Decrease In Respiratory Rate Research Articles

Effects of Bacterial Lysates on TLRs/NF-κB Pathway, Immune Function, and Prognosis in Children with Pulmonary Infection Caused by Streptococcus pneumoniae

Background: Bacterial lysates, as immunomodulators, may play a role in regulating the host immune response. Objectives: This study aimed to investigate the effects of bacterial lysates OM85-BV in treating pulmonary infections caused by Streptococcus pneumoniae in children. Methods: A total of 120 children with S. pneumoniae pulmonary infection were divided into two groups: The control group and the OM85-BV group, with a 1: 1 ratio. The control group received intravenous mezlocillin at 100 mL/kg/d, while the OM85-BV group, in addition to mezlocillin, received OM85-BV orally at 3.5 mg per dose. The improvement of clinical symptoms and pulmonary function indexes—including respiratory rate, tidal volume, volume to peak expiratory flow as a proportion of exhaled volume, and time to peak tidal expiratory flow as a proportion of expiratory time—were compared. Additionally, levels of C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), soluble interleukin-2 receptor (sIL-2R), T lymphocyte subsets, and immunoglobulins in serum were analyzed. Results: Compared to the control group, the OM85-BV group showed a significant decrease in respiratory rate and an increase in tidal volume, volume to peak expiratory flow, and time to peak tidal expiratory flow (P < 0.05 for all). The OM85-BV group also had significantly lower levels of serum inflammatory factors such as CRP, TNF-α, IL-6, and sIL-2R. In terms of immune function, the OM85-BV group showed increased levels of T lymphocyte subsets CD3+, CD4+, and CD4+/CD8+ ratios, with a decrease in CD8+, as well as elevated serum IgA and IgG levels. The total effective rate of treatment in the OM85-BV group was significantly higher than in the control group (P < 0.05). Conclusions: The addition of OM85-BV to the treatment of S. pneumoniae pulmonary infection in children significantly improves clinical symptoms, lung function, and immune function, while reducing the inflammatory response. OM85-BV appears to inhibit the activation of the toll-like receptors (TLRs) and nuclear factor kappa-B (NF-κB) pathway.

Response of Root Respiration to Warming and Nitrogen Addition Depends on Tree Species.

Roots contribute a large fraction of CO2 efflux from soils, yet the extent to which global change factors affect root-derived fluxes is poorly understood. We investigated how red maple (Acer rubrum) and red oak (Quercus rubra) root biomass and respiration respond to long-term (15 years) soil warming, nitrogen addition, or their combination in a temperate forest. We found that ecosystem root respiration was decreased by 40% under both single-factor treatments (nitrogen addition or warming) but not under their combination (heated × nitrogen). This response was driven by the reduction of mass-specific root respiration under warming and a reduction in maple root biomass in both single-factor treatments. Mass-specific root respiration rates for both species acclimated to soil warming, resulting in a 43% reduction, but were not affected by N addition or the combined heated × N treatment.Notably, the addition of nitrogen to warmed soils alleviated thermal acclimation and returned mass-specific respiration rates to control levels. Oak roots contributed disproportionately to ecosystem root respiration despite the decrease in respiration rates as their biomass was maintained or enhanced under warming and nitrogen addition. In contrast, maple root respiration rates were consistently higher than oak, and this difference became critical in the heated × nitrogen treatment, where maple root biomass increased, contributing significantly more CO2 relative to single-factor treatments. Our findings highlight the importance of accounting for the root component of respiration when assessing soil carbon loss in response to global change and demonstrate that combining warming and N addition produces effects that cannot be predicted by studying these factors in isolation.

Comparison of intra and postoperative analgesia efficacy of intraperitoneal levobupivacaine alone or in combination with dexmedetomidine in cats undergoing ovariohysterectomy; a randomized, prospective, blinded, clinical trial

This study aimed to compare the analgesic and cardiopulmonary effects of levobupivacaine with or without dexmedetomidine, in cats undergoing ovariohysterectomy. In this prospective, randomized, and blinded clinical trial, 24 healthy cats were recruited. Animals received either saline (S group; 2 mL NaCl), levobupivacaine alone (Lev; 0.35 mg/kg), or levobupivacaine with dexmedetomidine (LevDex group; 0.004 mg/kg), which was infiltrated intraoperatively into the subcutaneous tissue at various incision sites, including the right and left ovarian pedicles and the caudal aspect of the uterine body. Intraoperative analgesia was evaluated using a cumulative pain scale, while postoperative analgesia was assessed at various time points: before surgery (Tb), and at 0 (T0), 1 (T1h), 2 (T2h), 4 (T4h), 8 (T8h), 12 (T12h), and 24 (T24h) hours after the procedure, using the UNESP-Botucatu multidimensional composite pain scale (MCPS). Significant decreases in heart rate, respiratory rate, and mean arterial pressure were observed in LevDex group as compared to S and Lev groups (p < 0.05). The S group required significantly more rescue morphine doses than the LevDex group (p = 0.029), but the difference was not significant when compared to the Lev group (p = 0.123). At T1h and T2h, the S group had significantly higher MCPS scores than both the Lev and LevDex groups (p = 0.029). However, at T8h, no significant difference was found between the S and LevDex groups (p = 0.741). While adding dexmedetomidine to levobupivacaine may slightly prolong postoperative analgesia, this combination does not provide significant additional benefit over levobupivacaine alone in terms of response to surgical stimulation.

Effects of fire and fire-induced changes in soil properties on post-burn soil respiration

Abstract Background Boreal forests cover vast areas of land in the northern hemisphere and store large amounts of carbon (C) both aboveground and belowground. Wildfires, which are a primary ecosystem disturbance of boreal forests, affect soil C via combustion and transformation of organic matter during the fire itself and via changes in plant growth and microbial activity post-fire. Wildfire regimes in many areas of the boreal forests of North America are shifting towards more frequent and severe fires driven by changing climate. As wildfire regimes shift and the effects of fire on belowground microbial community composition are becoming clearer, there is a need to link fire-induced changes in soil properties to changes in microbial functions, such as respiration, in order to better predict the impact of future fires on C cycling. Results We used laboratory burns to simulate boreal crown fires on both organic-rich and sandy soil cores collected from Wood Buffalo National Park, Alberta, Canada, to measure the effects of burning on soil properties including pH, total C, and total nitrogen (N). We used 70-day soil incubations and two-pool exponential decay models to characterize the impacts of burning and its resulting changes in soil properties on soil respiration. Laboratory burns successfully captured a range of soil temperatures that were realistic for natural wildfire events. We found that burning increased pH and caused small decreases in C:N in organic soil. Overall, respiration per gram total (post-burn) C in burned soil cores was 16% lower than in corresponding unburned control cores, indicating that soil C lost during a burn may be partially offset by burn-induced decreases in respiration rates. Simultaneously, burning altered how remaining C cycled, causing an increase in the proportion of C represented in the modeled slow-cycling vs. fast-cycling C pool as well as an increase in fast-cycling C decomposition rates. Conclusions Together, our findings imply that C storage in boreal forests following wildfires will be driven by the combination of C losses during the fire itself as well as fire-induced changes to the soil C pool that modulate post-fire respiration rates. Moving forward, we will pair these results with soil microbial community data to understand how fire-induced changes in microbial community composition may influence respiration.

Exploring diaphragmatic response to high-flow nasal cannula in patients with COVID-19 pneumonia using ultrasound: a proof of concept study.

Recent studies have highlighted the recognition of diaphragmatic dysfunction as a significant factor contributing to respiratory disturbances in severely ill COVID-19 patients. In the field of noninvasive respiratory support, high-flow nasal cannula (HFNC) has shown effectiveness in relieving diaphragm dysfunction. This study aims to investigate the diaphragmatic response to HFNC in patients with COVID-19 pneumonia by utilizing ultrasound. This retrospective study was conducted in a medical-surgical intensive care unit (ICU) at a tertiary care center in Buenos Aires, Argentina (Sanatorio de Los Arcos) over a 16-month period (January 2021-June 2022). The study included patients admitted to the ICU with a diagnosis of COVID-19 pneumonia who were deemed suitable candidates for HFNC therapy by the attending physician. Diaphragm ultrasound was conducted, measuring diaphragmatic excursion (DE) both before and during the utilization of HFNC for these patients. A total of 10 patients were included in the study. A statistically significant decrease in respiratory rate was observed with the use of HFNC (p = 0.02), accompanied by a significant increase in DE (p = 0.04). HFNC leads to a reduction in respiratory rate and an increase in DE as observed by ultrasound in patients with COVID-19 pneumonia, indicating promising enhancements in respiratory mechanics. However, further research is required to validate these findings.

Pilot epinephrine dose-finding study to counter epidural-related blood pressure reduction

ObjectiveAn unwanted side effect associated with epidural analgesia is the reduction in blood pressure (BP) due to the sympathetic blockade. This study evaluated the hemodynamic effects of adding different epinephrine...

Exogenous melatonin delays yellowing in postharvest broccoli by regulation of ABA and carotenoid metabolite

Yellowing is the first visible sign of floret senescence and quality deterioration in broccoli, mainly caused by chlorophyll degradation and carotenoid accumulation. In this study, the impacts of melatonin (MLT) treatment on anabolism, catabolism and storage of carotenoid in postharvest broccoli associated with ABA regulation were investigated at transcript and metabolic levels. Results showed that MLT treatment effectively repressed yellowing and senescence along with a decrease in respiration rate and ethylene emission, enhancing endogenous MLT and abscisic acid (ABA) levels. A total of 925 metabolites were differentially expressed between the control and MLT treatment, which were mainly classified into amino acids, sugars, lipids, flavonoids and others. Specific analysis revealed that MLT treatment decreased sugars, lipids, flavonoids, and aromatic amino acids, but increased aliphatic amino acids. Meanwhile, MLT treatment suppressed the expression levels of genes related to carotenoid anabolism (BoPSY, BoPDS, BoZDS, BoCRTISO, BoLCYB, BoVDE, and BoZEP) and storage (BoOR), but the genes involved in carotenoid catabolism (BoNCED2, BoNCED6, BoCCD1 and BoCCD7) were up-regulated, which could collectively result in a decrease in the levels of β-carotene and lutein and an increase in ABA level. Moreover, correlation analysis indicated that lutein content was positively correlated with BoVDE, BoPDS and BoZDS, and negatively correlated with ABA level. Thus, MLT treatment slowed down the yellowing of broccoli during storage, which might be ascribed to inhibiting the anabolism and storage of carotenoid and promoting carotenoid catabolism and ABA biosynthesis.

Predictive value of invasive mechanical ventilation parameters for mortality in COVID-19 related ARDS: a retrospective cohort study

The 2019 coronavirus (COVID-19) can generate acute respiratory distress syndrome (ARDS), requiring advanced management within the Intensive Care Unit (ICU) using invasive mechanical ventilation (IMV However, managing this phenomenon has seen learning and improvements through direct experience. Therefore, this study aims were to describe the assessment of the different IMV variables in patients with post-COVID-19 hospitalized in the ICU and their relation with mortality. Observational and retrospective study. The sample was divided into two, the surviving group (SG) and the non-surviving group (NSG). Clinical data were extracted from the electronic clinical file and the respiratory therapist record sheet. The following information was obtained: Patient medical history: gender, age, co-morbidities, arterial gases, days on IMV, and IMV parameters. Out of a total of 101 patients, the total mortality was 32%. There was a significant decrease in respiratory rate (RR) (29.12 ± 4.24–26.78 ± 3.59, p = 0.006), Driving pressure (DP) (11.33 ± 2.39–9.67 ± 1.84, p = 0.002), Ventilatory rate (VR) (2.26 ± 0.66–1.89 ± 0.45, p = 0.001) and a significant rise in Static compliance (Cest) (35.49 ± 8.64–41.45 ± 9.62, p = 0.003) and relation between Arterial oxygen pressure/Inspirated oxygen fraction (PaO2/FiO2) (201.5 ± 53.98- 227.8 ± 52.11, p = 0.008) after 72 h of IMV, within the NSG compared to the SG. Apart from these points, multi-morbidity (HR = 3.208, p = 0.010) and DP (HR = 1.228, p = 0.030) and VR variables (HR = 2.267, p = 0.027) had more death probabilities. The results of this study indicate that there was a significant increase in RR, DP, VR, and CO2 and a significant drop in Cest and PaO2/FiO2 among the NSG compared with the SG. Apart from this, the DP and VR variables, multi-morbidity and being male. have more possibility of death.

Coral species-specific loss and physiological legacy effects are elicited by an extended marine heatwave.

Marine heatwaves are increasing in frequency and intensity, with potentially catastrophic consequences for marine ecosystems such as coral reefs. An extended heatwave and recovery time-series that incorporates multiple stressors and is environmentally realistic can provide enhanced predictive capacity for performance under climate change conditions. We exposed common reef-building corals in Hawai'i, Montipora capitata and Pocillopora acuta, to a 2-month period of high temperature and high PCO2conditions or ambient conditions in a factorial design, followed by 2months of ambient conditions. High temperature, rather than high PCO2, drove multivariate physiology shifts through time in both species, including decreases in respiration rates and endosymbiont densities. Pocillopora acuta exhibited more significantly negatively altered physiology, and substantially higher bleaching and mortality than M. capitata. The sensitivity of P. acuta appears to be driven by higher baseline rates of photosynthesis paired with lower host antioxidant capacity, creating an increased sensitivity to oxidative stress. Thermal tolerance of M. capitata may be partly due to harboring a mixture of Cladocopium and Durusdinium spp., whereas P. acuta was dominated by other distinct Cladocopium spp. Only M. capitata survived the experiment, but physiological state in heatwave-exposed M. capitata remained significantly diverged at the end of recovery relative to individuals that experienced ambient conditions. In future climate scenarios, particularly marine heatwaves, our results indicate a species-specific loss of corals that is driven by baseline host and symbiont physiological differences as well as Symbiodiniaceae community compositions, with the surviving species experiencing physiological legacies that are likely to influence future stress responses.

Clinical effects and adverse effects of intravenous lipid emulsion treatment in dogs and cats with suspected poisoning.

This retrospective study aimed to evaluate the effects on the clinical signs of poisoning and adverse effects of intravenous lipid emulsion treatment in 82 animals (dogs and cats) with suspected poisonings over 18 months. Physical examination parameters and state of consciousness were documented every hour after the intravenous administration of a bolus of 2 ml/kg and 0.25 ml/kg/min over 60 minutes of a 20% intravenous lipid emulsion. The modified Glasgow coma scale and laboratory findings (blood gas analysis, triglyceride, lactate) were evaluated initially and three hours after discontinuing intravenous lipid emulsion administration. A statistical evaluation of the occurrence of adverse effects and the development of laboratory values was performed. A decrease in respiratory rate in the second control (8-12 hours) after ILE was observed. Three hours after completing of the intravenous lipid emulsion, triglyceride concentration increased about 10 times (p <0.001). Venous carbon dioxide partial pressure, bicarbonate, base excess, as well as the electrolytes sodium, potassium and ionized calcium decreased significantly (p <0.001). Patients who experienced a worsening of the modified Glasgow coma scale had a higher increase in triglyceride concentrations (p = 0.041) and plasma lactate (p = 0.034) and a larger decrease in bicarbonate concentrations (p = 0.053) compared to others. About 54% (n = 44) of the patients showed adverse effects which could be attributed to the administration of intravenous lipid emulsion and may be associated with a higher triglyceride increase. All of them were completely reversible within 33 hours. Adverse effects associated with intravenous lipid emulsion therapy were observed in half of the patients and were associated with a higher increase in triglycerides.

Effects of hand catalepsy on subjective trance perception and relative parasympathetic tone in healthy volunteers during pleasant hypnotic session: a randomized controlled study.

This study was designed to evaluate the effects on hand catalepsy on parasympathetic tone assessed using Analgesia/Nociception Index (ANI) and on subjective rating of absorption, dissociation, and time perception among healthy volunteers. This was a randomized controlled trial including participants to a medical hypnosis congress in France. Ninety volunteers were randomized in two arms, all receiving a fifteen-minute positive hypnotic trance, with or without hand catalepsy. The relative parasympathetic tone assessed by ANI (Analgesia/Nociception Index), heart rate and respiratory rate were recorded at different times of the study protocol. The actual duration of the hypnotic session, calculated from eye closing to eye opening, was also recorded. At the end of the hypnotic trance, participants subjectively rated their level of absorption and dissociation on a 0-10 scale. They were also asked to estimate the duration of the hypnotic session from eye closing to eye opening. In total, ninety subjects were included in the study. One subject was excluded because of deviation in the protocol standard, leaving eighty-nine subjects for analysis. Subject characteristics were similar between groups. There was a statistically different increase in ANI and decrease in both heart rate and respiratory rate over time with no difference with or without hand catalepsy. There was no statistically significant difference in absorption and dissociation subjective scales between groups. The median [Q1-Q3] actual duration of hypnotic sessions was similar between the catalepsy and the control groups (9 [8-10] min vs. 8 [7-10] min, respectively). However, subjects in the catalepsy group estimated a longer duration of the hypnotic session (12 [10-15] min) than in the control group (10 [5-10] min) with a mean ± SD overestimation of 3 ± 4min (p < 0.001). Parasympathetic comfort increased during the hypnotic trance with no difference between groups. However, adding hand catalepsy to a pleasant hypnotic trance did not appear to increase feelings of absorption or dissociation but created time distortion on the longer side that could be useful in some clinical settings. Nevertheless, further study is still needed to determine more precisely the physiological and psychological effects on hand catalepsy during the hypnotic trance.

Effect of pursed lip breathing (PLB) exercises on respiratory rate among patients with pneumonia

Background: Pneumonia is an acute respiratory infection, commonly caused by viruses or bacteria. It can cause mild illness or even be life-threatening. When a person suffers from pneumonia, the alveolus will be filled with pus and fluid, which makes breathing painful and limits oxygen intake so that the patient will feel short of breath. PLB therapy will help develop the alveolus in the lung lobes so that it helps push the secretions in the respiratory tract during expiration and increase alveolus pressure. Purpose: To determine the respiratory rate (RR) using pursed lip breathing. Method: Study with evidence-based practice. The subjects used were 5 patients with pneumonia, data analysis using descriptive analysis. Results: The application carried out for 15 minutes in a span of 3 days, there was a decrease in respiratory rate in pneumonia patients. Conclusion: The Pursed Lips Breathing (PLB) technique is effective in reducing or reducing the rate of respiratory in patients with pneumonia.

Melatonin administration during the first half of pregnancy improves physiological response and reproductive performance of rabbits under heat stress conditions.

Context Melatonin may have a heat-stress-alleviating role during pregnancy. Aims To investigate the effects of melatonin administration during the first half of pregnancy on heat-tolerance capacity and pregnancy outputs of naturally heat-stressed rabbits. Methods Forty female rabbits were stratified equally into two experimental groups and daily received 1mg melatonin/kg body weight or not (control) for 15 consecutive days post-insemination. Heat tolerance indices, hormone profile, ovarian structures, and fetal loss were determined. Key results Treatment with melatonin significantly decreased respiration rate and rectal temperature, improved concentrations of nitric oxide, and tended to decrease malondialdehyde concentrations (P =0.064) compared to control. Melatonin treatment significantly increased concentrations of high-density lipoprotein, oestradiol, and progesterone compared to control. No significant differences in the numbers of visible ovarian follicles, corpora lutea, and total implantation sites on day 18 of pregnancy were observed between experimental groups. However, melatonin treatment significantly reduced the number of absorbed implantation sites and significantly improved amniotic fluid volume and conception rate compared to control. Conclusions Melatonin administration during the first half of pregnancy can improve reproductive performance of heat-stressed female rabbits. Implications Melatonin can improve fetal survivability via improving heat-tolerance capacity of does and steroidogenesis.

Study of gas exchange under different modes of ventilation in yoga breathing exercises

Yoga breathing exercises that develop the ability to voluntarily regulate the minute volume of respiration (MV) and maintain the state of hypoventilation, hypoxia and hypercapnia, can be considered as a way of hypoxic-hypercapnic training, potentially capable of influencing cerebral circulation and neuroprotective factors. However, at the moment, individual anthropometric features that affect the ability to develop a hypoventilation mode of breathing have not been studied, and methodological criteria for training have not been developed.Methods: The study involved 44 people (32 men and 12 women) who regularly practice yoga breathing techniques with a voluntary decrease in respiratory rate using maximum tidal volume (TV). Free breathing was recorded for 2 minutes, then each subject performed the respiratory hypoventilation pattern available to him or her (minimum RR values with maximum TV, inhalation and exhalation were of equal duration). The following parameters of external respiration were determined: respiratory rate (RR), minute ventilation (MV), tidal volume (TV), partial pressure of CO2 in the exhaled air at the end of exhalation (PetCO2 ), percentage of O2 in the exhaled air (FeO2) and hemoglobin saturation (SpO2 ).Results: Compared to breathing at rest (MV = M±SD 8.51 ± 2.57 (95% CI 7.72–9.29) l/min; PetCO2 = M±SD 36.98 ± 3.71 (95% CI 35.85–38.11) mm Hg), the mode with RR = 3 times/min (inspiration and expiration for 10 s), n = 44, leads to an increase in MV up to M±SD 12.02 ± 3.42 (95% CI 10.98–13.06) l/min (p &lt; 0.001) and a decrease of CO2 : PetCO2 = M±SD 33.99 ± 3.59 (95% CI 32.90–35.08) mm Hg (p &lt; 0.001) — that is, to development of alveolar hypocapnia. The mode with RR = 1.5 times/min (inhalation and exhalation for 20 s), n = 44, demonstrates a decrease in MV to M±SD 5.95 ± 1.59 (95% CI 5.46–6.43) l/min (p &lt; 0.001) and growth of PetCO2 up to M±SD 41.19 ± 3.71 (95% CI 40.06–42.32) mm Hg (p &lt; 0.001). The mode with RR = 1 time/min (inspiration and exhalation for 30 s), n = 24: with a decrease in RR to 1 time/min, a decrease in MV was observed to M±SD 4.22 ± 0.92 (95% CI 3.83–4.61) l / min (p &lt; 0.001) and an increase in PetCO2 up to M±SD 44.05 ± 3.05 (95% CI 42.76–45.33) mm Hg (p &lt; 0.001). The breathing pattern with RR = 1 r/min is accompanied by a statistically significant decrease in MV compared to rest, as well as an increase in PetCO2 and a decrease in FeO2 , that is, it is hypoventilation. We have proposed a ventilation coefficient (Qvent), which is the ratio MV/VC, which allows us to judge at what values of MV an individual reaches a state of hypoventilation. It was previously shown in this sample that the breathing exercise becomes hypoventilation when Qvent values are equal to or less than 1. With Qvent in the range from 1 to 2, the ventilation mode is within normal values, and when Qvent is more than 2, hyperventilation occurs.Conclusion: when performing yoga breathing exercises, variations in MV are observed both in the direction of hyperventilation and in the direction of hypoventilation with corresponding shifts in gas exchange (hypocapnia with hyperventilation, hypercapnia with hypoventilation). The MV values at which an individual reaches hypoventilation vary from person to person and can be predicted using the ventilation coefficient (Qvent).

Development of a heat load index and risk map for grazing sheep

ABSTRACT A total of 5500 measurements of the respiration rate of 123 sheep with and without access to shade were obtained on 40 days in the summers (January–April) of 2022(Year 1) and 2023(Year 2). Models to predict respiration rate (breaths per minute (BPM)) based on temperature, humidity, wind speed, and solar radiation were calibrated to the Year 1 unshaded dataset (R2 =0.35, RMSE=39 BPM) and validated with the Year 2 unshaded dataset (R2=0.58, RMSE=40 BPM). Respiration rate increased 6 BPM for each 1°C increase in temperature. The shade treatment decreased respiration rate by 24 BPM and the shaded model for respiration rate had a validation RMSE of 47 BPM. The between sheep variability in respiration rate was described by a standard deviation of 18.9 BPM. The probability of open mouth and tongue out behaviours both increased linearly from 200 BPM. We constructed a daily Heat Load Index based on the cumulative respiration rate greater than 200 BPM. Climate data and sheep density information were used to construct a heat stress risk map for New Zealand from October 2018 to March 2022. Heat stress risk was concentrated in January–February and was primarily located on the east coast of the North Island.

Impact of rotenone induced Parkinson’s disease on respiration and swallowing rate in drinking rats

Parkinson’s disease is a neurodegenerative disorder known to cause dysphagia, the major contributor to mortality via aspiration pneumonia. The neurological basis of swallowing dysfunction in Parkinson patients is poorly understood. To explore the mechanisms of swallowing dysfunction, we studied the impact of rotenone treatment on respiration rate and swallowing rate in liquid-drinking rats. We hypothesized that rotenone treatment will cause a decrease in respiratory and swallowing rate compared to untreated liquid-drinking rats. Six rats were injected with 2.75 mg/kg/day intraperitoneal rotenone for 16 days to create the parkinsonian phenotype and subsequently recorded with 200fps video fluoroscopy during barium-infused liquid drinking. Before the first injection and on day 4, 7, 10 and 16, the number of swallows and number of breaths in a ten second period of continuous drinking were scored. The data was then analyzed using Analysis of Variance to determine whether the rotenone injections impacted the respiration or swallowing rate. Rotenone injections led to a decrease in respiration rate (p=0.03), but no change in swallowing rate over a 16-day period (p&gt;0.05). Immunohistochemistry of the dorsolateral striatum of rats that received rotenone treatment for 8 days and 16 days showed significant reduction in tyrosine hydroxylase (TH) immunofluorescence with increased impact due to prolonged treatment (Kruskal Wallis test, p&lt;0.001). TH is the rate limiting step of catecholamine synthesis from tyrosine, confirming that rotenone is affecting dopamine production in this model of Parkinson’s disease. These results indicated that rotenone induced parkinsonian treatment has differential impacts on different brainstem mediated processes, swallowing and respiration. Thus, swallow-respiration coordination is likely impacted in these animals, potentially increasing risk of airway protection failure. Internal Rowan funding to F. Gould supported this work. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Potentiation of the depressant effect of alcohol by flunitrazepam in rats: an electrocorticographic, respiratory and electrocardiographic study.

Alcohol, a widely commercialized psychotropic drug, and the benzodiazepine Flunitrazepam, an anxiolytic widely prescribed for patients with anxiety and insomnia problems, are well known drugs and both act on the central nervous system. The misuse and the association of these two drugs are public health concerns in several countries and could cause momentary, long-lasting and even lethal neurophysiological problems due to the potentiation of their adverse effects in synergy. The present study observed the result of the association of these drugs on electrophysiological responses in the brain, heart, and respiratory rate in Wistar rats. 8 experimental groups were determined: control, one alcohol group (20% at a dose of 1ml/100g VO), three Flunitrazepam groups (doses 0.1; 0.2 and 0.3mg/kg) and three alcohol-Flunitrazepam groups (20% at a dose of 1ml/100g VO of alcohol, combined with 0.1; 0.2 and 0.3mg/kg of Flunitrazepam, respectively). The results showed that there was a more pronounced reduction in alpha and theta wave power in the alcohol-Flunitrazepam groups, a decrease in the power of beta oscillations and greater sedation. There was a progressive decrease in respiratory rate linked to the increase of Flunitrazepam dose in the alcohol-Flunitrazepam associated administration. It was observed alteration in heart rate and Q-T interval in high doses of Flunitrazepam. Therefore, we conclude that the association alcohol-Flunitrazepam presented deepening of depressant synergistic effects according to the increase in the dose of the benzodiazepine, and this could cause alterations in low frequency brain oscillations, breathing, and hemodynamics of the patient.

High velocity nasal insufflation versus non-invasive ventilation in acute respiratory failure: a comparative study

Background In order to treat respiratory failure, thermo-humidified nasal high flow oxygen (NHFO) therapy is being used more and more. In several clinical scenarios, NHFO has recently gained popularity as alternative noninvasive respiratory ventilation. Aim The aim is to assess the role of high velocity nasal insufflation (HVNI) versus noninvasive ventilation (NIV) in acute respiratory failure. Patients and methods This is a prospective randomized clinical study conducted on 60 patients admitted to the Chest Department at Menoufia University Hospital with acute respiratory failure. Patients were randomized to receive either noninvasive positive pressure ventilation using an oronasal mask or high-velocity nasal insufflation (initial flow was at 30-40 l/min; temperature was adjusted to 37°C; fraction of inspired oxygen 1.0) with clinical monitoring and arterial blood gas (ABG) monitoring after 2, 6, 12, and 24 h. Results The therapeutic impact of both, HVNI and NIV, on pressure of arterial carbon dioxide (PaCO2), hydrogen ion concentration, arterial oxygen saturation and pressure of arterial oxygen (PaO2) over time was almost similar. There was an improvement in dyspnea and a decrease in respiratory rate over time when compared with baseline results in both groups. There was no statistical difference between both groups. The failure rate in type I respiratory failure (RF) was 33.3% in the HVNI group and 28.6% in the NIV group (P-value 0.7). The failure rate in type II RF was 41.7% in the HVNI group and 25% in the NIV group (P-value 0.3). HVNI was more comfortable for patients and provided better communication and oral intake. Conclusion This study demonstrates that the HVNI was comparable to the NIV in the management of hypoxemic respiratory failure and could be used as a noninvasive method of ventilation alternative to the BiPAP in hypercapnic RF, with more comfortability and better communication in the HVNI group.

The Effects of Mixed Foliar Nutrients of Calcium and Magnesium on the Major Bypass Respiratory Pathways in the Pulp of ‘Feizixiao’ Litchi

During the period of ‘Feizixiao’ litchi fruit pericarp’s full coloring, there is a phenomenon of “sugar withdrawal” in the pulp, and the mixed foliar nutrients of calcium and magnesium (Ca+Mg) can effectively overcome this phenomenon. One of the reasons for this may be that it is related to the influence of the mixed nutrients of Ca+Mg on the bypass respiratory pathways of the pulp. The major fruit quality indicators, the rates of cytochrome and cyanide-resistant respiratory pathways (CP and AP) in the pulp and the activities of their key enzymes, were observed continuously in 2021 and 2022, and the deferentially expressed genes (DEGs) related to the two bypass respiratory pathways in the pulp were screened by RNA-seq analysis, with a qPCR of the random genes performed to verify the results. Ca+Mg treatment kept the content of the total soluble sugar in the pulp stable and higher than that the control in the ripening stage; Ca+Mg treatment increased the activities of electron-transferring enzymes in the electron transport chain, such as NADH dehydrogenase (ND), succinate dehydrogenase (SDH), cytochrome bc1 complex, and cytochrome c (Cyt c) through up-regulating their gene expression. In terms of the rate-limiting enzymes in the pulp, Ca+Mg treatment increased the activity of cytochrome oxidase (COX) in the CP pathway by up-regulating the expression of COX genes, then increased the CP respiratory rate and inhibited the CP respiratory rate decrease; meanwhile, it also inhibited the activity of AOX (alternate oxidase) in the pulp in the AP pathway by down-regulating the expression of AOX genes, then inhibited the increase in the AP respiration rate. The qPCR validation of randomly selected DEGs showed a significant unitary linear correlation between their expression levels and the results of the RNA-seq analysis. Therefore, one of the physiological mechanisms on the mixed foliar nutrients of Ca and Mg overcoming the phenomenon of “sugar withdrawal” in the ‘Feizixiao’ litchi pulp could be to promote CP and to inhibit AP, and then to delay the ripening and senescence of the pulp.

Establishing short-term occupational exposure limits (STELs) for sensory irritants using predictive and in silico respiratory rate depression (RD50) models

Sensory irritation is a health endpoint that serves as the critical effect basis for many occupational exposure limits (OELs). Schaper 1993 described a significant relationship with high correlation between the measured exposure concentration producing a 50% respiratory rate decrease (RD50) in a standard rodent assay and the American Conference of Governmental Industrial Hygienists (ACGIH®) Threshold Limit Values (TLVs®) as time-weighted averages (TWAs) for airborne chemical irritants. The results demonstrated the potential use of the RD50 values for deriving full-shift TWA OELs protective of irritant responses. However, there remains a need to develop a similar predictive model for deriving workplace short-term exposure limits (STELs) for sensory irritants. The aim of our study was to establish a model capable of correlating the relationship between RD50 values and published STELs to prospectively derive short-term exposure OELs for sensory irritants. A National Toxicology Program (NTP) database that included chemicals with both an RD50 and established STELs was used to fit several linear regression models. A strong correlation between RD50s and STELs was identified, with a predictive equation of ln (STEL) (ppm) = 0.86 * ln (RD50) (ppm) − 2.42 and an R2 value of 0.75. This model supports the use of RD50s to derive STELs for chemicals without existing exposure recommendations. Further, for data-poor sensory irritants, predicted RD50 values from in silico quantitative structure activity relationship (QSAR) models can be used to derive STELs. Hence, in silico methods and statistical modeling can present a path forward for establishing reliable OELs and improving worker safety and health.