Sunscreen use, wearing clothes, and number of nevi in 6- to 7-year-old European children. European Organization for Research and Treatment of Cancer Melanoma Cooperative Group

BACKGROUND

Previous epidemiologic studies have suggested that sunscreen use is associated with an increased risk of melanoma skin cancer. Because high nevi (mole) count in adults is a strong predictor of melanoma, we conducted a study examining the number of nevi in 6- to 7-year-old European children, according to their sunscreen use.

METHODS

Whole-body and site-specific counts of nevi 2 mm or larger were performed in 631 children in their first year of primary school in four European cities. Independently, parents were interviewed regarding sun exposure, sunscreen use, and physical sun protection of their child.

RESULTS

After adjustment for sun exposure and host characteristics (e.g., skin phototype, eye color), the relative risk for high nevus count on the trunk was 1.68 (95% confidence interval [CI] = 1.09-2.59) for the highest level of sunscreen use and 0.59 (95% CI = 0.36-0.97) for the highest level of wearing of clothes while in the sun. The sun protection factor had no effect on nevus counts despite a high median value of 17.4. Sunburn number was not associated with nevus count. The highest risk associated with sunscreen use was found among children who had never experienced sunburn.

CONCLUSIONS

In white, European children, sunscreen use appears to be associated with development of nevi, probably because it allows longer sun exposures. Wearing clothes may be an effective way to prevent proliferation of nevi. Since a high nevus count is a strong predictor of melanoma, sunscreen use may be involved in melanoma occurrence because it may encourage recreational sun exposure.

Impact of inherited polymorphisms in glutathione S-transferase M1, microsomal epoxide hydrolase, cytochrome P450 enzymes on DNA, and blood protein adducts of benzo(a)pyrene-diolepoxide

The benzo(a)pyrene (BaP) metabolite benzo(a)pyrenediolepoxide (BPDE) is strongly implicated as a causative agent of lung cancer. To assess the risk of exposure to BaP, we made a combined analysis of levels of BPDE adducts to hemoglobin (Hb), serum albumin (SA), and lymphocyte DNA in 44 patients with incident lung cancer, as a prototype of a population mainly exposed to tobacco-derived BaP. We also investigated whether genetic polymorphisms of cytochrome P450IA1 (CYPIA1), microsomal epoxide hydrolase (mEH), and glutathione S-transferase M1 (GSTM1), which are involved in BaP metabolism, can be determinants of adduct formation. BPDE-Hb, BPDE-SA, and BPDE-DNA adducts were quantified as BaP tetrols released from hydrolysis of macromolecules and measured by high-resolution gas chromatography-negative ion chemical ionization-mass spectrometry to achieve high specificity and sensitivity. Individuals with detectable Hb adducts were positive for SA adducts but not vice versa, suggesting that BPDE-Hb adducts are less informative indicators of BaP exposure. Using PCR methods on DNA, we characterized GSTM1 deletion, CYPIA1 MspI and exon 7 valine variants, and mEH polymorphisms at amino acid positions 113 (EH3) and 139 (EH4). Levels of BPDE adducts were no different among CYPIA1, mEH, and GSTM1 genotypes. However, individuals with measurable BPDE-SA adducts were CYPIA1 variant carriers more frequently (P = 0.03). There was a slightly higher percentage of DNA detectable adducts in subjects with CYPIA1 exon 7 valine polymorphism. When subjects were classified by both polymorphisms on the mEH gene, those with two slow alleles (EH3 homozygous mutated) and no fast alleles (EH4 homozygous wild type) had a lower frequency of BPDE-SA adducts and no DNA adducts (P = 0.06). These results are based on a small number of observations thus far, but this exploratory study suggests that CYPIA1 and mEH variants might have an impact on BPDE exposure markers such as BPDE-SA adducts. Chemical specificity in adduct measurements is important to identify the biomarkers that reflect BaP exposure more accurately.

Alcohol intake and risk of cancers of the colon and rectum

The relationship between alcohol drinking (mainly wine) and risk of colon and rectal cancer was considered in a case-control study conducted between 1991 and 1996 in six Italian centers. Cases were 1,225 patients < 75 years of age with histologically confirmed cancer of the colon and 728 patients with cancer of the rectum; controls were 4,154 patients admitted to hospital for a wide spectrum of acute, nonneoplastic diseases. Compared with never drinkers, the odds ratios (OR) for current drinkers in the higher quintile of total alcohol intake (> 51.82 g ethanol/day) were 1.01 for colon cancer and 0.90 for rectal cancer, and those for ex-drinkers were 1.20 and 1.07, respectively. The OR for wine drinkers in the highest quartile of intake were 1.07 for colon cancer and 0.97 for rectal cancer. No association was found with duration of the habit, time since starting, or age at starting. Among ex-drinkers, no association appeared with time since stopping. No significant heterogeneity was found across strata of age at diagnosis, sex, education, smoking status, physical activity, family history of colorectal cancer, beta-carotene, vitamin C, coffee, total fiber and folate intake, and number of meals per day. No significant association appeared for various intestinal subsites.

Identification and characterization of two cysteinyl-leukotriene high affinity binding sites with receptor characteristics in human lung parenchyma

We report the characterization of two distinct binding sites with receptor characteristics for leukotriene (LT)D4 and LTC4 in membranes from human lung parenchyma. The use of S-decyl-glutathione allowed us to characterize a previously unidentified high affinity binding site for LTC4. Computerized analysis of binding data revealed that each leukotriene interacts with two distinct classes of binding sites (Kd = 0.015 and 105 nM for LTC4 and 0.023 and 230 nM for LTD4) and that despite cross-reactivity, the two high affinity sites are different entities. LTD4 binding sites displayed features of G protein-coupled receptors, whereas LTC4 binding sites did not show any significant modulation by guanosine-5'-(beta, gamma-imido)triphosphate or stimulation of GTPase activity. The antagonists ICI 198,615 and SKF 104353 were unselective for the high and low affinity states of LTD4 receptor, whereas only SKF 104353 was able to recognize the two [3H]LTC4 binding sites although with different affinities. These data indicate that in human lung parenchyma, LTD4 and LTC4 recognize two different binding sites; these binding sites are different entities; and for LTD4, the two binding sites represent the interconvertible affinity states of a G protein-coupled receptor, whereas for LTC4, the high affinity site is likely to be a specific LTC4 receptor.

Population attributable risk for breast cancer: diet, nutrition, and physical exercise

BACKGROUND

The percentages of breast cancer cases in a given population attributable to specific risk factors (i.e., the population-attributable risks) can be calculated; determination of such risks associated with potentially modifiable risks factors, such as diet (e.g., levels of consumption of fruits, vegetables, vitamins, etc.), alcohol consumption, exercise, and body weight, are necessary to focus prevention strategies.

METHODS

With the use of data from a case-control study conducted in Italy from June 1991 through April 1994 on 2569 breast cancer case subjects and 2588 control subjects, we calculated multivariate odds ratios and population-attributable risks for breast cancer in relation to dietary beta-carotene and vitamin E intake, alcohol consumption, physical activity, and, for postmenopausal women, body mass index.

RESULTS

Among all subjects, the following attributable risks for the indicated risk factors were observed: 10.7% (95% confidence interval [CI] = 4.4%-17.0%) for high alcohol intake (i.e., >20 g/day), 15.0% (95% CI = 7.4%-22.9%) for low beta-carotene intake (i.e., <3366 microg/day), 8.6% (95% CI = -0.4%-17.5%) for low vitamin E intake (i.e., <8.5 mg/day), and 11.6% (95% CI = -0.1%-23.3%) for low levels of physical activity. The risks associated with alcohol and beta-carotene intake were larger among premenopausal women, and the risk associated with physical activity was larger among postmenopausal women. Being overweight accounted for 10.2 % (95% CI = 0.2%-20.2%) of breast cancer cases in postmenopausal women. Beta-carotene plus alcohol accounted for 28.1% (95% CI = 16.8-39.4) of the cases. Beta-carotene and physical activity accounted for 32% (95% CI = 14.3-49.8), and these three factors together accounted for 33% (95% CI = 19.9-46.1) of the breast cancer cases in the overall dataset.

CONCLUSION

Exposure to a few selected and potentially modifiable risk indicators explained about one third of the cases of breast cancer in this Italian population, indicating the theoretical scope for prevention of the disease.

Risk factors for high-grade cervical intraepithelial neoplasia in patients with mild cytological dyskaryosis: human papillomavirus testing versus multivariate tree analysis of demographic data

The objective of this study was to compare the use of molecular hybridization by hybrid capture methodology for human papillomavirus (HPV) with the use of demographic and lifestyle variables as intermediate triage in patients with cytological mild dyskaryosis. The study was designed as a prospective study using regression tree analysis of demographic data in consecutive patients who were subjected to colposcopic evaluation at the colposcopy clinic at the First Department of Obstetrics and Gynaecology, University of Milan (Milan, Italy). A total of 177 women were subjected to colposcopy because of a single routine Pap smear showing mild dyskaryosis. A structured interview, sampling for HPV testing for the detection of viral DNA by hybrid capture methodology, and colposcopic evaluation with cervical biopsies were performed for each subject. The accuracies of molecular hybridization for HPV and of the classification model based on the demographic and lifestyle variables in predicting patients with histologically high-grade cervical intraepithelial lesions were measured. The classification model based on the demographic and lifestyle variables showed comparable results with molecular hybridization for HPV (specificity, 0.75 versus 0.73; sensitivity, 0.61 versus 0.67, respectively). The use of demographic and lifestyle variables appears to be a simple and economic possibility for triaging patients with mild dyskaryotic smears in a screening program.

Pharmacological characterization of the cysteinyl-leukotriene antagonists CGP 45715A (iralukast) and CGP 57698 in human airways in vitro

1. Cysteinyl-leukotrienes (cysteinyl-LTs) are important mediators in the pathogenesis of asthma. They cause bronchoconstriction, mucus hypersecretion, increase in microvascular permeability, plasma extravasation and eosinophil recruitment. 2. We investigated the pharmacological profile of the cysteinyl-LT antagonists CGP 45715A (iralukast), a structural analogue of LTD4 and CGP 57698, a quinoline type antagonist, in human airways in vitro, by performing binding studies on human lung parenchyma membranes and functional studies on human isolated bronchial strips. 3. Competition curves vs [3H]-LTD4 on human lung parenchyma membranes demonstrated that: (a) both antagonists were able to compete for the two sites labelled by [3H]-LTD4; (b) as in all the G-protein coupled receptors, iralukast and CGP 57698 did not discriminate between the high and the low affinity states of the CysLT receptor labelled by LTD4 (Ki1=Ki2= 16.6 nM+/-36% CV and Ki1= Ki2 = 5.7 nM+/-19% CV, respectively); (c) iralukast, but not CGP 57698, displayed a slow binding kinetic, because preincubation (15 min) increased its antagonist potency. 4. In functional studies: (a) iralukast and CGP 57698 antagonized LTD4-induced contraction of human bronchi, with pA2 values of 7.77+/-4.3% CV and 8.51+/-1.6% CV, respectively, and slopes not significantly different from unity; (b) the maximal LTD4 response in the presence of CGP 57698 was actually increased, thus clearly deviating from apparent simple competition. 5. Both antagonists significantly inhibited antigen-induced contraction of human isolated bronchial strips in a concentration-dependent manner, lowering the upper plateau of the anti-IgE curves. 6. In conclusion, the results of the present in vitro investigation indicate that iralukast and CGP 57698 are potent antagonists of LTD4 in human airways, with affinities in the nanomolar range, similar to those obtained for ICI 204,219 and ONO 1078, two of the most clinically advanced CysLT receptor antagonists. Thus, these compounds might be useful drugs for the therapy of asthma and other allergic diseases.

Fibers and breast cancer risk

Data from a multicenter case-control study on breast cancer conducted in Italy were used to analyze the relationship between various types of fibers and breast cancer risk. Cases were 2,569 women with histologically confirmed, incident breast cancer; controls were 2,588 women admitted to the same network of hospitals for acute, nonneoplastic, non-hormone-related diseases. Cases and controls were interviewed between 1991 and 1994 using a validated food frequency questionnaire. The data were modeled through multiple logistic regression, controlling for demographic and reproductive breast cancer risk factors. The continuous odds ratios for the difference between the upper cut point of the fourth and the first quintile of intake were 0.90 [95% confidence interval = 0.82-0.98, p (for trend) < 0.05] for cellulose and 0.94 (95% confidence interval = 0.86-1.02) for soluble fibers. The protection tended to be stronger in premenopausal women. No material association was found for noncellulose polysaccharides and lignin. This study, based on a large data set from various Italian regions, suggests that fiber intake may confer some protection against breast cancer, particularly for cellulose and also for soluble fibers, i.e., those of vegetable origin. This possible protection has been related to an influence of fibers on levels and availability of estrogens and other steroid hormones in breast carcinogenesis.

Non-selective impairment of Wisconsin Card Sorting Test performance in patients with schizophrenia

Sixty-two schizophrenic patients and 26 healthy volunteers were administered the Wisconsin Card Sorting Test (WCST) a task putatively specific for frontal functions and the Wechsler Adult Intelligence Scale (WAIS). The purpose of this study was to evaluate the presence of specific frontal lobe deficits in the course of schizophrenia and the capacity of these tasks to discriminate between patients and controls. Schizophrenic patients showed a poorer performance than control subjects in both tests. No evidence emerged to support a higher discriminant power for the WCST in identifying schizophrenic subjects from healthy controls compared with the WAIS. Our data suggest that the deficit in WCST performance is not selective, but rather part of a more generalized neuropsychological impairment in schizophrenic patients.

Prospective study of surgical treatment of lung cancer in the elderly patient

BACKGROUND

In 1986 the authors began a prospective study to investigate operative mortality and long-term survival after surgery of patients in their seventh decade of life suffering from non-small cell lung cancer in Stages I and II.

METHODS

From 1986 to 1991, 519 lung cancer patients underwent radical surgery. Of this number, 54 were aged 70 years and older (Group A), while 465 fell within the 40-69 age range (Group B). The most widely applied operation in absolute terms was lobectomy (no difference between the two groups). Pneumonectomies were performed in greater number in Group B (p < .025), whereas minor resections were more numerous in Group A (p < .0005).

RESULTS

Operative mortality, i.e., within 30 days of operation, was higher in the elderly patients, but without any significant difference between the two groups (A, 5.5%; B, 1.3%). Morbidity presented a very similar pattern: Group A, 7.4%; Group B, 6.9%. Actuarial survival at 2 and 5 years for the patients in Stage I was distributed as follows: Group A, 78.2% and 52.1%; Group B, 80.0% and 57.8%.

CONCLUSIONS

No statistically significant difference exists between the survival rates of the two groups. The data gathered suggest that patients in their seventh decade of life can receive surgical treatment exactly as younger patients in the case of non-small cell lung cancer in Stages I and II.

Video-assisted thoracoscopic resection of pulmonary sequestration in an infant

Pulmonary sequestration is a congenital anomaly of lung parenchyma that can be definitively treated only with surgical resection. We report a case of an intralobar sequestration of the right lower pulmonary lobe in an infant successfully treated with video-thoracoscopic surgical removal of the involved lobe at 6 months of age.

Attributable risks for colorectal cancer in northern Italy

Using data from a case-control study conducted between 1985 and 1992 in northern Italy on 828 cases of colon cancer, 498 cases of rectal cancer and 2,024 controls in hospital for acute, non-neoplastic, non-digestive tract disorders, we estimated the percent population attributable risk (PAR) for colorectal cancer in relation to beta-carotene, vitamin C (as markers of a diet rich in fruit and vegetables), red meat and seasoning fat intake, daily meal frequency and family history of the disease. On the basis of multivariate odds ratios, adjusted for total calorie intake, a low intake of beta-carotene accounted for 39% of all the cases and a low intake of vitamin C for 14%. These two micronutrients together explained 43% of all colorectal cancer cases in this population. A high frequency of intake of red meat consumption explained 17% of all cases, and a high score of seasoning fats 4%. A higher daily meal frequency was responsible for 13% of the cases, and these 5 dietary factors together explained 63% of colorectal cancer cases in this population. Family history of colorectal cancer accounted for 4% of all cases. These estimates were similar for colon and rectal cancers separately, in males and females, and in younger and elderly subjects, except for seasoning fats and family history, whose PARs were apparently greater for colon cancer and at younger age. Thus, even though available dietary data were limited in several aspects, and the PAR estimates were based on somewhat arbitrary assumptions regarding the exposure distribution, about two-thirds of all colorectal cancers in this population could be explained in terms of a few risk factors or risk indicators considered. This would correspond to the avoidance of a large proportion of the over 18,000 deaths from colorectal cancer registered per year in the whole of Italy.

Software for attributable risk and confidence interval estimation in case-control studies

The increasing interest in obtaining model-based estimates of attributable risk (AR) and corresponding confidence intervals, in particular when more than one risk factor and/or several confounding factors are jointly considered, led us to develop a program based on the procedure described by Benichou and Gail for case-control data. This program is structured as an SAS-macro. It is suited to analysis of the relationship between risk factors and disease in case-control studies with simple random sampling of controls, in terms of relative risks and ARs, by means of unconditional logistic regression analysis. The variance of the AR is obtained by the delta method and is based on three components, namely, (i) the variance-covariance matrix of the vector of the estimated probabilities of belonging to joint levels of the exposure and confounding factors conditional on being a case, (ii) the variance-covariance matrix of the odds ratio parameter estimates from the logistic model, and (iii) the covariances between these probability and parameter estimates. Only a limited number of commands is requested from the user (i.e., the name of the work file and the names of the variables considered). The estimated relative risks for all the factors included in the model, the attributable risk for the exposure factor under consideration, and the corresponding 95% confidence intervals are given as outputs by the macro. Computational problems, if any, may arise for large numbers of covariates because of the resulting large size of vectors and matrices. The macro was tested for reliability and consistency on published data sets of case-control studies.

[Sclerosing hemangioma of the lung: a case report]

The authors present a case of sclerosing hemangioma, a rare benign neoplasm of the lung. The patient presented coughing, blood-tinded spuntum and thoracic pain; chest x-ray showed an irregular shadow close to right hilum. A right superior lobectomy was performed. Immunohistochemical and electronic microscopy studies of the lesion supported its origin from respiratory epithelium.

[Bronchial carcinoid tumors. Retrospective analysis of 32 cases]

Thirty-two cases of bronchial carcinoids (rate m/f = 1, average age 50.33 years) had been treated from 1970 to 1993. 62.5% of patients were symptomatic, 6% with specific symptoms. 62.5% of tumors had a central growth. Thirty-one patients underwent surgical treatment, another one a laser Nd:YAG coagulation. The operative mortality and morbidity were respectively 3% and 0%. 84.4% of tumours were typical carcinoid, 11% of those had lymphonodal metastases. Atypical carcinoids were found in 15.6% of patients, 40% had lymphnodal metastases. The global actuarial survival to 1, 5, 10 years were respectively 96, 88 and 84%. Statistically the survival difference between the typical and atypical carcinoid is relevant. The authors underline the preoperative cytologic diagnosis to perform a minimal lung resection in typical bronchial carcinoids.

Videothoracoscopy versus thoracotomy for the diagnosis of the indeterminate solitary pulmonary nodule

The solitary pulmonary nodule often presents a diagnostic challenge to the specialist because the nature of the nodule is often indeterminate at the end of the usual diagnostic process, and operation frequently is required before a definite diagnosis can be made. We have conducted a randomized, prospective trial to evaluate the diagnostic efficacy of video-assisted thoracic surgery versus muscle-sparing lateral thoracotomy. Between January 1991 and May 1994, 44 patients suffering from solitary pulmonary nodule were divided at random into two groups: the nodule was removed in 22 cases by video-assisted thoracic surgery and in 22 cases by lateral thoracotomy. Nineteen wedge resections, 1 segmentectomy, and 2 lobectomies were performed in the first group and 13 wedge resections, 8 segmentectomies, and 1 lobectomy in the second group. An "access" thoracotomy had to be performed in 5 patients in the video-assisted thoracic surgery group. The operating room time was 97.2 +/- 32.9 minutes in the video-assisted thoracic surgery group and 130.5 +/- 14 minutes in the lateral thoracotomy group (p > 0.05). In both groups a final diagnosis was made in 100% of cases. The postoperative hospital stay was 4.6 +/- 1.08 days in the video-assisted thoracic surgery group and 7.8 +/- 0.89 days in the lateral thoracotomy group (p < 0.01). Pain was evaluated on a visual analogue scale; the scores were 26.5 +/- 11.6 in the video-assisted thoracic surgery group and 48.3 +/- 12.8 in the lateral thoracotomy group (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Biologic and clinicopathologic factors as indicators of specific relapse types in node-negative breast cancer

PURPOSE AND METHODS

We evaluated, in 1,800 patients with node-negative tumors treated with locoregional therapy until relapse, the competitive risks for different types of metastasis by cell proliferation (3H-thymidine labeling index [3H-dT LI]), estrogen receptors (ERs), and progesterone receptors (PgRs), and by the integration of biologic and clinicopathologic information.

RESULTS

Hormone receptor status and proliferative activity of the primary tumor were not indicative of contralateral failures. Hormone receptors failed to predict the 8-year incidence of locoregional recurrence, but they were significant indicators of distant metastasis and overall survival. The latter finding was confirmed even in multivariate analysis. Conversely, cell proliferation predicted both locoregional and distant metastases and survival, regardless of patient age, tumor size, and ER and PgR status. Recursive partitioning and amalgamation analysis ascribed to cell proliferation an important prognostic role for locoregional recurrence together with patient age and tumor size.

CONCLUSION

Biologic markers, in particular cell proliferation, provide information for the different types of relapse and could complement the predictive role of pathologic staging.

The Bcl-2 protein: a prognostic indicator strongly related to p53 protein in lymph node-negative breast cancer patients

BACKGROUND

The bcl-2 gene (also known as BCL2) encodes for a mitochondrial protein thought to prevent apoptosis of normal cells. The protein has been detected by immunohistochemical procedures in hormonally regulated epithelia.

PURPOSE

We analyzed the predictive relevance of Bcl-2 expression on 6-year relapse-free and overall survival in lymph node-negative breast cancers in relation to pathologic (tumor size) and biologic ([3H]thymidine-labeling index, p53 protein expression, and estrogen receptor [ER] status) features.

METHODS

The expression of Bcl-2 and p53 was detected by immunohistochemistry on paraffin-embedded sections from 283 node-negative resectable breast cancers treated with local-regional therapy alone until relapse. The [3H]thymidine-labeling index was evaluated on histologic sections after incubation of fresh tumor tissue with [3H]thymidine, and ER content was determined by the dextran-coated charcoal absorption technique.

RESULTS

A significantly higher fraction of Bcl-2-positive cells was observed in small, ER-positive, slowly proliferating, and p53-negative tumors than in large, ER-negative, rapidly proliferating, and p53-positive tumors. A stronger association was observed between Bcl-2 and p53 expression than between these variables and [3H]thymidine-labeling index. In univariate analysis, Bcl-2 and p53 expression, [3H]thymidine-labeling index, tumor size, and ER status were indicators for relapse-free and, with the exception of tumor size, overall survival within 6 years of surgery. In multivariate analysis, Bcl-2 failed to maintain its prognostic role for relapse-free and overall survival in the presence of p53 expression, whereas the [3H]thymidine-labeling index was still statistically significant as a predictor for both events.

CONCLUSION

The predictive role of Bcl-2 expression on 6-year relapse-free and overall survival was mainly dependent on p53 expression.

Prognostic value of p53 expression in early-stage breast-carcinoma compared with tumor angiogenesis, epidermal growth-factor receptor, C-erbb-2, cathepsin-d, DNA-ploidy, parameters of cell-kinetics and conventional features

p53 expression detected by immunocytochemistry is emerging as a novel potentially useful prognostic indicator in breast carcinoma. However, additional research is warranted because a consensus has not yet been achieved on: i) methodology and quality control issues; ii) its association with other new biological prognostic indicators; iii) its prognostic value in multivariate analysis including conventional and new pathobiological features and; iv) its clinical usefulness either as a prognostic and predictive factor. This study was undertaken in a series of 165 early-stage breast cancer patients (median follow-up of 5 years) to compare the prognostic role of p53 expression with that of several other markers that have been found to be of value, using a multivariate statistical analysis. These factors are: tumour angiogenesis, epidermal growth factor receptor (EGFR), c-erbB-2 expression, cathepsin D, growth fraction by Ki-67 antibody, DNA ploidy and S-phase fraction. The main results observed were: i) 47 of 165 (28.5%) carcinomas had pAb 1801 staining and were considered as p53-positive; ii) p53 expression was weakly associated with S-phase fraction by flow cytometry (OR=1.86; p=0.085); iii) p53 expression was significantly associated with recurrence (p53 negative [-] versus weak positive [+] tumours: p=0.07 and odds ratio of 2.21; p53 negative [-] versus high positive [++] tumours: p=0.01 and odds ratio of 2.86) and death (p53-versus +: p=0.53 and odds ratio of 1.35; p53- versus ++: p=0.05 and odds ratio of 2.53); iv) the determination of p53 is able to identify a subset of high risk patients in c-erbB-2 negative tumours, this group being generally considered at good prognosis; v) In multivariate analysis on relapse-free survival including all the above markers only tumour angiogenesis, cathepsin D, EGFR and S-phase fraction and nodal status retained significance, and for overall survival only tumour angiogenesis was significant and independent. This new information on p53 expression could be useful to the clinician for a more rationale approach in defining prognosis of breast cancer patients. The prognostic value of p53 depends on which other markers are additionally analyzed and previous studies have not always assayed tumour angiogenesis, which is the most important factor in this series. p53 still need to be assessed as a potential predictor of response to chemo or radiotherapy, because of its role in monitoring DNA damage.

Efficacy of long-term administration of transdermal nitroglycerin in asymptomatic patients with effort-induced silent myocardial ischemia

The aim of our study was to investigate the effect of transdermal nitroglycerin (NTG) on effort-induced silent myocardial ischemia in asymptomatic patients treated with beta-blockers or calcium antagonists. The acute effect was compared to two different schedules, continuous (24 h/day) or intermittent (16 h/day), of long-term administration. Ten asymptomatic patients with coronary artery disease and a treadmill test positive for ischemia without angina were enrolled. Both acute (2 days) and long-term (24 days) evaluations were conducted in a randomized, double-blind, crossover fashion. The ergometric parameters were collected on the 1st and the 2nd day of the acute phase (placebo and transdermal NTG, respectively) and at the end of each 12-day period of long-term administration (continuous and intermittent, respectively). Transdermal NTG administration acutely increased (p < 0.05) both time to 1-mm ST segment depression (451 +/- 43.2 vs. 374 +/- 24.1 s) and total exercise time (561.3 +/- 43.2 vs. 419.5 +/- 24.5 s). The acute efficacy was maintained over long-term treatment, regardless of the modality of administration. During continuous and intermittent patch application, time to 1-mm ST segment depression was 437.9 +/- 30.4 and 422 +/- 33.4 s (p = NS vs. acute) and total exercise time was 498.8 +/- 30.4 and 495.1 +/- 33 s (p = NS vs. acute), respectively. Transdermal NTG increases, both acutely and chronically, exercise tolerance in asymptomatic patients with effort-induced silent myocardial ischemia. With the NTG dose we used, tolerance does not seem to be a problem over long-term administration.

A multiparametric study on the prognostic value of epidermal growth factor receptor in operable breast carcinoma

Epidermal growth factor receptor (EGFR) is a potentially useful new biological prognostic and predictive indicator in human breast cancer. Additional research on EGFR is warranted to enhance our information on: i) the method of choice for its detection and quality control issues; ii) its association with novel pathobiological markers of prognosis; iii) its prognostic value in multivariate analysis; and iv) its capability to predict response to hormone therapy and, in the future, to biological treatments using antibodies against the specific receptor or its ligands. In the present study we update previous data on EGFR status, determined immunocytochemically, by prolonging the period of observation up to 5 years and by including, in the multivariate analysis, several new biological indicators. The main results obtained are: i) EGFR is weakly associated with Ki-67 score (p = 0.073) and with p53 expression (p = 0.06); ii) EGFR is a significant indicator for recurrence (p < 0.01 and odds ratio of 2.82) but not for death (p = 0.27 and odds ratio of 1.49); iii) the prognostic power of EGFR is enhanced when combined with the knowledge of S-phase fraction; and iv) in multivariate analysis on relapse-free survival, EGFR and S-phase fraction (likelihood ratio test = 26.40; p < 0.01), c-erB-2 protein and p53 mutant protein expression (likelihood ratio test = 5.94; p = 0.05), cathepsin D (likelihood ratio test = 9.78; p < 0.01), and nodal status (likelihood ratio test = 7.32: p < 0.01) are significant and independent prognostic factors in early-stage breast carcinoma. This new information could be of help for a more rational approach in the use of EGFR as a marker in future clinical research.

Intratumoral microvessel density and p53 protein: correlation with metastasis in head-and-neck squamous-cell carcinoma

Squamous-cell carcinoma of the head and neck includes a heterogeneous group of tumours of the upper air and food passages for which prognosis is difficult to assess. In fact, patients in comparable stages may have diverse clinical courses and responses to similar treatments. In order to better define the prognosis of each patient there is therefore a need to identify novel biological markers which reflect more accurately growth rate, progression and metastatic potential of each tumour. We assessed whether metastases correlate with microvessel counts (i.e. intratumoral vascularity) using the CD-31 monoclonal antibody (MAb) and p53 mutant protein expression, determined in the primary by immunocytochemical methods in 70 patients with locally advanced head and neck cancer. Patients were treated with concurrent chemo-radiotherapy; 50 of these presented loco-regional node metastasis at diagnosis whereas 3 cases, initially node-negative, developed distant metastasis during the period of observation. No feature was predictive for objective response to treatment. The overall mean and median blood vessel density at "hot spots" was 37.42 and 36, respectively, and 57% of the tumours expressed p53 mutant proteins. These 2 biological markers were significantly associated. Patients with metastases (loco-regional and distant) had a significantly higher mean blood-vessel density than those without tumour spread. Also, patients with p53-positive (+/++) tumours had a significantly higher incidence of metastasis than those with negative ones. Multivariate analysis showed that both vascularity and stage, but not p53 expression, are significant and independent predictors of metastasis in this series.

Concurrent Carboplatin (CBDCA), Vindesine (VDS) and Radiotherapy in Stage III Non Small Cell Lung Cancer (NSCLC)

Aims

Aim of the study was to test, in a cooperative and prospective trial, the effectiveness and feasibility of a chemo-radio-therapy program in stage III non small cell lung cancer (NSCLC).

Methods

The schedule consisted in carboplatin (CBDCA) 150 mg/m2/iv on days 1, 3, 5 and vindesine VDS 2.5 mg/m2/iv on days 1, 8, 15, 22 every 4 weeks for 2 cycles followed by radiotherapy 60 Gy with CBDCA 50 mg/m2 weekly as radioenhancer. The same schedule was proposed as neoadjuvant treatment in 10/47 patients (stage III A) and as exclusive treatment in 37/47 (stage III B) admitted patients.

Results

In the neoadjuvant subgroup partial remission was obtained in 5/10 patients, and 3 of them underwent surgery with consequent CR. In the stage III B subgroup, 2 complete remissions were obtained (survival 14 and 9+ months). Toxicity was mild.

Conclusions

Our results confirm the feasibility of the schedule in stage III NSCLC.

Heterogeneity of binding sites for ICI 198,615 in human lung parenchyma

We have identified and characterized two different subclasses of binding site for the novel peptido-leukotriene (LT) antagonist, [3H]ICI 198,615, in membranes from human lung parenchyma using a receptor-ligand assay. This novel compound is representative of a new class of LT receptor antagonists and it has been demonstrated to be several orders of magnitude more potent and selective than most other LT antagonists described to date. The binding of [3H]ICI 198,615 is rapid, specific and saturable. Equilibrium was reached within 5-10 min. Non linear fitting of dissociation time courses has revealed the presence of two different components (K(off)1 = 8.3 +/- 6.8 x 10(-4) sec-1 and K(off)2 = 0.79 +/- 1.66 x 10(-3) sec-1) of the kinetic curves, suggesting heterogeneity of the binding sites. Computer analysis of equilibrium binding data obtained at 25 degrees results in a model with two classes of binding sites, a high affinity-low capacity class with Kd1 = 0.024 +/- 0.014 nM and Bmax1 = 0.015 +/- 0.004 pmol/mg protein and a low affinity-high capacity class with Kd2 = 6326 +/- 3859 nM and Bmax2 = 473 +/- 383 pmol/mg protein. In competition studies, LTD4 was also found to interact with two classes of binding site (Kd1 = 0.016 +/- 0.008 nM and Kd2 = 15195 +/- 8965 nM). On the contrary, LTE4 and LTC4 were found to interact with a homogeneous class of sites only with Kd = 7466 +/- 4629 nM and Kd = 428 +/- 73 nM, respectively. Furthermore, we have evaluated the effect of a number of LT antagonists on the binding of [3H]ICI 198,615. Ro 24-5913 (Kd = 3.0 +/- 2.1 nM), FPL55712 (Kd = 4945 +/- 2868 nM), LY171883 (Kd = 19628 +/- 12365 nM), SKF 104353 (Kd = 74.2 +/- 46 nM) and its enantiomer SKF 104373 (Kd = 13627 +/- 6813 nM) were found to interact with a single class of binding sites. The present studies indicate a heterogeneity of binding sites for ICI 198,615 in membranes from human lung parenchyma and that ICI 198,615 is a very potent and selective antagonist of LTD4 receptors in this tissue.

[The clinical and prognostic significance of symptomatic and silent ischemia on the exercise test in patients with a prior myocardial infarct]

The aim of the study was to assess clinical/prognostic significance of exercise-induced ischemia in patients with healed myocardial infarction. From May 1988 to January 1991, 777 consecutive patients underwent a symptom-limited (Bruce protocol) treadmill test at least 1 year after myocardial infarction. Clinical and ergometric data were entered in a prospective way in our data base. The exercise-test was positive in 231 out of 777 patients and 2 different subgroups were retrospectively identified depending on criteria of interruption: 156 patients with painless exercise-ST depression; 75 patients with painful exercise-ST depression. The main results (mean +/- SD) were analyzed with Student t test and chi 2 test. Patients with silent ischemia had longer exercise duration (547 +/- 153 s versus 395 +/- 173 s; p < 0.001) and higher double product (22.98 +/- 0.5 versus 19.71 +/- 0.4; p < 0.001) than symptomatic patients. Ischemic threshold was lower (double product: 17.98 +/- 0.4 versus 21.22 +/- 0.4; p < 0.001 with onset of ST depression at 297 +/- 148 s versus 448 +/- 147 s; p < 0.001) and time to ST normalization was longer (368 +/- 155 s versus 234 +/- 212 s; p < 0.001) in patients with painful ischemia. Patients with angina and ST depression had significantly higher prevalence of downsloping ST depression in the recovery phase (68% versus 37%; p < 0.001) and a higher prevalence of treadmill exercise score indicating high risk (49% versus 3.2%; p < 0.001). The 2 groups when compared with 99 patients with negative test post-AMI were significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective effect of nedocromil sodium on the IL1-induced release of GM-CSF from cultured human bronchial epithelial cells

Cultured human bronchial epithelial cells constitutively produce granulocyte-macrophage colony-stimulating factor (GM-CSF). The synthesis and release of GM-CSF is upregulated in bronchial epithelium of patients with symptomatic asthma and this may contribute to the local activation of inflammatory cells in their bronchial mucosa. The cause of this upregulation of GM-CSF expression is unknown, but an increased release of interleukin-1 (IL1) from other airway resident cells might be involved, as an increase in GM-CSF production can be induced in vitro in normal bronchial epithelial cells by IL1 and the airway secretions of asthmatics contain high amounts of this cytokine. In the present study, we have evaluated the effect of the anti-inflammatory and antiasthmatic drug, nedocromil sodium, on the spontaneous and IL1-induced expression of GM-CSF in cultured bronchial epithelial cells. This compound, at the concentration of 10(-5) M, reduced the IL1-induced increase in GM-CSF release from epithelial cells by more than 40%, but it did not affect the constitutive production of GM-CSF.

Mechanisms of calcium mobilization and phosphoinositide hydrolysis in human bronchial smooth muscle cells by endothelin 1

We have previously demonstrated that human bronchial smooth muscle cells possess a single class of high-affinity binding sites for endothelin 1. In this study, we further characterized the receptor for endothelin 1 and evaluated the signal transduction mechanisms of this peptide. Stimulation of cultured human bronchial smooth muscle cells with endothelin 1 induced mobilization of Ca2+ from both intracellular and extracellular pools with a biphasic increase in cytoplasmic free Ca2+ concentration. Endothelin 1 increased cellular levels of inositol phosphates and diacylglycerol, indicating activation of phospholipase C, but induced production of inositol phosphates in smooth muscle cell membranes only in the presence of guanosine 5'-O-(thiotriphosphate) (GTP gamma S). Treatment of smooth muscle cells with pertussis toxin failed to block the endothelin 1-induced increase in inositol phosphate production and Ca2+ mobilization. These results suggest that the receptor for endothelin 1 in bronchial smooth muscle is coupled to phospholipase C through a pertussis toxin-insensitive G protein. Affinity crosslinking experiments identified the endothelin 1 receptor as a single band with an apparent molecular weight of approximately 70,000 on sodium dodecyl sulfate polyacrylamide gel electrophoresis, further supporting the functional evidence that endothelin 1 receptor belongs to the G protein-linked rhodopsin type of receptor superfamily.

Time course of IL1 and IL6 synthesis and release in human bronchial epithelial cell cultures exposed to toluene diisocyanate

We have previously demonstrated that human bronchial epithelial cells release appreciable amounts of interleukin 1 (IL1) and interleukin 6 (IL6) when exposed to toluene diisocyanate (TDI) in vitro. TDI is an inflammatory and asthmogenic stimulus presumed to act at least in part through immunological mechanisms. The epithelial cell-derived IL1 and IL6 can promote T cell activation and proliferation in culture, and if this also happens in vivo they may contribute to the persistence of the inflammatory response of the bronchial mucosa observed in TDI-sensitive asthmatics. In this study, we confirmed the release of biologically active IL1 beta and IL6-like substances from bronchial epithelial cells exposed to isocyanates in vitro, and related the rate and the magnitude of the cytokine secretion with the pattern of IL1 beta and IL6 gene expression and the extent of epithelial cell injury. In the epithelial cell cultures exposed to TDI, there was a parallel, progressive increase in the expression of IL6 mRNA and in the secretion of IL6 protein between 48 hours and 6 days after exposure. By contrast, although increasing amounts of biologically active IL1 beta were detected in the supernatants of TDI-exposed epithelial cells throughout the 6-day period following exposure, augmented levels of IL1 beta mRNA were only evident 6 days after exposure, suggesting that TDI exposure might have initially affected the enzymatic cleavage of the intracellular IL1 beta precursor and the mechanisms which regulate the secretion of mature IL1 beta.

Eicosanoid release and mepyramine, LTC4 and LTD4 binding in passively sensitized human lung parenchyma in vitro

In vitro passive sensitization of human lung parenchyma with hyper-immune serum did not affect the release of prostaglandin D2 (PGD2) or leukotriene (LT)-like activity upon challenge with anti-IgE antibody with respect to control lung, despite a marked difference in IgE levels between control (C) and sensitized (S) tissue. Binding studies with [3H]LTC4, [3H]LTD4 and [3H]mepyramine (a histamine H1 antagonist) showed a statistically significant increase in the amount bound in sensitized vs control lung for [3H]mepyramine only. Contractile response to 5 x 10(-5) M histamine (H) in C and S lung parenchymal strips did not correlate with binding data. It is concluded that in vitro elevated IgE levels do not affect the interaction of sulfidopeptide leukotrienes with their putative receptors. As for the observed increase in [3H]mepyramine binding, this might not represent a true increase in histamine receptors on lung smooth muscle cells.

Interleukin-1 binds to specific receptors on human bronchial epithelial cells and upregulates granulocyte/macrophage colony-stimulating factor synthesis and release

Cultured human bronchial epithelial cells constitutively produce granulocyte/macrophage colony-stimulating factor (GM-CSF). An upregulation of the synthesis and release of GM-CSF from those cells might contribute to the persistence of infiltration and local activation of inflammatory cells in some inflammatory diseases of the airways, such as asthma. Increased levels of immunoreactive and biologically active interleukin-1 (IL-1) have been identified in the airway secretions of asthmatic patients, together with an increase in GM-CSF contents. As IL-1 is known to upregulate GM-CSF production in many cell populations, in this study we investigated the ability of IL-1 to bind to specific receptors on bronchial epithelial cells and promote GM-CSF synthesis and release. Bronchial epithelial cells possessed specific single-class surface receptors for recombinant IL-1. The addition of exogenous IL-1 led to a dose-dependent increase in the accumulation of GM-CSF mRNA and release of immunoreactive GM-CSF to the culture medium. Release of IL-1 in the bronchial mucosa during allergic and nonallergic responses may lead to enhanced GM-CSF synthesis and release by epithelial cells, thus promoting airway inflammation.

Human bronchial epithelial cells modulate CD3 and mitogen-induced DNA synthesis in T cells but function poorly as antigen-presenting cells compared to pulmonary macrophages

This study was undertaken to investigate the ability of bronchial epithelial cells (ECs) to function as accessory cells. Pulmonary monocytes were our reference cells. ECs and pulmonary monocytes were isolated from the bronchial mucosa and pulmonary parenchyma of subjects undergoing lobectomy for standard clinical reasons. Circulating autologous T cells were rigorously depleted of accessory cells to the extent that they lost the capacity to respond to mitogenic lectins alone. ECs restored mitogen-induced DNA synthesis and DNA synthesis triggered by CD3 cross-linking in T cells, as did pulmonary macrophages, and this was unrelated to HLA-DR expression. The ability of promoting T cell proliferation after CD3 cross-linking was, in part, due to the secretory products of ECs, since their supernatants were also effective. Interferon-gamma-treated ECs were capable of presenting antigens to autologous T cells. This was an HLA-DR-restricted phenomenon, but EC efficiency in this system was less than 40% of efficiency demonstrated by pulmonary monocytes. However, ECs greatly upregulated antigen-specific responses supported by pulmonary monocytes.

Miocamycin distribution in tonsillar and pulmonary tissues after repeated administration

Twenty patients undergoing tonsillectomy were treated with a peroral administration of 600 mg of miocamycin every 12 hours for 4 days. On the 5th day, after a last administration of a dose of 600 mg the ablation of the tonsils was carried out on groups of 4 subjects, each one at the following times after oral intake of the drug: 2, 4, 6, 8, 12 h. Twenty-nine patients, admitted to hospital to undergo lung resection were treated with peroral administration of miocamycin in accordance with the above mentioned dose scheme. The operation was carried out on groups of 5 subjects, each on the fifth day at the following times after the last administration: 2, 3, 4, 6, 8 and 12 h (4 subjects). Simultaneously blood was withdrawn for the determination of miocamycin in serum. Miocamycin was measured by a microbiological procedure using Sarcina lutea ATCC 9341. The highest levels of miocamycin were observed after 2h in tonsils (3.2 +/- 0.82 mg/kg) and serum (1.3 +/- 0.33 mg/l). After 12h miocamycin proved to be still measurable in the tissue (0.12 +/- 0.05 mg/kg), whereas it was not detected in serum. In pulmonary tissue, the highest levels of miocamycin were likewise identified at the 2nd hour (2.82 +/- 0.59 mg/kg), simultaneously with the highest serum levels (2.3 +/- 0.61 mg/l). At the 12th hour miocamycin could still be dosed in 3 tissue samples, with values between 0.1 and 0.2 mg/kg and was found just at dosing limits in only one serum sample.

Bronchial epithelial cells exposed to isocyanates potentiate activation and proliferation of T-cells

Bronchial epithelial cells release chemotactic factors for lymphocytes and express HLA-DR antigens. Thus they may contribute to the T-cell-mediated inflammatory responses involved in a number of pulmonary diseases such as asthma. In this study, the in vitro exposure of human bronchial epithelial cells to toluene 2,4-diisocyanate (TDI), an inflammatory and asthmogenic stimulus presumed to act at least in part through immunological mechanisms, provoked cell damage followed by proliferation of the cells that survived the injury. At the time of the proliferative response, epithelial cells released factors that upregulated the activation and proliferation of T lymphocytes presensitized by antigen receptor triggering. The T-cell activating factors were interleukin (IL) 1- and 6-like substances, as demonstrated by the ability of specific antisera to inhibit most of the biological effect, and by the ability of recombinant IL-1 and IL-6 to reproduce it. Appreciable amounts of immunoreactive IL-1 and IL-6 were indeed recovered in the supernatants of TDI-exposed epithelial cells. The release of these cytokines may represent an important mechanism by which epithelial cells respond to some environmental stimuli and contribute to the persistence of inflammatory responses in the airways.

Specific binding of endothelin on human bronchial smooth muscle cells in culture and secretion of endothelin-like material from bronchial epithelial cells

Endothelin, synthesized by endothelial cells, is the most potent vasoconstrictor and bronchoconstrictor agent known. We investigated endothelin release from human bronchial epithelial cells and the binding of the peptide to autologous bronchial smooth muscle cells in culture. Epithelial and smooth muscle cells were isolated by enzymatic digestion of bronchial tissue obtained on surgery, and cultured to confluency by standard methods. Epithelial cells stained positively for cytokeratin filaments. Smooth muscle cells stained uniformly for alpha-smooth muscle actin. Immunoreactive endothelin contents in the supernatants of epithelial cells extracted on C8 Amprep columns were evaluated by radioimmunoassay. Epithelial cells released appreciable amounts of immunoreactive endothelin into the culture medium (from 0.65 to 2.1 pmol/ml). A single specific binding site for [125I]endothelin 1 was identified on bronchial smooth muscle cells with an apparent Kd of 113 pM and a maximal binding capacity of 22.1 fmol/10(6) cells. At room temperature the binding was saturable, reached equilibrium at 120 min (25 pM endothelin 1), and was slowly and incompletely reversed by unlabeled endothelin over a period of 8 h. Conditioned medium from epithelial cells inhibited the [125I]endothelin 1 binding, dose dependently, and the effect was antagonized by monospecific antiserum. Thus, human bronchial smooth muscle cells possess specific binding sites for endothelin 1 and human bronchial epithelial cells secrete an endothelin-like material. This may have a role in the pathogenesis of asthma.

Pharmacokinetics and tissue distribution of amoxicillin plus clavulanic acid after oral administration in man

Augmentin (875 amoxicillin and 125 mg potassium clavulanate) was administered orally to patients with chronic bronchitis. Concentrations of amoxicillin and clavulanic acid were measured in serum, sputum and urine. Peak serum levels for amoxicillin of 11.23 +/- 2.61 micrograms/ml were observed at 2 hours and for clavulanic acid of 2.55 +/- 0.54 micrograms/ml at 1 hour. After 9 hours, 50% of the amoxicillin and 39% of the clavulanic acid had been renally excreted. The peak sputum concentration of amoxicillin was 1.31 +/- 0.42 micrograms/ml at 4 hours and of clavulanate was 0.79 +/- 0.23 micrograms/ml at 2 hours. Patients awaiting surgery received an oral dose of augmentin as above. Samples of lung, tonsil, middle ear mucosa and prostate were obtained and tissue concentrations of both compounds measured. Peak levels of amoxicillin ranged from 0.87 micrograms/g (tonsil) to 2.56 micrograms/g (lung) and of clavulanic acid from 0.20 micrograms/g (prostate) to 0.56 micrograms/g (lung) between 3 and 4 hours after dosing.

Eicosanoid release from human bronchial epithelial cells upon exposure to toluene diisocyanate in vitro

Epithelial injury and inflammation are involved in airway hyperresponsiveness and asthma induced by toluene diisocyanate. In that isocyanates are insoluble and highly reactive compounds, bronchial epithelial cells may represent the most important target cells of their toxic effect. We hypothesized that damage to airway epithelium by toluene diisocyanate may result in the release of metabolites of arachidonic acid, which are known to promote inflammation and to alter epithelial cell function and airway smooth muscle responsiveness. To test this hypothesis we examined eicosanoid products in the culture media of bronchial epithelial cells exposed in vitro to 8 and 18 ppb toluene diisocyanate. Epithelial cells derived from human bronchi obtained at surgery were cultured to confluency on collagen-coated microporous membranes. Those cells, which expressed differentiated characteristics of epithelial cells (they showed keratin-containing filaments and had a cobblestone appearance), were alternatively exposed to toluene diisocyanate or air for 30 min in a specially designed in vitro chamber. The production of metabolites of arachidonic acid was assessed by measuring the release of immunoreactive products into the cell medium at the end of the exposure and during a 2 hr period after exposure. This method revealed a predominant isocyanate-induced release of immunoreactive 15-hydroxyeicosatetraenoic acid. Release rate of this compound tended to be dose-related and was associated with cell damage as assessed by the release of lactate dehydrogenase in the medium.

Nedocromil sodium prevents the release of 15-hydroxyeicosatetraenoic acid from human bronchial epithelial cells exposed to toluene diisocyanate in vitro

The in vivo exposure to an asthmogenic stimulus, toluene diisocyanate (TDI), causes airway epithelial damage associated with inflammation and increased bronchial hyperresponsiveness. The latter mechanisms might partly be mediated by the release of eicosanoids from bronchial epithelial cells. We have previously demonstrated that the in vitro exposure of bronchial epithelial cells to TDI results in the release of immunoreactive 15-hydroxyeicosatetraenoic acid (15-HETE), a product of activation of the 15-lipoxygenase pathway with inflammatory properties. In the present study we show that TDI-induced release of 15-HETE from epithelial cells can be prevented by nedocromil sodium, an anti-asthmatic drug with anti-inflammatory properties. This mode of action of the compound may explain its clinical effectiveness in asthma.