Validation of two point-of-care tests against standard lab measures of NO in saliva and in serum

Saliva nitrite is higher in male children with autism spectrum disorder and positively correlated with serum nitrate

Objectives

Nitric oxide (NO) plays a vital role in neurological development. As an easily accessible and non-invasive fluid, saliva hasn't been evaluated for nitrite among children with autism spectrum disorder (ASD). This study aims to quantify saliva nitrite and explore its relation with serum NO.

Methods

Saliva sampling and pretreatment methods were optimized, followed by NO measurement via chemiluminescence for 126 ASD children and 129 normally developing children (ND).

Results

In the ASD group, saliva nitrite was significantly higher than that in the ND, with concentrations of 4.97 ± 3.77 μM and 2.66 ± 2.07 μM (p < 0.0001), respectively. Positive correlation was observed between saliva NO₂⁻ and serum NO₃⁻ in ASD children, which didn't exist in the ND group. Male children in the ASD group had significantly higher NO than that in boys of the ND group, without significant difference between girls in both groups. Correlation was not found between saliva or serum NO and severity of these ASD children.

Discussion

It is reported for the first time that saliva nitrite was positively correlated with serum nitrate in ASD children, with significantly higher NO only in autistic boys. Non-invasive saliva might serve as a predictor of health status of ASD children.

Neither a Multi-Ingredient Pre-Workout Supplement nor Caffeine Were Effective at Improving Markers of Blood Flow or Upper-Body Resistance Exercise Performance

Few studies have measured the effects of multi-ingredient pre-workout supplements on blood flow or heart rate variability or have compared a multi-ingredient pre-workout supplement to a matched single ingredient. This study examined the effects of a multi-ingredient pre-workout supplement, an equivalent amount of caffeine, and placebo on markers of resistance training performance, blood flow, blood pressure, and heart rate variability. The study utilized a randomized, placebo-controlled, repeated-measures, crossover design. Twelve resistance-trained males (22.75 ± 4.51 yrs; 183.4 ± 7.37 cm; 91.05 ± 17.77 kg) completed the study. Resistance exercise performance was defined as total work performed during elbow flexion and extension on an isokinetic dynamometer. Blood flow was calculated using time-averaged mean velocity and blood vessel diameter of the right brachial artery, which were measured via Doppler ultrasound. Heart rate was recorded using an electrocardiogram. Neither a multi-ingredient pre-workout supplement nor caffeine alone improved upper-body resistance exercise performance or markers of blood flow relative to placebo. No differences in heart rate variability were observed across treatments. A multi-ingredient pre-workout supplement was not effective at improving performance or blood flow and did not alter autonomic nervous system function.

The oral nitrate-reducing capacity correlates with peak power output and peak oxygen uptake in healthy humans

Interest in inorganic nitrate and nitrite has grown substantially over the past decade as research has revealed the role of these anions in enhancing nitric oxide (NO) availability through an oral pathway. Nitrite synthesis in the mouth seems to be an important mechanism to feed the circulatory system with this anion. This is interesting since greater plasma nitrite concentration has been associated with better fitness levels in humans, but this question has not been investigated in relation to salivary nitrite concentration. Additionally, no previous study has investigated the oral nitrate-reducing capacity in regards to peak oxygen uptake (VO_2peak) or peak power output (W_peak) in humans. Thus, the main goal of this study was to investigate whether salivary nitrite and nitrate concentration and the oral nitrate-reducing capacity were associated with VO2_peak and W_peak in healthy humans. Fifty individuals (22 females and 28 males; 38.8 ± 14.3 years/old; BMI = 22.8 ± 3.9) performed a graded exercise test on a cycle ergometer to assess their VO_2peak and W_peak. Unstimulated salivary samples were taken before and 20 min after exercise to measure nitrate/nitrite, pH and lactate. The oral nitrate-reducing capacity was also assessed in 25 subjects before and after exercise. Oral nitrate-reducing capacity was positively associated with W_peak (r_s = 0.64; P = 0.001) and the VO_2peak (r_s = 0.54; P = 0.005). Similar correlations were found when these variables were analysed after exercise. In addition, a significant decrease in salivary pH (pre: 7.28 ± 0.361; post-exercise: 7.16 ± 0.33; P = 0.003) accompanied by an increase of salivary lactate (pre: 0.17 ± 0.14 mmol/L; post-exercise: 0.48 ± 0.38; P < 0.001) was found after exercise. However, these changes did not have any impact on salivary nitrate/nitrite concentration and the oral nitrate-reducing capacity after exercise. In conclusion, this is the first evidence showing a link between the oral nitrate-reducing capacity and markers of aerobic fitness levels in healthy humans.

Influence of dental prosthetics technology on the dynamics of early predictors of destructive inflammatory process in the periimplant zone

An objective assessment of the morphofunctional characteristics of the state of soft tissues and bone structures adjacent to the dental implant allows to control the dynamics of the processes of osseointegration in the jaw-dental implant system. The aim of the work was to investigate the level of the β-CrossLaps, С-reactive protein (CRP), osteocalcin markers after orthopedic treatment of patients using dental implant supported advanced dental restoration technologies, to perform a biochemical analysis of the oral fluid of patients after restoration using dental implants and new two-part dental implants. In patients of the index group (52 people), the removable prostheses with metal frame and fixing elements or the commercially available dental implant supported removable prostheses were installed. For the patients of the control group (12 people), the commercially available dental implant supported removable prostheses of acrylic plastics were constructed. For all the patients after 6 months the level of β-CrossLaps, CRP, osteocalcin markers in the oral fluid was analysed. In patients of the index group, the average content of β-CrossLaps was 0.0126 ± 0.002 ng/ml, in the control group it was 0.0147 ± 0.002 ng/ml. The average content of the CRP in patients of the index group was 0.358 ± 0.019 mg/l, in patients of the control group it was 0.78 ± 0.01 mg/l. In patients of the index group, the average content of osteocalcin was 1.46 ± 0.25 ng/ml, in the control group it was 1.98 ± 0.31 ng/ml. It has been shown that biochemical markers of the oral fluid can be used to predict complications after the dental implants installation. Restoration with two-part dental implants of modern design is associated with fewer complications.