The Role of Trees in Winter Air Purification on Children’s Routes to School

Air pollution is now considered to be the world’s largest environmental health threat, accounting for millions of deaths globally each year. The social group that is particularly exposed to the harmful effects of air pollution is children. Their vulnerability results from higher breathing frequency and being subject to concentration peaks just above the ground. The negative effects of ambient particulate matter also depend on the time of exposure. A daily route to school can constitute an important component of children’s physical activity, but air pollution can pose a threat to their health. Numerous studies have proved that high loads of PM can be effectively reduced by vegetation. Little is known, however, on whether vegetation can also reduce PM during leaf dormancy. In this study we investigated the role of trees in air purification during the leafless period in children’s routes to selected schools located in Warsaw during winter. The results obtained show a weak impact of the tree canopy in winter.

The Effect of Caffeine on the Heart Rate Variability in Newborns

Background: Neonatal apnoea has been treated with caffeine, which affects the central nervous and the cardiovascular system. Heart rate variability (HRV) reflects the activity of the autonomic nervous system (ANS), and might be used as a measure of ANS maturation in newborns. We aimed to establish the effect of caffeine on HRV in newborns, and saught for a potential correlation between HRV and the postmenstrual age.Methods: In 25 newborns, hospitalized due to apnoea and treated with caffeine (2.5 mg/kg), we assessed breathing frequency, arterial oxygen saturation, body temperature, and the heart rate while they were sleeping in two bed positions (0° tilt and 30° head-up tilt). We assessed HRV by spectral analysis using fast Fourier transformation. The same protocol was reapplied 100 hours after caffeine withdrawal to assess control parameters.Results: Caffeine increased breathing frequency (p=0.023), but did not affect any other parameter assessed including HRV. We established a positive correlation between postmenstrual age and HRV during treatment with caffeine in a 30° head-up tilt position (total power: p=0.044; low-frequency band: p=0.039).Conclusions: Apparently, the maintenance dose of caffeine is too low to affect heart rate and HRV. A positive correlation between postmenstrual age and HRV might reflect maturation of ANS.Trial registration: NCT04869176, retrospectively registered on April 27th 2021.

STRESS RESPONSES OF THREE SPECIES OF CYPRINID: COMMON CARP (Cyprinus carpio), BONYLIP BARB (Osteochilus hasselty), AND TORSORO (Tor soro) SUBJECTED TO OXYGEN DEPLETION

Fish in stressed conditions will show symptoms of a decreased physiological function. These symptoms include changes in the respiration system (gills, breathing frequency) and blood hemoglobin. Cyprinid fish are active fish that require high oxygen levels. In a minimum oxygen condition, cyprinid fish are easy to get stressed. Despite the extensive literature on cyprinid biology, comparison of declined physiological functions due to oxygen depletion in cyprinid are few and far between. The purpose of this study was to determine the physiological reactions and organ responses of three species of Cyprinidae, common carp (Cyprinus carpio), nilem carp (Osteochilus hasselti), and Torsoro carp (Tor soro) challenged to oxygen depletion. The study was conducted using 18 fishes for each species with an average body weight of 48.11 ± 4.24 g. Oxygen depletion challenge was done by placing the test fish in closed and non-aerated aquaria (40 cm x 20 cm x 20 cm). The dissolved oxygen level in each aquarium was measured every 30 minutes. Fish breathing frequency was calculated by the frequencies of mouth movement every 30 minutes. Histological examination of gills and blood was taken from healthy fish (at the beginning of treatment) and at LC50 (lethal concentration). The results showed that oxygen depletion reduced blood hemoglobin levels down to 5.1 ± 1.4 gram%, 3.3 ± 1.15 gram%, and 1.5 ± 0.71 gram% for goldfish, nilem, and torsoro, respectively. The respiratory rate varied from normal to depleted conditions. When depletion occurred, the respiratory rate increased and decreased again when the fish started to get weak. In normal conditions, the breathing frequency of goldfish was 60 beats/minute, nilem was 108 ± 20.8 beats/minute, and Tor soro was 144 ± 31.7 beats/minute. The highest respiration frequency occurred in tor soro fish in the 150th minute with a value of 216 ± 0.0 beats/minute. The fastest mortality at LC50% occurred in torsoro at 245.00 ± 17.32 minutes.

Comparison of Two Metabolic Simulators Used for Gas Exchange Verification in Cardiopulmonary Exercise Test Carts

IntroductionMetabolic simulators (MS) produce simulated human breaths for the purpose of verification of cardiopulmonary exercise test (CPET) equipment. MS should produce consistent identical breaths with known CO2 and O2 gas concentrations over a range of breath rates and tidal volumes. Reliability of a CPET metabolic cart depends on ongoing quality control and maintenance of the device, including intermittent verification with a MS. We compared two MS devices against two standard CPET systems.MethodsThe Vacumed 17056 (Vacumetrics, Ventura, CA) and Relitech (Relitech Systems BV, Nijkerk, The Netherlands) were used with two standard metabolic carts (Vyntus CPX and Vyntus ONE, both Vyaire Medical, Mettawa, IL, United States). Tidal volume (VT) was set at 2 and 3 L and breathing frequency ranged from 20 to 80 breaths per minute for each MS. At each set point, we measured three sets of 40 breaths. Primary outcome parameters collected were VT, oxygen consumption (v.O2), carbon dioxide production (v.CO2), and respiratory exchange ratio (RER).ResultsVT, RER, v.O2, and v.CO2 results as obtained from both MS were all within the limits of acceptability, at both tidal volume settings, and all ventilatory rates. No significant trends were identified for either MS device. The Relitech MS produced tidal volumes that were closer to the target VT for both CPET carts at both VT and all rates, but the results of both MS were within acceptable ranges.ConclusionVerification of CPET equipment using either the VM or RT metabolic simulator, producing highly accurate and predictable simulated breaths of known composition, enabling CPET laboratory managers to rely on subject test data obtained during cardiopulmonary exercise testing.

Impact of wearing a surgical and cloth mask during cycle exercise

We sought to determine the impact of wearing cloth or surgical masks on the cardiopulmonary responses to moderate-intensity exercise. Twelve subjects (n=5 females) completed three, 8-min cycling trials while breathing through a: non-rebreathing valve (laboratory control), cloth, or surgical mask. Heart rate (HR), oxyhemoglobin saturation (SpO2), breathing frequency (Fb), mouth pressure, partial pressure of end-tidal carbon dioxide (PetCO2) and oxygen (PetO2), dyspnea, were measured throughout exercise. A subset of n=6 subjects completed an additional exercise bout without a mask (ecological control). There were no differences in Fb, HR or SpO2 across conditions (all p>0.05). Compared to the laboratory control (0.9±0.7cmH2O[mean±SD]), mouth pressure swings were greater with the surgical mask (4.7±0.9; p<0.0001), but similar with the cloth mask (3.6±4.8cmH2O; p=0.66). Wearing a cloth mask decreased PetO2 (-3.5±3.7mmHg) and increased PetCO2 (+2.0±1.3mmHg) relative to the ecological control (both p<0.05). There were no differences in end-tidal gases between mask conditions and laboratory control (both p>0.05). Dyspnea was similar between the control conditions and the surgical mask (p>0.05) but was greater with the cloth mask compared to laboratory (+0.9±1.2) and ecological (+1.5±1.3) control conditions (both p<0.05). Wearing a mask during short-term moderate-intensity exercise may increase dyspnea but has minimal impact on the cardiopulmonary response. Novelty bullets: • Wearing surgical or cloth masks during exercise has no impact on breathing frequency, tidal volume, oxygenation, heart rate • However, there are some changes in inspired and expired gas fractions that are physiologically irrelevant. • In young healthy individuals, wearing surgical or cloth masks during submaximal exercise has few physiological consequences.

Phase- and State-Dependent Modulation of Breathing Pattern by preBötzinger Complex Somatostatin Expressing Neurons

As neuronal subtypes are increasingly categorized, delineating their functional role is paramount. The preBötzinger Complex (preBötC) subpopulation expressing the neuropeptide somatostatin (SST) is classified as mostly excitatory, inspiratory-modulated and not rhythmogenic. We further characterized their phenotypic identity; 87% were glutamatergic and the balance were glycinergic and/or GABAergic. We then used optogenetics to investigate their modulatory role in both anesthetized and freely moving mice. In anesthetized mice, short photostimulation (100 ms) of preBötC SST+ neurons modulated breathing-related variables in a combinatory phase- and state-dependent manner; changes in inspiratory duration, inspiratory peak amplitude (Amp), and phase were different at higher (≥2.5 Hz) vs. lower (<2.5 Hz) breathing frequency. Moreover, we observed a biphasic effect of photostimulation during expiration that is probabilistic, i.e., photostimulation given at the same phase in consecutive cycles can evoke opposite responses (lengthening vs. shortening of the phase). This unexpected probabilistic state- and phase-dependent responses to photostimulation exposed properties of the preBötC that were not predicted and cannot be readily accounted for in current models of preBötC pattern generation. In freely moving mice, prolonged photostimulation decreased f in normoxia, hypoxia, or hypercapnia, and increased Amp and produced a phase advance, which was similar to the results in anesthetized mice when f≥2.5 Hz. We conclude that preBötC SST+ neurons are a key mediator of the extraordinary and essential lability of breathing pattern.Key points summaryWe transfected preBötzinger Complex (preBötC) somatostatin-expressing (SST+) neurons, which modulate respiratory pattern, but are not rhythmogenic, with channelrhodopsin to investigate phase- and state-dependent modulation of breathing pattern in anesthetized and freely behaving mice in normoxia, hypoxia, and hypercapnia.In anesthetized mice, photostimulation of preBötC SST+ neurons during inspiration increased inspiratory duration and amplitude regardless of baseline breathing frequency, f.In anesthetized mice with low f (<2.5 Hz), photostimulation of preBötC SST+ neurons during expiration evoked either phase advance or phase delay, whereas in anesthetized mice with high f (≥2.5 Hz) and in freely behaving mice in normoxia, hypoxia, or hypercapnia, photostimulation always evoked phase advance.Phase- and state-dependency is a function of overall breathing network excitability.The f-dependent probabilistic modulation of breathing pattern by preBötC SST+ neurons was unexpected, requiring reconsideration of current models of preBötC function, which neither predict nor can readily account for such responses.

Effect of Pursed Lip Breathing Exercise on Respiratory Frequency Among Tuberculosis Patients at Balai Besar Kesehatan Paru Masyarakat Makassar

Pulmonary tuberculosis patients tend to experience high respiratory frequency. The breathing muscles in patients who experience shortness of breath can work when respiratory abnormalities occur. This study aims to determine the effect of Pursed Lip Breathing Exercise on Respiratory Frequency among Pulmonary Tuberculosis Patients. The design in this study is a Quasi-Experimental design with a two-group approach, and a pre-test and post-test design. The sample is comprised of 20 patients in the Balai Besar Kesehatan Paru Masyarakat Makassar between 6 January – 8 February 2020. The instruments used in this study were the standard operational procedure of the Pursed Lip Breathing Exercise and the Respiratory Frequency Observation Sheet to determine the changes in the respiratory frequency of patients in the treatment and control groups. Statistics were analyzed using the T dependent test and Wilcoxon test. The Wilcoxon test result on the intervention group obtained the value of p = 0.004 or p < 0.05 and control group achieved p value = 0.157 or p > 0.05, it means the intervention group indicated influence and control group did not get any it. The intervention group that was treated by Pursed Lip Breathing Exercise acquired influence of breathing frequency on the pulmonary TB patients, but in another hand control group that only was measured the breathing frequency did not get any influence on the pulmonary TB patients. Keywords: Tuberculosis, Breathing Frequency, Pursed Lip Breathing Exercise

A relationship between temperature, oxygen dissolved in blood and viral infections

An investigation is made on the environmental factors that may determine the seasonal cycle of respiratory affections. The driving role of temperature is examined, for its inverse synergism with the dissolution of oxygen in human plasma. Two best-fit equations are discussed to interpolate the experimental data about the oxygen solubility and the saturation levels reached at various temperatures, referring to the value of the basic alveolar temperature. A vulnerable condition is when the airways temperature is lowered, e.g. breathing cold air, or increasing the breathing frequency. In winter, the upper airways reach lower temperatures and greater oxygen concentrations; the opposite occurs in summer. As low temperatures increase the dissolution of oxygen in plasma, and blood oxidation favours viral activity, an explanation is given to the seasonality of infections affecting the respiratory system.