PubMed Health⌕ Search

Biomedical subjects

J Balmes

Publications and source records attributed to J Balmes.

At least 37 records · Page 2Linked to original sources
PubMed1996

Predictors of carbon monoxide and hydrogen cyanide exposure in smoke inhalation patients.

OBJECTIVE: A prospective study of civilian (nonfirefighter) smoke inhalation patients was carried out to test the hypotheses that: 1) absorption of carbon monoxide and hydrogen cyanide from smoke can be predicted by clinical examination and historical data; and, more specifically 2) a history of exposure to burning synthetic polymers is an important predictor of systemic cyanide levels. METHODS: The study was conducted over a three-year period at six urban hospitals. Patients with or without burns who were exposed to smoke within five hours of hospital arrival were sampled for carboxyhemoglobin, whole blood cyanide, urine cotinine and urine creatinine. Controls consisted of a smaller group of smoking status-matched, nonsmoke-exposed burn patients. ANALYSIS: Historical information was obtained on SMOKING status, FIRETYPE (structural vs other), MATERIAL burned (natural vs synthetic) and LAGTIME (from exposure to sampling). A smoke inhalation SCORE (0-10) was assigned to each case, based on physical examination findings and changes on chest X ray, and carboxyhemoglobin and cyanide levels were entered into various multivariate linear regression models. RESULTS: A total of 40 cases and 9 controls were recruited, ranging in age from 15 to 92 years. Thirty-four cases were discharged alive and six expired in-hospital. Observed carboxyhemoglobin levels ranged from 1.2% to 41.6% in cases (mean 8.6%), and from 0.5 to 7.3% in controls (mean 2.9%). Observed cyanide levels ranged from nondetectable (< 0.05 micrograms/mL) to 2.79 micrograms/mL in cases (mean 0.25 micrograms/mL), and from nondetectable to 0.11 micrograms/mL in controls (mean 0.03 micrograms/mL). Among cases, linear regression models explained up to 35% of the observed variance in carboxyhemoglobin levels (p < 0.001) and up to 48% of the variance in cyanide levels (p = 0.0001). CONCLUSIONS: SCORE was the strongest predictor of both carboxyhemoglobin and cyanide levels; LAGTIME also explained significant variance for [log-transformed] carboxyhemoglobin. Historical factors, such as FIRETYPE, MATERIAL, and SMOKING status, did not explain significant variance in most of the statistical models employed.

Adolescent↗
PubMed1995

Distribution of integrins alpha v beta 6 and alpha 9 beta 1 and their known ligands, fibronectin and tenascin, in human airways.

We have previously identified two integrins, alpha 9 beta 1 and alpha v beta 6, from guinea pig airway epithelium. The extracellular matrix protein tenascin is a ligand for both of these receptors, and fibronectin is also a ligand for alpha v beta 6. In the present study, we used immunohistochemistry to examine the expression and spatial distribution of the alpha 9 subunit, alpha v beta 6, tenascin, and fibronectin in the proximal airways of 10 normal nonsmoking subjects and eight patients undergoing lung resection for cancer. We also performed the same analyses on sections of peripheral lung obtained from an additional seven subjects undergoing lung resection. alpha 9 was highly expressed throughout the airway epithelium (but not on alveolar epithelium) irrespective of clinical status. In contrast, alpha v beta 6 was expressed on proximal airway epithelial cells in four of eight smokers undergoing lung resection, but in none of the normal subjects and none of the distal airways examined. On bronchial epithelial cells cultured from resected airways, alpha v beta 6 was highly expressed on cells grown from patients who did not appear to express the receptor in vivo, as well as from subjects who did, suggesting that some component of the in vitro environment can induce expression. Although both tenascin and fibronectin were present below the proximal airway epithelium of both normal nonsmoking subjects and smokers, the spatial patterns of integrin and ligand expression were not congruent, because the integrins were present diffusely on the cell surface and on some cells that were not in contact with the basement membrane, whereas the ligands were present principally in the subepithelial layer. These findings are compatible with the existence of as-yet unidentified ligands for each of these integrins--for example, ligands involved in homotypic cell-cell interactions within the epithelium.

Biopsy↗
PubMed1994

The beta-carotene and retinol efficacy trial (CARET) for chemoprevention of lung cancer in high risk populations: smokers and asbestos-exposed workers.

CARET is a multicenter, two-armed, double-masked randomized chemoprevention trial in Seattle, Portland, San Francisco, Baltimore, Connecticut, and Irvine, to test whether oral administration of beta-carotene (30 mg/day) plus retinyl palmitate (25,000 IU/day) can decrease the incidence of lung cancer in high risk populations, namely, heavy smokers and asbestos-exposed workers. The intervention combines the antioxidant action of beta-carotene and the tumor suppressor mechanism of vitamin A. As of April 30, 1993, CARET had randomized 1,845 participants in the 1985-1988 pilot phase plus 13,260 "efficacy" participants since 1989; of these, 4,000 are asbestos-exposed males and 11,105 are smokers and former smokers (44% female). Accrual is complete everywhere except Irvine, which was the last center added (1991), and the safety profile of the regimen to date has been excellent. With 14,420 smokers, 4,010 asbestos-exposed participants, and 114,100 person-years through February 1998, we expect CARET to be capable of detecting a 23% reduction in lung cancer incidence in the two populations combined and 27, 49, 32, and 35% reductions in the smokers, female smokers, male smokers, and asbestos-exposed subgroups, respectively. CARET is highly complementary to the alpha-tocopherol-beta-carotene study in Finland and the Harvard Physicians Health Study (beta-carotene alone) in the National Cancer Institute portfolio of major cancer chemoprevention trials.

Aged↗
PubMed1993

Statistical design and monitoring of the Carotene and Retinol Efficacy Trial (CARET).

CARET is a chemoprevention trial of beta-carotene and vitamin A with lung cancer as the primary outcome. Participants at high risk for lung cancer are drawn from two populations: asbestos-exposed workers and heavy smokers. The intervention is a daily combination of 30 mg beta-carotene and 25,000 IU vitamin A as retinyl palmitate. Nearly 18,000 participants will be followed for a mean 6 years, yielding over 100,000 person-years of follow-up. We project that this sample size will have 80% power to detect a 23% decrease in the incidence of lung cancer cases. The purpose of this paper is to present the values of the key sample size parameters of CARET; our schemes for monitoring CARET for sample size adequacy, incidence of side effects, and efficacy of the study vitamins; an overview of the data collected; and plans for the primary, secondary, and ancillary analyses to be performed at the end of the trial. These approaches to the design, monitoring, and analysis of CARET are applicable for many other prevention trials.

Aged↗
PubMed1993

Occupational asthma in a pesticides manufacturing worker.

A 34-year-old chemical manufacturing worker had new onset of work-related asthma after several years of exposure to the fungicide, captafol. On specific bronchial challenge testing, he demonstrated a marked and persistent fall in FEV1. Cessation of exposure resulted in improved symptoms and pulmonary function. The delay in symptoms after several years of workplace exposure and the dual reaction demonstrated on specific bronchial challenge testing suggest sensitization to some component of technical-grade captafol, but an IgE response was not detected.

Adult↗
PubMed1992

Hospital records as a data source for occupational disease surveillance: a feasibility study.

To assess the feasibility of using hospital records for occupational disease surveillance and to evaluate the quality of the industry/occupation (I/O) information available in these records, the computer file of all discharge diagnoses from a large health maintenance organization during 1985 was reviewed. The frequencies of discharge diagnoses previously listed as Sentinel Health Events (Occupational), or SHE (O), were calculated and three possible SHE(O) diagnoses--lung cancer, bladder cancer, and toxic hepatitis--were selected for further review. Outpatient charts of patients discharged for each diagnosis were abstracted with regard to I/O information and the discharged patients were interviewed by telephone to obtain a lifetime occupational history. The accuracy of the I/O information obtained from the hospital chart was compared to that obtained by patient interview by number of digits matched on standard classification codes. The frequencies of matches for occupation and industry were greater for "usual" than for "last" categories with both cancer diagnoses, but were similar for "usual" and "last" categories with toxic hepatitis. To assess the proportion of each possible SHE(O) diagnosis that was related to workplace exposures, the I/O information obtained by interview was rated in a blinded fashion by an experienced occupational medicine physician. The highest probability ratings for work-relatedness were noted for lung cancer, primarily due to asbestos exposure. The results of this study suggest that hospital records can be used to identify possible SHE(O); if adequate I/O information is available, then work-relatedness can be assessed. However, the accuracy of I/O obtained from hospital charts is relatively low. The efficient and accurate collection of I/O information from hospital records will require the use of a simple, easily coded instrument to be routinely administered on admission.

Asbestos↗
PubMed1991

CARET, the beta-carotene and retinol efficacy trial to prevent lung cancer in asbestos-exposed workers and in smokers.

CARET is a two-armed, double-blind, randomized chemo-prevention trial to test the hypothesis that oral administration of beta-carotene 30 mg/day plus retinyl palmitate 25,000 IU/day will decrease the incidence of lung cancer in high-risk populations: heavy smokers and asbestos-exposed workers who have smoked. The agents combine anti-oxidant and nuclear tumor suppressor mechanisms. Fastidious monitoring for possible side effects is facilitated by inclusion of a Vanguard population. As of 31 December 1990, 6,105 participants of the 18,000 needed have been randomized in the trial. Efficacy results are expected in 1999.

Aged↗
PubMed1991

Respiratory effects of exposure of shipyard workers to epoxy paints.

Epoxy resin systems have been associated with occupational asthma in several case reports, but medical publications contain little on the potential adverse respiratory effects of these chemicals in exposed worker populations. To further evaluate the association of workplace exposure to epoxy paints and respiratory dysfunction, the cross workshift changes in pulmonary function and symptoms of 32 shipyard painters exposed to epoxy paints were compared with 28 shipyard painters not exposed to epoxy paints. The prevalence of lower respiratory tract symptoms was significantly higher among painters exposed to epoxy paints compared with controls. Among exposed painters the mean cross workshift change in forced expiratory volume in one second (FEV1) (-3.4%) was greater than the decrement in the non-exposed group (-1.4%). A significant linear relation was seen between % decrement in FEV1 and hours of exposure to epoxy paints. This study suggests that epoxy resin coatings as used by shipyard painters are associated with increased lower respiratory tract symptoms and acute decrements in FEV1. Adequate respiratory protection and medical surveillance programmes should be established in workplaces where exposure to epoxy resin systems occurs.

Adult↗
PubMed1991

Airway oedema and obstruction in guinea pigs exposed to inhaled endotoxin.

Protein extravasation and airway conductance (SGaw) were examined in awake guinea pigs exposed to inhaled endotoxin or saline for three hours. A significant increase in protein extravasation (as estimated by the leakage of protein bound Evans blue dye) was seen in the conducting airways of endotoxin exposed animals compared with saline exposed animals. Mean dye extravasation was significantly increased by one to threefold in the mainstem and hilar bronchi of endotoxin exposed animals. These changes in extravasation were accompanied by decrements in pulmonary function and by an influx of polymorphonuclear leucocytes into the airway wall. The SGaw decreased significantly by 60-90 minutes into exposure to endotoxin and had decreased by 22% and 34% at the end of exposure in the low and high dose endotoxin groups, respectively. Similar findings were obtained in animals exposed to cotton dust. Contrary to studies suggesting that platelet activating factor (PAF) is involved in the systemic and peripheral lung effects of endotoxin, pretreatment with the PAF antagonist WEB2086 did not prevent the conducting airway injury produced by inhaled endotoxin.

Aerosols↗
PubMed1991

Fatal injuries at work in California.

We examined deaths due to injury on the job reported from three readily accessible data sources in California for a 1-year period. Of 682 deaths identified as of February 1990 as having occurred on the job in 1983, county coroners identified 607 (89.0%), workers' compensation records identified 294 (43.1%), and the California Occupational Safety and Health Administration investigated 141 (20.7%). Most fatal injuries at work resulted from events that are not covered by current California Occupational Safety and Health Administration standards: transportation vehicle accidents and homicides. Demographic patterns suggest that fatal injuries on the job are nonrandom events, which may be prevented by additions to existing standards or increased enforcement of workplace safety standards and by efforts to target groups at highest risk. Improved surveillance of fatal occupational injuries will require changes in existing reporting mechanisms, similar to those proposed by the US Bureau of Labor Statistics.

Accidents, Occupational↗
PubMed1988

Soybean flour asthma: detection of allergens by immunoblotting.

A 43-year-old woman developed asthma 6 years after beginning work in a food-processing plant in which soybean flour was used as a protein extender. Symptoms of sneezing, coughing, and wheezing would begin within minutes of exposure to soybean flour and resolve 2 hours after exposure ceased. Skin tests were positive to a soy extract prepared from the flour. Airway hyperreactivity was confirmed by a positive bronchial challenge to methacholine. Bronchial challenge with soybean flour produced an immediate increase in specific airway resistance from 5.0 to 22.7 L. cm of H2O/L/sec. There was no response to challenge with lactose. The patient's allergic response to soy-flour extract was further characterized by several immunologic methods. IgE binding to soy-flour protein by direct RAST was 5.98 times that of a normal control serum. The soy-flour extract was separated by dodecyl sulfate-polyacrylamide gel electrophoresis. Twenty-four protein bands were detected in the crude soy-flour extract. After immunoblotting and subsequent autoradiography, nine proteins with molecular weights ranging from 54,500 to 14,875 were found. Cross-reactivity studies with other legumes demonstrated apparent immunologic identity between a component in green pea extract and a soybean protein with a molecular weight of 17,000. The clinical significance of this cross-reactivity is not known. We conclude that in this case of occupational asthma to soybean flour, multiple allergens were involved. Immunoblotting may be useful in identifying the allergens involved in occupational asthma.

Adult↗
PubMed1988

Pregnancy in a woman with severe pulmonary fibrosis secondary to hard metal disease.

The effect of interstitial pulmonary fibrosis on pregnancy is unclear. We present the findings in a 31-year-old woman with severe pulmonary fibrosis (vital capacity, 37 percent of predicted) secondary to hard metal disease who went through a successful term pregnancy. The patient was a grinder of tungsten-carbide drill bits who developed pneumonitis and subsequent fibrosis. Her therapy required steroids and cyclophosphamide for stabilization of her pulmonary function prior to her pregnancy. At six months' gestation, right heart catheterization showed normal cardiac output and pulmonary arterial and wedge pressures. Stage 2 exercise study demonstrated a maximum oxygen consumption of 1.17 L/min (53 percent of predicted). The patient was able to exercise to a maximum workload of 300 kpm/min (32 percent of predicted). She became hypoxemic (arterial oxygen pressure, 54 mm Hg) at 150 kpm/min. Her pregnancy concluded with an uncomplicated normal vaginal delivery requiring only supplemental oxygen and spinal anesthesia. Review of the few similar cases suggests that a woman can have a successful pregnancy despite severe pulmonary dysfunction.

Adult↗