Low intensity,long-term outpatient rehabilitation in COPD: a randomised controlled trial

Background

Most pulmonary rehabilitation programmes currently involve 2–3 sessions per week as recommended by international guidelines. We aimed to investigate whether relevant improvements in physical capabilities and quality of life in patients with chronic obstructive pulmonary disease (COPD) could be achieved by a long-term, low intensity, once weekly rehabilitation programme using limited resources.

Methods

100 patients with moderate to severe COPD were randomised to a continuous outpatient interdisciplinary rehabilitation programme or standard care. Physiotherapy-led supervised outpatient training sessions were performed once weekly in addition to educational elements. Outcome measures at baseline and after 26 weeks were 6-minute-walk-test, cycle ergometry, and health-related quality of life.

Results

37 patients in the training group and 44 patients in the control group completed the study. After 26 weeks there were clinically significant differences between the groups for 6 minute-walk-distance (+59 m, 95% CI 28–89 m), maximum work load (+7.4 Watt, 95% CI 0.5-13.4 Watt) and St. George’s Respiratory Questionnaire score (−5 points, 95% CI −10 to −1 points). Total staff costs of the programme per participant were ≤ €625.

Conclusion

Clinically meaningful improvements in physical capabilities and health-related quality of life may be achieved using long-term pulmonary rehabilitation programmes of lower intensity than currently recommended. Trial registration: clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01195402","term_id":"NCT01195402"}}NCT01195402.     

Pex19 is involved in importing dually targeted tail‐anchored proteins to both mitochondria and peroxisomes

Tail‐anchored (TA) proteins are embedded into their corresponding membrane via a single transmembrane segment at their C‐terminus whereas the majority of the protein is facing the cytosol. So far, cellular factors that mediate the integration of such proteins into the mitochondrial outer membrane were not found. Using budding yeast as a model system, we identified the cytosolic Hsp70 chaperone Ssa1 and the peroxisome import factor Pex19 as import mediators for a subset of mitochondrial TA proteins. Accordingly, deletion of PEX19 results in: (1) growth defect under respiration conditions, (2) alteration in mitochondrial morphology, (3) reduced steady‐state levels of the mitochondrial TA proteins Fis1 and Gem1, and (4) hampered in organello import of the TA proteins Fis1 and Gem1. Furthermore, recombinant Pex19 can bind directly the TA proteins Fis1 and Gem1. Collectively, this work identified the first factors that are involved in the biogenesis of mitochondrial TA proteins and uncovered an unexpected function of Pex19.      

Functional properties and lineage relationship of CD8+ T cell subsets identified by expression of IL-7 receptor alpha and CD62L

Three major subsets of Ag-experienced CD8+ T cells have been identified according to their expression of CD62L and CD127. These markers are associated with central memory T cells (CD62L+ CD127+), effector memory T cells (CD162L- CD127+), and effector T cells (CD62L- CD127-). In this study we characterized the development of these three populations during acute and chronic viral infections and after immunization with virus-like particles and determined their lineage relation and functional and protective properties. We found that the balance between the three subsets was critically regulated by the availability of Ag and time. After initial down-regulation of CD127, the responding CD8+ T cell population down-regulated CD62L and re-expressed CD127. Dependent on Ag availability, the cells then further differentiated into CD62L- CD127- effector cells or, in the absence of Ag, re-expressed CD62L to become central memory T cells. Although all three populations efficiently produced effector cytokines such as IFN-gamma, CD62L- CD127- effector cells exhibited the highest ex vivo lytic potential. In contrast, CD62L+ CD127+ central memory T cells most efficiently produced IL-2 and proliferated extensively in vitro and in vivo upon antigenic restimulation. Strikingly, only effector and effector memory, but not central memory, T cells were able to protect against peripheral infection with vaccinia virus, whereas central memory T cells were most potent at protecting against systemic infection with lymphocytic choriomeningitis virus, indicating that the antiviral protective capacities of specific CD8+ T cell subsets are closely related to the nature of the challenging pathogen.     

Receptor-Dependent and -Independent Axonal Retrograde Transport of Poliovirus in Motor Neurons

Poliovirus (PV), when injected intramuscularly into the calf, is incorporated into the sciatic nerve and causes an initial paralysis of the inoculated limb in transgenic (Tg) mice carrying the human PV receptor (hPVR/CD155) gene. We have previously demonstrated that a fast retrograde axonal transport process is required for PV dissemination through the sciatic nerves of hPVR-Tg mice and that intramuscularly inoculated PV causes paralytic disease in an hPVR-dependent manner. Here we showed that hPVR-independent axonal transport of PV was observed in hPVR-Tg and non-Tg mice, indicating that several different pathways for PV axonal transport exist in these mice. Using primary motor neurons (MNs) isolated from these mice or rats, we demonstrated that the axonal transport of PV requires several kinetically different motor machineries and that fast transport relies on a system involving cytoplasmic dynein. Unexpectedly, the hPVR-independent axonal transport of PV was not observed in cultured MNs. Thus, PV transport machineries in cultured MNs and in vivo differ in their hPVR requirements. These results suggest that the axonal trafficking of PV is carried out by several distinct pathways and that MNs in culture and in the sciatic nerve in situ are intrinsically different in the uptake and axonal transport of PV.In humans, paralytic poliomyelitis results from the invasion of the central nervous system by circulating poliovirus (PV), probably via the blood-brain barrier. This conclusion is supported by the finding that circulating PV after intravenous inoculation in mice appears to cross the blood-brain barrier at a high rate in a human PV receptor (hPVR/CD155)-independent manner (44). After the virus enters the central nervous system, it replicates in neurons, especially in motor neurons (MNs), inducing the cell death that causes paralytic poliomyelitis. Along with this route of dissemination, a neuron-specific pathway has been reported in humans (31), monkeys (18), and PV-sensitive transgenic (Tg) mice carrying the hPVR gene (34, 37). This neuron-specific pathway appears to be important in causing “provocation poliomyelitis,” which is triggered by injuries after PV ingestion (11). Using differentiated PC12 cells and a PV-sensitive Tg mouse line, we have shown that intramuscularly inoculated PV is taken up by endocytosis at synapses.hPVR is a member of the immunoglobulin (Ig) superfamily, with three linked extracellular Ig-like domains, followed by a membrane-spanning domain and a cytoplasmic domain. Two membrane-bound forms (α and δ) and two secreted forms (β and γ) of hPVR derived by alternative splicing are likely to be expressed in human cells (23). Membrane-bound hPVRs are considered to play important roles in the early steps of infection, such as the binding of the virus to the cell surface, its entry into the cell, and the uncoating of the virus. The N-terminal Ig-like domain harbors the sites for PV binding, and anti-hPVR monoclonal antibodies (MAbs) directed against this region block PV infection (9, 24, 39).hPVR has the ability to alter the conformation of PV from the 160S intact infectious particle to a 135S particle from which the viral capsid protein VP4 is missing (2, 29). PV-related materials recovered from the sciatic nerves of PV-sensitive Tg mice after intramuscular inoculation with PV were mainly composed of intact 160S virions. The amount of 160S particles recovered was greatly reduced by coinjection with MAb p286, which specifically recognizes hPVR (34). Thus, most of the intramuscularly inoculated PV is incorporated into the sciatic nerves of PV-sensitive Tg mice as intact particles in an hPVR-dependent manner. This surprising finding might be due to either of two alternative, yet not mutually exclusive, possibilities: (i) a small number of PVRs bound per virion does not result in a conformational change in the viral capsid with a loss of VP4, but it is sufficient to induce endocytosis of the virus on the cell surface, or (ii) a cellular inhibitor(s) of PV uncoating may exist in the endocytic pathway responsible for PV uptake and transport in Tg mice (34).This mouse strain also allowed us to demonstrate that PV inoculated into the calf was incorporated into the sciatic nerve and retrogradely transported through the axons as intact virion particles. Furthermore, PV dissemination via the neural pathway has been found to rely on a fast retrograde axonal transport system and was inhibited by MAb p286 (34). Moreover, the efficient direct interaction of the hPVR cytoplasmic domain with Tctex-1, a light chain of cytoplasmic dynein (21), has been suggested to play an important role in retrograde transport, together with microtubule integrity (33). Cytoplasmic dynein, a minus-end-directed microtubule-based motor complex (13, 14, 17, 43), is implicated in the transport of early and late endosomes, lysosomes, synaptic vesicles, and endoplasmic reticulum along microtubules (1, 8, 13, 14, 17, 43). Notwithstanding the recent progress in the understanding of PV trafficking, the molecular determinants of the axonal transport of PV in MNs have not yet been elucidated.Despite the importance of axonal retrograde transport in health and disease, the direct visualization of retrograde transport and its quantitative analysis have been hampered by the lack of a reliable assay for living MNs. Such an assay was established in MNs by using a nontoxic fluorescent fragment of tetanus toxin (TeNT H_C), which binds to MNs and is retrogradely transported (28). Here, we applied this assay to the visualization of PV in living MNs.We employed hPVR-Tg and non-Tg mice, together with cultured MNs isolated from these mice, to clarify the mechanisms of axonal retrograde transport of PV. Experiments involving cultured MNs showed that the entry and axonal transport of PV are strictly hPVR dependent. However, hPVR-independent axonal transport of PV can be observed in non-Tg as well as in hPVR-Tg mice, suggesting that multiple axonal transport routes for PV are present in vivo.     

Preparation, Tc-labeling and biodistribution studies of a PNA oligomer containing a new ligand derivative of 2,2′-dipicolylamine

A new azido derivative of 2,2′-dipicolylamine (Dpa), 2-azido-N,N-bis((pyridin-2-yl)methyl)ethanamine, (Dpa-N₃) was readily prepared from the known 2-(bis(pyridin-2-ylmethyl)amino)ethanol (Dpa-OH). It was demonstrated that Dpa-N₃ could be efficiently labeled with both [Re(CO)₃(H₂O)₃]Br and [^99mTc(H₂O)₃(CO)₃]⁺ to give [Re(CO)₃(Dpa-N₃)]Br and [^99mTc(CO)₃(Dpa-N₃)]⁺, respectively. Furthermore, Dpa-N₃ was successfully coupled, on the solid phase, to a Peptide Nucleic Acid (PNA) oligomer (H-4-pentynoic acid-spacer-spacer-tgca-tgca-tgca-Lys-NH₂; spacer = -NH-(CH₂)₂-O-(CH₂)₂-O-CH₂-CO-) using the Cu(I)-catalyzed [2 + 3] azide/alkyne cycloaddition (Cu-AAC, often referred to as the prototypical “click” reaction) to give the Dpa-PNA oligomer. Subsequent labeling of Dpa-PNA with [^99mTc(H₂O)₃(CO)₃]⁺ afforded [^99mTc(CO)₃(Dpa-PNA)] in radiochemical yields > 90%. Partitioning experiments in a 1-octanol/water system were carried out to get more insight on the lipophilicity of [^99mTc(CO)₃(Dpa-N₃)]⁺ and [^99mTc(CO)₃(Dpa-PNA)]. Both compounds were found rather hydrophilic (log D_o/w values at pH = 7.4 are −0.50: [^99mTc(CO)₃(Dpa-N₃)]⁺ and −0.85: [^99mTc(CO)₃(Dpa-PNA)]. Biodistribution studies of [^99mTc(CO)₃(Dpa-PNA)] in Wistar rats showed a very fast blood clearance (0.26 ± 0.1 SUV, 1 h p.i.) and modest accumulation in the kidneys (5.45 ± 0.45 SUV, 1 h p.i.). There was no significant activity in the thyroid and the stomach, demonstrating a high in vivo stability of the ^99mTc-labeled Dpa-PNA conjugate.     

Mitochondrial steps of arginine biosynthesis are conserved in the hydrogenosomes of the chytridiomycete Neocallimastix frontalis

Arginine biosynthesis in eukaryotes is divided between the mitochondria and the cytosol. The anaerobic chytridiomycete Neocallimastix frontalis contains highly reduced, anaerobic modifications of mitochondria, the hydrogenosomes. Hydrogenosomes also occur in the microaerophilic flagellate Trichomonas vaginalis, which does not produce arginine but uses one of the mitochondrial enzymes, ornithine transcarbamoylase, in a cytosolic arginine dihydrolase pathway for ATP generation. EST sequencing and analysis of the hydrogenosomal proteome of N. frontalis provided evidence for two mitochondrial enzymes of arginine biosynthesis, carbamoylphosphate synthase and ornithine transcarbamoylase, while activities of the arginine dehydrolase pathway enzymes were not detectable in this fungus.     

Aberrant cytokine pattern of the nasal mucosa in granulomatosis with polyangiitis

Introduction

In granulomatosis with polyangiitis (GPA), a complex autoimmune small-vessel vasculitis frequently associated with chronic necrotizing inflammation of the nasal mucosa, elevated nasal Staphylococcus (S.) aureus carrier rates are a risk factor for relapse. As cytokines are primarily involved in the regulation of defense against potentially pathogenic microorganisms, the aim of this study was to compare healthy individuals and GPA patients with respect to their baseline cytokine expression of nasal epithelial cells (NEC), which form the first barrier against such triggers. The ability of S. aureus to influence the nasal microenvironment''s cytokine secretion was assessed by exemplary stimulation experiments.

Methods

Baseline expression of 19 cytokines of primary NEC of GPA patients and normal controls (NC) was quantified by a multiplex cytokine assay. Stimulation experiments were performed with supernatants of S. aureus and expression of interleukin-8 was determined by ELISA.

Results

In GPA, an altered pattern of baseline cytokine expression with significantly up-regulated G-CSF and reduced interleukin (IL)-8 concentrations was observed. Both NEC of GPA patients and NC responded to stimulation with S. aureus, but GPA patients displayed a significantly lower IL-8 secretion and a diminished dynamic range of response towards the stimulus.

Conclusions

The data presented underline the hypothesis of a disturbed epithelial nasal barrier function in GPA. The dysregulated baseline expression of G-CSF and IL-8 and the reduced response to microbial stimulation may facilitate changes in the composition of the nasal flora and favour an imbalanced inflammatory response, which might be relevant for the disease course.     

An analysis of heat effects in different subpopulations of Bangladesh

A substantial number of epidemiological studies have demonstrated an association between atmospheric conditions and human all-cause as well as cause-specific mortality. However, most research has been performed in industrialised countries, whereas little is known about the atmosphere–mortality relationship in developing countries. Especially with regard to modifications from non-atmospheric conditions and intra-population differences, there is a substantial research deficit. Within the scope of this study, we aimed to investigate the effects of heat in a multi-stratified manner, distinguishing by the cause of death, age, gender, location and socio-economic status. We examined 22,840 death counts using semi-parametric Poisson regression models, adjusting for a multitude of potential confounders. Although Bangladesh is dominated by an increase of mortality with decreasing (equivalent) temperatures over a wide range of values, the findings demonstrated the existence of partly strong heat effects at the upper end of the temperature distribution. Moreover, the study demonstrated that the strength of these heat effects varied considerably over the investigated subgroups. The adverse effects of heat were particularly pronounced for males and the elderly above 65 years. Moreover, we found increased adverse effects of heat for urban areas and for areas with a high socio-economic status. The increase in, and acceleration of, urbanisation in Bangladesh, as well as the rapid aging of the population and the increase in non-communicable diseases, suggest that the relevance of heat-related mortality might increase further. Considering rising global temperatures, the adverse effects of heat might be further aggravated.     

Gas exchange pattern in the two‐spot ladybird beetle,Adalia bipunctata,differs in dry vs. moist air

Gas exchange patterns in the ladybird beetle, Adalia bipunctata (L.) (Coleoptera: Coccinellidae), were investigated using an infrared gaseous analyser (IRGA) and a coulometric O₂ respirometer (manometric–volumetric system). Before testing, the beetles were kept either in dry (dehydrated) or moist (hydrated) conditions for 1 day. Their subsequent gas exchange patterns did not depend on their state of humidity but rather were controlled by the humidity of the insect chamber during gas exchange measurement. If this chamber contained dry air, the beetles exhibited CO₂ release by burst, which we interpreted as cyclic gas exchange (CGE) with inter‐burst periods, but if the chamber was switched to contain moist air, then cyclic CO₂ release was soon abandoned and a pattern of continuous gas exchange appeared. Measurements with the coulometric respirometer in moist air showed that continuous gas exchange was often associated with weak abdominal pulsations, which we interpreted as active ventilation. Their metabolic rate was lower during gas exchange cycles than during continuous gas exchange. We revealed that in the ladybird beetle metabolic rate increased in moist air when the gas exchange pattern transitioned from cyclic to continuous.