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1.
Eur Respir J ; 63(2)2024 Feb.
Article in English | MEDLINE | ID: mdl-38097208

ABSTRACT

BACKGROUND: Pleural biopsy is the gold standard for diagnosis of pleural malignancy but a significant proportion will have an inconclusive biopsy despite ongoing clinical suspicion of malignancy. We investigated whether positron emission tomography-computed tomography (PET-CT) targeted pleural biopsy is superior to standard CT-guided pleural biopsy following an initial non-diagnostic biopsy. METHODS: The TARGET trial was a multicentre, parallel group randomised trial. Patients with a previous inconclusive pleural biopsy but an ongoing suspicion of pleural malignancy were randomised (1:1) to receive either CT-guided biopsy (standard care) or PET-CT followed by a targeted CT biopsy (intervention). The primary outcome was pleural malignancy correctly identified from the trial biopsy. RESULTS: Between September 2015 and September 2018, 59 participants were randomised from eight UK hospital sites: 29 to CT-only followed by targeted biopsy and 30 to PET-CT followed by targeted biopsy. The proportion of pleural malignancy correctly identified was similar between the groups (risk ratio 1.03 (95% CI 0.83-1.29); p=0.77). The sensitivity of the trial biopsy to identify pleural malignancy was 79% (95% CI 54-94%) in the CT-only group versus 81% (95% CI 54-96%) in the PET-CT group. CONCLUSIONS: The results do not support the practice of PET-CT to guide pleural biopsies in patients with a previous non-diagnostic biopsy. The diagnostic sensitivity in the CT-only group was higher than anticipated and supports the practice of repeating a CT-guided biopsy following an inconclusive result if clinical suspicion of malignancy persists.


Subject(s)
Pleural Diseases , Pleural Neoplasms , Humans , Positron Emission Tomography Computed Tomography , Tomography, X-Ray Computed , Image-Guided Biopsy/methods , Biopsy , Pleural Neoplasms/diagnostic imaging , Pleural Neoplasms/pathology
2.
Int J Mol Sci ; 24(9)2023 Apr 26.
Article in English | MEDLINE | ID: mdl-37175605

ABSTRACT

For practical applications of superconductors, understanding the vortex matter and dynamics is of paramount importance. An important issue in this context is the transition of the vortex glass, which is a true superconducting phase, into a vortex liquid phase having a linear dissipation. By using multi-harmonic susceptibility studies, we have investigated the vortex glass-vortex liquid phase transitions in CaKFe4As4 and BaFe2(As0.68P0.32)2 single crystals. The principle of our method relates the on-set of the third-harmonic susceptibility response with the appearance of a vortex-glass phase in which the dissipation is non-linear. Similar to the high-critical temperature cuprate superconductors, we have shown that even in these iron-based superconductors with significant lower critical temperatures, such phase transition can be treated as a melting in the sense of Lindemann's approach, considering an anisotropic Ginzburg-Landau model. The experimental data are consistent with a temperature-dependent London penetration depth given by a 3D XY fluctuations model. The fitting parameters allowed us to extrapolate the vortex melting lines down to the temperature of liquid hydrogen, and such extrapolation showed that CaKFe4As4 is a very promising superconducting material for high field applications in liquid hydrogen, with a melting field at 20 K of the order of 100 T.


Subject(s)
Superconductivity , Vitrification , Humans , Phase Transition , Anisotropy , Fever , Hydrogen
3.
Exp Ther Med ; 25(4): 181, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37006874

ABSTRACT

Tendon lesions have a great effect on the quality of life and medical spending. Thus is important to investigate the mechanisms responsible for tendon healing and to identify novel treatment options. The aim of the present study was to evaluate the effect of Selenium on the healing processes of injured tendons. A total of 20 Wistar male rats were used and were split into two groups with two different treatment methods. The first group received a normal food administration, while the second group received Na2SeO3. The animals were kept for 28 days. During the eighth day, all animals underwent surgical experimental Achilles tendon lesion and a Kessler-type suture. After three weeks, the animals were sacrificed and the tendon was extracted for histological evaluation in order to do a comparison according to the Movin scale (modified by Bonar). The histological evaluation revealed an even orientation of the collagen fibers in the case of the experimental group (Se) compared with the second group. The Bonar score was 1.62 for the Se group, while the control group had a Bonar score of 1.98. The average number of tenocytes in the Se group was lower which is demonstrated by a lower Bonar score (1.22), compared with the second group (Bonar Score 1.85). In addition, a slightly higher number of tenocytes compared with the intact tendon areas was recorded. In vascularization, a decreased amount of blood vessels in the experimental group (Se) was observed (Bonar Score 1.70), compared with the control group (Bonar score 1.96). The present study demonstrated that Selenium administration on murine models could be beneficial for tendon healing. Further clinical research is required in order for this to be confidently recommended.

4.
Methods Enzymol ; 669: 229-259, 2022.
Article in English | MEDLINE | ID: mdl-35644173

ABSTRACT

Coenzyme B12 (adenosylcobalamin) -dependent ethanolamine ammonia-lyase (EAL) is the signature enzyme in ethanolamine utilization metabolism associated with microbiome homeostasis and disease conditions in the human gut. The enzyme conducts a complex choreography of bond-making/bond-breaking steps that rearrange substrate to products through a radical mechanism, with themes common to other coenzyme B12-dependent and radical enzymes. The methods presented are targeted to test the hypothesis that particular, select protein and coupled solvent configurational fluctuations contribute to enzyme function. The general approach is to correlate enzyme function with an introduced perturbation that alters the properties (for example, degree of concertedness, or collectiveness) of protein and coupled solvent dynamics. Methods for sample preparation and low-temperature kinetic measurements by using temperature-step reaction initiation and time-resolved, full-spectrum electron paramagnetic resonance spectroscopy are detailed. A framework for interpretation of results obtained in ensemble systems under conditions of statistical equilibrium within the reacting, globally unstable state is presented. The temperature-dependence of the first-order rate constants for decay of the cryotrapped paramagnetic substrate radical state in EAL, through the chemical step of radical rearrangement, displays a piecewise-continuous Arrhenius dependence from 203 to 295K, punctuated by a kinetic bifurcation over 219-220K. The results reveal the obligatory contribution of a class of select collective protein and coupled solvent fluctuations to the interconversion of two resolved, sequential configurational substates, on the decay time scale. The select class of collective fluctuations also contributes to the chemical step. The methods and analysis are generally applicable to other coenzyme B12-dependent and related radical enzymes.


Subject(s)
Ethanolamine Ammonia-Lyase , Catalysis , Cobamides , Ethanolamine Ammonia-Lyase/chemistry , Ethanolamine Ammonia-Lyase/metabolism , Humans , Phosphothreonine/analogs & derivatives , Salmonella typhimurium/metabolism , Solvents/chemistry
5.
Nanomaterials (Basel) ; 12(10)2022 May 17.
Article in English | MEDLINE | ID: mdl-35630931

ABSTRACT

For high-field power applications of high-temperature superconductors, it became obvious in recent years that nano-engineered artificial pinning centers are needed for increasing the critical current and pinning potential. As opposed to the artificial pinning centers obtained by irradiation with various particles, which is a quite expensive approach, we have studied superconducting samples having self-assembled defects, created during the sample fabrication, that act as effective pinning centers. We introduced a simple, straight-forward method of estimating the frequency-dependent critical current density by using frequency-dependent AC susceptibility measurements, in fixed temperatures and DC magnetic fields, from the positions of the maxima in the dependence of the out-of-phase susceptibility on the amplitude of AC excitation magnetic field. The results are compatible with a model that stipulates a logarithmic dependence of the pinning potential on the probing current. A mathematical derivation allowed us to estimate from the experimental data the pinning potentials in various samples, and in various DC magnetic fields. The resulted values indicate large pinning potentials, leading to very small probability of magnetic flux escaping the pinning wells, hence, leading to very high critical currents in high magnetic fields.

6.
Materials (Basel) ; 15(7)2022 Mar 22.
Article in English | MEDLINE | ID: mdl-35407678

ABSTRACT

The deposition of a ferromagnetic layer can affect the properties of high-temperature superconductors underneath. We investigated the influence of ferromagnetic CaRuO3 on the properties of YBa2Cu3O7-x (YBCO) superconducting thin films when the layers are either in direct contact or separated by a barrier layer of 5 nm SrTiO3. Detailed measurements of the magnetic moment of the superconductor and ferromagnet as a function of temperature and magnetic field have been performed using SQUID magnetometry. Magnetometry and relaxation measurements show that the modification of the superconducting properties of YBCO strongly depends on the interaction with the ferromagnetic layer on top. The barrier layer has a significant impact on both the supercon-ducting properties of the YBCO film and the ferromagnetic ordering of CaRuO3. The physical properties mentioned above were discussed in correlation with the materials' structure determined by XRD analysis.

7.
Eur Respir J ; 59(2)2022 02.
Article in English | MEDLINE | ID: mdl-34413152

ABSTRACT

OBJECTIVE: Refractory symptomatic transudative pleural effusions are an indication for pleural drainage. There has been supportive observational evidence for the use of indwelling pleural catheters (IPCs) for transudative effusions, but no randomised trials. We aimed to investigate the effect of IPCs on breathlessness in patients with transudative pleural effusions when compared with standard care. METHODS: A multicentre randomised controlled trial, in which patients with transudative pleural effusions were randomly assigned to either an IPC (intervention) or therapeutic thoracentesis (TT; standard care). The primary outcome was mean daily breathlessness score over 12 weeks from randomisation. RESULTS: 220 patients were screened from April 2015 to August 2019 across 13 centres, with 33 randomised to intervention (IPC) and 35 to standard care (TT). Underlying aetiology was heart failure in 46 patients, liver failure in 16 and renal failure in six. In primary outcome analysis, the mean±sd breathlessness score over the 12-week study period was 39.7±29.4 mm in the IPC group and 45.0±26.1 mm in the TT group (p=0.67). Secondary outcomes analysis demonstrated that mean±sd drainage was 17 412±17 936 mL and 2901±2416 mL in the IPC and TT groups, respectively. A greater proportion of patients had at least one adverse event in the IPC group (p=0.04). CONCLUSION: We found no significant difference in breathlessness over 12 weeks between IPCs or TT. TT is associated with fewer complications and IPCs reduced the number of invasive pleural procedures required. Patient preference and circumstances should be considered in selecting the intervention in this cohort.


Subject(s)
Pleural Effusion, Malignant , Catheters, Indwelling/adverse effects , Drainage/adverse effects , Dyspnea/etiology , Dyspnea/therapy , Humans , Pleura , Pleural Effusion, Malignant/etiology , Pleural Effusion, Malignant/therapy
8.
J Chem Phys ; 154(17): 175101, 2021 May 07.
Article in English | MEDLINE | ID: mdl-34241057

ABSTRACT

Electron paramagnetic resonance (EPR) spectroscopy is used to address the remarkable persistence of the native Arrhenius dependence of the 2-aminopropanol substrate radical rearrangement reaction in B12-dependent ethanolamine ammonia-lyase (EAL) from Salmonella typhimurium from physiological to cryogenic (220 K) temperatures. Two-component TEMPOL spin probe mobility in the presence of 10 mM (0.08% v/v) 2-aminopropanol over 200-265 K demonstrates characteristic concentric aqueous-cosolvent mesodomain and protein-associated domain (PAD, hydration layer) solvent phases around EAL in the frozen solution. The mesodomain formed by the relatively small amount of 2-aminopropanol is highly confined, as shown by an elevated temperature for the order-disorder transition (ODT) in the PAD (230-235 K) and large activation energy for TEMPOL rotation. Addition of 2% v/v dimethylsulfoxide expands the mesodomain, partially relieves PAD confinement, and leads to an ODT at 205-210 K. The ODT is also manifested as a deviation of the temperature-dependence of the EPR amplitude of cob(II)alamin and the substrate radical, bound in the enzyme active site, from Curie law behavior. This is attributed to an increase in sample dielectric permittivity above the ODT at the microwave frequency of 9.5 GHz. The relatively high frequency dielectric response indicates an origin in coupled protein surface group-water fluctuations of the Johari-Goldstein ß type that span spatial scales of ∼0.1-10 Å on temporal scales of 10-10-10-7 s. The orthogonal EPR spin probe rotational mobility and solvent dielectric measurements characterize features of EAL protein-solvent dynamical coupling and reveal that excess substrate acts as a fluidizing cryosolvent to enable native enzyme reactivity at cryogenic temperatures.


Subject(s)
Electron Spin Resonance Spectroscopy , Ethanolamine Ammonia-Lyase/chemistry , Temperature , Ethanolamine Ammonia-Lyase/metabolism , Microwaves , Salmonella typhimurium/enzymology , Solvents/chemistry , Solvents/metabolism
9.
J Thorac Oncol ; 16(10): 1705-1717, 2021 10.
Article in English | MEDLINE | ID: mdl-34116230

ABSTRACT

INTRODUCTION: Malignant pleural mesothelioma (MPM) is difficult to diagnose. An accurate blood biomarker could prompt specialist referral or be deployed in future screening. In earlier retrospective studies, SOMAscan proteomics (Somalogic, Boulder, CO) and fibulin-3 seemed highly accurate, but SOMAscan has not been validated prospectively and subsequent fibulin-3 data have been contradictory. METHODS: A multicenter prospective observational study was performed in 22 centers, generating a large intention-to-diagnose cohort. Blood sampling, processing, and diagnostic assessment were standardized, including a 1-year follow-up. Plasma fibulin-3 was measured using two enzyme-linked immunosorbent assays (CloudClone [used in previous studies] and BosterBio, Pleasanton, CA). Serum proteomics was measured using the SOMAscan assay. Diagnostic performance (sensitivity at 95% specificity, area under the curve [AUC]) was benchmarked against serum mesothelin (Mesomark, Fujirebio Diagnostics, Malvern, PA). Biomarkers were correlated against primary tumor volume, inflammatory markers, and asbestos exposure. RESULTS: A total of 638 patients with suspected pleural malignancy (SPM) and 110 asbestos-exposed controls (AECs) were recruited. SOMAscan reliably differentiated MPM from AECs (75% sensitivity, 88.2% specificity, validation cohort AUC 0.855) but was not useful in patients with differentiating non-MPM SPM. Fibulin-3 (by BosterBio after failed CloudClone validation) revealed 7.4% and 11.9% sensitivity at 95% specificity in MPM versus non-MPM SPM and AECs, respectively (associated AUCs 0.611 [0.557-0.664], p = 0.0015) and 0.516 [0.443-0.589], p = 0.671), both inferior to mesothelin. SOMAscan proteins correlated with inflammatory markers but not with asbestos exposure. Neither biomarker correlated with tumor volume. CONCLUSIONS: SOMAscan may prove useful as a future screening test for MPM in asbestos-exposed persons. Neither fibulin-3 nor SOMAscan should be used for diagnosis or pathway stratification.


Subject(s)
Asbestos , Lung Neoplasms , Mesothelioma , Pleural Neoplasms , Biomarkers, Tumor , Calcium-Binding Proteins , Extracellular Matrix Proteins , GPI-Linked Proteins , Humans , Lung Neoplasms/diagnosis , Mesothelioma/diagnosis , Mesothelioma/etiology , Pleural Neoplasms/diagnosis , Pleural Neoplasms/etiology , Proteomics , Retrospective Studies
10.
Breathe (Sheff) ; 13(2): 117-122, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28620431

ABSTRACT

Can you diagnose this patient and identify the uncommon cause of his illness? http://ow.ly/t4nX30bzJFz.

11.
Proc Natl Acad Sci U S A ; 113(40): E5962-E5971, 2016 10 04.
Article in English | MEDLINE | ID: mdl-27647906

ABSTRACT

Voltage-gated proton (Hv1) channels are involved in many physiological processes, such as pH homeostasis and the innate immune response. Zn2+ is an important physiological inhibitor of Hv1. Sperm cells are quiescent in the male reproductive system due to Zn2+ inhibition of Hv1 channels, but become active once introduced into the low-Zn2+-concentration environment of the female reproductive tract. How Zn2+ inhibits Hv1 is not completely understood. In this study, we use the voltage clamp fluorometry technique to identify the molecular mechanism of Zn2+ inhibition of Hv1. We find that Zn2+ binds to both the activated closed and resting closed states of the Hv1 channel, thereby inhibiting both voltage sensor motion and gate opening. Mutations of some Hv1 residues affect only Zn2+ inhibition of the voltage sensor motion, whereas mutations of other residues also affect Zn2+ inhibition of gate opening. These effects are similar in monomeric and dimeric Hv1 channels, suggesting that the Zn2+-binding sites are localized within each subunit of the dimeric Hv1. We propose that Zn2+ binding has two major effects on Hv1: (i) at low concentrations, Zn2+ binds to one site and prevents the opening conformational change of the pore of Hv1, thereby inhibiting proton conduction; and (ii) at high concentrations, Zn2+, in addition, binds to a second site and inhibits the outward movement of the voltage sensor of Hv1. Elucidating the molecular mechanism of how Zn2+ inhibits Hv1 will further our understanding of Hv1 function and might provide valuable information for future drug development for Hv1 channels.


Subject(s)
Ion Channel Gating/genetics , Ion Channels/genetics , Zinc/metabolism , Animals , Binding Sites , Female , Fluorometry/methods , Humans , Hydrogen-Ion Concentration , Immunity, Innate/genetics , Ion Channels/metabolism , Mutation , Patch-Clamp Techniques/methods , Protons , Xenopus laevis/metabolism , Zinc/chemistry
12.
Lancet Oncol ; 17(8): 1094-1104, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27345639

ABSTRACT

BACKGROUND: The use of prophylactic radiotherapy to prevent procedure-tract metastases (PTMs) in malignant pleural mesothelioma remains controversial, and clinical practice varies worldwide. We aimed to compare prophylactic radiotherapy with deferred radiotherapy (given only when a PTM developed) in a suitably powered trial. METHODS: We did a multicentre, open-label, phase 3, randomised controlled trial in 22 UK hospitals of patients with histocytologically proven mesothelioma who had undergone large-bore pleural interventions in the 35 days prior to recruitment. Eligible patients were randomised (1:1), using a computer-generated sequence, to receive immediate radiotherapy (21 Gy in three fractions within 42 days of the pleural intervention) or deferred radiotherapy (same dose given within 35 days of PTM diagnosis). Randomisation was minimised by histological subtype, surgical versus non-surgical procedure, and pleural procedure (indwelling pleural catheter vs other). The primary outcome was the incidence of PTM within 7 cm of the site of pleural intervention within 12 months from randomisation, assessed in the intention-to-treat population. This trial is registered with ISRCTN, number ISRCTN72767336. FINDINGS: Between Dec 23, 2011, and Aug 4, 2014, we randomised 203 patients to receive immediate radiotherapy (n=102) or deferred radiotherapy (n=101). The patients were well matched at baseline. No significant difference was seen in PTM incidence in the immediate and deferred radiotherapy groups (nine [9%] vs 16 [16%]; odds ratio 0·51 [95% CI 0·19-1·32]; p=0·14). The only serious adverse event related to a PTM or radiotherapy was development of a painful PTM within the radiotherapy field that required hospital admission for symptom control in one patient who received immediate radiotherapy. Common adverse events of immediate radiotherapy were skin toxicity (grade 1 in 50 [54%] and grade 2 in four [4%] of 92 patients vs grade 1 in three [60%] and grade 2 in two [40%] of five patients in the deferred radiotherapy group who received radiotherapy for a PTM) and tiredness or lethargy (36 [39%] in the immediate radiotherapy group vs two [40%] in the deferred radiotherapy group) within 3 months of receiving radiotherapy. INTERPRETATION: Routine use of prophylactic radiotherapy in all patients with mesothelioma after large-bore thoracic interventions is not justified. FUNDING: Research for Patient Benefit Programme from the UK National Institute for Health Research.


Subject(s)
Lung Neoplasms/surgery , Mesothelioma/surgery , Neoplasms, Second Primary/prevention & control , Pleural Neoplasms/surgery , Postoperative Complications/radiotherapy , Aged , Female , Follow-Up Studies , Humans , Lung Neoplasms/radiotherapy , Lung Neoplasms/secondary , Male , Mesothelioma/radiotherapy , Mesothelioma/secondary , Mesothelioma, Malignant , Neoplasm Staging , Neoplasms, Second Primary/radiotherapy , Pain/prevention & control , Pleural Neoplasms/pathology , Pleural Neoplasms/radiotherapy , Prognosis , Quality of Life , Radiotherapy, Adjuvant , Research Design , Survival Rate
13.
Respir Med ; 104(8): 1171-8, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20185285

ABSTRACT

BACKGROUND: Cardiovascular manifestations in COPD include increased arterial stiffness, ischaemic heart disease, chronic heart failure and cor pulmonale. We hypothesised that sub-clinical right (RV) and left ventricular (LV) dysfunction occurs in patients with COPD, related to the severity of airflow obstruction, arterial stiffness and systemic inflammation. METHODS: Thirty six patients and 14 controls, all free of overt cardiovascular disease underwent tissue Doppler echocardiography, spirometry, measurement of aortic pulse wave velocity (PWV) and venous sampling for inflammatory markers. RESULTS: Mean LV myocardial strain and strain rate were less in patients than controls, p<0.05. LV isovolumic relaxation time (IVRT) was prolonged in patients (125+/-15.2ms) compared with controls (98.2+/-21.1ms), p<0.01, indicating LV diastolic dysfunction. The RV free wall strain and strain rate were less in patients than controls, both p<0.05, indicating RV systolic dysfunction. Patients had sub-clinical pulmonary arterial hypertension with a greater RV myocardial relaxation time and Tei index, both p<0.01. Patients with mild airways obstruction had LV and RV dysfunction and evidence of increased RV afterload compared with controls. In multivariate analyses aortic PWV predicted LV IVRT, p<0.01, while FEV(1) predicted RV Tei index and myocardial relaxation time, both p<0.01. CONCLUSIONS: Patients with COPD have sub-clinical left ventricular dysfunction related to arterial stiffness, and right ventricular dysfunction related to airways obstruction. Both right and left ventricular dysfunction are present in patients with mild airways obstruction suggesting that cardiac co-morbidities commence early in the development of COPD.


Subject(s)
Blood Flow Velocity/physiology , Pulmonary Disease, Chronic Obstructive/physiopathology , Ventricular Dysfunction, Left/physiopathology , Ventricular Dysfunction, Right/physiopathology , Aged , Body Composition/physiology , Case-Control Studies , Echocardiography, Doppler , Female , Humans , Male , Pulmonary Disease, Chronic Obstructive/complications , Pulmonary Disease, Chronic Obstructive/diagnostic imaging , Risk Assessment , Surveys and Questionnaires , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Left/etiology , Ventricular Dysfunction, Right/diagnostic imaging , Ventricular Dysfunction, Right/etiology
14.
Eur J Appl Physiol ; 103(6): 635-46, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18478253

ABSTRACT

Because the anomalous respiratory characteristics of competitive swimmers have been suggested to be due to inspiratory muscle work, the respiratory muscle and pulmonary function of 30 competitively trained swimmers was assessed at the beginning and end of an intensive 12-week swim training (ST) program. Swimmers (n = 10) combined ST with either inspiratory muscle training (IMT) set at 80% sustained maximal inspiratory pressure (SMIP) with progressively increased work-rest ratios until task failure for 3-days per week (ST + IMT) or ST with sham-IMT (ST + SHAM-IMT, n = 10), or acted as controls (ST only, ST, n = 10). Measures of respiratory and pulmonary function were assessed at the beginning and end of the 12 week study period. There were no significant differences (P > 0.05) in respiratory and pulmonary function between groups (ST + IMT, ST + SHAM-IMT and ST) at baseline and at the end of the 12 week study period. However, within all groups significant increases (P < 0.05) were observed in a number of respiratory and pulmonary function variables at the end of the 12 week study, such as maximal inspiratory and expiratory pressure, inspiratory power output, forced vital capacity, forced expiratory and inspiratory volume in 1-s, total lung capacity and diffusion capacity of the lung. This study has demonstrated that there are no appreciable differences in terms of respiratory changes between elite swimmers undergoing a competitive ST program and those undergoing respiratory muscle training using the flow-resistive IMT device employed in the present study; as yet, the causal mechanisms involved are undefined.


Subject(s)
Adaptation, Physiological , Breathing Exercises , Exercise/physiology , Inhalation , Lung/physiology , Respiratory Muscles/physiology , Swimming , Adolescent , Adult , Female , Forced Expiratory Volume , Humans , Male , Spirometry , Total Lung Capacity , Vital Capacity
15.
J Cyst Fibros ; 6(6): 384-90, 2007 Nov 30.
Article in English | MEDLINE | ID: mdl-17400035

ABSTRACT

BACKGROUND: Weight loss and loss of fat-free mass (FFM) are associated with peripheral muscle wasting in cystic fibrosis (CF) although whether this co-exists with loss of diaphragm mass remains unclear. METHODS: FFM was determined by dual-energy X-ray absorptiometry and bioelectrical impedance in 40 adults with CF and 30 age-matched healthy subjects (HS). Diaphragm thickness at functional residual capacity (FRC) [TDIrel] and total lung capacity (TLC) [TDIcont] and thickening ratio (TR) were assessed by ultrasonography. Inspiratory muscle strength and work capacity were determined by maximal inspiratory pressure (PImax), and sustained PImax (SPImax); pulmonary function (RV, VC and TLC) and physical activity status (PAS) were also determined. RESULTS: When the CF patients were assessed as a group (low and normal FFM) they had similar age, weight, height and PAS compared to the HS, although patients had lower FFM (p<0.05), VC and TLC than the HS (p<0.01). In addition, although PImax, TDIrel, TDIcont and TR were similar between the patients and the HS, SPImax was lower in the patients (p<0.01). When analyses were made between patients with low versus normal FFM and between patients with low FFM and HS no significant differences were found between overall weight although TDIrel, TDIcont, TR and PAS were all reduced in patients with low FFM (p<0.01). CONCLUSIONS: PImax is relatively well preserved in adults with CF although there is a relationship between the loss of inspiratory muscle work capacity, FFM, PAS and pulmonary function. Furthermore loss of FFM is associated with loss of diaphragm muscle mass.


Subject(s)
Body Composition/physiology , Cystic Fibrosis/metabolism , Respiratory Muscles/anatomy & histology , Respiratory Muscles/physiology , Adipose Tissue , Adolescent , Adult , Female , Humans , Male , Respiration , Respiratory Function Tests
16.
Thorax ; 62(2): 109-14, 2007 Feb.
Article in English | MEDLINE | ID: mdl-16928709

ABSTRACT

BACKGROUND: Pulmonary rehabilitation can improve the functional capacity, but has a variable effect on the low fat-free mass (FFM) in patients with chronic obstructive pulmonary disease. HYPOTHESIS: Pulmonary rehabilitation would not affect catabolic drives such as systemic inflammation and also protein breakdown. METHODS: Patients (n = 40) were studied at the start of an 8-week in-patient pulmonary rehabilitation programme, at the end of the programme and 4 weeks later. FFM and functional capacity (quadriceps strength, handgrip strength and peak workload) were assessed. Pseudouridine (PSU) urinary excretion (cellular protein breakdown) and inflammatory status were determined. Healthy participants had a single baseline assessment (n = 18). RESULTS: PSU, (IL)-6 and soluble tumour necrosis factor (sTNF)alpha R75 were increased in patients compared with healthy participants, whereas FFM and functional capacity were reduced (all p < 0.01). PSU was inversely related to both FFM and skeletal muscle function. FFM and functional parameters increased with rehabilitation, but PSU and inflammatory status were unaffected. The gain in FFM was lost 4 weeks after the completion of rehabilitation (p < 0.01). CONCLUSION: The anabolic effect of pulmonary rehabilitation improved FFM, but it did not reverse the increased protein breakdown or systemic inflammation. Thus, on cessation of pulmonary rehabilitation the FFM gains were lost owing to a loss of anabolic drive.


Subject(s)
Inflammation/metabolism , Proteins/metabolism , Pulmonary Disease, Chronic Obstructive/rehabilitation , Biomarkers/urine , Body Composition , Body Mass Index , Exercise Test , Female , Forced Expiratory Volume/physiology , Humans , Interleukin-6/metabolism , Male , Middle Aged , Muscle Strength , Muscle, Skeletal/physiology , Pseudouridine/urine , Pulmonary Disease, Chronic Obstructive/metabolism , Tumor Necrosis Factor-alpha/urine
17.
J Cyst Fibros ; 5(2): 105-12, 2006 May.
Article in English | MEDLINE | ID: mdl-16403491

ABSTRACT

Exercise is associated with release of inflammatory mediators in the circulation and there is evidence that the exercising muscles and tendons are sources of interleukin-6. Due to the catabolic effects of some cytokines, increased release in circulation might contribute to alterations in body composition in adults with cystic fibrosis. We hypothesised that exercise of moderate intensity would generate increased blood concentrations of some inflammatory mediators. We investigated the change in blood concentrations of interleukin-6, tumour necrosis factor alpha and their soluble receptors after a structured exercise (box stepping) of intensity similar to that encountered during activities of daily living in 12 adults with cystic fibrosis and mean (95% confidence interval) FEV1 55.6 (44.4, 66.8)% predicted, body mass index 23.0 (21.3, 24.6) kg/m2 and 12 healthy subjects. The increments post-exercise for all inflammatory mediators and lactate corrected for the work performed until voluntary exhaustion were greater for patients, while the total work was less for patients (all p<0.01). Daytime variability of the inflammatory mediators was assessed in eight patients and was less than the change due to exercise. We report greater increments in circulating concentrations of some cytokines with moderate exercise in adults with cystic fibrosis compared to healthy subjects.


Subject(s)
Cystic Fibrosis/blood , Exercise/physiology , Inflammation/blood , Adult , Anaerobic Threshold , Cystic Fibrosis/physiopathology , Female , Forced Expiratory Volume , Humans , Inflammation/physiopathology , Interleukin-6/blood , Lactic Acid/blood , Male , Oxygen Consumption , Receptors, Interleukin-6/blood , Receptors, Tumor Necrosis Factor/blood , Tumor Necrosis Factor-alpha/metabolism
18.
Chest ; 129(1): 39-49, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16424411

ABSTRACT

BACKGROUND: Previous research has demonstrated that fish oil supplementation has a protective effect on exercise-induced bronchoconstriction (EIB) in elite athletes, which may be attributed to its antiinflammatory properties. Since EIB in asthma involves proinflammatory mediator release, it is feasible that fish oil supplementation may reduce the severity of EIB in asthmatic subjects. STUDY OBJECTIVES: To determine the efficacy of fish oil supplementation on severity of EIB in subjects with asthma. DESIGN: Randomized, double-blind, crossover study. SETTING: Lung function and exercise testing in a university research laboratory. PATIENTS AND MEASUREMENTS: Sixteen asthmatic patients with documented EIB entered the study on their normal diet and then received either fish oil capsules containing 3.2 g of eicosapentaenoic acid and 2.0 g of docohexaenoic acid (fish oil diet, n = 8) or placebo capsules (placebo diet, n = 8) daily for 3 weeks. At the beginning of the study (normal diet) and at the end of each treatment phase, the following pre-exercise and postexercise measures were assessed: (1) pulmonary function; (2) induced sputum differential cell count percentage and proinflammatory eicosanoid metabolite (leukotriene C4 [LTC4]-leukotriene E4 [LTE4] and prostaglandin D2 [PGD2]) and cytokine (interleukin [IL]-1beta and tumor necrosis factor [TNF]-alpha) concentrations; and (3) eicosanoid metabolites leukotriene B4 (LTB4) and leukotriene B5 (LTB(5)) generation from activated polymorphonuclear leukocytes (PMNLs). RESULTS: On the normal and placebo diet, subjects exhibited EIB. However, the fish oil diet improved pulmonary function to below the diagnostic EIB threshold, with a concurrent reduction in bronchodilator use. Induced sputum differential cell count percentage and concentrations of LTC4-LTE4, PGD2, IL-1beta, and TNF-alpha were significantly reduced before and following exercise on the fish oil diet compared to the normal and placebo diets. There was a significant reduction in LTB4 and a significant increase in LTB5 generation from activated PMNLs on the fish oil diet compared to the normal and placebo diets. CONCLUSION: Our data suggest that fish oil supplementation may represent a potentially beneficial nonpharmacologic intervention for asthmatic subjects with EIB.


Subject(s)
Asthma/prevention & control , Bronchoconstriction/drug effects , Dietary Supplements , Fish Oils/therapeutic use , Adult , Asthma/metabolism , Asthma/physiopathology , Cross-Over Studies , Double-Blind Method , Eicosapentaenoic Acid/analogs & derivatives , Eicosapentaenoic Acid/metabolism , Exercise Test/adverse effects , Female , Follow-Up Studies , Forced Expiratory Volume/drug effects , Humans , Leukocyte Count , Leukotriene B4/analogs & derivatives , Leukotriene B4/metabolism , Male , Sputum/cytology , Sputum/metabolism , Treatment Outcome
19.
Am J Respir Crit Care Med ; 170(12): 1286-93, 2004 Dec 15.
Article in English | MEDLINE | ID: mdl-15374843

ABSTRACT

We hypothesized that in patients with chronic obstructive pulmonary disease, loss of fat-free mass (FFM) and loss of bone mineral density (BMD) were related to (1) each other and may be clinically inapparent, (2) urinary markers of cellular and bone collagen protein breakdown, and (3) severity of lung disease. Eight-one patients and 38 healthy subjects underwent dual-energy X-ray absorptiometry to determine body composition and BMD. Urinary protein breakdown markers, inflammatory mediators, and their soluble receptors were determined. Thirty-three patients had a low fat-free mass index (kg/m(2)), 17 of whom had a normal body mass index. Thirty-two percent of patients (13% of healthy subjects) had osteoporosis at the hip or lumbar spine. The marker of cellular protein breakdown was elevated in patients and related to lung disease severity and body composition. The marker of bone collagen breakdown was greater in patients with osteoporosis. Inflammatory mediators were elevated in patients. Loss of FFM and loss of BMD were related, occurred commonly, and could be subclinical in patients with chronic obstructive pulmonary disease. Loss of both was greatest with severe lung disease. Increased excretion of cellular and bone collagen protein breakdown products in those with low FFM and BMD indicates a protein catabolic state in these patients.


Subject(s)
Body Composition , Bone Density , Pulmonary Disease, Chronic Obstructive/metabolism , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Pulmonary Disease, Chronic Obstructive/complications
20.
Chest ; 126(2): 405-11, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15302725

ABSTRACT

STUDY OBJECTIVES: To investigate the effects of high-intensity inspiratory muscle training (IMT) on inspiratory muscle function (IMF), diaphragm thickness, lung function, physical work capacity (PWC), and psychosocial status in patients with cystic fibrosis (CF). DESIGN: Twenty-nine adult patients with CF were randomly assigned to three groups. Two groups were required to complete an 8-week program of IMT in which the training intensity was set at either 80% of maximal effort (group 1; 9 patients) or 20% of maximal effort (group 2; 10 patients). A third group of patients did not participate in any form of training and acted as a control group (group 3; 10 patients). INTERVENTIONS: In all patients, baseline and postintervention measures of IMF were determined by maximal inspiratory pressure (Pimax), and sustained Pimax (SPimax); pulmonary function, body composition, and physical activity status were also determined. In addition, diaphragm thickness was measured at functional residual capacity (FRC) and total lung capacity (TLC) [TDIcont], and the diaphragm thickening ratio (TR) was calculated (TR = thickness during Pimax at FRC/mean thickness at FRC). Subjects also completed an incremental cycle ergometer test to exhaustion and two symptom-related questionnaires, prior to and following training. RESULTS: Following training, significant increases in Pimax and SPimax (p < 0.05), TDIcont (p < 0.05), TR (p < 0.05), vital capacity (p < 0.05), TLC (p < 0.05), and PWC (p < 0.05) were identified, and decreases in anxiety scores (p < 0.05) and depression scores (p < 0.01) were noted in group 1 patients compared to group 3 patients. Group 2 patients significantly improved Pimax and SPimax (both p < 0.05) only with respect to group 3 patients. No significant differences were observed in group 3 patients. CONCLUSION: An 8-week program of high-intensity IMT resulted in significant benefits for CF patients, which included increased IMF and thickness of the diaphragm (during contraction), improved lung volumes, increased PWC, and improved psychosocial status.


Subject(s)
Breathing Exercises , Cystic Fibrosis/therapy , Exercise Tolerance/physiology , Lung/physiopathology , Adult , Body Composition , Cystic Fibrosis/physiopathology , Diaphragm/diagnostic imaging , Diaphragm/physiopathology , Female , Functional Residual Capacity , Humans , Male , Motor Activity , Surveys and Questionnaires , Total Lung Capacity , Ultrasonography
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