Persistence of High Levels of Serum Complement C5a in Severe COVID-19 Cases After Hospital Discharge.

Evidence supports a role of complement anaphylatoxin C5a in the pathophysiology of COVID-19. However, information about the evolution and impact of C5a levels after hospital discharge is lacking. We analyzed the association between circulating C5a levels and the clinical evolution of hospitalized patients infected with SARS-CoV-2. Serum C5a levels were determined in 32 hospitalized and 17 non-hospitalized patients from Clinica Universidad de Navarra. One hundred and eighty eight serial samples were collected during the hospitalization stay and up to three months during the follow-up. Median C5a levels were 27.71 ng/ml (25th to 75th percentile: 19.35-34.96) for samples collected during hospitalization, versus 16.76 ng/ml (12.90-25.08) for samples collected during the follow-up (p<0.001). There was a negative correlation between serum C5a levels and the number of days from symptom onset (p<0.001). C5a levels also correlated with a previously validated clinical risk score (p<0.001), and was associated with the severity of the disease (p<0.001). An overall reduction of C5a levels was observed after hospital discharge. However, elevated C5a levels persisted in those patients with high COVID-19 severity (i.e. those with a longest stay in the hospital), even after months from hospital discharge (p=0.020). Moreover, high C5a levels appeared to be associated with the presence of long-term respiratory symptoms (p=0.004). In conclusion, serum C5a levels remain high in severe cases of COVID-19, and are associated with the presence of respiratory symptoms after hospital discharge. These results may suggest a role for C5a in the long-term effects of COVID-19 infection.

Lung function decline is associated with serum uric acid in Korean health screening individuals.

We performed a retrospective cohort study of 19,237 individuals who underwent at least three health screenings with follow-up periods of over 5 years to find a routinely checked serum marker that predicts lung function decline. Using linear regression models to analyze associations between the rate of decline in the forced expiratory volume in 1 s (FEV1) and the level of 10 serum markers (calcium, phosphorus, uric acid, total cholesterol, total protein, total bilirubin, alkaline phosphatase, aspartate aminotransferase, creatinine, and C-reactive protein) measured at two different times (at the first and third health screenings), we found that an increased uric acid level was significantly associated with an accelerated FEV1 decline (P = 0.0014 and P = 0.037, respectively) and reduced FEV1 predicted % (P = 0.0074 and P = 8.64 × 10-7, respectively) at both visits only in non-smoking individuals. In addition, we confirmed that accelerated forced vital capacity (FVC) and FEV1/FVC ratio declines were observed in non-smoking individuals with increased serum uric acid levels using linear mixed models. The serum uric acid level thus potentially predicts an acceleration in lung function decline in a non-smoking general population.

Respiratory Muscle and Lung Function in Lung Allograft Recipients: Association with Exercise Intolerance.

BACKGROUND: In lung transplant recipients (LTRs), restrictive ventilation disorder may be present due to respiratory muscle dysfunction that may reduce exercise capacity. This might be mediated by pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). OBJECTIVE: We investigated lung respiratory muscle function as well as circulating pro-inflammatory cytokines and exercise capacity in LTRs. METHODS: Fifteen LTRs (6 female, age 56 ± 14 years, 63 ± 45 months post-transplantation) and 15 healthy controls matched for age, sex, and body mass index underwent spirometry, measurement of mouth occlusion pressures, diaphragm ultrasound, and recording of twitch transdiaphragmatic (twPdi) and gastric pressures (twPgas) following magnetic stimulation of the phrenic nerves and the lower thoracic nerve roots. Exercise capacity was quantified using the 6-min walking distance (6MWD). Plasma IL-6 and TNF-α were measured using enzyme-linked immunosorbent assays. RESULTS: Compared with controls, patients had lower values for forced vital capacity (FVC; 81 ± 30 vs.109 ± 18% predicted, p = 0.01), maximum expiratory pressure (100 ± 21 vs.127 ± 17 cm H2O, p = 0.04), diaphragm thickening ratio (2.2 ± 0.4 vs. 3.0 ± 1.1, p = 0.01), and twPdi (10.4 ± 3.5 vs. 17.6 ± 6.7 cm H2O, p = 0.01). In LTRs, elevation of TNF-α was related to lung function (13 ± 3 vs. 11 ± 2 pg/mL in patients with FVC ≤80 vs. >80% predicted; p < 0.05), and lung function (forced expiratory volume after 1 s) was closely associated with diaphragm thickening ratio (r = 0.81; p < 0.01) and 6MWD (r = 0.63; p = 0.02). CONCLUSION: There is marked restrictive ventilation disorder and respiratory muscle weakness in LTRs, especially inspiratory muscle weakness with diaphragm dysfunction. Lung function impairment relates to elevated levels of circulating TNF-α and diaphragm dysfunction and is associated with exercise intolerance.

Activation of complement component 3 is associated with airways disease and pulmonary emphysema in alpha-1 antitrypsin deficiency.

INTRODUCTION: Alpha-1 antitrypsin (AAT) deficiency (AATD) is associated with early onset emphysema. The aim of this study was to investigate whether AAT binding to plasma constituents could regulate their activation, and in AATD, exploit this binding event to better understand the condition and uncover novel biomarkers of therapeutic efficacy. METHODS: To isolate AAT linker proteins, plasma samples were separated by size exclusion chromatography, followed by co-immunoprecipitation. AAT binding proteins were identified by mass spectrometry. Complement turnover and activation was determined by ELISA measurement of C3, C3a and C3d levels in plasma of healthy controls (n=15), AATD (n=51), non-AATD patients with obstructive airway disease (n=10) and AATD patients post AAT augmentation therapy (n=5). RESULTS: Direct binding of complement C3 to AAT was identified in vivo and in vitro. Compared with healthy controls, a breakdown product of C3, C3d, was increased in AATD (0.04 µg/mL vs 1.96 µg/mL, p=0.0002), with a significant correlation between radiographic pulmonary emphysema and plasma levels of C3d (R2=0.37, p=0.001). In vivo, AAT augmentation therapy significantly reduced plasma levels of C3d in comparison to patients not receiving AAT therapy (0.15 µg/mL vs 2.18 µg/mL, respectively, p=0.001). DISCUSSION: Results highlight the immune-modulatory impact of AAT on the complement system, involving an important potential role for complement activation in disease pathogenesis in AATD. The association between plasma C3d levels and pulmonary disease severity, that decrease in response to AAT augmentation therapy, supports the exploration of C3d as a candidate biomarker of therapeutic efficacy in AATD.

A simplified quantitative acid-base approach for patients with acute respiratory diseases.

The Stewart-Figge acid-base model has been criticized for being mathematically complex. We aimed to develop simpler formalisms, which can be used at the bedside. The following simplifications were used: (1) [Ca2+] and [Mg2+] are replaced by their mid-reference concentrations (2) pH is set to 7.4. In the new model [SIDa] is replaced by its adjusted form, [SIDa, adj] = [Na+] + [K+] - [Cl-] + 6.5 and [SIG] is replaced by "bicarbonate gap", [BICgap] = [SIDa, adj] - (0.28⋅[Albumin]) - (1.82⋅[Phosphatei])- [HCO3̄]. The diagnostic performance of the model was tested in 210 patients with acute respiratory diseases and 17 healthy volunteers. [BICgap] was also compared to albumin-corrected anion gap ([AGc]). The concordant correlation coefficient between [SIDa, adj] and [SIDa] and between [BICgap] and [SIG] was 0.98 in both comparisons. The mean bias (limits of agreement) of [SIDa, adj] - [SIDa] and of [BICgap] - [SIG] were 0.53 meq/l (- 0.46 to 1.53) and 0.50 meq/l (- 0.70 to 1.70), respectively. A [SIDa, adj] < 50.4 meq/l had an accuracy of 0.995 (p < 0.001) for the diagnosis of strong ion (SI) acidosis, while a [SIDa, adj] > 52.5 meq/l had an accuracy of 0.997 (p < 0.001) for the diagnosis of SI alkalosis. A [BICgap] > 11.6 meq/l predicted unmeasured ion (UI) acidosis with an accuracy of 0.997 (p < 0.001), while an [AGc] > 19.88 meq/l predicted UI acidosis with an accuracy of 0.994 (p < 0.001). The "[BICgap] model" is a reliable tool for the assessment of acid-base disorders in patients with acute respiratory diseases. [BICgap] is not inferior to [AGc] in the diagnosis of UI acidosis.

Association of Severe Hyperoxemia Events and Mortality Among Patients Admitted to a Pediatric Intensive Care Unit.

Importance: A high Pao2, termed hyperoxemia, is postulated to have deleterious health outcomes. To date, the association between hyperoxemia during the ongoing management of critical illness and mortality has been incompletely evaluated in children. Objective: To examine whether severe hyperoxemia events are associated with mortality among patients admitted to a pediatric intensive care unit (PICU). Design, Setting, and Participants: A retrospective cohort study was conducted over a 10-year period (January 1, 2009, to December 31, 2018); all 23 719 PICU encounters at a quaternary children's hospital with a documented arterial blood gas measurement were evaluated. Exposures: Severe hyperoxemia, defined as Pao2 level greater than or equal to 300 mm Hg (40 kPa). Main Outcomes and Measures: The highest Pao2 values during hospitalization were dichotomized according to the definition of severe hyperoxemia and assessed for association with in-hospital mortality using logistic regression models incorporating a calibrated measure of multiple organ dysfunction, extracorporeal life support, and the total number of arterial blood gas measurements obtained during an encounter. Results: Of 23 719 PICU encounters during the inclusion period, 6250 patients (13 422 [56.6%] boys; mean [SD] age, 7.5 [6.6] years) had at least 1 measured Pao2 value. Severe hyperoxemia was independently associated with in-hospital mortality (adjusted odds ratio [aOR], 1.78; 95% CI, 1.36-2.33; P < .001). Increasing odds of in-hospital mortality were observed with 1 (aOR, 1.47; 95% CI, 1.05-2.08; P = .03), 2 (aOR, 2.01; 95% CI, 1.27-3.18; P = .002), and 3 or more (aOR, 2.53; 95% CI, 1.62-3.94; P < .001) severely hyperoxemic Pao2 values obtained greater than or equal to 3 hours apart from one another compared with encounters without hyperoxemia. A sensitivity analysis examining the hypothetical outcomes of residual confounding indicated that an unmeasured binary confounder with an aOR of 2 would have to be present in 37% of the encounters with severe hyperoxemia and 0% of the remaining cohort to fail to reject the null hypothesis (aOR of severe hyperoxemia, 1.31; 95% CI, 0.99-1.72). Conclusions and Relevance: Greater numbers of severe hyperoxemia events appeared to be associated with increased mortality in this large, diverse cohort of critically ill children, supporting a possible exposure-response association between severe hyperoxemia and outcome in this population. Although further prospective evaluation appears to be warranted, this study's findings suggest that guidelines for ongoing management of critically ill children should take into consideration the possible detrimental effects of severe hyperoxemia.

Interleukin-6 and amyotrophic lateral sclerosis.

BACKGROUND: IL-6 is an inflammatory cytokine that is a possible factor in progression of the disease. We have investigated venous blood levels of IL-6 in controls and ALS patients in relation to clinical staging and respiratory function. METHODS: We studied 82 patients with ALS and 43 age and gender-matched healthy control subjects. Blood was drawn at the same time of day in the mornings to avoid diurnal variation. IL-6 levels were estimated according to a fixed protocol. Clinical measures included ALSFRS-R, vital capacity, and mean bilateral phrenic nerve CMAP amplitude. A multi-regression data analysis was used in addition to conventional statistical methods. RESULTS: IL-6 levels were positively correlated with increasing age in the control group. In ALS patients mean IL-6 levels were raised but the levels were markedly variable from case to case and did not reach significance (p 0.1). In addition to age effects reduction in phrenic nerve CMAP amplitude was correlated with increased IL-6 levels (p 0.026). CONCLUSIONS: IL-6 levels were physiologically influenced by aging in controls and by respiratory dysfunction in ALS. There was marked variability in levels from case to case, which might be related to respiratory factors, which cause pulmonary inflammation.

Metabolic Determinants of Impaired Pulmonary Function in Patients with Newly Diagnosed Type 2 Diabetes Mellitus.

AIMS: Impaired lung function associates with deterioration of glycemic control and diabetes-related oxidative stress in long-standing type 2 diabetes. We hypothesized that recent-onset type 2 diabetes patients exhibit abnormal pulmonary function when compared to glucose-tolerant controls and that the frequencies of single-nucleotide polymorphisms (SNPs), known to associate with lung dysfunction, are different between both groups. METHODS: Type 2 diabetes patients with a known disease duration<1 year (n=34) had similar age, sex distribution and BMI as overweight controls (n=26). Lung function was assessed by spirometry comprising predicted forced vital capacity (FVC%), predicted forced expiratory volume in one second (FEV1%) and the FEV1/FVC ratio. Multivariable linear regressions were performed to investigate group differences, which were adjusted for potential confounders such as age, sex, BMI, height and smoking status. SNP genotyping was conducted using real-time polymerase chain reaction-based allelic discrimination. RESULTS: Patients with type 2 diabetes had lower FEV1%, FEV1/FVC and VO2max (all p<0.05). Among patients with type 2 diabetes, FEV1% correlated positively with VO2max (r=0.40, p<0.05) and FEV1/FVC correlated negatively with HbA1c (r=-0.49, p<0.01). Regression analyses across the whole cohort indicated that the group differences in FEV1/FVC can be explained by the confounding effect of HbA1c. The frequencies of the SNPs rs1042713, rs1079572, rs11172113, rs12504628, rs1422795, rs1481345, rs2235910, rs2277027, rs2284746, rs4341, rs7068966, rs925284, rs993925 and rs3824658 did not differ between both groups. CONCLUSIONS: Recent-onset type 2 diabetes patients exhibit reductions in features of pulmonary function, which might be at least in part resulting from glucotoxicity.

Association of serum bilirubin level with lung function decline: a Korean community-based cohort study.

BACKGROUND: Bilirubin has been reported to be associated with respiratory diseases due to its antioxidant action. We aimed to evaluate the relationship between serum bilirubin concentration and annual lung function decline in the Korean general population. METHODS: The study included 7986 subjects aged 40-69 years from the Ansung-Ansan cohort database I (2001-2002)-III (2005-2006). We analyzed the relationships between serum bilirubin level and forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, and mean forced expiratory flow between 25 and 75% of FVC (FEF25-75%) at baseline, as well as the annual average changes in these lung parameters. RESULTS: The FEV1, FVC, and FEF25-75% were significantly associated with serum bilirubin levels after adjustment for age, sex, body mass index (BMI), and smoking status (all P < 0.001). When stratified according to smoking status, these relationships were significant in never-smokers. Additionally, serum bilirubin level was negatively associated with the annual decline in FEV1 and FVC, and positively associated with the annual decline in FEV1/FVC after adjustment for age, sex, BMI, baseline lung function, and smoking status (all P < 0.001). CONCLUSIONS: We found significant associations of serum bilirubin levels with FEV1, FVC, and FEF25-75% in the general population, especially in never-smokers. Moreover, serum bilirubin levels were related with the annual decline in FEV1, FVC, and FEV1/FVC ratio.

Respiratory subtype of panic disorder: Can serum phosphate levels be a possible outcome to group cognitive-behavior therapy?

OBJECTIVE: Panic disorder (PD) respiratory subtype (RS) was described in order to cluster patients according to their symptoms. These patients are characterized by experiencing a relatively high number of noticeable respiratory symptoms during a panic attack (PA) and a higher reactivity to CO2. In this study, we aimed to evaluate the clinical relevance of this diagnostic category, evaluating if there are different responses to cognitive-behavioral therapy in patients with panic disorder RS as compared to those with the non-respiratory subtype (NRS), using serum phosphate as a biological marker. METHODS: Patients were assessed by a clinical interview followed by a structured diagnostic interview (M.I.N.I) and classified as RS or NRS based on symptoms. The severity of PD was evaluated throughout the PDSS, CGI, HAM-A, STAI and the BDI rating scales. All patients underwent 12 structured sessions of group-CBT for PD and had their blood collected at baseline and after treatment to assess phosphate levels. RESULTS: One hundred and thirty-eight patients have been assessed, and 102 were included in this trial. Sixty-nine patients completed the treatment protocol, 42 were classified as RS and 27 as NRS. Both RS and NRS patients improved in all clinical scales (p < 0.001). The mean phosphate levels increased from 2.44 mg/dl ±â€¯0.49 at baseline to 3.38 mg/dl ±â€¯0.52 (p < 0.01) in the RS group as well as from 2.46 mg/dl ±â€¯0.64 at baseline to 3.46 mg/dl ±â€¯0.61 (p < 0.01) in the NSR group. LIMITATIONS: Small sample size and the lack of assessment of other clinical and physiological parameters, such as respiratory variables. CONCLUSION: Our findings suggest that both RS and NRS benefit from group CBT and that there was a change in phosphate levels after effective treatment in both groups. Our data support the idea that there is a reversal of the conditions that promote hypophosphatemia as chronic hyperventilation after CBT treatment, whereas it is in disagreement to the presence of two different PD subtypes based on phosphate levels once their rates did not differ at baseline and had a similar increase after effective treatment.

Potential Biomarkers for NSAID-Exacerbated Respiratory Disease.

Asthma is a common chronic disease with several variant phenotypes and endotypes. NSAID-exacerbated respiratory disease (NERD) is one such endotype characterized by asthma, chronic rhinosinusitis (CRS) with nasal polyps, and hypersensitivity to aspirin/cyclooxygenase-1 inhibitors. NERD is more associated with severe asthma than other asthma phenotypes. Regarding diagnosis, aspirin challenge tests via the oral or bronchial route are a standard diagnostic method; reliable in vitro diagnostic tests are not available. Recent studies have reported various biomarkers of phenotype, diagnosis, and prognosis. In this review, we summarized the known potential biomarkers of NERD that are distinct from those of aspirin-tolerant asthma. We also provided an overview of the different NERD subgroups.

Changes in the level of cardiac troponine and disorders in pulmonary gas exchange as predictors of short- and long-term outcomes of patients with aneurysm subarachnoid haemorrhage.

SUBJECT: Cardiopulmonary abnormalities are common after aneurysmal subarachnoid haemorrhage (aSAH). However, the relationship between short- and long-term outcome is poorly understood. In this paper, we present how cardiac troponine elevations (cTnI) and pulmonary disorders are associated with short- and long-term outcomes assessed by the Glasgow Outcome Scale (GOS) and Extended Glasgow Outcome Scale (GOSE). METHODS: A total of 104 patients diagnosed with aSAH were analysed in the study. The non-parametric U Mann-Whitney test was used to evaluate the difference between good (GOS IV-V, GOSE V-VIII) and poor (GOS I-III, GOSE I-IV) outcomes in relation to cTnI elevation and pulmonary disorders. Outcome was assessed at discharge from the hospital, and then followed up 6 and 12 months later. Pulmonary disorders were determined by the PaO2/FiO2 ratio and radiography. The areas under the ROC curves (AUCs) were used to determine the predictive power of these factors. RESULTS: In the group with good short-term outcomes cTnI elevation on the second day after aSAH was significantly lower (p = .00007) than in patients with poor short-term outcomes. The same trend was observed after 6 months, although there were different results 12 months from the onset (p = .024 and n.s., respectively). A higher peak of cTnI was observed in the group with a pathological X-ray (p = .008) and pathological PaO2/FiO2 ratio (p ≪ .001). cTnI was an accurate predictor of short-term outcomes (AUC = 0.741, p ≪ .001) and the outcome after 6 months (AUC = 0.688, p = .015). CONCLUSION: The results showed that cardiopulmonary abnormalities perform well as predictive factors for short- and long-term outcomes after aSAH.

[The role of extracorporeal removal of CO2 (ECCO2R) in the management of respiratory diseases]. / Place de l'épuration extracorporelle de CO2 (ECCO2R) dans la prise en charge des pathologies respiratoires.

INTRODUCTION: The aim of extracorporeal removal of CO2 (ECCO2R) is to ensure the removal of CO2 without any significant effect on oxygenation. ECCO2R makes use of low to moderate extracorporeal blood flow rates, whereas extracorporeal membrane oxygenation (ECMO) requires high blood flows. STATE OF THE ART: For each ECCO2R device it is important to consider not only performance in terms of CO2 removal, but also cost and safety, including the incidence of hemolysis and of hemorrhagic and thrombotic complications. In addition, it is possible that the benefits of such techniques may extend beyond simple removal of CO2. There have been preliminary reports of benefits in terms of reduced respiratory muscle workload. Mobilization of endothelial progenitor cells could also occur, in analogy to the data reported with ECMO, with a potential benefit in term of pulmonary repair. The most convincing clinical experience has been reported in the context of the acute respiratory distress syndrome (ARDS) and severe acute exacerbations of chronic obstructive pulmonary disease (COPD), especially in patients at high risk of failure of non-invasive ventilation. PERSPECTIVES: Preliminary results prompt the initiation of randomized controlled trials in these two main indications. Finally, the development of these technologies opens new perspectives in terms of long-term ventilatory support.

Red cell distribution width as a novel predictor of postoperative respiratory adverse events after adenotonsillectomy.

BACKGROUND: Respiratory adverse events are commonly observed after adenotonsillectomy in children with sleep-disordered breathing. Preoperative prediction of these events enhances quality of care and resource management in facilities while encouraging precautions against them. Red cell distribution width, a measure of erythrocyte size variability, has recently been linked to adverse outcomes in a variety of disorders. Red cell distribution width has also been found to be associated with severity of obstructive sleep apnea in adults due to hypoxia-mediated inflammation. AIM: The objective of this study was to evaluate whether elevated red cell distribution width is associated with postoperative respiratory adverse events in children with symptoms of sleep-disordered breathing. METHODS: A prospective, observational, assessor-blinded study was conducted with consecutive children undergoing elective adenotonsillectomy for treatment of sleep-disordered breathing. Under general anesthesia, adenoidectomy was performed by curettage, and tonsillectomy was carried out by dissection. The primary outcome was the occurrence of an adverse event during emergence or in the postanesthesia care unit (PACU). RESULTS: Among 287 patients, with mean ± sd age 7.49 ± 3.21, the frequency of respiratory complications during emergence was 62 (22.30%) and in PACU was 56 (20.14%). Mean ± sd red cell distribution width was 14.36 ± 1.06 in patients with complications and higher than that in those without complications 13.53 ± 0.59. Red cell distribution width had an adjusted odds ratio 7.28 (95% CI: 4.30-13.28) and area under the curve value 0.74 (95% CI: 0.67-0.81) to predict postoperative complications. A cutoff value for red cell distribution width was found to be 14.7. CONCLUSION: Our study showed that preoperative elevated red cell distribution width is associated with an increased risk of respiratory adverse events in children undergoing adenotonsillectomy for sleep-disordered breathing.

Epigenetic regulation of redox state mediates persistent cardiorespiratory abnormalities after long-term intermittent hypoxia.

KEY POINTS: The effects of short-term (ST; 10 days) and long-term (LT; 30 days) intermittent hypoxia (IH) on blood pressure (BP), breathing and carotid body (CB) chemosensory reflex were examined in adult rats. ST- and LT-IH treated rats exhibited hypertension, irregular breathing with apnoea and augmented the CB chemosensory reflex, with all these responses becoming normalized during recovery from ST- but not from LT-IH. The persistent cardiorespiratory responses to LT-IH were associated with elevated reactive oxygen species (ROS) levels in the CB and adrenal medulla, which were a result of DNA methylation-dependent suppression of genes encoding anti-oxidant enzymes (AOEs). Treating rats with decitabine either during LT-IH or during recovery from LT-IH prevented DNA methylation of AOE genes, normalized the expression of AOE genes and ROS levels, reversed the heightened CB chemosensory reflex and hypertension, and also stabilized breathing. ABSTRACT: Rodents exposed to chronic intermittent hypoxia (IH), simulating blood O2 saturation profiles during obstructive sleep apnoea (OSA), have been shown to exhibit a heightened carotid body (CB) chemosensory reflex and hypertension. CB chemosensory reflex activation also results in unstable breathing with apnoeas. However, the effect of chronic IH on breathing is not known. In the present study, we examined the effects of chronic IH on breathing along with blood pressure (BP) and assessed whether the autonomic responses are normalized after recovery from chronic IH. Studies were performed on adult, male, Sprague-Dawley rats exposed to either short-term (ST; 10 days) or long-term (LT, 30 days) IH. Rats exposed to either ST- or LT-IH exhibited hypertension, irregular breathing with apnoeas, an augmented CB chemosensory reflex as indicated by elevated CB neural activity and plasma catecholamine levels, and elevated reactive oxygen species (ROS) levels in the CB and adrenal medulla (AM). All these effects were normalized after recovery from ST-IH but not from LT-IH. Analysis of the molecular mechanisms underlying the persistent effects of LT-IH revealed increased DNA methylation of genes encoding anti-oxidant enzymes (AOEs). Treatment with decitabine, a DNA methylation inhibitor, either during LT-IH or during recovery from LT-IH, prevented DNA methylation, normalized the expression of AOE genes, ROS levels, CB chemosensory reflex and BP, and also stabilized breathing. These results suggest that persistent cardiorespiratory abnormalities caused by LT-IH are mediated by epigenetic re-programming of the redox state in the CB chemosensory reflex pathway.

An ultra-high-performance liquid chromatography-tandem mass spectrometric method for the determination of hederacoside C, a drug candidate for respiratory disorder, in rat plasma.

Hederacoside C is a principal bioactive pharmaceutical ingredient of Hedera helix leaf extracts. H. helix extracts have long been used in folk medicine for the treatment of respiratory disorders. Currently, hederacoside C is investigated as a promising candidate for the treatment of respiratory diseases. In this study, an accurate, sensitive, rapid, and reliable bioanalytical method was developed for the determination of hederacoside C in rat plasma using ultra high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). For sample preparation, plasma proteins were precipitated with 0.1% acetic acid in acetonitrile. Waters UPLC BEH C18 (2.1mm I.D.×100mm, 1.7µm) column was used for chromatographic separation. A gradient elution of mobile phases consisting of 0.02% acetic acid in distilled water (solvent A) and 0.02% acetic acid in acetonitrile (solvent B) was used at a flow rate of 0.3mL/min. The multiple reaction monitoring (MRM) mode was used for mass spectrometric detection; the MRM transitions were m/z 1219.7→m/z 469.2 for hederacoside C and m/z 1108.3→m/z 221.2 for ginsenoside Rb1 (internal standard) in the negative ionization mode. A calibration curve was constructed in the range of 10-1000ng/mL. The intra- and inter-day precision and accuracy were within 5%. The developed UPLC-MS/MS method was successfully applied in a pharmacokinetic study of hederacoside C in rats. Hederacoside C was quickly but inadequately absorbed from the gastrointestinal tract of rats resulting in extremely low bioavailability and relatively slow clearance.

Research: Comparison of the Accuracy of a Pocket versus Standard Pulse Oximeter.

BACKGROUND: Pulse oximetry has become an essential tool in clinical practice. With patient self-management becoming more prevalent, pulse oximetry self-monitoring has the potential to become common practice in the near future. This study sought to compare the accuracy of two pulse oximeters, a high-quality standard pulse oximeter and an inexpensive pocket pulse oximeter, and to compare both devices with arterial blood co-oximetry oxygen saturation. METHODS: A total of 95 patients (35.8% women; mean [±SD] age 63.1 ± 13.9 years; mean arterial pressure was 92 ± 12.0 mmHg; mean axillar temperature 36.3 ± 0.4°C) presenting to our hospital for blood gas analysis was evaluated. The Bland-Altman technique was performed to calculate bias and precision, as well as agreement limits. Student's t test was performed. RESULTS: Standard oximeter presented 1.84% bias and a precision error of 1.80%. Pocket oximeter presented a bias of 1.85% and a precision error of 2.21%. Agreement limits were -1.69% to 5.37% (standard oximeter) and -2.48% to 6.18% (pocket oximeter). CONCLUSION: Both oximeters presented bias, which was expected given previous research. The pocket oximeter was less precise but had agreement limits that were comparable with current evidence. Pocket oximeters can be powerful allies in clinical monitoring of patients based on a self-monitoring/efficacy strategy.

[Pneumology and Sports: An Outpatient Endurance Training with Sports Medical Guidance as an Effective Non-pharmacological Therapy in Pneumology - a Feasibility Study]. / Pneumologie und Sport: Ein ambulantes Ausdauertraining mit sportmedizinischer Anleitung als effektive nicht-medikamentöse Therapiemaßnahme in der Pneumologie - eine Projektstudie.

BACKGROUND: In the process of medical rehabilitation muscular endurance training is the main focus. Unfortunately, outpatient rehabilitation opportunities are limited and specialized pulmonary exercise groups ("lung sport groups") rarely available. Therefore we developed an outpatient endurance sports program for patients with respiratory diseases and evaluated its effectiveness. METHODS: In this feasibility study 31 patients (50 ±â€Š15 years) with diverse respiratory diseases were included. By professional functional exercise testing (incl. CPET and lactate measurement according to the standards of DGP and DGSP) the patients optimal training zone was determined and an individualized 12 week lasting aerobic endurance training with ≥ 3 sessions of 20 - 60 min/week realized. RESULTS: After completion of the exercise training program a significant improvement in dyspnoea (Borg-Scale: 65.7 ±â€Š12.2 vs. 62.2 ±â€Š12.6, p = 0.013), body constitution (BMI: 25.7 ±â€Š3.3 vs. 24.3 ±â€Š3.2 kg/m(2), p = 0.018; portion of body fat: 24.8 ±â€Š5.8 vs. 23.8 ±â€Š6.4 %, p = 0.043) as well as physical capacity (VO2 at 4 mmol/l Laktat: 24.2 ±â€Š6.9 vs. 26.5 ±â€Š7.6 ml/min/kg, p < 0.01; performance at 4 mmol/l Laktat: running/walking (n = 14) + 1.1 km/h, p = 0.018 and biking/bicycle ergometer (n = 17) + 8.7 Watt, p = 0.019) was recorded. These positive developments were also observed in mental and physical quality of life (quality of life questionnaire SF-36: physical score + 9.7 points, mental score + 4.5 points). CONCLUSION: The evaluated exercise program can easily be trained by the patient in a self-dependent setting and was seen to be an effective sports medical treatment in patients with diverse pulmonary diseases.

"Real life use" of troponin in the emergency department: a survey of over 3000 cases.

INTRODUCTION: The aim of this study was to identify clinical variables which may be independently associated with positivity of a cardiac troponin I (cTnI) assay in a large population of patients admitted to the emergency department (ED). MATERIALS AND METHODS: 3166 subjects, with at least two troponin I tests ordered within 6 hours in the ED, were studied. Patient data were statistically analyzed to identify clinical associations with increased values of Troponin I. RESULTS: Although patients with diagnosis of acute coronary syndrome displayed troponin I values significantly higher than those of other groups, positivity to troponin I (>40 ng/L) was also observed in patients with other clinical conditions. In multivariate analysis, age, elevated heart rate and electrocardiographic changes were independently associated with troponin I positivity at admission. In the whole study population troponin I positivity exhibited high sensitivity and negative predictive value, counterbalanced by low specificity and limited positive predictive value. CONCLUSIONS: Troponin I positivity should be combined with history and clinical evaluation and cautiously interpreted in the ED, especially in patients exhibiting factors associated with higher troponin I levels such as older age, elevated heart rate or ECG changes.