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At least 19 recordsLinked to original sources
PubMed1979

[Experimental studies of long-term aerosol inhalation. An inhalation apparatus for long-term exposure with concentration regulation facilities (author's transl)].

A "multipurpose" inhalation system for long-term experiments was developed to study health effects of the exposure to various kinds of aerosols appearing in general working environments as well as in the ambient atmosphere. In order to carry out a continuous inhalation study on animals for their life-span, at least two essential conditions should continuously be fulfilled. (1) Steady maintenance of the appropriate sanitary conditions for the animals placed in the inhalation box. (2) Constant feeding of aerosol at an appropriately regulated concentration level. The developed system described in the present paper has been proved to be satisfactory from the above viewpoints. This inhalation system was applied to an experimental study attempting to simulate the polluted lungs in the urban dwellers. Heavy oil combustion products were chosen as the inhalation material, which were made to be inhaled by the male rats of SD-JCL strain for their life-span. The present report is mainly concerned with the construction of the inhalation system including a newly devised regulation facility of the aerosol concentration. Operating characteristics and actual data obtained are described. Details of the exposure conditions and pathological findings obtained will be described in the succeeding reports.

Aerosols↗
PubMed1992

Acute resistant asthma caused by excessive beta-2-adrenoceptor agonist inhalation and reversed by inhalation of beclomethasone.

With the aim of devising an improved beta 2-agonist treatment regimen for patients presenting with acute severe resistant asthma, a double-blind, placebo-controlled randomised study of the effect of fenoterol and beclomethasone inhalations was done in 40 patients. Fenoterol inhalations had minimal effect in acute resistant asthma, but significant improvement was obtained when beclomethasone inhalations were given before fenoterol inhalations. Sequential beclomethasone and fenoterol inhalations can therefore be used as a preliminary emergency treatment for these patients.

Administration, Inhalation↗
PubMed1975

[The inhalation of beta stimulators. Effect of the inhaled aerosol deposited in the oropharynx and in the bronchial tree].

Inhaled aerosols are predominatly deposited in the oropharynx and only a minor portion penetrates into the sublaryngeal airways. The effectiveness of both components of an orciprenaline aerosol was tested in 12 asthmatics. For this purpose they were given an inhalation on one day and, on the next, the entire oropharynx was sprayed with the inhalant. Evaluation of the corresponding bronchodilator effects was based on repeated measurements of specific airway conductance. The results show that the inhalation is about 6 times as effective as the spray, and thus prove the superiority of inhalation therapy over oral or peroral medication with beta-stimulants in the treatment of bronchial asthma.

Adult↗
PubMed1979

In vivo responses to inhaled proteins. II. Induction of interstitial pneumonitis and enhancement of immune complex-mediated alveolitis by inhaled concanavalin A.

An animal model of environmental lung disease is described in which phytomitogen, antigen, or both, are administered in aerosol form to previously immunized or immunologically naive rabbits. Inhalation of concanavalin A alone induced an interstitial pneumonitis in nonimmunized rabbits. Inhalation of concanavalin A alone induced an interstitial pneumonitis in nonimmunized rabbits. Inhalation of bovine serum albumin (BSA) alone typically produced only focal eosinophilic granulomas in BSA-immunized animals, and no injury whatever in nonimmune animals. However, simultaneous administration of BSA-concanavalin A aerosol mixtures to BSA-immunized rabbits induced a severe interstitial pneumonitis and granulomatous vasculitis, together with areas of frank parenchymal necrosis. When repeated on a chronic basis over a 4- or 8-week interval, challenge with BSA-concanavalin A aerosols resulted in both acute necrotic lesions as well as areas of frank interstitial fibrosis. Necrotic foci in acutely injured lungs were associated with interstitial deposits of BSA, rabbit anti-BSA antibody, and complement. Electron microscopy revealed numerous neutrophils within the pulmonary interstitial spaces of these animals, often in association with collagen and elastin fibers. The pattern of injury in immune rabbits induced by antigen-concanavalin A aerosols, in its nonnecrotizing form, is consistent with that of an extrinsic allergic alveolitis. However, the severe, necrotizing form of acute injury closely resembles changes seen in Wegener's granulomatosis. Possible mechanisms of injury produced by antigen and phytomitogen inhalation are discussed.

Aerosols↗
PubMedDate not supplied

[Proposal of environmental and biological monitoring and health surveillance of the exposed to inhalation anesthetics. Consensus. A Study Group on Occupational Exposure to Inhalation Anesthetics].

The Study Group on Occupational Exposure to Inhalation Anaesthetics of the Lombardy Association of Occupational Health and Industrial Hygiene prepared a document that was discussed during the Congress "Occupational Risks due to Inhalation Anaesthetics", held in Brescia, Italy, on May 12, 1992. The same document was then approved by the Directory Council of the Lombardy Association of Occupational Health and Industrial Hygiene. Data on environmental concentrations of Nitrous Oxide collected from 1989 to 1991 in 269 operating rooms of 47 hospitals in Lombardy are reported. The measured levels are considerably lower than those collected from the same Study Group from 1985 to 1987 in 111 operating rooms. The methodologies for exposure control are discussed, regarding both environmental and biological monitoring. These two techniques are complementary and can be used with standardized methods. The review of the literature on the early effects showed, even with some uncertainty at the current exposure levels, effects on liver and Central Nervous System. Still controversial are the data regarding the reproductive toxicity. Health surveillance programs have been organized in the last 5 years in 18 Lombardy hospitals and they indicate no cases of pathologies due to inhalation anesthetics on 1498 subjects. Operative proposals are suggested on the methodology and the frequency of environmental/biological monitoring and health surveillance. The "technical limit values" reported in the document from the Italian Ministry of Health are also discussed. Finally, research topics are suggested in order to assess the early effects of exposure.

Anesthesia, Inhalation↗
PubMed1992

[Bronchial asthma treated with long-acting beta 2 agonist. Comparison between formoterol (12 mu/g) inhaled twice daily and salbutamol (200 mu/g) inhaled 4 times daily].

Forty patients with stable asthma and daily need for inhaled beta 2-agonist, were included in a randomized double-blind study. They were treated for six weeks with inhaled beta 2-agonist, either salbutamol, 4 x 200 micrograms daily, of formoterol, 2 x 12 micrograms and 2 x placebo daily. This was preceded by a run-in period, where all patients received terbutalin-inhalation, 4 x 500 micrograms daily. Twenty patients were given formoterol and 18 salbutamol. One patient in the salbutamol-treated group discontinued treatment after three weeks, because of deterioration of asthma. On a diary card, patients recorded peak expiratory flow rate (PEFR) morning and evening before medication, score of asthma symptoms (scale 0-3; 0 = no symptoms, and 3 = severe symptoms) and use of additional doses of beta 2-agonist. Forced expiratory volume in 1 sec. (FEV1), forced vital capacity (FVC) and PEFR were obtained after 0, three and six weeks of treatment. Blinded global assessment of the treatment was performed by both patient and physician at the end of the study. During run-in the two groups of patients were different. The group subsequently treated with salbutamol had a statistical significant (ss) higher morning-PEFR, ss fewer asthma-symptom scores than one during night and ss less need for additional puffs of beta 2-agonist. During treatment, the formoterol-treated group showed an ss increase in morning-PEFR, as compared to run-in. Furthermore this group had ss fewer nocturnal symptom scores than one and ss less need for extra beta 2-agonist during night, than the salbutamol-treated group.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMedDate not supplied

Aerosol inhalation and depth of deposition in the human lung. The effect of airway obstruction and tidal volume inhaled.

Ten patients with chronic bronchitis, whose FEV1.0 varied between 0.48 and 3.00 1, inhaled uniform 5-micronm particles tagged with technetium-99 in tidal volumes (VT) varying between 750 and 1830 ml. Their chests were scanned after inhalation to ascertain depth of deposition of the particles, and clearance from the lungs was monitored for 5 hr by serial whole-lung gamma counting. A significant inverse relationship (P less than .05) was found between depth of deposition after inhalation (D), measured horizontally across the lung as percentage per inch, and rate of clearance of the particles (5-hr retention [%] = 100- % cleared at 5 hr=69.12-3.02D). This confirmed previous findings. The depth of deposition depended directly on the FEV1.0 and VT (5-hr retention [%] = 0.026VT + 12.67FEV1.0-4.13); this resulted in a 14%-75% range for 5-hr retention. Regression slopes for VT and FEV1.0 were independently significant (P less than .05). The findings suggest that, as commonly administered at present, the therapeutic efficiency of most drugs given be aerosol will be reduced in proportion to the degree of airway obstruction as measured by the FEV1.0. The efficiency can be enhanced by increasing the depth of inspiration of the aerosol.

Aerosols↗
PubMed1976

A study of the inhalation of pentachlorophenol by rats. Part II. A new inhalation exposure system for high doses in short exposure time.

An exposure system has been designed which is applicable for short time, acute exposures of rats to the aerosol of pesticides. The aerosol is generated by compressed air aspiration. Larger droplets are removed by a cyclone separation. The exposure chamber has 12 inhalation sites separated from the animal containers by rubber seals which insure inhalation as the only route of exposure.

Aerosols↗
PubMed1977

Investigations of cigarette smoke dosages in inhalation experiments with Syrian hamsters. I. Concentration of cigarette smoke in the inhalation chamber and of carbon monoxide in the blood.

We tested 20 different smoke inhalation machines and determined that 60% of the gas phase and 40% of the total paritulate matter reached the inhalation chamber; the remainder was lost in the exhaust gases. After determining these concentration percentages, we were able to calculate precisely the dosage of each puff of smoke administered to Syrian hamsters in our smoking machine. We also determined that the CO-Hb content in the blood of the hamsters rose to 60%; this CO-Hb value was a limiting factor for time of exposure to smoke, since too-high concentrations of CO-Hb would have killed the animals. On the basis of these results, we concluded that the animals should be exposed as long as possible to attain a high dose of smoke, but because of toxic effects the exposure time should not exceed 20 minutes, and the CO-Hb content should not exceed 60%.

Air↗
PubMed1976

A study of inhalation of pentachlorophenol by rats. IV. Distribution and excretion of inhaled pentachlorophenol.

It appears that in the rat repeated respiratory exposures to PCP do not result in an increase in the body burden of this compound as would be suspected from the 24 hour half-life determined from a single inhalation exposure. These results suggest some mechanism induced by prior exposure to PCP that increases the ability of the animals to remove this compound from its body. Increased excretion may be a factor in this activity, however, it cannot account for the total effect. Storage appears unlikely, since the elimination rate and time period remain unchanged after five doses as compared to after one. Increased matebolism may be the explanation, although this mechanism can only be inferred from these data. Quantitative metabolic results will be necessary to support this hypothesis.

Aerosols↗
PubMedDate not supplied

Inhalation toxicity studies on cigarette smoke II. Tobacco smoke inhalation dosimetry studies on small laboratory animals.

A newly developed exposure system has been used to carry out smoke dosimetry studies on rats, mice, hamsters and guinea pigs. In all species, smoke total particulate matter (TPM) deposited in significant amounts in the lower respiratory system (LRS) at dose levels ranging from 0.515 to 1.710 mg TPM/g respiratory tissue. Nasal deposition of smoke particulates did occur in all of the species examined. The significance of these dosimetry data in relation to the conduct of long-term comparative inhalation toxicity studies with tobacco smoke is discussed.

Air↗
PubMedDate not supplied

Inhalation toxicity studies on cigarette smoke III. Tobacco smoke inhalation dosimetry study on rats.

Smoke inhalation dosimetry studies have been carried out on rats, using a new exposure system. A range of cigarettes, tobacco types and smoke concentrations was used. Penetration of smoke into the lungs was clearly demonstrated, and loads of total particulate matter (TPM) of up 1 mg were detected in the lower respiratory system of rats. The mass of TPM deposited was affected by the smoke concentration during exposure. Deposition of TPM in the head of the rat was low in relation to total respiratory system deposition. A pattern of predominantly lung deposition was achieved under the conditions used for this series of experiments. This pattern was not affected by changes in smoke dilution level, cigarette or tobacco type.

Animals↗
PubMed1975

Inhalation carcinogenicity of alpha halo ethers. I. The acute inhalation toxicity of chloromethyl methyl ether and bis(chloromethyl)ether.

A range of acute studies were performed with chloromethyl methyl either (CMME) and bis(chloromethyl)ether (BCME), including 14-day LC50's following single seven-hour inhalation exposures. The LC50's for CMME were 55 ppm for rats and 65 ppm for hamsters. The LC50's for BCME were 7 ppm for both species. All animals showed characteristic changes of acute irritation of the respiratory tract manifested by congestion, edema, and hemorrhage. Severe shortening of life span was seen in 30-day exposures of rats to CMME and in all studies with BCME. Incidences of mucosal changes, including atypia, were generally increased in a dose-related manner in both species. The carcinogenicity of BCME in these range finding experiments was demonstrated by a skin cancer in a rat after three exposures and a nasal tumor in a hamster after one exposure to 1 ppm BCME.

Animals↗
PubMed1975

Aerosol metallic paints: deliberate inhalation. A study of inhalation and or ingestion of copper and zinc particles.

The preliminary and limited study was made in an area where the metallic spray paints are used as an intoxicant by a significant percentage of the student-population. Laboratory tests show that individuals misusing these unique products are ingesting and/or inhaling large amounts of copper and zinc which are excreted in the urine and are possibly retained in body tissue. No previous reports have been found on this form of substance misuse, and apparently no studies have been conducted to determine the physiological effects of such an overload of heavy metals.

Administration, Intranasal↗
PubMed1979

Inhalation bioassay chemistry--Walton Horizontal Smoking Machine for inhalation exposure of rodents to cigarette smoke.

Studies of experimental tobacco smoke carcinogenesis have suffered from the lack of a conveniently available and well-characterized device for exposing animals to tobacco smoke for inhalation. The Walton Horizontal Smoking Machine, a commercially available system designed to expose up to 20 mice to the smoke of a single cigarette, may fulfill this need. This system produced a uniform smoke aerosol of predictable concentration and appropriate composition for cigarettes with high delivery of nicotine (40 mg total particulate matter, 2.6 mg nicotine, and 17 cm3 carbon monoxide per cigarette) and with low delivery of nicotine (30 mg total particulate matter, 0.3 mg nicotine, and 17 cm3 carbon monoxide). In this experiment C57BL and DBA/2Bd strains of mice were used. Limitations of the concept of exposing animals to standing smoke were defined.

Animals↗