Left atrial receptor inhibition of cardiac efferent vagal activity in the dog

1. The tachycardia produced by atrial receptor stimulation has been reported to be 'solely' due to an increased sympathetic activity, but not inhibitable by propranolol. We examined the effect of left atrial balloon inflation in chloralose-anaesthetized dogs on heart rate with and without propranolol (1.0 mg/kg) and on the activity in single cardiac efferent fibres of the vagus nerve. 2. Propranolol reduced the cardiac response to balloon inflation by one-third, but did not abolish the tachycardia. Efferent cardiac vagal activity was 3.8 +/- 0.4 spikes/s and 2.3 +/- 0.7 spikes/s prior to and during balloon inflation respectively. 3. It was concluded that the left atrial receptors produce a tachycardia by decreasing cardiac parasympathetic and increasing sympathetic efferent activities.

Assessment of clinical laboratory techniques in the measurement of oxygen saturation in whole blood

The accuracy and advantages of determining percentage of hemoglobin oxygen saturation of whole blood by advanced instruments of oximetry, gas chromatography, and the computation of oxygen saturation from pO2 and pH data are compared with the Van Slyke-Neill manometric method. It was found that oximetry is extremely fast, less expensive, and more accurate than in the past, the apparatus requires little training to operate and has diminutive service maintenance. The gas chromatograph proved to be highly accurate and could serve as a standard calibration check method in place of the more time-consuming Van Slyke-Neill apparatus for oximetry and pO2 and pH electrode instrumentation. Computation of O2 saturation from pO2 and pH data also proved to be accurate, confirming that this method is more useful during cardiac surgery because it can provide additional acid-base information. In the low oxygen saturation range (less than 60%), all three methods proved to be of similar sensitivity.

Memory performance on the ChAMP in autism spectrum disorder with and without attention-deficit/hyperactivity disorder

Memory difficulties have been identified in youth with neurodevelopmental conditions including autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). The Child and Adolescent Memory Profile (ChAMP) is a newer memory measure with a burgeoning research base. This study seeks to explore memory performance on the Lists and Objects subtests of the ChAMP in a clinical sample of those with ASD with/without co-occurring ADHD. Participants were 146 youth referred for a neuropsychological evaluation (M age = 11.8 years; 76.03% male) diagnosed with ASD (N = 92 with ADHD, N = 54 without). Logistic regression (p = .393) indicated ChAMP performance is not predictive of whether the ASD group had co-occurring ADHD indicating there is no additive effect on memory. Compared to the ChAMP examiner's manual ASD sample, this study sample performed significantly better (p <.001) on all ChAMP measures. While the ChAMP is sensitive to memory difficulties in neurodevelopmental disorders, as indicated by the performance of the manual sample, the ASD sample of the manual may differ from other ASD samples. There were no differences between verbal and visual memory performance across the present study's sample.

Assessing opacification and flow rates of contrast media in neonate and pediatric cardiac catheterization

The accuracy and advantages of determining the flow rates of opaque media in catheters used in the infant and pediatric age group is essential in obtaining proper opacification with minimum toxicity to the patient. Flow rates expressed as cubic centimeters per second and grams of iodine per second were determined by using representative standard pediatric catheters in various sizes and lengths. Three representative opaque medias were used to determine these findings. Although present-day injector pumps are frequently calibrated in delivery rates, they cannot be applied directly to the cardiac catheters usually used with infants and small children.

Feasibility of using a biofeedback device in mindfulness training - a pilot randomized controlled trial

Background

Stress can negatively impact an individual’s health and well-being and high levels of stress are noted to exist among college students today. While traditional treatment methods are plagued with stigma and transfer problems, newly developed wearable biofeedback devices may offer unexplored possibilities. Although these products are becoming commonplace and inexpensive, scientific evidence of the effectiveness of these products is scarce and their feasibility within research contexts are relatively unexplored. Conversely, companies are not required, and possibly reluctant, to release information on the efficacy of these products against their claims. Thus, in the present pilot, we assess the feasibility of using a real-time respiratory-based biofeedback device in preparation for a larger study. Our main aims were to assess device-adherence and collaboration with the company that develops and sells the device.

Method

Data were collected from 39 college students who self-identified as experiencing chronic stress at a Southwestern university in the USA. Students were randomized into either a mindfulness-only control group without a biofeedback device (n = 21), or an experimental group with biofeedback device (n = 18). Both groups received mindfulness meditation training. Pre-test and post-test procedures were conducted 2 weeks apart. Further, both participant compliance and company compliance were assessed and collaboration with the company was evaluated.

Results

Participant device-adherence as well as the company’s collaboration necessary for a full-scale study was determined to be low. This may also have affected our results which showed a strong main effect for time for all outcome variables, suggesting all groups showed improvement in their levels of stress after the intervention period. No group by time effects were identified, however, indicating no added benefit of the biofeedback device.

Conclusions

Our findings suggest feasibility of future studies requires full collaboration and detailed and agreed upon data sharing procedures with the biofeedback company. The particular device under investigation added no value to the intervention outcomes and it was not feasible to continue a larger-scale study. Further, as the technology sector is innovating faster than it can validate products, we urge for open science collaborations between public and private sectors to properly develop evidence-based regulations that can withstand technological innovation while maintaining product quality, safety, and effectiveness.

Trial registration

NCT02837016. Registered 19 July 2016.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00807-1.