| 31. |
- Bondesson, Eva, et al.
(författare)
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Exhaled breath condensate-site and mechanisms of formation
- 2009
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Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7163 .- 1752-7155. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Exhaled breath condensate (EBC) analysis is a promising tool for diagnosis and management of pulmonary diseases. Its clinical usefulness is still limited however due to unresolved issues around e. g. reproducibility, anatomical site of origin of EBC solutes and mechanisms of EBC formation. To gain some knowledge on these issues, three different airway deposition patterns of an aqueous aerosol containing technetium-99m were studied in eight healthy non-smoking subjects. EBC was collected 20 min after each radioaerosol administration and analyzed for gamma radiation and electrolytes. Radioaerosol deposition in preferentially central lung compared with preferentially peripheral lung resulted in 3.8 times higher EBC radioactivity. EBC concentrations of Na+ and K+ correlated significantly indicating dilution by water vapor to be a major source of variability. Since Na+/K+- and Na+/S2--concentration ratios, but not Na+/Cl--or Na+/Ca2+-, were comparable to those previously reported for alveolar lining fluid (ALF), some mechanisms other than dilution are likely also to be involved. In conclusion, our findings indicate that EBC derives mainly from the central airways, that the electrolyte composition of EBC does not consistently reflect that of ALF, and that EBC concentrations of electrolytes are determined not only by ALF dilution with water vapor but also by other mechanisms.
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| 32. |
- Bondesson, Eva, et al.
(författare)
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In vitro and in vivo aspects of quantifying intrapulmonary deposition of a dry powder radioaerosol.
- 2002
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Ingår i: International Journal of Pharmaceutics. - 1873-3476. ; 232:1-2, s. 149-156
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Tidskriftsartikel (refereegranskat)abstract
- Pulmonary delivery of pharmaceutical aerosols can be quantified using gamma scintigraphy. Technetium-99m, the most commonly used radionuclide in scintigraphic studies, cannot be incorporated into the drug molecule and, therefore, may be distributed differently from the drug itself, particularly if the drug is presented as a solid in a liquid suspension or as a dry powder formulation. This study demonstrated the importance of using conditions relevant to the in vivo situation in the in vitro characterisation of a dry powder aerosol of 99mTc-labelled lactose. The influence of inspiratory flow on the distribution of aerosol within the lungs was investigated in eight healthy subjects who inhaled the 99mTc-labelled lactose at four flows (30,40,60 and 80 l/min). No differences in penetration index (PI) or count density distribution of radioactivity were seen, indicating that regional distribution of aerosol in healthy airways was insensitive to differences in the inspiratory effort exerted by the subject while inhaling the experimental dry powder radioaerosol.
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| 33. |
- Bondesson, Eva, et al.
(författare)
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Planar gamma scintigraphy - points to consider when quantifying pulmonary dry powder aerosol deposition
- 2003
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Ingår i: International Journal of Pharmaceutics. - 1873-3476. ; 251:1-2, s. 33-47
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Tidskriftsartikel (refereegranskat)abstract
- Methodological aspects of planar gamma scintigraphy used to quantify pulmonary aerosol deposition were investigated using an experimental dry powder formulation. Particles of micronized salbutamol sulphate were labelled with technetium-99m and admixed to an ordered mixture of unlabelled micronized salbutamol sulphate and larger carrier particles of lactose. The radioaerosol was administered to 24 healthy subjects, 12 in each of two consecutive, similarly designed studies. Pulmonary deposition was determined using two methods: repeated planar imaging, and pharmacokinetic assessments following charcoal co-administration to prevent gastrointestinal salbutamol absorption. After due consideration had been taken to ensure appropriate radiolabelling, image acquisition and processing procedures, a scintigraphic estimate of 26.2% (24.2-28.4%) was obtained, which did not significantly differ from the pharmacokinetic estimate of 26.4% (24.4-28.7%). In summary, pre-study validation of the radiolabelling technique, quality control of radioaerosols produced during the study, correction for re-distribution of radiolabel from the lungs, selection of regions of interest, assessment of lung contours, correction for tissue attenuation of gamma rays and establishment of the actual recovery of radioactivity in the scintigraphic measurements could potentially affect the accuracy of the scintigraphic estimate of pulmonary deposition and, thus, should be carefully considered in the design or evaluation of any such study.
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| 34. |
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| 35. |
- Bondesson, Eva, et al.
(författare)
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Site of deposition and absorption of an inhaled hydrophilic solute
- 2007
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Ingår i: British Journal of Clinical Pharmacology. - : Wiley. - 1365-2125 .- 0306-5251. ; 63:6, s. 722-731
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Tidskriftsartikel (refereegranskat)abstract
- Aims To characterize the absorption kinetics and bioavailability of an inhaled hydrophilic solute deposited at various sites within the airways. Methods Nine healthy nonsmokers received one intravenous, one oropharyngeal and two pulmonary doses of technetium-99 m-labelled diethylene triamine pentaacetic acid (Tc-99m-DTPA) in an open and crossover fashion. Pulmonary doses were administered as nebulized large and fine droplet-sized aerosols by Pari and UltraVent nebulizers at fairly rapid and slow inhalation flows, respectively. Plasma concentration-time profiles and 24 h urinary excretion of radioactivity were determined. One dose of Tc-99m-labelled Nanocoll, as a marker of mucociliary clearance (MCC), was also administered by Pari for similar lung deposition as the Tc-99m-DTPA and followed by repeated chest gamma-imaging. Results Intrapulmonary deposition patterns of Tc-99m-DTPA differed significantly (the mean ratio of penetration index (Pari : UltraVent) was 76% with 95% CI 63%, 91%). However, no differences in rate or extent of Tc-99m-DTPA absorption were detected. Mean absorption time was 1.8 h (mean difference (Pari-UltraVent): -0.1 h with 95% CI -0.6 h, 0.3 h) and the bioavailability was 70% (mean ratio (Pari : UltraVent): 101% with 95% CI 90%, 115%). The pulmonary elimination half-life of Tc-99m-Nanocoll (8 h and 45 min) was significantly longer than that of Tc-99m-DTPA (less than 2 h). The oral bioavailability of Tc-99m-DTPA was estimated to be 3.1%. Conclusions The main elimination pathway of the inhaled hydrophilic solute Tc-99m-DTPA from the lungs is trans-epithelial absorption. Despite different intrapulmonary radioaerosol deposition patterns, as verified by gamma scintigraphy, no differences in Tc-99m-DTPA absorption kinetics or bioavailability were detected.
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| 36. |
- Bornmyr, S, et al.
(författare)
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Effect of local cold provocation on systolic blood pressure and skin blood flow in the finger
- 2001
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Ingår i: Clinical Physiology. - : Wiley. - 1365-2281 .- 0144-5979. ; 21:5, s. 570-575
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Tidskriftsartikel (refereegranskat)abstract
- Demonstration of increased vascular cold reactivity in patients with Raynaud's syndrome is difficult. For medico-legal reasons, it is important to get objective measures of vasospasm in these patients. Evaluation of the degree of vasospasm also provides prognostic information which is useful for patient management. In this study, we compare two methods of arterial circulation measurement. The laser Doppler scanning is a new method, which uses the recently developed laser Doppler perfusion imaging (LDPI) instrument. The aim of the present study was to compare the effect on finger skin blood flow measured with LDPI with changes in finger systolic blood pressure during local cold provocation. The effect of such provocation, skin blood flow and systolic blood pressure, were studied in 15 healthy controls. Six patients with known traumatic vasospastic disease (TVD) were also tested with both methods. Finger skin blood flow was measured with LDPI on the distal phalanx of the index finger of the left hand, every minutes during 6 min of local heating at 40 degrees C followed by local cooling for 3 min at 15 degrees C and then for 3 min at 10 degrees C. Finger systolic blood pressure was measured with strain-gauge method before and after local cooling to 10 degrees C with a cuff perfused with water of desired temperature. The test was performed in the same finger within a week of the laser Doppler scanning. Local finger cooling to 15 degrees C and 10 degrees C caused a significant decrease in blood flow, most marked at 10 degrees C. There was, however, no correlation between the decrease in blood flow and blood pressure. In the TVD-patients decreases in skin blood flow were similar compared with the healthy controls. In contrast, the changes in systolic blood pressure, were outside normal range (systolic quotient <0.65) in five of the six patients (83%), and also in 11 of the 15 healthy controls (73%). In conclusion, there is no correlation between the decrease in finger skin blood flow and systolic blood pressure during local cold provocation. For diagnosis of traumatic vasospastic disease (TVD), local cold-induced changes in finger systolic blood pressure seems superior to changes in skin blood flow, but the ideal clinical method for demonstrating increased cold-induced vasospasm is, however, still lacking.
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| 37. |
- Brådvik, Ingela, et al.
(författare)
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Kinetics of lung clearance of 99mTc-DTPA in smoking patients with sarcoidosis compared to healthy smokers.
- 2002
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Ingår i: Respiratory Medicine. - : Elsevier BV. - 1532-3064 .- 0954-6111. ; 96:5, s. 317-321
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Tidskriftsartikel (refereegranskat)abstract
- Investigation of lung clearance of 99mTc-labelled diethylene triamine penta-acetic acid (DTPA) in smoking sarcoid patients has been impeded by difficulties to differ between pathology of clearance kinetics caused by sarcoidosis and by smoking. This study explores the kinetics of lung clearance of 99mTc-DTPA in 15 current smokers with intrathoracic sarcoidosis. The results are compared with findings from 16 healthy smokers. Measurements of lung clearance over 180 min, i.e. longer than usual, revealed in II of the sarcoid patients a bi-exponential lung clearance course, which is pathologic. All healthy smokers also showed a bi-exponential lung clearance. In the analysis of the bi-exponential curve an initial fast, and a slow clearance component could be separated. The smokers with sarcoidosis had a significantly higher elimination rate of the slow component than the healthy smokers. Thus, analysis of the late part of the lung clearance curve may be rewarding in smoking sarcoid patients. The study shows that lung clearance of 99mTc-DTPA may be a method useful also in smoking patients with sarcoidosis.
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| 38. |
- C-Bergstrand, Ingar, et al.
(författare)
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Timolol increased retrobulbar flow velocities in untreated glaucoma eyes but not in ocular hypertension
- 2001
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Ingår i: Acta Ophthalmologica Scandinavica. - : Wiley. - 1395-3907. ; 79:5, s. 455-461
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To investigate retrobulbar blood flow velocities and the effects of topical timolol treatment in eyes with newly detected, previously untreated open angle glaucoma or ocular hypertension. METHODS: Fifteen eyes with open angle glaucoma (OAG) and 12 eyes with ocular hypertension (OH), in the same number of patients, all untreated and newly detected, were examined with colour Doppler imaging of retrobulbar vessels before and after 1 month of topical timolol treatment (0.5% Timoptic BID). RESULTS: Baseline central retinal artery end diastolic velocity was lower (48%, p=0.0002) and resistive index higher (7.6%, p=0.018) in the OAG group than in the OH group. In the glaucoma group mean end diastolic velocity increased by 41%, (p=0.006) while resistive index decreased by 5.8%, (p=0.02) on treatment, while no significant changes were seen in the OH group. Blood flow velocities in the ophthalmic artery did not change with treatment. Baseline IOP and IOP reduction did not differ between OAG and OH group. CONCLUSION: Peripheral resistance to blood flow was found to be increased in untreated glaucoma eyes as compared to a similar group of eyes with ocular hypertension. Timolol treatment diminished resistance significantly in the glaucoma group, but not in the ocular hypertension group. Thus the two groups responded differently to timolol treatment. The reaction to IOP lowering treatment could indicate defective autoregulation in the glaucoma group.
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| 39. |
- Casselbrant, Andreas, et al.
(författare)
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Common physiologic and proteomic biomarkers in pulmonary and coronary artery disease
- 2022
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 17:3
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Chronic obstructive pulmonary disease (COPD) and coronary artery disease (CAD) are leading causes of global morbidity and mortality. There is a well-known comorbidity between COPD and CAD, which is only partly explained by smoking and other known common risk factors. In order to better understand the relationship between COPD and CAD, we analyzed myocardial perfusion, pulmonary function and novel cardiovascular biomarkers in patients with symptoms suggesting myocardial ischemia.METHODS: A total of 396 subjects from the Swedish Biomarkers and Genetics CardioPulmonary Physiology Study (BiG CaPPS) were included, all of whom had been referred to myocardial perfusion imaging due to suspected myocardial ischemia. Subjects performed myocardial perfusion imaging (MPI), pulmonary function tests (PFT) and analysis of 92 proteomic biomarkers, previously associated with cardiovascular disease. Linear regression was used to study the relationship between MPI and PFT results and proteomic biomarkers.RESULTS: Subjects with CAD (n = 159) had lower diffusing capacity (DLCO) than patients without CAD (6.64 versus 7.17 mmol/(min*kPa*l); p = 0.004) in models adjusted for common covariates such as smoking, but also diabetes and brain natriuretic peptide (BNP). The association remained significant after additional adjustment for forced expiratory volume in one second (FEV1) (p = 0.009). Subjects with CAD, compared with subjects without CAD, had higher total airway resistance (0.37 vs 0.36 kPa/(l/s); p = 0.036). Among 92 protein biomarkers, nine were associated with a combined diagnosis of CAD and airflow obstruction: VSIG2, KIM1, FGF-23, REN, XCL1, GIF, ADM, TRAIL-R2 and PRSS8.SIGNIFICANCE: Diffusing capacity for carbon monoxide is decreased in patients with CAD, independently of decreased FEV1, diabetes, and elevated BNP. Several cardiovascular biomarkers are associated with co-existent CAD and airflow obstruction, but none with airflow obstruction only. The current findings indicate that the interaction between CAD and lung function is complex, including mechanisms beyond the known association between CAD and reduced ventilation.
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| 40. |
- Cereda, Maurizio, et al.
(författare)
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Quantitative imaging of alveolar recruitment with hyperpolarized gas MRI during mechanical ventilation
- 2011
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Ingår i: Journal of Applied Physiology. - : American Physiological Society. - 1522-1601 .- 8750-7587. ; 110:2, s. 499-511
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to assess the utility of He-3 MRI to noninvasively probe the effects of positive end-expiratory pressure (PEEP) maneuvers on alveolar recruitment and atelectasis buildup in mechanically ventilated animals. Sprague-Dawley rats (n = 13) were anesthetized, intubated, and ventilated in the supine position (He-4-to-O-2 ratio: 4:1; tidal volume: 10 ml/kg, 60 breaths/min, and inspiration-to-expiration ratio: 1:2). Recruitment maneuvers consisted of either a stepwise increase of PEEP to 9 cmH(2)O and back to zero end-expiratory pressure or alternating between these two PEEP levels. Diffusion MRI was performed to image He-3 apparent diffusion coefficient (ADC) maps in the middle coronal slices of lungs (n = 10). ADC was measured immediately before and after two recruitment maneuvers, which were separated from each other with a wait period (8-44 min). We detected a statistically significant decrease in mean ADC after each recruitment maneuver. The relative ADC change was -21.2 +/- 4.1 % after the first maneuver and -9.7 +/- 5.8 % after the second maneuver. A significant relative increase in mean ADC was observed over the wait period between the two recruitment maneuvers. The extent of this ADC buildup was time dependent, as it was significantly related to the duration of the wait period. The two postrecruitment ADC measurements were similar, suggesting that the lungs returned to the same state after the recruitment maneuvers were applied. No significant intrasubject differences in ADC were observed between the corresponding PEEP levels in two rats that underwent three repeat maneuvers. Airway pressure tracings were recorded in separate rats undergoing one PEEP maneuver (n = 3) and showed a significant relative difference in peak inspiratory pressure between pre- and poststates. These observations support the hypothesis of redistribution of alveolar gas due to recruitment of collapsed alveoli in presence of atelectasis, which was also supported by the decrease in peak inspiratory pressure after recruitment maneuvers.
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