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Biomedical subjects

M Martel

Publications and source records attributed to M Martel.

At least 19 recordsLinked to original sources
PubMed2001

Initial experience of emergency physicians using the intubating laryngeal mask airway: a case series.

OBJECTIVE: Although the intubating laryngeal mask airway (ILMA) is widely available, its use by emergency physicians (EPs) has not been reported. The authors report the initial experience of EPs using the ILMA. A review of their experience and the relevant anesthesia literature provides a basis for EPs to use the ILMA more confidently and effectively. METHODS: Between January 2000 and January 2001, the ILMA was used on a convenience sample of emergency department (ED) patients undergoing "routine" intubations, and "rescue" situations, after failed rapid-sequence intubation (RSI). Patients were identified from the ED resuscitation case database. Chart review and intubating physician interviews focused on success of the device, complications encountered, and "pearls" of the device's use as perceived by the intubating physician. RESULTS: Ventilation with the appropriate-size ILMA occurred in less than 15 seconds in all "routine" intubations; tracheal intubation was subsequently accomplished in less than 1 minute. Eight of nine "routine" patients had blind tracheal intubation through the ILMA. One patient required fiberoptic bronchoscopy to guide the endotracheal tube into the trachea. Of the "rescue" intubations, all patients (n = 7) were successfully ventilated and five were successfully intubated using the ILMA. CONCLUSIONS: In this case series, the ILMA was easy to use in acute resuscitations, and proved to be invaluable in cases of failed RSI.

Adult↗
PubMed2001

The intubating laryngeal mask airway: suggestions for use in the emergency department.

With the increased use of rapid-sequence induction and its potential complications, emergency physicians need a rescue device for unexpected difficult intubations. The intubating laryngeal mask airway (ILMA) is an ideal rescue airway since it can be placed quickly and can provide adequate ventilation in nearly all patients. It can then be used as conduit for endotracheal intubation, while ventilation is ongoing. The authors review the current literature on the ILMA. In conjunction with their experience using the ILMA in the emergency department (ED), a modification of the American Society of Anesthesiologists difficult airway algorithm was derived for use in the ED. The ILMA appears to be valuable for managing difficult airways.

Emergency Medicine↗
PubMed1996

Effect of exposure to silica on human alveolar macrophages in supporting growth activity in type II epithelial cells.

BACKGROUND: The proliferative response of type II cells is an important event following silica-induced lung injury. Alveolar macrophages, when activated by fibrogenic agents, secrete various biological mediators which affect cell growth. METHODS: Human alveolar macrophages from normal volunteers were incubated in serum-free medium or in the presence of increasing concentrations of silica. Alveolar macrophage conditioned media were diluted and added to type II cell cultures for proliferation studies. Purified type II pneumocytes were isolated from fetal rat lungs for bioassays. Growth factor activities were partially characterised by size exclusion chromatography. Each fractionated mitogenic peak was preincubated with monoclonal antibody against platelet derived growth factor (PDGF) or antisera against insulin-like growth factor 1 (IGF-1) or fibroblast derived growth factor (FGF) in order to study the nature of each activity. RESULTS: Conditioned media from alveolar macrophages exposed to silica induced an increase in type II cell DNA synthesis and cell number over that seen when type II cells were incubated with unstimulated alveolar macrophage supernatants. Size exclusion of alveolar macrophage supernatants exposed to silica showed four peaks of type II cell stimulating activity with apparent molecular weights of 38, 22, 16, and 8 kDa. Anti-PDGF antibody significantly reduced the activity of the first and second peaks, antiserum against IGF-1 partially reduced the activity of the first and fourth peaks, and antiserum against FGF reduced only the third peak of activity. CONCLUSIONS: Human alveolar macrophages exposed to silica in vitro release mitogens for type II pneumocytes including PDGF-like, IGF-1-like, and FGF-like molecules. These agents are likely to be involved in the epithelial repair and type II cell hyperplasia observed in silicosis.

Adult↗
PubMed1993

Phospholipid content of bronchoalveolar lavage fluid in granite workers with silicosis in Quebec.

BACKGROUND: Some of the prominent features of silicosis are hyperplasia and hypertrophy of epithelial type II cells, which in experimental animals are often accompanied by accumulation of phospholipids in the lung. METHODS: The total phospholipid content of lung lavage fluid and its composition in 28 granite stone cutters with long term exposure to silica dust (23 with radiological silicosis) was compared with that of lavage fluid in 15 normal volunteers, 15 patients with untreated idiopathic pulmonary fibrosis, and 19 patients with untreated stage 2 or 3 sarcoidosis. All lavage fluid was obtained at the time of first pulmonary investigation, which also included lung function tests. RESULTS: In the normal subjects total phospholipid content was 1.13 (0.16) micrograms phosphorus/ml of lung lavage, in the patients with idiopathic pulmonary fibrosis 0.52 (0.07) microgram/ml (p < 0.05), and in the patients with sarcoidosis 1.02 (0.20) microgram/ml composition being in the range reported in humans. In the patients with silicosis total phospholipid content was significantly decreased to an average of 0.46 (0.08) microgram/ml compared with the findings in normal subjects and patients with sarcoidosis. Within the group exposed to silica changes in total phospholipid content did not correlate with the severity of the radiographic disease, changes in lung function, the cellularity of lung lavage fluid, or hyaluronate concentrations. The secretory capacity of rat epithelial type II cells was not significantly different when cultured with bronchoalveolar lavage fluid from all four groups of subjects. CONCLUSIONS: Total phospholipid content in lung lavage fluid was significantly reduced in granite workers with radiological evidence of lung disease, but showed no correlation with radiological or functional markers of disease severity.

Adolescent↗
PubMed1992

Hyaluronan (hyaluronic acid) in lung lavage of asbestos-exposed humans and sheep.

The concentration of hyaluronan was measured in the bronchoalveolar lavage fluid (BALF) of 18 control subjects and 27 workers from the asbestos mills and mines of Québec, 9 without asbestosis and 18 with asbestosis. Hyaluronan was also measured in the BALF of 9 control sheep exposed to 100 ml phosphate-buffered saline (PBS) at 10 day intervals for 39 months, and 13 sheep exposed at the same intervals to 100 mg chrysotile in 100 ml PBS for 24 months. At month 24, the asbestos-exposed sheep were classified into 3 groups: (A) 4 sheep exposed to PBS alone, (B) 4 sheep exposed to 10 mg chrysotile asbestos every 10 days, and (C) 5 sheep exposed to 100 mg chrysotile asbestos every 10 days for 15 months. The BALF hyaluronan averaged 53.9 +/- 7.4 ng/ml in human controls, 67.5 +/- 10.3 ng/ml in asbestos-exposed workers without asbestosis, and 206 +/- 83 ng/ml in workers with asbestosis (p less than 0.05 vs. normal). In the control sheep, BALF hyaluronan was 34.7 +/- 6.9 ng/ml, and it was 31.5 +/- 17.8 ng/ml in the low-dosage asbestos-exposed group (A), 83.0 +/- 27.7 ng/ml in the intermediate-dose group (B), and 248.0 +/- 134.7 ng/ml in the high-dosage group (C) (p less than 0.05 vs. controls). In contrast, the release of plasminogen activator, a protease that may play a role in limiting the fibrotic process, was increased in group A, but not in groups B and C. In conclusion, BALF hyaluronan constitutes an indicator of lung interstitial tissue changes that may reflect the activity of the fibrosing alveolitis associated with chronic asbestos exposure.

Adult↗
PubMed1989

Isolation and initial characterization of a Schizosaccharomyces pombe mutant exhibiting temperature-dependent radiation sensitivity due to a mutation in a previously unidentified rad locus.

We have isolated a mutant of the yeast Schizosaccharomyces pombe which exhibits sensitivity to UV light when grown at either 30 degrees or 37 degrees C, as compared to the parental wild-type strain. This increased sensitivity is more pronounced when cells are grown at 37 degrees C. The mutant is also sensitive to 18 MeV electrons at the high temperature. Tetrad analysis of spores generated by crossing the mutant and a Rad+ strain revealed that sensitivity to both types of radiation cosegregate 2:2, relative to wild-type resistance, indicating that a single altered chromosomal locus is responsible for the radiation sensitivities observed. In addition, analysis of spores resulting from crosses between the mutant and all other known S. pombe rad mutants indicates that the temperature-dependent sensitivity described in this report is mediated by a mutation in a previously unidentified rad locus.

Alleles↗
PubMed1989

Effect of aluminum inhalation on alveolar phospholipid profiles in experimental silicosis.

In the sheep tracheal lobe model of silicosis, we have recently reported that total phospholipid, lecithin, and phosphatidylglycerol levels were elevated in lung lavage. To investigate further this observation, we obtained complete phospholipid profiles of lung lavage in 10 sheep exposed to saline only (Sa group), 10 sheep exposed to aluminum lactate inhalation only (Al group), 10 sheep exposed to 100 mg Minusil-5 in saline followed by monthly saline inhalation (Si group), and 10 sheep exposed to 100 mg Minusil-5 in saline followed by monthly aluminum lactate inhalation (Si-Al group). The following phospholipid components were measured: total phospholipids, phosphatidylglycerol (PG), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine, disaturated phosphatidylcholine, sphingomyelin, and lyso-phosphatidylcholine. All values were comparable in the Sa group, Al group, and Si-Al group. In the Si group, there was a significant increase in total phospholipid to approximately 200% of the control values. The phospholipid profile of this group demonstrated an increase in all of the phospholipid components with some enrichment of the fraction of PG, PE, and PI. We concluded that lung exposure to silica dust significantly increases the concentration of phospholipids in the alveoli. This increase is of a large spectrum of alveolar phospholipids and is completely suppressed by aluminum lactate inhalation.

Administration, Inhalation↗
PubMed1989

Quartz exposure, retention, and early silicosis in sheep.

The purposes of this study were (1) to investigate the chronology of events in cellular and biochemical changes thought to be important in the development of silicosis, (2) to relate these to changes in lung function and radiograph, and (3) to evaluate the relation of quartz exposure and retention to individual response leading to early silicosis. Thirty-six sheep were exposed by repeated intratracheal infusion at 10-day intervals to 100 mg Minusil-5 in 100 ml saline (Si group), and 10 sheep were exposed at the same intervals to 100 ml saline (control). All sheep were investigated at 3-month intervals by chest radiograph, lung function, and lung lavage. At month 9, chest radiograph score of parenchymal opacities was significantly increased at 2.8 +/- 0.6 versus 0.4 +/- 0.4 in the Si group (p less than .05), establishing early radiologic silicosis. Lung function was significantly altered with reduction in lung compliance, vital capacity, and diffusion capacity (p less than .05). Lung lavage cellularity revealed significant increase in total cells (X 2.5), macrophages (X3), and neutrophils (X3). Albumin in BAL remained at the control level. Fibronectin production was significantly increased, as was the fibroblast growth activity, without significant change in procollagen 3 at this early stage of disease. Total phospholipids were significantly elevated in the Si-exposed sheep, and the profile demonstrated an increase in all the phospholipid components. Spontaneous release of hydrogen peroxide by alveolar cells was not increased, but in the presence of phorbol myristate acetate (PMA) higher levels of peroxide were found in the quartz-exposed sheep (p less than .05). The cellular and biochemical alterations of lung lavage preceded other changes. At month 12, there were good correlations (r greater than .49, p less than .001) between parameters evaluating related phenomena but poor correlations between measurements evaluating different aspects of the disorder. To investigate the heterogeneity in the individual response of sheep to the same exposure (susceptibility), individual quartz retention levels at month 12 were measured and found to correlate well with individual parameters of disease activity. We concluded that in early silicosis of sheep, cellular and biochemical changes in lung lavage preceded derangements of pulmonary function and radiographic abnormalities. Thereafter, parameters of lung lavage, lung function, and radiograph were significantly interrelated, but for a given exposure the degree of quartz retention appeared to determine the intensity of the silicotic process.

Animals↗
PubMed1988

In vivo determination of the profile of benzodiazepine ligands by comparing the inhibition of 3H-Ro 15-1788 binding to the modulation of cGMP levels in mouse cerebellum.

The in vivo effects of various benzodiazepine (BZD) ligands belonging to different chemical families were studied comparatively in mouse cerebellum using displacement of 3H-Ro 15-1788 binding and cGMP content as biochemical tools. It was possible to differentiate four classes of compounds with regard to these biochemical parameters. The first class of compounds such as diazepam and suriclone induced a net effect on in vivo 3H-Ro 15-1788 binding and a dose-dependent decrease of cGMP levels. A second class of drugs such as ZK 91296 and CGS 9896 showed in vivo activities in displacement studies but relatively small or moderate activities on cGMP levels. A third class was represented by Ro 15-1788 itself which prevented dose-dependently the in vivo 3H-Ro 15-1788 binding but was devoid of effect on cGMP levels. Finally, a fourth class of compounds (CGS 8216, FG 7142, beta-CCM and DMCM) showed in vivo displacement of 3H-Ro 15-1788 with concomitant increase of cGMP levels. The first class of compounds represents full agonists, the second class, partial agonists, the third class, the antagonist Ro-15-1788 itself, and the fourth class corresponds to inverse agonists. Thus it is proposed to use 3H-Ro 15-1788 binding and cGMP levels to differentiate in vivo BZD ligands acting on the BZD receptor/GABA receptor/chloride ionophore complex.

Animals↗
PubMed1988

Aluminum inhalation reduces silicosis in a sheep model.

In recent studies, we have documented that the biologic activity of quartz can be substantially reduced by surface chemistry modification with aluminum lactate treatment of the particles. In the present study, we evaluated the efficacy of aluminum lactate inhalation to reduce the biologic activity of experimental silicosis in the sheep tracheal lobe model. Four groups of 10 sheep were exposed once to either 100 ml phosphate-buffered saline (PBS) followed by aerosol inhalation of 10 ml PBS at monthly intervals (PBS-PBS group), to 100 ml PBS followed by inhalation of 100 mg aluminum lactate in 10 ml PBS (PBS-Al group), to 100 mg of quartz in 100 ml PBS followed by inhalation of 10 ml PBS (Si-PBS group), or to 100 mg of quartz in 100 ml PBS followed by inhalation of 100 mg aluminum lactate in 10 ml PBS (Si-Al group). Bronchoalveolar lavage (BAL) was repeated at monthly intervals for 6 months from before exposure (Month 0), and all sheep were autopsied at Month 6. All aerosol inhalations were carried out 24 h after BAL starting at Month 1 and monthly thereafter. In the PBS-PBS group and PBS-Al group, all BAL analyses remained at control levels and lung histology remained normal. In the Si-PBS group, BAL analyses documented significant sustained 3- to 10-fold increases in macrophages, lymphocytes, neutrophils, immunoglobulins, lactate dehydrogenase, glycosaminoglycans, lecithin, and phosphatidylglycerol, with histopathologic changes of nodular silicosis (pathologic score, 2.9 +/- 0.9) and mean retention of quartz at 2.83 +/- 0.98 micrograms/mg lung tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1987

Late aluminum therapy reduces the cellular activities of simple silicosis in the sheep model.

To evaluate the biological effects of aluminum lactate therapy on nodular silicosis, we exposed the tracheal lobe of three groups of sheep containing eight sheep per group to either 11 mg of Al lactate in 100 ml saline (Al group), 100 mg of Minusil-5 in 100 ml saline (Si group), or 100 mg of Minusil-5 in 100 ml saline followed by 11 mg of Al lactate at monthly intervals 4 months after exposure (Si Al-treated group). The lung biological processes were evaluated by sequential lung lavage analyses of cellularity and biochemistry of supernatant and by autopsy analyses of cellularity and biochemistry of supernatant and by autopsy analyses of lung tissue histopathology and quartz content. Al lactate alone did not have any significant effect. Silica exposure produced the silicotic nodules and significant increases on lung lavage of cellularity, enzyme release, surfactant, and glycosaminoglycan accumulations. Al lactate therapy at month 4 after exposure did not decrease the pathological score of disease, but it significantly reduced all markers of cellular hyperactivity. This therapy was associated with a 65% reduction of the quartz retention in lung tissue and might help to prevent long-term progression of the disease process.

Aluminum↗
PubMed1987

Maternal age and primary cesarean section rates: a multivariate analysis.

To study the effect of maternal age on primary cesarean section rates, 3458 consecutive deliveries were analyzed. The cesarean section rates in primiparous women less than 25, 25 to 34, and over 34 years of age were 13.1%, 18.5%, and 28.2%, respectively. A similarly dramatic rise with advancing maternal age was seen in multiparous women with rates of 3.4%, 4.7%, and 10.1%, respectively, in the three age groups. The strong association between cesarean section and maternal age persisted after multivariate adjustment for induction of labor, epidural anesthesia, meconium-stained amniotic fluid, and fetal distress, and thus these factors do not explain the relationship.

Abruptio Placentae↗
PubMed1987

The lung biological activity of American attapulgite.

Attapulgite is a fibrous mineral industrially consumed at the rate of over a million tons per year but the biological activity of the material is not fully known. To evaluate the in vivo toxicity of the fibrous material, we exposed the tracheal lobe of 16 sheep to a single exposure of either 100 ml saline, 100 mg UICC asbestos fibers in 100 ml saline, 100 mg short asbestos fibers in 100 ml saline, or 100 mg attapulgite in 100 ml saline. The animals were studied by bronchoalveolar lavage (BAL) at Days 2, 12, 24, 40, and 60 and by autopsy at Day 60. In the saline-exposed sheep, BAL and lung histology did not change. In the UICC asbestos-exposed animals, we reproduced the BAL changes previously reported (R. Bégin, M. Rola-Pleszczynski, S. Massé, Y. Berthiaume, and G. Drapeau, 1985, Environ. Res. 36, 389-404). In the short asbestos-exposed sheep, there were no significant BAL changes. In the attapulgite sheep, we found significant and sustained increases in total BAL cells (X2, P less than 0.05), macrophages (X2, P less than 0.05), neutrophils (X5, P less than 0.01), fibronectin (X2-3, P less than 0.05), lactate dehydrogenase (X2, P less than 0.05), beta-glucuronidase (X2, P less than 0.05), but BAL cellularity returned to control levels by Day 60 whereas in the UICC asbestos-exposed sheep, it remained significantly above control. Lung histology demonstrated the characteristic peribronchiolar fibrosing alveolitis in the UICC asbestos-exposed sheep, whereas macrophagic alveolitis with minimal airway distortion was seen in the short asbestos-exposed sheep and in all of the attapulgite-exposed sheep but three which had typical peribronchiolar alveolitis quite similar to that observed in UICC-exposed sheep, but of lower intensity. In conclusion, the study documents that attapulgite is not an inert material for lung tissue; it does produce a macrophagic and neutrophilic alveolitis in the early inflammatory phase of lung reaction with peribronchiolar involvement in some sheep. Whether or not this initial attapulgite induced alveolitis leads to lung fibrosis remains to be evaluated in a longer follow-up study of attapulgite-exposed animals.

Animals↗
PubMed1987

Sustained efficacy of aluminum to reduce quartz toxicity in the lung.

In a recent study of the sheep tracheal lobe model, we have demonstrated that surface chemistry modification of quartz by aluminum lactate significantly alters the biological activity of quartz for at least 2 months after exposure. In the present study, we have extended our observations of the biological reaction of the lung tissue to aluminum treated quartz and to untreated quartz, added lung lavage analyses of surfactant and glycosaminoglycans as additional indicators of activity of the quartz-induced lung injury and analyzed lung lavage and tissue retention of the minerals. The tracheal lobe of 8 sheep was exposed to either 11 mg of aluminum lactate in 100 ml saline (Al group), 100 mg of quartz (Minusil-5) in 100 ml saline (Si group) or 100 mg of quartz treated with 11 mg of Al lactate in 100 ml saline (Si-Al group). The 24 sheep were studied by lung lavage at month 9, 0.13, 1, 2, 3, 5, 7, 9, and 10 and by autopsy at month 10. In the Al group, we found no significant change over time, the pathologic score was 0.38 +/- 0.15 and Si undetectable. In the Si group, we found significant sustained increases in total lavage cells, macrophages, lymphocytes, neutrophils, glycosaminoglycans, lactate dehydrogenase, phosphatidylcholine and phosphatidylglycerol. Histologically we found a macrophagic lymphocytic alveolitis with early nodular silicotic lesions; the pathological score was 3.0 +/- 0.8 at month 10 with an average quartz tissue level of 1.4 +/- 0.4 micrograms/mg. In the Si-Al group, all these changes were significantly reduced early and remained so up to 10 months after exposure; the pathological score was 1.1 +/- 0.4 and lung levels of quartz were undetectable. The data thus demonstrated that Al treatment of quartz significantly reduces the biological activity of quartz and increases its clearance with essentially no detectable particle retention in the lung 10 months after exposure.

Aluminum↗
PubMed1986

Enzyme activities of lung lavage in asbestosis.

We analyzed lung lavage supernatant for amylase, lactate dehydrogenase (LD), alkaline phosphatase (ALP), beta-glucuronidase (beta G), and albumin, and a differential count was made of the cellular component of lung lavage in 18 normal controls and 36 long-term asbestos workers of the mines and mills of Québec. The men were concomitantly evaluated by the usual clinical, radiological, functional parameters and 67Ga lung scan. In 7 workers without asbestosis and normal 67Ga scan, lavage enzyme activities, albumin and cell counts were comparable to those of controls. Of 9 without sufficient criteria for asbestosis but increased 67Ga lung uptake, cell counts documented significant increases in the mean number of macrophages (X 2), lymphocytes (X 2) and neutrophils (X 3). Supernatant analyses showed significant increases in amylase (X 4-5), LD (X 2.5), ALP (X 1.5) and beta G (X 2-4). These changes were comparable to those in the lavage of workers with well established asbestosis except that in the latter, the lymphocyte count was slightly lower but the neutrophil count higher (p less than 0.05). These data document that enzyme activities of lung lavage can differentiate asbestos workers with early or late asbestosis from controls and asbestos workers without disease.

Adult↗
PubMed1986

Fibronectin and procollagen 3 levels in bronchoalveolar lavage of asbestos-exposed human subjects and sheep.

To evaluate the potential interest of levels of fibronectin and procollagen 3 in bronchoalveolar lavage fluid as markers of fibrogenic activity, we characterized the time course of changes in fibronectin and procollagen 3 levels in the tracheal lobe of sheep exposed to nonfibrogenic and fibrogenic materials. We correlated these observations with those of bronchoalveolar lavage in long-term asbestos workers in various stages of disease activity. Following studies before exposure, the tracheal lobe of three groups of 24 sheep were exposed once to 100 ml of phosphate-buffered saline solution (PBS), to 100 mg of latex beads in 100 ml of PBS, or to 100 mg of chrysotile fibers in 100 ml of PBS. Bronchoalveolar lavages were obtained at 0, 1, 2, 4, 8, and 12 months after exposure, and four or five sheep per group were killed after each lavage for histopathologic analysis. Fibronectin in bronchoalveolar lavage fluid increased significantly only in the asbestos-exposed sheep to values two to three times above controls or latex-exposed sheep and remained elevated during the 12 months of the study. Levels of procollagen 3 in bronchoalveolar lavage fluid were increased significantly only during the first two months following exposure in the asbestos-exposed sheep only. In the asbestos workers without disease, levels of fibronectin and procollagen 3 in bronchoalveolar lavage fluid were comparable to controls, but these levels were significantly elevated in those with asbestos-associated alveolitis or asbestosis. This study documents that the measurement of levels of fibronectin and procollagen 3 in bronchoalveolar lavage fluid assesses fibrogenic activity of alveolitis and should be useful to predict its progression in a fibrotic process. In asbestos workers the potential use of these markers is primarily related to early detection of asbestos-induced pulmonary injury.

Adult↗