936 resultados para respiratory physiology


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Impairment of lung liquid absorption can lead to severe respiratory symptoms, such as those observed in pulmonary oedema. In the adult lung, liquid absorption is driven by cation transport through two pathways: a well-established amiloride-sensitive Na(+) channel (ENaC) and, more controversially, an amiloride-insensitive channel that may belong to the cyclic nucleotide-gated (CNG) channel family. Here, we show robust CNGA1 (but not CNGA2 or CNGA3) channel expression principally in rat alveolar type I cells; CNGA3 was expressed in ciliated airway epithelial cells. Using a rat in situ lung liquid clearance assay, CNG channel activation with 1 mM 8Br-cGMP resulted in an approximate 1.8-fold stimulation of lung liquid absorption. There was no stimulation by 8Br-cGMP when applied in the presence of either 100 μM L: -cis-diltiazem or 100 nM pseudechetoxin (PsTx), a specific inhibitor of CNGA1 channels. Channel specificity of PsTx and amiloride was confirmed by patch clamp experiments showing that CNGA1 channels in HEK 293 cells were not inhibited by 100 μM amiloride and that recombinant αβγ-ENaC were not inhibited by 100 nM PsTx. Importantly, 8Br-cGMP stimulated lung liquid absorption in situ, even in the presence of 50 μM amiloride. Furthermore, neither L: -cis-diltiazem nor PsTx affected the β(2)-adrenoceptor agonist-stimulated lung liquid absorption, but, as expected, amiloride completely ablated it. Thus, transport through alveolar CNGA1 channels, located in type I cells, underlies the amiloride-insensitive component of lung liquid reabsorption. Furthermore, our in situ data highlight the potential of CNGA1 as a novel therapeutic target for the treatment of diseases characterised by lung liquid overload.

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Questionnaire studies indicate that high-anxious musicians may suffer from hyperventilation symptoms before and/or during performance. Reported symptoms include amongst others shortness of breath, fast or deep breathing, dizziness and thumping heart. However, no study has yet tested if these self-reported symptoms reflect actual cardio respiratory changes. Disturbances in breathing patterns and hyperventilation may contribute to the often observed poorer performance of anxious musicians under stressful performance situations. The main goal of this study is to determine if music performance anxiety is manifest physiologically in specific correlates of cardio respiratory activity. We studied 74 professional music students divided into two groups (i.e. high-anxious and lowanxious) based on their self-reported performance anxiety in three distinct situations: baseline, private performance (without audience), public performance (with audience). We measured a) breathing patterns, end-tidal carbon dioxide (EtCO2, a good non-invasive estimator for hyperventilation), ECG and b) self-perceived emotions and self-perceived physiological activation. The poster will concentrate on the preliminary results of this study. The focus will be a) on differences between high-anxious and low-anxious musicians regarding breaths per minute and heart rate and b) on the response coherence between self-perceived palpitations and actual heart rate.

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T O THE E DITOR-Besides viruses, Mycoplasma pneumoniae and Chlamydia pneumoniae are common causes of community-acquired respiratory infections (CARI) in children. However, the causal agent of CARI remains unknown in many cases [ 1]. Growing evidence suggests that Chlamydia-related bacteria might have a pathogenic role in humans [ 2, 3]. Parachlamydia acanthamoebae and Protochlamydia naegleriophila have been detected in respiratory clinical samples [ 4, 5], and the role of Parachlamydia acanthamoebae in pneumonia is supported by in vitro studies and animal models [ 6]. Rhabdochlamydia crassificans and Rhabdochlamydia porcellionis are intracellular pathogens of arthropods that also belong to the Chlamydiales order [ 7, 8]. A recent analysis suggests that Rhabdochlamydia species might affect morbidity and mortality in premature newborns [ 9], but their role ...

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Pneumocystis jirovecii pneumonia (PCP) is a common opportunistic infection. Microscopic diagnosis, including diagnosis using the Merifluor-Pneumocystis direct fluorescent antigen (MP-DFA) test, has limitations. Real-time PCR may assist in diagnosis, but no commercially validated real-time PCR assay has been available to date. MycAssay Pneumocystis is a commercial assay that targets the P. jirovecii mitochondrial large subunit (analytical detection limit, ≤3.5 copies/μl of sample). A multicenter trial recruited 110 subjects: 54 with transplants (40 with lung transplants), 32 with nonmalignant conditions, 13 with leukemia, and 11 with solid tumors; 9 were HIV positive. A total of 110 respiratory samples (92% of which were bronchoalveolar lavage [BAL] specimens) were analyzed by PCR. Performance was characterized relative to investigator-determined clinical diagnosis of PCP (including local diagnostic tests), and PCR results were compared with MP-DFA test results for 83 subjects. Thirteen of 14 subjects with PCP and 9/96 without PCP (including 5 undergoing BAL surveillance after lung transplantation) had positive PCR results; sensitivity, specificity, and positive and negative predictive values (PPV and NPV, respectively) were 93%, 91%, 59%, and 99%, respectively. Fourteen of 83 subjects for whom PCR and MP-DFA test results were available had PCP; PCR sensitivity, specificity, PPV, and NPV were 93%, 90%, 65%, and 98%, respectively, and MP-DFA test sensitivity, specificity, PPV, and NPV were 93%, 100%, 100%, and 98%. Of the 9 PCR-positive subjects without PCP, 1 later developed PCP. The PCR diagnostic assay compares well with clinical diagnosis using nonmolecular methods. Additional positive results compared with the MP-DFA test may reflect low-level infection or colonization.

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The aim of the study was to measure the energy used for growth of healthy fullterm and breast-fed Gambian infants. The weight gain (WG) of 14 infants (mean age +/- SEM 17 +/- 1 d, weight 3.581 +/- 0.105 kg) was measured over a 2-week period; the energy intake (EI) from breast milk was assessed for 24 h in the middle of the study period by weighing the infant before and after each breast-feed. On the same day, sleeping energy expenditure (SEE) and respiratory quotient (RQ) were measured for 30 min on five occasions through the 24-h period. EI averaged 502 +/- 25 kJ/kg.d, and SEE 230 +/- 6 kJ/kg.d; thus, an average of 272 kJ/kg.d were available for physical activity and the energy stored for growth. The total energy spent by infants while sleeping and for periods of physical activity was calculated to be 1.7 x SEE. The mean RQ measured on five occasions averaged 0.879 +/- 0.009. SEE was correlated with WG (r = 0.747, P less than 0.005), with a slope of the regression line of 5.5 kJ/g; this value can be considered as an estimate of the energy spent for new tissue synthesis in the resting infant. The efficiency of weight gain was lower in this study (67%) than in studies conducted on fast-growing preterm infants or children recovering from malnutrition.

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The Iowa Influenza Surveillance Network (IISN) is comprised of physicians, schools, child care centers, businesses, and long term care facilities who track the occurrence on influenza-like illness. In addition, the state influenza coordinator tracks the number of deaths due to pneumonia and influenza in Des Moines weekly as part of the 122-Cities Morbidity and Mortality reporting system sponsored by CDC.

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The Iowa Influenza Surveillance Network (IISN) is comprised of physicians, schools, child care centers, businesses, and long term care facilities who track the occurrence on influenza-like illness. In addition, the state influenza coordinator tracks the number of deaths due to pneumonia and influenza in Des Moines weekly as part of the 122-Cities Morbidity and Mortality reporting system sponsored by CDC.

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Weekly report of the Iowa Influenza Surveillance Network produced by the Iowa Department of Public Health.

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Weekly report of the Iowa Influenza Surveillance Network produced by the Iowa Department of Public Health.

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Weekly report of the Iowa Influenza Surveillance Network produced by the Iowa Department of Public Health.

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Weekly report of the Iowa Influenza Surveillance Network produced by the Iowa Department of Public Health.

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Weekly report of the Iowa Influenza Surveillance Network produced by the Iowa Department of Public Health.

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Weekly report of the Iowa Influenza Surveillance Network produced by the Iowa Department of Public Health.

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Weekly report of the Iowa Influenza Surveillance Network produced by the Iowa Department of Public Health.