg folic acid bolus resulted in immediate increase of urinary catabolites. In the main study pABG and apABG concentrations in spot urine correlated well with their excretion in 24 hour urine. In healthy men consuming habitual diet, pABG showed closer correlation with PF (rs = 0.676) and RCF (rs = 0.649) than apABG (rs = 0.264, ns and 0.543). Supplementation led to significantly increased folate in plasma and red cells as well as elevated urinary folate catabolites, while only pABG correlated significantly with PF (rs = 0.574) after 12 weeks. Quantification of folate catabolites in fasted spot urine seems suitable as a non-invasive alternative to blood or 24 hour urine analysis for evaluation of folate status in populations consuming habitual diet. In non-steady-state conditions (folic acid supplementation) correlations between folate marker (RCF, PF, urinary catabolites) decrease due to differing kinetics

    Constitutive activity of NF-kappa B in myeloid cells drives pathogenicity of monocytes and macrophages during autoimmune neuroinflammation

    Get PDF
    The NF-κB/REL-family of transcription factors plays a central role in coordinating the expression of a wide variety of genes controlling immune responses including autoimmunity of the central nervous system (CNS). The inactive form of NF-κB consists of a heterodimer which is complexed with its inhibitor, IκB. Conditional knockout-mice for IκBα in myeloid cells (lysMCreIκBαfl/fl) have been generated and are characterized by a constitutive activation of NF-κB proteins allowing the study of this transcription factor in myelin-oligodendrocyte-glycoprotein induced experimental autoimmune encephalomyelitis (MOG-EAE), a well established experimental model for autoimmune demyelination of the CNS

    Reinforcement learning or active inference?

    Get PDF
    This paper questions the need for reinforcement learning or control theory when optimising behaviour. We show that it is fairly simple to teach an agent complicated and adaptive behaviours using a free-energy formulation of perception. In this formulation, agents adjust their internal states and sampling of the environment to minimize their free-energy. Such agents learn causal structure in the environment and sample it in an adaptive and self-supervised fashion. This results in behavioural policies that reproduce those optimised by reinforcement learning and dynamic programming. Critically, we do not need to invoke the notion of reward, value or utility. We illustrate these points by solving a benchmark problem in dynamic programming; namely the mountain-car problem, using active perception or inference under the free-energy principle. The ensuing proof-of-concept may be important because the free-energy formulation furnishes a unified account of both action and perception and may speak to a reappraisal of the role of dopamine in the brain

    Motor expertise modulates the unconscious processing of human body postures

    Get PDF
    Little is known about the cognitive background of unconscious visuomotor control of complex sports movements. Therefore, we investigated the extent to which novices and skilled high-jump athletes are able to identify visually presented body postures of the high jump unconsciously. We also asked whether or not the manner of processing differs (qualitatively or quantitatively) between these groups as a function of their motor expertise. A priming experiment with not consciously perceivable stimuli was designed to determine whether subliminal priming of movement phases (same vs. different movement phases) or temporal order (i.e. natural vs. reversed movement order) affects target processing. Participants had to decide which phase of the high jump (approach vs. flight phase) a target photograph was taken from. We found a main effect of temporal order for skilled athletes, that is, faster reaction times for prime-target pairs that reflected the natural movement order as opposed to the reversed movement order. This result indicates that temporal-order information pertaining to the domain of expertise plays a critical role in athletes’ perceptual capacities. For novices, data analyses revealed an interaction between temporal order and movement phases. That is, only the reversed movement order of flight-approach pictures increased processing time. Taken together, the results suggest that the structure of cognitive movement representation modulates unconscious processing of movement pictures and points to a functional role of motor representations in visual perception

    Evaluation of a combined thiourea and hydrogen peroxide regimen to bleach bloodstained teeth

    Get PDF
    The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.Background: Current techniques for intra-coronal bleaching of stained root-filled teeth employ oxidative bleaching with hydrogen peroxide. However, concern over the potential for invasive cervical resorption following the use of hydrogen peroxide has been expressed by many researchers, and recommendations have been made to limit the use of this agent. A reductive-oxidative bleaching process using a thiourea and hydrogen peroxide regimen is proposed as an effective and safer bleaching combination. The efficacy of this novel bleaching regimen is evaluated in this study. Methods: The study involved a quantitative and qualitative spectrophotometric assessment of the ability of two amine (bleaching) agents, aqueous thiourea and acidified thiourea, to alter the absorption spectra of haemoglobin and methaemoglobin compared to hydrogen peroxide. In addition, extracted premolar teeth discoloured by blood were subjected to different bleaching regimens using amine reducing agents and hydrogen peroxide. The change in the colour of the bloodstained dentine samples was measured at each stage of the bleaching process with a Photometer and Reflectance Densitometer. Comparisons of different treatments were made using a method of least significant difference and/or analysis of variance. Results: Spectrophotometric studies showed that acidified thiourea solution greatly reduced the colour of the haemoglobin and methaemoglobin in the visible range (330–760nm). Aqueous thiourea had no effect on the presence of haemoglobin and methaemoglobin. Reflection Densitometer and Photometer scores indicate that the greatest bleaching effect was achieved by the combined acidified thiourea and hydrogen peroxide regimen. Conclusion: The recognition that bleaching discoloured teeth is a chemical process, which can be achieved by both reducing and oxidizing agents, offers the possibility of developing new and safer clinical bleaching protocols. It is concluded that the bleaching regimen which employs the sequential use of 0.1M acidified thiourea and 30% w/v hydrogen peroxide is as effective at bleaching bloodstained dentine as 30% w/v hydrogen peroxide alone. However, the addition of thiourea to the bleaching regimen has the potential benefit of reducing the level of damaging hydroxyl radicals and achieving a safer bleaching process.K. Maiolo, PD Marin, TE Bridges and GS Heithersa

    Impact of concomitant thyroid pathology on preoperative workup for primary hyperparathyroidism

    Get PDF
    BACKGROUND: The former standard surgical treatment in patients with primary hyperparathyroidism (pHPT) has been bilateral cervical exploration. New localization techniques and the possibility of intraoperative measurement of intact parathormone (iPTH) permit a focused, minimally invasive parathyroidectomy (MIP). The introduction of MIP without complete neck exploration leads to the potential risk of missing thyroid pathology. The aim of the present study is to evaluate the value of MIP in respect to coexisting thyroid findings and their impact on preoperative workup for primary hyperparathyroidism. METHODS: This is a prospective study including 30 consecutive patients with pHPT (median age 65 years; 17 females, 13 males). In all patients preoperative localization was performed by ultrasonography and 99m Tc-MIBI scintigraphy- Intraoperative iPTH monitoring was routinely done. RESULTS: Ten patients (33%) had a concurrent thyroid finding requiring additional thyroid surgery, and two patients (7%) with negative localization results underwent bilateral neck exploration. Therefore, MIP was attempted in 18 (60%) patients. The conversion rate to a four gland exploration was 6% (1/18). The sensitivities of 99m Tc-MIBI scanning and ultrasonography were 83.3% and 76.6%, respectively. The respective accuracy rates were 83.3% and 76.6%. Of note, the combination of the two modalities did not improve the sensitivity and accuracy in our patient population. During a median follow-up of 40 months, none of the patients developed persistent or recurrent hypocalcaemia, resulting in a 100% cure rate. CONCLUSION: Coexisting thyroid pathology is relatively frequent in patients with pHPT in our region. Among patients having pHPT without any thyroid pathology, the adenoma localization is correct with either ultrasonography or 99m Tc-MIBI scintigraphy in the majority of cases. MIP with iPTH monitoring are highly successful in this group of patients and this operative technique should be the method of choice

    A chronology of global air quality

    Get PDF
    Air pollution has been recognized as a threat to human health since the time of Hippocrates, ca 400 BC. Successive written accounts of air pollution occur in different countries through the following two millennia until measurements, from the eighteenth century onwards, show the growing scale of poor air quality in urban centres and close to industry, and the chemical characteristics of the gases and particulate matter. The industrial revolution accelerated both the magnitude of emissions of the primary pollutants and the geographical spread of contributing countries as highly polluted cities became the defining issue, culminating with the great smog of London in 1952. Europe and North America dominated emissions and suffered the majority of adverse effects until the latter decades of the twentieth century, by which time the transboundary issues of acid rain, forest decline and ground-level ozone became the main environmental and political air quality issues. As controls on emissions of sulfur and nitrogen oxides (SO2 and NOx) began to take effect in Europe and North America, emissions in East and South Asia grew strongly and dominated global emissions by the early years of the twenty-first century. The effects of air quality on human health had also returned to the top of the priorities by 2000 as new epidemiological evidence emerged. By this time, extensive networks of surface measurements and satellite remote sensing provided global measurements of both primary and secondary pollutants. Global emissions of SO2 and NOx peaked, respectively, in ca 1990 and 2018 and have since declined to 2020 as a result of widespread emission controls. By contrast, with a lack of actions to abate ammonia, global emissions have continued to grow

    Rethinking ‘Rational Imitation’ in 14-Month-Old Infants: A Perceptual Distraction Approach

    Get PDF
    In their widely noticed study, Gergely, Bekkering, and Király (2002) showed that 14-month-old infants imitated an unusual action only if the model freely chose to perform this action and not if the choice of the action could be ascribed to external constraints. They attributed this kind of selective imitation to the infants' capacity of understanding the principle of rational action. In the current paper, we present evidence that a simpler approach of perceptual distraction may be more appropriate to explain their results. When we manipulated the saliency of context stimuli in the two original conditions, the results were exactly opposite to what rational imitation predicts. Based on these findings, we reject the claim that the notion of rational action plays a key role in selective imitation in 14-month-olds

    Artificial Gravity Reveals that Economy of Action Determines the Stability of Sensorimotor Coordination

    Get PDF
    Background: When we move along in time with a piece of music, we synchronise the downward phase of our gesture with the beat. While it is easy to demonstrate this tendency, there is considerable debate as to its neural origins. It may have a structural basis, whereby the gravitational field acts as an orientation reference that biases the formulation of motor commands. Alternatively, it may be functional, and related to the economy with which motion assisted by gravity can be generated by the motor system
    corecore