Effects of lead microparticles on the growth characteristics of the BHK21 fibroblast cell line.

BHK21 fibroblastic cells were exposed in vitro to lead microparticles produced by pyrolysis of the organic lead used as an antiknock agent in gasoline. Although non-cytolethal, 10 micrograms of lead/10(6) cells rapidly inhibited cell growth kinetics as well as [3H]thymidine and L-[3H]leucine incorporation by the BHK21 cell line. The growth rate inhibition provoked by chronic exposure to lead microparticles became reversible when the cells were cultured without the microparticulate pollutant. The cloning efficiency of BHK21 cells was impaired by lead concentrations above 1 mg/10(6) cells.

In vitro cytotoxicity of cadmium microparticles for rabbit pulmonary alveolar macrophages.

A cytotoxic effect of cadmium monoxide microparticles on rabbit pulmonary alveolar macrophages was observed in vitro from 1 to 2 microg of metal cadmium per million cells (and per milliliter of incubation medium). This threshold was close to the one observed with lead microparticles, which in addition appeared to have a faster cytotoxic action. On the other hand, cadmium microparticles inhaled in vivo are known to be much more toxic to the respiratory system and much more slowly cleared from it than lead particles. These contradictions can be partially explained by our observation that in vitro the ability of alveolar macrophages to phagocytize microparticles was significantly lower for cadmium monoxide than for lead monoxide microparticles.

Toxic effects of cadmium microparticles on the respiratory system. An experimental study on rats and mice.

An experimental study on rats and mice. Scand. j. work environ. & health 3 (1977) 116--121. Experiments on male, specific pathogen-free rats (193) and mice (66) are reported. The test and control animals received a single 15-min exposure to cadmium (cadmium oxide) and aluminum (alumina) microparticles, respectively. The air cadmium content was 10 mg/m3, and 4 microgram of this metal was retained by the lungs of the rats. The animals were observed for 24 days. The following significant differences appeared between the control and test groups: in the cadmium exposed rats the relative lung weight (percentage of body weight) became temporarily higher; the absolute number of alveolar macrophages decreased at first and then increased; numerous polymorphonuclear and lymphocytic cells appeared in the alveoli. According to these inflammatory phenomena, at the 48th h after exposure, there was an alteration in the clearance kinetics of inhaled bacteria and an increase in the death rate of cadmium exposed animals following a test infection with Salmonella enteritidis (rats) or Pasteurella multocida (mice) aerosols. The mechanism of cadmium toxic action on the respiratory system is discussed.

Natural and acquired resistance of mice to infection by airborne Klebsiella pneumoniae after subchronic intoxication by cadmium administered orally.

Mice daily ingested about 22 mg of cadmium per kg of body weight in drinking water for 30 days. On the 30th day, the liver and kidneys of the mice contained about 18 micrograms of Cd2+ per g of fresh organ. A group of these mice was immunized against Klebsiella pneumoniae using two injections of vaccine, the first on the 7th day and the second on the 14th day of intoxication. On the 28th day, the non-immunized and the immunized mice were infected via a respiratory route by one lethal dose 50% of K. pneumoniae (the LD50 for the immunized mice was 2.4 times higher than the LD50 for the non-immunized mice). Comparison with the non-intoxicated control mice showed that the ingestion of Cd2+ did not significantly modify the natural resistance or the acquired resistance of the mice to the infection by airborne K. pneumoniae.

Opposite effects of inhaled cadmium microparticles on mouse susceptibility to an airborne bacterial and an airborne viral infection.

An experimental study on 489 mice is reported. The test animals were submitted to a single 15-mn exposure to atmosphere containing about 10 mg of cadmium microparticles (CdO) per m3 of air and the controls to an equivalent amount of aluminium microparticles (Al2o3). At the 48th hour after exposures, the test and control mice were submitted to a bacterial (Pasteurella multocida) or to a viral (Orthomyxovirus influenzae A) challenge, via the respiratory route. The exposure to cadmium significantly increased the death-rate of mice submitted to the bacterial challenge, but it significantly decreased the death-rate following the viral challenge.

Sex-related factors in acute carbon monoxide intoxication in one strain of mice.

In the OF1 mouse strain, males are less resistant than females to acute carbon monoxide intoxication. Castration of males increases their resistance to carbon monoxide. For Neonates injected with four different doses of testosterone (20-500 mg per kg) or oestradiol (2-50 mg per kg), more effect on resistance to carbon monoxide in the (adult) mice was found for oestradiol than for testosterone. Pregnancy decreases resistance to carbon monoxide intoxication. Experiments performed with males and females of different ages, in various societal conditions, show the effects of sex-related dimorphism and aggressiveness. The sex-related difference in carbon monoxide resistance is not modified by a previous hypoxic stress (nitrogen hypoxia, carbon monoxide intoxication, sodium cyanide injection) but is suppressed when the CO intoxication is carried out at a low ambient temperature (13 degrees C).

The experience of dyspnea during weaning.

OBJECTIVE: To compare the degree of dyspnea experienced by ventilator-dependent patients receiving synchronized intermittent mandatory ventilation (SIMV) versus T-piece or pressure support ventilation (PSV) weaning. The relationship between self-reported perceptions of dyspnea and physiologic variables observed during weaning trials was examined. Variables included heart rate, respiratory rate, minute ventilation, and oxygen saturation as measured by a pulse oximeter. DESIGN: Quasi-experimental, counterbalanced design with repeated measures. SETTING: Medical intensive care unit of a large university-affiliated medical center. PATIENTS: Nine mechanically ventilated patients diagnosed with chronic obstructive lung disease. The patients were admitted for respiratory failure between May 1990 to November 1990. Six tolerated SIMV 4 versus T-piece trials; three were placed in the SIMV 8 versus PSV trials. PROCEDURE: Each patient's perception of dyspnea was measured using a visual analog scale (VAS) at the initiation and at 5-minute intervals of 20-minute weaning trials. Physiologic indicators were noted simultaneously with VAS ratings of dyspnea. RESULTS: Findings indicated no difference in the degree of dyspnea experienced between weaning methods compared. Within-subject regression analysis on VAS scores revealed individual differences in the relationship between physiologic indicators and perceptions of dyspnea. CONCLUSIONS: The patient's experience of dyspnea during the weaning process can be a valuable guide to observe the patient's progress. The VAS serves as a reliable, easy-to-use tool for quantifying the patient's perception of dyspnea.

Sex-related factors in acute hypoxia survival in one strain of mice.

In mice of different ages from the OF1 mouse strain, males are less resistant than females to a normobaric hypoxia obtained in a few hours by a progressive lowering of normoxic PO2 with nitrogen flushing. Injection of estradiol to castrated males and spayed females increases hypoxic survival. Neonates which have been injected with a high dose of estradiol show, when adult, a high hypoxic resistance. In adult females, hypoxic survival is lower during diestrus than during estrus. Pregnancy decreases resistance to hypoxia. Experiments, performed with males and females of different ages, show the effects of sex-related dimorphism and aggressiveness. Hypoxias at various ambient temperatures demonstrate that the sex difference in hypoxic survival persists in spite of variations in rectal temperatures.

Holistic care of the critically ill: meeting both patient and family needs.

Holistic care of the critically ill includes meeting the needs of both the patient and the patient's family. The critical care nurse needs to be prepared to deal with the family's special needs during a time of crisis, including making decisions about the withdrawal of life support. This article addresses such issues, and includes care of the family once technological support has been withdrawn and the patient is transferred from the Intensive Care Unit.

[In vitro and in vivo effect of cadmium microparticles on antibody receptors of alveolar macrophage membranes]. / Effet du cadmium microparticulaire, in vitro et in vivo, sur les récepteurs membranaires d'anticorps des macrophages alvéolaires.

Microparticles of cadmium oxide inhibited antibody-mediated rosette formation by Rat alveolar macrophages. After 4 h of contact in vitro, the 50% inhibiting amount of the pollutant, expressed as metal-Cd, was about 6,000 ng per million cells. 48 h after exposure via the respiratory route, 3,000 hg of Cd per gram of rat fresh lung lowered the percentage of rosette-forming macrophages by about 25%.

[Toxicokinetic study of vanadium after intramuscular and intratracheal administration to rats]. / Etude toxicocinétique du vanadium apprès administration au Rat les voies intramusculaires et intratrachéales.

The toxicokinetic study, made in the rat with 48V under VOCl2, shows that vanadium does not accumulate in the system. 66% of the radioactivity is found in urines 24 hrs. after the inoculation by intramuscular method. After intratracheal deposit, a part of the vanadium is eliminated very rapidly. The other which is lower is fixed on the pulmonary tissues.

Impaired acquired resistance of mice to Klebsiella pneumoniae infection induced by acute NO2 exposure.

The natural resistance of nonimmunized C57Bl/6 mice to an intraperitoneal Klebsiella pneumoniae challenge was not significantly affected by prior continuous exposure to 20 ppm NO2 for 4 days. In contrast, the acquired resistance of mice immunized just before and infected just after NO2 exposure was seriously impaired. This could not be explained by the loss of appetite (about 30%) observed in NO2 treated mice, for neither the natural nor acquired resistance of control air exposed mice given approximately 70% ad libitum food and water were significantly modified.

[Effect of lead microparticles introduced into the respiratory system of the sensitivity of mice to Pasteurella multocida infection via aerosol]. / Effet du plomb microparticulaire, introduit dans l'appareil respiratoire, sur la sensibilité de la Souris à l'infection par aérosol de Pasteurella multocida.

Lead microparticles, resulting from the pyrolysis of organic lead used as an anti-knock agent in gasoline, were introduced into the lungs of Mice, during a short single exposure. When 6 microgram of lead were retained in the lungs (mean value per Mouse), the phagocytic ability of the pulmonary alveolar macrophages harvested 6 and 18 hrs. later, was significantly reduced. It was observed, in the same conditions, that the resistance of Mice to experimental infection by aerosolized Pasteurella multocida, was significantly reduced. When 3 microgram of lead were retained in the lungs, there was no significant difference between control and intoxicated Mice.

[Effects in the rat of a weak dose of acrolein inhaled continuously]. / Effets, chez le rat, d'une faible dose d'acroléine inhalée en continu

The results of an experiment on 173 S. P. F. rats inhaling 0.55 ppm of acrolein, compared to 173 control rats, are reported. In what concerns the respiratory apparatus, this dose of acrolein affects its defense mechanisms, leading to a greater susceptibility to the airborne Salmonella enteritidis infection, compared to the control group. These phenomena disappear spontaneously when intoxication is prolonged more than three weeks. On the contrary, the general toxic action, manifesting itself through diminished weight growth and under-nourishment, compared to control group, lasts as long as intoxication and disappears only after acrolein inhalation has stopped. These results are discussed.