[Diet and antioxidant--a nutritional intervention study]

It has been implicated that high vegetable intake is associated with a decreased risk for various forms of cancer in epidemiological studies. A major defense system against cancer has shown to be antioxidants. Glutathione S-transferases (GSTs), one of the major defense ststems against oxidative damage, can be induced by antioxidant and addition of vegetables to their normal diet. Serum retinol and a-tocopherol were determined by HPLC and the gene expression of GST pi in lymphocytes was measured by reverse transcription-polymerase chain reaction (RT-PCR) techniques. The results showed that there was on significant difference in the levels of serum retinol and a-tocopherol before and after the addition of vegetables. GST pi mRNA levels in lymphocytes were higher in four out of five subjects after addition of vegetables. The results suggested that it might be other antioxidants than vitamin A and E in the vegetables that induced the gene transcription of GST pi.

Dietary and lifestyle correlates of passive smoking in Hong Kong, Japan, Sweden, and the U.S.A

From epidemiologic studies in several countries, passive smoking has been associated with increased risk for lung cancer, respiratory diseases, and coronary heart disease. Since the relative risks derived from those studies are weak, i.e. relative risk less than two, we investigated whether poorer diets and less healthy lifestyles might act as confounders and be correlated with having a smoking husband on a cross-cultural basis. Characteristics of never-smoked wives with or without smoking husbands were compared between 530 women from Hong Kong, 13,047 from Japan, 87 from Sweden, and 144 from the U.S. In all four sites, wives with smoking husbands generally ate less healthy diets. They had a tendency to eat more fried food but less fruit than wives with nonsmoking husbands. Other healthy traits, e.g. avoiding obesity, dietary cholesterol and alcohol, or taking vitamins and participating in preventive screening were also less prevalent among wives with smoking husbands. These patterns suggest that never-smoked wives with smoking husbands tend to share the same less healthy dietary traits characteristic of smokers, and to have dietary habits associated with increased risk for lung cancer and heart disease in their societies. These results emphasize the need to take into account the potential confounding effects of diet and lifestyle in studies evaluating the health effects of passive smoking, especially since it is known that the current prevalence rates of smoking among men is indirectly associated with social class and education in affluent urban societies.

Airborne (1-->3)-beta-D-glucan and airway disease in a day-care center before and after renovation

Changes in symptoms and airway responsiveness among persons who worked in a day-care center that had microbial growth problems were assessed before and after renovation. Before and after the building renovation, the investigators used the Limulus assay with (1-->3)-beta-D-glucan-specific lysate to measure airborne levels of (1-->3)-beta-D-glucan, a cell-wall component of molds. Airway responsiveness and subjective symptoms were measured among 14 female employees with a methacholine test and a standardized questionnaire. After the renovation, (1-->3)-beta-D-glucan-glucan levels decreased from 11.4 to 1.4 ng/m3. The number of persons who had increased airway responsiveness decreased after the renovation. Two employees developed a classical allergy to cat and pollen during the observation period. Although the study included only a few subjects and was based on only one day-care center, the data suggest that (1-->3)-beta-D-glucan may be related to airways inflammation caused by indoor air pollution.

Pulmonary cell infiltration after chronic exposure to (1-->3)-beta-D-glucan and cigarette smoke

OBJECTIVE AND DESIGN

To evaluate the effect of a microbial cell wall component--(1-->3)-beta-D-glucan--on the inflammatory effect induced by cigarette smoke in a subchronic exposure situation.

MATERIAL

Groups of guinea-pigs were exposed 5 days/week to cigarette smoke, an aerosol of (1-->3)-beta-D-glucan, or to both.

METHODS

The numbers of different inflammatory cells were studied in histological sections, enzyme digested lung tissue and in lung lavage. Cell enzyme production was measured.

RESULTS

Exposure to (1-->3)-beta-D-glucan or cigarette smoke caused only minor alterations in inflammatory cells. Given together they caused an increase in cellularity in the tissue with significantly increased numbers of macrophages, lymphocytes, neutrophils and eosinophils. There was also an increase in subepithelial eosinophils. Lung lavage cell enzyme production was slightly lower in the combined exposure group.

CONCLUSION

The results demonstrate that (1-->3)-beta-D-glucan synergistically increases the inflammation induced by cigarette smoke. The mechanism may be a downregulation of the macrophage control of inflammatory cell migration into the lung tissue.

Pet birds and risk of lung cancer in Sweden: a case-control study

OBJECTIVE

To investigate the association between keeping birds and the risk of lung cancer in Sweden.

DESIGN

Case control study based on cases of lung cancer and community controls. Interviews were performed by two nurses specially trained for this project.

SETTING

Three major referral hospitals located in southwest Sweden.

SUBJECTS

All patients aged 75 and under with newly diagnosed lung cancer and of Scandinavian birth who lived in one of 26 municipalities in Gothenburg and Bohus county or Alvsborg county. Potential control subjects matched on county of residence, sex, and closest date of birth were selected from population registries. In the context of a larger case-control study, information on pet birds was obtained from 380 patients with lung cancer (252 men) and 696 controls (433 men).

MAIN OUTCOME MEASURES

Odds ratios for lung cancer in relation to whether or not pet birds were kept and the duration of keeping pet birds.

RESULTS

The adjusted odds ratio for ever versus never exposed to pet birds at home was 0.94 (95% confidence interval 0.64 to 1.39) for men and 1.10 (0.64 to 1.90) for women. There was no evidence of a trend for increased risk of lung cancer with duration of bird ownership.

CONCLUSION

Bird keeping does not seem to confer any excess risk of lung cancer to Swedish men or women.

Advanced laryngeal cancer T3-T4 in Sweden: a retrospective study 1986-1990. Survival and locoregional control related to treatment

Different treatment modalities for advanced laryngeal cancer are much discussed in the literature. One-hundred-and-sixty patients with T3-4, N0-3, M0-1 laryngeal cancer diagnosed in Sweden between 1986 and 1990 were retrospectively analysed. One hundred (65 T3: 35 T4) received radical radiotherapy with salvage surgery (RRSS) in case of residual or recurrent disease. Thirty-eight (11T3: 27 T4) patients received surgery with or without radiotherapy (S +/- RT). Twenty-two patients received no treatment. After a median follow up of 4.4 years, the estimated 5-year actuarial corrected survival and 3-year locoregional control were 59% and 44% for T3 RRSS and 47% and 54% for T3 S +/- RT. No significant difference between the different treatment modalities was found. The 5-year corrected survival rate and the locoregional control at 3 years between T4-RRSS (32%; 26%) and T4-S + RT (58%; 68%) groups were significantly different (p < 0.05 and p < 0.01). This might suggest that surgery with or without radiotherapy still has its place as a treatment modality for patients with advanced T4 laryngeal carcinoma.

Magnesium in drinking water and death from acute myocardial infarction

The relation between death from acute myocardial infarction and the level of magnesium in drinking water was examined using mortality registers and a case-control design. The study area comprised 17 municipalities in the southern part of Sweden that have different magnesium levels in the drinking water. Cases were men in the area who had died of acute myocardial infarction between ages 50 and 69 years during the period 1982-1989 (n = 854). The controls were men of the same age in the same area who had died from cancer during the same time period (n = 989). In both groups, only men who consumed water supplied from municipal waterworks were included in the study. The subjects were divided into quartiles according to the drinking water levels of magnesium and calcium and the quotient between magnesium and calcium. The odds ratios for death from acute myocardial infarction in the groups were inversely related to the amount of magnesium in drinking water. For the group with the highest levels of magnesium in drinking water, the odds ratio adjusted for age and calcium level was 0.65 (95 percent confidence interval 0.50-0.84). There was no such relation for calcium. For the magnesium/calcium quotient, the odds ratio was lower only for the group with the highest quotient. These data suggest that magnesium in drinking water is a important protective factor for death from acute myocardial infarction among males.

Lung cancer, smoking and diet among Swedish men

In a prospective case-control lung cancer study in the west of Sweden, the relationship between lung cancer, smoking and dietary factors was investigated. Suspected cases were collected from pulmonary units at two central hospitals in the area investigated and population controls of the same age and sex were selected from registers. The majority of cases and controls were interviewed by specially trained nurses, using a food frequency questionnaire. The lung cancer diagnosis (ICD 7, 162.1) was made using data from the local cancer register. In an analysis based on 308 cases and 504 controls, a dose-related increase in lung cancer risk for smokers was found, although no significant risk was found for males smoking 1-10 cigarettes/day for less than 20 years. A lower consumption of vegetables was related to a higher risk, both for smokers and nonsmokers. A higher consumption of milk was related to an increased risk.

Dietary factors and lung cancer among men in west Sweden

BACKGROUND

Previous studies have reported an association between tea drinking and lung cancer. In view of these data, the relationship between tea drinking as well as other dietary factors and lung cancer was investigated in a case-control study in the west of Sweden.

METHODS

Patients with suspected lung cancer were collected from pulmonary units at central hospitals in the area investigated, and population controls were matched for age. The material reported here comprises 308 male cases with a confirmed diagnosis of lung cancer and 504 controls. The participants were interviewed by specially trained nurses, using a questionnaire to assess smoking, dietary habits, occupational exposures and conditions in the residential area (local air pollution). This paper reports the results from dietary factors studied with a food frequency technique.

RESULTS

The results demonstrated a strong protective effect of vegetables (odds ratio [OR] = 0.69, 95% confidence interval [CI]: 0.46-1.05, and OR = 0.37, 95% CI: 0.23-0.61 for intermediate and high consumption classes respectively). A low OR was consistent for all histological types of lung cancer. High consumption of fruits did not show any similar protective effect. Drinking milk was associated with a dose-response related risk increase after adjustment for smoking and vegetable consumption (P for trend = 0.07). Odds ratio was 1.73, 95% CI: 1.00-3.01 for high consumption of milk.

CONCLUSIONS

High intake of vegetables had a strong protective effect among males. Diet is thus a potential confounding factor in studies on lung cancer and environmental factors and should thus be taken into consideration in the planning of such studies.

Environmental magnesium deficiency as a cardiovascular risk factor

Magnesium is abundant in nature and the major routes of intake are through food and water. Through changes in the treatment of foodstuffs and altered diets, as well as increased use of surface water with low magnesium content, magnesium deficiency is present in modern society. Magnesium deficiency causes cardiac arrhythmia and several studies suggest that a low level of magnesium in drinking water is a risk factor for myocardial infarction, particularly among men. Before general prevention programmes can be recommended, risk groups must be defined and experimental intervention programmes performed.

Monocyte responsiveness and a T-cell subtype predict the effects induced by cotton dust exposure

The aim of the study was to evaluate whether peripheral cellular parameters could predict susceptibility to decreased lung function and associated symptoms, in response to a single exposure to cotton dust. Previously nonexposed subjects (n = 42) inhaled an aerosol of cotton dust in a model cardroom during a period of 5 h. The subjects were examined before the exposure for FEV1, procoagulant activity (PCA) in blood mononuclear cells (BMNC), and serum IgE antibodies against a pool of inhalant antigens. Blood lymphocytes were typed into the helper/inducer (CD4+) and cytotoxic/suppressor (CD8+) T cells in combination with surface markers subdividing these populations. A questionnaire was used to identify atopic and nonatopic subjects. Immediately after exposure, the subjects were tested for FEV1 and PCA, and symptoms were recorded with a questionnaire. The dust exposure induced a decrease in FEV1 that was larger for the atopic group, but did not change the PCA in BMNC. The decrease in FEV1 was positively related to the preexposure PCA in both atopics and nonatopics. Symptoms from the airways after the exposure were reported to the same extent in the atopic and nonatopic group, and the subject group reporting chest tightness had a larger preexposure PCA. The atopic group had a larger proportion of blood CD8+ T lymphocytes negative for the monoclonal antibody anti-S6F1 (CD8+S6F1-), and in this group the decrease in FEV1 was significantly related to the proportion of this cell type. Also, in the atopic group, the proportion of CD8+S6F1- cells correlated positively with the preexposure PCA, and a negative correlation was found for this cell and serum levels of IgE.(ABSTRACT TRUNCATED AT 250 WORDS)

Longitudinal study of the health of cotton workers

OBJECTIVES

To follow up a group of newly employed workers in a cotton mill, and to report changes in symptoms over time.

METHODS

A group of 110 mill workers at a cotton mill in Shijiazhuang, China, was investigated by questionnaire, skin testing, and spirometric measurements of airway responsiveness through forced expiratory volume in one second (FEV1). The workers were examined before starting work, at 10 weeks, and at one year.

RESULTS

Decreases in FEV1 over shifts were small at 10 weeks and one year, and slightly higher among people with skin reactions to cotton dust extracts. Airway responsiveness, defined as the average decrease in FEV1 after 1.25 mg methacholine was increased at 10 weeks. It remained about the same after one year, except in the workers positive for the skin test, in whom it was further increased. Subjective symptoms of chest tightness and cough with phlegm increased progressively at 10 weeks and one year; nasal irritation remained unchanged and dry cough decreased between 10 weeks and one year.

CONCLUSION

The results suggest that the airway inflammation caused by cotton dust increases with increasing exposure time and that the changes are more notable in workers with reactivity to cotton dust extract.

Bronchial reactivity and work-related symptoms in farmers

Work-related respiratory symptoms and bronchial reactivity were studied in 76 never-smoking farmers and in a control group not exposed to organic dusts. The farmers were divided into those working with vegetables/grain crops, animals but not swine, and with swine. The extent of symptoms was evaluated using a specific organic dust questionnaire. Bronchial reactivity was assessed with the methacholine challenge test. An increased incidence of organic dust toxic syndrome (ODTS), mucous membrane irritation (MMI), and chronic bronchitis (CB) was found among farmers working with swine or other animals. Pulmonary function baseline values were normal. Bronchial reactivity was increased and related to subjective symptoms of MMI and CB. There was also a relation between fatigue at work and bronchial reactivity.

Oxygen metabolites from lavage and interstitial lung cells after inhalation of endotoxin in guinea pigs

Airborne endotoxins play a role in a variety of occupational diseases such as byssinosis and humidifier's disease and are associated with pulmonary and systemic symptoms. An excess generation of oxygen free radicals (including superoxide anion, O2-) by inflammatory cells has been suggested in endotoxemia. We have studied the release of superoxide from guinea-pig lung lavage and interstitial cells and blood monocytes (BMs) at different times after an acute inhalation exposure to bacterial endotoxin. O2- generation was measured by the O2- dismutase-inhibitable reduction of ferricytochrome c, after stimulation with phorbol-myristate-acetate (PMA) or opsonized zymosan (OZ). After endotoxin exposure, the spontaneous release of O2- remained unchanged for the three cell types. From 4 h after exposure until 48 h afterwards, lung lavage cells produced more O2- after PMA or OZ stimulation than did cells from unexposed guinea pigs. The pattern of O2- generation by interstitial cells followed that of lung lavage macrophages. O2- production remained unchanged in BMs at all times. These results suggest that endotoxin inhalation induced a priming of lavage and interstitial cells, mainly macrophages, associated with an increase in O2- production. As O2- production by BMs remained unchanged, this cell is unlikely to be responsible for the systemic symptoms seen after endotoxin inhalation.

Pulmonary inflammation induced by repeated inhalations of beta(1,3)-D-glucan and endotoxin

In an animal model of hypersensitivity pneumonitis (HP) guinea-pigs were exposed for 5 weeks to an aerosol of bacterial endotoxin, beta(1,3)-D-glucan (curdlan) or a combination. Exposure to endotoxin or curdlan showed only small changes in inflammatory cells in airways or the lung wall, histologically or in terms of enzyme secretion from alveolar macrophages. When the two agents were given together, a histology resembling HP was seen with alveolar infiltrates and early granulomas. Inflammatory cells in airways were increased and enzyme production of macrophages was changed, suggesting an effect of curdlan on the inflammatory regulating capacity of airway macrophages. The results suggest that interference with macrophage function and inflammation are important components in the development of HP.

Hematological, blood biochemical, and cytological bronchoalveolar lavage studies in prepubertal gilts after endotoxin inhalation and ingestion

The effect of oral intake of endotoxin (ET) combined with inhalation of ET-contaminated feed-dust was studied in 6 prepubertal gilts. The animals were given 100 mg of ET each in their ordinary feed ration and meanwhile stayed for 4 h in a continuous flow exposure chamber where the endotoxin concentration was approximately 9 micrograms/m3. Blood samples were collected during the exposure and for 8 h afterwards. Bronchoalveolar lavage (BAL) was performed 24-26 h after the exposure. Six additional animals received ordinary feed and were exposed to feed-dust without added ET. Blood samples were analysed for total white blood cell count (B-WBC) and differential count: polymorphonuclear (PMN) and mononuclear (MN); total red blood cell count (B-RBC); platelets (B-PLT); total serum bile acids (S-BA); glutamate dehydrogenase (S-GLDH); and a blood plasma prostaglandin F2 alpha metabolite (15-ketodihydro-PGF2 alpha; P-PG). The major findings were decreased numbers of MN, PMN and B-RBC 3 to 6 h after the start of the ET exposure and increased numbers of neutrophilic granulocytes in the BAL fluid of the ET-exposed animals. It is concluded that a combined oral and airborne ET challenge induces hematological and cytological changes that may contribute to the development of respiratory disorders.

Effects of antioxidants and PAF receptor antagonist in intestinal shock in the rat

In a model of intestinal ischemia-reperfusion resulting in hypotension, mucosal lesions in the small intestine and mortality, the effects of a combination of superoxide dismutase (SOD) and catalase (cat) or a PAF receptor antagonist were tested. Intestinal ischemia was induced in rats and continued for 60 min. After this, the intestine was reperfused. A PAF receptor antagonist, BN 52021, was given 50 min before ischemia in one group, and SOD + cat was given 10 min before reperfusion in one group. One group received normal saline and one group were controls. Blood pressure, mucosal lesions, plasma volume, and endotoxin in plasma were determined up to 3 hr after reperfusion. Mortality was determined over 4 days. Endogenous endotoxin was not found in any of the groups, but the first types of SOD and cat used were contaminated with endotoxin, resulting in exogenous endotoxemia in animals which received those substances. Later endotoxin-free enzymes were used. Neither SOD + cat nor PAF antagonist had any effect on the hypotension or mucosal lesions. Plasma volume remained at the level of the control group after administration of either regimen. Mortality decreased in the group that received SOD + cat. The effects of SOD + cat indicate that free radicals were released in this model at reperfusion, and the effects of the PAF receptor antagonist indicate that PAF participates in membrane damage, but is an intermediary mechanism in the shock model used. The clearance of infused endotoxin from plasma was less effective in the shocked animals, possibly due to a shock effect on reticuloendothelial system (RES).(ABSTRACT TRUNCATED AT 250 WORDS)

(1-->3)-beta-D-glucan in indoor air, its measurement and in vitro activity

The underlying mechanisms of the biological activity of (1-->3)-beta-D-glucan was investigated using macrophages from guinea pigs or mice. The results showed that these cells expressed (1-->3)-beta-D-glucan specific receptors on their surface, and that the release of TNF-alpha from cells was modulated by the presence of (1-->3)-beta-D-glucan.