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PubMed1989

[Effects of air pollutants on the respiratory system in young children].

A one year study on a random sample of 1225 Swiss children aged 0-5 years was conducted in four different areas (two urban, one suburban and one rural) of Switzerland to investigate the relationship between air pollution and respiratory symptoms. For each child daily symptoms over a six week period were recorded by their parents in the form of a standard diary and air pollution was assessed by personal NO2-samplers. 20% of the diaries were validated by comparison with the attending pediatrician's case-notes and showed good agreement (87%). The frequency of respiratory symptoms per child per day was found to increase with increasing levels of NO2 measured outdoors, but not with NO2 concentration indoors (when other indoor sources for NO2 where present). Possible other factors were accounted for by multiple regression analysis and the variables "season" and "child's susceptibility to colds" also showed a significant association with respiratory symptoms. But the relationship between NO2 outdoors and respiratory symptoms per child per day remained statistically significant. The multiple regression model explains 7% of the total variability. The result indicates that air pollution is a contributory factor in the development of respiratory symptoms in children.

Air Pollutants↗
PubMedDate not supplied

[Passive smoking--(un)recognized effects on the respiratory system].

Passive smokers are exposed to a quantitatively smaller but qualitatively different smoke than active smokers. Clinical and epidemiological investigations indicate that allergic and nonallergic subjects are susceptible to tobacco smoke. The most frequent symptoms are eye irritation and blinking, nasal and throat irritation, nausea and headache. Acute effects on respiratory system are manifested by increase of airway resistance and decrease of airway specific conductance. Chronic effects include deterioration of pulmonary function, exacerbation of allergy, chronic pulmonary diseases, angina pectoris and increase of relative risk of lung cancer. Children are sensitive to tobacco smoke even before birth and exposure during the first year of life increases the risk of respiratory disease. Passive smoking at workplace is recognized as a cause of occupational respiratory diseases and the tollerable concentration of cigarette smoke is suggested for 8-hour exposure of healthy workers.

Humans↗
PubMedDate not supplied

Coordination of sympathetic and respiratory systems: neurophysiological experiments.

Many sympathetic neurons exhibit respiratory rhythmicity in their activity which is due to a central coupling between respiratory neurons and neurons of autonomic pathways. The presence or absence and the pattern of this respiratory modulation depend on the function of sympathetic neurons and on the way by which both systems are coupled. In the cat, neurons supplying resistance vessels such as muscle vasoconstrictor and visceral vasoconstrictor neurons are activated during inspiration and suppressed during postinspiration. In contrast, most cutaneous vasoconstrictor neurons show no respiratory modulation in their activity, some are inhibited during inspiration and activated during expiration, and others exhibit a weak peak during inspiration. Sudomotor neurons are preferentially active during postinspiration and "inspiratory-type" neurons only during inspiration. In addition to the central coupling between presympathetic and respiratory neurons, cardiovascular afferents, notably the arterial baroreceptors, contribute an important peripheral reflex component of respiratory modulation, but only in neurons of muscle and visceral vasoconstrictor pathways.

Animals↗
PubMed1999

Elastic pressure-volume curves of the respiratory system reveal a high tendency to lung collapse in young pigs.

OBJECTIVE: To study pressure-volume (P/V) curves over a wide pressure and volume range in pigs. DESIGN: Dynamic and static P/V curves (P(dyn)/V and P(st)/V) and compliance of the respiratory system were studied. The effects of recruitment, positive end-expiratory pressure (PEEP) and body position were analysed. SETTING: Research animal laboratory. MATERIALS: Seven anaesthetised, paralysed and ventilated healthy pigs of 21 kg. MEASUREMENTS: P/V curves up to a pressure of about 40 cmH(2)O were recorded with a computer-controlled ventilator. P(st)/V curves were obtained with the static occlusion method and P(dyn)/V curves during an insufflation at a low, constant flow rate. RESULTS: P(dyn)/V recording showed a complex pattern. During the insufflation compliance increased, fell, increased and fell again. A 2nd P(dyn)/V recording immediately following the 1st one was displaced towards higher volumes and showed only one maximum of compliance. The difference between the two curves reflected: (1) lung collapse during a period of 5 min of ventilation at zero end-expiratory pressure (ZEEP) following a recruitment manoeuvre, (2) recruitment during the measurement of the 1st P(dyn)/V curve. These observations were similar in the supine and in the left lateral position. After ventilation at PEEP, 4 cmH(2)O, the signs of collapse and recruitment were reduced. It was confirmed that PEEP offers a partial protection against collapse. P(st)/V curves showed higher volumes and higher compliance values compared to P(dyn)/V curves. This reflects the influence of viscoelastance on P(dyn)/V curves. CONCLUSION: The study demonstrates a particularly strong tendency to lung collapse in pigs.

Age Factors↗
PubMed1986

Bronchoscopic and radiologic features of Kaposi's sarcoma involving the respiratory system.

In a group of 61 patients admitted to New England Deaconess Hospital, Boston, with a diagnosis of acquired immune deficiency syndrome (AIDS), 25 were found to have Kaposi's sarcoma involving the skin and mucous membranes. Of these 25 patients, eight had lesions involving the respiratory system. Radiographically, patients with Kaposi's sarcoma had hilar and mediastinal adenopathy with perihilar parenchymal infiltration which progressed to diffuse bilateral infiltrates over a period of months. This pattern and the tempo of its evolution were distinctly different from the diffuse infiltrates seen in patients with Pneumocystis carinii pneumonia. Bronchoscopy was performed in seven of the eight patients, revealing characteristic lesions of Kaposi's sarcoma in the airways. We propose that parenchymal pulmonary Kaposi's sarcoma can be strongly suspected in a patient with AIDS who has the following features: a characteristic radiologic pattern; endobronchial Kaposi's sarcoma at bronchoscopy; and no evidence of opportunistic infection. In this subset of patients, further diagnostic intervention such as open lung biopsy, a procedure with potential morbidity in these ill individuals, may be unnecessary.

Acquired Immunodeficiency Syndrome↗
PubMed1988

[Evaluation of the development of the respiratory system in big-city adolescents, e.g., students of the Technical School of Mechanics and the Grammar School in Lódź (II)].

In 104 students from Secondary Technical School of Mechanics (TM) and 37 students from Grammar School (LO, 15-19 year-old, a longitudinal study of respiratory system was carried out. During the whole period of studies such spirographic parameters as VC, FEV1, FIV1, IMBC and Ziemssen and Amar indices were assessed. Spirographic parameters were assessed on the Pulmotest Godard. The subjects from each school were divided into two sub-groups: those practising in a sporting club (sport group--SG) and those who do not practise any sport in an organized way (non-sport group--NSG). In the students from TM and LO spirographic parameters were increased during the whole period of investigation and they reached the highest level in the first and second form. No differences were observed between students of TM and LO as regards the test parameters. The highest values were observed in the sport subgroups--the differences in the first and second forms being statistically significant.

Adolescent↗
PubMed1999

Effect of negative expiratory pressure on respiratory system flow resistance in awake snorers and nonsnorers.

In spontaneously breathing subjects, intrathoracic expiratory flow limitation can be detected by applying a negative expiratory pressure (NEP) at the mouth during tidal expiration. To assess whether NEP might increase upper airway resistance per se, the interrupter resistance of the respiratory system (Rint,rs) was computed with and without NEP by using the flow interruption technique in 12 awake healthy subjects, 6 nonsnorers (NS), and 6 nonapneic snorers (S). Expiratory flow (V) and Rint,rs were measured under control conditions with V increased voluntarily and during random application of brief (0.2-s) NEP pulses from -1 to -7 cmH(2)O, in both the seated and supine position. In NS, Rint,rs with spontaneous increase in V and with NEP was similar [3.10 +/- 0.19 and 3.30 +/- 0.18 cmH(2)O x l(-1) x s at spontaneous V of 1.0 +/- 0.01 l/s and at V of 1.1 +/- 0.07 l/s with NEP (-5 cmH(2)O), respectively]. In S, a marked increase in Rint,rs was found at all levels of NEP (P < 0.05). Rint,rs was 3.50 +/- 0.44 and 8.97 +/- 3.16 cmH(2)O x l(-1) x s at spontaneous V of 0.81 +/- 0.02 l/s and at V of 0.80 +/- 0.17 l/s with NEP (-5 cmH(2)O), respectively (P < 0.05). With NEP, Rint,rs was markedly higher in S than in NS both seated (F = 8.77; P < 0.01) and supine (F = 9.43; P < 0.01). In S, V increased much less with NEP than in NS and was sometimes lower than without NEP, especially in the supine position. This study indicates that during wakefulness nonapneic S have more collapsible upper airways than do NS, as reflected by the marked increase in Rint,rs with NEP. The latter leads occasionally to an actual decrease in V such as to invalidate the NEP method for detection of intrathoracic expiratory flow limitation.

Adult↗
PubMed2001

Historical cohort study of US man-made vitreous fiber production workers: VI. Respiratory system cancer standardized mortality ratios adjusted for the confounding effect of cigarette smoking.

To date, the US cohort study of man-made vitreous fiber workers has provided no consistent evidence of a relationship between man-made vitreous fiber exposure and mortality from malignant or non-malignant respiratory disease. Nevertheless, there have been small, overall excesses in respiratory system cancer (RSC) among workers from the fiberglass and rock/slag wool production plants included in the study that were unexplained by estimated worker exposures to respirable fiber or other agents present in the plants. The present investigation was designed to provide a quantitative estimate of the extent to which the overall excess in RSC mortality observed at the total cohort level among male fiberglass and rock/slag wool workers is a result of the positive confounding effects of cigarette smoking. Because cigarette-smoking data were neither available nor obtainable at the individual level for all members of the fiberglass and rock/slag wool cohorts, we used the "indirect" method to adjust RSC standardized mortality ratios (SMRs) at the group (cohort and plant) level. Our adjustment suggested that cigarette smoking accounts for all of the 7% and 24% excesses in RSC observed, respectively, for the male fiberglass and rock/slag wool cohorts in the latest mortality updates. The same conclusion was reached regardless of which of several alternative formulations were used to adjust local rate-based RSC SMRs. We found that our smoking adjustments were robust with respect to several alternative characterizations and (with the exception of one fiberglass plant) produced adjusted RSC SMRs that were lower than their unadjusted counterparts. Further, all statistically significantly elevated unadjusted SMRs were reduced to not statistically significant levels. These results reaffirm that RSC SMRs based on US and local rates must take into account the potential confounding effects of cigarette smoking. They also suggest that the use of local county mortality rate-based SMRs may not help to adjust for cigarette smoking to the degree suggested by some investigators.

Adolescent↗
PubMed1997

[Multiple extramedullary plasmacytomas from the whole respiratory system].

Extramedullary plasmacytoma occurs most commonly in the upper respiratory tract, but rarely develops in the lung. We have recently studied an unusual case of multiple extramedullary plasmacytomas, presumably preceding localized myelomatous bone lesions. This rather unique case is, to the best of our knowledge, the first documented report of widespread multiple extramedullary plasmacytomas confined to a single organ system. A 50-year-old man was hospitalized for assessment of bilateral hilar masses on a chest radiograph. An open lung biopsy specimen was obtained, revealing plasmacytoma of the lung. Biopsy specimens from the nasal fossa also demonstrated plasma cell tumor. Moreover, a bronchoscopy revealed that the both main-stem bronchi appeared to be involved by hemorrhagic tumorous lesions. However, a biopsy could not be done because of the high risk of bleeding. Electrophoresis revealed an IgA (kappa) type M-component (2.8 g/dl) in the serum and kappa type Bence Jones proteins (0.5 g/day) in the urine. The clinical course of the present case accurately corresponds to multiple extramedullary plasmacytomas with a localized bone involvement, but not to extensive extramedullary disease associated with aggressive multiple myeloma. The occurrence of multiple extramedullary plasmacytomas confined to the respiratory system may be due to an endobronchial metastatic process or to a multicentric autochthonous process.

Bence Jones Protein↗