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At least 541 records · Page 30Linked to original sources
PubMed1986

[Effects of chromium compounds on the respiratory system. Part 4. Long-term inhalation of chromic acid mist in electroplating to ICR female mice].

In order to determine the effect on the respiratory system of long-term inhalation of chromic acid in electroplating, histopathological examination was performed on mice (ICR, female, n = 50) exposed to chromic acid mist for 12 months (30 min/d, 2 d/wk), by using the authors' miniaturized chromium electroplating system. After 12 months' exposure, the mice were kept for 6 months without exposure. In the upper respiratory tract, round perforations were found in the nasal septum in 6 mice that were sacrificed or died after 10 months' exposure. The perforations were located near the point of the septum, the thinnest part of the nasal septum, and were of pin-hole sige. On the epithelium of the trachea and bronchus, loss of cilia, proliferation of goblet cells or basal cells, and squamous metaplasia were observed in almost all of the exposed mice. These changes appeared to be more advanced in mice exposed for a longer period. In the lung, development of benign adenoma was observed in one mouse in the 6- to 9-months' exposure group, in three in the 10- to 14-months' exposure group and in one in the group examined after 15 to 18 months. Furthermore, adenocarcinomas were found in two mice, one of which died at 17 months and the other was sacrificed 18 months after initiation of exposure. In conclusion, the finding that adenomas and adenocarcinomas were observed in mice exposed to chromic acid mist suggests the need to give careful attention to the possibility of respiratory cancers in chromium electroplating workers.

Adenocarcinoma↗
PubMed2000

Postbypass pulmonary artery pressure influences respiratory system compliance after ventricular septal defect closure.

It is reported that surgical correction of left-to-right shunt improves respiratory function in paediatric cardiac patients. However, such correction sometimes does not result in an improvement of respiratory compliance. The purpose of this study was to look for factors determining changes in respiratory system compliance (Crs) in patients who underwent closure of ventricular septal defect (VSD closure). In a prospective study, 17 children (< 10 kg) who underwent VSD closure were enrolled. They were divided into two groups, according to postbypass mean pulmonary artery pressure (mPAP). The patients were allocated to Group C if mPAP was < or = 18 mmHg (n=12) and to Group PH if > 18 mmHg (n=5). We compared the ratio of postoperative Crs to preoperative Crs (Cpost/Cpre) between the groups. A multiple occlusion technique was used to measure Crs. The Cpost/Cpre in group C was larger than that in group PH (1.11+/-0.17 vs. 0.81+/-0.12, P<0.01). There was a correlation between postbypass mPAP and Cpost/Cpre (r(s)=0.49, P<0.05), but no correlation was noted between preoperative mPAP, Qp/Qs or Rp/Rs and Cpost/Cpre. We concluded that high postbypass mPAP was associated with a perioperative decrease in Crs after VSD closure.

Blood Pressure↗
PubMed1994

[Side effects of interferon on endocrine and respiratory system in 545 cases of chronic hepatitis C].

We investigated the side effects of interferon (IFN) on the endocrine and respiratory system in 545 cases of chronic hepatitis C. Eleven of 494 (2.2%) patients with chronic hepatitis C who were treated with natural or recombinant interferon (IFN) developed thyroid disease while on treatment. Eight patients developed hyperthyroidism and 3 patients developed hypothyroidism. All 11 patients required definitive therapy, who became euthyroid after the therapy. Two patients received nIFN alpha and one patient received rIFN alpha 2b developed diabetes mellitus. Two patients received rIFN alpha 2a and rIFN alpha 2b, respectively, developed interstitial pneumonia 12 weeks and 24 weeks later, respectively. One patient showed positive reaction for RA test and LE factor and positive LE cell, and complained of fever, arthralgia and dry cough. These phenomenon disappeared after the cessation of IFN therapy.

Adult↗
PubMed1994

Computer determined compliance of the respiratory system (Crs) in ventilated newborn infants.

We describe a simple, low cost technique for computerized measurements of compliance of the respiratory system (Crs) by airway occlusion technique in intubated newborn infants. Tidal volumes of 5, 7.5, and 10 mL/kg were injected from a calibrated syringe into the endotracheal tube via a three-way stop cock and a t-piece. Airway pressure was measured by means of a differential pressure transducer. The analog pressure signal was fed into an optically isolated signal conditioning termination panel and an analog input board which was connected to the PC bus. The signal was amplified and A/D converted by the input board and processed by the digital computer. Crs was determined as the ratio of the injected tidal volume to the difference between the endexpiratory pressure and the pressure at airway occlusion. The software is written in Turbo Pascal (Borland Int.) and includes a patient data base and facilities for system configuration, calibration of transducers, data acquisition, handling, calculation of Crs, reporting and archive storage. Data sampling frequency may be individually set at 60 to 200 Hz. Synchronous measurements in 10 newborn infants using analog pressure amplification and polygraphic recording showed that pressures were correctly determined by the computer and that amplitude and frequency response of the pressure recordings were adequate.

Airway Resistance↗
PubMed2000

Impairment of the respiratory system in diabetic autonomic neuropathy.

Diabetic autonomic neuropathy (DAN) may affect up to 30% of the diabetic population. Sometimes DAN becomes clinically manifest causing specific symptoms and signs; more often, however, DAN is responsible for subtle alterations detectable only by functional tests, as in the case of the respiratory system. At first, abnormalities both in the bronchomotor tone and aspecific airway responsiveness to different stimuli were recognised in diabetic patients with DAN, indicating a defective control of mechanisms which regulate the bronchial calibre in these subjects. Subsequently, peculiar changes in breathing pattern and greater ventilatory requirements have been observed during incremental exercise in diabetics with DAN, suggesting an altered control of breathing in stressful conditions. Alterations in either peripheral or central chemosensitivity have been repeatedly shown in these patients, with marked differences related to the severity of DAN, concerning the neuro-muscular and ventilatory responsiveness to CO2. Following anecdotal reports, respiratory disturbances during sleep have been more carefully investigated in diabetic subjects and greater prevalence of sleep apnea, mainly in the obstructive form, has been found in the presence of DAN. The underlying mechanisms of sleep disordered breathing, however, are poorly understood in DAN and further studies are needed to elucidate them.

Autonomic Nervous System Diseases↗
PubMed1993

Effect of lung lavage on the stress relaxation of the respiratory system.

To test the hypothesis that lowering the concentrations of surfactant molecules at the gas-liquid interface increases viscoelastic dissipation in the lungs, the amplitude and time course of stress relaxation were quantified before and after lavage of the lungs with warm saline in five newborn and five 8-wk-old anesthetized piglets. Stress relaxation was separated from other dissipative pressure losses by fitting the pressure decays that follow airway occlusions performed during a period of constant inspiratory flow to a double-exponential regression. The amplitude of stress relaxation (defined by the term of the regression with the longest time constant) related linearly to the changes in respiratory system volume and elastic recoil preceding the occlusions both before and after the lavage. Lung lavage increased the slope of both relationships without altering the time course of the relaxations. In addition to being consistent with the proposed hypothesis, these results suggest that viscoelastic pressure losses remain linked to the elastic stresses generated during lung inflation, as proposed by Fredberg and Stamenovic's structural dumping theory (J. Appl. Physiol. 67: 2408-2419, 1989).

Air Pressure↗
PubMed1998

Pathological studies on camelpox lesions of the respiratory system in the United Arab Emirates (UAE).

Three dromedary camels (Camelus dromedarius), which died from generalized camelpox with lesions in the respiratory system, were investigated. Histopathological lesions in the lung consisted of small, sometimes confluent foci of proliferated bronchial epithelium, necrosis and fibrosis. Orthopoxvirus cameli was demonstrated in all three cases by transmission electron microscopy and the virus was isolated from the lung and trachea on Dubca cells. It was proved by restriction enzyme analysis of the viral DNA that the isolates were identical. Immunohistochemical examination showed numerous poxvirus antigen-positive cells in the bronchial epithelia. Immunolabelled material was found in bronchial epithelial cells with hydropic degeneration and in infiltrating macrophages.

Animals↗
PubMed2002

Equal increases in respiratory system elastance reflect similar lung damage in experimental ventilator-induced lung injury.

OBJECTIVE: We hypothesized that a 50% increase in respiratory system elastance (Ers) would indicate similar degree of lung damage (equi-damage, ED), independently of ventilation strategy. DESIGN AND SETTING: A prospective, randomized animal laboratory investigation at a university hospital laboratory. SUBJECTS: 35 anesthetized, paralyzed, mechanically ventilated male Sprague-Dawley rats. INTERVENTIONS: Each rat was ventilated with a different combination of tidal volume, positive end-expiratory pressure, and inspired fraction of oxygen. Ers was determined throughout the experiment; the studies were interrupted when Ers reached 150% (ED) of its baseline value, or after 5 h. MEASUREMENTS AND RESULTS: Lung wet to dry weight ratio (W/D) was assessed. Morphological damage of the lung was scored on a grading of perivascular edema, hemorrhage, and breaks in the alveolar septa to obtain a total injury score. Twenty-four rats achieved an Ers of 150%: nine within 1 h (class 1), nine in 1-2 h (class 2), and six in 2-5 h (class 3). Eleven rats did not reach the target 50% increase in Ers (class 4). W/D was higher in rats that reached the target than in those that did not. W/D did not differ among rats that reached ED. Similarly, the total injury score did not differ among classes 1-3 but was higher than class 4. CONCLUSIONS: In the setting of VILI a 50% increase in Ers corresponds to an equal level of lung damage, irrespective of ventilatory setting and time of ventilation.

Animals↗
PubMed2004

[The volume of surgery on the abdominal cavity organs in patients with associated cardiovascular and respiratory system diseases].

The cardiovascular and respiratory disturbances are the main risk factor in acute and chronic surgical deseases of the abdominal cavity organs, including oncological. It is limits the possibility and volume of the diagnostics and surgical tactics choice. The complicated current of main disease is a risk factor of operation perform and the reason of the undertaking inadequate and palliative intervention, which significant reduce of the quality of life. Real by risk level reductions in surgery is a determination of tissues viability, estimation of compensatory reserve sick evidences for determination for operation performance including simultaneous and staged.

Abdominal Cavity↗
PubMed1983

Some functional mechanical implications of the structural design of the respiratory system in newborn mammals.

A high chest wall/lung compliance ratio is an obligatory structural requirement in the newborn. A flexible chest wall is an essential prerequisite for the delivery through the birth canal, and relatively stiff lungs result from the presence of the fluid in the interstitium. A high compliance yields a long time constant, which may help in raising the end expiratory level, an important functional priority in the neonatal respiration. It is likely, however, that the goal of maintaining a high mean lung volume is mainly achieved through closure of the glottis and/or inspiratory muscle activity during expiration. A relatively long time constant during inspiration may generate some functional problems, such as volume instability to pressures applied and not ready responses to inspiratory pressure swings. Some evidence suggests that in dynamic conditions the compliance of the respiratory system is smaller than the passive value, effectively reducing the inspiratory time constant. A comparative analysis of the tracheal dimensions, matched by studies of expiratory flows at a fixed driving pressure in animals of different ages, indicate that in the newborn the trachea has a relatively smaller volume and larger air-flow resistance. This latter factor is probably offset by the smaller upper airway resistance in the newborn. If the trachea was representative of the whole dead space, it would seem, therefore, that the structure of the newborn mammalian lung favors the alveolar ventilatory function, without a substantial increase in the energetic losses.

Animals↗
PubMed2003

Brucellosis and the respiratory system.

Brucellosis is a zoonotic disease that remains endemic worldwide. Its clinical manifestations and focal complications are often troublesome in making a diagnosis. Involvement of the respiratory system in brucellosis is an acknowledged but rare event that is only occasionally described in literature. We describe 37 cases of respiratory involvement during the course of brucellosis that presented as pneumonia, bronchopneumonia, pleural effusion with a predominance of monocytic or lymphocytic infiltrates, and paroxysmal dry cough. We also discuss aspects of the respiratory pathology, radiological characteristics, coexisting complications, and aspects of treatment of respiratory brucellosis.

Adolescent↗
PubMed1996

Excitatory drive to the respiratory system in REM sleep.

REM sleep is sometimes divided into tonic and phasic stages. Tonic REM sleep processes are both excitatory and inhibitory to the respiratory system. Inhibitory effects arise from the atonic processes of the REM state and include atonia of thoracoabdominal and extrathoracic airway muscles. Excitatory effects include increases in respiratory rate, central respiratory drive and rate of rise of diaphragmatic activity. The combination of these varying antagonistic effects determines the level of ventilation.

Brain Stem↗