Heart rate response determines long term exercise capacity after heart transplantation

BACKGROUND: Exercise capacity after heart transplantation (HTx) remains limited despite normal left ventricular systolic function of the allograft. Various clinical and haemodynamic parameters are predictive of exercise capacity following HTx. However, the predictive significance of chronotropic competence has not been demonstrated unequivocally despite its immediate relevance for cardiac output. AIMS: This study assesses the predictive value of various clinical and haemodynamic parameters for exercise capacity in HTx recipients with complete chronotropic competence evolving within the first 6 postoperative months. METHODS: 51 patients were enrolled in this exercise study. Patients were included when at least >6 months after HTx and without negative chronotropic medication or factors limiting exercise capacity such as significant transplant vasculopathy or allograft rejection. Clinical parameters were obtained by chart review, haemodynamic parameters from current cardiac catheterisation, and exercise capacity was assessed by treadmill stress testing. A stepwise multiple regression model analysed the proportion of the variance explained by the predictive parameters. RESULTS: The mean age of these 51 HTx recipients was 55.4 +/- 13.2 yrs on inclusion, 42 pts were male and the mean time interval after cardiac transplantation was 5.1 +/- 2.8 yrs. Five independent predictors explained 47.5% of the variance observed for peak exercise capacity (adjusted R2 = 0.475). In detail, heart rate response explained 31.6%, male gender 5.2%, age 4.1%, pulmonary vascular resistance 3.7%, and body-mass index 2.9%. CONCLUSION: Heart rate response is one of the most important predictors of exercise capacity in HTx recipients with complete chronotropic competence and without relevant transplant vasculopathy or acute allograft rejection.

Diastolic dysfunction of the cardiac allograft and maximal exercise capacity

BACKGROUND: Peak oxygen uptake (peak Vo(2)) is an established integrative measurement of maximal exercise capacity in cardiovascular disease. After heart transplantation (HTx) peak Vo(2) remains reduced despite normal systolic left ventricular function, which highlights the relevance of diastolic function. In this study we aim to characterize the predictive significance of cardiac allograft diastolic function for peak Vo(2). METHODS: Peak Vo(2) was measured using a ramp protocol on a bicycle ergometer. Left ventricular (LV) diastolic function was assessed with tissue Doppler imaging sizing the velocity of the early (Ea) and late (Aa) apical movement of the mitral annulus, and conventional Doppler measuring early (E) and late (A) diastolic transmitral flow propagation. Correlation coefficients were calculated and linear regression models fitted. RESULTS: The post-transplant time interval of the 39 HTxs ranged from 0.4 to 20.1 years. The mean age of the recipients was 55 +/- 14 years and body mass index (BMI) was 25.4 +/- 3.9 kg/m(2). Mean LV ejection fraction was 62 +/- 4%, mean LV mass index 108 +/- 22 g/m(2) and mean peak Vo(2) 20.1 +/- 6.3 ml/kg/min. Peak Vo(2) was reduced in patients with more severe diastolic dysfunction (pseudonormal or restrictive transmitral inflow pattern), or when E/Ea was > or =10. Peak Vo(2) correlated with recipient age (r = -0.643, p < 0.001), peak heart rate (r = 0.616, p < 0.001) and BMI (r = -0.417, p = 0.008). Of all echocardiographic measurements, Ea (r = 0.561, p < 0.001) and Ea/Aa (r = 0.495, p = 0.002) correlated best. Multivariate analysis identified age, heart rate, BMI and Ea/Aa as independent predictors of peak Vo(2). CONCLUSIONS: Diastolic dysfunction is relevant for the limitation of maximal exercise capacity after HTx.

In vitro comparison of the complement-scavenging capacity of different intravenous immunoglobulin preparations

BACKGROUND AND OBJECTIVES: Complement inhibition is considered important in the mechanism of action of intravenous immunoglobulin (IVIG) in a number of inflammatory and autoimmune disorders. The capacity of different IVIG preparations to 'scavenge' activated C3 and thereby inhibit complement activation was assessed by a new in vitro assay. MATERIALS AND METHODS: Diluted human serum as a complement source, with or without addition of different concentrations of IVIG, was incubated in microtitre plates coated with heat-aggregated human IgG. Complement scavenging was measured by detecting reduced C3 binding and determining fluid phase C3b-IgG complex formation. Complement activation induced by the IVIG preparations was measured as C5a formation. RESULTS: All IVIG preparations exhibited a dose-dependent inhibition of C3b deposition, correlating strongly with binding of C3b to fluid-phase IgG, but the extent of complement scavenging varied considerably between different IVIG preparations. At an IVIG concentration of 0.9 mg/ml, the inhibition of C3b deposition ranged from 72 +/- 16% to 22 +/- 4.1%. The reduction of C3b deposition on the complement-activating surface was not due to IVIG-induced complement activation in the fluid phase, as shown by the low C5a formation in the presence of serum. CONCLUSION: In vitro analysis allows comparison of the complement-inhibitory properties of IVIG preparations. The extent of complement scavenging varies between the products.

Revenue Management in Make-To-Order Manufacturing: Case Study of Capacity Control at ThyssenKrupp VDM

While revenue management (RM) is traditionally considered a tool of service operations, RM shows considerable potential for application in manufacturing operations. The typical challenges in make-to-order manufacturing are fixed manufacturing capacities and a great variety in offered products, going along with pronounced fluctuations in demand and profitability. Since Harris and Pinder in the mid-90s, numerous papers have furthered the understanding of RM theory in this environment. Nevertheless, results to be expected from applying the developed methods to a practical industry setting have yet to be reported. To this end, this paper investigates a possible application of RM at ThyssenKrupp VDM, leading to considerable improvements in several areas.

Utilizing the full Capacity of Sorting Systems with new Infeed Technology

Utilisation of sorting systems’ maximum performance demands continuous conveying of goods by infeed lines to sorters. This is the case especially for sorters with one single infeed line, because the sorters’ performance is limited by the performance of the infeed line. Within this paper different infeed line constructions at the Rotary Sorter with diverse performances will be presented. The focus lies on a specific conveying system to synchronise the goods with the sorter by a performance of 6000 pieces per hour with one dynamic infeed line. By this means there is no extensive adjustment control of serial conveyors in the infeed line any longer.

Plant invasiveness is not linked to the capacity of regeneration from small fragments: an experimental test with 39 stoloniferous species

Fragmentation and vegetative regeneration from small fragments may contribute to population expansion, dispersal and establishment of new populations of introduced plants. However, no study has systematically tested whether a high capacity of vegetative regeneration is associated with a high degree of invasiveness. For small single-node fragments, the presence of internodes may increase regeneration capacity because internodes may store carbohydrates and proteins that can be used for regeneration. We conducted an experiment with 39 stoloniferous plant species to examine the regeneration capacity of small, single-node fragments with or without attached stolon internodes. We asked (1) whether the presence of stolon internodes increases regeneration from single-node fragments, (2) whether regeneration capacity differs between native and introduced species in China, and (3) whether regeneration capacity is positively associated with plant invasiveness at a regional scale (within China) and at a global scale. Most species could regenerate from single-node fragments, and the presence of internodes increased regeneration rate and subsequent growth and/or asexual reproduction. Regeneration capacity varied greatly among species, but showed no relationship to invasiveness, either in China or globally. High regeneration capacity from small fragments may contribute to performance of clonal plants in general, but it does not appear to explain differences in invasiveness among stoloniferous clonal species

Science for the Carpathians: Using Regional Capacity to Cope with Global Change

Emphasizing the global and regional importance of mountain ecosystem services and referring to the anticipated future environmental changes affecting the provision of these services, this chapter takes a closer look at the Carpathian Mountains. In addition to climate change and general effects of globalization, rapid socioeconomic transformations after the fall of the Iron Curtain pose an extra challenge to the sustainable development of the region. Describing the early efforts of organizing mountain science through programs such as UNESCO MAB and UNEP at the global scale, this chapter focuses on the recent history of research coordination for the European mountains, in particular on the activities of the Carpathian Convention and the European Program of the Mountain Research Initiative, which were among main driving factors for the initiation of the Science for the Carpathians (S4C) network. This regional mountain research network was established in 2008 to foster scientific collaboration and communication and to promote applied research and capacity building, which in turn would support sustainable development in the Carpathian Mountains. Forum Carpaticum, a biennial open science conference, has become a central activity of the S4C network counting more than 400 members today.

Exploring Water Governance Arrangements in the Swiss Alps From the Perspective of Adaptive Capacity

In times of increasing uncertainty because of climate and socioeconomic changes, the ability to deal with uncertainty and surprise is an essential requirement for the sustainability of alpine water governance. This article aims to contribute to the understanding of the adaptive capacity of water governance arrangements in the Swiss Alps and to propose options for reforms. To this purpose, we evaluated the current arrangements and the ways the actors have dealt with water shortages in the past, based on qualitative interviews and a document review. The research revealed that the adaptive capacity of the investigated arrangements is rather high with regard to reactive ways of responding to water shortage problems. However, there is limited capacity to proactively anticipate possible changes and to find prospective solutions on a regional scale. We conclude that with increased environmental and social pressures, forms of proactive water resource governance should be introduced, taking into account the welfare of people in both upstream and downstream areas.

Role of amylase, mucin, IgA and albumin on salivary protein buffering capacity: a pilot study

It has been suggested that proteins serve as major salivary buffers below pH5. It remains unclear, however, which salivary proteins are responsible for these buffering properties. The aim of this pilot study was to evaluate the correlation between salivary concentration of total protein, amylase, mucin, immunoglobulin A (IgA), albumin and total salivary protein buffering capacity at a pH range of 4-5. In addition, the buffering capacity and the number of carboxylic acid moieties of single proteins were assessed. Stimulated saliva samples were collected at 9:00, 13:00 and 17:00 from 4 healthy volunteers on 3 successive days. The buffering capacities were measured for total salivary protein or for specific proteins. Also, the concentration of total protein, amylase, mucin, IgA and albumin were analysed. Within the limits of the current study, it was found that salivary protein buffering capacity was highly positively correlated with total protein, amylase and IgA concentrations. A weak correlation was observed for both albumin and mucin individually. Furthermore, the results suggest that amylase contributed to 35 percent of the salivary protein buffering capacity in the pH range of 4-5.

Subclinical thyroid dysfunction and functional capacity among elderly

Background: Subclinical thyroid dysfunction is common among older people and has been associated with decreased functional capacity but with conflicting data. The aim of this study was to assess the association between subclinical thyroid dysfunction and functional capacity in an elderly population. Methods: We included 5182 participants with a mean age of 75.2 years from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER). Self-reported functional capacity was assessed using the Barthel Index (BI) and the Instrumental Activities of Daily Living (IADL) scores at baseline and during follow-up. Participants with subclinical hyperthyroidism (n=65) and subclinical hypothyroidism (n=173) were compared to euthyroid participants (n=4944). The association between persistent subclinical thyroid dysfunction and functional capacity and decline was also investigated. Results: At baseline, compared to euthyroid participants (BI 19.73±SE 0.06; IADL 13.52±0.02), there was no difference in functional capacity for participants with subclinical hyperthyroidism (BI 19.60±0.09; IADL 13.51±0.12, p>0.05) or subclinical hypothyroidism (BI 19.82±0.06; IADL 13.55±0.08, p>0.05). Over a mean 3.2-year follow-up period, there was no association between thyroid function and annual decline of either BI or IADL (p>0.05). No association was found between persistent subclinical thyroid dysfunction and functional capacity at baseline or during follow-up (p>0.05). Results were similar after excluding participants with a maximum BI and/or IADL score at baseline. Conclusion: Among well-functioning community-dwelling elderly, we found no evidence that subclinical thyroid dysfunction contributes to decreased functional capacity.