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1.
Front Cell Dev Biol ; 11: 1165581, 2023.
Article in English | MEDLINE | ID: mdl-37795260

ABSTRACT

Adequate lung epithelial repair relies on supportive interactions within the epithelial niche, including interactions with WNT-responsive fibroblasts. In fibroblasts from patients with chronic obstructive pulmonary disease (COPD) or upon in vitro cigarette smoke exposure, Wnt/ß-catenin signalling is distorted, which may affect interactions between epithelial cells and fibroblasts resulting in inadequate lung repair. We hypothesized that cigarette smoke (CS), the main risk factor for COPD, interferes with Wnt/ß-catenin signalling in fibroblasts through induction of cellular stress responses, including oxidative- and endoplasmic reticulum (ER) stress, and thereby alters epithelial repair support potential. Therefore, we assessed the effect of CS-exposure and the ER stress inducer Thapsigargin (Tg) on Wnt/ß-catenin signalling activation in MRC-5 fibroblasts, and on their ability to support lung epithelial organoid formation. Exposure of MRC-5 cells for 15 min with 5 AU/mL CS extract (CSE), and subsequent 6 h incubation induced oxidative stress (HMOX1). Whereas stimulation with 100 nM Tg increased markers of both the integrated stress response (ISR - GADD34/PPP1R15A, CHOP) and the unfolded protein response (UPR - XBP1spl, GADD34/PPP1R15A, CHOP and HSPA5/BIP), CSE only induced GADD34/PPP1R15A expression. Strikingly, although treatment of MRC-5 cells with the Wnt activator CHIR99021 upregulated the Wnt/ß-catenin target gene AXIN2, this response was diminished upon CSE or Tg pre-exposure, which was confirmed using a Wnt-reporter. Furthermore, pre-exposure of MRC-5 cells to CSE or Tg, restricted their ability to support organoid formation upon co-culture with murine pulmonary EpCam+ cells in Matrigel at day 14. This restriction was alleviated by pre-treatment with CHIR99021. We conclude that exposure of MRC-5 cells to CSE increases oxidative stress, GADD34/PPP1R15A expression and impairs their ability to support organoid formation. This inhibitory effect may be restored by activating the Wnt/ß-catenin signalling pathway.

2.
Respir Med ; 148: 60-62, 2019 03.
Article in English | MEDLINE | ID: mdl-30827477

ABSTRACT

Human blood monocytes are divided into populations based on the differential expression of CD14 and CD16 receptors: CD14 + CD16(classical), CD14 + CD16 + (intermediate), and CD14-CD16+ (non-classical). Given their functional differences and their role in pathogenesis of chronic obstructive pulmonary disease (COPD), monocyte profiling is of clinical interest. Here we investigated blood monocyte subsets in clinically stable COPD patients with alpha1-antitrypsin (AAT) deficiency (PiZZ, n = 7) and with normal AAT variant (PiMM, n = 7). Peripheral whole blood was collected in sodium heparin tubes and incubated with LPS (from E. coli; 1 µg/ml) or placebo for 6 h at 37 °C, 5% CO2. To profile monocyte subsets we performed flow cytometry analysis based on HLA-DR and CD14/CD16 staining. HLA-DR + subsets of cells did not differ between PiZZ and PiMM COPD, and healthy controls (n = 7), used as a reference. Monocyte profiling, which express the CD14 and CD16, but not the HLA-DR (HLA-DR-) showed that intermediate monocytes subset was lowest in PiZZ group, and almost totally disappeared from blood treated with LPS. The non-classical subset was almost absent in PiZZ patients independently of LPS treatment. Recent studies demonstrate that non-classical monocytes exhibit a unique ability to protect the vascular endothelium under both homeostatic and inflammatory conditions whereas intermediate monocytes are recruited at a later stage of inflammation, and are associated with secretion of cytokines/chemokines and wound healing. Evident alterations in blood monocyte subsets together with a partial reduction of AAT levels, an important anti-inflammatory protein, can be key factors for the early manifestation of emphysema in some PiZZ AATD carriers.


Subject(s)
Monocytes/metabolism , Pulmonary Disease, Chronic Obstructive/blood , alpha 1-Antitrypsin Deficiency/genetics , alpha 1-Antitrypsin/metabolism , Aged , Female , Flow Cytometry/methods , HLA-DR Antigens/metabolism , Humans , Inflammation/metabolism , Lipopolysaccharide Receptors/metabolism , Male , Middle Aged , Phenotype , Pulmonary Disease, Chronic Obstructive/physiopathology , Receptors, IgG/metabolism , alpha 1-Antitrypsin/genetics , alpha 1-Antitrypsin Deficiency/complications
3.
Neth J Med ; 76(7): 336-338, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30220659

ABSTRACT

Lyme disease (LD) is the most common tick-borne illness. The diagnosis of LD is difficult because of the great variation in clinical manifestations. Although abdominal pain is generally not considered a sign of LD, in this case report we describe a patient with unexplained severe abdominal pain that eventually turned out to be LD due to radiculopathy. Since the incidence of LD is rising it is important to realise that severe abdominal pain could be the first clinical manifestation of early neuroborreliosis.


Subject(s)
Abdominal Pain/microbiology , Lyme Disease/complications , Lyme Disease/diagnosis , Radiculopathy/microbiology , Aged , Female , Humans
4.
Ned Tijdschr Geneeskd ; 160: D1022, 2016.
Article in Dutch | MEDLINE | ID: mdl-27879186

ABSTRACT

Health insurance organisations grant reimbursement for drug treatment on the basis of results of placebo-controlled randomised clinical trials showing a clinically meaningful and statistically significant effect over placebo. This often proves problematic in rare diseases as well as in many chronic diseases that are difficult to treat. Clinical scientists may address the issue by testing the drug on surrogate outcome parameters and ask for post-marketing studies conducted by expert reference centres as expediency research, using budgets provided by the government to show that the drug really works in terms of real-life patient experience. In the past 5 years, the pharmaceutical industry has released an increasing number of expensive drugs for rare diseases; this jeopardises the solidarity of health insurance cover for all EU citizens. To facilitate drug development, a new model might benefit all key players involved. The foundation Fair Medicine recently called for coalitions that jointly develop medicines based on contribution and complementarity, sharing responsibilities, risks and rewards.


Subject(s)
Insurance, Health, Reimbursement , Pharmaceutical Preparations/economics , Budgets , Europe , Humans , National Health Programs , Rare Diseases
6.
QJM ; 109(5): 331-6, 2016 May.
Article in English | MEDLINE | ID: mdl-26819296

ABSTRACT

BACKGROUND: Mesenchymal stromal cells (MSCs) may reduce inflammation and promote tissue repair in pulmonary emphysema. AIM: To study the safety and feasibility of bone marrow-derived autologous (BM-) MSC intravenous administration to patients with severe emphysema. DESIGN: A phase I, prospective open-label study registered at ClinicalTrials.gov as NCT01306513 Eligible patients had lung volume reduction surgery (LVRS) on two separate occasions. During the first LVRS bone marrow was collected, from which MSCs were isolated and expanded ex vivo After 8 weeks, patients received two autologous MSC infusions 1 week apart, followed by the second LVRS procedure at 3 weeks after the second BM-MSC infusion. METHODS: Up to 3 weeks after the last MSC infusion adverse events were recorded. Using immunohistochemistry and qPCR for analysis of cell and proliferation markers, emphysematous lung tissue obtained during the first surgery was compared with lung tissue obtained after the second surgical session to assess BM-MSC effects. RESULTS: From 10 included patients three were excluded: two did not receive MSCs due to insufficient MSC culture expansion, and one had no second surgery. No adverse events related to MSC infusions occurred and lung tissue showed no fibrotic responses. After LVRS and MSC infusions alveolar septa showed a 3-fold increased expression of the endothelial marker CD31 (P = 0.016). CONCLUSIONS: Autologous MSC treatment in severe emphysema is feasible and safe. The increase in CD31 expression after LVRS and MSC treatment suggests responsiveness of microvascular endothelial cells in the most severely affected parts of the lung.


Subject(s)
Mesenchymal Stem Cell Transplantation/methods , Pulmonary Emphysema/therapy , Stromal Cells/transplantation , Adult , Aged , Bone Marrow Cells/cytology , Cell Proliferation , Endothelial Cells/cytology , Endothelial Cells/metabolism , Female , Follow-Up Studies , Humans , Immunohistochemistry , Lung/blood supply , Lung/surgery , Male , Middle Aged , Neovascularization, Physiologic , Platelet Endothelial Cell Adhesion Molecule-1/metabolism , Pneumonectomy , Prospective Studies , Pulmonary Emphysema/pathology , Pulmonary Emphysema/physiopathology , Severity of Illness Index , Transplantation, Autologous , Treatment Outcome
7.
QJM ; 108(1): 33-8, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25024353

ABSTRACT

BACKGROUND: Exercise intolerance (EI) in systemic sclerosis (SSc) is difficult to manage by the clinician. The peripheral chemoreflex drive compensates for metabolic acidosis during exercise and may be related to EI. AIM: To assess the global peripheral chemoreflex drive (GPCD) in patients with SSc at rest and during exercise. METHODS: Consecutively tested SSc patients (n = 49) were evaluated by pulmonary function tests, carbon dioxide (CO2) rebreathing studies and non-invasive cardiopulmonary exercise testing (CPET). Results of their CO2 rebreathing tests were compared with those of controls (n = 32). Respiratory compensation for metabolic acidosis during CPET was defined by the occurrence of a sharp increase in minute ventilation (VdotE) and the ventilatory equivalent for CO2 (V'E and V'CO2) at the end of the isocapnic buffer phase. Euoxic (eVHR) and hyperoxic (hVHR) ventilatory responses to hypercapnia were measured and its difference (eVHR - hVHR) was considered to reflect the GPCD. RESULTS: In 45 patients with SSc, CPET results showed respiratory compensation at the occurrence of metabolic acidosis. eVHR - hVHR in patients with diffuse cutaneous SSc (dcSSc) differed significantly from that in patients with limited cutaneous SSc (lcSSc) and from that in controls (0.47 ± 0.38 (dcSSc) vs. 0.90 ± 0.77 (lcSSc) and 0.90 ± 0.49 (controls) l/min/mmHg; P = 0.04 and P = 0.03, respectively). CONCLUSIONS: Respiratory compensation for metabolic acidosis occurred in all patients. However, the GPCD was diminished in dcSSc patients, suggesting an altered control of breathing. Its assessment may help the clinician to better understand reported EI and exertional dyspnea in dcSSc patients.


Subject(s)
Chemoreceptor Cells/physiology , Exercise/physiology , Reflex/physiology , Scleroderma, Systemic/physiopathology , Acidosis/etiology , Acidosis/physiopathology , Aged , Case-Control Studies , Exercise Test/methods , Female , Humans , Hypercapnia/physiopathology , Male , Middle Aged , Respiratory Function Tests/methods , Scleroderma, Systemic/complications
8.
Clin Exp Rheumatol ; 32(6 Suppl 86): S-60-7, 2014.
Article in English | MEDLINE | ID: mdl-25068203

ABSTRACT

OBJECTIVES: During cardiopulmonary exercise testing (CPET) compromised pulmonary vasculature in patients with systemic sclerosis (SSc) may lead to increases in pulmonary arterial pressures (PAP) and decreased oxygen uptake. We hypothesised that this may lead into a disproportional heart rate (HR) increase with a corresponding V'O2/HR breakpoint and relates to systolic PAP at rest. METHODS: In a prospective design we evaluated V'O2/HR slopes for breakpoints. To understand its physiological meaning, we evaluated V'O2/HR and V'O2/mPAP slopes for breakpoints in a historic data set of SSc patients, in which CPET and right heart catheterisation was performed simultaneously. V'O2/HR slopes with a peak oxygen uptake outside the normal range were defined as pathologic. RESULTS: A breakpoint occurred in both V'O2/mPAP and V'O2/HR slope in 16/34 patients in the historic dataset and occurred in the V'O2/mPAP slope at a lower V'O2in 15 patients. In the prospective dataset, 73/121 patients showed a V'O2/HR breakpoint and achieved a significantly lower peak oxygen uptake compared to 48/121 patients without a V'O2/HR breakpoint (p=0.036). Mean systolic PAP in 41/121 patients with a pathologic V'O2/HR slope differed significantly from patients without a pathologic V'O2/HR slope (p=0.027). In 27/121 patients with a systolic PAP < 35 mmHg a pathologic V'O2/HR slope was observed. CONCLUSIONS: SSc patients with a V'O2/HR breakpoint are characterised by a decreased oxygen uptake, likely caused by sudden PAP increases during exercise. Importantly, in patients with normal resting SPAP pathologic V'O2/HR slopes were observed. This suggests that these patients are at risk for developing pulmonary hypertension.


Subject(s)
Arterial Pressure/physiology , Heart Rate/physiology , Hypertension, Pulmonary/diagnosis , Oxygen Consumption/physiology , Pulmonary Artery/physiopathology , Scleroderma, Systemic/physiopathology , Adult , Aged , Cardiac Catheterization , Exercise Test , Female , Humans , Hypertension, Pulmonary/etiology , Hypertension, Pulmonary/physiopathology , Lung Diseases/diagnosis , Lung Diseases/etiology , Lung Diseases/physiopathology , Male , Middle Aged , Prospective Studies , Scleroderma, Systemic/complications , Vascular Diseases/diagnosis , Vascular Diseases/etiology , Vascular Diseases/physiopathology
9.
Med Phys ; 41(2): 021905, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24506626

ABSTRACT

PURPOSE: Whole lung densitometry on chest CT images is an accepted method for measuring tissue destruction in patients with pulmonary emphysema in clinical trials. Progression measurement is required for evaluation of change in health condition and the effect of drug treatment. Information about the location of emphysema progression within the lung may be important for the correct interpretation of drug efficacy, or for determining a treatment plan. The purpose of this study is therefore to develop and validate methods that enable the local measurement of lung density changes, which requires proper modeling of the effect of respiration on density. METHODS: Four methods, all based on registration of baseline and follow-up chest CT scans, are compared. The first naïve method subtracts registered images. The second employs the so-called dry sponge model, where volume correction is performed using the determinant of the Jacobian of the transformation. The third and the fourth introduce a novel adaptation of the dry sponge model that circumvents its constant-mass assumption, which is shown to be invalid. The latter two methods require a third CT scan at a different inspiration level to estimate the patient-specific density-volume slope, where one method employs a global and the other a local slope. The methods were validated on CT scans of a phantom mimicking the lung, where mass and volume could be controlled. In addition, validation was performed on data of 21 patients with pulmonary emphysema. RESULTS: The image registration method was optimized leaving a registration error below half the slice increment (median 1.0 mm). The phantom study showed that the locally adapted slope model most accurately measured local progression. The systematic error in estimating progression, as measured on the phantom data, was below 2 gr/l for a 70 ml (6%) volume difference, and 5 gr/l for a 210 ml (19%) difference, if volume correction was applied. On the patient data an underlying linearity assumption relating lung volume change with density change was shown to hold (fitR(2) = 0.94), and globalized versions of the local models are consistent with global results (R(2) of 0.865 and 0.882 for the two adapted slope models, respectively). CONCLUSIONS: In conclusion, image matching and subsequent analysis of differences according to the proposed lung models (i) has good local registration accuracy on patient data, (ii) effectively eliminates a dependency on inspiration level at acquisition time, (iii) accurately predicts progression in phantom data, and (iv) is reasonably consistent with global results in patient data. It is therefore a potential future tool for assessing local emphysema progression in drug evaluation trials and in clinical practice.


Subject(s)
Disease Progression , Pulmonary Emphysema/diagnostic imaging , Tomography, X-Ray Computed/methods , Adult , Aged , Female , Humans , Image Processing, Computer-Assisted , Lung/diagnostic imaging , Lung/pathology , Lung/physiopathology , Male , Middle Aged , Pulmonary Emphysema/pathology , Pulmonary Emphysema/physiopathology , Respiration
11.
Arthritis Care Res (Hoboken) ; 63(6): 909-17, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21312348

ABSTRACT

OBJECTIVE: To compare the effectiveness of a multidisciplinary team care program with usual outpatient care in patients with systemic sclerosis (SSc; scleroderma). METHODS: We performed a randomized controlled trial comparing a 12-week multidisciplinary team care program (1 day per week; individual treatments, group exercises, and group education) with outpatient clinic care. Outcome measures included the Hand Mobility in Scleroderma (HAMIS) test, grip strength, maximal mouth opening (MMO), 6-minute walk distance (6MWD), maximum aerobic capacity (VO(2max) ), Checklist Individual Strength 20 (CIS-20), SSc Health Assessment Questionnaire (HAQ), and Short Form 36 (SF-36), assessed at 0, 12, and 24 weeks. Statistical comparisons of change scores were done by analysis of covariance. RESULTS: Twenty-eight patients were assigned to the intervention group (mean age 53.9 years, 15 of 28 with diffuse SSc) and 25 were assigned to the control group (mean age 51.7 years, 15 of 25 with diffuse SSc). Twenty-five patients (89%) in the intervention group completed the treatment program. At 12 weeks, there was a significantly greater improvement in grip strength (2.2 versus -1.8 kg; P = 0.001), MMO (1.4 versus -0.9 mm; P = 0.011), 6MWD (42.8 versus 3.9 meters; P = 0.021), and HAQ score (-0.18 versus 0.13; P = 0.025) in the intervention group, whereas differences for the other outcome measures did not reach significance. At 24 weeks, the effect on grip strength persisted. CONCLUSION: In patients with SSc, a 12-week multidisciplinary day patient treatment program was more effective than regular outpatient care with respect to 6MWD, grip strength, MMO, and HAQ score, but not for VO(2max) , HAMIS test, CIS-20, SF-36, and visual analog scale for pain. This study provides a first step in quantifying the effect of a multidisciplinary team care program and warrants the conduct of further intervention studies.


Subject(s)
Ambulatory Care/standards , Patient Care Team/standards , Scleroderma, Systemic/therapy , Adult , Ambulatory Care/methods , Female , Humans , Male , Middle Aged , Scleroderma, Systemic/physiopathology , Treatment Outcome
12.
Child Care Health Dev ; 36(5): 703-8, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20412145

ABSTRACT

OBJECTIVE: This study aimed to describe changes in parents' resolution regarding their young child's diagnosis of cerebral palsy over a period of 1 year, and to describe the changes in strategies of resolution. METHODS: In this longitudinal study, 38 parents of children with cerebral palsy (mean age 18.4 months, SD = 1.1 at baseline) were followed with the Reaction to Diagnosis Interview, assessing their personal reactions to their child's diagnosis (i.e. resolution status). Changes at main and subclassification level of the Reaction to Diagnosis Interview were investigated using a binominal test. RESULTS: Twenty-nine parents (76%) were found to be stable with respect to their main resolution status (i.e. 'resolved' or 'unresolved'), while 24% of the parents either had changed from 'unresolved' to 'resolved' or in the opposite way. Furthermore, of the 28 parents who were classified as 'resolved' at both times, 15 (54%) had changed at subclassification level with respect to the specific strategies used. CONCLUSION: Resolution at a main level of parental reactions to their child's diagnosis was predominantly stable. Most parents were classified as 'resolved' at both baseline and follow-up assessment. However, more detailed analyses at subclassification level showed that most parents with a 'resolved' main status showed changing patterns of resolution strategies to their child's diagnosis, suggesting that resolution is an ongoing process.


Subject(s)
Adaptation, Psychological , Cerebral Palsy/psychology , Parents/psychology , Stress, Psychological/psychology , Adult , Cerebral Palsy/diagnosis , Disability Evaluation , Female , Humans , Infant , Longitudinal Studies , Male , Stress, Psychological/diagnosis , Stress, Psychological/etiology , Time Factors
13.
Child Care Health Dev ; 35(5): 673-80, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19320906

ABSTRACT

BACKGROUND: For parents, receiving a diagnosis, typically in early childhood, that their child has cerebral palsy may conjure up high distress and anxiety. Resolution of these initial reactions may help parents to focus on the challenges and needs of their children. AIMS: of the study were to test whether parents of older children displayed resolution more often than parents of younger children, and whether parents of children with less severe cerebral palsy also showed more resolution. METHOD: Resolution of reactions to diagnosis was assessed with the Reaction to Diagnosis Interview, in a clinic-based sample of 255 parents of children with cerebral palsy aged between 1.4 and 17.3 years. Physicians rated motor ability using the Gross Motor Function Classification System. RESULTS: Overall, the responses of 81.6% of the parents were predominantly indicative of resolution. Unresolved reactions were significantly more often found among parents of younger children and parents of children with more severe motor disabilities. Among parents of teenage children, resolution was more often apparent from a focus on action to better the lives of their children, whereas in parents of younger children, it was more apparent from their focus on constructive thoughts and information seeking. CONCLUSIONS: Given time, the large majority of parents may resolve their reactions to the diagnosis that their child has cerebral palsy. Parents of the most severely affected children may need specific support which, given the age trends, might be aimed at different resolution processes for parents of younger and older children.


Subject(s)
Cerebral Palsy/psychology , Parents/psychology , Truth Disclosure , Adaptation, Psychological , Adolescent , Age Factors , Cerebral Palsy/diagnosis , Child , Child, Preschool , Disability Evaluation , Female , Humans , Infant , Male , Motor Skills Disorders/diagnosis , Severity of Illness Index , Social Support , Stress, Psychological , Surveys and Questionnaires
14.
Eur Respir J ; 32(4): 931-7, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18614560

ABSTRACT

The genetic factors that contribute to the development of chronic obstructive pulmonary disease (COPD) are poorly understood. Many candidate genes have been proposed, including enzymes that protect the lung against oxidative stress, such as microsomal epoxide hydrolase (EPHX1) and glutamate-cysteine ligase (GCL). To date, most reported findings have been for EPHX1, particularly in relation to functional variants associated with fast and slow metabolism of epoxide intermediates. The present study aimed to identify any association of variation in these genes with COPD susceptibility or severity. In total, 1,017 white COPD patients and 912 nondiseased age and sex matched smoking controls were genotyped for six single nucleotide polymorphisms (SNPs) in EPHX1 (including the fast and slow variants and associated haplotypes), and eight SNPs in the two genes encoding GCL. GCL is a rate-limiting enzyme in the synthesis of glutathione, a major contributor to anti-oxidant protection in the lung. No association of variation was found in EPHX1 or GCL with susceptibility to COPD or disease severity. This is the largest reported study to date and is well powered to detect associations that have been previously suggested. The current data indicate that these genetic variants are unlikely to be related to susceptibility or disease severity in white chronic obstructive pulmonary disease patients.


Subject(s)
Epoxide Hydrolases/genetics , Glutamate-Cysteine Ligase/genetics , Pulmonary Disease, Chronic Obstructive/genetics , Case-Control Studies , Female , Genetic Predisposition to Disease , Genetic Variation , Genotype , Glutathione/metabolism , Haplotypes , Humans , Male , Polymorphism, Single Nucleotide , Risk Factors , Smoking
15.
Eur Respir J ; 31(3): 509-15, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18057056

ABSTRACT

The objectives of the present study were to reappraise chest radiography for the diagnosis of emphysema, using computed tomography (CT) as the reference standard, and to establish whether or not chest radiography is useful for phenotyping chronic obstructive pulmonary disease (COPD). Patients (n = 154) who had undergone posteroanterior and lateral chest radiography and CT for diagnostic purposes were studied. CT data were scored for emphysema using the picture-grading method. Chest radiographs were examined independently by five raters using four criteria for emphysema that had been validated against lung pathology. These criteria were then used to assess the prevalence of emphysema in 458 COPD patients. Patients with and without evidence of emphysema were compared with regard to age, sex, smoking history, body mass index (BMI), forced expiratory volume in one second (FEV(1)), diffusing capacity of the lung for carbon monoxide (D(L,CO)) and health status. Chest radiography yielded a sensitivity of 90% and a specificity of 98% for emphysema. Of the 458 COPD patients, 245 showed radiological evidence of emphysema. Emphysemic patients had a significantly lower BMI, FEV(1) and D(L,CO), greater restriction of physical activity and worse quality of life than nonemphysemic patients. There was no difference across the two groups with regard to age, sex or smoking history. Chest radiography is a simple means of diagnosing moderate-to-severe emphysema. It is useful in phenotyping chronic obstructive pulmonary disease and may aid physicians in their choice of treatment.


Subject(s)
Emphysema/diagnostic imaging , Mass Chest X-Ray , Total Lung Capacity , Aged , Cohort Studies , Emphysema/classification , Female , Forced Expiratory Volume , Humans , Male , Middle Aged , Phenotype , Sensitivity and Specificity , Smoking/adverse effects , Tomography, X-Ray Computed
17.
Eur Respir J ; 29(6): 1138-43, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17331971

ABSTRACT

To explore if change in the extent of emphysema correlated with change in lung function, the effect of resection of emphysematous tissue was studied by computed tomography (CT) densitometry. In addition, the current authors studied how surgery-induced change in emphysema related to lung density in control subjects. In total, 30 patients (14 females; mean+/-sd age 59+/-10 yrs) with severe emphysema before and 3 months after lung volume reduction surgery (LVRS), 48 patients with moderate emphysema and 76 control subjects were investigated. Lung density (15th percentile point) of both lungs and heterogeneity of lung density between 12 isovolumetric partitions in each lung were calculated from chest CT images. The 15th percentile point and its heterogeneity could distinguish controls from subjects with moderate emphysema with a sensitivity and specificity of >95%. LVRS significantly increased lung density by 5.0+/-10.9 g.L(-1) (n=30). Improvement in the diffusing capacity of the lung for carbon monoxide and in residual volume significantly correlated with an increase in lung density (n=20 and 28, respectively). Change in forced expiratory volume in one second did not correlate with change in lung density. In conclusion, lung density 15th percentile point is a valuable surrogate marker for detection of both the extent of and reduction in emphysema.


Subject(s)
Pulmonary Emphysema/surgery , Adult , Densitometry/methods , Female , Forced Expiratory Volume , Humans , Lung/pathology , Lung Volume Measurements , Male , Middle Aged , Pneumonectomy/methods , Time Factors , Tomography, X-Ray Computed/methods , Treatment Outcome
19.
Proc Inst Mech Eng H ; 220(4): 533-9, 2006 May.
Article in English | MEDLINE | ID: mdl-16808069

ABSTRACT

Clinical studies have shown that adequate fixation of ceramic cups using bone cement is difficult to achieve. As the cement-ceramic bond strength is low, a satisfactory fixation strength requires a cup design that allows mechanical interlocking, although such a design will probably promote cement cracking and therefore cup loosening in the long term. An investigation has been carried out to establish whether a cemented ceramic cup can be designed in such a way that both a satisfactory initial fixation strength is obtained and cement cracking is reduced to levels found around PE cups functioning well in vivo. By means of finite element analysis, the fatigue loading of three geometrically different cemented acetabular cups, with ceramic and PE material properties, has been simulated, and the severity of the crack patterns produced in the cement has been analysed. Furthermore, the fixation strength has been analysed by simulating a pull-out test prior to and after fatigue testing. All ceramic cups produced much larger amounts of cement damage during fatigue testing than any PE cup, caused by stress concentrations in the cement that were attributable to the high stiffness of the ceramic. Even a completely smooth ceramic cup produced more damage than a sharp-grooved PE cup. Owing to the excessive cement cracking, the fixation strength of the ceramic cups dropped after fatigue loading. It is concluded that cemented ceramic cups have an increased risk of long-term mechanical failure by comparison with PE cups, and that a ceramic cup design that combines sufficient fixation strength with low cement failure may be difficult to achieve.


Subject(s)
Acetabulum/physiopathology , Arthroplasty, Replacement, Hip/adverse effects , Arthroplasty, Replacement, Hip/methods , Bone Cements/adverse effects , Cementation/adverse effects , Cementation/methods , Joint Instability/physiopathology , Acetabulum/surgery , Adhesiveness , Arthroplasty, Replacement, Hip/instrumentation , Computer Simulation , Equipment Failure Analysis/methods , Finite Element Analysis , Humans , Joint Instability/etiology , Models, Biological , Prosthesis Failure
20.
Eur Respir J ; 28(2): 323-9, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16571611

ABSTRACT

The slope of phase III of the single-breath nitrogen wash-out test (sbN2-test) measures ventilation inhomogeneity and, in smokers, is strongly associated with small airways pathology. The present authors aimed to study ventilation inhomogeneity in emphysema related to type Z alpha1-antitrypsin (AAT) and to assess its relationship with indices of parenchymal damage and airways obstruction. A total of 18 subjects, consisting of ex-smokers with type Z AAT and emphysema (confirmed by computed tomography scan), were studied in a cross-sectional design. Post-bronchodilation flow-volume curves and gas transfer parameters were measured; sbN2-test curves were obtained and the slope of phase III was determined. The mean value of the slope (4.6+/-1.3% N2 x L(-1)) was higher than reference values +2sd; it was significantly correlated with the transfer factor of the lung for carbon monoxide (R = -0.75) and the transfer coefficient of the lung for carbon monoxide (R = -0.58), but not with airways obstruction. There was no correlation between phase III slope values and cumulative smoking. In patients with type Z alpha1-antitrypsin emphysema, the increased ventilation inhomogeneity predominantly reflects parenchymal abnormalities, demonstrating that measurement of airways obstruction is not sufficient to characterise the disease. Determination of the sensitivity of the single-breath nitrogen wash-out test slope in detecting disease progression may give complementary information to spirometry.


Subject(s)
Genetic Diseases, Inborn/physiopathology , Pulmonary Emphysema/physiopathology , alpha 1-Antitrypsin/genetics , Adult , Breath Tests/methods , Cross-Sectional Studies , Female , Genetic Diseases, Inborn/genetics , Genetic Diseases, Inborn/pathology , Humans , Lung/pathology , Lung/physiopathology , Male , Middle Aged , Nitrogen/analysis , Pulmonary Emphysema/genetics , Pulmonary Emphysema/pathology
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