Identification of an optimal prolactin threshold to determine prolactinoma size using receiver operating characteristic analysis.

Prolactinomas represent the most common type of secretory pituitary neoplasms, with a therapeutic management that varies considerably based on tumour size and degree of hyperprolactinemia. The aim of the current study was to evaluate the relationship between serum prolactin (PRL) concentrations and prolactinoma size, and to determine a cut-off PRL value that could differentiate micro- from macro-prolactinomas. A retrospective cohort study of 114 patients diagnosed with prolactinomas between 2007 and 2017 was conducted. All patients underwent gadolinium enhanced pituitary MRI and receiver operating characteristic (ROC) analyses were performed. 51.8% of patients in this study were men, with a mean age at the time of diagnosis of 42.32 ± 15.04 years. 48.2% of the total cohort were found to have microadenomas. Baseline serum PRL concentrations were strongly correlated to tumour dimension (r = 0.750, p = 0.001). When performing the ROC curve analysis, the area under the curve was 0.976, indicating an excellent accuracy of the diagnostic method. For a value of 204 µg/L (4338 mU/L), sensitivity and specificity were calculated at 0.932 and 0.891, respectively. When a cut off value of 204 µg/L (4338 mU/L) was used, specificity was 93.2%, and sensitivity 89.1%, acceptable to reliably differentiate between micro- and macro- adenomas.

Probing the architecture of visual number sense with parietal tRNS.

Theoretical accounts of the visual number sense (VNS), i.e., an ability to discriminate approximate numerosities, remain controversial. A proposal that the VNS represents a process of numerosity extraction, leading to an abstract number representation in the brain, has been challenged by the view that the VNS is non-numerical in its essence and amounts to a weighted integration of continuous magnitude features that typically change with numerosity. In the present study, using two-alternative forced-choice paradigm, we aimed to distinguish between these proposals by probing brain areas implicated in the VNS with transcranial random noise stimulation (tRNS). We generated predictions for the stimulation-related changes in behavioural performance which would be compatible with alternative mechanisms proposed for the VNS. First, we investigated whether the superior parietal (SP) area hosts a numerosity code or whether its function is to modulate weighting of continuous stimulus features. We predicted that stimulation may affect the VNS precision if the SP role is representational, and that it may affect decision threshold if its role is modulatory. Second, we investigated whether the intraparietal (IP) area hosts a numerosity code independently of codes for continuous stimulus features, or whether their representations overlap. If the numerosity code is independent, we predicted that IP stimulation may improve the VNS but not continuous magnitude judgements. Our results were consistent with the hypotheses of a modulatory role of the SP and of the independence of the numerosity code in the IP, whereby suggesting that VNS is an emergent abstract property based on continuous magnitude statistics.

Detection of anti-IgA antibodies using the particle gel immunoassay: a rapid test for increased patient safety.

BACKGROUND: Patient safety is a major issue in transfusion medicine and commands continuous efforts to develop valid control methods aiming to avoid serious transfusion-related complications. Anti-IgA antibodies can cause anaphylactic transfusion reactions in IgA-deficient individuals. Since standard quantitative methods for anti-IgA measurement require considerable time to be performed, in an emergency situation it can be a challenge to prevent or to quickly interpret and manage acute transfusion reactions suspected to be a consequence of anti-IgA. The purpose of this study was to test and validate at our transfusion centre a rapid assay for the identification of patients with anti-IgA antibodies. MATERIALS AND METHODS: Forty-six samples (6 from healthy controls and 40 from IgA-deficient patients) were collected. Sera were analysed blindly by three different clinical laboratory technologists using two DiaMed particle gel immunoassays (ID-PaGIA) for IgA deficiency and for antibodies to IgA. The results were subsequently checked with the results of a fluorescence enzyme immunoassay conducted in the reference immunology laboratory. RESULTS: The ID-PaGIA had a sensitivity of 91.7% and specificity of 97.1% for the IgA deficiency test. With regards to the detection of anti-IgA antibodies, the sensitivity was 89.3% and the specificity 100%. The reproducibility of the test was 100%. DISCUSSION: The ID-PaGIA screening assays are suitable for the investigation of transfusion-related anaphylactic reactions in a routine blood bank laboratory. Although the gel card technique does not quantify the level of anti-IgA antibodies, it is readily available, providing an effective and simple method for the diagnosis of anti-IgA related anaphylaxis and guidance for the appropriate transfusion practice in an emergency.