Low sAA Levels Research Articles

Validation of an automated immunoturbidimetric assay for feline serum amyloid A

BackgroundSerum Amyloid A (SAA) is a major acute phase protein in cats, increasing rapidly in response to various inflammatory diseases. An automated latex-enhanced immunoturbidimetric assay for human SAA (LZ-SAA, Eiken), previously validated for use in cats, has had further major modification (VET-SAA, Eiken) for specific use in veterinary diagnostic laboratories but has yet to be validated in cats.ResultsIntra-assay and inter-assay CVs for the VET-SAA assay ranged from 1.88–3.57% and 3.98–6.74%, respectively. Linearity under dilution was acceptable with no prozone effect observed. Limit of detection was 1.65 mg/L and limit of quantification was 6 mg/L. Haemoglobin and triglyceride showed no adverse interference, but bilirubin produced positive bias in samples with low SAA. Comparison with the LZ-SAA assay showed significant correlation with proportional bias increasing as SAA concentration increased, likely related to differing calibration standards. SAA was significantly higher in patients with inflammatory disease compared with non-inflammatory disease, and in patients with moderate to highly elevated α1-AGP compared with patients with normal α1-AGP. Improvement of the assay range may be required to fully evaluate differences between disease groups at low SAA levels. Based on ROC curve analysis, at a cut-off point of 20.1 mg/L the VET-SAA assay discriminated between inflammatory and non-inflammatory disease with sensitivity of 0.93 and specificity of 0.99.ConclusionsThe automated VET-SAA assay is a robust, precise, and accurate method for measurement of feline SAA which can clearly identify patients with inflammatory disease. It should be a valuable biomarker for use in feline medicine.

Predictive value of serum amyloid a levels for requirement of concomitant methotrexate in tocilizumab initiation: A post hoc analysis of the SURPRISE study

Objectives: To identify predictive factors for remission by tocilizumab monotherapy in rheumatoid arthritis (RA) patients.Methods: This is a post hoc analysis of the SURPRISE study, a 2-year randomized, controlled study comparing the efficacy of tocilizumab with (ADD-ON) and without methotrexate (SWITCH). The primary endpoint was DAS28-ESR remission (<2.6) at week 24. The change in modified total Sharp score from baseline to week 52 (ΔmTSS/year) was also assessed as an endpoint. The effect of clinical parameters at baseline on remission was estimated by logistic regression analysis.Results: In SWITCH (n = 96), CRP, SAA, RF, and DAS28 at baseline showed predictive value for DAS28 remission in unadjusted analysis. Adjusted analysis confirmed SAA and DAS28 as predictive factors, with SAA having the highest value (ROC-AUC = 0.731). Furthermore, structural remission (ΔmTSS/year ≤ 0.5) rate was significantly higher in patients with SAA of < 50.0 μg/mL than other patients. In contrast, in ADD-ON (n = 98), only DAS28 showed predictive value for DAS28 remission. In patients with SAA < 50.0 μg/mL, both DAS28 remission and structural remission rate were comparable between SWITCH and ADD-ON.Conclusion: RA patients with low SAA levels at baseline may benefit similarly from tocilizumab with and without methotrexate.Trial registration number: NCT01120366.

Effect of saliva collection methods and oral hygiene on salivary biomarkers

The aim of this study was to evaluate the influence of unstimulated and stimulated saliva collection methods, as well as tooth brushing, on the secretion rate of salivary total protein, nitrite, total antioxidant capacity and alpha-amylase. Saliva of 14 healthy individuals were collected with stimulation using Salivette®, Parafilm® and chewing gum and without stimulation from spit with and without fluid accumulation, before and after oral hygiene. Total protein, nitrite, total antioxidant capacity and alpha-amylase concentration (sAA) were evaluated. The collection of saliva stimulated with Parafilm® and chewing gum increased the salivary flow (1.5 ± 0.4 and 3.4 ± 0.7 mL/min, respectively) and the secretion rate of salivary total protein (1.0 ± 0.2 and 2.3 ± 0.5 mg/min, respectively). Also, chewing gum increases the salivary nitrite secretion (213 ± 58 nmol/min) and total antioxidant capacity (410 ± 47 nmol trolox eq/min). Interestingly, the unstimulated method without saliva accumulation prior to collection resulted in low sAA levels (23,531 ± 7979 pixel density). Furthermore, oral hygiene decreased salivary flow (1.3 ± 0.5 to 1.0 ± 0.4 mL/min), reduced the secretion rate of total protein (1.0 ± 0.5 to 0.6 ± 0.2 mg/min, p < .05) and increased sAA (13,159 ± 7114 to 20,075 ± 25,656 pixel density, p < .05). The type of stimulation can activate autonomous receptors responsible for the secretion and composition of saliva. Therefore, the evaluation of saliva collection methods and oral hygiene on salivary biomarkers is important for understanding and standardizing variations in salivary composition to strengthen the use of saliva as a diagnostic fluid.

Diurnal salivary alpha-amylase dynamics among dementia family caregivers.

The study examined diurnal regulation of salivary alpha-amylase (sAA) in association with daily stressors, adult day services (ADS) use, and other caregiving characteristics. A sample of 165 family caregivers of individuals with dementia (IWD) completed an 8-day diary study. Caregivers provided 5 saliva samples across the 8 days. On some days, caregivers provided all or most of the care. On other days, their relative attended ADS for part of the day. A 3-level unconditional linear spline model was fit to describe the typical sAA diurnal rhythms. Predictors were then added to the unconditional model to test the hypotheses on ADS use and daily stressors. Daily ADS use did not have an effect on diurnal sAA regulation. However, controlling for daily ADS use, greater ADS use over the 8 days was associated with a more prominent rise between 30 min after wake-up and before lunch, and a more prominent decline between before lunch and late afternoon. Fewer ADS days were associated with a more flattened sAA diurnal rhythm. Additionally, greater daily care-related stressor exposures had a within-person association with lower sAA levels in the late afternoon. Care-related stressor exposures had significant within- and between-person associations with sAA diurnal slopes. Furthermore, daily positive experiences had a significant between-person association with sAA diurnal slopes. Caring for a disabled family member may heighten the vulnerability to potential physiological conditions. Respite from care stressors from ADS use may have some biobehavioral benefits on sAA regulations. (PsycINFO Database Record

Clinical, Functional and Structural Studies of Humans and Merino Sheep Corneas from Two Different Regions of Argentina

Objective: The purpose of our work was to study and compare the cornea and tear film of people and sheep inhabiting in a region of Argentinean Patagonia (PATG), and in a geographically and climatically different region in the Argentinean Pampa (CAPT). Methods: Using cross sectional study, corneal examinations were performed in people and Merino sheep inhabiting PATG and CAPT regions, respectively. All people completed a questionnaire related to work activity, diet, and the use of hats or sunglasses during their life. Eyes from all participants were examined with a portable handheld slitlamp biomicroscope (BM) to evaluate corneal appearance, epithelium integrity, and transparency. Later on, in a subgroup of participants we studied eyeblinking frequency (EBF), ocular surface staining (FS), breakup time (BUT), Schirmer Tear Test (STT), corneal structure using confocal laser scanning microscopy (CLSM) and light microscopy (LM), and concentrations of serum ascorbate (sAA). Results: BM studies revealed numerous cases of Climatic Droplets Keratopathy (CDK) only in people inhabiting the PATG region. CLSM studies confirmed typical punctiform deposits at the Bowman´s layer in CDK patients living in that region. CLSM images from sheep did not show any abnormalities at the Bowman´s layer but exhibited small hyper reflective dots at the epithelium only in animals pasturing in the PATG region. FS and EBF mean values were significant higher in sheep grazing in the PATG region (p <0.05). No differences were found in surface eye tests when people from both regions were analyzed. Low sAA levels were found only in CDK people living in PATG region. Conclusions: CDK is a multi-factorial disease not only associated to harsh climate. We provide data that low sAA levels can play a role in its genesis in Patagonia patients’... Sheep pasturing in this region with a high prevalence of CDK have high concentration of sAA and did not present any sub epithelial corneal abnormalities.

Climatic Droplet Keratopathy in Argentina: Involvement of Environmental Agents in Its Genesis Which Would Open the Prospect for New Therapeutic Interventions.

Climatic droplet keratopathy (CDK) is a degenerative corneal disease of unknown etiology. We described CDK for the first time in Latin America in the Argentinean Patagonia (El Cuy). A deeper knowledge of CDK pathogenic mechanisms will provide new therapeutic strategies. For that reason we investigated the prevalence of CDK in El Cuy and its existence in other 3 provinces with similar climate. Patients eyes were examined, habits throughout lives were inquired about, and serum ascorbate (sAA) was determined. All individuals work outdoors for most of the day. All regions had normal O3 levels. Individuals from regions 1, 2, and 3 had very low consumption of vegetables/fruits and low sAA levels. Conversely, region 4 individuals had balanced diet and higher sAA concentrations. CDK was only found in region 3 where individuals had partial deficiency of sAA and did not use eye protection. No CDK was found in regions 1 and 2 where individuals had similar work activities and dietary habits to those in region 3 but wear eye protection. No disease was found in region 4 where individuals work outdoors, have balanced diet, and use eye protection. To summarize, the CDK existence was related not only to climate but also to the dietary habits and lack of protection from sunlight.

Pupil and salivary indicators of autonomic dysfunction in autism spectrum disorder

Dysregulated tonic pupil size has been reported in autism spectrum disorder (ASD). Among the possible sources of this dysregulation are disruptions in the feedback loop between norepinephrine (NE) and hypothalamic systems. In the current study, we examined afternoon levels of salivary alpha-amylase (sAA, a putative correlate of NE) and cortisol (used to assess stress-based responses) in two independent samples of children with ASD. We found a larger pupil size and lower sAA levels in ASD, compared to typical and clinical age-matched controls. This was substantiated at the individual level, as sAA levels were strongly correlated with tonic pupil size. Relatively little diurnal variation in sAA taken in the home environment in the ASD group was also observed, while typical controls showed a significant linear increase throughout the day. Results are discussed in terms of potential early biomarkers and the elucidation of underlying neural dysfunction in ASD.

Salivary alpha amylase and cortisol levels in children with global developmental delay and their relation with the expectation of dental care and behavior during the intervention

The purpose of this study was to analyze the alpha-amylase (sAA) and cortisol levels in children with Global developmental delay (GDD) before and after dental treatment and its association with the children's behavior during treatment. The morning salivary cortisol levels and activity of sAA of 33 children with GDD were evaluated before and after dental treatment and were compared to 19 healthy children. The behavior of children with GDD during dental care was assessed by the Frankl scale. Children with GDD showed lower levels of sAA activity than healthy children, but this result was not significant. The salivary cortisol levels were similar between GDD and healthy children. GDD children showed increased levels of sAA (but not cortisol) prior to the dental treatment as compared to the post-treatment phase. GDD children who showed less favorable behavior during dental care had higher levels of sAA and salivary cortisol than GDD children with more favorable behavior, but only the sAA results were significant. In conclusion, GDD children show hyperactivity of the SNS-axis in anticipation of dental treatment which indicates the need for strategies to reduce their anxiety levels before and during dental care.

Interparental aggression and parent–adolescent salivary alpha amylase symmetry

The present study examined salivary alpha amylase (sAA), a putative marker of adrenergic activity, in family members engaging in family conflict discussions. We examined symmetry among family members' sAA levels at baseline and in response to a conflict discussion. The relation between a history of interparental aggression on parent–adolescent sAA symmetry also was examined. Participants were 62 families with a mother, father, and biological child age 13–18 ( n = 29 girls). After engaging in a relaxation procedure, families participated in a 15-minute triadic family conflict discussion. Participants provided saliva samples at post-relaxation/pre-discussion, immediately post-discussion, and at 10 and 20 min post-discussion. Participants also reported on interparental physical aggression during the previous year. Across the sample we found evidence of symmetry between mothers' and adolescents' sAA levels at baseline and around the discussion. Interparental aggression was associated with lower sAA levels among fathers. Interparental aggression also affected patterns of parent–child sAA response symmetry such that families reporting interparental aggression exhibited greater father–adolescent sAA symmetry than did those with no reports of interparental aggression. Among families with no interparental aggression history, we found consistent mother–adolescent symmetry. These differences suggest different patterns of parent–adolescent physiological attunement among families with interparental aggression.

Effects of the Naked Neck (Na) Gene on the Sulfur-Containing Amino Acid Requirements of Broilers

Full-sibling normal (na/na) and naked neck (Na/na) chickens were fed from 28 to 42 d of age on one of five diets with different SAA contents (from 5.4 to 7.0 g/kg). The experimental diets were made by adding DL-methionine to a well-balanced corn, soybean, and cornstarch diet containing 5.4 g SAA/kg and 161 g crude protein/kg. Dietary SAA influenced the growth rate of both genotypes similarly. There were no significant differences (P > 0.125) in body weight gain due to genetics or a diet by genetics interaction. Body weight gains were maximized at 6.24 ± 0.45 (R2 = 0.171) and 5.96 ± 0.52 g/kg SAA (R2 = 0.107) for the na/na and Na/na stocks, respectively. There was a significant SAA by genotype interaction for feed efficiency: the na/na birds were more efficient at low SAA levels, but the Na/na birds were more efficient at high SAA levels. Feather weight gain increased in a linear manner with increasing dietary SAA and was greater in na/na than Na/na birds with high dietary SAA concentrations. Abdominal fat decreased with increasing dietary SAA; and although the Na/na birds had significantly more abdominal fat than their na/na siblings (P = 0.049), on average the difference was small and complicated by differences in body weight. Analysis of covariance showed (a significant interaction) that the relationship between abdominal fat and body weight was different for the na/na and Na/na chickens. Although the shape of the response curves of na/na and Na/na chickens to dietary SAA are different, the quantitative requirements are very similar during the growing period.