Association of salivary alpha-amylase and salivary flow rate with working memory functioning in healthy children.

The aim of this study was to examine the association between auditory and visual working memory (WM) performance and salivary alpha-amylase (sAA) and salivary flow rate (SFR) in a sample of 63 children (38 boys). WM was assessed by means of WISC-V subtests: four auditory subtests (Digit Span and Letter-Number Sequencing) and one visual subtest (Picture Span). SAA activity, output, and SFR were measured at baseline (10 min prior to testing), one minute prior to testing, one minute after the end of the auditory WM subtests and one minute after the end of the visual WM subtest. Our statistical analyses showed an association among SAA activity, output and SFR levels and the number of recalled digits in the last attempt score in Letter-Number Sequencing subtest. Specifically, our results showed that working performance in this task was associated with a concurrent decrease in SFR (r(63) = -0.423, p < .05). This salivary measure was the best predictor of this specific index of working memory performance (ß = -0.423, p < .05). These results show that the changes in SFR, which represents changes in parasympathetic tone, could be employed in future studies as a noninvasive marker of working memory performance in child studies.

Application of κ free light chains in cerebrospinal fluid as a biomarker in multiple sclerosis diagnosis: development of a diagnosis algorithm.

BACKGROUND: The determination of κ free light chains (KFLC) in cerebrospinal fluid (CSF) by nephelometry is a feasible alternative to immunoglobulin G oligoclonal bands (OCB) in the evaluation of intrathecal synthesis of immunoglobulin in multiple sclerosis (MS) and other demyelinating diseases. The aim of this study was to assess the diagnostic value of KFLC and its inclusion in a procedure algorithm along with OCB interpretation. METHODS: A cross-sectional study, which included 123 patients with a CSF OCB request, was carried out. Isoelectric focusing followed by immunofixation was used to detect OCB, and nephelometry was used to analyze KFLC. The KFLC index was calculated using CSF/serum quotient of KFLC and albumin. The KFLC index was compared with MS diagnosis to find the optimal cutoff. It was obtained from the receiver operating characteristic (ROC) curves and the Youden method. RESULTS: The CSF KFLC median was 1.66 mg/L in the MS group, whereas in other central nervous system diseases, KFLC showed generally no or only moderate increase in CSF (median 0.10 mg/L). KFLC index showed a significant difference between groups. ROC analysis for CSF KFLC concentration, and KFLC indexes were 91.88% and 93.94%, respectively. The best cutoff for the KFLC index was 2.91 for MS diagnosis (sensitivity: 83.78%; specificity: 85.88%). The proposed algorithm showed high sensitivity (89.19%) and specificity (84.71%). CONCLUSIONS: KFLC determination is rapid and automatized, but it has no higher sensitivity and specificity than OCB in MS diagnosis. Nevertheless, when used in screening, it could reduce the number of manual OCB tests.

Fear of falling among elderly patients with dizziness and syncope in a tilt setting.

The objectives of this study were to assess the prevalence of fear of falling (FOF) among patients over age 60 with dizziness, falls, or syncope; and to analyze risk factors associated with FOF, including data from the tilt table test. This study included 200 older patients referred to a geriatric outpatient clinic specializing in dizziness, falls, and syncope. The primary outcome measure was the proportion of patients who experienced FOF (yes vs. no) and whether FOF restricted leaving home alone or performing activities of daily living. FOF occurred in 50 per cent of patients in this population. Among these, 44 per cent gave up going out alone and 10 per cent stopped doing basic activities of daily living. Beyond age 75, FOF was associated with recurrent dizziness, depression, and symptoms on standing, but not prior falls.

Association between Salivary Alpha-Amylase and Executive Functioning in Healthy Children.

The main aim of this study was to confirm the relationship between executive performance and salivary alpha-amylase (SAA) activity in a sample of 64 healthy children (39 boys), and compare it to the association of SAA output and salivary flow rate (SFR). Executive functioning was assessed via fluency, trail-making, rings and inhibition tasks from the Batería de Evaluación Neuropsicológica de la Función Ejecutiva en Niños [Battery of Neuropsychological Assessment for Executive Function in Children] (ENFEN), merged into an ENFEN total score. SAA activity, output, and SFR were measured at baseline, one minute before, and one minute after the end of a neuropsychological testing session. Our results confirmed a direct, linear and significant association between SAA activity and executive functioning, r(64) = .351, p < .05, and extended it to SAA output, r(64) =.431, p < .05. The mean level of SAA output was the best predictor of executive functioning (ß = .431, p < .05) and explained 18.2 % of the variance in ENFEN total score. In sum, and compared to SAA activity, measuring SAA output may be a more precise and indirect marker to assess executive functioning in children.

Cognitive performance and morning levels of salivary cortisol and alpha-amylase in children reporting high vs. low daily stress perception.

The aim of the present study was to assess the effects of daily stress perception on cognitive performance and morning basal salivary cortisol and alpha-amylase levels in healthy children aged 9-12. Participants were classified by whether they had low daily perceived stress (LPS, n = 27) or a high daily perceived stress (HPS, n = 26) using the Children Daily Stress Inventory (CDSI). Salivary cortisol and alpha-amylase were measured at awakening and 30 minutes later. Cognitive performance was assessed using the Cognitive Drug Research assessment system. The HPS group exhibited significantly poorer scores on speed of memory (p < .05) and continuity of attention (p < .05) relative to the LPS group. The HPS group also showed significantly lower morning cortisol levels at awakening and at +30 minutes measures in comparison with the LPS group (p < .05), and mean morning cortisol levels were negatively correlated with speed of memory (p < .05) in the 53 participants. No significant differences were observed between both groups in alpha-amylase levels. These findings suggest that daily perceived stress in children may impoverish cognitive performance via its modulating effects on the HPA axis activity.

Mid-regional pro-adrenomedullin as prognostic biomarker in septic shock.

BACKGROUND: The aim was to ascertain the prognostic value of mid-regional pro-adrenomedullin (MR-proADM), measured within 24 hours from the onset of septic shock (SS). METHODS: We performed a prospective, observational study on all patients admitted to our hospital's Intensive Care Unit with SS over a one year period from January to December 2011 to examine the outcomes in 100 consecutive SS cases. Demographic data and severity score (APACHEII and SOFA) were recorded. MR-proADM, C-reactive protein and procalcitonin were measured within the first 24 hours from SS onset. The outcome variable studied was 28-day mortality. Data were evaluated with non-parametric statistics bivariant and multivariate analyses for survival analysis. RESULTS: In patients who died within 28 days (36%), MR-proADM, Lactate, APACHE II as well as SOFA were significantly higher compared with survivors. MR-proADM showed the best association with 28-day mortality, as well as a prognostic value (logrank test: P=0.0012). Statistical significance was also seen in the Cox regression analysis (P=0.0004) for all patients with a Relative Risk of 1.26 times that of the baseline for each mmol/L of increase in MR-proADM. CONCLUSIONS: In our study MR-proADM levels measured on admission correlates with 28-day mortality in patients with septic shock.

Salivary alpha-amylase changes promoted by sustained exposure to affective pictures.

We studied the changes in salivary alpha-amylase (sAA) and other psychophysiological indices (heart rate, skin conductance, and corrugator supercilii activity) elicited by sustained exposure to affective pictures. Thirty-nine subjects viewed five blocks of pictures depicting mutilations, human attack, neutral scenes, sport/adventure, and erotica. Each block comprised 12 pictures of the same content. Saliva samples were collected before and after each block of pictures. The results showed that mutilation pictures promoted the greatest increase in sAA activity and output, as well as greater corrugator supercilii activity than pleasant pictures. Skin conductance response did not differ among high arousal picture contents. Changes in sAA varied with the affective valence but not with the arousal ratings of the pictures. Our results point to sAA as an index directly related to the unpleasantness elicited by sustained exposure to affective stimuli.