Exercise capacity reflects airflow limitation rather than hypoxaemia in patients with pulmonary arteriovenous malformations

Background: Pulmonary arteriovenous malformations (PAVMs) generate a right-to-left shunt. Impaired gas exchange results in hypoxemia and impaired CO2 clearance. Most patients compensate effectively but a proportion are dyspneic, and these are rarely the most hypoxaemic. Aim: To test degrees of concurrent pathology influencing exercise capacity. Design: Replicate, sequential single centre, prospective studies. Methods: Cardiopulmonary exercise tests (CPET) were performed in 26 patients with PAVMs, including individuals with and without known airflow obstruction. To replicate, relationships were tested prospectively in an independent cohort where self-reported exercise capacity evaluated by the Veterans Specific Activity Questionnaire (VSAQ) was used to calculate metabolic equivalents at peak exercise (METS N = 71). Additional measurements included oxygen saturation (SpO2), forced expiratory volume in 1 second (FEV1), vital capacity (VC), exhaled nitric oxide (FeNO), haemoglobin and iron indices. Results: By CPET, the peak work-rate was only minimally associated with low SpO2 or low arterial oxygen content (CaO2=1.34 x SpO2 x haemoglobin), but was reduced in patients with low FEV1 or VC. Supranormal work-rates were seen in patients with severe right-to-left shunting and SpO2 80% predicted. VSAQ-calculated METS also demonstrated little relationship with SpO2, and in crude and CaO2-adjusted regression, were lower in patients with lower FEV1 or VC. Bronchodilation increased airflow even where spirometry was in the normal range: exhaled nitric oxide measurements were normal in 80% of cases, and unrelated to any PAVM-specific variable. Conclusions: Exercise capacity is reduced by relatively mild airflow limitation (obstructive or restrictive) in the setting of PAVMs

Protein and folic acid content in the maternal diet determine lipid metabolism and response to high-fat feeding in rat progeny in an age-dependent manner

Maternal diet during gestation can exert a long-term effect on the progeny’s health by programming their developmental scheme and metabolism. The aim of this study is to analyze the influence of maternal diet on lipid metabolism in 10- and 16-week-old rats. Pregnant dams were fed one of four diets: a normal protein and normal folic acid diet (NP-NF), a protein-restricted and normal folic acid diet (PR-NF), a protein-restricted and folic-acid-supplemented diet (PR-FS), or a normal protein and folic-acid-supplemented diet (NP-FS). We also tested whether prenatal nutrition determines the reaction of an organism to a postweaning high-fat diet. Blood biochemistry and biometrical parameters were evaluated. The expression patterns of PPARα, PPARγ, and LXRα in the liver and adipose tissue were examined by real-time PCR. In the 10-week-old, rats folic acid supplementation of the maternal diet was associated with reduced circulating glucose and total cholesterol concentrations (P < 0.01 and P < 0.001, respectively). Neither prenatal diets nor postnatal feeding affected blood insulin concentrations. In the 16-week-old rats, body weight, abdominal fat mass and central adiposity were reduced in the progeny of the folic acid–supplemented dams (P < 0.01, P < 0.001 and P < 0.01, respectively). Maternal protein restriction had no effect on biometry or blood biochemical parameters. Folic acid supplementation of the maternal diet was associated with reduced expression of PPARα, PPARγ, and LXRα in the liver (P < 0.001). Reduced protein content in the maternal diet was associated with increased PPARα mRNA level in the liver (P < 0.001) and reduced LXRα in adipose tissue (P < 0.01). PPARα and PPARγ transcription in the liver, as well as LXRα transcription in adipose tissue, was also dependent on interaction effects between prenatal and postnatal diet compositions. PPARγ transcription in the liver was correlated with the abdominal fat mass, body weight, and calorie intake, while PPARγ transcription in adipose tissue was correlated with reduced body weight and calorie intake. Total serum cholesterol concentration was correlated with LXRα transcription in the liver. Folic acid supplementation of the maternal diet may have favorable effects for lipid metabolism in the progeny, but these effects are modified by the postnatal diet and age. Furthermore, the expression of LXRα, PPARα, and PPARγ in the liver and adipose tissue largely depends on the protein and folic acid content in the maternal diet during gestation. However, the altered transcription profile of these key regulators of lipid metabolism does not straightforwardly explain the observed phenotype

The Veterans Specific Activity Questionnaire (VSAQ) - a new and efficient method of assessing exercise capacity in patients with pulmonary arteriovenous malformations

INTRODUCTION: Assessment of performance status is an important component of clinical management of patients with pulmonary arteriovenous malformations (PAVMs). Usual methods are time-consuming and insensitive to variationswithinnormal or supranormal exercise capacity.METHODS: TheVeterans Specific Activity Questionnaire (VSAQ) wasmodifiedto facilitate completion by patients independently. Patient-reported activity limitations were converted to the MRC Dyspnea scale, NYHA Classification,and metabolic equivalents (METs) in which 1 MET equals the consumption of 3.5 ml O2per kilogram of body weight. RESULTS: The study population of71 patients with PAVMswas aged 20-85 (median 52) years.SaO2was80-99.5% (median 96%), and haemoglobin73-169g/L in females and 123-197g/L in males (p5; MRC Dyspnea Scale 1 or 2; NYHA Class I). SaO2was inversely associated with the MRC Dyspnea scale and NYHA class, but not theVSAQ. Raw VSAQ scores captured a marked difference between malesand females. METSwere also higherin malesat 3.97-15.55(median 8.84)kcal/kg/hour, compared to 1.33-14.4(median 8.25)kcal/kg/hour(p=0.0039). There was only a modest association between METsand oxygen saturation (SaO2, p=0.044), but a stronger association between METsand haemoglobin (p=0.001).In crude and sex-adjusted regression, the arterial oxygen content (CaO2) was more strongly associated with METsthan either SaO2or haemoglobin in isolation.CONCLUSION: The VSAQ,capturing patient reported outcome measures,is an efficient and quantifiable measure of exercise capacity that can be readily employed in clinical services particularly wherepatients have normal to high exercise tolerance. In the PAVM population, exercise capacityreflects haemoglobin andCaO2more than SaO2, even where SaO2measurements are low

Persistent Object Systems: From Technology to Market

Abstract. This text describes how persistent object system technology developed in European basic research is being used by a small German startup software company to realize innovative customer-oriented information services on the Internet. The description of this particular \entrepreneurial experiment &quot; is intended to provide some input to the discussion of possibilities to stimulate the uptake of academic research results by industry in Germany

Triage assessment of cardiorespiratory risk status based on measurement of the anaerobic threshold, and estimation by activity limitation in patients with pulmonary arteriovenous malformations and hereditary haemorrhagic telangiectasia

BACKGROUND: Rapid triaging, as in the current COVID-19 pandemic, focuses on age and pre-existing medical conditions. In contrast, preoperative assessments use cardiopulmonary exercise testing (CPET) to categorise patients to higher and lower risk independent of diagnostic labels. Since CPET is not feasible in population-based settings, our aims included evaluation of a triage/screening tool for cardiorespiratory risk. METHODS: CPET-derived anaerobic thresholds were evaluated retrospectively in 26 patients with pulmonary arteriovenous malformations (AVMs) who represent a challenging group to risk-categorise. Pulmonary AVM-induced hypoxaemia secondary to intrapulmonary right-to-left shunts, anaemia from underlying hereditary haemorrhagic telangiectasia and metabolic equivalents derived from the 13-point Veterans Specific Activity Questionnaire (VSAQ) were evaluated as part of routine clinical care. Pre-planned analyses evaluated associations and modelling of the anaerobic threshold and patient-specific variables. RESULTS: In the 26 patients (aged 21-77, median 57 years), anaerobic threshold ranged from 7.6-24.5 (median 12.35) ml.min-1kg-1 and placed more than half of the patients (15, 57.7%) in the >11 ml.min-1kg-1 category suggested as lower-risk for intra-abdominal surgeries. Neither age nor baseline SpO2 predicted anaerobic threshold, or lower/higher risk categories, either alone or in multivariate analyses, despite baseline oxygen saturation (SpO2) ranging from 79 to 99 (median 92)%, haemoglobin from 108 to 183 (median 156)g.L-1. However, lower haemoglobin, and particularly, arterial oxygen content and oxygen pulse were associated with increased cardiorespiratory risk: Modelling a haemoglobin increase of 25g.L-1 placed a further 7/26 (26.9%) patients in a lower risk category. For patients completing the VSAQ, derived metabolic equivalents were strongly associated with anaerobic threshold enabling risk evaluations through a simple questionnaire. CONCLUSIONS: Baseline exercise tolerance may override age and diagnostic labels in triage settings. These data support approaches to risk reduction by aerobic conditioning and attention to anaemia. The VSAQ is suggested as a rapid screening tool for cardiorespiratory risk assessment to implement during triage/screening